JP3169449U - Gripping device - Google Patents

Abstract

A gripping device capable of gripping a workpiece having various diameters with the same gripping force and easily gripping a workpiece having a flange or a curved portion. A main body 10 having a central space 11 and a notch 12, a first, second and third gripping claws 20a, 20b and 20c which advance and retreat in a radial direction, and a first gripping claw 20a are driven. A drive mechanism, a link mechanism 40 that connects the first gripping claw 20a and the second gripping claw 20b, and a link mechanism 40 ′ that connects the second gripping claw 20b and the third gripping claw 20c are provided. The link mechanism 40 includes a pair of arms 41a and 41b that swing about the support shafts 50a and 50b, and the link mechanism 40 ′ includes a pair of arms 41a ′ and 41b ′ that swing about the support shafts 50a ′ and 50b ′. Is provided. When the first gripping claws 20a are driven by the drive mechanism, the first, second and third gripping claws 20a, 20b and 20c are moved synchronously by the coupling relationship via the link mechanisms 40 and 40 ′, and the space 11 The workpiece W inside is gripped. [Selection] Figure 1

Description

  The present invention relates to a gripping device that grips a rod-shaped workpiece by a plurality of claws that operate in synchronization.

  Conventionally, as a general gripping device for gripping a rod-shaped workpiece, a general-purpose chuck (a scroll chuck or a hydraulic chuck) provided with an opening for inserting the workpiece into the center of the main body is known. Then, a workpiece | work is inserted in the said opening part, and the workpiece | work after insertion is hold | gripped with a some nail | claw.

  Such a chuck is generally used for gripping and supporting or fixing a workpiece during machining. For example, the chuck is mounted on a main spindle of a lathe in turning, and is fixed on a table in machining.

  As another application, when a predetermined member is fixed to a rod-shaped workpiece by welding or the like, it may be used to hold and fix the workpiece.

  However, in the case of such a general-purpose chuck, for example, when the rod-shaped workpiece is provided with flange portions at both ends thereof, and the outer diameter of the flange portion is larger than the diameter of the opening portion, Since the said flange part cannot pass through an opening part, there existed a problem that this could not be hold | gripped.

  On the contrary, after the rod-shaped workpiece is gripped by the general-purpose chuck, for example, when a flange having a diameter larger than the diameter of the opening is fixed to the end thereof by welding or the like, the rod-shaped workpiece after welding is fixed. Cannot be extracted from the general-purpose chuck, so that the general-purpose chuck cannot be used in such a case.

  Furthermore, in the case of a part of an extremely curved workpiece (for example, a workpiece having a substantially L shape), in order to insert / remove the workpiece into / from the opening, the posture of the workpiece is changed when passing through the curved portion. It must be changed and the work cannot be performed smoothly.

  In order to solve such problems, a material indexing device disclosed in Japanese Patent Application Laid-Open No. 11-156655 has been proposed.

  The material indexing device includes a main body frame having a notch groove, and a plurality of chucks provided so as to move forward and backward toward the center of the notch groove by an interlocking mechanism. The surface of each chuck has a swingable C-shape in which an operating groove provided obliquely with respect to the advancing / retreating direction of the chuck and a plurality of pin shafts respectively engaged with the operating groove are provided. It consists of a movable member and drive means for swinging the movable member. Thus, according to this material indexing device, since the workpiece can be inserted into the central portion from the outside through the notch groove, the above-described problem does not occur.

JP-A-11-156655

  However, the material index apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 11-156655 has the following problems.

  First, a process of moving the chuck forward and backward in synchronization with the material indexing apparatus will be described with reference to FIG.

  As shown in FIG. 6A, in the material index apparatus, first, the movable member 62 is swung in the direction indicated by the arrow L by the driving means. Then, in accordance with the swing of the movable member 62, the pin shaft 63 presses the side surface of the operating groove 61, so that a pressing force (gripping force) in the arrow P direction acts on the side surface. As a result, as shown in FIG. 6B, the chuck 60 is moved toward the workpiece W ′ inserted in the center of the notch groove, and grips the workpiece W ′.

  Further, by swinging the movable member 62 in the direction opposite to the arrow L direction, the pin shaft 63 presses the side surface facing the side surface, and the chuck 60 pushes away from the workpiece W ′. Works.

