WO2011037091A1

WO2011037091A1 - Screw engagement type clamp device, clamp system, and fluid pressure actuator

Info

Publication number: WO2011037091A1
Application number: PCT/JP2010/066232
Authority: WO
Inventors: 慶多朗米澤
Original assignee: 株式会社コスメック
Priority date: 2009-09-28
Filing date: 2010-09-17
Publication date: 2011-03-31
Also published as: JP5666460B2; JPWO2011037091A1

Abstract

A piston (21) is inserted between a cylinder hole (20) and a guide tube (15) so as to be able to rotate and to reciprocate in the axis direction, the cylinder hole (20) being provided in a housing (5), the guide tube (15) being provided at the center portion of the housing (5) on the tip side thereof. A ball screw mechanism (28) is provided between the piston (21) and the housing (5). An output rod (30) is inserted in a tube hole (29) of the guide tube (15) and a tube hole (24) of the piston (21) so as to be able to rotate and to move in the axis direction. The input section (41) of the output rod (30) is connected to the output section (42) of the piston (21) so as to be able to rotate and to transmit power. An engaging bolt (50) provided to the tip of the output rod (30) is configured so that the engaging bolt (50) is able to engage with a female thread hole (12) of an object (10) to be affixed.

Description

Screw engagement type clamping device, clamping system, and fluid pressure actuator

The present invention relates to a screw engagement type clamping device using a pressure fluid and a clamping system using the clamping device, and further to a fluid pressure actuator suitable for use in the clamping device.

Conventionally, this type of screw engagement type clamping device is disclosed in Patent Document 1 (International Publication WO 2006/100958).
The prior art is configured as follows.
An annular piston is inserted into the cylinder hole of the housing so as to be movable in the vertical direction. The rotating member is inserted into the cylindrical hole of the piston in a state where movement in the vertical direction is prevented. A ball screw mechanism is provided between the piston and the rotating member. Then, when the piston in the housing is locked and moved by the pressure fluid, the rotating member is rotated around the axis by the ball screw mechanism, and the rotating member rotates the output rod. Then, the engaging bolt provided at the tip of the output rod engages with the female screw hole of the fixed object. Thereby, the fixed object is pulled and fixed to the housing.

International Publication Gazette WO WO 2006/100958

The above prior art is excellent in that the object to be fixed can be strongly fixed to the housing, but there is room for improvement in the following points.
Since it is necessary to insert the rotating member inside the piston, the outer diameter of the piston portion into which the rotating member is inserted increases. Therefore, the annular pressure receiving cross-sectional area (effective cylinder area) obtained by subtracting the pressure receiving cross-sectional area of the piston portion from the pressure receiving cross-sectional area of the piston body is reduced, and the output of the clamping device is low. Further, since the rotating member described above is necessary, the number of parts is increased and there is a limit to downsizing of the clamping device.
An object of the present invention is to provide a high-power and compact screw-engaged clamping device.

In order to achieve the above object, the present invention, for example, as shown in FIG. 1 to FIG. 6 or FIG. 9 to FIG. The apparatus to be fixed by pulling with is configured as follows.
A piston 21 is inserted between the cylinder hole 20 provided in the housing 5 and the guide cylinder 15 provided at the center portion on the front end side of the housing 5 so as to be reciprocally movable and rotatable in the axial direction. A ball screw mechanism 28 is provided between the piston 21 and the housing 5.
The output rod 30 is inserted into the cylinder hole 29 of the guide cylinder 15 and the cylinder hole 24 of the piston 21 so as to be rotatable and movable in the axial direction. The input portion 41 of the output rod 30 is connected to the output portion 42 of the piston 21 so as to be capable of rotational transmission. The engaging bolt 50 provided at the tip of the output rod 30 is configured to be engageable with the female screw hole 12 of the fixed object 10.

The present invention has the following effects.
When the lock is driven, the piston in the housing is locked and moved in the distal direction by the pressure fluid. Then, the piston moves in the tip direction while rotating around the axis by the ball screw mechanism, and at the same time, the piston rotates the output rod. Then, the engagement bolt provided at the tip of the output rod engages with the female screw hole of the fixed object, and the fixed object is pulled and fixed to the housing by the screw engaging force.
And since the said piston reciprocates, rotating an output rod, rotating with a ball screw mechanism, unlike the said prior art example, it is not necessary to provide another component for rotating an output rod inside a piston. . Therefore, in the present invention, the outer diameter dimension of the piston portion into which the above-described another part has been inserted in the conventional example can be reduced. Accordingly, the annular pressure receiving cross-sectional area (effective cylinder area) obtained by subtracting the pressure receiving cross-sectional area of the piston portion from the pressure receiving cross-sectional area of the piston body is increased, and the output of the clamping device is increased. In addition, since the other parts can be omitted, the inner diameter of the cylinder hole can be reduced, and a compact and small clamping device can be provided. Furthermore, since the above-described separate parts are not necessary, the number of parts is reduced, and the manufacturing cost of the clamping device can be reduced.

In the present invention, for example, as shown in FIG. 3 or FIG. 9, a first working chamber 62 to which pressure fluid is supplied in order to retract the output rod 30 to the release position is formed on the distal end side of the piston 21, Preferably, a second working chamber 64 to which a pressure fluid is supplied in order to advance the output rod 30 to the lock position is formed on the proximal end side of the piston 21.
In the embodiment of FIG. 9, when pressure oil is used as the pressure fluid, the ball screw mechanism can be disposed in the second working chamber, and the ball screw mechanism is supplied to the second working chamber. Lubricated by. Therefore, the ball screw mechanism has a low friction and a long life, and does not require maintenance for a long time.

In the present invention, for example, as shown in FIG. 3 or FIG. 9, the pressure receiving sectional area of the piston 21 in the first working chamber 62 is larger than the pressure receiving sectional area of the piston 21 in the second working chamber 64. It is preferable to set.
In this case, the release driving force can be set to a value larger than the lock driving force.

