JPH0463610A - Work driving center - Google Patents

Abstract

PURPOSE:To cope with a center hole having a different size and in a different shape by sliding forward and backward a center piece through a rod through rotational operation of a screw member. CONSTITUTION:A through-hole 3 is formed on a central line for interconnecting the forward end surface of a base body 1 and the terminal surface of a shank 2 and a center piece 4 blocks rotation and is movably inserted. A screw member 14 is screwed in a screw part 13 formed in the inner periphery of the through- hole 3 in a direction extending from the terminal side of the shank 2 to the base body 1, and the terminal of the center piece 4 is connected to the tip of a rod 18 having a terminal rotatably engaged-through with a through-hole 17 formed in the axis of the screw member. When a center hole (a) of a work A is engaged with the tip of the center piece 4 to set the work A, a spring 22 is compressed by push-in, and the center piece 4 is pressed in. A claw 9 of a drive piece 8 is cut through the end surface of the work A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a work driving center.

[Conventional technology]

The conventional work driving center is Tokuhei 1-34
As shown in Japanese Patent No. 725, a center piece is movably inserted from the tip onto the central axis of a base body having a shank at the end, and the center piece is urged toward the tip side within the base body inside the center piece insertion end. A spring is provided, and drive pieces extending in the central axis direction having claws at equal positions in the circumferential direction of the base are inserted so as to be retractable. This structure includes a means (ring) for adjusting the degree of protrusion.

[Problem to be solved by the invention]

The center piece of the driving center configured as described above is stopped in a fixed position by the stopper (by bringing the end flange of the center piece into contact with the end surface of the guide member), so the protruding length of the tip with respect to the tip of the claw is In the case where the center hole a is provided directly on the end face of the workpiece A as shown in FIG. 4, the center piece can be pushed into the center hole a.

However, the workpiece A shown in FIGS. 5 and 6
A recessed step B is formed on the end surface of the recessed step B.
If the center hole a is provided on the bottom surface of the center hole a, the center piece cannot be pushed into the center hole a.

For this reason, there is a problem in that a work driving center having a large protruding length at the tip of the center piece is required.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a work driving center that can freely adjust the protruding length of the tip end of a center piece and can readily respond to center holes of different sizes and shapes.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a base body having a shank at the end thereof, a center piece movably inserted from the tip onto the center line of the base body, and a center piece incorporated into the base body. a spring for pushing out the center piece in the direction toward the tip of the base body; a drive piece having claws disposed at equal circumferential positions of the base body and inserted so as to be retractable in the direction of the central axis; In the work driving center, a through hole is provided that communicates from the distal end surface of the base body to the distal end surface of the shank, and rotation is prevented in this through hole. Insert the center piece, provide a threaded portion in the distal direction from the shank side above the white eyebrow of the through hole, screw a threaded member into this threaded portion so that it can be rotated from the outside, and then turn the end into this threaded member. The tip of the movably engaged rod is fixed to the end of the center piece, and both ends of a compression spring fitted on the outside of the rod are in contact with the center piece and the screw member.

[Effect]

In the workpiece driving center according to the present invention configured as described above, first, the center hole provided on one end surface of the workpiece is fitted to the tip of the centerpiece, and the remaining one Push the center of the tailstock into the center hole provided on the end face to set the workpiece.

By this pushing, the center piece is pushed in and the claws bite into the end face of the workpiece.

At this time, the drive piece is pushed back by the end face of the workpiece, and due to the tapered surface contact with the ring, is pushed toward the central axis and pressed against the bottom of the groove, thereby preventing rattling.

Additionally, if there is a step between the contact surface between the workpiece and the winter melon, the degree to which the winter melon is pushed back will change based on the step, but the ring will respond to this change by moving in the radial direction via the tapered surface. , the pressing force toward the central axis of the drive piece is made uniform to prevent rattling of the drive piece. When the ring is moved, the rear surface of the ring comes into sliding contact with the pin, so there is no problem with its movement.

Furthermore, if there is a step between the end surface of the workpiece and the center hole provided in the end surface, an operating member such as a screwdriver may be engaged with the screw member, and the screw member may be rotated together by rotating the operating member. When the screw member is moved to the opposite side of the shank, the center piece is slid in the same direction via the rod, so that the protruding length of the tip of the center piece relative to the claw becomes thicker.

For this purpose, the tip of the center piece is fitted into a center hole provided on one end surface of the workpiece having a step, and a claw is inserted into the end surface of the workpiece.

[Embodiments] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In the figure, reference numeral 1 denotes a base body having a shank 2 at its end, and a through hole 3 communicating with the tip surface of the base body 1 on the center line of the bundle end face of the shank 2 is provided.

Reference numeral 4 denotes a center bee steer which is movably inserted into the i-hole 3 while preventing rotation.

The distal end side of the center piece 4 is made to protrude from the distal end surface of the base body 1, and rotation of the center piece 4 is prevented by providing a key groove 5 in the axial direction of the outer peripheral surface of the center piece 4 as shown in the figure. Key 6 incorporated into base 1 in groove 5
Insert the tip and secure it.

Further, the base body 1 is provided with grooves 7 which are arranged radially with the tip surface of the base body 1 open and are aligned along the center line.

