JPH081414A - Machine tool chuck device - Google Patents

Abstract

(57) [Summary] [Purpose] In a chuck device in which a chuck holding a work is detachably mounted on a spindle, the work gripping force by the chuck can be adjusted according to the work, and it can be used for various works. To provide a chuck device for a machine. The chuck 1 includes a chuck body 2 having a front surface provided with a claw 4 for holding a work W, and a rear surface provided with mounting portions 5 and 6a for a spindle S and a setup side D, respectively.
A pawl opening / closing shaft 7 that is provided in the chuck body 2 so as to be non-rotatably and slidably provided so as to penetrate the central axis portion of the chuck main body 2 and move in the axial direction to open and close the pawl 4.
A lock mechanism 8 that locks the claw 4 to hold the claw 4 in a work gripping state, and actuating means 24 and 25 of the lock mechanism 8 are provided. On the other hand, on the main shaft S side and the setup side D, a clamping means 40 for detachably clamping the chuck body 2 and a pawl opening / closing shaft driving means 50 for engaging the pawl opening / closing shaft 7 and moving it in the axial direction. Is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck device for a machine tool in which a chuck holding a workpiece is removably mounted on a spindle such as a lathe.

[0002]

2. Description of the Related Art Attachment and detachment work of a work with respect to a chuck fixed to a main shaft of a lathe is usually performed by an operator or a loader. However, in the case of thin-walled work, it is difficult to automatically mount the work with a loader, and when work mounting accuracy is required, centering work is required, and the work required by the worker is time-consuming, which causes a decrease in work efficiency. Was becoming.

As a means for solving such a problem, there is known a chuck device in which a work is attached to the chuck outside the machine to perform centering work and the chuck holding the work can be attached to and detached from the spindle. (For example, the actual development 5
9-183707, JP-A-61-219547).

[0004]

However, in the one described in Japanese Utility Model Laid-Open No. 59-183707 mentioned above,
Since the work is held by the chuck using a spring,
The setting range of the gripping force (clamping force) corresponding to the weight and shape of the work is small, and it is difficult to adjust the gripping force because it is performed manually from the front side of the chuck. On the other hand, in the one disclosed in Japanese Patent Application Laid-Open No. 61-219547, the chucking force for gripping the work is attached to the main spindle, and the gripping force when the work is gripped by the claw opening / closing drive device of the main spindle and the setting side. There is a difference between the gripping force of the work due to the spring, and the mounting accuracy of the work changes due to the difference in the work gripping force, which has a problem of affecting the machining accuracy. Further, in order to cope with a heavy work, it is necessary to enlarge the spring, which causes a problem that the device itself becomes large.

The present invention has been made in view of the above circumstances, and is capable of improving the work efficiency and the machine operating rate by gripping a work piece by a chuck on the setup side outside the machine, as in the conventional apparatus described above. As a matter of fact, the gripping force by the chuck can be automatically adjusted over a wide range according to the work, and moreover, between the work holding force on the spindle side and the setup side and the work holding force during the exchange or transfer of the work. An object of the present invention is to provide a chuck device for a machine tool that does not cause a difference and can handle various works.

[0006]

In order to achieve the above object, the present invention is a chuck device in which a chuck holding a work is detachably mounted on a spindle side and a setup side of a machine tool. A chuck body having a front surface provided with a claw for gripping a work, and a rear surface provided with a mounting portion for the spindle side and a setup side, and a slidably provided through a central axis portion of the chuck body. A claw opening and closing shaft that moves in the axial direction to open and close the claw; and a lock mechanism that is provided in the chuck body and that locks the claw opening and closing shaft to hold the claw in a workpiece gripping state, and
The actuating means of the lock mechanism is provided on the arm that grips the chuck body and replaces or conveys it.

The actuating means of the lock mechanism may be provided in the chuck body.

On the other hand, on the main shaft side and the setup side, there are provided clamp means for detachably clamping the chuck body, and pawl opening / closing shaft driving means for engaging the pawl opening / closing shaft and moving it in the axial direction. Is provided.

