JP2018075695A - Gripper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gripper which enables quick change of jaws.SOLUTION: A gripper 1 supports a workpiece with multiple jaws 10. Each jaw 10 includes: a master jaw 11 which is provided so as to slide in a radial direction; and a clamp jaw 60 which supports the workpiece. The master jaw 11 has: a shaft hole 13; and a removal prevention member 15 which is slidably inserted into a through hole 14 communicating with the shaft hole 13. The clamp jaw 60 has: a shaft part 61 which fits in the shaft hole 13; and a workpiece support part 62. The shaft part 61 is inserted into the shaft hole 13 and a tip of the removal prevention member 15 engages with an engagement part 63 to detachably attach the clamp jaw 60 to the master jaw 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gripper used for conveying an article or the like with an industrial robot or the like.

  Some industrial robots have a gripper attached to the tip of an articulated arm in order to grasp and carry an article. Gripper includes hand type that imitates human hand and suction cup type that uses vacuum suction. However, if the target article is a machined product (work), it can be used for assembly as well as transportation. Since it is used, high accuracy is required. For this reason, a gripper of a type similar to a chuck used in a machine tool such as a lathe is often used for transferring a workpiece.

  Conventional examples of chucks used in machine tools include, for example, Patent Document 1 and Patent Document 2. In general, in this type of chuck, a plurality of radially sliding jaws are radially arranged on the front surface of a cylindrical chuck body. As these jaws slide toward the center, the workpiece disposed in the front center of the chuck body is sandwiched by the jaws.

  The jaw includes a master jaw that is slidably supported on the chuck body, and a clamp jaw that is detachably attached to the master jaw and grips a workpiece. The clamp jaw is replaced according to the workpiece to be supported.

  In a machine tool, since a workpiece supported by a chuck is processed, it is necessary to firmly support the workpiece. Therefore, the clamp jaw is generally fixed to the master jaw by fastening bolts. Specifically, screw holes (usually two) are formed on the front surface of the master jaw. A bolt hole that overlaps the screw hole is formed in the clamp jaw so as to penetrate from the front surface to the back surface of the clamp jaw. A counterbore hole for receiving the head of the bolt is recessed in the front surface of the clamp jaw. Then, the clamp jaw is fixed to the master jaw by screwing the bolt inserted into the bolt hole into the screw hole.

JP 2014-237212 A Japanese Patent Laying-Open No. 2015-58529

  In the gripper similar to the chuck described above, the clamp jaw is generally fastened and fixed to the master jaw by a bolt with the same structure as the chuck.

  Therefore, when replacing the clamp jaws, the bolts that clamp all the clamp jaws are removed and replaced with another clamp jaws, and then the bolts are tightened to fix the clamp jaws to the master jaw. Such work is necessary.

  In addition, since the size and shape of the workpiece that can be handled by one clamp jaw is limited, the replacement operation of the clamp jaw is a heavy burden especially in fields where there are many types of workpieces handled, such as industrial robots. .

  Also, since the counterbore hole is recessed in the front surface of the clamp jaw, when gripping the workpiece, the workpiece may come into contact with the edge of the counterbore hole, and the workpiece may be damaged or deformed. .

  SUMMARY OF THE INVENTION An object of the present invention is to provide a gripper that can prevent damage to a workpiece and that allows a jaw to be quickly changed according to a workpiece to be gripped.

  The disclosed means relates to a gripper that supports a workpiece located at a central portion with a plurality of jaws that slide in a radial direction.

  Each of the jaws includes a master jaw provided on the gripper main body so as to be slidable in a radial direction, and a clamp jaw attached to the master jaw and supporting a workpiece. The master jaw includes a shaft hole extending perpendicular to the sliding direction, a through hole communicating with the shaft hole from the outside in the radial direction of the shaft hole, and a slidably inserted into the through hole so that a tip is formed in the shaft hole. A retaining member capable of protruding. The clamp jaw is fitted to the shaft hole and has a shaft portion formed with an engagement portion that engages with the distal end of the retaining member, and a workpiece support portion that is provided at the base end of the shaft portion and supports the workpiece. And have. The clamp jaw is detachably attached to the master jaw when the shaft portion is inserted into the shaft hole and the tip of the retaining member is engaged with the engagement portion.

