JP5103225B2 - Chuck device - Google Patents

Description

  The present invention relates to a chuck device having a finger provided with a chuck claw and centering and gripping a workpiece.

In order to grip and convey a workpiece such as a gear, the chuck device has a plurality of gripping claws for gripping a workpiece, that is, a workpiece, and each gripping claw is driven by an electric motor or a pneumatic cylinder. Open and close. As a chuck device for centering and gripping a work whose outer peripheral surface has a cylindrical shape such as a gear, there is a 3-jaw type. For example, the chuck device described in Patent Document 1 has a workpiece pressing claw attached to a motor-driven cam plate and two workpiece gripping claws driven to open and close by the cam plate. The work hand described in Patent Document 2 has three chuck blocks that are each mounted on a disk-shaped base so as to be slidable in the radial direction, and the chuck block is rotatably mounted on the disk-shaped base. The cam plate is slid in the radial direction by rotating the cam plate, and the cam plate is driven by an electric motor. Patent Document 3 discloses a pair of first hand members that approach and separate from each other and a pair of second hands that move toward and away from each other in a direction perpendicular to the first hand member in order to grip a rectangular workpiece. An electric hand having a pair of hand members, and each pair of hand members is driven by a separate electric motor.
Japanese Utility Model Publication No. 5-26287 Japanese Utility Model Publication No. 63-151290 JP 2006-310216 A

  In order to be able to grip multiple types of workpieces with different outer diameters with one chuck device, it is preferable to increase the opening / closing movement range of the gripping claws, An increase in size of the chuck device is inevitable. In particular, if the gripping claws are mounted so as to slide on the plate, the gripping claws greatly protrude outward in the radial direction of the workpiece, and thus the size of the chuck device cannot be reduced. Furthermore, in the chuck device used for gripping and transporting the workpiece, it is necessary to hold the workpiece gripped by the gripping claw until the end of transport. Therefore, when an electric motor is used as the gripping claw drive source It is necessary to energize the electric motor during conveyance to hold the gripping claws in the gripping state.

  An object of the present invention is to provide a small chuck device that holds a plurality of types of workpieces having different outer diameters.

The chuck device according to the present invention is a chuck device for gripping a workpiece by three fingers each provided with a gripping claw, and support pins for swingably supporting the fingers are respectively located on the surface side at the same distance from the gripping center. A support plate provided with a cylindrical body projecting on the back side, and a drive pin attached to each of the fingers is formed in an arcuate notch formed on the support plate radially inward of the support pin A cam member having a drive portion having a guide hole that penetrates through the portion and a cylindrical portion that is rotatably fitted to the outside of the cylindrical body, and a rotating means that rotates the cam member has, said the drive pins radially inward of the support pins each of the fingers is rotated by the cam member is swung about the support pins, gripping the workpiece by the gripping claws And wherein the Rukoto.

In the chuck device of the present invention, the rotating means includes a drive shaft that is incorporated in the cylinder so as to be reciprocally movable in the axial direction, and a long hole formed in the cylinder to pass through the drive shaft. And an engaging member that engages with a cam groove formed in the cylindrical portion of the cam member, and the cam member is rotated by the drive shaft .

  According to the chuck device of the present invention, the three fingers are swingably mounted on the surface side of the support plate, and the fingers are swung via the drive pins by the turning means provided on the support plate. The gripping claws do not protrude greatly outward in the radial direction of the support plate. As a result, a workpiece having a desired outer diameter can be gripped while being centered without increasing the size of the chuck device. Each finger synchronously oscillates toward the gripping center, and if the gripping claw is an outer diameter workpiece between the position farthest from the gripping center and the closest position, the outer diameters differed from each other A plurality of workpieces can be gripped. If the gripping claws are gripped by the inner peripheral surface of the hole formed in the workpiece, it is possible to grip a workpiece having a hollow hole such as a pipe or a cylinder.

  The rotating means has a cylindrical body provided on the support plate, and converts the axial movement of the drive shaft incorporated in the cylindrical body into a rotational movement of a cam member mounted on the outer side of the cylindrical body to swing the finger. Since it is made to move, the radial dimension of the chuck device can be reduced, and the size reduction of the chuck device can be achieved.

