JP5524034B2 - Chuck device - Google Patents

Description

  The present invention relates to a retractable chuck device used for a lathe or the like.

  An example of a retractable chuck device used for a lathe is shown in FIG. These retractable chuck devices 1 hold the workpiece w concentrically with the chuck body 2 while retracting. Generally, a gripping claw (jou) 3 provided at the front portion of the chuck body 2 is moved in the radial direction by the advancement / retraction of the draw bar 8 and the like, and the outer periphery or inner periphery of the workpiece w is gripped by the gripping claw 3.

  In the configuration of the apparatus, a plurality of gripping claws 3 are provided radially around the axis 6 of the chuck body 2. A draw bar 8 concentric with the shaft center 6 is provided along the shaft center 6 of the chuck body 1 so as to be able to advance and retract in the axial direction.

  The chuck body 2 is formed with the same number of inclined holes 9 as the gripping claws 3 that gradually spread from the rear toward the front toward the outer diameter side, and the shaft-shaped master jaw 5 is fitted in each of the inclined holes 9. It fits. Each gripping claw 3 is provided at the front end of the master jaw 5, and the master jaw 5 provided with the gripping claw 3 is slidable along the length direction of the inclined hole 9.

  The draw bar 8 is connected to the actuator 4 via a draw bar connecting member (draw bar bolt) 8a. The protrusion 4a provided on the outer diameter portion of the actuator 4 engages with the engagement groove 5a provided on the inner diameter portion of the master jaw 5, and the master jaw 5 and the actuator 4 are coupled so as not to be relatively movable in the axial direction. Has been.

When the draw bar 8 is retracted in the axial direction with respect to the chuck body 1, the master jaw 5 is pulled backward via the actuator 4. When the master jaw 5 is pulled rearward, the gripping claws 3 move inward in the radial direction, the gripping claws 3 grip the outer periphery of the workpiece w, and the workpiece w is gripped concentrically with the central shaft 6.
At that time, the rear surface of the workpiece w is brought into close contact with the front surface 7a of the stopper 7 provided on the chuck body 2, and the rear surface of the workpiece w functions as a reference surface due to the adhesion, so that the workpiece w is correctly positioned and correctly gripped. The posture is maintained (see, for example, Patent Documents 1, 2, and 3).

  The draw bar 8 is advanced and retracted in the axial direction by a draw bar driving mechanism provided outside the chuck body 2. As this draw bar drive mechanism, for example, by applying hydraulic pressure to a hydraulic cylinder provided outside the chuck body 2, a piston provided in the hydraulic cylinder is advanced and retracted, and the draw bar 8 is operated in conjunction with the advance and retreat of the piston. is there.

  Further, in the configuration including the master jaw 5 that operates in accordance with the movement of the draw bar 8 in the axial direction, a fluid pressure circuit is disposed in the chuck body 2, and the fluid supplied through the fluid pressure circuit is supplied to the master jaw 5. Alternatively, by directly acting on a member that can move integrally with the master jaw 5 and moving the master jaw 5 in the axial direction, the pull-in amount of the gripping claw 3 based on the operation of the draw bar 8 can be adjusted. There are some (see, for example, Patent Document 4).

JP 2008-221365 A JP 2002-103109 A JP 2000-343307 A JP 2006-123038 A

  According to the retractable chuck device 1 shown in FIG. 5, the shaft-like master jaw 5 fits slidably in the inclined hole 9 formed in the chuck body 2. The actuator 4 that moves in the axial direction together with the draw bar 8 moves the master jaw 5 in the inclined hole 9 and moves the gripping claws 3 in the radial direction.

  However, according to the retractable chuck device 1, a moment is gradually applied to the master jaw 5 by gripping the workpiece w by the gripping claws 3, and the chuck body 2 counters the moment. This is because the outer surface of the master jaw 5 and the inner surface of the inclined hole 9 slide. For this reason, since it opposes a big moment, there exists a tendency for the chuck body 2 to enlarge. It is not preferable that the apparatus is enlarged.