  In other words, this gripper is a type in which a workpiece is sandwiched and supported by two or more jaws that slide in the radial direction, and each jaw is configured by attaching a clamp jaw to a master jaw provided in the main body. The master jaw has a shaft hole extending in a direction perpendicular to the sliding direction (here, the cross-sectional shape may be circular or polygonal), and a through hole communicating with the shaft hole from the outside in the radial direction A retaining member is slidably inserted into the hole. On the other hand, the clamp jaw has a shaft part that fits into the shaft hole and a work support part that supports the work, and the shaft part is formed with an engaging part that engages with the tip of the retaining member. . The clamp jaw is detachably attached to the master jaw by inserting the shaft portion into the shaft hole and engaging the tip of the retaining member with the engaging portion.

  Therefore, if the retaining member is slightly slid so that the distal end of the retaining member protrudes into the shaft hole by the amount of engagement between the distal end of the retaining member and the engaging portion, the shaft portion cannot be extracted from the shaft hole. The shaft portion can be extracted from the shaft hole by sliding the retaining member slightly in the opposite direction to the extent that the engagement between the tip of the retaining member and the engaging portion is disengaged. That is, since the clamp jaw can be detached from the master jaw with a slight operation, a quick change of the clamp jaw is possible.

  Since the clamp jaw is attached to the master jaw via the shaft portion, it is not necessary to provide a bolt hole or counterbore hole in the work support portion. Therefore, there is no risk of damaging the workpiece at the edge of the counterbore hole, and the workpiece support portion can be made smaller or thinner. In addition, the strength of the clamp jaw is improved.

  Specifically, the master jaw has a master-side rotation restricting structure, and the clamp jaw cooperates with the master-side turn restricting structure so that the workpiece support portion is positioned. It is preferable to have a clamp side rotation restricting structure for restricting the rotation of the clamp jaw with respect to the master jaw.

  By doing so, the rotation of the clamp jaw is restricted, and the clamp jaw can be accurately positioned, so that the workpiece can be supported with high accuracy.

  In this case, the work support part has a plurality of holding parts for holding the work at different positions in the circumferential direction with respect to the center line of the shaft part, and the master side rotation restriction structure and the clamp side rotation restriction Depending on the structure, any one of the plurality of holding portions may be selected and used.

  That is, since it is not necessary to provide a bolt hole or counterbore hole in the work support part, in addition to increasing the degree of freedom of the form of the work support part, by the master side rotation restriction structure and the clamp side rotation restriction structure, Since the clamp jaw can be accurately positioned, a plurality of clamping portions can be formed on the workpiece support portion. Therefore, if a plurality of clamping parts are provided at different positions in the circumferential direction with respect to the center line of the shaft part, the clamp jaws can be rotated around the shaft part without removing the clamp jaws from the master jaws. To select and use the sandwiching part. Accordingly, the clamp jaw can be replaced more easily and in a shorter time.

  More specifically, the master jaw has a support surface that receives the work support portion when the clamp jaw is attached, and the shaft is arranged so that the work support portion is pressure-bonded to the support surface. You may make it the position of the front-end | tip of the said retaining member protruding in a hole and the position of the said engaging part being offset.

  If it does so, a clamp jaw can be firmly fixed to a master jaw only by sliding a retaining member slightly.

  Further, the master jaw communicates with the shaft hole and has an upstream fluid path through which fluid flows, and the clamp jaw, when attached to the master jaw, communicates with the upstream fluid path. It can also have a side fluid path.

  If it does so, since fluids, such as air, can be supplied to a clamp jaw through a master jaw, it is not necessary to carry out attachment or detachment work of a fluid course every time a clamp jaw is replaced, and it is excellent in workability.

  According to the present invention, the workpiece can be prevented from being damaged, and can be quickly changed to a jaw adapted to the workpiece to be gripped, so that a high-performance and easy-to-handle gripper can be realized.

