U.S. patent application number 15/590312 was filed with the patent office on 2017-10-26 for shaping apparatus and shaping method.
This patent application is currently assigned to NIKON CORPORATION. The applicant listed for this patent is NIKON CORPORATION. Invention is credited to Yuichi SHIBAZAKI.
Application Number | 20170304947 15/590312 |
Document ID | / |
Family ID | 55953915 |
Filed Date | 2017-10-26 |
United States Patent
Application |
20170304947 |
Kind Code |
A1 |
SHIBAZAKI; Yuichi |
October 26, 2017 |
SHAPING APPARATUS AND SHAPING METHOD
Abstract
This shaping apparatus is equipped with: a movement system which
moves a target surface; a measurement system for acquiring position
information of the target surface in a state movable by the
movement system, a beam shaping system that has a beam irradiation
section and a material processing section which supplies a shaping
material irradiated by a beam from beam irradiation section; and a
controller. On the basis of 3D data of a three-dimensional shaped
object to be formed on a target surface and position information of
the target surface acquired using the measurement system, the
controller controls the movement system and the beam shaping system
such that a target portion on the target surface is shaped by
supplying the shaping material while moving the target surface and
the beam from beam irradiation section relative to each other.
Inventors: |
SHIBAZAKI; Yuichi;
(Kumagaya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NIKON CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
NIKON CORPORATION
Tokyo
JP
|
Family ID: |
55953915 |
Appl. No.: |
15/590312 |
Filed: |
May 9, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2014/080151 |
Nov 14, 2014 |
|
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15590312 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 10/00 20141201;
B23K 26/08 20130101; B33Y 50/02 20141201; Y02P 10/295 20151101;
Y02P 10/25 20151101; B29C 64/153 20170801; B23K 26/144 20151001;
B22F 3/1055 20130101; B23K 26/03 20130101; B23K 26/342 20151001;
B23K 26/0734 20130101; B22F 2301/00 20130101; B23K 26/06 20130101;
B23K 26/0648 20130101; B23K 26/0665 20130101; B23K 26/073 20130101;
B23K 2103/14 20180801; B23K 26/1462 20151001; B23K 26/705 20151001;
B29C 64/393 20170801; B22F 2003/1056 20130101; B23K 26/032
20130101; B29C 64/268 20170801; B33Y 30/00 20141201 |
International
Class: |
B23K 26/342 20140101
B23K026/342; B23K 26/073 20060101 B23K026/073; B23K 26/03 20060101
B23K026/03; B33Y 10/00 20060101 B33Y010/00; B33Y 50/02 20060101
B33Y050/02; B33Y 30/00 20060101 B33Y030/00; B23K 26/08 20140101
B23K026/08; B23K 26/06 20140101 B23K026/06 |
Claims
1. A shaping apparatus that forms a three-dimensional shaped object
on a target surface, comprising: a movement system that moves the
target surface; a measurement system that acquires position
information of the target surface in a state movable by the
movement system; a beam shaping system that has a beam irradiation
section which emits a beam and a material processing section which
supplies shaping material to be irradiated by the beam from the
beam irradiation section; and a controller that controls the
movement system and the beam shaping system based on 3D data of a
three-dimensional shaped object which is to be formed on the target
surface and position information of the target surface acquired
using the measurement system, so that shaping is applied to the
target portion on the target surface by supplying the shaping
material from the material processing section while relatively
moving the target surface and the beam from the beam irradiation
section.
2. The shaping apparatus according to claim 1, wherein the
measurement system includes a three-dimensional measuring
machine.
3. The shaping apparatus according to claim 1, wherein the
measurement system can measure position information of at least
three points on the target surface.
4. The shaping apparatus according to claim 1, wherein the
measurement system can measure a three-dimensional shape of the
target surface.
5. The shaping apparatus according to claim 1, wherein the
controller acquires position information of at least a part of a
surface of a part added on the target surface by the shaping using
the measurement system after the shaping.
6. The shaping apparatus according to claim 1, wherein the movement
system has a movable member which can hold a workpiece, and the
target surface includes at least a part of a surface of the
workpiece held by the movable member.
7. The shaping apparatus according to claim 6, further comprising:
a carrier system that loads the workpiece before processing on the
movable member and unloads the workpiece after processing from the
movable member, wherein the controller controls the carrier
system.
8. The shaping apparatus according to claim 6, further comprising:
a sensor that receives the beam at a light receiving section
provided at the movable member.
9. The shaping apparatus according to claim 6, wherein the
controller controls position and attitude of the movable member
under a reference coordinate system, and by acquiring the position
information, the target surface is correlated with the reference
coordinate system.
10. The shaping apparatus according to claim 6, wherein the
controller acquires position information of at least a part of a
surface of a part added on the target surface of the workpiece by
the shaping using the measurement system, while making the movable
member hold the workpiece to which the shaping is applied.
11. The shaping apparatus according to claim 10, wherein the
controller acquires dimension error of the part added based on the
position information acquired using the measurement system.
12. The shaping apparatus according to claim 11, wherein the
controller makes pass/fail decision of additive manufacturing using
the dimension error.
13. The shaping apparatus according to claim 12, wherein the
controller applies corrective processing using the beam shaping
system to the workpiece that resulted in failure on the pass/fail
decision while the movable member remains holding the workpiece,
based on the dimension error.
14. The shaping apparatus according to claim 13, wherein the
controller performs the corrective processing using a beam from the
beam irradiation section.
15. The shaping apparatus according to claim 10, wherein the
controller controls the beam shaping system and the movement system
based on the position information of at least a part of the surface
of the part added, and applies shaping to a target portion on a
target surface including the at least a part of a surface of the
part added.
16. The shaping apparatus according to claim 10, wherein the
controller adjusts at least one of the measurement system, the beam
shaping system, and the movement system based on the position
information of at least a part of the surface of the part
added.
17. The shaping apparatus according to claim 16, wherein the
controller acquires tendency of drift of the apparatus in the
shaping based on the position information, and adjusts at least one
of the measurement system, the beam shaping system, and the
movement system in response to results acquired.
18. The shaping apparatus according to claim 1, further comprising:
a sensor that receives the beam at a light receiving section.
19. The shaping apparatus according to claim 18, wherein the sensor
can measure intensity distribution of the beam.
20. The shaping apparatus according to claim 18, wherein the
controller makes the sensor receive the beam at the light receiving
section while moving the light receiving section of the sensor.
21. The shaping apparatus according to claim 18, wherein the beam
irradiation section has a condensing optical system which emits the
beam, and the light receiving section of the sensor can receive the
beam emitted from the condensing optical system.
22. The shaping apparatus according to claim 21, wherein the light
receiving section is placed to receive the beam in one of a rear
focal plane and near the rear focal plane of the condensing optical
system.
23. The shaping apparatus according to claim 21, wherein the light
receiving section can receive the beam from the condensing optical
system while moving in at least one of a direction parallel to an
optical axis and a direction perpendicular to the optical axis on
an exit side of the condensing optical system.
24. The shaping apparatus according to claim 21, wherein the sensor
can measure intensity distribution of the beam in a first plane
perpendicular to the optical axis on the exit side of the
condensing optical system.
25. The shaping apparatus according to claim 24, wherein the first
plane is one of the rear focal plane of the condensing optical
system and a plane near the rear focal plane.
26. The shaping apparatus according to claim 24, wherein the
controller adjusts the intensity distribution of the beam in the
first plane, based on a result of the measurement using the
sensor.
27. The shaping apparatus according to claim 21, wherein the
controller adjusts an angle of at least one incident beam incident
on a second plane perpendicular to an optical axis on an incidence
plane side of the condensing optical system, based on the result of
the measurement using the sensor.
28. The shaping apparatus according to claim 27, wherein the second
plane includes one of the front focal plane of the condensing
optical system and a plane near the front focal plane.
29. The shaping apparatus according to claim 27, wherein the at
least one incident beam includes a plurality of beams having
different incidence angles with respect to the second plane.
30. The shaping apparatus according to claim 18, wherein the
controller performs adjustment of at least one of the beam shaping
system and the movement system, based on a result of measurement
performed using the sensor.
31. The shaping apparatus according to claim 30, wherein the
adjustment of the beam shaping system based on the result of
measurement performed using the sensor includes adjusting the
material processing section.
32. The shaping apparatus according to claim 31, wherein the
adjusting the material processing section includes adjusting supply
operation of the shaping material by the material processing
section.
33. The shaping apparatus according to claim 31, wherein the
material processing section has at least one supply port to supply
the shaping material, and supply state of the shaping material from
the at least one supply port is adjusted, based on the result of
measurement performed using the sensor.
34. The shaping apparatus according to claim 33, wherein the at
least one supply port is movable, and the at least one supply port
is moved, based on the result of measurement performed using the
sensor.
35. The shaping apparatus according to claim 33, wherein the
material processing section has a plurality of supply ports to
supply the shaping material, at least one supply port is selected
from the plurality of supply ports, based on the result of
measurement performed using the sensor, and the shaping material is
supplied from the at least one supply port that is selected.
36. The shaping apparatus according to claim 33, wherein supply
amount per unit time of the shaping material from the at least one
supply port is adjustable.
37. The shaping apparatus according to claim 36, wherein the
controller determines the supply amount from the at least one
supply port, based on the result of measurement performed using the
sensor.
38. The shaping apparatus according to claim 1, wherein the beam
irradiation section has a condensing optical system which emits the
beam, and the controller adjusts intensity distribution of the beam
in a first plane perpendicular to the optical axis on the exit
plane side of the condensing optical system, based on measurement
result of the measurement system.
39. The shaping apparatus according to claim 38, wherein the first
plane is one of the rear focal plane of the condensing optical
system and a plane near the rear focal plane.
40. The shaping apparatus according to claim 38, wherein the
controller adjusts the intensity distribution of the beam in the
first plane by adjusting an angle of at least one incident beam
incident on a second plane perpendicular to an optical axis on an
incidence plane side of the condensing optical system.
41. The shaping apparatus according to claim 40, wherein the second
plane includes one of the front focal plane of the condensing
optical system and a plane near the front focal plane.
42. The shaping apparatus according to claim 40, wherein the at
least one incident beam includes a plurality of beams having
different incidence angles with respect to the second plane.
43. The shaping apparatus according to claim 1, wherein the
adjustment of the beam shaping system based on the measurement
result of the measurement system includes adjusting the beam
irradiation section.
44. The shaping apparatus according to claim 1, wherein the
adjustment of the beam shaping system based on the measurement
result of the measurement system includes adjusting the material
processing section.
45. The shaping apparatus according to claim 44, wherein the
adjustment of the material processing section includes adjusting
supply operation of the shaping material by the material processing
section.
46. The shaping apparatus according to claim 44, wherein the
material processing section has at least one supply port to supply
the shaping material, and supply state of the shaping material from
the at least one supply port is adjusted, based on the measurement
result of the measurement system.
47. The shaping apparatus according to claim 46, wherein the at
least one supply port is movable, and position of the at least one
supply port is adjusted, based on the result of measurement
performed using the sensor.
48. The shaping apparatus according to claim 46, wherein the
material processing section has a plurality of supply ports to
supply the shaping material, and at least one supply port is
selected from the plurality of supply ports based on the
measurement result of the measurement system, and the shaping
material is supplied from the at least one supply port that is
selected.
49. The shaping apparatus according to claim 46, wherein supply
amount per unit time of the shaping material from the at least one
supply port is adjustable.
50. The shaping apparatus according to claim 49, wherein the
controller determines the supply amount from the at least one
supply port, based on the measurement result of the measurement
system.
51. The shaping apparatus according to claim 1, wherein a molten
pool of the shaping material is formed, by supplying the shaping
material so that the shaping material is irradiated by the beam
emitted from the beam irradiation section.
52. The shaping apparatus according to claim 51, wherein shaping is
applied to the target portion by relatively moving the target
surface and the beam from the beam irradiation section while
forming the molten pool on the target portion.
53. The shaping apparatus according to claim 1, wherein the
three-dimensional shaped object is made of a plurality of layers
which are laminated, and the controller controls the movement
system and the beam shaping system, based on laminated cross
section data for multiple layers acquired from 3D data of the
three-dimensional shaped object.
54. A shaping method to form a three-dimensional shaped object on a
target surface, comprising: measuring position information of the
target surface; and applying shaping to a target portion on the
target surface by supplying shaping material irradiated by the beam
while relatively moving the target surface and a beam, based on 3D
data of a three-dimensional shaped object to be formed on the
target surface and the position information of the target surface
that is measured.
55. The shaping method according to claim 54, wherein in the
measuring, three-dimensional position information of at least a
part of the target surface is measured.
56. The shaping method according to claim 55, wherein as the
three-dimensional position information, three-dimensional shape of
the target surface is measured.
57. The shaping method according to claim 54, wherein the target
surface includes at least a part of a surface of a workpiece held
by a movable member whose position and attitude is controlled under
a reference coordinate system, the method further comprising:
correlating position and attitude of the target surface with the
reference coordinate system, based on the measured position
information.
58. The shaping method according to claim 57, further comprising:
measuring position information of at least a part of the surface of
the part added on the target surface by the shaping while keeping
the workpiece to which the shaping is applied loaded on the movable
member.
59. The shaping method according to claim 58, wherein
three-dimensional shape is measured as the position information of
at least a part of the surface of the part added on the target
surface by the shaping.
60. The shaping method according to claim 58, further comprising:
acquiring dimension error of the part added based on the position
information that has been measured.
61. The shaping method according to claim 60, further comprising:
using the dimension error to make pass/fail decision of additive
manufacturing.
62. The shaping method according to claim 61, further comprising:
applying corrective processing using the beam to the workpiece that
resulted in failure on the pass/fail decision while the movable
member remains holding the workpiece, based on the dimension
error.
63. The shaping apparatus according to claim 58, wherein shaping is
applied to the target portion on the target surface including the
at least a part of the surface of the part added, based on the
position information of at least a part of the surface of the part
added.
64. The shaping method according to claim 54, wherein the target
surface includes at least a part of the surface of the movable
member whose position and attitude is controlled under a reference
coordinate system, the method further comprising: correlating
position and attitude of the target surface with the reference
coordinate system, based on the measured position information.
65. The shaping method according to claim 54, wherein the
three-dimensional shaped object is made of a plurality of layers
which are laminated, and applying the shaping to the target portion
on the target surface is repeatedly performed for each layer, based
on laminated cross section data for multiple layers acquired from
3D data of the three-dimensional shaped object.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application PCT/JP2014/080151, with an international filing date of
Nov. 14, 2014, the disclosure of which is hereby incorporated
herein by reference in its entirety, which was not published in
English.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a shaping apparatus and a
shaping method, and more particularly to a shaping apparatus and a
shaping method to forma three-dimensional shaped object on a target
surface. The shaping apparatus and the shaping method related to
the present invention can be suitably applied when forming
three-dimensional shaped objects by rapid prototyping (may also be
called 3D printing, additive manufacturing, or direct digital
manufacturing).
Description of the Background Art
[0003] Technology of forming a 3D (three-dimensional) shape
directly from CAD data is called rapid prototyping (also may be
called 3D printing, additive manufacturing, or direct digital
manufacturing, but rapid prototyping will be used in general
below), and has contributed mainly to fabricate prototypes aimed
for confirming shapes in an extremely short lead time. Shaping
apparatus that form three-dimensional shaped objects by rapid
prototyping such as a 3D printer can be broadly classified, when
classified by materials which are handled, into devices that handle
resin and devices that handle metal. Metallic three-dimensional
shaped objects fabricated by rapid prototyping are used exclusively
as actual parts, unlike the case of objects made by resin. That is,
the parts are used such that they function as apart of an actual
machine structure (whether the actual machine be mass produced or
prototypes), and not as prototype parts for confirming shapes. As
existing metallic 3D printers (hereinafter shortly referred to as
M3DP (Metal 3D printer)), two types, PBF (Powder Bed Fusion) and
DED (Directed Energy Deposition) are well known.
[0004] In PBF printers, a thin layer of powdered sintered metal is
formed on a bed where an object to be worked is mounted, a high
power laser beam is scanned thereon using a galvano mirror or the
like, and the part where the beam hits is melted and solidified.
When drawing of one layer is completed, the bed is lowered by one
layer thickness, spreading of powdered sintered metal is resumed
thereon, and the same process is repeated. Shaping is repeated
layer by layer in the manner described above so that the desired
three-dimensional shape can be acquired.
[0005] PBF substantially has some problems due to its shaping
principle, such as; (1) insufficient fabrication accuracy of parts,
(2) high roughness in surface finish, (3) slow processing speed,
and (4) troublesome sintered metal powder handling that takes time
and effort.
[0006] In DED printers, a method of depositing melted metal
material on a processing subject is employed. For example, powdered
metal is jetted around the focus of a laser beam condensed by a
condensing lens. The powdered metal melts into a liquid form by
irradiation of a laser. When the processing subject is located
around the focus, the liquefied metal is deposited on the
processing subject, cooled, and then is solidified again. This
focal part is, in a way, the tip of a pen that allows successive
drawing of "lines with thickness" on the processing subject
surface. A desired shape can be formed by one of the processing
subject and a processing head (as in a laser and a powder jet
nozzle) moving relatively in an appropriate manner on the basis of
CAD data, with respect to the other (for example, refer to U.S.
Patent Application Publication No. 2003/0206820).
[0007] As it can be seen from this, with DED, because powder
material is jetted from the processing head by a necessary amount
only when necessary, this saves waste and processing does not have
to be performed in a large amount of surplus powder.
