JP6208482B2 - Work gripping device that automatically replaces jaws. - Google Patents

Description

  The present invention relates to a structure of a workpiece gripping device that automatically replaces a jaw.

In recent years, in order to improve productivity, there has been a growing demand for comprehensive automation of machine tools and peripheral devices.
To answer this question, even with a workpiece gripping device attached to a machine tool, it is possible to automatically replace the jaws of the chuck that grips the workpiece according to the size and shape of the workpiece without having to remove the manpower. Various workpiece gripping devices have been proposed.

JP-A-5-318210

In the above-described prior art, the claw engagement / disengagement device that engages the rack teeth is used to engage and disengage the claw that is detachable.
This claw engagement / disengagement device locks and releases claw attachment / detachment by the operation of a claw removal cylinder provided on the outside of the chuck, and the claw engagement / disengagement device is different from the chuck operation by the cylinder that drives the chuck. Detachment is performed.
For this reason, since the chucking operation and the replacement of the claw are not performed together, there is a problem that the attaching / detaching operation of the claw of the chuck cannot be performed safely and reliably.

In order to solve the above problems, the present invention is a workpiece gripping device for automatically exchanging jaws, comprising a chuck portion for gripping a workpiece, and a cylinder portion for transmitting a driving force to the chuck portion. Has a first cylinder part that generates an acting force to the plunger part of the chuck, and a second cylinder part that adjusts a moving range of the first cylinder part when the plunger part is moved backward of the chuck, the chuck part Is provided with a hollow portion on the rear side of the chuck body, the first piston of the first cylinder is moved rearward in the axial direction by driving the second cylinder portion, and the plunger portion in which the hollow portion is moved rearward is stored. The plunger is separable from the master jaw .

  In the present invention, the cylinder is driven and moved when the chuck is opened and closed and the plunger claw is replaced, thereby linking the operation of the cylinder and the operation of the lock mechanism of the master jaw to perform the automatic jaw replacement operation more safely and reliably. Can be done. Furthermore, the above-described effects can be realized with a simple configuration.

It is sectional drawing of the workpiece holding apparatus which concerns on the Example of this invention. It is sectional drawing of the workpiece | work holding | grip and cancellation | release state of the workpiece | work holding | grip apparatus which concerns on the Example of this invention. It is sectional drawing of the jaw replacement | exchange start state of the workpiece | work holding device which concerns on the Example of this invention. It is sectional drawing of the jaw replacement | exchange state of the workpiece holding apparatus which concerns on the Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail.
A workpiece gripping apparatus according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the workpiece gripping apparatus according to the present invention includes a chuck portion 1 that grips a workpiece 25 and a cylinder portion 4 that is a drive source of the chuck portion 1.

The chuck portion 1 is provided with a soft jaw 2 and a master jaw 3 detachably attached to the workpiece body 25 toward the front side of the chuck body 7.
When the jaws are automatically replaced, the jaws in which the soft jaw 2 and the master jaw 3 are integrated are replaced.
The master jaw 3 can be slid in the chuck radial direction by an engagement groove (not shown), and can be exchanged outside by an automatic exchange device.

Inside the chuck body 7, there is provided a plunger portion 9 for receiving a driving force of a cylinder portion 4 described later, and a draw nut 15 connected to a draw pipe 26 provided between the cylinder portion 4 and the chuck portion 1. It is provided to engage with.
The plunger portion 9 moves back and forth in the axial direction inside the chuck in accordance with the operation of the draw pipe 26 that moves back and forth in the axial direction by driving the cylinder portion 4.
The plunger portion 9 includes a plunger 27 that engages with the draw nut 15 and a wedge plunger 28 that is engaged with the plunger and is slidably fitted to the master jaw 3 at the wedge portion, although not shown in the cross-sectional view. It is configured.
The master jaw 3 is movable in the radial direction by the movement of the wedge plunger 28.

In order to enable the plunger portion 9 to move further rearward after the engagement with the master jaw 3 is released when the plunger portion 9 moves rearward of the chuck body 7 inwardly on the rear side of the chuck body 7. An empty portion 8 having a space for storing 9 is provided.
By accommodating the plunger part 9 in the empty part 8, the backward movement of the plunger part 9 can be greatly allowed.

A lock pin 10 for engaging and disengaging the master jaw 3 is incorporated in the chuck body 7. The lock pin 10 is provided in order to prevent the master jaw 3 from being detached when the engagement between the master jaw 3 and the plunger portion 9 is released during jaw replacement. The front end is fitted into a locking hole 16 provided in the master jaw 3.
The lock pin 10 is provided with a spring 11 as a biasing means so as to be constantly pressed toward the master jaw.