[0009]

The claw opening / closing shaft is moved in the axial direction by the claw opening / closing shaft driving device in a state where the chuck body is clamped by the clamping device on the setup side, and the work is held by an arbitrary gripping force by the claw interlocking with this. In this work gripping state, the pawl open / close shaft is locked by the lock mechanism, and the pawl is held in the work gripping state. Subsequently, the pawl opening / closing shaft and the pawl opening / closing shaft driving means are disengaged, the clamping means is returned to an unclamping state, and the chuck body holding the work is replaced with a replacement arm, a robot hand, or other suitable conveying means as a spindle. Transfer to the side. Then, after clamping the chuck body by the clamp means on the spindle side, the pawl opening / closing shaft is engaged with the pawl opening / closing axis driving means on the spindle side, and is pushed and pulled in the axial direction to hold the work gripping force,
Unlock the lock mechanism. In this way,
The workpiece gripping force is maintained in the process of the chuck body on the spindle side as well. Further, the gripping force of the work by the claw is automatically set according to the weight and shape of the work, and there is no difference between the work gripping force on the spindle side and the setup side and the work gripping force during the work exchange or the conveyance. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional front view showing a spindle side of a lathe equipped with a chuck device according to the present invention, and FIG. 2 is a vertical sectional front view showing a setup side and a main portion of a spindle side. In the chuck device, the chuck 1 mounted on the main shaft S and the chuck 1'mounted on the setup device D are rotated 180 degrees by the exchange arm 30 while gripping the work W, and are exchanged. There is. Since the chuck 1 and the chuck 1'have the same structure, only the chuck 1 will be described below.

The chuck 1 includes a chuck body 2, a plurality of claws 4 mounted on the front surface of the chuck body 2 via a master jaw 3 so as to be slidable in a radial direction, and a peripheral portion of a rear end surface of the chuck body 2. An annular coupling 5 that is fixed and meshes with the coupling 43 that is fixed to the front end surface of the main shaft S, and is provided in the central portion of the rear end surface of the chuck body 2.
Circular recess 6 with which a clamp shaft 41 of a main shaft S described later engages
And a pawl opening / closing shaft 7 that is non-rotatably and slidably provided through the central axis portion of the chuck body 2 and that moves in the axial direction to open / close the pawl 4, and a pawl opening / closing shaft provided in the chuck body 2. The lock mechanism 8 locks the claws 7 to hold the claws 4 in a work gripping state. As shown in FIG. 4, four engaging claws 6a are provided in the circular recess 6 in the radial direction at the peripheral edge of the opening at regular intervals in the circumferential direction. The claw opening / closing shaft 7 has a small-diameter shaft portion 7a protruding toward the front side of the chuck body 2, and a wedge plunger 10 is attached to the shaft portion 7a via a disc spring 9. The disc spring 9 locks the pawl opening / closing shaft 7 in the axial direction by a lock mechanism 8 described later to hold the pawl 4 in a work gripping state, and the pulling force of the pawl opening / closing shaft 7 by a pawl opening / closing shaft drive shaft 51 described later or When the pressing force is released, even if the pawl opening / closing shaft 7 slightly moves in the direction in which the work holding force is reduced, the spring pressure is applied so as to compensate the work holding force. The wedge plunger 10 is engaged with the master jaw 3, and when the pawl opening / closing shaft 7 moves in the axial direction, the pawl 4 moves in the radial direction via the wedge plunger 10 and the master jaw 3 to open and close. There is. A rear end portion of the pawl opening / closing shaft 7 projects rearward from the circular recess 6, and a locking ring 11 with which a pawl opening / closing shaft drive shaft 51, which will be described later, is detachably engaged with an outer peripheral surface of the protruding shaft portion 7b. Are provided in a plurality of rows at regular intervals in the axial direction. As shown in FIG. 6, each locking ring 11 has three notches 11
a is provided.

As shown in FIG. 3, the lock mechanism 8 has a cavity 12 provided in the central portion of the chuck body 2.
A pair of clamp plates 13 and 13 arranged to face each other so as to sandwich the pawl opening / closing shaft 7 from both sides, and both clamp plates 1
3, 13 and a pair of wedge plates 15 and 15 interposed between the tapered guide surface 14 on the inner surface of the cavity 12 and both wedge plates 15 and 15
Pressing members 16 and 17 for pressing and supporting the lock shaft 20 from both ends, and a lock shaft 20 slidably fitted in two through holes 18 and 19 that face each other in the diametrical direction of the chuck body 2 and penetrate to the cavity 12. The unlock shaft 21 and the lock shaft 2 are provided.
0 and the unlock shaft 21 are prevented from coming out of the chuck body 2 by the flange portions provided at the inner ends thereof, respectively, and by the springs 22 and 23 interposed between the pressing members 16 and 17, The lock shaft 20 and the pressing member 16, and the unlock shaft 21 and the pressing member 17 are urged in a direction in which they are separated from each other. A needle 26 is provided between the wedge plate 15 and the clamp plate 13 and between the wedge plate 15 and the taper guide surface 14 so that the wedge plates 15 and 15 can move smoothly.

