Gas generator

• US 9,994,189 B2
• Filed: 09/24/2014
• Issued: 06/12/2018
• Est. Priority Date: 10/11/2013
• Status: Active Grant

• Current Assignee: Daicel Corporation
• Original Assignee: Daicel Corporation
• Inventors: Imoto, Katsuhiro, Hanano, Teppei, Yamashita, Haruhiko
• Primary Examiner(s): Bergin, James S
• Application Number:
  US14/917,840
• Publication Number:
  US 20160214564A1
• Time in Patent Office: 1,357 Days
• Field of Search: 102530, 280741, 280736, 280740
• 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

Abstract

The present invention provides a gas generator wherein a diffuser portion having a gas discharge port is disposed at one end of a cylindrical housing; an ignition device is disposed at the other end of the cylindrical housing; an axially-movable metallic partition wall having a plurality of through-holes is disposed between the ignition device and the diffuser portion; a space between the partition wall and the ignition device is an ignition device chamber charged with a molded article of a first gas generating agent; a space between the partition wall and the diffuser portion is a combustion chamber charged with a molded article of a second gas generating agent; the partition wall has a circular bottom surface and an annular wall extending, in a single direction, perpendicularly to an outer circumference of the circular bottom surface, and the circular bottom surface is disposed so as to be on the diffuser portion side; the ignition device has an igniter having a disk-shaped ignition portion protruding toward the partition wall and a metallic annular member having an annular wall and disposed around the ignition portion; and the annular wall of the annular member protrudes to the partition wall further than the distal end surface of the ignition portion.

Claims

1. A gas generator, comprising:

a cylindrical housing having a first end and a second end opposite to the first end;

a diffuser portion provided with a gas discharge port and disposed at the first end of the cylindrical housing;

an ignition device disposed at the second end of the cylindrical housing,

a first partition wall having a plurality of through-holes and disposed between the ignition device and the diffuser portion;

an ignition device chamber defined by the first partition wall and the ignition device, and being charged with a molded article of a first gas generating agent;

a combustion chamber defined between the first partition wall and the diffuser portion, and being charged with a molded article of a second gas generating agent;

the first partition wall including a circular bottom surface and an annular wall, the annular wall extending in a single direction perpendicular to an outer circumference of the circular bottom surface, the circular bottom surface opposing the diffuser portion;

the ignition device including an igniter having a disk-shaped ignition portion which faces the first partition wall, and an annular member having an annular bottom surface wall and disposed around the ignition portion; and

a distance between the annular bottom surface of the annular member and the first partition wall is shorter than a distance between a distal end surface of the ignition portion and the first partition wall,

wherein the annular bottom surface of the annular member extends between the ignition portion of the igniter and the cylindrical housing, and the molded article of the first gas generating agent is disposed closer to the diffuser portion than the annular bottom surface.

2. The gas generator according to claim 1, wherein

the annular member includes:

the annular bottom surface, an inner annular wall extending perpendicularly to an inner circumference of the annular bottom surface, and an outer annular wall extending perpendicularly to an outer circumference of the annular bottom surface, the inner annular wall and the outer annular wall having the same length; and

the inner annular wall abuts against the ignition portion, the outer annular wall abuts against an inner wall surface of the cylindrical housing, and the annular bottom surface opposes the first partition wall.

3. The gas generator according to claim 1, wherein

the annular member includes:

the annular bottom surface and an inner annular wall extending perpendicularly to an inner circumference of the annular bottom surface; and

the inner annular wall abuts against the ignition portion, an outer circumferential edge portion of the annular bottom surface abuts against an inner wall surface of the cylindrical housing, and the annular bottom surface opposes the first partition wall.

4. The gas generator according to claim 3 wherein the annular member only has the annular bottom surface and the inner annular wall.

5. The gas generator according to claim 1, wherein

the annular member includes:

the annular bottom surface, an inner annular wall extending perpendicularly to an inner circumference of the annular bottom surface, and an outer annular wall extending perpendicularly to an outer circumference of the annular bottom surface, the inner annular wall and the outer annular wall having different lengths; and

the inner annular wall abuts against the ignition portion, the outer annular wall abuts against an inner wall surface of the cylindrical housing, and the annular bottom surface opposes the first the partition wall.

6. The gas generator according to claim 5 wherein a length of the outer annular wall is shorter than a length of the inner annular wall.

7. The gas generator according to claim 1, further comprising:

a second partition wall having a plurality of through-holes and defining the combustion chamber, wherein

the first partition wall and the second partition wall each has a circular bottom surface and an annular wall extending in a single direction perpendicular to an outer circumference of the circular bottom surface;

the first partition wall is disposed closer to the ignition device chamber than the second partition wall, with each of the first and second partition walls being disposed such that the circular bottom surface thereof opposes the diffuser portion;

a capacity of the ignition device chamber, corresponding to a charged amount of the molded article of the first gas generating agent, is determined by a position of the first partition wall in an axial direction of the cylindrical housing; and

a capacity of the combustion chamber, corresponding to a charged amount of the molded article of the second gas generating agent, is determined by a position of the second partition wall in the axial direction.

8. The gas generator according to claim 1 wherein the annular member is press-fitted between the inner wall surface of the cylindrical housing and the ignition portion.

9. A gas generator, comprising:

a cylindrical housing having a first end and a second end opposite to the first end;

a diffuser portion provided with a gas discharge port and disposed at the first end of the cylindrical housing;

a partition wall having a plurality of through-holes and disposed between first end and the second end, the partition wall including a circular bottom surface provided with the through-holes;

an ignition device chamber defined by the partition wall and the second end, and being charged with a molded article of a first gas generating agent;

a combustion chamber defined between the partition wall and the diffuser portion, and being charged with a molded article of a second gas generating agent;

an ignition device including an igniter provided with an ignition portion and being disposed in the ignition device chamber at the second end of the cylindrical housing such that the ignition portion faces the partition wall;

an annular member having an annular bottom surface and disposed around the ignition portion such that a distance between the annular bottom surface and the partition wall is shorter than a distance between a distal end surface of the ignition portion and the partition wall, the annular bottom surface extending between the ignition portion and the cylindrical housing, and the molded article of the first gas generating agent is disposed closer to the diffuser potion than the annular bottom surface.