U.S. patent application number 17/833342 was filed with the patent office on 2022-09-22 for apparatus for producing an object by means of additive manufacturing.
The applicant listed for this patent is Additive Industries B.V.. Invention is credited to Daniel Anthonius Johannes Kersten, Mark Johannes Magielsen, Johannes Franciscus Willebrordus Peeters, Mark Herman Else Vaes, Rob Peter Albert Van Haendel, Adrianus Johannes Petrus Maria Vermeer, Chris Patrick Webb, Jonas Wintermans.
Application Number | 20220297188 17/833342 |
Document ID | / |
Family ID | 1000006381596 |
Filed Date | 2022-09-22 |
United States Patent
Application |
20220297188 |
Kind Code |
A1 |
Vaes; Mark Herman Else ; et
al. |
September 22, 2022 |
APPARATUS FOR PRODUCING AN OBJECT BY MEANS OF ADDITIVE
MANUFACTURING
Abstract
An apparatus for producing an object by additive manufacturing
including a process chamber for receiving a bath of material
configured to be solidified, wherein a surface level of the bath of
material defines an object working area. A support positions an
object to be produced in relation to the surface level. A plurality
of solidifying devices are configured to solidify a selective part
of the bath of material and operate in substantially the entire
object working area. A controller individually controls each of the
plurality of solidifying devices such that each device can operate
on in a different part of the object working area. A method for
producing an object using the apparatus.
Inventors: |
Vaes; Mark Herman Else;
(Eindhoven, NL) ; Van Haendel; Rob Peter Albert;
(Eindhoven, NL) ; Magielsen; Mark Johannes;
(Eindhoven, NL) ; Webb; Chris Patrick; (Eindhoven,
NL) ; Kersten; Daniel Anthonius Johannes; (Eindhoven,
NL) ; Wintermans; Jonas; (Eindhoven, NL) ;
Vermeer; Adrianus Johannes Petrus Maria; (Eindhoven, NL)
; Peeters; Johannes Franciscus Willebrordus; (Eindhoven,
NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Additive Industries B.V. |
Eindhoven |
|
NL |
|
|
Family ID: |
1000006381596 |
Appl. No.: |
17/833342 |
Filed: |
June 6, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15528892 |
May 23, 2017 |
|
|
|
PCT/NL2015/050819 |
Nov 24, 2015 |
|
|
|
17833342 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 50/02 20141201;
B29C 64/277 20170801; B33Y 40/00 20141201; B33Y 10/00 20141201;
B22F 10/30 20210101; B22F 10/20 20210101; B22F 12/90 20210101; B29C
64/393 20170801; B33Y 30/00 20141201 |
International
Class: |
B22F 10/20 20060101
B22F010/20; B29C 64/393 20060101 B29C064/393; B29C 64/277 20060101
B29C064/277; B22F 12/90 20060101 B22F012/90; B33Y 10/00 20060101
B33Y010/00; B33Y 30/00 20060101 B33Y030/00; B33Y 50/02 20060101
B33Y050/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2014 |
NL |
2013860 |
Nov 24, 2014 |
NL |
2013861 |
Nov 24, 2014 |
NL |
2013862 |
Nov 24, 2014 |
NL |
2013863 |
Nov 24, 2014 |
NL |
2013864 |
Nov 24, 2014 |
NL |
2013865 |
Nov 24, 2014 |
NL |
2013866 |
Claims
1. An apparatus for producing an object by additive manufacturing,
comprising: a process chamber configured to receive a bath of
material configured to be solidified, wherein a surface level of
the bath of material defines an object working area; a support
configured to position an object to be produced in relation to the
surface level of the bath of material; a plurality of solidifying
devices each configured to solidify a selective part of the bath of
material, wherein each of the plurality of solidifying devices is
configured to operate in at least substantially the entire object
working area; and a controller configured to individually control
each of the plurality of solidifying devices, wherein the
controller is configured to simultaneously operate each of the
plurality of solidifying devices in different parts of the object
working area.
2. The apparatus according to claim 1, wherein each of the
plurality of solidifying devices is configured to emit
electromagnetic radiation.
3. The apparatus according to claim 2, wherein the apparatus
further comprises a plurality of deflectors configured to deflect
electromagnetic radiation emitted by each of the plurality of
solidifying devices.
4. The apparatus according to claim 3, wherein the plurality of
deflectors are positioned proximal a line perpendicular to a plane
defined by the object working area, and wherein the line passes
through a geometrical center of gravity of the object working
area.
5. The apparatus according to claim 2, wherein the plurality of
deflectors are positioned above a center part of the object working
area such that a central or neutral position of electromagnetic
radiation beams of each of the plurality of solidifying devices is
located more towards the center part than to peripheral parts of
the object working area.
6. The apparatus according to claim 2, wherein a type of
electromagnetic radiation emitted by the plurality of solidifying
devices differs for at least two of the plurality of solidifying
devices.
7. The apparatus according to claim 1, wherein the apparatus
comprises four solidifying devices.
8. The apparatus according to claim 7, wherein the apparatus
comprises four deflectors configured to deflect electromagnetic
radiation emitted by the four solidifying devices,
respectively.
9. The apparatus according to claim 8, wherein the four solidifying
devices and the four deflectors are arranged in a geometrical
pattern.
10. The apparatus according to claim 1, wherein power provided by
the plurality of solidifying devices is mutually different.
11. The apparatus according to claim 1, wherein the controller is
configured to individually control the plurality of solidifying
devices such that only one of the solidifying devices is active at
a time.
12. A method for producing an object by additive manufacturing,
comprising the steps of: providing a bath of material configured to
be solidified, wherein a surface level of the bath of material
defines an object working area; and simultaneously operating a
plurality of solidifying devices in substantially the entire object
working area to simultaneously solidify different parts of an
object to be produced.
13. The method according to claim 12, further comprising the step
of solidifying a contour of the object to be produced using one of
the plurality of solidifying devices while simultaneously
solidifying an internal part of the object to be produced with
another one of the plurality of solidifying devices.
14. The method according to claim 12, wherein solidifying is
achieved using electromagnetic radiation.
15. The method according to claim 12, wherein at least one of the
plurality of solidifying devices is configured to preheat a
selective part of the bath of material and at least one other of
the plurality of solidifying devices is configured to solidify the
preheated selective part of the bath of material, and wherein the
method further comprises the steps of: preheating, by the at least
one of the plurality of solidifying devices, different parts of the
object to be produced, and; solidifying, by the a least one other
of the plurality of solidifying devices, the preheated different
parts of the object to be produced.
Description
CROSS-REFERENCE AND INCORPORATION BY REFERENCE
[0001] This Continuation application claims the benefit of priority
of U.S. application Ser. No. 15/528,892 filed May 23, 2017, which
claims the benefit of priority of PCTNL2015/050819 filed Nov. 24,
2015, which claims the benefit of priority of NL2013860 filed Nov.
24, 2014, NL2013861 filed Nov. 24, 2014, NL2013862 filed Nov. 24,
2014, NL2013863 filed Nov. 24, 2014, NL2013864 filed Nov. 24, 2014,
NL2013865 filed Nov. 24, 2014 and NL2013866 filed Nov. 24, 2014,
the entirety of which are incorporated herein by reference.
BACKGROUND
[0002] The invention, from a first point of view, relates to an
apparatus for producing an object by means of additive
manufacturing, comprising a process chamber for receiving a bath of
material which can be solidified by exposure to electromagnetic
radiation; a support for positioning the object in relation to the
surface level of the bath of material; and a solidifying device for
solidifying a layer of the material on the surface level by means
of electromagnetic radiation.
[0003] 3D printing or additive manufacturing refers to any of
various processes for manufacturing a three-dimensional object.
Traditional techniques like injection molding can be less expensive
for manufacturing, for example, polymer products in high
quantities, but 3D printing or additive manufacturing can be
faster, more flexible and less expensive when producing relatively
small quantities of three-dimensional objects.
[0004] It is anticipated that additive manufacturing becomes more
and more important in the future, as the increasing competitive
pressure forces companies to not only manufacture more economically
with a constant high product quality but also to save time and
costs in the area of product development. The life span of products
is continuously shortened. In addition to product quality and
product costs, the moment of market introduction is becoming
increasingly important for the success of a product.
[0005] The three-dimensional object may be produced by selectively
solidifying, in a layer-like fashion, a powder, paper or sheet
material to produce a three-dimensional, 3D, object. In particular,
a computer controlled additive manufacturing apparatus may be used
which sequentially sinters a plurality of layers to build the
desired object in a layer-by-layer fashion. Primarily additive
processes are used, in which successive layers of material are laid
down under computer control. These objects can be of almost any
shape or geometry, and are produced from a 3D model or other
electronic data source.
[0006] In order to print a three-dimensional object, a printable
model is to be created with a computer design package or via a 3D
scanner, for example. Usually, the input is a 3D CAD file such as
an STL file, a STEP file or a IGS file. Before printing the object
from a CAD file, the file is to be processed by a piece of
software, which converts the model into a series of thin subsequent
layers. Further, apparatus settings and vectors are generated for
controlling the creation of each of the subsequent layers.
[0007] A laser comprised in the computer controlled additive
manufacturing apparatus follows these settings and vectors to
solidify successive layers of material to build the 3D object from
a series of cross sections. These layers, which correspond to the
virtual cross sections from the CAD model, are during this process
joined or fused at the same time to create the final 3D object.
[0008] One of the challenges in the manufacturing of
three-dimensional objects, in particular in additive manufacturing
of metal objects, is how to accurately solidify selective parts of
the layer.
[0009] U.S. Pat. No. 5,832,415 discloses a method for calibrating
the deflection control of a laser beam. The method disclosed
comprises the step of producing a test pattern with the laser beam.
Actual positions of the laser beam on the digitized test pattern
are compared to predetermined desired coordinates. This information
is used to generate a correction table. The correction table is
then used to control the deflection of the laser beam.
[0010] The accuracy and speed of calibration obtained with the
known method does not satisfy the current demands in additive
manufacturing.
BRIEF SUMMARY
[0011] It is therefore an object of the invention to improve the
accuracy of the apparatus for producing an object by means of
additive manufacturing.
[0012] To this end, the invention, from a first point of view,
provides an apparatus for producing an object by means of additive
manufacturing, including: [0013] a process chamber for receiving a
bath of material which can be solidified by exposure to
electromagnetic radiation; [0014] a support for positioning the
object in relation to the surface level of the bath of material;
[0015] a solidifying device for solidifying a selective layer-part
of the material on the surface level by means of electromagnetic
radiation; [0016] a registering device for registering a
characteristic related to the surface level of the bath of
material; and [0017] a control unit connected to the registering
device and arranged for using the characteristic obtained by the
registering device for controlling the position of the
electromagnetic radiation emitted by the solidifying device.
[0018] The apparatus according to the invention, from a first point
of view, comprises a registering device for registering a
characteristic related to the surface level of the bath of
material. The apparatus furthermore comprises a control unit
connected to the registering device and arranged for using the
characteristic obtained by the registering device for controlling
the position of the electromagnetic radiation emitted by the
solidifying device. With this, the registering device, and the
control unit are arranged for calibrating, or controlling, a
position of the electromagnetic radiation generated by the
solidifying device on the surface level of the bath of material,
such that a more accurate positioning of said radiation is
possible. This enables direct feedback, and renders possible quick
and cost-effective calibration. Rather than creating a test
pattern, which is evaluated off-site, the registering device may
also used to register a characteristic related to the surface level
of the bath of material on-site, and this information may be
directly (on-site) fed to the control unit, which is able to
control, directly or indirectly, at least the position on the
surface level of the electromagnetic radiation generated by the
solidifying device. Hence, the invention provides an apparatus with
which direct calibration is possible, using the registering device.
With this, it is possible to calibrate the apparatus more often and
more cost-effective, since the time-consuming and expensive
off-site evaluation of a test pattern is not necessary anymore.
This allows for compensating of irregularities, especially those
having a small time-scale or high frequency, such as
thermo-mechanical deformations. This leads to improved accuracy of
the device according to the invention. With this, the object of the
invention is achieved.
[0019] According to the invention, the control unit is arranged to
use the characteristic obtained by the registering device for
controlling the position of the electromagnetic radiation emitted
by the solidifying device. This may be performed during the
solidifying process, i.e., when the solidifying device is
solidifying a selective layer-part of the material on the surface
level by means of electromagnetic radiation, or may be performed in
a more offline setting, i.e., when the solidifying device is not
solidifying the selective layer-part of the material on the surface
level. Both situations are covered by the present invention.
[0020] As stated above, the characteristic related to the surface
level of the bath may be a characteristic of a calibration area
related to said surface level of the bath. Said characteristic may
be a geometric characteristic, and is in particular related to a
position within or on a plane defined by the surface level of the
bath, i.e., an XY-position. Specifics of the characteristic will
become apparent from the following description.
[0021] According to the invention, the registering device comprises
at least one imaging device, in particular an optical imaging
device, such as a camera unit. The imaging device is arranged for
registering an image of the calibration area related to the surface
level of the bath of material, which yields information about the
calibration area, which is related to the surface level of the bath
of material. This characteristic may be used to control the
solidifying device for controlling the position of electromagnetic
radiation on the surface level of the bath of material.
[0022] Furthermore, the apparatus comprises at least one
calibration element provided on or near the support, for instance
on or near the surface level of the bath of material, wherein the
control means are arranged for controlling the solidifying device
based on a geometric characteristic of the calibration element
registered by the registering device.
[0023] With the invention as defined in this first point of view,
it is possible to obtain the characteristic during manufacturing of
a single product, for instance in between the manufacturing of
different individual layers of said product, for example after
manufacturing of each single layer, and for using the
characteristic obtained by the registering device in these
different instances for controlling the position of the
electromagnetic radiation emitted by the solidifying device during
manufacturing of a subsequent layer. This allows a precise control,
and adjustment, during manufacturing of a single product.
[0024] In particular, this makes it possible to guide the
solidifying device to the calibration element, and to view, using
the imaging device, the characteristic created by the solidifying
device on or near the calibration element. Viewing may be done
whilst creating the characteristic, or after the characteristic has
been created. In any event, this provides information with which
the device can be calibrated. Manual or automated optimisation
schemes making use of the images obtained by the imaging device may
be used to direct the solidifying device on to the calibration
element.
[0025] According to the present invention, the characteristic may
be a geometric characteristic, for example in the form of a circle,
parallel lines, a triangle, a pentagon, etc, or a spot.
[0026] Furthermore, in case the characteristic is a spot, the spot
size created by the solidifying device can be viewed, this also
allows for a spot size calibration of the solidifying device.
[0027] Further, the sharpness, i.e., focus, of the characteristic
can be viewed, allowing for a focus calibration of the solidifying
device. The sharpness can, for example, be determined based on
contrast transitions, width of particular solidified lines,
etc.
[0028] Further advantageous embodiments of the invention from a
first point of view are described in the depending claims. Some of
these will be elucidated below.