FIG. 3 shows an unlocked state in which the pawl opening / closing shaft 7 is not locked with respect to the chuck body 2.
In this unlocked state, the pawl opening / closing shaft 7 moves in the axial direction to open / close the pawl 4, and the pawl opening / closing shaft 7 is locked by the lock mechanism 8 while the workpiece W is held by the pawl 4. Further, an operating cylinder 24 that operates the lock shaft 20 that is the operating means of the lock mechanism 8 to lock the pawl opening / closing shaft 7 to the chuck body 2, and an unlock shaft 21 that operates the pawl opening / closing shaft 7 from the locked state. Working cylinder 25 to return to locked state
Are provided on the exchange arm 30.

As shown in FIG. 2, the exchange arm 30 has a central portion fixed to a drive shaft 31 which is rotated 180 degrees and axially moved and driven by a known drive means, and has chucks 1 and 1'at both ends thereof. Chuck insertion holes 32, 32 'for holding the holes. The working cylinders 24 and 25 described above are arranged in the inner wall portions of the chuck insertion holes 32 and 32 ′ so as to face the lock shaft 20 and the unlock shaft 21, respectively. The actuating cylinders 24 and 25 also have the role of supporting and fixing the chucks 1 and 1 ′ to the exchange arm 30 while the piston rods 24 a and 25 a project to press the lock shaft 20 and the unlock shaft 21. Further, tapered wall surfaces 33, 33 'are provided on the inner peripheral edge portions of the chuck insertion holes 32, 32' on the spindle S side and the setup device D side. When the chuck 1 is clamped to the spindle S, the tapered wall surface 33 is closely fitted to the front cover 34 of the headstock to prevent cutting oil and cutting chips from entering. Similarly, the tapered wall surface 3
When the chuck 1'is clamped to the setup device D, the reference numeral 3'closely fits the front cover 34 'of the chuck 1'to prevent cutting oil and chips from entering.

The spindle S side and the setup device D are respectively
Clamping devices 40, 40 'for removably clamping the chuck body 2 of the chucks 1, 1', and a pawl opening / closing shaft drive device 50 for engaging the pawl opening / closing shaft 7 and moving the same in the axial direction,
And 50 '. Clamping device 40, 40 '
Since the claw opening / closing shaft driving devices 50 and 50 'have substantially the same structure, only the clamp device 40 and the claw opening / closing shaft driving device 50 will be described below.

The clamp device 40 has a cylindrical clamp shaft 41 inserted through a through hole of the main shaft S so as to be movable in the axial direction and rotatably, and pushes and pulls the clamp shaft 41 from the rear side of the main shaft S in the axial direction. And a coupling cylinder 43 fixed to the front end surface of the main shaft S and meshing with the coupling 5 of the chuck body 2.

As shown in FIG. 4, four pressing claws 44 are provided on the outer periphery of the tip end portion of the clamp shaft 41 in the radial direction at regular intervals in the circumferential direction. Is moved forward and swung, the notch portion between the engaging claws 6a of the chuck body 2 is fitted into the pressing claw 44,
It is adapted to be rotationally displaced by a predetermined angle to engage with the engaging claw 6a. Further, as shown in FIG. 5, a cam groove 45 extending obliquely in the circumferential direction is provided on the outer peripheral surface of the clamp shaft 41, and the pin 4 fixedly projected to the inner wall of the main shaft S is provided in the cam groove 45.
6 is engaged (see FIG. 1), and the clamp shaft 41 is engaged with and disengaged from the engaging claw 6a as the clamp shaft 41 moves in the axial direction, so that it can be rotationally displaced by the predetermined angle.

The pawl opening / closing shaft drive device 50 includes a clamp shaft 41.
Claw open / close shaft drive shaft 51 rotatably and rotatably inserted in the through hole of the claw open / close cylinder 52 for pushing / pulling the claw open / close shaft drive shaft 51 from the rear side of the main shaft S in the axial direction.
And a rotation drive device 53 for driving the pawl opening / closing shaft 7 and the drive shaft 51 to rotate the pawl opening / closing shaft drive shaft 51 by a predetermined angle.

