U.S. patent number RE31,288 [Application Number 06/109,261] was granted by the patent office on 1983-06-28 for machine tool.
This patent grant is currently assigned to Kabushiki Kaisha Komatsu Seisakusho. Invention is credited to Hiroshi Matsuzaki, Yoshihiro Tsukiji.
United States Patent |
RE31,288 |
Matsuzaki , et al. |
June 28, 1983 |
Machine tool
Abstract
A machine tool comprises a table mounted on a bed and adapted to
be moved in the direction of longitudinal axis of the bed, said
table being arranged to be driven or rotated, intermittently
indexed and controlled of the turning position thereof; vertical
columns installed in a plane extending at right angles to the bed
and having vertically sliding rails or vertical slides; a cross
rail mounted on said vertical slides so as to be slidably moved in
the vertical direction; a saddle mounted on said cross rail so as
to be slidably moved in the horizontal direction; said saddle being
arranged to slidably move the ram means in a direction at right
angles to said cross rail; said ram means having a lower end face
on which a turning tool can be fixedly mounted; said ram means
having in the front face or the side of the lower end thereof a
turret head adapted to be rotated and indexed in a plane extending
at right angles to said table face, said turret head having a main
spindle which is adapted to be rotated or driven and on which a
rotary machining tool can be mounted so as to effect facing or
milling, boring, drilling and tapping and reaming etc. of a work,
said turning tool fixedly mounted on the lower end face of said ram
means being adapted to effect turning or cutting of the work by
rotating the table having the work on it.
Inventors: |
Matsuzaki; Hiroshi (Kanazawa,
JP), Tsukiji; Yoshihiro (Komatsu, JP) |
Assignee: |
Kabushiki Kaisha Komatsu
Seisakusho (Tokyo, JP)
|
Family
ID: |
27309774 |
Appl.
No.: |
06/109,261 |
Filed: |
January 3, 1980 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
829193 |
Aug 30, 1977 |
04118844 |
Oct 10, 1978 |
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Foreign Application Priority Data
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Aug 30, 1976 [JP] |
|
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51-102691 |
Aug 30, 1976 [JP] |
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51-102692 |
Aug 30, 1976 [JP] |
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51-102693 |
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Current U.S.
Class: |
29/27C; 409/213;
483/44; 29/26A; 409/211; 409/233 |
Current CPC
Class: |
B23C
1/14 (20130101); B23Q 1/48 (20130101); B23Q
3/15506 (20130101); B23B 31/263 (20130101); B23Q
16/10 (20130101); B23C 1/002 (20130101); B23Q
3/15526 (20130101); Y10T 483/1767 (20150115); Y10T
409/308344 (20150115); Y10T 409/308232 (20150115); Y10T
409/309464 (20150115); Y10T 29/5107 (20150115); Y10T
29/5114 (20150115) |
Current International
Class: |
B23Q
1/25 (20060101); B23Q 16/00 (20060101); B23Q
1/48 (20060101); B23Q 16/10 (20060101); B23Q
3/155 (20060101); B23B 31/02 (20060101); B23B
31/26 (20060101); B23C 1/00 (20060101); B23C
1/14 (20060101); B23Q 003/155 (); B23C
001/12 () |
Field of
Search: |
;409/211,212,213,230,233,235,183 ;29/27C,26A,39,568 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Briggs; William R.
Attorney, Agent or Firm: Armstrong, Nikaido, Marmelstein
& Kubovcik
Claims
What we claim is:
1. A complex machine tool.Iadd., .Iaddend.comprising.Iadd.:
.Iaddend.
a bed;
a table mounted on the bed so as to be slidably moved in .[.the.].
.Iadd.a .Iaddend.direction of .Iadd.the .Iaddend.longitudinal axis
thereof;
rotating means mounted on said bed to rotate said table;
transfer means mounted on said bed so as to transfer said table in
the direction of .Iadd.the .Iaddend.longitudinal axis of the
bed;
rotary indexing means .[.adapted to index.]. .Iadd.for indexing
.Iaddend.said table;
a pair of columns installed vertically on either side of said
bed;
a cross rail transversely supported on said columns;
ram means attached to said cross rail .[.and adapted to be moved at
right angles to the face of said table.]. .Iadd.for a vertical
movement.Iaddend.;
.Iadd.means for moving said ram means in a direction at right
angles to the face of said table; .Iaddend.
a tool post mounted .[.on.]. to .[.the.]. .Iadd.a .Iaddend.lower
end face of said ram means .[.and having.]. .Iadd.for receiving
.Iaddend.a turning tool .[.fixedly secured thereto.].;
.Iadd.first tool clamper means provided within said ram means for
clamping and unclamping the turning tool in said tool post;
.Iaddend.
a turret head mounted on one face of said ram means, said turret
head having a .[.rotating.]. main spindle .Iadd.rotatably supported
therein .Iaddend.for mounting a rotary machining tool;
.Iadd.means provided within said ram means for indexing said turret
head means; .Iaddend.
.Iadd.second tool clamper means provided within said ram means for
clamping and unclamping the rotary machining tool in said turret
head; .Iaddend.and
.[.a turret head rotating means adapted to rotate said turret
head.]. .Iadd.means for driving said main spindle for rotary
machining operations.Iaddend.. .[.