[0029] In an embodiment the imaging device is arranged for making
an image of the calibration element, and wherein the registering
device is arranged for determining the geometric characteristic of
the calibration element based on the image obtained by the imaging
device. An image of the calibration element may be taken by means
of the imaging device, for example, and the image obtained provides
information on the geometric position of the calibration element
with respect to the surface level of the bath of material.
Information obtained from evaluation of the image, for example by
the imaging device or by the control means, may be used to
calibrate or control the position of the electromagnetic radiation
emitted by the solidifying device.
[0030] In an embodiment the imaging device is arranged such that an
optical path of the imaging device, during use of the imaging
device, at least partly coincides with an optical path of the
electromagnetic radiation generated by the solidifying device,
during use of the solidifying device. This provides the advantage
that the imaging device uses the same, or at least partially the
same, optical path as the solidifying device. The part of the
calibration area viewed by the imaging device thus substantially
directly corresponds to the position of the electromagnetic
radiation on the surface level of the bath of material to be
solidified. This gives a more direct feedback between the image
obtained and the controlling, or calibration, of the solidifying
device.
[0031] In an embodiment the apparatus comprises a deflector unit,
which is arranged for deflecting electromagnetic radiation emitted
by the solidifying device towards the surface level of the bath of
material, and wherein the imaging device is arranged such that the
characteristic is registered via the deflector unit. As described
above, the image obtained by the imaging device via the deflector
unit then relates, or even substantially corresponds to the
position of electromagnetic radiation emitted by the solidifying
device via the deflector unit. It should be noted in this sense,
that the term controlling the solidifying device expressly includes
those cases wherein the position of the electromagnetic radiation
emitted by the solidifying device is controlled by means of
controlling the deflector unit.
[0032] In an embodiment the apparatus comprises a plurality of
calibration elements provided on or near the support, for instance
on or near the surface level of the bath of material. A plurality
of calibration elements improves the accuracy of the calibration,
and thus improves the accuracy with which the electromagnetic
radiation may be positioned on the surface level of the bath.
[0033] In an embodiment, at least one of the plurality of
calibration elements is assigned to a registering frame comprising
the registering device, and wherein at least one of the plurality
of calibration elements is assigned to a support frame comprising
the support. This embodiment provides the advantage that
temperature gradients within the apparatus and subsequent effects
of thermal expansion may be registered. In particular, by using
calibration elements on both the registering frame and the support
frame, it is possible to account for differences in thermal
expansion, for instance due to different operating temperatures, or
different thermal expansion coefficients. In an embodiment, the
solidifying device or a deflection unit belonging to said
solidifying device is also assigned to the registering frame as
well. This way, the thermal effects registered by the registering
device may be used for more accurately controlling the position of
the electromagnetic radiation emitted by the solidifying
device.
[0034] According to an aspect, the invention, from a first point of
view, provides a method for calibrating an apparatus for producing
an object by means of laser sintering, in particular an apparatus
according to the invention as described above. The apparatus
comprises a process chamber for receiving a bath of material which
can be solidified by exposure to electromagnetic radiation, a
support for positioning the object in relation to the surface level
of the bath of material, and a solidifying device for solidifying a
layer of the material on the surface level by means of
electromagnetic radiation. The method according to the invention
comprises the step of registering a characteristic related to the
surface level of the bath of material, and using the characteristic
for controlling the position of electromagnetic radiation emitted
by the solidifying device. Advantages of the method have been
explained in the foregoing with respect to the apparatus according
to the invention.
[0035] In an embodiment, the step of registering comprises the step
of obtaining an image of at least part of the calibration area.
[0036] In an embodiment, the step of registering comprises the step
of obtaining an image of a calibration element provided on or near
the support.
[0037] In an embodiment, the apparatus further comprises a
registering device for registering the characteristic related to
the surface level of the bath of material, and a control unit
connected to the registering device, wherein the method comprises
the step of feeding the characteristic to the control unit, and
using the control unit for controlling the position of the
electromagnetic radiation emitted by the solidifying device.
[0038] In an embodiment, the method comprises the step of repeating
the step of registering the characteristic at least once during the
production of the object. The invention according to this
embodiment provides the advantage that the calibration may be
performed even during a single cycle of producing one or more
objects by means of additive manufacturing.
[0039] In an embodiment, the method comprises the step of
solidifying the layer of material, and wherein the step of
repeating the step of registering the characteristic is performed
after the step of solidifying.
[0040] In an embodiment, the method comprises the step of moving
the support after the layer of material has been solidified, adding
further material for generating a further layer of material to be
solidified, and solidifying the further layer using the solidifying
device.
[0041] The calibration may in this way be performed in between the
solidifying of different layers of a single object. This improves
the accuracy since it accounts for changes and disturbances
occurring during the production of a single object.
[0042] It is thinkable to make an image of the electromagnetic
radiation emitted by the solidifying device, and using this image
for controlling the position thereof. This provides a direct
feedback.
[0043] In an embodiment, the method comprises the step of only
registering the characteristic when the solidifying device is free
from emitting electromagnetic radiation.
[0044] The present invention, according to a second point of view,
relates to an apparatus for producing an object by means of
additive manufacturing, comprising a process chamber for receiving
a bath of material which can be solidified, a support for
positioning the object in relation to the surface level of the bath
of material, a solidifying device for solidifying a selective part
of the material, and a recoating device which can be displaced
along the surface of the bath for levelling the surface of the
bath.
[0045] To reduce operational costs of the apparatus, it is an
object to fully utilize the capacity of the apparatus and, at the
same time, make sure that the total production lead time of a
three-dimensional object is minimized, i.e., the production queue
is minimized.
[0046] One of the challenges in the manufacturing of
three-dimensional objects, in particular in additive manufacturing
of metal objects, is how to accurately deposit the layer to be
solidified. The thickness of the layer largely determines the
accuracy with which the object can be produced. It is furthermore
desirable that the layer of material is level, in particular that
the surface of the material defines a (flat) plane. It is in this
sense especially important that the layer of material, such as a
liquid or a powder, is deposited in such a way that a relatively
small, substantially level layer of material having a uniform layer
thickness is obtained. Furthermore, all this should be reached in
as little time as possible to improve the cost--effectiveness of
the apparatus.
[0047] U.S. Pat. No. 5,582,876 A discloses an apparatus for
additive manufacturing which comprises a process chamber for
receiving a bath of liquid material which can be solidified, a
movable support for positioning the object in relation to the
surface level of the bath of liquid material; a laser for
solidifying a selective part of the liquid material; and a wiper
which can be displaced along the surface of the bath for levelling
the surface of the bath of liquid material before the step of
solidifying. The lower end of the wiper facing the surface of the
bath is formed to flexibly yield in a direction opposite to the
direction of displacement.
[0048] The accuracy and speed of the known apparatus, and in
particular of the known wiper, do not satisfy the current additive
manufacturing demands with respect to thickness, uniformness and
speed of depositing and/or levelling the layer of material.
[0049] It is furthermore a drawback of the known apparatus, that
the wiper is prone to damage by parts of the object to be produced
protruding above the bath of material.
[0050] It is therefore an object of the invention to provide an
apparatus for producing an object by means of additive
manufacturing, which alleviates or reduces the drawbacks of the
prior art, and in particular with which the recoating of the bath
of material can be performed more effective, with decreased chance
of damage to the wiper. More in particular, it is an object to
provide an apparatus which achieves the levelling of the layer of
material with at least one of more accuracy, increased uniformness,
and increased speed.
[0051] To this end, the invention provides an apparatus for
producing an object by means of additive manufacturing, including:
[0052] a process chamber for receiving a bath of powdered material
which can be solidified; [0053] a support for positioning the
object in relation to the surface level of the bath of material;
[0054] a solidifying device for solidifying a selective part of the
material; and [0055] a recoating device which can be displaced
along the surface of the bath for levelling the surface of the
bath, wherein the recoating device comprises at least one elongated
levelling member having a levelling element, wherein at least an
end of the levelling element facing the surface of the bath is
arranged to be displaceable in at least a direction substantially
transversal to the plane defined by the surface (L) of the bath
upon encountering a force exceeding a threshold.
[0056] The apparatus according to the invention comprises in
particular a recoating device, such as a wiper, which can be
displaced along the surface of the bath of powdered material for
levelling the surface of the bath, wherein the recoating device
comprises at least one elongated levelling member having a
levelling element facing the surface of the bath. An end of the
levelling element facing the surface of the bath is arranged to be
displaceable in at least a direction substantially transversal to
the plane defined by the surface of the bath upon encountering a
force exceeding a threshold. The levelling element is thus arranged
to move away from the surface of the bath of material, upon
encountering a part of the object to be produced protruding from
the surface of the bath of material, such that damage to the
levelling element, and thus to the recoating device, is prevented.
This makes the recoating device more durable, and thus the layer of
material may be recoated more accurately.
[0057] The threshold may be designed, based upon expected forces on
the levelling element. In particular, during recoating the forces
exerted on the levelling element are relatively small. When the
levelling element hits a part of the object to be produced, the
force is increased enormously. The force may then be increased by a
factor 10, or even by a factor 100. It is possible to anticipate
this, and to arrange the levelling element to move in at least a
direction substantially transversal to the plane defined by the
surface of the bath upon encountering a force exceeding a
threshold. The threshold may be set at a desired level, for
instance by designing the levelling element such that the levelling
element moves upon encountering a specific force exceeding a
threshold value.
[0058] Thus, with the recoating device having the levelling element
as described above, the object of the invention is achieved.
[0059] Further advantageous embodiments of the present invention,
from a second point of view, are described and some of these will
be elucidated below.
[0060] In an embodiment, the levelling element is flexibly
connected to the elongated levelling member for allowing the
levelling element to be displaced in at least the direction
transversal to the plane defined by the surface of the bath upon
encountering the force exceeding the threshold. The flexible
connection may be arranged by means of a spring element and/or
damping element.
[0061] In an embodiment, the levelling element is designed to be
flexibly deflectable in a direction counter to the displacing
direction as well. Due to the flexible design, the risk of damage
to the object is reduced, for instance when the levelling element
hits a part of the object protruding above the level of the bath of
material. The deflection in a direction counter to the displacing
direction automatically ensures a movement in a direction
transversal to the plane defined by the surface level of the bath.
The levelling element is thus able to move past the object, without
damage to the product and/or the levelling element.
[0062] In an embodiment, the levelling member has a plurality of
levelling elements. By providing a plurality of levelling elements,
each of which are flexibly deflectable in a direction counter to
the displacing direction, it is possible to improve the uniformness
of the surface level of the bath. Since a plurality of levelling
elements are provided, each of which are individually flexibly
deflectable, the recoating device is able to respond to local
differences on the surface level, for instance due to protruding
parts of the object to be produced which may urge a single
levelling element to deflect, without affecting, or only minimally
affecting, the other levelling elements of the levelling member.
Thus, the influence of these disturbances on the uniformness of the
material layer is limited to a relatively small region, whereas in
the prior art, such a disturbance influences a relatively larger
region. Thus, with the recoating device having a plurality of
levelling elements, the object of the invention is achieved.
[0063] In an embodiment, the plurality of levelling elements are
positioned side by side, as seen in the displacing direction. Thus,
a comb like structure is obtained, wherein each of the levelling
elements covers, during use, a different part of the layer of
material. Thus, disturbances in the layer of material, due to
protruding parts of the object, for instance, only affect a part of
the plurality of levelling elements, and thus only a part of the
levelling member is affected by these disturbances, instead of the
complete levelling member.
[0064] In an embodiment, the plurality of levelling elements are at
least partly positioned behind each other, as seen in the
displacing direction. In this embodiment, the plurality of
levelling elements are arranged for covering, during use, identical
or similar parts of the layer of material. Thus, a single part of
the layer of material is under the influence of at least two
levelling elements during a single movement of the recoating
device, thus improving the speed with which the layer of material
may be levelled.
[0065] In an embodiment, an interspace is formed between the
plurality of levelling elements of the elongated levelling member.
This ensures that disturbances on a single levelling element do
not, or only minimally, influence the other of the plurality of
levelling elements.
[0066] In an embodiment, the recoating device comprises at least
one further elongated levelling member. The further elongated
levelling member is in an embodiment also arranged to be
displaceable in at least a direction substantially transversal to
the plane defined by the surface of the bath upon encountering a
force exceeding a threshold. The further elongated levelling member
may be arranged in such a way that the threshold for this further
elongated levelling member is substantially equal to the threshold
for the elongated levelling member.
[0067] The further elongated levelling member may have a plurality
of further levelling elements that face the surface of the bath.
These are in an embodiment designed to be flexibly deflectable in a
direction counter to the displacing direction as well. In
particular, the levelling elements and further elements are each
positioned side by side, in their respective levelling member. The
at least one further elongated levelling member may be positioned
behind the levelling member, as seen in the displacing direction.
In effect, two levelling members, each having a plurality of
levelling elements positioned side by side, may be positioned
behind each other, as seen in the direction of displacement. This
improves both the speed and uniformity with which the layer of
material may be deposited.
[0068] In an embodiment, at least part of the further levelling
elements of the further levelling member are positioned in a
staggered relationship with respect to the levelling elements of
the at least one elongated levelling member. Thus, as seen in the
direction of displacement, the further levelling elements are not
positioned directly behind the levelling elements, but are shifted
over a small distance. This ensures that disturbances, such as
protruding parts of the object, hitting one of the levelling
elements are less likely to hit further levelling elements
positioned behind said one of the levelling elements. Furthermore,
the further levelling elements positioned behind said one of the
levelling elements may aid in levelling at least part of the layer
of material influenced by the disturbance. Thus, the uniformity of
the layer of material is increased.
[0069] In an embodiment, the at least one elongated levelling
member has a plate-like shape. In particular, the levelling member
is designed as a leaf-spring. Such a levelling member is relatively
easy to produce, is relatively cheap and yields optimal
results.
[0070] In an embodiment, the levelling member having the levelling
elements is integrally formed. For instance, the levelling member
may be formed from a single plate. This single plate may, in an
embodiment, be tooled to form the plurality of levelling elements
at one edge of the plate.
[0071] In an embodiment, the plurality of levelling elements are
formed as teeth, extending from the elongated levelling member.
This is relatively easy to produce, and provides for a relatively
cheap design.
[0072] In an embodiment, at least part of the levelling members, in
particular the plurality of levelling elements, comprise metal, or
are made of metal, such as stainless steel. In an embodiment, the
levelling member and levelling elements consist of metal. Metal is
very durable. The risk of damage to individual levelling elements
is minimized.
[0073] In an embodiment, wherein the levelling elements are
substantially rectangular. In particular, this allows desired
characteristics of the levelling elements, in particular the
desired flexibility of the levelling elements, to be designed in a
relatively easy manner.
[0074] In general, dimensions and characteristics of the levelling
elements can be obtained using beam deflection formulae (or
"vergeet-me-nietjes" in Dutch). These may be used to design the
material and dimension of the levelling element, for a given
threshold force. For deflection of a cantilever beam, having a
concentrated load at the free end, this formula reads
f=F*L.sup.3/(3*E*I); wherein E is the modulus of Elasticity or
Young's modulus, L is the height of the levelling element and I is
the area moment of inertia. This area moment of inertia, for a
plate like levelling element having a rectangular cross section,
reads 1=b*t.sup.3/12, wherein t is the thickness of the levelling
element and b is the width of the levelling element. These formulae
are in principle well known to those skilled in the art.