A connecting hole 5 into which a rear end projecting shaft portion 7b of the claw opening / closing shaft 7 of the chuck 1 is fitted at the tip of the claw opening / closing shaft drive shaft 51.
4 are provided, and three locking claws 55 are provided on the inner wall surface of the connection hole 54 at regular intervals in the circumferential direction (see FIG. 6). The locking claws 55 are provided in a plurality of rows in the axial direction at the same pitch as the locking ring 11 of the claw opening / closing shaft 7, and are locked with the locking claw 55 regardless of the position of the claw opening / closing shaft 7 during connection. Ring 11
And are engaged. At the rear end of the pawl opening / closing shaft drive shaft 51, a flange portion 56 and a clutch tooth 57 that engages / disengages with a rotary drive device 53 described later are provided.

The piston 58 of the opening / closing cylinder 52 has an insertion hole 59 penetrating in the axial direction, and an enlarged diameter portion 60 is provided on the inner peripheral portion of the insertion hole 59 and spring accommodating chambers 6 arranged on both sides thereof.
1, 61 are provided. The rear end portion of the pawl opening / closing shaft drive shaft 51 is inserted into the insertion hole 59 of the piston 58, the flange portion 56 is fitted into the enlarged diameter portion 60, and is slidable in the axial direction within the range of the enlarged diameter portion 60. , And is rotatable, and the springs 62, 62 that are compressed in the spring accommodating chambers 61, 61 press the flange portion 56 from both sides so that the pawl opening / closing shaft drive shaft 5
1 is supported in the expanded diameter portion 60 in a neutral state. The reason why the flange portion 56 and the springs 62, 62 are provided is as follows. That is, in the state where the chuck body 2 is clamped to the main shaft S by the clamp device 40, the piston 58 reciprocates to push and pull the pawl opening / closing shaft drive shaft 51 through the flange portion 56, and the drive shaft 51 is locked. Claw open / close shaft 7 connected via claw 55 and locking ring 11
The work W is gripped by opening and closing the claw 4 by moving the claw 4 in the axial direction. At this time, the position of the claw opening / closing shaft 7 arbitrarily changes with respect to the chuck body 2 depending on the diameter of the work W. . Therefore, although the locking ring 11 and the locking claw 55 are provided in a plurality of rows, they cannot be engaged when the locking ring 11 and the locking claw 55 are located on the same circumference. The shaft drive shaft 51 is displaced in the axial direction, the positional deviation is absorbed by the springs 62, 62, and the locking claw 55 is engaged with the locking ring 11. As a result, the locking claw 55 and the locking ring 11 are securely engaged, and the claw opening / closing shaft drive shaft 51 is connected to the claw opening / closing shaft 7.

The rotary drive device 53 includes a pawl opening / closing shaft drive shaft 51.
Has a cylindrical rotating shaft 66 rotatably supported by a fixed supporting member 65, and an operating shaft 67 is slidably inserted in the rotating shaft 66 in the axial direction. There is. The operating shaft 67 is provided at the tip thereof with the clutch teeth 5 of the pawl opening / closing shaft drive shaft 51.
7 is provided with a clutch tooth 68, which is biased rearward by a spring 69 installed in the rotary shaft 66, and is moved forward against the spring 69 by a cylinder 70 connected to the rear portion of the rotary shaft 66. The clutch teeth 68 mesh with the clutch teeth 57 when driven. Pressure oil is supplied to the cylinder 70 via a rotary joint 71. On the other hand, the rotary shaft 66 is rotated by the drive gear device 72, and the pawl opening / closing shaft drive shaft 51 is rotated at a predetermined angle via the clutch teeth 68 and the clutch teeth 57 meshed with the operating shaft 67 that rotates together with the rotary shaft 66. The locking claw 55 and the locking ring 11 are engaged or disengaged by rotating the locking claw 55 only.

As described above, the clamp device 40 'and the pawl opening / closing shaft drive device 50' of the setup device D have the same structure as the clamp device 40 and the pawl opening / closing shaft drive device 50 on the main shaft S side. Although not described in detail, the pressure of the pressure oil supplied to the opening / closing cylinder 52 on the main shaft S side and the opening / closing cylinder 52 ′ of the setup device D (see FIG. 2) (the work W by the pawls 4 and 4 ′ is thereby increased). The gripping force is determined according to the work W, and the pressure set in the setup device D is determined by the spindle S.
The opening / closing cylinder 52 on the side is automatically set. Therefore, the gripping force of the claw 4'set by the opening / closing cylinder 52 'of the setup device D does not change even when the chuck 1'is mounted on the spindle S. Moreover, since the pawl opening / closing shaft 7 is locked when the work is gripped by the chuck 1 ', the work gripping force can be kept constant even during the work changing operation.

