JPS62203702A - Collet chuck fastener - Google Patents

Abstract

PURPOSE:To miniaturize a fastener in order to simplify setting it to an engine lathe by reciprocally moving the taper part of a collet by means of a link device moved by an air cylinder, for contracting and extending the diameter of the grip part of the collet. CONSTITUTION:In the case of a fastener 8 which lets a rod-like workpiece through the hole of a rotary axis 11 for chucking, the taper axis part 10a of a collet 10 is plunged to the taper 9a of a holder 9 in order to contract the diameter of a grip part 10l for clamping the workpiece. Movement of the collet 10 relative to the holder9 is made by switching air into an air cylinder (actuator). By the above motion, links 22, 23 are operated in order to reciprocally move the rotary axis 11 for reciprocal motion of the collet 10. Therefore, the fastener is miniaturized in order to be simply fitted to an engine lathe.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a collet chuck fastening device used in ordinary lathes.

[Conventional technology]

In general, chucks for ordinary lathes include a three-way chuck with three claws to attach the workpiece, a four-way chuck with two pairs of claws (four in total), or a collet chuck with no claws. is used. Among these, the collet chuck consists of a collet that has a tapered surface on the outside and a slit that extends in the axial direction on the large diameter side of the tapered surface, and a holder into which this collet is inserted so that it can move forward and backward. By moving the collet forward and backward with a toggle, the taper is used to tighten the collet and attach the workpiece.

There are two types of means for tightening and removing a workpiece using this collet chuck: a manual method using human power, and a mechanical method using fluid pressure, tTII force, etc.

[Problem that the invention seeks to solve]

However, with such conventional collet chucks, there is a natural limit to the force that the operator can output with manual collet chucks, so they can only be used for mounting small-diameter workpieces, so-called It is only used on small lathes called bench laces. In addition, mechanical collet chucks can produce large clamping forces, so they can theoretically be used to process somewhat large workpieces, but because the equipment is large, they are only used for special-purpose machines such as axle-axis automatic lathes. However, there were no collet chucks available that were small enough to be used on ordinary lathes but had a large clamping force.

This invention was made by paying attention to these conventional problems, and allows ordinary lathes to be used as they are without any modification, is small in size, has a large clamping force, and is suitable for ordinary lathes. The object of the present invention is to provide a collet chuck fastening device that is easy to install.

[Means for solving problems]

In order to solve the above object, the present invention is configured such that the chuck is movable relative to the rotating shaft passing through the hole of the cylindrical processing spindle to which the chuck is attached, in the axial direction so as to be in contact with each other through tapered surfaces, and a collet chuck in which a collet is connected to the rotating shaft and the other holder is fixed to the chuck; and a shaft provided at the other end of the rotating shaft that allows the rotating shaft to advance and retreat in the axial direction with respect to the processing spindle. The present invention is characterized in that a collet chuck fastening device is provided with an advancing/retracting mechanism and an actuator capable of tightening the collet chuck by operating the shaft advancing/retracting mechanism.

[Effect]

In this invention, the holder of the collet chuck is attached to the chuck, and the collet is attached to the rotating shaft passing through the hole of the processing spindle, and the actuator is actuated to move the shaft advance/retreat mechanism back and forth to move the rotating shaft in the axial direction. By moving it, a workpiece can be clamped and removed from a collet chuck, so that it can be used as it is in an ordinary lathe, and a large clamping force can be obtained despite the small size of the device.

〔Example〕

The present invention will be explained below based on illustrated embodiments.

FIGS. 1 to 4 show an embodiment of the present invention, which is applied to an ordinary lathe.

First, to explain the configuration, l shown in Figs. 1 and 2 is the headstock, 2 is the bed, 3 is the carriage placed on the bed 2,
4 is a tailstock.

A cylindrical processing spindle 5 is rotatably supported on the head stock 1 via a bearing (not shown). A flange 5a is formed at the end of the processing spindle 5 on the forward/multiple machine 3 side, and the end face of this flange 5a has a
For example, a three-way chuck 6 is attached with a plurality of bolts 7. This chuck 6 has three claws 6a.
The collet chuck 8 is fixed by.

The collet chuck 8 is composed of a holder 9 that is tightened and fixed to the chuck 6 side, and a collet 10 that is inserted into a hole in the holder 9, as shown in an enlarged cross-sectional view in FIG. A taper 9a is formed on the inner peripheral surface of the holder 9, and a boss 9b is formed on the opposite side to the direction in which the diameter of the taper 9a increases, and this boss 9b is held by the claw 6a of the chuck 6. be done. In this embodiment, the holder 9 is formed of a ring member having a taper 9a and a boss member having a boss 9b, and both members are fastened together with a plurality of bolts 9c.