2. A complex machine tool as defined in claim 1, further comprising
a turret head turning and indexing means provided within the ram
means..]. .[.3. A complex machine tool as defined in claim 1,
further comprising means provided within the ram means for clamping
and unclamping the tool mounted on the turret head and the tool
mounted on the tool post,
respectively..]. 4. A complex machine tool as defined in claim 1,
wherein said .[.turret head rotating.]. .Iadd.main spindle driving
.Iaddend.means comprises a first motor mounted on the upper part of
said ram means, a gear train connected to said motor, a drive unit
connected to said gear train and .[.adapted to be moved.].
.Iadd.moveable .Iaddend.up and down along a slide face mounted on
the front face of said ram means serving as a guide, and a clutch
connected to the lower part of said drive unit to
transmit the output of said motor to the turret head. 5. A complex
machine tool as defined in claim 4, further comprising a second
motor mounted on the upper part of said ram means and adapted to
adjust the phase of said turret head main spindle and that of said
clutch and move the latter to a position to permit the clutch to be
engaged, and means for preventing said gear train from being
actuated at the same time by said first motor and said second
motor, the arrangement being made to ensure engagement of the
clutch for transmitting the power to said turret head and mounting
of a
tool on the main spindle of said turret head. 6. A complex machine
tool as defined in claim 3, wherein said tool clamping and
unclamping means comprises a hydraulic cylinder mounted within said
ram means and having a piston rod, a crank shaft having an
eccentric shaft portion connected to said piston rod, first and
second rods operatively connected to the eccentric shaft portion of
said crank shaft, respectively, said first rod being .[.adapted to
unclamp.]. .Iadd.unclamping .Iaddend.the tool when projecting
towards the upper end of the main spindle of said turret head so as
to urge against the upper end and clamp the tool when the rod is
returned so as to disengage it from the main spindle of the turret
head, said second rod extending on the upper part of the tool post
for turning tool, and a first sleeve connected to said second rod,
the arrangement being made such that when said second rod is moved
downwards the tool mounted on said tool post is unclamped, whilst
the second rod is moved
upwards the tool is clamped. 7. A complex machine tool as defined
in claim 6, further comprising a second sleeve kept in contact with
the outer periphery of said first sleeve, wherein a plurality of
balls accommodated within said first sleeve are arranged to drop
from said first sleeve and engage with the inner peripheral surface
of said second sleeve thereby
clamping a tool. 8. A complex machine tool as defined in claim 2,
wherein said turret head .[.turning and.]. indexing means comprises
clutch means provided between the front face of said ram means and
the face of said turret head on the side of the ram, an indexing
shaft fixedly secured to said turret head and adapted to be
inserted rotatably and slidably in the horizontal direction into
said ram means, an indexing lever attached to said indexing shaft,
a rod mounted within said ram means so as to be moved vertically in
a plane extending at right angles to said indexing shaft, an
engaging member mounted in an end face of said rod and adapted to
engage with said indexing lever, and a hydraulic cylinder connected
to said rod so as to move it vertically, the arrangement being made
such that said turret head can be unclamped, indexed and clamped
during one stroke of
vertical movement of said rod. 9. A complex machine tool as defined
in claim 8, further comprising a bearing for the indexing shaft
mounted thereon, said bearing having a projecting part, said rod
having a cam
groove with which said projecting part is engaged. 10. A complex
machine tool as defined in claim 9, further comprising another rod
connected to said hydraulic cylinder, said another rod having a cam
groove, the cam grooves of said rod and said another rod being
formed oppositely, said projecting part formed in the bearing for
said indexing shaft and another projecting part being arranged to
engage with each other.
Description
BACKGROUND OF THE INVENTION:
This invention relates to a machine tool, and more particularly to
a complex machine tool having composite machining functions and
arranged so as to enable a plurality of machining processes to be
made on a workpiece once loaded or mounted thereon.
Heretofore, most of the combination of machining processes includes
milling, boring and drilling etc. i.e. cutting work by rotation of
tool, and there is few combining a turning process. Furthermore,
the two machining systems have substantially lost their inherent
applicabilities to general purposes for use because of troublesome
tool replacing and positioning operations, and have been
semi-exclusively used. Consequently, the rate of operation of them
could not be improved on the production line for manufacturing a
small amount of products of various kinds.
In view of the above-mentioned circumstances, numerical controls
(NC) of machine tools have been rapidly developed since 1960, and
automatic tool changers (ATC) have been used jointly with them, and
therefore complex machine tools having high applicabilities to
general uses have appeared in the market. In particular, the
"Machining Center" has been employed widely as a representative one
at the recent time.
However, these machining systems comprise milling machines or
boring machines as base machines and have their principal functions
to effect cutting of workpieces by rotating their tools, and
therefore turning work has been required to be made by means of a
separate or independent machine.
For this reason, if the turning work is made by means of the
machines, it is required to effect profile cutting by means of a
small-diameter end mill, as a result a number of problems are
encountered such as a remarkable increase in the number of cutting
processes, decreased economy of operation and also incapability of
obtaining a predetermined initial surface roughness of a workpiece
to be machined etc. On the other hand, the turning machine has been
advanced in a single-function automation, however delayed in having
complex function. The prior art for it includes U.S. Pat. Nos.
3,523,469, 3,703,027, 3,212,364 and 3,851,364; however, any of
these is arranged to rotate the table at a fixed position, stated
more specifically, they are only conventional turning machines each
having a table rotating and indexing arrangement mounted thereon or
having a ram means provided with a rotary tool mounting head.
Therefore, in turning work, the workpiece can be turned or cut only
by the face of the tool in parallel with the cross rail passing
through the centre of the table so that the tools to be mounted on
the tool arbor can be located only in the above-mentioned plane.