  Here, the gripping force is a component force along the advancing / retreating direction of the chuck 60 of the force by which the pin shaft 63 vertically presses the side surface of the operating groove 61. Therefore, when the force acting from the driving means is constant, the magnitude of the gripping force depends on the angle θ (0 ° <θ <90 °) formed by the advancing / retreating direction of the chuck 60 and the operating groove 61. To do.

  That is, with reference to the value of θ in FIG. 6A, as shown in FIG. 6C, the gripping force is reduced by making the value of θ smaller than this, and conversely, FIG. As shown, the gripping force is increased by increasing the value of θ. Note that the lengths of the arrows P, Q, and R illustrated in FIGS. 6A, 6C, and 6D conceptually indicate the magnitude of the gripping force.

  Further, the stroke amount in the advancing / retreating direction of the chuck 60 also depends on the value of θ, and the stroke amount increases in FIG. 6C when the state of FIG. ) Decreases.

  That is, the gripping force and the stroke amount are in a mutually contradictory relationship. In order to secure a large gripping force, the stroke amount must be reduced. To secure a large stroke amount, the gripping force must be decreased. Must be reduced. Therefore, in the material index device, the gripping force and the stroke amount cannot be increased at the same time.

  For this reason, when it is necessary to grip various workpieces W ′ having different diameters, if it is attempted to secure a large stroke amount, sufficient gripping force cannot be secured, and conversely, sufficient gripping is achieved. If it is going to secure force, the stroke amount will become small and the problem that the diameter of the workpiece | work W 'which can be gripped will be produced will arise.

  That is, in order to grip the workpiece W ′ having various diameters with a sufficient gripping force, it is necessary to replace the chuck 60 with a length corresponding to the diameter of the workpiece W ′. In addition, there is a problem that a plurality of chucks having different lengths must be prepared in advance.

  The present invention has been made in view of the above circumstances, and can grip a workpiece having a non-uniform shaft diameter or a curved workpiece, and can appropriately handle a workpiece having various diameters without changing the nail. An object of the present invention is to provide a gripping device that can be gripped with a sufficient gripping force.

The present invention for solving the above problems
A space for receiving a rod-shaped workpiece is provided at the center, and the radially outer space that is perpendicular to the axis of the workpiece inserted into the center space communicates with the center space. A main body for receiving the workpiece into the space of the central portion through the notch,
A plurality of gripping claws that are respectively engaged with guide portions formed in the main body along the radial direction, and are movable forward and backward in the radial direction;
A drive mechanism for driving one of the plurality of gripping claws to advance and retract in the radial direction;
A gripping device that is arranged between the gripping claws and is connected to the gripping claws located on both sides of the gripping claws, and includes a link mechanism that advances and retracts the plurality of gripping claws in synchronization.
The link mechanism includes a pair of arms that are pivotally supported by a support shaft fixed to the main body in parallel with the work axis, and swing in a plane parallel to the radial direction around the support shaft.
The pair of arms is provided such that one end thereof is engaged with the corresponding gripping claw and the other end is mutually engaged with the other end of the other arm,
The gripping claws driven by the drive mechanism and the other gripping claws are advanced in synchronization by the connection relationship of the link mechanism, and the workpieces received in the space of the central portion are moved forward. The present invention relates to a gripping device configured to be gripped by a gripper.

  According to this gripping device, first, the rod-shaped workpiece is inserted from the radially outer side through the notch and is positioned at the center of the main body. In this case, it is assumed that each gripping claw is located at a retracted position outward in the radial direction so that a rod-shaped workpiece can be inserted.

  Then, the corresponding gripping claw is driven by the drive mechanism and moved (advanced) in the radial direction toward the workpiece. As a result, the arm engaged with the gripping claw swings around the support shaft according to the movement of the gripping claw, and the other arm engaged with the other end of the arm synchronizes with the arm. It swings around the support shaft. Then, by the swinging of the other arm, another gripping claw engaged with one end of the other arm advances in the radial direction toward the workpiece.

  In addition to the two gripping claws, one or more gripping claws are provided, that is, a total of three or more gripping claws are provided, and the gripping claws are connected in a chain by the link mechanism. Similarly, in response to the advancement of the gripping claws driven by the drive mechanism toward the workpiece, the plurality of other gripping claws are synchronized with the workpiece due to the chain connection relationship of the link mechanism. Move forward.

