Gas generator

• US 8,585,085 B2
• Filed: 01/24/2013
• Issued: 11/19/2013
• Est. Priority Date: 03/12/2012
• Status: Active Grant

• Current Assignee: Daicel Corporation
• Original Assignee: Daicel Corporation
• Inventors: Kobayashi, Tomoharu, Yamazaki, Masayuki, Ukita, Shinichiro
• Primary Examiner(s): TO, TOAN C
• Application Number:
  US13/749,537
• Publication Number:
  US 20130233196A1
• Time in Patent Office: 299 Days
• Field of Search: 280/736, 280/741, 102/530
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• 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

Abstract

A gas generator includes a diffuser shell and a closure shell, a housing formed by joining the diffuser shell and the closure shell, inside the housing, an ignition device chamber defined by a cup-shaped container, a combustion chamber enclosing the ignition device chamber, an annular or flat plate-shaped filter facing the top plate, a retainer supporting the filter, the retainer including a bottom surface and a cylindrical wall surface extending from an outer circumferential edge of the bottom surface, the cylindrical wall surface having a gas passage, the retainer being fixed by the cylindrical wall against a circumferential wall plate. During actuation, when the housing is deformed the retainer and the filter move to abut the top plate of the diffuser shell, combustion gas passes through the filter and the gas passage to be discharged from the gas discharge port.

Claims

1. A gas generator, comprising:

a diffuser shell having a top plate and an upper circumferential wall plate provided with a gas discharge port,

a closure shell having a bottom plate and a lower circumferential wall plate,

a housing forming an outer shell and being obtained by joining and integrating the upper circumferential wall plate and the lower circumferential wall plate,

inside the housing,

an ignition device chamber defined by a cup-shaped container, which is positioned at a central part of the bottom plate of the closure shell, and accommodating an ignition device therein,

a combustion chamber formed to enclose the ignition device chamber and being loaded with a gas generating agent,

an annular or flat plate-shaped filter disposed to face the top plate,

a retainer supporting the filter,

the retainer including a bottom surface and a cylindrical wall surface extending from an outer circumferential edge of the bottom surface at least towards the top plate of the diffuser shell, the cylindrical wall surface having a combustion gas passage,

the retainer supporting at least part of an outer circumferential surface and a lower surface of the filter by the bottom surface and the cylindrical wall surface, respectively,

the retainer being fixed by directly or indirectly press-fitting the cylindrical wall surface to a circumferential wall plate which is formed by the upper circumferential wall plate and the lower circumferential wall plate,

during actuation,

when the housing is deformed in both directions of the top plate of the diffuser shell and the bottom plate of the closure shell, and the retainer and the filter move into attachment to the top plate of the diffuser shell, combustion gas passing through the filter, then passing through the combustion gas passage in the cylindrical wall surface of the retainer and being discharged from the gas discharge port.

2. A gas generator according to claim 1, wherein

the retainer has a depression and a protrusion in the circumferential direction thereof at a circumferential edge of the cylindrical wall surface in a side of the top plate of the diffuser shell, and

when the housing is deformed both in the direction of the top plate and in the direction of the bottom plate and both the retainer and the filter move towards the top plate of the diffuser shell during actuation,

the protrusion of the cylindrical wall surface of the retainer is abutted against the top plate of the diffuser shell, and the depression of the cylindrical wall surface of the retainer forms the combustion gas passage.

3. A gas generator according to claim 1, wherein

inside the housing,

a cylindrical member is disposed by press-fitting into the lower circumferential wall plate of the closure shell such that a gap is formed between the cylindrical member and the top plate of the diffuser shell, and between the cylindrical member and the gas discharge port formed in the upper circumferential wall plate;

and

the retainer is press-fitted and fixed to the cylindrical member.

5. A gas generator according to claim 1, wherein

the filter and the retainer are in an annular shape, a lower surface of the filter is supported by an annular bottom surface of the retainer, and an outer circumferential surface of the filter is supported by the cylindrical wall surface of the retainer, and

the retainer has a through-hole serving as a gas passage on a side of the inner circumferential edge of the annular bottom surface which faces the filter.

6. A gas generator according to claim 1, wherein

the retainer is in an annular shape;

the filter is in an annular shape having an outer circumferential surface, an annular top surface, and an annular tilted surface, and has a substantially triangular shape, in a cross section thereof in a thickness direction, the smallest thickness of the filter being in a side of the central axis of the housing, and

only part of the annular tilted surface of the filter in a side of the outer circumferential surface is supported by the bottom surface of the retainer, and the outer circumferential surface of the filter is supported by the cylindrical wall surface of the retainer.

7. A gas generator according to claim 1, wherein

the filter and the retainer are in an annular shape, and

an inner circumferential surface of the filter is arranged to protrude toward a central axis of the housing.

4. A gas generator, comprising:

a diffuser shell having a top plate and an upper circumferential wall plate provided with a gas discharge port,

a closure shell having a bottom plate and a lower circumferential wall plate,

a housing forming an outer shell and being obtained by joining and integrating the upper circumferential wall plate and the lower circumferential wall plate and including a circumferential wall plate,

the housing having a step portion formed in the upper circumferential wall plate, an inner diameter of a portion in the upper circumferential wall plate, which is provided with a gas discharge port in the diffuser shell being made less than an inner diameter of the remaining portion of the upper circumferential wall plate by the step portion,

inside the housing,

an ignition device chamber defined by a cup-shaped container, which is positioned at a central part of the bottom plate of the closure shell, and accommodating an ignition device therein

a combustion chamber formed to enclose the ignition device chamber and being loaded with a gas generating agent,

an annular or flat plate-shaped filter disposed to face the top plate,

a retainer supporting the filter,

the retainer including a bottom surface which supports at least part of a lower surface of the filter,

the retainer being fixed at a circumferential edge thereof by press-fitting into an inner circumferential surface of the circumferential wall plate with a gap provided at the step portion,

during activation when the housing is deformed in both directions of the top plate of the diffuser shell and the bottom plate of the closure shell, and when movement of the retainer is blocked by the circumferential edge of the retainer abutting against the step portion, the filter being in close contact with the top plate of the diffuser shell, combustion gas passing through the filter and being discharged from the gas discharge port.