JP3013080B2 - Shaft heading method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forging a shaft having a center brim having at least one shaft having a rectangular cross section.

[0002]

2. Description of the Related Art Conventionally, in the case of forming a shaft part having a middle brim having at least one shaft having a rectangular cross section, the shaping of the shaft having a rectangular cross section is a post-process because the cross-sectional reduction rate of extrusion exceeds the processing limit. Often done in. In this case, the axis of the cylinder is crushed to form an axis having a rectangular cross section, or cutting is performed.

[0003]

However, when a cylinder having a rectangular cross section is formed by crushing the axis of a cylinder, there is a disadvantage that the accuracy of the center axes of the shafts on both sides of the center flange cannot be obtained. In addition, when the post-process is performed by cutting, there is a disadvantage that the cost is increased due to a reduction in the yield of the material and the production speed.

[0004]

SUMMARY OF THE INVENTION According to the present invention, in order to form the center axes of the shafts on both sides sandwiching such a center brim with high precision and high material yield and to produce them at an appropriate cost, both sides are formed by forging. Was formed.

[0005]

According to the present invention, the shaping of a shaft having a rectangular cross section is preformed into a conical shape having an elliptical cross section, and then extruding to a shaft having a rectangular cross section. It can be pressed within the processing limit, enabling extrusion of a shaft with a rectangular cross section. This makes it possible to forge and form a shaft having a central brim shape having a rectangular cross-section shaft on at least one side, and has an effect that the center shafts of the shafts on both sides of the central brim can be produced with high accuracy and at an appropriate cost.

[0006]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 illustrates a shaft having a central brim having a rectangular cross-section. The shaft is composed of a shaft 1, a shaft 2 having a rectangular cross section, and a shaft 3 having an irregular cross section.

FIG. 2 shows a step of forging the shaft shown in FIG. FIG. 2 shows a front view, a bottom view, a plan view of each step, and a left side view of the head in the second to fifth steps.

In the cutting step, first, the wire is cut into a predetermined length and processed into a raw material 4. In the first step, a portion of the shaft 3 having an irregular cross section is extruded and processed into a first step shape 5. In the second step, the portion formed into the center brim 1 and the shaft 2 having a rectangular cross section is pre-upset-molded and processed into the second step shape 6. In the third step, in order to perform a preliminary shape processing for extruding the shaft 2 having a rectangular cross section, it is set up in a cylindrical shape having an elliptical cross section and processed into a third step shape 7. In a fourth step, a closed extrusion is performed on a conical shape 11 having an elliptical cross section, and in a fifth step, a shaft 12 having a rectangular cross section is extruded without a reduction rate of the cross section exceeding a processing limit. It is processed into the fourth process shape 8. In the fifth step, the shaft 12 having a rectangular cross section is extruded and, at the same time, the inner brim 13 is upset and processed into the fifth step shape 9. Then, in a sixth step, the middle brim shape is trimmed and processed into a sixth step shape 10.

[0009]

As described above, the shaping of a shaft having a rectangular cross section is preformed into a conical shape having an elliptical cross section, and then the extrusion is performed. And press forming can be performed. As a result, the center axes of the shafts on both sides of the center brim can be produced with high accuracy and at an appropriate cost.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing illustrating the shape of a shaft having a central brim having a rectangular cross-section while explaining an embodiment.

FIG. 2 is a drawing showing a shaft forging process for explaining an embodiment.

[Explanation of symbols]

1: Middle flange 2: Axis with rectangular cross section 3: Axis with irregular cross section 4: Material 5: First process shape 6: Second process shape
7: Third process shape 8: Fourth process shape 9: Fifth process shape 10: Sixth process shape 11: Conical shape with elliptical cross section 12: Shaft with rectangular cross section 13: Middle brim

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21K 1/06

Claims (1)

(57) [Claims] 1. A method of forging and forming a shaft having a middle brim having at least one shaft having a rectangular cross-section, wherein extrusion of the shaft having a rectangular cross-section is preformed into a conical shape having an elliptical cross-section. And then extruding a shaft having a rectangular cross section into a target shaft having a rectangular cross section.