JPH0230190Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a clamping device that clamps and holds an object with a pair of opposing clamping plates. The present invention relates to a clamping device that allows tightening of the clamping part and freely changing the position where the clamping part is fixed to the base frame.

[Prior art]

A conventional clamping device that clamps and holds an object with a pair of clamping plates has a pair of clamping plates facing each other on a base frame so as to be movable toward and away from each other. The U-shaft is screw-fitted to each of the clamping plates, and the distance between the clamping plates is changed by rotation of the lead screw shaft.

When using such a clamping device for cutting or drilling, the workpiece is clamped and fixed to the clamping plate by rotating the lead screw shaft, and the clamping device is then fixed at a predetermined position on the bed of the machine tool. However, if the machine tool concerned cannot shift the position of the cutting tool forward, backward, left or right relative to the bed, such as a small drilling machine, the clamping device may be constructed so that the clamping plates are kept at a predetermined distance from the base frame. Since the clamping device cannot be moved parallel or rotationally on the machine tool bed, the clamping device itself must be moved and reinstalled on the bed of the machine tool every time the machining position is changed or the workpiece is replaced. As a result, processing efficiency is significantly reduced.

Furthermore, since clamping and fixing of the workpiece by the clamping device described above is achieved only by the rotational clamping force of the lead screw shaft, if the clamping force is not sufficient, the lead screw may be damaged due to vibrations during machining. The U-shaft became loose and the workpiece was not fully fixed, which could reduce machining accuracy or cause the workpiece to fly off due to the cutting resistance from the blade, potentially resulting in personal injury.

[Problem that the invention attempts to solve]

The above-mentioned conventional clamping device cannot move the clamping plates in parallel or rotationally on the base frame while maintaining the clamping plates at a predetermined interval, and the operability is extremely poor. If the rotational tightening force of the lead screw shaft is insufficient due to caution, etc., there is a problem in that it is difficult to ensure that the object is fixed completely. Therefore, the objective is to obtain good operability and a state in which the object is completely fixed.

[Means for solving problems]

The present invention, as a means to solve the above problems,
An object can be held under pressure by moving a pair of opposing clamping plates toward and away from each other, and a lead screw shaft is attached to one of the clamping plates that can be slid on the bed. At the same time, a cylinder tube that can be rotated concentrically with the tube is provided at a predetermined position on the bed, and a cylinder tube that can rotate integrally with the tube and that can slightly slide in the axial direction is installed inside the cylinder tube. A threaded cylindrical body that is allowed to move and is screwed into the lead screw shaft is provided, and is slidable in the axial direction by fluid pressure at the inner part thereof, and by the sliding movement, the above-mentioned A holding part is formed by airtightly sealing a piston that can project a lead screw shaft together with a threaded cylinder, and the above-mentioned bed is fixed at a desired position on the base frame, and is fixed in one direction by a biasing member. A push rod is built into the casing so that its tip protrudes, and is moved against the elastic force of the biasing member by fluid pressure via the diaphragm. The structure includes a fixing part that is inserted into a relatively large through hole drilled in the frame, and allows the tip of the push rod to engage with the bed, and clamps and fixes the base frame at a desired position by the bed and casing. It is something to be taken.

[Effect]

According to the above-mentioned means, by rotating the cylinder tube and moving the lead screw shaft forward, both clamping plates are brought into contact with the object, and a pressing force in the advancing direction is further applied to the lead screw shaft via the piston. By doing so, the object is held under pressure between both clamping plates. The bed, on which the clamping plates for holding the object under pressure are disposed, is clamped and fixed from the top and bottom of the base frame together with a fixing part provided on the lower surface of the base frame, and when compressed fluid is supplied to the fixing part, The bed, base frame, and fixed portion are released from their mutual locking state and are allowed to move relatively freely.

〔Example〕

FIG. 1 is a schematic perspective view showing a vice according to an embodiment of the present invention.

The vise shown in the figure is used by being fixed to the bed of a machine tool such as a drilling machine (not shown) via a base frame 1. First, the general configuration will be explained based on Fig. 1. A second clamping plate 4 is slidably disposed opposite to the first clamping plate 3 on the bed 2.
The second clamping plate 4 is fixed to the tip of the lead screw shaft 6 which is advanced and moved by the rotation of the rotatable cylinder tube 5 above, and the cylinder tube 5 is rotated to separate the clamping plates 3 and 4. While holding the workpiece by changing the distance of
A gripping portion 7 is provided on the base frame 1 and configured to urge the lead screw shaft 6 to advance further by compressed air supplied to the cylinder tube 5 to further tighten the workpiece. This clamping part 7 has
The compressed air supplied to the cylinder tube 5 is controlled to a predetermined pressure, and the cylinder tube 5
A pressure adjustment unit 9 whose pressure can be arbitrarily set by rotating an adjustment ring 8 provided concentrically with the pressure adjustment unit 9.
combine. Furthermore, a fixing part 10 is provided that can lock the bed 2 placed on the base frame 1 from the bottom side of the base frame 1, and when compressed air is supplied to the fixing part 10, the fixed state is released and the base is fixed. The bed 2 is allowed to move for free positioning on the frame 1, and the fixing state of the clamping part 7 to the base frame 1 is maintained by turning off the supply of compressed air after the positioning.

