JP2024024856A - clamp device - Google Patents

Abstract

An object of the present invention is to provide a clamp device that can be put into a compact release state. SOLUTION: A piston rod (8) is moved forward and backward by a piston (3) provided in a housing (1). A movable member (17) that moves relative to the piston rod (8) is connected to the piston rod (8). The movable member (17) is urged upward by the advancing spring (13). A clamp arm (24) is rotatably connected to the movable member (17) via a first link member (20). The clamp arm (24) is rotatably connected to the housing (1) via a second link member (22). The connecting member (16) is rotatably connected to the second link member (22) via a third link member (23). [Selection diagram] Figure 1

Description

The present invention relates to a clamping device for fixing objects to be clamped, such as workpieces, workpiece pallets, molds, tools, etc., to a table, a movable part of a robot, or the like.

Conventionally, this type of clamp device is described in Patent Document 1 (Japanese Patent Application Publication No. 8-336734). The conventional technology is configured as follows.
In the above-mentioned clamp device, the piston rod is moved in the vertical direction by a piston provided within the housing. A connecting block is fixed to the tip of the piston rod. One end of the first link member is rotatably connected to the connection block in a vertical plane. Further, one end portion of the second link member is rotatably connected in a vertical plane to a pivot portion provided on the housing. One end of the third link member is rotatably connected in a vertical plane to an intermediate portion in the longitudinal direction of the second link member. The other end of the third link member is rotatably connected to the connection block within a vertical plane. The other end of the first link member is rotatably connected to the left side of the clamp arm, and the other end of the second link member is rotatably connected to a longitudinally intermediate portion of the clamp arm. Ru. The tip end surface of the piston rod can come into contact with the back surface of the left portion of the clamp arm. When the clamping device is driven to lock and clamp the workpiece, the connecting block is raised via the piston and the piston rod by pressure oil supplied to the clamping device. As a result of the upward movement, the first link member rotates clockwise with respect to the connection block, and the second link member rotates clockwise with respect to the pivot portion. Then, the clamp arm is raised and moved to the right. The upper end surface of the piston rod engages with the back surface of the clamp arm, and the piston rod uses the connecting portion between the clamp arm and the second link member as a fulcrum to push the clamp arm down onto the workpiece and fix it on the table.

Japanese Patent Application Publication No. 8-336734

The above conventional technology has the following problems.
It is sometimes desirable for the clamp device to be able to fix a workpiece that is located far away from the clamp device. In this case, the problem can be solved by increasing the lengths of the clamp arm, each link member, and the piston rod. However, increasing the length of each member increases the movable range of each member. For this reason, the clamp arm comes into contact with the piston rod or the connecting block during the release drive of the clamp device, making it impossible to bring the clamp device into a compact release state.
SUMMARY OF THE INVENTION An object of the present invention is to provide a clamping device that can be brought into a compact released state.

In order to achieve the above object, the present invention, for example, as shown in FIGS. 1A to 3, has a clamp device configured as follows.
A drive mechanism D provided within the housing 1 causes the piston rod 8 to advance toward the distal end and retreat toward the proximal end. A movable member 17 that is movable relative to the piston rod 8 in the axial direction is connected to the piston rod 8 . The movable member 17 is urged by the urging mechanism B toward the distal end side with respect to the housing 1 or the piston rod 8. The piston rod 8 is formed with engaging portions 19a and 30a. The engaging portions 19a, 30a face the locking portions 18a, 31 formed on the movable member 17 at a predetermined interval on the tip side, and the locking portions 18a, 31 face the locking portions 18a, 31 on the tip side. It is possible to contact from A first link member 20 is rotatably connected to the movable member 17 . The second link member 22 connected to the housing 1 is rotatable in a plane parallel to the plane in which the first link member 20 rotates. A third link member 23 rotatably connected to the movable member 17 is rotatably connected to the second link member 22 . A clamp arm 24 is rotatably connected to the first link member 20 and rotatably connected to the second link member 22 . The clamp arm 24 can come into contact with the piston rod 8. Further, the clamp arm 24 has a pressing portion that can come into contact with the object to be clamped 26 .