[0075] As an example, it is conceived that each levelling element
should be able to take a force of 0.3 N. At this force, the
levelling element should bend, in such a way that the levelling
element is able to pass over the product in the bath of material.
In the example, the levelling element is made of stainless steel.
The Modulus of Elasticity (E-modulus) equals E=210 GPa. In this
example, the levelling element has a length (I) of 10 mm, a width
(b) of 2.2 mm and a thickness (t) of 0.1 mm. This yields an inertia
of 183e-18 m.sup.4. The corresponding deflection is 2.6 mm. The
rise of the levelling element is in this case
10-(10.sup.2-2.6.sup.2).sup.1/2=0.35 mm, wherein use is made of
geometrics, here in particular an approximation using the
Pythagorean theorem. It is to be understood that different
calculation models, as well as different designs are conceivable,
based on different desires relating to material, desired rise,
desired force, etcetera.
[0076] In the following, example measurements are given, which are
mainly based on the above design parameters, wherein use is made of
levelling elements made of stainless steel.
[0077] The levelling elements may have a width, as seen in a
direction transverse to the displacing direction, that ranges
between 0.5 mm to 5.0 mm, in particular in between 1.0 mm and 3.0
mm, more in particular in between 1.5 mm and 2.5 mm, such as, for
instance, 1.8 mm.
[0078] The levelling elements may have a height, as seen in a
direction normal to the plane formed by the displacing direction
and the width, that is equal to at least 2 times the width, in
particular at least 4 times the width, more in particular at least
6 times the width.
[0079] The levelling elements may have a thickness, as seen in the
displacing direction, that is equal to or less than 1/20 times the
length, in particular 1/50 times the length, more in particular
1/100 times the length.
[0080] The interspace may have a width, as seen in a direction
transverse to the displacing direction, that ranges between 0.0 mm
to 1.6 mm, in particular in between 0.5 mm and 1.4 mm, more in
particular in between 1.0 mm and 1.3 mm, such as, for instance, 1.2
mm. In particular, the width of the interspace may be substantially
equal to the width of the levelling element.
[0081] The number of the plurality of levelling elements of the at
least one elongated levelling member is, in an embodiment, at least
10. The number depends, amongst others, on the dimensions of the
bath of material. The number may range in between 10 and 200, in
particular between 50 and 150, and more in particular between 80
and 100. A higher number yields a more uniform layer of material,
since it reduces the influence of parts of the object protruding
above the surface level of the material. A higher number also leads
to relatively higher costs for producing the recoating device. It
has been found that a number in between 80 and 100 provides, in an
embodiment, an optimum between accuracy and costs.
[0082] In an embodiment, the levelling elements in one levelling
member substantially have an identical form. This is relatively
easy to produce.
[0083] In an embodiment, the levelling elements of the further
levelling member substantially have a different form than the
levelling elements in the at least one levelling member. This
design helps to improve the accuracy and uniformity of the
levelling of the layer of material.
[0084] In an embodiment, an edge of the levelling elements facing
the surface of the bath is rounded. This yields a further
improvement in the accuracy and uniformity of the layer of
material
[0085] In an embodiment, the recoating device comprises a
substantially rigid plowing member, positioned before the elongated
levelling member. The plowing member is arranged to provide a first
coarse step in levelling the layer of material, and then the
elongated levelling member may be used to more precisely control
the thickness and uniformity of the layer of material.
[0086] According to an aspect, the invention, from a second point
of view, provides the use of the apparatus according to the
invention.
[0087] According to an embodiment, the use comprises the levelling
of a powdered layer of material.
[0088] From a third point of view, the invention relates to an
apparatus for producing an object by means of additive
manufacturing, comprising a process chamber for receiving a bath of
material which can be solidified; a solidifying device for
solidifying a selective part of the material; and a support
structure being movable in a shaft for positioning the object in
relation to the bath of material.
[0089] In a known apparatus, a bath of material is laid down on the
movable support structure, and the laser is used to form a first
layer of the object to be formed. Then the movable support
structure is lowered by means of a spindle for a given distance,
the bath of material is replenished, and the laser is used to form
an additional layer on top of the first layer already formed.
[0090] To reduce operational costs of the apparatus, it is an
object to fully utilize the capacity of the apparatus and, at the
same time, make sure that the total production lead time of a
three-dimensional object is minimized, i.e., the production queue
is minimized.
[0091] One of the challenges in the manufacturing of
three-dimensional objects, in particular in additive manufacturing
of metal objects, is how to produce accurate and reproducible
objects. The known apparatus does not satisfy the ever-increasing
additive manufacturing demands, in particular with accuracy and
reproducibility of the objects produced.
[0092] It is therefore an object of the invention to provide an
apparatus for producing an object by means of additive
manufacturing with improved characteristics, in particular wherein
an object may be produced with more accuracy and improved
reproducibility.
[0093] To this end, the invention provides an apparatus for
producing an object by means of additive manufacturing, including:
[0094] a process chamber for receiving a bath of material which can
be solidified; [0095] a solidifying device for solidifying a
selective part of the material; and [0096] a support structure
being movable in a shaft for positioning the object in relation to
the bath of material, wherein at least said support structure is
provided with guiding means for guiding the support structure along
the shaft during movement thereof.
[0097] The apparatus for producing an object by means of additive
manufacturing according to the invention comprises a process
chamber for receiving a bath of material which can be solidified; a
solidifying device for solidifying a selective part of the
material; and a support structure being movable in a shaft for
positioning the object in relation to the bath of material. The
accuracy and reproducibility of the apparatus is improved due to
that at least said support structure is provided with guiding means
for guiding the support structure along the shaft during movement
thereof. The guiding means ensure that the movable support
structure may be positioned more accurately, such that also the
formation of layers during forming of the product may be performed
with more accuracy. Ultimately, this makes it possible to produce
objects with more reproducible results. With this, the object of
the invention is achieved.
[0098] The guiding means are in an embodiment in contact with the
shaft. In some embodiments, an interspace may be formed between the
guiding means and the shaft, i.e., the guiding means are free from
contact with the shaft.
[0099] The guiding means may comprise at least one of an air
bearing, magnetic bearing, hydrostatic bearing, dynamical bearing,
a sliding block, and/or a wheel element.
[0100] In an embodiment, the guiding means comprises at least one
wheel element connected to the support structure, and displaceable
along a first wall of the shaft. A wheel element provides for a
relatively cost--effective guiding means. The at least one wheel
element may be connected to the movable support structure, such
that the wheel element may roll along the first wall of the shaft.
It should be noted that the term first wall of the shaft also
includes elements directly and fixedly connected thereto. For
instance, the first wall of the shaft may be provided with a guide
bar or guiding profile, and the wheel element may be in contact
with the guide bar or the guiding profile. This is to be understood
that the wheel element is displaceable along a first wall of the
shaft.
[0101] In an embodiment, the support structure comprises a
suspension element for the wheel element. The suspension may be a
rigid suspension structure that connects the wheel element to the
support structure. This aids in compensating for tolerances, such
as for instance due to thermal expansion, or may improve the
accuracy of the guiding means in general. However, a more flexible
connection, is also conceivable, as will be explained below.
[0102] In an embodiment, the suspension element is movably, in
particular pivotally connected to the support structure. This
allows the support structure to better follow the wall of the
shaft, and thus increases the ease and accuracy with which the
support structure may be moved.
[0103] In an embodiment, the guiding means comprise at least one
further wheel element connected to the support structure. In
particular, the further wheel element may be displaceable along the
first wall of the shaft.
[0104] In an embodiment, the at least one further wheel element is
displaceable along a second wall of the shaft. The second wall
differs from the first wall. By providing further wheel elements,
displaceable along the first or the second wall, the accuracy of
the positioning of the support structure is improved, since it
reduces the degrees of freedom of the movable platform.
[0105] The further wheel element may be embodied, without
limitation, as described above with respect to the wheel element.
This includes the possibility of providing a further suspension
element, including a further suspension element that is pivotally
connected to the support structure, as well as the positioning of
said further wheel element onto the same structural components as
the first wheel element.
[0106] In an embodiment, the apparatus comprises a further
suspension element for the at least one further wheel element, said
further suspension element being movably, in particular pivotally
connected to the support structure, and wherein the suspension
element and the further suspension element are movably coupled to
each other by means of a coupling element. A coupling element is
provided, which is attached to both the suspension element and the
further suspension element. This means that movement of the first
suspension element leads to movement of the further suspension
element, via the coupling element. This allows for a more smooth
and accurate guiding of the support structure along the shaft.
[0107] In an embodiment, the coupling element comprises a spring
and/or damping member. This provides for a relatively
cost--effective coupling member. In addition the spring and/or
damping member also ensures that the wheel element and the further
wheel element are biased or urged to their respective wall of the
shaft, such that smooth and accurate displacement along the shaft
is possible.
[0108] In an embodiment, the suspension element and the further
suspension element are interlinked to be pivotably movable in
opposite directions. This ensures that the support platform itself
is positioned centrally between the first wall and the second wall.
In particular, when the first wall of the shaft is opposed to the
second wall, it allows for a more accurate positioning of the
support platform in between the first and second wall, since
production tolerances of the shaft are levelled out by the guiding
mechanism described above.
[0109] From a fourth point of view, the present invention relates
to an apparatus for producing an object by means of additive
manufacturing, comprising a process chamber for receiving a bath of
material which can be solidified, a support for positioning the
object in relation to the surface level of the bath of material, a
solidifying device for solidifying a selective part of the
material, and a recoating device which can be displaced along the
surface of the bath for levelling the surface of the bath.
[0110] To reduce operational costs of the apparatus, it is an
object to fully utilize the capacity of the apparatus and, at the
same time, make sure that the total production lead time of a
three-dimensional object is minimized, i.e., the production queue
is minimized.
[0111] Many different types of apparatuses are available nowadays,
ranging from apparatuses capable of producing just a few objects in
a day to apparatuses which are specifically tailored to perform
mass production of objects. These apparatuses may further be
distinguished in their size, some apparatuses are capable of
producing objects having a relatively small size and other
apparatuses are able to produce objects of a large size. Further,
some objects which have been produced may require additional steps
before the object is finalized, such as a heat treatment to relieve
stresses built up in the produced object or a polishing process to
further polish the produced object.
[0112] One of the challenges in the manufacturing of
three-dimensional objects, in particular in additive manufacturing
of metal objects, is to provide for an apparatus which is suitable
for any of the above-mentioned purposes. For example, an apparatus
capable of producing small and relatively large sized objects,
whether in bulk or just a few samples thereof.
[0113] It is therefore an object of the invention to provide for a
versatile apparatus for producing an object by means of additive
manufacturing.
[0114] To this end, the invention, according to the fourth point of
view, provides, in a first aspect thereof, in a modular additive
manufacturing system for producing an object by means of additive
manufacturing, said modular system comprising a control module
arranged for controlling said system, and a plurality of adjacently
positioned, interconnecting modules, said interconnecting modules
including: [0115] at least one additive manufacturing module,
including: [0116] a process chamber for receiving a bath of
material which can be solidified; [0117] a solidifying device for
solidifying a selective part of the material for producing said
object; [0118] and at least one of: [0119] an exchange module
arranged for exchanging said produced object, [0120] a heat
treatment module arranged for providing a thermal process to
relieve stresses built up in produced objects, and [0121] a storage
module arranged for storing produced objects.
[0122] The invention is characterized in that each of said
interconnecting modules comprise separate, mutually interconnecting
guiding elements, said interconnecting guiding elements forming a
single guiding rail, wherein said modular system further comprises
a handling robot for transporting objects between said
interconnecting modules over said single guiding rail.
[0123] It was the insight of the inventors that, in order to obtain
a versatile apparatus for producing an object by means of additive
manufacturing, a modular system may be provided, wherein the
modular system may comprise a plurality of suitable modules
adjacently positioned and connected to each other. The advantage
hereof is that the system may be build up with different types of
modules resulting in a system which is tailored to the needs of the
customer. For example, a plurality of additive manufacturing
modules may be used within a system in case the system should be
suitable for mass production.
[0124] Another advantage of the present invention is that the
system may be expanded, i.e., upgraded, over time with more
modules. In case the need for producing objects changes over time,
it may be decided to replace existing modules with other modules
more suitable to meet that need.
[0125] According to the present invention, the modular additive
manufacturing system is a single apparatus which is construed using
a plurality of modules. As such, the system is a closed system,
meaning that it is not possible for a person and/or operator to
easily access the object which is being produced by the system.
[0126] The main aspect of the modular additive manufacturing system
according to the present invention is the additive manufacturing
module which includes: [0127] a process chamber for receiving a
bath of material which can be solidified; and [0128] a solidifying
device for solidifying a selective part of the material for
producing said object.
[0129] The inventors found that the flexibility and the
employability of such a module is improved in case other types of
modules can easily be connected to that module.
[0130] After the solidifying device has solidified the bath of
material in the process chamber, an object is produced. The
inventors found that, depending on the requirements for the
produced object, additional process steps may be performed on the
produced object. These additional process steps are to be performed
in a closed system, i.e., without the object leaving the system, as
in such a case environment cannot be controlled. A controlled
environment is necessary to make sure that the requirements for the
produced object are met. The inventors noted that, in order to
provide for a modular system as described above, each of the
modules is to be equipped with interconnecting guiding elements,
such that, when connected, the interconnecting guiding element form
a single guiding rail over which the handling robot is able to be
moved. In such a case, it is not necessary to provide for a new
guiding rail each time a module is replaced.
[0131] According to the present invention, the handling robot is
able to move over the single guiding rail. The exact movement of
the robot may be controlled by the control module. As such, a data
connection between the control module and the handling robot is to
be provided. The data connection may, for example, be comprised by
a cable connected to the handling robot and to the control module.
In another example, the data connection is provided by data lines
provided in, or provided by the single guiding rail. A single
guiding rail in the form a railroad track is, for example, suitable
as a means for guiding the handling robot between the different
interconnecting modules and, at the same time, provide for data
exchange between the handling robot and the control module for
controlling the handling robot.
[0132] The handling robot may also require power for driving itself
over the single guiding rail. According to the invention, the power
may be provided by the control module, again over separate cables
between the handling robot and the control module, or incorporated
in the singe guiding rail.
[0133] According to the present invention, the exchange module is
arranged for exchanging the produced object. This means that the
produced object may be safely taken from the module, by, for
example, a person, such that the object can be transported to its
destination. As such, the exchange module may be regarded as a
temporary storage location wherein produced objects are to be
stored before they are processed by a shipping service, or the
like.
[0134] Instead of replacing modules present in the system, it may
also be decided to add new modules such as: [0135] at least one
heat treatment module arranged for providing a thermal process to
relieve stresses built up in produced objects; or [0136] at least
one storage module arranged for storing produced objects.
