TUBE STOCK FOR HYDROFORMING, AND METHOD AND DEVICE FOR FORMING TUBE STOCK FOR HYDROFORMING

摘要

PPROBLEM TO BE SOLVED: To provide a hydroforming tube stock which suppresses generation of buckling and cracks in the bend of a tube stock even if the radius of curvature of the bend is further reduced, and also to provide a method and device for forming this tube stock. PSOLUTION: A linear tube stock W is placed on a die 4 (a), with a recess of a prescribed depth formed by raising an outer punch 8 (d). Successively, by lowering an inner punch 2, with the outer punch 8 stopped, the recess is made deeper while bending is performed (e, f). Then, by lowering the inner punch 2 further, with the outer punch 8 stopped, the recess is made deepest while bending is performed (g, h). Furthermore, by simultaneously lowering the outer punch 8 and the inner punch 2, bending is performed, with the depth of the recess maintained (i, j). PCOPYRIGHT: (C)2004,JPO