  Thus, in this way, all other gripping claws move forward in synchronization with the gripping claws driven by the drive mechanism, so that the rod-shaped workpiece positioned at the central portion is gripped by the gripping claws. The

  As described above, in the present invention, since the workpiece can be inserted from the radial direction, even a workpiece having a large diameter or a curved portion can be easily inserted into the center portion. And can be gripped.

  In the present invention, the workpiece is gripped by the gripping claws driven by the drive mechanism and the other gripping claws connected to the gripping claws by the link mechanism. The structure is such that the thrust output from the vehicle becomes the gripping force, and the amount of movement stroke by the drive mechanism becomes the stroke amount of each gripping claw.

  Therefore, there is no correlation between the gripping force and the stroke amount, and each can be set to an independent value, and even when it is necessary to grip various workpieces having different diameters, The stroke amount can be set to an appropriate value, and the necessary gripping force can also be set to an appropriate value.

  Thus, according to the present invention, even a workpiece with a non-uniform shaft diameter, such as having a flange at the end or a curved workpiece, can be easily gripped without requiring a complicated operation. In addition, it is not necessary to use a preliminary claw that is conventionally required for gripping workpieces of various diameters, and it is possible to reduce costs and troublesome parts management.

  As a specific aspect of the drive mechanism, a nut fixed to one of the gripping claws, a threaded engagement with the nut, and disposed along the advancing and retracting direction of the gripping claw, The structure which consists of a feed screw hold | maintained at the said main body rotatably can be mentioned. According to this drive mechanism, when the feed screw is rotated to move the nut, the gripping claw fixed to the nut moves forward and backward.

  Further, each of the pair of arms has an arc-shaped surface centered on each of the support shafts at the other end outer peripheral surface, and a tooth surface along the axial direction of the support shaft is formed on each of the outer peripheral surfaces. The other ends may be configured to engage with each other by meshing the tooth surfaces. In this way, since the swinging force (power) of one arm is transmitted to the other arm via the meshing relationship, this power can be transmitted without loss.

  Further, the link mechanism may be disposed in an internal space formed in the main body. In this way, the entire apparatus can be made compact, and the link mechanism can be protected from chips, dust, external force, heat and the like generated during processing.

  As described above, according to the gripping device according to the present invention, even a workpiece with a non-uniform shaft diameter or a curved workpiece can be easily gripped without requiring a complicated operation, A conventional claw that is conventionally required for gripping a workpiece having a diameter is not necessary, and cost reduction and troublesome parts management can be eliminated.

It is a front view of a grasping device concerning one embodiment of the present invention. It is sectional drawing of the arrow AA direction in FIG. (A) is sectional drawing of the arrow BB direction in FIG. 1, (b) is sectional drawing of the arrow CC direction in FIG. It is a front view which shows the state which hold | gripped the large diameter workpiece | work with the holding | grip apparatus which concerns on this embodiment. It is a front view which shows the state which hold | gripped the small diameter workpiece | work with the holding | grip apparatus which concerns on this embodiment. It is explanatory drawing for demonstrating the advance / retreat operation | movement of the chuck | zipper in the material index apparatus of a prior art example.

  Hereinafter, specific embodiments of the gripping device according to the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 to 3, the gripping device 1 of this example includes a space 11 formed in the center and a notch 12 formed radially outward from the space 11. A main body 10 having a letter shape and a work piece that is provided at equal intervals in the circumferential direction of the main body 10 (in this example, at 120 ° intervals) and that can be moved back and forth along the radial direction and inserted into the space 11 The first, second and third gripping claws 20a, 20b, 20c having the same shape gripping W, the drive mechanism 30 for moving the first gripping claw 20a back and forth, the first gripping claws 20a and the second gripping claws 20b And between the second gripping claw 20b and the third gripping claw 20c, respectively, and the first gripping claw 20a and the second gripping claw 20b, and the second gripping claw 20b and the third gripping claw. 20c, that is, these first gripping claws 20a, Two gripping claws 20b and third gripping claw 20c is configured from a link mechanism 40, 40 'for connecting a chain reaction.

  The radial direction refers to the center of the workpiece W at the gripping position where the rod-shaped workpiece W is disposed in the space 11 and is gripped by the first, second and third gripping claws 20a, 20b and 20c. It means a direction perpendicular to the axis O.

