JP3405081B2 - Work fixing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work fixing device, and more particularly to a work fixing device for fixing works having different outer shapes by gripping.

[0002]

2. Description of the Related Art In friction welding, for example, the end faces of workpieces to be joined are brought into contact with each other and relatively moved while being pressurized to generate frictional heat at the joining interface, and an upset thrust force is applied to both workpieces. To join. As relative movement, generally, the first work is rotated to fix the second work, and the third work is sandwiched between the first and second work, and the first and second work are Alternatively, one of the third works may be fixed and the other may be rotated, or the work may be vibrated instead of being rotated.

The friction welding device generally holds a work fixing device for fixing at least one work by non-rotatably holding it, and another work holding device so as to face the fixed work on the same axis. And a workpiece rotating device that rotates as a relative motion, and a joining surface between the workpiece fixed to the workpiece fixing device and the workpiece gripped and rotated by the workpiece rotating device is pressed so as to press them relative to each other and the upset thrust is applied. And a thrust device for giving. Then, in order to regulate the retreat of the works when pressing the joining faces of the works against each other, the work fixing device and the work rotating device are respectively provided with stopper members with which the end faces opposite to the work joining surface are brought into contact. ing.

In such a friction welding apparatus, in order to join the workpieces with high precision, the joining surface of each workpiece that is in contact with the stopper member is projected from the workpiece fixing device and the workpiece rotating device by a predetermined length. In addition, it is necessary to securely hold and fix the work at an accurate position.

As a conventional work fixing device, the actual work fixing device 4
As disclosed in Japanese Patent Laid-Open No. 5-5634, a pair of grasping tools detachably attached to a pair of clamp bases are provided with symmetrical cross-shaped grasping grooves on the inner surfaces thereof, and each grasping groove has a cross section. There is known a grasping tool for a pipe member in a clamping device of a friction welding machine, in which a groove is cut into a substantially semicircular shape.

In this pipe member grasping tool, the diameters of the vertical grasping groove and the lateral grasping groove formed in a cross shape in the grasping tool are different from each other, and the opposing inner surfaces of the grasping tool are displaced by 90 °, Two types of straight pipes can be grasped with a single tool.

As another conventional work fixing device, as disclosed in Japanese Examined Patent Publication No. 4-2351, a pair of sliders are arranged on the bed so as to face each other with a pressure contact axis therebetween. The claw holder is installed rotatably around an axis parallel to the press contact axis with respect to the slider, and the claw holder is provided with a plurality of clamp claws having different clamp surfaces in the circumferential direction and engages with the claw holder. A clamping device for a friction welding machine is known which is provided with a fixing mechanism for fixing or releasing the claw holder to the slider by detaching it.

In this clamping device for a friction welding machine, a clamp base is installed on a bed, and a pair of sliders are arranged on the clamp base so as to face each other with a pressure welding axis interposed therebetween. It is slidably mounted on a guide bar fixed horizontally. In the detailed description of the clamping device for the friction welding machine, two clamping devices are installed so as to grip the workpieces near both ends.

Further, the fixing mechanism for fixing or releasing the claw holder to the slider has an engagement hole formed on the claw holder side in the circumferential direction at equal intervals on the contact sliding surface between the claw holder and the slider. And a positioning pin projecting correspondingly to the slider side so as to be disengageable from the engagement hole, a lock cylinder is formed in the slider, and a pawl holder is attached to the piston rod of the lock cylinder. . When the position of the clamp claw is exchanged, the piston rod of the lock cylinder is extended in the axial direction to move the claw holder away from the slider. Then, since the positioning pin comes out of the engagement hole, the claw holder is rotated around the axis of the piston rod to reposition the clamp claw.

[0010]

Among the above-mentioned conventional techniques, in the one disclosed in Japanese Utility Model Publication No. 45-5634, the gripping tools are formed so that the gripping grooves having different diameters are perpendicular to each other. Therefore, there is a problem that only two types of different shapes can be handled for the workpiece to be gripped. Then, when it is necessary to grip a work having a shape other than the two types formed on the gripping tool, the gripping tool must be replaced, and in order to replace the gripping tool, the work must rely on manual work. There has been a problem that the replacement work is troublesome. In addition, when the work has a certain length, it can only partially grip the work, and the work cannot be rotated by gripping it so as to surely face each other on the same axis. There was a problem that could not be fixed to.

