METHOD OF PRODUCING CASTING HAVING HOLLOW PART

摘要

PROBLEM TO BE SOLVED: To improve the productivity and reduce the production cost of a casting by realizing the thinning and lightening of the casting, then preventing or suppressing the breakage of sand cores caused by molten metal and facilitating the removal of core sand after casting. SOLUTION: A steering head turnably supporting a steering shaft of a steering mechanism supporting a front wheel in a motorcycle is produced by die casting wherein molten metal is poured into a cavity 60 formed of a mold 50 provided with a sand core 51 forming a first hollow part and a metal core 52 forming a through-hole for inserting the steering shaft. The flow velocity of the molten metal at the outlet 63a of a gate 63 is adjusted into a range of 5 to 15 m/s. Further, the gate 63 is formed at a position where the molten metal directly after the passage of the gate 63 comes in contact with the metal core 52 inside the cavity, and is thereafter comes in contact with the sand core 51. COPYRIGHT: (C)2004,JPO