Patent ID: 6182487
Filing Date: 2001-02-06
Classification: B21D,Y10T

Abstract:
A fabrication method for a metal vessel characterized in the steps of:fabricating a cylinder including a shell member and a bottom member, with one end of the shell member made integral to the bottom member by welding, the other end of the shell member providing an opening part;disposing said cylinder in a die comprising a moving die and a stationary die in a state wherein said moving die and said stationary die are separated, so that said opening part is on the stationary die side and said bottom member is on the moving die side; andfabricating a metal vessel provided with an expanded shell part having a diameter larger than the diameter of said opening part and bottom member by carrying outhydraulic bulge formation in such a manner that the length of the weld between the shell member and the bottom member is approximately the same before and after the hydraulic bulge formation by moving said die towards said stationary die, expanding said shell member of said cylinder, and at the same time injecting a liquid into said cylinder and then applying pressure.