Thus, the number of the tools to be mounted thereon is limited
thereby increasing the number of times of replacement of tools.
Further regarding the milling, boring and drilling work etc. to be
combined, because of the table of stationary type, when machining
the face of a workpiece in parallel with the table or the upper
surface of the workpiece placed on the table, the parts of the
workpiece other than that placed on the circumference thereof
require a programme to be made for determining a machining position
by calculating coordinates based on the relationship between the
table indexing angle and the position of the saddle, and the
operation becomes complicated or troublesome. Furthermore,
regarding machining of the face of the workpiece at right angles to
the table face or the side of the workpiece mounted on the table,
only centripetal machining of it can be effected, and therefore
faces of the workpiece in parallel with the central axial plane
thereof cannot be machined.
SUMMARY AND OBJECTS OF THE INVENTION
In view of the foregoing circumstances, the present invention
provides a complex machine tool having a turning machine as a base
machine therefor, and have the following objects.
(1) To enable complex machining of the workpiece including a
turning process to be effected.
(2) To enable complex machining of the workpiece excluding turning
process to be effected.
(3) To enable milling, boring and drilling etc. of the upper
surface and for sides of the workpiece once loaded on the machine
tool and also turning of the inner and outer surfaces thereof to be
effected.
(4) To enable milling, boring and drilling etc. of the faces of the
workpiece at right angles to the table face.
(5) To enable cutting of three-dimensional curved faces of the
workpiece to be effected.
(6) To enable profile cutting of the workpiece to be effected.
(7) To enable formation of rectilineal or curved grooves on the
inner and outer faces of the workpiece including slotting to be
effected.
(8) To enable turning, milling boring, drilling, reaming, tapping
and other special machining to be combined.
(9) To improve the operational efficiency of the machine tool on
the production line for manufacturing a small amount and various
kinds of products and also improve the efficiency of investment in
facilities.
(10) To minimize the manpower required.
(11) To enable heavy cutting of the workpiece as compared with
conventional machines of the kind specified.
(12) To enable tools to be mounted rigidly or fixedly on both
turning tool post and the end of main spindle of the turret
head.
(13) To enable the use of tools mounted in a plane extending
radially relative to the centre of the table by positioning the ram
means and the table relative to each other, and enable various
kinds of cutting to be effected by means of a tool once
replaced.
(14) To enable multi-shaft unit to be mounted by means of the
turning tool post and the end of the main spindle of the turret
head, thereby enabling multi-shaft simultaneous machining work to
be effected, and
(15) To enable measuring instrument and tip removing means to be
mounted on the end of the main spindle of the turret head, and
enable them to be programmed in the composite processes.
The complex machine tool according to the present invention is
capable of satisfying required functions of conventional turning
machines in the turning process, and also can deal with or machine
even a workpiece having curved or elliptical faces to be
machined.
In conventional machine tools of the kind specified, tools can be
located only in a lane in parallel with the cross rail and passing
through the centre of the table; however, according to the present
invention, tools can be placed in a plurality of planes extending
radially and passing through the centre of the table and therefore
various kinds of machining can be effected by means of the tool
once mounted. In a complex process including milling, boring and
drilling etc., the present invention enables calculation of
coordinates on the plane in parallel with the table face to be made
easily and compilation of programme to be simplified, and also
enables drilling and milling of faces of the workpiece extending at
right angles to the table face and in parallel with a plane passing
through the centre of the workpiece to be effected easily.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 is an overall perspective view of a machine tool according
to the present invention;
FIG. 2 is a skeleton drawing showing a driving system for the
machine tool according to the present invention;
FIG. 3 is a longitudinal sectional view of a turret head;
FIG. 4 is a sectional view taken along the line IV--IV in FIG. 3,
the upper half thereof showing a condition wherein the clutch is
made operative, whilst the lower half showing a condition wherein
the clutch is inoperative;
FIG. 5 is a partly broken view taken in the direction shown by "V"
in FIG. 4 showing a condition when the cap at the right hand end is
removed;
FIG. 6 is a skeleton drawing for explaining the operation of a
turret head drive means and a tool clamping and unclamping
means;
FIG. 7 is a longitudinal sectional view showing the details of the
tool clamping and unclamping means and;
FIG. 8 is a partly broken rear view of the tool clamping and
unclamping means.
DESCRIPTION OF THE PREFERRED EMBODIMENT:
The construction of the present invention will now be described in
detail below with reference to the accompanying drawings. FIG. 1
illustrates an overall arrangement of one preferred embodiment of a
complex machine tool. Reference numeral 2 denotes a column spanning
a bed 1 and having vertical slides 3 and 3' mounted in the front
thereof and which is adapted to guide the vertical sliding motion
of a cross rail 5 coupled with slide units 4 and 4'. Reference
numeral 6 indicates a saddle slidably mounted on the cross rail 5
and having in the front face thereof a guide means which enables a
ram means "A" to be slidably moved in the direction at right angles
to the cross rail 5, the ram means "A" having a slide way 9 engaged
therewith.
The vertical sliding motion of the ram means "A" can be achieved by
a conventional mechanism comprising a motor-driven screw feeding
arrangement or a hydraulic cylinder and the example shown employs a
screw feeding arrangment comprising a servo motor 11.
The ram means "A" has in the lower end face thereof a tool post on
which is mounted a cutting tool 8, and also has a turret head "B"
capable of being freely rotated and indexed in the front or side of
the lower end thereof, the turret head "B" having a main spindle on
which a turning or cutting tool 10 can be mounted.