It is the schematic which looked at the gripper of embodiment from the front. It is a schematic sectional drawing in the arrow II-II line in FIG. The master jaw is in the standby position. It is a figure equivalent to Drawing 2 showing the state where a master jaw is in a support position. It is a figure which shows an example of a clamp jaw. The longitudinal section (left side of the figure) and front (right side of the figure) of the clamp jaw are shown. In order to explain the fixing of the clamp jaw, a part of the figure is separately enlarged. It is a figure which shows another example of a clamp jaw. The longitudinal section (left side of the figure) and front (right side of the figure) of the clamp jaw are shown. It is the schematic which shows another form of the securing member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely illustrative in nature and does not limit the present invention, its application, or its use. In addition, when expressing a direction by description, unless it mentions especially, let the side by which a workpiece | work is supported be a front side, and let the opposite side be a back side.

  1 and 2 show a gripper 1 to which the present invention is applied. The gripper 1 is mainly used in an industrial robot in order to transport and assemble a gripping object (work) made of a material processed by a machine tool or a processed product. Therefore, in this embodiment, the case where the gripper 1 is used for the articulated arm 2 of the industrial robot will be described as an example.

  The gripper 1 has a disk-like appearance with a large thickness, and its end surface on the back side is attached by fastening a bolt B1 to an attachment surface 2a provided at the tip portion of the articulated arm 2. Yes. A plurality of (three in the illustrated gripper 1) jaws 10 that slide in the radial direction are provided on the end surface on the front side of the gripper 1 in order to grip the workpiece located at the center portion from the inside or the outside. Are arranged at equal intervals.

  Each jaw 10 includes a master jaw 11 provided on the main body of the gripper 1 and a clamp jaw 60 that supports the workpiece so that the jaws 10 can correspond to a plurality of workpieces having different sizes and shapes. The master jaw 11 is detachably attached. Although details will be described later, the clamp jaw 60 is devised so that it can be replaced, that is, quick-changed by a simple operation in a short time.

<Main body of gripper 1>
The main body of the gripper 1 is composed of a body 20, a piston 30, a plunger 40, a cover 50 and the like together with the master jaw 11. The body 20 is composed of a rear body 21 and a front body 22 in a cylinder shape.

  The rear body 21 is made of a bottomed cylindrical member, and includes a disk-shaped bottom wall portion 21a that constitutes the bottom surface, and a cylindrical peripheral wall portion 21b that is continuous with the periphery of the bottom wall portion 21a.

  The front body 22 is made of a substantially disc-shaped member having a large thickness with a circular opening 22a formed at the center thereof, and is fastened to the protruding end of the peripheral wall 21b with a bolt B2 so as to close the opening of the rear body 21. Thus, the rear body 21 is assembled. On the front side of the front body 22, a Y-shaped recess 22b is formed extending radially from the center in three directions. An elastic ring-shaped seal member 23 is provided at the joint between the rear body 21 and the front body 22, and a cylinder space 24 that is sealed by assembling the piston 30 is formed inside the body 20. Yes.

  The piston 30 includes a disk-shaped partition wall portion 31 having an outer diameter substantially the same as the inner diameter of the peripheral wall portion 21 b, a rod portion 32 erected at the center of the partition wall portion 31, and the like. The piston 30 is slidably assembled to the body 20 along the center line J by accommodating the partition wall 31 in the cylinder space 24 in a state where the rod portion 32 is inserted into the opening 22a. . A sealing material 33 is attached to an end portion around the partition wall portion 31, and the space between the partition wall portion 31 and the peripheral wall portion 21b is sealed. A sealing material 34 is also attached to the inner peripheral surface of the opening 22a, and the space between the rod 32 and the opening 22a is also sealed. Thereby, the cylinder space 24 is partitioned into a first chamber 24a on the back side and a second chamber 24b on the front side by the partition wall 31 in a sealed state.