The present invention has the following effects.
The clamp device includes a movable member that is biased toward the distal end side by a biasing mechanism, and the movable member is movable relative to the piston rod in the axial direction. Therefore, when switching the clamp device from the locked state to the released state, the piston rod can be lowered before the movable member, with the movable member remaining at the tip side position. Therefore, when the clamp arm moves backward, the piston rod is retracted to the base end side of the movable region of the clamp arm. Therefore, the clamp arm and the piston rod are prevented from interfering with each other and becoming unable to retreat. This allows the piston rod to move the movable member toward the proximal end side through the engaging portion and the locking portion against the biasing force toward the distal end side of the biasing mechanism while avoiding interference. can. As a result, the clamp device of this embodiment can be brought into a compact released state.

In the present invention, it is preferable to add the following configurations (1) and (2).
(1) As shown in FIGS. 1A to 3, a guide portion 19 is formed in the piston rod 8 in a concave shape so as to extend in the axial direction. The engaging portion 19a is formed on the peripheral wall of the guide portion 19 on the distal end side. A connecting member 18 protruding from the movable member 17 is inserted into the guide portion 19 so as to be movable in the axial direction. The locking portion 18a is formed on the connecting member 18.
In this case, while the clamp device is being switched from the locked state to the released state, the piston rod applies a biasing force toward the distal end of the biasing mechanism on the movable member via the engaging portion of the guide portion and the locking portion of the connecting member. firmly push it toward the proximal end against the Thereby, the clamp arm, the movable member, etc. are moved by the piston rod toward the proximal end so as to approach the housing, and in a direction away from the object to be clamped, so that the clamp device can be compactly brought into the released state.

(2) As shown in FIGS. 4A to 6, an engaging member 30 is provided to protrude from the outer peripheral wall of the piston rod 8. The engaging member 30 is formed with an engaging portion 30a. A locking portion 31 is formed on the movable member 17 .
In this case, while the clamp device is being switched from the locked state to the released state, the piston rod urges the movable member toward the distal end side of the biasing mechanism via the engaging portion of the engaging member and the locking portion of the movable member. It is reliably pushed toward the proximal end against the force. Thereby, the clamp arm, the movable member, etc. are moved by the piston rod toward the proximal end so as to approach the housing, and in a direction away from the object to be clamped, so that the clamp device can be compactly brought into the released state.

FIG. 1A is a side cross-sectional view showing the first embodiment of the present invention and showing the clamp device in a released state. FIG. 1B is a plan view showing the clamp device. FIG. 2 is an explanatory diagram of the operation of the clamp device. FIG. 3 is a sectional view showing the clamp device in a locked state. FIG. 4A is a side cross-sectional view showing a second embodiment of the present invention and showing a released state of the clamp device. FIG. 4B is a plan view showing the clamp device. FIG. 5 is an explanatory diagram of the operation of the clamp device. FIG. 6 is a sectional view showing the clamp device in a locked state.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1A to 3.
A housing 1 of a clamp device is bolted to a table T serving as a fixed base. A cylinder hole 2 is formed in the housing 1 in the vertical direction, and a piston 3 is inserted into the cylinder hole 2 so as to be movable in the vertical direction (axial direction) in a sealed manner. A lock chamber 4 is formed between the piston 3 and the lower wall 1a of the housing 1, and a release chamber 5 is formed between the piston 3 and the upper wall 1b of the housing 1. A supply/discharge passage 6 for compressed air (pressure fluid) is formed in the body 1c of the housing 1, and compressed air from a compressed air supply source (pressure fluid supply source) is supplied to the lock chamber 4 through the supply/discharge passage 6. be excluded. Further, compressed air is supplied to and discharged from the release chamber 5 through another supply and discharge path 7. In the clamp device of this embodiment, a drive mechanism D is constituted by the piston 3, the lock chamber 4, the release chamber 5, the supply/discharge passages 6 and 7, and the like.

A piston rod 8 is provided to protrude upward from the piston 3, and an upper portion of the piston rod 8 protrudes upward from the upper surface of the housing 1. The piston rod 8 has a large diameter portion 8a and a small diameter portion 8b formed in order from the base end side. The compressed air supplied to the lock chamber 4 advances the piston rod 8 upward (toward the tip side) via the piston 3, and the compressed air supplied to the release chamber 5 advances the piston rod 8 downward via the piston 3. (proximal side).