  The main body 10 is composed of a hollow member composed of a front end surface portion (upper surface portion in FIG. 1), a rear end surface portion (lower surface portion in FIG. 1), and a side surface portion connecting them, and the internal space 13 Link mechanisms 40 and 40 'are provided.

  Further, three guide grooves 14a, 14b, 14c having a substantially I-shaped cross section are formed on the front end surface portion along the radial direction and at equal intervals in the circumferential direction (120 ° intervals in this example). The through holes 15a and 15b are formed between the guide groove 14a and the guide groove 14b, and the through holes 15a 'and 15b' are formed between the guide groove 14b and the guide groove 14c, respectively. .

  Engaging grooves 21a, 21a, 21b, 21b, 21c, and 21c that engage with the inner protrusions of the guide grooves 14a, 14b, and 14c are provided on both side surfaces of the gripping claws 20a, 20b, and 20c, respectively. Engaging grooves 22a, 22b, and 22c are formed on the lower surface thereof in directions orthogonal to the advance and retreat directions, respectively. Thus, the gripping claws 20a, 20b, 20c are guided by the guide grooves 14a, 14b, 14c, respectively, and move along the radial direction.

  The drive mechanism 30 is inserted into a through hole 35 formed in the outer peripheral side surface portion of the main body 10, and a feed screw 32 disposed below the first gripping claw 20a along the advancing / retreating direction thereof. A nut 31 fixed to the lower surface of the first gripping claw 20a, and a bearing 36 that rotatably supports the feed screw 32 in a state of being inserted into the through hole 35. , And a stop lid 34 for preventing the bearing 36 from coming out of the through hole 35.

  According to the drive mechanism 30, by rotating the feed screw 32, the nut 31 screwed into the nut and the first gripping claw 20a fixed to the nut 31 are radially formed along the guide groove 14a. Advance and retreat.

  The head of the feed screw 32 is formed in a square shape, and the feed screw 32 can be rotated about its axis using a handle or a spanner as appropriate.

  The link mechanism 40 has a pair of first arm 41a and second arm 41b having a substantially L shape having a curved portion, and a support shaft 50a that supports the first arm 41a so as to be swingable in the direction of arrows DE. And a support shaft 50b that supports the second arm 41b so as to be swingable in the direction of arrow FG. Further, the link mechanism 40 ′ has a substantially L-shaped pair of third arm 41a ′ and fourth arm 41b ′ that also have a curved portion, and the third arm 41a ′ can swing in the direction indicated by arrows HI. And a support shaft 50b 'for supporting the fourth arm 41b' so as to be swingable in the direction of arrows JK.

  The first arm 41a, the second arm 41b, the third arm 41a ′, and the fourth arm 41b ′ each have the same shape, and the first arm 41a and the second arm 41b have virtual reference lines along the radial direction. Similarly, the third arm 41a 'and the fourth arm 41b' are arranged symmetrically with respect to a virtual reference line along the radial direction.

  One end 42a of the first arm 41a is engaged with the engagement groove 22a of the first gripping claw 20a, and one end 42b of the second arm 41b is engaged with the engagement groove 22b of the second gripping claw 20b. . Further, the outer peripheral surface of the other end of the first arm 41a has an arc-shaped surface centered on the support shaft 50a, and similarly, the outer peripheral surface of the other end of the first arm 41b has an arc shape centered on the support shaft 50b. The tooth surfaces 43a and 43b are formed along the axial direction of the support shafts 50a and 50b, respectively, and these tooth surfaces 43a and 43b mesh with each other.

  Similarly, one end 42a ′ of the third arm 41a ′ is engaged with the engagement groove 22b of the second gripping claw 20b, and one end 42b ′ of the fourth arm 41b ′ is engaged with the engagement groove 22c of the third gripping claw 20c. Further, the outer peripheral surface of the other end of the third arm 41a ′ forms an arc-shaped surface centering on the support shaft 50a ′, and the outer peripheral surface of the other end of the fourth arm 41b ′ is the support shaft 50b. Are formed in the shape of a circular arc centered on ', and tooth surfaces 43a' and 43b 'are formed along the axial direction of the support shafts 50a' and 50b ', respectively, and these tooth surfaces 43a' and 43b 'are mutually connected. It is in a meshed state.