  The plunger 40 is made of a Y-shaped member and has three projecting portions 41 that project radially from the center. On both side surfaces of each overhanging portion 41, inclined grooves 41a inclined downward from the center side from the front side to the back side are formed to face each other. The plunger 40 is assembled to the piston 30 in a state where the plunger 40 is fitted in the Y-shaped recess 22 b of the front body 22. Specifically, the plunger 40 is integrated with the piston 30 by fastening and fixing the mounting bolt 43 to the protruding end of the rod portion 32 protruding from the body 20 through the opening 22a. Therefore, the plunger 40 reciprocates along the center line J as the piston 30 slides.

  The cover 50 is attached to the front body 22 so as to cover the central portion of the Y-shaped recess 22b.

  Each master jaw 11 is formed of a long rectangular parallelepiped member, is fitted into the Y-shaped recess 22b of the front body 22, and is connected to the plunger 40 in a state where it cannot be removed. Specifically, flange portions 11 a that are prevented from coming off by the front body 22 are provided on both side surfaces on the long side of each master jaw 11. In addition, a pair of inclined piece portions 11b and 11b inclined downward from the center side from the front side to the back side are provided at the center side end portion of each master jaw 11, and these inclined piece portions 11b and 11b are provided. Is fitted in each inclined groove 41a. Thus, each master jaw 11 slides in the radial direction as the piston 30 slides.

  That is, when the first chamber 24a is pressurized by air pressure control and the second chamber 24b is depressurized, the piston 30 moves to the front side as shown in FIG. Move to an open position outward. As the second chamber 24b is pressurized by air pressure control and the first chamber 24a is depressurized, the piston 30 moves to the back side as shown in FIG. Move to the closed position in the direction.

  Therefore, when the workpiece is gripped from the outside, the workpiece is gripped by moving each master jaw 11 radially inward. When the workpiece is gripped from the inside, the workpiece is gripped by moving each master jaw 11 radially outward.

  A support surface 11 c that supports the clamp jaw 60 is formed on the front side of each master jaw 11. A shaft hole 13 having a circular cross section that extends perpendicular to the direction in which the master jaw 11 slides (slide direction) is formed in the support surface 11c. Further, a through hole 14 extending in the sliding direction and communicating with the shaft hole 13 from the radially outer side is formed at the outer peripheral end of each master jaw 11.

  A thread groove is formed on the inner peripheral surface of the through hole 14 (female screw). In this through hole 14, a retaining bolt 15 (an example of a retaining member) having a retaining portion 15 a having a spherical or substantially frustoconical shape at the top of the through hole 14 is in a state in which the retaining portion 15 a can protrude into the shaft hole 13. It is screwed (inserted slidably). On the other hand, the head of the retaining bolt 15 protrudes outside the master jaw 11 so that the slide position can be detected.

  In addition, a positioning pin 16 (an example of a master side rotation restricting structure) that protrudes from the support surface 11c is provided at a portion adjacent to the shaft hole 13 of the support surface 11c.

  Furthermore, each master jaw 11 is provided with an upstream fluid path 17 through which air flows in communication with the shaft hole 13. Specifically, a ring-shaped recess 17a that is slightly recessed is formed on a part of the inner peripheral surface of the shaft hole 13, and the ring-shaped recess 17a is an end on the outer peripheral side of the master jaw 11 through a long hole. It communicates with the connection port 17c provided in. The upstream fluid path 17 is not an essential structure for the master jaw 11.

<Clamp jaw>
FIG. 4 shows an example of the clamp jaw 60 (clamp jaw 60A). The illustrated clamping jaw 60A is configured to be able to handle a plurality of workpieces having different sizes and shapes without being removed from the master jaw 11. Since the clamp jaw 60 can be exchanged, various types of clamp jaws 60 can be attached depending on the purpose of use. Therefore, the clamp jaw 60A has a common basic structure corresponding to the master jaw 11.

