JP2549847Y2 - Work holding device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work gripping device which is used in a transfer device for transferring a work.
In particular, the present invention relates to an improvement in a driving mechanism of a claw member for gripping a work.

[0002]

2. Description of the Related Art In a production plant for automobile parts and the like in which the production process is relatively automated, a loader device and an unloader device for automatically loading and unloading a work to and from a processing device on a production line are transported. Many devices have been introduced. Among them, many of the transfer devices such as so-called robots are provided with a work gripping device at a portion corresponding to a hand, and provided at a tip of an arm member with a gripping mechanism corresponding to each work. The work gripping device automatically performs operations such as gripping the work at the receiving position and releasing the work at the processing position of the processing device. Then, in a kind of such a work gripping device, a plurality of claw members equally arranged in a circumferential direction around the one axis in a plane perpendicular to the one axis are driven in association with each other in the radial direction. There is a type in which a work is gripped and released by being moved toward and away from each other. FIGS. 9 to 13 show two examples of such a work holding device.

[0003] A workpiece gripping device 11 shown in Figs.
0 is an example in which a rack and a pinion are used for the internal mechanism, FIG. 9 is a front view as viewed from the axial direction of the work, and FIG.
And FIG. 11 are a sectional view taken along line XX and a sectional view taken along line XI-XI of FIG. In the case of this device, three claw member holders 114 and 11 to which three claw members 112 are respectively attached are provided.
6, 118 are uniformly arranged in the circumferential direction in one plane perpendicular to the axial direction of the workpiece to be gripped, and LM
It is arranged movably in the radial direction via guides 120, 122, 124, 126. Those claw member holders 11
4, 116, 118 are racks 128, 130,
132, and their racks 128, 130,
132 meshes with a pair of pinions 134. The rod 1 integrally connected to the claw member holder 114
Reference numeral 36 denotes a cylinder or the like in the axial direction thereof,
Are reciprocated in the up and down direction, the three claw member holders 114, 116, and 118 are interlocked, and the three claw members 112 are moved toward and away from each other.

Further, a work holding device 140 shown in FIGS. 12 and 13 is an example in which a cylinder is incorporated in a chuck body. FIG. 12 is a front view seen from the axial direction of the work, and FIG. FIG. In the case of this apparatus, three claw member holders 142 to which claw members (not shown) are respectively attached are equally arranged in the circumferential direction in one plane perpendicular to the axial direction of the workpiece to be gripped, and include the axes thereof. The pins are rotatably disposed around three pins 144 respectively perpendicular to the three planes. On the other hand, a piston 148 is provided in the chuck body 146 concentrically with the axis of the workpiece, and the three claw member holders 14 engaged with the piston 148 are provided.
2 is rotated in conjunction with the projecting and retracting operations of the piston 148.

[0005]

