| 摘要 |
PURPOSE:To produce easily and efficiently a crank shaft by holding the required parts having a space from each other of a metallic bar with holding bodies and displacing the required parts at the intermediate parts thereof in the direction at a right angle to the axial line direction of the bar material by means of forming bodies thereby forming recessed eccentric parts. CONSTITUTION:Three pieces of holding bodies 11, 12, 13 having holes 11a, 12a, 13a to be inserted with a bar material 14 are used, and the central holding body among these bodies, i.e. 12, is stuck as a stationary holding body on a horizontal plane 15. The holding bodies on both sides are disposed as slidable holding bodies 11, 13 on both sides of the stationary holding body apart from each other at a required space. The material 14 is inserted into the holes 11a, 12a, 13a of the bodies 11, 12, 13 and the parts at the intermediate of the respective holding bodies are softened by heating or the like. The intermediate part between the left body 11 and the body 12 is pressed with a pressing body 16, and while the intermediate part between the body 12 and the right body 13 is pulled by the horizontal piece 17 of a tensile body 17, a lower eccentric part 14a and an upper eccentric part 14b are simultaneously formed. |