[0137] In an example, an order of said modules is said control
module, followed by said at least one additive manufacturing
module, followed by a remainder of said interconnecting modules,
and ending with said exchange module.
[0138] The inventors noted that, in order to gain efficiency in
producing the objects, the at least one additive manufacturing
modules should be placed adjacently to each other. This is
especially beneficially in situations wherein the control module
further provides for utilities like cooling, gas provisioning,
etc., such that these utilities do not need to be distributed over
all the modules of the system. These utilities are, for example,
only required by the additive manufacturing modules such that these
modules are placed adjacently to each other.
[0139] In another example, a first side of an interconnecting
module is connected to a second side of another interconnecting
module, wherein the interconnecting guiding elements of said
interconnecting modules extend between said first side and said
second side of said interconnecting modules.
[0140] The guiding elements may also be extendable in towards the
first side and the second side of the interconnecting module such
that the guiding elements may be connected to each other once the
modules are already placed adjacently to each other.
[0141] In a further example, said interconnecting guiding elements
comprise mutually complementing shapes at said first and second
side of their interconnecting modules, respectively, thereby
resulting in a mating connection between said interconnecting
modules.
[0142] In yet another example, the interconnecting guiding elements
are mounted to a back side of said interconnecting modules.
[0143] In a further example, the interconnecting modules are
connected to each other such that said modular system is dust
tight.
[0144] In an example, the control module is arranged for providing
utilities comprising at least one of gas, power supply, cooling,
data communication, to said interconnecting modules.
[0145] Here, each of said interconnecting guiding elements may
comprise interconnecting distributing elements, said distributing
elements forming a single distributing rail, wherein said utilities
are being distributed over said modular system using said
distributing rail.
[0146] The interconnecting distributing elements may further be
arranged for data communication, and wherein each of the
interconnecting modules comprise an electronic identification, and
wherein said interconnecting modules are arranged for communicating
said electronic identifications over said distributing elements to
said control module for indicating a type of module and an order of
adjacent positioned interconnecting modules, wherein said control
module is arranged for controlling said handling robot based on
said received identifications.
[0147] In another example, each module may be arranged with
detection means for detecting the presence of the handling robot at
its corresponding interconnecting guiding element. The detection
means may be arranged, for example, as an optical gate, wherein an
optical path of the gate is being interrupted every time the
handling robot passes the detection means.
[0148] The mechanical location of the detection means at each of
the modules may be used, by the control module, to control the
handling robot. For example, the control module may use this
information to calibrate the position of the handling robot at the
single guiding rail.
[0149] One of the advantageous hereof is that adding or replacing
modules have the beneficial effect that the control module does not
need to be updated. The control module is able to use the
information of the detection means to calibrate and/or control the
handling robot over the single guiding rail.
[0150] The expressions, i.e., the wording, of the different aspects
comprised by the system according to the present invention should
not be taken literally. The wording of the aspects is merely chosen
to accurately express the rationale behind the actual function of
the aspects.
[0151] In accordance with the present invention, different aspects
applicable to the above-mentioned examples of the system, including
the advantages thereof, correspond to the aspects which are
applicable to the interconnecting module, according to the present
invention.
[0152] The invention, according to the fourth point of view,
provides, in a second aspect thereof, in an interconnecting module
arranged for operation in a modular system for producing an object
by means of additive manufacturing according to fourth point of
view, said interconnecting module being any of: [0153] an additive
manufacturing module, including: [0154] a process chamber for
receiving a bath of material which can be solidified; [0155] a
solidifying device for solidifying a selective part of the material
for producing said object; [0156] an exchange module arranged for
exchanging said produced object, said interconnecting modules
further include: [0157] a heat treatment module arranged for
providing a thermal process to relieve stresses built up in
produced objects; and [0158] a storage module arranged for storing
produced objects; and [0159] said interconnecting module includes
separate, mutually interconnecting guiding elements such that said
interconnecting module may be connected to a further
interconnecting module, where said interconnecting guiding elements
forming a single guiding rail when said modules are connected such
that a handling robot is able to transport objects between said
interconnecting modules, when connected, over said single guiding
rail.
[0160] The above-mentioned and other features and advantages of the
invention will be best understood from the following description
referring to the attached drawings. In the drawings, like reference
numerals denote identical parts or parts performing an identical or
comparable function or operation.
[0161] From a fifth point of view, the invention relates to an
apparatus for producing an object by means of additive
manufacturing, comprising a process chamber for receiving a bath of
material which can be solidified, wherein a surface level of the
bath of material defines an object working area; a support for
positioning the object in relation to the surface level of the bath
of material; and a plurality of solidifying devices, each arranged
for solidifying a selective part of the material.
[0162] To reduce operational costs of the apparatus, it is an
object to fully utilize the capacity of the apparatus and, at the
same time, make sure that the total production lead time of a
three-dimensional object is minimized, i.e., the production queue
is minimized.
[0163] It is an object of the invention to provide an apparatus for
producing an object by means of additive manufacturing, with which
an object may be more quickly produced, in a cost-effective
way.
[0164] To this end, the invention provides an apparatus for
producing an object by means of additive manufacturing, including:
[0165] a process chamber for receiving a bath of material which can
be solidified, wherein a surface level of the bath of material
defines an object working area; [0166] a support for positioning
the object in relation to the surface level of the bath of
material; [0167] a plurality of solidifying devices, each arranged
for solidifying a selective part of the material, wherein each of
the plurality of solidifying devices is arranged for being able to
operate in at least substantially the entire object working area;
and [0168] control means arranged for individually controlling the
plurality of solidifying devices, wherein the control means are at
least arranged for simultaneously operating the plurality of
solidifying devices in different parts of the object working
area.
[0169] According to the invention the apparatus comprises a
plurality of solidifying devices, wherein each of the plurality of
solidifying devices is arranged for being able to operate in
substantially the entire object working area; as well as control
means arranged for controlling the plurality of solidifying
devices, wherein the control means are arranged for simultaneously
operating the plurality of solidifying devices in different parts
of the object working area. With this, the plurality of solidifying
devices may be controlled to work in substantially the entire
object working area, such as for instance, at least 80%, preferably
at least 90% of the object working area, such that it is possible
to solidify different parts of a single object, in the same process
chamber, at the same time. By simultaneously solidifying different
parts of a single object, this object may be produced more quickly,
and total production time of the object may be decreased. In
particular, this means that with the apparatus according to the
invention a larger number of objects may be produced in a given
time unit, compared to devices known from the prior art. With this,
the object of the invention is achieved.
[0170] In an embodiment, the plurality of solidifying devices are
arranged for emitting electromagnetic radiation. In an embodiment,
the type of electromagnetic radiation emitted by the plurality of
solidifying devices may be the same for each and every solidifying
device. However, it is conceivable, in an embodiment, that the type
of electromagnetic radiation emitted by the plurality of
solidifying devices differs for at least two of the plurality of
solidifying devices.
[0171] In an embodiment, the apparatus comprises a plurality of
deflector means arranged for deflecting electromagnetic radiation
emitted by each of the plurality of solidifying devices. Said
deflector means are known per se, but the use of a plurality of
such deflector means allows simultaneous solidifying of the layer
of material for quicker production times, as well as for a compact
construction of the apparatus.
[0172] In an embodiment, the plurality of deflector means are
positioned near a line perpendicular to the plane defined by the
object working area, and which line passes through geometrical
centre of gravity of the object working area. In other words, the
deflector means are substantially provided above a centre part of
the object working area. This allows each of the plurality of
solidifying devices to be able to reach substantially the entire
object working area, such that, for instance, simultaneous
solidifying of different parts of a single object may occur.
[0173] In an embodiment, the apparatus comprises a total number of
four solidifying devices. A total number of four devices provides
for improved speed of manufacturing, whilst being able to keep a
compact design of the apparatus, and whilst keeping total costs of
the apparatus under control. Likewise, a total number of four
deflector means may be provided. The four solidifying devices and
four deflector means may be arranged in a geometrical pattern.
[0174] According to an aspect, the invention according to the fifth
view provides a method for producing an object by means additive
manufacturing, in particular using an apparatus as described above.
The method comprises the steps of providing a bath of material
which can be solidified, wherein a surface level of the bath of
material defines an object working area. According to the
invention, the method comprises the step of simultaneously
operating a plurality of solidifying devices in substantially the
entire object working area for simultaneously solidifying different
parts of the product to be produced. In other words, the capacity
of the plurality of solidifying devices is combined to produce a
single product.
[0175] It is noted that the advantages of the invention are also
achieved when the plurality of solidifying devices are used for
producing several products. It is conceivable that each solidifying
device is used for producing a respective of a plurality of
products. However, the plurality of solidifying devices may be
used, according to the method of the invention, for producing
different parts of a single product to be produced, at a given
moment. This speeds up the time with which this product, or layer
of the product, may be produced.
[0176] In an embodiment, the method comprises the step of
solidifying a contour of the object to be produced with one of the
plurality of solidifying devices, and simultaneously solidifying an
internal part of the object to be produced with a further of the
plurality of solidifying devices.
[0177] In an embodiment, the method comprises the step of
solidifying parts of the object working area by means of
electromagnetic radiation.
[0178] In another embodiment, a first of the plurality of
solidifying devices is used as a preheat device, and a second of
the plurality of solidifying devices is used to solidify the
preheated part of the material which can be solidified.
[0179] The plurality of solidifying devices may be similar
solidifying devices, or different solidifying devices. For
instance, the power provided by the solidifying devices may be
mutually different.
[0180] It will be apparent to those skilled in the art that the
control unit is arranged for individually controlling the plurality
of solidifying devices, such that it is possible that only one of
the solidifying devices is active, and the remaining of said
solidifying devices is inactive.
[0181] It is noted that it is very advantageous to combine the
invention according to the first point of view with the invention
according to the fifth point of view. In particular, this means
that a registering device may be provided in the form of an imaging
device for each solidifying device. Then, a calibration routine, as
described for the first point of view for a single solidifying
device, may be performed for each of the available solidifying
devices. This ensures that the plurality of different solidifying
devices may work together in an accurate way.
[0182] In a sixth point of view, the invention relates to an
apparatus for producing an object by means of additive
manufacturing, comprising a process chamber for receiving a bath of
material which can be solidified by exposure to electromagnetic
radiation; a support for positioning the object in relation to the
surface level of the bath of material; and a solidifying device for
solidifying a layer of the material on the surface level by means
of electromagnetic radiation.
[0183] One of the disadvantages of these apparatuses is their
limited capacity in producing the three-dimensional objects as well
as their limited capability in flexibility for producing the
objects.
[0184] As such, one of the challenges in the manufacturing of
three-dimensional objects using a computer controlled additive
manufacturing apparatus is to fully utilize the capacity of the
apparatus.
[0185] It is an object to provide for a system for managing
production of objects by means of additive manufacturing, which
system is arranged for providing the possibility to manage a
plurality of apparatuses for producing said objects by means of
additive manufacturing.
[0186] It is another object to provide for an apparatus for
producing an object by means of additive manufacturing, which
apparatus is suitable for operation in said system.
[0187] In a first aspect of the invention, according to the sixth
point of view, there is provided a system for managing production
of objects by means of additive manufacturing, said system
connected to, or comprising, a plurality of apparatuses for
producing an object by means of additive manufacturing, each of
said apparatuses including: [0188] a process chamber for receiving
a bath of material which can be solidified; [0189] a solidifying
device for solidifying a selective part of the material for
producing said object; [0190] a control device for controlling said
apparatus for producing said object based on a print job; and
[0191] interface means arranged for receiving said print job over a
public network; [0192] wherein each of said plurality of
apparatuses are connected to each other via said public network,
and wherein said system comprises a central server arranged for
determining geographical location information of said plurality of
apparatuses, for acquiring a print job, for selecting at least one
of said plurality of apparatuses based on said geographical
location information of said apparatuses and for transmitting said
print job to said selected apparatus.
[0193] It was the insight of the inventors that the digital
processes, i.e. the generation of the designs for the objects to be
produced as well as the corresponding print jobs, can be decoupled
from the actual physical processes, i.e. the production of the
object by an apparatus based on a print job. The system according
to the present invention supports such a subdivision of processes
as each of the apparatuses are connected to each other via the
public network.
[0194] The improved system according to the present invention is
based on the concept that the total capacity for producing objects
is increased by connecting multiple apparatuses to each other
thereby creating a cluster of apparatuses, each of which may be, at
least partly, controlled by the central server. As such, a
distributed manufacturing system is provided.
[0195] The inventors found that the decision to which apparatus a
print job is to be sent should at least be based on the
geographical location information of the apparatuses.
[0196] The geographical location information may be any of Global
Positioning System, GPS, coordinates, country, city, area code,
postal code, Internet Protocol, IP, address ranges, static sales
information, or the like. The geographical location information of
the apparatuses may be considered static information, for example
pre-stored in a database of the central server, or may be regarded
as more dynamic information such that an apparatus needs to inform
the central server about its geographical location information.
[0197] The apparatus may then be arranged to transmit its
geographical location information periodically, for example yearly,
monthly, or the like, or may transmit its geographical location
information only once a change of location has been detected by the
apparatus.
[0198] One of the advantages of the system is that the total
production lead time of objects, i.e., three-dimensional objects,
may be minimized in case apparatuses combine forces, i.e., work
together. The inventors noted that it may be more efficient to
distribute the total amount of objects to be produced, or print
jobs, over each of the available apparatuses such that more
capacity is obtained for producing these objects.
[0199] In accordance with the present invention, the total amount
of objects, or print jobs, to be produced by the system may be
evenly distributed among all of the apparatuses, or among a subset
of the plurality of apparatuses. In an alternative, each object, or
print job, to be produced may be provided with a priority status.
The priority statuses of each object or print job may then be used,
by the central server, as a further input for selecting one of the
plurality of apparatuses.
[0200] In the context of the present invention, the material used
may be any type of material suitable for additive manufacturing
such as, but not limited to liquid, powder, paper or sheet material
like stainless steels or other types of alloys.
[0201] According to the present invention, different physical sizes
of apparatuses may exist, for example having a relatively small
process chamber suitable for producing three-dimensional objects
having a size comparable to a pen, telephone, cup, etc, or having a
relatively large process chamber suitable for producing
three-dimensional objects having a size comparable to a desk,
chair, or even larger. In case the central server, according to the
present invention, is faced with multiple three-dimensional
objects, or multiple print jobs, ranging from a relatively small
size to a relatively large size, the central server may decide to
further select apparatuses based on their specific capability.
[0202] According to the invention, the central server is arranged
for acquiring a print job. The print job may, for example, be
received by the central server, from an engineer or designer, via
the public network. The print job may also be located in a print
queue designated in the central server.
[0203] In an example, the server comprises a database, wherein said
database comprises identifications and corresponding geographical
location information of each of said plurality of apparatuses.
[0204] One of the advantages hereof is that the security of the
database is under control of the system itself.
[0205] In another example, the plurality of apparatuses are
connected to each other via said central server.
