Gas generator and assembling method thereof

• US 10,239,483 B2
• Filed: 07/06/2017
• Issued: 03/26/2019
• Est. Priority Date: 10/04/2012
• Status: Active Grant

• Current Assignee: Daicel Corporation
• Original Assignee: Daicel Corporation
• Inventors: Okuyama, Takashi
• Primary Examiner(s): Hayes, Bret
• Application Number:
  US15/643,327
• Publication Number:
  US 20170305384A1
• Time in Patent Office: 628 Days
• Field of Search: 1022025-20212, 10220214, 102530, 102531, 280741
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 2021/26076 characterised by casing
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06D 5/00 Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets explosive compositions containing an oxidizer, fuels for rocket engines intended for reaction with an oxidant other than air C06B
• CPC Class Codes: F42B 3/04 for producing gas under pressure generators of inflation fluid especially adapted for vehicle air bags B60R21/26
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A gas generator includes, a housing with a gas discharge port, an igniter assembly and a gas generating agent in the housing; and a metallic cup of constant inner diameter covering the igniter to define a charging chamber. The igniter assembly includes a main body, including an ignition portion and an electro-conductive pin integrated with a metallic collar by a resin. The metallic collar has a fixing portion inserted into a hole in a bottom surface of the housing and a remaining portion projecting inward from the bottom surface of the housing, and a guide portion. An inner circumferential wall surface of the metallic cup and an outer circumferential wall surface of the fixing portion are press-fitted, and an annular gap is formed between the inner circumferential wall of the metallic cup member and an outer circumferential wall surface of the guide portion.

Claims

1. A gas generator, comprising:

a housing provided with a gas discharge port and accommodating, therein, a gas generating agent;

an igniter assembly accommodated in the housing, the igniter assembly including an igniter main body, which includes an ignition portion and an electro-conductive pin, a metallic collar, and a resin integrating the igniter main body and the metallic collar; and

a metallic cylindrical member disposed inside the housing, the metallic cylindrical member covering the igniter assembly and defining, therein, an ignition chamber;

the metallic collar having,

a fixing portion including an insertion portion inserted into a hole in a bottom surface of the housing, and

the resin having,

a guide portion being axially in connection with the fixing portion, a portion of the metallic cylindrical member corresponding to the fixing portion and the resin having a constant diameter;

the guide portion including a second guide portion formed axially in contact with the fixing portion, and a first guide portion formed axially in contact with the second guide portion;

the metallic cylindrical member, the resin, and the metallic collar satisfying

D1=D6, where D1 is an outer diameter of the fixing portion and D6 is an outer diameter of the first guide portion,

D1>

D7, where D7 is an outer diameter of the second guide portion,

D1=D6≥

R1, where R1 is an inner diameter of the metallic cylindrical member; and

the metallic cylindrical member being fixed in a state in which an inner circumferential wall surface of the metallic cylindrical member and an outer circumferential wall surface of the fixing portion are press-fitted, and an annular gap is formed between the inner circumferential wall surface of the metallic cylindrical member and an outer circumferential wall surface of the second guide portion, and the inner circumferential wall surface of the metallic cylindrical member and an outer circumferential wall surface of the first guide portion are abutted against each other.

2. The gas generator according to claim 1, wherein the metallic cylindrical member is made from stainless steel, and the metallic collar is made from aluminum.

3. A method for assembling the gas generator according to claim 1, comprising the step of:

fitting and fixing the metallic cylindrical member to the igniter assembly that is fixed to the bottom surface of the housing, wherein,

the fitting and fixing step further includes,

aligning a central axis of the metallic cylindrical member and a central axis of the igniter assembly when the metallic cylindrical member is fitted to the igniter assembly from a side of the ignition portion thereof,

inserting and fixing an opening of the metallic cylindrical member to the fixing portion through the guide portion, and

correcting a displacement of the central axis of the metallic cylindrical member and a central axis of the igniter assembly while inserting the opening of the metallic cylindrical member through the guide portion, when the central axis of the metallic cylindrical member and the central axis of the igniter assembly are displaced with respect to each other.