The ram means "A" accomodates inside the lower end thereof a
clamping and unclamping arrangement "E" for the cutting tool 8
(refer to FIGS. 6, 7 and 8) and a turning and indexing as well as
clamping and unclamping arrangement "C" for the turret head "B"
(refer to FIGS. 3, 4 and 5), and further accommodates within the
front or side thereof a pusher means "F" (constituting part of the
tool clamping and unclamping arrangement ) adapted to unclamp the
cutting tool when the cutting tool 10 is downwardly indexed by the
turret head "B".
Reference numeral 12 denotes a variable-speed motor adapted to
rotate or drive the main spindle of the turret head "B" and which
is an electric or hydraulic motor arranged to spline-connect an
output shaft through a gear box 13 within drive unit 14 which has
an output shaft to drive a clutch disposed within a clutch box
15.
At that time the drive unit 14 and the clutch box 15 are vertically
moved as an integral unit by a feed mechanism on a guide rail 66
mounted on the ram means "A." When the drive unit 14 and the clutch
box 15 have been lowered, a clutch 16 for the turret head "B" and a
clutch 73 disposed within the clutch box 15 are engaged and then
driven by rotation.
The clutches 16 and 73 are adapted to be engaged and disengaged
only when the clutch groove is disposed vertically, and the
engagement and disengagement of them can be achieved by effecting
phase control by using the motor 17. Reference numeral 18 denotes a
motor used for moving the cross rail 5 upwards and downwards
through a gear box 19.
Reference numeral 20 denotes a servo motor serving to turn ball
screw 21 to move the saddle 6 along the cross rail 5.
Reference numeral 23 represents a tool changer which comprises a
rotary cylinder 22 and a change arm 24 and which cooperates with a
tool assister 25 to exchange a tool 27 of tool magazine 26 with new
one in the same manner as in the case of the tools 8 and 10.
Further, comparatively heavy tools like turning tools may be
directly picked up by moving the ram means to a tool selected by
the tool magazine without using the above-mentioned tool chamber.
Mounted on the bed 1 are rails 30 and 31 on which a base 29 is
slidably mounted. A table 28 is rotatably mounted on the base
29.
Attached to the bed 1 are a table turning arrangement "G" and a
table moving arrangement "J." The base 29 is provided with a rotary
indexing arrangement "H."
Reference numeral 32 denotes a servo motor for turning and indexing
the table 28, 33 a motor for moving the table 34 a motor for
turning and driving the table, and 35 a transmission mechanism.
Reference numeral 36 indicates a control means adapted to send out
and receive control signals such as electrical and hydraulic
pressure signals to and from the machine tool through a cable duct
37.
In the complex machine tool thus constructed, the movement of the
tool in the direction of the longitudinal axis of the bed will be
referred to as movement in the direction of Y axis, the servo motor
33 as motor for movement in the direction of Y axis, the horizontal
movement of the cross rail 5 as movement in the direction of X
axis, the servo motor 20 as motor for movement in the direction of
X axis, the vertical movement of the ram means as movement in the
direction of Z axis, and the servo motor 11 as motor for movement
in the direction of Z axis.
FIG. 2 is a skelton diagram of a driving system for easier
understanding of the machine tool according to the present
invention.
A shaft 38 is rotatably supported through a bearing 39 so as to
freely turn the table 28 on the base 29 mounted on the bed 1, and a
ring gear 40 is fitted in the lower part of the table 28.
When the table driving motor 34 is actuated, its output is
transmitted through a transmission means 43 to a driven pulley 42
thereby driving or rotating shaft 44. Within a transmission
mechanism 35 there is provided a speed change gear which can be
selectively changed to change gear train so as to change the number
of rotations of a shaft 45. The transmission of the output to a
table driving shaft 47 is made on or off by rendering a
transmission clutch 46 operative or inoperative. The power
transmitted to the shaft 47 is transmitted through a gear train 48
and bevel gears 49 and 49' to a pinion 50.
The pinion 50 is engaged with the ring gear 40 fitted in the lower
part of the table as an integral part thereof so that the table can
be rotated about the shaft 38 at a selected speed. It is a well
known technique that a D.C. variable speed motor is employed as the
motor 34 and a power transmission gear having a simplified
construction is employed.
The servo motor 32 is mounted on the base 29, and its power is
transmitted through a gear train 51 or directly through reduction
gear comprising worm gears 52 and 52' and through a clutch 53 to a
pinion 54. The pinion 54 is engaged with the ring gear 40 fitted in
the lower part of the table 28 as an integral unit thereof so that
the table 28 can be rotated about the shaft 38. The clutch 53 is
interlocked with a brake 162 so that when any one of the two is
rendered operative the other is rendered inoperative. The same
relationship is held between the brake 162 and the clutch 46.
Therefore, when either one of the clutches 53 and 46 is actuated,
the brake 162 is released. Further, the clutches 53 and 46 are
interlocked to each other so that when any of the two is rendered
operative the other is rendered inoperative. The motor 33 for
movement in Y axis is adapted to rotate the ball screw 56 through a
gear train 55 so that because of a nut 57 threadably engaged with
the ball screw being fixedly secured to the base 29 the table 28
can be moved and positioned on the bed 1 in the direction of Y
axis. At that time, because table driving shaft 47 has a spline
formed over the entire length thereof, gear 48 can be engaged with
the splined driving shaft 47, and therefore there is no
interference with the movement of the base 29. Installed on the
column 2 is a motor 18 the output shaft of which is fitted with a
worm 60 to drive a worm wheel 61. The worm 60 and the worm wheel 61
are accommodated within the gear box 19. An output shaft 62
connected to the worm wheel 61 is threadably engaged with a nut 63
fixedly and integrally secured to the cross rail 5 so as to move
the cross rail up and down along the vertical slide 3.