A cylindrical support member 9 is fitted onto the large diameter portion 8a via a sealing member 10 so as to be movable along the outer peripheral surface of the piston rod 8 in a sealed manner. The support member 9 is hermetically inserted into the insertion hole 11 formed in the upper wall 1b of the housing 1 via the sealing member 12. Further, an upper spring receiver 14a (spring receiver 14), an advancing spring 13, and a lower spring receiver 14b (spring receiver 14) are installed between the upper surface of the piston 3 and the lower surface of the support member 9, and the advancing spring 13 is attached to the piston. 3 and the support member 9 are urged away from each other. In the clamp device of this embodiment, the biasing mechanism B is configured by the compression spring as the advance spring 13 and the spring receiver 14.

A connecting member 15 is integrally formed on the upper part of the support member 9 (or separate members are connected and fixed together). A guide hole 16 is formed in the connecting member 15 in the vertical direction (axial direction), and the small diameter portion 8b of the piston rod 8 is fitted into the guide hole 16. In the clamp device of this embodiment, a movable member 17 is configured by the support member 9 and the connection member 15. The movable member 17 is guided in the axial direction along the outer peripheral surface of the piston rod 8. Instead of the support member 9 and the connection member 15 being integrally formed, the support member 9 and the connection member 15 may be formed of separate members as in a clamp device of a second embodiment described later. good. Further, the supporting member 9 may be omitted and the movable member 17 may be configured only by the connecting member 15.

A mounting hole is formed perpendicular to the guide hole 16 of the connecting member 15, and a connecting pin (connecting member) 18 is inserted into the mounting hole. Therefore, the connecting pin 18 is provided to protrude from the inner peripheral surface of the guide hole 16 toward the inside of the guide hole 16 . The connecting pin 18 is inserted into a long hole (guide portion) 19 that is formed in the middle of the piston rod 8 in the longitudinal direction and extends in the axial direction (vertical direction) of the piston rod 8 . Therefore, the connecting pin 18 of the connecting member 15 is guided in the vertical direction along the inner peripheral surface of the elongated hole 19. A locking portion 18a is formed on the upper wall of the connecting pin 18, and an engaging portion 19a is formed on the upper end wall of the elongated hole 19. The engaging portion 19a faces the locking portion 18a from above with a predetermined distance therebetween, and can come into contact with the locking portion 18a.

A through hole is formed in the left side wall of the connecting member 15, and a pin is inserted into the through hole. Both ends of the pin protrude from the side wall surface of the connecting member 15. One end portions 20a of the two first link members 20, which are rotatable in a vertical plane using the end portions of the pins as rotational pivots, are connected by pins so as to sandwich the connecting member 15 therebetween.

A pivot portion 21 is provided to protrude upward from the upper portion of the housing 1, and one end portion 22a of two second link members 22 is attached to the pivot portion 21 with a pin rotatable within a vertical plane so as to sandwich the pivot portion 21 therebetween. Concatenated.

One end 23a of the third link member 23 is connected with a pin to the longitudinal intermediate portion 22b of the second link member 22 so as to be rotatable within a vertical plane. The other end 23b of the third link member 23 is pin-coupled to the connecting member 15 so as to be rotatable in a vertical plane. In the clamping device of this embodiment, both ends of the connecting pin 18 protruding outward from the outer wall surface of the connecting member 15 are used as rotational shafts on the other end 23b side of the third link member 23. . Note that the configuration is not limited to this, and the rotation support shaft on the other end portion 23b side may be provided separately from the connecting pin 18.

The other end 20b of the first link member 20 is rotatably connected to the left portion 24a of the clamp arm 24 with a pin. Further, the other end portion 22c of the second link member 22 is connected by a pin to a longitudinally intermediate portion 24b of the clamp arm 24 so as to be rotatable within a vertical plane.

In the clamp device of the above embodiment, the clamp arm 24, the two first link members 20, the two second link members 22, and the two third link members 23 are rotatable in parallel vertical planes. There is.

The upper end surface 8c of the piston rod 8 can come into contact with the lower surface 24d of the clamp arm 24 on the one end 24a side. Further, a pressing portion 25 is formed on the lower surface of the other end portion 24c of the clamp arm 24, and the pressing portion 25 can come into contact with a workpiece 26 as an object to be clamped.

