JPH07185977A - Workpiece clamping device - Google Patents

Abstract

PURPOSE:To enable positions of a support surface and a clamp due to the kind of a workpiece to extensively meet change. CONSTITUTION:A workpiece clamping device is provided with a rotating member 6 provided on a base free to rotate around a standard axis, a sheet base 14 provided on the rotating member 6 free to rotate around an eccentric axis decentered against the standard axis of the rotating member and free to displace in the eccentric axis direction and with a standard sheet to support a workpiece formed on it and a clamping member 20 provided on the rotating member free to displace in the eccentric axis direction independently from the sheet base 14 and free to rotate around the eccentric axis integrally with the sheet base 14 and to press a workpiece W. Additionally this is constituted of drive means B; 34, 27 to rotationally drive the rotating member 6, drive means 28-33 to rotationally drive the sheet base and the clamping member synchronously with rotation of the rotating member and drive means 11, 15 to drive the sheet base and the clamping member relatively in the opposite directions along the eccentric axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work clamp device, and more particularly to a work clamp device for a machine tool.

[0002]

2. Description of the Related Art In a conventional work clamping device, as shown in Japanese Utility Model Laid-Open No. 63-166331, a guide rod having a clamper at its tip is slidably supported by a supporting member. A wedge hole is bored so as to pass through the guide rod laterally, the wedge is inserted into the wedge hole, and a spring force is applied to each of the wedge and the guide rod to form a clamp unit. A centering rod is erected on the top of the main shaft of the lathe, and the clamp unit is fixed on the pallet according to the clamp position of the workpiece supported by the centering rod. There is a fixed flange that is locked by.

[0003]

When there are many kinds of workpieces, the positions of the support surface and the clamp, that is, the clamp positions, change depending on the kinds of workpieces. However, the above-mentioned conventional clamping device can cope with the displacement of the clamp position in the vertical direction only within the range of the shape error of the same type of workpiece, and therefore, there are many types of workpieces, It cannot be applied when the clamp position is displaced in the horizontal direction depending on the type of object. The present invention provides a workpiece clamping device capable of adapting to various types of workpieces, even if the mounting position is fixed, the positions of the support surface and the clamp for the workpiece are variable in the horizontal plane direction.

[0004]

SUMMARY OF THE INVENTION A workpiece clamping device according to the present invention includes a rotating member provided on a base so as to be rotatable about a reference axis and a rotating member eccentric with respect to the reference axis. A seat base provided on a rotating member that is freely displaceable in the eccentric axis direction, and has a reference sheet for supporting a workpiece, and a seat base that is displaceable in the eccentric axis direction independently of the seat base. A clamp member that is provided on the rotating member so as to be rotatable around an eccentric axis integrally with the base, presses the workpiece, drive means that rotationally drives the rotating member, and rotates the sheet base and the clamp member. And a driving means for driving the seat base and the clamp member in relatively opposite directions along the eccentric axis.

[0005]

First, the clamp position corresponding to the shape and size of the workpiece is adjusted. To this end, when the rotating member is rotationally driven around the reference axis line by the driving means, the seat base and the clamp member are both centered on the reference axis line, and the range of which the locus is a circle whose radius is the eccentric amount of the eccentric axis line. It is appropriately displaced within. At that time, the seat base and the clamp member are always oriented in the same direction on the base by the synchronous drive device. Therefore, the orientation with respect to the workpiece does not change regardless of the displacement on the eccentric circumference.

The clamp member is located at a position apart from the reference sheet at a predetermined position in the axial direction. Therefore, in order to stably clamp the processed portion of the workpiece placed and fixed on the mounting table, the driving means is used so that the reference sheet and the clamp member face each other with the fastening portion in between. Thus, the rotary member is rotationally driven around the reference axis. At that time, as described above, the orientation of the seat base and the clamp member with respect to the workpiece does not change.

