JP2004025334A - Collet chuck device with guide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collet chuck device structure consisting of a simple structure wherein the flaw of a work is prevented in inserting a workpiece, and facilitating the replacing work of a workpiece positioning stopper in a collet chuck device provided on the main spindle of a NC automatic lathe. <P>SOLUTION: This device has a collet chuck structure comprising: a sleeve provided on the inside of the main spindle of the lathe; a collet chuck provided on the inside of the sleeve, and opened and closed by the relative movement with the sleeve to selectively grasp a bar material (work); a stopper for positioning the bar material provided on the inside of the collect chuck; and a spring-energized center guide pin provided on the stopper. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a collet chuck device which is provided inside a main spindle provided in a numerically controlled automatic lathe or the like and grips a workpiece made of a bar.
[0002]
[Prior art]
An NC automatic lathe is provided with a spindle that is rotated by a spindle motor.
A sleeve is provided on the inner peripheral side of the main shaft, and a collet chuck is provided on the inner peripheral side.
A conventional structure of such a collet chuck will be described with reference to FIG.
The illustration of the main shaft and the sleeve and the like provided on the inner peripheral side of the main shaft is omitted.
[0003]
The distal end of the collet chuck 120 is provided with a chuck claw 121 having a split groove. The relative movement between the taper portion 121b of the chuck claw and the taper portion 122a of the chuck head 122 causes the inner wall 121a of the chuck claw 121 to move. The work 1 is configured to be gripped.
In many cases, the work is automatically inserted into the chuck jaws by a work loader or the like.However, a collet chuck is formed in a sleeve shape to ensure the processing accuracy of the work, and a stopper for positioning the insertion of the work is provided on the inner peripheral side. 130 is installed.
The stopper 130 is provided with a stopper head 131 for positioning the work at the front end thereof, has a screw portion 132 at the rear end portion, and can be adjusted by a lock nut 133.
[0004]
However, such a collet chuck structure has the following problems.
Since the gap between the outer diameter of the gripping portion of the work 1 and the inner wall of the chuck claw 121a cannot be made large due to the adjustment relationship between the gripping force of the chuck claw 121 and the return force at the time of opening, the work is caught by the chuck claw. When the workpiece is inserted into the inside, there is a problem that the workpiece hits the inner wall or the like of the chuck claw and the surface of the workpiece is damaged.
[0005]
Further, since the insertion depth (length) differs depending on the work, it is necessary to replace the stopper 130.
In such a case, in such a conventional structure, the lock nut 133 at the rear end of the stopper and the cover 123 must be removed and pulled out rearward.
Therefore, there is a problem that such a working space is required behind the headstock.
[0006]
[Problems to be solved by the invention]
The present invention has been made in consideration of the above-described technical problems of the related art, and is intended to provide a collet chuck device provided on a main spindle of an NC automatic lathe, which can prevent the occurrence of scratches at the time of inserting a work, and can easily replace a work positioning stopper. It is an object of the present invention to provide a collet chuck device structure having a simple structure.
[0007]
[Means for Solving the Problems]
The technical gist of the present invention is that a lathe is provided on the inner peripheral side of a main shaft of a lathe, and is provided on an inner peripheral side of the sleeve, and is opened or closed by a relative movement with respect to the sleeve to form a bar (work). The collet chuck has a collet chuck structure in which a stopper for inserting and positioning the bar is provided on the inner peripheral side of the collet chuck for selectively gripping the rod, and a center guide pin biased by a spring is provided on the stopper. .
[0008]
In addition, if the stopper head is detachably attached to the tip of the stopper, the replacement of the positioning stopper head according to the work can be easily performed from the spindle head side.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a collet chuck device according to the present invention.
In addition, the illustration of the main shaft of the lathe and the sleeve provided on the inner peripheral side thereof is omitted.
At the tip of the collet chuck 20, a chuck claw 21 having a split groove structure is screwed.