[0008] As described above, although DED has been improved compared
to PBF on points such as handling of powder metal as a raw
material, there still are many points to be improved.
[0009] Under such circumstances, it is strongly hoped that
convenience as a machine tool of a shaping apparatus that forms a
three-dimensional shaped object is to be improved, that is to say,
economic rationality of manufacturing is to be improved.
SUMMARY OF THE INVENTION
[0010] According to a first aspect of the present invention, there
is provided a shaping apparatus that forms a three-dimensional
shaped object on a target surface, comprising: a movement system
that moves the target surface; a measurement system that acquires
position information of the target surface in a state movable by
the movement system; a beam shaping system that has a beam
irradiation section which emits a beam and a material processing
section which supplies shaping material to be irradiated by the
beam from the beam irradiation section; and a controller that
controls the movement system and the beam shaping system based on
3D data of a three-dimensional shaped object which is to be formed
on the target surface and position information of the target
surface acquired using the measurement system, so that shaping is
applied to the target portion on the target surface by supplying
the shaping material from the material processing section while
relatively moving the target surface and the beam from the beam
irradiation section.
[0011] Here, the target surface is a surface where the target
portion of shaping is set.
[0012] According to this apparatus, it becomes possible to form a
three-dimensional shaped object on the target surface with good
processing accuracy.
[0013] According to a second aspect of the present invention, there
is provided a shaping method to form a three-dimensional shaped
object on a target surface, comprising: measuring position
information of the target surface; and applying shaping to a target
portion on the target surface by supplying shaping material to be
irradiated by the beam while relatively moving the target surface
and a beam, based on 3D data of the three-dimensional shaped object
to be formed on the target surface and the position information of
the target surface that is measured.
[0014] According to this method, it becomes possible to form a
three-dimensional shaped object on the target surface with good
processing accuracy.
BRIEF DESCRIPTION OF DRAWINGS
[0015] In the accompanying drawings;
[0016] FIG. 1 is a block diagram showing an overall structure of a
shaping apparatus according to an embodiment;
[0017] FIG. 2 is a view schematically showing a structure of a
movement system along with a measurement system;
[0018] FIG. 3 is a perspective view showing the movement system on
which a workpiece is mounted;
[0019] FIG. 4 is a view showing abeam shaping system along with a
table on which the workpiece is mounted;
[0020] FIG. 5 is a view showing an example of a structure of a
light source system structuring a part of a beam irradiation
section that the beam shaping system has;
[0021] FIG. 6 is a view showing a state where a parallel beam from
a light source is irradiated on a mirror array, and an incidence
angle of a reflection beam from each of a plurality of mirror
elements to a condensing optical system is individually
controlled;
[0022] FIG. 7 is a view showing a material processing section that
the beam shaping system is equipped with along with the condensing
optical system;
[0023] FIG. 8 is a view showing a plurality of supply ports formed
in a nozzle of the material processing section and an open/close
member which opens/closes each of the plurality of supply
ports;
[0024] FIG. 9A is a view showing circle A in FIG. 4 enlarged, and
FIG. 9B is a view showing a relation between a straight line area
and scan direction shown in FIG. 9A;
[0025] FIG. 10 is a view showing an example of an irradiation area
of a beam formed on a shaping surface;
[0026] FIG. 11 is a block diagram showing an input/output relation
of a controller that mainly structures a control system of the
shaping apparatus;
[0027] FIG. 12 is a view showing an arrangement of a measurement
device on a table;
[0028] FIG. 13 is a view showing component parts that structure the
measurement device arranged inside the table, along with a
measurement member;
[0029] FIG. 14A is a view showing an optical arrangement when
measuring intensity distribution of the beam in a rear focal plane
of the condensing optical system, and FIG. 14B is a view showing an
optical arrangement when measuring intensity distribution of the
beam in a pupil plane;
[0030] FIG. 15 is a flowchart corresponding to a series of
processing algorithm of the controller;
[0031] FIGS. 16A and 16B are views used for describing an effect of
the shaping apparatus according to the embodiment in comparison
with the conventional art;
[0032] FIG. 17 is a view showing an example of a measurement device
for measuring intensity distribution of the beam in a shaping
surface; and
[0033] FIGS. 18A and 18B are views used to describe an example when
increasing thickness of a coating layer by widening a width of a
straight line area.
DESCRIPTION OF EMBODIMENTS
[0034] Hereinafter, an embodiment will be described with reference
to FIGS. 1 to 18B. FIG. 1 is a block diagram showing an entire
structure of a shaping apparatus 100 according to the
embodiment.
[0035] Shaping apparatus 100 is a M3DP (Metal 3D printer) that
employs DED (Directed Energy Deposition). Shaping apparatus 100 can
be used to form a three-dimensional shaped object on a table 12 to
be described later by rapid prototyping, as well as to perform
additive manufacturing by three-dimensional shaping on a workpiece
(e.g. an existing component). The present embodiment will focus on
describing the latter case where additive manufacturing is
performed on the workpiece. At the actual manufacturing site, it is
common to make a desired component by further repeating processing
on a component formed using a different manufacturing method, a
different material, or a different machine tool, and the
requirement is potentially the same for additive manufacturing by
three-dimensional shaping.
[0036] Shaping apparatus 100 is equipped with four systems; a
movement system 200, a carrier system 300, a measurement system
400, and a beam shaping system 500, and a controller 600 including
these systems that has overall control of shaping apparatus 100. Of
these parts, carrier system 300, measurement system 400, and beam
shaping system 500 are placed spaced apart from one another in a
predetermined direction. In the description below, for the sake of
convenience, carrier system 300, measurement system 400, and beam
shaping system 500 are to be placed spaced apart from one another
in an X-axis direction (refer to FIG. 2) to be described later
on.
[0037] FIG. 2 schematically shows a structure of movement system
200, along with that of measurement system 400. Further, FIG. 3
shows movement system 200 on which a workpiece W is mounted in a
perspective view. In the description below, the lateral direction
of the page surface in FIG. 2 will be described as a Y-axis
direction, a direction orthogonal to the page surface will be
described as the X-axis direction, a direction orthogonal to the
X-axis and the Y-axis will be described as a Z-axis direction, and
rotation (tilt) directions around the X-axis, the Y-axis, and the
Z-axis will be described as .theta.x, .theta.y, and .theta.z
directions, respectively.
[0038] Movement system 200 changes position and attitude of a
target surface (in this case, a surface on workpiece W on which a
target portion TA is set) TAS (for example, refer to FIGS. 4 and
9A) for shaping. Specifically, by driving the workpiece having the
target surface and the table to be described later on where the
workpiece is mounted in directions of six degrees of freedom
(6-DOF) (in each of the X-axis, the Y-axis, the Z-axis, the
.theta.x, the .theta.y, and the .theta.z directions), position in
directions of 6-DOF of the target surface is changed. In this
description, as for the table, the workpiece, the target surface
and the like, position in directions of three degrees of freedom
(3-DOF) in the .theta.x, the .theta.y, and the .theta.z directions
will be referred to collectively as "attitude", and corresponding
to this, the remaining directions of three degrees of freedom
(3-DOF) in the X-axis, the Y-axis, and the Z-axis directions will
be referred to collectively as "position".
[0039] As an example of a drive mechanism for changing the position
and attitude of the table, movement system 200 is equipped with a
Stewart platform type 6-DOF parallel link mechanism. Movement
system 200 is not limited to a system that can drive the table in
directions of 6-DOF.
[0040] Movement system 200 (excluding a stator of a planar motor to
be described later on) is placed on a base BS installed on a floor
F so that its upper surface is almost parallel to an XY plane, as
shown in FIG. 2. Movement system 200 has a slider 10 having a
regular hexagonal shape in a planar view that structures a base
platform, table 12 that structures an end effector, six expandable
rods (links) 14.sub.1 to 14.sub.6 for connecting slider 10 and
table 12, and expansion mechanisms 16.sub.1 to 16.sub.6 (not shown
in FIG. 3, refer to FIG. 11) provided in each rod to make each rod
expand and contract, as shown in FIG. 3. Movement system 200
employs a structure so that the movement of table 12 can be
controlled in 6-DOF within a three-dimensional space by separately
adjusting the length of rods 14.sub.1 to 14.sub.6 with expansion
mechanisms 16.sub.1 to 16.sub.6. Movement system 200 is provided
with features such as high accuracy, high rigidity, large
supporting force, and easy inverse kinematic calculation, since the
system is equipped with a Stewart platform type 6-DOF parallel link
mechanism as a drive mechanism of table 12.
[0041] In shaping apparatus shaping 100 according to the
embodiment, position and attitude of the workpiece (table 12) are
controlled with respect to beam shaping system 500, or more
specifically, a beam from a beam irradiation section to be
described later on so that a shaping object of a desired shape is
formed of the workpiece at times such as additive manufacturing to
the workpiece. In principle, contrary to this, the beam from the
beam irradiation section may be movable or the beam and the
workpiece (table) may both be movable. As it will be described
later on, because beam shaping system 500 has a complex structure,
it is easier to move the workpiece instead.
[0042] Table 12 here consists of a plate member having a shape of
an equilateral triangle with each apex cut off. Workpiece W subject
to additive manufacturing is mounted on the upper surface of table
12. A chuck mechanism 13 (not shown in FIG. 3, refer to FIG. 11)
for fixing workpiece W is provided at table 12. As chuck mechanism
13, for example, a mechanical chuck or a vacuum chuck is used.
Table 12 also has a measurement device 110 (refer to FIGS. 12 and
13) provided that includes a measurement member 92 which has a
circular shape in a planar view as shown in FIG. 3. Measurement
device 110 will be described in detail later on. Note that the
shape of table 12 is not limited to the shape shown in FIG. 3, and
may be any shape such as a rectangular plate shape or a disk
shape.
[0043] In this case, as is obvious from FIG. 3, rods 14.sub.1 to
14.sub.6 are each connected to slider 10 and table 12 via universal
joints 18 at both ends of the rods. Rods 14.sub.1 and 14.sub.2 are
connected near one apex position of the triangle of table 12, and
are placed so that slider 10 and these rods 14.sub.1 and 14.sub.2
structure a roughly triangular shape. Similarly, rods 14.sub.3 and
14.sub.4 and rods 14.sub.5 and 14.sub.6 are connected,
respectively, near each of the remaining apex positions of the
triangle of table 12, and are placed so that slider 10 and rods
14.sub.3 and 14.sub.4, and slider 10 and rods 14.sub.5 and 14.sub.6
each structure a roughly triangular shape.
[0044] These rods 14.sub.1 to 14.sub.6 each have a first shaft
member 20 and a second shaft member 22 relatively movable in each
axial direction as in rod 14.sub.1 representatively shown in FIG.
3, and one end (lower end) of the first shaft member 20 is attached
to slider 10 via universal joint 18 and the other end (upper end)
of the second shaft member 22 is attached to table 12 via a
universal joint.
[0045] Inside the first shaft member 20, a stepped columnar hollow
portion is formed, and in the lower end side of the hollow portion,
for example, a bellows type air cylinder is housed. To this air
cylinder, a pneumatic circuit and an air pressure source (none of
which are shown) are connected. By controlling pneumatic pressure
of compressed air supplied from the air pressure source via the
pneumatic circuit, internal pressure of the air cylinder is
controlled, which makes a piston that the air cylinder has move
reciprocally in the axial direction. The air cylinder, in the
returning process, is made to use gravitational force that acts on
the piston when incorporated in the parallel link mechanism.
[0046] At the upper end side inside the hollow portion of the first
shaft member 20, an armature unit (not shown) is placed consisting
of a plurality of armature coils placed lined in the axial
direction.
[0047] Meanwhile, one end (lower end) of the second shaft member 22
is inserted into the hollow portion of the first shaft member 20.
At the one end of the second shaft member 22, a small diameter
section having a diameter smaller than other sections is formed,
and a tubular mover yoke consisting of a magnetic member is
provided around this small diameter section. At the outer periphery
of the mover yoke, a hollow columnar magnet body consisting of a
plurality of permanent magnets of the same size, that is, a
cylindrical magnet body is provided. In this case, the mover yoke
and the magnet body structure a hollow columnar magnet unit. In the
embodiment, the armature unit and the magnet unit structure a shaft
motor which is a type of electromagnetic linear motor. In the shaft
motor structured in the manner described above, by supplying a
sinusoidal drive current of a predetermined period and a
predetermined amplitude to each coil of the armature unit serving
as a stator, Lorentz force (drive force) is generated by an
electromagnetic interaction which is a type of electromagnetic
reciprocal action between a magnetic pole unit and the armature
unit, which is used to relatively drive the second shaft member 22
in the axial direction with respect to the first shaft member
20.
[0048] That is to say, in the embodiment, the air cylinder and the
shaft motor described above structure expansion mechanisms 16.sub.1
to 16.sub.6 (refer to FIG. 11) previously described that make rods
14.sub.1 to 14.sub.6 expand and contract by relatively moving the
first shaft member 20 and the second shaft member 22 in the axial
direction.
[0049] The magnet unit serving as the mover of the shaft motor is
supported in a non-contact manner with respect to the armature unit
serving as the stator, via an air pad provided on the inner
circumferential surface of the first shaft member 20.
[0050] Although illustration is omitted in FIG. 3, rods 14.sub.1 to
14.sub.6 each have absolute linear encoders 24.sub.1 to 24.sub.6
provided for detecting the position of the second shaft member 22
in the axial direction with the first shaft member 20 as a
reference, and the output of these linear encoders 24.sub.1 to
24.sub.6 is to be supplied to controller 600 (refer to FIG. 11).
The position of the second shaft member 22 in the axial direction
detected by linear encoders 24.sub.1 to 24.sub.6 correspond to the
respective length of rods 14.sub.1 to 14.sub.6.
[0051] On the basis of the output of linear encoders 24.sub.1 to
24.sub.6, controller 600 controls expansion mechanisms 16.sub.1 to
16.sub.6 (refer to FIG. 11). Details on the structure of the
parallel link mechanism similar to movement system 200 of the
embodiment are disclosed in, for example, U.S. Pat. No. 6,940,582,
and controller 600 controls the position and the attitude of table
12 according to a method similar to the one disclosed in the above
U.S. Patent., using inverse kinematic calculation via expansion
mechanisms 16.sub.1 to 16.sub.6.
[0052] In movement system 200, because expansion mechanisms
16.sub.1 to 16.sub.6 provided at each of rods 14.sub.1 to 14.sub.6
have the air cylinder and the shaft motor which is a kind of
electromagnetic linear motor placed in series (or parallel) to one
another, controller 600 moves table 12 roughly and greatly by
pneumatic control of the air cylinder as well as in a fine manner
by the shaft motor. As a consequence, this allows the position in
directions of 6-DOF (i.e., position and attitude) of table 12 to be
controlled within a short time accurately.
[0053] Rods 14.sub.1 to 14.sub.6 each have an air pad for
supporting the magnet unit serving as the mover of the shaft motor
in a noncontact manner with respect to the armature unit serving as
the stator, therefore, friction which becomes a nonlinear component
when controlling the expansion/contraction of the rods with the
expansion mechanisms can be avoided, which allows more highly
precise control of position and attitude of table 12.
[0054] In the embodiment, because the shaft motor is used as the
electromagnetic linear motor structuring expansion mechanisms
16.sub.1 to 16.sub.6 and the magnet unit using the cylindrical
magnet is used in the mover side of the shaft motor, this generates
magnetic flux (magnetic field) in all directions of radiation
direction of the magnet and the magnetic flux in all directions can
be made to contribute to generating the Lorentz force (drive force)
by electromagnetic interaction, which allows thrust obviously
larger when comparing to, for example, a normal linear motor or the
like to be generated and allows easier downsizing when compared to
a hydraulic cylinder or the like.
[0055] Consequently, according to movement system 200 with rods
each including the shaft motor, downsizing, lighter weight and
improving output can be achieved at the same time, and this can be
suitably applied to shaping apparatus 100.
[0056] In controller 600, low frequency vibration can be controlled
by controlling air pressure of the air cylinder that structure each
of the expansion mechanisms and high frequency vibration can be
isolated by current control to the shaft motor.
[0057] Movement system 200 is further equipped with a planar motor
26 (refer to FIG. 11). At the bottom surface of slider 10, a mover
of planar motor 26 consisting of a magnet unit (or a coil unit) is
provided, and corresponding to this, a stator of planar motor 26
consisting of a coil unit (or a magnet unit) is housed inside base
BS. At the bottom surface of slider 10, a plurality of air bearings
(air hydrostatic bearings) are provided surrounding the mover, and
by the plurality of air bearings, slider 10 is supported by
levitation via a predetermined clearance (gap or space) on the
upper surface (guide surface) of base BS finished to have high
degree of flatness. Slider 10, by the electromagnetic force
(Lorentz force) generated by the electromagnetic interaction
between the stator and mover of planar motor 26, is driven within
the XY plane in a noncontact manner with respect to the upper
surface of base BS. In the embodiment, movement system 200 can
freely move table 12 between the placement positions of measurement
system 400, beam shaping system 500, and carrier system 300, as
shown in FIG. 1. Note that movement system 200 may be equipped with
a plurality of tables 12 on which workpiece W is mounted
separately. For example, while processing using beam shaping system
500 is being performed on the workpiece held by one table of the
plurality of tables, measurement using measurement system 400 may
be performed on the workpiece held by another table. Even in such a
case, each table can be freely moved between the placement
positions of measurement system 400, beam shaping system 500, and
carrier system 300. Or, in the case a structure is employed where a
table for holding the workpiece when performing measurement
exclusively using measurement system 400 and a table for holding
the workpiece when performing processing exclusively using beam
shaping system 500 are provided and the workpiece may be loaded and
unloaded on/from the two tables with a workpiece carrier system or
the like, each slider 10 may be fixed on base BS. In the case of
providing a plurality of tables 12, each table 12 is to be movable
in directions of 6-DOF, and the position in directions of 6-DOF of
each table 12 is to be controllable.
