JPH02139152A - Grip device for work - Google Patents

Abstract

PURPOSE:To enlarge the application range of a grip claw by equipping plural grip parts gripping a work at the opposite parts of a set of gripping claws whose one end is pivotally fitted by a pivot to a moving element and providing the guide means of the moving element that the gripping center of plural gripping parts is moved to the same position on a back plate. CONSTITUTION:Gripping parts 2, 2' and 3, 3' are provided in opposition at a different distance from a pivot 5 on the gripping claws 1, 1' fitted freely rotatably to the pivot 5 whose one end is fixed to a moving element 4. The engagement of the claws 1, 1' and pivot 5 is loose and thereis some gap. The gripping parts 2, 2' and 3, 3' are made a V groove and the superpositions are reduced as far as possible like the work diameter gripped by the gripping parts 2, 2' being in 20-40mm and at the gripping parts 3, 3' the diameter being in 40-85mm, for example. A backing plate 6 is provided at the back part of the claws 1, 1' toward the work main shaft base 10, a guide groove 7 of a straight line in parallel to the line connecting the gripping centers O2, O3 of the gripping parts 2, 2' and 3, 3' thereon and the roller 4c of the moving element 4 is rolled on the opposed raceway surface 7a thereof.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention is suitable for use in a workpiece grasping device, particularly a chuck for mounting a workpiece on the main shaft of a metal machine tool, an autoloader, a handling device such as a robot, etc. This invention relates to a device for grasping a workpiece.

``Prior art and problems to be solved by the invention'' Conventionally, Kelly chucks, work drivers, etc. are used when attaching a workpiece to the spindle of a machine tool. Of these, Kelly is not suitable for automation, but chucks and work drivers are. When automating such a workpiece grasping device, the wider the range of applicable diameters, the fewer opportunities for setup changes. It is more preferable if only one workpiece grasping device is required for handling workpieces from the minimum diameter to the maximum diameter within the range of the machine tool's capabilities.

However, in conventional power chucks used as automatic chucks, the gripping jaws must be replaced every time the diameter of the workpiece is changed, and there is little adaptability to the size of the workpiece. Automated scroll chucks have also been commercialized, but they have a complex structure, are expensive, tend to break down, are difficult to improve reliability, and have the drawback of being too large for their gripping ability. The work driver has a narrow range of diameters to which workpieces can be applied.1. If the range is exceeded, the gripping claw must be replaced.

From the above points of view, it is desired that a single grasping device can grasp workpieces having a wide range of diameters, especially when a variety of workpieces are machined in an FMSJ.

The above is a case where the workpiece is attached to the main shaft of a machine tool, but autoloaders and robots (hereinafter referred to as loaders)
Regarding gripping claws such as the above, it is desirable that a single gripping claw can grasp workpieces of various sizes.

Loader gripping devices are often of the type that opens and closes in the shape of an alligator mouth.

A grasping claw that opens and closes in a 670-shape has disadvantages in that the center of the workpiece moves when the diameter of the workpiece changes, and that the range in which the workpiece can be grasped is small in relation to the size of the diameter of the workpiece.

Regarding the former, if the workpiece is cylindrical, by changing the shape of the part of the gripping claw that contacts the workpiece into a curved shape instead of a V-groove, it is possible to reduce the center deviation due to the diameter of the workpiece. It is known that the range of diameters of cylindrical workpieces can be expanded by gripping jaws. However, the gripping part of such an alligator-shaped gripping claw that contacts the workpiece has a special concave curve, making it difficult to process, and the gripping position where it contacts the workpiece is not the appropriate position to apply gripping force. There is a drawback that it cannot be done.

Furthermore, with conventional alligator-shaped grasping claws, it is often difficult to grasp both cylindrical and irregularly shaped parts of the workpiece with one grasping claw.

Due to the above-mentioned problems with the alligator-shaped grasping jaws, the scope of conventional gripping jaws that can accommodate differences in the size or shape of the workpiece is limited, and if this cannot be accommodated, the gripping jaws must be replaced with other alligator-shaped gripping jaws that are suitable for the workpiece. ing. Therefore, when changing the workpiece,
A large amount of work time is required to change the setup of the workpiece grasping device.

The present invention focuses on the size of the portion grasped by the grasping claws of the workpiece,
It is an object of the present invention to provide a workpiece gripping device that can be adapted to a large range of workpieces regardless of the type without replacing gripping claws.