The saddle 6 is adapted to be moved horizontally on the cross rail
5, and can be moved and positioned by the motor 20 for movement in
the direction of X axis as previously explained with reference to
FIG. 1.
The motor 11 for movement in the direction of Z axis has an output
shaft 64 in the form of ball screw which is threadably engaged with
a nut 65 fixedly and integrally secured to the saddle 6 so that the
ram means "A" can be moved and positioned relative to the saddle in
the direction of Z axis.
The ram means "A" has in the lower end face a turning tool post 158
on which a turning tool can be mounted, and also has in the front
thereof turret head "B" interlocked with an indexing arrangement
"C" adapted to be turned and indexed about a shaft 67 and clamped
and unclamped.
The turret head "B" has a main spindle 69 having a tapered portion
formed in the leading end thereof on which a cutting tool can be
mounted. The main spindle 69 is engaged with bevel gers 70 and 71,
and the bevel gear 71 is connected to the clutch 16. Disposed in
the front face of the ram means "A"]is a turret head main spindle
driving arrangement "D." The variable-speed motor 12 is mounted on
a gear box 78 installed on the upper part of the ram means "A," and
has an output shaft adapted to transmit the power through a clutch
79 and bevel gears 81 to a first output shaft 77. Since the first
output shaft 77 is spline-connected to a second output shaft 76 by
a spline coupling 82 of a drive unit 14, even when the drive unit
14 is moved downwards due to extension of the rod of a feed
cylinder 83 along the slide way secured to the front face of the
ram means "A" as a guide, there is no interruption of power
transmission.
Installed under the drive unit 14 is a clutch box 15 adapted to
rotate a clutch shaft 72 installed in the direction at right angles
to the second output shaft 76 and a clutch 73 mounted on the
leading end thereof through bevel gear trains 74 and 75.
The turret head main spindle driving arrangement "D" will receive a
descending command signal sent by the control device and descend to
the bottom dead centre set by the cylinder 83 where the clutches 16
and 73 are engaged with each other so that a command signal of
completion of preparation for driving the motor 12 is sent to the
control device. As a result, the motor 12 is rotated at a
programmed speed so as to drive or rotate the main spindle 69 of
the turret head "B." Further, the motor 17 is connected through a
clutch 80 to a bevel gear group 81, and serves to adjust the phase
of engagement of the clutches 16 and 73 in the regular order. When
the motor 12 is driven, the clutch 79 is rendered operative, and
the clutch 80 is rendered inoperative. Whilst, when the motor 17 is
driven, the reverse operation is made, and therefore the gear train
81 cannot be driven simultaneously.
Further, the above-mentioned phase adjustment serves to regulate
the phase of the turret head main spindle 69 to ensure the
relationship with the A.T.C. (automatic tool changer).
Moreover, there is provided a balance cylinder 84 mounted between
the ram means "A" and the saddle 6 for balancing the operation of
the ram means.
Though the outline of construction of the present invention is
described hereinabove, the construction of every main component
part will now be described in detail below.
Turret Head "B"
FIG. 3 is a longitudinal sectional view of the turret head "B"
mounted on the front face of the lower end of ram means "A." The
turret head comprises a casing 85 in which the main spindle 69 is
rotatably supported by bearings 86 and 87. The main spindle 69 has
a tapered portion formed in one end thereof which can be registered
with a tapered portion formed in an arbor of a turning cutting
tool. The main spindle 69 is provided in the other end thereof with
a tool mounting and dismounting draw bar means. When a rod 88 of a
pushing means "F" accommodated in the ram means "A" is pushed down,
the rod 88 abuts against the upper end of the draw bar 89, and is
moved down against the biasing force of a spring 9 when it is given
a further stroke. Thus, a sleeve 91 fitted to the leading end of
the draw bar 89 is slidably moved down so that balls 92 can be
seated in an inner bore groove 93 formed in the main spindle 69,
and so the inner surface of the sleeve 91 becomes smooth or free
from hindrance. Under such condition the stepped portion formed in
the upper part of the arbor of the tool can be accommodated in the
sleeve, and when pushing force is released, the draw bar 89 is
pushed upwardly by the resiliency of the spring 90 thereby enabling
the arbor of the tool to be held securely and registered with the
tapered portion.
When the pushing means "F" is actuated again, the balls 92 will be
put under the same condition as the tool's arbor is inserted so
that the tool can be easily mounted and dismounted. Further, keyed
to the outer face of the main spindle 69 is a bevel gear 70 which
is engaged with a bevel gear 71 fitted in front of the casing 85.
The clutch 16 is inserted in the inner bore of a gear 71 so as to
hold the main spindle 69 and the pawl 16a in a parallel
relationship thereby connecting the clutch 16 and the gear 71 as an
integral unit.
The main spindle 69 has a groove 95 formed in a part of the outer
face thereof.
A cam 98 having one end engaged with the leading end of a pin 96
inserted in the clutch 16 is held by a pin 99 so that it can be
freely turned when pushed by the leading end of the clutch, and the
outer end of the cam abuts against the leading end of a push pin
100. The pin 96 is always biased outwardly by a spring 102, and its
stroke end is limited by a snap ring 97.
Further, the push pin 100 is always biased inwardly by a spring 101
so that the lower end of the cam tends to be moved towards the main
spindle.
