JP2014108470A - Clamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamp device which is easy in processing and can reduce manufacturing cost.SOLUTION: A lower housing (1) and an upper housing (2) are arranged in series in the vertical direction. A piston (12) is vertically movably inserted into the lower housing (1). A clamp rod (15) arranged parallel to the piston (12) is vertically movably inserted into the upper housing (2). A connecting member (56) for connecting an input part (15a) of the clamp rod (15) and an output part (55) of the piston (12) to each other has a recessed part (56a) engaged in the radial direction with a projecting part (55a) radially projecting from the output part (55), and is axially movably inserted into the second housing (2).

Description

  The present invention relates to a clamp device for fixing a fixed object such as a workpiece or a mold to a fixed side member. More specifically, in order to avoid interference between the clamp device and the fixed object, the fluid pressure of the clamp device is described. The present invention relates to a technique in which the axis of a clamp rod is offset from the axis of a cylinder.

  As this type of clamping device, there is one described in Patent Document 1 (Japan: JP 2009-279745 A (published on December 3, 2009)). The prior art is configured as follows.

  A lower main body member (first housing) and an upper main body member (second housing) are arranged in series in the vertical direction. A piston member of a hydraulic cylinder for clamping is inserted into the lower body member so as to be movable in the vertical direction. A clamp rod is inserted into the upper body member so as to be movable in the vertical direction. The clamp rod is disposed at a predetermined interval in the horizontal direction with respect to the piston member.

  An L-shaped connecting member for connecting the piston member to the clamp rod is provided. The L-shaped connecting member includes a first vertical axis fixed to the piston member with a bolt, a horizontal axis extending horizontally from the upper end of the first vertical axis, and an upper side from the end of the horizontal axis. And a second longitudinal axis extending to the front. The second vertical axis has a common axis with the axis of the clamp rod, and the T leg of the clamp rod is engaged with a T groove formed in the upper end portion of the second vertical axis. Yes.

Japanese Unexamined Patent Publication No. 2009-279745 (released December 3, 2009)

  According to the configuration of Patent Document 1, the L-shaped connecting member that connects the clamp rod and the piston member includes the first vertical axis, the horizontal axis, and the second vertical axis, so that the shape is complicated and high. Dimensional accuracy is required. For this reason, there is a problem that it is difficult to process the L-shaped connecting member and the manufacturing cost of the clamping device increases.

  An object of the present invention is to provide a clamping device that can be easily processed and can reduce the manufacturing cost.

  In order to solve the above-described problems, the clamping device according to the present invention is configured as follows, for example, as shown in FIGS.

  That is, the first housing 1 and the second housing 2 arranged in series, the piston 12 inserted in the first housing 1 so as to be movable in the axial direction, and moved in the axial direction in the second housing 2 And a clamp rod 15 inserted as possible. The clamp rod 15 has an axis C2 that is radially separated from the axis C1 of the piston 12. A connecting member 56 is inserted into the second housing 2 so as to connect the input portion 15 a of the clamp rod 15 and the output portion 55 of the piston 12. The connecting member 56 is used in an engagement state X in which the output member 55 is engaged in the radial direction. The connecting member 56 is assembled with the output unit 55 so that the engagement state X is changed from the disengaged state Y in which the engagement with the output unit 55 is released. Then, between the output portion 55 in the engaged state X and the inner side surface 2b of the second housing 2, the output portion 55 interferes with the inner side surface 2b in the disengaged state Y. A gap G for prevention was formed.

  Due to the above features, the present invention has the following effects.

  When assembling both the output part and the connecting member by using the gap formed so as to prevent the output part from interfering with the inner surface of the second housing in the disengaged state, The piston and the clamp rod can be connected by smoothly engaging. Therefore, the present invention can provide a connection structure having a simple shape, unlike the L-shaped connection member having the conventional structure described above. As a result, the clamping device can be easily processed and the manufacturing cost can be reduced.

  In the clamping device according to the present invention, it is preferable that the gap G is formed on the opposite side of the connecting member 56 with the output portion 55 interposed therebetween.

  According to the above configuration, the connecting member incorporated in the second housing can be assembled by engaging the connecting member with the output part by moving the connecting part from the opposite side to the output part across the output part. it can.

  In the clamping device according to the present invention, the gripper 20 disposed on the outer peripheral side of the clamp rod 15 so as to be inserted into the hole 18 of the fixed object W and in close contact with the inner peripheral surface of the hole 18, and the gripper 20 A support cylinder 21 provided in the second housing 2 so as to be pushed in the distal direction, the support cylinder 21 having a cylinder hole into which the connecting member 56 is inserted, and a spring for biasing the support cylinder 21 in the distal direction 47 and a spring chamber 46 provided in the first housing 1 so as to accommodate the spring 47 are preferably provided.

  According to the above configuration, the configuration for fixing the object to be fixed to the second housing by bringing the gripper into close contact with the hole of the object to be fixed becomes simple and compact.

  In the clamp device according to the present invention, the output portion 55 of the piston 12 is provided with a convex portion 55a that can be relatively engaged with the concave portion 56a provided in the connecting member 56 in the radial direction. preferable.

  According to the said structure, the structure which engages a connection member and the output part of a piston becomes simple and compact.

  In the clamping device according to the present invention, a groove 57 extending in the axial direction is formed on the outer peripheral surface of the piston rod 58 projecting from the piston body 54 of the piston 12 in the distal direction, whereby the convex portion is formed in the output portion 55. Preferably 55a is formed.

  According to the said structure, the structure of a piston rod becomes simple and compact.

  In the clamping device according to the present invention, it is preferable that the groove 57 constitutes a part of the spring chamber 46.