"Means for Solving the Problems" A first aspect of the present invention includes a plurality of grasping parts for grasping a workpiece at opposing parts of a pair of grasping claws, one end of which is pivotally connected to a slider. A guide means for the movable element is provided on the back plate so that the grasping center of the grasping part moves to the same position,
This is a workpiece grasping device that includes a grasping claw opening/closing device, a driving device for the opening/closing device, and a grasping claw moving device.

A second invention of the present invention is the workpiece grasping device according to the first invention, wherein the guide means for the mover is a guide for engaging the mover provided on a line connecting a plurality of grasping centers of the grasping claws.

A third aspect of the present invention is that a nut is rotatably supported at the tip of a pair of grasping claws parallel to a pivot that connects the grasping claws and the slider, and the nuts are mutually orthogonal to the rotational axis of the nut. Screw into each nut an opening/closing screw that has a reverse-hand female thread on one shaft and a reverse-hand male thread on the other, and connect the gripping centers of the multiple gripping parts of the gripping claw. A guide means for guiding the opening/closing screw so as to be movable in parallel is provided between the opening/closing screw and the back plate, a tool handle is provided on the opening/closing screw, a wrench is detachably attached to the tool handle, and the wrench is inserted through the shaft coupling. The workpiece grasping device according to the first invention or the second invention is connected to a rotating prime mover and includes a wrench and means for attaching and detaching an opening/closing male screw.

A fourth aspect of the present invention is that a cam follower is fixed to each of a pair of grasping claws and one of the back plates, and a cam groove is provided on the other side to which the cam follower engages, and the cam groove is provided with a plurality of grasping claws. The cam follower is parallel to the line connecting the gripping centers of the gripping parts, and the cam follower is A first linear groove to be engaged and a grasping pawl that can be engaged by a cam follower are pivotally connected to each of the first linear grooves at a position where the grasping center of the grasping part grasps a predetermined workpiece. The workpiece grasping device according to the second aspect of the invention is characterized in that the workpiece grasping device is formed of an arcuate groove centered on the pivot axis.

A fifth invention of the present invention is the workpiece grasping device according to any one of the first to fourth inventions, wherein the back plate is fixed to the spindle end of the workpiece headstock of a machine tool.

A sixth aspect of the present invention is the workpiece grasping device according to any one of the first to fourth aspects, wherein the back plate is fixed to an autoloader or a robot.

"Function" According to the first aspect of the present invention, if a plurality of gripping parts are provided corresponding to the size or shape of the portion of the workpiece to be gripped, the workpiece gripping center of the applied gripping parts can be set at the same position. By moving the opening/closing device and its driving device at the same position, large and small workpieces or different types of workpieces can be grasped at the same position.

In the second aspect of the present invention, when the mover moves according to the guide on the back plate, the grasping center moves to the same position.

Therefore, if there are three or more grasping parts, it is effective to make the guide straight.

In the sixth aspect of the present invention, when opening and closing the grasping claw, the wrench attachment/detachment means is coupled to the tool handle of the male screw for opening and closing the wrench,
The rotating prime mover rotates the opening/closing screw via the shaft coupling to open and close the grasping pawl. After the grasping pawl opens and closes, the wrench attachment/detachment means detaches the wrench from the opening/closing male screw. This allows the grasping claws that have grasped the workpiece to rotate or move together with the back plate.

The fourth aspect of the present invention is that when the grasping claws are opened beyond the opening degree that allows grasping the maximum workpiece diameter, or when the grasping claws are fully closed, the center of any grasping part of the grasping claws is at a predetermined position between the back plate and the grasping claws. When the grasping pawl closes or opens at that position, the slider enters the arcuate groove and the grasping pawl does not move, with the desired grasping portion at a fixed position.

The fifth aspect of the present invention is that the grasping claws supported on the back plate side, the back plate, and the opening/closing device of the grasping claws rotate together with the main shaft of the machine tool, and the grasping claw moving device and the opening/closing device are rotated at a fixed stop position. It is connected and driven by a driving device.

In a sixth aspect of the present invention, at least the grasping claw supported on the back plate side, the back plate, and the opening/closing device for the grasping claw move together with the autoloader and the robot, and the autoloader,
If the robot carries a grasping claw moving device and a driving device for the opening/closing device, the opening/closing device, its moving device, and the driving device operate at any position, and the grasping portion of the grasping claw is switched. If the moving device for the grasping claw and the drive device for the opening/closing device are provided at a fixed position, the opening/closing position, the moving device, and the drive device are engaged/disengaged at the fixed position, and the grasping portion of the grasping claw is switched. .