FIG. 2 is a sectional view showing details of the clamping portion 7. As shown in FIG. In the cross-sectional structure of the inside of the cylinder tube 5 shown in the figure, the upper half shows the state before the piston is urged to advance by compressed air, and the lower half shows the state in which the piston is urged to advance to the maximum extent.

In the figure, reference numeral 4 denotes the second clamping plate which is slidable on the bed 2, and the clamping plate 4 is screwed to the left end of the lead screw shaft 6.

Reference numeral 5 designates the cylinder tube fixed to the flange portion of the stepped cylindrical housing block 15 by screw fitting, and by pivoting the boss portion of the housing block 15 to the holder 16 fixed to the bed 2, the cylinder The tube 5 is rotatably supported concentrically with the lead screw shaft 6. A stop ring 17 that comes into contact with the end surface of the holder 16 is fitted onto the outer periphery of the boss portion of the housing block 15 protruding from the holder 16 to prevent the housing block 15 from falling off from the holder 16.

Reference numeral 18 denotes a threaded cylindrical body which is threadedly fitted to the lead screw shaft 6 in the cylinder of the cylinder tube 5. On the outer periphery of the threaded cylindrical body 18, a threaded cylindrical body is formed along the inner periphery of the housing block 15 in the axial direction. A key 20 that can be loosely fitted into a keyway 19 is fixed. The threaded cylindrical body 18 is rotated integrally with the cylinder tube 5 via the key 20, so that the lead screw shaft 6 that is threaded thereon can be moved forward and backward relative to the threaded cylindrical body 18, and By sliding the key 20 together with the cylinder body 18 in the key groove 19, the lead screw shaft 6 can be moved forward and backward together with the screw cylinder body 18.

In order to move the lead screw shaft 6 forward and backward together with the threaded cylinder 18, the inside of the cylinder tube 5 has a multi-stage cylinder structure.

Therefore, first, in the cylinder of the cylinder tube 5, 25 is a thin inner diameter portion 25 having approximately the same outer diameter.
A and a thick inner diameter part 25B are formed concentrically, and 26 is a boss part 26A and a flange part 2.
6B and a through hole 26C, which are concentric with each other. The cylinder 25 and the piston 26 are mutually connected to the thick inner diameter portion 25B of the cylinder 25.
The boss portion 26A of the piston 26 is slidably fitted into the cylinder 25, and the flange portion 26B of the piston 26 is slidably fitted into the thin inner diameter portion 25A of the cylinder 25, so that four stages having the same structure are arranged in series. It is inserted into the cylinder of the cylinder tube 5. 2
Reference numeral 7 denotes a boss portion 27A that fits into the through hole 26C of the piston 26 and a thin inner diameter portion 25 of the cylinder 25.
It is a disc-shaped end piston comprising a flange portion 27B that is slidably fitted into A, and functions as a first-stage piston. The through hole 26C of the piston 26 functions as a through hole for the lead screw shaft 6, and can be loosely fitted onto the same shaft 6.

Reference numeral 28 denotes a head cover inserted into the inner periphery of the right-hand opening end of the cylinder tube 5, which covers the four-stage cylinder 25 inserted into the cylinder of the cylinder tube 5 in the left-right direction between it and the right-hand end surface of the housing block 15. The right end surface of the head cover 28 is positioned and fixed by a stop ring 30 fitted and fixed to the cylinder tube 5 so as to abut and fix each other.

Reference numeral 31 denotes a compression coil spring provided between the housing block 15 and the threaded cylinder body 18. The spring 31 elastically biases the threaded cylinder body 18 in the right direction with respect to the housing block 15, thereby The stage piston 26 and the first stage end piston 27 are integrally pressed and biased to the right. Piston 26 and end piston 2 that are biased to press
In order to apply fluid pressure to the head cover 7 to resist the pressing force, a pressure adjusting section 9 is provided at the center of the head cover 28.
By combining these, compressed air can be supplied into the cylinder tube 5.

Here, the compressed air supplied into the cylinder of the cylinder tube 5 is transferred to the piston 26 and the end piston 2.
7 is constructed between the inner peripheral surface of the cylinder tube 5 and the outer peripheral surface of the cylinder 25.

