WO2021177385A1

WO2021177385A1 - Clamping device

Info

Publication number: WO2021177385A1
Application number: PCT/JP2021/008321
Authority: WO
Inventors: 春名　陽介
Original assignee: 株式会社コスメック
Priority date: 2020-03-06
Filing date: 2021-03-04
Publication date: 2021-09-10
Also published as: KR20220001990U; CN219925208U; DE212021000326U1

Abstract

A through hole (30) is formed in a peripheral wall of a plug portion (2) of a housing (1). An engaging member (31a) and a lock member (31b) are inserted into the through hole (30). A support portion (36) is formed on an outer peripheral wall of an output rod (3). In the clamp device in a clamped state, when an external force acts in the direction of separating the housing (1) and a work pallet (WP), the lock member (31b) is received by the support portion (36), so that a state in which a part of the lock member (31b) protrudes from the through hole (30) outward from the outer peripheral surface of the plug portion (2) is maintained.

Description

Clamping device

INDUSTRIAL APPLICABILITY The present invention is suitable for firmly fixing an object to be fixed such as a work pallet, a work, a mold, a tool, etc. to a clamp pallet, a table, a tip of a robot arm, etc. as a base, and maintaining the fixed state. Clamping device.

Conventionally, there is a clamp device of this type described in Patent Document 1 (International Publication No. 2013/122039). The prior art is configured as follows.

A tubular plug part is projected upward from the housing. The output rod is inserted into the tubular hole of the plug portion so as to be movable in the axial direction of the tubular hole. An engaging ball is inserted into the peripheral wall of the plug portion, and the engaging ball is moved in the radial direction of the tubular hole by a drive mechanism via an output rod. A mounting hole is provided in the work pallet so that the plug portion can be inserted. The locking portion provided in the mounting hole can come into contact with the engaging ball. The drive mechanism has a clamp chamber to which compressed air is supplied and discharged. A holding spring is installed in the clamp chamber.

If the compressed air in the clamp chamber disappears for some reason while the clamp device clamps the work pallet, the clamp state of the clamp device is maintained by the urging force of the holding spring.

International Publication No. 2013/122030

The above conventional technology has room for the following improvements.

As described above, when the compressed air in the clamp chamber disappears and the clamping device is maintained in the clamped state by the urging force of the holding spring, the urging force of the holding spring (force to maintain the clamped state) is applied. An excessive external force may act in the direction of separating the housing and the work pallet. Even in such a case, there is room for improvement in preventing the work pallet from being removed from the clamping device by an external force.

An object of the present invention is to propose a clamp device for improving the above points.

In order to achieve the above object, in the present invention, for example, as shown in FIGS. 1 to 14, the clamp device is configured as follows.

A tubular plug portion 2 is projected from the housing 1. The output rod 3 is inserted into the tubular hole 2a of the plug portion 2 so as to be movable in the axial direction of the tubular hole 2a. The engaging member 31a and the locking member 31b are inserted into the through hole 30 formed in the peripheral wall of the plug portion 2. When the output rod 3 is moved in the axial direction by the drive mechanism D, the engaging member 31a and the lock member 31b are moved in the through hole 30.

Support portions

36, 36A are formed on the outer peripheral wall of the output rod 3 so as to be able to come into contact with the lock member 31b. Mounting holes 42 are provided in the clamp objects WP and W so that the plug portion 2 can be inserted. The locking portion 44 of the mounting hole 42 can come into contact with the engaging member 31a and the locking member 31b. When an external force acts in a direction in which the housing 1 and the clamp target objects WP and W are separated from each other in a clamped state in which the engaging member 31a is engaged with the locking portion 44, the locking member 31b is supported by the supporting portion. By receiving the

clamps

36 and 36A, a state in which a part of the lock member 31b protrudes outward from the outer peripheral surface of the plug portion 2 is maintained from the through hole 30.

The above invention has the following effects.

By maintaining a state in which a part of the lock member protrudes outward from the outer peripheral surface of the plug portion from the through hole, the clamp object is unintentionally removed from the plug portion (clamp device) by the lock member. Can be prevented.

The present invention preferably has the following configurations (1) to (8).

(1) For example, as shown in FIG. 9, the lock member 31b is made larger than the engaging member 31a.

In this case, the receiving of the lock member by the support portion is stable, and it is possible to further prevent the clamp object from being unintentionally removed from the plug portion.

(2) For example, as shown in FIG. 4, the

support portions

36, 36A are formed parallel to the axial direction.

In this case, the support portion can be easily formed.

(3) For example, as shown in FIGS. 4 and 5, a groove 38 extending along the axial direction is formed on the outer peripheral wall of the output rod 3. The support portion 36 is a bottom wall of the groove 38 having an arc-shaped cross section perpendicular to the axial direction, and is composed of a bottom wall extending parallel to the axial direction.

In this case, the receiving of the lock member by the support part is stable.

(4) For example, as shown in FIG. 7, the

support portions

36, 36A with respect to the axial direction so as to expand outward in the radial direction of the output rod 3 toward the clamp drive direction of the output rod 3. Is tilted.

In this case, when an external force acts in the direction of separating the housing and the object to be clamped, the locking portion provided on the object to be clamped pushes the output rod in the direction of driving the clamp via the lock member. Therefore, the pushing force and the pushing force of the external force in the direction of unclamping the output rod via the locking portion and the engaging member are balanced. In other words, the force with which the external force pushes the output rod in the direction of unclamping is weakened. As a result, it becomes easier to maintain a state in which a part of the lock member protrudes from the through hole to the outside of the outer peripheral surface of the plug portion.

(5) For example, as shown in FIG. 7, a groove 38 extending along the axial direction is formed on the outer peripheral wall of the output rod 3. The support portion 36 is the bottom wall of the groove 38 having an arc-shaped cross section perpendicular to the axial direction, and the support portion 36 extends outward in the radial direction toward the clamp driving direction with respect to the axial direction. It consists of a sloping bottom wall.

In this case, the receiving of the lock member by the support part is stable.

(6) For example, as shown in FIG. 6, the support portion 36 is a recess into which the lock member 31b is fitted.

In this case, the receiving of the lock member by the support part is stable.

(7) For example, as shown in FIG. 6, in a cross-sectional view of the output rod 3 parallel to the axial direction, the recess is a virtual straight line (L) extending in the radial direction of the output rod 3 from the center of the recess. ) Is symmetrical.

In this case, the lock member moves the output rod in the axial direction of the tubular hole so that the lock member coincides with the center of the recess, and after the movement, the relative movement between the lock member and the output rod is restricted, and the support portion. The reception of the lock member is more stable.

(8) For example, as shown in FIG. 6, the lock member 31b is a sphere, and the recess is formed in a spherical shape.

In this case, the number of contact points between the lock member and the support portion increases, or the contact range between the lock member and the support portion becomes wider, so that the support portion receives the lock member more stably.

In order to achieve the above object, in the present invention, for example, as shown in FIG. 15, the clamp device is configured as follows.

Housing 1 has a guide cylinder portion 78. The engaging member 31a and the locking member 31b are inserted into the through hole 30 formed in the peripheral wall of the guide cylinder portion 78. The engaging member 31a and the locking member 31b are moved in the through hole 30 by the drive mechanism D. The tubular piston 5 constitutes the drive mechanism D. The piston 5 is arranged outside the guide cylinder portion 78. Support

portions

36, 36A are formed on the inner peripheral wall of the piston 5 so that they can come into contact with the lock member 31b. Protrusions 82 are provided on the clamp target objects WP and W so that they can be inserted into the guide cylinder portion 78. The protrusion 82 has a locking portion 44 that can come into contact with the engaging member 31a and the locking member 31b. In a clamped state in which the engaging member 31a is engaged with the locking portion 44, when an external force acts in a direction that separates the housing 1 from the clamped objects WP and W, the locking member 31b is supported. By receiving the

portions

36 and 36A, a state in which a part of the lock member 31b protrudes from the through hole 3 is maintained inward from the inner peripheral surface of the guide cylinder portion 78.