When the clamp member and the reference sheet come to a position where the clamp portion of the workpiece is sandwiched, the clamp member is displaced in the axial direction by the driving means to press the clamp portion of the workpiece, and the reference sheet is correspondingly moved. Also advances with respect to the clamping part of the workpiece. As a result, the fastening portion of the workpiece is sandwiched and gripped by the clamp member and the reference sheet.

When the workpiece is removed, each drive means is reversed. Then, contrary to the above-mentioned fastening operation, the clamp member and the reference sheet are separated from the fastening portion of the workpiece in the axial direction, and then the rotary member is rotatably driven around the reference axis to be appropriately separated from the fastening portion of the workpiece. Position and release the work piece.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A work clamp device according to an embodiment of the present invention will be described with reference to the drawings. The workpiece clamping device A is
As shown in FIG. 1, a turning drive device B is provided. Figure 2
As shown in FIG.
It is provided in a hollow housing 2 formed in a part of a base 1 provided with. A rotary cylindrical body 6 is rotatably fitted around a reference axis O1 in a cylindrical hole 4 formed in the hollow housing 2 in the vertical axis. The rotary cylindrical body 6 has an eccentric hole having a bottom in the vertical axis direction. 5 is formed centering on an eccentric axis O2 which is eccentric from the reference axis O1. The upper end surface of the rotating cylindrical body 6 is pressed by an annular lid body 7 fixed to the upper surface of the hollow housing 2.

The flange portion 6a formed on the upper end of the rotary cylinder 6 is sandwiched between the step portion of the cylindrical hole 4 and the outer peripheral cylindrical portion 7a of the lid 7 fitted in the opening of the cylindrical hole 4. Cage,
The rotating cylindrical body 6 is vertically restricted. The opening of the eccentric hole 5 is a stepped large diameter portion 5a, and the inner peripheral cylindrical portion 7b of the lid 7 is fitted into the large diameter portion 5a from above to form a fixed wedge portion 8a. An annular movable wedge member 8 having a movable wedge portion 8b formed in an upper portion is slidably fitted vertically between the lower end of the portion 7b and the stepped portion of the large diameter portion 5a, and the inner circumference of the lid body 7 is fitted. The inner peripheral surfaces of the cylindrical portion 7b and the movable wedge member 8 have eccentric holes 5
The inner circumferential surface is the same as the inner circumferential surface, and is an extension of the eccentric hole 5. The fixed wedge portion 8a and the movable wedge portion 8b engage with each other to act as a wedge.

In the eccentric hole 5 of the rotating cylinder body 6 (including the inner peripheral cylindrical portion 7b of the lid body 7 and the movable wedge member 8), a cylinder body 9 slightly protruding from the upper surface of the lid body 7 is fitted. . Cylindrical body 9
Has a cylinder hole 11 formed on the upper surface and opening on the upper surface,
A spline hole 12 opened on the lower surface is formed in the lower part, and the cylinder hole 11 and the spline hole 12 which are in a coaxial relationship are communicated with each other by a shaft hole 13. A spline sleeve 1 having a central hole having the same diameter and the same diameter as the shaft hole 13 in the spline hole 12.
7 is inserted by spline connection, and spline sleeve 1
The lower end of 7 penetrates the bottom of the eccentric hole 5 and projects from the lower surface of the rotary cylinder 6, and is rotatably supported at the bottom of the eccentric hole 5 via a rolling bearing 18.

On the upper end surface of the cylindrical body 9, a reference sheet base 14 is provided.
Is fixed, the cylinder hole 11 and the reference sheet base 14
And a lower surface of the cylinder form a cylinder. A piston 15 is fitted in the cylinder hole 11, and a rotary rod 16 extending downward from the piston 15 is slidably fitted in a shaft hole 13 and a central hole of a spline sleeve 17 in a vertically slidable manner.

