Method and apparatus for manufacturing inner ring and outer ring

Abstract

The present invention provides a method for easily manufacturing an inner ring and an outer ring, capable of improving a rate of finished products and reducing material cost. Firstly, forging heated disk-shaped raw produce to form so as to form a first shaping produce which is provided with a tapered dent that the diameter of the tapered inner surface is shortened gradually toward the inner side on the center of one end face, the bottom face of the tapered dent is provided with a circular hole which diameter is less than that of the inner ring to be manufactured and having a thin-wall bottom on the center. Subsequently, stamping the thin-wall bottom of the first shaping produce so as to form a second shaping produce with a circular through hole. Subsequently, protruding the perimeter of the circular through hole of the second shaping produce towards, simultaneously expanding the through hole so as to form a third shaping produce having an outer ring part, a middle ring part and an inner ring part. Finally, stamping the third shaping produce secondarily by inner / outer forging dies and inner / outer press heads so as to form the inner ring, the outer ring and the middle ring which is used as the stamping residual material.

Description

technical field [0001] The present invention mainly relates to a method and device for manufacturing inner and outer rings of bearings from a cylindrical raw material. Background technique [0002] Conventionally, as methods for manufacturing inner and outer rings of ball bearings, the following manufacturing methods are known. For example, Figure 27 As shown, a cylindrical raw material 10A that has been heated and cut into a predetermined size is subjected to upsetting processing to form Figure 27 The disk-shaped raw material 10B shown in (b); After that, in the first process, the disk-shaped raw material 10B is forged and formed to form a Figure 27 A first molded product 10C composed of a large-diameter outer ring portion 11 shown in (c) and a small-diameter bottomed inner ring portion 12 protruding concentrically with the outer ring portion 11 via an intermediate ring portion 13 ; Next, In the second process, in the state where the first molded product 10C is fitted in ...

AI Technical Summary

Problems solved by technology

At this time, the blanking waste of the bottom portion 12a of the bottomed inner ring portion 12 has the same diameter as the inner diameter of the inner ring R1′ to be manufactured, and the first molded product 10C is directly formed from the above-mentioned disc-shaped raw material 10B. During the manufacturing process, the punching waste of the bottom 12a is left in a thick-walled shape, thus generating a very large waste of material

Therefore, there are problems of low yield and high material cost

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