Gas generator

Abstract

A gas generator includes a lower shell, an upper shell, a holding portion, an igniter, and a filter. The lower shell is made of a press-formed product formed by press-working one plate-shaped member made of metal, and includes a protruding cylindrical portion and an opening provided in the protruding cylindrical portion. The holding portion is formed from a resin-molded portion formed by attaching an insulating fluid resin material to a bottom plate portion so as to reach a part of an outer surface from a part of an inner surface of the bottom plate portion of the lower shell through the opening and solidifying the same, and includes an accommodation recess portion in a portion opposed to a top plate portion. The igniter is held by the holding portion while it is inserted in the accommodation recess portion from a side of the top plate portion and fitted therein.

1 . A gas generator, comprising:
 a short cylindrical housing which is constituted of a top plate portion and a bottom plate portion closing axial end portions and a circumferential wall portion provided with a gas discharge opening and includes therein a combustion chamber accommodating a gas generating agent;   an igniter for burning said gas generating agent; and   a holding portion provided on said bottom plate portion, for holding said igniter,   said housing at least having a lower shell including said bottom plate portion and an upper shell including said top plate portion,   said lower shell including a protruding cylindrical portion provided to protrude toward said top plate portion and an opening provided at an axial end portion of said protruding cylindrical portion, which is located on a side of said top plate portion,   said holding portion being formed from a resin-molded portion which is formed by attaching a fluid resin material to said bottom plate portion so as to reach a part of an outer surface of said bottom plate portion from a part of an inner surface of said bottom plate portion through said opening and solidifying the fluid resin material so that at least a part of the resin-molded portion is secured to said bottom plate portion and including an accommodation recess portion for accommodating said igniter in a portion opposed to said top plate portion, and   said igniter being held by said holding portion while it is inserted in said accommodation recess portion from a side of said top plate portion and fitted in said accommodation recess portion.   
     
     
         2 . The gas generator according to  claim 1 , wherein
 one of said igniter and said holding portion is provided with a locking portion,   the other of said igniter and said holding portion is provided with a locked portion, and   said igniter is held by said holding portion as said locking portion is locked to said locked portion.   
     
     
         3 . The gas generator according to  claim 2 , wherein
 said locking portion has a groove portion extending along a circumferential direction, in a portion on a main surface on a side locked to said locked portion, which corresponds to a root of said locking portion.   
     
     
         4 . The gas generator according to  claim 1 , wherein
 said igniter is held by said holding portion by being fixed to said holding portion with an adhesive.   
     
     
         5 . The gas generator according to  claim 1 , further comprising a first rotation prevention mechanism for preventing said igniter from rotating relative to said holding portion. 
     
     
         6 . The gas generator according to  claim 1 , further comprising a second rotation prevention mechanism for preventing said holding portion from rotating relative to said lower shell. 
     
     
         7 . The gas generator according to  claim 1 , wherein
 said lower shell is made of a press-formed product formed by press-working one plate-shaped member made of metal.   
     
     
         8 . The gas generator according to  claim 1 , wherein
 said igniter includes an agent loaded portion accommodating an agent for burning said gas generating agent and a terminal pin connected to said agent loaded portion for igniting said agent, and   said terminal pin is arranged to pass through said opening in said lower shell.   
     
     
         9 . The gas generator according to  claim 8 , wherein
 said holding portion includes an insertion hole through which said terminal pin is inserted,   said terminal pin has, in a root portion, a flexion portion which is formed such that a part thereof juts out,   said insertion hole has a site allowing reception of said flexion portion of said terminal pin, in a portion facing said accommodation recess portion, and   the site allowing reception of said flexion portion is provided only at a prescribed position in a circumferential direction around a central axis of said insertion hole.