JP2003181718A - Broaching jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broaching jig that can maintain the cylindricity of a machined diameter, which is formed by inner-face broaching of a hollow, cylindrical thin-wall work, at a cylindricity within an allowable range of accuracy equivalent to that in the case of processing thick-wall work. <P>SOLUTION: In the inner-face broaching of the hollow, cylindrical thin-wall work 10, the external circumference face 15 of the thin-wall work 1 is engaged, with a small gap put in between, with the internal circumference face 16 of a hollow, cylindrical auxiliary jig 11, so that the work can be broached by attaching the internal circumference face 17 of the hollow, cylindrical auxiliary jig 11 to the internal circumference face 13 of a work receiver 12, and so that the combined thickness of the thin-wall work 10 and the auxiliary jig 11, when they are engaged with each other, has sufficient rigidity required. <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 inner surface broaching of a thin hollow cylindrical work piece.

[0002]

2. Description of the Related Art It is well known that, in the inner broaching process for processing splines and serrations, the cylindricity of the processing diameter of a hollow cylindrical work does not become straight, for example, issued on June 10, 1965, In "5.7.4 Broaching accuracy", page 357, edited by Seikigakukai, "New Precision Machinery Handbook" by Corona, it appears remarkably when the wall thickness is not the same, but even if the wall thickness is uniform, it is a hollow cylindrical shape. It has been introduced that, for thin-walled workpieces, the cylindricity of the machining diameter of the workpiece does not become straight.

In the conventional inner surface broaching of a hollow cylindrical work, as shown in FIG. 3, a work support 2 is fixed to a bolster 3 fixed to a table 4 of a broaching machine, and is slightly smaller than the outer diameter of the work 1. The work 1 is attached to the work support 2 having a large inner diameter, and the broach 5 is inserted to broach the inner surface of the work. The work support 2 is replaced when the outer diameter of the work 1 changes. As shown in FIG. 3, the guide portion 51 of the brooch 5 is arranged from above from the pilot hole 6 of the work 1.
The work piece 1 is displaced so as to be concentric with the broach 5, the brooch 5 is inserted into the prepared hole 6 of the work 1, and then the broach 5 is moved downward to follow the guide portion 51
The inner diameter of the work piece is sequentially cut by 52. As described in the above "New Handbook for Precision Machinery", page 357, section 5.7.4,
The broached inner diameter is generally a trumpet shape with a large inlet side and a small outlet side, or a drum shape with a large inner diameter in the center. The reason for the distortion is considered to be that a force is applied in the inlet circumferential direction of the work at the start of cutting and the work is deformed (becomes larger in the outer circumferential direction). When the inner surface broaching is performed by the method shown in FIG. 3, the inner diameter of the central portion becomes a drum shape.

[0004]

As described above, in the conventional inner surface broaching of a hollow cylindrical work, the inner diameter of the work is not straight, but when the work is thick as shown in FIG. There was no problem because it is within the range generally accepted from the viewpoint of the function of the product. However, due to recent global environmental problems, there is a tendency toward weight reduction and weight reduction in manufacturing, and it is required to reduce the wall thickness of the work to be broached on the inner surface. An object of the present invention is to maintain the cylindricity of a machining diameter generated when broaching an inner surface of a hollow cylindrical thin-walled work at a cylindricity of an allowable range equivalent to that when machining a thick-walled work. It is to provide a broaching jig that can perform.

[0005]

Therefore, according to the present invention, in the inner surface broaching of a hollow cylindrical thin-walled work, the inner peripheral surface of the hollow cylindrical auxiliary jig is fitted to the outer peripheral surface of the thin-walled work with a slight clearance from the outer peripheral surface. The broach is characterized in that it can be broached by attaching it to the work holder and that the total thickness of the thin work and the hollow cylindrical auxiliary jig when fitted together has sufficient rigidity. The problem of the present invention described above has been solved by providing a processing jig.

[0006]

With the above construction, the cylindricity of the machining diameter generated when the inner surface of the hollow cylindrical thin work is broached with a simple device is as accurate as that of the thick work. The present invention provides a broaching jig that can maintain the cylindricity.

[0007] Preferably, the bottom surface of the work receiving plate may be flat so that the same bottom surface receives the thin work and the hollow cylindrical auxiliary jig. However, the bottom surface of the work receiving plate receives the hollow cylindrical auxiliary jig. And a second bottom surface for receiving the thin work, the bottom surface having a step. With such a stepped bottom surface, the thin-walled work and the hollow cylindrical auxiliary jig are independently supported during the broaching process, so that the work can be easily removed from the hollow cylindrical auxiliary jig after the processing.

More preferably, the outer peripheral surface of the thin-walled work and the inner peripheral surface of the hollow cylindrical auxiliary jig may be fitted with each other with a slight gap of 5 μm which does not affect the machining error. By making the outer peripheral surface and the inner peripheral surface of the hollow cylindrical auxiliary jig into a clearance-fitting clearance, it is possible to maintain the cylindricity of the machining diameter with higher accuracy.

