| 摘要 |
PURPOSE:To make a camshaft manufacturable inexpensively and lightweightly, by molding it by means of cold drawing and plastic working as the main process. CONSTITUTION:At the time of molding a camshaft, cold drawing is applied to the blank pipe made up of cutting a hollow steel pipe 10 in the required size while scales are removed from the outer circumferential surface, and roundness and smoothness in both inside and outside diameters 11 and 12 are improved. Next, an end part of this pipe is pressed by a hydraulic press or the like, forming such a thick part 13 that is plastically deforced in a radial direction. Afterward, a hollow bar 16 is inserted into a bore part of this thick part 13 and clamped by brazing, whereby a clearance 163 as a lubricating oil passage is formed up. In addition, a cam 20 and a journal 21 are inserted into the circumference of the camshaft and clamped thereat, thus a proper oil passage is cut. Finally, a thread groove 161 for gear locking and a taper part 162 for various parts contact locking are machined to a hollow end part of the hollow bar 16. |
