To obtain a strain-free high-quality sheet metal component removing wrinkles caused during stretch molding, in the stretch molding method to produce the sheet metal component with a complex curved surface using an intermediary work which has a curved section with a U-shaped cross section formed by bending a flat sheet metal material.

A sheet metal material is bent at a fixed bending radius to form a bent section having a single curved surface and the U-shaped cross section, and then both right and left end portions of the bent section are squeezed to form the intermediary work 110. While a molding die 20 with the complex curved surface is inserted into the curved section of the intermediary work 110 so that the molding face 21 is arranged to come into close contact with the inside face of the bent section, both the right and the left ends 111 of the intermediary work are gripped by stretch arms 31, 32 and pulled obliquely downwards. Then, the middle part 113 of the intermediary work 110 is pinched by two arms 11, 12 of a squeezing device 10 and pressed so as to remove wrinkles caused on the intermediary work 110.

COPYRIGHT: (C)2005,JPO&NCIPI