Therefore, first of all, the head cover 28 has a third
As shown in the figure, there are two stepped portions 28A and 2 smaller than the maximum outer diameter on the left end surface.
8B, and a groove 28C is provided in the diametrical direction across the stepped portion in order to guide the compressed air supplied from the pressure adjustment portion 9 toward the outer circumference. In addition, the left side end surface of each cylinder 25 is also provided with 2
In addition to forming step stepped portions 25C and 25D, a chamfered portion 25E along the axial direction is provided on the circumferential side of the maximum outer diameter portion, and the inner circumference of the cylinder tube 5 is formed by the chamfered portion 25E and stepped portion 25C. A compressed air flow path is formed between the surface and the surface. The compressed air supplied from the pressure adjustment unit 9 to this flow path via the stepped portion 28A of the head cover 28 is supplied through a half-moon-shaped through hole 25F that communicates the two stepped portions of each cylinder 25. It is guided into the opposing space between the left end surface of the cylinder 25 and the right end surface of the flange portion of the piston 26, which acts as a pressing force on the piston 26 in the advancing direction against the biasing force of the compression coil spring 31. Such a pressing force is transmitted to the lead screw shaft 6 via the threaded cylinder 18, and becomes a force that presses the coaxial shaft 6 in the advancing direction.

The compressed air is transferred to the piston 26 and the end piston 2.
In order to prevent leakage of the compressed air and regulate the flow path in the circuit leading to the cylinder 7, O-rings 32 and 33 are fitted between the cylinder tube 5, the housing block 15, and the head cover 28, respectively, and O-rings 32 and 33 are fitted between the cylinder 25 and each piston. 26 and end piston 2
7 and the piston seal 34 such as an O-ring.
Thereby, airtightness is maintained in the opposing space between the left end surface of the cylinder 25 and the right end surface of the flange portion of the piston 26, and in the opposing space between the left end surface of the head cover 28 and the right end surface of the end piston 27. In addition, the end piston 27 and the piston 2
Exhaust holes 27C and 26D are formed in the left end surface of each of the pistons 6 in the axial direction, thereby creating a space between the left end surface of the end piston 27 and the cylinder 25, and a space between the left end surface of the piston 26 and the cylinder 25. is communicated with the through hole 26C of the piston 26, so that when the piston 26 and the end piston 27 slide relative to the cylinder 25, intake and exhaust are performed in such a way that no negative pressure is generated in the opposing space. .

The clamping portion 7 configured as described above has the end piston 27 resiliently biased by the compression coil spring 31 in a state where compressed air is not supplied.
is in contact with the head cover 28, and assumes the state shown in the upper cross-sectional structure of the inside of the cylinder tube 5 in FIG. To clamp the workpiece placed on the bed 2, turn the cylinder tube 5 in a predetermined direction in that state and rotate the lead screw shaft 6 until the opposing surfaces of both clamping plates 3 and 4 come into contact with the workpiece. Advance and move. At this time, there is no need to further turn the cylinder tube 5 to tighten it.

Next, when compressed air is supplied into the cylinder of the cylinder tube 5 through the pressure regulator 9, the compressed air is formed between the inner circumferential surface of the cylinder tube 5 and the outer circumferential surface of the cylinder 25 from the inner surface of the head cover 28. The piston is guided through a passageway into a space where the left end surface of the head cover 28 and the right end surface of the end piston 27 face each other, and into a space where the left end surface of the cylinder 25 and the right end surface of the flange portion of the piston 26 face each other. When compressed air is introduced into these opposing spaces that are kept airtight, the compressed air exerts a pressing force in the advancing direction against the biasing force of the compression coil spring 31 on the piston 26 and the end piston 27, respectively. The pressing force is transmitted to the lead screw shaft 6 via the threaded cylinder 18, which is allowed to slide in the axial direction by the key 20, and becomes a force that presses the coaxial shaft 6 in the advancing direction. As a result, the second clamping plate 4 receives the pressing force and clamps and fixes the workpiece between it and the first clamping plate 3. To release the clamping and fixing state of the workpiece, operate the pressure regulator 9 to cut off the supply of compressed air to the cylinder tube 5 and return the inside of the tube 5 to atmospheric pressure.
It is only necessary to release the pressing state of the workpiece by the second clamping plate 4, and thereby the workpiece can be removed from the bed 2 as it is, and if necessary, the lead screw shaft 6 can be moved back. The second clamping plate 4 may be separated from the workpiece by rotating the cylinder tube 5 in the direction shown in FIG.