For example, as shown in FIGS. 3 to 6, it is preferable to add the following configuration to the present invention. The ball screw mechanism 28 includes a female spiral groove 56 formed on the housing 5 with a plurality of pitches, and at least one male spiral groove 57 formed on the outer peripheral surface of the small diameter portion 21a provided on the proximal end side of the piston 21 with approximately one pitch. , And a plurality of balls 58 inserted between the female spiral groove 56 and the male spiral groove 57 so as to roll freely. A circulation path 59 that connects the start end and the end of the male spiral groove 57 so as to allow the ball 58 to get over the partition wall 60 formed between adjacent groove portions of the female spiral groove 56. Is formed in a concave shape on the outer peripheral surface of the small diameter portion 21 a of the piston 21.
In this case, since the outer peripheral surface of the piston can be effectively used as an installation space for the circulation path, the size of the housing in the radial direction is reduced. As a result, the clamping device becomes even more compact.

For example, as shown in FIGS. 9 to 10C, the following configuration is preferably added to the present invention.
The ball screw mechanism 28 includes a male spiral groove 57 formed in a plurality of pitches on the outer peripheral surface of the small diameter portion 21a provided on the proximal end side of the piston 21, and at least one female spiral groove 56 formed in the housing 5 side at approximately one pitch. And a large number of balls 58 inserted between the male spiral groove 57 and the female spiral groove 56 so as to roll freely. A circulation path 59 that connects the start end and the end of the female spiral groove 56 so as to allow the ball 58 to get over the partition wall 60 formed between adjacent groove portions of the male spiral groove 57. Is formed in a concave shape on the housing 5 side.
In this case, since the inner peripheral surface on the housing side can be effectively used as an installation space for the circulation path, the size of the housing in the radial direction is reduced. As a result, the clamping device becomes even more compact.
A plurality of male spiral grooves having a plurality of pitches are formed on the outer peripheral surface of the small diameter portion of the piston, which is a male-side component of the ball screw mechanism. Therefore, the ball screw processing can be easily performed as compared with the case where it is performed on the female part. Further, since the piston as a component of the ball screw mechanism is a small component compared to the housing, it is easy to perform a hardening process such as quenching.

In the present invention, for example, as shown in FIGS. 9 to 10C, a ball circulation member 96 in which the female spiral groove 56 is formed is disposed in the cylindrical hole of the housing 5, and the ball circulation member 96 It is preferable to provide a circulation path block 97 in which the circulation path 59 is formed.
In this case, the circulation path is formed in a circulation path block that is a separate component from the housing. Therefore, it is easy to process the circulation path. Further, by removing the circulation path block from the ball circulation member, it is easy to assemble and remove the ball from the ball circulation member.

In the present invention, for example, as shown in FIG. 3 or FIG. 9, in the released state in which the output rod 30 is retracted to the proximal end side, the distal end of the output rod 30 is seated on which the fixed object 10 is supported. It is preferable to be disposed at a position withdrawn from the surface S.
In this case, when the above-mentioned fixed object is carried in or out of the seating surface, the fixed object is carried in both from the direction perpendicular to the seating surface and in the direction parallel to the seating surface. Unloading is possible. In addition, the seating surface is easy to clean.

In the present invention, for example, as shown in FIG. 3 or 9, it is preferable to provide an advancing means 47 that presses the output rod 30 toward the female screw hole 12.
In this case, when the screw engagement between the engagement bolt of the output rod and the female screw hole of the fixed object is started, the advancement means presses the rotating bolt against the female screw hole, so that the screw engagement can be reliably performed. .
Further, in the released state, even when the tip of the output rod is disposed at a position retracted from the seating surface, when the piston is driven to lock, the piston moves with the movement toward the tip side. The advancing means can move the output rod to the tip side.

In the present invention, for example, as shown in FIG. 3 or FIG. 9, a manual operation portion 44 is provided at the proximal end portion of the housing 5 in a state where it can be rotated and prevented from moving in the axial direction. It is preferable to insert the base end portion of the output rod 30 into the portion 44 so as to be capable of rotational transmission.
In this case, when the engagement bolt of the output rod and the female screw hole of the fixed object are fixed by seizing or the like, the above-mentioned fixed state can be released by rotating the manual operation portion by human power or the like. As a result, the production line can be quickly restored when the above-mentioned seizure or the like occurs.

It is preferable to add the following configuration (A) or (B) to the present invention.
(A) The outer peripheral surface of the engaging bolt 50 is constituted by a multi-thread screw (preferably a double thread).
(B) The ball screw mechanism 28 is constituted by a multi-thread screw (preferably a double thread).
In this case, since the engagement bolt and the female screw hole are engaged with each other a plurality of times during one rotation of the engagement bolt, the engagement becomes quick and rotation loss is reduced. Further, since a plurality of pitches are screwed in one rotation, the number of rotations of the piston may be small, and the moving distance of the piston can be shortened. Therefore, since the height of the housing can be reduced, the clamping device can be made more compact.

In the present invention, for example, as shown in FIG. 3 or FIG. 9, the radial direction of the output rod 30 is between the cylindrical hole 29 of the guide tube 15 of the housing 5 and the outer peripheral surface of the output rod 30. You may form the annular clearance 79 which accept | permits movement to.
In this case, since the output rod is allowed to move in the radial direction with respect to the housing, it is possible to absorb the misalignment between the shaft center of the female screw hole of the fixed object and the shaft center of the output rod.

In the present invention, for example, as shown in FIGS. 5 and 6, the output rod 30 is moved into the tube hole 29 of the guide tube 15 of the housing 5 during the movement of the output rod 30 from the release position to the lock position. The rod 30 may be inserted in a state in which movement in the radial direction is prevented.
In this case, the axis of the output rod can be used as a positioning reference.

In the present invention, for example, as shown in FIG. 12 (see FIGS. 5 and 6), the tube hole of the guide tube 15 of the housing 5 is moved in the middle of moving the output rod 30 from the release position to the lock position. In 29, the output rod 30 may be inserted in a state that prevents movement in a predetermined radial direction and allows movement in a radial direction orthogonal to the predetermined radial direction.
In this case, positioning is performed in the predetermined radial direction, and misalignment can be allowed in the radial direction perpendicular thereto.

As a clamping system using the clamping device of the present invention, it is conceivable to use at least one clamping device according to each of the inventions described above, or to use a combination of clamping devices according to a plurality of inventions.