[0206] The plurality of apparatuses may have a direct connection to
the central server comprised by the system, for example for
exchanging process data or the like. However, according to the
present invention, it is not necessary for the plurality of
apparatuses to directly communicate, or exchange data, to each
other over the public network.
[0207] In an example, the server is arranged for receiving process
information from any of the apparatuses, the process information
being any of a type of material said apparatuses are able to
process, object size said apparatuses are able to produce,
capability of said apparatuses for producing objects, accuracy of
objects, speed at which objects are produced, material properties
for objects to be produces, detail size of objects to be produced,
and wherein said server is further arranged for selecting said at
least one of said plurality of apparatuses based on said process
information.
[0208] Selecting the at least one of the plurality of apparatuses
may then further be based on the available process information for
each of the apparatuses. For example, a print job requiring a
certain type of material, and a certain size of process chamber,
needs to be sent to an apparatus capable of processing such a print
job.
[0209] In a further example, the apparatuses are connected to said
server via a private network across said public network.
[0210] The advantage hereof is that it enables an apparatus to
receive and/or send data across said public network as if it was
directly connected to the private network, while benefiting from
the functionality, security and management policies of the private
network. For example, A Virtual Private Network, VPN, is created by
establishing a virtual point-to-point connection through the use of
dedicated connections, virtual tunnelling protocols, or traffic
encryptions.
[0211] In an example, the print job comprises geographical location
information to which an object is to be shipped, and wherein said
selecting at least one of said plurality of apparatuses includes:
[0212] selecting at least one of said plurality of apparatuses
having geographical location information in a geographical
proximity of said geographical location information to which said
object is to be shipped.
[0213] The inventors found that it may be advantageous if the
production location of the object, i.e., location of the selected
apparatus, and the geographical location information whereto the
object is to be shipped, are matched to each other. For example, it
may be advantageous to produce an object in the Netherlands in case
the object is to be shipped to the Netherlands, as this reduces the
transport time, as well as the corresponding transportation costs,
required for transporting a produced object. As such, an apparatus
is selected which is geographically oriented closely to the
destination location of the object to be produced.
[0214] The central server may further be arranged to select an
apparatus from said plurality of apparatuses based on costs and/or
carbon footprint of the object to be produced.
[0215] In a further example, the central server comprises occupancy
information of each of said plurality of apparatuses, and wherein
said selecting at least one of said plurality of apparatuses
includes: [0216] selecting at least one of said plurality of
apparatuses based on said occupancy information.
[0217] The advantage hereof is that print jobs may be distributed
over the available plurality of apparatuses such that the total
amount of workload for producing the objects is also distributed
among these apparatuses. Besides taking into account the
geographical location information of the apparatuses, the central
server may select apparatuses for the print jobs such that the
print jobs are evenly distributed over the apparatuses.
[0218] In an example, the object comprises a plurality of print
jobs, and wherein said server is arranged for selecting at least
one of said apparatuses for transmitting at least one of said
plurality of print jobs such that a total production lead time of
said object is minimized.
[0219] The inventors noted that in some cases a three-dimensional
object is comprised by a plurality of print jobs, i.e., a plurality
of different parts to construe the three-dimensional model. The
total production lead time, i.e., the time required for producing
the complete three-dimensional object, may be reduced in case each
of the parts are created by a different apparatus.
[0220] In a further example, at least one of said apparatuses is
arranged for transmitting, to said central server, its geographical
location information, for example periodically or on request by the
central server.
[0221] The at least one of said apparatuses may further possess a
network address, and the at least one of said apparatuses may be
arranged for determining its geographical location information by
deducing said geographical location information from said network
address.
[0222] In an example, the central server is arranged for storing
process information for said print jobs. The process information
may be any of design, process settings, layer deposition strategy,
simulation data, production data, measurement data, or the like.
The central server may store such a data in its secure database.
The process information may also be transmitted to the apparatuses
along with corresponding print jobs.
[0223] In a further example, the public network is the
internet.
[0224] In another example, a print job comprises at least one of a
print model of an object, one or more series of subsequent layers
of said object, apparatus settings and vectors for said object,
wherein said apparatus settings may comprise any of type of
material, temperature settings, accuracy settings.
[0225] In a second aspect of the invention, according to the sixth
point of view, there is provided an apparatus for producing an
object by means of additive manufacturing, said apparatus suitable
to be used in a system according to the sixth point of view as
described above, wherein said apparatus includes: [0226] a process
chamber for receiving a bath of material which can be solidified;
[0227] a solidifying device for solidifying a selective part of the
material for producing said object; [0228] a control device for
controlling said apparatus for producing said object based on a
print job; and [0229] interface means arranged for receiving said
print job over a public network.
[0230] The expressions, i.e., the wording, of the different aspects
comprised by the apparatus according to the present invention
should not be taken literally. The wording of the aspects is merely
chosen to accurately express the rationale behind the actual
function of the aspects.
[0231] In accordance with the present invention, different aspects
applicable to the above-mentioned examples of the system, including
the advantages thereof, correspond to the aspects which are
applicable to the apparatus, according to the present
invention.
[0232] The above-mentioned and other features and advantages of the
invention will be best understood from the following description
referring to the attached drawings. In the drawings, like reference
numerals denote identical parts or parts performing an identical or
comparable function or operation.
[0233] The invention is not limited to the particular examples
disclosed below in connection with a particular type of computer
controlled additive manufacturing apparatus.
[0234] In a seventh point of view, the present invention relates to
an apparatus for producing an object by means of additive
manufacturing, comprising a process chamber for receiving a bath of
material which can be solidified; a structure for positioning the
object in relation to the surface level of the bath of material; a
solidifying device for solidifying a layer of the material on the
surface; and an extraction device fluidly connected to the process
chamber and arranged for extracting material out of the process
chamber.
[0235] To reduce operational costs of the apparatus, it is an
object to fully utilize the capacity of the apparatus and, at the
same time, make sure that the total production lead time of a
three-dimensional object is minimized, i.e., the production queue
is minimized.
[0236] One of the challenges in the manufacturing of
three-dimensional objects, in particular in additive manufacturing
of metal objects, is related to the deposition of the layer to be
solidified. According to prior art practice, powdered layer of
material is removed from the process chamber by means of a suction
device after having solidified selective parts of said layer of
material. Then, a new bath of material to be solidified is
deposited in the process chamber. Removing of powder takes a lot of
time, and is relatively difficult when complex objects are being
produced.
[0237] The accuracy and speed of production of the known apparatus,
and in particular of the powder extraction, do not satisfy the
current additive manufacturing demands.
[0238] It is therefore an object of the invention to provide an
apparatus for producing an object by means of additive
manufacturing, with which improved speed and accuracy of
manufacturing may be obtained, and in particular wherein the powder
extraction can be performed with increased speed and increased
effectivity.
[0239] Thereto, the invention provides an apparatus for producing
an object by means of additive manufacturing, including: [0240] a
process chamber for receiving a bath of powdered material which can
be solidified; [0241] a structure for positioning the object in
relation to the surface level of the bath of material; [0242] a
solidifying device for solidifying a layer of the material on the
surface; [0243] an extraction device fluidly connected to the
process chamber and arranged for extracting material out of the
process chamber; and [0244] blowing means for inducing a gaseous
flow in the process chamber affecting the material to be extracted,
wherein said blowing means comprise a plurality of blow nozzles
fluidly connected to the process chamber and directed in a
plurality of different directions.
[0245] The apparatus comprises, a process chamber for receiving a
bath of material which can be solidified, in particular a bath of
powdered material that can be solidified in order to make metal
products. A structure is provided for positioning the object in
relation to the surface level of the bath of material. A
solidifying device, such as a laser device, for solidifying a layer
of the material on the surface, in particular by means of
electromagnetic radiation, is provided. To remove powder of the
bath of material, for example after having solidified selective
parts of the layer of material, an extraction device is provided
which is fluidly connected to the process chamber and arranged for
extracting material out of the process chamber. According to the
invention, the apparatus comprises blowing means for inducing a
gaseous flow in the process chamber effecting the material to be
extracted. By using a gaseous flow in the process chamber, the
material to be extracted is affected and blown around in the
process chamber, and the possibility of the extraction device being
able to extract said material is increased.
[0246] To further improve the possibility of extraction of material
from the process chamber, said blowing means comprise a plurality
of blow nozzles fluidly connected to the process chamber and
directed in a plurality of different directions. By providing a
plurality of nozzles, having a plurality of different directions,
it is possible to induce a flow over the support structure which is
able to better reach the various parts of the support structure.
This way, the coverage of the blowing means is improved, such that
an improved part of material in the process chamber is subjected to
the gaseous flow, and is picked up by this gaseous flow, such that
extraction of material is improved, both in speed and in amount.
The use of a plurality of nozzles having a plurality of directions
decreases the chance of formation of so called "lee" sides behind
the object being produced, said "lee" sides being parts of the bath
of material where the object to be produced provides a shelter from
the gaseous flow. Thus, the apparatus according to the invention is
able to extract more material in less time, and thus the goal of
the invention is achieved.
[0247] In an embodiment, at least one of the plurality of blow
nozzles is a movable nozzle. The apparatus may be arranged, for
instance by means of drive means connected to a control unit, for
moving the movable nozzle during blowing of the blowing means, such
that the flow induced in the process chamber is subject to changes
in directions. This means that the nozzle is able to reach a bigger
part of the process area, such that more material to be solidified
is affected by the flow induced. Thus, material extraction, in
particular powder extraction, may be improved by using one or more
movable nozzles. In particular, the plurality of nozzles may be
movable nozzles, or a combination of stationary nozzles and movable
nozzles may be used.
[0248] In an embodiment, the at least one movable nozzle is
arranged to be moved by the flow discharged by said movable nozzle.
Rather than being moved by drive means and a control unit, it is
possible to arrange the nozzle in such a way that the nozzle is
moved by the forces exerted by the flow discharged by said nozzle.
For instance, the nozzle end may be arranged in the form of a
flexible hose or tube being provided with a freely movable end. In
such an embodiment, flow discharged through the nozzle will
automatically lead to movement of the freely movable end of the
flexible hose or tube, such that a movable nozzle is obtained.
Advantageous of this embodiment is that it delivers a relatively
randomized pattern of movement of the flow directions discharged by
said movable nozzle. Furthermore, this embodiment is relatively
cheap.
[0249] In an embodiment, the plurality of nozzles are arranged for
inducing gaseous flows having different pressures. One of the
nozzles may then be arranged for providing a flow having a
relatively low pressure, and the other may be arranged for
providing a flow having a relatively large pressure, which may be
used to induce turbulences in the flow pattern.
[0250] In an embodiment, the plurality of nozzles are arranged for
inducing gaseous flows having different volume flows. One of the
nozzles may be arranged for inducing a gaseous flow having a
relatively large volume flow, in particular that substantially
corresponds to the volume flow being extracted by the extraction
means. The other nozzle may then be arranged for inducing a
relatively small flow, affecting a relatively small area of the
process chamber. This, in particular in combination with the
different pressures as described above, improves the amount of
material extracted by the apparatus.
[0251] In an embodiment, the extraction device comprises an
extraction tube connected to a pumping unit, wherein an inlet
opening of the extraction tube is positioned within the process
chamber. This allows for extraction of material from the process
chamber.
[0252] In an embodiment, the extraction device is provided with a
filter unit for filtering a flow of liquid or powdered material
extracted from the process chamber. For instance, it is possible to
filter particles from the gaseous flow, in order to collect
particles, which may, for instance, be re-used again in solidifying
a further layer. It is furthermore possible to filter and collect
unwanted particles, for instance particles having a specific
dimension, such as particles exceeding a certain dimension.
[0253] In an embodiment, the filter unit is a cyclone filter. A
cyclone filter is a very effective filter for filtering flows
containing solid particles, and collecting these solid particles.
The cyclone filter is thus effective for filtering powder material
to be solidified.
[0254] In an embodiment, the extraction device comprises a holder
for holding material extracted from the process chamber. The holder
may be used for permanently or temporarily storing the extracted
material. The holder may be connected to a recoating device, which
uses part or all of the extracted material for laying down a
further layer of material to be solidified in the process
chamber.
[0255] In an embodiment, the extraction device comprises an exhaust
tube for exhausting a gas flow associated with the material
extracted from the process chamber. This allows for the gas flow to
be exhausted to the environment.
[0256] In an embodiment, the cyclone filter is connected to the
holder and the exhaust tube, for collecting material in the holder,
and venting the gas through the exhaust tube. As indicated above,
this allows the gas with material to be passed through the cyclone
filter, in such a way that the particle material is collected and
the gas is exhausted through the exhaust tube.
[0257] According to an aspect, the invention provides a method of
using an apparatus according to the invention, in particular a
method for extracting material out of the process chamber of said
device, wherein the method comprises the step of inducing a gaseous
flow in the process chamber for effecting the material to be
extracted. According to the invention, the plurality of blow
nozzles are used for inducing a plurality of jets that are directed
in a plurality of different directions. The advantages of such a
method and/or usage have already been described above with respect
to the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0258] Embodiments of the invention will be described in the
following in connection with the Figures. In the Figures:
[0259] FIG. 1 is an overview of an apparatus according to a first
embodiment of the present invention, for additive manufacturing an
object;
[0260] FIG. 2 is an overview of an apparatus according to a second
embodiment of the present invention, for additive manufacturing an
object;
[0261] FIG. 3 is a schematic top view of the support of the
apparatus according to an embodiment of the invention; and
[0262] FIG. 4 is a schematic top view of the support of the
apparatus according to a further embodiment of the invention.
[0263] Embodiments of the invention, from a second point of view,
will be described in the following in connection with the Figures.