  If the drive shaft is a piston rod of a pneumatic cylinder and the axial movement of the piston rod is converted into the rotational movement of the cam member by compressed air, the size of the chuck device can be reduced as compared with the case where an electric motor is used as the drive source. it can. In addition, if compressed air is continuously supplied to the pneumatic cylinder while the pneumatic cylinder is used as a drive source and the workpiece is gripped by the gripping claw, the gripping claw will apply a clamping force to the workpiece, so that the workpiece is securely held. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a partially cutaway front view showing a chuck device according to an embodiment of the present invention, FIG. 2 is a perspective view of FIG. 1, FIG. 3 is a plan view of FIG. FIG. 5 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 5 is a bottom view of FIG.

  As shown in FIGS. 1 and 2, this chuck device has a disk-shaped base 11. When gripping and transporting a workpiece by the chuck device, the base 11 is attached to the transport device, and the base 11 is provided with a plurality of mounting holes 12 for attaching the base 11 to the transport device as shown in FIG. Is formed. A support plate 13 is attached to the base 11 in parallel with the base 11 by three connecting rods 14. As shown in FIG. 4, the center O of the support plate is the gripping center, and each connecting rod 14 is the same distance from the gripping center O and is arranged at equal intervals of 120 degrees in the circumferential direction. ing. The support plate 13 is substantially triangular as shown in FIG. 4, but it may be circular. The pedestal 11 is not limited to a plate material, and may be a housing.

  Three fingers 15 are mounted on the surface side of the support plate 13 so as to be swingable around the support pins 16. The support pin 16 is attached to the support plate 13 so as to be coaxial with the connecting rod 14 and supports the finger 15 at its base end portion so as to be swingable. Accordingly, the three support pins 16 are mounted on the support plate 13 at the same distance from the gripping center O and at intervals of 120 degrees in the circumferential direction. A gripping claw 17 is provided at the tip of each finger 15 so as to protrude toward the front of the support plate 13, and the workpiece is gripped by the three gripping claws 17. The inner surface of the gripping claw 17 is a flat gripping surface, and the gripping surface is subjected to a mesh-like knurling process to prevent the workpiece from sliding from the gripping claw 17 when the workpiece is gripped by its outer peripheral surface. Yes. In FIG. 4, the workpiece with the maximum diameter that is gripped by the gripping claws 17 is indicated by the symbol W <b> 1, and the workpiece with the minimum diameter is indicated by the symbol W <b> 2.

  The workpiece can be gripped by the gripping claws 17 as well as the type gripped by the gripping claws 17 on the outer peripheral surface thereof, and in this case, the inner periphery of the hole can be gripped. The outer surface of the gripping claw 17 is brought into contact with the surface. In that case, it is preferable to perform knurling by making the outer peripheral surface of the gripping claw 17 into an arc shape.

  As shown in FIG. 1, a cylindrical body 18 is integrally provided on the back side of the support plate 13. The cylindrical body 18 is perpendicular to the back surface of the support plate 13 and protrudes from the support plate 13, and the tip is in contact with the pedestal 11, and the center axis P is coaxial with the gripping center O. A pneumatic cylinder 21 is attached to the pedestal 11, and a piston rod 22 of the pneumatic cylinder 21 protrudes into the cylindrical body 18 and is incorporated into the cylindrical body 18. The piston rod 22 is driven to reciprocate in the axial direction. It is the axis. The cylindrical body 18 may be formed by a member different from the support plate 13 and the cylindrical body 18 may be fixed between the support plate 13 and the base 11.

  A cam member 23 is rotatably mounted on the outside of the cylindrical body 18. The cam member 23 has a cylindrical portion 23a that is rotatably fitted to the cylindrical body 18, and a circular drive portion 23b that is integrally provided at an end portion of the cylindrical portion 23a. An engagement pin 24 is attached to the tip of the piston rod 22 as an engagement member. The engagement pin 24 penetrates the piston rod 22 in the radial direction, and both ends protrude from the piston rod 22. A long hole 25 through which the engagement pin 24 passes is formed in the cylindrical body 18 so as to extend in the axial direction, and two long holes 25 are formed so as to face the cylindrical body 18. When the piston rod 22 is driven in the axial direction, the engagement pin 24 is guided to the long hole 25, and the piston rod 22 reciprocates in the axial direction without rotating. The axial length of the long hole 25 corresponds to the reciprocating stroke of the piston rod 22.

  A helical cam groove 26 is formed in the cylindrical portion 23 a of the cam member 23, and the end of the engagement pin 24 is engaged with the cam groove 26. Therefore, when the piston rod 22 moves in the axial direction, the cam member 23 rotates due to the engagement pin 24 moving in the axial direction engaging with the cam groove 26. A driving pin 27 is fixed to each finger 15, and the driving pin 27 passes through a notch portion 29 formed in the support plate 13 and from the back surface of the finger 15 toward the driving portion 23 b of the cam member 23. The drive pin 27 engages with a guide hole 28 formed to extend in the radial direction in the drive portion 23b.

