METHOD FOR MANUFACTURING HOUSING OF HYDRAULIC SHOCK ABSORBING DEVICE

摘要

PURPOSE: A method for manufacturing a housing of a hydraulic shock absorbing device is provided to improve the endurance and reliability of the hydraulic shock absorbing device by allowing an upper end of the housing to be easily sealed. CONSTITUTION: A copper pipe is cut in a predetermined size. The copper pipe is gripped into a chuck of a numerically controlled lathe by a fixing jig. An upper end of the copper pipe is pressed by a jig, so that the upper end of the copper pipe is plastically deformed. That is, the upper end of the copper pipe is inwardly bent. Then, a center of the upper sealing portion of the copper pipe is thermally molten by a frictional heat generated by a friction between the jig and the center of the upper portion of the copper pipe. The outer surface of the upper sealing portion of the copper pipe is cut by using a bite to obtain the superior external appearance.