SEALING SYSTEM FOR HYDROFORMING

摘要

PURPOSE: A sealing system is provided to effectively prevent a leakage of liquid with only pressure of a pump. CONSTITUTION: A sealing system comprises piston portions(17,124) assembled in a punch portion having a hole as a passage of liquid; a center hole(16) of the piston portions to flow the liquid; a hole(111) between a shaft of the piston portion and the punch portion and a cylinder; an O-ring(119) located between an O-ring support(19) in the end of the punch portion and a head portion(17) of the piston portions; a hole(114) of a body portion to prevent liquid pressure when a piston receives pressure; and a spring to return the piston portions when the liquid pressure is removed. In inserting the end of the punch portion(18) into a tube with small force, The forming limit of a tube material is improved by delaying a breakage of the tube. The O-ring is easily replaced when the O-ring is corroded.