However, when the main spindle is driven, the clutch 16 will push
head 96a of the pin 96 against the biasing force of the spring 102
when it is engaged with the clutch 73 of the turret head driving
arrangement "D" so that the cam 98 is disengaged from the groove 95
thereby enabling the main spindle to be rotated freely by the
clutches 16 and 73.
Next, when it is desired to stop the main spindle, the motor 12 is
stopped and the clutch 79 is rendered inoperative and the clutch 80
is rendered operative so as to rotate the motor 17 at a slow speed,
and then the slow rotation is transmitted to the main spindle 69.
At that time, the output to be transmitted from the motor 17
through the first output shaft 77, the second output shaft 76 and
the gear trains 74 and 75 to the clutch 73 has the number of
revolutions having a predetermined ratio to that of the motor 17 so
that the turret head main spindle, the power of which is
transmitted through the clutch 16, and the gear trains 70 and 71
will have the same ratio of revolutions.
In order to set the main spindle 69 at a predetermined position, a
cam means and a limit switch (not shown) are provided within a
phase reference signal generating means 161 mounted on one end of a
shaft 163 connected through a clutch to the motor 17 so that when
the phase cam turned the limit switch on braking force is applied
to the motor 17 and at the same time the clutch 80 is rendered
inoperative. Further, this limit switch serves to turn the power
supply on simultaneously with the generation of start signal for
the motor 17. After the stop of the motor 17, the limit switch is
held for a short time and then released, and the arrangment is made
such that even if the motor 12 is energized no signal is
generated.
As for the phase reference signal generating means, non-contact
system comprising a combination of reed switches and magnets should
preferably be employed, because mechanical switching contacts such
as limit switches will make switching by the rotation of the motor
12 and damage contacts by fatigue.
After the phase of the main spindle 69 and the clutch are adjusted
in such a manner, the clutches 16 and 73 are disengaged. Since when
the clutches 16 and 73 are disengaged, the pin 96 is pushed
outwardly by the force of the spring 102, the cam 98 is urged
against the outer face of the main spindle 69 by the push pin 100
and the spring 101. When the cam 95 is seated in the groove 95, the
main spindle 69 and the clutch 16 will stop at a predetermined
phase so that the mounting and dismounting of the tool by the
A.T.C. and the phase of engagement of clutches can be made
correctly. The casing 85 is slidably and rotatably guided by a
socket 103 formed in the front part of the ram means "A," and a
half coupling 104 fixedly secured to the ram means "A" is engaged
with a half coupling 105 fixedly secured to the casing 85 by an
engaging member 106. Further, because the casing 85 is fixedly
secured to a flange 108 fixedly secured to the shaft 67, the casing
can be rotated within a bearing 109 mounted in the ram means
"A."
Reference numeral 110 denotes a cooling liquid passage, and finned
cap 111 serves to transmit the heat generated when the main spindle
69 within the casing 85 is driven or rotated to the cooling liquid
thereby controlling the temperature rise in the turret head
"B."
Turret Head Indexing Arrangement "C"
The bearing 109 has a plurality of cavities 116 formed in the
periphery thereof for accommodating springs 114 and pins 113, the
end faces of the pins abutting against the inner face of the ram
means "A" thereby preventing possible chattering of the turret head
"B" during the indexing operation. Indexing turning lever 112 is
engaged with a roller 115 attached to an indexing clamp rod 117.
Further, as shown in FIG. 4, indexing clamp rods 117 and 118 are
arranged to slidably move within guide holes 119 and 120,
respectively. In this case, because projections 121 and 122 formed
on either side of the bearing 109 are engaged with cam grooves 123
and 124, respectively, the bearing 109 will move in the direction
of the axis of the shaft 67 against the biasing force of the spring
114. Therefore, the engaging member 106 of the clutches 104 and 105
is disengaged so as to permit rotation of the turret head "B."
Further continuous movement of the rods 117 and 118 allows movement
of the roller 115 engaging with the indexing turning lever 112, and
the shaft 67 is indexed by an angle set within a predetermined
stroke of the rods so that the turret head "B" can be indexed in
the same manner. Further, because the cam grooves 123 and 124 of
the rods 117 and 118 are set so as to move the bearing 109
backwards at the upper and lower ends of the entire stroke and move
it forwards at the intermediate part thereof, the clutch members
104 and 105 will clamp the ram means "A" and the turret head "B" at
the upper and lower ends of the stroke and unclamp them at the
intermediate part thereof.
FIG. 5 shows the turret head "B" indexing clamp arrangement in
which the main spindle 69 of the turret head "B" is located
vertically, and the indexing lever 112 is directed downwards. When
it is desired to index the above-mentioned main spindle 69 by a
phase of 90.degree., the indexing clamp cylinder 171 is actuated to
move the piston rod 68 upwards so that the rod 117 fixedly secured
to the bracket 107 and the rod 118 suspended from a plate spring
group 126 with a degree of freedom of movement can be moved upwards
within the guide holes 119 and 120. Regarding clamping and
unclamping of the turret head "B," the roller 115 engaged with the
lever 112 will engage with Y-shaped groove 126 formed or engraved
in the lever and move upwardly along the groove to reach a point
127a. Within a region where unrestrained engagement of the roller
115 and the Y-shaped groove 127 is permissible or from the
condition shown in the drawing to the point 127a, the lever 112
will not turn and during this stroke the shaft 67 is moved forwards
thereby unclamping the turret head "B" by the clutches 104 and 105.