In the above-described embodiment, the operating cylinders 24 and 25 for operating the lock mechanism 8 of the pawl opening / closing shaft 7 are provided in the replacement arm 30, but as shown in FIG.
4, 25 may be built in the chuck body 2. In this case, when the chuck 1 is mounted on the spindle S, the chuck body 2
The coupler 83 provided at the inlets of the pressure oil supply passages 81, 82 provided at the main shaft S is connected to the leakless coupler 86 provided at the outlets of the oil passages 84, 85 provided at the main shaft S so that the pressure oil having a predetermined pressure is provided. Is supplied to the working cylinders 24, 25 through the oil passages 81, 82. On the other hand, when the chuck 1 is detached from the main shaft S, the leaking couplers 83 and 86 are closed at the same time. The setup device D has the same structure. Adopting such a configuration is convenient for exchanging and transporting the chuck 1 using a normal robot hand.

[0025]

As described above in detail, in the chuck device of the present invention, the claw opening / closing shaft slidably provided on the chuck body is moved in the axial direction by the claw opening / closing shaft driving means on the main shaft side and the setup side. Since the pawl opening / closing shaft is locked by the lock mechanism provided in the chuck main body while holding the work with the pawl interlocking with this, the pawl is held in the work holding state. The force is automatically set in a wide range corresponding to the work, and there is no difference between the work holding force on the spindle side and the setup side and the work holding force during the exchange or transfer of the work. Therefore, it is possible to improve the mounting accuracy, and thus to perform highly accurate processing extremely efficiently.

Further, the whole chucking device can be constructed compactly, which is very advantageous in handling including chuck replacement or carrying operation.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a spindle side of a lathe provided with a chuck device according to the present invention.

FIG. 2 is a vertical cross-sectional front view showing a main part of the setup device and a spindle side.

FIG. 3 is a vertical sectional view of a central portion of the chuck.

FIG. 4 is an enlarged cross-sectional view of a main part taken along line 4-4 of FIG.

FIG. 5 is a plan view of an essential part of the clamp shaft.

6 is an enlarged cross-sectional view of a main part taken along the line 6-6 of FIG.

FIG. 7 is a vertical cross-sectional front view of essential parts showing another embodiment.

[Explanation of symbols]

 1 chuck 2 chuck body 4 claw 5,43 coupling 6a engaging claw 7 claw opening / closing shaft 8 locking mechanism 11 locking ring 20 lock shaft 21 unlocking shaft 24, 25 working cylinder 40, 40 'clamping device 41 clamping shaft 44 pressing Claw 45 Cam groove 46 Pins 50, 50 'Claw open / close shaft drive device 51 Claw open / close shaft drive shaft 52 Open / close cylinder 53 Rotation drive device 54 Connection hole 55 Locking claw

Claims (3)

[Claims] 1. A chuck device in which a chuck holding a work is detachably mounted on a spindle side and a setup side of a machine tool, wherein the chuck has a claw for holding the work on a front surface and a spindle on a rear surface. Side, and a chuck body provided with a mounting portion for the setup side, a claw opening and closing shaft that is slidably provided through the central axis portion of the chuck body and that moves in the axial direction to open and close the claw, A lock mechanism provided on the chuck main body for locking the pawl opening / closing shaft to hold the pawl in a work gripping state; and an operating means of the lock mechanism gripping the chuck main body for replacement or transportation. A chuck device for machine tools installed on the arm. 2. A chuck device in which a chuck holding a work is detachably mounted on a spindle side and a setup side of a machine tool, wherein the chuck has a front surface provided with a claw for holding the work and a rear surface provided with a spindle. Side, and a chuck body provided with a mounting portion for the setup side, a claw opening and closing shaft that is slidably provided through the central axis portion of the chuck body and that moves in the axial direction to open and close the claw, A machine tool provided on the chuck body, comprising a lock mechanism for locking the claw opening / closing shaft and holding the claw in a work gripping state, and the operating means of the lock mechanism is provided on the chuck body. Chuck device. 3. A clamp means for detachably clamping the chuck body, and a pawl opening / closing shaft driving means for engaging the pawl opening / closing shaft and moving the pawl opening / closing shaft in the axial direction on the main shaft side and the setup side. The chuck device for a machine tool according to claim 1 or 2, further comprising: