The suspicious looking element tube for liquid pressure bulging, and the liquid pressure bulging device which uses this, liquid pressure bulging method, and the liquid pressure bulging item

摘要

The suspicious looking element tube for liquid pressure bulging of this invention (TP2), applying on the other hand from one side of axial direction, as it possesses the circumference which major diameter gradually increases or decreases, or, the retention section where at least one side on edge side, the aforementioned circumference increases the said one side facing toward the tube end surface of edge side (TP2a and TP2b) it forms, furthermore, it is possible to form the parallel body to the edge side which does not form the retention section. The processed device which uses this suspicious looking element tube, with process method, pushing processing to axial direction from the tube end becomes possible even with when the suspicious looking element tube where cross section changes largely in axial direction is used. Because of this, in the liquid pressure bulging item where liquid pressure bulging is administered, it becomes possible more than ever to obtain big tube expander ratio.