However, in the former case, in which the claw member holder provided with the rack meshing with the pinion is guided in the radial direction by the LM guide, rattling of the rack and pinion and breakage of the meshing teeth may occur. This tends to cause the gripping operation of the claw member to vary or to be unable to obtain a gripping force, and a large moment acts on the LM guide due to the lateral load caused by the engagement between the rack and the pinion. The sliding portion is easily damaged, and there is a problem in its durability in terms of strength. On the other hand, in the case of the latter provided with the claw member holder that engages with the piston, the cylinder is provided in the axial direction of the work, so that the thickness dimension of the chuck body cannot be inevitably increased. In addition to being inapplicable to a narrow processing apparatus, there is a disadvantage that the type of work that can be gripped is limited because the movement of the claw member is an arc movement.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a work gripping device having sufficient durability and versatility to a work, and having a small thickness and a compact structure. Is to provide.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a transfer device for transferring a work, which is disposed in a plane perpendicular to one axis. A work holding device of a type in which a plurality of claw members are driven in conjunction with each other in the radial direction to approach and separate from each other, thereby holding and releasing a work, wherein (a) a chuck body, and (b) a chuck body. A mounting surface on which the claw member is mounted is provided on the chuck body so as to be movable in a radial direction perpendicular to the one axis, and an engagement projecting in a direction parallel to the one axis behind the mounting surface. A plurality of claw member holders each having a projection,
(C) a plurality of spiral cam grooves respectively engaging with the engagement protrusions of the plurality of claw member holders, and an engagement portion having an abutment surface parallel to the uniaxial center; The plurality of claw member holders are arranged to be rotatable about the one axis and driven in the first rotation direction to drive the plurality of claw member holders toward the inner peripheral side to approach each other, while the first
A cam member which is rotated in a second rotation direction opposite to the rotation direction to drive the plurality of claw member holders to the outer peripheral side to be separated from each other; and (d) in a plane perpendicular to the one axis. A cylinder bore having an axis substantially parallel to the rotation locus of the engaging portion of the cam member and provided in the chuck body, and a push portion to be brought into contact with the engaging portion on one end side. And a piston disposed in the cylinder bore so as to be capable of linearly reciprocating movement, and a fluid pressure is applied to the other end of the piston so that the pushing portion is pushed out from the cylinder bore side to push the piston. A single-acting cylinder that pushes the engaging portion, and that rotates the cam member in one of the first rotation direction and the second rotation direction in which the claw member grips the work. (E) driving the single-acting cylinder By rotating the cam member, which has been further rotated, in a direction opposite to the one rotation direction, the thrusting portion of the piston is kept in contact with the engaging portion, and the cylinder bore side is maintained. And a return means for pushing back.

The return means is constituted, for example, in the same manner as the single-acting cylinder and is provided with another single-acting cylinder provided so as to push another engaging portion provided on the cam member, or the chuck. It is constituted by a spring member or the like disposed between the main body and one end of the cam member.

[0009]

In the above-described work holding device, the pushing portion of the piston pushes the engaging portion of the cam member by driving the single-acting cylinder, so that the cam member is moved in the first rotation direction and the second rotating direction. The plurality of claw member holders rotated in one of the rotation directions and engaged with the cam groove of the cam member via the engagement protrusion are driven in the inner circumferential direction or the outer circumferential direction. To or away from each other. Thereby, the claw member attached to the claw member holder grips the work. On the other hand, when the fluid pressure, which is the driving source of the single-acting cylinder, is released, the cam member is rotated in a direction opposite to the one rotation direction by the return means,
The plurality of claw member holders are driven in the opposite direction so that the claw members release the work, and the pushing portion of the piston is retracted while maintaining the abutting state with the engaging portion of the cam member, and the piston is retracted. It is pushed back to the end side. In this case, the single-acting cylinder is driven by a pushing portion that presses each other in a direction substantially along the rotation locus of the engaging portion of the cam member and the engaging portion, and a cam mechanism including the cam groove and the engaging projection. The force is transmitted very smoothly, and no large moment acts on the member for guiding the claw member holder in the radial direction from the lateral direction. For this reason, rattling or damage is less likely to occur in a portion that receives a force acting due to the driving force of the single-acting cylinder, and the claw member holder is compared with a conventional work gripping device in which a driving mechanism is configured by a rack and a pinion. And the durability of the cam member is sufficiently ensured.

In addition, since the cam member and the single-acting cylinder are disposed in a plane perpendicular to the axis, the thickness of the chuck body in the direction of the axis does not extremely increase, and the cylinder can be moved in one direction. It is possible to make the work gripping device thinner and more compact than in the case of disposing it in the axial direction. Further, since the claw member holder is linearly reciprocated in the radial direction, a larger movement stroke of the claw member can be secured as compared with a conventional work gripping device in which the claw member holder and the like are moved in an arc. Within the range, various works having different diameters can be gripped.