[0058] Planar motor 26 is not limited to the motor that employs the
air levitation method, and a planar motor employing a magnetic
levitation method may also be used. In the latter case, the air
bearings do not have to be provided in slider 10. As planar motor
26, both motors of a moving-magnet type and a moving-coil type can
be used.
[0059] Controller 600, by controlling at least one of the amount
and the direction of electric current supplied to each coil of the
coil unit structuring planar motor 26, can drive slider 10 freely
in the X and Y two-dimensional directions on base BS.
[0060] In the embodiment, movement system 200 is equipped with a
position measurement system 28 (refer to FIG. 11) that measures
position information of slider 10 in the X-axis direction and the
Y-axis direction. As position measurement system 28, a
two-dimensional absolute encoder can be used. Specifically, on the
upper surface of base BS, a two-dimensional scale is provided that
has a strip shaped absolute code of a predetermined width covering
the whole length in the X-axis direction, and correspondingly on
the bottom surface of slider 10, a light source such as a light
emitting element is provided as well as an X head and a Y head that
are structured by a one-dimensional light receiving element array
arranged in the X-axis direction and a one-dimensional light
receiving element array arranged in the Y-axis direction that
respectively receive reflection light from the two-dimensional
scale illuminated by the light beam emitted from the light source.
As the two-dimensional scale, for example, a scale is used that has
a plurality of square reflective portions (marks) arranged
two-dimensionally at a predetermined period on a non-reflective
base material (having a reflectance of 0%) along two directions
orthogonal to each other (the X-axis direction and the Y-axis), and
whose reflection characteristics (reflectance) of the reflective
portions have gradation that follow predetermined rules. As the
two-dimensional absolute encoder, a structure similar to the
two-dimensional absolute encoder disclosed in, for example, U.S.
Patent Application Publication No. 2014/0070073 may be employed.
According to the absolute two-dimensional encoder having a
structure similar to that of U.S. Patent Application Publication
No. 2014/0070073, the encoder allows measurement of two-dimensional
position information with high precision which is around the same
level as the conventional incremental encoder. Because the encoder
is an absolute encoder, origin detection is not necessary unlike
the incremental encoder. Measurement information of position
measurement system 28 is sent to controller 600.
[0061] In the embodiment, as it will be described later on,
position information (shape information in the embodiment) within
the three-dimensional space of at least a part of the target
surface (e.g. the upper surface) of workpiece W mounted on table 12
is measured using measurement system 400, and then additive
manufacturing (shaping) is performed on workpiece W after the
measurement. Accordingly, controller 600, when measuring position
information within the three-dimensional space of at least a part
of the target surface on workpiece W, correlates the measurement
results, measurement results of linear encoders 24.sub.1 to
24.sub.6 provided at rods 14.sub.1 to 14.sub.6 at the time of
measurement, and measurement results of position measurement system
28, so that the position and attitude of the target surface of
workpiece W mounted on table 12 can be correlated with a reference
coordinate system (hereinafter called a table coordinate system) of
shaping apparatus 100. This allows position control in directions
of 6-DOF with respect to a target value of target surface TAS on
workpiece W thereinafter according to open loop control on the
position of table 12 in directions of 6-DOF based on the
measurement results of linear encoders 24.sub.1 to 24.sub.6 and
position measurement system 28. In the embodiment, since absolute
encoders are used as linear encoders 24.sub.1 to 24.sub.6 and
position measurement system 28, origin search is not required which
makes reset easy. Note that the position information within the
three-dimensional space to be measured with measurement system 400
used for making position control in directions of 6-DOF with
respect to the target value of target surface TAS on workpiece W
according to open loop control on the position of table 12 in
directions of 6-DOF is not limited to shape, and is sufficient if
the information is three-dimensional position information of at
least three points corresponding to the shape of the target
surface.
[0062] In the embodiment, while the case has been described of
using planar motor 26 as a drive device for driving slider 10
within the XY plane, a linear motor may also be used instead of
planar motor 26. In this case, instead of the two-dimensional
absolute encoder previously described, the position measurement
system that measures position information of slider 10 may be
structured using the absolute linear encoder. The position
measurement system that measures position information of slider 10
is not limited to the encoders and may also be structured by using
an interferometer system.
[0063] In the embodiment, while an example was given of the case
when the mechanism for driving the table is structured using the
planar motor which drives the slider within the XY plane and the
Stewart platform type 6-DOF parallel link mechanism in which the
slider structures the base platform, the mechanism is not limited
to this, and the mechanism for driving the table may also be
structured by other types of parallel link mechanisms, or a
mechanism other than the parallel link mechanism. For example, a
slider that moves in the XY plane and a Z-tilt drive mechanism that
drives table 12 in the Z-axis direction and an inclination
direction with respect to the XY plane on the slider may be
employed. As an example of such Z-tilt drive mechanism, a mechanism
can be given that supports table 12 at each apex position of the
triangle from below, via joints such as, e.g. universal joints, and
also has three actuators (such as voice coil motors) that can move
each supporting point independently from one another in the Z-axis
direction. However, the structure of the mechanism for driving the
table in movement system 200 is not limited to these structures,
and the mechanism only has to have the structure of being able to
drive the table (movable member) on which the workpiece is mounted
in directions of at least 5-DOF that are directions of 3-DOF within
the XY plane, the Z-axis direction, and the inclination direction
with respect to the XY plane, does not necessarily have to be
equipped with a slider that moves within the XY plane. For example,
the movement system can be structured with a table and a robot that
drives the table. In any structure, reset can be performed easily
when the measurement system for measuring the position of the table
is structured using a combination of the absolute linear encoder,
or a combination of the linear encoder and an absolute rotary
encoder.
[0064] Other than this, instead of movement system 200, a system
that can drive table 12 in directions of at least 5-DOF, which are
directions of 3-DOF within the XY plane, the Z-axis direction, and
the inclination direction (.theta.x or .theta.y) with respect to
the XY plane may be employed. In this case, table 12 in itself may
be supported by levitation (supported in a non-contact manner) via
a predetermined clearance (gap or space) on the upper surface of a
support member such as base BS, by air floatation or magnetic
levitation. When such structure is employed, since the table moves
in a noncontact manner with respect to the supporting member, this
is extremely advantageous in positioning accuracy and contributes
greatly to improving shaping accuracy.
[0065] Measurement system 400 performs measurement of the
three-dimensional position information of the workpiece, e.g.
measurement of shape, to correlate the position and the attitude of
the workpiece mounted on table 12 to the table coordinate system.
Measurement system 400 is equipped with a laser noncontact type
three-dimensional measuring machine 401, as shown in FIG. 2.
Three-dimensional measuring machine 401 is equipped with a frame 30
installed on base BS, a head section 32 attached to frame 30, a
Z-axis guide 34 mounted on head section 32, a rotating mechanism 36
provided at the lower end of Z-axis guide 34, and a sensor section
38 connected to the lower end of rotating mechanism 36.
[0066] Frame 30 consists of a horizontal member 40 extending in the
Y-axis direction and a pair of column members 42 supporting
horizontal member 40 from below at both ends of the Y-axis
direction.
[0067] Head section 32 is attached to horizontal member 40 of frame
30.
[0068] Z-axis guide 34 is attached movable in the Z-axis direction
to head section 32 and is driven in the Z-axis direction by a Z
drive mechanism. 44 (not shown in FIG. 2, refer to FIG. 11).
Position in the Z-axis direction (or displacement from a reference
position) of Z-axis guide 34 is measured by a Z encoder 46 (not
shown in FIG. 2, refer to FIG. 11).
[0069] Rotating mechanism 36 rotationally drives sensor section 38
continuously (or in steps of a predetermined angle) around a
rotation center axis parallel to the Z-axis within a predetermined
angle range (e.g. within a range of 90 degrees (.pi./2) or 180
degrees (.pi.)) with respect to head section 32 (Z-axis guide 34).
In the embodiment, the rotation center axis of sensor section 38
according to rotating mechanism 36 coincides with a center axis of
a line beam irradiated from an irradiation section to be described
later on that structures sensor section 38. Rotation angle (or
position of the sensor section in the .theta.z direction) from a
reference position of sensor section 38 according to rotating
mechanism 36 is measured by a rotation angle sensor 48 (not shown
in FIG. 2, refer to FIG. 11) such as, for example, a rotary
encoder.
[0070] Sensor section 38 is structured mainly of an irradiation
section 50 that irradiates a line beam for performing optical
cutting on a test object (workpiece W in FIG. 2) mounted on table
12, and a detection section 52 that detects the surface of the test
object in which an optical cutting surface (line) appears by being
irradiated by the line beam. Sensor section 38 also has an
arithmetic processing section 54 connected that acquires the shape
of the test object on the basis of image data detected by detection
section 52. Arithmetic processing section 54 in the embodiment is
included in controller 600 (refer to FIG. 11) that has overall
control over each part structuring shaping apparatus 100.
[0071] Irradiation section 50 is structured of parts such as a
cylindrical lens (not shown) and a slit plate having a thin
strip-shaped cutout, and generates a fan-shaped line beam 50a by
receiving illumination light from a light source. As the light
source, LED, laser light source, SLD (super luminescent diode) or
the like can be used. In the case of using the LED, the light
source can be formed at a low cost. In the case of using the laser
light source, a line beam with low aberration can be formed since
the light source is a point light source, and since wavelength
stability is superior and half bandwidth small, a filter of a small
bandwidth can be used to cut stray light, which can reduce the
influence of disturbance. In the case of using the SLD, in addition
to the properties of the laser light source, since coherence of the
SLD is lower than that of the laser, speckle generation at the test
object surface can be suppressed. Detection section 52 is used for
imaging line beam 50a projected on the surface of the test object
(workpiece W) from a direction different from the light irradiation
direction of irradiation section 50. Detection section 52 is
structured with parts (not shown) such as an imaging lens and a
CCD, and as it is described later on, images the test object
(workpiece W) each time table 12 is moved and line beam 50a is
scanned at a predetermined interval. Positions of irradiation
section 50 and detection section 52 are decided so that an incident
direction to detection section 52 of line beam 50a on the surface
of the test object (workpiece W) and a light irradiation direction
of irradiation section 50 form a predetermined angle .theta.. In
the embodiment, the above predetermined angle .theta. is set to,
e.g. 45 degrees.
[0072] The image data of the test object (workpiece W) imaged by
detection section 52 is sent to arithmetic processing section 54
where a predetermined arithmetic processing is performed to
calculate the surface height of the test object (workpiece W) so
that a three-dimensional shape (surface shape) of the test object
(workpiece W) can be acquired. Arithmetic processing section 54, in
the image of the test object (workpiece W), calculates the height
of the test object (workpiece W) surface from a reference plane
using a principle of triangulation for each pixel in the
longitudinal direction in which the optical cutting surface (line)
(line beam 50a) extends and performs arithmetic processing to
acquire the three-dimensional shape of the test object (workpiece
W), on the basis of position information of optical cutting surface
(line) by line beam 50a deformed according to the unevenness of the
test object (workpiece W).
[0073] In the embodiment, controller 600 moves table 12 in a
direction substantially orthogonal to the longitudinal direction of
line beam 50a projected on the test object (workpiece W) so that
line beam 50a scans the surface of test object (workpiece W).
Controller 600 detects rotation angle of sensor section 38 with
rotation angle sensor 48, and moves table 12 in the direction
substantially orthogonal to the longitudinal direction of line beam
50a based on the detection results. As described, in the
embodiment, since table 12 is moved on measurement of the shape or
the like of the test object (workpiece W), as a premise, the
position and the attitude of table 12 (position in directions of
6-DOF) are constantly set to a predetermined reference state at the
point when table 12 enters an area under sensor section 38 of
measurement system 400 holding workpiece W. The reference state is
a state in which, e.g. rods 14.sub.1 to 14.sub.6 are all at a
length corresponding to a neutral point (or a minimum length) of an
expansion/contraction stroke range, and at this time, the position
in each of the Z-axis, the .theta.x, the .theta.y and the .theta.z
directions of table 12 is (Z, .theta.x, .theta.y,
.theta.z)=(Z.sub.0, 0, 0, 0). In this reference state, position (X,
Y) within the XY plane of table 12 coincides with the X and the Y
positions of slider 10 measured with position measurement system
28.
[0074] Then, the measurement described above to the test object
(workpiece W) begins, and the position in directions of 6-DOF of
table 12 is controlled by controller 600 on the table coordinate
system, also during the measurement. That is, controller 600
controls the position in directions of 6-DOF of table 12 by
controlling planar motor 26 based on the measurement information of
position measurement system 28 and by controlling expansion
mechanisms 16.sub.1 to 16.sub.6 based on the measurement values of
linear encoders 24.sub.1 to 24.sub.6.
[0075] In the case of using the optical cutting method as in
three-dimensional measuring machine 401 according to the present
embodiment, line beam 50a irradiated on the test object (workpiece
W) from irradiation section 50 of sensor section 38 is preferably
arranged in a direction orthogonal to a relative movement direction
between sensor section 38 and table 12 (test object (workpiece W)).
For example, in FIG. 2, when the Y-axis direction is set as the
relative movement direction between sensor section 38 and table 12
(test object (workpiece W)), line beam 50a is preferably arranged
along the X-axis direction. This arrangement allows relative
movement to the test object (workpiece W) while effectively using
the whole area of line beam 50a at the time of measurement, and the
shape of the test object (workpiece W) can be measured optimally.
Rotating mechanism 36 is provided so that the direction of line
beam 50a and the relative movement direction described above can be
orthogonal constantly.
[0076] Three-dimensional measuring machine 401 described above is
structured similarly to the shape measurement apparatus disclosed
in, for example, U.S. Patent Application Publication No.
2012/0105867. However, while scanning of the line beam with respect
to the test object in directions parallel to the X, Y planes is
performed by movement of the sensor section in the apparatus
described in U.S. Patent Application Publication No. 2012/0105867,
the embodiment differs on the point that the scanning is performed
by moving table 12. In the embodiment, scanning of the line beam
with respect to the test object in a direction parallel to the
Z-axis may be performed by driving either Z-axis guide 34 or table
12.
[0077] In the measurement method of using three-dimensional
measuring machine 401 according to the present embodiment, by using
the optical cutting method, a linear projection pattern consisting
of a line beam is projected on the surface of the test object, and
each time with the linear projection pattern is scanned with
respect to the whole surface of the test object surface, the linear
projection pattern projected on the test object is imaged from an
angle different from the projection direction. Then, from the
captured image of the test object surface that was imaged, the
height of the test object surface from the reference plane is
calculated using the principle of triangulation for each pixel in
the longitudinal direction of the linear projection pattern, and
the three-dimensional shape of the test object surface is
acquired.
[0078] Other than this, as the three-dimensional measuring machine
that structures measurement system 400, a device having a structure
similar to an optical probe disclosed in, for example, U.S. Pat.
No. 7,009,717 can also be used. This optical probe is structured by
two or more optical groups, and includes two or more visual field
directions and two or more projection directions. One optical group
includes one or more visual field direction and one or more
projection direction, and at least one visual field direction and
at least one projection direction differ between the optical
groups, and data acquired from the visual field direction is
generated only from a pattern projected from the projection
direction in the same optical group.
[0079] Measurement system 400 may be equipped with a mark detection
system 56 (refer to FIG. 11) for optically detecting an alignment
mark instead of the three-dimensional measuring machine 401, above,
or in addition to the three-dimensional measuring machine described
above. Mark detection system 56 can detect an alignment mark
formed, for example, on the workpiece. Controller 600, by
accurately detecting each center position (three-dimensional
coordinate) of at least three alignment marks using mark detection
system 56, calculates the position and attitude of the workpiece
(or table 12). Such mark detection system 56 can be structured
including, e.g. a stereo camera. A structure may also be employed
in which mark detection system 56 optically detects alignment marks
arranged beforehand at a minimum of three places on table 12.
[0080] In the embodiment, controller 600 scans the surface (target
surface) of workpiece W and acquires the surface shape data, using
the three-dimensional measuring machine 401 in the manner described
above. Then, controller 600 performs least-square processing and
performs correlation of the three-dimensional position and attitude
of the target surface on the workpiece to the table coordinate
system using the surface shape data. Here, because the position of
table 12 in directions of 6-DOF is controlled on the table
coordinate system by controller 600 also during the time of
measurement to the test object (workpiece W) described above,
control of the position (that is, position and attitude) of
workpiece W in directions of 6-DOF including the time of additive
manufacturing by three-dimensional shaping can all be performed by
an open-loop control of table 12 according to the table coordinate
system, after the three-dimensional position and attitude have been
correlated to the table coordinate system.
[0081] In addition to the position measurement of the workpiece or
the like before starting the additive manufacturing, measurement
system 400 of the present embodiment is also used for shape
detection of components (workpiece) after the additive
manufacturing, and details thereon will be described later.
[0082] FIG. 4 shows beam shaping system 500, along with table 12 on
which workpiece W is mounted. As shown in FIG. 4, beam shaping
system 500 includes a light source system 510, and is equipped with
a beam irradiation section 520 that emits a beam, a material
processing section 530 that supplies a powdery shaping material,
and a water shower nozzle 540 (not shown in FIG. 4, refer to FIG.