  Further, according to the retractable chuck device described in FIG. 5 or Patent Documents 1 to 4, the draw bar 8 is used as means for driving the actuator 4, so that the type and application of the retractable chuck device 1 are used. Depending on the situation, it may be assumed that a slight distortion that may occur in the draw bar 8 affects the centering of the workpiece w. This is because the drawbar 8 reaches a drawbar drive mechanism provided outside the chuck body 2 and thus has to be a member having a certain length along the axial direction of the chuck body 2.

  Therefore, depending on the type and application of the retractable chuck device 1, the pressure of the fluid supplied to the fluid circuit disposed in the chuck body 2 without using the draw bar 8 as means for operating the gripping claws 3, that is, In some cases, it may be desirable to move the actuator 4 in the axial direction by fluid pressure.

  However, if the actuator 4 is operated only by the fluid pressure of the fluid circuit in the chuck body 2, the pressure receiving area for moving the actuator 4 in the axial direction may be insufficient. This is because the size of the cross section perpendicular to the axis of the chuck body 2 is limited. If the pressure receiving area is insufficient, there may be a situation where the force for gripping the workpiece w is insufficient.

  Accordingly, the first object of the present invention is to provide a retractable chuck device that can withstand a large moment acting on the master jaw without increasing the size of the device, and further, a fluid disposed in the chuck body. When the actuator is moved in the axial direction by the fluid pressure of the pressure circuit, a second problem is to ensure a sufficient force for gripping the workpiece without increasing the size of the apparatus.

  In order to solve the first problem, the present invention provides an actuator that moves forward and backward along the axis of the chuck body in the chuck body, and the actuator equally divides a plurality of inclined holes around the axis. The tilt hole extends in a direction inclined with respect to the axis, and a master jaw is inserted into the tilt hole, and the master jaw and the actuator extend along the direction in which the tilt hole extends. The rear end of each master jaw is supported by the chuck body, and a gripping claw is provided at the front end thereof, and at least the front end of the master jaw is moved forward and backward in the axial direction of the actuator. Has adopted a retractable chuck device in which the gripping claw grips the workpiece by moving in the radial direction with respect to the shaft center.

  According to this configuration, the inclined hole of the actuator holds the outer surface of the master jaw on its inner surface, and opposes the moment acting on the master jaw on its entire inner surface. Therefore, a retractable chuck device that can withstand a large moment acting on the master jaw can be realized without increasing the size of the device.

  It should be noted that the inner surface of the inclined hole of the actuator and the outer surface of the master jaw may be configured to contact intermittently over the entire circumference, but they are in continuous contact over the entire circumference. It is desirable that It is because the area which should receive a moment increases because a contact area increases.

  Further, it is desirable that the inner surface of the inclined hole of the actuator and the outer surface of the master jaw are in contact with each other in a longer range along the direction in which the inclined hole extends. It is because the length which should receive a moment increases because a contact range becomes long along an inclined hole. Furthermore, although the structure which contacts intermittently over the contact range full length may be sufficient as the contact, it is desirable that they are contacting continuously over the full length.

  In this configuration, the rear end of the master jaw may be supported by an elastic member with respect to the chuck body. If there is an elastic member, the master jaw itself can be prevented from being bitten in the inclined hole by elastic deformation.

  In each of the above-described configurations, for example, a draw bar can be employed as a driving unit that moves the actuator in the axial direction with respect to the chuck body. Further, as means other than the draw bar, for example, a fluid circuit may be provided in the chuck body, and the actuator may be pressed by the fluid pressure supplied to the fluid circuit.

  In order to solve the second problem when the actuator is operated by the fluid pressure guided into the chuck body as described above, the present invention provides a cylinder device in the chuck body in each of the above-described configurations. A fluid circuit communicating from the fluid supply means outside the chuck body to the cylinder device is disposed, and the actuator is advanced and retracted by a fluid pressure supplied to the fluid circuit. A first cylinder part and a second cylinder part arranged in parallel along a direction are provided, and the first piston arranged in the first cylinder part and the second piston arranged in the second cylinder part are arranged in an axial direction. The first piston moves in one axial direction in the first cylinder portion, and the second piston moves in the second cylinder. When the actuator moves in one axial direction in the Linda part, the actuator moves in one axial direction, the gripping claw grips the workpiece, and the first piston moves in the other axial direction in the first cylinder part. And the second piston moves in the second cylinder part to the other axial direction, so that the actuator moves to the other axial direction and the gripping claw releases the grip of the workpiece. A retractable chuck device can be employed.

