JPH0319018B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pallet changing device for a machine tool, which is suitable for continuous unmanned operation of a machine tool, particularly an NC machine tool.

[Conventional technology]

The ideal structure for automatic pallet changer (hereinafter referred to as APC) pool lines installed close to machine tools is a three-dimensional structure that utilizes three-dimensional space to save space. In recent years, there has been an increasing demand for a closed-loop configuration to increase the number of pallets, and for better cleaning of the workpieces attached to the pallets. The current situation is that conventional APCs do not match the above ideal structure.

[Problem that the invention seeks to solve]

Therefore, in a three-dimensional APC that utilizes three-dimensional space, the pallet exchange device that exchanges pallets between the pallet exchange position on the pool line and the pallet exchange position on the machine tool table is based on conventional technology. First, it is large in size, and it also takes a long time to change pallets, which poses a problem in that production efficiency cannot be improved.

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems in view of the above circumstances, and to provide a three-dimensional APC that is space-saving and compact, increases the number of pallets, and allows quick exchange of pallets. The purpose of the present invention is to provide a mechanical pallet changing device.

[Means and actions for solving problems]

The present invention provides a pallet exchange device for exchanging pallets with workpieces attached between the pallet exchange position on the table of the machine tool and the pallet transfer port at the pallet transport position. a base; a first movable body guided to be movable in the vertical direction on the base; a first drive body that moves the first movable body up and down;
A second movable body guided horizontally in a straight line on the first movable body.
a moving body, a second driving body that drives the second moving body, a link mechanism provided on the second moving body and capable of reciprocating rocking motion while maintaining a parallel posture, and a link mechanism of the link mechanism. a bracket fixed to one end and movable in the horizontal direction while maintaining the same posture as the link mechanism operates;
A rotatable twin arm consisting of a pallet transfer port of the pallet transfer device and a rotatable twin arm that grips a pallet at a pallet exchange position on the table, and a rotary drive body that is provided on the bracket and rotates the twin arm. The arm is positioned in two steps between the pallet transfer port position of the pallet conveying device and the pallet exchange position on the table to exchange pallets.

Therefore, the pallet exchange device of the present invention is much more compact than the conventional one, and the pallet can be transported much faster. As a result, the pallet exchange time is significantly shortened.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is an overall plan view of an NC machine tool to which the pallet changing device of the present invention is applied.

In FIG. 1, a column 2 is placed on a bed 1 of a horizontal machining center, and is guided by a guide 3 and moved in the Z-axis direction. A spindle head 4 is attached to the front surface of the column 2 and is moved in the Y-axis direction, which is perpendicular to the plane of the paper. A main spindle is rotatably supported on the main spindle head 4, and a tool is inserted into the main spindle to perform predetermined machining on the work W.

A table 5 is placed on a bed 1' extending in front of the bed 1, and is moved in the X-axis direction.

On the table 5, a pallet 6 on which a workpiece W is to be placed is conveyed and placed as shown by the arrow from the delivery port 9a of the pallet conveyance device 9 by the twin arms 8 of the pallet exchange device 7 according to the present invention.

The pallet exchange device 7 according to the present invention has a bed 1'.
The pallet pool 10 is installed in the front of the pallet pool 10.

A plurality of pallets 6 are attached to the pallet conveying device 9 in a closed loop at regular intervals. A cleaning device 11 is provided at the left end of the pallet conveying device 9, and the cleaning device 11 cleans the pallet on which the workpiece is attached as necessary.

2 is an enlarged front sectional view of the pallet exchanging device shown in FIG. 1, FIG. 3 is a sectional view taken along the line -- in FIG. 2, and FIG. 4 is a sectional view taken along the line -- in FIG.

(1) First, the pallet conveying device 9 is conveyed to the pallet delivery port of the pallet exchange device of the present invention.
The specific structure of will be explained.