11). Note that beam shaping system 500 does not have to be equipped
with water shower nozzle 540.
[0083] Light source system 510, as is shown in FIG. 5, is equipped
with a light source unit 60, a light guide fiber 62 connected to
light source unit 60, and a double fly-eye optical system 64 and a
condenser lens system 66 placed on the exit side of light guide
fiber 62.
[0084] Light source unit 60 has a housing 68, and a plurality of
laser units 70 which are housed inside housing 68 and are arranged
parallel to one another in the shape of a matrix. As laser unit 70,
a unit that serves as a light source can be used such as various
types of lasers that perform pulse oscillation or continuous wave
oscillating operation, an Nd:YAG laser, a fiber laser, or a
GaN-based semiconductor laser.
[0085] Light guide fiber 62 is a fiber bundle structured by
randomly bundling many optical fiber strands that has a plurality
of incident ports 62a connected individually to the light-emitting
end of the plurality of laser units 70 and a light-emitting section
62b that has more light-emitting ports than the number of incident
ports 62a. Light guide fiber 62 receives a plurality of laser beams
(hereinafter appropriately shortened to as a "beam")) emitted from
each of the plurality of laser units 70 via each incident port 62a
and distributes the beam to the plurality of light-emitting ports
so that at least a part of each laser beam is emitted from a common
light-emitting port. In this manner, light guide fiber 62 mixes and
emits the beams emitted from each of the plurality of laser units
70. This allows the total output to be increased according to the
number of laser unit 70s when compared to the case when a single
laser unit is used. However, the plurality of laser units do not
have to be used in the case the output acquired is enough using a
single laser unit.
[0086] Light-emitting section 62b here has a sectional shape
similar to a whole shape of an incident end of a first fly-eye lens
system that structures an incident end of double fly-eye optical
system 64 which will be described next, and the light-emitting
ports are provided in an approximately even arrangement within the
section. Therefore, light guide fiber 62 also serves as a shaping
optical system that shapes the beam mixed in the manner described
above so that the beam is shaped similar to the whole shape of the
incident end of the first fly-eye lens system.
[0087] Double fly-eye optical system 64 is a system for making a
uniform cross-sectional intensity distribution of the beam
(illumination light), and is structured with a first fly-eye lens
system 72, a lens system 74, and a second fly-eye lens system 76
arranged sequentially on a beam path (optical path) of the laser
beam behind light guide fiber 62. Note that a diaphragm is provided
in the periphery of the second fly-eye lens system 76.
[0088] In this case, an incidence plane of the first fly-eye lens
system 72 and an incidence plane of the second fly-eye lens system
76 are set optically conjugate to each other. A focal plane (a
surface light source to be described later is formed here) on the
exit side of the first fly-eye lens system 72, a focal plane (a
surface light source to be described later is formed here) on the
exit side of the second fly-eye lens system 76, and a pupil plane
(entrance pupil) PP of a condensing optical system (to be described
later on) are set optically conjugate to one another. Note that in
the embodiment, a pupil plane (entrance pupil) PP of a condensing
optical system 82 coincides with a focal plane on the front side
(refer to FIGS. such as, for example, 4, 6 and 7).
[0089] The beam mixed by light guide fiber 62 is incident on the
first fly-eye lens system 72 of double fly-eye optical system 64.
With this, a surface light source, i.e. secondary light source
consisting of many light source images (point light sources), is
formed on a focal plane on the exit side of the first fly-eye lens
system 72. The laser beams from each of the many point light
sources are incident on the second fly-eye lens system 76 via lens
system 74. With this, a surface light source (a tertiary light
source) in which many fine light source images distributed in a
uniform manner within an area of a predetermined shape are formed
on a focal plane on the exit side of the second fly-eye lens system
76.
[0090] Condenser lens system 66 emits the laser beam emitted from
the tertiary light source described above as a beam that has
uniform illuminance distribution.
[0091] Note that by performing optimization on the area of the
incident end of the second fly-eye lens system 76, the focal
distance of condenser lens system 66 and the like, the beam emitted
from condenser lens system 66 can be regarded as a parallel
beam.
[0092] Light source 510 of the embodiment is equipped with an
illuminance uniformizing optical system that is equipped with light
guide fiber 62, double fly-eye optical system 64, and condenser
lens system 66, and using this illuminance uniformizing optical
system, mixes the beams emitted from each of the plurality of laser
units 70 and generates a parallel beam having a cross-section with
uniform illuminance distribution.
[0093] Note that the illuminance uniformizing optical system is not
limited to the structure described above. The illuminance
uniformizing optical system may be structured using a rod
integrator or a collimator lens system.
[0094] Light source unit 60 of light source system 510 is connected
to controller 600 (refer to FIG. 11), and controller 600
individually controls the on/off of the plurality of laser units 70
structuring light source unit 60. With this control, the amount of
light of the laser beam (laser output) irradiated (on the target
surface) on workpiece W from beam irradiation section 520 is
adjusted.
[0095] Beam irradiation section 520, other than light source system
510, has a beam section intensity conversion optical system 78, a
mirror array 80 which is a type of spatial light modulator (SLM:
Spatial Light Modulator), and a condensing optical system 82 which
condenses the light from mirror array 80 that are sequentially
arranged on the optical path of the parallel beam from light source
system 510 (condenser lens system 66), as shown in FIG. 4. The
spatial light modulator here is a general term for an element that
spatially modulates the amplitude (intensity), phase, or state of
polarization of light advancing in a predetermined direction.
[0096] Beam section intensity conversion optical system 78 performs
conversion of the intensity distribution of the cross sectional
surface of the parallel beam from light source system 510
(condenser lens system 66). In the embodiment, beam section
intensity conversion optical system 78 converts the parallel beam
from light source system 510 into a parallel beam having a donut
shape (annular shape) with the intensity of an area including the
center of the cross sectional surface being substantially zero.
Beam section intensity conversion optical system 78, in the
embodiment, is structured, for example, with a convex conically
shaped reflection mirror and a concave conically shaped reflection
mirror that are sequentially placed on the optical path of the
parallel beam from light source system 510. The convex conically
shaped reflection mirror has a conically shaped reflection surface
formed on its outer peripheral surface on the light source system
510 side, and the concave conically shaped reflection mirror,
consisting of an annular-shaped member having an inner diameter
larger than the outer diameter of the convex conically shaped
reflection mirror, has a reflection surface facing the reflection
surface of the convex conically shaped reflection mirror formed on
its inner peripheral surface. In this case, when viewing from an
arbitrary sectional surface that passes through the center of the
concave conically shaped reflection mirror, the reflection surface
of the convex conically shaped reflection mirror and the reflection
surface of the concave conically shaped reflection mirror are
parallel. Consequently, the parallel beam from light source system
510 is reflected radially by the reflection surface of the convex
conically shaped reflection mirror, and by this reflection beam
being reflected by the reflection surface of the concave conically
shaped reflection mirror, the beam is converted into the annular
shaped parallel beam.
[0097] In the embodiment, the parallel beam that passes through
beam section intensity conversion optical system 78 is irradiated
on the workpiece, via mirror array 80 and condensing optical system
82 in the manner to be described later on. By converting the
intensity distribution of the cross sectional surface of the
parallel beam from light source system 510 using beam section
intensity conversion optical system 78, it becomes possible to
change intensity distribution of the beam incident on pupil plane
(entrance pupil) of condensing optical system 82 from mirror array
80. In addition, by converting the intensity distribution of the
cross sectional surface of the parallel beam from light source
system 510 using beam section intensity conversion optical system
78, it becomes possible to substantially change intensity
distribution in the exit plane of condensing optical system 82 of
the beam emitted from condensing optical system 82.
[0098] Note that beam section intensity conversion optical system
78 is not limited to the combination of the convex conically shaped
reflection mirror and the concave conically shaped reflection
mirror, and may be structured using a combination of a diffractive
optical element, an afocal lens, and a conical axicon system as is
disclosed in, for example, U.S. Patent Application Publication No.
2008/0030852. Beam section intensity conversion optical system 78
is sufficient if it performs conversion of the intensity
distribution of the cross sectional surface of the beam, and
various structures can be considered. Depending on the structure of
beam section intensity conversion optical system 78, it is possible
to make the parallel beam from light source 510 such that the
intensity in the area including the center of the cross sectional
surface is not nearly zero, but smaller than the intensity on the
outer side of the area.
[0099] Mirror array 80, in the embodiment, has a base member 80A
that has a surface which forms an angle of 45 degrees (.pi./4) with
respect to the XY plane and an XZ plane (hereinafter caller a
reference surface for the sake of convenience), e.g. M (=P.times.Q)
mirror elements 81.sub.p,q (p=1 to P, q=1 to Q) arranged in a
matrix shape of, e.g. P rows and Q columns, on the reference
surface of base member 80A, and a drive section 87 (not shown in
FIG. 4, refer to FIG. 11) including M actuators (not shown) that
separately drive each mirror element 81.sub.p,q. Mirror array 80
can substantially form a large reflection surface parallel to the
reference surface by adjusting tilt of numerous mirror elements
81.sub.p,q with respect to the reference surface.
[0100] Each mirror element 81.sub.p,q of mirror array 80, for
example, is structured rotatable around a rotation axis parallel to
one diagonal line of mirror element 81.sub.p,q and a tilt angle of
its reflection surface with respect to the reference surface can be
set to an arbitrary angle within a predetermined angle range. The
angle of the reflection surface of each mirror element is measured
using a sensor that detects a rotation angle of the rotation axis,
e.g. a rotary encoder 83.sub.p,q (not shown in FIG. 4, refer to
FIG. 11).
[0101] Drive section 87, for example, includes an electromagnet or
a voice coil motor serving as an actuator, and the individual
mirror elements 81.sub.p,q are driven by the actuator and operate
at an extremely high response.
[0102] Of the plurality of mirror elements structuring mirror array
80, each of the mirror elements 81.sub.p,q illuminated by the
annular shape parallel beam from light source system 510 emits a
reflection beam (parallel beam) according to the tilt angle of the
reflection surface and makes the beam enter condensing optical
system 82 (refer to FIG. 6). Note that although the reason for
using mirror array 80 and the reason for making the annular shape
parallel beam enter mirror array 80 in the embodiment is to be
described later on, the parallel beam does not necessarily have to
be an annular shape, and the cross sectional surface shape (cross
sectional surface intensity distribution) of the parallel beam
entering mirror array 80 may be made different from the annular
shape, or beam section intensity conversion optical system 78 may
not have to be provided.
[0103] Condensing optical system 82 is a high numerical aperture
(N.A.) and low aberration optical system having a numerical
aperture of, e.g. 0.5 or more, or preferably 0.6 or more. Because
condensing optical system 82 has a large diameter, low aberration,
and high N.A., the plurality of parallel beams from mirror array 80
can be condensed on a rear focal plane. Although details will be
described later on, beam irradiation section 520 can condense the
beam emitted from condensing optical system 82 into, for example, a
spot shape or a slit shape. In addition, because condensing optical
system 82 is structured using one or a plurality of large diameter
lenses (FIG. 4 representatively shows one large diameter lens), the
area of incident light can be enlarged, which allows more light
energy to be taken in when compared to the case of using a
condensing optical system with a small N.A. Consequently, the beam
condensed using condensing optical system 82 according to the
embodiment is extremely sharp and will have high energy density,
which is connected directly with improving the processing accuracy
of additive manufacturing by shaping.
[0104] In the embodiment, as it will be described later on, a case
in which shaping (machining processing) is performed by moving
table 12 in a scan direction (the Y-axis direction as an example in
FIG. 4) parallel to the XY plane and relatively scanning the beam
and workpiece W that has target surface TAS of shaping at the upper
end in the scan direction (scan direction). It goes without saying
that table 12 may be moved in at least one of the X-axis direction,
the Z-axis direction, the .theta.x direction, the .theta.y
direction, and the .theta.z direction, during the movement of table
12 in the Y-axis direction on shaping. In addition, as it will be
described later on, powdery shaping material (metal material)
supplied from material processing section 530 is melted by the
energy of the laser beam. Consequently as it is previously
described, if the total amount of energy that condensing optical
system 82 takes in becomes larger, the amount of energy of the beam
emitted from condensing optical system 82 becomes larger, and this
increases the amount of metal that can be melted in a unit time. If
the amount of the shaping material supplied and the speed of table
12 are increased accordingly, this increases throughput of shaping
processing by beam shaping system 500.
[0105] However, even if the total output of the laser is increased
using the method previously described, because the speed of the
scanning operation of table 12 cannot actually be increased to
infinity, throughput that takes full advantage of the laser power
cannot be achieved. To solve this issue, in shaping apparatus 100
of the embodiment, as it will be described later on, an irradiation
area of a slit shaped beam (hereinafter called a straight line area
(refer to reference code LS in FIG. 9B)) can be formed instead of
an irradiation area of a spot shaped beam on a surface (hereinafter
called shaping surface) MP (refer to, e.g. FIGS. 4 and 9A) where
target surface TAS of shaping is to be aligned, and shaping
(machining processing) can be performed while relatively scanning
workpiece W with respect to a beam forming straight line area LS
(hereinafter called a straight line beam) in a direction
perpendicular to the longitudinal direction of the beam. This
allows a greatly broad area (e.g. an area larger by several times
to several tens of times) to be processed at once when compared to
the case of scanning the workpiece with a spot shaped beam. Note
that, although shaping surface MP described above is a rear focal
plane of condensing optical system 82 in the embodiment as it will
be described later on, the shaping surface may be a surface near
the rear focal plane. In addition, in the embodiment, although
shaping surface MP is perpendicular to an optical axis AX at the
exit side of condensing optical system 82, the surface does not
have to be perpendicular.
[0106] As a method of setting or changing the intensity
distribution of the beam on shaping surface MP (e.g. a method of
forming the straight line area as in the description above), for
example, a method can be employed in which an incidence angle
distribution of the plurality of parallel beams incident on
condensing optical system 82 is controlled. In a lens system that
condenses the parallel beam at one point like condensing optical
system 82 of the embodiment, the focal position at the rear focal
plane (condensing plane) is determined by the incidence angle of
parallel beam LB (e.g. refer to FIGS. 4 and 6) on pupil plane
(entrance pupil) PP. The incidence angle here is decided from, a.
an angle .alpha.(0.ltoreq..alpha.<90 degrees (.pi./2)) which is
an angle that the parallel beam incident on pupil plane PP of
condensing optical system 82 forms with respect to an axis parallel
to optical axis AX of condensing optical system 82, and b. a
reference axis (e.g. an angle .beta.(0.ltoreq..beta.<360 degrees
(2.pi.) with respect to the X-axis (X.gtoreq.0)) on a
two-dimensional orthogonal coordinate system (X, Y) of an
orthogonal projection to pupil plane PP (XY coordinate plane) of
the parallel beam incident on pupil plane PP when the
two-dimensional orthogonal coordinate system (X, Y) orthogonal to
the optical axis (AX) that has a point on the optical axis (AX)
serving as an origin is set on the pupil plane. For example, the
beam that is incident on pupil plane PP of condensing optical
system 82 perpendicularly (parallel to the optical axis) condenses
on optical axis AX, and the beam that is slightly tilted with
respect to condensing optical system 82 (with respect to optical
axis AX) condenses at a position slightly shifted from the position
on optical axis AX. By using this relation and making the incidence
angle (incident direction) of the plurality of parallel beams LB
incident on pupil plane PP of condensing optical system 82 have an
appropriate angle distribution when reflecting and making the
parallel beam from light source system 510 enter condensing optical
system 82, intensity distribution of the beam within shaping
surface MP such as, e.g. at least one of position, number, size and
shape of the irradiation area in the shaping surface, can be
arbitrarily changed. Consequently, it is naturally easy to form
areas such as, e.g. a straight line area, a three line area, or a
broken straight line area (refer to FIG. 10), and is also easy to
form a spot shaped irradiation area.
[0107] In condensing optical system 82 of the embodiment, since the
structure is employed so that pupil plane (entrance pupil) PP
coincides with the front focal plane, the condensing position of
the plurality of parallel beams LB can be controlled accurately in
a simple manner by changing the incidence angle of the plurality of
parallel beams LB using mirror array 80, however, the structure of
the pupil plane (entrance pupil) PP and the front focal plane
coinciding does not necessarily have to be employed.
[0108] If the shape and size of the irradiation area formed on the
shaping surface are not variable, the position of the irradiation
area can also be changed by controlling the incidence angle of one
parallel beam incident on the pupil plane of condensing optical
system 82 using a solid mirror of a desired shape.
[0109] However, in the case of performing additive manufacturing
(shaping) to the workpiece, the area of the target surface on which
the target portion of shaping is not always set constantly on a
flat surface. That is, relative scanning of the straight line beam
is not always possible. At places such as near the outline of the
workpiece, or around the border of a solid area and a hollow area,
the border may be tilted, narrow or curved, making it difficult to
apply relative scanning of the straight line beam. For instance,
since it is difficult to paint out such an area with a wide brush,
a thin brush corresponding to the area or a thin pencil will be
necessary, that is to say, the brushes and the thin pencil are to
be used to suit their use freely real time and continuously.
Similarly, near the outline edge of the workpiece or around the
border of the solid area and the hollow area, requirements such as
changing the width in the scan direction (relative moving
direction) of the irradiation area of the beam or changing the size
(e.g. the length of the straight line beam), number or position
(position of the irradiation point of the beam) of the irradiation
area occur.