The above invention has the following effects.

By maintaining a state in which a part of the lock member protrudes inward from the inner peripheral surface of the guide cylinder portion from the through hole, the clamp object is not intended to be clamped from the guide cylinder portion (clamp device) by the lock member. It can be prevented from being removed.

The present invention preferably has the following configurations (1) to (3).

In this case, the receiving of the lock member by the support portion is stable, and it is possible to further prevent the clamp object from being unintentionally removed from the guide cylinder portion.

(2) For example, as shown in FIG. 15, the

support portions

36, 36A are formed parallel to the axial direction of the tubular hole 78a of the guide tubular portion 78.

In this case, the support portion can be easily formed.

(3) For example, as shown in FIG. 15, a groove 38 extending along the axial direction is formed on the inner peripheral wall of the piston 5. The support portion 36 is a bottom wall of the groove 38 having an arc-shaped cross section perpendicular to the axial direction, and is composed of a bottom wall extending parallel to the axial direction.

In this case, the receiving of the lock member by the support part is stable.

According to the present invention, it is possible to prevent the object to be clamped from being unintentionally removed from the clamping device by an external force.

FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention and showing an unclamped state of a clamping device. FIG. 2 is an operation explanatory view of the clamp device, and is a cross-sectional view similar to FIG. FIG. 3 is a cross-sectional view showing a clamped state of the clamping device, which is similar to FIG. FIG. 4 is an enlarged view of a portion A in FIG. 3, showing a support portion and the like provided in the clamp device. FIG. 5 is a cross-sectional view taken along the line CC in FIG. FIG. 6 is an enlarged view showing a first modification of the support portion shown in FIG. 4, and is similar to FIG. 4 above. FIG. 7 is an enlarged view showing a second modification of the support portion shown in FIG. 4, which is similar to FIG. 4 above. FIG. 8 is an enlarged view showing a third modification of the support portion shown in FIG. 5, which is similar to FIG. 5 above. FIG. 9 shows a second embodiment of the present invention and is a schematic cross-sectional view showing a clamped state of the clamping device. FIG. 10 shows a third embodiment of the present invention and is a schematic cross-sectional view showing an unclamped state of the clamping device. FIG. 11 is a cross-sectional view showing a clamped state of the clamp device, which is similar to FIG. 10. FIG. 12 is an enlarged view of a portion B in FIG. 10, and is a view showing a holding valve provided in the clamp device. FIG. 13 is an enlarged view of a portion C in FIG. 11 and is a diagram showing a holding valve provided in the clamp device. FIG. 14 is an operation explanatory view showing the holding valve of the clamp device, and is a view similar to FIG. FIG. 15 shows a fourth embodiment of the present invention and is a schematic cross-sectional view showing a clamped state of the clamping device.

Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

In this embodiment, a clamp device for fixing a work pallet (clamp object) WP as a movable block to a clamp pallet CP as a reference block is illustrated.

The housing 1 of the clamp device is fixed to the clamp pallet CP by a plurality of bolts (not shown). A tubular plug portion 2 is integrally projected upward from the housing 1. The upper rod portion 3a of the output rod 3 is inserted into the tubular hole 2a of the plug portion 2 so as to be movable in the vertical direction (axial direction of the tubular hole 2a). A cylinder hole 4 is provided in the housing 1, and a drive mechanism D is provided in the cylinder hole 4. The drive mechanism D moves the output rod 3 in the vertical direction. The drive mechanism D is configured as follows.

The first piston 5 fixed to the lower part of the output rod 3 is inserted into the large diameter hole 4a of the cylinder hole 4 so as to be movable in the vertical direction. An annular second piston 6 is vertically (cylinder hole) between the small diameter hole 4b of the cylinder hole 4 formed above the large diameter hole 4a of the cylinder hole 4 and the outer peripheral surface of the lower rod portion 3b of the output rod 3. It is inserted so as to be movable in the axial direction of 4). The second piston 6 is hermetically inserted into the small diameter hole 4b via the outer sealing member 7, and is hermetically fitted to the lower rod portion 3b of the output rod 3 via the inner sealing member 8. NS.

A clamp chamber 10 is formed between the first piston 5 and the second piston 6. The first unclamp chamber 11 is formed between the first piston 5 and the bottom wall of the mounting hole of the clamp pallet CP as the lower wall 9 of the housing 1, and the second piston 6 and the upper wall 1a of the housing 1 are formed. A second unclamp chamber 12 is formed between the two. The second unclamp chamber 12 and the first unclamp chamber 11 are communicated with each other by a communication passage 13 formed inside the lower rod portion 3b of the output rod 3. Further, the clamp chamber 10 communicates with the compressed air supply / discharge port 15 via the supply / discharge passage 14 formed in the housing 1. The second unclamp chamber 12 communicates with a compressed air supply / discharge port (not shown) via a supply / discharge passage 16 formed in the housing 1.

A holding spring 17 is mounted between the first piston 5 and the second piston 6 in the clamp chamber 10. The holding spring 17 is composed of a compression coil spring and urges the first piston 5 and the second piston 6 in a direction in which they are separated from each other.

In this first embodiment, the holding spring 17 is configured so that the lower end of the spring is received by the first piston 5 and the upper end of the spring is received by the second piston 6. Instead of this, the stopper 51 of the second piston 6 provided in the cylinder hole 4 is projected inward in the radial direction so that the lower end of the spring is received by the stopper 51 and the upper end of the spring is received by the second piston 6. You may. Further, as the holding spring 17, other types of springs such as a disc spring can be used instead of the illustrated compression coil spring.

The structure for connecting the first unclamp chamber 11 and the second unclamp chamber 12 may be a communication hole provided in the body of the housing 1 instead of the communication passage 13 provided in the output rod 3. Further, it may be a pipe provided on the outside of the housing 1.

The booster mechanism 20 is arranged in the second unclamp chamber 12. The boosting mechanism 20 is configured such that the compressed air supplied to the clamp chamber 10 reverses the force pushing the second piston 6 upward to a downward force, converts the boosting force, and transmits the boosting force to the output rod 3. ..

The booster mechanism 20 described above is configured as follows. That is, the receiving cylinder 21 projects downward from the upper wall 1a toward the inside of the second unclamp chamber 12. Four lateral grooves are formed in the lower portion of the receiving cylinder 21 at predetermined intervals in the circumferential direction. The receiving portion 22 is formed by the bottom wall of each lateral groove. Further, four recesses are formed on the outer peripheral wall of the lower rod portion 3b of the output rod 3 at predetermined intervals in the circumferential direction. The transmission portion 23 is formed by the bottom wall of each recess. The transmission portion 23 is inclined so as to approach the axis of the output rod 3 (the depth of the recess becomes deeper) as it goes upward. A wedge space 24 is formed between the receiving portion 22 and the transmitting portion 23 so as to become narrower toward the inside of the cylinder hole 4 in the radial direction (see FIG. 2). The engaging ball 25 is inserted into the wedge space 24. The engaging ball 25 is formed in a tapered shape on the inner peripheral wall of the second piston 6 so as to push the engaging ball 25 inward in the radial direction so that the boosting portion 26 narrows as it goes downward. A pushing portion 27 is provided in a tapered shape on the upper side of the boosting portion 26.