  Specifically, the clamp jaw 60 </ b> A has a columnar shaft portion 61 that fits into the shaft hole 13, and a block-shaped work support portion 62 provided at the base end of the shaft portion 61. The shaft portion 61 is a portion that is inserted into the shaft hole 13, and the workpiece support portion 62 is a portion that supports the workpiece. A part of the outer peripheral surface of the shaft portion 61 has an annular groove 63 (engagement portion) having a V-shaped cross section, with which the retaining portion 15a enters and contacts when the clamp jaw 60A is attached to the master jaw 11. Is formed. Further, when the clamp jaw 60A is attached to the master jaw 11, the workpiece support portion 62 has a supported surface 62a received by the support surface 11c and a pin hole 64 into which the positioning pin 16 is inserted (clamp side rotation restriction). An example of a structure) is formed. The pin hole 64 is a long hole that is substantially the same width as the outer diameter of the positioning pin 16 and extends in the radial direction with respect to the center of the shaft portion 61.

  When the clamp jaw 60A is attached to the master jaw 11, the shaft 61 is inserted into the shaft hole 13 with the retaining bolt 15 loosened so that the retaining portion 15a does not protrude into the shaft hole 13, and the retaining bolt 15 is tightened to prevent the clamping jaw 60A. The portion 15 a is projected into the shaft hole 13 so as to enter the annular groove 63. When removing the clamp jaw 60A from the master jaw 11, the clamp jaw 60A can be removed from the master jaw 11 by loosening the retaining bolt 15 and extracting the shaft portion 61 from the shaft hole 13 so that the retaining portion 15a comes out of the annular groove 63. Can do. Thus, the clamp jaw 60A can be attached to and detached from the master jaw 11 only by rotating the retaining bolt 15 several times, so that the clamp jaw 60A can be quickly changed.

  Since the clamp jaw 60A is attached to the master jaw 11 via the shaft portion 61, it is not necessary to provide a bolt hole or counterbore hole in order to fasten the bolt B to the work support portion 62. Therefore, there is no possibility of damaging the workpiece at the edge of the counterbore hole, and the workpiece support 62 can be made smaller or thinner. Further, the strength of the clamp jaw 60A is also improved.

  Further, when the clamp jaw 60 </ b> A is attached to the master jaw 11, the clamp jaw 60 </ b> A is devised so as to be firmly fixed to the master jaw 11. That is, when the retaining portion 15a enters the annular groove 63, the position of the retaining portion 15a and the position of the annular groove 63 are offset so that the supported surface 62a is pressed against the support surface 11c. Specifically, as shown in an enlarged view in FIG. 4, the distance from the supported surface 62a to the center of the annular groove 63 is set to be smaller than the distance from the support surface 11c to the center of the retaining portion 15a. A deviation d1 is provided between the center position of the retaining portion 15a and the center position of the annular groove 63.

  As a result, when the retaining bolt 15 is tightened, the retaining portion 15a enters the back of the annular groove 63 as shown by an arrow a1, so that the retaining portion 15a pushes the inclination on the back side of the annular groove 63, and the shaft portion 61 However, as shown by the arrow a2, it is drawn to the back side. As a result, since the supported surface 62a is pressure-bonded to the support surface 11c, the clamp jaw 60A is more firmly fixed to the master jaw 11 as the retaining bolt 15 is tightened.

  Further, when the clamp jaw 60A is attached to the master jaw 11, the positioning pin 16 is inserted into the pin hole 64 so that the clamp jaw 60A is accurately positioned with respect to the master jaw 11 at a predetermined position. It has become. That is, the clamp jaw 60A may be rotated only by inserting the shaft portion 61 into the shaft hole 13 and fixing, but the clamp pin 60A is rotated by inserting the positioning pin 16 into the pin hole 64. The clamp jaw 60A is positioned at a predetermined position.

  In order to clamp the workpiece, usually, one clamping portion 65 corresponding to the workpiece is provided at a portion facing the center side or the non-center side of the workpiece support portion 62. Therefore, each time a workpiece having a different size or shape is gripped, it is necessary to replace it with a clamp jaw 60 adapted to the workpiece. On the other hand, the gripper 1 is excellent in convenience because the clamp jaw 60 can be quickly changed as described above. In addition, the clamp jaw 60A is configured so that it can be quickly changed without being removed from the master jaw 11.