[0009]

1 is a schematic sectional view of a broaching jig according to a first embodiment of the present invention, and FIG. 2 is a second view of the present invention.
It is a schematic sectional drawing of the broaching jig of embodiment.
1, in the inner surface broaching of the hollow cylindrical thin-walled work 10, the outer peripheral surface 15 of the thin-walled work 10 is fitted with the inner peripheral surface 16 of the hollow cylindrical auxiliary jig 11 with a slight gap, The inner peripheral surface 17 of the hollow cylindrical auxiliary jig 11 can be fitted and fitted to the inner peripheral surface 13 of the work holder 12 to perform broaching, and the thin-walled workpiece 10 and hollow cylindrical shape when fitted The broaching jig is such that the total thickness of the auxiliary jig 11 has sufficient rigidity. 3 is a bolster fixed to the table 4 of the broaching machine. Thin wall work
The outer peripheral surface 15 of 10 and the inner peripheral surface 16 of the hollow cylindrical auxiliary jig 11 are
They are fitted with a slight gap of 5 μm, which does not affect the processing error. The same applies to the gap between the outer peripheral surface 17 of the hollow cylindrical auxiliary jig 11 and the inner peripheral surface 13 of the work holder 12.
Fitted with a gap of μm.

With this construction, the cylindricity of the machining diameter generated when the inner surface of the hollow cylindrical thin work is broached is maintained at the cylindricity of the allowable range equivalent to that when machining the thick work. It now provides a broaching jig that can. The outer peripheral surface 15 of the thin-walled work 10 and the inner peripheral surface 16 of the hollow cylindrical auxiliary jig 11 are fitted with a slight gap of 5 μm which does not affect the processing error, so the work is a hollow cylindrical auxiliary jig. It can be removed from the jig by hand using a hand tool.

In FIG. 1, the bottom surface 14 of the work receiving plate 12 is made flat, and the hollow cylindrical auxiliary jig 11 is fixed to the work receiving plate 12 by using another device. At 14, the thin workpiece 10 and the hollow cylindrical auxiliary jig 11 are received. On the other hand, in FIG. 2, the bottom surface of the work holder 22 is a first bottom surface 23 for receiving the hollow cylindrical auxiliary jig 21,
By forming a stepped bottom surface consisting of the second bottom surface 24 for receiving the thin-walled work 10, the thin-walled work and the hollow cylindrical auxiliary jig are independently supported during the broaching process. The work can be easily removed from the jig.

The gap between the outer peripheral surface 15 of the thin-walled work 10 and the inner peripheral surface 16 of the hollow cylindrical auxiliary jig 11 is determined by the accuracy of the cylindricity of the allowable machining diameter. When the precision is high, the gap is a tight fit, and the work is removed from the hollow cylindrical auxiliary jig after processing using a machine such as a press machine. The wall thickness of the hollow cylindrical auxiliary jigs 11 and 21 is determined by the accuracy of the cylindricity of the machined diameter, because the thicker the cylinder, the less the deformation that affects the inner diameter of the broached piece.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a broaching jig according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a broaching jig according to a second embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing inner broaching of a conventional hollow cylindrical work.

[Explanation of symbols]

3 ... Bolster 4 ... Broach table 5 ... Brooch 10 ... Thin-walled workpieces 11, 21 ... Hollow cylindrical auxiliary jig 12, 22 ... Work holder 14 ... Work holder bottom 23 ... First bottom surface of gold 22 ...

Continued front page    (72) Inventor Kazuo Matsui             1-1 1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture             Ceremony company Fujikoshinai F-term (reference) 3C050 BC01

Claims (4)

[Claims] 1. In the inner surface broaching of a hollow cylindrical thin-walled work, the thin-walled work is fitted on the outer peripheral surface of the hollow cylindrical auxiliary jig with a slight gap between the outer peripheral surface and the inner peripheral surface of the jig, and is attached to a work holder. Can be broached,
A broaching jig characterized in that the total thickness of the thin work and the hollow cylindrical auxiliary jig when fitted together has sufficient rigidity. 2. The broaching jig according to claim 1, wherein the bottom surface of the work receiving plate is flat, and the same bottom surface receives the thin work and the hollow cylindrical auxiliary jig. 3. The bottom surface of the work receiving plate is a stepped bottom surface including a first bottom surface for receiving the hollow cylindrical auxiliary jig and a second bottom surface for receiving the thin work piece. The broaching jig according to claim 1. 4. The broaching process according to claim 1, wherein the outer peripheral surface of the thin-walled work and the inner peripheral surface of the hollow cylindrical auxiliary jig are fitted with a stop fit. Jig.