  According to the said structure, since a part of groove | channel can be utilized as a spring chamber, the lateral width of a clamp apparatus can be made compact.

FIG. 1 is an elevation view of a clamping device according to an embodiment of the present invention. 2A is a cross-sectional view taken along line 2A-2A in FIG. 2B is a cross-sectional view taken along line 2B-2B in FIG. FIG. 3 is an elevation view for explaining a method of assembling the clamp device.

  Hereinafter, embodiments of the present invention will be described in detail.

  1 to 3 show a clamping device according to an embodiment of the present invention. First, the configuration of the clamping device will be described with reference to FIGS.

(Configuration of clamp device)
The housing H of the clamping device is fixed to the base plate P of the machine tool. The housing H includes a lower housing 1 as a first housing and an upper housing 2 as a second housing. The lower housing 1 and the upper housing 2 are fixed in series in the vertical direction by a plurality of connecting bolts (not shown). The housing H is fixed to the base plate P by a plurality of fastening bolts (not shown) inserted through the lower housing 1 and the upper housing 2 in the vertical direction.

  A hydraulic cylinder 10 is disposed in the lower housing 1. The hydraulic cylinder 10 includes a through hole 11 formed upward from the lower surface of the lower housing 1 and a piston 12 inserted into the through hole 11.

  As will be described later, a clamp rod 15 is arranged in the upper portion of the upper housing 2 so as to be movable in the vertical direction (axial direction) and in the horizontal direction (radial direction). In the present embodiment, the clamp rod 15 is driven to release by being moved upward (toward the distal end) by the piston 12, and is driven to be locked by being moved downward (toward the proximal end) by the piston 12. The FIG. 1 shows a released state in which the clamp rod 15 has moved upward.

  The axis C2 of the clamp rod 15 is arranged in parallel to the left center direction (radial direction) with a predetermined interval with respect to the axis C1 of the piston 12.

  On the outer periphery of the upper part of the clamp rod 15, a plurality of grippers 20 inserted into the holes 18 of the workpiece W as a fixed object and a support cylinder 21 are arranged vertically. A seating surface 23 for receiving the lower surface of the workpiece W is formed in an annular shape on the upper surface of the upper housing 2 on the outer peripheral side of the gripper 20. The gripper 20 functions as a gripping member for lining the inner peripheral surface of the hole 18.

  In this embodiment, four grippers 20 are arranged at predetermined intervals in the circumferential direction. Each gripper 20 includes a thin contact portion 26 provided at an upper portion, a trunk portion 27 provided at an intermediate height, and a lower flange 28. A plurality of saw-toothed projections 29 are formed on the outer periphery of the contact portion 26 in the vertical direction. Moreover, the inclined surface 30 is formed in the inner periphery of each contact | adherence part 26 so that it may approach the axial center C2 of the clamp rod 15 as it goes below.

  A wedge surface (wedge portion) 32 that engages with the inclined surface 30 from above is formed on the upper portion of the clamp rod 15. Four wedge surfaces 32 are provided corresponding to the inclined surfaces 30. In this embodiment, the wedge surface 32 and the inclined surface 30 are constituted by flat surfaces.

  A thin ring 34 made of an elastic body such as rubber is attached to the body portions 27 of the four grippers 20. The elastic force of the ring 34 urges the gripper 20 inward in the radial direction.

  A dust seal 36 is attached to the peripheral wall of the upper hole 2 a of the upper housing 2. The elastic force of the dust seal 36 urges the clamp rod 15 and the gripper 20 inward in the radial direction toward the axis C <b> 2 of the clamp rod 15.

  The support cylinder 21 includes an upper wall 40 that receives the four grippers 20 from below, and an annular wall 41 that protrudes downward from the outer peripheral portion of the upper wall 40. A cylindrical hole of the support cylinder 21 is formed by the upper wall 40 and the inner peripheral surface of the annular wall 41. The support cylinder 21 is inserted into an accommodation hole 44 provided in the upper housing 2 so as to be vertically movable. Further, an advancing spring 47 made of a compression coil spring is attached to the spring chamber 46 disposed in the first housing 1 below the support cylinder 21 to urge the support cylinder 21 in the distal direction. A disk-shaped spring receiver 48 is provided on the advance spring 47. The spring receiver 48 supports the lower end of the annular wall 41 of the support cylinder 21.

  The advance spring 47 urges the gripper 20 upward via the spring receiver 48 and the support cylinder 21. That is, in this embodiment, the advance spring 47, the spring receiver 48, and the support cylinder 21 constitute a support mechanism that pushes up the gripper 20 with a predetermined force.

  A C-shaped retaining ring 50 is mounted on the upper end of the spring chamber 46 in plan view. The retaining ring 50 is a member for temporarily assembling the advancing spring 47 and the like in the lower housing 1 when assembling a clamp device described later.

  The through-hole 11 includes a large-diameter cylinder hole 51 and small-diameter holes 52a, 52b, and 52c that are sequentially formed upward.

  The piston 12 includes a piston main body 54 that is inserted into the cylinder hole 51 in a close-packed manner, and a piston rod 58 that protrudes upward from the piston main body 54. An output portion 55 is provided on the upper portion of the piston rod 58. A groove 57 extending in the axial direction is formed on the outer peripheral surface of the piston rod 58 (see FIG. 2B). The groove 57 constitutes a part of the spring chamber 46.

  A connecting member 56 that is connected to the clamp rod 15 is inserted into the cylindrical hole of the support cylinder 21. The connecting member 56 is disposed coaxially with the clamp rod 15. A T groove 56b is formed in the upper end portion of the connecting member 56, and a T leg (input portion) 15a provided at the lower end of the clamp rod 15 is engaged with the T groove 56b.