According to the clamping part 7, a predetermined clamping force can be obtained by the pressing force of the piston 26 and the end piston 27, regardless of the rotational clamping force of the cylinder tube 5, and the clamping force can be applied to the five-stage piston. 26 and the end piston 27, so that a stable and sufficient fixed state can be achieved regardless of the rotational tightening force of the cylinder tube 5. Furthermore,
The piston 26 and the end piston 27 extend from the position where the end piston 27 abuts the head cover 28 to the position where the piston 26 abuts the housing block 15, as shown in the vertical cross-sectional structure inside the cylinder tube 5 in FIG. Since it is possible to integrally slide and move within the range of the maximum stroke S, even if the state of contact of the second clamping plate 4 with the workpiece is incomplete, as long as it is within the range of the maximum stroke S. , it is possible to clamp and fix the workpiece in a normal state.

FIG. 4 is a sectional view showing details of the pressure adjusting section 9. As shown in FIG.

In the figure, reference numeral 40 denotes a joint screwed to the center of the head cover 28 of the cylinder tube 5, and a stepped cylindrical front case 41 is pivotally supported on the stepped outer periphery of the joint 40, and the stepped cylindrical front case 41 is further attached to the inner periphery of the front case 41. Stepped cylindrical rear case 4
2 by screw-fitting and fixing the pressure adjusting part 9.
It constitutes the outer cylindrical body of.

The joint 40 is provided with a fluid passage 43 that communicates the inside of the cylinder of the rear case 42 and the cylinder of the cylinder tube 5 with each other, and the corner edge of the fluid passage 43 is formed into a conical surface 45 that can be closed with a valve ball 44. A bush 47 in which a slider 46 is loosely fitted so as to be slidable in the vertical direction is fitted directly above the conical surface 45 in FIG. A compression coil spring 49 is interposed, an O-ring 50 is fitted to the upper part of the collar 48, and a cushion 51 made of an elastic material such as rubber is fixed to the lower end of the slider 46.

The upper end of the slider 46 protrudes from the outer periphery of the joint 40, and a groove cam 52 is provided on the inner peripheral surface of the front case 41 to abut against the upper end of the slider 46 and displace the slider 46 in a sliding manner. . This groove cam 5
2 is eccentric with respect to the inner circumferential surface of the front case 41, and has an exhaust hole 53 communicating with the outer circumferential surface of the front case 41 in a part thereof, as shown in FIG. The state of the slider 46 shown in FIG. 4 is such that its upper end is at the deepest position of the grooved cam 52, at which time the cushion 51 is separated from the valve ball 44, and the fluid passage 43
The path from the O-ring 50 to the exhaust hole 53 is
occluded by At this time, the rear case 42
When compressed air is being supplied to the fluid passage 43 from the side, the valve ball 44 floats upward in FIG. 7
will be available for supply. On the other hand, when the front case 41 is rotated relative to the joint 40 to bring the upper end of the slider 46 to the shallowest position of the grooved cam 52, the cushion 51 presses the valve ball 44 against the conical surface 45 and fixes it. At the same time, the passage from the fluid passage 43 to the exhaust hole 53 is released from being blocked by the O-ring 50, thereby cutting off the supply of compressed air to the cylinder tube 5, and The inside of the cylinder tube 5 is returned to atmospheric pressure via the exhaust hole 53.

Reference numeral 55 denotes a lock ball elastically biased so as to be able to come out and retract from the left end surface of the flange portion of the joint 40, and a pair of conical lock holes 56 and 57 into which the lock ball 55 can be inserted are provided in the front case 41 as shown in FIG. A circular arc groove 58 is formed at both ends of the inner end surface. The arcuate groove 58 is connected to the joint 4 by the lock ball 55 coming into contact with both edges thereof.
When the lock ball 55 comes into contact with the upper edge of the arcuate groove 58 in FIG. The upper end of the mover 52 is at the deepest position of the grooved cam 52, thereby maintaining the compressed air supply state to the cylinder tube 5 described above. Also,
When the lock ball 55 comes into contact with the lower edge of the arcuate groove 58 in FIG.
At this time, the upper end of the slider 52 takes the shallowest position of the grooved cam 52, thereby maintaining the above-mentioned exhaust state in the cylinder tube 5.

Reference numeral 60 denotes a nipple that is hermetically sealed by screwing into the right opening of the rear case 42, and receives compressed air from an external air source (not shown). In the cylinder of the rear case 42, the nipple 60 is
A valve body 62 having a gasket 61 at its tip is housed so as to be able to protrude and retract in the axial direction under the advancing force of a compression coil spring 63, and is a bottomed cylindrical shape that abuts the gasket 61 of the valve body 62 and has an opening at one end. The valve seat 64 is hermetically sealed to the nipple 60 by screw fitting so that the tip of the nipple 60 is fitted over the valve seat 64. Here, the accommodating portion for accommodating the valve body 62 in the nipple 60 includes a fitting hole 66 into which the valve body 62 is slidably inserted;
The fitting hole 66 has a plurality of linear grooves 67 provided along the axial direction on the inner peripheral surface thereof, and the compressed air supplied through the nipple 60 passes through the linear grooves 67 to the gasket 61 and the valve seat 64. The abutment part is guided outward. A plurality of annular through-holes 68 with relatively small inner diameters that form compressed air passages are bored in the bottom of the valve seat 64 located inside the contact area between the gasket 61 and the valve seat 64, and in the center thereof, A coil spring 63 contacts the center of the valve body 62 and compresses the valve body 62.
A pin 69 that can be expanded in the axial direction against the urging force of is slidably fitted.

