JPS6320641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chuck for a machine tool, and in particular to a chuck suitable for gripping annular workpieces.

In a conventional chuck of this kind, for example, as shown in FIG. 1, grooves 2 extending in the axial direction are provided at four locations (or several locations) on the circumference of a workpiece gripping portion 1 having a cylindrical outer diameter surface. On the inner diameter of the chuck body 3, which allows the workpiece gripping part 1 to expand and contract elastically in the radial direction,
A chuck opening/closing shaft 4 that can be moved back and forth in the axial direction is inserted, and by advancing the shaft 4, the workpiece gripping portion 1 is expanded and an annular workpiece W fitted to the outer diameter of the chuck opening/closing shaft 4 is inserted.
By gripping the workpiece W and retracting the shaft 4, the diameter of the workpiece gripping portion 1 is elastically reduced, thereby making it possible to remove the workpiece W. A nozzle 5 for removing the workpiece W is placed near the chuck, and the workpiece W is automatically removed by pressurized air jetted from the nozzle 5.

However, in order to automate the loading and unloading of workpieces in such chucks, it has conventionally been necessary to use pressurized air at least when taking out the workpieces, and the amount of pressurized air used per day has become extremely large, increasing costs. It's expensive.

Chips generated during processing may change the position of the nozzle or the position of the air pipe that supplies pressurized air to the nozzle. If the position of the nozzle or air pipe changes in this way, the workpiece that has been processed cannot be quickly removed from the chuck, which may cause problems with the workpiece that has been loaded for the next cycle of processing. do.

Loading errors may cause damage to the blade. In addition, it takes a lot of man-hours to adjust the chuck and air nozzle. The noise of the pressurized air ejected from the nozzle is high, increasing factory noise. The work is difficult due to the mist contained in the pressurized air. There were many shortcomings.

This invention solves the above-mentioned drawbacks of the conventional chuck, and in particular eliminates the need for pressurized air to remove the workpiece at the completion of machining, thereby achieving cost and energy savings, reducing the number of air adjustment steps, and reducing the load. The purpose of this is to eliminate printing errors.

To explain an embodiment, as shown in FIGS. 2, 3, and 4, a chuck is formed at the tip of a chuck body 10 fixed to the tip of the machine body M or the main shaft by screwing or the like. A workpiece gripping part 11 having a cylindrical outer diameter surface is provided with four (or several) axial grooves 12 on the circumference, and a tapered hole 13 on the inner diameter thereof.
, the tip tapered shaft portion 14 of the chuck opening/closing shaft 15
In the chuck, which is designed to grip and remove the annular workpiece W by expanding and contracting the workpiece gripping part 11 in the diametrical direction by moving the shaft 15 forward and backward, the chuck is configured to grip and remove the annular workpiece W. A push-out member 17 having the same number of blades 16 as the grooves 12 that are slidably positioned is installed in the chuck body 10, and the tips of the blades 16 of the member 17 slide within the grooves 12 to push the workpiece. A push-out spring 20 is provided between the push-out member 17 and the step 19 provided on the chuck opening/closing shaft 15. It is something that The extrusion spring 20
The push-out member 17 is urged in the axial direction so that the tip of the blade 16 of the push-out member 17 projects from the positioning step portion 18 in the direction of the outer diameter axis of the workpiece gripping portion 11 . Note that the push-out spring 20 is not necessarily connected to the push-out member 17 and the stepped portion 1 of the chuck opening/closing shaft 15.
There is no need to arrange it between the chuck body 1 and the chuck body 1.
0 and the extrusion member 17 so that the member 17 is biased in the same direction as described above, or between the machine main body M or the main shaft and the extrusion member 17, etc. can. Further, in the embodiment, the chuck opening/closing shaft 15 pushes out the pushing member 17.
Although the configuration in which the member 17 is slidably supported in the axial direction by penetrating the extrusion member 1 is shown, the extrusion member 1
7 may be configured to be slidably supported on the chuck body 10 in the axial direction.

In the figure, reference numeral 21 denotes a push rod that is moved back and forth by hydraulic pressure or the like to actuate the chuck opening/closing shaft 15 in the axial direction, and 22 is a return spring that biases the chuck opening/closing shaft 15 in the opposite direction to the push rod 21.

The present invention has the above-described configuration, and the workpiece W is rotated by a loading device (not shown) in a state where the chuck opening/closing shaft 15 is retracted by the force of the spring 22 as shown in FIG. It fits into the outer periphery of the workpiece gripping part 11 of the chuck body 10, moves the push-out member 17 backward (to the right) against the bias of the spring 20, and moves the blade 16 to the positioning stepped part 18.
The end face of the workpiece W is retracted into the positioning step 1.
8.

In this state, the push rod 21 is moved to the left as shown by the arrow in FIG. The workpiece W is fixed by making contact with the tapered hole 13 of the inner diameter and expanding the gripping part 11 provided with the groove 12 in the vertical direction.