Among the above-mentioned conventional techniques, Japanese Patent Publication No.
In the one disclosed in Japanese Patent No. 2351, since the fixing mechanism is configured to move the claw holder in the axial direction of the piston rod of the lock cylinder, the rotation shaft of the claw holder supports both ends. Therefore, the piston rod is attached in a so-called cantilever state. In the cantilever holder mounted in this cantilevered state, there is a limit in gripping the work with a necessary gripping force and securely fixing the work in a non-rotatable manner.

Further, in particular, in the one disclosed in Japanese Examined Patent Publication No. 4-2351, a clamp base provided with two sliders is installed on the bed in order to grip both ends of the work. However, since the distance between the two clamp bases cannot be adjusted arbitrarily, the amount of protrusion from the claw holder may not be appropriate depending on the length of the work. Therefore, there is a problem in that the work cannot be gripped corresponding to the outer shapes of the plurality of works. In addition to this, when exchanging the position of the clamp claw, each claw holder installed on the slider is released by separating the engaging hole from the positioning pin,
There is a problem that it takes a lot of work because it is necessary to perform a rotating operation.

The present invention has been made in view of the above problems, and a first object thereof is to provide a work fixing device capable of surely gripping and fixing a work corresponding to a plurality of work outer shapes. Especially.

A second object of the present invention is to provide a work fixing device which can hold and fix a work of a plurality of lengths in a properly projected state.

[0015]

In order to achieve the above-mentioned first object, the invention according to claim 1 grasps a plurality of claw members having a plurality of grasping portions formed in conformity with a plurality of workpiece outer shapes. A unit is provided which is rotatably provided so that the gripping portion corresponding to the work is located at the work gripping position, and the both ends of the rotation shaft of each claw member are supported so as to be able to approach and separate from the work, respectively. .

In order to achieve the second object,
The invention according to claim 2 is the invention according to claim 1, wherein a plurality of units are provided so as to be relatively movable in the axial direction of the workpiece, and at least one unit has a drive means for rotating the claw member. The other unit is characterized in that it is connectable to the drive means so as to rotate the claw member following the drive means.

In the invention according to claim 1, the claw member of the unit is rotated so that the gripping portion corresponding to the work to be gripped faces the work, and then the claw member is non-rotatably engaged and positioned. . Then, each claw member is moved close to the work, and the work is gripped and fixed by the gripping portion. Since each of the claw members supports both ends of its rotating shaft, it is possible to reliably grip the work.

In the invention according to claim 2, the unit having the drive means for rotating the claw member and the other unit are moved relatively close to each other, and the claw member of the other unit is rotated by the rotating means. The gripping portion corresponding to the workpiece to be gripped is positioned so as to face the workpiece by being rotated by being driven by the claw member.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION One embodiment of a work fixing device according to the present invention is applied to a friction welding device for joining a work W ₁ and a work W ₂ according to FIGS. 1 to 6. Will be described in detail. In the drawings, the same reference numerals denote the same or corresponding parts.

First, a friction welding device to which the work fixing device 1 according to the present invention is applied will be described with reference to FIG. The friction welding device in this embodiment is provided with a work W.
A workpiece fixing device 1 for fixing by gripping the ₁ non-rotatably, a spindle unit 2 as a work rotating device for rotating by gripping so as to face the workpiece W ₂ on the same axis as the axis of the workpiece W _1, thrust device 3 for providing the upset thrust with pressing the bonded surface of the workpiece W ₂ to be rotated by gripping the work fixing device workpiece W ₁ which is fixed to 1 and the spindle unit 2 so as to press relative to each other to each other It has and. In the following description, the end surface that is the joint surface of the work W ₁ and the work W ₂ is the front end surface, and the end surface that is opposite to the joint surface is the rear end surface.

As shown in FIG. 1, the main spindle unit 2 has a main spindle 1 having a chuck 10 for gripping a work W _2.
1 and a rotary servomotor 14 for rotating the main shaft 11 via gears 12, 13, etc., and a linear guide 15 provided on the base 4 via a slide member 16 in the axial direction of the workpiece W ₂ . It is slidably mounted (in the left-right direction in FIG. 1). A brake disc 17 is provided on the main shaft 11, and the main shaft 11 can be braked by operating a brake caliper 18. A stopper member 19 is provided at an end portion of the main shaft 11 opposite to the side where the chuck 10 is provided so as to contact the rear end surface of the work W ₂ and regulate its retreat.