"Embodiments" Examples of the present invention will be described below with reference to the drawings. This embodiment shows an example where it is provided in front of the workpiece headstock of a grinding machine. 1 and 2 are front views, FIG. 3 is a sectional view taken along line AA in FIG. 1, and FIG. 4 is a sectional view taken along line BB in FIG. 1.

Grasping claws 1 and 11, which are rotatably attached to a pivot shaft 5 whose one end is fixed to a slider 4, are provided with grasping portions 2, 2I and 6, 3I facing each other at different distances from the pivot shaft 5. The gripping claws 1, 11 and the pivot shaft 5 are loosely fitted, and there is a slight gap.

In this example, each grasping claw 1, 11 is attached to a common pivot 5, but each grasping claw 1, 1! may each be mounted on separate pivots. Grasping parts 2, 2I and 6
, 31 form a V-groove, and for example, the diameter of the workpiece grasped by the grasping parts 2 and 2I is 20 to 4Qlll, the grasping part le,
31, the diameter of the workpiece is 40 to 851 m, so that the overlap is as small as possible.

Such a shape of the gripping parts 2.21 and 3,61 is adopted when the workpiece is cylindrical and has a wide application range, for example from 20 to 85 mm in diameter. Although a plurality of grasping parts are provided, it is also possible to provide three or more grasping parts. In addition, if the part to be grasped of the workpiece is of an irregular shape, grasping parts 2, 21 and 3, 61 are used.
The shape can be adapted to the shape of the irregular shape. In addition, grasping units 2, 2! are provided so that the grasped parts of a plurality of workpieces can grasp workpieces having different shapes. and grasping part 3, 3I
can also have different shapes.

A back plate 6 is provided on the back of the gripping claws 1, 11 facing the workpiece headstock 10. back plate 6
The grasping center 02 of the grasping parts 2, 2I of the grasping claws 1, 11,
A straight guide groove 7 is provided which is parallel to the line connecting the grasping centers 03 of the grasping parts 3 and 3. The guide groove 7 is a T groove, and the groove 7
A mover 4 is inserted inside. The mover 4 is the mover 4
A roller 4c is rotatably attached to a roller shaft 4b fixed to a. The roller shaft 4b is parallel to the pivot shaft 5, and the roller 4C rolls on the opposing raceway surface 7a of the guide groove 7.

This article talks about the opening/closing device of the grasping claw. - Set of gripping claws 1.1
8.81 is supported rotatably at the center parallel to the pivot 5. For that purpose, oak) 8.81
is the cylindrical hole 1a provided in the grasping claw 1.11.

They fit loosely into each t'a. (Oak) 8.81 has internal threads 8a and 8' that intersect with the axis of rotation and are opposite to each other.
A is a provision. The opening/closing screw 9 is provided with male threads 9a and 9b with opposite hands on one shaft.
It is screwed into 31.

Guide means for guiding the opening/closing screw 9 so as to be movable parallel to the line connecting the gripping centers 02, 03 of the plurality of gripping parts 2, 21 and 3, 3I of the gripping claws 1, 11; the opening/closing screw 9 and the back plate 6; It is provided for. In this example, as shown in FIG.
A slider 11 that penetrates the entire length of the slider 11 and fits into the guide groove 7.
An opening/closing screw 9 is attached to a bracket 12 fixed to the bracket 12 . The mover 11 has the same shape as the mover 4 that regulates the base side of the grasping claws 1 and 11 described above, and only the corresponding numerals 11a, 11b, and 11c are shown in the figure and their explanation will be omitted.

A collar 13 is fixed between the male threads 9a and 9b of the opening/closing screw 9, which are opposite in direction. The collar 13 is fitted into a long hole 12a provided in the bracket 12. Opening/closing screw 9
The bracket 12 is loosely inserted on both sides of the collar 13. In addition, the portion where the opening/closing screw 9 passes through the grasping claws 1, 11 is the opening/closing screw 9 regardless of the opening degree of the grasping claws 1, 11.
It is removed as a long hole or fork to allow movement.