On the other hand, when the single-acting cylinder is driven,
The pushing portion of the piston pushes the engaging portion until the claw member grips the workpiece, and when the cam member is rotated in the opposite rotation direction by the return means, the pushing portion engages with the pushing portion. Because the piston is pushed back while the contact state with the part is maintained, the cam member is moved in both rotation directions by a double-acting cylinder using a combination of a rack and a pinion or an engagement between a pin and a long hole, for example. Compared to the case of driving, the abrasion resistance and impact resistance at the engagement portion between the piston and the cam member are excellent, and high durability is obtained.
Even if wear occurs at the contact point between the push end of the piston and the contact surface of the engaging portion of the cam member, the stroke between the piston and the cam member is increased only by a slight increase in the stroke of the piston. There is no danger of rattling or the like, and problems such as instability of the gripping operation and breakage of each part can be satisfactorily avoided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a partially cutaway front view of the work gripping device 10 according to one embodiment of the present invention. The chuck body 12 is integrally attached to the distal end of an arm 14 of a loader device as a transfer device. As can be seen from FIG. 3, which is a cross section taken along line III-III in FIG. 14, a second member 12b connected to the side opposite to the arm 14 with respect to the first member 12a, and a second member 12b
The third member 12c is fixed to the second member 12b so as to substantially cover the front opening of the third member 12b, and the fourth member 12d is fixed to the front side of the third member 12c. . Between the second member 12b and the third member 12c, a shaft 18 is erected on one central axis, and the center of the shaft 18 is set in a plane perpendicular to the axis of the shaft 18 with respect to the axis 120. Three claw member holders 20 are provided in three directions divided into three equally spaced angles. The third member 12c and the fourth member 1
2d is composed of three child parts 22 and 24 each divided by the above three directions. Further, the internal cross section of the arm 14, the first member 12a, and the second member 12b in FIG. 3 shows a cross section partially shifted from the position of III-III shown in FIG.

As shown in FIG. 4, which is a cross-sectional view taken along the line IV-IV in FIG. 2, the claw member holder 20 is configured such that the child parts 22 and 24 of the third member 12c and the fourth member 12d are moved relative to the second member 12b. It is slidably fitted into a guide rail 26 having a T-shaped cross section formed by being fixed by being fixed in a radially linear manner. A claw member 30 is integrally fixed to a mounting surface 28 provided on the front side of the claw member holder 20 by bolting, and the three claw member holders 20 are driven in conjunction with each other from the inner peripheral side to the outer peripheral side. As a result, the three claw members 30 abut on and engage with the inner peripheral surface 34 (see FIG. 3) of the work 32 from the axis to the outer circumferential direction, thereby gripping the work 32. . Further, the claw member holder 20 has an engagement protrusion 36 protruding rearward of the mounting surface 28 in parallel with the axis and in the rearward direction, that is, rightward in FIG. On the other hand, a cam groove 40 is formed on the front side of the cam member 38 rotatably disposed around the shaft 18, that is, on the left side surface of the flange portion 39 in FIG. 3. The engagement protrusion 36 is engaged.

As is apparent from FIG. 5, which shows a part of a cross section taken along the line VV in FIG. 3, the cam groove 40 is uniformly formed in the circumferential direction corresponding to the engaging projection 36 of the claw member holder 20. It is provided in a spiral shape at three spaced locations, and each of the cam grooves 40 is accurately formed such that the same spiral shape is shifted by a phase of 120 °. Therefore,
The engagement projections 36 respectively engaged with the three cam grooves 40 are:
The respective radial positions are kept even, and the cam member 38 is rotated counterclockwise to the shaft 18 in FIG. Side, and the claw member holder 20 is moved to the outer peripheral side via the engagement protrusion 36, while the cam member 38 is rotated clockwise so that the engagement protrusion 36 is located outside the cam groove 40. Wall 4
The claw member holder 20 is moved to the inner peripheral side while being pulled into the inner peripheral side while slidingly contacting 1b. A bush 42 for smooth rotation is inserted between the cam member 38 and the shaft 18. In this embodiment, the clockwise direction in FIG. 5 corresponds to the first rotation direction, and the counterclockwise direction corresponds to the second rotation direction.