As shown in FIG. 1, in the case of this embodiment, the thrust device 3 includes an arm 2 provided on the spindle unit 2.
0 and the press-contact feed shaft 2 inserted in the arm 20
1 and a press-contacting servomotor 22 for rotating the press-contacting feed shaft 21 about its axis, and the main spindle unit 2 is moved relative to the workpiece fixing device 1. A female thread portion (not shown) is formed on the arm 20,
A thread groove is formed on the press-contact feed shaft 21, and the female thread portion of the arm 20 is screwed into the thread groove of the press-contact feed shaft 21. The press-contact shaft 21 is rotatably supported by a bearing 23. Servo motor for pressure welding 22
Is driven to rotate the pressure welding shaft 21 about its axis, so that the front end surface of the workpiece W ₂ gripped and rotated by the spindle unit 2 is rotated with respect to the front end surface of the workpiece W ₁ fixed to the workpiece fixing device 1. The main spindle unit 2 in which the arm 20 is screwed to the press-contacting shaft 21 is moved so as to be pressed by pressing. Further, the thrust device 3 detects a movement of the spindle unit 2 so as to press the work W ₂ against the work W ₁ with a predetermined force (not shown).
Is provided. In this embodiment, the case where the main spindle unit 2 is moved relative to the work fixing device 1 has been described, but the present invention is not limited to this, and the work fixing device 1 can be moved relative to the main spindle unit 2. It can also be configured to be moved manually.

Next, the work fixing device 1 according to the present invention, which is applied to the friction welding device configured as described above, will be described in detail mainly with reference to FIGS. 2 to 6. In addition, in this embodiment, as shown in FIGS. 4 and 5, the outer shape of the work W ₁ gripped by the work fixing device 1 has three types of circular cross-sections having different diameters W _1a , W _1b , and W _1c . The present invention is not limited to this, but the present invention is not limited to this, and the gripping portion may be formed so as to be able to match two kinds or four kinds or more of works, and a work having a cross section other than a circular shape is also possible. You may form a holding part so that it can hold | grip. Further, the work fixing device 1 according to the present invention is
It can also be applied to an apparatus other than the friction welding apparatus that requires fixing of a work.

The work fixing device 1 according to the present invention, a plurality of workpiece contour W _1a, W _1b, in accordance with the W _1c plurality of gripping portions 30 _a, 30 _b, 30 a plurality _{of c} is formed of the claw member 31
The grip portion 30 corresponding to the work which grips _a, 30 _b,
30 One of the _c but provided rotatably so as to be positioned on the workpiece gripping position, respectively toward and away from rotatably supported by the unit 5A both ends of the rotation shaft 32 of each pawl member 31 with respect to the workpiece W _1, 5B.

Further, the work fixing device 1 according to the present invention is
The units 5A and 5B are provided so as to be movable relative to _each other in the axial direction of the work W ₁ , and at least one unit 5A includes the claw member 3
0 has a drive means 33 for rotating, and the other unit 5B follows the drive means 33, and the claw member 3
1 can be connected to the drive means 33 so as to rotate 1.

As shown in FIG. 3, in this embodiment, a clamp base 35 (see FIG. 1) is provided on the base 4, and the clamp base 35 extends in the axial direction of the work W _1. The rail 36 is provided so as to do so. The clamp base 35, a fixed base 37 of the unit 5A for fixing by gripping the front end of the workpiece W ₁ is provided, the movable base 38 of the unit 5B for fixing by gripping the rear end of the workpiece W ₁ is It is slidably mounted on the rail 36 via a slide member 39. This allows
The unit 5B is capable of moving the workpiece W _{1 in} the axial direction while facing the unit 5A. The clamp base 35, in contact with the rear end face of the workpiece W _1, the workpiece when the pressed workpiece W ₁ and W ₂ together W
A stopper member (not shown) for restricting the backward movement of ₁ is provided.

