JP2000126915A - Loader chuck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide loader chucks of many kinds at a low cost. SOLUTION: Multiple drive pieces 6 are provided on one side face of a chuck main body 3 movably in the radial direction against the axis of the chuck main body 3, and a piece moving device 40 synchronously moving the drive pieces 6 in the radial direction is provided in the chuck main body 3. A fitting plate 17 facing one side face of the chuck main body 3 is provided, and the drive pieces 6 and driven pieces 18 releasable from the axial direction of the chuck main body 3 are provided on the fitting plate 17 movably in the radial direction. Pawls 19 holding a work on the driven pieces 18 are provided, and connecting devices 30 connecting the fitting plate 17 to one side face of the chuck main body 3 releasably from the axial direction are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck for a loader that supplies or unloads a work on a machine tool, a production line, or the like.

[0002]

2. Description of the Related Art A conventional loader chuck is provided with a plurality of workpiece holding claws moving in a radial direction on one side surface of a chuck body, and a plurality of driving pieces mounted in the chuck body to synchronize the above-mentioned driving pieces in a radial direction. The piece moving device to be moved is formed as an integrated unit, and the loader chuck formed as this unit is detachably attached to a loader arm such as a robot.

[0003]

In the above-mentioned conventional device, the claw and the driving device for driving the claw are formed as an integral unit.
Removal requires labor. In addition, since the amount of movement of the claw in the radial direction by the piece moving device is substantially constant, for a large-diameter work, the large-diameter workpiece is configured so that the claw moves radially on the large-diameter side. The loader chuck is mounted on the loader arm, and for small-diameter work, a small-diameter loader chuck in which the claw is moved in the radial direction on the small diameter side is mounted on the loader arm. In such a case, since various types of loader chucks each including a claw and a drive unit are prepared, the cost becomes high and the storage space increases. There was a problem such as. SUMMARY OF THE INVENTION An object of the present invention is to provide a novel loader chuck that eliminates the above-mentioned disadvantages by enabling a claw and a driving device that drives the claw to be separable.

[0004]

SUMMARY OF THE INVENTION The present invention is configured as follows to solve the above-mentioned drawbacks. That is, according to the first aspect of the present invention, a plurality of driving pieces are provided on one side surface of the chuck body so as to be movable in a radial direction with respect to an axis of the chuck body, and each of the driving pieces is provided in the chuck body. Provide a piece moving device that moves in the radial direction in synchronization with,
Providing a mounting plate facing one side of the chuck body,
The mounting plate is provided with a driven piece that can be disengaged from the axis line direction of the drive piece and the chuck body so as to be movable in a radial direction, a claw for holding a work is provided on each driven piece, and the mounting plate is provided with the mounting plate. A connection device is provided on one side surface of the chuck main body so as to be detachably connected from the axial center line direction.
Further, in the invention according to claim 2, the connection device is configured such that the connection shaft protrudes from the shaft center portion of the mounting plate and is detachable from the shaft center portion of the chuck body, and is movable in the chuck body in the radial direction. And an engagement / disengagement tool whose inner end is engaged / disengaged from the direction perpendicular to the connection shaft. In the invention according to claim 3, the connecting shaft (2
When the engagement and disengagement tool (32) is engaged with the engagement shaft (2),
2) is provided with a holding spring that presses and biases in the axial direction. According to a fourth aspect of the present invention, in the frame moving device, a cam plate in which a plurality of arc-shaped cams are spirally arranged at substantially equal intervals in a circumferential direction is formed around the axis of the chuck body. And a drive cylinder that slidably engages each of the driving pieces with each of the cams and rotates the cam plate forward and reverse through a linear / rotational motion conversion mechanism. .