The above clamping device operates as follows, as shown in FIGS. 1A to 3.
In the clamp device in the initial state (released state) of FIG. 1A, compressed air is discharged from the lock chamber 4 and compressed air is supplied to the release chamber 5. Therefore, the compressed air in the release chamber 5 moves the piston rod 8 to the lower limit position via the piston 3. The piston rod 8 forces the movable member 17 via the engaging portion 19a of the elongated hole 19 and the locking portion 18a of the connecting pin 18 to apply an upward biasing force to the advancement spring 13 and an upward force to the compressed air in the lock chamber 4. It is pushed to the lower limit position against the pressing force. Therefore, the first link member 20, the second link member 22, and the third link member 23 move the clamp arm 24 away from the workpiece 26 to the left, and in the height direction, the clamp arm 24 is positioned at a lower position than the clamp position described later. It is retracted to the clamp position.

When the clamp device is switched from the released state shown in FIGS. 1A and 1B to the locked state shown in FIG. 3, compressed air is discharged from the release chamber 5 and compressed air is supplied to the lock chamber 4. Then, a pressing force corresponding to the pressure of the compressed air in the lock chamber 4 moves the piston rod 8 upward via the piston 3. Therefore, the restriction on the upward movement of the locking part 18a of the connecting member 15 by the engaging part 19a of the piston rod 8 is released, and the urging force of the advance spring 13 moves the movable member 17 upward. Then, the first link member 20 is moved clockwise relative to the movable member 17. At this time, the movable member 17 pushes the second link member 22 via the third link member 23, so that the second link member 22 is moved clockwise relative to the pivot portion 21. Then, the first link member 20 and the second link member 22 move the clamp arm 24 upward and to the right while maintaining it in a substantially horizontal state. Subsequently, as shown in FIG. 2, when the clamp arm 24 is moved to the lock position, the pressing portion 25 of the clamp arm 24 comes into contact with the upper surface of the workpiece 26. At this time, the piston 3 pushes the work 26 onto the table T via the advancing spring 13, the movable member 17, the first link member 20, the second link member 22, and the clamp arm 24. Therefore, the movable member 17, the first link member 20, the second link member 22, and the clamp arm 24 are received by the workpiece 26. Thereafter, the piston 3 and the piston rod 8 are raised, leaving the movable member 17 and the like behind, and the upper end surface 8c of the piston rod 8 comes into contact with the lower surface 24d of the clamp arm 24. Therefore, the piston 3 strongly presses the work 26 against the table T from above via the piston rod 8 and the clamp arm 24. Therefore, the upward movement of the piston 3 and piston rod 8 is stopped. This switches the clamp device from the released state of FIGS. 1A and 1B to the locked state of FIG. 3.

When the clamp device is switched from the locked state shown in FIG. 3 to the released state shown in FIGS. 1A and 1B, compressed air is discharged from the lock chamber 4 and compressed air is supplied to the release chamber 5. Then, the compressed air in the release chamber 5 moves the piston rod 8 down via the piston 3. At this time, the advance spring 13 causes the clamp arm 24 to press the upper surface of the workpiece 26 via the movable member 17, the first link member 20, and the second link member 22, and the pressed state is maintained. Next, as shown in FIG. 2, the engaging portion 19a of the long hole 19 of the piston rod 8 comes into contact with the locking portion 18a on the connecting pin 18 of the movable member 17. Then, the piston rod 8 moves the movable member 17 down through the engaging portion 19a and the locking portion 18a of the connecting pin 18 against the upward biasing force of the advancement spring 13. Subsequently, the movable member 17 rotates the first link member 20 in the counterclockwise direction relative to the movable member 17. Thereby, the movable member 17 rotates the second link member 22 in the counterclockwise direction with respect to the pivot portion 21 via the third link member 23. Then, the clamp arm 24 is moved to the left and once raised, and then moved to the left and lowered. The piston 3 is received by the lower wall 1a of the housing 1 and stopped. This switches the clamp device from the locked state of FIG. 3 to the released state of FIGS. 1A and 1B.