In the Figures:
[0264] FIG. 5 is an overview of an apparatus according to the
present invention, from a second point of view, for additive
manufacturing an object;
[0265] FIGS. 6a-6c are a front view, and side views of a first
embodiment of the levelling member according to the present
invention from a second point of view;
[0266] FIGS. 7a and 7b are a front view and side view of a second
embodiment of the levelling member according to the present
invention from a second point of view;
[0267] FIGS. 8a and 8b are a front view and side view of a third
embodiment of the levelling member according to the present
invention from a second point of view;
[0268] FIGS. 9a and 9b are a front view and side view of a fourth
embodiment of the levelling member according to the present
invention from a second point of view;
[0269] FIGS. 10a-10c are a front view, and side views of a fifth
embodiment of the levelling member according to the present
invention from a second point of view;
[0270] FIG. 11 is an overview of an apparatus according to the
present invention from to a third point of view for additive
manufacturing an object;
[0271] FIG. 12 is a side view of an embodiment of the movable
support according to the invention from to a third point of
view;
[0272] FIG. 13 is a top view of an embodiment of the movable
support according to the invention from to a third point of
view;
[0273] FIG. 14 is a perspective view of an embodiment of the
movable support according to the invention from to a third point of
view;
[0274] FIG. 15 is a side view of an embodiment of the movable
support according to the invention from to a third point of
view;
[0275] FIG. 16 is an overview of an apparatus for additive
manufacturing an object according to a fourth point of view;
[0276] FIG. 17a is an overview of a modular system for producing an
object by means of additive manufacturing, according to the present
invention from to a fourth point of view;
[0277] FIG. 17b is a cross sectional view of the modular system,
showing the handling robot according to the present invention from
to a fourth point of view;
[0278] FIG. 18 is an example showing the handling robot and the
single guiding rail, according to the present invention from to a
fourth point of view;
[0279] FIG. 19 discloses different types of examples of modular
systems for producing an object, according to the present invention
from to a fourth point of view;
[0280] FIG. 20 discloses an example of a specific interconnecting
guiding element, as well as interconnecting guiding elements
forming a single guiding rail;
[0281] FIG. 21 is an overview of an apparatus according to the
present invention from a fifth point of view for additive
manufacturing an object;
[0282] FIG. 22 is a top view of the object working area in the
apparatus according to the invention from a fifth point of
view;
[0283] FIG. 23 is an overview of an apparatus according to the
present invention from a sixth point of view for additive
manufacturing an object;
[0284] FIG. 24 discloses an overview of a system for managing
production of objects by means of additive manufacturing according
to the present invention from a sixth point of view;
[0285] FIG. 25 is an overview of an apparatus according to the
present invention from a seventh point of view for additive
manufacturing an object;
[0286] FIG. 26 is a schematic overview of an embodiment of the
apparatus according to the invention from a seventh point of view;
and
[0287] FIG. 27 is a schematic overview of a further embodiment of
the apparatus according to the invention from a seventh point of
view.
[0288] FIG. 1 shows an overview of an apparatus 1 for producing an
object 2 by means of additive manufacturing, according to a first
embodiment of the invention. The apparatus 1 is build from several
frame parts 11, 13. The apparatus comprises a process chamber 3 for
receiving a bath of material 4 which can be solidified. In a lower
frame part 11, a shaft is formed, wherein a support 5 is provided
for positioning the object 2 in relation to the surface level L of
the bath of material 4. The support 5 is movably provided in the
shaft, such that after solidifying a layer, the support 5 may be
lowered, and a further layer of material may be solidified on top
of the part of the object 2 already formed. In a top part 13 of the
apparatus 1, a solidifying device 7 is provided for solidifying a
selective part of the material. In the embodiment shown, the
solidifying device 7 is a laser device, which is arranged for
producing electromagnetic radiation in the form of laser light, in
order to melt a powdered material provided on the support, which
then, after cooling forms a solidified part of the object to be
produced. As can be seen, the electromagnetic radiation 71 emitted
by the laser device 7 is deflected by means of a deflector unit 74,
which uses a rotatable optical element 75 to direct the emitted
radiation 71 towards the surface L of the layer of material 4.
Depending on the position of the deflector unit 74, radiation may
be emitted on different parts of the surface level L of the bath of
material.
[0289] The top frame part 13 is provided with a support structure
14, extending mainly parallel to the plane formed by the surface
level L of the bath of material 4. This support structure 14
provides strength to the top frame part.
[0290] The apparatus 1 according to the invention comprises a
registering device 81, here in the form of an imaging device 81,
for registering a characteristic related to the surface level L of
the bath of material. The apparatus according to the invention
further comprises a control unit 91 connected, by means of line 93,
to the registering device 81 and arranged for using the
characteristic obtained by the registering device for controlling
the position of the electromagnetic radiation emitted by the
solidifying device. To this end, the control unit 91 may be
connected, by means of line 92, to the solidifying device, and/or
to the deflector unit 74, by means of line 94.
[0291] As can be seen in FIG. 1, the registering device comprises
at least one imaging device, in particular an optical imaging
device, such as a camera unit 81. The camera unit is arranged for
making one or more images of calibration elements 82 provided on or
near the support 5, in the example shown connected to the lower
frame part 11. The one or more images of one or more of the
calibration elements 82 obtained by the registering device are
processed by the registering device itself, or are fed to the
control unit for being processed there. In particular, the
processing step includes obtaining a geometric characteristic of
the calibration element 82 registered by the registering device 81.
This geometric characteristic may be used for controlling the
solidifying device 7 or the deflector unit 74, in order to control
the position of the electromagnetic radiation 72 emitted by the
solidifying device 7.
[0292] As an alternative (not shown) to the embodiment shown in
FIG. 1, the registering device 81 may be positioned on or near the
support 5. For instance, the calibration element 82 shown in FIG. 1
may be substituted by a registering device 81, which is arranged
for directly registering the electromagnetic radiation 72 emitted
by the solidifying device 7. In this embodiment, the position of
the registering device 81 is then directly related to the position
of the surface level L of the bath of material. For calibrating the
apparatus 1, the electromagnetic radiation 72 is then controlled in
such a way as to reach the registering device 81. When the
electromagnetic radiation 72 reaches the registering device 81 on
or near the support 5, i.e., when the registering device 81 detects
the electromagnetic radiation 72 emitted, then the actual position
of the electromagnetic radiation (i.e. the position of the
registering device) is known, as well as the target position of the
electromagnetic radiation (i.e. the position intended to be
reached). The actual position may be compared to the target
position, and the difference may be used by the control unit 91 to
calibrate the position of electromagnetic radiation emitted by the
solidifying device 7 during solidifying selective parts of the
surface level L of the bath. In particular, the use of a plurality
of registering devices 81, for instance, but not limited to, a
total of four or six devices 81, provided on different locations on
or near the surface level L of the bath of material 4, may be used
to improve the accuracy of the calibration.
[0293] FIG. 2 shows a second embodiment of the apparatus 1. Similar
parts are indicated by the same reference numeral. The apparatus 1
largely corresponds to the apparatus as shown in FIG. 1, and for
reasons of conciseness, mainly the differences will be described.
As can be seen in FIG. 2, the main difference is that the position
of the imaging device 81 differs with respect to the embodiment
shown in FIG. 1. Here, the imaging device 81 is arranged such that
an optical path 71 of the imaging device 81, during use of the
imaging device 81, at least partly coincides with an optical path
71 of the electromagnetic radiation generated by the solidifying
device 7, during use of the solidifying device. It should be
expressly noted in this respect, that the imaging device 81 and the
solidifying device 7 do not necessarily have to be operated at the
same time, although this is conceivable. For instance, in an
embodiment, the characteristic is only registered when the
solidifying device is free from emitting electromagnetic radiation.
In the embodiment shown, use is made of an optical device, such as
a semi-transparent mirror element, or a single lens reflex
arrangement, to be able to obtain an image of the calibration area,
using the registering means 81, via the deflector unit 74, and to
use the information obtained by the registering means 81, to
calibrate or control the deflector unit 74 and/or the solidifying
device 7 for controlling the position of electromagnetic radiation
on the surface level L of the bath of material.
[0294] Advantageous of the apparatus 1 according to the invention,
is that a step of registering the characteristic related to the
surface level L of the bath of material 4 may be repeated at least
once during the production of the object 2.
[0295] In particular, the method according to the invention
provides the possibility of solidifying the layer of material, and
repeating the step of registering the characteristic directly after
the step of solidifying. This means that calibration is possible
after solidifying of each, or a plurality of layers, which renders
calibration during production of an object possible.
[0296] FIG. 3 shows a schematic overview of a top side of the lower
frame part 11 with the top part of the support 5 and surface level
L of the bath of material. Here it can be seen that a total of four
elements 82a-82d are provided. These four elements may be
registering devices for directly registering electromagnetic
radiation emitted by the solidifying device. However, these four
elements 82a-82 may also be the calibration elements as described
in detail with respect to FIG. 2. The elements 82a-82d are
positioned on two opposed sides of the generally rectangular bath
of material 4. With the registering of the geometric position of
the four elements 82a-82d, it is possible to use interpolation to
more accurately control the position of electromagnetic radiation
on the surface level L of the bath of material.
[0297] FIG. 4 shows a further schematic overview of an embodiment
of the top side of the lower frame part 11 with the top part of the
support 5 and surface level L of the bath of material. Here it can
be seen that a total of six elements 82a-82f are provided. As for
FIG. 3, these six elements may be registering devices for directly
registering electromagnetic radiation emitted by the solidifying
device, or may be calibration elements as described in detail with
respect to FIG. 2. Here it can be seen that four elements 82a-82d
are assigned to the lower part frame 11 to which the support 5 is
thermally connected, whereas two elements 82e-82f are assigned to
the top frame part 13 to which the solidifying device 7 is
thermally connected. This embodiment provides the advantage that
temperature gradients within the apparatus and subsequent effects
of thermal expansion may be registered. In particular, by using
elements 82a-f connected to either one of the top frame 13 and the
bottom frame 12, it is possible to account for differences in
thermal expansion, for instance due to different operating
temperatures, or different thermal expansion coefficients. It is
also conceivable that it is accounted for thermal expansion of the
object to be produced, for instance by adapting the apparatus
settings and vectors to be followed by the solidifying device, for
instance by slightly increasing the size of the contours of the
object to be produced.
[0298] FIG. 5 shows an overview of an apparatus 1001 for producing
an object 1002 by means of additive manufacturing. The apparatus
1001 is built from several frame parts 1011, 1012, 1013. The
apparatus comprises a process chamber 1003 for receiving a bath of
material 1004 which can be solidified. In a lower frame part 1011,
a shaft is formed, wherein a support 1005 is provided for
positioning the object 1002 in relation to the surface level L1 of
the bath of material 1004. The support 1005 is movably provided in
the shaft, such that after solidifying a layer, the support 1005
may be lowered, and a further layer of material may be solidified
on top of the part of the object 1002 already formed. In a top part
1013 of the apparatus 1001, a solidifying device 1007 is provided
for solidifying a selective part of the material. In the embodiment
shown, the solidifying device 1007 is a laser device, which is
arranged for producing electromagnetic radiation in the form of
laser light, in order to melt a powdered material provided on the
support, which then, after cooling forms a solidified part of the
object to be produced. However, the invention is not limited to the
type of solidifying device. As can be seen, the electromagnetic
radiation 1071 emitted by the laser device 1007 is deflected by
means of a deflector unit 1074, which uses a rotatable optical
element 1075 to direct the emitted radiation 1071 towards the
surface L1 of the layer of material 1004. Depending on the position
of the deflector unit 1074, radiation may be emitted, as an
example, according to rays 1072, 1073.
[0299] The apparatus 1001 shown further comprises a recoating
device 1009 which can be displaced along the surface L1 of the bath
for levelling the surface L1 of the bath of material 1004. The
recoating device 1009 is moved along the surface of the bath, in
the direction of movement D1. The recoating device 1009 according
to the invention may be embodied in several ways, which will be
explained by reference to FIGS. 6 to 9. In general, however, the
recoating device according to the invention comprises at least one
elongated levelling member having a plurality of levelling elements
that face the surface of the bath and that are designed to be
flexibly deflectable in a direction counter to the displacing
direction D1.
[0300] FIGS. 6a-6c show a recoating device 1109 according to a
first embodiment of the invention. As can be seen in FIGS. 6a and
6b, the recoating device 1109 comprises a general frame 1105, to
which an elongated levelling member 1101 is attached. The elongated
levelling member 1101 comprises a plurality of independent
levelling elements 1103, each positioned side by side as seen in
FIG. 6a. Between neighbouring levelling elements 1103, an
interspace S is formed. The interspace is substantially equal to
the width of the levelling elements 1103, as seen in the front view
of FIG. 6a. Each of the plurality of the levelling elements 1103 is
designed to be flexibly deformable in a direction opposite to the
direction of displacement D1. The design according to the invention
allows for a single levelling element 1103a to be deformed in a
different manner compared to a further levelling element 1103b,
which aids in the improvement of the uniformity and accuracy of the
thickness of the levelling of the layer of material. This is best
understood from FIG. 6c.
[0301] FIG. 6c shows the recoating device 1109 during use. The
recoating device 1109 is displaced in the direction of movement,
indicated by arrow D1, over the surface level L1 of the layer of
material 4 to be solidified. A part of the object 1002 to be
solidified protrudes from a desired surface level. This part 1002
is in the line of movement of one of the levelling elements 1103a,
1103b only. It can be seen that a first levelling element 1103a is
not influenced by this part of the object, since the object 1002 is
not in the line of movement of this first levelling element 1103a.
The object is, however, in the line of movement of the second
levelling element 1103b. Due to this, the second levelling element
1103b is flexed to a further extent, compared to the first
levelling element 1103a. Thus, from the above it is clear that a
small disturbance, for instance in the form of a protruding part of
the object 1002, does only influence a relatively small part of the
recoating device 1109, without affecting other parts of the
recoating device 1109. This leads to improved control of the
levelling of the surface layer L1 of the material 1004 to be
solidified.
[0302] FIGS. 7a and 7b show a recoating device 1209 according to a
second embodiment of the invention. The recoating device 1209
comprises a general frame 1205, to which an elongated levelling
member 1201 is attached. The elongated levelling member 1201
comprises a plurality of independent levelling elements 1203, each
positioned side by side as seen in FIG. 7a. Between neighbouring
levelling elements 1203, an interspace is formed. The recoating
device 1209 according to the second embodiment comprises a further
elongated levelling member 1211, which is best viewable in FIG. 7b.
The further elongated levelling member 1211 is positioned behind
the elongated levelling member 1201, as seen in the direction of
movement. The further elongated levelling member 1211 comprises a
plurality of further levelling elements 1213. In the embodiment
shown, the further levelling elements 1213 are positioned in a
staggered relationship with respect to the levelling elements 1203,
such that a complete coverage of the surface layer L1 of material
is obtained during movement of the recoating device 1209. Thus,
parts of the material moving through the interspace formed by
neighbouring levelling elements 1203 are levelled by the further
levelling elements 1213 provided behind the levelling elements
1203. In the embodiment shown, the further levelling member 1203 is
positioned directly behind the levelling member 1213.
[0303] FIGS. 8a and 8b show a recoating device 1309 according to a
third embodiment of the invention. This embodiment is very similar
to the second embodiment described by means of FIGS. 7a to 7b. For
reasons of conciseness, it is referred to the general description
of that embodiment. The main difference in the third embodiment, is
that the further levelling member 1311 is positioned at a distance
S, or interspace S, from the levelling member 1301. This gives more
room for independent flexion of the individual levelling elements
1303 and the further levelling elements 1313. The interspace may be
designed, and its parameters are mainly based on easy of
manufacturing.
[0304] FIGS. 9a and 9b show a recoating device 1409 according to a
fourth embodiment of the invention. This embodiment is very similar
to the third embodiment, and for reasons of conciseness mainly the
differences will be described. As can be seen in FIG. 9b, a total
number of four levelling members 1401, 1411, 1421, 1431 is used,
each being positioned at distance from each other, as seen in the
direction of movement. Each levelling member 1401, 1411, 1421, 1431
comprises a plurality of levelling elements 1403, 1413, 1423, 1433
that are flexibly deformable in a direction opposite to the
direction of movement D1. In front of the recoating device 1409, a
substantially rigid plowing member is provided. This plowing member
is relatively thick compared to the elongated levelling member, and
is designed to provide a first coarse step in levelling the layer
of material. As can be seen in FIG. 9b, the recoating device is
additionally provided with a further substantially rigid plowing
member 1408, which is designed to be active when the recoating
device 1409 is moved in a direction of movement D1' that is
opposite to the direction of movement D1. This provides for a first
coarse step in levelling the layer of material, independent of the
fact whether the recoating device is moved in forward (D1) or
backward (D1') direction. Thus, this improves the speed with which
the layer of material may be levelled.