[0110] Therefore, in the embodiment, mirror array 80 is employed,
and controller 600 makes each mirror element 81.sub.p,q operate at
an extremely high response so that the incidence angle of the
plurality of parallel beams LB entering pupil plane PP of
condensing optical system 82 can be controlled respectively. This
allows intensity distribution of the beam on shaping surface MP to
be set or changed. In this case, controller 600 can change the
intensity distribution of the beam on shaping surface MP, such as,
for example, at least one of shape, size, and number of the
irradiation area of the beam, during relative movement of the beam
and target surface TAS (a surface on which target portion TA of
shaping is set, and in the embodiment, a surface on workpiece W).
In this case, controller 600 can continuously or intermittently
change the intensity distribution of the beam on shaping surface
MP. For example, it is possible to continuously or intermittently
change the width of the straight line area in the relative moving
direction during relative movement of the beam and target surface
TAS. Controller 600 can also change the intensity distribution of
the beam on shaping surface MP according to the relative position
of the beam and target surface TAS. Controller 600 can also change
the intensity distribution of the beam on shaping surface MP
according to a required shaping accuracy and throughput.
[0111] In addition, in the embodiment, controller 600 detects the
state of each mirror element (in this case, tilt angle of the
reflection surface) using rotary encoder 83.sub.p,q previously
described, and by this detection, monitors the state of each mirror
element real time so that the tilt angle of the reflection surface
of each mirror element of mirror array 80 can be accurately
controlled.
[0112] Material processing section 530, as shown in FIG. 7, has a
nozzle unit 84 which has a nozzle member (hereinafter shortly
described as a nozzle) 84a provided below the exit plane of
condensing optical system 82, a material supplying device 86
connected to nozzle unit 84 via a piping 90a, a plurality of, e.g.
two, powder cartridges 88A and 88B each connected to material
supplying device 86 via piping. FIG. 7 shows condensing optical
system 82 and the parts below of FIG. 4, when viewed from the -Y
direction.
[0113] Nozzle unit 84 extends in the X-axis direction below
condensing optical system 82, and is equipped with a nozzle 84a
that has at least one supplying port for supplying powdered shaping
material, and a pair of support members 84b and 84c that support
both ends in the longitudinal direction of nozzle 84a and also have
each upper end connected to the housing of condensing optical
system 82. To one of the support members, 84b, one end (the lower
end) of material supplying device 86 is connected via piping 90a,
and support member 84b has a supply path formed inside that
communicates piping 90a with nozzle 84a. In the embodiment, nozzle
84a is placed directly below the optical axis of condensing optical
system 82, and in its lower surface (bottom surface), has a
plurality of supply ports provided that will be described later on.
Note that nozzle 84a does not necessarily have to be placed on the
optical axis of condensing optical system 82, and may be placed at
a position slightly shifted from the optical axis to one side of
the Y-axis direction.
[0114] To the other end (the upper end) of material supplying
device 86 is connected to piping 90b and 90c serving as supply
paths to material supplying device 86, and powder cartridges 88A
and 88B are connected to material supplying device 86 via piping
90b and 90c, respectively. In one of the powder cartridges, 88A,
powder of a first shaping material (e.g. titanium) is stored. In
the other powder cartridge, 88B, powder of a second shaping
material (e.g. stainless steel) is stored.
[0115] Note that in the embodiment, although shaping apparatus 100
is equipped with two powder cartridges for supplying two types of
shaping material to material supplying device 86, the number of
powder cartridges that shaping apparatus 100 is equipped with may
be one.
[0116] While the powder from powder cartridges 88A and 88B to
material supplying device 86 may be supplied so that powder
cartridges 88A and 88B each have a function of forcibly supplying
the powder to material supplying device 86, in the embodiment,
material supplying device 86 is made to have a function of
switching between piping 90b and 90c, as well as a function of
performing suction of the powder from either powder cartridge 88A
or 88B by using vacuum. Material supplying device 86 is connected
to controller 600 (refer to FIG. 11). Material supplying device 86
is connected to controller 600 (refer to FIG. 11). At the time of
shaping, controller 600 performs switching between piping 90b and
90c using material supplying device 86, selectively chooses between
the powder of the first shaping material (e.g. titanium) from
powder cartridge 88A and the powder of the second shaping material
(e.g. stainless steel) from powder cartridge 88B, and supplies the
powder of one of the shaping materials to nozzle 84a from material
supplying device 86 via piping 90a. Note that by changing the
structure of material supplying device 86, a structure may be
employed in which the powder of the first shaping material from
powder cartridge 88A and the powder of the second shaping material
from powder cartridge 88B are supplied simultaneously to material
supplying device 86 when necessary, and the mixture of the two
shaping materials can be supplied to nozzle 84a via piping 90a.
Note that a nozzle connectable to powder cartridge 88A and another
nozzle connectable to powder cartridge 88B may be provided below
condensing optical system 82 so as to supply the powder at the time
of shaping from either one of the nozzles, or from both of the
nozzles.
[0117] In addition, controller 600 can adjust the supply amount per
unit time of the shaping material supplied to nozzle 84a from
powder cartridges 88A and 88B via material supplying device 86. For
example, by adjusting the amount of powder supplied to material
supplying device 86 from at least either one of powder cartridges
88A or 88B, the amount of shaping material per unit time supplied
to nozzle 84a via material supplying device 86 can be adjusted. For
example, by adjusting the vacuum level used to supply the powder to
material supplying device 86 from powder cartridges 88A and 88B,
the amount of shaping material per unit time supplied to nozzle 84a
can be adjusted. Alternately, it is also possible to adjust the
amount of shaping material per unit time supplied to nozzle 84a by
providing a valve for adjusting the amount of powder supplied to
piping 90a from material supplying device 86.
[0118] Here, although it is not shown in FIG. 7, a plurality of,
e.g. N supply ports 91.sub.i (i=1 to N), are actually formed at an
equal spacing in the X-axis direction on the lower surface (bottom
surface) of nozzle 84a and each supply port 91.sub.i can be
opened/closed individually by an open/close member 93.sub.i, as
shown in FIG. 8. Note that FIG. 8, for the sake of convenience,
shows 12 supply ports 91.sub.i as an example, and is drawn to
explain the relation between the supply port and the open/close
member. However, the number of supply ports formed is actually more
than 12 and the partition between adjacent supply ports is
narrower. However, the number of supply ports is not limited, as
long as the supply ports are arranged along almost the entire
length in the longitudinal direction of nozzle 84a. For example,
the supply port may be one slit shaped opening that is arranged
along almost the entire length in the longitudinal direction of
nozzle 84a.
[0119] Open/close member 93.sub.i, as is representatively shown as
93k in FIG. 8 indicated by an arrow as the k.sup.th open/close
member, is drivable sliding in the +Y direction and -Y direction to
open/close supply port 91.sub.i. Open/close member 93.sub.i is not
limited to the slide drive, and may be structured rotatable in the
inclination direction with one end serving as a center.
[0120] Each open/close member 93.sub.i is driven and controlled by
controller 600, via an actuator not shown. Controller 600 performs
open/close control of each of the plurality of supply ports, e.g. N
supply ports 91.sub.i, using each open/close member 93.sub.i
according to the intensity distribution of the beam on the shaping
surface, such as for example, setting (or change) of the shape, the
size, and the arrangement of the irradiation area of the beam
formed on the shaping surface. This allows the supply operation of
the shaping material by material processing section 530 to be
controlled. In this case, controller 600 selects at least one
supply port of the plurality of supply ports 91.sub.i, and only
open/close member 93.sub.i that closes the selected at least one
supply port operates under the open control, or for example, is
driven in the -Y direction. Consequently, in the embodiment, the
shaping material can be supplied using only a part of the plurality
of, or N supply ports 91.sub.i.
[0121] In addition, according to at least one of the supply amount
control per unit time of the shaping material supplied to nozzle
84a via material supplying device 86 and the open/close control
using the arbitrary open/close member 93.sub.i previously
described, controller 600 can adjust the supply amount per unit
time of the shaping material from supply port 91.sub.i
opened/closed by the arbitrary open/close member 93.sub.i.
Controller 600 determines the supply amount per unit time of the
shaping material from the arbitrary supply port 91.sub.i according
to the intensity distribution of the beam on the shaping surface,
such as setting (or change) of the shape, the size, and the
arrangement of the irradiation area of the beam formed on the
shaping surface. Controller 600 determines the supply amount per
unit time from each supply port 91.sub.i based on, for example, the
width of the scan direction of the straight line area previously
described.
[0122] Note that a structure may be employed in which the opening
degree of each supply port 91.sub.i is adjustable with each
open/close member 93.sub.i. In this case, controller 600 may adjust
the opening degree of each supply port 91.sub.i with each
open/close member 93.sub.i, for example, according to the width of
the scan direction of the straight line area previously
described.
[0123] Other than this, at least one supply port that supplies the
powdered shaping material may be movable. For example, a structure
may be employed in which one slit shaped supply port extending in
the X-axis direction is formed on the lower surface of nozzle 84a
and nozzle 84a is made movable, for example, in at least either the
X-axis direction or the Y-axis direction with respect to the pair
of support members 84b and 84c, and controller 600 may move nozzle
84a that has the supply port formed on its lower surface according
to intensity distribution change of the beam on the shaping
surface, that is, change in shape, size, and position of the
irradiation area of the beam. Note that nozzle 84a may also be
movable in the Z-axis direction.
[0124] Or, nozzle 84a may be structured from a main section and at
least two movable members that are movable in at least one of the
X-axis direction and the Y-axis direction within the XY plane with
respect to the main section and have a supply port formed at the
bottom surface, and at least a part of the movable members may be
moved, by controller 600, according to intensity distribution
change of the beam on the shaping surface. Also in this case, at
least a part of the movable members may be movable in the Z-axis
direction.
[0125] Further, a structure may be employed in which one supply
port and another supply port of the plurality of supply ports are
relatively movable. Or, for example, the position in the Y-axis
direction may differ between the one supply port described above
and the another supply port described above. Or, the position in
the Z-axis direction may differ between the one supply port
described above and the another supply port described above.
[0126] Note that moving of at least one supply port may be
performed not only with setting or changing the intensity
distribution of the beam, but may be moved also for other
purposes.
[0127] As is previously described, the plurality of supply ports
91.sub.i provided at nozzle 84a are arranged orthogonal to the
optical axis of condensing optical system 82 in the X-axis
direction at an equal spacing across the entire length of nozzle
84a, with only little space between adjacent supply ports 91.sub.i.
Therefore, as indicated by a black arrow in FIG. 9A, if the
powdered shaping material PD is supplied directly down along the
Z-axis direction parallel to optical axis AX of condensing optical
system 82 from each of the plurality of supply ports 91.sub.i of
nozzle 84a, then shaping material PD will be supplied to the
straight line area LS (irradiation area of the straight line beam)
previously described directly below optical axis AX of condensing
optical system 82. In this case, the supply of shaping material PD
from nozzle 84a can be performed by using self-weight of shaping
material PD or by blowout to which a slight blowout pressure is
applied. Consequently, a complicated mechanism such as a gas flow
generation mechanism for guiding the shaping material in the case
when the shaping material is supplied from an oblique direction
with respect to the target surface of the shaping will not be
required. In addition, it is extremely advantageous that the
shaping material can be supplied perpendicularly at close range to
the workpiece as in the embodiment when securing processing
accuracy on shaping.
[0128] Note that a gas supply port may be provided at nozzle 84a.
The gas flow of the gas supplied from the gas supply port may be
used to guide the shaping material supplied or may be used for
other purposes such as to contribute to shaping.
[0129] In the embodiment, since the annular shape parallel beam is
irradiated on mirror array 80, the reflection beam from mirror
array 80 enters a partial area (a partial area where N.A. is large)
near the periphery of condensing optical system 82 and is condensed
at the exit end of condensing optical system 82, that is on shaping
surface MP (coincides with the rear focal plane of condensing
optical system 82 in the embodiment) of condensing optical system
82 via an area in a peripheral end part distanced from the optical
axis of a terminal end lens positioned at the exit end of beam
irradiation section 520 (refer to FIG. 4). That is, the straight
line beam, for example, is formed only by the light that passes
through the area near the periphery of the same condensing optical
system 82. Therefore, a beam spot (laser spot) with high quality
can be formed when compared to the case when a beam spot light that
passes separate optical systems are condensed on the same area. In
addition, in the embodiment, a limit can be set to the beam
irradiated on nozzle 84a provided in the center below the exit
plane (lower end surface) of condensing optical system 82.
Therefore, in the embodiment, it becomes possible to use all the
reflection beams from mirror array 80 to form the spot, and parts
such as a light shielding member to limit the beam irradiating on
nozzle 84a will not necessarily have to be arranged at the part
corresponding to nozzle 84a on the incident surface side of
condensing optical system 82. For such reasons, the annular shape
parallel beam is used to illuminate mirror array 80.
[0130] Note that the optical member positioned at the exit end of
condensing optical system 82 only has to be a member that at least
can form an optical surface at an area distanced from an optical
axis of a surface on the exit side and condense a beam on a shaping
surface (rear focal plane) via the optical surface. Consequently,
this optical member may be a member having at least one of the exit
surface and the incidence plane perpendicular to the optical axis
of condensing optical system in the area including the optical
axis, or having a hole formed in the area including the optical
axis. The optical member positioned at the exit end of condensing
optical system 82 may be structured arranging a donut shaped
condensing lens with a hole in the center part area including the
optical axis.
[0131] Note that to limit the beam incident on nozzle 84a from
condensing optical system 82, for example, a limit member 85
indicated by a double dotted line in FIG. 7 may be provided at the
incidence plane side (e.g. pupil plane PP) of condensing optical
system 82. Limit member 85 limits the beam from condensing optical
system 82 when entering nozzle 84a. As limit member 85, although a
light shielding member may be used, parts such as a light
attenuation filter may also be used. In such a case, the parallel
beam incident on condensing optical system 82 may be a parallel
beam having a circular sectional shape, or may be an annular shape
beam. In the latter case, because the beam is not irradiated on
limit member 85, it becomes possible to use the reflection beam
from mirror array 80 exclusively for forming the spot.
[0132] Note that although the beam incident on nozzle 84a from
condensing optical system 82 does not necessarily have to be
shielded completely, to prevent the beam from condensing optical
system 82 being incident on nozzle 84a, the beam may be made
incident only from separate periphery end part areas (e.g. two
circular arc areas) at both sides of the optical axis in the Y-axis
direction at the exit plane of a terminal end lens of condensing
optical system 82.
[0133] Water shower nozzle 540 (refer to FIG. 11) is used on the
so-called quenching. Water shower nozzle 540 has a supply port that
supplies a cooling liquid (cooling water) and spouts the cooling
liquid at a cooling target. Water shower nozzle 540 is connected to
controller 600 (refer to FIG. 11). Controller 600 controls light
source unit 60 on quenching so that thermal energy of the beam from
beam irradiation section 520 is adjusted to an appropriate value
for quenching. Then, after irradiating the beam on the surface of
the workpiece to increase the temperature to a high degree,
controller 600 can perform quenching by spouting the cooling liquid
at the high temperature part to rapidly cool the part, via water
shower nozzle 540. In this case, it is also possible to perform
additive manufacturing to the workpiece according to
three-dimensional shaping and quenching simultaneously. Note that
when the quenching process is performed simultaneously with the
additive manufacturing, it is desirable to use a metal having
excellent quenchability as the shaping material.
[0134] In the embodiment, at the time of additive manufacturing or
the like to the workpiece, as is shown in FIG. 9A which is an
enlarged view of FIG. 4 and circle A of FIG. 4, the beam
(illustrated as beams LB1.sub.1 and LB1.sub.2 for the sake of
convenience in FIG. 9A) that passes though the vicinity of the
periphery end part of condensing optical system 82 and though the
optical path of nozzle 84a on the +Y side and -Y side (the front
and the rear of the scan direction of workpiece W (table 12)) is
condensed directly below nozzle 84a, and straight line area LS with
a longitudinal direction in the X-axis direction (orthogonal
direction of the page surface in FIG. 9A) is formed on the shaping
surface (refer to FIG. 9B), and to the straight line beam that
forms straight line area LS, powdered shaping material PD is
supplied along the Z-axis (along an XZ plane including optical axis
AX) parallel to optical axis AX of condensing optical system 82 via
the plurality of supply ports 91.sub.1 of nozzle 84a. This forms a
linear molten pool WP extending in the X-axis direction directly
below nozzle 84a. Formation of such molten pool WP is performed
while table 12 is scanned in the scan direction (+Y direction in
FIG. 9A). This makes it possible to form a bead (melted and
solidified metal) BE of a predetermined width that covers the
length in the longitudinal direction (X-axis direction) of the
straight line beam (molten pool WP).
[0135] In this case, when the incidence angle of the plurality of
parallel beams LB incident on condensing optical system 82 is
adjusted, for example, so that the number of parallel beams LB
incident on condensing optical system 82 are not reduced while the
width in the X-axis direction or the Y-axis direction or both of
the straight line beam are gradually narrowed, condensing density
(energy density) of the beam increases. Consequently, in response,
by increasing the supply amount of the powder (shaping material)
per unit time and increasing the relative moving speed of target
surface TAS, it becomes possible to keep the thickness of bead BE
to be formed constant, and also to keep the level of throughput
high. However, such adjustment method is not limiting, and other
adjustment methods can be used to keep the thickness of bead BE to
be formed constant. For example, laser output (energy amount of the
laser beam) of at least one of the plurality of laser units 70 may
be adjusted according to the width in the X-axis direction or the
Y-axis direction or both of the straight line beam, or the number
of parallel beams LB incident on condensing optical system 82 from
mirror array 80 may be changed. In this case, although the
throughput slightly decreases when compared to the adjustment
method described above, the adjustment is simple.
