JP2001198711A - Collet chuck for nc lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation of a workpiece and to perform chucking. SOLUTION: In a chuck main body 1 with a rear end part clampable at a power chuck 30 of an NC lathe, a center hole 2, a tapered hole 3, a large diameter hole 4, a cut-out groove 5 and a through hole 6 are formed. A hollow collet 10 having a tapered part 11, a screw part 12, a key groove 13, a clamping part 14, and a relief hole 15 and a plurality of pawl parts 17 is inserted by passing through the center hole 2. A whirl-stop is performed by a key 7. A suppression ring 20 is inserted from the large diameter hole 4. A bar-shaped turning jig is inserted into an operation hole 22 via the cut-out groove 5. The suppression ring 20 is manually rotated. The collet 10 is screwed into a screw hole 21 of the suppression ring 20 and is driven to the left side. The pawl parts 17 are closed and a workpiece W is clamped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collet chuck for an NC lathe capable of gripping, for example, a resin having a low rigidity or a pipe-like work having a small inner thickness and being deformable with high precision.

[0002]

2. Description of the Related Art In general, in an NC lathe, particularly a CNC lathe incorporating a recent computer, all commands relating to cutting and information on machining means are transmitted via a punch card to an NC lathe.
Input to the device, tool selection, selected tool path,
The starting and stopping of the spindle and the number of revolutions, the cutting and feeding of the blade, etc. are determined automatically by the NC unit, and machining is automatically performed. The operation can be freely changed only by changing the machining program. I have.

The NC lathe whose operation can be changed only by changing a processing program in this way is suitable for processing, for example, camera parts and lens frame parts which are produced in small quantities of many models due to its flexibility, multi-function, high precision, and the like. It has become widely used instead of general-purpose lathes, because of the spread of interactive programs and the ease of program creation.

Conventionally, in order to chuck a workpiece with this kind of NC lathe, a power chuck that releases or grips the workpiece by opening or closing three or four claws mainly controlled by hydraulic pressure or pneumatic pressure is used. Has been used.

FIG. 3 is a side sectional view showing an example of a wedge-shaped power chuck 30 having the simplest structure.
A draw bar 31 driven in the axial direction by hydraulic pressure or pneumatic pressure moves a wedge 32 moving integrally therewith in the same direction, thereby forming three or four claws 33 (only one of the claws 33 is shown in the drawing). Is driven in the closing direction or the opening direction to automatically grip and release the outer diameter portion of the workpiece (not shown).

FIG. 4 is a side view showing a state in which the workpiece W is gripped by a plurality of claws 33 (two of them are shown in the figure) of such a power chuck 30. As a power chuck for an NC lathe, a scroll chuck in which a plurality of claws automatically grips or releases a workpiece in association with the rotation thereof through an inner plate having a spiral groove is also available. Used.

[0007]

However, in such a conventional power chuck for an NC lathe, a plurality of claws grip an outer diameter portion of a workpiece by hydraulic pressure or pneumatic pressure. Static gripping force is, for example, 57K
N, which makes it extremely difficult to finely adjust the work piece tightening torque, so that low-rigidity resins and thin-walled pipe-like work pieces are easily deformed and become unworkable. There was a point.

Further, a collet chuck has not been supplied particularly to a power chuck supplied to a large-sized NC lathe. The present invention has been made in view of the above points, and an object of the present invention is to provide a collet chuck for an NC lathe capable of safely performing a multi-step process on a small-diameter workpiece that is easily deformed.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is a collet chuck for an NC lathe which grips a workpiece interposed between a power chuck of the NC lathe and the workpiece. A chuck body having a central hole capable of gripping the outer diameter portion at the rear end by the power chuck, a tapered hole expanding to the front end side and a large diameter hole formed at the rear end side, and a center of the chuck main body. A hollow collet having a plurality of openable and closable claw portions formed with a tapered portion on the front end side through which a hole can be inserted and engaged with the tapered hole of the chuck body, a hollow collet having a screw portion on a rear end side, and a screw of the collet A locking ring which has a screw hole which can be screwed into the part and which can be inserted into and removed from the large-diameter hole of the chuck main body; and a rotation stopping means for restricting the collet to the chuck main body so that it cannot rotate. In its axial direction There is provided an NC collet chuck lathe provided with a withdrawal causing driving means.