A fluid pressure actuator suitable for application to the clamping device of the present invention is configured as follows, for example, as shown in FIGS. 9 to 10C.
A piston 21 is inserted into a cylinder hole 20 provided in the housing 5 so as to be capable of reciprocating and rotating in the axial direction. A ball screw mechanism 28 is provided between the piston 21 and the housing 5.
The ball screw mechanism 28 includes a male spiral groove 57 formed in a plurality of pitches on the outer peripheral surface of the small diameter portion 21a provided on the proximal end side of the piston 21, and at least one female spiral groove 56 formed in the housing 5 side at approximately one pitch. And a large number of balls 58 inserted between the male spiral groove 57 and the female spiral groove 56 so as to roll freely.
A circulation path 59 that connects the start end and the end of the female spiral groove 56 so as to allow the ball 58 to get over the partition wall 60 formed between adjacent groove portions of the male spiral groove 57. Is formed in a concave shape on the housing 5 side.

In this case, since the inner peripheral surface on the housing side can be effectively used as an installation space for the circulation path, the size of the housing in the radial direction is reduced. As a result, the fluid pressure actuator can be made compact.
A plurality of male spiral grooves having a plurality of pitches are formed on the outer peripheral surface of the small diameter portion of the piston, which is a male-side component of the ball screw mechanism. Therefore, the ball screw processing can be easily performed as compared with the case where it is performed on the female part. Further, since the piston as a component of the ball screw mechanism is a small component compared to the housing, it is easy to perform a hardening process such as quenching.

In the invention of the fluid pressure actuator described above, for example, as shown in FIG. 9, the first working chamber 62 to which the pressure fluid is supplied in order to retract the piston 21 in the proximal direction is provided at the distal end side of the piston 21. Preferably, the second working chamber 64 to which the pressure fluid is supplied is formed on the proximal end side of the piston 21 in order to advance the piston 21 in the distal direction.
In this case, the ball screw mechanism can be disposed in the second working chamber, and when pressure oil is used as the pressure fluid, the ball screw mechanism is lubricated by the pressure oil supplied to the second working chamber. Therefore, the ball screw mechanism has a low friction and a long life, and does not require maintenance for a long time.

The usage form of the screw engagement type clamp apparatus of 1st Embodiment of this invention is shown. It is a top view of the clamp apparatus in said usage pattern. It is sectional drawing of the elevation view of the release state of the said clamp apparatus FIG. 4A is a plan view of the clamping device. 4B is a partial cross-sectional view of the lower part of FIG. It is a figure similar to said FIG. 3 which shows the initial state of the lock raise of the said clamp apparatus. It is a figure similar to FIG. 3 which shows the locked state of the said clamp apparatus. FIG. 5 is a partial view similar to FIG. 3, showing a modified example of the clamping device according to the first embodiment. FIG. 8 is a view similar to FIG. 6, showing another usage pattern of the clamping device according to the first embodiment. FIG. 4 is a view similar to FIG. 3, showing a clamp device according to a second embodiment of the present invention. FIG. 10A is a cross-sectional view of the ball circulation member provided in the clamp device of FIG. 9 described above. 10B is a cross-sectional view taken along line 10B-10B of FIG. 10A. FIG. 10C is a sectional view taken along line 10C-10C of FIG. 10A. FIG. 10 is a partial view similar to FIG. 9, showing a modified example of the clamp device according to the second embodiment. It is a cross-sectional view showing a modification of the guide tube of the present invention. It is a longitudinal cross-sectional view which shows the modification of the bolt for engagement of this invention. It is a schematic diagram of the planar view of the clamping system using each said clamp apparatus.

5: housing, 10: fixed object (work), 12: female screw hole, 15: guide cylinder, 20: cylinder hole, 21: piston, 21a: small diameter part, 24: cylinder hole of piston 21, 28: ball screw mechanism, 29: cylinder hole (guide hole) of the guide cylinder 15, 30: output rod, 41: input section, 42: output section, 44: manual operation section, 47: advance means (advance spring), 50: engagement bolt, 56 : Female spiral groove, 57: male spiral groove, 58: ball, 59: circulation path, 60: partition wall, 62
: First working chamber (release chamber), 64: second working chamber (lock chamber), 79: annular gap, 96: ball circulation member, 97: circulation path block, S: seating surface.

1 to 6 show a first embodiment of the present invention.
In this 1st Embodiment, the case where a workpiece | work is fixed and cancelled | released with the screw engagement type clamp apparatus is illustrated. First, the configuration of the clamping device will be described with reference to FIGS.

A jig plate 2 as a support is provided on a table 1 such as a machine tool. The jig plate 2 includes a flange portion 2a. The seating block 3 is fixed to the upper surface of the flange portion 2a by a plurality of (here, three as shown in FIG. 2) mounting bolts 3b, and the lower surface of the flange portion 2a is connected to the clamping device 4 (4a). The upper part of the housing 5 is fixed by a plurality (here, two as shown in FIG. 2) of mounting bolts 5a. As shown in FIG. 4A, a plurality of mounting bolt holes 5b for mounting bolts 5a are formed on the upper surface of the housing 5 (eight here).
A reference surface 11 and a female screw hole 12 are processed in advance on a workpiece 10 as a fixed object. The female screw hole 12 is opened downward in the reference surface 11.

As shown in FIG. 2, the seating block 3 is a substantially semicircular member in plan view, and a U-shaped cutout 3 a is formed at one end thereof. When the seating block 3 is attached to the jig plate 2, the output rod 30 of the clamp device 4 is disposed in the notch 3a. On the upper surface of the seating block 3, a seating surface S that supports the workpiece 10 is provided in the vicinity of the notch 3a (see the portion indicated by the two-dot chain line in FIG. 2). Then, as shown in FIG. 1 or FIG. 3, the workpiece 10 is fixed on the seating block 3 so that the right end thereof is arranged to the right of the right end of the seating block 3. For this reason, the cutting tool does not interfere with the seating block 3, and five-face machining for the workpiece 10 is possible. Further, as shown in FIG. 2, the notch 3a into which the output rod 30 of the clamping device 4 is inserted is opened to the right, so that chips and cutting oil easily flow out to the right. Easy measures against powder and cutting oil. Since the jig pallet, the assembly jig, etc. need only be slightly larger than the fixed object such as a workpiece, the space can be reduced and the equipment cost can be reduced.

In order to blow air onto the seating surface S or the tip of the output rod 30 (a male screw portion 53 of the engagement bolt 50 described later), the clamp device 4 or the seating block 3 is provided with an air blow mechanism. preferable.