  It should be noted that the distance from the axis of the support shaft 50a to the engagement point of the one end 42a, the distance from the axis of the support shaft 50b to the engagement point of the one end 42b, and the axis of the support shaft 50a ′ to the one end 42a. The distance from the engagement point “′” and the distance from the axis of the support shaft 50 b ′ to the engagement point at the one end 42 b ′ are the same distance.

  Similarly, the distance from the axis of the support shaft 50a to the engagement point of the other end of the first arm 41a, the distance from the axis of the support shaft 50b to the engagement point of the other end of the second arm 41b, the support shaft The distance from the axis of 50a 'to the engagement point at the other end of the third arm 41a' and the distance from the axis of the support shaft 50b 'to the engagement point at the other end of the fourth arm 41b' are the same distance. ing.

  The support shafts 50a, 50b, 50a ', and 50b' are inserted and held in through holes 15a, 15b, 15a ', and 15b' formed in the main body 10, respectively.

  Next, a mode in which the rod-shaped workpiece W is gripped by the gripping device 1 having the above configuration will be described.

  First, the workpiece W is inserted from the outside through the notch 12 and positioned at the center of the main body 10. At this time, each of the gripping claws 20a, 20b, 20c is assumed to be positioned at a suitably retracted position outward in the radial direction so that the workpiece W can be inserted.

  Next, the feed screw 32 is rotated (when the feed screw 32 is a right-hand screw, it is rotated to the left), and the first gripping claw 20a to which the nut 31 is fixed is directed toward the center side of the main body 10. Move. Accordingly, the first arm 41a engaged with the first gripping claw 20a is urged in the direction indicated by the arrow D around the support shaft 50a in accordance with the movement of the first gripping claw 20a.

  Then, this urging force is transmitted to the second arm 41b by the meshing relationship of the tooth surfaces 43a and 43b, and the second arm 41b is urged in the direction indicated by the arrow F. Further, the second arm 41b and the second gripping claw The second gripping claw 20b is urged toward the center side by the engagement relationship with 20b.

  The third arm 41a ′ is biased in the direction indicated by the arrow H by the engagement relationship between the second gripping claw 20b and the third arm 41a ′, and the fourth arm is engaged by the meshing relationship between the tooth surfaces 43a ′ and 43b ′. 41b 'is urged in the arrow J direction, and the third gripping claw 20c is urged toward the center side by the engagement relationship between the fourth arm 41b' and the third gripping claw 20c.

  Thus, by advancing the first gripping claw 20a to the center side by the feed screw 32, the urging force is transmitted to the second gripping claw 20b via the link mechanism 40, and further from the second gripping claw 20b. As a result, the first gripping claw 20a, the second gripping claw 20b, and the third gripping claw 20c are synchronously advanced toward the center side, and are transmitted to the third gripping claw 20c via the link mechanism 40 ′. 11 is gripped by the first gripping claws 20a, the second gripping claws 20b, and the third gripping claws 20c.

  Note that the gripping force with respect to the workpiece W depends on the screwing amount of the feed screw 32 after the tips of the gripping claws 20a, 20b, and 20c contact the workpiece W. Therefore, the workpiece W can be gripped with an appropriate gripping force by appropriately adjusting the screwing amount.

  Then, after gripping the workpiece W and performing necessary processing as described above, when removing the gripped workpiece W, the feed screw 32 is rotated in the reverse direction so that the first gripping claw 20a is moved in the radial direction. Move outward, that is, in a direction away from the workpiece W. As a result, the first gripping claw 20a, the second gripping claw 20b, and the third gripping claw 20c are synchronously moved outward in the radial direction by an operation opposite to the gripping operation described above. The gripping by the claw 20a, the second gripping claw 20b, and the third gripping claw 20c is released. Thereafter, the workpiece W is removed through the notch 12.

  Thus, according to the gripping device 1 according to the present embodiment, the space 11 communicates with the outside through the notch 12, and the workpiece W is inserted into the space 11 through the notch 12. For example, a portion that can be gripped even with a rod-shaped workpiece W having a non-uniform shaft diameter, such as having a flange or the like having a diameter larger than that of the space 11 at one end or both ends thereof. Can be inserted into the space 11 through the notch 12 and gripped, and even a partly curved workpiece W can be obtained without performing the conventional complicated work. Can be easily gripped.