An actuator 70 controls the opening and closing of the valve body 62 by pressing the pin 69 and displacing it in the axial direction, and has a bottomed cylindrical shape with an opening at one end, through which the cylindrical portion is inserted. The valve seat 64 is slidably and loosely fitted onto the outer periphery of the valve seat 64, and a boss portion protruding outward from the bottom thereof is slidably and loosely fitted into the joint 40, and each sliding surface is fitted with an O-ring 71.
and 72, airtightness is maintained. A plurality of through holes 73 are annularly bored in the boss portion of the actuator 70 outside the contact portion with the pin 69, and the compressed air is introduced into the fluid passage 43 of the joint 40 through the holes 73. The actuator 70 receives a rightward biasing force from the compression coil spring 74, and the pressure in the valve chamber 75 surrounded by the cylindrical portion of the actuator 70 is caused by the biasing force of the compression coil spring 74. When the pressure is below a determined critical value, the valve body 42 is pushed to the right via the pin 69 to separate the gasket 61 and the valve seat 64, thereby allowing compressed air to flow into the valve chamber 75. Valve chamber 7
When the pressure at 5 increases, the actuator 70 moves against the elastic force of the compression coil spring 74 due to the pressure, and when the pressure exceeds a critical value, the actuator 70 moves so that the packing 61 moves against the valve seat 64. The valve chamber 75 is moved back to a position where it can come into contact with the valve chamber 75, thereby blocking the inflow of compressed air and suppressing the pressure increase in the valve chamber 75. Furthermore, when the pressure in the valve chamber 75 becomes equal to or less than the critical value from this state, the actuator 70 moves the valve body 62 to the right via the pin 69 as described above to separate the packing 61 and the valve seat 64, and Compressed air is allowed to flow into the valve chamber 75 until the pressure at the valve chamber 75 reaches a critical value. Such a valve body 6 by the actuator 70
2, the compressed air supplied to the clamping portion 7 is maintained at a predetermined pressure.

Reference numeral 80 denotes a spring seat ring that locks one end of the compression coil spring 74 at the stepped inner diameter portion, and as shown in FIG. A pair of protrusions 8 that can be loosely fitted into notches 42A and 42B of a predetermined width formed in the axial direction from the inner circumferential surface to the outer circumferential surface of the
2 and 83 are provided, and both such protrusions 82 and 83 are loosely fitted into the notches 42A and 42B,
By loosely fitting the ring 81 into the inner diameter part of the rear case 42, the spring seat ring 80 can be attached to the rear case 4.
Sliding movement is allowed within the cylinder of No. 2 while rotation is restricted. At this time, the projections 82 and 83 have a height that allows them to protrude from the outer peripheral surface of the central annular groove 42C of the rear case 42, and the rear case 42 is screwed into the front case 41 on the outer periphery of the projections 82 and 83. External thread 8 equal to the mating external thread 42D
form 4.

8 has its inner circumferential surface screwed into the male thread 84 of the spring seat ring 80 and abuts against the opposing end surfaces of the rear case 42 and front case 41, which are screwed and fixed to each other. According to the direction and amount of rotation, the spring seat ring 80 screwed into it is displaced in the axial direction, and the displacement is controlled via the compression coil spring 74. A resilient force corresponding to the amount is applied to the actuator 70. Therefore, the critical pressure of the valve chamber 75, which serves as a reference for controlling the opening and closing of the valve body 62 described above, can be arbitrarily set by rotating the adjustment ring 8.

Reference numeral 85 denotes an indicator needle fixedly protruding from the end surface of the spring seat ring 80 in the axial direction, and can be slidably fitted into an axial through hole 87 communicating with a window 86 bored on the outer periphery of the rear case 42. A length corresponding to the amount of displacement of the spring seat ring 80 is exposed through the window 86.
The length of the indicator needle 85 exposed in the window 86 is proportional to the rotation speed and rotation angle of the adjustment ring 8. ring 8
Appropriate scales 88 are attached, such as numerical values corresponding to the critical pressure of the valve chamber 75, which can be set by rotating the valve chamber 75.