According to a fifth aspect of the present invention, the driving cylinder is a cylinder with a clutch, and the cylinder with the clutch is provided with a restricting body integrally connected to a piston in a cylinder case and moved in the axial direction. An engagement plate that is axially moved in the cylinder case by being sandwiched between the regulating body and the piston and that is movable in the axial direction by a predetermined amount with respect to the piston and the regulating body; An output body that is moved in a direction, and when the engagement plate is moved in one direction between the piston and the regulating body by a load from the output body, the engagement body frictionally engages with the inner peripheral surface of the cylinder case. A combination piece is provided, and the piston and the regulating body are
When one of the piston and the restricting body approaches the engaging plate by the operating force of the piston, a releasing body for releasing the frictional engagement of the engaging piece is provided. According to a sixth aspect of the present invention, the engagement piece is spherical, and the contact surface of the engagement plate with which the engagement piece abuts is radially outwardly inclined toward the piston in one direction. This is the configuration. The invention according to claim 7 is
An elastic body for urging the engagement piece in the frictional engagement direction is provided.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view of a loader chuck according to the present invention, FIG. 2 is a sectional view corresponding to II-II in FIG.
3 is a cross-sectional view corresponding to III-III in FIG. 1, and FIG.
FIG. 5 is a front view corresponding to V, FIG. 5 is a cross-sectional view corresponding to VV in FIG.
FIG. 6 is a sectional view corresponding to VI-VI in FIG. 2. 1 and 2, reference numeral 1 denotes a loader arm, and reference numeral 2 denotes a loader chuck that is pivotally attached to a tip end (lower end) of the loader arm 1 via a pivot 2a. This loader chuck 2
Has jaws 15 and 16 having substantially the same structure for holding a work detachably on two opposing surfaces of the chuck body 3 formed in a rectangular parallelepiped shape, that is, on both right and left sides in FIG.

As shown in FIGS. 2 and 3, the chuck body 3 has a disk-shaped support plate 5 fixed to the left and right sides thereof, and three drive pieces 6 are circularly mounted on the support plate 5 in this embodiment. It is equally spaced in the circumferential direction and movably locked in the radial direction. A cylindrical engaging pin 7 protruding outward and a cylindrical cam pin 8 protruding inward are fixed to each of the driving pieces 6, and these cam pins 8 are connected to a cam plate 41 of a piece moving device 40 to be described later. The three driving pieces 6 are synchronously moved in the radial direction by rotating the cam plate 41 in the forward and reverse directions by engaging with the spiral cam 42 (FIG. 5) formed in FIG. The jaw 1 is provided at the center of the chuck body 3 and each support plate 5.
A cylindrical holding shaft 10 for holding 5 and 16 is inserted, and both ends thereof are fixed to the chuck body 3 via the support plate 5.

The jaws 15 and 16 have substantially the same structure, and one of them, that is, the jaw 15 on the left in FIG.
Will be described as a representative. In FIG. 2, reference numeral 17 denotes a disk-shaped mounting plate, on which three driven pieces 18 opposed to the driving pieces 6 are arranged equally in the circumferential direction and can be moved in the radial direction. To lock. Each of the driven pieces 18 includes:
A work clamping claw 19 is fixed to the outer surface of the work so as to protrude outward, and an engagement recess 20 is formed in the inner surface of the work so as to engage and lock the engagement pin 7. In this case, the initial position of the claw 19 in the radial direction is appropriately set according to the size of the work to be clamped. Further, an auxiliary plate 21 is fixed to the outer surface side of the mounting plate 17, and the connecting shaft 22 fitted and locked to the outer end of the holding shaft 10 is inserted through the axial center of the auxiliary plate 21.

The connecting shaft 22 has a large-diameter regulating flange 22a at the center in the longitudinal direction.
Is brought into contact with the right surface (inner surface) of the auxiliary plate 21, so that the right end 22 b of the connecting shaft 22 can be fitted to the outer end of the holding shaft 10 so as to be directed rightward from the mounting plate 17. Protrude by an amount. A spring receiver 28 is attached to the left end (outer end) of the connecting shaft 22, and a holding spring 29 made of a disc spring is interposed between the spring receiver 28 and the auxiliary plate 21. The connecting shaft 22 is urged to move leftward (outward). A slide pin 24 is slidably fitted to the left shaft center of the connection shaft 22, and a detection plate 25 for detecting the arrival of a work is connected to the outer end (left end) of the slide pin 24. . Reference numeral 26 denotes a return spring that presses and biases the detection plate 25 outward, and reference numeral 27 denotes a stopper pin that regulates the outward movement of the detection plate 25 at a predetermined value.

