Gas generator

• US 10,166,501 B2
• Filed: 01/25/2016
• Issued: 01/01/2019
• Est. Priority Date: 02/09/2015
• Status: Active Grant

• Current Assignee: Daicel Corporation
• Original Assignee: Daicel Corporation
• Inventors: Imoto, Katsuhiro, Yamazaki, Masayuki
• Primary Examiner(s): Abdosh, Samir
• Application Number:
  US15/539,781
• Publication Number:
  US 20180264389A1
• Time in Patent Office: 1,072 Days
• Field of Search: 102530
• CPC Class Codes: B01D 2279/10 for air bags, e.g. inflators therefor
• CPC Class Codes: B01D 46/0005 Mounting of filtering elements within casings, housings or frames B01D46/2422 takes precedence
• CPC Class Codes: B01D 46/001 Means for connecting filter housings to supports
• CPC Class Codes: B01D 46/2403 characterised by the physical shape or structure of the filtering element
• CPC Class Codes: B01J 7/00 Apparatus for generating gases production of inert gas mixtures B01J19/14; for generating specific gases, see the relevant subclasses, e.g. C01B, C10J ; in "air bags" on vehicles B60R21/26; for starter gas F02C7/26; blasting cartridges for producing gas under pressure F42B3/04
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• CPC Class Codes: B60R 2021/26058 using a combination of inflators
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• 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

Abstract

The present invention provides a gas generator in which short-passing of combustion gas is prevented.

A cylindrical filter 30 including a first annular end surface 32 abutted against a top plate 12 and a second annular end surface 33 abutted against a bottom plate 21 is disposed inside a housing 10. A corner portion 75 formed by a bottom surface 71 and an outer circumferential wall 74 of a support member 70 is abutted against an abutting portion between the second annular end surface 33 and the bottom plate 21 to prevent the short-passing of the combustion gas from this portion.

Claims

1. A gas generator comprising a housing foamed by a diffuser shell provided with a gas discharge port, and a closure shell, a cylindrical filter disposed inside the housing, a first combustion chamber and a second combustion chamber arranged inside the cylindrical filter,

the cylindrical filter being disposed such that an outer circumferential surface is spaced apart from the gas discharge port, a first annular end surface is abutted against a top plate of the diffuser shell, and a second annular end surface is abutted against a bottom plate of the closure shell,

the first combustion chamber being a space on the outer side of an ignition device chamber provided with an ignition device for a first-b gas generating agent filled inside the first combustion chamber, and the second combustion chamber being filled with a second gas generating agent,

the ignition device chamber being a space filled with a first-a gas generating agent and surrounded by a cylindrical first holder, a first igniter and a first cup member provided with a plurality of first communication holes penetrating a circumference wall thereof in a thickness direction,

the cylindrical first holder being fixed to a first hole of the bottom plate of the closure shell, the first igniter being fixed inside the cylindrical first holder, and the first cup member being press-fitted to an inner side of the cylindrical first holder from an opening of the first cup member,

the second combustion chamber being a space filled with the second gas generating agent and surrounded by a cylindrical second holder, a second igniter and a second cup member provided with a plurality of second communication holes penetrating a circumferential wall thereof in a thickness direction,

the cylindrical second holder being fixed to a second hole of the bottom plate of the closure shell, the second igniter being fixed inside the cylindrical second holder, the second cup member being press-fitted to an outer side of the cylindrical second holder from an opening of the second cup member, and a surface of the circumferential wall including the plurality of the second communication holes being covered with a cover member from the outside,

further, a support member for the cylindrical filter being disposed on a bottom surface of the closure shell,

the support member including a bottom surface provided with holes corresponding to the first hole and the second hole formed in a bottom plate of the closure shell, and an outer circumferential wall provided vertically from an outer circumference of the bottom surface,

part of the outer circumferential wall of the support member being held from both sides in a thickness direction between the first holder and the cylindrical filter,

the bottom surface of the support member being held from both sides in a thickness direction between the bottom plate of the closure shell and an annular end surface of the opening of the second cup member press-fitted to the cylindrical second holder,

the outer circumferential wall of the support member being abutted against an inner circumferential surface of the cylindrical filter on the side of the second annular end surface so that a corner portion formed by the bottom surface and the outer circumferential wall of the support member is abutted against an abutting portion between the second annular end surface of the cylindrical filter and the bottom plate of the closure shell,

when the second igniter is actuated and the second gas generating agent in the second combustion chamber is ignited and burned to raise an internal pressure, a combustion gas flowing out between the second communication holes and the cover member in a direction of the bottom plate of the closure shell.

2. The gas generator according to claim 1, wherein a ratio (h2/h1) of a height (h2) of the outer circumferential wall of the support member to a height (h1) of the inner circumferential surface of the cylindrical filter is within a range of 0.1 to 0.2.

3. The gas generator according to claim 1, wherein

the diffuser shell includes an inner flat surface and an upper annular inclined surface inclined downward to the outer circumference of the diffuser shell,

the closure shell includes an inner flat surface and a lower annular inclined surface inclined upward to the outer circumference of the closure shell,

the first annular end surface of the cylindrical filter has an inclined surface capable of abutting against the upper annular inclined surface, and the second annular end surface of the cylindrical filter has an inclined surface capable of abutting against the lower annular inclined surface, and

the first annular end surface of the cylindrical filter is abutted against the upper annular inclined surface of the diffuser shell, and the second annular end surface of the cylindrical filter is abutted against the lower annular inclined surface of the closure shell.