In the pressure adjustment unit 9 configured as described above, when compressed air is not supplied from an air source (not shown) through the nipple 60, the actuator 70 receives the elastic biasing force of the compression coil spring 74 through the pin 69. A state is adopted in which the valve body 62 is separated from the valve seat 64. In this state, the nipple 60
When compressed air is supplied from the valve chamber 75 , the linear groove 67 and the through hole 68 guide the compressed air to the valve chamber 75 . As the pressure in the valve chamber 75 increases, the actuator 70
receives the pressure and retreats to the left against the elastic force of the compression coil spring 74, and when the pressure reaches the critical pressure, the actuator 70 is moved so that the gasket 61 is in the valve seat as shown in FIG. The valve body 62 is moved back to the left until it comes into contact with the valve body 64, thereby blocking the inflow of compressed air and suppressing the pressure increase in the valve chamber 75. Furthermore, when the pressure in the valve chamber 75 becomes lower than the critical pressure from this state, the actuator 70
is moved to the right by the elastic force, separating the packing 61 and the valve seat 64, and causing compressed air to flow into the valve chamber 75 until the pressure in the valve chamber 75 reaches a critical value. The valve body 6 with such an actuator 70
By repeating the opening/closing control operation No. 2, the compressed air supplied to the clamping portion 7 can be maintained at a predetermined pressure.

In connection with the clamping operation in the clamping section 7, both clamping plates 3 and 4 are moved by rotating the cylinder tube 5 and moving the lead screw shaft 6 forward.
When applying the front case 41 to the workpiece, the front case 41 is rotated relative to the joint 40, and the lock ball 55 is fitted and fixed in the lock hole 57. As a result, the upper end of the slider 46 takes the shallowest position of the grooved cam 52, and the valve ball 44 is pressed and fixed against the conical surface 45 via the cushion 51, thereby closing the fluid passage 43. The passage from the fluid passage 43 to the exhaust hole 53 is released from being blocked by the O-ring 50, and as a result, the supply of compressed air to the cylinder tube 5 is cut off and the inside of the cylinder tube 5 is brought to atmospheric pressure. The condition inside the cylinder tube 5 at this time is as shown in the upper cross-sectional structure of the inside of the cylinder tube in FIG. After completing the operation of abutting the holding plates 3 and 4 against the workpiece, the front case 41 is relatively rotated in the opposite direction to the above, and the lock ball 55 is fitted and fixed in the lock hole 56. As a result, the upper end of the slider 46 is connected to the grooved cam 5.
By adopting the deepest position of 2, the cushion 51
is spaced apart from the valve ball 44 and the fluid passage 43
The path from the air to the exhaust hole 53 is closed by the O-ring 50, and as a result, the compressed air guided to the fluid passage 43 through the valve chamber 75 causes the valve ball 44 to float under the pressure and the cylinder tube 5
flows into the cylinder. When compressed air flows into the cylinder tube 5, as described above, the pressure acts on the piston 26 and the end piston 27 to press the lead screw shaft 6 in the advancing direction, and the second clamping plate 4 receives the pressing force. A state in which the workpiece is clamped and fixed between the first clamping plate 3 is achieved. To release the clamped and fixed state of the workpiece, turn the front case 41 in the opposite direction to the above to cut off the supply of compressed air to the cylinder tube 5, and at the same time, move the inside of the tube 5 through the exhaust hole 53. Just return it to atmospheric pressure.

The force for fixing the workpiece in the clamping device 7 is proportional to the pressure of the compressed air supplied from the pressure adjustment section 9, and the pressure changes depending on the material of the workpiece, the degree of machining, etc. Set by manual operation. First, in order to increase the fixing force, the spring seat ring 80 is moved to the right, and the adjustment ring 8 is rotated in a direction that increases the elastic biasing force of the compression coil spring 74. In this case, the critical pressure of the valve chamber 75 becomes higher, which becomes the pressure reference for the opening/closing control of the valve body 62 and the valve seat 64, that is, the reference pressure for the pressure control by the actuator 70, so that the compressed air supplied to the cylinder tube 5 becomes higher. As the steady pressure increases, the fixing force increases. To reduce the fixing force, perform the operation opposite to the above. When the adjustment ring 8 is rotated, the indicator needle 85 is exposed to the window 86 by a length corresponding to the amount of rotation.
The adjustment ring 8 may be rotated until the tip of the adjustment ring 5 reaches a predetermined scale 88.

FIG. 7 is a sectional view showing details of the fixing part 10.

Reference numeral 90 designates a disc-shaped bottom casing, which has an annular groove 91 on its upper surface through which compressed air flows in from an air source (not shown), and a top casing 93 on which a sheet-shaped diaphragm 92 extends outward from the annular groove 91. The casings 90, 93 and the diaphragm 92 are fixed with screws so as to keep their contact surfaces airtight.