A base portion 20a of the clamp arm 20 extending upward from the piston 15 penetrates the reference sheet base 14 in a rectangular cross section, is slidable in the vertical direction with respect to the reference sheet base 14, and is integrally formed in the rotation direction. Has become. Base 20a
The tip end portion of the clamp arm 20 protruding upward from is a clamp claw portion 20b that extends in the radial direction and faces the reference sheet 14a formed on the outer peripheral portion of the upper surface of the reference sheet base 14. For the reference sheet base 14, a stopper 21 that restricts the rising range is provided on the lid 7.

The cylindrical body 9 is formed with passages 22a, 22b which are open at the upper end and the lower end of the cylinder hole 11. The passage 22 of the cylindrical body 9 is provided in the rotating cylindrical body 6.
oil grooves 23a on the inner peripheral surface where a and 22b communicate with each other within a movable range,
23b and oil passages 23a and 23b, and passages 24a,
24b is formed, and a passage 25a opened to the inner peripheral surface of the large-diameter portion 5a above the movable wedge member 8 and the step portion,
25b is formed. The hollow housing 2 is provided with a locking hydraulic cylinder 26 that locks the rotation of the rotary cylinder 6 in the radial direction. That is, the piston 26a of the lock hydraulic cylinder 26 is moved forward and backward by hydraulic pressure, presses the outer peripheral surface of the rotary cylinder 6 to lock it in forward movement, and releases the rotary cylinder 6 rotatably in backward movement. There is.

A worm wheel 27 and a first gear 28 are coaxially attached to the lower end of the rotary cylinder 6, and the lower end of the spline sleeve 17 protruding from the lower surface of the rotary cylinder 6 has Rotating arm 29 extending in the radial direction
The base of is fixed. (See FIG. 1) As shown in FIGS. 1 and 3, inside the base 1, a first intermediate gear 30 meshing with a first gear 28 and another second intermediate gear 31 are coaxially and integrally rotated. The second intermediate gear 3 is provided freely.
A second gear 32 that meshes with 1 is rotatably provided. Eccentric pin 33 planted in the eccentric position on the second gear 32
The tip end of is rotatably supported by the tip end of the rotating arm 29.

A drive shaft 35 attached to a worm 34 meshing with the worm wheel 27 and rotatably supported.
Is projected from the base 1, and a shaft coupling member 36 is attached to the tip thereof. As shown in FIG. 1, the swivel drive device B provided in the workpiece clamp device A is installed on the base 1, and the housing 40 of the swivel drive device B has a drive shaft 35 of the workpiece clamp device A. Guide rail 41 parallel to
The piston rod 42a of the hydraulic cylinder 42 for advancing and retracting is connected to the housing 40.

A servomotor 43 is mounted on the housing 40, and a hollow shaft 44 is rotatably provided in a coaxial relationship with the drive shaft 35 of the workpiece clamping device A via a rolling bearing 45. The hollow shaft 44 is connected to the motor shaft of the servomotor 43 and is rotationally driven. The shaft coupling member 46, which is inserted into the tip of the hollow shaft 44 so as to be able to move forward and backward and is engageable with the shaft coupling member 36 of the drive shaft 35 of the workpiece clamping device A, is moved forward by the compression coil spring 47 in the hollow shaft 44. Is elastically pressed against.

The operation and action of the above work clamp device will be described. As shown in FIG. 4, the work W placed on the work placement table 3 is fastened by a clamp device C that is appropriately installed. When a part of the workpiece W is drilled, for example, the workpiece clamp device A shown in FIGS. 1 and 2 performs a natural clamp on the processed portion in order to stabilize the workpiece. (See FIGS. 1, 2 and 4)

First, the reference sheet 14a of the work clamp device A is positioned just below the machined portion according to the shape and size of the work W to be fastened. To this end, the hydraulic circuit is switched for the lock hydraulic cylinder 26, the piston 26a is retracted, and the lock of the rotary cylinder 6 is released.