  Further, the distance between the engagement point between each gripping claw 20a, 20b, 20c and each arm 41a, 41b, 41a ′, 41b ′ and the support shaft 50a, 50b, 50a ′, 50b ′ is the same distance. Since the distances between the meshing points between the arms 41a, 41b, 41a ′, 41b ′ and the support shafts 50a, 50b, 50a ′, 50b ′ are the same, the gripping claws 20a, 20b , 20c become the same value, and the workpiece W can be gripped in a state where its axis is aligned with the central axis O, that is, in a centered state.

  Furthermore, as described above, the gripping force with respect to the workpiece W depends on the screwing amount of the feed screw 32, whereas the stroke amounts of the gripping claws 20a, 20b, and 20c do not depend on this. Regardless, the optimum stroke amount can be obtained by appropriately adjusting the length of the feed screw 32 and the length of the guide grooves 14a, 14b, 14c provided in the main body 10.

  Therefore, even when it is necessary to grip various workpieces W having different diameters, the stroke amounts of the gripping claws 20a, 20b, and 20c can be appropriately set accordingly, and the necessary gripping can be performed. The force can also be set to an appropriate value. Thus, according to the gripping device 1 of the present example, the conventionally required spare claws are unnecessary, and cost reduction and troublesome parts management can be eliminated.

  For reference, FIG. 4 shows a state where a relatively large diameter workpiece W is gripped, and FIG. 5 shows a state where a relatively small diameter workpiece W is gripped.

  As mentioned above, although specific embodiment of this invention was described, the specific aspect which this invention can take is not limited to these at all.

  For example, in the above example, three gripping claws, that is, the first gripping claw 20a, the second gripping claw 20b, and the third gripping claw 20c are provided. However, the present invention is not limited to this. May be provided, or may be provided with four or more gripping claws. In this case as well, as in the above example, the link mechanism is provided between the gripping claws, and a plurality of gripping claws are connected in a chain by the link mechanisms.

DESCRIPTION OF SYMBOLS 1 Gripping device 10 Main body 11 Space 12 Notch 13 Internal space 14a, 14b, 14c Guide groove 15a, 15b, 15a ', 15b' Through-hole 20a First gripping claw 20b Second gripping claw 20c Third gripping claw 21a, 21b , 21c engagement groove 22a, 22b, 22c engagement groove 30 drive mechanism 31 nut 32 feed screw 34 stop lid 40, 40 'link mechanism 41a first arm 41b second arm 41a' third arm 41b 'fourth arm 42a, 42b, 42a ', 42b' engaging portion 43a, 43b, 43a ', 43b' tooth surface W workpiece

Claims (4)

A space for receiving a rod-shaped workpiece is provided at the center, and the radially outer space that is perpendicular to the axis of the workpiece inserted into the center space communicates with the center space. A main body for receiving the workpiece into the space of the central portion through the notch,
A plurality of gripping claws that are respectively engaged with guide portions formed in the main body along the radial direction, and are movable forward and backward in the radial direction;
A drive mechanism for driving one of the plurality of gripping claws to advance and retract in the radial direction;
A gripping device that is arranged between the gripping claws and is connected to the gripping claws located on both sides of the gripping claws, and includes a link mechanism that advances and retracts the plurality of gripping claws in synchronization.
The link mechanism includes a pair of arms that are pivotally supported by a support shaft fixed to the main body in parallel with the work axis, and swing in a plane parallel to the radial direction around the support shaft.
The pair of arms is provided such that one end thereof is engaged with the corresponding gripping claw and the other end is mutually engaged with the other end of the other arm,
The gripping claws driven by the drive mechanism and the other gripping claws are advanced in synchronization by the connection relationship of the link mechanism, and the workpieces received in the space of the central portion are moved forward. A gripping device characterized in that the gripping device is configured to be gripped by.   The drive mechanism is fixed to one of the gripping claws, and is screwed into the nut and disposed along the advancing and retreating direction of the gripping claw, and is held by the main body so as to be rotatable about the axis. The gripping device according to claim 1, wherein the gripping device is constituted by a feed screw.   Each of the pair of arms has an arcuate surface centered on each of the support shafts at each other outer peripheral surface, and a tooth surface along the axial direction of the support shaft is formed on each of the outer peripheral surfaces. The gripping device according to claim 1 or 2, wherein the other ends are engaged with each other by engaging surfaces.   The gripping device according to claim 1, wherein the link mechanism is disposed in an internal space of the main body.

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