[0136] In shaping apparatus 100 according to the embodiment,
measurement device 110 is provided that receives the beam from
condensing optical system 82 and performs measurement processing.
For example, measurement device 110 can receive the beam from
condensing optical system 82 and measure the optical properties and
the like of the beam. In the embodiment, measurement device 100 is
used to control the intensity distribution of the beam. In the
embodiment, measurement device 110 measures the intensity
distribution of the beam at the rear focal plane of condensing
optical system 82 (coincides with shaping surface MP in the
embodiment), and the intensity distribution of the beam at pupil
plane PP of condensing optical system 82 (coincides with the front
focal plane in the embodiment).
[0137] Measurement device 110, as is shown in FIG. 12, has
measurement member 92 that structures a part of the upper surface
of table 12, and remaining component parts housed inside table
12.
[0138] FIG. 13 shows a perspective view of the component parts
which is a part of measurement device 110 and are arranged inside
table 12, along with measurement member 92. As shown in FIG. 13,
measurement device 110 is equipped with measurement member 92, a
first optical system 94, an optical system unit 95, and a light
receiver 96.
[0139] Measurement member 92 is placed within a circular opening
formed on the upper surface of table 12 in a state where its upper
surface is flush (coplanar) with the remaining part of table 12.
Measurement member 92 has a base material that can transmit the
beam from condensing optical system 82, formed of, e.g. quartz or
the like, and on the surface of the base material, a thin light
shielding film that also functions as a reflection film is formed
by vapor deposition of metal such as chromium, and in the center
part of the light shielding film, a circular opening 92a is formed.
Consequently, the upper surface of measurement member 92 includes
the surface of the light shielding film and the base material
surface within opening 92a. Note that since the light shielding
film formed is extremely thin, in the description below, the
surface of the light shielding film and the base material within
opening 92a will be described as being positioned in the same
plane. Although the light shielding film does not necessarily have
to be formed, by forming the light shielding film, an effect of
suppressing the influence of flare or the like on measurement can
be expected.
[0140] The first optical system 94 is placed below measurement
member 92. The beam via opening 92a of measurement member 92 is
incident on the first optical system 94. Note that in the
embodiment, although the first optical system 94 is a collimator
optical system, it does not necessarily have to be a collimator
optical system.
[0141] Optical system unit 95 has a circular rotary plate 101 that
has a rotation shaft 101a provided in the center. In rotary plate
101, an opening section 97 and a lens (second optical system) 98
are placed spaced apart at a predetermined angle with rotation
shaft 101a as the center. By the rotation of rotation shaft 101a,
that is by rotating rotary plate 101, either opening section 97 or
lens 98 can be selectively placed on the optical path of the light
via the first optical system (the position corresponding to an
optical axis AX1). Rotation of rotation shaft 101a is performed by
a drive device 102 (not shown in FIG. 13, refer to FIG. 11) under
the instructions of controller 600.
[0142] Opening section 97 allows the parallel beam emitted from the
first optical system 94 to pass. By placing this opening section 97
on the optical path of the beam via condensing optical system 82
and also moving the first optical system 94 or at least one of the
optical elements structuring the first optical system 94, it
becomes possible for light receiver 96 to measure the intensity
distribution of the beam in the pupil plane (entrance pupil) PP
(coincides with the front focal plane in the embodiment) of
condensing optical system 82. Note that measurement device 110 does
not have to be able to measure the intensity distribution of the
beam in the pupil plane (entrance pupil) PP of condensing optical
system 82. In this case, lens 98 may be fixed.
[0143] Lens 98 structures a relay optical system with the first
optical system 94, and the upper surface of measurement member 92
where opening 92a is formed and the light receiving surface of the
light receiving elements (to be described later) of light receiver
96 are made optically conjugate.
[0144] Light receiver 96 has a light receiving element 96a
consisting of parts such as a two-dimensional CCD (hereinafter
called "CCD") and an electric circuit 96b such as an electric
charge transfer control circuit. It goes without saying that a CMOS
image sensor may also be used as light receiving element 96a. Light
receiving results (light receiving data) of light receiver 96 are
output to controller 600 (refer to FIG. 11). CCD 96a has an area
large enough to receive all parallel lights that are incident on
the first optical system 94 via opening 92a, emitted from the first
optical system 94, and then passes through opening section 97. The
light receiving surface of CCD 96a is made optically conjugate with
the upper surface of measurement member 92 (forming surface of
opening 92a) by the relay optical system structured by the first
optical system 94 and lens 98. Each pixel of CCD 96a has a size in
which a plurality of pixels are included within the irradiation
area of the beam condensed via the relay optical system described
above. CCD 96a has one or a plurality of reference pixels
determined, and a reference point of the reference pixels and table
12, such as for example, position relation with the center point,
is known. Consequently, controller 600 can be informed of the
positional relation between the beam incident on CCD 96a and the
reference pixel from the output of light receiver 96, and can
acquire the position information of the beam (e.g. condensing
position information of the beam) in the table coordinate
system.
[0145] Note that the light receiving surface of CCD 96a is
conjugate with the pupil plane of condensing optical system 82, in
a state where the upper surface (base material surface) of
measurement member 92 coincides with the rear focal plane (shaping
surface MP) of condensing optical system 82 and opening section 97
is placed on the optical path of the beam via opening 92a and the
first optical system 94.
[0146] Alternately, the light receiving surface of CCD 96a may be
made conjugate with the pupil plane of condensing optical system 82
by placing an optical system (optical member) in rotary plate 101,
instead of opening section 97. Alternately, on measurement, the
upper surface of measurement member 92 may be placed at a position
shifted in an optical axis AX direction from the rear focal plane
of condensing optical system 82.
[0147] In addition, optical system unit 95 is not limited to the
description above. For example, lens 98 may be inserted/withdrawn
without using rotary plate 101, for example, by holding lens 98
with a movable member and the movable member being moved in a
direction perpendicular to the optical axis (e.g. along the X-axis
direction).
[0148] As is obvious from the description above, in the embodiment,
because measurement device 110 including measurement member 92 is
provided in table 12 that is freely movable in directions of 6-DOF,
measurement member 92 that functions as the light receiving section
can receive the beam from condensing optical system 82 while moving
in at least one of the Z-axis direction parallel to optical axis AX
on the exit surface side of condensing optical system 82, the
X-axis direction, and the Y-axis direction perpendicular to optical
axis AX.
[0149] Measurement of the intensity distribution of the beam in the
rear focal plane of condensing optical system 82 is performed, for
example, as follows.
[0150] Controller 600, first of all, based on measurement values of
position measurement system 28 and linear encoders 24.sub.1 to
24.sub.6, moves table 12 by controlling planar motor 26 and
expansion mechanism 16.sub.1 to 16.sub.6 based on known target
values (such as design information), and positions opening 92a of
measurement member 92 at a position on optical axis AX of
condensing optical system 82.
[0151] Controller 600 also rotates rotary plate 101 via drive
device 102, and places lens 98 on the optical path of the beam via
opening 92a and the first optical system 94. Then, in this state,
the intensity distribution of the beam in the rear focal plane of
condensing optical system 82 is measured, based on light receiving
data (also described as LRD1, refer to FIG. 11) which is light
receiving results of the beam condensed on the light receiving
plane of CCD 96a by lens 98.
[0152] FIG. 14A shows an optical arrangement when measuring the
intensity distribution of the beam in the rear focal plane of
condensing optical system 82, expanding along optical axis AX1 of
measurement device 110 and optical axis AX of condensing optical
system 82 (however, the upstream side from condensing optical
system 82 is omitted). At this time, the reflection surface of each
mirror element 81.sub.p,q of mirror array 80 is to be set to a
design angle such that a desired intensity distribution of the beam
(shape, size, placement and the like of the irradiation area of the
beam) can be acquired in the rear focal plane.
[0153] In the optical arrangement shown in FIG. 14A, when
controller 600 makes at least one laser unit 70 of light source
unit 60 oscillate a laser beam and a parallel beam is emitted from
light source system 510, the parallel beam is reflected by each of
the plurality of mirror elements 81.sub.p,q of mirror array 80 so
that a plurality of parallel beams are formed that are incident on
condensing optical system 82. The plurality of parallel beams that
are incident on condensing optical system 82 are condensed on the
rear focal plane by condensing optical system 82, and are incident
on opening 92a positioned in the rear focal plane or close to the
rear focal plane.
[0154] The light that has passed through opening 92a is condensed
on the optically conjugate plane of measurement member 92, namely
on the light receiving surface of CCD 96a by the relay optical
system consisting of the first optical system and lens 98.
Consequently, the intensity distribution of the light receiving
surface of CCD 96a is the intensity distribution of the beam within
the upper surface of measurement member 92. CCD 96a receives the
beam that has the intensity distribution, and light receiving data
LRD1 obtained by photoelectric conversion is sent from light
receiver 96 (electric circuit 96b) to controller 600 (refer to FIG.
11).
[0155] Then, controller 600 takes in the above light receiving data
LRD1 while performing stepping movement of table 12 in the Z-axis
direction via expansion mechanisms 16.sub.1 to 16.sub.6 based on
measurement values of linear encoders 24.sub.1 to 24.sub.6, and
based on light receiving data LRD1 taken in, for example, finds a
position in the Z-axis direction in which the area of the
irradiation area of the beam formed on the light receiving surface
of CCD 96a becomes minimum. The area of the irradiation area of the
beam formed on the light receiving surface of CCD 96a becomes
minimum when the upper surface of measurement member 92 coincides
with the rear focal plane of condensing optical system 82 and an
irradiation area of the sharpest beam is formed within opening 92a.
Consequently, controller 600 can decide that the Z position of
table 12 where the beam that has the least number of pixels is
received is the Z position where the upper surface of measurement
member 92 coincides with the rear focal plane, based on light
receiving data LRD1 from light receiver 96. In the embodiment,
because the rear focal plane serves as shaping surface MP,
controller 600 can acquire the intensity distribution of the beam
in shaping surface MP (shape, size, placement and the like of the
irradiation area of the beam) based on light receiving data LRD1 of
the Z position. When the intensity distribution of the beam in
shaping surface MP (shape, size, placement and the like of the
irradiation area of the beam) differs from a desired state,
controller 600 adjusts, for example, the angle of at least apart of
the plurality of mirror elements 81.sub.p,q of mirror array 80 to
adjust the intensity distribution of the beam in shaping surface MP
to a desired state.
[0156] In addition, position and the like on the table coordinate
system of the irradiation area of the beam in shaping surface MP
(the rear focal plane of condensing optical system 82) can be
acquired from a position relation between the intensity
distribution of the beam in the light receiving surface of CCD 96a
and one or a plurality of reference pixels in a state where the
upper surface of measurement member 92 coincides with the rear
focal plane.
[0157] Note that in the case when the Z position of the rear focal
plane of condensing optical system 82 is known and the Z position
is decided to be unchanged, the stepping movement in the Z-axis
direction does not have to be performed.
[0158] In the embodiment, controller 600 performs measurement of
intensity distribution of the beam in the pupil plane (entrance
pupil) of condensing optical system 82 described below, after
performing the measurement of the intensity distribution of the
beam in shaping surface MP (shape, size, placement and the like of
the irradiation area of the beam) described above.
[0159] Measurement of intensity distribution of the beam in the
pupil plane (entrance pupil) PP (coincides with the front focal
plane in the embodiment) of condensing optical system 82 is
performed, for example, in the manner below.
[0160] After completing the measurement of the intensity
distribution of the beam in shaping surface MP (shape, size,
placement and the like of the irradiation area of the beam)
described above, controller 600 rotates rotary plate 101 via drive
device 102 and places opening section 97 on the optical path of the
beam via opening 92a and the first optical system 94, while
maintaining the position of table 12 at the position where the
upper surface of measurement member 92 (forming surface of opening
92a) is positioned on optical axis AX of condensing optical system
82 at the same height as shaping surface MP. Then, measurement of
intensity distribution of the beam in the pupil plane PP is
performed in this state.
[0161] FIG. 14B shows an optical arrangement when measurement of
intensity distribution of the beam in pupil plane PP is performed,
expanding along optical axis AX1 of measurement device 110 and
optical axis AX of condensing optical system 82 (however, the
upstream side from condensing optical system 82 is omitted). As
shown in FIG. 14B, in this state, because opening section 97 is
placed on the optical path of the beam, the parallel beam via the
first optical system 94 is incident on CCD 96a structuring light
receiver 96 without interruption. In this case, the light receiving
surface of CCD 96a can be regarded as being placed at a position
conjugate with pupil plane PP of condensing optical system 82 and
therefore can receive the light beam corresponding to the intensity
distribution of the beam in pupil plane PP. Therefore, controller
600 takes in light receiving data of light receiver 96 (also
described as LRD2, refer to FIG. 11), and based on light receiving
data LRD2, acquires the intensity distribution of the beam in pupil
plane PP. Then, data of the acquired intensity distribution is
stored in memory.
[0162] Controller 600 can adjust the angle of at least a part of
the plurality of mirror elements 81.sub.p,q of mirror array 80
based on the intensity distribution of the beam in pupil plane
PP.
[0163] Note that controller 600 may perform measurement of the
intensity distribution of the beam in pupil plane PP each time the
intensity distribution of the beam in shaping surface MP is
measured, or once each time the intensity distribution of the beam
in shaping surface MP is measured a predetermined number of
times.
[0164] FIG. 11 shows a block diagram indicating an input/output
relation of controller 600 that mainly structures a control system
of shaping apparatus 100. Controller 600 includes a workstation (or
a microcomputer) and the like and has overall control over
constituent parts of shaping apparatus 100.
[0165] The basic function of shaping apparatus 100 according to the
embodiment structured in the manner described above is to add a
desired shape by three-dimensional shaping to an existing component
(workpiece). The workpiece is supplied to shaping apparatus 100 and
then is carried out from shaping apparatus 100 after a desired
shape is accurately added. At this point, the actual shaping data
of the shape that has been added is sent to an external device,
such as a host device. The series of operations performed in
shaping apparatus 100 is automated, and the workpiece supply can be
performed in a lot unit, with a given quantity collected on a
pallet serving as one lot.
[0166] FIG. 15 shows a flowchart corresponding to a series of
processing algorithms of controller 600. Although controller 600
performs processing in each step (including decision) in the
flowchart below, the description related to controller 600 will be
omitted except when required.
[0167] When a start command is input to controller 600 from the
outside, processing that follows the flowchart in FIG. 15 is
started.
[0168] First, in step S2, a count value n of a counter that shows a
workpiece number within a lot is initialized (n.rarw.1).
[0169] In the next step S4, a pallet (not shown) on which one lot
of workpieces before performing additive manufacturing is carried
in from the outside to a predetermined carry-in/carry-out position
within shaping apparatus 100. This carry-in is performed by a
carry-in/carry-out device (not shown) according to instructions
from controller 600. One lot here is, e.g. i.times.j, and i.times.j
workpieces are loaded arranged in an i row j column matrix shape on
a pallet. That is, on the upper surface of the pallet, load
positions (mount positions) of the workpieces are assigned arranged
in an i row j column matrix shape, and the workpieces are loaded
(mounted) at each loading position. For example, a mark is arranged
at each load position, and the position on the pallet of each mark
is known. In the description below, one lot, as an example, is
4.times.5=20, and on the upper surface of the pallet, marks are
arranged in a matrix shape placement of four rows and five columns,
and a workpiece is to be loaded on each mark. For example, the
1.sup.st to 5.sup.th workpieces in the lot are arranged
respectively at the first row first column position to the first
row fifth column position, the 6.sup.th to 10.sup.th workpieces are
arranged respectively at the second row first column position to
the second row fifth column position, the 11.sup.th to 15.sup.th
workpieces are arranged respectively at the third row first column
position the third row fifth column position, and the 16.sup.th to
20.sup.th workpieces are arranged respectively at the fourth row
first column position to the fourth row fifth column position.
[0170] In the next step S6, the n.sup.th workpiece in the lot is
taken out from the pallet and is loaded on table 12. At this time,
movement system 200 is to be at a loading/unloading position set
near the position where carrier system 300 within shaping apparatus
100 is installed. In addition, at this time, table 12 is in the
reference state (Z,.theta.x, .theta.y,.theta.z)=(Z.sub.0,0,0,0)
previously described, and the XY position of table 12 coincides
with the X, Y position of slider 10 measured by position
measurement system 28.
[0171] Specifically, controller 600 specifies position (i,j) on the
pallet of the workpiece to be taken out referring to count value n,
and also gives instructions to carrier system 300 to take out the
workpiece at the specific position (i,j). In response to this
instruction, carrier system 300 takes the workpiece out from the
pallet and is loaded on table 12. For example, in the case n=1,
then the workpiece at the first row first column position is taken
out and is mounted on table 12.
[0172] Next, in step S7, table 12 on which the workpiece is loaded
is moved to an area below measurement system 400 (sensor section
38). This movement of table 12 is performed by controller 600
controlling planar motor 26 based on the measurement information of
position measurement system 28 so that movement system 200 is
driven in the X-axis direction (and the Y-axis direction) on base
BS. Table 12 maintains the reference state previously described
also during this movement.