A lower housing part 7 is fixed to the upper housing part 6 of the housing 5 fixed to the flange part 2 a by a plurality of connecting bolts 8. A guide tube 15 is inserted into the center portion of the upper housing portion 6. The upper flange 16 of the guide tube 15 is fixed to the upper portion of the upper housing portion 6 by a large number (here, eight) of fastening bolts 17.
An annular partition member 18 is disposed in the lower portion of the upper housing portion 6. The partition member 18 is prevented from rotating by a rotation preventing pin 19 on the upper surface of the peripheral wall of the cylindrical hole of the lower housing portion 7. A groove 65a serving as a passage for pressure oil supplied to a lock chamber (second working chamber) 64, which will be described later, is formed in the upper outer periphery of the partition member 18. A large-diameter cylinder hole 20 is formed in the upper housing portion 6.
An annular piston 21 is inserted between the cylinder hole 20 and the outer peripheral surface of the guide cylinder 15 so as to be reciprocally movable in the vertical direction (axial direction) and rotatable about the axial center.

A small diameter portion 21 a is provided on the lower end side (base end side) of the piston 21, and the small diameter portion 21 a includes a cylindrical hole of the partition member 18 and a rod receiving hole 22 provided in the lower housing portion 7. , Is inserted into. A large-diameter portion 21b as a piston body is provided on the upper end side of the piston 21.
The rod receiving hole 22 is formed to have a smaller diameter than the cylinder hole 20, and can move the input portion 41 and the base end portion 43 of the output rod 30 disposed inside the small diameter portion 21 a of the piston 21 in the vertical direction. To house.
Further, a ball screw mechanism 28 described later is provided between the small diameter portion 21 a of the piston 21 and the rod receiving hole 22 of the housing 5.

A guide hole 29 is formed by the cylindrical hole of the guide cylinder 15. The guide hole 29 is disposed radially inward from the cylindrical hole 24 of the piston 21. An output rod 30 is inserted into the guide hole 29 so as to be rotatable about an axis and movable in the vertical direction (axial direction).
A packing 31 having a dust seal function and a sealing function is mounted between the upper end of the guide hole 29 of the guide cylinder 15 and the outer peripheral surface of the output rod 30.

In the guide hole 29 of the guide tube 15, female

fitting portions

32, 32 protrude inward in the radial direction with a predetermined interval in the vertical direction (axial direction), and these female

fitting portions

32, 32. An annular groove 33 is formed between the two. Further, male

fitting portions

34 and 34 are formed on the outer peripheral surface of the output rod 30 with a predetermined interval in the vertical direction, and annular

concave grooves

35 and 35 are formed above the male

fitting portions

34 and 34. The

In the released state of FIG. 3 in which the output rod 30 is retracted downward, the female fitting portion 32 and the male fitting portion 34 are separated from each other in the vertical direction, and the output rod 30 has a radius within the guide hole 29. It can move in the direction.
On the other hand, in the locked state of FIG. 6 in which the output rod 30 is advanced upward, the female fitting portion 32 and the male fitting portion 34 are fitted almost entirely, and output to the guide hole 29. The rod 30 is restrained in the radial direction.
As a result, the clamping device 4 (4a) of the first embodiment prevents the output rod 30 from moving in the radial direction in the locked state of FIG. 6, and in the clamping system of FIG. It is configured as a shape clamping device.
The male fitting portion 34 is formed with a groove portion 34a that serves as a passage for compressed air for detecting a locked state, which will be described later. Therefore, even when the female fitting portion 32 and the male fitting portion 34 are fitted over almost the entire circumference, the fitting gap 79 between the output rod 30 and the guide hole 29 is provided in the male fitting portion 34. It communicates vertically. The groove 34 a may be provided in the female fitting portion 32 instead of being provided in the male fitting portion 34.

The input portion 41 of the output rod 30 is inserted into the output portion 42 of the piston 21 so as to be able to rotate and move in the vertical direction (axial direction). Here, the input portion 41 of the output rod 30 has a hexagonal cross-sectional shape, and the output portion 42 of the piston 21 is a hexagonal cylindrical hole. An annular gap 80 is formed on the outer peripheral side of the input part 41 between the cylindrical hole of the output part 42.

A base end portion 43 is provided below the input portion 41 of the output rod 30. A manual operation unit 44 is provided at the lower end (base end) of the housing 5 in a state where the manual operation unit 44 is rotatable and prevented from moving in the vertical direction. And the base end part 43 of said output rod 30 is inserted in the cylinder hole of the manual operation part 44 so that rotation transmission is possible. Here, the base end portion 43 of the output rod 30 has a hexagonal cross-sectional shape, and the manual operation portion 44 has a hexagonal cylindrical hole. An annular gap 81 is formed between the outer peripheral surface of the base end portion 43 and the cylindrical hole of the manual operation portion 44.
Therefore, when the engagement bolt 50 of the output rod 30 and the female screw hole 12 of the workpiece 10 are fixed by seizing or the like and cannot be released by the release torque of the clamping device 4, the manual operation unit 44 is rotated by a spanner or the like. The fixed state can be released.

The annular gap 80 formed between the input portion 41 of the output rod 30 and the output portion 42 of the piston 21, and the base end portion 43 of the output rod 30 and the manual operation portion 44. An annular gap 81 formed between the cylindrical hole serves as a passage for exhausting compressed air for detecting a locked state, which will be described later, and allows the output rod 30 to be misaligned.
Further, the fitting between the input portion 41 of the output rod 30 and the output portion 42 of the piston 21 and the fitting between the proximal end portion 43 of the output rod 30 and the cylindrical hole of the manual operation portion 44 are performed. It is only necessary that the rotation transmission is possible and the relative movement is possible in the vertical direction (axial direction). Instead of the above hexagonal fitting, for example, quadrilateral fitting may be used.

A stopper 45 is mounted between the input part 41 and the base end part 43 at the lower part of the output rod 30. Then, an advancing spring 47 (advancing means) is mounted between the stopper 45 and a retaining ring 46 disposed at the upper part of the manual operation unit 44. The advance spring 47 functions as an elastic body that biases the output rod 30 upward. The stopper 45 is divided into two substantially semicircular diameters for easy assembly and disassembly.

