| 摘要 |
PURPOSE:To thicken the thickness of rings, etc. at small diameter parts and to prevent damage due to load in forming a shaft having eccentric parts by fitting rings or eccentric blocks to a blank tube, by depressing the parts at which small diameter parts such as rings etc. are positioned. CONSTITUTION:Among positions at which eccentric parts are to be formed by fitting rings to a blank tube 1, the positions where small diameter parts are positioned finally are depressed 1a, 1a by a roller, press, etc. Rings 2 of definite thickness having inner diameter slightly larger than the outer diameter of the material tube 1 are inserted into the tube 1 and matched to depessed parts 1a. Then, the tube 1 is bulged, and areas including depressed parts of the tube 1, that is, depressed part 1a and opposite parts 1b or either of them are bulged together with rings 2 by a specified amount. Since the positions at which small diameter parts 2a of the rings 2 in the tube 1 are to be positioned are depressed beforehand, the amount of projection after bulding can be made small. |