  As the cylinder device for operating the actuator, the first cylinder part and the second cylinder part are provided in parallel along the axial direction, so that a large working area of the piston receiving the fluid pressure can be secured. For this reason, sufficient force for gripping the workpiece can be ensured without increasing the size of the apparatus.

  In the configuration including this cylinder device, for example, a configuration in which a first piston and a second piston that operate the actuator are integrated can be employed.

  As the integrated structure, for example, the second piston has a connecting portion protruding toward the first piston, and the second piston and the first piston are joined via the connecting portion. The configuration can be adopted.

  Further, the connecting portion enters the first cylinder portion through a through hole that penetrates a partition wall that separates the first cylinder portion and the second cylinder portion, and a front end of the connecting portion is connected to the first cylinder portion. A configuration in which one piston is abutted or joined can be employed.

In addition, in each said structure, each of the 1st piston and the 2nd piston should just operate an actuator according to the axial direction advance / retreat, for example, each of the 1st piston and the 2nd piston, It is possible to employ a configuration in which the actuator is pressed in the axial direction in accordance with the advance / retreat of the axial direction, and the actuator is moved by the pressing.
Further, the first piston or the second piston, or both, and the actuator may be formed as separate members, and these members may be coupled to move integrally.
Furthermore, it is possible to adopt a configuration in which the first piston, the second piston, or both, and the actuator are formed as an integral member.

  Further, the fluid supply to the first cylinder part and the second cylinder part may be performed by separate fluid supply means, but may be configured to be performed from the same fluid supply means. If the fluid is supplied by the same fluid supply means, the means for controlling the fluid supply timing to the first cylinder part and the second cylinder part and the fluid pressure at the time of supply can be omitted.

  The present invention can be a retractable chuck device that can withstand a large moment acting on the master jaw without increasing the size of the device, and also by the fluid pressure of the fluid pressure circuit disposed in the chuck body. When the actuator is moved in the axial direction, a sufficient force for gripping the workpiece can be ensured.

1 shows a first embodiment, (a) is a front sectional view, (b) is a right side view. Enlarged view of the main part of FIG. 2nd embodiment is shown, (a) is front sectional drawing, (b) is a right view. The principal part enlarged view which shows another example of an elastic member A conventional example is shown, (a) is a front sectional view, (b) is a right side view.

  1st Embodiment of this invention is described based on FIG.1 and FIG.2. In this retractable chuck device 10, the work w is pulled backward by the gripping claws 13, the rear end surface of the work w is brought into contact with the contact portion 17 a of the stopper 17, and in this state, the work w is chucked by the gripping claws 13. It is held concentrically with the axis 16 of the main body 12.

  In this embodiment, the outer periphery of the workpiece w is gripped by the gripping claws 13, but as a modification, the present invention can also be applied to the case where the inner periphery of the workpiece w is gripped by the gripping claws 13.

  As shown in FIG. 1A, the chuck body 12 is configured by connecting a rear plate 12a and a front plate 12b with a bolt 12d via a connecting member 12c. In the space between the rear plate 12a and the front plate 12b, an actuator 14 that moves forward and backward along the axis 16 of the chuck body 12 is provided.

  The actuator 14 has a plurality of inclined holes 19 around the axis 16 in an equally divided direction. In this embodiment, three inclined holes 19 are provided.

  Each inclined hole 19 extends in a direction inclined with respect to the axis 16 of the chuck body 12. In this embodiment, the inclined hole 19 is in an inclined direction gradually toward the outer diameter side from the rear to the front of the chuck body 12, but depending on the shape of the workpiece w to be gripped and the setting of the gripping portion. In some cases, the direction is the reverse direction, that is, the inclination direction gradually toward the inner diameter side from the rear to the front of the chuck body 12.