[0305] FIGS. 10a-10c show a recoating device 1509 according to a
fifth embodiment of the invention. As can be seen in FIGS. 10a and
10b, the recoating device 1509 comprises a general frame 1505, to
which an elongated levelling member 1501 is attached. The elongated
levelling member 1501 comprises a single levelling element 1503.
The levelling element 1503 is connected to the frame 1505 by means
of a spring 1521, which allows the levelling element 1503 to move
at least in a direction substantially transversal to the plane
defined by the surface level L1 of the bath of material 1004. The
levelling element may additionally be designed to be flexibly
deformable in a direction opposite to the direction of displacement
D1. The design according to the invention allows for a single
levelling element 1503 to move upwards upon encountering a specific
force thereon, for passing an object 1002, as can be seen in FIG.
10c. Thus with the spring 1521, the levelling element is flexibly
connected to the elongated levelling member for allowing the
levelling element to be displaced in at least the direction
transversal to the plane defined by the surface of the bath upon
encountering the force exceeding the threshold. It is noted that
the levelling element, due to the relatively thin construction, is
flexibly deflectable in a direction counter to the displacing
direction as well.
[0306] FIG. 11 shows an overview of an apparatus 2001 for producing
an object 2002 by means of additive manufacturing. The apparatus
2001 is built from several frame parts 2011, 2012, 2013. The
apparatus comprises a process chamber 2003 for receiving a bath of
material 2004 which can be solidified. In a lower frame part 2011,
a shaft is formed, wherein a support 2005 is provided for
positioning the object 2002 in relation to the surface level L2 of
the bath of material 2004. The support 2005 is movably provided in
the shaft 2050, in a direction generally indicated by arrow Z, such
that after solidifying a layer, the support 2005 may be lowered,
and a further layer of material may be solidified on top of the
part of the object 2002 already formed. In a top part 2013 of the
apparatus 2001, a solidifying device 2007 is provided for
solidifying a selective part of the material. In the embodiment
shown, the solidifying device 2007 is a laser device, which is
arranged for producing electromagnetic radiation in the form of
laser light, in order to melt a powdered material provided on the
support, which then, after cooling forms a solidified part of the
object to be produced. However, the invention is not limited to the
type of solidifying device. As can be seen, the electromagnetic
radiation 2071 emitted by the laser device 2007 is deflected by
means of a deflector unit 2074, which uses a rotatable optical
element 2075 to direct the emitted radiation 2071 towards the
surface L2 of the layer of material 2004. Depending on the position
of the deflector unit 2074, radiation may be emitted, as an
example, according to rays 2072, 2073.
[0307] FIG. 12 shows a schematic side view of an embodiment of the
support 2005 according to the invention. FIG. 12 shows the movable
support 2005, having a build platform 2052 and a spindle 2051,
which is movably provided, in a direction indicated by arrow Z,
within a shaft 2050. Now referring back to FIG. 11, it can be seen
that the shaft 2050 is part of the lower frame 2011, and that the
movable support 2005 is movable within the shaft 2050 for
positioning the build platform 2052 at a desired height in order to
produce the object 2002. Now referring to FIG. 12, it can be seen
that the support 2005, and in particular the build platform 2052,
is provided with a first wheel element 2054 and a second wheel
element 2055, both of which are displaceable along opposite walls
of the shaft 2050. Thus, the support structure 2005 is provided
with guiding means 2054, 2055 in contact with the shaft 2050 for
guiding the support structure 2005 along the shaft 2050 during
movement thereof.
[0308] FIG. 13 shows a top view of an embodiment of the movable
support 2005 having guiding means 2054-2059, preferably in the form
of wheel elements. In total, six guiding elements 2054-2059, which
can be wheel elements 2054-2059, are visible in FIG. 13, although
it is conceivable to use more or less guiding elements.
Furthermore, it can be seen that pairs of opposing guiding elements
are formed here. For instance, guiding element 2054 is positioned
opposite to guiding element 2055, guiding element 2056 is opposed
to guiding element 2057, and guiding element 2058 is opposed to
guiding element 2059. The positioning of these pairs of guiding
elements 2054-2059, preferably in the form of guiding wheels
2054-2059, aids in constraining the degrees of freedom. It is noted
that a small offset may be present, between opposed guiding
elements, without substantially affecting the constraining in the
degrees of freedom.
[0309] FIG. 14 shows a schematic view in perspective of a further
embodiment of the build platform 2052 of the movable support,
having all guiding elements as described with respect to the top
view of FIG. 13, and having additional pairs of guiding elements,
for which only a single guiding element 2064, 2066 is visible in
FIG. 14. It is noted that directly opposite each of the two guiding
elements 2064, 2066 a further guiding element, preferably in the
form of a guiding wheel, is provided. The further guiding elements
are positioned directly below the guiding elements 2057, 2055
depicted in FIG. 13, such that opposing pairs of guiding elements
are formed.
[0310] In principle any solid object has a total of 6 degrees of
freedom (DOF): 3 DOF for translational movements and 3 DOF for
rotational movements. By using the pairs of guiding elements
2054-2059 in FIG. 13, and 2054-2059, 2064, 2066 in FIG. 14, the
number of DOF are reduced, by constraining certain movements. The
guiding means shown in FIG. 13 would constrain any DOF related to
translational movement and/or rotational movement within a plane
defined by the surface of the build platform 2052, i.e., within the
plane defined by the drawing of FIG. 13. The guiding means shown
in, and described with respect to, FIG. 14, having a total of 5
pairs of guiding elements, would additionally constrain the
remaining DOF related to rotational movement, such that only the
DOF related to movement in the axial direction (indicated by arrow
D2), i.e., the desired movement of the build platform 2052, remains
unconstrained.
[0311] FIG. 15 schematically shows an embodiment of a pair of
guiding elements for a movable support structure. FIG. 15
schematically shows the shaft in the form of two opposed wall parts
2050, 2050', within which the build platform 2052 is movably
provided. The build platform 2052 is movable in the direction Z by
means of, for example, a spindle, as also indicated in FIGS. 11 and
12. Other ways of driving the support structure 2052 in the
direction Z are conceivable of course, and the way of driving is
not limited to the invention.
[0312] According to the invention, from the third point of view,
guiding elements in the form of a wheel element 2054 and a further
wheel element 2055 are provided. The wheel element 2054 is
connected to the build platform 2052, by means of a suspension
element 2541, and is movable along a first wall 2050 of the shaft.
The further wheel element 2055 is also connected to the build
platform by means of a further suspension element 2551, and is
movable along a second wall 2050' of the shaft. The first wall 2050
of the shaft is directly opposed to the second wall 2050', and is
facing said second wall 2050'. The suspension elements 2541, 2551
are each pivotally connected to the build platform 2052, such that
pivotal movement about axes 2542, 2552, respectively, of the
suspension elements 2541, 2551 is possible. As can be seen in FIG.
15, the suspension element 2541 and the further suspension element
2551 are movably coupled to each other by means of a coupling
element 2045, in the form of a hinge element 2045. The coupling
element furthermore comprises a spring and/or damping member 2046,
which is connected to the build platform 2052 of the movable
support structure and, in the embodiment shown in FIG. 15, to the
further suspension element 2551. It is noted that the spring and/or
damping member 2046 may additionally or alternatively be connected
to the suspension element 2541.
[0313] The coupling between the suspension element 2541 and the
further suspension element 2551 is such that these elements 2541,
2551 are interlinked to be pivotably movable in opposite
directions. The spring and/or damping element 2046 is designed to
be a compression spring, which presses onto the hinge 2045, and
biases or urges the wheel elements 2054, 2055 outwards, such that
both wheels 2054, 2055 are in good contact with their respective
wall 2050, 2050'. The construction described above implies that if
the support structure experiences thermal expansion, for instance
in the direction indicated by arrow X, then the axes 2542, 2552
will be positioned further apart, which, in the prior art, may lead
to uncertainties in the exact position of the build platform 2052.
With the structure described above, the compression spring 2046
urges the wheel elements 2054, 2055 into contact with their
respective wall parts 2050, 2050' with the center part of the
support structure 2052 being positioned exactly in between the wall
parts 2050, 2050'. Thus, the guiding means described here with
respect to FIG. 15 may be used to ensure an accurate and
reproducible positioning of the build platform 2052, even in cases
where temperature gradients lead to thermal expansion of the build
platform 2052 and/or the shaft.
[0314] It is noted that all five pairs of guiding elements
described and shown in FIG. 14 are, in an embodiment, construed as
the pair of guiding elements shown in FIG. 15, enabling an accurate
and reproducible positioning in all translational and rotational
DOF, except for translational movement in the Z direction.
[0315] FIG. 16 shows an overview of an apparatus 3001 for producing
an object 3002 by means of additive manufacturing. The apparatus
3001 is built from several frame parts 3011, 3012, 3013. The
apparatus comprises a process chamber 3003 for receiving a bath of
material 3004 which can be solidified. In a lower frame part 3011,
a shaft is formed, wherein a support 3005 is provided for
positioning the object 3002 in relation to the surface level L3 of
the bath of material 3004. The support 3005 is movably provided in
the shaft, such that after solidifying a layer, the support 3005
may be lowered, and a further layer of material may be solidified
on top of the part of the object 3002 already formed. In a top part
3013 of the apparatus 3001, a solidifying device 3007 is provided
for solidifying a selective part of the material. In the embodiment
shown, the solidifying device 3007 is a laser device, which is
arranged for producing electromagnetic radiation in the form of
laser light, in order to melt a powdered material provided on the
support, which then, after cooling forms a solidified part of the
object to be produced. However, the invention is not limited to the
type of solidifying device. As can be seen, the electromagnetic
radiation 3071 emitted by the laser device 3007 is deflected by
means of a deflector unit 3074, which uses a rotatable optical
element 3075 to direct the emitted radiation 3071 towards the
surface L3 of the layer of material 3004. Depending on the position
of the deflector unit 3074, radiation may be emitted, as an
example, according to rays 3072, 3073.
[0316] FIGS. 17a and 17b show the modular system 3101 for producing
an object by means of additive manufacturing from different angles.
The modular system 3101 comprises a control module 3102, two
adjacently placed and connected additive manufacturing modules
3103, 3104, a heat treatment module 3105 and an exchange module
3106.
[0317] The additive manufacturing modules 3103, 3104 comprise a
process chamber for receiving a bath of material which can be
solidified and a solidifying device for solidifying a selective
part of the material for producing said object.
[0318] The control module 3102 may be equipped with a user
interface 3109 for inputting various data relating to the process
of producing the object. Such data may, for example, be the models
of the objects to be produced, the specific order and the type of
modules provided in the modular system 3101, etc.
[0319] Further, each of the modules 3102, 3103, 3104, 3105, 3106
may be provided with a frame 3107, which frame 3107 is used for
connecting the modules to each other.
[0320] In FIG. 17b, the handling robot 3108 is shown, which is
guided over the single guiding rail which is placed, or mounted, at
the back side 3110 of the modules 3102, 3103, 3104, 3105, 3106.
[0321] FIG. 18 is an example showing the handling robot 3201 and
the single guiding rail 3202, 3203, according to the present
invention.
[0322] Here, the single guiding rail comprises two different parts,
i.e., referred to with reference numeral 3202 and 3203, such that
data communication and the provisioning of power from the control
module to the handling robot 3201 is made possible. The data
communication and the provisioning of power may then be transported
over these two parts 3202, 3203.
[0323] FIG. 19 discloses different types of examples of modular
systems for producing an object, according to the present
invention.
[0324] In the top example, a control module 3102 is adjacently
positioned to an additive manufacturing module 3103, which is then
connected to the exchange module 3106. This setup is considered to
be the minimal setup of the system to function properly.
[0325] In more advanced setups, i.e., the second setup from the
top, the control module 3102 is connected to two adjacently
positioned additive manufacturing modules 3103, which are
subsequently connected to a storage module 3121, and finally ending
with an exchange module 3106.
[0326] An even more detailed setup is shown in the third setup from
the top, where a single control module 3102 is connected to two
adjacently positioned additive manufacturing modules 3103, which
are connected to a heat treatment module 3105, a storage module
3121 and an exchange module 3106.
[0327] Finally, a very detailed and extended setup is shown in the
fourth setup from the top, in which a monitoring module 3122 is
connected to a control module, which is connected to three
adjacently positioned additive manufacturing modules 3103, which
are connected to two storage modules 3121, which are connected to
two heat treatment modules 3105, which are finally connected to an
exchange module 3106. This setup may, for example, be used for mass
production of objects.
[0328] FIG. 20 discloses an example of a specific interconnecting
guiding element 3301, as well as interconnecting guiding elements
forming a single guiding rail.
[0329] In the present example, the interconnecting guiding element
3301 comprises, at a first end thereof, a dowel pin 3302 and, at a
second end thereof, a corresponding hole 3303.
[0330] The dowel pin 3202 may have a smaller diameter than its
corresponding hole 3303 such that it can freely slip in, or may
have a larger diameter so that it must be pressed into its hole
3303.
[0331] Two modules 3304, 3305, may then be connected to each other
by aligned the modules next to each other such that the dowel pin
3302 of the first module 3304 is aligned with the hole 3303 of the
second module 3305. By connecting the first module 3304 with the
second module 3305, a single guiding rail is formed as the guiding
elements of the first module 3304 and the second module 3305 are
connected, i.e., the dowel pin 3202 is pushed into its
corresponding hole (or vice versa).
[0332] The inventors noted that the use of dowel pins 3202 in
combination with holes 3303 may serve as solid reference points to
control the positioning of the modules adjacent to each other. The
use of dowel pins 3202 in combination with their mating holes 3303
may result in less mechanical play between two adjacently placed
modules 3304, 3305.
[0333] Control of the handling robot, by the control module, may be
achieved via data and/or power connections integrated in the
interconnecting guiding element 3301 or via separate cables
connected between the handling robot and the control module.
[0334] FIG. 21 shows an overview of an apparatus 4001, for
producing an object 4002 by means of additive manufacturing,
according to an embodiment of the present invention. The apparatus
4001 is built from several frame parts 4011, 4012, 4013. The
apparatus comprises a process chamber 4003 for receiving a bath of
material 4004 which can be solidified. In a lower frame part 4011,
a shaft is formed, wherein a support 4005 is provided for
positioning the object 4002 in relation to the surface level L4 of
the bath of material 4004. The support 4005 is movably provided in
the shaft, such that after solidifying a layer, the support 4005
may be lowered, and a further layer of material may be solidified
on top of the part of the object 4002 already formed. In a top part
4013 of the apparatus 4001, a first solidifying device 4007 is
provided for solidifying a selective part of the material by means
of electromagnetic radiation. As can be seen, the electromagnetic
radiation 4071 emitted by the laser device 4007 is deflected by
means of a first rotatable deflector unit 4075 to direct the
emitted radiation 4071 towards the surface L4 of the layer of
material 4004. In the top part 4013 of the apparatus 4001, a
further solidifying device 4007 is provided for solidifying a
further selective part of the material.