The collet 10 also includes a tapered shaft portion 10a whose diameter increases as it moves from the middle part in the axial direction toward one end, a guide shaft portion 10b that slides into contact with the boss hole of the holder 9, and a threaded shaft portion 10.
c, and a through hole 10d that penetrates in the axial direction is provided in the axial center portion, and the end portion on the tapered 10a side has a smaller diameter than the other portion, thereby allowing a rod-shaped workpiece (not shown) to be inserted. A grip portion 10e for gripping is formed.

Further, the tapered shaft portion 10a of the collet 10 is formed with a slit 10r extending from the shaft center portion in all directions in the radial direction to the vicinity of the guide shaft portion 10b. One end of a cylindrical rotating shaft 1) passing through both holes of the processing spindle 5 and chuck 6 is screwed to the threaded shaft portion 10c.

In addition, the holder 9 of the collet chuck 8 and the cholera 1-10
A plurality of springs 12 are provided between the collet 10 and the chuck 6 to urge the collet 10 away from the chuck 6, thereby constantly urging the rotating shaft 1) toward the reciprocating table 3.

A sleeve case 13, a thrust bearing 14, a collar 15, and a thrust bearing 16 are sequentially fitted onto the opposite side of the rotating shaft 1) from the collet chuck 8 side, and rotation of the rotating shaft 1) prevents these from falling off. This is prevented by a stopper nut 17 screwed into a threaded portion provided on the shaft 1). Further, a taper is formed on the collet chuck 8 side of the sleeve case 12, and by inserting this tapered tip into the gap between the processing spindle 5 and the rotating shaft 1.
).

18 is a lock nut for preventing the stopper nut 17 from loosening.

The sleeve case 13 and collar 15 are connected to the rotating shaft 1)
A pair of link brackets 20 and 21 are provided on the outside of the collar 15.
It is configured to be rotatable relative to the collar 15 and movable in the axial direction. Such two link brackets 20.21
have the same shape, and have bosses 20a and 21a on one end surface of the ring-shaped main body, and a pair of protrusions 20b and 21b that protrude in the axial direction on the other end surface, separated by 180 degrees. One by one.

Between each pair of convex portions 20b and 21b, one end of each of the links 22 and 23 is swingably supported by a pin 24, and the other ends of both links 22 and 23 are overlapped with each other. As shown in the figure, each is supported swingably by bolts 25. Each bolt 25 is threaded into each upper end of two levers 27 and 28 which are supported at their midpoints by a pivot 26 and combined in an X-shape. Between the lower ends of both levers 27 and 28 is a single-acting air cylinder 30, which is an example of an integrated actuator.
The hanging is passed freely so that it can swing freely.

In addition, the length of the two links 22.23 in a straight state is longer than the total length of the collar 15 and the length between the bosses 20a and 21a of the two link brackets 20.21, and the length of the two links 22.23 in the straight state is longer than the length between the bosses 20a and 21a of the two link brackets 20.21. There will be advances and retreats.

A pair of clevises 31 are formed on the cylinder tube side of the air cylinder 30 so as to be able to hold one of the levers 27, and are rotatably connected by a pin 32. The tip passes through a hole in the other lever 28 and is connected by a nut 34 that is screwed into the protruding end of the lever. Then, the lever 28 located on the front side in the rotational direction of the processing spindle 5 is always biased by the return spring 35 in a direction opposite to the rotational direction, so that both levers 27 and 28 swing around at the beginning of the rotation of the processing spindle 5. is prevented.

Further, as shown in FIG. 1.2, a near compressor 37, which is a fluid pressure device, is connected to the pressure chamber of the air cylinder 30 via, for example, a three-way switching valve 36. Air from the near compressor 37 is supplied to the air cylinder 30 through the operation.

The above sleeve case 13, thrust bearing 14.1
6, Collar 15, Stopper Naft 17, Link Bracket 20.21, Links 22, 23, and Lever 27.2
8 constitutes a shaft movement mechanism.

This collet chuck fastening device is usually installed on a lathe through the following assembly process, for example.

First, the collet chuck 8 and the rotating shaft 1) are integrated by screwing the rotating shaft 1) and the collet 10 in advance, and the rotating shaft 1) of the rotating shaft assembly is mounted on a lathe. Processing spindle 5 from the fixed chuck 6 side
is inserted into the hole, and its tip is projected to the outside of the headstock 1, and the post 9a of the holder 9 is tightened and fixed with the chuck 6. A sleeve case 13 is attached to the protruding end of the rotating shaft 1).
, the thrust hair ring 14, the collar 15, the two ring brackets 20, 21, and the thrust bearing 16 are sequentially fitted to the outside, and the stopper nut 17 and lock nut 18 are screwed to the outside thereof.

Next, two links 22.2 are attached to the upper ends of the two levers 27.28, each having an air cylinder 30 attached between the lower ends of the two levers 27.28, which are swingably supported in advance on a link bracket 20.21.
A bolt 25 passing through the overlapping portion between the two is screwed together. A return stopper 3 is provided between the lever 28 and the headstock 3.
5, and the installation on the lathe is completed.