[0173] In the next step S8, measurement is performed of position
information within a three-dimensional space (three-dimensional
shape information in the embodiment) which is at least apart of the
target surface of the workpiece loaded on table 12 in a reference
state, using measurement system 400. Hereinafter, it becomes
possible to control the position in directions of 6-DOF of the
target surface on the workpiece on the table coordinate system
(reference coordinate system) according to open loop control, based
on the measurement results.
[0174] In the next step S9, table 12, on which the workpiece having
completed measurement of position information (shape information)
of at least apart of the target surface is mounted, is moved to an
area below beam shaping system 500 (nozzle unit 84) in a similar
manner as is previously described.
[0175] In the next step S10, additive manufacturing according to
three-dimensional shaping is applied in which the shape
corresponding to 3D data is added to the workpiece on table 12.
This additive manufacturing is performed as follows.
[0176] That is, controller 600 converts the three-dimensional CAD
data of the shape to be added by additive manufacturing (shape in
which the shape of the workpiece subject to additive manufacturing
is removed from the shape of the object made after additive
manufacturing has been applied) serving as three-dimensional
shaping data to, e.g. STL (Stereo Lithography) data, and then
furthermore generates data for each layer sliced in the Z-axis
direction from this three-dimensional STL data. Then, controller
600 controls movement system 200 and beam shaping system 500 so
that additive manufacturing is performed on each layer of the
workpiece based on the data of each layer, and repeatedly performs
formation of the straight line area and formation of the linear
molten pool by supplying shaping material from nozzle 84a to the
straight line beam while scanning table 12 in the scan direction,
for each layer. Here, position and attitude control of the target
surface on the workpiece at the time of additive manufacturing is
performed taking into consideration the position information (shape
information in the embodiment) of the target surface measured
earlier. For example, the position information (shape information)
of target surface TAS acquired using measurement system 400 is used
to position target portion TA on target surface TAS of workpiece W
to the irradiation area of the beam in shaping surface MP. Besides
this, controller 600 also controls beam shaping system 500 based on
the position information (shape information) of target surface TAS
acquired using measurement system 400. The contents of this control
includes all various controls of beam irradiation section 520
described earlier as a method of setting or changing the intensity
distribution of the beam on the shaping surface, such as, the
shape, the size, and the arrangement of the irradiation area of the
beam formed on the shaping surface, and all various controls
related to the supply operation of the shaping material by material
processing section 530 which is described as being performed in
response to the setting or change of the intensity distribution of
the beam.
[0177] Here, in the description above, shaping accompanied with
scanning operation of table 12 is to be performed presupposing that
target surface (e.g. upper surface) TAS on which target portion TA
of additive manufacturing of workpiece W is set is a plane set to a
surface perpendicular to the optical axis of condensing optical
system 82 by adjusting the tilt of table 12. However, the target
surface where the target portion of additive manufacturing of the
workpiece is set is not always a plane where the straight line beam
can be used. However, shaping apparatus 100 according to the
embodiment is equipped with movement system 200 that can set
arbitrarily the position of table 12 on which the workpiece is
loaded in directions of 6-DOF. Therefore, in such a case,
controller 600, while controlling measurement system 200 and beam
irradiation section 520 of beam shaping system 500 based on the
three-dimensional shape of the workpiece measured using measurement
system 400 and adjusting the width in the X-axis direction of the
beam irradiation area on shaping surface MP so that the target
surface (e.g. upper surface) of workpiece W positioned on shaping
surface MP can be regarded flat enough so that additive
manufacturing can be performed in the irradiation area of the beam
in shaping surface MP, performs the open/close operation of each
supply port 91i via each open/close member 93i of nozzle 84a and
supplies the shaping material from the required supply ports to the
beam irradiated on the irradiation area. This allows the shaping to
be applied at necessary parts even when the upper surface (target
surface) of the workpiece is not flat.
[0178] Note that on performing shaping by forming layers of beads,
additive manufacturing (bead formation) may be performed with a
beam whose width in the X-axis direction of the irradiation area in
the shaping surface is narrow, and after forming a plane having a
relatively large area, additive manufacturing (bead formation) may
be performed on the plane using a straight line beam whose width in
the X-axis direction of the irradiation area in the shaping surface
is widened. For example, on performing shaping on an uneven target
surface, additive manufacturing (bead formation) to fill the recess
part may be performed with a beam whose width in the X-axis
direction of the irradiation area in the shaping surface is narrow,
and after forming a plane, additive manufacturing (bead formation)
may be performed on the plane using a straight line beam whose
width in the X-axis direction of the irradiation area in shaping
surface MP is widened. Even in such a case, it goes without saying
that the powdered shaping material is supplied from one or the
plurality of supply ports that are chosen in response to the change
of size (width) of the irradiation area of the beam in shaping
surface MP.
[0179] After the additive manufacturing to the workpiece has been
completed, in step S11, table 12 on which workpiece W that has
undergone additive manufacturing is loaded is moved to an area
below measurement system 400.
[0180] In the next step S12, the shape of the workpiece on table 12
will be inspected using three-dimensional measuring machine 401 of
measurement system 400. Specifically, controller 600 measures the
three-dimensional shape of the workpiece that has undergone
additive manufacturing with the workpiece loaded on table 12 using
three-dimensional measuring machine 401, and acquires a dimension
error of the three-dimensional shape of the measured workpiece with
respect to the three-dimensional shape of the workpiece that has
undergone additive manufacturing acquired from the design value.
Here, the workpiece that has undergone additive manufacturing
subject to inspection (the workpiece on table 12) includes both the
workpiece to which only the first additive manufacturing has been
applied and the workpiece to which a corrective processing to be
described later on has been applied.
[0181] After inspection has been completed, in the next step S14,
by deciding whether or not the dimension error acquired from the
inspection is under a threshold value determined in advance,
pass/fail decision of additive manufacturing, that is, the decision
of whether the additive manufacturing level is acceptable or not is
made. And, when the decision made in this step S14 is positive,
that is when the processing level is acceptable, then the operation
proceeds to step S15.
[0182] Meanwhile, in the case the decision made in step S14 is
negative, that is, when the level is not acceptable, the operation
proceeds to S19, and after table 12 on which the workpiece is
loaded is moved to the area below beam shaping system 500, then in
step S20, corrective processing to the workpiece loaded on table 12
is performed. This corrective processing is performed, for example,
based on the dimension error acquired earlier in the inspection so
that the dimension error is reduced to zero as much as possible in
a similar manner as normal shaping using a 3D printer, by forming a
molten pool while table 12 is in a stationary state or is moved at
an extremely slow speed using the beam (e.g. a spot shaped beam)
from beam irradiation section 520 of beam shaping system 500. In
this case, when the dimension error acquired from the inspection is
a plus (positive) value, that is, when a shape thicker than
necessary is applied on the target surface of the workpiece by the
additive manufacturing, the shaping material of the excess part has
to be removed. In the embodiment, while controller 600 irradiates
the beam from beam irradiation section 520 of beam shaping system
500 without supplying the shaping material on the excess part on
the target surface of the workpiece and melts the shaping material
of the excess part, controller 600 also moves table 12 while
performing rapid acceleration/deceleration so that the melted
shaping material is removed from the target surface of the
workpiece. Note that along with, or instead of moving table 12
while performing rapid acceleration/deceleration, a compressed air
exhausting device for blowing away the melted shaping material may
be provided in beam shaping system 500. Or, a removing apparatus
that does not melt the shaping material with the beam but has a
cutter or the like used to mechanically remove excess shaping
material may be provided within beam shaping system 500. In any
case, a recovery apparatus is preferably arranged within beam
shaping system 500 that collects the shaping material that has been
removed from the target surface of the workpiece (the melted
shaping material or the shaping material mechanically removed). The
recovery apparatus may be provided completely separate from nozzle
84a, or in the case a recovery port is provided in the nozzle for
excess powdered shaping material that was not melted, the recovery
port may also serve as the recovery port for collecting the above
removed shaping material.
[0183] When the corrective processing described above has been
completed, the operation returns to step S11 and after table 12 on
which workpiece W that has undergone additive manufacturing is
loaded is moved to an area below measurement system 400, in the
next step S12, the shape of the workpiece on table 12 is inspected
using three-dimensional measuring machine 401 of measurement system
400. Then in step S14, the pass/fail decision of additive
manufacturing is made, that is, the decision is made of whether the
additive manufacturing level is acceptable or not. Then, when the
decision made in step S14 is negative again (not acceptable),
hereinafter, loop processing (including decision making) of steps
S19, S20, S11, S12 and S14 is repeated and corrective processing is
applied further if necessary until the decision made in step S14 is
accepted, that is, the inspection result of the shape after
corrective processing is accepted. In step S15, table 12 on which
the workpiece that has undergone additive manufacturing (including
corrective processing) is moved to the loading/unloading position
previously described.
[0184] In step S15, table 12 on which the workpiece that has
undergone additive manufacturing (including corrective processing)
is moved to the loading/unloading position previously
described.
[0185] In the next step S16, the n.sup.th workpiece that has
undergone processing loaded on table 12 is returned to the pallet.
Specifically, controller 600 specifies a position on the pallet
referring to count value n, and gives instructions to carrier
system 300 to return the workpiece to the specific position on the
pallet. In response to the instructions, the workpiece that has
undergone additive manufacturing is taken from table 12 by carrier
system 300 and is returned to the specific position on the pallet.
Around the time of instructions to carrier system 300, controller
600 sends the actual shape data of the added shape acquired in the
shape inspection of the workpiece performed immediately before in
step S12 to an external device, such as a host device.
[0186] When processing of step S16 is executed, then the operation
moves to step S22. At this point, the workpiece is not located on
table 12. In step S22, count value n of the counter is incremented
by one (n.rarw.n+1).
[0187] In the next step S24, the decision is made of whether or not
count value n exceeds N (N is the number of workpieces in one lot,
N=20 in the embodiment). Then, when the decision made in step S24
is negative, that is, when there is a workpiece in the lot that has
not yet been processed, the operation returns to step S6 and
repeats steps S6 to S24 until the decision in step S24 turns
positive. In this manner, the series of processing described above
(including decision making) is performed on the second workpiece
and the workpieces thereafter. Then, when processing to all the
workpieces in the lot is completed and the decision made in step
S24 turns positive, the operation proceeds to step S26 where
instructions are given to a carry-in/carry-out device (not shown)
to carry out the pallet on which the processed workpieces are
loaded outside of the device, and this completes the series of
processing in this routine.
[0188] Note that in the description above, although table 12 on
which workpiece W that has undergone additive manufacturing is
loaded was moved downward to the area below measurement system 400
after additive manufacturing to the workpiece and inspection of the
shape of the workpiece on table 12 was performed using the
three-dimensional measuring machine 401, table 12 on which
workpiece W that has undergone additive manufacturing is loaded may
be moved to the loading/unloading position to return the workpiece
that has been machined to the pallet without performing the
inspection after the additive manufacturing to the workpiece has
been completed. That is, inspection of the shape of the workpiece
that has undergone additive manufacturing and the corrective
processing previously described that uses the inspection results do
not necessarily have to be performed. Or, table 12 on which
workpiece W that has undergone additive manufacturing is loaded may
be moved downward to the area below measurement system 400 after
additive manufacturing to the workpiece has been completed and
inspection of the shape of the workpiece on table 12 may be
performed using the three-dimensional measuring machine 401, then,
regardless of the inspection results, table 12 may be moved to the
loading/unloading position to return the workpiece that has
undergone additive manufacturing to the pallet without performing
corrective processing. In this case as well, the actual shaping
data of the shape that has been added acquired resulting from the
inspection is sent to an external device, such as a host device. In
addition, when corrective processing has been performed, shape
inspection of the workpiece does not have to be performed. That is,
after step S20, the operation may proceed to the next step S15, and
then table 12 on which the workpiece that has undergone corrective
processing is loaded may be moved to the loading/unloading position
previously described.
[0189] In addition, in the description above, after the additive
manufacturing to the workpiece has been completed, table 12 on
which workpiece W that has undergone additive manufacturing is
loaded was moved to an area below measurement system 400 to perform
inspection of the shape of the workpiece that has undergone
processing in order to decide whether corrective processing is
necessary or not. However, not limiting to this, table 12 on which
workpiece W is loaded may be moved to an area below measurement
system 400 during the additive manufacturing to the workpiece, and
after the position information (shape information) of the target
surface including the additive part is acquired, table 12 on which
workpiece W is loaded may be moved to the area under beam shaping
system 500 again to resume shaping based on the position
information (shape information) of the target surface including the
acquired additive part.
[0190] As is described in detail so far, with shaping apparatus 100
and the shaping method executed by shaping apparatus 100 according
to the embodiment, it becomes possible to measure the
three-dimensional shape of the target surface of the workpiece in a
state loaded on table 12 without detaching the workpiece to which
additive manufacturing is applied from table 12, and based on the
measurement results, for example, it becomes possible to decide
whether the shape after processing is acceptable or not (0K/NG).
And, when the processing is not acceptable, beam shaping system 500
can be used for corrective processing while keeping the state where
the workpiece is loaded on table 12, which is extremely
efficient.
[0191] In addition, in the process of massively producing
components, to make the components and to perform size inspection
on the spot is extremely convenient when controlling quality. This
is because drift is unavoidable in accuracy of a device due to
various factors. By performing inspection on the spot, controller
600 can recognize the tendency of the drift and can provide
feedback to the processing accuracy based on the recognized
results. That is, controller 600 acquires the tendency of the drift
of the device in shaping, based on the position information (shape
information) of the target surface of the workpiece acquired using
measurement system 400, and according to the results acquired, at
least one of measurement system 400, beam shaping system 500 and
movement system 200 can be adjusted, allowing dimension variation
to be suppressed and yield and dispersion in quality to be
improved.
[0192] Note that controller 600 may adjust at least one of
measurement system 400, beam shaping system 500 and movement system
200 not only when acquiring the tendency of the drift of the device
in shaping, based on the position information (shape information)
of the target surface of the workpiece acquired using measurement
system 400. The workpiece in this case includes at least one of the
workpiece before applying additive manufacturing, the workpiece
after applying additive manufacturing, and the workpiece after
applying corrective processing.
[0193] In the case of shaping apparatus 100 according to the
embodiment, as is obvious from the description so far, since there
is virtually no reaction force accompanying the processing, the
fixed state of the workpiece differs from machine tools such as a
processing center that directly connects to processing accuracy and
finish, therefore the workpiece does not have to be firmly fixed on
table 12. In addition, because shaping apparatus 100 is equipped
with measurement system 400, even if the workpiece is loaded on
table 12 roughly to some extent by carrier system 300, it does not
matter since measurement system 400 specifies the position with
respect to the coordinate system again later on. Because this
three-dimensional shape measurement (an embodiment of the
three-dimensional alignment) according to measurement system 400 is
performed, it becomes possible to automate a series of operations
including loading the workpiece onto table 12 and unloading the
workpiece that has undergone additive manufacturing from table 12
by carrier system 300, which in turn allows efficient
production.
[0194] In addition, with shaping apparatus 100 according to the
embodiment, the intensity distribution of the beam within shaping
surface MP previously described can be changed continuously when
necessary not only before starting the shaping of relatively moving
the beam and target surface TAS but also during the relative
movement of the beam and target surface TAS, and can also be
changed according to the relative position of target surface TAS
and the beam and to the required shaping accuracy and throughput.
This allows shaping apparatus 100 to form a shaping object on
target surface TAS of workpiece W with high processing accuracy and
high throughput by, e.g. rapid prototyping.
[0195] In addition, in shaping apparatus 100, in the case of
performing additive manufacturing (shaping) of a relatively wide
area on a flat target surface TAS, the method previously described
is employed in which powdered shaping material PD is supplied from
nozzle 84a to the straight line beam to form a linear molten pool
WP directly below nozzle 84a and molten pool WP is formed scanning
table 12 in the scan direction (+Y direction in FIG. 4). With this
method, a shape that was generated by reciprocating the spot shaped
beam dozens of times with the conventional 3D printer or the like
as shown in FIG. 16B can be generated by reciprocating table 12
with respect to the straight line beam several times as shown in
FIG. 16A. With the embodiment, the shaping object can be formed on
the target surface of the workpiece in an extremely short time when
compared to the shaping that uses the conventional spot shaped beam
in the so-called one-stroke shaping. That is, throughput can be
improved also in this respect.
[0196] In addition, with shaping apparatus 100 according to the
embodiment, because the intensity distribution change of the beam
within the shaping surface of condensing optical system 82 is
performed by changing the tilt angle of the reflection surface of
each mirror element of mirror array 80, as the intensity
distribution change, change of at least one of position, number,
size and shape of the irradiation area of the beam within the
shaping surface can be easily performed. Consequently, by setting
the irradiation area, for example, to a spot shape or a slit shape
(line shape), and applying the three-dimensional shaping to the
target surface on the workpiece using the method previously
described, a three-dimensional shaped object can be formed with
high accuracy.
[0197] In addition, shaping apparatus 100 according to the
embodiment has a plurality of, e.g. two powder cartridges 88A and
88B, and inside each of the powder cartridges 88A and 88B, the
powder of the first shaping material (e.g. titanium) and the powder
of the second shaping material (e.g. stainless steel) are stored.