  A concave portion 56a that faces the output portion 55 at the upper end of the piston rod 58 is formed in the lower portion of the connecting member 56 (see FIG. 2A). At the upper end of the output portion 55, a convex portion 55a that can be relatively engaged with the concave portion 56a in the horizontal direction is formed. The convex portion 55 a is provided at the upper end of the output portion 55 by forming a groove 57 extending in the vertical direction on the outer peripheral surface of the piston rod 58. When the convex portion 55a is relatively engaged with the concave portion 56a in the horizontal direction, the clamp rod 15 is coupled to the piston 12.

  A gap G for assembling the output portion 55 and the connecting member 56 is formed between the right side surface of the output portion 55 and the inner side surface 2 b of the upper housing 2. The connecting member 56 is used in an engagement state X (see FIG. 1) in which the output member 55 is engaged in the radial direction. The connecting member 56 is assembled with the output unit 55 so that the engagement state X is changed from the disengaged state Y (see FIG. 3) where the engagement with the output unit 55 is released. Between the output portion 55 in the engagement state X and the inner side surface 2b of the upper housing 2, the output portion 55 is prevented from interfering with the inner side surface 2b in the disengagement state Y. A gap G is formed. The gap G is formed on the side opposite to the connecting member 56 with the output portion 55 interposed therebetween.

  A lock chamber 62 is formed above the piston body 54, and a release chamber 63 is formed below the piston body 54. The lock chamber 62 communicates with a lock supply / exhaust passage 65 in the lower housing 1. Further, the release chamber 63 communicates with a release supply / exhaust port 67.

  Further, a seating detection hole 70 is opened in the seating surface 23 formed in the upper part of the upper housing 2. The detection hole 70 communicates with a supply port (not shown) of pressurized air for abnormality detection via an air supply path 71.

  Further, an air blow passage 73 is opened above the through hole 11 below the spring chamber 46. Pressurized air for air blowing supplied to the passage 73 has a gap between the spring chamber 46, a vertical groove (not shown) formed in the outer peripheral surface of the connecting member 56, and the adjacent grippers 20 and the like. It passes through and is discharged outside the housing H.

  The clamp device having the above-described configuration is provided with a mechanism for detecting an operation abnormality (clamp failure). An annular space is formed between the small diameter holes 52a, 52b, 52c of the through hole 11 and the piston rod 58, and the annular space constitutes a valve chamber 77 of the valve mechanism. A cylindrical valve member 78 is inserted into the valve chamber 77 via the inner sealing member 79 and the outer sealing member 80 in a tightly sealed manner. The outer diameter dimension of the valve member 78 is set to a value smaller than the outer diameter dimension of the piston main body 54.

  An inlet 86 of the valve mechanism is opened in the peripheral wall of the small diameter hole 52b. The inlet 86 communicates with the air supply path 71 via an inlet path 87. Further, the outlet 91 of the valve mechanism is formed in the peripheral wall of the small diameter hole 52c. The outlet 91 communicates with the outside of the housing H. Reference numeral 88 indicates the valve seat of the valve mechanism.

(Assembly method of clamping device)
As shown in FIG. 3, the clamp device having the above-described configuration is assembled in the following procedure.

  First, the lower housing 1 is assembled in the following procedure. That is, the valve member 78 and the piston 12 are mounted on the lower housing 1 from below. Then, the advance spring 47 and the spring receiver 48 are mounted on the lower housing 1 from above, and the spring receiver 48 is received by the retaining ring 50.

  Next, a subassembly such as the clamp rod 15 is assembled in the following procedure. In other words, the T leg 15 a at the lower end of the clamp rod 15 is fitted in the horizontal direction in the T groove 56 b at the top of the connecting member 56. The support cylinder 21 and the four grippers 20 are inserted into the connecting member 56 and the clamp rod 15 from above. Thereafter, the ring 34 is fitted on the outer periphery of the four grippers 20 to complete the subassembly. Then, the subassembly is inserted into the upper housing 2 from the lower side.

  Next, as shown in FIG. 3, the upper housing 2 is arranged on the upper side of the lower housing 1, and the clamp rod 15 and the connecting member 56 are pushed down with respect to the support cylinder 21 and the gripper 20. As a result, the four grippers 20 expand in diameter and move outward in the radial direction.

  Thereafter, the upper housing 2 is moved rightward with respect to the lower housing 1, and the concave portion 56 a of the connecting member 56 is engaged with the convex portion 55 a of the output portion 55 of the piston rod 58. Then, as shown in FIG. 1, a gap G is formed between the right side surface of the piston rod 58 and the inner side surface 2 b of the upper housing 2. Subsequently, the lower housing 1 and the upper housing 2 are fixed by a plurality of connecting bolts (not shown).

  As described above, the connecting member 56 is assembled with the output unit 55 so as to change from the disengaged state Y (see FIG. 3) in which the engagement with the output unit 55 is released to the engaged state X (see FIG. 1). . And the gap G (refer FIG. 1) for preventing the output part 55 interfering with the inner surface 2b of the 2nd housing 2 in the said engagement release state Y (refer FIG. 3) is the said engagement state X. Are formed between the output portion 55 and the inner side surface 2b.

(Clamping device operation)
As shown in FIG. 1, the clamp device having the above-described configuration operates as follows.

  In the release state of FIG. 1, the pressure oil in the lock chamber 62 is discharged and the pressure oil is supplied to the release chamber 63. As a result, the piston 12, the connecting member 56 and the clamp rod 15 are raised, the support cylinder 21 and the four grippers 20 are held in the raised position by the advance spring 47, and the gripper 20 is contracted by the elastic force of the ring 34. It has been switched to the diameter state.

  Further, the gripper 20 and the clamp rod 15 are positioned coaxially with the axis of the connecting member 56 by the elastic force of the dust seal 36.