Due to this fixation, the loading device is moved backward and away from the workpiece W, and the chuck is rotated to process a desired portion of the workpiece W.

When the machining is completed, the rotation of the chuck is stopped, and the push rod 21 is moved backward (to the right) by the hydraulic device. As a result, the chuck opening/closing shaft 15, which is biased in the backward direction by the spring 22, moves backward (to the right) following the backward movement of the push rod 21. Therefore, a gap is created between the tapered shaft portion 14 and the tapered hole 13 on the inner diameter of the workpiece gripping portion 11, and the workpiece gripping portion 11 provided with the groove 12 is closed due to its elastic restoring force. Reduce the diameter of 11.

Since the gripping force on the workpiece W is eliminated by reducing the diameter of the gripping portion 11, the pushing member 17, which is biased by the spring 20, moves forward (to the left) at the same time as the reduction operation, and pushes the tip of the blade 16. The workpiece W, which is made to protrude in the axial direction from the positioning step part 18 and released from the gripping force due to the reduction in diameter, is pushed out to the left from above the workpiece gripping part 11 and removed from the chuck body 10.

That is, almost simultaneously with the retraction of the push rod 21, the workpiece W is automatically removed from the chuck body 10 in preparation for loading the next workpiece.

In the embodiment, when the chuck opening/closing shaft 15 retreats (moves to the right), the spring 20 advances the pushing member 17 (moves to the left).
chuck opening/closing shaft 15 for expanding and contracting the diameter of 1;
Since the stroke of the forward and backward movement of the opening/closing shaft 15 is only a few millimeters at most, the effect of the backward movement of the opening/closing shaft 15 on the biasing force of the spring 20 against the extrusion member 17 can be ignored. Since the pushing force (biasing force of the spring 20) for pushing out the workpiece W from the workpiece gripping part 11 only needs to be extremely small, the removal operation of the workpiece W from the workpiece gripping part 11 can be performed extremely smoothly. There is no problem in the backward movement of the push-out member 17 when the workpiece is loaded onto the workpiece gripping portion 11.

As described above, this invention eliminates the need to use pressurized air as in the conventional method to remove the workpiece from the chuck body, eliminates the need to arrange a nozzle for blowing out pressurized air around the chuck, and removes the workpiece from the chuck body. Problems caused by nozzle placement are completely eliminated. In other words, the consumption of pressurized air is
At least for workpiece removal, the amount of pressurized air used in the entire factory is reduced to zero, resulting in cost savings and energy savings. There is no need to worry about breakage of cutlery, etc., and the number of man-hours required to adjust the pressure air is reduced, and problems such as factory noise and deterioration of workability due to mist can be eliminated.

Furthermore, the present invention has an extremely simple structure in which a push-out member and a spring for biasing the member are added to a conventional chuck of this type, so it can be used not only for newly manufactured chucks but also for conventional chucks. It is also extremely easy to modify the chuck.
For example, it can be expanded and applied to all types of single-function machine tools.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a conventional chuck device, FIG. 2 is a longitudinal sectional front view of an embodiment of the invention, FIG. 3 is a longitudinal sectional front view showing a workpiece gripping state, and FIG. 4 is an exploded view. 10...chuck body, 11...workpiece gripping part, 1
2...Split groove, 13...Tapered hole, 14...Tapered shaft portion, 15...Chuck opening/closing shaft, 16...Blade, 17...
Push-out member, 18... Positioning step portion, 20... Push-out spring, 22... Return spring.

Claims (1)

[Claims] 1. A workpiece gripping portion having a cylindrical outer diameter surface formed at the tip of the chuck body is provided with axial grooves at several locations around the circumference, and a chuck opening/closing shaft is inserted into the tapered hole on the inner diameter of the workpiece gripping portion having a cylindrical outer diameter surface formed at the tip of the chuck body. In a chuck for machine tools, the tapered shaft at the tip is exposed, and the chuck opening/closing shaft is moved back and forth in the axial direction to expand and contract the workpiece gripping part in the diametrical direction to attach and detach the inner diameter of the annular workpiece. The chuck body is equipped with an extrusion member equipped with a vane that is slidable in the axial direction within the groove, and the tip of the vane is moved from the positioning step of the workpiece gripping part to the outer diameter of the gripping part. A push-out spring is provided that urges the push-out member in the axial direction so that the tip of the blade of the push-out member projects from the positioning step portion in the direction of the outer diameter axis of the workpiece gripping portion. Naruchatsuku. 2. The chuck according to claim 1, wherein an extrusion spring is interposed between the stepped portion formed on the chuck opening/closing shaft and the extrusion member. 3. The chuck according to claim 1 or 2, wherein the extrusion member is provided with the same number of blades as the axial grooves provided in the chuck body.