Gas generator

• US 8,585,086 B2
• Filed: 02/12/2013
• Issued: 11/19/2013
• Est. Priority Date: 03/19/2012
• Status: Active Grant

• Current Assignee: Daicel Corporation
• Original Assignee: Daicel Corporation
• Inventors: Yamazaki, Masayuki, Matsuda, Naoki
• Primary Examiner(s): TO, TOAN C
• Application Number:
  US13/765,317
• Publication Number:
  US 20130239839A1
• Time in Patent Office: 280 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 housing comprising circumferential wall plates of a diffuser shell and a closure shell,
  • an ignition device chamber,
  • a combustion chamber surrounding the ignition device chamber and containing a gas generating agent,
  • an annular or flat-plate filter disposed facing the top plate and spaced from the circumferential wall plate,
  • a first support including a disk-shaped portion abutting against and supporting an upper surface of the filter, including communication holes only at a section in contact with the filter,
  • a second support including an annular flat portion abutting against and supporting a lower surface of the filter and cylindrical wall portion fixed to the housing.

A gap is formed between the top plate of the housing and the circumferential wall plate and the first support member, when a pressure inside the combustion chamber increases due to combustion and the top plate is deformed.

Claims

1. A gas generator comprising:

a diffuser shell which has a top plate and an upper circumferential wall plate provided with a gas discharge port, a closure shell which has a bottom plate and a lower circumferential wall plate, a housing, as an outer shell, obtained by joining and integrating only the upper circumferential wall plate and the lower circumferential wall plate,

in the housing,

an ignition device chamber defined by a cup-shaped container which accommodates an ignition device,

a combustion chamber defined to surround the ignition device chamber and charged with a gas generating agent,

an annular or flat-plate filter disposed to face the top plate and to be spaced from the upper circumferential wall plate,

a first support member abutting against and supporting an upper surface of the filter,

a second support member abutting against and supporting an lower surface of the filter,

the first support member including,

a disk-shaped portion and an annular wall portion, the disk-shaped portion provided with a plurality of communication holes formed only at a section in contact with the upper surface of the filter,

one surface of the disk-shaped portion abutting against the top plate, the other surface of the disk-shaped portion abutting against the upper surface of the filter, the annular wall portion abutting against a part of an outer circumferential surface of the filter;

the second support member including,

a substantially cylindrical wall portion and an annular flat portion formed at a circumference in one end of the substantially cylindrical wall portion, and

the substantially cylindrical wall portion being fixed to the housing, the annular flat portion abutting against the lower surface of the filter,

and, during actuation, a gap being formed between the top plate and the first support member; and

a gap being formed between the upper circumferential wall plate and the first support member,

when a pressure inside the combustion chamber increases due to combustion gas generated by combustion of the gas generating agent and the top plate of the diffuser shell is deformed.

2. The gas generator according to claim 1, wherein

a circumferential wall step is formed in a circumferential wall plate including the upper circumferential wall plate and the lower circumferential wall plate,

the second support member has an annular step between the substantially cylindrical wall portion and the annular flat portion,

a step surface of the annular step is formed to be abutted against a step surface of the circumferential wall step,

a gap is present between the step surface of the circumferential wall step and the step surface of the annular step prior to actuation, and

the step surface of the annular step is abutted against the step surface of the circumferential wall step during actuation.

3. The gas generator according to claim 1, wherein

the second support member further has a protrusion that protrudes towards the top plate of the diffuser shell at a circumference of the annular flat portion,

the filter has a depression for inserting the protrusion at the lower surface abutted against the annular flat portion, and

the second support member is arranged such that the substantially cylindrical wall portion is fixed to the housing, the annular flat portion is abutted against the lower surface of the filter, and the protrusion is inserted into the depression in the lower surface of the filter.

4. The gas generator according to claim 1, wherein

a plurality of concave portions concaved to an inside of the housing are formed with a spacing therebetween in the top plate of the diffuser shell or in a boundary section of the top plate and the upper circumferential wall plate of the diffuser shell,

the first support member has the annular wall portion at a circumference of the disk-shaped portion, and

a distal end of the plurality of concave portion is abutted against a portion including a boundary section of the disk-shaped portion and the annular wall portion of the first support member.

5. The gas generator according to claim 1, wherein the second support member is formed from a metal with a higher thermal conductivity than that of the first support member.

6. A gas generator comprising:

a diffuser shell which has a top plate and an upper circumferential wall plate provided with a gas discharge port, a closure shell which has a bottom plate and a lower circumferential wall plate, a housing, as an outer shell, obtained by joining and integrating only the upper circumferential wall plate and the lower circumferential wall plate,

in the housing,

an ignition device chamber defined by a cup-shaped container which accommodates an ignition device,

a combustion chamber defined to surround the ignition device chamber and charged with a gas generating agent,

an annular or flat-plate filter disposed to face the top plate and to be spaced from the upper circumferential wall plate,

a single cup-shaped support member abutting against at least an upper surface of the filter to support the filter,

the single cup-shaped support member having a disk-shaped portion and a cylindrical wall portion formed at the circumference of the disk-shaped portion and provided with a communication hole, the disk-shaped portion being provided with a plurality of communication holes formed only at a section in contact with an upper surface of the filter,

one surface of the disk-shaped portion abutting against the top plate and the other surface of the disk-shaped portion abutting against the upper surface of the filter, and

at least part of the cylindrical wall portion being arranged to abut against an outer circumference of the filter, an opening end of the cylindrical wall portion fixed to the housing,

and, during actuation, a gap being formed between the top plate and the first support member; and

a gap being formed between the upper circumferential wall plate and the first support member, when a pressure inside the combustion chamber increases due to combustion gas generated by combustion of the gas generating agent and the top plate of the diffuser shell is deformed.

7. The gas generator according to claim 6, wherein

the cup-shaped support member has

the disk-shaped portion, a cylindrical wall portion formed at a circumference of the disk-shaped portion, and a protrusion formed in an inner circumferential surface of the cylindrical wall portion, and the disk-shaped portion has the plurality of communication holes only in a section that is in contact with the upper surface of the filter,

one surface of the disk-shaped portion is abutted against the top plate, and the other surface of the disk-shaped portion is abutted against the upper surface of the filter,

the protrusion is abutted against a circumference of a lower surface of the filter, and

at least part of the cylindrical wall portion is arranged to be abutted against an outer circumferential surface of the filter.

8. The gas generator according to claim 6, wherein

a circumferential wall step is formed in a circumferential wall plate including the upper circumferential wall plate and the lower circumferential wall plate,

the cup-shaped support member has an annular step at the cylindrical wall portion,

a step surface of the annular step is formed to be abutted against a step surface of the circumferential wall step,

a gap is present between the step surface of the circumferential wall step and the step surface of the annular step prior to actuation, and

the step surface of the annular step is abutted against the step surface of the circumferential wall step during actuation.

9. The gas generator according to claim 6, wherein

the annular or flat-plate filter is supported by the single cup-shaped support member abutted against at least the upper surface of the filter, and an annular member having an annular flat portion and an annular wall surface, and

in the annular member, the annular wall surface is abutted against the cylindrical wall portion of the cup-shaped support member, and the annular flat portion is abutted against the lower surface of the annular or flat-plate filter.