In FIGS. 2 and 3, a gear box 13, which is a driving source for conveying a plurality of pallets 6, is attached to a support 12a of a fixed base 12. As shown in FIGS. An index motor 14 is attached to the gear box 13. gear box 13
A pinion 15 is fitted to the output shaft of the index motor 14, a gear 16 is meshed with the pinion 15, and a sprocket wheel 17 is fitted to the shaft of the gear 16. Another sprocket wheel (not shown) is attached to the other end of the pallet conveying device 9, and a chain 18 is wound between the pair of sprocket wheels. The rotation from the index motor 14 is transmitted to the pinion 15 via the output shaft, and further transmitted to the sprocket wheel 17 via the gear 16 meshed with the pinion 15. Chain 1 is attached to sprocket wheel 17.
Since the index motor 8 is wound around the index motor 14, the rotation of the index motor 14 is ultimately caused by the chain 18.
and the pallet 6 is indexed. An upper guide 19a and a U-shaped lower guide 19b are attached to the upper and lower parts of the gear box 13, and the upper guide 19a and the lower guide 19 are connected to each other.
The cam floor 20 is guided to b. Since the cam floors 20 are attached to both ends of the chain 18, they guide the movement of the wound chain 18. Pots 21 are attached at regular intervals of the wound chain 18. A tapered holder 6a attached to the lower part of the pallet 6 is removably inserted into each pot 21.

The V-shaped grip 6b of the tapered holder 6a of the pallet 6 grips the grip 8a of the twin arm 8, and the pallet 6 is removed from the pot 21 by moving the twin arm 8 upward.
(FIG. 3) When the pallet 6 is removed from the pot 21, the lock pin 22 is unlocked by the action of the lock/unlock cylinder 23.

The pallet conveying device 9 used in the present invention is not installed in a conventional planar manner, but has a three-dimensional closed loop structure.

(2) The pallet exchange device of the present invention includes a base, a first movable body guided so as to be movable in the vertical direction on the base, and a movable body guided to move the first movable body in the vertical direction. a first movable body that moves, and a second movable body that is linearly and horizontally guided on the first movable body.
a moving body, and a second moving body that drives this second moving body.
A description will be given of the driving body and the link mechanism provided in the second movable body and capable of reciprocating rocking motion while maintaining a parallel posture.

In particular, in FIGS. 2 to 4, a first
A vertical movement cylinder 24, which is a driving body, is attached.

A rod 2 is attached to the upper part of the vertical movement cylinder 24.
5 is attached, and furthermore, the supporting portion 26a of the first moving table 26 constituting the first moving body is fitted at the tip of the rod 25. A guide 26b (FIGS. 2 and 3) is integrally attached to the rear end of the first movable table 26 and is slid up and down along the guide sliding surface 27.

A guide 26d is attached to the upper part of a support member 26c that is integrally attached to both sides of the first moving table 26. A guide sliding surface 28 along which a guide 26d is guided is integrally attached to the lower part of a second moving base 29 constituting the second moving body.

Next, a second movable body that is linearly and horizontally guided on the first movable body, a second driving body that drives this second movable body, and a second movable body that is provided on the second movable body and maintains a parallel posture. A link mechanism that can maintain and perform reciprocating rocking motion will be described.

Thus, the second moving table 29 is placed on the first moving table 26 via the guide sliding surface 28.

Support parts 29a (Fig. 4) extending downward are attached to both ends of the second moving table 29, and a swinging cylinder 30, which is a second driving body, is attached to the upper side of one end of the support part 29a. It will be done. A rod 31 is attached to the lower part of the swinging cylinder 30 so as to be slidable up and down.

Support portions 29a supported at both end portions of the second movable table 29 are pivotally supported by a swing shaft 32 via bearings 33 so as to be swingable.

A first link 34 is fitted to both ends of the swing shaft 32, and the other end of the rod 31 is fitted to the lower part of the first link 34 via a pin 35. On the other hand, the first link 34 extends upward and its tip end is attached to a shaft 37 supported at the bottom of the bracket 36.