FIG. 1 is a sectional view of the work gripping device 10 as viewed from the rear side. On the back side of the cam groove 40 in the flange portion 39 of the cam member 38, a pair of engaging portions 48 and 50 having contact surfaces 44 and 46 respectively parallel to the axis of the shaft 18 are integrally formed with the hub portion 52. Is provided. The contact surfaces 44 and 46 are formed in a partially cylindrical curved surface having a predetermined curvature, and
8, 50 are arranged symmetrically in FIG. A pair of single-acting cylinders for rotating and driving the cam member 38 are provided in the direction in which the contact surfaces 44 and 46 of the pair of engaging portions 48 and 50 are opposed to each other, that is, above them in FIG. 54 and 56 are chuck bodies 1
2 and are integrally incorporated.

The single-acting cylinder 54 on the side of the engagement portion 48 has an axis substantially parallel to the rotation locus of the engagement portion 48 when the cam member 38 rotates in a plane perpendicular to the axis of the shaft 18. Cylindrical member 59 having a cylinder bore 58 formed therein
And a piston 66 having a pushing portion 62 abutting on the engaging portion 48 on one end side and arranged in the cylinder bore 58 so as to be able to linearly reciprocate. The single-acting cylinder 56 on the side of the engaging portion 50 has an axis substantially parallel to the rotation locus of the engaging portion 50 when the cam member 38 rotates in a plane perpendicular to the axis of the shaft 18. Cylinder bore 6
0 having a bottomed cylindrical member 61 and a pushing portion 64 to be brought into contact with the engaging portion 50 at one end, and a piston 6 disposed in the cylinder bore 60 so as to be able to linearly reciprocate.
8 is provided. On the other hand, the oil passage 70 in the first member 12a
Hydraulic oil is led into the arm 72 through the arm 14, and the hydraulic pressure of the hydraulic oil adjusted to a predetermined pressure by a hydraulic circuit (not shown) is alternately applied by switching the switching valve. Thereby, the piston 6
6, 68, that is, inside the upper ends of the cylinder bores 58, 60 in FIG.
Hydraulic oil is supplied through the.

The contact surfaces 44 of the engaging portions 48 and 50
Pushing parts 62 and 64 respectively abutting on
Is a flat surface perpendicular to the axial direction of the cylinder bores 58, 60. In addition, the pistons 66 and 68 have a portion on the side of the push portions 62 and 64, that is, a lower portion of FIG. Are notched with a gap with the flange portion 39, and slits 74 and 76 are respectively provided in a part of the outer peripheral surface along the axial direction, and the slits 74 and 76 are provided. The rotation preventing pins 80 formed at the tips of the bolts 78 from the outer peripheral side engage with each other to prevent the pistons 66 and 68 from rotating around the axis.

When the hydraulic oil is supplied to the single-acting cylinder 54, the piston 66 is moved inside the cylinder bore 58 in a direction in which the piston 62 protrudes the pushing portion 62, that is, downward in FIG. At the same time as pushing the engaging portion 48 of the cam member 38 to rotate the cam member 38 clockwise of the shaft 18, the pushing portion 64 abutting on the engaging portion 50 on the single-acting cylinder 56 side is retracted, Push piston 68 back into cylinder bore 60. At this time, since there is a resistance to send out the hydraulic oil in the cylinder bore 60 to the hydraulic circuit side, the cam member 38 has an appropriate operating speed.
Is rotated. Thereby, the claw member holder 20 is driven in the outer peripheral direction to be separated from each other, and the claw member 30 grips the work 32. When the work 32 is not present, the piston 68 is not connected to the cylinder bore 60.
1 is pushed back to the other end side, ie, the upper moving end in FIG. On the other hand, when the hydraulic oil is supplied to the single-acting cylinder 56 side, the piston 68 is moved in the cylinder bore 60 in the direction of protruding the pushing portion 64, that is, downward in FIG. At the same time as pushing the engaging portion 50 of the cam member 38 to rotate the cam member 38 counterclockwise of the shaft 18, the pushing portion 6 abutting on the engaging portion 48 on the single-acting cylinder 54 side.
2 is retracted, and the piston 66 is pushed back to the other end in the cylinder bore 58, that is, to the upper moving end in FIG. As a result, the claw member holders 20 are driven in the inner circumferential direction to approach each other, and the claw members 30 release the work 32. Therefore, the above operation is alternately repeated by switching the operation state of the hydraulic oil pressure. In this case, the single-acting cylinder 56 and the engaging portion 50 function as return means.