The above embodiment has the following advantages.
The clamping device includes a movable member 17 that is urged upward by an advancing spring 13, and the movable member 17 is movable relative to the piston rod 8 in the vertical direction. Therefore, when switching the clamp device from the locked state to the released state, the piston rod 8 can be lowered before the movable member 17, with the movable member 17 remaining in the locked position (upper position). Therefore, when the clamp arm 24 moves backward, the piston rod 8 is retracted below (towards the proximal end) the movable region of the clamp arm 8. Therefore, the clamp arm 24 and the piston rod 8 are prevented from interfering with each other and becoming unable to retreat. As a result, in a state where such interference can be avoided, the piston rod 8 moves the movable member 17 through the engaging portion 19a of the elongated hole 19 and the locking portion 18a of the connecting pin 18 to the upper part of the advancing spring 13. It can be lowered against forces. As a result, the clamp device of this embodiment can be brought into a compact released state.

4A to 6 illustrate a second embodiment of the invention. In this second embodiment, the same reference numerals are attached to the same members (or similar members) as the constituent members of the first embodiment described above in principle.

This second embodiment differs from the first embodiment described above in the following points.
The movable member 17 of the clamp device of this embodiment is constituted by a cylindrical support member 9 and a connection member 15 that is a separate member from the support member 9. The upper end surface of the support member 9 can come into contact with the lower surface of the connecting member 15. Instead of forming the supporting member 9 and the connecting member 15 separately, they may be formed integrally as in the clamp device of the first embodiment. Further, the supporting member 9 may be omitted and the movable member 17 may be configured only by the connecting member 15.

In the clamp device of the first embodiment, the connecting pin 18 is projected from the inner peripheral wall of the guide hole 16 of the connecting member 15 into the guide hole 16, and the connecting pin 18 is inserted into the long hole 19 of the piston rod 8. has been done. On the other hand, in the clamp device of the second embodiment, although the connecting pin 18 is provided, it is not provided to protrude into the guide hole 16 from the inner circumferential wall of the guide hole 16 . Moreover, the elongated hole 19 is not provided in the piston rod 8. In the clamp device of this embodiment, an engaging member 30 is provided protruding from the outer circumferential wall of the piston rod 8, and an engaging portion 30a is formed on the lower wall of the engaging member 30. A locking portion 31 facing below the engaging portion 30a with a predetermined interval is formed on the upper surface of the connecting member 15. The engaging portion 30a can engage with the locking portion 31.

The procedure for switching the clamp device from the released state of FIGS. 4A and 4B to the locked state of FIG. 6 is almost the same as that of the clamp device of the first embodiment.

When the clamp device is switched from the locked state shown in FIG. 6 to the released state shown in FIGS. 4A and 4B, compressed air is discharged from the lock chamber 4 and compressed air is supplied to the release chamber 5. Then, the compressed air in the release chamber 5 moves the piston rod 8 down via the piston 3. At this time, the advance spring 13 causes the clamp arm 24 to press the upper surface of the workpiece 26 via the support member 9, the connection member 15, the first link member 20, and the second link member 22, and the pressed state is maintained. There is. Next, as shown in FIG. 5, the engaging portion 30a of the engaging member 30 of the piston rod 8 comes into contact with the locking portion 31 of the connecting member 15. Then, the piston rod 8 pushes the connecting member 15 downward through the engaging member 30 and the locking portion 31 against the upward biasing force of the advance spring 13. Subsequently, the connecting member 15 rotates the first link member 20, the second link member 22, and the third link member 23 in the counterclockwise direction. As a result, the clamp arm 24 is moved to the left and once raised, and then moved to the left and lowered. The piston 3 is received by the lower wall 1a of the housing 1 and stopped. This switches the clamp device from the locked state of FIG. 6 to the released state of FIGS. 4A and 4B.

The clamp device of this embodiment has the following effects.
In the middle of switching the clamp device from the locked state to the released state, the piston rod 8 moves the connecting member 15 and the support member 9 above the advancing spring 13 via the engaging part 30a and the locking part 31 of the engaging member 30. It is pushed downward against the urging force of. As a result, the clamp arm 24, movable member 17, etc. are moved downward and to the left (away from the workpiece 26) so as to approach the housing 1 by the piston rod 8, and the clamp device is brought into a compact release state. Can be done.

Further, in the clamping device of this embodiment, since the elongated hole 19 unlike the clamping device of the first embodiment is not provided in the piston rod 8, the rigidity of the piston rod 8 can be increased.