A chuck head 22 is provided on the outer periphery of the chuck claw so as to open or close the chuck claw at the tapered portion.
[0010]
The collet chuck is formed in a sleeve shape, and has a stopper 30 provided on the inner peripheral side.
A guide piece 34 for guiding and supporting the inside of the collet sleeve is provided at an appropriate position on the outer peripheral portion of the stopper 30. The guide piece 34 is formed in a cylindrical shape from the front of the stopper 30 and a spring member 42 is disposed therein. The center guide pin 41 is attached to the tip of the stopper 30 so as to push out the pin 41.
[0011]
FIG. 3 is an enlarged view of the vicinity of the chuck pawl portion of the collet chuck.
The chuck 1 is screwed to the tip of the collet chuck 20, and the work 1 is inserted in a state where the chuck claw 21 is opened due to the movement interaction between the tapered portion 21 b of the chuck claw 21 and the tapered portion 22 a of the chuck head 22. Then, the outer periphery of the work is gripped by closing the chuck claws.
The stopper 30 is arranged on the inner peripheral side of the collet chuck. The stopper 30 has a cylindrical shape halfway in front of the stopper, and includes a center guide pin 41 that is pushed out by a spring member 42.
The center guide pin 41 is supported by the stopper head holder 35, and the stopper head 31 is detachably attached to the stopper holder 35.
[0012]
As shown in FIG. 3A, the tip of the center guide pin 41 has a conical shape. Inserted in.
Accordingly, as shown in FIG. 3B, the work 1 is inserted into the chuck jaws while being supported and guided by the center guide pin 41, so that the outer periphery of the work can be prevented from hitting the inner wall 21a of the chuck jaws, and inserted. No scuffing at the time occurs.
Since the center guide pin 41 is biased by a spring, it retreats so as to follow the insertion of the work.
[0013]
Since the stopper head is detachably attached to the stopper head holder 35, it can be replaced with a stopper head 31a having a different length, for example, as shown in FIG.
Also in this case, since the center guide pin 41 is supported by the spring member 42, there is no need to replace the center guide pin 41.
[0014]
A method for replacing the stopper head will be described with reference to FIG.
The screwed chuck claw 21 is removed, the lock nut 33 of the rear end screw portion 32 of the stopper 30 is returned, and the stopper 30 is pushed forward from behind the cover member 23.
Then, the stopper head 31 protrudes forward of the chuck head 22, so that the stopper head 31 can be replaced in a space in front of the main shaft.
[0015]
【The invention's effect】
In the present invention, since the center guide pin is provided on the inner side of the chuck pawl of the collet chuck so as to be able to move forward and backward, the center of the work is positioned by the center guide pin and the work is moved to the chuck portion. The attachment / detachment is made possible, and it is possible to reliably prevent a hit on the outer periphery of the work.
[0016]
In addition, since the stopper head is detachably attached to the tip of the stopper for positioning the insertion depth (length) of the work, the stopper can be replaced in the space in front of the main shaft.
This space in front of the spindle is a space originally required for machining the work, and it is no longer necessary to provide a special space behind the spindle for replacement of the stopper as in the related art.
[Brief description of the drawings]
FIG. 1 shows a sectional view of an apparatus for a collet chuck according to the present invention.
FIG. 2 shows a method of replacing a work positioning stopper head.
FIG. 3 shows a method of inserting a work into a collet chuck.
FIG. 4 shows another example of a stopper head.
FIG. 5 shows an example of a conventional collet chuck structure.
[Explanation of symbols]
1 bar (work)
Reference numeral 1a: Center hole 20 on the end surface of the work 20 Collet chuck 21 Chuck claw 21a Chuck claw inner wall 21b Taper portion 22 of chuck claw 22 Chuck head 22a Taper portion of chuck head 23 Cover member 30 Stopper 31, 31a Stopper head 32 Stopper rear end screw portion 33 Lock Nut 34 Stopper guide piece 35 Stopper head holder 41 Center guide pin 42 Spring member

Claims (2)

A sleeve provided on the inner peripheral side of the main shaft of the lathe; and a collet chuck provided on the inner peripheral side of the sleeve and opened or closed by relative movement with the sleeve to selectively grip a bar (work). A collet chuck device with a guide, characterized in that a stopper for inserting and positioning the bar is provided inside the inner peripheral side of the rod, and a center guide pin biased by a spring is provided on the stopper. 2. The collet chuck device with a guide according to claim 1, wherein a stopper head is detachably attached to a tip of the stopper.

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