JP2003275903A - Anti-vibration tool for workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-vibration tool enabling higher accuracy lathe machining of a workpiece with reference to a center of rotation of a bearing fitted into the workpiece. <P>SOLUTION: After machining a bearing fitting part of a workpiece W, a bearing 3 is fitted into the workpiece, and holding the workpiece W with reference to the bearing 3, a shaft end 2 of the workpiece is machined in the state. To realize the machining, the anti-vibration tool provided with a support bracket 10 attached to a tail stock or a turret of the lathe and a support ring 17 supporting an outer ring of the bearing 3 fixed to the support bracket and attached to the workpiece W is applied. It is desirable that the support bracket is provided with a pressing body which can freely rotate around a main spindle axis and presses a tip of the workpiece without defining a position of its axial center being energized in an advancing direction. It is further desirable that the support bracket is provided with an air nozzle 19 jetting air to a machining part 2 of the workpiece. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steady rest used when turning a front end of a work based on an outer ring of a bearing fitted to the work.

[0002]

2. Description of the Related Art When machining a long work piece or a work piece having a large mass in an intermediate portion by a lathe, if the base end of the work piece is simply gripped by a chuck of a spindle, whirling occurs in the work piece and high precision turning is possible. Cannot be processed. Therefore, in order to prevent whirling of the work, as shown in FIG. 2, a center hole is machined at the tip of the work W, and the center 5 mounted on the tailstock is fitted into this center hole for machining. . The tip of the center 5 and the center hole of the work W are both conical, and by pressing the work W in the axial direction by the center 5, the center of the center hole is held by the center 5 on the spindle axis of the lathe.

As another means for preventing the whirling of the work, as shown in FIG. 3, a method of supporting an intermediate part of the work W whose end is gripped by a chuck 4 by a support base 8 mounted on a turret of a lathe is known. is there. Usually, the support base 8 is provided with two or three rollers that come into contact with the peripheral surface of the work W. This method is often used when machining a long work piece that has both ends supported by a chuck and a tailstock (or chucks with opposed spindles) but still has whirling and bending due to processing reaction forces in the middle part. There is.

[0004]

When machining the peripheral surface of a work with a lathe, there is a case where it is desired to perform machining with reference to the rotation center of a bearing mounted on the work, not as the reference of the shaft center of the work. For example, when the rotor W of the electric motor shown in FIGS. 1 to 3 is machined, the outer peripheral portion 2 of the shaft tip is not based on the shaft center of the work but is based on the center of rotation of the bearing 3 fitted into this shaft. There is a demand for processing. When the rotor W is incorporated into an electric motor, the shaft rotates about the rotation center of the bearing 3 that supports the rotor W. Therefore, when an encoder or the like is attached to the outer peripheral portion 2 at the tip of the shaft, the outer peripheral portion of the rotor W is borne by the bearing. This is because the standard processing can prevent whirling of the member attached to this portion with higher accuracy.

Since the rotor of the electric motor has a large mass in the middle portion, a steady rest is necessary when turning the shaft end of the rotor. However, the steady rest means shown in FIG.
Since the workpiece is held with reference to the axis of the workpiece (accurately, the axis of the center hole machined in the workpiece), the outer peripheral portion of the tip cannot be machined with reference to the bearing.

Further, even in the conventional means shown in FIG. 3, the work is performed on the basis of the outer periphery of the work, and the work cannot be performed on the basis of the bearing. Furthermore, the means shown in FIG. 3 cannot prevent the workpiece from swinging in the direction in which it floats up from the support table 8, and is therefore incomplete as a steady rest.

An object of the present invention is to make it possible to perform turning of a work with a higher accuracy by using the rotation center of the bearing fitted in the work as a reference.

[0008]

The present invention enables the turning of the shaft end of the rotor W of the electric motor as described above to be performed on the basis of the outer ring of the bearing fitted to the work. After processing the bearing fitting portion of, the bearing 3 is fitted into the work, and then the bearing 3
A method is proposed in which the workpiece W is held on the basis of, and the shaft end 2 of the workpiece is machined in this state. In order to realize this machining, the bearing 3 fitted on the workpiece W on the lathe machine base is mounted. We propose a jig to support.

That is, the steady tip of the work of the present invention comprises a support bracket 10 mounted on the tail stock or turret of a lathe, and a bearing 3 mounted on the work W fixed to the end of the support bracket. And a support ring 17 for supporting the outer ring.

A more preferable steady rest jig is a support bracket 10 for supporting an outer ring of a bearing 3 which is mounted on a tail stock or a turret of a lathe and is inserted into a work W.
The support bracket is provided with a pressing body 11 that is freely rotatable around the main axis of the lathe and is biased in the advancing direction to press the tip of the work W without defining the position of its axis.

More preferably, the support bracket is
An air nozzle 1 for injecting air toward the processing part 2 of the workpiece
9 is provided.