An engagement bolt 50 is provided at the upper end (tip) of the output rod 30. The bolt 50 includes a tapered portion 51, a shoulder portion 52, and a male screw portion 53 in order downward. The male screw portion 53 is configured to be able to engage with the female screw portion 12 a of the female screw hole 12 of the workpiece 10. In the first embodiment, the male screw portion 53 and the female screw portion 12a are a right screw and a parallel screw.
Further, the output rod 30 is provided with an enlarged diameter portion 54 above the input portion 41. An upper thrust bearing 55 is placed on the upper surface of the enlarged diameter portion 54. The upper thrust bearing 55 is configured by a low friction sliding bearing.

The ball screw mechanism 28 is configured as follows.
A plurality of female spiral grooves 56 are formed in the rod housing holes 22 of the lower housing portion 7. Further, the male spiral groove 57 is formed on the outer peripheral surface of the small diameter portion 21a of the piston 21 at almost one pitch. A large number of balls 58 are inserted between the female spiral groove 56 and the male spiral groove 57 so as to roll freely. In addition, a circulation path 59 that communicates the starting end portion and the terminal end portion of the male spiral groove 57 is formed in a concave shape on the outer peripheral surface of the small diameter portion 21 a of the piston 21. The action of the circulation path 59 allows the ball 58 to get over the partition wall 60 formed between adjacent groove portions of the female spiral groove 56.
In the first embodiment, the female spiral groove 56 and the male spiral groove 57 are constituted by right-hand screws. Moreover, instead of providing only one male spiral groove 57 formed with substantially one pitch, a plurality of male spiral grooves 57 may be provided at intervals in the axial direction.

A release chamber (first working chamber) 62 formed on the upper side of the piston 21 communicates with a first oil supply / discharge port 63 for pressure oil, and a lock chamber (second working chamber) 64 formed on the lower side of the piston 21. The pressure oil is communicated with the second oil supply / discharge port 65 through the groove 65a of the partition member 18. The pressure receiving cross-sectional area of the piston 21 in the release chamber 62 is set to a value larger than the pressure receiving cross-sectional area of the piston 21 in the lock chamber 64, thereby setting the release driving force to a value larger than the lock driving force. .

A first supply port 71 through which compressed air for detecting the release state is supplied is provided at the lower part of the lower housing part 7. In addition, a second supply port 72 to which compressed air for detecting a lock state is supplied is provided at an intermediate height portion of the lower housing portion 7.
The first supply port 71 is communicated with the external space via a first opening / closing portion 73 disposed so as to face in the vertical direction between the lower end portion of the lower housing portion 7 and the lower end surface of the piston 21. Yes. Further, the second supply port 72 is vertically moved between the lower end surface of the guide cylinder 15 constituting a part of the housing 5 and the upper surface of the upper thrust bearing 55 as shown in a locked state of FIG. It communicates with the external space via the second opening / closing part 74 arranged to face the direction.

The clamp device 4 operates as follows, as shown in the release state of FIG. 3, the initial state of the lock rise of FIG. 5, and the lock state of FIG.
In the release state of FIG. 3, the pressure oil in the lock chamber 64 is discharged and the pressure oil is supplied to the release chamber 62, and the piston 21 is lowered. Therefore, the output rod 30 is disposed at a release position that is retracted downward. At this time, the output rod 30 is pressed upward by the urging force of the advance spring 47, but is prevented from rising by the output portion 42 of the piston 21 via the stopper 45.

In this state, when the workpiece 10 is placed on the seating block 3, a part of the reference surface 11 of the workpiece 10 comes into contact with the seating surface S of the seating block 3. The female screw hole 12 of the workpiece 10 is disposed substantially above the output rod 30. At this time, the distal end of the output rod 30 is disposed at a position retracted by a distance A below the seating surface S of the seating block 3.

In the release state, the compressed air from the first supply port 71 is stopped by the first opening / closing part 73. For this reason, it can confirm that the clamp apparatus 4 is a release state by detecting the pressure rise of the 1st supply port 71. FIG.
In the released state, the compressed air from the second supply port 72 is supplied to the oblique path 76 of the lower housing part 7, the longitudinal path 77 of the upper housing part 6, the lateral path 78 of the guide cylinder 15, the output rod 30 and the guide. The fitting gap 79 between the hole 29, the fitting gap 80 between the input portion 41 of the output rod 30 and the output portion 42 of the piston 21, the base end portion 43 of the output rod 30 and the manual operation portion 44. It can be discharged to the outside through the fitting gap 81 between the cylinder holes in order.

When the clamp device 4 in the released state in FIG. 3 is switched to the locked state in FIG. 6, the pressure oil in the release chamber 62 is discharged and the pressure oil is supplied to the lock chamber 64 to raise the piston 21. Then, the piston 21 rises while rotating the output rod 30 and enters the initial state of the lock rise as shown in FIG. That is, the taper portion 51 of the bolt 50 is inserted into the female screw hole 12 of the workpiece 10, and then the shoulder portion 52 of the bolt 50 contacts the lower part of the peripheral wall of the female screw hole 12. In this state, the upper end of the male screw portion 53 of the bolt 50 is engaged with the lower end of the female screw portion 12 a of the female screw hole 12 by the urging force of the advance spring 47.
When switching from the released state of FIG. 3 to the initial state of the lock rise of FIG. 5, if the shaft center of the female screw hole 12 and the shaft center of the output rod 30 are misaligned, the tapered portion 51 is Since the insertion resistance is received from the hole 12, the output rod 30 is aligned in the radial direction by the resistance.

Subsequently, the pressure oil in the release chamber 62 is discharged and the pressure oil is supplied to the lock chamber 64 to raise the piston 21. Then, as shown in FIG. 6, the output rod 30 rotates in the clockwise direction when viewed from the bottom, and the male screw portion 53 of the bolt 50 is screwed into the female screw portion 12a.
As a result, the output rod 30 first rises and the thrust bearing 55 comes into contact with the lower end surface of the guide cylinder 15, and then the work 10 is strongly attached to the seating surface S of the seating block 3 by the screwing force of the bolt 50. Press. Here, the number of ridges into which the male thread portion 53 is screwed is set to about 3 to 5 ridges.