On the front side of the fourth member 12d, a claw member 86 of a type for gripping the outer peripheral surface 84 of the work 82 as shown in FIG. , A pressing plate 88 functioning as described above is provided. The pressing plate 88 has a disk shape and has three notches 90 each having a predetermined gap from a radial movement space of the three claw member holders 20 as shown in FIG. It has. The pin 94 screwed to the tip of the shaft 18 is passed through the center of the through hole 92 of the pressing plate 88, so that the pressing plate 88 is supported movably in the axial direction of the shaft 18. 6 is allowed to move forward, ie, leftward in FIG. And
Between the pressing plate 88 and the second member 12b, pressing projections 98 urged by a compression coil spring 96 are disposed at three positions evenly spaced in the circumferential direction near the outer periphery. 88 is urged forward. FIG. 3 shows the pressing plate 88.
Is biased by the compression coil spring 96 and is located at the front moving end.

Therefore, when the work 82 is gripped,
When the arm 14 is driven forward in the axial direction of the shaft 18, the pressing plate 88 abutted on the work 82 is moved rearward against the urging force of the compression coil spring 96, and the state is maintained. When the single-acting cylinder 56 is driven, the work 82 is gripped by the claw member 86 (the state shown in FIG. 6), but when the work 82 is released, the pressing plate is pressed by the urging force of the compression coil spring 96. 88 functions to push the work 82 forward. This is a mechanism for pressing the work 82 against the chuck of the spindle so that the work 82 is accurately positioned and gripped by the chuck of the spindle when the work 82 is carried into a chuck of the spindle such as a lathe. It is. In the case where the claw member 86 is used by being attached to the claw member holder 20 as described above, the single-acting cylinder 54 and the engaging portion 48 function as return means.

Next, the operation in the case where the work gripping device 10 configured as described above is used with the claw member 30 mounted thereon will be described.

First, when hydraulic pressure is applied to the hydraulic oil in the oil passage 72 and the hydraulic oil is supplied from the oil passage 72 to the single-acting cylinder 56, the pushing portion 64 of the piston 68 makes contact with the contact surface 46. The cam member 38 is turned in the first counterclockwise direction of the shaft 18 in FIG. This rotation stops when the piston 66 pushed back to the engagement portion 48 reaches the other end of the cylinder bore 58 as shown in FIG. The positional relationship of the claw member holder 20 in this state is as follows.
As shown in FIG. 8, the engagement projections 36 engaged with the cam grooves 40 are located on the innermost side and are brought closest to each other, and as shown by a dashed line in FIG.
The outer diameter of the tip portion is the smallest. Arm 1 in this state
4 is driven to the receiving position of the work 32, and the tip of the claw member 30 is inserted into the inner peripheral surface 34 of the work 32.

Next, when the switching valve of the hydraulic circuit is switched, hydraulic pressure is applied to the hydraulic oil in the oil passage 70 and the hydraulic oil is supplied from the oil passage 70 to the single-acting cylinder 54 side. The pushing member 62 pushes the engaging portion 48 in a state of contact with the contact surface 44, and the cam member 38
Is rotated in the second clockwise direction of the shaft 18. This rotation stops when the claw member 30 presses the inner circumferential surface 34 of the work 32 in the outer circumferential direction and grips the work 32 properly. At this time, as shown in FIG. 5, a force corresponding to the projecting force of the pushing portion 62 based on the hydraulic pressure acting on the other end of the piston 66 is applied to the engaging projection 36 of the claw member holder 20 by the cam groove. Although it is made to act in the contact direction via the inner wall surface 41a of the inside 40, the lateral moment applied to the guide rail 26 from the claw member holder 20 based on this force is small. When the gripping of the work 32 is completed,
The arm 1 is held in a state where the gripping force for the work 32 is held.
4 is driven, and the work gripping device 10 is moved to a release position where the work 32 should be released.

When the work gripping device 10 is positioned at the release position, the switching valve of the hydraulic circuit is switched again to supply the operating oil from the oil passage 72 to the single-acting cylinder 56 side, and the pushing portion 64 of the piston 68 is pushed. The engagement portion 50 is pushed to rotate the cam member 38 in the first rotation direction, and the gripping state of the work 32 is released. When the work 32 is completely released and the piston 66 reaches the moving end on the other end side in the cylinder bore 58 and is moved to the position where the claw member holder 20 is closest, the arm 14 is again received by the work 32. Position, and thereafter the above operation is repeated.

In the operation when the work 82 is gripped and released by the claw member 86, the operation state of the hydraulic pressure applied to the single-acting cylinders 54 and 56 by the switching valve of the hydraulic circuit is simply reversed. , The detailed description thereof will be omitted.

As described above, the work holding device 1 of the present embodiment
0, the pushing portions 62, 64 and the engaging portions 48, 50 which press each other in a direction substantially along the rotation locus of the engaging portions 48, 50 of the cam member 38, and the cam groove 40 of the cam member 38. The driving force of the single-acting cylinders 54 and 56 is transmitted very smoothly by the cam mechanism including the engaging projections 36 of the claw member holder 20 and the guide rail 26 that guides the claw member holder 20 in the radial direction. Large moment does not act from the lateral direction. For this reason, damage is less likely to occur in a portion that receives a force acting due to the driving force of the single-acting cylinders 54 and 56, and compared with the work gripping device 110 in FIGS. Thus, the durability of the claw member holder 20 and the cam member 38 is sufficiently ensured.

Since the cam member 38 and the pair of single-acting cylinders 54 and 56 are disposed in a plane perpendicular to the axis of the shaft 18, the thickness of the chuck body 12 in the axial direction of the shaft 18 is extremely small. Therefore, it is possible to make the entire apparatus thinner and more compact than when a double-acting cylinder or the like is disposed in the axial direction. This makes it possible to supply the workpieces 32, 82, etc., even to a processing device in which the space for entering the workpiece gripping device 10 is narrow.

Further, since the claw member holder 20 is linearly reciprocated in the radial direction, the claw member holder and the like engaged with the cylinder disposed in the axial direction are caused to perform an arc movement as shown in FIGS. The moving stroke of the claw member holder 20 can be secured larger than that of the work holding device 140,
The pawl members 30 and 86 can grip various works 32 or 82 having different diameters within the range of the movement stroke.

Further, in the work gripping device 10 of the present embodiment, a pair of single-acting cylinders 54 and 5 for rotating the cam member 38 in the second rotation direction and the first rotation direction, respectively.
6 is arranged, and one of them is made to function as a return means for one of them.
A claw member 30 that engages with and grips the inner peripheral surface 34 of the work 32 without disposing a dedicated member as a return unit;
Claw member 86 that engages with and grips outer peripheral surface 84 of work 82
There is an advantage that both types of claw members can be mounted and used.

In the work gripping device 10 of this embodiment, when the single-acting cylinders 54, 56 are driven during the gripping operation, the pistons 66, 86 are held until the pawl members 30, 86 grip the workpieces 32, 82. While the pushing portions 62 and 64 push the engaging portions 48 and 50, the single-acting cylinders 56 and 54 are driven as a return means at the time of the releasing operation to rotate the cam member 38 in the opposite rotation direction. In this case, since the pistons 66 and 68 are pushed back while the contact state between the pushing portions 62 and 64 and the engaging portions 48 and 50 is maintained, for example, a combination of a rack and a pinion or a pin and a length is used. Compared to a case in which the cam member is driven in both rotation directions by a double-acting cylinder using engagement with the holes, wear resistance and resistance to the engagement between the pistons 66 and 68 and the cam member 38 are reduced.撃性 excellent, high durability can be obtained. Further, the contact surfaces 44 of the tips of the pushing portions 62, 64 of the pistons 66, 68 and the engaging portions 48, 50 of the cam member 38,
Even if wear occurs at the point of contact with the
There is no danger of rattling between the pistons 66 and 68 and the cam member 38 due to a slight increase in the strokes of the cylinders 6 and 68, and the gripping operation becomes unstable or each part is damaged. The problem is well avoided.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above-described embodiment, the work gripping device 10 disposed at the tip of the arm 14 of the loader device has been described. However, in another work gripping device disposed on a turret head of an NC lathe or the like. The present invention can be similarly applied.

Further, in the above-described embodiment, the three claw members 30 or the three claw members 86 are 12
Although the case has been described in which the positions are evenly arranged at three positions every 0 °, the number and the arrangement positions of the claw members 30 and 86 can be appropriately changed.

In the above-described embodiment, both types of the claw member 30 that engages and grips the inner peripheral surface and the claw member 86 that engages and grips the outer peripheral surface are used. Although it has been assumed that the member can be attached, even in the case of a work gripping device that is configured exclusively for one type of claw member by providing only one single-acting cylinder, etc. good.

In the above-described embodiment, the engagement protrusion 36 of the claw member holder 20 is engaged with the cam groove 40 of the cam member 38 as it is.
A roller may be provided between the cam groove 40 and the roller so that the roller comes into rolling contact with the cam groove 40. In this case, the generation of frictional heat at the contact portion is suppressed, and the rotational driving force of the cam member 38 is more efficiently converted into the gripping driving force of the claw member holder 20.

In the above-described embodiment, the contact surfaces 44, 46 of the engaging portions 48, 50 of the cam member 38 are formed into a partially cylindrical curved surface, and the single-acting cylinder 54,
Pushing portions 62, 64 of pistons 66, 68 at 56
Are flat, but instead, the contact surfaces 44 and 46 are made flat and the pushing portions 62 and 64 are pressed.
A relatively smooth sliding contact state can be obtained even if the tip of the first member is formed into a partial cylindrical curved surface.

Further, the cam member 38 in the above-described embodiment is used.
The cam groove 40 has a spiral shape in which the clockwise direction around the shaft 18 in FIG. 5 is the first rotation direction and the clockwise direction is the second rotation direction in the counterclockwise direction. And the shaft 1 in FIG.
A cam member in which a cam groove is formed in a spiral shape such that the left rotation around 8 is the first rotation direction and the right rotation is the second rotation direction may be used. In this case, the supply control of the hydraulic oil by the switching valve of the hydraulic circuit is performed in a manner reverse to that of the above-described embodiment.

In the above-described embodiment, the cylinder bores 58, 60 are provided by the bottomed cylindrical members 59, 61 assembled in the chuck body 12, but the cylinder bores 58, 60 are not necessarily separate from the chuck body 12. It is not necessary to constitute the body, and the cylinder bores 58 and 60 may be formed directly in the chuck body 12.

In the above-described embodiment, the engaging portions 48 and 50 of the cam member 38 are provided on the back side of the flange portion 39. However, the engaging portions may be provided on the outer peripheral side of the flange portion 39. Alternatively, a cylinder bore of a single-acting cylinder may be provided in the same plane as the flange portion 39 corresponding to the engaging portion. In this case, the thickness of the chuck body can be further reduced.

In the above-described embodiment, the pushing portions 62 and 64 are provided integrally with the pistons 66 and 68, respectively. However, the pushing portions 62 and 64 are pushed from other members integrally connected to the piston by screwing or the like. The part may be configured.

In the above-described embodiment, the hydraulic oil is supplied from the hydraulic circuit to the other ends of the pistons 66, 68 in the single-acting cylinders 54, 56. When a large gripping force is not required, for example, when air is supplied, air may be supplied from the pneumatic circuit.

Further, the piston 6 in the above-described embodiment is used.
The slits 74 and 76 are formed in the 6, 68, respectively, and the detent pins 80 are engaged. However, it is not always necessary to provide such a detent mechanism.

In the above-described embodiment, a pair of single-acting cylinders 54 and 56 are provided, and when they are driven to release the work, they function as return means, respectively. In the case of a dedicated workpiece gripping device of either an inner diameter gripping type nail member or an outer diameter gripping type nail member, it is not always necessary to use a single-acting cylinder as the return means. A compression coil spring inserted between the chuck body 12 and the engaging portion 50; a tension coil spring having one end locked to the chuck body 12 and the other end locked to the cam member 38; And one end and the other end thereof are wound around the chuck body 1.
The return means can be configured by using a spring member such as a torsion coil spring locked to the cam member 38 and the cam member 38, or using an electrically operated device such as a solenoid.

In the above embodiment, the work 8
2, a pressing plate 88 for pressing when releasing is provided.
Providing such a member is not essential in the present invention.

Although not specifically exemplified, the present invention can be embodied in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a work gripping device according to one embodiment of the present invention as viewed from the back side.

FIG. 2 is a front view of the work holding device of FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is a view showing a cross section taken along line VV in FIG. 3 with a part thereof omitted;

FIG. 6 is a diagram illustrating a case where a claw member of a different type from the claw member in FIG. 2 is used.

7 is a view for explaining the operation when the work gripping device of FIG. 1 uses the claw member of FIG. 2, and is a cross-sectional view of the work gripping device as viewed from the back side.

8 is a diagram for explaining an operation when the work gripping device in FIG. 1 uses the claw members in FIG. 2, and is a diagram corresponding to FIG. 5;

FIG. 9 is a front view illustrating an example of a conventional work holding device.

FIG. 10 is a sectional view taken along line XX in FIG. 9;

FIG. 11 is a sectional view taken along line XI-XI in FIG. 9;

FIG. 12 is a front view illustrating another example of a conventional work holding device.

13 is a sectional view taken along the line XIII-XIII in FIG.

[Explanation of symbols]

 10: Work gripper 12: Chuck body 20: Claw member holder 28: Mounting surface 30, 86: Claw member 32, 82: Work 36: Engagement projection 38: Cam member 40: Cam groove 44, 46: Contact surface 48 , 50: engaging portion 54, 56: single acting cylinder 58, 60: cylinder bore 62, 64: pushing portion 66, 68: piston

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Yoshinori Murakami 6 Toyota Town, Toyota City, Aichi Prefecture Kyoho Manufacturing Co., Ltd. (56) References JP-A-60-5032 (JP, A) JP-A-55- 106781 (JP, A) Japanese Utility Model 4-79803 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A plurality of claw members disposed on a transfer device for transferring a work and disposed in a plane perpendicular to one axis are driven in conjunction with each other in a radial direction to approach and separate from each other. A workpiece gripping device of a type for gripping and releasing the workpiece, wherein the chuck body and the chuck body are respectively disposed movably in a radial direction orthogonal to the one axis, and the claw member is provided. A plurality of claw member holders each including a mounting surface to be mounted, and an engagement protrusion protruding in a direction parallel to the one axis on the rear side of the mounting surface; and the engagement protrusions of the plurality of claw member holders. A plurality of spiral cam grooves to be engaged with each other, and an engaging portion having a contact surface parallel to the one axis are provided on the chuck main body so as to be rotatable around the one axis. Rotate in the first rotation direction As a result, the plurality of claw member holders are driven toward the inner peripheral side to approach each other, while being rotated in a second rotation direction opposite to the first rotation direction, the plurality of claw member holders are moved. A cam member driven to the outer peripheral side to be separated from each other, and provided on the chuck main body having an axis substantially parallel to a rotation locus of an engaging portion of the cam member in a plane perpendicular to the one axis. A cylinder bore, and a piston having a pushing portion to be brought into contact with the engagement portion on one end side and arranged in the cylinder bore so as to be able to linearly reciprocate, and a fluid pressure on the other end side of the piston. Is actuated and the pushing portion is pushed out from the cylinder bore side, so that the pushing portion pushes the engaging portion, and the claw member in the first rotation direction and the second rotation direction is The cam portion is moved in one rotation direction for gripping the work. A single-acting cylinder for rotating the material, and the cam member rotated by the driving of the single-acting cylinder is rotated in a direction opposite to the one rotation direction, so that the pushing portion of the piston is pushed. A work holding device comprising: a return unit that pushes back to the cylinder bore side while maintaining a contact state with the engagement portion.