In the illustrated case, the grooves 7 are provided at three equal positions.

Further, a plate-shaped drive piece 8 having a rectangular cross section is fitted into each groove 7 so as to be freely retractable and protrusive, and a claw 9 is provided at the tip edge of the drive piece 8.

10 is a base 1 so that the end surface of the drive piece 8 is exposed.
A ring 11 movable in the radial direction of the base body 1 is installed in the hollow chamber 10, and the inner peripheral surface of the ring 11 and the distal edge of the drive piece 8 are Tapered surface portion 12 that slopes toward the outer peripheral tip surface of the base body 1
is provided, and when a certain drive piece 8 is retracted, the ring 11 moves in the radial direction through its tapered surface portion 12 and pushes out the other drive piece 8, thereby reducing the pushing force of each drive piece 8 toward the central axis side. It should be uniform.

Reference numeral 13 denotes a threaded portion extending from the distal end of the inner peripheral shank 2 of the through hole 3 toward the base body 1, and a threaded member 14 that is rotated and moved from the outside is screwed into this threaded portion 13. ing.

The screw member 14 is rotated by engaging a screwdriver in a groove 15 provided on the end face in the illustrated case.

Reference numeral 18 denotes a rod whose end having a retaining head is rotatably penetrated and engaged with a through hole 17 provided in the axis of the screw member 14, and the end of the center piece 4 is attached to the tip of this rod 18. It is connected.

In the case shown in the figure, the above connection is made by providing a screw hole 19 inward from the end surface of the center piece 4, screwing the threaded part 20 provided at the tip of the rod 18 into this screw hole 19, and screwing the screw 21 into the screw hole 19. It is done by including.

A compression spring 22 is fitted on the outside of the rod 18 and has both ends abutted against the center piece 4 and the screw member 14, and the center piece 4 is pushed out by the spring 22.

In the figure, 23 is a removable plug that is screwed in, and 24 is a pin that allows the ring 11 to slide smoothly.

This embodiment is constructed as described above, and its operation will be explained next.

First, fit the center hole a provided on one end surface of the workpiece A into the tip of the center piece 4 (as shown in FIG. 4), and fit the tail stock into the center hole (not shown) provided on the remaining end surface. Push in the center of workpiece A
Set. By this pushing, the spring 22 is compressed and the center piece 4 is pushed in, and the claws 9 of each drive piece 8 bite into the end face of the workpiece A.

Further, as shown in FIGS. 5 and 6, if a recessed step B is formed on the end surface of the workpiece A and a center hole a is provided in the bottom of the recessed step B, first the plug 23 is removed, then an operating member such as a screwdriver is secured to the screw member 14, and the screw member 1 is rotated by rotating the operating member.
When the screw member 14 is moved in the opposite direction of the shank 2 while rotating the center piece 4, the center piece 4 is slid in the open direction via the rod 18, so that the protruding length of the tip of the center piece 4 with respect to the claw S is growing.

Therefore, the center piece 4 is pushed into the center hole a as shown in FIG. 3 without being affected by the level difference between the end surface of the work A and the center hole a, and the claws 9 bite into the end surface of the work A.

〔effect〕

As described above, according to the work driving center according to the present invention, the center piece can be slid forward and backward through the rod by rotating the screw member. ,
Even if a recessed step is formed on the end surface of the workpiece and a center hole is provided at the bottom of the recessed step, the center piece cannot be pushed into the center hole and the claws can be bit into the end surface of the workpiece. can.

Therefore, it is possible to solve the problem of requiring a plurality of work driving centers whose center pieces have different protruding lengths.

[Brief explanation of the drawing]

The drawings show an embodiment of the work driving center according to the present invention, in which Fig. 1 is a longitudinal side view, Fig. 2 is a front view of the same, Fig. 3 is a longitudinal side view with the center piece advanced, and Fig. 4 is a longitudinal side view. 6 to 6 are partially cutaway side views of the workpiece. 1... Base body, 2... Shank, 3... Through hole, 4... Center piece, 5... Keyway, 6.・
...Key 7...Groove, 8...
...Drive piece, 9...Claw,
10...Hollow chamber, 11...Ring,
12...Tapered surface part, 13...
・Screw part, 14...Screw member, 17...
...Through hole, 19...Screw hole, 21...Screw,

Claims (1)

[Claims] (1) a base body having a shank at the end; a center piece movably inserted from the tip onto the center line of the base body;
a spring that is incorporated into the base body and pushes out the center piece toward the distal end of the base body; a drive piece that is disposed at equal circumferential positions of the base body and has claws that are inserted so as to be retractable in the direction of the central axis; In a work driving center, a through hole is provided that communicates from the distal end surface of the base body to the distal end surface of the shank. The center piece is inserted while preventing rotation, and a threaded part is provided from the inner periphery of the through hole toward the distal end from the shank side, and a threaded member is screwed into this threaded part so as to be rotatable from the outside. The tip of the rod whose end is rotatably engaged with the threaded member is fixed to the end of the center piece, and both ends of the compression spring fitted on the outside of this rod are brought into contact with the center piece and the threaded member. A distinctive work driving center.