As shown in FIGS. 4 and 5, each of the units 5A and 5B has a plurality of works W _1a , W _1b , W, respectively.
In accordance with the outer shape of _1c plurality of gripping portions 30 _a, 30 _b, 30
_c is formed, the work W _1a for gripping, W _1b, a plurality of pawl members 31 rotatably supported to the grip portion 30 _a, 30 _b, 30 _c corresponding to W _1c is facing the workpiece, Housing 4 for supporting both ends of the rotary shaft 32 of the claw member 31
0, 41 and the gripping portions 30 _a , 30 _b , 30 _c of the claw member 31 supported by the housings 40, 41 for gripping and releasing the workpieces W _1a , W _1b , W _1c .
Pawl member moving means for toward and away from the movement (the code according to the in the figure is omitted), to position the predetermined gripper, i.e. one of the gripping portions 30 _a, 30 _b, 30 _c in the workpiece holding position Positioning means (the reference numerals are omitted in the drawing).

In this embodiment, a pair of claw members 31 are provided so as to sandwich the work W ₁ from both sides. Each claw member 31 is formed in a substantially cylindrical shape, and a rotary shaft 32 is provided at the center of its radial cross section. Then, on the outer peripheral surface of the pawl member 31, three different contours W _1a of the workpiece W ₁ in diameter, W _1b, in accordance with the W _1c three gripper 30 _a, 30 _b, 30 _c is, pawl member It is formed so as to extend in the axial direction at appropriate intervals in the circumferential direction of 31.

As shown in FIG. 2, the housings 40 and 41 are provided on the fixed and movable bases 37 and 38 so as to be slidable in the radial direction of the work W ₁ . Housing 40,
41 rotatably supports both ends of the rotary shaft 32 of the claw member 31.

As shown in FIGS. 4 and 5, the claw member moving means includes a cylinder 50 for moving _one housing 40, which supports both ends of the rotation shaft of the claw member, toward and away from the work W ₁ . A link mechanism that moves the other housing 41 toward and away from the work W ₁ in conjunction with the movement of the one housing 40 is provided. A rod 51 is slidably inserted through the fixed base 37 and the movable base 38 so as to penetrate therethrough. An elongated hole 52 is formed in a portion of the fixed and movable bases 37, 38 where the housing 40 is provided, and a block 53 that connects the one housing 40 and the rod 51 is arranged in the elongated hole 52. There is. Fixed and movable base 37,
A bracket 54 is provided on one side of the armature 38, and the substantially center of the arm 55 is attached to the pin 56 on the bracket 54.
Is rotatably pivoted by. The other housing 4
A bracket 57 is provided on the outer side of 1. Slots 58 and 59 are formed at both ends of the arm 55, and the end of the rod 51 and the slot 58 on one end side of the arm 55, and the slot 59 and the bracket 57 on the other end side of the arm 55 are respectively formed. The pins 60 and 61 are pivotally attached to each other.

As shown in FIG. 4, the unit 5A, one of the gripping portions 30 _a, 30 _b, 30 _c as a positioning means for positioning the workpiece holding position, the motor that rotates drive the pawl member 31 70 and the grips 30 _a , 30 _b , 30
It is composed of a locking mechanism 71 that locks a predetermined grip portion of _c in a non-rotatable position at a position facing the work W ₁ . As the motor 70, a stepping motor or the like that can be rotated at a desired angle is used. As shown in FIGS. 2 and 4, the rotation shaft 32 of the claw member 31 and the motor 7
The 0 drive shaft is provided with pulleys 72 and 73, respectively, and a belt 74 is wound around both pulleys 72 and 73. The locking mechanism 71 includes the grips 3 of the claw member 31.
And 0 _a, 30 _b, 30 _c and the engaging recesses are formed, respectively, respectively on the outer peripheral surface of the diagonal _{75 a, 75 b, 75 c} , with respect to the respective engaging recesses 75 _a, 75 _b, 75 _c And a wedge member 76 that is moved forward and backward in the radial direction of the pawl member 31. Note that FIG. 4 shows the case where the engagement recess 75 _a is in a position facing the wedge member 76 so as to be engaged with the wedge member 76. The wedge member 76 is inserted into the housings 40 and 41, and the housings 40 and 41 are provided with a cylinder 77 as an actuator for moving the wedge member 76 forward and backward. By moving the wedge member 76 forward and backward with respect to the claw member 31, it is possible to support both ends of the rotary shaft 32 of the claw member 31.