In the above-mentioned collet chuck for an NC lathe, the rotation stopping means comprises a key groove formed along the axial direction of the collet, and a key groove of the collet which is fitted in the radial direction from the outer peripheral surface of the chuck body. Preferably, the driving means includes a collet and a plurality of operation holes that can be operated from outside through a notch groove formed in a circumferential direction on an outer peripheral portion of the chuck body. It is preferable that it is made up of a holding ring having.

[0011] The collet chuck for an NC lathe according to the present invention is constructed as described above, so that a resin having a low rigidity or a pipe-shaped workpiece having a small inner thickness can be used as a powerful power chuck of the NC lathe by hydraulic or pneumatic pressure. It is possible to finely adjust the tightening torque according to the rigidity of the workpiece without receiving the deformation due to the tightening torque, and it is possible to perform the multi-step processing while avoiding the deformation.

[0012]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the present invention together with a power chuck and a workpiece, and FIG. 2 is an exploded perspective view showing only the collet chuck.

As shown in FIG. 1, a collet chuck for an NC lathe according to the present invention comprises a chuck body 1 which is gripped by a normal NC lathe power chuck 30 at an outer diameter portion on a rear end side (left end side in the figure). The collet 10 includes a collet 10 inserted through the center hole 2 of the chuck body 1 and a retaining ring 20 screwed to a rear end of the collet 10.

The chuck body 1 has a tapered hole 3 whose diameter gradually increases at the front end (right end in the figure) of the center hole 2 and a large diameter hole 4 at the rear end. On the surface, a semicircular cutout groove 5 communicating with the large diameter hole 4 along the circumferential direction and a radial through hole 6 communicating with the center hole 2 are formed.

On the other hand, the collet 10 which can be inserted into the center hole 2 of the chuck body 1 has the chuck body 1 at the front end.
A tapered portion 11 that engages with the tapered hole 3 is formed with a threaded portion 12 and a key groove 13 on the outer peripheral surface on the rear end side.
In the center of the workpiece W, a gripping portion 14 capable of gripping a part of the outer diameter of the workpiece W is formed in a hollow cylindrical shape having a larger-diameter relief hole 15 at a rear portion thereof, as shown in FIG. A plurality of openable / closable claw portions 17 are formed by a plurality of (three in the figure) slits 16 along the axial direction from the distal end side, and the key groove 13 and the through hole 6 of the chuck body 1 are inserted and fitted. The key 7 forms a rotation stopping means for the collet 10.

The holding ring 20 which can be inserted into and removed from the large-diameter hole 4 of the chuck body 1 has a screw hole 21 at the center and a plurality of operation holes 22 at substantially equal intervals on the outer periphery. A bar-shaped turning jig (not shown) can be inserted into any one of the operation holes 22 and operated in the circumferential direction through the notch groove 5 of the center hole 2 of the chuck body 1.
The screw means 12 of the collet 10 inserted into the screw hole 21 is screwed into the screw hole 21 to drive the collet 10 in its axial direction.

Next, the operation of the embodiment configured as described above will be described. The collet 10 is inserted through the center hole 2 from the tip of the chuck body 1, and the key 7 is inserted through the through hole 6 of the chuck body 1 and the tip is inserted into the collet 1.
The collet 10 is engaged with the key groove 13 to prevent the collet 10 from rotating.

On the other hand, the holding ring 11 is inserted from the large-diameter hole 4 of the chuck body 1, the above-mentioned turning jig is inserted from the notch groove 5 of the chuck body 1, and the tip thereof is held in the operating hole 2 of the holding ring 20.
2, the retaining ring 20 is rotated in the circumferential direction, and the threaded portion 12 of the collet 10 is screwed into the threaded hole 21 so that the tapered portion 11 is engaged with the tapered hole 3 of the chuck body 1. In this state, the rear end of the chuck body 1 is firmly gripped by the power chuck 30 of the NC lathe to prepare for the preparation.