[0335] The top part 4013 of the apparatus 4001 also comprises a
further solidifying device 4007 for solidifying a selective part of
the material by means of electromagnetic radiation. As can be seen,
the electromagnetic radiation 4071' emitted by the further laser
device 4007' is deflected by means of a further rotatable deflector
unit 4075' to direct the emitted radiation 4071' thereof towards
the surface L4 of the layer of material 4004.
[0336] In the embodiment shown, the solidifying device 4007 and the
further solidifying device 4007' are laser devices, which is
arranged for producing electromagnetic radiation in the form of
laser light, in order to melt a powdered material provided on the
support, which then, after cooling forms a solidified part of the
object to be produced. However, the invention is not limited to
this type of solidifying device, but comprises in general
solidifying devices that use electromagnetic radiation.
Furthermore, the type of electromagnetic radiation emitted by the
plurality of solidifying devices may be the same for each and every
solidifying device, although it is conceivable that the type of
electromagnetic radiation emitted by the plurality of solidifying
devices differs for at least two of the plurality of solidifying
devices.
[0337] It can be seen furthermore in FIG. 21, that the plurality of
deflector means 4075, 4075' are positioned near a line C
perpendicular to the plane defined by the object working area L4,
and which line C passes through geometrical centre of gravity of
the object working area L4. In other words, the deflector means
4075, 4075' are substantially provided above a centre part of the
object working area L4. This allows each of the plurality of
solidifying devices to easily reach substantially the entire object
working area, such that, for instance, simultaneous solidifying of
different parts of a single object may occur.
[0338] The above will be better understood from FIG. 22, which
shows a top view of the object working area L4. Here the apparatus
comprises a total of four solidifying devices, each being able to
direct a beam of electromagnetic radiation 4073-4073''' to the
object working area. A total number of four devices provides for
improved speed of manufacturing, whilst being able to keep a
compact design of the apparatus, and whilst keeping total costs of
the apparatus under control. Likewise, a total number of four
deflector means may be provided. The four solidifying devices and
four deflector means may be arranged in a geometrical pattern. FIG.
22 shows the central or neutral position of each of the
electromagnetic radiation beams 4073-4073''', and said position may
be changed, during operation of the apparatus, by means of
deflecting the electromagnetic radiation via the plurality of
deflector means. Since the plurality of deflector means are
substantially located above the centre part C of the object working
area, which means that the central or neutral position of each of
the electromagnetic radiation beams 4073-4073''' is located more
towards the centre part C than to a peripheral part P of the object
working area, it is relatively easy for each of the plurality of
beams of electromagnetic radiation to reach substantially the
entire object working area. Thus, this enables, amongst others, to
simultaneously solidify different parts of a single object.
[0339] Referring back to FIG. 21, it can be seen that the apparatus
4001 further comprises control means 4074 arranged for controlling
the plurality of solidifying devices 4007, 4007', wherein the
control means are arranged for simultaneously operating the
plurality of solidifying devices 4007, 4007' in different parts of
the object working area L4.
[0340] Thus, with the apparatus shown in FIG. 21, the plurality of
solidifying devices 4007, 4007' may be controlled to work in
substantially the entire object working area L4, such that it is
possible to solidify different parts of a single object 4002 at the
same time. By simultaneously solidifying different parts of a
single object, this object may be produced more quickly, and total
production time of the object may be decreased. The invention is
described above by means of preferred embodiments.
[0341] FIG. 23 shows an overview of an apparatus 5001 for producing
an object 5002 by means of additive manufacturing. The apparatus
5001 is built from several frame parts 5011, 5012, 5013. The
apparatus comprises a process chamber 5003 for receiving a bath of
material 5004 which can be solidified. In a lower frame part 5011,
a shaft is formed, wherein a support 5005 is provided for
positioning the object 5002 in relation to the surface level L5 of
the bath of material 5004. The support 5005 is movably provided in
the shaft, such that after solidifying a layer, the support 5005
may be lowered, and a further layer of material may be solidified
on top of the part of the object 5002 already formed. In a top part
5013 of the apparatus 5001, a solidifying device 5007 is provided
for solidifying a selective part of the material. In the embodiment
shown, the solidifying device 5007 is a laser device, which is
arranged for producing electromagnetic radiation in the form of
laser light, in order to melt a powdered material provided on the
support, which then, after cooling forms a solidified part of the
object to be produced. However, the invention is not limited to the
type of solidifying device. As can be seen, the electromagnetic
radiation 5071 emitted by the laser device 5007 is deflected by
means of a deflector unit 5074, which uses a rotatable optical
element 5075 to direct the emitted radiation 5071 towards the
surface L5 of the layer of material 5004. Depending on the position
of the deflector unit 5074, radiation may be emitted, as an
example, according to rays 5072, 5073.
[0342] FIG. 24 discloses an overview of a system 5105 for managing
production of objects by means of additive manufacturing. The
system 5105 comprises a plurality of apparatuses 5102, each of
which connected to a public network. The apparatuses 5102 are
suitable for producing an object by means of additive
manufacturing, wherein each apparatus 5102 comprises a process
chamber for receiving a bath of material which can be solidified, a
solidifying device for solidifying a selective part of the material
for producing the object, a control device for controlling the
apparatus for producing the object based on a print job, and
interface means arranged for receiving the print job over a public
network 5101.
[0343] The system 5105 further comprises a central server 5103,
which central server has a database 5104 for storing geographical
location information of the plurality of apparatuses 5102. The
geographical location information may be manually inputted in the
database 5104 once an apparatus has been sold, or the geographical
location information may be automatically updated in the database
by the central server 5103, for example every time the central
server 5103 receives updated geographical location information from
any of the plurality of apparatuses 5102.
[0344] The central server 5103 is responsible for distributing
print jobs over the plurality of apparatuses 5102. Hereto, the
central server 5103 selects one of the apparatuses 5102 to be used
for producing the corresponding object. The selection process is at
least based on the geographical location information of the
plurality of apparatuses 5102.
[0345] FIG. 25 shows an overview of an apparatus 6001 for producing
an object 6002 by means of additive manufacturing. The apparatus
6001 is built from several frame parts 6011, 6012, 6013. The
apparatus comprises a process chamber 6003 for receiving a bath of
material 6004 which can be solidified. In a lower frame part 6011,
a shaft 6050 is formed, wherein a support 6005 is provided for
positioning the object 6002 in relation to the surface level L6 of
the bath of material 6004. The support 6005 is movably provided in
the shaft 6050, such that after solidifying a layer, the support
6005 may be lowered, and a further layer of material may be
solidified on top of the part of the object 6002 already formed. In
a top part 6013 of the apparatus 6001, a solidifying device 6007 is
provided for solidifying a selective part of the material. In the
embodiment shown, the solidifying device 6007 is a laser device,
which is arranged for producing electromagnetic radiation in the
form of laser light, in order to melt a powdered material provided
on the support, which then, after cooling forms a solidified part
of the object 6002 to be produced. However, the invention is not
limited to the type of solidifying device 6007. As can be seen, the
electromagnetic radiation 6071 emitted by the laser device 6007 is
deflected by means of a deflector unit 6074, which uses a rotatable
optical element 6075 to direct the emitted radiation 6071 towards
the surface L6 of the layer of material 6004. Depending on the
position of the deflector unit 6074, radiation may be emitted, as
an example, according to rays 6072, 6073.
[0346] The apparatus 6001 shown further comprises an extraction
device 6009 fluidly connected to the process chamber 6003 and
arranged for extracting material 6004 out of the process chamber.
Blowing means 6010 are provided on the opposite side of the process
chamber 6003 for inducing a gaseous flow in the process chamber
6003 effecting the material to be extracted. Furthermore, a further
blowing means 6093 is provided above, and directed to, the level L6
of material 6004. Thus, as follows from FIG. 25, the blowing means
6010, 6093 comprise a first blow nozzle 6010 provided on the
left-hand side, as seen in FIG. 26, of the process chamber 6003 and
directed to the extraction means 6009. The blowing means 6010, 6093
further comprise a second blow nozzle 6093 provided on the top
right-hand side, as seen in FIG. 26, of the process chamber 6003
and directed to the center of the level L6 of the material 6004. It
can thus readily be seen that the first blow nozzle 6010 and the
second blow nozzle 6093 are directed in opposite directions. In
effect, a plurality of blow nozzles 6010, 6093 are provided that
are fluidly connected to the process chamber 6003 and directed in a
plurality of different directions. With this, the blowing means are
able to affect a larger part of the surface level L6 of the
material 6004, such that in principle more material is taken up by
the gaseous stream and may be extracted by means of the extraction
device 6009.
[0347] In particular, the first blow nozzle 6010 is arranged to
provide a relatively large volume flow at a relatively low
pressure, and the second blow nozzle 6093 is arranged for providing
a relatively small volume flow at a relatively high pressure. The
first blow nozzle 6010 is arranged for providing a volume flow that
substantially corresponds to the volume extracted by the extraction
means 6009. The second blow nozzle 6093 is arranged for providing
bursts of flow, provided at a relatively high pressure, for
inducing local disturbances in the flowing pattern, for instance
turbulences, to affect a larger amount of material on the surface
level L6 of the process chamber 6003.
[0348] In the embodiment shown in FIG. 25, the first 6010 and
second 6093 blowing nozzles are connected, via lines 6082 and 6084,
to a control unit 6094, which may be used to start and/or stop the
blowing nozzles 6010, 6093. The extraction device 6009, for
instance in the form of a suction device 6009, is also connected to
this control unit 6094, such that operation thereof may be
synchronized. It is, however, conceivable that the extraction
device 6009 is provided with a separate control unit. FIG. 26
further shows that the extraction device 6009 is connected to a
holder 6090 for holding the material 6004 extracted from the
process chamber, for instance for later re-use.
[0349] The nozzles 6010 in FIG. 25 are embodied as a stationary
nozzle, and the nozzle 6093 may be embodied as a movable nozzle.
Driving means may be provided (not shown), which are known per se,
and that may be used to aim the nozzle to different parts of the
processing chamber 6003, in particular during blowing of the
nozzles. This way, the jet released by the nozzle may be aimed,
randomly or deliberately, towards different parts of the surface
level L6 of the bath of material 6004. For instance, the nozzle may
be tilted up and down, or moved from left to right, during
deliberate aiming. In an embodiment, the free end of the movable
nozzle is freely movable, for instance in the form of a freely
movable flexible hose or tube, such that the least one movable
nozzle is arranged to be moved by the flow discharged by said
movable nozzle. This induces a randomized flow in the process
chamber 6003 during blowing of the nozzle, which leads to an
improved chance of picking up and extracting more material. Further
nozzles may be provided, which may be movable nozzles as described
above.
[0350] FIG. 26 shows an embodiment of the apparatus according to
the invention, having two additional nozzles 6092, 6093, which may
be movable nozzles 6092, 6093, and in which in particular details
of the apparatus downstream of the extraction device 6009 are
shown. The extraction device 6009 comprises an extraction tube 6121
comprising a pumping unit (shown as one unit 6121), wherein an
inlet opening of the extraction tube 6121 is positioned within the
process chamber 6003. Furthermore, the extraction device 6009 is
fluidly connected, via line 6087, to a filter unit 6101, in
particular a cyclone filter unit 6101, which may be used to filter
the extracted gaseous flow containing the material extracted from
the process chamber. For instance, this allows powdered material
contained in the flow to be filtered and collected for further
usage. The cyclone filter unit 6101 is connected, via line 6111, to
a first holder 6103 or collector, for collecting powdered material
filtered by the filter unit 6101. The gaseous flow may, after
having passed the filter unit 6101, be exhausted by the apparatus
by means of exhaust tube 6114 and exhaust outlet 6104. In this way,
the gaseous flow may be vented through the exhaust tube 6114 and
outlet 6104. In a preferred embodiment, the exhaust tube 6114 is
connected to the blowing means 6010, such that the filtered gas
flow may once again be introduced into the process chamber.
[0351] The first holder 6103 is connected, via line 6112, to a
second holder 6102, provided above the first holder 103. Material
collected in the first holder 6103 may be transferred via line 6112
to the second holder 6102, for later use. An overflow line 6113 is
provided between the second holder 6102 and the filter unit 6101,
which may be used to filter the extracted material a plurality of
times, by re-feeding said material back to the filter unit a number
of times, for instance.
[0352] Thus, the extraction device 6009 may be connected to one or
more holders 6103, 6102 for holding material extracted from the
process chamber. This material may be re-used, for instance for
laying down a further layer of material to be solidified.
[0353] FIG. 27 shows a further embodiment of the apparatus
according to the invention, which mainly differs from the
embodiment shown in FIG. 25 in that the blowing means 6010 comprise
a blowing unit 6095 having a plurality of blowing nozzles 6099 is.
The nozzles 6099 of this blowing unit 6095 are directed towards the
extraction device 6009, in order to blow material 6004 from the
process chamber 6003 towards the extraction device. The nozzles
6099 are, in the embodiment shown, mainly directed in a horizontal
direction. The nozzles 6099 are, in an embodiment, arranged for
being stationary, such that a generally horizontal flow towards the
extraction device 6009 is obtained. To improve the extraction of
material 6004, the nozzle 6093 is provided and directed in a
different direction relative to the nozzles 6099 of the further
blowing unit 6095. This ensures that material positioned partly
behind the object 6002, when viewed in the blowing direction of the
nozzles 6099 of the further blowing unit 6095, as indicated by
region R in FIG. 27, may be affected by the nozzle 6093, such that
removal of material in this region R is also possible. To enhance
the extraction of material 6004, one or more of the nozzles 6099,
6092, 6097 shown in FIG. 27, and in particular one of the nozzles
6092 and 6093, may be embodied as movable nozzles.
[0354] Furthermore, FIG. 27 schematically shows that the apparatus
comprises a movable cover-element 6120, which is arranged to be
movable within the process chamber 6003 for covering a top part of
the process chamber during use of the blowing means 6010 and
extraction means 6009. The movable cover-element 6120 may then be
used to divide the volume of the process chamber into two parts,
such that the volume of the part comprising the bath of material is
reduced. This increases the ease with which the powdered material
can be removed from the process chamber, and ensures furthermore
that the other part is protected by the cover-element, in such a
way that damage to the apparatus in this other part due to moving
powdered particles is prevented. The cover-element 6120 may be
embodied as a pivotable element, or a translatable element.
[0355] The first to seventh point of view may be incorporated
independently from each other, which different points of view have
been described above. In particular, the protection sought is
defined in the attached claims.
* * * * *