As shown in FIG. 5, the unit 5B is provided with the same locking mechanism as the unit 5A. Then, when the unit 5B is moved closer to the unit 5A, the end faces of the rotating shaft 32 of the claw member 31 of the unit 5A and the rotating shaft 32 of the claw member 31 of the unit 5B facing each other are moved to the end faces. An engaging mechanism that engages with each other is provided so that the claw member 31 of the unit 5B is driven following the rotation of the claw member 31 driven by the motor 70 of 5A. As shown in FIG. 2, this engagement mechanism is such that a protrusion 80 having a rectangular cross section is provided on the end surface of the rotary shaft 32 of one unit 5A and the end portion of the rotary shaft 32 of the other unit 5B. It is composed of a fitting recess 81 provided so as to fit the portion 80 relatively non-rotatably. The engagement mechanism is not limited to this, such as a meshing clutch,
Any method can be adopted as long as it can relatively unrotatably and detachably connect the claw members.

The mechanism for moving the unit 5B mounted on the rail 36 in the axial direction of the work W ₁ is the rail 3
A pair of screw shafts 90 are provided so as to be rotatable around an axis along the axis 6, and a motor 91 as an actuator for rotationally driving the shaft screws 90. As shown in FIG. 3, the screw shaft 90 has both ends pivotally attached to a support 92, and a pulley 93 is provided at one end thereof. Further, a pulley 94 is also provided on the drive shaft of the motor 91, and as shown in FIG. 4, the pulleys 93, 94 are wound around a belt 98 via idle pulleys 95, 96, 97. As a result, both screw shafts 90 rotate in synchronization.
As the motor 91, a stepping motor or the like that can be rotated at a desired angle can be used. A trapezoidal screw having a trapezoidal cross section is formed on the screw shaft 90, and the trapezoidal screw is screwed to the movable base 38 of the unit 5B. By driving the motor 91, the double screw shaft 90
Are rotated by a predetermined angle in synchronization with each other, the unit 5B screwed to the movable base 38 moves in the axial direction so as to correspond to the length of the work W ₁ . Further, the screw shaft 90 also has a function of receiving thrust during friction welding.

The work fixing device 1 according to the present invention is
In this embodiment, the unit 5A is the work W ₁
Is fixedly disposed so as to grip the front end of, but unit 5B is described by way of example are movable arranged to grip the trailing end of the workpiece W _1, it is not limited thereto. In addition to this embodiment, the unit 5B fixedly arranged to grip the front end of the workpiece W _1, it may be movable placing unit 5A so as to grip the rear end of the workpiece W _1. In addition, depending on the necessity of the workpiece to be fixed, the unit 5A,
In addition to 5B, the unit may be fixed or movable.

Next, in the work fixing device 1 according to the present invention,
An operation for changing the stage for matching the grip portion 30 to the outer shape of the work W _{1 and} an action for changing the stage to correspond to the length of the work W ₁ will be described mainly with reference to FIG. 6.
First, work information such as the diameters and lengths of the works W ₁ and W ₂ , and the margin of deviation is input to a control device (not shown) (S1). Based on these pieces of work information, the control device drives the motor 91 to rotate the screw shaft 90 synchronously, and brings the unit 5B close to the unit 5A (S2). As a result, the fitting recess 81 of the unit B is fitted into the protrusion 80 of the unit 5A, and the rotary shafts 32 of the claw members 31 of the unit 5A and the unit B are connected to each other. Then, in a state where the cylinder 77 is driven so as to retract, and the engagement of the claw member 31 of the wedge member 76 with the engagement concave portion 75 is released (S3), the motor 70 of the unit 5A is driven to outline the workpiece W ₁ . Gripping part 30
_The claw member 31 is rotated so that one of _a , 30 _b , and 30 _c faces the work W ₁ (S4). At this time, since the rotation shaft 32 of the claw member 31 of the unit 5A and the rotation shaft 32 of the claw member 31 of the unit 5B are connected, the claw member 31 of the unit 5B interlocks with the claw member 31 of the unit 5A. And rotates to grip the work pieces 30 _a , 3
One of 0 _b and 30 _c is located so as to face the work W ₁ .