When the roller 115 has abutted against the point 127a, the shaft
67 is turned, and when the roller 115 has reached a point 127b the
lever 112 is directed horizontally. Thereafter the roller 115 will
return from the point 127b to the point 127a, then the lever 112
will abut against a stopper 129. The stroke of movement from the
point 127a through the point 127b to the point 127a is referred to
as an indexing stroke. After that the roller 115 will reach a
region 127c; however, because the region 127c extends vertically,
the lever 112 will not turn. Stated in brief, the stroke of
movement within the region 127c is the clamping stroke of the
clutches 104 and 105 after completion of the indexing.
Reference numeral 126 denotes a bracket provided with stopper means
128 and 129 having shock absorbing function. When the lever 112
abuts against either of the stopper means, it will have a correct
indexing angle and a projection 130 formed in the rear part of the
lever 112 will actuate any of limit switches LS1 and LS2 so as to
send out a command signal of completion of indexing to the control
device.
Turret Head Driving Unit "D"
Referring to FIG. 6, bracket 133 mounted on the upper face of the
ram means has a gear box 78 formed therein, and the variable-speed
motor 12 mounted on the gear box is arranged to rotate bevel gears
81 through a clutch 79 thereby driving the first output shaft 77.
The first output shaft 77 has its splined portion 77a formed in the
lower part thereof which is engaged with a coupling shaft 170
rotatably mounted within the drive unit 14 and having a splined
portion formed in the inner face thereof. Therefore, a second power
take-out shaft 76 having a splined part engaged with the lower part
of the coupling shaft 170 is rotated so as to rotate bevel gears 75
and 74 installed within the clutch box 15, drive a shaft 132 and
drive a clutch 73 attached to the shaft and clutch 16 fitted on the
side of the turret head thereby driving or rotating the main
spindle 69 of the turret head.
Control or extension and contraction of the rod 131 of the cylinder
83 secured between the above-mentioned bracket 133 and the drive
unit 14 enables the turret head driving unit to slidably move up
and down between the groove formed in the rear face of the drive
unit 14 and the guide way 9 provided in the front face of the ram
means "A."
Therefore, during turning or cutting work, because of the clutch
box 15 being located at a high position in front of the ram means,
there is no interference with a workpiece being machined, so that
the minimum diameter of workpiece to be machined can be reduced
considerably.
Tool Clamping and Unclamping Arrangement "EF"
As can be seen from FIG. 6, a hydraulic cylinder 135 is mounted
inside the ram means, and its rod 136 is held by bearings 137 and
137', the rod having at its end a rack 138 which engages, as shown
in FIG. 7, with a gear or teeth 140 formed or engraved in a crank
shaft 139 thereby rotating the shaft. The crank shaft 139 is
supported between the front wall of the ram means and an inner rub
141 and is concentric with the above-mentioned gear 140. The axis
of cranks 139a and 139b is offset from that of the shaft 139 by a
predetermined amount thereby allowing levers 142 and 143 to effect
crank motion when they are rotated. Connected with the lever 142
through a free fulcrum 145 is a push rod 88 adapted to reciprocate
through a guide hole 146 formed in the ram means. Such
reciprocatory movements of the push rod 88 will push down or return
the draw bar 89 fitted to the upper end of the turret head main
spindle 69 from the predetermined position thereof thereby clamping
or unclamping the leading end of the arbor for the turning cutting
tool. This is referred to as a pushing arrangement.
Further, the lever 143 is coupled with the bracket 149 by means of
the free fulcrum 148, and as shown in FIG. 8, the bracket 149
having on both sides draw bars 150 and 151 suspended from plate
springs 147 and 147, respectively. This is for the purpose of not
forcing movements of sleeves 152 and 153 which will be mentioned
later and allowing them to have a degree of freedom.
The draw bars 150 and 151 have sleeves 152 and 153 threadably
engaged with their leading ends, the sleeves being adapted to
slidably move within cylindrical members 154 and 155, respectively.
The above-mentioned cylindrical members 154 and 155 each has a
large diameter groove 156 formed inside thereof, and when the draw
bars are moved downwards by the crank motion, the sleeves 152 and
153 will move down together so that balls 157 accommodated within a
plurality of holes formed in the leading ends of the sleeves can be
seated in the groove 156 and there is no hindrance in the bores of
sleeves 152 and 153 thereby not preventing the insertion of
pullstuds.
At that time, for mounting the turning or cutting tool 8 on the
lower end face of the ram means, when a plurality of pull-studs are
inserted into the sleeves and the cylinder 135 is actuated so as to
move the draw bars 150 and 151 upwards, the balls 157 will enter
constricted portions of the pullstuds and move upwards to the
position shown in FIG. 7 so as to clamp the tool 8. For this
reason, the turning or cutting tool 8 can be held securely between
the pullstuds and the lower end face of the ram means and therefore
can resist heavy cutting work. This is so-called clamping and
unclamping arrangement of the turning or cutting tool 8.
Because the offset phase of the crank shaft 139 is the same, the
turning or cutting tool can be held securely by means of both the
main spindle of the turret head and the pullstuds mentioned here
depending on the requirements of the tool to be mounted. In this
case, the tool 10 to be usually mounted on the turret head cannot
of course be employed.
When it is desired to effect heavier cutting work, it is desirable
to mount the tool 8 by means of both the aforementioned tool post
for turning tool and the main spindle of the turret head.
Operation
The operation of the complex machine tool according to the present
invention i.e. machining of workpieces by a complex process
including turning, milling, boring and drilling will now be
described in detail hereinbelow.