A shaft 38 is fitted into the middle of the lower part of the second moving table 29, one end of the shaft 38 is attached to a side end of the second moving table 29, and a second link 39 is attached to the other end. The other end of the second link 39 is connected to the first link 34 of the bracket 36, as shown in FIG.
It is attached via a shaft 40 to the opposite side where it is attached. The twin arm 8 is attached to the upper surface of the bracket 36.

When the vertical movement cylinder 24 is operated, the rod 25 moves up and down, and the first moving table 26 moves up and down. The rod 25 is attached to the support part 26a of the first moving table 26, a bracket 36 is attached to the first moving table 26 via the second moving table 29 and the first link 34, and the twin arm 8 is attached to the bracket 36. Therefore, when the rod 25 moves up and down, the twin arm 8 moves up and down, and when the twin arm 8 grips the pallet, the pallet 6 moves and is disengaged from the pot 21.

When the swinging cylinder 30 pivotally supported by the other end 29b of the second moving table 29 is operated, the rod 31 moves up and down. The rod 31 is attached to one end of the second moving table 29, and the rod 31 is attached to one end of the second moving table 29.
The supporting portion 29a is fitted to the swing shaft 32, the first link 34 is fitted to the swing shaft 32, and the first link 34 is connected to the shaft 37 supported by the bracket 36.
Since the second link 39 is attached to the first link 34 and the bracket 36, when the rod 31 moves up and down, the first link 34 and the second link 39 move left and right with the swing shaft 32 as a fulcrum. to sway. (Fig. 3) If you return the rod 31 upward, the first link 3
4. The second link 39 swings to positions 34' and 39', respectively. The twin arm 8 then moves to the left to the 8' position.

(3) Next, a description will be given of a bracket that is fixed to one end of the link mechanism and is movable in the horizontal direction while maintaining the same posture as the link mechanism operates.

In FIGS. 2 to 4, one end of the horizontal movement cylinder 41 is installed in the first movement table 26, and the operation of the horizontal movement cylinder 41 causes the guide sliding surface 28 of the second movement table 29 to move to the first movement. It moves to the left while being guided along a guide 26d attached to the top of the stand 26. (Figures 2 and 3) The second moving table 29 has a swing shaft 32 and a first link 3.
Since it is integrated with the support shaft 37 supported by the bracket 36 via the bracket 4, the movement of the second moving table 29 causes the bracket 36 to move horizontally from position 36' (the position moved by swinging) to position 36''. do.

The twin arm 8 grips the pallet 6.
moves from position 8' to position 8'' and grips the processed pallet 6 on table 5.

(4) The pallet gripping/swivel mechanism of the swing drive body that swings the twin arm 8 will be explained.

5 is an enlarged sectional view of the bracket 36 portion in FIG. 3, and FIG. 6 is a sectional view taken along the line -- in FIG.

In Figures 5 and 6, bracket 3
6 includes a rack 42 and a gear 43 of a pinion shaft 43.
The pinion shaft 43 is rotatably supported by the bracket 36 via bearings 44a and 44b.

The rotating shaft 4 is connected to a fixed shaft 45 attached to the upper part of the bracket 36 via a plurality of bearings 46.
7 is fitted, and the gear 47a carved on the lower part of the pivot shaft 47 meshes with the gear 43b carved on the upper part of the pinion shaft 43. The twin arm 8 is inserted between the bracket 36 and the pivot shaft 47, and the twin arm 8 is attached to the pivot shaft 47.

A cap 48 is attached to the upper part of the pivot shaft 47 to cover the pivot shaft 47.

The rack 42 is housed in a turning cylinder 49 mounted within the bracket 36.
A piston 50 is attached to both ends.

When the rack 42 is caused to reciprocate by supplying pressure oil to the oil chamber 51 or 52 provided in the turning cylinder 49 (FIG. 6), the rack 42 moves toward the pinion shaft 43. Since the pinion shaft 43 is meshed with the gear 43a, the pinion shaft 43 rotates. Since the gear 43b of the pinion shaft 43 meshes with the gear 47a of the pivot shaft 47, rotation of the pinion 43 is transmitted to the pivot shaft 47. Since the twin arm 8 is attached to the pivot shaft 47, the rotation of the pivot shaft 47 is transmitted to the twin arm 8, and the twin arm 8 is rotated 180 degrees.

