SPOOL VALVE AND MANUFACTURING METHOD FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a spool valve that permits the manufacture even of a thin-walled collar and is fitted with a lightweight collar with a high material yield. SOLUTION: The spool valve 5 is so constructed that a plurality of collars 4 with an annular void 3 manufactured through molding from a metal plate are fitted about a shaft material and arranged in given positions, and the shaft material is radially reduced along both ends of the collars 4 in rolling dies to cause a plastic flow of metal, which forms annular ridges 7a and 7b of a diameter larger than the inside diameter of the collars 4 along both ends of the collars 4 to thus fix the collars 4 on a shaft 2.