In this state, when a part of the workpiece W to be machined is inserted into the holding portion 14 of the collet 10 and the holding ring 20 is further rotated in the screwing direction by a turning jig, the collet 10 is moved to the state shown in FIG. The tapered portion 11 displaces the claw portion 17 in the center direction, and the grip portion 14 grips the shaft portion of the workpiece W.

At this time, the force for gripping the workpiece W is NC
The gripping torque can be finely adjusted manually without using hydraulic pressure or pneumatic pressure on the lathe side. This makes it possible to prevent deformation of low-rigidity resin and thin-walled pipes, making it possible to grip the large-sized NC lathe. The processing of small items by the method becomes easy.

In machining, a special tool is not required. For example, spherical data can be automatically formed only by giving data of a spherical surface. Further, the above-mentioned collet chuck can be used in combination with a general-purpose machine, and its use range is expanded.

In the above embodiment, the collet 10
Although the rotation stopping means is constituted by the key 7 and the key groove 13, the invention is not limited to this. The rotation stopping means may be a spline shaft and a boss. A mechanism can be used.

[0023]

As described above, according to the present invention,
The NC lathe prevents and deforms low rigidity and easily deformable workpieces, enabling high-precision machining in multiple steps. This collet chuck can also be used with general-purpose machines other than NC lathes. To expand the range of use.

In the above-mentioned collet chuck for an NC lathe, when the means for stopping the rotation of the collet is made up of a key and a key groove, the rotation of the collet can be stopped with a simple and inexpensive structure, and the collet can be moved along the axis. When a screw mechanism is used as the driving means for moving in the direction, it is possible to securely grip the workpiece in accordance with the operation force with a small operation force, and at the same time, it is possible to finely adjust the grip force. Become.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention together with a power chuck and a workpiece.

FIG. 2 is a perspective view showing only the collet chuck.

FIG. 3 is a sectional view showing an example of a conventional power chuck for an NC lathe.

FIG. 4 is a side view showing a state in which a workpiece is held by a conventional power chuck for an NC lathe.

[Explanation of symbols]

 1: Chuck body 2: Center hole 3: Tapered hole 4: Large diameter hole 5: Notch groove 6: Through hole 7: Key 10: Collet 11: Tapered portion 12: Screw portion 13: Key groove 14: Grip portion 17: Claw part 20: Holding ring 21: Screw hole 22: Operation hole

Claims (3)

[Claims] An NC lathe collet chuck interposed between a power chuck of an NC lathe and a workpiece to grip the workpiece, wherein the power chuck can grip an outer diameter portion at a rear end. A chuck body having a center hole, a tapered hole expanding toward the front end side and a large-diameter hole formed at the rear end side, and a taper hole of the chuck body which can be inserted through the center hole of the chuck body and which is located at the front end side. A plurality of openable / closable claw portions having a tapered portion that engages with a hollow collet having a threaded portion at a rear end side, and a screw hole capable of being screwed into a threaded portion of the collet. It consists of a retaining ring that can be inserted and removed from the large diameter hole,
A collet chuck for an NC lathe, comprising: a rotation stopping means for restricting the collet to the chuck body so as not to rotate; and a driving means for moving the collet forward and backward in the axial direction. 2. The rotation stopping means comprises a key groove formed along the axial direction of the collet, and a key which is fitted in the radial direction from the outer peripheral surface of the chuck body and engages with the key groove of the collet. The collet chuck for an NC lathe according to claim 1, wherein: 3. The driving means comprises a collet and a retaining ring having a plurality of operation holes operable from outside through a notch groove formed in a circumferential direction in an outer peripheral portion of the chuck body. 3. The collet chuck for an NC lathe according to claim 1, wherein