Six through holes 30 are formed in the upper portion of the peripheral wall of the plug portion 2 at predetermined intervals in the circumferential direction. Each through hole 30 movably supports the ball 31 between the radial inner position shown in FIG. 1 and the radial outer position shown in FIG. 3 (outer position). Three of the six balls 31 are engaging balls 31a, and the remaining three balls are locking balls 31b. Engagement balls 31a and lock balls 31b are alternately inserted into the through holes 30. In this embodiment, the six through holes 30 are arranged on the peripheral wall of the plug portion 2 so as to be at the same height position in the axial direction. As a result, the dimension of the plug portion 2 in the height direction can be reduced as compared with the case where the

balls

31a and 31b are arranged at different height positions in the axial direction on the peripheral wall of the plug portion 2. As a result, the clamp device can be made compact.

On the outer peripheral wall of the upper rod portion 3a of the output rod 3, the pressing surface 32 and the retracting groove 33 are vertically connected to each other so as to correspond to the engaging ball 31a. The pressing surface 32 is formed so as to expand upward. By moving the pressing surface 32 to a position facing the engaging ball (engaging member) 31a, the engaging ball 31a is outward so as to project outward in the radial direction from the outer peripheral surface of the plug portion 2. Moved to position. The retracting groove 33 is at a position facing the engaging ball 31a, and by moving to a retracting position where the ball 31a can be inserted, the engaging ball 31a has a diameter larger than the outer peripheral surface of the plug portion 2. It becomes possible to move inward in the direction.

As shown in an enlarged view in FIG. 4, a support surface formed straight in the vertical direction on the outer peripheral wall of the upper rod portion 3a of the output rod 3 in correspondence with the locking ball (lock member) 31b. The (support portion) 36 and the evacuation groove 37 are formed so as to be connected vertically.

In the present embodiment, the support surface 36 is formed parallel to the axial direction of the tubular hole 2a. The axial direction of the output rod 3 and the axial direction of the tubular hole 2a are the same directions. The support surface 36 is formed on the outer peripheral wall of the upper rod portion 3a so as to be perpendicular to the axial direction of the through hole 30.

A groove 38 extending along the axial direction of the output rod 3 (cylinder hole 2a) is formed on the outer peripheral wall of the rod portion 3a of the output rod 3, and the support surface 36 is formed by the bottom wall of the groove 38. ing. The bottom wall of the groove 38 has an arcuate cross section perpendicular to the axial direction of the output rod 3 (cylindrical hole 2a). The bottom wall of the groove 38 extends parallel to the axial direction of the output rod 3 (cylinder hole 2a).

By moving the support surface 36 to a position facing the locking ball 31b, the state in which the locking ball 31b is moved to an outer position protruding outward in the radial direction from the outer peripheral surface of the plug portion 2 is maintained. Will be done. A state in which a part of the ball 31b protrudes from the through hole 30 outward from the outer peripheral surface of the plug portion 2 is maintained. By moving the retracting groove 37 to a retracting position where the locking ball 31b can be inserted facing the locking ball 31b, the locking ball 31b moves inward in the radial direction from the outer peripheral surface of the plug portion 2. It will be possible.

Instead of the support surface 36 being formed straight in the vertical direction as in the above embodiment, the locking ball 31b can be fitted as in the first modification of the present embodiment shown in FIG. The support surface 36 may be formed by a spherical surface. That is, the support surface 36 may be formed in a spherical shape. As a result, when the locking ball 31b is pushed inward in the radial direction of the plug member 2 by an external force, the locking ball 31b fits into the spherical support surface 36. As a result, the state in which the locking ball 31b protrudes to the outer position (protruding position) is maintained. Further, since the number of contact points between the ball 31b and the support surface 36 is increased or the contact range is widened, the reception of the ball 31b by the support surface 36 is stable.

The support surface 36 is not limited to a spherical surface. The support surface 36 may be a recess having a flat bottom. That is, the support surface 36 may be a recess into which the locking ball 31b is fitted, as a broader concept.

As shown in FIG. 6, the recess (support surface 36) extends in the radial direction of the output rod 3 from the center of the recess in a cross-sectional view parallel to the axial direction of the output rod 3, as in the present embodiment. It is preferable that the shape is symmetrical with respect to the virtual straight line L. As a result, the ball 31b moves the output rod 3 in the axial direction so that the ball 31b coincides with the center of the recess, and after the movement, the relative movement between the ball 31b and the output rod 3 is restricted, and the recess (support). The reception of the ball 31b by the surface 36) becomes more stable.

Further, as in the second modification of the present embodiment shown in FIG. 7, the support surface 36 extends outward in the radial direction of the output rod 3 as it goes toward the clamp drive direction of the output rod 3 ( It may be inclined with respect to the axial direction of the tubular hole 2a). The clamp drive direction of the output rod 3 is the downward direction in FIG. 7. The specific configuration is as follows, for example.

The support surface is inclined by θ (°) with respect to the axial direction of the tubular hole 2a of the plug portion 2 and expands (moves away from the axial center) toward the lower side (the direction in which the output rod 3 is driven by the clamp). 36 is formed. As a result, when the locking ball 31b is pushed inward in the radial direction of the plug member 2 by an external force, the locking ball 31b lowers the output rod 3 via the supporting surface 36 which is an inclined surface. Push in (clamp drive direction). Then, the force that pushes the output rod 3 downward and the force that the engaging ball 31a pushes the output rod 3 upward (in the unclamping drive direction) via the pressing surface 32 due to an external force are balanced. As a result, the movement of the output rod 3 in the vertical direction is restricted, and the state in which the lock member 31b protrudes to the outer position can be more easily maintained.

As in the case of FIG. 4, a groove 38 extending along the axial direction of the output rod 3 (cylinder hole 2a) is formed on the outer peripheral wall of the rod portion 3a of the output rod 3, and the support surface 36 has a support surface 36. It is composed of the bottom wall of the groove 38. The bottom wall of the groove 38 has an arcuate cross section perpendicular to the axial direction of the output rod 3 (cylindrical hole 2a). In this modification, the bottom wall of the groove 38 is oriented with respect to the axial direction of the output rod 3 (cylindrical hole 2a) so as to expand outward in the radial direction of the output rod 3 toward the clamp drive direction of the output rod 3. It is tilted.

In order to apply this second modification to the third embodiment described later, in the clamp device as in the third embodiment, the support surface 36 is θ (°) with respect to the axial direction of the tubular hole 2a of the plug portion 2. ) Is inclined, and is formed so as to expand (move away from the axial center) toward the upper side (the direction in which the output rod 3 is driven by the clamp, the upward direction in FIG. 11).

FIG. 8 shows a third modification of the support surface 36. In the first embodiment and the second modification, the support surface 36 is formed by the bottom wall of the groove 38 having an arcuate cross section perpendicular to the axial direction of the output rod 3 (cylindrical hole 2a). On the other hand, in the third modification, the support surface 36A is flat. The support surface 36A is formed parallel to the axial direction of the output rod 3 (cylinder hole 2a). When the support surface 36A receives the ball 31b, a state in which a part of the ball 31b protrudes outward from the outer peripheral surface of the plug portion 2 is maintained from the through hole 30.

As in the second modification shown in FIG. 7, the support surface 36A formed of a flat surface is such that the output rod 3 expands outward in the radial direction of the output rod 3 toward the clamp drive direction of the output rod 3. It may be inclined with respect to the axial direction of (cylindrical hole 2a).

Further, in FIG. 8, the pressing surface 32A corresponding to the pressing surface 32 in the first embodiment or the like is also made flat.