  Further, the valve member 78 of the valve mechanism is raised by the piston body 54 and closes the valve seat 88. A contact gap is formed between the outer peripheral portion of the upper end surface of the piston body 54 and the upper wall of the lock chamber 62.

  In the released state, the workpiece W is lowered by some lifting means or its own weight, and the gripper 20 is inserted into the hole 18 of the workpiece W. Then, the lower surface of the workpiece W is received by the seating surface 23 of the upper housing 2 and the seating detection hole 70 is closed.

  When the clamp device is switched from the released state of FIG. 1 to the locked state, the pressure oil in the release chamber 63 is discharged and the pressure oil is supplied to the lock chamber 62.

  Then, the piston 12, the connecting member 56, and the clamp rod 15 are lowered with respect to the support cylinder 21 and the gripper 20 held at the raised position by the urging force of the advance spring 47.

  Accordingly, the gripper 20 is expanded in diameter by the wedge surface 32 of the clamp rod 15 (moved outward in the radial direction), and the gripper 20 is engaged with the inner peripheral surface of the hole 18 of the workpiece W. Subsequently, due to the descending force of the clamp rod 15, the gripper 20 in a state of being in close contact with the inner peripheral surface of the hole 18 pulls the workpiece W downward through the hole 18. At the same time, the gripper 20 and the support are supported. The cylinder 21 descends against the urging force of the advance spring 47. Thereby, the workpiece W is strongly pressed against the seating surface 23.

  In this locked state, the valve member 78 of the valve mechanism is raised by the pressure in the lock chamber 62 to close the valve seat 88, and the seating detection hole 70 is also closed by the lower surface of the workpiece W. Accordingly, in the locked state, since the pressure of the pressurized air for abnormality detection supplied to the air supply path 71 increases, it can be confirmed that the operation of the clamping device is normal.

  Note that when the clamp device is switched from the locked state to the released state of FIG. 1, the pressure oil in the lock chamber 62 may be discharged and the pressure oil supplied to the release chamber 63. As a result, the clamping device is switched to the released state in a procedure almost opposite to the locking operation described above.

(effect)
The above embodiment has the following effects.

  By utilizing the gap G formed so as to prevent the output portion 55 from interfering with the inner side surface 2b of the second housing 2 in the disengaged state Y, both the output portion 55 and the connecting member 56 are used. When assembling, the piston 12 and the clamp rod 15 can be connected by smoothly engaging the both. Therefore, the present invention can provide a connection structure having a simple shape, unlike the L-shaped connection member having the conventional structure described above. As a result, the clamping device can be easily processed and the manufacturing cost can be reduced.

  Further, the connecting member 56 assembled in the second housing 2 is moved from the opposite side of the gap G toward the output unit 55 with the output unit 55 interposed therebetween, whereby the connecting member 56 is engaged with the output unit 55 and assembled. be able to. Further, the structure for fixing the work W to the second housing 2 by bringing the gripper 20 into close contact with the hole 18 of the work W becomes simple and compact.

  And the structure which engages the connection member 56 and the output part 55 of piston 12 becomes simple and compact by providing the convex part 55a corresponding to the recessed part 56a. Moreover, since the convex part 55a is formed by forming the groove | channel 57 in the outer peripheral surface of the piston rod 58, the structure of the piston rod 58 becomes simple and compact. Further, since a part of the groove 57 can be used as the spring chamber 46, the lateral width of the clamping device can be made compact.

(Modification of the embodiment)
The above embodiment can be modified as follows.

  Although four grippers 20 and wedge surfaces 32 are arranged at predetermined intervals in the circumferential direction, two, three, or five or more may be arranged.

  The arrangement posture of the clamp device may be reversed upside down, laterally, or obliquely with respect to the illustrated posture.

  Further, the pressure fluid used in the clamping device may be another liquid or a gas such as compressed air instead of the exemplified pressure oil.

  The fixed object to which the present invention is applied may be a work pallet or a mold instead of the illustrated work W.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims.

DESCRIPTION OF SYMBOLS 1 1st housing 2 2nd housing 2b Inner surface 12 Piston 15 Clamp rod 15a T leg (input part)
18 hole 20 gripper 21 support cylinder 46 spring chamber 47 spring 54 piston main body 55 output part 55a convex part 56 connecting member 56a concave part 57 groove 58 piston rod C1, C2 shaft center W work (fixed object)
G Clearance X Engagement state Y Disengagement state

  The present invention relates to a clamp device for fixing a fixed object such as a workpiece or a mold to a fixed side member. More specifically, in order to avoid interference between the clamp device and the fixed object, the fluid pressure of the clamp device is described. The present invention relates to a technique in which the axis of a clamp rod is offset from the axis of a cylinder.

  As this type of clamping device, there is one described in Patent Document 1 (Japan: JP 2009-279745 A (published on December 3, 2009)). The prior art is configured as follows.

  A lower main body member (first housing) and an upper main body member (second housing) are arranged in series in the vertical direction. A piston member of a hydraulic cylinder for clamping is inserted into the lower body member so as to be movable in the vertical direction. A clamp rod is inserted into the upper body member so as to be movable in the vertical direction. The clamp rod is disposed at a predetermined interval in the horizontal direction with respect to the piston member.

  An L-shaped connecting member for connecting the piston member to the clamp rod is provided. The L-shaped connecting member includes a first vertical axis fixed to the piston member with a bolt, a horizontal axis extending horizontally from the upper end of the first vertical axis, and an upper side from the end of the horizontal axis. And a second longitudinal axis extending to the front. The second vertical axis has a common axis with the axis of the clamp rod, and the T leg of the clamp rod is engaged with a T groove formed in the upper end portion of the second vertical axis. Yes.