A tool handle portion 9C is provided at the end of the opening/closing screw 9, and a first
As shown in the figure, a hexagonal wrench hole 9d is formed at the center of the end. The opening of the hex wrench hole 9d has a truncated hexagonal pyramid shape and expands outward from the crest hole 9d to form an introduction part 9e.
It's Toshide.

FIG. 5 is a plan view of the grasping pawl moving device and the drive device of the opening/closing device. The driving device for the above opening/closing device is as follows. The tip 14a of the wrench 14, which is detachably attached to the hexagonal wrench hole 9d of the tool handle 9C of the opening/closing screw 9, has a spherical hexagonal shape. A spherical hexagonal means that even if the axes of the wrench 14 and the opening/closing screw 9 intersect,
The wrench 14 and the hexagonal wrench hole 9d are rigidly connected in terms of rotation so that rotation is transmitted, and the tip portion 14a of the wrench 14 can move in the axial direction within the hexagonal wrench hole 9d. Therefore, the tip portion 14a is an envelope surface that engages with the hexagonal wrench hole 9d in which a spherical great circle portion rotates based on a hexagonal shape. Hex wrench hole 9d and wrench 14
The shape of the tip portion 14d may be any other tooth type.

The wrench 14 is connected to a rotary motor, such as a motor with a worm reduction gear (hereinafter referred to as a reduction morph) 16I, via a shaft coupling, such as a universal joint 15. The universal joint 15 has four headed pins 19 implanted in the axial direction at equal intervals near the outer periphery of a disk 18 to which a torque limiter 171ζ is fixed to the output shaft 16a of the deceleration motor 16. A compression coil spring 21 inserted into the pin 19 between the flexible plate 20 and the disk 18 causes the flexible plate 20 to move around the pin 19.
The pressure is applied towards the head of the person. A wrench 14 is attached to the center of a wrench attachment member 22 fixed to the center of the flexible plate 20, and is detachably fixed thereto.

The device for moving the grasping claw and the device for attaching and detaching the wrench to the opening/closing device are as follows. The deceleration motor 16 is fixed to the saddle 25. The saddle 23 has a slide bearing 24
, and is guided by two parallel vertical guide bars 25 . The guide bar 25 has a fluid pressure cylinder 2 parallel to the guide bar 25 between the guide bars 25 that move in the left and right direction.
5a is fixed, and its piston rod is connected to the saddle 2.
It is fixed at 3. The slide 26 is guided via a slide bearing 29 to a lateral guide bar 28 fixed to a table 55 so as to be adjustable in its longitudinal position with respect to the front part of the workpiece headstock 10. The bracket part 26a to which the slide bearing 29 of the slide 26 is fixed has a stopper 26b, 2 that abuts against the stand 27).
6C is screwed in so that its position can be adjusted, and slide 2
6. Determine the movement limit position. As shown in FIGS. 2 and 5, a clevis-type cylinder 31 is pivotally supported on a stand 27 with a pin 30.
The piston rod of slides 2 through the bracket 34.
It is fixed at 6.

6(a) and 6(b) are front views of the back plate 6. FIG.

In connection with the grasping claw moving device, the back plate 6 is provided with a regulating cam groove 52 for regulating the movement of the grasping claw 1.1. The grasping claws 1, 11 are provided with a cam follower 33 (FIGS. 1 and 2), and the cam follower 36 is movably fitted into the regulating cam groove 32. The regulating cam groove 32 has two circular arc grooves 32 with radii R+ and Rz around the pivot shaft 5.
A, 52b are connected to a straight groove 32c parallel to the line connecting the grasping centers 02, 03, and as shown in FIG. The cam follower 33 is fitted into the open position at a certain position. The radius R1 and the radius R2 are equal, and the grasping part 2,
The grasping center 02 of 21 is the spindle center 10 of the workpiece headstock 10
0, the cam follower 33 can enter the circular arc groove 32a of radius R1 from the straight groove 32C end, and the gripping center 03 of the gripping parts 3, 3+ is the center of the main shaft of the workpiece headstock 10. The radius R at the position that coincides with 100
The cam follower 33 can enter into the circular arc groove 32b of No. 6 from the end of the straight groove 32C.