  The drive portion 23b of the cam member 23 has a disk shape, but the drive portion 23b may be formed by three strip-shaped members each having the guide hole 28 formed therein.

  6 is a plan view showing the support plate 13 with the cam member 23 assembled thereto, FIG. 7 is a sectional view taken along the line BB in FIG. 6, and FIG. 8 is a side view in the direction of arrow C in FIG.

  As shown in FIG. 6, the support plate 13 is formed with three attachment holes 14a to which the connecting rods 14 are attached, and the support pins 16 are attached to the attachment holes 14a. When the radial direction line passing through the gripping center O and the center of the support pin 16 is R, and the guide direction line, which is the direction in which the guide hole 28 extends, is T, the guide rod 22 is in the retracted limit state. The hole 28 is inclined at an angle α with respect to the radial line R, and the angle α is about 30 degrees. When the piston rod 22 reaches the forward limit position, the guide hole 28 rotates counterclockwise by an angle 2α from the position shown in FIG.

  Thus, since the radial direction line R and the guide direction line T have an angle, when the cam member 23 is rotated, the drive pin 27 is guided in the guide hole 28 while moving in the circumferential direction, and is moved in the radial direction. Moving. As a result, the three fingers 15 rotate synchronously around the support pin 16, and the gripping claw 17 provided at the tip of the finger 15 swings along an arcuate locus centering on the support pin 16. Will do.

  When the cam member 23 rotates, the guide hole 28 moves in the circumferential direction, and the drive pin 27 also moves in the radial direction while moving in the circumferential direction, so that interference between the drive pin 27 and the support plate 13 occurs. In order to avoid this, the notch 29 formed in the support plate 13 has an arc shape, and the support plate 13 has three notches 29 corresponding to the respective drive pins 27. Each notch 29 has a circumferential length corresponding to the circumferential movement stroke of the guide hole 28 and a radial width corresponding to the length of the guide hole 28. . Therefore, when the piston rod 22 as the drive shaft moves in the axial direction, the engagement pin 24 that is guided in the elongated hole 25 formed in the cylindrical body 18 and moves in the axial direction rotates the cam member 23, thereby driving the drive pin. The finger 15 swings around the support pin 16 through the support 27. As described above, the cylindrical body 18 and the cam member 23 constitute a rotating means.

  As shown in FIG. 1, a cylindrical cover member 31 is attached to the outside of the cylindrical portion 23 a, and a through hole 32 for attaching the engagement pin 24 is formed in the cover member 31. When the cover member 31 is rotated after attaching the engagement pin 24 to the attachment hole formed in the piston rod 22 from the through hole 32, the end surface of the engagement pin 24 is covered by the cover member 31 and the engagement pin 24 is removed. Is prevented. A set screw 33 is provided on the cover member 31 in order to fix the cover member 31 to the cam member 23 in a state where the end surface of the engagement pin 24 is covered by the cover member 31.

  The pneumatic cylinder 21 has a forward pressure chamber and a backward pressure chamber formed by a piston to which a piston rod 22 is attached. As shown in FIG. 1, a supply / discharge port 34a communicating with the forward pressure chamber is formed. And a supply / exhaust port 34 b communicating with the pressure chamber for retraction is formed in the pneumatic cylinder 21. Therefore, when compressed air is supplied from the supply / discharge port 34a to the pressure chamber for forward movement, the piston rod 22 is moved forward, and when compressed air is supplied from the supply / discharge port 34b to the pressure chamber for backward movement, the piston is moved as shown in FIG. The rod 22 is driven to the retreat limit position.

  In order to center and grip a workpiece having a circular outer peripheral surface such as a gear, first, as shown in FIG. 1, the chuck device approaches the workpiece while the piston rod 22 is in the retracted limit position. By doing so, the work is caused to enter the three gripping claws 17. Next, when compressed air is supplied from the supply / discharge port 34 a to the pressure chamber for forward movement, the piston rod 22 moves forward toward the support plate 13 in the cylindrical body 18. Thus, when the engagement pin 24 is guided by the long hole 25 and moves together with the piston rod 22, the cam member 23 is rotated by the engagement between the engagement pin 24 and the cam groove 26.