Each of the above embodiments can be modified as follows.
The pressure fluid may be another gas or a gas such as pressurized oil instead of the illustrated compressed air.
The above-mentioned drive mechanism D is a double-acting device consisting of a piston 3 inserted into a cylinder hole 2 in a housing 1, a lock chamber 4 formed on the lower side of the piston, a release chamber 5 formed on the upper side, etc. It is a type air cylinder. Alternatively, it may be a single-acting air cylinder that includes a release spring in the release chamber, or a single-acting air cylinder that includes a lock spring in the lock chamber. Further, the drive mechanism is not limited to an air cylinder, but may be a hydraulic cylinder, a motor, a ball screw shaft, or other drive mechanism.
The biasing mechanism B described above is composed of a compression spring as the advancing spring 13 and a spring receiver 14. However, the movable member 17 is not limited to this, and a pressure fluid (compressed air, compressed other gas, pressure oil, etc.) is sealed in a working chamber formed on the lower side of the movable member 17, and the pressure of the compressed fluid in the working chamber causes the movable member to move. The structure may be such that it is biased upward (toward the tip side). Further, the advancing spring 13 is not limited to being installed between the piston 3 and the movable member 17. Instead of this configuration, the advancing spring 13 (biasing mechanism B) may be installed between the upper wall 1b of the housing 1 and the movable member 17, and the advancing spring 13 (biasing mechanism B) may be installed between the outer peripheral wall of the piston rod 8 and the movable member 17. It may be installed between.
As shown in FIGS. 1B and 4B, the clamping device of this embodiment includes two each of the first link member 20, the second link member 22, and the third link member 23, but is not limited thereto. Instead, one or three or more may be provided.
Instead of the long hole 19 passing through the piston rod 8 so as to extend in the vertical direction, the concave guide part is not penetrated but is formed in the shape of a groove having a bottom wall and extending in the vertical direction. It may also be a groove.
It goes without saying that various other changes can be made within the scope of those skilled in the art.

1: Housing, 8: Piston rod, 17: Movable member, 18: Connecting member, 18a: Locking portion, 19: Guide portion (elongated hole), 19a: Engaging portion, 20: First link member, 22: First 2 link member, 23: third link member, 24: clamp arm, 25: pressing portion, 26: clamp object (work), 30: engaging member, 30a: engaging portion, 31: locking portion, D: Drive mechanism, B: biasing mechanism.

Claims (3)

a piston rod (8) that is advanced toward the distal end and retracted toward the proximal end by a drive mechanism (D) provided within the housing (1);
A movable member (17) connected to the piston rod (8) so as to be able to move relative to the piston rod (8) in the axial direction, the movable member (17) being connected to the housing (1) by the biasing mechanism (B). or a movable member (17) that is biased toward the tip side with respect to the piston rod (8);
Engagement parts (19a, 30a) formed on the piston rod (8), and locking parts (18a, 31) formed on the movable member (17) at a predetermined interval on the tip side. an engaging part (19a, 30a) that faces the engaging part (19a, 30a) and can come into contact with the locking part (18a, 31) from the tip side;
a first link member (20) rotatably connected to the movable member (17);
a second link member (22) connected to the housing (1) and rotatable in a plane parallel to a plane in which the first link member (20) rotates;
a third link member (23) rotatably connected to the movable member (17) and rotatably connected to the second link member (22);
a clamp arm (24) rotatably connected to the first link member (20) and rotatably connected to the second link member (22), the clamp arm (24) being rotatably connected to the piston rod (8); A clamp arm (24) that can come into contact with the object to be clamped (26) and has a pressing portion (25) that can come into contact with the object to be clamped (26).
A clamp device characterized by: The clamping device according to claim 1,
A guide portion (19) is formed in the piston rod (8) in a concave shape so as to extend in the axial direction,
The engaging portion (19a) is formed on the peripheral wall on the distal end side of the guide portion (19),
A connecting member (18) protruding from the movable member (17) is inserted into the guide portion (19) so as to be movable in the axial direction,
A clamp device characterized in that the locking portion (18a) is formed on the connecting member (18). The clamping device according to claim 1,
An engagement member (30) is provided to protrude from the outer peripheral wall of the piston rod (8),
An engaging portion (30a) is formed in the engaging member (30),
A clamp device characterized in that a locking portion (31) is formed on the movable member (17).