Japanese Unexamined Patent Publication No. 2009-279745 (released December 3, 2009)

  According to the configuration of Patent Document 1, the L-shaped connecting member that connects the clamp rod and the piston member includes the first vertical axis, the horizontal axis, and the second vertical axis, so that the shape is complicated and high. Dimensional accuracy is required. For this reason, there is a problem that it is difficult to process the L-shaped connecting member and the manufacturing cost of the clamping device increases.

  An object of the present invention is to provide a clamping device that can be easily processed and can reduce the manufacturing cost.

In order to achieve the above object, the clamping device according to the first invention is configured as follows, for example, as shown in FIGS.
That is, the first housing 1 and the second housing 2 arranged in series, the piston 12 inserted in the first housing 1 so as to be movable in the axial direction, and moved in the axial direction in the second housing 2 And a clamp rod 15 inserted as possible. The clamp rod 15 has an axis C2 that is radially separated from the axis C1 of the piston 12. A connecting member 56 that connects the input portion 15a of the clamp rod 15 and the output portion 55 of the piston 12 is engaged with the output portion 55 in a radial direction so as to be engageable and disengageable in the radial direction. It is inserted into the housing 2 so as to be movable in the axial direction.
With the above configuration, the first invention can provide a simple-shaped connection structure, unlike the L-shaped connection member having the conventional structure described above. As a result, the clamping device can be easily processed and the manufacturing cost can be reduced.

Moreover, in order to achieve the said objective, as shown in FIGS. 1-3, the clamp apparatus which concerns on 2nd invention is comprised as follows, for example.
That is, the first housing 1 and the second housing 2 arranged in series, the piston 12 inserted in the first housing 1 so as to be movable in the axial direction, and moved in the axial direction in the second housing 2 And a clamp rod 15 inserted as possible. The clamp rod 15 has an axis C2 that is radially separated from the axis C1 of the piston 12. A connecting member 56 is inserted into the second housing 2 so as to connect the input portion 15 a of the clamp rod 15 and the output portion 55 of the piston 12. The connecting member 56 is used in an engagement state X in which the output member 55 is engaged in the radial direction. The connecting member 56 is assembled with the output unit 55 so that the engagement state X is changed from the disengaged state Y in which the engagement with the output unit 55 is released. Then, between the output portion 55 in the engaged state X and the inner side surface 2b of the second housing 2, the output portion 55 interferes with the inner side surface 2b in the disengaged state Y. A gap G for prevention was formed.

Due to the above features, the second invention has the following operational effects.

When assembling both the output part and the connecting member by using the gap formed so as to prevent the output part from interfering with the inner surface of the second housing in the disengaged state, The piston and the clamp rod can be connected by smoothly engaging. Therefore, unlike the L-shaped connecting member having the conventional structure described above, the second invention can provide a connecting structure having a simple shape. As a result, the clamping device can be easily processed and the manufacturing cost can be reduced.

In the clamping device according to the second aspect of the present invention, it is preferable that the gap G is formed on the opposite side of the connecting member 56 with the output portion 55 interposed therebetween.

  According to the above configuration, the connecting member incorporated in the second housing can be assembled by engaging the connecting member with the output part by moving the connecting part from the opposite side to the output part across the output part. it can.

In the clamp devices according to the first and second inventions described above, the clamp device is disposed on the outer peripheral side of the clamp rod 15 so as to be inserted into the hole 18 of the fixed object W and closely contact the inner peripheral surface of the hole 18. A gripper 20, a support cylinder 21 provided in the second housing 2 so as to push the gripper 20 in the distal direction, a support cylinder 21 having a cylinder hole into which the connecting member 56 is inserted, and the support cylinder 21 It is preferable that a spring 47 for urging the spring 47 in the distal direction and a spring chamber 46 provided in the first housing 1 so as to accommodate the spring 47 are provided.

  According to the above configuration, the configuration for fixing the object to be fixed to the second housing by bringing the gripper into close contact with the hole of the object to be fixed becomes simple and compact.

In the clamping device according to each of the above inventions, the output portion 55 of the piston 12 is provided with a convex portion 55a that can be relatively engaged with the concave portion 56a provided in the connecting member 56 in the radial direction. It is preferable.

  According to the said structure, the structure which engages a connection member and the output part of a piston becomes simple and compact.

In the clamping device according to each of the above-described inventions, a groove 57 extending in the axial direction is formed on the outer peripheral surface of the piston rod 58 projecting from the piston main body 54 of the piston 12 in the distal direction. It is preferable to form the convex part 55a.

  According to the said structure, the structure of a piston rod becomes simple and compact.

In the clamping device according to each of the above inventions, the groove 57 preferably constitutes a part of the spring chamber 46.

  According to the said structure, since a part of groove | channel can be utilized as a spring chamber, the lateral width of a clamp apparatus can be made compact.

FIG. 1 is an elevation view of a clamping device according to an embodiment of the present invention. 2A is a cross-sectional view taken along line 2A-2A in FIG. 2B is a cross-sectional view taken along line 2B-2B in FIG. FIG. 3 is an elevation view for explaining a method of assembling the clamp device.

  Hereinafter, embodiments of the present invention will be described in detail.

  1 to 3 show a clamping device according to an embodiment of the present invention. First, the configuration of the clamping device will be described with reference to FIGS.

(Configuration of clamp device)
The housing H of the clamping device is fixed to the base plate P of the machine tool. The housing H includes a lower housing 1 as a first housing and an upper housing 2 as a second housing. The lower housing 1 and the upper housing 2 are fixed in series in the vertical direction by a plurality of connecting bolts (not shown). The housing H is fixed to the base plate P by a plurality of fastening bolts (not shown) inserted through the lower housing 1 and the upper housing 2 in the vertical direction.