If the axis 5 is the fixed point of the movement limit, the grasping parts 2, 2! and 6
, 3I, the gripping centers 02 and 06 move by a minute amount in the direction of the guide groove 7, so that the gripping centers 02 and 06 move by a minute amount in the direction of the guide groove 7, so that the gripping centers 02 and 06 move a small amount in the direction of the guide groove 7, so that the gripping centers 02 and 06 of the workpiece headstock 10 and the gripping center 02. Ox does not match. Therefore, the arc groove 32aj
By modifying the arc 2b, the main axis center 100 can be accurately aligned with the grasping centers 02 and 03. However, for axis 5 and nut 8.81, guide 7
It is necessary to be able to displace the small amount grasping claws 1 and 11 in the direction of . In this example, the workpiece is a so-called center work that is supported at both centers, so the circular arc grooves a2a and szb are used as the pivot shafts 5 and 8.81, and the grasping claws 1. II is a loose fit with play, and the workpiece is floatingly supported.

Figure 'IIXz is a front view of the main spindle fixed position stopping device provided on the workpiece headstock 10. When the present invention is applied to a workpiece headstock, a main spindle fixed position stopping device is required. Stop position control plate B5 fixed to workpiece spindle 10a
A back plate 6 is fixed to.

A pre-stop deceleration dog 36, a fixed position stop dog 7, and an index plate 38 are arranged on the circumference of the stop position control plate δ5. The remachine cover δ9 has each dog δ6. &
A switch 41,42 activated by 7 is provided. A remachine cover 69 is attached to the notch groove 58a of the index plate 38.
A notch 44 guided by a vertical guide member 41s fixed to can move in and out. The notch 44 has its piston rod fixed to the edge of the notch 44, and is driven by a fluid pressure cylinder 45 fixed to the remachining cover 39.

The main spindle fixed position stopping device is not limited to this, but may be driven by a numerical control device, and the mounting position may be on the rear end side of the workpiece headstock 10.

FIG. 8 shows a grinding machine to which the present invention is applied. A whetstone 53 is supported by a whetstone shaft 54 which is horizontally rotatably driven on a whetstone head 52 which can reciprocate in the direction of the arrow X shown on the machine stand 51 . A workpiece headstock 1o and a tailstock 57 are arranged facing each other on a table 55 that reciprocates in the Z direction parallel to the grinding wheel shaft 54. The workpiece W is supported by 69.6N. The workpiece spindle 10a is provided with the spindle fixed position stop device 62 described above, the workpiece gripping head 63 consisting of gripping claws 1 and 11 attached to the back plate 6 via the slider 4, and an opening/closing device. On the table 55, a driving device and grasping pawl moving device 64 (integrated in this example) for the opening/closing device is disposed.

When the grinding of the workpiece W supported by both centers 59 and 61 and gripped by the gripping claws 1 and 11 is completed, the grinding wheel 5 is removed together with the grinding wheel head 52.
3 moves away from the workpiece in the X direction, and the table 55 stops.

When the workpiece spindle 10a of the workpiece headstock 10 is in a rotating state, the workpiece W is held by the grasping claws 1. II grasping part 2゜2 or 6.
31. It is assumed that a workpiece with a diameter of 201 m is grasped by the metal gripping parts 2, 2. The fluid pressure cylinder 25a advances the piston rod, the saddle 2δ is at the lower limit position, and the wrench 14 is away from the range of movement of the opening/closing screw 9. The slide 26 is at the right end position.

When the spindle fixed position stop device 62 receives a stop signal while the workpiece spindle 10a is rotating in the direction of the arrow 46 in FIG. 7, the proximity switch 41 is energized and the pre-stop deceleration dog 36 When the operator operates the proximity switch 41, the workpiece spindle is decelerated to a low speed, and then the proximity switch 42 for stopping at a fixed position is energized. Then, when the fixed position stop dog 37 further operates the proximity switch 41, the workpiece spindle is controlled to a very slow speed, and the fixed position stop dog 37 causes the proximity switch 41 to operate.
2 is operated, a braking device (not shown) works to stop the workpiece main shaft 10a. The brake is then released, the hydraulic cylinder 45 is energized, the notch 44 is advanced into the notch groove 38a, and the workpiece spindle is accurately positioned and regulated against rotation. In this position, the guide groove 7 of the back plate 6 and the guide bar 28 of the moving device are parallel.

