METHOD FOR FORMING HOLLOW PRODUCT

PURPOSE:To form a hollow product having high accurate shaped dimension with good workability by inserting a slide core into a through hole in a fusible core set into cavity in forming die and injecting forming material into the cavity after die-clamping. CONSTITUTION:The fusible core B made of low m.p. alloy of Sn-Bi, etc., having the through hole b1 is set into the cavity 8 in the forming die 4 under die opening condition. One pair of the slide cores 5, 6 are inserted into this through hole b1 from both sides thereof, and the other side core 7 is engaged with projecting part b3 in the core B and fitting recessed parts 5a, 5b, 6b and fitting projecting parts 6a, 7a in these are abutted. By this method, after clamping the forming die 4 under condition of supporting the core B, the forming material is injected into the above cavity 8 at high pressure to form the hollow product A with the above core B embedded into the hollow part a1. After that, the hollow product A is taken out from the forming die 4 and successively, the above fusible core B is heated, eluted and removed from the hollow part a1 in the hollow product A.