  That is, a plurality (four in the illustrated example) of sandwiching portions 65 are provided on the workpiece support portion 62 of the clamp jaw 60A at different positions in the circumferential direction with respect to the center line C of the shaft portion 61. Each clamping part 65 is comprised by the curved surface from which the distance from the centerline C differs and which has a different curvature. A plurality of pin holes 64 for positioning each clamping portion 65 are provided at predetermined positions facing the center side of the work support portion 62.

  Accordingly, any one of the plurality of sandwiching portions 65 can be selected and used. Specifically, after the retaining bolt 15 is loosened so that the retaining portion 15a comes out of the annular groove 63, the clamp jaw 60A can be rotated by moving the shaft portion 61 and extracting the positioning pin 16 from the pin hole 64. Therefore, the clamp jaw 60A is rotated so that the desired clamping portion 65 faces the center side or the opposite center side of the workpiece support portion 62. By inserting the positioning pin 16 into the pin hole 64 corresponding to the pinching portion 65 and pushing the shaft portion 61 into the shaft hole 13 and tightening the retaining bolt 15, the clamp jaw 60A can be clamped without removing it. Substantially the same effect as the replacement of the jaw 60A can be obtained.

  FIG. 5 shows another example of the clamp jaw 60 (clamp jaw 60B). The exemplified clamping jaw 60B is configured such that the gripping state of the workpiece can be detected by a change in air pressure. The basic structure such as the shaft portion 61 and the workpiece support portion 62 is the same as that of the previous clamp jaw 60A as described above. The clamping jaw 60B is provided with one clamping portion 65 and one pin hole 64. Connected to the connection port 17c of the master jaw 11 is an air supply path 71 connected to an air pressure control device capable of supplying constant pressurized air and an air pressure detection device (not shown) for detecting a change in air pressure. Yes.

  A downstream fluid path 72 that communicates with the upstream fluid path 17 when attached to the master jaw 11 is formed inside the clamp jaw 60B. Specifically, a pair of O-rings 73 and 73 arranged with a space therebetween are attached to the shaft portion 61. These O-rings 73 and 73 are positioned on both sides of the region of the shaft portion 61 (fluid path relay region) facing the ring-shaped recess 17a when the clamp jaw 60B is attached to the master jaw 11 in an appropriate state. Are arranged. Thereby, the ring-shaped recess 17a is sealed, and a ring-shaped sealed space communicating with the outside of the master jaw 11 is formed around the fluid path relay region.

  In the clamp jaw 60B, a downstream fluid path 72 having one end opened in the fluid path relay region and the other end opened in the clamping part 65 is formed. The downstream fluid path 72 is formed by combining holes drilled and closing unnecessary openings with a lid. The open end 72a of the downstream fluid path 72 that opens to the holding portion 65 is a fine hole, and is configured to be blocked by the work when the work is properly held.

  According to the clamp jaw 60B, if air is supplied to the upstream fluid path 17 and the downstream fluid path 72 at a constant pressure, the opening end 72a of the downstream fluid path 72 can be obtained when the workpiece is properly clamped. Is closed, and the air supply path 71, the upstream fluid path 17, and the downstream fluid path 72 are maintained at a constant pressure. When the work is not properly clamped or when the work is separated from the gripper 1, the air flows out from the opening end 72 a, and the air supply path 71, the upstream fluid path 17, and the downstream fluid path 72 are Air pressure decreases. By detecting the change in the air pressure with the air pressure detection device, it is possible to detect the gripping state of the workpiece by the gripper 1.

  Although two types of the clamp jaw 60 are illustrated, the form of the clamp jaw 60 is not limited to these. For example, the number of the clamping parts 65 is not limited to four or one, but may be two, three, five or more. The shape of the sandwiching portion 65 is not limited to a curved surface, and may be a flat surface or an uneven surface. The shape and size of the work support 62 can be changed as appropriate according to the specifications.

  Further, the retaining member is not limited to the retaining bolt 15. Although not shown, a cylindrical screw member in which a polygonal concave portion connected to the tool is formed at the end may be used. Such a screw member is advantageous in that it does not get in the way because it can be prevented from protruding greatly from the through hole 14.

