To provide a hydro-forming technique for laminated plate materials, which can form a product having a swelled portion larger than other portions, without causing faults, such as cracks caused by the reduction of its thickness.
The laminated plate material 10 includes a plurality of straight edge sides composing abutting portions, and the swelled portion 17 preliminarily formed by press working so as to be larger than other portions in the region which does not include the edge sides. A plurality of the edge sides have been joined by butt welding. The laminated plate material is put in a forming die 40 with recessed portions 41a, 42a. Then, a medium for applying an internal pressure to the inside space 11 of the laminated plate material is introduced into the inside space 11. The product 20 having a shape corresponding to the shape of the recessed portion is formed by supplying materials from the swelled portion.
KANEFUSA HIDETO
MASHIMA SATOSHI
YOSHITOME MASAO
HATANO YASUJI
TAKAHASHI YOSHIO
CALSONIC KANSEI CORP
Yasuo Nara
Etsuko Saito
Katsuyuki Utani
Toshifumi Fujii