A release pin 12 is provided on the chuck body 7 in order to suppress movement of the lock pin 10 toward the master jaw by the spring 11.
The release pin 12 is engaged with the lock pin 10, and is engaged so that the inclined surface 13 provided on the release pin 12 and the tapered surface 14 provided on the lock pin 10 are in contact with each other. The taper surface 14 is constituted by respective joining portions before and after the release pin 12 and above and below in the drawing.

The release pin 12 is provided so as to be movable in the chuck radial direction, and is provided so that the inner end in the radial direction is in contact with and locked to the outer peripheral surface of the plunger portion 9.
When the plunger portion 9 is housed in the empty portion 8 of the chuck body 7, it does not come into contact with the plunger portion 9 of the release pin 12 described above, and the release pin 12 is moved inward in the radial direction. The movement of the lock pin 10 is released from inhibiting the movement of the lock pin 10 toward the master jaw.

Next, the cylinder part 4 will be described.
The cylinder part 4 is connected to the chuck part 1 via a draw pipe 26.
The cylinder part 4 of the present invention is a combination of two cylinders, and includes a first cylinder part 5 and a second cylinder part 6.
The cylinder body 17 includes an intermediate wall 21 in an inner hollow portion, and a first piston chamber 19 and a second piston chamber 22 are formed.

As the first cylinder portion 5, a first piston portion 20 is slidably provided inside the first piston chamber 19, and a chuck side front end portion of the first piston portion 20 is connected to a draw pipe 26. .
The rear part of the first piston part 20 forms a shaft part 18 extending rearward in the axial direction, and is provided through the second piston chamber 22.

A second piston portion 23 is slidably provided in the second cylinder portion 6 inward of the second piston chamber 22.
The second piston portion 23 is slidably provided through the shaft portion 18 of the first piston portion 20, and the front end portion of the second piston portion 23 exceeds the intermediate wall 21 of the cylinder body 17 and is first slidable. A stopper portion 24 that protrudes into the piston chamber 19 is formed, can be brought into contact with the rear portion of the flange portion 29 of the first piston portion 20, and is configured to suppress the rearward movement of the first piston portion 20. .
Therefore, the movement range of the first cylinder part 5 is adjusted by driving the second cylinder part 6.
The first cylinder part 5 and the second cylinder part 6 described above are each connected to a separate pressure pipe and can be driven independently.

The operation of the embodiment of the present invention will be described below.
As shown in FIG. 2, when the chuck portion 1 grips and releases the workpiece 25 by the soft jaw 2, the cylinder portion 4 has the second piston portion 23 of the second cylinder portion 6 to the forefront of the chuck portion. The stopper portion 24 of the second piston portion 23 protrudes into the first piston chamber 19.
Therefore, when the first piston part 20 is moved to the rear side, the first piston part 20 comes into contact with the protruding portion of the stopper part 24, and the stopper part 24 suppresses the movement of the first piston part 20 to the rear side. 5, the sliding range of the first piston portion 20 is reduced.
The driving force of the plunger portion 9 of the chuck portion 1 is transmitted through the draw pipe 26 in the longitudinal movement range of the first piston portion 20 in the axial direction.

The operation of gripping the workpiece of the chuck portion 1 is performed within the movement range of the first piston portion 20 suppressed by the stopper portion 24 of the second piston portion 23 described above.
The axial movement transmitted to the plunger portion 9 is converted into the radial movement of the master jaw 3 by the wedge action of the plunger portion 9, and the workpiece is gripped and released by the radial movement of the soft jaw 2.

When the replacement of the master jaw 3 is started, the master jaw 3 is separated from the chuck portion 1 by accommodating the plunger portion 9 in the empty portion 8 of the chuck body 7 by the operation of the second cylinder portion 6. .
First, the first piston part 20 is moved toward the rear in the axial direction. At this time, since the second piston portion 23 is in the state of being moved forward in the axial direction, the first piston portion 20 is in contact with the second piston portion 23 and the backward movement is suppressed.

As shown in FIG. 3, in this state, the second cylinder portion 6 is driven, and the second piston portion 23 is moved rearward in the axial direction. Along with this, the first piston part 20 can be moved further rearward.
When the first piston part 20 moves rearward, the plunger part 9 is further moved rearward of the chuck via the draw pipe 26. The plunger portion 9 that has moved rearward of the chuck is housed in the empty portion 8 of the chuck body 7.

