| 摘要 |
PURPOSE:To obtain a titled joint outer ring of high dimensional accuracy without being restricted by the shape of extruded product by performing hot and cold, forward and backward extrusion after working a columnar metallic material to materials of a small diameter body and a large diameter head. CONSTITUTION:A columnar metallic material 20 is hot drawn and upset to form a material 23 consisting of a small diameter body 21 and a large diameter head 22. Then, a hot treated material having ring part 24, shaft part 25 etc. and nearly the same shape with the product is made by hot forward and backward extrusion. Plural concave grooves 26 are formed on the side wall of the ring part 24 and a concavity 28 having a small hole 27 is formed at the bottom. This hot treated material is further subjected to cold forward and backward extrusion and some working is added to obtain the shape of the product. Desired joint outer ring can be obtained by finishing the grooves 26 if necessary. |