(5) The operation of the pallet exchange device according to the present invention will be explained.

The pallet 6 is located between the pallet exchange position on the table 5 on the machine side and the delivery port 9 of the pallet transport device 9.
a (Fig. 1).

(a) First, the tapered holder 6a of the pallet 6 is inserted into the pots 21 attached at regular intervals to the winding chain 18 formed by a three-dimensional closed loop of the pallet conveying device 9. Palette 6
A workpiece W to be machined is mounted on top, the index motor 14 is activated to rotate the wound chain 8, and the workpiece W to be machined is indexed to the delivery port 9a.

(b) By activating the horizontal movement cylinder 41 and moving the second moving table 29 to the right, the twin arm 8 moves to the right. (Solid line position in Figure 3) The pallet gripping part 8a at the tip of the twin arm 8 holds the V of the pallet 6.
It is gripped by the letter-shaped grip part 6b.

(c) When the pallet 6 is gripped by the twin arm 8, the lock/unlock cylinder 23 is activated to move the lock pin 22 to the right (Fig. 3), and the pallet 6 and pot 21 are freed. .

(d) By activating the vertical movement cylinder 24 to extend the rod 25 and push up the first moving table 26, the twin arm 8 is pushed upward and the pallet 6 is pulled out from the pot 21.

(e) Activate the swing cylinder 30 and
By swinging the link 34 and the second link 39 to the left, the first link 34 and the second link 39 are moved to positions 34' and 39' (Fig. 3),
Twin arm 8 is moved to position 8'.

(f) Activate the vertical movement cylinder 24 to retract the rod 25, push down the first moving table 26, and return the twin arm 8 to its original horizontal position.

(g) By activating the horizontal movement cylinder 41 and moving the second moving table 29 to the left,
Twin arm 8 is moved to the left. (3rd
Figure) A gripping portion 8a at the tip of the other end of the twin arm 8 grips the pallet 6 on which the processed workpiece is placed on the table 5.

(At this point, the grip part 8 of the twin arm 8
Both a pallets for next processing and processed pallets are held respectively. ) (h) The twin arm 8 is pushed upward by activating the vertical movement cylinder 24 to extend the rod 25 and push the first moving table 26 upward.

(i) By activating the turning cylinder 49 and rotating the rack 42, the twin arm 8 is turned 180 degrees. (In this state, the pallet for the next processing and the processed pallet are exchanged with each other.) (j) The twin arm 8 is pushed down. (As a result, the pallet for next processing is placed on the table 5.) (k) Operate the horizontal movement cylinder 41,
Move the second moving table 29 to the right (the third
), the twin arm 8 is moved to position 8'. (The pallet for next processing comes off the twin arm 8 and is placed on the table 5 as it is.) (l) The vertical movement cylinder 24 is activated, the rod 25 is extended, and the first moving table 26 is pushed upward. As a result, the twin arm 8 is pushed upward.

(m) Activate the swing cylinder 30 to swing the first link 34 and the second link 39 to the right from positions 34' and 39' to positions 34 and 39, respectively.
39 (Figure 3), twin arm 8
is moved to the right.

(n) Activate the vertical movement cylinder 24,
By retracting the rod 25 and pushing down the first moving table 26, the twin arm 8 is pushed down. (As a result, the processed pallet is inserted into the empty pot 21 that is waiting at the delivery port 9a of the conveyance device 9.) (o) Activate the lock/unlock cylinder 23 and move the lock pin 20 to the left. The moved and processed pallet is locked in the pot 21.

(p) Activate the horizontal movement cylinder 41,
The second moving table 29 is moved to the left, and the twin arm 8 is moved to the intermediate position.