A recess 40 is opened on the lower surface of the work pallet WP. A ring member 41 is attached to the recess 40, and the ring member 41 is fixed to the work pallet WP by a plurality of bolts. The mounting hole 42 is formed by the inner peripheral hole of the ring member 41, and the plug portion 2 can be inserted into the mounting hole 42 (see FIG. 2). In this embodiment, the mounting hole 42 is formed in the ring member 41, but as in the third embodiment shown in FIGS. 10 to 14 described later, the inner peripheral hole of the recess 40 of the work pallet WP is used. The mounting hole 42 may be configured.

The locking portion 44 is formed in the mounting hole 42 of the ring member 41 in a tapered shape so as to expand upward. The seating surface 45 is formed by the lower surface of the ring member 41. The seating surface 45 can come into contact with the seating surface 46 formed on the upper wall 1a of the housing 1 (see FIG. 2). A seating detection ejection hole 47 is opened in the seating surface 46, and compressed air is supplied to the ejection hole 47.

The above clamp device operates as follows.

In the unclamped state of FIG. 1, compressed air is discharged from the clamp chamber 10 and compressed air is supplied to the first unclamp chamber 11 and the second unclamp chamber 12. As a result, the compressed air in the first unclamp chamber 11 pushes the first piston 5 upward to bring the first piston 5 into contact with the stepped portion 50 of the cylinder hole 4. Further, the compressed air in the second unclamp chamber 12 pushes the second piston 6 downward to bring the second piston 6 into contact with the stopper 51 provided in the cylinder hole 4. The stopper 51 is, for example, a retaining ring 51. Therefore, a slight gap can be formed in the vertical direction between the pushing portion 27 of the second piston 6 and the engaging ball 25, or between the receiving portion 22 and the engaging ball 25 (FIG. FIG. Not shown).

Further, since the first piston 5 raises the output rod 3, the engaging ball 31a can be moved to the retracted position in the retracting groove 33, and the locking ball 31b is in the retracting groove 37. It is possible to move to the evacuation position of. The work pallet WP is carried above the clamp device in the unclamped state shown in FIG.

When clamping the work pallet WP to the clamp pallet CP, first lower the work pallet WP. Then, as shown in FIG. 2, the seating surface 45 of the ring member 41 mounted on the work pallet WP is received by the seating surface 46 of the housing 1.

When the clamp device is clamp-driven, the compressed air in the first unclamp chamber 11 and the second unclamp chamber 12 is discharged and the compressed air is supplied to the clamp chamber 10 in the unclamped state of FIG. Then, first, the compressed air in the clamp chamber 10 pushes the first piston 5 downward and the second piston 6 upward. At the initial stage of the clamp drive stroke, the push portion 27 of the second piston 6 is received by the receiving portion 22 of the receiving cylinder 21 and the outer peripheral surface of the lower rod portion 3b via the engaging ball 25, so that it is above the second piston 6. Movement to is restricted. Therefore, at the initial stage of the clamp drive stroke, the output rod 3 is lowered by the first piston 5.

When the output rod 3 is lowered to a height position where the engaging ball 25 faces the transmission portion 23, first, as shown in FIG. 2, the transmission portion 23 provided on the output rod 3 and the receiver provided on the receiving cylinder 21 are provided. A wedge space 24 is formed between the portion 22 and the push portion 27, and the push portion 27 pushes the engaging ball 25 into the wedge space 24. As a result, boosting drive is started.

Then, the boosting portion 26 of the second piston 6 strongly pushes the engaging ball 25 inward in the radial direction. As a result, the upward thrust acting on the second piston 6 is converted downward through the boosting portion 26, the engaging ball 25, the receiving portion 22, and the transmitting portion 23, and the output rod 3 is downwardly converted. It will be driven. Therefore, the output rod 3 is strongly driven downward by the resultant force of the pushing force by the boosting mechanism 20 and the pushing force by the first piston 5.

When the clamping device is clamped from the unclamped state to the clamped state, the extrusion portion 33a forming a part of the retract groove 33 of the output rod 3 pushes the engaging ball 31a to the outward protruding position in the radial direction. At the same time, the extruded portion 37a forming a part of the retracting groove 37 of the output rod 3 pushes the locking ball 31b to the outward protruding position in the radial direction. Then, each pressing surface 32 of the output rod 3 presses the locking portion 44 of the work pallet WP downward via the engaging ball 31a. As a result, the seating surface 45 of the work pallet WP is received by the seating surface 46 of the housing 1. As a result, the clamping device is switched from the unclamped state of FIG. 1 to the clamped state of FIG. At this time, the locking ball 31b faces the support surface 36 of the output rod 3 formed straight in the vertical direction, and is between the ball 31b and the support surface 36, or between the ball 31b and the locking portion. A sliding gap of about 0.05 to 0.1 mm is formed between the rod and the 44. Therefore, unlike the ball 31a, the ball 31b does not press the locking portion 44 downward.

When the clamp device is switched from the clamped state of FIG. 3 to the unclamped state of FIG. 1, the compressed air of the clamp chamber 10 is discharged and compressed into the first unclamped chamber 11 and the second unclamped chamber 12 in the clamped state. Supply air. Then, first, the compressed air in the second unclamp chamber 12 lowers the second piston 6. At this time, immediately after the start of the upward movement of the output rod 3, the ascending of the output rod 3 is restricted by the transmitting portion 23, the engaging ball 25, the receiving portion 22, and the boosting portion 26 of the piston 6. As the second piston 6 descends, a gap is formed between the engaging ball 25 and the boosting portion 26, or between the engaging ball 25 and the transmitting portion 23, so that the first unclamping is performed. The compressed air in the chamber 11 raises the first piston 5 and the output rod 3.

Next, when the retracting groove 33 and the retracting groove 37 of the output rod 3 rise to the height positions facing the

balls

31a and 31b, the balls 31a and the balls 31b are inside the retracting groove 33 and the retracting groove 37 (output rod 3). It becomes possible to move inward in the radial direction of. As a result, as shown in FIG. 1, the work pallet WP can be smoothly removed from the clamp pallet 1.

In the clamp device in the clamped state, the supply of compressed air to the clamp device may be stopped due to some cause, for example, an emergency stop of the system including the clamp device. Even in such a case, the clamped state of the clamping device is maintained by the urging force of the holding spring 17. Further, in the clamped state, an external force exceeding the urging force of the holding spring 17 may act on the work pallet WP in a direction away from the clamp pallet CP. In this case, the external force tends to push the output rod 3 upward (unclamping direction) via the locking portion 44, the engaging ball 31a, and the pressing surface 32. However, the locking ball 31b pushed by the locking portion 44 is received by the support surface 36. As a result, the locking ball 31b and the engaging ball 31a are maintained in a state in which a part of each of the locking ball 31b and the engaging ball 31a protrude outward from the outer peripheral surface of the plug portion 2 from the through hole 30. As a result, the work pallet WP is prevented from being unintentionally removed from the clamp pallet CP.

FIG. 9 shows a second embodiment of the present invention. In this second embodiment, in principle, the same reference numbers are assigned to the same members (or similar members) as the constituent members of the first embodiment. In this embodiment, the locking ball 31b is made larger than the engaging ball 31a. According to this, the receiving of the ball 31b by the support surface 36 is stable, and it is possible to further prevent the work pallet WP from being unintentionally removed from the plug portion 2. In addition, the contact area between the support surface 36 and the ball 31b becomes large. As a result, even if a large load acts on the contact portion, the contact portion is prevented from being worn or damaged, and as a result, the durability of the contact portion is improved.

Corresponding to the fact that the ball 31b is made larger than the ball 31a, in this embodiment, the through hole 30 into which the ball 31b is inserted is made larger than the through hole 30 into which the ball 31a is inserted. When there is no great difference between the size of the ball 31b and the size of the ball 31a, the through hole 30 into which the ball 31b is inserted and the through hole 30 into which the ball 31a is inserted may have the same size.