  The inclined holes 19 are formed in the same number as the gripping claws 13 to be installed, and the shaft-shaped master jaws 15 are fitted into the inclined holes 19 exactly. The master jaw 15 and the actuator 14 are relatively movable along the direction in which the inclined hole 19 extends.

A grip claw 13 is provided at the front end 15 a of each master jaw 15. The gripping claw 13 is fixed to the front end 15a of the master jaw 15 with a bolt 13a.
For this reason, as shown in FIG. 1B, the same number of gripping claws 13 as the master jaws 15 are radially provided in an equal direction around the axis 16 of the chuck body 12. In this embodiment, three grip claws 13 are provided.

  Further, in this embodiment, the master jaw 15 has a circular cross section, and the inclined hole 19 also has a circular cross section. Relative movement is performed.

  Further, the rear end 15 b of each master jaw 15 is supported by the rear plate 12 a of the chuck body 12.

  As shown in FIG. 1A, the supporting structure is such that the locking bolt 11 is inserted into a bolt insertion hole 11 b provided in the rear plate 12 a, and the locking bolt 11 is a screw hole in the rear end 15 b of the master jaw 15. 15c.

  In addition, since the elastic member 11a is provided between the rear end 15b of the master jaw 15 and the front surface of the rear plate 12a, the master jaw 15 is connected to the chuck body 12 via the elastic member 11a. It is in a supported state. That is, in a normal state, the rear end surface of the master jaw 15 and the front surface of the rear plate 12a are supported via the elastic member 11a without directly touching.

  In this embodiment, a disc spring is employed as the elastic member 11a, but other elastic members such as a coil spring and rubber may be employed.

  A cylinder device 20 for operating the actuator 14 is provided in the chuck body 12.

  As shown in FIG. 1B, the cylinder device 20 includes a first cylinder part 21 and a second cylinder part 22 disposed in the chuck body 12. The first cylinder part 21 and the second cylinder part 22 are juxtaposed along the axial direction of the chuck body 12.

  A fluid circuit 30 is connected to the first cylinder part 21 and the second cylinder part 22. The fluid circuit 30 passes through the central shaft member 23 disposed along the axis 16 and communicates with the fluid supply means outside the chuck body 12.

  A first piston 21a is disposed in the first cylinder part 21, and the cylinder chamber on the rear side is the first cylinder part rear chamber 21b and the cylinder chamber on the front side is in front of the first cylinder part. It is a chamber 21c. The first piston 21 a has a circular cross section, and the central axis of the circular cross section coincides with the axis 16 of the chuck body 12.

In this embodiment, the first piston 21a and the actuator 14 are formed as an integral member. For this reason, the 1st piston 21a and the actuator 14 move to an axial direction integrally.
Alternatively, the first piston 21a and the actuator 14 may be formed as separate members and joined together so that both move together in the axial direction.

  Further, a second piston 22a is disposed in the second cylinder portion 22, and the second cylinder 22 is sandwiched between the second piston 22a, the rear cylinder chamber is the second cylinder portion rear chamber 22b, and the front cylinder chamber is the second cylinder. It is a front chamber 22c. The second piston 22 a has a circular cross section, and the central axis of the circular cross section coincides with the axis 16 of the chuck body 12.

  Further, the second piston 22a disposed in the second cylinder portion 22 has a connecting portion 22d protruding forward. The connecting portion 22d has a columnar shape, and the central axis of the column coincides with the axis 16 of the chuck body 12.

The connecting portion 22 d enters the first cylinder portion 21 through a through hole 12 f that penetrates the partition wall 12 e that separates the first cylinder portion 21 and the second cylinder portion 22. Further, the front end of the connecting portion 22d is in contact with the rear surface of the first piston 21a and is integrated with the first piston 21a in that state.
In this integration, a shaft hole is provided in each of the connecting portion 22d of the second piston 22a and the first piston 21a, and the protruding end 23a of the central shaft member 23 is press-fitted into each shaft hole. . That is, the first piston 21 a and the second piston 22 a are joined via the protruding end 23 a of the central shaft member 23.

  With the inner surface of the through hole 12f and the outer surface of the connecting portion 22d maintained in a liquid-tight state, the connecting portion 22d extends along the direction of the axis 16 together with the first piston 21a and the second piston 22a with respect to the chuck body 12. Move.

