Gas generator

Patent metadata

Field	Value
Publication number	US-10046727-B2
Application number	US-201515522507-A
Country	US
Kind code	B2
Filing date	Nov 2, 2015
Priority date	Dec 3, 2014
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

The present invention provides a gas generator including a cylindrical housing in which an ignition device is attached at a first end portion thereof and a diffuser portion provided with a gas discharge port is attached at a second end portion thereof, an annular end surface being formed on the side of the second end portion, a cylindrical flow path forming member being disposed in the cylindrical housing, an inner space of the cylindrical flow path forming member being partitioned by a partition wall into a first chamber on the side of the first end portion and a second chamber on the side of the second end portion, a space, which includes the first chamber, being a combustion chamber filled with a gas generating agent, and the second chamber forming part of a gas discharge path, in the cylindrical flow path forming member, a first cylindrical space, which is formed between a first wall surface of the cylindrical flow path forming member on the side of the first chamber and the inner wall surface of the cylindrical housing, and a second cylindrical space, which is formed between a second wall surface of the cylindrical flow path forming member on the side of the second chamber and the inner wall surface of the cylindrical housing, being continuous in an axial direction, and the second cylindrical space being a cylindrical space with a length L from a boundary with the first cylindrical space to the annular end surface, and having an annular pocket portion with a length L 1 from the annular end surface to the second communication holes, and at least part of a surface of the annular pocket portion being provided with a concave-convex portion.

First claim

The invention claimed is:

1. A gas generator comprising
a cylindrical housing in which an ignition device is attached at a first end portion thereof and a diffuser portion provided with a gas discharge port is attached at a second end portion thereof,
an annular end surface which is in contact with an inner wall surface of the cylindrical housing being formed between the second end portion of the cylindrical housing and the diffuser portion,
a cylindrical flow path forming member being disposed in the cylindrical housing and extending from the side of the first end portion toward the second end portion,
an inner space of the cylindrical flow path forming member being partitioned by a partition wall into a first chamber on the side of the first end portion and a second chamber on the side of the second end portion,
a space, which includes the first chamber in the cylindrical flow path forming member, being a combustion chamber filled with a gas generating agent, and the second chamber in the cylindrical flow path forming member forming part of a gas discharge path for a combustion gas generated by combustion of the gas generating agent to enter the diffuser portion,
in the cylindrical flow path forming member,
an upstream end portion being positioned on the side of the first end portion of the cylindrical housing, a downstream end portion being positioned on the side of the second end portion of the cylindrical housing, and the downstream end portion being abutted against the annular end surface,
a first cylindrical space being formed between a first wall surface of the cylindrical flow path forming member on the side of the first chamber and the inner wall surface of the cylindrical housing, a second cylindrical space being formed between a second wall surface of the cylindrical flow path forming member on the side of the second chamber and the inner wall surface of the cylindrical housing, and the first cylindrical space and the second cylindrical space being arranged to form a space continuous in an axial direction, and
a plurality of first communication holes being formed in the first wall surface on the side of the first chamber and a plurality of second communication holes being formed in the second wall surface on the side of the second chamber,

the second cylindrical space being a cylindrical space with a length L from a boundary with the first cylindrical space to the annular end surface, and having an annular pocket portion with a length L 1 from the annular end surface to the second communication holes, and
at least part of an inner circumferential surface of the annular pocket portion being provided with a concave-convex portion as means for collecting a combustion residue included in the combustion gas generated by combustion of the gas generating agent.

2. The gas generator according to claim 1 , wherein the concave-convex portion for collecting the combustion residue generated by combustion of the gas generating agent is formed in the range of L 1 on an outer circumferential surface of the second wall surface on the side of the second chamber.

3. The gas generator according to claim 1 , wherein the concave-convex portion for collecting the combustion residue generated by combustion of the gas generating agent includes concave portions continuously formed in the circumferential direction and convex portions continuously formed in the circumferential direction, and the concave portions and the convex portions are arranged alternately in the axial direction in the range of L 1 on an outer circumferential surface of the second wall surface on the side of the second chamber.

4. The gas generator according to claim 1 , wherein the concave-convex portion for collecting the combustion residue generated by combustion of the gas generating agent includes concave portions continuously formed in the circumferential direction and convex portions continuously formed in the circumferential direction, the concave portions and the convex portions are arranged alternately in the axial direction in the range of L 1 on an outer circumferential surface of the second wall surface on the side of the second chamber, and the convex portions are inclined toward the annular end surface.

5. The gas generator according to claim 1 , wherein in the concave-convex portion for collecting the combustion residue generated by combustion of the gas generating agent, a height difference between the concave portion and the convex portion is within a range of 0.2 mm to 2 mm.

6. A gas generator comprising
a cylindrical housing in which an ignition device is attached at a first end portion thereof and a diffuser portion provided with a gas discharge port is attached at a second end portion thereof,
an annular end surface which is in contact with an inner wall surface of the cylindrical housing being formed between the second end portion of the cylindrical housing and the diffuser portion,
a cylindrical flow path forming member being disposed in the cylindrical housing and extending from the side of the first end portion toward the second end portion,
an inner space of the cylindrical flow path forming member being partitioned by a partition wall into a first chamber on the side of the first end portion and a second chamber on the side of the second end portion,
a space, which includes the first chamber in the cylindrical flow path forming member, being a combustion chamber filled with a gas generating agent, and the second chamber in the cylindrical flow path forming member forming part of a gas discharge path for a combustion gas generated by combustion of the gas generating agent to enter the diffuser portion,
in the cylindrical flow path forming member,
an upstream end portion being positioned on the side of the first end portion of the cylindrical housing, a downstream end portion being positioned on the side of the second end portion of the cylindrical housing, and the downstream end portion being abutted against the annular end surface,
a first cylindrical space being formed between a first wall surface of the cylindrical flow path forming member on the side of the first chamber and the inner wall surface of the cylindrical housing, a second cylindrical space being formed between a second wall surface of the cylindrical flow path forming member on the side of the second chamber and the inner wall surface of the cylindrical housing, and the first cylindrical space and the second cylindrical space being arranged to form a space continuous in an axial direction, and
a plurality of first communication holes being formed in the first wall surface on the side of the first chamber and a plurality of second communication holes being formed in the second wall surface on the side of the second chamber,

the second cylindrical space being a cylindrical space with a length L from a boundary with the first cylindrical space to the annular end surface, and having an annular pocket portion with a length L 1 from the annular end surface to the second communication holes, and
an annular filter being disposed in the annular pocket portion as means for collecting a combustion residue included in the combustion gas generated by combustion of the gas generating agent.

7. The gas generator according to claim 6 , wherein the annular filter is disposed such that at least the inner circumferential surface thereof is abutted against an outer circumferential surface of the second wall surface on the side of the second chamber and that the annular filter occupies part of a space of the annular pocket portion.

8. The gas generator according to claim 6 , wherein the annular filter has a bulk density of 1 to 3 g/cm 3 .

Assignees

• Daicel Corp

Inventors

• Hanano Teppei
• Yamazaki Masayuki

Classifications

• B60R21/264 Primary

  using instantaneous generation of gas, e.g. pyrotechnic (B60R21/268 takes precedence) · CPC title

• B60R21/261 Primary

  with means other than bag structure to diffuse or guide inflation fluid · CPC title

• B60R2021/26011

  using a filter through which the inflation gas passes · CPC title

• B60R21/2346

  Soft diffusers · CPC title