Simultaneously with the stop of the workpiece spindle 10a, an unloader (not shown) grips the workpiece W, and at the same time the mandrel of the tailstock 57 retreats. On the other hand, the fluid pressure cylinder 25a that raises the wrench 14 moves the piston rod backward and the saddle 23
, and the deceleration motor 16 also rises, so the universal joint 1'5 also rises. When the wrench 14 was previously separated from the hexagonal wrench hole 9d of the opening/closing screw 9, all the compression coil springs 21 were equal and pushed up the flexible plate 20, so the wrench neck was aligned with the output shaft of the deceleration motor 16. It's not falling. When the wrench 14 rises, the tip 14a of the wrench 14 is guided by the introduction part 9e of the tool handle 9C of the opening/closing screw 9 and enters the hexagonal wrench hole 9d. At that time, wrench 1
Even if there is a misalignment between the hexagonal wrench hole 9d and the opening/closing screw 9, the flexible plate 20 presses the compression coil spring 21 and tilts, so the hexagonal wrench hole 9d and the wrench 14 are fitted together without difficulty. When the deceleration motor 16 is energized, the wrench 14 rotates, the opening/closing screw 9 rotates, and the distance between the two nuts +-a and at begins to widen, the grasping portions of the grasping claws 1 and 11 that were pressing the workpiece W are 2, 2I, the cam follower 63 moves into the arcuate groove 32 of the cam groove 32 around the pivot shaft 5.
b toward the straight groove 32c and open it. At the same time, the unloader moves away from the workpiece headstock 10 in the axial direction, and the workpiece W
is removed from the grasping claws 1 and 11. Thereafter, the unloader carries out the workpiece W to a required location, and a loader (not shown) transports a new workpiece W between the workpiece headstock 10 and the valve head 57, and carries the workpiece W toward the workpiece headstock 10. to support one end of the workpiece W with the headstock center 59, and
The mandrel 7 advances and the center 61 enters the center hole of the workpiece W. Once the workpiece W is supported by both centers 59, 61, the loader releases the workpiece W and leaves.

If the new workpiece W has the same diameter as the previous workpiece W or the diameter that can be gripped with the gripping parts 2 and 2 blindly, that is, the diameter 40111 or less, the deceleration motor 16 is reversed and the wrench 14 and opening/closing screw 9 are Rotate in the opposite direction to close the grasping claws 1 and 11. Workpiece W
If the difference in diameter is within the range of 20 to 401 m and the grasping center 02 does not coincide with the center 100 of the main axis of the workpiece,
The grasping claws 1, 11 are loosely fitted to the pivot shaft 5, and the nuts 8, 8' are in the cylindrical holes 1a, 1' of the grasping claws 11.
Since it is loosely fitted to the center 59, it floats and its centers are aligned, so that no unnecessary radial load is applied to the center 59.

If the diameter of the newly supplied workpiece W exceeds 401111, the deceleration motor 16 further tightens the opening/closing screw 9 with the grasping claw 1.
, 11 are rotated to open more than after the maximum grip, and the cam follower 63 comes to the corner of the arcuate groove 32b and the straight groove 52C and stops. At this point, the cylinder 31 for moving the slide 26 is energized and its piston rod moves forward, so the slide 26 moves to the left from the position shown in FIG. 1, and the stopper 26C hits the base 27ζ and stops. Due to this movement, the hydraulic cylinder 25a1 carried by the slide 26, the saddle 26, and the deceleration motor 1
6. The universal joint 15, wrench 14, etc. move together, and the wrench 14 pushes the opening/closing screw 9 to the left.
Grasp the claw through the claw 1. In II, the movers 4 and 11 are guided by the guide groove 7, the cam follower 33 is guided by the straight groove 32c and moves to the left, and the grasping center 03 of the grasping part 3.6I is aligned with the workpiece main axis foa.
Move to the center +00 position.

At this position, the diameter of the workpiece W mentioned above is 20~Jo
Similarly to the grasping operation of the workpiece W by the grasping sections 2 and 21 in the case of "in", a workpiece W having a diameter of 40 to 85 mm is grasped by the grasping sections 3 and 3'. With this closing operation of the grasping claws 1 and 11, the cam follower 3δ enters the arcuate groove 32a.

When the workpiece W is grasped, the piston rod of the fluid pressure cylinder 25a moves forward to lower the saddle 23, and the wrench 14 is separated from the tool handle 9C of the opening/closing screw 9.

When it is confirmed that the wrench 14 is separated from the opening/closing screw 9, the piston rod of the hydraulic cylinder 45 of the main shaft fixed position stop device moves in the backward direction, and the notch 44 is pulled up and released from the notch groove 38a of the index plate 38. break away. At this time, the workpiece main shaft 10a rotates, the grindstone head 52 advances, the grindstone 53 acts on the workpiece W, and the table 55 reciprocates to perform processing.