10 to 14 show a third embodiment of the present invention. In the third embodiment, the same members (or similar members) as the constituent members of the first embodiment will be described with the same reference numbers in principle. In this embodiment, a clamping device for fixing a work (clamping object) W as a movable block to a table T as a reference block is exemplified. The difference between this third embodiment and the above-mentioned first embodiment is as follows.

In FIGS. 10 and 11, the ring member 41, the second piston 6, the second unclamp chamber 12, the holding spring 17, the boosting mechanism 20, and the like in the first embodiment of FIG. 1 are omitted.

In the clamp device of the first embodiment described above, the upper rod portion 3a of the output rod 3 outputs the balls 31a and the balls 31b by moving the output rod 3 downward (retracting side) in the axial direction by the drive mechanism D. The rod 3 is pushed outward in the radial direction and clamp-driven. On the other hand, in the clamp device of the second embodiment, the output rod 3 is moved upward (advanced side) in the axial direction by the drive mechanism D, so that the upper rod portion 3a of the output rod 3 becomes the ball 31a and the ball 31b. Is pushed outward in the radial direction of the output rod 3 and clamp-driven.

The housing 1 of the clamp device is fixed to the table T by a plurality of bolts (not shown). The output rod 3 inserted into the tubular hole 2a of the plug portion 2 of the housing 1 is moved in the vertical direction by the drive mechanism D. The drive mechanism D is provided in the cylinder hole 4 formed in the housing 1. The drive mechanism D is configured as follows.

The piston 5 connected to the output rod 3 is inserted into the cylinder hole 4 so as to be movable in the vertical direction. A clamp chamber 10 is formed on the lower side of the piston 5, and an unclamp chamber 52 is formed on the upper side of the piston 5. Further, the clamp chamber 10 communicates with the compressed air supply / discharge port 15 via the supply / discharge passage 14 formed in the housing 1. The unclamp chamber 52 communicates with the compressed air supply / discharge port 53 via the supply / discharge passage 16 formed in the housing 1.

A holding valve 60 is provided in the middle of the above supply / discharge passage 14, and the holding valve 60 shuts off and opens the supply / discharge passage 14. The holding valve 60 is configured as follows, as shown in FIGS. 12 to 14 (FIGS. 10 and 11).

A mounting hole 61 is formed in the upper wall 1a of the housing 1 in the left-right direction. The casing 62 of the holding valve 60 is screwed into the female screw portion of the mounting hole 61. A valve hole 63 is formed in the casing 62 in the left-right direction. The valve hole 63 has a medium-diameter hole 63a, a small-diameter hole 63b, and a large-diameter hole 63c in this order from the left side. A valve seat 64 is formed at a step portion formed between the medium-diameter hole 63a and the small-diameter hole 63b. The valve seat 64 is formed in a tapered shape so as to taper toward the right. The valve member 65 is inserted into the medium-diameter hole 63a so as to be movable in the left-right direction. A groove is formed in the outer peripheral wall of the valve member 65 in the circumferential direction, and an O-ring as a sealing member is mounted on the groove. The valve surface 66 is formed by the outer peripheral portion of the O-ring, and the valve surface 66 can come into contact with the valve seat 64. A valve closing spring 68 is mounted between the bottom surface of the recess 67 formed on the left wall of the valve member 65 and the bottom surface of the valve hole 63 (mounting hole 61), and the valve closing spring 68 attaches the valve member 65 to the valve seat 64. We are urging towards. A communication groove 65a is formed in the outer peripheral wall of the valve member 65 in the left-right direction, and a through hole 65b is formed in the valve member 65 so as to communicate the communication groove 65a and the recess 67. A pressure relief hole 65c opened on the right end surface of the valve member 65 is opened in the peripheral wall of a groove formed in the valve member 65 in the circumferential direction. The groove-side opening of the pressure relief hole 65c is sealed by an O-ring as a sealing member.

The operating member 69 is movable in the left-right direction and is inserted in a tightly packed manner in the above-mentioned large-diameter hole (valve hole 63 on the opposite side of the valve seat 64 with the valve seat 64 in between) 63c. A protrusion 69b is projected from the main body 69a of the operating member 69 toward the valve member 65. The left end surface of the protrusion 69b can come into contact with the right end surface of the valve member 65. A valve chamber 70 is formed on the left side of the operating member 69 in the large diameter hole 63c, and a pressure receiving chamber is formed on the right side of the operating member 69 (the end surface side opposite to the end surface of the operating member 69 facing the valve member 65). 71 is formed. The pressure receiving chamber 71 is communicated with the unclamp chamber 52 by a communication passage 74 and a through hole 76 formed in the peripheral wall of the casing 62. Further, a through hole 75 is formed in the peripheral wall of the casing 62. The through hole 75 communicates the valve chamber 70 on the left side of the operating member 69 with the compressed air source side flow path 14a of the supply / discharge passage 14. Further, the clamp chamber side flow path 14b of the supply / discharge passage 14 communicates with the medium diameter hole 63a of the valve hole 63. In the present embodiment, the through hole 75, the valve hole 63, the communication groove 65a, the through hole 65b, the pressure relief hole 65c or the valve opening gap, the recess 67, and the like form a part of the supply / discharge passage 14. ..

The ball 31 is movably supported in the through hole 30 of the plug portion 2. The evacuation groove 33 and the pressing surface 32 are vertically connected to each other on the outer peripheral wall of the upper rod portion 3a of the output rod 3 so as to correspond to the engaging ball (engaging member) 31a. Here, in the first embodiment shown in FIGS. 1 to 3, the evacuation groove 33 and the pressing surface 32 are formed in order from the lower side on the outer peripheral wall of the output rod 3, but in the present embodiment, the evacuation groove 33 is formed. And the pressing surface 32 are formed in order from the upper side. Further, the pressing surface 32 is formed so as to expand downward. Further, on the outer peripheral wall of the upper rod portion 3a of the output rod 3, a support surface (support portion) 36 formed straight in the vertical direction with the retracting groove 37 corresponding to the lock ball (lock member) 31b. Are formed in a row above and below. Similar to the pressing surface 32, in the present embodiment, the support surface 36 is formed on the lower side of the evacuation groove 37.

A mounting hole 42 is formed in the lower wall of the work W, and the plug portion 2 can be inserted into the mounting hole 42 (see FIG. 11). The locking portion 44 is formed in the mounting hole 42 in a tapered shape so as to expand upward. The seating surface 45 is formed by the lower surface of the work W. The seating surface 45 can come into contact with the seating surface 46 formed on the upper wall 1a of the housing 1 (see FIG. 11).

The above clamp device operates as follows.

In the unclamped state of FIGS. 10 and 12, compressed air is discharged from the clamp chamber 10 and compressed air is supplied to the unclamp chamber 52. As a result, the compressed air in the unclamp chamber 52 pushes the piston 5 downward, and the lower surface of the upper rod 3a of the output rod 3 is in contact with the bottom surface of the tubular hole 2a. Therefore, the engaging ball 31a can be moved to the retracted position in the retracted groove 33, and the locking ball 31b can be moved to the retracted position in the retracted groove 37. The work W is carried above the clamp device in the unclamped state.

In the unclamped state shown in FIG. 10 above, the compressed air supplied to the unclamped chamber 52 is supplied to the pressure receiving chamber 71 of the holding valve 60 via the communication passage 74 and the gangway 76 formed in the housing. ing. The compressed air in the pressure receiving chamber 71 moves the valve member 65 to the left via the operating member 69, so that the holding valve 60 is opened.

When fixing the work W to the table T, first lower the work W. Then, as shown in FIG. 11, the mounting hole 42 of the work W is externally fitted into the plug portion 2, and the seating surface 45 of the work W is received by the seating surface 46 of the housing 1.

When the clamping device clamps and drives from the unclamped state of FIG. 10 (and FIG. 12) to the clamped state of FIG. 11 (and FIG. 13), the compressed air of the unclamping chamber 52 is discharged and compressed in the unclamped state. Compressed air from the air source is supplied to the valve chamber 70 of the holding valve 60 through the compressed air source side flow path 14a of the supply / discharge passage 14 and the through hole 75. Then, the compressed air in the valve chamber 70 moves the operating member 69 to the right and maintains the state in which the valve member 65 is moved to the left limit position (the valve opening state of the holding valve). Therefore, the compressed air in the valve chamber 70 is supplied to the clamp chamber 10 through the valve opening gap of the holding valve 60, the communication groove 65a, the through hole 65b, the recess 67, and the clamp chamber side flow path 14b of the supply / discharge passage 14 in this order. NS. Then, the compressed air in the clamp chamber 10 pushes the first piston 5 upward. Next, the extrusion portion 33a forming a part of the evacuation groove 33 of the output rod 3 pushes the engaging ball 31a to an outward position in the radial direction, and the extrusion portion 33a forming a part of the evacuation groove 37 of the output rod 3 is extruded. The portion 37a pushes the locking ball 31b to an outward position in the radial direction. Then, the engaging ball 31a presses the locking portion 44 of the work W downward. As a result, the seating surface 45 of the work P is received by the seating surface 46 of the housing 1. As a result, the clamping device is switched from the unclamped state of FIG. 10 to the clamped state of FIG. At this time, the locking ball 31b faces the support surface 36 of the output rod 3 formed straight in the vertical direction. Since a sliding gap of about 0.05 to 0.1 mm is formed between the ball 31b and the support surface 36, or between the ball 31b and the locking portion 44, the locking ball 31b is a work. Do not press the locking portion 44 of W downward.

When switching the clamp device from the clamped state of FIG. 11 to the unclamped state of FIG. 10, in the clamped state, first, the supply of compressed air to the clamp chamber 10 is stopped, and the compressed air is supplied to the unclamping chamber 52. .. Then, the compressed air in the unclamp chamber 52 is supplied to the pressure receiving chamber 71 through the communication passage 74. Next, the compressed air in the pressure receiving chamber 71 moves the valve member 65 to the left via the operating member 69 to open the holding valve. Then, the compressed air in the clamp chamber 10 is discharged to the outside through the supply / discharge passage 14 and the inside of the holding valve 60. Subsequently, the compressed air in the unclamp chamber 52 lowers the piston 5. Then, the retracting groove 33 and the retracting groove 37 of the output rod 3 descend to the height positions facing the

balls

31a and 31b. As a result, the

balls

31a and 31b are inside the retracting groove 33 and the retracting groove 37, and can move inward in the radial direction of the output rod 3. As a result, as shown in FIG. 10, the work W can be smoothly removed from the plug portion 2.

In the clamp device in the clamped state, the supply of compressed air to the clamp device may be stopped due to some cause, for example, an emergency stop of the system including the clamp device. In such a case, first, the compressed air in the clamp chamber 10 of the clamp device tries to be discharged to the outside through the clamp chamber side flow path 14b of the supply / discharge passage 14, but the valve hole 63 from the clamp chamber 10 is discharged. As shown in FIG. 14, the holding valve 60 is closed by the compressed air acting on the medium-diameter hole 63a (the recess 67 formed in the left wall of the valve member 65) moving the valve member 65 to the right. Will be done. As a result, the pressure of the clamp chamber 10 of the clamping device is held by the holding valve 60, and the clamped state of the clamping device is maintained. Further, in the clamped state, an external force exceeding the pressure of the compressed air in the clamp chamber 10 held by the holding valve 60 may act on the work W in a direction away from the table T. In this case, an external force attempts to push the output rod 3 downward (unclamping direction) via the locking portion 44 of the work W, the engaging ball 31a, and the pressing surface 32. However, the locking ball 31b pushed by the locking portion 44 is received by the support surface 36. As a result, the ball 31b and the ball 31a are maintained in a state in which a part of each of the ball 31b and the ball 31a protrudes outward from the outer peripheral surface of the plug portion 2 from the through hole 30. As a result, the work W is prevented from being unintentionally removed from the plug portion 2.

In the clamp device not provided with the holding spring 17 of the first embodiment and the holding valve 60 of the second embodiment, the output is output even when the supply of compressed air is stopped, as in the above embodiment. The output rod 3 and the

pistons

5 and 6 may be maintained in a clamped state due to a frictional force generated between the sealing member mounted on the rod 3 and the

pistons

5 and 6 and the cylinder hole and the like. Also in this case, when an external force exceeding the above frictional force acts on the work pallet WP or the like in a direction away from the clamp pallet CP or the like, the work pallet WP presses against the locking portion 44 and the engaging ball 31a. The output rod 3 is pushed in the unclamping direction via the surface 32. However, the locking ball 31b that the locking portion 44 pushes inward in the radial direction of the output rod is received by the support surface 36. Therefore, similarly to the first and second embodiments, the ball 31b and the ball 31a are maintained in a state in which a part of each of the ball 31b and the ball 31a protrudes outward from the outer peripheral surface of the plug portion 2 from the through hole 30. , The work pallet WP can be prevented from being unintentionally removed from the clamp pallet CP.

FIG. 15 shows a fourth embodiment of the present invention. In the fourth embodiment, the same members (or similar members) as the constituent members of the first and third embodiments described above will be described with the same reference numbers in principle.

The housing 1 of the clamp device is fixed to the clamp pallet CP by a plurality of bolts 77. The housing 1 includes a guide cylinder portion 78 having a flange portion whose seating surface 46 is formed on an end surface in the axial direction, a tubular block portion 79 having supply /

discharge passages

14, 16 and the like formed inside, and a guide cylinder portion. It is composed of a ring member 80 that seals the space between the 78 and the block portion 79.

Six through holes 30 are formed in the axial direction of the peripheral wall of the guide cylinder portion 78 at predetermined intervals in the circumferential direction. Each through hole 30 movably supports the ball 31 between a radial inner position and a radial outer position of the peripheral wall. Three of the six balls 31 are engaging balls 31a, and the remaining three balls are locking balls 31b. Engaging balls 31a and locking balls 31b are alternately inserted into the through holes 30 in the circumferential direction of the guide cylinder portion 78.

A cylinder hole 4 is provided in the housing 1, and a drive mechanism D is provided in the cylinder hole 4. The drive mechanism D moves the ball 31 in the through hole 30. The drive mechanism D is configured as follows.

The tubular piston 5 is inserted into the outside of the guide cylinder portion 78 (inside the cylinder hole 4) so as to be movable in the vertical direction. The unclamp chamber 52 is formed on the lower side of the piston 5, and the clamp chamber 10 is formed on the upper side of the piston 5. The clamp chamber 10 communicates with the compressed air supply / discharge port 15 via the supply / discharge passage 14 formed in the block portion 79. The unclamp chamber 52 communicates with the compressed air supply / discharge port 53 via the supply / discharge passage 16 formed in the block portion 79.

The piston 5 has a tubular operating portion 81, and a pressing surface 32 and a retracting groove 33 are vertically connected to each other on the inner peripheral wall of the operating portion 81 so as to correspond to the engaging ball 31a. The pressing surface 32 is formed so as to narrow as it goes upward. By moving the pressing surface 32 to a position facing the engaging ball (engaging member) 31a, the engaging ball 31a protrudes inward in the radial direction from the inner peripheral surface of the guide cylinder portion 78. Is moved to the inner position. The retracting groove 33 is at a position facing the engaging ball 31a, and by moving to a retracting position where the ball 31a can be inserted, the engaging ball 31a is moved from the inner peripheral surface of the guide cylinder portion 78. Can also be moved outward in the radial direction.

Similar to the clamp device of the first embodiment, the inner peripheral wall of the operation portion 81 of the piston 5 has a support surface (support portion) formed straight in the vertical direction in correspondence with the locking ball (lock member) 31b. ) 36 and the retracting groove 37 are vertically connected to each other.

Similar to the first embodiment, in the present embodiment, the support surface 36 is formed parallel to the axial direction of the cylinder hole 78a of the guide cylinder portion 78. The axial direction of the pull stud 82 and the axial direction of the tubular hole 78a, which will be described later, are the same directions. The support surface 36 is formed on the inner peripheral wall of the operating portion 81 so as to be perpendicular to the axial direction of the through hole 30.

Further, as in the first embodiment, in the present embodiment, a groove 38 extending along the axial direction of the piston 5 (cylinder hole 78a) is formed on the inner peripheral wall of the operating portion 81 of the piston 5 to support the piston 5. The surface 36 is formed by the bottom wall of the groove 38. The bottom wall of the groove 38 has an arcuate cross section perpendicular to the axial direction of the piston 5 (cylinder hole 78a). The bottom wall of the groove 38 extends parallel to the axial direction of the piston 5 (cylinder hole 78a).

By moving the support surface 36 to a position facing the locking ball 31b, the locking ball 31b is moved to an inner position protruding inward in the radial direction from the inner peripheral surface of the guide cylinder 78. Is maintained. A state in which a part of the ball 31b protrudes from the through hole 30 is maintained inward from the inner peripheral surface of the guide cylinder portion 78. By moving the retracting groove 37 to a retracting position where the locking ball 31b can be inserted facing the locking ball 31b, the locking ball 31b is radially outward from the inner peripheral surface of the guide cylinder 78. It becomes possible to move to.

A recess 40 is opened on the lower surface of the work pallet WP. A pull stud (protrusion) 82 is attached to the recess 40, and the pull stud 82 is fixed to the work pallet WP by a bolt. The pull stud 82 can be inserted into the guide cylinder portion 78 constituting the housing 1.

The locking portion 44 is formed in a tapered shape on the outer peripheral surface of the pull stud 82 so as to narrow as it goes upward.

The above clamp device operates as follows.

In the unclamped state, compressed air is discharged from the clamp chamber 10 and compressed air is supplied to the unclamp chamber 52. As a result, the compressed air in the unclamp chamber 52 pushes the piston 5 upward, and the piston 5 is moved upward. Therefore, the engaging ball 31a can be moved to the retracted position in the retracted groove 33, and the locking ball 31b can be moved to the retracted position in the retracted groove 37. The work pallet WP is carried above the clamp device in the unclamped state.

When clamping the work pallet WP to the clamp pallet CP, first lower the work pallet WP. Then, as shown in FIG. 15, the seating surface 45 on the lower surface of the work pallet WP is received by the seating surface 46 of the guide cylinder portion 78 constituting the housing 1.

When the clamp device is clamp-driven, the compressed air in the unclamping chamber 52 is discharged and the compressed air is supplied to the clamp chamber 10 in the unclamped state. Then, the compressed air in the clamp chamber 10 pushes the piston 5 downward. As a result, the extruding portion 33a forming a part of the retracting groove 33 of the operating portion 81 constituting the piston 5 pushes the engaging ball 31a to the inward position in the radial direction, and the retracting groove 37 of the operating portion 81 The extruded portion 37a forming a part pushes the locking ball 31b to an inward position in the radial direction. Then, the engaging ball 31a presses the locking portion 44 of the pull stud 82 downward. As a result, the clamping device is switched from the unclamped state to the clamped state of FIG. At this time, the locking ball 31b faces the support surface 36 of the operating portion 81 formed straight in the vertical direction. Since a sliding gap of about 0.05 to 0.1 mm is formed between the ball 31b and the support surface 36, or between the ball 31b and the locking portion 44, the locking ball 31b is a work. Do not press the locking portion 44 of the pallet WP downward.

When the clamp device is switched from the clamped state of FIG. 15 to the unclamped state, the compressed air in the clamp chamber 10 is discharged and the compressed air is supplied to the unclamped chamber 52 in the clamped state. Then, the compressed air in the unclamp chamber 52 raises the piston 5.

When the evacuation groove 33 and the evacuation groove 37 of the operation unit 81 rise to a height position facing the balls 31a and the balls 31b, the balls 31a and the balls 31b are inside the evacuation grooves 33 and the evacuation grooves 37 (in the radial direction of the piston 5). It becomes possible to move to (inside). As a result, the work pallet WP can be smoothly removed from the clamp pallet 1.

In the clamp device in the clamped state shown in FIG. 15, the supply of compressed air to the clamp device may be stopped due to some cause, for example, an emergency stop of the system including the clamp device. In the clamped state, an external force may act on the work pallet WP in a direction away from the clamp pallet CP. In this case, the external force tends to push the piston 5 upward (unclamping direction) via the locking portion 44 of the pull stud 82, the engaging ball 31a, and the pressing surface 32. However, the locking ball 31b pushed by the locking portion 44 is received by the support surface 36. As a result, the locking ball 31b and the engaging ball 31a are maintained in a state in which a part of each of the locking ball 31b and the engaging ball 31a protrude inward from the inner peripheral surface of the guide cylinder portion 78 from the through hole 30. As a result, the work pallet WP is prevented from being unintentionally removed from the clamp pallet CP.

In the fourth embodiment shown in FIG. 15, the support surface 36 may be a recess into which the locking ball 31b is fitted, as in the first modification of the support portion of the first embodiment shown in FIG. Further, the recess (support surface 36) is symmetrical with respect to a virtual straight line extending in the radial direction of the piston 5 from the center of the recess in a cross-sectional view parallel to the axial direction of the piston 5, as in the case of FIG. It may be in the shape of. Further, the concave portion may be formed in a spherical shape.

In the fourth embodiment shown in FIG. 15, the support surface 36 is inclined with respect to the axial direction of the piston 5 (cylinder hole 78a) so as to narrow inward in the radial direction of the piston 5 toward the clamp driving direction of the piston 5. You may be doing it. The clamp driving direction of the piston 5 is the downward direction in FIG. This modification of the fourth embodiment corresponds to the second modification of the support portion of the first embodiment shown in FIG. 7. In the second modification of the support portion of the first embodiment, the support surface 36 is formed so as to expand outward in the radial direction of the output rod 3 toward the clamp drive direction of the output rod 3. On the other hand, in the above-described modification of the fourth embodiment, the support surface 36 is formed so as to narrow inward in the radial direction of the piston 5 toward the clamp drive direction of the piston 5.

According to this, when an external force acts in the direction of separating the housing 1 and the work pallet WP, the locking portion 44 provided on the work pallet WP pushes the piston 5 in the direction of clamping and driving the piston 5 via the ball 31b. Therefore, the pushing force and the pushing force of the external force in the direction of unclamping the piston 5 via the locking portion 44 and the ball 31a are balanced. In other words, the force with which the external force pushes the piston 5 in the direction of unclamping is weakened. As a result, it becomes easier to maintain a state in which a part of the ball 31b protrudes from the through hole 30 inward of the inner peripheral surface of the guide cylinder portion 78.

When the support surface 36 is formed so as to narrow inward in the radial direction of the piston 5 toward the clamp drive direction of the piston 5, the support surface 36 has a groove having an arcuate cross section, as in the embodiment shown in FIG. It may be composed of 38 bottom walls. The bottom wall of the groove 38 is inclined with respect to the axial direction of the piston 5 (cylinder hole 78a) so as to narrow inward in the radial direction of the piston 5 toward the clamp driving direction of the piston 5.

In the fourth embodiment shown in FIG. 15, the locking ball 31b may be made larger than the engaging ball 31a as in the second embodiment shown in FIG.

Each of the above embodiments can be changed as follows.

The reference block may be a mounting block attached to the tip of the robot arm instead of the clamp pallet CP, the machining center, or the table T of various machines. Further, the movable block may be a tool block that is detachably attached to the attachment block of the robot arm instead of the work pallet WP or the work W.

The above-mentioned reference block and movable block may be arranged upside down, or may be connected horizontally or diagonally instead of being connected in the above-exemplified vertical direction.

The

unclamp chambers

11, 12, and 52 may be equipped with a return spring in addition to being configured to be able to supply and discharge the unclamping pressure fluid.

The transmission unit 23 and the reception unit 22 are preferably provided in three or four in the circumferential direction, but may be two or less or five or more.

The pressing surface 32 and the retracting groove 33, or the supporting surface 36 and the retracting groove 37 are preferably provided in three or four in the circumferential direction, but may be two or less or five or more. Further, the number of arrangements of the pressing surface 32 and the support surface 36 may not be the same, and the arrangement positions may not be provided at equal intervals.

In the above embodiment, the pressing surface 32 and the supporting surface 36 are arranged at the same position in the axial direction of the output rod 3 or the axial direction of the piston 5. The pressing surface 32 and the supporting surface 36 may be arranged at offset positions in the axial direction of the output rod 3 or the axial direction of the piston 5.

The ball 31 (ball 31a and ball 31b) is not limited to the illustrated ball (sphere), and may be a member having another shape, for example, a columnar or rectangular member. Further, the engaging ball 31a and the locking ball 31b of the above embodiment are balls 31 having the same shape and the same dimensions, but the present invention is not limited to this, and members having different shapes or different dimensions may be used.

The pressure fluid for clamping and unclamping may be nitrogen gas or the like or a liquid such as pressure oil instead of compressed air.

Further, the clamping device of the present invention is not limited to the use of clamping work pallets and workpieces, and can also be used for fixing devices such as molds and attachments, support devices, and tool changers.

The external force acts on the housing side or the clamp object side so as to separate the clamp object from the housing of the clamp device. That is, there are cases where an external force acts on the object to be clamped with respect to the housing fixed to the table or the like, and there are cases where the external force acts on the housing side while being fixed to some member.

It goes without saying that the present invention can make other changes within the range that can be assumed by those skilled in the art.

1: Housing 2: Plug part, 2a: Cylinder hole 3: Output rod, 5: Piston, 30: Through hole, 31a: Ball (engagement member), 31b: Ball (lock member), 36: Support surface ( Support part), 36A: Support surface (support part), 38: Groove, 42: Mounting hole, 44: Locking part, 78: Guide cylinder part, 78a: Tube hole, 82: Pull stud (projection), D: Drive Mechanism, L: Virtual straight line, WP: Work pallet (clamp object), W: Work (clamp object).

Claims

Housing (1) and
A tubular plug portion (2) projecting from the housing (1) and
An output rod (3) inserted into the tubular hole (2a) of the plug portion (2) so as to be movable in the axial direction of the tubular hole (2a).
An engaging member (31a) and a locking member (31b) inserted into a through hole (30) formed in the peripheral wall of the plug portion (2), and the output rod (3) is driven by a drive mechanism (D). The engaging member (31a) and the locking member (31b) that are moved in the through hole (30) by being moved in the axial direction,
Support portions (36, 36A) formed on the outer peripheral wall of the output rod (3) so as to be able to come into contact with the lock member (31b).
A mounting hole (42) provided in the clamp object (WP, W) so that the plug portion (2) can be inserted, and abuts on the engaging member (31a) and the locking member (31b). With a mounting hole (42) having a locking portion (44) that is possible,
When an external force acts in a direction in which the housing (1) and the clamp object (WP, W) are separated from each other in a clamped state in which the engaging member (31a) is engaged with the locking portion (44). When the support portion (36, 36A) receives the lock member (31b), a part of the lock member (31b) is outward from the outer peripheral surface of the plug portion (2) through the through hole (30). ), The clamp device is characterized in that it is maintained in a protruding state.
In the clamping device of claim 1,
The locking member (31b) is larger than the engaging member (31a).
A clamp device characterized by that.
In the clamping device of claim 1 or 2,
The support portions (36, 36A) are formed parallel to the axial direction.
A clamp device characterized by that.
In the clamping device of claim 3,
A groove (38) extending along the axial direction is formed on the outer peripheral wall of the output rod (3).
The support portion (36) is a bottom wall of the groove (38) having an arcuate cross section perpendicular to the axial direction, and is composed of a bottom wall extending parallel to the axial direction.
A clamp device characterized by that.
In the clamping device of claim 1 or 2,
The support portion (36, 36A) is inclined with respect to the axial direction so as to spread outward in the radial direction of the output rod (3) toward the clamp driving direction of the output rod (3).
A clamp device characterized by that.
In the clamping device of claim 5,
A groove (38) extending along the axial direction is formed on the outer peripheral wall of the output rod (3).
The support portion (36) is the bottom wall of the groove (38) having an arc-shaped cross section perpendicular to the axial direction, and the shaft extends outward in the radial direction toward the clamp driving direction. Consists of a bottom wall that slopes in the direction,
A clamp device characterized by that.
In the clamping device of claim 1 or 2,
The support portion (36) is a recess into which the lock member (31b) is fitted.
A clamp device characterized by that.
In the clamping device of claim 7,
In a cross-sectional view of the output rod (3) parallel to the axial direction, the recess has a shape symmetrical with respect to a virtual straight line (L) extending in the radial direction of the output rod (3) from the center of the recess. Has been
A clamp device characterized by that.
In the clamping device of claim 8,
The lock member (31b) is a sphere and
The recess is formed in a spherical shape.
A clamp device characterized by that.
A housing (1) having a guide cylinder (78) and
The engaging member (31a) and the locking member (31b) inserted into the through hole (30) formed in the peripheral wall of the guide cylinder portion (78), and the through hole (30) is provided by the drive mechanism (D). The engaging member (31a) and the locking member (31b) that are moved within,
A tubular piston (5) constituting the drive mechanism (D), and a piston (5) arranged outside the guide cylinder portion (78).
Support portions (36, 36A) formed on the inner peripheral wall of the piston (5) so as to be able to come into contact with the lock member (31b).
A protrusion (82) provided on the clamp object (WP, W) so as to be insertable into the guide cylinder portion (78), and abuts on the engaging member (31a) and the locking member (31b). With a protrusion (82) having a locking portion (44) that is possible,
When an external force acts in a direction in which the housing (1) and the clamp object (WP, W) are separated from each other in a clamped state in which the engaging member (31a) is engaged with the locking portion (44). When the support portion (36, 36A) receives the lock member (31b), a part of the lock member (31b) is formed into the through hole inward from the inner peripheral surface of the guide cylinder portion (78). A clamp device characterized in that the state of protrusion from (30) is maintained.
In the clamping device of claim 10,
The locking member (31b) is larger than the engaging member (31a).
A clamp device characterized by that.
In the clamping device of claim 10 or 11.
The support portions (36, 36A) are formed parallel to the axial direction of the tubular hole (78a) of the guide tubular portion (78).
A clamp device characterized by that.
In the clamping device of claim 12,
A groove (38) extending along the axial direction is formed on the inner peripheral wall of the piston (5).
The support portion (36) is a bottom wall of the groove (38) having an arcuate cross section perpendicular to the axial direction, and is composed of a bottom wall extending parallel to the axial direction.
A clamp device characterized by that.