  In this embodiment, the first piston 21a and the second piston 22a are joined as separate members, but the first piston 21a and the second piston 22a may be formed as an integral member. Is possible.

  The fluid circuit 30 includes a first fluid path 31 that communicates from the fluid supply means to the second cylinder portion rear chamber 22b with respect to the second cylinder portion 22 that is positioned relatively rearward. The first fluid path 31 is provided so as to penetrate the central shaft member 23 in the axial direction. Note that air is present in the second cylinder portion front chamber 21c and is released to the atmosphere through the second fluid passage 32 provided in the chuck body 10. The second fluid passage 32 communicates with the second cylinder portion front chamber 22c through the passage 32a.

For the first cylinder portion 21 positioned relatively forward, the third fluid passage 33 communicates from the second cylinder portion rear chamber 22b to the first cylinder portion rear chamber 22b, and the fluid supply means to the first cylinder portion. A fourth fluid path 34 leading to the front chamber 21c is provided.
The third fluid path 33 is provided on the outer periphery of the protruding end 23a of the central shaft member 23, and forms a fluid passage between the third fluid path 33 and the inner surface of the shaft hole of the second piston 22a. The third fluid passage 33 communicates with the first cylinder portion rear chamber 21b through the passage 33a. The fourth fluid path 34 is provided so as to penetrate the central shaft member 23 including the protruding end 23a in the axial direction over the entire length.

The hydraulic fluid is supplied to these fluid circuits 30 at a predetermined pressure from the fluid supply means, and the first piston 21a of the first cylinder portion 21 and the first cylinder portion 22 of the second cylinder portion 22 are supplied by the supplied hydraulic pressure (fluid pressure). The two pistons 22a advance and retract along the direction of the axis 16.
In this embodiment, fluid is simultaneously supplied to the first fluid path 31 and the third fluid path 33 at the same pressure, and the fourth fluid path 34 is separated from the first fluid path 31 and the third fluid path 33. Also, the fluid is set to be supplied.

  Specifically, fluid pressure is introduced into the first cylinder portion front chamber 21 c of the first cylinder portion 21 through the fourth fluid passage 34. At this time, the fluid pressures in the first cylinder portion rear chamber 21b and the second cylinder portion rear chamber 22b are kept open.

  Due to the fluid pressure, the first piston 21 a disposed in the first cylinder portion 21 moves rearward in the axial direction within the first cylinder portion 21.

  At the same time, the fluid pressure causes the second piston 22 a disposed in the second cylinder portion 22 to move rearward in the axial direction within the second cylinder portion 22. At this time, since the connecting portion 22d of the second piston 22a and the first piston 21a are joined, the first piston 21a and the second piston 22a integrally move rearward in the axial direction. Is moved rearward in the axial direction.

  In this way, the first cylinder portion 21 and the second cylinder portion 22 cooperate to move the actuator 14 rearward in the axial direction, and the movement of the actuator 14 causes the gripping claws 13 to move in the inner diameter direction, so that the workpiece w Grab the outer periphery of the.

  In addition, fluid pressure is introduced into the first cylinder part rear chamber 21 b of the first cylinder part 21 and the second cylinder part rear chamber 22 b of the second cylinder part 22 through the first fluid path 31 and the third fluid path 33. The At this time, the fluid pressure in the first cylinder portion front chamber 21c is kept open. Further, the second cylinder portion front chamber 22c is always open to the atmosphere through the second fluid passage 32 as described above. However, in order to press the second piston 22a rearward here, the second cylinder portion front chamber 22c is provided. When the configuration capable of introducing the fluid pressure into 22c is employed, the fluid pressure in the second cylinder portion front chamber 22c is released.

First, the first piston 21 a moves forward in the axial direction in the first cylinder portion 21 by the fluid pressure through the first fluid path 31 and the third fluid path 33.
At the same time, the second piston 22 a disposed in the second cylinder portion 22 moves forward in the axial direction within the second cylinder portion 22 due to the fluid pressure through the first fluid passage 31.
In this way, the first piston 21a and the second piston 22a integrally move forward in the axial direction, and the actuator 4 is moved forward in the axial direction by the movement.