[0036] When the position is to fit one of the outer shape of the workpiece W ₁ of the two units 5A, the grip portion 30 _a of the pawl member 31 of 5B, 30 _b, 30 _c, and driven to extend the cylinder 77 , The wedge member 76 is moved forward in the radial direction of the workpiece W ₁ to engage with the engaging recessed portion 75 of the claw member 31 (S5), and the claw member 31 is positioned so as not to rotate and the claw member 31 is gripped. The stage change of the unit 30 is completed. Then, the motor 91 is driven to drive the left and right screw shafts 9
1 is rotated synchronously to separate the unit 5B from the unit 5A to a predetermined position (S6).
The stage change to correspond to the length of the workpiece W ₁ is completed (S7).

Next, the work W _{1 is held} by the grip portion 3 of the claw member 31.
The operation for gripping and fixing with 0 will be described. Since this operation is the same in the unit 5A and the unit 5B, it will be described based on FIG. 4 depending on the case of the unit 5A. When the cylinder 50 is driven to extend in order to move the claw member 31 closer to the work W ₁ , the block 53 provided in the one housing 40 moves in the elongated hole 52 and the rod 51 slides to the left in FIG. 4. To do. Then, the arm 55 connected to the rod 51 rotates clockwise around the pin 56 in FIG. 4 and presses the other housing 41 provided with the bracket 57. Therefore, as the one claw member 31 moves closer to the work W ₁ , the other claw member 31 moves closer to the work W ₁ . When the gripping of the claw member 31 with respect to the work W ₁ is released, similarly, the cylinder 50 is driven to retract so that the one housing 4
The pawl member 31 supported by the other housing 41 is interlocked with the separation of the pawl member 31 supported by 0 from the work W _1.
Also separates from the work W ₁ .

In this embodiment, the other claw member 31 is moved toward and away from the work W _{1 in} conjunction with the movement of one claw member 31 toward and away from the work W ₁ . However, the present invention is not limited to this, and a cylinder is provided in each of the housings 40 and 41 that support both ends of the rotating shaft 32 of the claw member 31, so that the pair of claw members 31 can approach and approach the work W ₁ separately. It can also be configured to move apart.

[0039]

According to the first aspect of the present invention, the gripping portion corresponding to the workpiece to be gripped by the plurality of claw members in which the plurality of gripping portions are formed in conformity with the outer shapes of the plurality of workpieces is located at the workpiece gripping position. It is rotatably provided so that both ends of the rotary shaft of each claw member are supported so as to be able to move toward and away from the work respectively, so that the work can be handled in accordance with a plurality of work outlines. Can be securely grasped and fixed.

According to the invention of claim 2, a plurality of units are provided so as to be relatively movable in the axial direction of the work, and at least one unit has a drive means for rotating the claw member, The other unit is connectable to the drive unit so that the claw member is rotated by following the drive unit, so that the other unit can be grasped in a state in which it is properly projected corresponding to a plurality of works of length. And can be fixed.

[Brief description of drawings]

FIG. 1 is a front view showing a friction welding device to which a work fixing device according to the present invention is applied.

FIG. 2 is a front view of a work fixing device according to the present invention.

FIG. 3 is a cross-sectional plan view of the work fixing device according to the present invention.

FIG. 4 is an explanatory view of the unit A of the work fixing device according to the present invention as viewed in the direction of line AA in FIG.

5 is an explanatory view of a unit B of the work fixing device according to the present invention as viewed in the direction of line BB in FIG.

FIG. 6 is a flow chart showing the control of the stage change for adapting to the length of the work of the work fixing apparatus according to the present invention.

[Explanation of sign]

1 work fixing device 5A, 5B unit 30 _a, 30 _b, 30 _c gripper 31 claw member 32 pivot shaft 33 rotating means 40, 41 the housing 70 motor 71 locking mechanism 75 _a, 75 _b, 75 _c engaging recess 76 wedge member 77 cylinder 80 protrusion 81 fitting recess

Claims (2)

(57) [Claims] 1. A plurality of claw members, each of which has a plurality of gripping portions formed in accordance with a plurality of workpiece outer shapes, are rotatably provided so that a gripping portion corresponding to a workpiece to be gripped is located at a workpiece gripping position. A work fixing device comprising a unit that supports both ends of a rotating shaft of a claw member so as to be able to approach and separate from a work, respectively. 2. A plurality of units are provided so as to be relatively movable in the axial direction of the work, at least one unit has a drive means for rotating a claw member, and the other units are the drive means. The work fixing device according to claim 1, wherein the work fixing device is connectable to the drive means so as to rotate the claw member following the driving.