(q) Activate the index motor 14,
The next workpiece to be processed on the transport device is indexed and positioned at the delivery port 9a.

After performing the prescribed processing on the workpiece mounted on the pallet 6 placed on the table 5, the above
By repeating the operations (a) to (q), pallets are automatically exchanged.

〔effect〕

In the present invention, pallets are exchanged between the pallet exchange position on the machine table and the delivery port of the pallet conveying device, and the pallet exchange is performed using a base of the pallet exchange device and a platform that can be moved vertically on this base. a first movable body to be guided; a first driving body for vertically moving the first movable body; a second movable body guided horizontally in a straight line on the first movable body; a second driving body for driving the second moving body; a link mechanism provided on the second moving body and capable of reciprocating rocking motion while maintaining a parallel posture; and a link mechanism fixed to one end of the link mechanism A bracket that can be moved horizontally while maintaining the same posture as it moves;
a twin arm provided on the bracket and capable of swinging to grip the pallet at the pallet transfer port of the pallet transfer device and a pallet exchange position on the table; and a swing drive body provided on the bracket and rotating the twin arm. The rotatable twin arms are positioned in a two-step movement between the pallet transfer port position of the pallet conveying device and the pallet exchange position on the table, and the pallet exchange is performed. The pallet exchange device itself can be manufactured compactly. In particular, a pallet transport linkage mechanism is provided for rapid transport. The use of twin arms and tapered holder type pallets makes it easy to transport pallets, and as a result, pallet exchange time is greatly shortened. The reason for the particularly compact size is the use of a swing system with a link mechanism.

Furthermore, since the pallet conveying device has a three-dimensional closed loop shape, the number of pallets can be increased compared to the conventional method, and workpieces can be cleaned better.

The pallet exchange device of the present invention is particularly suitable for continuous unmanned operation of NC machine tools.

[Brief explanation of the drawing]

FIG. 1 is an overall plan view of an NC machine tool to which the pallet changing device of the present invention is applied. Figure 2 is an enlarged front sectional view of the pallet exchange device in Figure 1, and Figure 3 is a sectional view taken along the - line in Figure 2 and 4.
The figure is a sectional view taken along the line -- in FIG. 3. 5 is an enlarged cross-sectional view of the bracket portion in FIG. 3, and FIG. 6 is a cross-sectional view taken along the line -- in FIG. 5... table, 6... pallet, 7... pallet exchange device, 8... twin arm, 9... pallet transport device, 10... pallet pool, 11... cleaning device, 1
4... Index motor, 18... Chain, 21
...Pot, 22...Lock pin, 23...Lock/unlock cylinder, 24...Vertical movement cylinder,
25... Rod, 26... First moving base, 29... Second moving base, 30... Rocking cylinder, 34... First link, 36... Bracket, 39... Second link, 41
...Horizontal movement cylinder, 42...Rack, 43...Pinion, 47...Swivel shaft, 49...Swivel cylinder.

Claims (1)

[Scope of Claims] 1. A pallet exchange device for a machine tool that exchanges a pallet with a workpiece attached between a pallet exchange position on a table disposed in the machine tool and a pallet transfer port at a pallet transport position. a base of the pallet exchange device; a first movable body guided to be movable in the vertical direction on the base; a first drive body that moves the first movable body up and down; a second movable body that is linearly and horizontally guided on the movable body; a second driving body that drives the second movable body; and a reciprocating oscillating body that is provided on the second movable body and maintains a parallel attitude. a link mechanism capable of dynamic movement; a bracket fixed to one end of the link mechanism and movable in the horizontal direction while maintaining the same posture as the link mechanism operates; It consists of a twin arm that can pivot to grip the pallet at the pallet transfer port and a pallet exchange position on the table, and a swing drive body that is provided on the bracket and swings the twin arm, and the twin arm that can pivot is configured to transport the pallet. A pallet exchange device for a machine tool, characterized in that the pallet is exchanged by positioning the pallet by a two-step movement operation between the pallet delivery port position of the device and the pallet exchange position on the table.