And, at the time of additive manufacturing (at the time of
shaping), controller 600 performs switching of the supply path of
the powder to nozzle unit 84 using material supplying device 86,
that is, performs switching between piping 90b and 90c. By this
switching, the powder of the first shaping material (e.g. titanium)
from powder cartridge 88A and the powder of the second shaping
material (e.g. stainless steel) from powder cartridge 88B is
selectively supplied to nozzle unit 88A. Consequently, by only
switching the powder material that controller 600 supplies
depending on the section, joint shape of different kinds of
materials can be generated easily. In addition, the switching can
be performed almost instantly. Furthermore, by supplying different
kinds of materials that are mixed, an "alloy" can be made on the
spot, or the composition may be changed or gradated depending on
location.
[0198] With shaping apparatus 100 according to the embodiment,
controller 600 can measure the intensity distribution of the beam
within shaping surface MP at an adequate frequency by the method
previously described using measurement device 110 and perform
calibration that is necessary. For example, controller 600 can
control parts such as mirror array 80 and adjust the intensity
distribution of the beam within shaping surface MP, based on the
measurement results of the intensity distribution of the beam
within shaping surface MP using measurement device 110.
[0199] In addition, controller 600 may perform measurement of the
intensity distribution of the beam within shaping surface MP using
measurement device 110, for example, prior to shaping processing
(additive manufacturing) to the workpiece, and based on the
measurement results, may adjust at least one of the beam shaping
system 500 and movement system 200 during the shaping processing.
In this case as well, subsequently to the measurement of the
intensity distribution of the beam within shaping surface MP, the
intensity distribution of the beam within pupil plane PP may be
measured, and based on the results, adjustment (control) of at
least one of the beam shaping system 500 and movement system 200
during the shaping processing may be performed.
[0200] As adjustment (control) of movement system 200 in this case,
position control of table 12 for positioning target portion TA on
target surface TAS of workpiece W to the irradiation area of the
beam in shaping surface MP can be representatively given.
[0201] In addition, the contents of adjustment (control) of beam
shaping system 500 includes all various controls of beam
irradiation section 520 described earlier as a method of setting or
changing the intensity distribution of the beam on the shaping
surface, such as the shape, the size, and the arrangement of the
irradiation area of the beam formed on the shaping surface, and all
contents of various controls related to the supply operation of
shaping materials by material processing section 530 described as
an operation performed in response to the setting or change of the
intensity distribution of the beam.
[0202] In addition, in the case the measurement of the intensity
distribution of the beam within shaping surface MP cannot be
performed at once with light receiver 96 in a state where table 12
is stationary, such as when the arrangement range of the
irradiation area of the beam in shaping surface MP is broad, the
measurement of the intensity distribution of the beam within
shaping surface MP is performed while moving table 12 (opening 92a
of measurement member 92) in at least one direction of the X-axis
direction and the Y-axis direction within the XY plane.
[0203] Note that in shaping apparatus 100 according to the
embodiment, although all component parts of measurement device 100
are provided at table 12, the embodiment is not limited to this,
and if the optical conjugate relation between the light receiving
surface of CCD 96a and the forming surface of opening 92a of
measurement member 92 can be maintained, the component parts of
measurement device 110 other than measurement member 92 may be
provided outside of table 12.
[0204] In addition, a movable member that has a sensor device
similar to measurement device 110 described above loaded and is
movable separately from table 12 can be provided separate to table
12. In this case, the mover only has to be movable in three axial
directions in the X-axis, the Y-axis, and the Z-axis, and a
structure may be employed in which controller 600 can control
(manage) the position of the movable member and the sensor on the
table coordinate system. Controller 600 can use the sensor device
to perform the measurement of the intensity distribution of the
beam within the shaping surface previously described. In this case
as well, the measurement of the intensity distribution of the beam
in pupil plane PP may be performed. In addition, in this case,
controller 600 may perform control of at least one of the beam
shaping system 500 and movement system 200 described above during
shaping processing, based on the intensity distribution of the beam
within shaping surface MP measured using the sensor device. Other
than this, controller 600 can perform measurement of the intensity
distribution of the beam in the shaping surface previously
described using the sensor device concurrently with measuring the
workpiece on table 12 using measurement system 400.
[0205] Note that as it is obvious from the description so far,
measurement device 100 may also be used as an unevenness sensor
that detects the unevenness of intensity of the beam inside the
irradiation area (intensity distribution).
[0206] In addition, wavefront aberration of condensing optical
system 82 may be measured using measurement device 110. For
example, in the free space of rotary plate 101 shown in FIG. 13,
such as the area inside the circle illustrated by an imaginary line
(two-dot chain line) in FIG. 13, a plurality of microlenses
disposed in a matrix shape to form a microlens array that makes the
forming surface of opening 92a and the light receiving surface of
CCD 96a optically conjugate may be disposed. In this case, by
rotating rotary plate 101 to position the microlens array on the
optical path of the parallel beam emitted from the first optical
system and disposing a pattern plate on which a pinhole pattern is
formed serving as a light transmitting section, for example, on the
exit side of the second fly-eye lens system 76, it is possible to
structure a Shack-Hartmann type wavefront aberration sensor that
can measure the wavefront aberration of condensing optical system
82 can be structured. In this case, the pattern plate is structured
insertable into and extractable from the exit side of the second
fly-eye lens system 76. When the structure that enables wavefront
aberration measurement is employed, even if the position of the
rear focal plane of condensing optical system 82 changes, the
position after the change of the rear focal plane of condensing
optical system 82 can be measured, and based on this, the position
of shaping surface MP can be changed or the position of the upper
surface of measurement member 92 can be adjusted on measurement
processing by measurement device 110. In addition, when the
structure that enables wavefront aberration measurement is
employed, along with this, a structure that enables adjustment of
optical properties of condensing optical system 82 may also be
employed. For example, condensing optical system 82 may be
structured with a plurality of lenses, and part of the lenses may
be made drivable in the optical axis AX direction and an
inclination direction (tilt direction) with respect to a plane
orthogonal to optical axis AX with driving elements such as a
piezoelectric element. In such a case, the optical properties of
condensing optical system 82 can be adjusted by driving a movable
lens in at least one direction of the optical axis AX direction and
the tilt direction.
[0207] Other than this, instead of measurement device 110 described
above, as shown in FIG. 17, light receiver 96 previously described
may be disposed on the upper surface of table 12 so that the light
receiving surface of CCD 96a is flush (coplanar) with the other
part of table 12. And this light receiver 96 may measure the
intensity distribution of the beam in shaping surface MP. In this
case as well, by making measurement possible not only in the state
where table 12 is still but also in scan measurement where the
intensity distribution of the beam is measured while table 12 is
moving, finite pixel effects of CCDs and mirror arrays can be
removed and correct measurement results can be acquired. As is
described, by measuring the intensity distribution of the beam
using the sensor that receives the beam from condensing optical
system 82, the intensity distribution of the beam can be controlled
considering variation factors such as thermal aberration of
condensing optical system 82. In addition, by controlling mirror
array 80 based on the results, the intensity distribution of the
beam in the rear focal plane and the like of condensing optical
system 82 can be set with good precision to a desired state.
[0208] Note that in the embodiment above, the case has been
described where an irradiation area of a single linear beam
(straight line beam) is formed with beam shaping system 500 and
workpiece W is scanned in the scan direction (e.g. Y-axis
direction) with respect to the straight line beam. However, with
beam shaping system 500, as is previously described, by making the
incidence angle of the plurality of parallel beams LB incident on
condensing optical system 82 have an appropriate angle
distribution, the intensity distribution of the beam in shaping
surface MP can be changed freely. Consequently, with shaping
apparatus 100, at least one of position, number, size and shape of
the irradiation area of the beam on shaping surface MP can be
changed, and as is previously described, areas such as, e.g. a
straight line area, a three line area, or a broken straight line
area (refer to FIG. 10) can be formed as the irradiation area of
the beam.
[0209] In the description so far, the description was made on the
premise of a usage increasing as much as possible thickness
controllability of the molten pool (coating layer) using the point
in which energy density of the beam irradiated on the straight line
area drastically decreases at the time of defocus when the straight
line area is made as narrow and sharp as possible. However, in this
case, the coating layer becomes very thin, and when a layer of the
same thickness is to be added, additive manufacturing (shaping) has
to be performed separately on many layers (has to be repeatedly
laminated frequently), which is a disadvantage from a productivity
standpoint.
[0210] Consequently, there may be a case when the thickness of the
coating layer needs to be increased taking into consideration a
balance between the required shaping accuracy and throughput. In
such a case, controller 600 changes the intensity distribution of
the beam within the shaping surface according to the required
shaping accuracy and the throughput, or specifically, may control
the tilt angle of each mirror element 81.sub.p,q of mirror array 80
so that the width of the straight line area widens slightly. For
example, straight line area LS illustrated in FIG. 18B changes to
straight line area LS'. This slows the energy density change at the
time of defocus and increases thickness h of the high energy area
in the vertical direction as is shown in FIG. 18A, which allows the
thickness of the layer generated in one scan to be increased, thus
improving productivity.
[0211] As is described so far, a major feature of shaping apparatus
100 according to the embodiment is that the device is more
convenient with solutions that comply with the requirements at the
actual processing site when compared to the conventional metal 3D
printer.
[0212] Note that in the embodiment above, while the case has been
described as an example where a fixed amount collected on a pallet
serves as a lot and the workpieces are machined by lots, this is
not limiting, and the workpieces may be machined one by one. In
this case, along with carrier system 300 receiving the workpiece
before processing from an external carrier system and loading the
workpiece on table 12, carrier system also 300 unloads the
workpiece that has undergone processing from table 12 and then
hands the workpiece to the external carrier system.
[0213] Note that in the embodiment above, while the case has been
described where mirror array 80 is used as the spatial light
modulator, instead of this, a digital mirror device consisting of
multiple digital micromirror devices (Digital Micromirror Device:
DMD (registered trademark)) made based on MEMS technology that are
disposed in a matrix shape to form a large area may be used. In
such a case, it becomes difficult to measure the state of each
mirror element (e.g. tilt angle) with an encoder or the like. In
such a case, a detection system may be used that irradiates a
detection light on the surface of the large area digital mirror
device, receives the reflection light from the multiple mirror
elements structuring the digital mirror device, and detects the
state of each mirror element based on the intensity distribution of
the reflection light. In this case, the detection system may be a
system that detects each state of the multiple mirror elements
based on image information acquired by imaging an image formed by
the digital mirror device with an imaging means.
[0214] Note that in shaping apparatus 100 according to the
embodiment above, a detection system 89 indicated by a virtual line
in FIG. 11 may be used along with rotary encoder 83.sub.p,q. As
this detection system 89, a detection system may be used that
irradiates a detection light on the surface of mirror array 80,
receives the reflection light from the multiple mirror elements
81.sub.p,q structuring mirror array 80, and detects the state of
each mirror element 81.sub.p,q based on the intensity distribution
of the reflection light. As the detection system, a system having a
structure similar to the one disclosed in, for example, U.S. Pat.
No. 8,456,624, can be used.
[0215] In addition, in the embodiment above, while the example was
given of using a variable type mirror array 80 in which the tilt
angle of the reflection surface of each mirror element 81.sub.p,q
with respect to the reference surface is variable, the embodiment
is not limited to this, and a mirror array having a structure in
which each mirror element is tiltable with respect to the reference
surface and also displaceable in a direction orthogonal to the
reference surface may be employed. In addition, each mirror element
does not necessarily have to be tiltable with respect to the
reference surface. The mirror array which is displaceable in the
direction orthogonal to the reference surface in this manner is
disclosed in, for example, U.S. Pat. No. 8,456,624. Other than
this, a mirror array of a type having mirror elements that are each
rotatable around two axes that are parallel to the reference
surface and orthogonal to each other (that is, tilt angle in two
directions that are orthogonal are variable) may be employed. The
mirror array that can change the tilt angle in two directions that
are orthogonal in the manner above is disclosed in, for example,
U.S. Pat. No. 6,737,662. In these cases as well, the detection
system disclosed in U.S. Pat. No. 8,456,624 can be used to detect
the state of each mirror element.
[0216] Note that a detection system that irradiates a detection
light on the surface of mirror array 80 and receives the reflection
light from the multiple mirror elements 81.sub.p,q structuring
mirror array 80 may be used. Or, as the detection system, a sensor
that individually detects the tilt angle and spacing of each mirror
element with respect to the reference surface (base) may be
provided at the mirror array (optical device).
[0217] Note that in the embodiment above, although the case has
been described where the intensity distribution of the beam on the
shaping surface is changed by individually controlling the
incidence angle of the plurality of parallel beams incident on the
pupil plane of condensing optical system 82, not all beams of the
plurality of parallel beams incident on the pupil plane of
condensing optical system 82 have to be controllable (changeable).
Consequently, in the case such as controlling the incidence angle
of the parallel beam incident on condensing optical system 82 using
the mirror array similar to the embodiment described above, the
state of the reflection surface (at least one of position and tilt
angle) does not have to be variable in all mirror elements. In
addition, in the embodiment above, although the case has been
described where mirror array 80 is used for controlling the
incidence angle of the plurality of parallel beams incident on
condensing optical system 82, that is, for changing the intensity
distribution of the beam on the shaping surface, instead of the
mirror array, a spatial light modulator (non-emitting image display
device) described below may be used. As a transmission type spatial
light modulator, other than a transmission type liquid crystal
display element (LCD: Liquid crystal display), an electrochromic
display (ECD) and the like can be given as an example. In addition,
as a reflection type spatial light modulator, other than the
micromirror array described above, examples such as a reflection
type liquid crystal display element, an electrophoretic display
(EPD: Electro Phonetic Display), electronic paper (or electronic
ink) and a diffraction type light valve (Grating Light Valve) can
be given. In addition, in the embodiment above, although the case
has been described where the mirror array (a kind of spatial light
modulator) is used for changing the intensity distribution of the
beam on the shaping surface, the spatial light modulator may be
used for other purposes.
[0218] In addition, as is described above, although condensing
optical system 82 preferably has a larger diameter, a condensing
optical system with a numerical aperture NA smaller than 0.5 may
also be used.
[0219] Note that in the embodiment described above, although
examples were given of the case where titanium and stainless steel
powder were used as the shaping materials, not only iron powder or
other metal powder but also powder other than metal such as
powdered nylon, polypropylene, and ABS may also be used. In
addition, in the case of using material other than powder, such as
filler wire used in welding as the shaping material, this can be
applied to shaping apparatus 100 according to the embodiment
described above. However, in this case, instead of the supply
system for supplying powder such as the powder cartridge and the
nozzle unit, a wire feeding device and the like are to be
provided.
[0220] In addition, in the embodiment above, although the case has
been described where powdered shaping material PD is supplied from
each of the plurality of supply ports 91.sub.i of nozzle 84 along
the Z-axis direction parallel to optical axis AX of condensing
optical system 82, the embodiment is not limited to this, and the
shaping material (powder) may be supplied from a direction tilted
with respect to optical axis AX. Or, the shaping material (powder)
may be supplied from a direction tilted with respect to the
vertical direction.
[0221] Note that in shaping apparatus 100 of the embodiment
described above, nozzle 84a that the material processing section is
equipped with may have a recovery port (suction port) for
collecting the powdered shaping material that was not melted, along
with the supply port of the shaping material previously
described.
[0222] While the example was described so far of adding a shape to
an existing workpiece, the usage of shaping apparatus 100 according
to the embodiment is not limited to this, and it is possible to
generate a three-dimensional shape by shaping on table 12 where
nothing exists similar to an ordinary 3D printer. This case is none
other than applying additive manufacturing to a workpiece called
"nothing". When shaping the three-dimensional shaped object on such
table 12, by optically detecting alignment marks at a minimum of
three places formed in advance on table 12 with mark detection
system 56 (refer to FIG. 11) that measurement system 400 is
equipped with, controller 600 only has to acquire position
information in directions of 6-DOF of the target surface of the
shaping set on table 12 and perform three-dimensional shaping while
controlling the position and attitude of the target surface on
table 12 with respect to (the irradiation area of) the beam based
on the results.
[0223] Note that in the embodiment above, although the case has
been described as an example where controller 600 controls each
constituent part; movement system 200, carrier system 300,
measurement system 400, and beam shaping system 500, the embodiment
is not limited to this, and the controller of the shaping system
may be structured by a plurality of hardware that each include a
processing device such as a microprocessor. In this case, the
movement system 200, carrier system 300, measurement system 400,
and beam shaping system 500 may each have a processing device, or
the controller may be a combination of a first processing device
that controls at least two of movement system 200, carrier system
300, measurement system 400, and beam shaping system 500 and a
second processing device that controls the remaining systems, or a
combination of a first processing device that controls two of the
four systems describe above and a second processing device and a
third processing device that individually control the remaining two
systems. In any case, the processing devices are each in charge of
a part of the functions of controller 600 described above. Or the
controller of the shaping system may be structured by a processing
device such as a plurality of microprocessors and a host computer
that has overall control over these processing devices.
[0224] At least a part of the components in each of the embodiments
above can be appropriately combined with at least other parts of
the components in each of the embodiments above. A part of the
components does not have to be used in the components in each of
the embodiments above. In addition, to the extent permitted by law,
the disclosures of all publications and the U.S. Patents referred
to in each of the embodiments above are incorporated herein by
reference as a part of the present specification.
[0225] While the above-described embodiment of the present
invention is the presently preferred embodiment thereof, those
skilled in the art of lithography systems will readily recognize
that numerous additions, modifications, and substitutions may be
made to the above-described embodiment without departing from the
spirit and scope thereof. It is intended that all such
modifications, additions, and substitutions fall within the scope
of the present invention, which is best defined by the claims
appended below.
* * * * *