  A hydraulic cylinder 10 is disposed in the lower housing 1. The hydraulic cylinder 10 includes a through hole 11 formed upward from the lower surface of the lower housing 1 and a piston 12 inserted into the through hole 11.

  As will be described later, a clamp rod 15 is arranged in the upper portion of the upper housing 2 so as to be movable in the vertical direction (axial direction) and in the horizontal direction (radial direction). In the present embodiment, the clamp rod 15 is driven to release by being moved upward (toward the distal end) by the piston 12, and is driven to be locked by being moved downward (toward the proximal end) by the piston 12. The FIG. 1 shows a released state in which the clamp rod 15 has moved upward.

  The axis C2 of the clamp rod 15 is arranged in parallel to the left center direction (radial direction) with a predetermined interval with respect to the axis C1 of the piston 12.

  On the outer periphery of the upper part of the clamp rod 15, a plurality of grippers 20 inserted into the holes 18 of the workpiece W as a fixed object and a support cylinder 21 are arranged vertically. A seating surface 23 for receiving the lower surface of the workpiece W is formed in an annular shape on the upper surface of the upper housing 2 on the outer peripheral side of the gripper 20. The gripper 20 functions as a gripping member for lining the inner peripheral surface of the hole 18.

  In this embodiment, four grippers 20 are arranged at predetermined intervals in the circumferential direction. Each gripper 20 includes a thin contact portion 26 provided at an upper portion, a trunk portion 27 provided at an intermediate height, and a lower flange 28. A plurality of saw-toothed projections 29 are formed on the outer periphery of the contact portion 26 in the vertical direction. Moreover, the inclined surface 30 is formed in the inner periphery of each contact | adherence part 26 so that it may approach the axial center C2 of the clamp rod 15 as it goes below.

  A wedge surface (wedge portion) 32 that engages with the inclined surface 30 from above is formed on the upper portion of the clamp rod 15. Four wedge surfaces 32 are provided corresponding to the inclined surfaces 30. In this embodiment, the wedge surface 32 and the inclined surface 30 are constituted by flat surfaces.

  A thin ring 34 made of an elastic body such as rubber is attached to the body portions 27 of the four grippers 20. The elastic force of the ring 34 urges the gripper 20 inward in the radial direction.

  A dust seal 36 is attached to the peripheral wall of the upper hole 2 a of the upper housing 2. The elastic force of the dust seal 36 urges the clamp rod 15 and the gripper 20 inward in the radial direction toward the axis C <b> 2 of the clamp rod 15.

  The support cylinder 21 includes an upper wall 40 that receives the four grippers 20 from below, and an annular wall 41 that protrudes downward from the outer peripheral portion of the upper wall 40. A cylindrical hole of the support cylinder 21 is formed by the upper wall 40 and the inner peripheral surface of the annular wall 41. The support cylinder 21 is inserted into an accommodation hole 44 provided in the upper housing 2 so as to be vertically movable. Further, an advancing spring 47 made of a compression coil spring is attached to the spring chamber 46 disposed in the first housing 1 below the support cylinder 21 to urge the support cylinder 21 in the distal direction. A disk-shaped spring receiver 48 is provided on the advance spring 47. The spring receiver 48 supports the lower end of the annular wall 41 of the support cylinder 21.

  The advance spring 47 urges the gripper 20 upward via the spring receiver 48 and the support cylinder 21. That is, in this embodiment, the advance spring 47, the spring receiver 48, and the support cylinder 21 constitute a support mechanism that pushes up the gripper 20 with a predetermined force.

  A C-shaped retaining ring 50 is mounted on the upper end of the spring chamber 46 in plan view. The retaining ring 50 is a member for temporarily assembling the advancing spring 47 and the like in the lower housing 1 when assembling a clamp device described later.

  The through-hole 11 includes a large-diameter cylinder hole 51 and small-diameter holes 52a, 52b, and 52c that are sequentially formed upward.

  The piston 12 includes a piston main body 54 that is inserted into the cylinder hole 51 in a close-packed manner, and a piston rod 58 that protrudes upward from the piston main body 54. An output portion 55 is provided on the upper portion of the piston rod 58. A groove 57 extending in the axial direction is formed on the outer peripheral surface of the piston rod 58 (see FIG. 2B). The groove 57 constitutes a part of the spring chamber 46.

  A connecting member 56 that is connected to the clamp rod 15 is inserted into the cylindrical hole of the support cylinder 21. The connecting member 56 is disposed coaxially with the clamp rod 15. A T groove 56b is formed in the upper end portion of the connecting member 56, and a T leg (input portion) 15a provided at the lower end of the clamp rod 15 is engaged with the T groove 56b.

  A concave portion 56a that faces the output portion 55 at the upper end of the piston rod 58 is formed in the lower portion of the connecting member 56 (see FIG. 2A). At the upper end of the output portion 55, a convex portion 55a that can be relatively engaged with the concave portion 56a in the horizontal direction is formed. The convex portion 55 a is provided at the upper end of the output portion 55 by forming a groove 57 extending in the vertical direction on the outer peripheral surface of the piston rod 58. When the convex portion 55a is relatively engaged with the concave portion 56a in the horizontal direction, the clamp rod 15 is coupled to the piston 12.

  A gap G for assembling the output portion 55 and the connecting member 56 is formed between the right side surface of the output portion 55 and the inner side surface 2 b of the upper housing 2. The connecting member 56 is used in an engagement state X (see FIG. 1) in which the output member 55 is engaged in the radial direction. The connecting member 56 is assembled with the output unit 55 so that the engagement state X is changed from the disengaged state Y (see FIG. 3) where the engagement with the output unit 55 is released. Between the output portion 55 in the engagement state X and the inner side surface 2b of the upper housing 2, the output portion 55 is prevented from interfering with the inner side surface 2b in the disengagement state Y. A gap G is formed. The gap G is formed on the side opposite to the connecting member 56 with the output portion 55 interposed therebetween.

