PURPOSE: To obtain a car wheel made of Al, in which a thickness of the rim part is high in its accuracy and uniform, and the surface is smooth, by squeezing in advance a rim forming part of a cylindrical body made of Al, and thereafter, forming a rim by a roll.
CONSTITUTION: An H-type cylindrical member 22 made of Al or an Al alloy is formed by means of hot forming, etc. A mandrel 16 is fitted and inserted into one side of this cylindrical member 22, a holding mandrel is inserted into the other side,and a middle bottom 23 is inserted and held by pressing from both sides. The mandrel 16 is rotated, and also a squeezing roll 18 is made to contact by pressing to the outside surface of a cylindrical part 24, and traversed. As for the squeezed cylindrical part 24, the rim forming part has a uniform thickness and becomes a smooth surface, and it becomes the ground whose yield strength is raised. An inside forming roll 3 and an inside forming roll 25 are pressed against a squeezed cylindrical member 22a, and an outside roll 4 is made to contact by pressing to its outside circumference, by which a rim is formed, and a desired wheel is obtained.
HATSUTORI SHIGEO
HOSOMI KOUJI
TAKAHARA TERUYUKI
KAWAI HIROSHI
KAWAKAMI JIYUNJIROU
Next Patent: PUNCH DAMAGE DETECTING METHOD