At the time of the above-mentioned screwing, when the piston 21 makes one rotation, the piston 21 rises by the lead amount of the ball screw of the ball screw mechanism 28, and the output rod 30 rises by the screw pitch of the male screw portion 53. That is, the amount of movement of the piston 21 and the output rod 30 when the piston 21 makes one rotation differs depending on the difference between the lead of the ball screw and the screw pitch of the male screw portion 53.
When the engagement bolt 50 or the ball screw mechanism 28 is constituted by a double thread screw, the bolt 50 and the female screw hole 12 are engaged twice while the bolt 50 is rotated once. (Every 180 °), the meshing becomes quick and the rotation loss is reduced to 1/2. Further, since the bolt 50 is screwed by 2 pitches in one rotation, the number of rotations of the piston 21 may be small, and the lifting distance of the piston 21 becomes 1/2. Therefore, since the height of the housing 5 can be reduced, the clamping device 4 can be made more compact.

In the locked state, the compressed air in the second supply port 72 is supplied to the lower end of the fitting gap 79 through the oblique path 76, the longitudinal path 77, and the lateral path 78, but is stopped by the second opening / closing portion 74 at the lower end. ing. For this reason, it can confirm that the clamp apparatus 4 is a locked state by detecting the pressure rise of the 2nd supply port 72. FIG.
In the locked state, the compressed air from the first supply port 71 can be discharged to the outside through the fitting gap 81 between the base end portion 43 of the output rod 30 and the cylindrical hole of the manual operation portion 44. .

When switching the clamp device 4 in the locked state in FIG. 6 to the released state in FIG. 3, the pressure oil in the lock chamber 64 is discharged and the pressure oil is supplied to the release chamber 62 to lower the piston 21. Then, as shown in FIG. 3, the output rod 30 rotates counterclockwise when viewed from the bottom, and the output rod 30 descends according to the screwing of the male threaded portion 53 of the bolt 50 and the female threaded portion 12a. The state is released. Thereafter, the workpiece 10 may be moved.

The first embodiment has the following advantages.
Since the piston 21 reciprocates while rotating by the ball screw mechanism 28 to rotate the output rod 30, unlike the conventional example described above, another component for rotating the output rod 30 is provided inside the piston 21. There is no need. Therefore, the outer diameter dimension of the small diameter portion 21a of the piston 21 can be reduced. Therefore, the annular pressure receiving cross-sectional area (effective cylinder area) obtained by subtracting the pressure receiving cross-sectional area of the small-diameter portion 21a from the pressure receiving cross-sectional area of the large-diameter portion 21b of the piston 21 is increased, and the output of the clamping device is increased. Moreover, since another said part can be abbreviate | omitted, the internal diameter of the cylinder hole 20 can be made small, and a compact and small clamp apparatus can be provided. Furthermore, since the above-described separate parts are not necessary, the number of parts is reduced, and the manufacturing cost of the clamping device can be reduced.
In addition, another embodiment described later has the same advantages as described above.

7 to 14 show a modified example and another embodiment of the present invention. In these modified examples and other embodiments, the same members (or similar members) as the constituent members of the first embodiment will be described in principle with the same reference numerals.

FIG. 7 is a partial view similar to FIG. 3 and showing a modification of the first embodiment.
In this modification, an annular spacer (not shown) having a predetermined thickness is inserted between the lower portion of the lower housing portion 7 and the lower end portion of the piston 21. For this reason, as shown in FIG. 7, the tip of the output rod 30 is disposed at a position protruding upward from the seating surface S of the seating block 3 in the released state in which the output rod 30 is retracted downward. Here, in the released state, when the work is lowered, the lower part of the peripheral wall of the female screw hole 12 of the work 10 is received by the shoulder 52 of the bolt 50. At that time, the workpiece 10 is temporarily positioned.
In FIG. 3, instead of providing the annular spacer having the predetermined thickness between the lower portion of the lower housing portion 7 and the lower end portion of the piston 21, the lower end portion of the lower housing portion 7 is replaced with the spacer. You may make it protrude upward by the part.

In this modification, a seating sensing air hole 85 is provided in the seating surface S of the seating block 3. The air hole 85 communicates with the longitudinal path 77 of the upper housing portion 6 through the lateral path 86 of the seating block 3 and the longitudinal path 87 of the jig plate 2. The air hole 85 is closed when the work 10 is brought into contact with the seating surface S of the seating block 3. Therefore, not only the pressure increase due to the contact between the lower end surface of the guide cylinder 15 and the upper surface of the upper thrust bearing 55 but also the pressure increase due to the contact between the workpiece 10 and the seating surface S of the seating block 3 inside the clamp device 4. By detecting simultaneously, it can confirm that the clamp apparatus 4 is a locked state.

FIG. 8 shows another usage pattern of the clamping device according to the first embodiment, and is a cross-sectional view of the main part of the usage pattern, similar to FIG.

In this usage mode, a test pressure fluid can be supplied to the female screw hole 12 of the test object 92.
A hollow rod 93 is connected to the piston 21 instead of the output rod 30 of FIG. A lower portion 43 of the hollow rod 93 is connected to the nozzle 94.

In the state of FIG. 8, the piston 21 is raised and the hollow rod 93 is rotated. As a result, the engagement bolt 50 provided at the upper end of the hollow rod 93 is connected in a sealed manner to the female screw hole 12 of the test object 92. A test pressure fluid such as compressed air is supplied into the DUT 92 through the nozzle 94 and the flow passage 95 in the hollow rod 93.
The female screw hole 12 of the DUT 92 and the male screw portion of the bolt 50 may be tapered screws instead of parallel screws.

9 and 10 show a clamping device according to a second embodiment of the present invention. FIG. 9 is a partial view showing the released state and similar to FIG. FIG. 10A is a cross-sectional view of the ball circulation member provided in the clamp device of FIG. 9 described above. 10B is a cross-sectional view taken along line 10B-10B in FIG. 10A, and FIG. 10C is a cross-sectional view taken along line 10C-10C in FIG. 10A.

The second embodiment differs from the first embodiment in the following points.
An annular ball circulation member 96 is disposed in the lower portion of the upper housing portion 6 of the housing 5. The ball circulation member 96 is fixed to the upper surface of the peripheral wall of the cylindrical hole of the lower housing part 7 by mounting bolts 100. The ball circulation member 96 has a holding hole 96a extending in the radial direction. A circulation path block 97 is provided in the holding hole 96a. An annular retaining ring 99 is mounted on the outer peripheral surface of the ball circulation member 96. The retaining ring 99 serves to stop the circulation block 97 from rotating and temporarily hold the assembly block during assembly.