In the embodiment, a straight groove S2c is provided in the cam groove 32 at a position where the grasping claws 1 and 11 are opened to a greater extent than the maximum grasping diameter of the workpiece. However, conversely, the straight groove 32c may be provided in a closed position smaller than the minimum gripping diameter of the workpiece, for example, in a closed state without gripping the workpiece W (6th line groove 32c).
Figure mountain)). In this case, the grasping parts 2, 2I and 6, 51 are exchanged with the grasping claws 1, 11 in the closed state without grasping the workpiece, and when the grasping claws 1, 11 are opened further, the movement of the grasping claws 1, 11 is stopped. It turns out you can't do it.

FIG. 9 is a perspective view of an embodiment showing a detachable head of an autoloader, robot, or the like. A case is shown in which the entire workpiece grasping device is carried by the attachment/detachment head. The grasping claws 1 and 11 are fixed to pivot shafts 5 and 51 that penetrate through a detachable head main body (corresponding to a back plate) 71 and are slidably fitted together. axis 5,
The pinions 72 and 72' fixed to the pinion 51 are the grasping claws 1 and 1.
1 and is engaged with a rack 74 that reciprocates by a cylinder 73 fixed to the detachable head main body 71.

The detachable head main body 71 is fitted into a guide block 76 at the tip of the loader arm 75 so as to be able to move in and out.
The piston rod of the cylinder 77 fixed at 6 is fixed to the detachable head main body 71.

The gripping parts 2, 21 and 6, 31 of the gripping claws are replaced by the cylinder 7.
When 7 is energized, the detachable head main body 71 moves to the guide block 7.
6, the rack 74 reciprocates by the cylinder 73, the pinions 72, 721 rotate, and the grasping claws 1, 11 open and close.

〔Effect of the invention〕

The first aspect of the present invention is that the grasping claw is provided with a plurality of grasping parts, and the grasping claw can be moved and positioned at the same position, so that in the case of one cylindrical workpiece, the diameter range of the workpiece that can be grasped is reduced. It is possible to eliminate the need to replace gripping claws, and it is also possible to adapt multiple gripping parts to the size of irregularly shaped workpieces, and each gripping part can be used to handle different irregularly shaped workpieces. The shape adapts to the workpiece, reducing the need to replace the grasping claw. This makes it possible to provide a workpiece grasping device that is optimal for FMS.

In the second aspect of the present invention, since the guide of the slider is provided on the line connecting the grasping centers, it is easy to increase the number of grasping parts and it is easy to move the grasping parts to the same position.

In the third aspect of the present invention, the opening/closing device is connected to the grasping pawl and the back plate, and the opening/closing device and its driving device are made detachable. Since the body consists of only the grasping claw, its carrier, and the opening/closing device, the rotating body portion that rotates with the main shaft of the workpiece and drives the workpiece becomes lightweight, and the structure of the rotating body portion becomes simple. Furthermore, since the drive device of the opening/closing device is moved in the direction of moving the grasping claws and is arranged to also serve as a moving device for the grasping claws, the moving device for the grasping claws is excluded from the part that rotates together with the main shaft of the workpiece. The rotating part that drives the layered workpiece is lightweight and simple.

The fourth aspect of the present invention is to provide a cam groove and a cam follower between the grasping claw and the back plate to regulate the movement of the grasping claw, so that the grasping claw can be opened and closed only when the grasping center 02 or O5 is at a fixed position. Because of this, the grasping claws that grasp the workpiece do not move.

The fifth aspect of the present invention can be used at the main shaft end of a machine tool.

The sixth aspect of the present invention can be used for an autoloader or a robot.

[Brief explanation of the drawing]