  A lock chamber 62 is formed above the piston body 54, and a release chamber 63 is formed below the piston body 54. The lock chamber 62 communicates with a lock supply / exhaust passage 65 in the lower housing 1. Further, the release chamber 63 communicates with a release supply / exhaust port 67.

  Further, a seating detection hole 70 is opened in the seating surface 23 formed in the upper part of the upper housing 2. The detection hole 70 communicates with a supply port (not shown) of pressurized air for abnormality detection via an air supply path 71.

  Further, an air blow passage 73 is opened above the through hole 11 below the spring chamber 46. Pressurized air for air blowing supplied to the passage 73 has a gap between the spring chamber 46, a vertical groove (not shown) formed in the outer peripheral surface of the connecting member 56, and the adjacent grippers 20 and the like. It passes through and is discharged outside the housing H.

  The clamp device having the above-described configuration is provided with a mechanism for detecting an operation abnormality (clamp failure). An annular space is formed between the small diameter holes 52a, 52b, 52c of the through hole 11 and the piston rod 58, and the annular space constitutes a valve chamber 77 of the valve mechanism. A cylindrical valve member 78 is inserted into the valve chamber 77 via the inner sealing member 79 and the outer sealing member 80 in a tightly sealed manner. The outer diameter dimension of the valve member 78 is set to a value smaller than the outer diameter dimension of the piston main body 54.

  An inlet 86 of the valve mechanism is opened in the peripheral wall of the small diameter hole 52b. The inlet 86 communicates with the air supply path 71 via an inlet path 87. Further, the outlet 91 of the valve mechanism is formed in the peripheral wall of the small diameter hole 52c. The outlet 91 communicates with the outside of the housing H. Reference numeral 88 indicates the valve seat of the valve mechanism.

(Assembly method of clamping device)
As shown in FIG. 3, the clamp device having the above-described configuration is assembled in the following procedure.

  First, the lower housing 1 is assembled in the following procedure. That is, the valve member 78 and the piston 12 are mounted on the lower housing 1 from below. Then, the advance spring 47 and the spring receiver 48 are mounted on the lower housing 1 from above, and the spring receiver 48 is received by the retaining ring 50.

  Next, a subassembly such as the clamp rod 15 is assembled in the following procedure. In other words, the T leg 15 a at the lower end of the clamp rod 15 is fitted in the horizontal direction in the T groove 56 b at the top of the connecting member 56. The support cylinder 21 and the four grippers 20 are inserted into the connecting member 56 and the clamp rod 15 from above. Thereafter, the ring 34 is fitted on the outer periphery of the four grippers 20 to complete the subassembly. Then, the subassembly is inserted into the upper housing 2 from the lower side.

  Next, as shown in FIG. 3, the upper housing 2 is arranged on the upper side of the lower housing 1, and the clamp rod 15 and the connecting member 56 are pushed down with respect to the support cylinder 21 and the gripper 20. As a result, the four grippers 20 expand in diameter and move outward in the radial direction.

  Thereafter, the upper housing 2 is moved rightward with respect to the lower housing 1, and the concave portion 56 a of the connecting member 56 is engaged with the convex portion 55 a of the output portion 55 of the piston rod 58. Then, as shown in FIG. 1, a gap G is formed between the right side surface of the piston rod 58 and the inner side surface 2 b of the upper housing 2. Subsequently, the lower housing 1 and the upper housing 2 are fixed by a plurality of connecting bolts (not shown).

  As described above, the connecting member 56 is assembled with the output unit 55 so as to change from the disengaged state Y (see FIG. 3) in which the engagement with the output unit 55 is released to the engaged state X (see FIG. 1). . And the gap G (refer FIG. 1) for preventing the output part 55 interfering with the inner surface 2b of the 2nd housing 2 in the said engagement release state Y (refer FIG. 3) is the said engagement state X. Are formed between the output portion 55 and the inner side surface 2b.

(Clamping device operation)
As shown in FIG. 1, the clamp device having the above-described configuration operates as follows.

  In the release state of FIG. 1, the pressure oil in the lock chamber 62 is discharged and the pressure oil is supplied to the release chamber 63. As a result, the piston 12, the connecting member 56 and the clamp rod 15 are raised, the support cylinder 21 and the four grippers 20 are held in the raised position by the advance spring 47, and the gripper 20 is contracted by the elastic force of the ring 34. It has been switched to the diameter state.

  Further, the gripper 20 and the clamp rod 15 are positioned coaxially with the axis of the connecting member 56 by the elastic force of the dust seal 36.

  Further, the valve member 78 of the valve mechanism is raised by the piston body 54 and closes the valve seat 88. A contact gap is formed between the outer peripheral portion of the upper end surface of the piston body 54 and the upper wall of the lock chamber 62.

  In the released state, the workpiece W is lowered by some lifting means or its own weight, and the gripper 20 is inserted into the hole 18 of the workpiece W. Then, the lower surface of the workpiece W is received by the seating surface 23 of the upper housing 2 and the seating detection hole 70 is closed.

  When the clamp device is switched from the released state of FIG. 1 to the locked state, the pressure oil in the release chamber 63 is discharged and the pressure oil is supplied to the lock chamber 62.

  Then, the piston 12, the connecting member 56, and the clamp rod 15 are lowered with respect to the support cylinder 21 and the gripper 20 held at the raised position by the urging force of the advance spring 47.