  That is, the first cylinder portion 21 and the second cylinder portion 22 cooperate to move the actuator 14 forward in the axial direction, and the movement of the actuator 14 causes the gripping claws 13 to move in the outer diameter direction, so that the workpiece w Release the grip.

At this time, the pressure receiving surface of the first piston 21a of the first cylinder portion 21 is in a range indicated by reference sign S1 shown in FIG. 1A, and the pressure receiving surface of the second piston 22a of the second cylinder portion 22 is indicated by reference sign S2. Therefore, a larger pressure-receiving area is ensured for the cross-sectional area of the chuck body 12 (the cross-sectional area of the cross section perpendicular to the axis 16) than when a single cylinder portion is provided. The release of the grip can be ensured.
Therefore, even after the turning, even when the gripping claw 13 that grips the workpiece w is somewhat biting into the outer surface of the workpiece, the gripping claw 13 is loaded by applying a fluid pressure with its large pressure receiving area. Can be released smoothly from the workpiece w.

  In this embodiment, the connecting portion 22d of the second piston 22a is joined to the first piston 21a. However, a configuration in which the connecting portion 22d is joined to the actuator 14 is also conceivable. Further, a mode is also conceivable in which the connecting portion 22d is brought into contact with the first piston 22a or the actuator 14 so that one presses the other through the contacting portion, that is, the contacting portion is not joined. .

  Further, when the actuator 14 advances and retreats along the direction of the axis 16 of the chuck body 12, at least the front end 15 a of the master jaw 15 moves in the radial direction with respect to the axis 16 of the chuck body 12. (Since the rear end 15b of the master jaw 15 is supported by the chuck body 12 with the locking bolt 11, it hardly moves in the radial direction.) When the gripping claw 13 grips the workpiece w by the movement, the master Since the rear end 15b of the jaw 15 is supported by the chuck body 12 via the elastic member 11a, the master jaw 15 itself is prevented from being bitten in the inclined hole 19 by elastic deformation. ing. Further, it is possible to prevent the workpiece w from floating away from the stopper 17.

  At this time, from the time before gripping the workpiece w to the time when the gripping of the workpiece w is completed, the rear end surface of the master jaw 15 and the front surface of the rear plate 12a are supported directly through the elastic member 11a without touching. The elastic force of the elastic member 11a is set so that the state that has been achieved is maintained. That is, the elastic force of the elastic member 11a is set so that the one gap indicated by the reference symbol w1 in FIG. 2 does not disappear until the gripping of the workpiece w is completed.

As a modification of this embodiment, for example, the actuator 14 is provided with lubricating means facing the inner surface of the inclined hole 19, and the lubricating means slides between the outer surface of the master jaw 15 and the inner surface of the inclined hole 19. It is possible to lubricate the surface.
This lubricating means may be disposed in the actuator 14 as described above, or may be disposed on the outer periphery of the master jaw 15.

  As a material of this lubrication means, any material that can exhibit a lubrication function between sliding surfaces may be used, for example, a resin or solid lubricant impregnated with a lubricant, or a lubrication function between sliding surfaces without lubrication. It is possible to employ known materials that can exhibit the above. In the case of using a resin impregnated with a lubricant, for example, each cylinder chamber of the cylinder device 20 or an oil passage led from the fluid circuit 30 is led to the place where the lubrication means is disposed, so that the labor of refueling can be saved easily. The lubricating function can be maintained.

  A second embodiment of the present invention is shown in FIG. In this embodiment, the cylinder device 20 is used as a means for operating the actuator 14 in the first embodiment, whereas a draw bar 18 is used as a means for operating the actuator 14.

  Since the drawbar 18 and the actuator 14 are joined by the drawbar bolt 18a via the connecting member 14a, if the drawbar 18 moves in the axial direction forward, the actuator 14 also moves in the axial direction forward, and the drawbar 18 moves in the axial direction. If it moves rearward, the actuator 14 also moves rearward in the axial direction.

  Since the operations of the master jaw 15 and the gripping claws 13 and the other main configurations accompanying the operation of the actuator 14 are the same as those in the first embodiment, the description thereof is omitted.

  Furthermore, another example of the elastic member 11a is shown in FIG. In this example, a leaf spring is employed as the elastic member 11a disposed between the rear end 15b of the master jaw 15 and the front surface of the rear plate 12a. The elastic member 11a is fixed with a bolt 11d.

  The leaf spring has a recess 11c on the rear surface, and the recess 11c forms a gap w2 between the chuck plate 12 and the rear plate 12a. The master jaw 15 is in a state of being supported by the chuck main body 12 via the elastic member 11a, and the elastic member 11a does not disappear until the grip of the workpiece w is finished. The elastic force is set. Other configurations are the same as those of the above-described embodiment, and thus description thereof is omitted.

1,10 Retractable chuck device 2,12 Chuck body 3,13 Holding claw 4,14 Actuator 5,15 Master jaw 6,16 Axes 7,17 Stopper 8,18 Drawbar 9,19 Inclined hole 11 Locking bolt 11a Elastic Member 11b Bolt insertion hole 11c Recess 20 Cylinder device 21 First cylinder portion 21a First piston 21b First cylinder portion rear chamber 21c First cylinder portion front chamber 22 Second cylinder portion 22a Second piston 22b Second cylinder portion rear chamber 22c Second cylinder part front chamber 22d Connecting part 23 Center shaft member 23a Projecting end 30 Fluid circuit 31 First fluid path 32 Second fluid path 33 Third fluid path 34 Fourth fluid path

Claims (4)

An actuator (14) that advances and retreats along the axis (16) of the chuck body (12) is provided in the chuck body (12), and the actuator (14) has a plurality of inclined holes around the axis (16). (19) are equally divided, each inclined hole (19) extends in a direction inclined with respect to the axis (16), and a master jaw (15) is inserted into the inclined hole (19). The master jaw (15) and the actuator (14) are relatively movable along the direction in which the inclined hole (19) extends, and the rear end (15b) of each master jaw (15) is the chuck body. (12) is supported at its front end (15a) by a gripping claw (13),
As the actuator (14) advances and retreats in the direction of the axis (16), at least the front end (15a) of the master jaw (15) moves in the radial direction with respect to the axis (16). A retractable chuck device in which the gripping claws (13) grip the workpiece (w).   The retractable chuck device according to claim 1, wherein the rear end (15b) of the master jaw (15) is supported by the chuck body (12) via an elastic member (11a). . A cylinder device (20) is provided in the chuck body (12), a fluid circuit (30) communicating from a fluid supply means outside the chuck body (12) to the cylinder device (20) is disposed, and the actuator ( 14) is advanced and retracted by the fluid pressure supplied to the fluid circuit (30),
The cylinder device (20) includes a first cylinder part (21) and a second cylinder part (22) arranged in parallel along the axial center (16) direction, and is disposed in the first cylinder part (21). The first piston (21a) and the second piston (22a) disposed in the second cylinder part (22) are integrally moved along the axial center (16) direction,
The first piston (21a) moves in the axial direction (16) in the first cylinder portion (21) and the second piston (22a) moves in the axial direction in the second cylinder portion (22). 16) By moving in one direction, the actuator (14) moves in one direction in the axial center (16) and the gripping claws (13) grip the workpiece (w).
The first piston (21a) moves to the other side in the axial center (16) direction in the first cylinder part (21), and the second piston (22a) has an axial center ( 16) The actuator (14) moves in the axial direction (16) in the other direction by moving in the other direction, and the grip claw (13) releases the grip of the workpiece (w). Item 3. The retractable chuck device according to Item 1 or 2.   The second piston (22a) has a connecting portion (22d) protruding toward the first piston (21a), and the connecting portion (22d) includes the first cylinder portion (21) and the second cylinder portion. The first cylinder portion (21d) enters the first cylinder portion (21f) through a through hole (12f) that penetrates the partition wall (12e) separating (22), and the front end of the connecting portion (22d) is connected to the first piston ( 21. The retractable chuck device according to claim 3, wherein the retractable chuck device is in contact with or joined to 21a).

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