1 and 2 are front views of the embodiment of the present invention, FIG. 3 is a sectional view taken along line AA in FIG. 1, and FIG. 4 is a sectional view taken along line BB in FIG.
Fig. 5 is a plan view of Fig. 2, Fig. 6 (alb) is a front view of the back plate, Fig. 7 is a front view of the main shaft fixed position stop device, and Fig. 8 is a grinding machine according to an application example of the present invention. The plan view and FIG. 9 are perspective views showing an example of application to a grasping section of an autoloader and a robot. 1.1... Grasping claw 1 a, I'a... Cylindrical hole
2.2+. 6.3I... Grasping unit 4... Mover 4a... Movable base
4b...Roller axis 4c...Roller 5,5I/Pivot
6... Back plate 7... Guide groove 7a... Raceway surface 8, 81... Narrow l-8a. 81a1 female thread 9. - Opening/closing screws 9a, 9b -・
Male thread 9C...Tool handle 9d...Hexagonal punch hole
9C...Introduction part 10...Workpiece headstock 10a...Workpiece spindle 11...Movers 12...Bracket 12a
・・Long hole 13・・Collar 14・・Wrench 14ae
・Tip 15...Free vertical hand 16...Deceleration motor 16
a.. Output shaft 17. Torque limiter 18.. Disk 19.. Pin 20.. Flexible plate 21. Compression coil spring 22.. Wrench mounting member 23.. Saddle □ 24.
・Slide bearing 25・・Guide bar 25a・・
Fluid pressure cylinder 26...Slide 26a -Bracket part 26b, 26c...Stopper 27...Base 28...Guide bar 29...Slide bearing 3
0... Pin 61 ・Cylinder 32 ・Cam groove 32
aj2b - arc groove 52cm/straight groove 33...
Cam follower 34.Bracket 35.Stop position control plate 36.Pre-stop deceleration dog 37.Fixed position stop dog 68.Index plate δ8a..Notch groove 39
・・Remachine cover 41, 42・・Proximity switch 4
3. Guide member 44. Notch 45. Fluid pressure cylinder 46. Arrow 51. Machine base 52. Grinding wheel head 53.
... Grindstone 54 - Grinding wheel shaft 551 Toe pull 57 Tailstock 59 ... Center 61 Fist center 62 ... Main spindle fixed position stop bag [63 - Workpiece grasping head 64 ... Drive device and grasping claw moving device 71 - Attachment/detachment Head body 72, 7
21..Pinion 73..Cylinder 74..Rack 75.Loader arm 76..Guide block 77.
・Cylinder 100 Centered around the spindle. Patent applicant: Nippei Toyama Co., Ltd.

Claims (1)

[Scope of Claims] 1. A pair of gripping claws, one end of which is pivotally connected to the slider, are provided with a plurality of gripping parts for gripping the workpiece at opposing parts thereof, and the gripping centers of the plurality of gripping parts are the same. A workpiece grasping device, comprising: a back plate having a guide means for the movable element that moves to a position; a grasping claw opening/closing device; a driving device for the opening/closing device; and a grasping claw moving device. 2. The workpiece grasping device according to claim 1, wherein the guide means for the moving element is a guide that is engaged with the moving element and is provided on a line connecting a plurality of grasping centers of the grasping claws. 3. A nut is rotatably supported at the tips of a pair of grasping claws in parallel to a pivot that connects the grasping claws and the slider, and the nuts are mutually opposite-handed female threads that are perpendicular to the axis of rotation of the nut. The opening/closing male screw, which is made by dividing one shaft into two and providing opposite-handed male threads, can be screwed into each nut, making it possible to move parallel to the line connecting the gripping centers of the multiple gripping parts of the gripping claw. A guide means for guiding the opening/closing screw is provided between the opening/closing screw and the back plate, a tool handle is provided on the opening/closing screw, a wrench is detachably attached to the tool handle, and the wrench is connected to the rotating prime mover via a shaft coupling. 3. The workpiece grasping device according to claim 1, further comprising a wrench and means for attaching and detaching an opening/closing male screw. 4. A cam follower is fixed to one of the pair of grasping claws and the back plate, and a cam groove in which the cam follower engages is provided on the other, and the cam groove is the grasping center of the plurality of grasping parts of the grasping claw. The first position parallel to the line connecting the cam followers and engaged by the cam follower when the grasping claws are opened to a greater extent than the maximum opening for grasping the workpiece, or when the grasping claws are fully closed without grasping the workpiece. a linear groove and a circular arc centered on a pivot shaft to which a cam follower can engage a grasping pawl at a position where the grasping center of the grasping section grasps a predetermined workpiece from the first linear groove; 3. The workpiece gripping device according to claim 2, characterized in that the workpiece gripping device is formed of a groove. 5. The workpiece grasping device according to any one of claims 1 to 4, wherein the back plate is fixed to a main shaft end of a workpiece headstock of a machine tool. 6. The workpiece grasping device according to any one of claims 1 to 4, wherein the back plate is fixed to an autoloader or a robot.