Reference numeral 94 denotes a push rod built into the space formed between the upper surface of the diaphragm 92 and the inner surface of the top casing 93 to allow slight vertical movement within the space. The pressure receiving part 95 forms a disk-shaped pressure receiving part 95 that contacts over a wide range, and the pressure receiving part 95 is elastically biased by a disc spring 96 inserted between the upper surface of the part 95 and the downward inner surface of the top casing 93, and the diaphragm 9
It comes into contact with the top surface of 2. The upper end of the push rod 94 protrudes from the top casing 93 and is inserted into a relatively large through hole 9 formed in the center of the base frame 1.
It reaches above 7.

98 is a rectangular long lock plate with a downwardly convex cross section, the center of which is pivoted to the upper end boss portion 99 of the push rod 94;
A stop disk 100 for preventing the lock plate 98 from falling off is fixed to the upper surface of the boss portion 99 with a screw, and the lock plate 98 is prevented from rotating relative to the push rod 94 and sliding slightly in the vertical direction. I'm starting to tolerate it. In addition, in order to prevent the push rod 94 from rotating within both casings 90 and 93 when the lock plate 98 is rotated relative to the push rod 94, the pressure receiving portion is attached to the pin 101 that protrudes downward within the top casing 93. 95 is slidably fitted and supported. Further, in order to prevent the lock plate 98, which is allowed to slide slightly up and down relative to the push rod 94, from wobbling, a disc spring 102 is interposed between the lock plate 98 and the stop disk 100.

Reference numeral 103 denotes a sliding groove having a downwardly convex cross section and formed on the bottom side of the bed 2 along the longitudinal direction, and is almost similar in shape to the lock plate 98, with the plate 98 extending in the longitudinal direction. It is slidably inserted along the . Such lock plate 9
The downward step portion 104 of No. 8 is in contact with the upward step portion 105 of the sliding groove 103 . When compressed air is not supplied to the lower surface of the diaphragm 92 as shown in FIG. The thickness is set to be smaller than the thickness dimension from the top to the bottom surface of the base frame 1, so that the downward stepped portion 104 of the lock plate 98 and the top casing 9
The upper surface of the base frame 1 fixes the base frame 1 and the bed 2 to each other by pinching the upward stepped portion 105 of the sliding groove 103 and the lower surface of the base frame 1 by the resilient force of the disc spring 96. diaphragm 92
By supplying compressed air to the underside of the push rod 94
When the lock plate 98 is raised to the maximum limit regulated by the inner surface shape of the top casing 93 against the biasing force of the disc spring 96, the downward stepped portion 104 of the lock plate 98
The distance from to the top surface of the top casing 93 is
The thickness dimension from the upward stepped portion 105 of the sliding groove 103 to the lower surface of the base frame 1 is increased to a greater extent, and thereby the base frame 1 is formed by the downward stepped portion 104 of the lock plate 98 and the upper surface of the top casing 93. and release the bed 2 from its fixed state.

According to the fixing part 10 configured as above, when compressed air is supplied to the lower surface of the diaphragm 92,
Since the clamping force of the base frame 1 and the bed 2 between the downward stepped portion 104 of the lock plate 98 and the upper surface of the top casing 93 is released, the bed 2 can be fixed to the base within the range in which the push rod 94 can move within the through hole 97. The bed 2 can be slid and rotated to any position relative to the frame 1, and can also be slid and moved relative to the lock plate 98 along its longitudinal direction. The bed 2 can be set at any appropriate position and orientation over a wide range. Therefore, once the base frame 1 has been fixed to the bed of a machine tool such as a drilling machine, when changing the machining position or replacing the workpiece, it is only necessary to supply compressed air to the fixing part 10. The clamping part 7 can be changed to a desired position on the base frame 1, and there is no need to fix the vise itself to a new position each time, thereby significantly improving processing efficiency. Furthermore, since the fixing part 10 fixes the bed 2 and the base frame 1 when the supply of compressed air is cut off, there is a risk that the fixing state will loosen during processing. This can significantly reduce the amount of damage compared to a structure that achieves this condition, contributing to improved safety.

Note that the present invention is not limited to the above-mentioned embodiments, and can be modified in various ways without departing from the gist thereof. For example, although the holding portion 7 of the above embodiment has a cylinder structure having five stages of pistons inside its cylinder tube, the number of stages may be greater or less than that. Furthermore, although the compressed air flow path inside the cylinder tube is configured by providing a chamfered portion on the outer circumferential surface of the cylinder, it may be configured by providing a straight groove along the axial direction on the inner circumferential surface of the cylinder tube. . Furthermore, in the above embodiment, the pressure adjustment section is used to return the inside of the cylinder tube to atmospheric pressure, but if such a pressure adjustment section is not used, the inside of the cylinder tube can be A valve operable to communicate with atmospheric pressure may be provided. In that case, the pressure adjustment section may be changed to a type that controls the opening and closing of the pressure control valve based on the imbalance between the pressure through the diaphragm and the elastic force of the spring, or the pressure may be adjusted directly on the air source side. It is also possible to do this.