The ball screw mechanism 28 is configured as follows.
On the outer peripheral surface of the small diameter portion 21a provided on the lower side (base end side) of the piston 21, a plurality of male spiral grooves 57 made of right-hand screws are formed. Further, the female spiral groove 56 is formed in the ball circulation member 96 at almost one pitch. A large number of balls 58 are inserted between the male spiral groove 57 and the female spiral groove 56 so as to freely roll. In addition, a circulation path 59 is formed in the circulation path block 97 so as to make the start end portion and the end end portion of the female spiral groove 56 communicate with each other. Due to the action of the circulation path 59, the ball 58 is allowed to get over the partition wall 60 formed between adjacent groove portions of the male spiral groove 57.

Also, an annular gap 79 is formed between the guide hole 29 and the outer peripheral surface of the output rod 30. As a result, in the clamping device 4 (4b) of the second embodiment, the output rod 30 is movable in the radial direction over the entire circumference. In the clamping system of FIG. It is configured as.

The second embodiment described above has the following advantages.
A plurality of male screw grooves 57 having a plurality of pitches are formed on the outer peripheral surface of the small diameter portion 21a of the piston 21, which is a male-side component of the ball screw mechanism 28. Therefore, the ball screw processing can be easily performed as compared with the case where it is performed on the female part. Further, since the piston 21 as a part of the ball screw mechanism 28 is a small part as compared with the housing 5, it is easy to perform a hardening process such as quenching.
The circulation path 59 is formed in a circulation path block 97 which is a separate part from the housing 5. Therefore, it is easy to process the circulation path 59. Further, by removing the circulation path block 97 from the ball circulation member 96, the operation of assembling and removing the ball 58 from the ball circulation member 96 is easy.
Further, since the ball screw mechanism 28 is disposed in the lock chamber 64, the ball screw mechanism 28 is lubricated by the pressure oil supplied to the lock chamber 64. Therefore, the ball screw mechanism 28 has a low friction and a long life, and does not require maintenance for a long time.

FIG. 11 is a partial view similar to FIG. 9 and showing a modification of the second embodiment.
In this modification, the release state or the locked state of the clamp device 4 is detected by the limit switch 101. The limit switch 101 includes a detection switch 102 in a released state and a detection switch 103 in a locked state, which are arranged at a predetermined interval in the vertical direction (axial direction). The output rod 30 has a protruding portion 104 provided below the base end portion 43. An operation tool 105 is fixed to the lower part of the protruding portion 104. The operation tool 105 operates the

switches

102 and 103 described above.
Note that the released state or the locked state of the clamp device 4 may be detected by a proximity switch, a reed switch, or the like instead of the limit switch.

FIG. 12 is a view showing a modification of the guide cylinder 15 of the present invention.
A guide hole 29 of the guide cylinder 15 is formed in an elliptical shape in plan view, and an output rod 30 is inserted into the guide hole 29. Thus, the projecting

portions

106 and 106 facing in the radial direction are provided on the peripheral wall of the guide hole 29, and the

relief portions

107 and 107 are provided between the projecting

portions

106 and 106.
Therefore, the output rod 30 is configured to be movable in the left-right direction on FIG. 12 with respect to the housing 5 and not movable in the vertical direction on FIG. In other words, the clamping device 4 (4c) of this modification is configured as a so-called diamond-cut clamping device in the clamping system shown in FIG.

When changing the rotational phase of the

protrusions

106 and 106 with respect to the housing 5, the fastening bolt 17 may be removed to change the rotational phase of the guide cylinder 15 relative to the housing 5. Incidentally, as shown in FIG. 4, when eight fastening bolts 17 are used, the rotational phase can be changed every 45 degrees.

Note that the guide hole 29 may be changed to an oblong shape in plan view instead of being formed in an elliptical shape in plan view. Further, instead of the output rod 30 being directly inserted into the guide hole 29 of the guide tube 15, at least one intermediate sleeve may be disposed between the guide hole 29 and the output rod 30. In this case, at least one of the outer peripheral surface of the intermediate sleeve and the guide hole is provided with the protruding

portions

106 and 106 facing in the radial direction, and the

relief portions

107 and 107 are provided between the protruding

portions

106 and 106. . At this time, it is preferable to arrange two intermediate sleeves at predetermined intervals in the vertical direction (axial direction), but it is also possible to arrange only one relatively long one. Two or more may be arranged.

FIG. 13 shows a modification of the engagement bolt 50 of the present invention.
In this modification, the engaging bolt 50 is detachably screwed to the upper end portion of the output rod 30 instead of being integrally provided at the upper end portion (tip end portion) of the output rod 30. Therefore, the screw diameter of the engaging bolt 50 can be easily changed or replaced.

FIG. 14 is a schematic view in plan view of a clamping system using the clamping device of each of the above embodiments.
In this case, the four female screw holes 121, 122, 123, and 124 are diagonally arranged in the workpiece 10, the datum type clamp device 4 a of FIG. 3 is made to correspond to the first female screw hole 121, and the second female screw hole 122 is 9 corresponds to the 12 diamond-cut clamp devices 4c, and the third female screw hole 123 and the fourth female screw hole 124 correspond to the free clamp device 4b of FIG.
The direction in which the protrusions 106 and 106 (see FIG. 12) of the diamond-cut clamping device 4c face each other is set to a direction that prevents the workpiece 10 from rotating around the first female screw hole 121. is there.

Each of the above-described embodiments and modifications can be changed as follows.
The ball screw mechanism 28 and the engaging bolt 50 may be left-hand screws instead of the illustrated right-hand screws.
Either the release state detection unit or the lock state detection unit described above may be omitted, or both may be omitted.
The fixed object of the clamping device according to the present invention may be a jig, a pallet, a mold, an assembled product, or the like, instead of the exemplified workpiece.
The installation posture of the clamp device may be an upside-down posture with respect to the illustrated posture, or may be a horizontal posture or an oblique posture.
In the clamping system, a plurality of

clamp devices

4a, 4b and 4c of the same type may be used, or different types may be used in combination. Good.
The piston of the fluid pressure actuator according to the present invention may not be annular.