When the work W having the bearing 3 inserted therein is gripped by the chuck 4 of the lathe and the tip outer peripheral portion 2 of the work is machined on the basis of the bearing, the steady rest jig having the above-mentioned structure is used. Since the fine vibration of the work tip caused by the rotation of the work is suppressed, it is possible to process the work tip outer peripheral portion 2 based on the bearing with higher accuracy. Further, by providing the air nozzle 19 on the support bracket 10 that supports the bearing and injecting the air ejected from the air nozzle to the processed portion of the workpiece, it is possible to avoid the chips generated in the processed portion from adhering to the bearing.

[0013]

1 is a view showing an embodiment of a steady rest jig of the present invention. The steady rest jig of the illustrated embodiment includes a support bracket 10 and a pressing body 11, and the pressing body 11 includes a shank 14 fitted to a quill 13 fitted to a tailstock 12 of a lathe, and a shank 14. A U-shaped support bracket 10 integrated with the shank, and a work W which is fixed to the tip of this support bracket with a bolt 16.
And a support ring 17 for supporting the outer ring of the bearing 3 mounted on.

The U-shaped support bracket 10 is provided with a reinforcing rib 18 for securing the rigidity of the tip end portion for fixing the support ring 17, and the nozzle 19 directed to the work portion 2 of the work is provided on this reinforcing rib. It is provided. To this nozzle, pressurized air for cleaning is supplied from the center of the quill 13 through the hollow hole 20 of the shank 14 and the through hole 21 of the support bracket.

A dish-shaped cover 22 is provided at the tip of the support bracket 10 so as to cover the bearing 3 of the work, and the inner diameter side of the support ring 17 is tapered to facilitate insertion of the bearing 3. A section 23 is provided. The position of the support bracket 10 around the center of the spindle is positioned by the recessed hole 37 provided in the support bracket 10 so as to face the bolt head of the bolt 36 embedded in the tip of the quill 13 so as not to hinder the processing of the tip outer peripheral portion 2. ing.

The pressing body 11 has a partially spherical pressing surface 24, is biased in the advancing direction by a coil spring 25, and is freely rotatable by a ball bearing 26. The pressing body 11 only presses the work W with the partially spherical pressing surface 24, does not define the axis of the work, and does not need to process a center hole at the tip of the work.

Next, the mounting structure of the pressing body 11 in the illustrated embodiment will be described. Shank 14 to support bracket 10
A cylinder block 27 is fitted into the tip end portion of the hollow hole 20 extending to the base side, and a ram 28 is fitted into the cylinder block so as to be movable in the axial direction. The ram 28 has screw rods 29 and 30 at both ends, and the screw rod 2 on the base end side is provided.
Reference numeral 9 penetrates the coil spring 25, further penetrates the bottom wall 27a of the cylinder block 27, and a nut 31 for a stopper is screwed to the projecting end thereof. The ball bearing 26 is fitted and inserted into the screw rod 30 on the tip side of the ram 28, and is fixed by a nut 32. The outer ring of the ball bearing 26 is fixed by a bearing case 33 having a union structure, a screw 34 extending from the pressing body 11 is screwed into the tip of the bearing case, and a lock nut 35 is provided.
It is fixed at. The protruding length of the pressing body 11 can be adjusted by loosening the lock nut 35 and moving the screw 34 forward and backward. The advancing end of the pressing body 11 when separated from the work is defined by a stopper nut 31.

[0018]

By using the jig of the present invention described above, it is possible to machine the bearing mounting portion of the work in advance and fit the bearing in the relevant portion, and then perform the turning of the work with the outer ring as a reference. Since the entire circumference of the outer ring of the bearing fitted to the work is supported, the work can be completely prevented from swinging, and the work can be machined with high precision on the basis of the bearing. Furthermore, by not supporting the bearing and not defining the shaft center of the work, but by providing a pressing body that presses the shaft end, it is possible to more completely prevent fine vibration and shake of the work when the work is supported via the bearing. This makes it possible to perform more precise turning based on the Bearn ring standard.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a steady rest according to the present invention.

FIG. 2 is a schematic side view showing a first example of a conventional steady rest.

FIG. 3 is a schematic side view showing another conventional steady rest.

[Explanation of symbols]

2 Tip outer circumference 3 bearings 10 support bracket 11 Pressing body 17 Support ring 19 nozzles W work

Claims (3)

[Claims] 1. A support bracket (10) mounted on a tailstock or a turret of a lathe, and a bearing (3) fixed to a tip of the support bracket and mounted on a work (W).
And a support ring (17) for supporting the outer ring of the workpiece. 2. A support bracket (10) mounted on a tailstock or turret of a lathe for supporting an outer ring of a bearing (3) inserted into a work (W), and the support bracket around the spindle axis of the lathe. A steady rest for a workpiece fitted with a bearing, which is freely rotatable and has a pressing body (11) that is biased in the advancing direction and presses the tip of the workpiece (W) without specifying the position of its axis. jig. 3. A workpiece machining section on the support bracket
The steady rest according to claim 1 or 2, further comprising an air nozzle (19) for injecting air toward (2).