A connecting device 30 is provided for connecting the right end portion 22b of the connecting shaft 22 and the holding shaft 10 in a detachable manner. This connecting device 30 is as follows. That is,
As shown in FIG. 3, an engagement groove 31 orthogonal to the axis of the connection shaft 22 with two surfaces removed is formed in the right end 22 b of the connection shaft 22 on the jaw 15 side, and the support plate on the chuck body 3 side is formed. 5 is provided on the rear surface (the right surface in FIG. 2) with an engagement member 32 which is moved in the radial direction by a lock cylinder 33, and a fork-like engagement with the engagement groove 31 is provided at the axial end of the engagement member 32. Is formed (FIG. 5). in this case,
The positional relationship between the engagement groove 31 and the engagement piece 32a is such that the connecting shaft 22 compresses the holding spring 29 and restricts the holding flange 29a.
Are brought into contact with each other when they contact the outer end of the holding shaft 10.

The engagement body 32 is moved in the radial direction by connecting the engagement body 32 to a feed screw 34 screwed to the outer peripheral portion of the chuck body 3 as shown in FIG. The engaging member 32 may be moved in the radial direction by rotating the engaging member 32 forward and backward with a tool. Also,
As shown in FIG. 8, the engagement means between the connection shaft 22 and the engagement body 32 is formed by forming an engagement hole 31 ′ perpendicular to the axis of the connection shaft 22 at the right end 22 b of the connection shaft 22. An engagement pin 32a 'that fits into the engagement hole 31' is attached to the end of the shaft 32 on the shaft center side, and the engagement body 32 is moved in the radial direction by a lock cylinder 33, whereby the engagement pin 32a 'is You may make it fit in the engagement hole 31 '.

The piece moving device 40 for moving the driving pieces 6 in the radial direction in synchronization with each other is as follows.
That is, the holding shaft 10 provided at the center of the chuck body 3
As shown in FIGS. 2 and 3, the pair of pinions 43 and 44 are rotatably supported by facing each other in the axial direction.
As shown in FIG. 3, two racks 45 and 46 are individually engaged with the rack 44 from the left and right. Each rack 45, 46
As shown in FIG. 6, left and right clutch-equipped drive cylinders 50 and 51 provided in the chuck body 3 are moved vertically in FIG.

The drive cylinders 50 and 51 have substantially the same structure except that they have different directions. The drive cylinder 51 on the right will be described as a representative. In FIG. 6, reference numeral 52 denotes a cylinder case.
3. A retraction cylinder chamber 54 is formed, and an inner cylinder 52a for preventing wear is fitted and fixed to the inner periphery of the forward cylinder chamber 53. A forward piston 56 and a backward piston 57 integrally connected to the cylinder chambers 53 and 54 by a rod 55 are slidably fitted. 53a is a forward supply port for supplying a working fluid (oil or air) to the forward cylinder chamber 53, and 54a is a backward supply port for supplying a working fluid to the backward cylinder chamber 54.

A disk-shaped engaging plate 58 is disposed on the lower surface of the upper advancing piston 56 so as to be movable in the vertical direction, and a ring-shaped restricting body 59 is disposed on the lower surface of the engaging plate 58. The body 59 is fixed to the lower retraction piston 57 via the connecting pin 60, and the engagement plate 58
Is restricted in the axial direction (vertical movement) with respect to the upper forward piston 56 by a predetermined value or more.

The engagement plate 58 has an output body 61 disposed below the engagement plate 58 and is slidably fitted to the rod 55 to provide a buffer between the output body 61 and the engagement plate 58. The output body 61 and the engagement plate 58 are connected to each other by a connection collar 63 screwed to the output body 61 so as to be able to move slightly in the direction of contact and separation.
The above-described rack 46 is formed on the output body 61, and the rack 46 is engaged with the above-described pinion 44. As shown in FIG. 2, a disc-shaped cam plate 41 is coaxially fixed to the shaft end of the pinion 44. The cam plate 41 has three arc-shaped slits as shown in FIG. Are formed in a spiral shape at substantially equal intervals in the circumferential direction, and the cam pins 8 of the driving pieces 6 described above are slidably engaged with the respective cams 42.

Reference numeral 65 denotes a clutch device 65 provided on the drive cylinder 51. This clutch device 65 is shown in FIG.
As shown in the figure, the lower part of the outer periphery of the engagement plate 58 is stepwise reduced in diameter, and this small diameter surface is formed on a cam surface 66 having a larger diameter toward the lower side. A large number of engaging pieces 67 made of steel balls are arranged in the circumferential direction between the inner surface and the inner peripheral surface, and a large number of elastic bodies (coils) corresponding to the respective engaging pieces 67 are provided on the end surface of the small diameter step portion of the engaging plate 58. Spring)
The engagement pieces 67 are urged downward (toward the large diameter side of the cam surface 66) by the reaction force of the elastic bodies 68.