Claims

An apparatus for pulling and fixing a fixed object (10) provided with a female screw hole (12) by a screw engaging force of an engaging bolt (50),
The piston (21) can be reciprocated in the axial direction between a cylinder hole (20) provided in the housing (5) and a guide tube (15) provided at the center of the front end of the housing (5). And insert in a rotatable manner,
A ball screw mechanism (28) is provided between the piston (21) and the housing (5);
An output rod (30) is inserted into the cylindrical hole (29) of the guide cylinder (15) and the cylindrical hole (24) of the piston (21) so as to be rotatable and movable in the axial direction, and the output rod (30 ) Is connected to the output portion (42) of the piston (21) so as to be capable of rotational transmission, and the engaging bolt (50) provided at the tip of the output rod (30) is connected to the output portion (42) of the piston (21). A screw engagement type clamping device characterized in that it can be engaged with the female screw hole (12) of the fixed object (10).
The clamping device according to claim 1, wherein
A first working chamber (62) to which a pressure fluid is supplied to retract the output rod (30) to the release position is formed at the distal end side of the piston (21), and the output rod (30) is moved to the lock position. A screw engagement type clamping device characterized in that a second working chamber (64) to which a pressure fluid is supplied in order to advance is formed on the proximal end side of the piston (21).
The clamping device of claim 2,
The pressure receiving cross-sectional area of the piston (21) in the first working chamber (62) is set to a value larger than the pressure receiving cross-sectional area of the piston (21) in the second working chamber (64). Screw engaging clamp device.
The clamping device according to claim 1, wherein
The ball screw mechanism (28) has a female spiral groove (56) formed in a plurality of pitches in the housing (5) and an outer peripheral surface of a small diameter portion (21a) provided on the base end side of the piston (21) at approximately one pitch. And at least one male spiral groove (57) formed, and a plurality of balls (58) inserted between the female spiral groove (56) and the male spiral groove (57) in a rollable manner,
The start and end of the male spiral groove (57) are allowed to allow the ball (58) to get over the partition wall (60) formed between adjacent groove portions of the female spiral groove (56). A screw engagement type clamping device, characterized in that a circulation path (59) communicating with the portion is formed in a concave shape on the outer peripheral surface of the small diameter portion (21a) of the piston (21).
The clamping device according to claim 1, wherein
The ball screw mechanism (28) includes a male spiral groove (57) formed in a plurality of pitches on the outer peripheral surface of the small diameter portion (21a) provided on the base end side of the piston (21), and approximately 1 on the housing (5) side. A pitch formed at least one female spiral groove (56), and a plurality of balls (58) inserted between the male spiral groove (57) and the female spiral groove (56) in a freely rolling manner,
The starting end and the terminal end of the female spiral groove (56) so as to allow the ball (58) to get over the partition wall (60) formed between adjacent groove portions of the male spiral groove (57). A screw engagement type clamping device, characterized in that a circulation path (59) communicating with the portion is formed in a concave shape on the housing (5) side.
The clamping device according to claim 5, wherein
A ball circulation member (96) in which the female spiral groove (56) is formed is disposed in the cylindrical hole of the housing (5), and the circulation path (59) is formed in the ball circulation member (96). A screw engagement type clamping device, characterized in that a circulation path block (97) is provided.
The clamping device according to claim 1, wherein
In the released state in which the output rod (30) is retracted to the base end side, the position where the tip of the output rod (30) is retracted from the seating surface (S) on which the fixed object (10) is supported. A screw-engagement type clamping device, wherein
The clamping device according to claim 1, wherein
A screw engagement type clamping device comprising an advancing means (47) for pressing the output rod (30) toward the female screw hole (12).
The clamping device according to claim 1, wherein
A manual operation portion (44) is provided at a proximal end portion of the housing (5) in a state of being rotatable and prevented from moving in the axial direction, and the output rod (30) is provided at the manual operation portion (44). A screw engagement type clamping device, wherein the base end portion of the screw is inserted so as to be capable of rotational transmission.
The clamping device according to claim 1, wherein
A screw engagement type clamping device, wherein an outer peripheral surface of the engagement bolt (50) is constituted by a multi-threaded screw.
The clamping device according to claim 1, wherein
A screw engagement type clamping device, wherein the ball screw mechanism (28) is constituted by a multi-thread screw.
The clamping device according to claim 1, wherein
An annular ring that allows the output rod (30) to move in the radial direction between the tube hole (29) of the guide tube (15) of the housing (5) and the outer peripheral surface of the output rod (30). A screw-engagement type clamping device characterized in that a gap (79) is formed.
The clamping device according to claim 1, wherein
In the middle of moving the output rod (30) from the release position to the lock position, the output rod (30) is placed in the radial direction in the tube hole (29) of the guide tube (15) of the housing (5). A screw-engagement type clamping device, which is inserted in a state in which movement to is prevented.
The clamping device according to claim 1, wherein
In the middle of moving the output rod (30) from the release position to the locked position, the output rod (30) is inserted into a predetermined hole (29) of the guide cylinder (15) of the housing (5). A screw-engaged clamping device, wherein the screw-engaged clamping device is inserted in a state that prevents movement in a radial direction and allows movement in a radial direction perpendicular to the predetermined radial direction.
A clamping system using at least one screw engagement type clamping device according to any one of claims 12 to 14.
One screw-engaged clamp device according to claim 13 is used, one screw-engaged clamp device according to claim 14 is used, and at least one screw-engaged clamp device according to claim 12 is used. Clamping system.
A clamping system using at least two screw engagement type clamping devices according to claim 12.
The piston (21) is inserted into the cylinder hole (20) provided in the housing (5) so as to be reciprocally movable in the axial direction and rotatable.
A ball screw mechanism (28) is provided between the piston (21) and the housing (5);
The ball screw mechanism (28) includes a male spiral groove (57) formed in a plurality of pitches on the outer peripheral surface of the small diameter portion (21a) provided on the base end side of the piston (21), and approximately 1 on the housing (5) side. A pitch formed at least one female spiral groove (56), and a plurality of balls (58) inserted between the male spiral groove (57) and the female spiral groove (56) in a freely rolling manner,
The starting end and the terminal end of the female spiral groove (56) so as to allow the ball (58) to get over the partition wall (60) formed between adjacent groove portions of the male spiral groove (57). A fluid pressure actuator characterized in that a circulation path (59) for communicating with a portion is formed in a concave shape on the housing (5) side.
The fluid pressure actuator of claim 18,
A first working chamber (62) to which pressure fluid is supplied to retract the piston (21) in the proximal direction is formed on the distal end side of the piston (21), and the piston (21) is advanced in the distal direction. A fluid pressure actuator characterized in that a second working chamber (64) to which a pressure fluid is supplied is formed on the base end side of the piston (21).