To form a formed product of high dimensional accuracy by a hydroforming die structure at a low cost without any complicated die structure.
A die 1 is split into an upper die 2 and a lower die 3, and recessed portions 8 and 9 to constitute a cavity 7 are formed in the inner side of mating surfaces 6a thereof. A pocket is formed on both sides of the recessed portion 9 and upper and lower adjustment shims 10 are disposed on the mating surfaces 6a of the lower die 3. When the upper and lower dies 2 and 3 overlap, the cavity height is adjusted by the thickness of the upper and lower adjustment shims 10. A pair of adjustment slits 12 are formed in the vertical direction on right and left sides of the cavity 7 of the upper and lower dies 2 and 3. Shims are inserted in these adjustment slits 12, and the cavity 7 is dimensional-adjusted in the width direction.
Arihara Koichi
Matsushima Tetsuo