Next, in the turning drive unit B, the hydraulic circuit is switched for the hydraulic cylinder 42, and the piston 42 is moved.
When a is retracted, the housing 40 moves to the guide rail 41.
The shaft coupling member 45 that is guided by
The shaft coupling member 36 on the side of the workpiece clamping device A and the compression coil spring 47 are elastically coupled by the spring force. When the rotation of the workpiece clamping device A is stopped, this coupling causes the shaft coupling member 45 in the orbiting drive device B to compress and retract the compression coil spring 47, and disengage from the engagement with the shaft coupling member 36.

Therefore, when the servomotor 43 is controlled and driven by a predetermined number of revolutions, the hollow shaft 44 and the shaft coupling members 45, 3 are driven.
The worm 34 rotates a predetermined number of revolutions via the drive shaft 6 and the drive shaft 35. Therefore, since the worm wheel 27, that is, the rotating cylindrical body 6 rotates by a predetermined rotation angle, the cylindrical body 9, that is, the reference sheet base 14, rotates about the central axis of the rotating cylinder 6 by a predetermined turning angle with the eccentric amount as a radius. Then, it is displaced to a predetermined position.

At that time, together with the worm wheel 27, the first
Since the gear 28 rotates and the second gear 32 rotates through the first intermediate gear 30 and the second intermediate gear 31 at a predetermined gear ratio by a predetermined angle, the eccentric pin 33 is connected to the center axis of the second gear 32. Around the predetermined turning angle with the eccentric amount as the radius.
Then, the rotating arm 29 rotates about the central axis of the cylindrical body 9 by a predetermined rotating angle, and the spline sleeve 17 rotates by a predetermined rotating angle so as to offset the rotating angle of the rotating cylindrical body 6.

Then, through the spline sleeve 17 and the spline hole 12, the cylindrical body 9, that is, the reference sheet base 14, is inserted.
Is rotated and the clamp arm 20 is integrally fixed to the reference sheet 14 at the base portion 20a.
And the clamp arm 20 integrally rotate by a predetermined rotation angle. Therefore, the reference sheet 14a and the clamp claw portion 20b
Is always maintained in the same direction by offsetting the change in direction of the reference sheet base 14 due to the revolving rotation of the predetermined angle by the rotation of the reference sheet base 14. Thus, the reference sheet 14a and the clamp claw portion 20 are positioned at positions vertically opposed to each other with the processed portion of the workpiece W to be fastened in between. Then, by switching the hydraulic circuit to the lock hydraulic cylinder 26, the piston 26a advances and the rotary cylinder 6 is locked to the hollow housing 2.

Next, when the passage 25a communicates with the external supply source and the passage 25b communicates with the oil tank, the large diameter portion 5 of the eccentric hole 5 is formed.
At a, since the pressure oil is supplied to the upper side of the movable wedge member 8 and discharged from the lower side, the pressure oil causes the movable wedge member 8 to move.
Is pushed down, the engagement between the fixed wedge portion 8a and the movable wedge portion 8b is released, and the cylindrical body 9 is vertically movable in the eccentric hole 5.

Therefore, when the passage 24a communicates with the external supply source and the passage 24b communicates with the oil tank, the pressure oil flows into the upper portion of the cylinder hole 11 through the oil groove 23a and the passage 22a and the cylinder hole 11 Pressure oil from the bottom of the passage 22b
And the oil 15 is discharged through the oil groove 23b, so that the piston 15 is pushed down by the pressure oil. Therefore, the clamp arm 20 descends, the clamp claw portion 20b contacts the workpiece W and is restrained from descending, and then the cylindrical body 9, that is, the reference sheet base 14 is pressed.
Rises. Then, the processed portion of the workpiece W is grasped by being vertically sandwiched between the reference sheet 14a and the clamp claw portion 20b.