Further, an annular release member 69 is formed on the outer peripheral portion of the restricting member 59 so as to protrude toward the engaging plate 58 (upward). When the restricting body 59 approaches (contacts) the engagement plate 58, the release body 69 causes the end face of the release body 69 to move each engagement piece 67 upward (to the small diameter side of the cam surface 66). The frictional engagement between the engagement piece 67 and the inner peripheral surface of the cylinder case 52 is released. The drive cylinder 50 (51) with a clutch described above can be applied not only to the loader chuck but also to a drive cylinder for an unloading device and a work transfer device.

According to the above embodiment, the lock cylinder 33
When the engaging body 32 is moved outward in the radial direction by (or the feed screw 34), the engaging piece 32a (or the engaging pin 32) is moved.
a ′) is the engagement groove 31 (or the engagement hole 31 ′) of the connection shaft 22.
Break away from When the jaws 15 and 16 are pulled axially outward with respect to the chuck body 3 in this state, the right end 22b of the connecting shaft 22 is separated from the holding shaft 6 and the driven piece 18
Is released from the engaging pin 7 of the driving piece 6, and the jaws 15, 16 can be removed from the chuck body 3.

In a state where the engaging body 32 is moved radially outward, the jaws 15 and 16 are made to approach the chuck body 3, and the connecting shaft 22 and the engaging recess 2 of the driven piece 18 are moved.
0 is fitted to the holding shaft 6 on the chuck body 3 side and the engaging pin 7 of the driving piece 6, and in this state, the connecting shaft 22 is moved inward against the reaction force of the holding spring 29, and the regulation is performed. The flange 22a is brought into contact with the end surface of the holding shaft 6. Next, when the engaging body 32 is moved inward in the radial direction, the engaging piece 32a (or the engaging pin 32a ') is engaged with the engaging groove 31 (or the engaging hole 31') of the connecting shaft 22, The above jaw 15,
16 is connected to the chuck body 3, and the two engaging portions are brought into close contact with each other by the reaction force of the holding spring 29, so that the engaging force is increased and generation of abnormal noise due to play at the engaging portions is prevented. Become.

In this case, for the jaws 15 and 16, for example, a jaw for a small diameter for clamping a small diameter work and a jaw for a large diameter for clamping a large diameter work are prepared, and these are appropriately selected. Attach it to the chuck body 3. The small-diameter jaws are arranged such that the initial position of the claw 19 in the radial direction is on the predetermined small-diameter side, and the large-diameter jaws are arranged such that the initial position of the claw 19 in the radial direction is on the predetermined large-diameter side. And the driven piece 18 has a common initial position in the radial direction so that the driven piece 18 can be disengaged from the driving piece 6 of the chuck body 3.

In the state where the jaws 15 and 16 are connected to the chuck body 3, the working fluid is supplied from the forward supply port 53a in FIG.
3 and presses the forward piston 56 downward, the regulating body 59 moves downward together with the forward piston 56 via the rod 55, the backward piston 57, and the connecting pin 60, and the forward piston 56 The engaging plate 58 is pressed and moved downward. In this case, the lower surface of the advancing piston 56 forms one of the releasing members referred to in the present application. Then, the engagement piece 67 is moved to the small diameter side of the cam surface 66 and the engagement plate 5 is moved.
8 moves downward together with the advance piston 56. As a result, the output body 61 moves downward via the disc spring 62,
The pinion 44 is moved through the rack 46 by the arrow A in FIG.
Rotate in the direction.

When the pinion 44 is rotated in the direction of arrow A, the cam plate 41 connected thereto is rotated in the direction of arrow B in FIG.
2, the chuck body 3 is moved in the axial direction of the chuck body 3 in synchronization. Accordingly, the driven pieces 18 engaged with the driving pieces 6 are synchronously moved in the axial direction, and the respective driven pieces 1 are moved.
8 are moved in the axial direction in synchronization with each other,
The claws 19 grip the work.

In this state, the working fluid supplied from the forward supply port 53a drops due to a power failure or a failure of the pump for some reason, and the pawl 19 opens radially outward due to the load of the work. 6, the above-described pinion 44 is rotated in the direction opposite to the arrow A in FIG. 6, and the right output body 61 moves upward in the same figure via the rack 46, and engages with the engaging plate via the disc spring 62. 58 is to be moved upward. Then, the engagement piece 6
7 rolls to the large diameter side of the cam surface 66 and the cylinder case 52
The engagement plate 58 is firmly frictionally engaged with the inner cylinder 52a, and the upward movement (retreating direction) of the engagement plate 58 is prevented. As a result, the movement of the claw 19 outward in the radial direction is prevented, and the detachment of the work is prevented.

Next, when releasing the clamping of the work, the working fluid is supplied from the retreat supply port 54a. Then, for example, the rightward retraction piston 57 in FIG. 6 moves upward, and both the forward piston 56 and the regulating body 59 move upward via the rod 55 and the connecting pin 60. The upward movement of the regulating body 59 causes the release body 69 provided on the regulating body 59 to press and move the engaging piece 67 upward, that is, to the small diameter side of the cam surface 66, as shown in FIG. The engagement of the joint piece 67 with the inner cylinder 3 of the cylinder case 52 is released. Next, the regulating body 59 presses and moves the engaging plate 58 upward, and the engaging plate 58 moves the output body 61 upward through the connecting collar 63, and moves the pinion 44 through the rack 46 in the direction opposite to the arrow A. Rotate to.

Thus, the cam plate 41 is rotated in the direction opposite to the arrow B in FIG. 5, and the respective driving pieces 6 are synchronously moved by the spiral cams 42 so as to be radially outward with respect to the axis of the chuck body 3. Be moved. As a result, each driven piece 18 is synchronously moved outward in the radial direction, and each claw 1 attached thereto is moved.
9 moves synchronously outward in the radial direction to release the work.

[0026]

As is apparent from the above description, according to the first aspect of the present invention, the mounting plate detachably connected to the chuck body is detachably connected to the driving piece on the chuck body side. Since the driven piece that is moved in the radial direction is provided and the driven piece is provided with the claw for holding the work, the claw portion side (jaw) is small. For this reason, a plurality of claw portions having different operating ranges in which the positions of the claws on the claw portion side in the radial direction are prepared are selected, and these are selected and attached to the chuck body side, thereby obtaining various types of loader chucks at low cost. In addition to this, the spare claw portion side is a small item, so that the storage space for this is small.
Further, in the invention according to claim 2, the connecting shaft provided on the shaft center of the mounting plate is fitted to the shaft center of the chuck body, and is disengaged from the chuck body side in a direction orthogonal to the connecting shaft. Since the engaging and disengaging tool is provided, the structure can be simplified and the claw portion side can be firmly connected to the chuck body side. Further, in the invention according to claim 3, when the connecting shaft and the engagement / disengagement tool are engaged, the connecting spring is pressed and urged in the axial direction by the holding spring. The engagement force increases due to the close contact, and the generation of abnormal noise due to play at the engagement portion is prevented. Further, in the invention according to claim 4, the driving piece is engaged with a spiral cam formed on a disc-shaped cam plate, and this cam plate is positively moved by a driving cylinder via a linear / rotational motion converting mechanism. Since the driving piece is moved in the radial direction by the reverse rotation, the size of the chuck body is reduced. Further, in the invention according to claim 5, since the clutch device for preventing the piston from moving in the retreating direction is provided in the cylinder case, the drive cylinder with the clutch is reduced in size. In the invention according to claim 6, the engagement piece of the clutch device is spherical, and the contact surface of the engagement plate with which the engagement piece abuts is a cam surface inclined in a tapered shape. become. In the invention according to claim 7, since the engagement piece of the clutch device is pressed and urged by the elastic body in the frictional engagement direction, the operation of the clutch is performed quickly. And so on.

[Brief description of the drawings]

FIG. 1 is a front view of a loader chuck according to the present invention.

FIG. 2 is a sectional view corresponding to II-II in FIG.

FIG. 3 is a sectional view corresponding to III-III in FIG. 1;

FIG. 4 is a front view corresponding to IV-IV in FIG. 2;

FIG. 5 is a sectional view corresponding to VV in FIG. 2;

FIG. 6 is a sectional view corresponding to VI-VI in FIG. 2;

FIG. 7 shows a second embodiment of the coupling device according to the invention;
It is a considerable sectional view.

FIG. 8 shows a third embodiment of the coupling device according to the invention.
It is a considerable sectional view.

FIG. 9 is an enlarged sectional view of a clutch device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Loader arm 2 Loader chuck 2a Rotating shaft 5 Support plate 6 Driving piece 7 Engagement pin 8 Cam pin 10 Holding shaft 15, 16 Jaw 17 Mounting plate 18 Driven piece 19 Claw 20 Engagement concave part 21 Auxiliary plate 22 Connecting shaft 22a Regulatory flange 22b Right end 24 Slide pin 25 Detection plate 26 Return spring 27 Stopper pin 28 Spring receiver 29 Holding spring 30 Connecting device 31 Engagement groove 31 'Engagement hole 32 Engagement body 32a Engagement piece 32a' Engagement pin 33 Lock cylinder 34 Feed screw Reference Signs List 40 Drive device 41 Cam plate 42 Cam 43,44 Pinion 45,46 Rack 50,51 Drive cylinder 52 Cylinder case 52a Inner cylinder 53 Advance cylinder chamber 53a Advance supply port 54 Retreat cylinder chamber 54a Retreat supply port 55 Rod 56 Forward piston (one solution Body) 57 retract piston 58 engaging plate 59 regulating member 60 connecting pin 61 output shaft 62 disc spring 63 connecting collar 65 clutch device 66 cam surface 67 Kakarigokoma 68 elastic 69 release member (the other release member)

Claims (7)

[Claims] A plurality of driving pieces (6) are provided on one side surface of the chuck body (3) so as to be movable in the radial direction with respect to the axis of the chuck body (3). And a piece moving device (40) for synchronizing and moving the driving pieces (6) in the radial direction with the chuck body (3).
A mounting plate (17) facing one side is provided, and the driving pieces (6) and the chuck body (3) are provided on the mounting plate (17).
A driven piece (18) that can be disengaged from the axial center direction is provided so as to be movable in the radial direction, a claw (19) for holding a work is provided on each driven piece (18), and the mounting plate (17) is attached. A loader chuck provided with a connecting device (30) that is detachably connected to one side surface of the chuck body (3) from an axial direction thereof. 2. The chuck body (3), wherein the coupling device (30) projects from an axis of the mounting plate (17).
A connecting shaft (22) that can be fitted to and removed from the shaft center of the chuck body (3); 2. The loader chuck according to claim 1, further comprising an engaging / disengaging tool (32). 3. A holding spring for urging the connecting shaft (22) in the axial direction when the connecting shaft (22) and the engaging / disengaging tool (32) are engaged with each other. Item 2. A loader chuck according to Item 2. 4. The chuck body (3), wherein the piece moving device (40) comprises a cam plate (41) in which a plurality of arc-shaped cams (42) are spirally arranged at substantially equal intervals in a circumferential direction. The cam (4) is provided rotatably about its axis.
2) The driving pieces (6) are slidably engaged with the driving pieces (6), and the cam plate (41) is moved by the linear / rotational motion converting mechanisms (45, 4).
3) The drive cylinder (50, 5) that rotates forward and reverse through
The loader chuck according to claim 1, 2 or 3, wherein 1) is provided. 5. The driving cylinder (50, 51) is a cylinder with a clutch, and the cylinder with the clutch is integrally connected to a piston (56) in a cylinder case (52) and is restricted from moving in the axial direction. A body (59) is provided. The body (59) is axially moved in the cylinder case (52) while being sandwiched between the regulating body (59) and the piston (56). An engagement plate (58) movable in the axial direction by a predetermined amount is provided for the output member (6) moved in the axial direction by the engagement plate (58).
1), and when the engagement plate (58) is moved in one direction between the piston (56) and the regulating body (59) by a load from the output body (61), the cylinder case (5) is moved.
An engagement piece (67) that frictionally engages with the inner peripheral surface of 2) is provided, and the piston (56) or the regulating body (59) is applied to the piston (56) and the regulating body (59) by the operating force of the piston (56). ) When one of them approaches the engagement plate (58),
A release member (5) for releasing the frictional engagement of the engagement piece (67)
The loader chuck according to claim 4, wherein (6, 69) is provided. 6. The engaging piece (67) has a spherical shape, and the contact surface of the engaging plate (58) with which the engaging piece (67) comes into contact with the piston (56) in the radial direction as it goes in one direction. The loader chuck according to claim 5, characterized in that the cam surface (66) is inclined outward. 7. The loader chuck according to claim 5, further comprising an elastic body (68) for urging the engagement piece (67) in a frictional engagement direction.