  The guide hole 28 extends in the radial direction, and the radial direction line R and the guide direction line T have an acute angle. When the cam member 23 rotates and the guide hole 28 moves, the drive pin 27 moves in the circumferential direction. While moving toward the gripping center O. As a result, the workpiece receives a gripping force from three points on the outer peripheral surface by the three gripping claws 17, and the workpiece is gripped in a state where the center of the workpiece coincides with the gripping center O of the support plate 13.

  FIG. 9 is a plan view showing the movement trajectory of the gripping claws 17. In FIG. 9, the state in which the gripping claw 17 is farthest from the gripping center O is indicated by a solid line, and at this time, the piston rod 22 is in the retreat limit position. When the gripping claw 17 approaches the gripping center O, the piston rod 22 is moved forward to rotate the cam member 23 counterclockwise in FIG. The guide hole 28 is rotated by the rotation of the cam member 23, and the finger 15 swings in an arcuate locus around the support pin 16. As described above, when the workpiece is gripped and released, the finger 15 swings along an arcuate locus. Therefore, even when the workpiece W1 having the maximum diameter is gripped, the support plate 13 is gripped radially outward. It is prevented that the nail | claw 17 protrudes greatly. Thereby, it is possible to grip not only a small-diameter workpiece but also a large-diameter workpiece while achieving downsizing of the chuck device. As long as the outer diameter of the work that can be gripped is a dimension between the maximum diameter and the minimum diameter, a work with any outer diameter can be gripped.

  When the workpiece is conveyed while being gripped by the chuck device, the compressed air is supplied to the forward pressure chamber of the pneumatic cylinder 21. Thereby, a clamping force to the workpiece is always applied to the gripping claw 17 by the compressed air in the pressure chamber, and the workpiece can be securely gripped while preventing the workpiece from falling. In addition, when the pneumatic cylinder 21 is used as a drive source, a desired fastening force can be maintained on the workpiece without increasing the size of the chuck device.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the piston rod 22 of the pneumatic cylinder 21 is used as the drive shaft, and the cam member 23 is rotated by air pressure. However, the cam member is driven by the electric motor using the nut driven by the rotary shaft of the electric motor as the drive shaft. You may make it drive. Further, in the chuck device shown in FIG. 1, the cylinder 18 and the cam member 23 constitute a driving means for rotating the driving pin 27, and the linear reciprocation of the piston rod 22 as the driving shaft is performed by the cam member 23. The rotation is converted into a rotational motion, but a piston type rotary actuator or vane type rotary actuator driven by air pressure is used as a rotation means to be provided on the support plate 23 so that the drive pin 27 is directly driven. Also good.

It is a partially cutaway front view showing a chuck device which is an embodiment of the present invention. FIG. 2 is a perspective view of FIG. 1. It is a top view of FIG. It is the sectional view on the AA line of FIG. It is a bottom view of FIG. It is a top view which shows the support plate with which the cam member was assembled | attached. It is the BB sectional view taken on the line of FIG. It is a side view of the arrow C direction of FIG. It is a top view which shows the movement locus | trajectory of a holding nail | claw.

Explanation of symbols

11 Pedestal 12 Mounting hole 13 Support plate 14 Connecting rod 15 Finger 16 Support pin 17 Holding claw 18 Cylindrical body 21 Pneumatic cylinder 22 Piston rod (drive shaft)
23 cam member 23a cylindrical part 23b drive part 24 engagement pin (engagement member)
25 Long hole 26 Cam groove 27 Drive pin 28 Guide hole 31 Cover member 32 Through hole 33 Set screw 34a, 34b Supply / exhaust port

Claims (3)

A chuck device for gripping a workpiece by three fingers each provided with a gripping claw,
Support pins for swingably supporting the fingers are provided on the surface side at the same distance from the gripping center, and a support plate provided with a cylinder projecting on the back side ;
The drive unit and the cylindrical body each having a guide hole in which a drive pin attached to each finger penetrates and engages with the support plate through an arc-shaped notch formed radially inward of the support pin A cam member having a cylindrical portion that is rotatably fitted to the outside of
Rotation means for rotating the cam member ,
Chuck, characterized in that the said drive pin radially inward of the support pin is rotated by said cam member is swung each of the fingers around the support pin, to hold the workpiece by the gripping claws apparatus. 2. The chuck device according to claim 1, wherein the rotation unit includes a drive shaft that is incorporated in the cylindrical body so as to be reciprocally movable in an axial direction, and a long hole formed in the cylindrical body to pass through the drive shaft. And a engaging member that engages with a cam groove formed in the cylindrical portion of the cam member, and the cam member is rotated by the drive shaft . 3. The chuck device according to claim 2, wherein the drive shaft is a piston rod of a pneumatic cylinder.

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