Air bag inflator with pressure regulation

摘要

An inflator (10) comprises a housing (20) defining a combustion chamber (144). An inflation fluid source (152) in the combustion chamber (144) in the housing (20) is actuatable to provide inflation fluid under pressure. An initiator (94) is provided in the housing (20) for actuating the inflation fluid source (152). The housing (20) has a fluid passage (150) for directing flow of inflation fluid out of the housing. The housing (20) deforms due to the pressure of inflation fluid in the housing upon actuation of the inflation fluid source (152) by the initiator (94). The flow area of the fluid passage (150) increases due to deformation of the housing (20) and varies in accordance with the pressure of inflation fluid in the housing upon actuation of the inflation fluid source (152). The housing (20) comprises first and second housing parts (40, 30) having respective engageable portions (84, 46) that move, upon actuation of the fluid source (152), from a first condition in abutting engagement with each other to a second condition spaced apart from each other to vary the flow area of the fluid passage (150). The first housing part (40) comprises a one-piece metal member that supports the initiator (94) and at least partially defines the combustion chamber (144). The combustion chamber (144) extends around the initiator (94). The one-piece metal member (40) includes a first portion (70) supporting the initiator (94) and defining a radially inner wall of the combustion chamber (144) and a second portion (64) defining a radially outer wall of the combustion chamber.