When it has been checked that the shafts of the machine tool occupy
their starting positions simultaneously with switching on the power
source for the NC control device and the machine tool, the machine
tool is ready for start. At that time, when the start button is
depressed, the machine tool is automatically controlled by a
previously programmed signal.
When it is desired to effect turning as the first process, the
machine tool is actuated to move a designated tool out of a
plurality of tool accommodated in a tool magazine directly below
the tool assister shaft 160, and at the same time the ram means is
moved at a tool replacing position. Then, the tool assister shaft
160 will move downwards and then move upwards with a designated
tool held thereby. When the tool assister shaft 160 reaches its
upper end of stroke, the arm 24 of the tool changer 23 mounted on
the side of the ram means is rotated so as to receive a tool held
by the tool assister shaft 160. The arm 24 which has received the
tool will descend and withdraw the holding part completely from
within the shaft. When the arm has been rotated by an angle of
180.degree. from the tool assiter, the above-mentioned designated
tool is moved just below the lower end face 158 of the ram on which
a turning tool is mounted. After that, when the arm 24 is moved
upwards, the pullstud attached to the tool is inserted into the
sleeve 153. At that time, because the draw bar 151 occupies its
lower position, the balls 157 will not become an obstacle.
Thereafter, the draw bar 151 is moved upwards, and the tool is
mounted rigidly by the lower end face 158 of the ram means and the
pullstuds so as to resist sufficiently the cutting resistance.
Alternatively, as aforementioned, the ram means per se will move to
the position of the tool magazine thereby enabling replacement of
the tool to be effected without using ATC. The arm 24 is rotated by
an angle of 90.degree. and wait at its upper end position until the
next replacement of the tool. When the arm 24 has returned to its
original position, the programme will proceed further and the tool
point of the ram means is moved directly above the machining
position of the workpiece. At that time, the table is moved from
the loading position towards the cross rail and is positioned so
that the tool point on the X--X axis passes through the table
centre. When the tool point has been positioned at a previously
programmed cutting position, the table is given a predetermined
number of revolutions and a start signal is sent to the Z--Z axis.
As a result, the ram means is moved downwards and its speed is
controlled by an input signal for cutting feed so as to repeat the
required number of turning of the outer and inner faces of a
workpiece and then return to its original position (Top dead centre
of the ram).
The characteristic feature of the machine tool of the present
invention resides in that the table can be moved in the direction
of Y axis while it is rotated. Therefore, unlike the conventional
machine tool wherein the tool point can be located only on a plane
on the X--X axis passing through the table centre, the tool point
can be located also on a plane on the Y--Y axis and composite
planes on the X and Y axes and therefore various kinds of turning
work can be effected. Further, the time required for replacement of
tool which occupies a considerably large part of the machining
cycle time can be reduced so much.
In the turning process too, the machine tool enables the
replacement of a various kinds of tools to be effected, and also
permits a single or a plurality of shafts to make sequential
motion. The tools which have completed their machining work will be
returned to the original positions of the magazine, and then the
shafts will be returned to their original positions.
Next, when milling work is effected, the manner of replacing the
tool is the same as in the above-mentioned case; however, because
the assister 160 prepares for the tool for the next process, the
tool replacement will be effected one step earlier.
Further, the tool is mounted on the end of the main spindle 69 of
the turret head and can be fixedly secured by means of the balls 92
within the sleeve 91, the tapered portion and the key way of the
main spindle's flange. When the tool has been mounted on the end of
the main spindle 69, the turret head driving unit 14 is moved
downwards. As a result, the clutches 16 and 73 are engaged with
each other so as to rotate the motor 12 thereby rotating the main
spindle at the number of revolutions to meet a predetermined
cutting condition.
When cutting the face of a workpiece in parallel with the face of
the table, the turret head "B" will place the main spindle 69
vertically or in parallel with the ram means, whilst when cutting
the face of a workpiece extending at right angles to the face of
the table, the main spindle 69 is indexed, turned by an angle of
90.degree. and positioned in parallel with the table 28 by the
turret head indexing arrangement "C." The amount of cutting is
given by either the X axis or the Z axis, but the amount of cutting
feed is given by the movement of the table or by either the Y axis
or Z axis.
Then, the table can be indexed at a desired angle and so the outer
peripheral surface of the multifaced faces can be machined.
Next, when effecting boring and drilling etc., a tool is mounted on
the main spindle of the turret head and the main spindle is rotated
in the same manner as in the case of milling work. The only
difference resides in that in case of boring and milling the
cutting feed is made by either the X axis or the Z axis, whilst
positioning of the machining is made mainly by the X--Y axis and
the table indexing.
When machining faces of a workpiece extending at right angles to
the table face by the conventional stationary table type machine
tool, only indexing of the table can be effected so that machining
is limited only to perforation towards the centre and boring work,
Therefore, face machining or milling work cannot be effected.
Thus, upon completion of turning, milling, boring, perforation,
tapping and reaming of a workpiece once loaded or machining of the
upper face, the outer and inner peripheral surfaces of the
workpiece, the X, Y and Z axis and the table indexing are returned
to their original points and the tool is accommodated in the tool
magazine by the action of the A.T.C. so that the machine tool can
be stopped by a command signal of completion of machining and waits
for the next start signal.
It is to be understood that the foregoing description is merely
illustrative of the preferred embodiment of the invention and that
the scope of the invention is not to be limited thereto, but is to
be determined by the scope of the appended claims.
* * * * *