Next, the effect will be explained.

In FIG. 3, the upper half of the figure shows a non-chuffing state, and the lower half shows a chucking state. Although not shown, a bar material is used as the workpiece, and the rod-shaped workpiece is attached so as to pass through the hole of the rotating shaft 1). Switching between the chucking state and the non-chucking state is performed by operating the switching valve 36.

That is, when the switching valve 36 is set to the non-chucking side, the air in the near compressor 37 is discharged from the switching valve 36 to the atmosphere, and the air is not supplied to the air cylinder 30, so that the expansion force by the air cylinder 30 is reduced. The two levers 27, 28 are not acted upon.

On the other hand, a plurality of springs 12 are compressed between the holder 9 of the collet chuck 8 and the collet 10, and the springs 12 always act to urge the collet 10 toward the carriage 3. Therefore, since the rotating shaft 1) screwed to the collet 10 is in a position shifted to the right in the figure, the stopper nut 17 screwed to the rotating shaft 1) is connected to one link via the thrust bearing 16. Press the bracket 21 toward the chuck 6. As a result, the two links 22 and 23 are in a bent state as shown in the figure.

Next, when the switching valve 36 is switched to the chaffing side, the air from the near compressor 37 is supplied to the air cylinder 30 via the switching valve 36, so the air cylinder 30 expands to form two X-shaped The levers 27, 28 are pushed apart between their lower ends. As a result, the distance between the lower ends of the two levers 27.28 is expanded according to the ratio of their lengths, so that 2
Since the two links 22, 23 change to a straight line state as shown in the lower half, the distance between the two link brackets 20° 21 increases by the change in the horizontal length of both links 22, 23.

At this time, among the two link brackets 20 and 21,
The link bracket 20 on the headstock 1 side is the sleeve case 1
3, the other link bracket 21 moves to the left in the figure against the biasing force of the spring 12, and at the same time the thrust bearing 16
, stopper nut 17, lock nut 18 and rotating shaft 1
) and cholera) 10 in the same direction. As a result, the tapered shaft portion 10a of the collet 10 is pressed against the taper of the holder 9, and due to the pressing force, the tapered shaft portion 10a
The diameter of the gripping portion 10e is reduced, thereby tightening the workpiece, and thus fastening the workpiece.

After that, when the machining spindle 5 is rotated, the chuck 6, holder 9, collet 10, rotating shaft 1)
, the lock nut 18, the stopper nut 17, and the sleeve case 13 rotate together, but the two link brackets 20.21 are rotatable relative to the rotating shaft 1) via the collar 15 and the left and right thrust bearings 14.16. It consists of both link brackets 20.21
only does not rotate. Therefore, link bracket 20.2
The X-shaped levers 27, 28 suspended on the X-shaped levers 1 maintain the suspended state shown in FIG. 4 etc. by their own weight and do not rotate. Further, although rapid acceleration occurs at the beginning of the rotation of the processing spindle 5, the rotational force acting on the lever 28 is received by the return spring 35, so that the rotational movement of the X-shaped lever 27, 28 is suppressed. This can be reliably prevented.

In the above embodiment, an air compressor is used as the fluid pressure device to operate the shaft advance/retreat mechanism with air, but the invention is not limited to this, and for example, a hydraulic device such as oil may be used. Of course.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a collet chuck including a rotating shaft passing through a hole in a processing spindle, a collet and a holder, a shaft advancing/retracting mechanism for moving the rotating shaft back and forth, and an actuator for operating the rotating shaft. Since the collet chuck fastening device is configured with the following, it is possible to provide a collet chuck fastening device that is small in size, has a strong fastening force, and can be used in an existing ordinary lathe.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a right side view, and FIG. 3 is an enlarged sectional view taken along the line m-m in FIG. 1 for explaining the invention in detail. , FIG. 4 is an enlarged view of the main part of FIG. 2.

Claims (2)

[Claims] (1) A rotating shaft passing through a hole in a cylindrical processing spindle to which the chuck is attached is configured to be relatively movable in the axial direction so as to be in contact with each other through tapered surfaces, and one of the collets is connected to the rotating shaft. a collet chuck in which the other holder is fixed to the chuck; a shaft advancing/retracting mechanism provided at the other end of the rotating shaft that allows the rotating shaft to advance and retreat in the axial direction with respect to the processing spindle; and this shaft advancing/retracting mechanism. A collet chuck fastening device characterized by comprising: an actuator capable of operating; and a collet chuck fastening device. (2) The shaft advancing and retracting mechanism includes a pair of mutually opposing brackets that are rotatably fitted onto the rotating shaft, one end of which is swingably connected to each bracket, and the other end of which is swingably connected to each other. Claim 1 consisting of a pair of links and a lever that swings the pair of links.
The collet chuck fastening device described in .