Next, the passage 25b is connected to an external supply source and the passage 25a is connected to an oil tank, and in the large diameter portion 5a of the eccentric hole 5, pressure oil is supplied to the lower side of the movable wedge member 8 and the upper side. Therefore, the movable wedge member 8 is pushed up by the pressure oil, the fixed wedge portion 8a and the movable wedge portion 8b are engaged, the cylinder 9 is fixed, and the pressure oil is supplied to the cylinder hole 11.・ Stop discharging. Thus, the processed portion of the workpiece W is naturally clamped by the reference sheet 14a and the clamp claw portion 20b, and appropriate processing is performed. After the processing is completed, the above operations are performed in reverse order, and the workpiece W is removed from the workpiece mounting table 3.

[0027]

According to the workpiece clamping device of the present invention, when the positions of the support surface and the clamp are changed depending on the type of the workpiece, the workpiece clamping device is fixed even if the mounting position is fixed. The position of the support surface and the clamp with respect to is variable.

Therefore, in order to deal with various work pieces, the work piece fixing area is wide, but it does not become large. Furthermore, since it is not necessary to change the mounting location to support various types of workpieces, work efficiency is high and even if the mounting location is constant, various workpiece clamping devices are available for replacement mounting. Since it is not necessary to do so, it not only improves work efficiency but also reduces costs.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view showing the outline of a work clamp device with a swing drive device according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the workpiece clamping device according to the embodiment of the present invention.

FIG. 3 is a sectional view of a synchronous rotation drive mechanism of the workpiece clamping device according to the embodiment of the present invention.

FIG. 4 is a plan view of the workpiece clamping device according to the embodiment of the present invention.

[Explanation of symbols]

A Work clamp device B Swing drive device 1 Base 2 Hollow housing 3 Work placement table 4 Cylindrical hole 5 Eccentric hole 5a Large diameter part 6 Rotating cylindrical body (rotating member) 6a Flange part 7 Lid body 7a Outer peripheral cylindrical part 7b Circumferential cylindrical part 8 Movable wedge member 8 8a Fixed wedge 8b Movable wedge part 9 Cylindrical body 11 Cylinder hole 12 Spline hole 13 Shaft hole 14 Reference sheet base 14a Reference sheet 15 Piston 16 Rotating rod 17 Spline sleeve 18, 45 Rolling bearing 20 Clamp arm 20a Base portion 20b Clamp claw portion 21 Stopper 22a, 22b; 24a, 24b; 25a, 25b Passage 23a, 23b Oil groove 26 Locking hydraulic cylinder 26a Piston 27 Worm wheel 28 1st gear 29 Rotating arm 30 1st intermediate gear 31 31st 2 Intermediate gear 32 Second gear 33 Eccentric pin 34 War 35 the drive shaft 36, 46 a shaft coupling member 40 housing 41 guide rail 42 the hydraulic cylinder 42a a piston rod 43 servo motor 44 hollow shaft 47 a compression coil spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumio Maida 1-11-11 Yanagibashi, Taito-ku, Tokyo Incorporated Toyohken (72) Inventor Tsutomu Sugiura 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Corporation In-house (72) Inventor Takuo Shibata 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Hiroyuki Ota 1 Toyota Town, Toyota City, Aichi Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A rotating member provided on a base so as to be rotatable about a reference axis, and a rotating member rotatable about an eccentric axis eccentric with respect to the reference axis of the rotating member and displaceable in the eccentric axis direction. And a seat base on which a reference sheet for supporting the workpiece is formed, and is displaceable in the eccentric axis direction independently of the seat base and is rotatable around the eccentric axis integrally with the seat base. A clamp member that is provided on the rotating member and presses a workpiece, a driving unit that rotationally drives the rotating member, a sheet base and a clamp member that synchronize with rotation of the rotating member, and cancel the rotation of the rotating member. Work clamp device including drive means for rotationally driving the seat base and drive means for driving the seat base and the clamp member in opposite directions along the eccentric axis.