  Further, a push-type retaining member may be provided so that the clamp jaw 60 can be replaced without using a tool. FIG. 6 shows a specific example. The retaining member 80 in the illustrated example includes a cylindrical main body 81 fixed to the through hole 14, a rod 82 that is housed in the main body 81 so as to be retractable and has a retaining portion 15 a at the tip. Although not shown, the main body 81 has a coil spring or the like that elastically biases the rod 82, and when the knob 83 is pushed in, a restriction position where the retaining portion 15 a protrudes into the shaft hole 13 and a retaining portion 15 a are provided. It is configured to be switched to a non-restricting position that retreats from the shaft hole 13.

  With this retaining member 80, no tool is required, and the clamp jaw 60 can be replaced with a single touch, which is even more convenient.

  In addition, the gripper concerning this invention is not limited to embodiment mentioned above, The other various structure is included.

  For example, the number of jaws 10 is not limited to three as long as it is plural.

  The cross-sectional shape of the shaft hole 13 and the shaft portion 61 is not limited to a circle. For example, it may have a polygonal cross-sectional shape such as a quadrangle or a pentagon. If the cross-sectional shapes of the shaft hole 13 and the shaft portion 61 are polygonal, the rotation of the clamp jaw 60 can be restricted, so that the positioning pin 16 can be omitted. That is, the shaft hole 13 and the shaft portion 61 can constitute a master side rotation restricting structure and a clamp side rotation restricting structure.

  The fluid flowing through the upstream fluid path 17 and the downstream fluid path 72 is not limited to air. An inert gas, washing water, coolant, or the like may be used. Not only pressurized air but also decompressed air may be used. The fluid flowing out or inflowing from the downstream fluid path 72 can be used for various purposes such as cleaning and cooling as well as workpiece detection.

DESCRIPTION OF SYMBOLS 1 Gripper 10 Jaw 11 Master jaw 13 Shaft hole 14 Through hole 15 Stop bolt (an example of a stop member)
15a Detachment part 16 Positioning pin (an example of a master side rotation restriction structure)
20 Body 30 Piston 40 Plunger 60 Clamp jaw 61 Shaft part 62 Work support part 63 Annular groove (engagement part)

Claims (5)

A gripper that supports a workpiece located in a central portion with a plurality of jaws that slide in a radial direction,
Each of the jaws
A master jaw provided on the gripper main body so as to be slidable in the radial direction;
A clamp jaw attached to the master jaw and supporting the workpiece;
Have
The master jaw is
An axial hole extending perpendicular to the sliding direction;
A through hole communicating with the shaft hole from the outside in the radial direction of the shaft hole;
A retaining member that is slidably inserted into the through hole and whose tip can project into the shaft hole;
Have
The clamp jaw is
A shaft portion formed with an engagement portion that fits into the shaft hole and engages with the tip of the retaining member;
A workpiece support portion provided at a base end of the shaft portion to support the workpiece;
Have
A gripper in which the clamp jaw is detachably attached to the master jaw when the shaft portion is inserted into the shaft hole and the tip of the retaining member is engaged with the engagement portion. The gripper of claim 1,
The master jaw has a master side rotation restricting structure,
The clamp jaw, in cooperation with the master side rotation restricting structure, restricts the rotation of the clamp jaw with respect to the master jaw so that the work support portion is positioned. Have gripper. The gripper according to claim 2,
The work support part has a plurality of holding parts for holding the work at different positions in the circumferential direction with respect to the center line of the shaft part,
A gripper that can be selected and used by any one of the plurality of holding portions by the master side rotation restriction structure and the clamp side rotation restriction structure. In the gripper according to any one of claims 1 to 3,
The master jaw has a support surface that receives the workpiece support when the clamp jaw is attached;
A gripper in which the position of the tip of the retaining member protruding into the shaft hole and the position of the engaging portion are offset so that the work supporting portion is crimped to the supporting surface. In the gripper according to any one of claims 1 to 4,
The master jaw communicates with the shaft hole and has an upstream fluid path through which a fluid flows,
The clamp jaw has a downstream fluid path that communicates with the upstream fluid path when attached to the master jaw.

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