Further, although the above embodiment is a vise, it is also possible to modify the base frame of the same example and fix it to the bed or main frame of a machine tool to configure it as a dedicated device for the machine tool. Also,
Although the clamping part and the fixing part have a structure in which they operate by being supplied with compressed air as a compressed fluid, they can also be changed to a structure applicable to hydraulic pressure.

[Effect of idea]

The clamping device of the present invention rotates the cylinder tube to move the lead screw shaft forward and abut the pair of clamping plates against the object. By applying further pressing force, the object is clamped and held between both clamping plates, so the specified clamping and fixing force can be reliably obtained by the pressing force of the piston, regardless of the rotational clamping force of the cylinder tube. Therefore, there is no risk that the fixing state of the object will loosen during processing, reducing machining accuracy, or that the object will fly off, causing personal injury, and it is possible to achieve a stable and sufficient fixing state of the object.

In addition, the bed, which is equipped with a pair of clamping plates that clamp and hold the object, can be elastically loaded from the top and bottom of the base frame together with a fixing part provided on the bottom surface of the base frame through a relatively large through hole. The fixed state of the bed and base frame is released when the bed and base frame are clamped and fixed by force, and compressed fluid is supplied to the fixed part to resist the elastic force. When released, the bed can be set in any suitable position and in any suitable orientation over a wide range on the base frame, thereby once the base frame is fixed on the bed of a machine tool such as a drilling machine. Afterwards, when changing the processing position for the workpiece or replacing the workpiece, the clamping part can be moved to the desired position on the base frame by simply supplying compressed air to the fixed part, and each time the clamping device itself There is no need to re-fix it in a new position, and the work efficiency can be significantly improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the clamping device according to the present invention. Figure 1 is a schematic perspective view showing the entire vise, and Figure 2 shows details of the clamping part, with the upper half inside the cylinder tube being shown in detail. The lower half is a sectional view showing the state before the piston is urged forward by compressed air, and the lower half is a sectional view showing the state where the piston is urged forward to the maximum extent. Figure 3 is an exploded perspective view showing the detailed cylinder structure inside the cylinder tube. , FIG. 4 is a sectional view showing details of the pressure adjustment section, FIG. 5 is a perspective view of a joint included in the pressure adjustment section, FIG. 6 is an exploded perspective view showing the mounting structure of the adjustment ring, and FIG. 7 FIG. 2 is a cross-sectional view showing details of the fixing part. 1...Base frame, 2...Bed, 3...
First clamping plate, 4... Second clamping plate, 5... Cylinder tube, 6... Lead screw shaft, 7... Clamping part, 8... Adjustment ring, 9... Pressure adjustment part, 1
0... Fixed part, 18... Threaded cylinder, 25... Cylinder, 26... Piston, 27... End piston, 28... Head cover, 40... Joint, 41... Front case, 42... Rear case , 60...Nitspur, 61...Patsukin, 62
... Valve body, 64 ... Valve seat, 70 ... Actuator, 74 ... Compression coil spring, 80 ... Spring seat ring, 84 ... Male thread, 85 ... Indicator needle, 86 ... Window, 90 ... bottom casing, 9
2...Diaphragm, 93...Top casing, 94...Push rod, 95...Pressure receiving part,
96...Disc spring, 97...Through hole, 98...Lock plate, 103...Sliding groove.

Claims (1)

[Scope of utility model registration request] An object can be held under pressure by moving a pair of opposing clamping plates toward and away from each other, and a lead screw shaft is attached to one of the clamping plates that can be slid on the bed. At the same time, a cylinder tube that can be rotated concentrically with the tube is provided at a predetermined position on the bed, and a cylinder tube that can rotate integrally with the tube and that can slightly slide in the axial direction is installed inside the cylinder tube. A threaded cylindrical body that is allowed to move and is screwed into the lead screw shaft is provided, and is slidable in the axial direction by fluid pressure at the inner part thereof, and by the sliding movement, the above-mentioned A holding part is formed by airtightly sealing a piston that can project a lead screw shaft together with a threaded cylinder, and the above-mentioned bed is fixed at a desired position on the base frame, and is fixed in one direction by a biasing member. A push rod is built into the casing so that its tip protrudes, and is moved against the elastic force of the biasing member by fluid pressure via the diaphragm. The fixing part is inserted into a relatively large through hole drilled in the frame, the tip of the push rod can be engaged with the bed, and the base frame is clamped and fixed at a desired position by the bed and casing. Features a clamping device.