At this time, as the plunger portion 9 moves backward, the release pin 12 is moved in the chuck radial direction.
When the plunger portion 9 moves rearward, the release pin 12 that has been restricted from moving inward of the chuck radius by abutting against the outer peripheral surface of the plunger portion 9 does not come into contact with the plunger portion 9 and remains in the chuck radial direction. To be moved.
When the release pin 12 moves inward in the chuck radial direction, the lock pin 10 engaged with the release pin 12 on the inclined surface is urged toward the master jaw side by the spring 11, so that the movement by the release pin is suppressed. Is released and moves to the master jaw side.
The lock pin 10 moved to the master jaw side is fitted into a locking hole 16 provided in the master jaw 3, and the chuck portion 1 and the master jaw 3 are engaged via the lock pin 10 to fix the master jaw 3. Is done.

  Thereafter, as shown in FIG. 4, when the second piston portion 23 is further moved rearward in the axial direction, the plunger portion 9 is further moved rearward of the chuck, and the wedge portion fitted to the master jaw 3 (not shown) is moved. As a result, the plunger portion 9 is completely disengaged from the master jaw 3, and the plunger portion 9 is completely stored in the empty portion 8.

When the automatic jaw replacement preparation is performed by the workpiece gripping device as described above, the jaws are automatically replaced by a separate device.
When exchanging the jaw, the lock pin 10 is moved backward by the movement of the release pin 12 by a separate device, the master jaw 3 is disengaged from the engaging hole 16, and the master jaw 3 and the chuck portion are moved. The jaws can be removed by releasing the integration with 1.
Then, the jaws are exchanged separately by the apparatus, and the new jaws after the exchange are attached to the chuck portion 1 by the reverse operation to the above, and the workpiece 25 can be gripped and released.

In the present invention, the cylinder part 4 includes a first cylinder part 5 and a second cylinder part 6, and the first cylinder part 5 is provided with a movement range limited by driving of the second cylinder part 6. Within the restricted movement range, the soft jaw 2 provided in the chuck portion 1 is moved in the radial direction via the plunger portion 9.
Then, by driving the second cylinder portion 6, the rearmost portion in the moving range of the first cylinder portion 5 can be expanded rearward and the plunger portion 9 can be accommodated behind the chuck body 7. By providing this, the movement range of the plunger portion 9 can be increased, and the plunger portion 9 can be separated from the master jaw 3 in conjunction with the driving of the cylinder portion 4. Thereby, the automatic replacement | exchange operation | work of a jaw can be performed safely and reliably.
Note that the embodiment of the present invention is not necessarily limited to the configuration of the above-described embodiment. While the invention has been described in terms of a preferred embodiment, such descriptions are not limiting and, of course, various modifications are possible.

DESCRIPTION OF SYMBOLS 1 Chuck part 2 Soft jaw 3 Master jaw 4 Cylinder part 5 1st cylinder part 6 2nd cylinder part 8 Empty part 9 Plunger part 10 Lock pin 11 Spring 12 Release pin 20 1st piston part 23 2nd piston part 26 Draw pipe

Claims (2)

A workpiece gripping device for automatically exchanging jaws, comprising: a chuck portion for gripping a workpiece; and a cylinder portion for transmitting a driving force to the chuck portion, wherein the cylinder portion generates an acting force on a plunger portion of the chuck. A first cylinder part, and a second cylinder part for adjusting a moving range of the first cylinder part when the plunger part is moved rearward of the chuck, wherein the chuck part includes an empty part on the rear side of the chuck body, The first piston of the first cylinder is moved rearward in the axial direction by driving the two cylinder parts , the empty part accommodates the plunger part moved rearward, and the plunger part is separable from the master jaw . A workpiece gripping device characterized by the above. The chuck portion is provided inward of the chuck body, has a lock pin for fixing the chuck body and the master jaw by being engaged with the master jaw, and an urging means for pressing the lock pin toward the master jaw side. A release pin that engages the lock pin with an inclined surface and suppresses the movement toward the master jaw side, and the release pin is pressed toward the plunger side and is brought into contact with the plunger to be locked. The contact of the release pin with the plunger portion is released by the movement of the lock portion to the empty portion, the inhibition of the movement of the lock pin to the master jaw side is released, and the lock pin is fitted to the master jaw and chucked. The workpiece gripping device according to claim 1, wherein the part and the master jaw are fixed .