  Accordingly, the gripper 20 is expanded in diameter by the wedge surface 32 of the clamp rod 15 (moved outward in the radial direction), and the gripper 20 is engaged with the inner peripheral surface of the hole 18 of the workpiece W. Subsequently, due to the descending force of the clamp rod 15, the gripper 20 in a state of being in close contact with the inner peripheral surface of the hole 18 pulls the workpiece W downward through the hole 18. At the same time, the gripper 20 and the support are supported. The cylinder 21 descends against the urging force of the advance spring 47. Thereby, the workpiece W is strongly pressed against the seating surface 23.

  In this locked state, the valve member 78 of the valve mechanism is raised by the pressure in the lock chamber 62 to close the valve seat 88, and the seating detection hole 70 is also closed by the lower surface of the workpiece W. Accordingly, in the locked state, since the pressure of the pressurized air for abnormality detection supplied to the air supply path 71 increases, it can be confirmed that the operation of the clamping device is normal.

  Note that when the clamp device is switched from the locked state to the released state of FIG. 1, the pressure oil in the lock chamber 62 may be discharged and the pressure oil supplied to the release chamber 63. As a result, the clamping device is switched to the released state in a procedure almost opposite to the locking operation described above.

(effect)
The above embodiment has the following effects.

  By utilizing the gap G formed so as to prevent the output portion 55 from interfering with the inner side surface 2b of the second housing 2 in the disengaged state Y, both the output portion 55 and the connecting member 56 are used. When assembling, the piston 12 and the clamp rod 15 can be connected by smoothly engaging the both. Therefore, the present invention can provide a connection structure having a simple shape, unlike the L-shaped connection member having the conventional structure described above. As a result, the clamping device can be easily processed and the manufacturing cost can be reduced.

  Further, the connecting member 56 assembled in the second housing 2 is moved from the opposite side of the gap G toward the output unit 55 with the output unit 55 interposed therebetween, whereby the connecting member 56 is engaged with the output unit 55 and assembled. be able to. Further, the structure for fixing the work W to the second housing 2 by bringing the gripper 20 into close contact with the hole 18 of the work W becomes simple and compact.

  And the structure which engages the connection member 56 and the output part 55 of piston 12 becomes simple and compact by providing the convex part 55a corresponding to the recessed part 56a. Moreover, since the convex part 55a is formed by forming the groove | channel 57 in the outer peripheral surface of the piston rod 58, the structure of the piston rod 58 becomes simple and compact. Further, since a part of the groove 57 can be used as the spring chamber 46, the lateral width of the clamping device can be made compact.

(Modification of the embodiment)
The above embodiment can be modified as follows.

  Although four grippers 20 and wedge surfaces 32 are arranged at predetermined intervals in the circumferential direction, two, three, or five or more may be arranged.

  The arrangement posture of the clamp device may be reversed upside down, laterally, or obliquely with respect to the illustrated posture.

  Further, the pressure fluid used in the clamping device may be another liquid or a gas such as compressed air instead of the exemplified pressure oil.

  The fixed object to which the present invention is applied may be a work pallet or a mold instead of the illustrated work W.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims.

DESCRIPTION OF SYMBOLS 1 1st housing 2 2nd housing 2b Inner surface 12 Piston 15 Clamp rod 15a T leg (input part)
18 hole 20 gripper 21 support cylinder 46 spring chamber 47 spring 54 piston main body 55 output part 55a convex part 56 connecting member 56a concave part 57 groove 58 piston rod C1, C2 shaft center W work (fixed object)
G Clearance X Engagement state Y Disengagement state

Claims (6)

A first housing (1) and a second housing (2) arranged in series;
A piston (12) inserted into the first housing (1) so as to be axially movable;
A clamp rod (15) inserted into the second housing (2) so as to be movable in the axial direction, wherein the axial center (C2) is radially separated from the axial center (C1) of the piston (12). A clamping rod (15) having
A connecting member (56) inserted into the second housing (2) so as to connect the input part (15a) of the clamp rod (15) and the output part (55) of the piston (12); A coupling member (56) used in an engaged state (X) engaged in a radial direction with the output portion (55),
The connecting member (56) is assembled with the output portion (55) so as to change from the disengaged state (Y) where the engagement with the output portion (55) is released to the engaged state (X). ,
Between the output part (55) in the engaged state (X) and the inner surface (2b) of the second housing (2), the output part (55) is in the disengaged state (Y). A clamping device, wherein a gap (G) is formed to prevent interference with the inner surface (2b). The clamping device according to claim 1, wherein
The said clearance gap (G) is a clamp apparatus formed in the opposite side to a connection member (56) on both sides of the said output part (55). The clamping device according to claim 1 or 2,
A gripper (20) disposed on the outer peripheral side of the clamp rod (15) so as to be inserted into the hole (18) of the fixed object (W) and in close contact with the inner peripheral surface of the hole (18); (20) a support cylinder (21) provided in the second housing (2) so as to push in the distal direction, and a support cylinder (21) having a cylinder hole into which the connecting member (56) is inserted; A clamp device comprising: a spring (47) for urging the support cylinder (21) in the distal direction; and a spring chamber (46) provided in the first housing (1) so as to accommodate the spring (47). . The clamping device according to claim 3,
The output portion (55) of the piston (12) is provided with a convex portion (55a) that can be relatively engaged with the concave portion (56a) provided in the connecting member (56) in the radial direction. A clamping device. The clamping device according to claim 4, wherein
A groove (57) extending in the axial direction is formed on the outer peripheral surface of the piston rod (58) projecting from the piston body (54) of the piston (12) in the distal direction, whereby the output section (55) is A clamp device in which a convex portion (55a) is formed. The clamping device according to claim 5, wherein
The clamping device, wherein the groove (57) constitutes a part of the spring chamber (46).

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