Gas generator

• US 7,600,783 B2
• Filed: 07/06/2006
• Issued: 10/13/2009
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Ryobo, Eiichi, Yamazaki, Masayuki, Numoto, Kenji
• Primary Examiner(s): Dickson; Paul N.
• Assistant Examiner(s): Gooden, Jr.; Barry
• Application Number:
  US11/481,053
• Publication Number:
  US 20070013179A1
• Time in Patent Office: 1,195 Days
• Field of Search: 280/736, 280/740, 280/741, 280/742, 280/743.1
• US Class Current: 280/741
• 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

Abstract

A gas generator that can prevent erroneous operation in which the combustion of a gas generating agent inside one combustion chamber is caused by the combustion of a gas generating agent in the other combustion chamber. Two combustion chambers 30, 50 are separated by a partition wall 35. The partition wall 35 is fixed by discontinuous protrusions 61, 62 formed in a housing 11. Air tightness between two combustion chambers 30, 50 is ensured by two retainers 80, 90.

Claims

1. A gas generator for an air bag, comprising:

a cylindrical housing;

two combustion chambers provided in the housing and being adjacent to each other in an axial direction of the cylindrical housing;

a partition wall separating the two combustion chambers;

an ignition device and a gas generating agent stored in each of the combustion chambers;

a gas discharge port provided at each of the combustion chambers;

two rows of plural projections which are formed discontinuously in a circumferential direction with intervals on the inner surface of the cylindrical housing and that holds and fixes the partition wall; and

a retainer press-inserted into at least one of the two combustion chambers, the retainer including a peripheral wall section having a first peripheral wall and a second peripheral wall, having a diameter larger than the first peripheral wall, that abuts an inner circumferential surface of the cylindrical housing, such that the two combustion chambers are separately air-sealed.

2. The gas generator according to claim 1, wherein the retainer is disposed inside the combustion chamber that is to be actuated first.

3. The gas generator according to claim 1, wherein the retainer has a disk section, formed integrally with the first peripheral wall, that abuts against the partition wall.

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

a cylindrical filter disposed in each of the two combustion chambers, and at least one of the cylindrical filters being supported and positioned by a first protrusion formed in the retainer.

5. The gas generator according to claim 1 or 2, further comprising:

a flame transmission tube for transmitting ignition energy generated from the ignition device is disposed in at least one of the two combustion chambers,

wherein an opening portion at one end of the flame transmission tube is connected to the ignition device, and an opening portion at the other end of the flame transmission tube abuts against and is closed by the retainer and positioned by a second protrusion provided in the retainer.

6. The gas generator according to claim 1, wherein the retainer is disposed inside both of the two combustion chambers.

7. The gas generator according to claim 1, wherein the retainer has a disk section and a protruding section formed integrally with the peripheral wall section, the protruding section including an inner annular protruding section and an outer annular protruding section, and the disk section including a first disk portion surrounded by the inner annular protruding section, a second disk section defined between the inner annular protruding section and the outer annular protruding section, and a third disk section defined between the outer annular protruding section and the first peripheral wall.

8. The gas generator according to claim 7, further comprising;

a cylindrical filter disposed in each of the two combustion chambers, one end of at least one of the cylindrical filters being supported and positioned by being inserted in the third disk section.

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

a flame transmission tube for transmitting ignition energy generated from the ignition device is disposed in at least one of the two combustion chambers,

wherein an opening portion at one end of the flame transmission tube is connected to the ignition device, and an opening portion at the other end of the flame transmission tube is supported and position by being inserted in the first disk portion.

10. A gas generator for an air bag, comprising:

a cylindrical housing defining therein a combustion chamber and including two rows of plurality of projections formed discontinuously in a circumferential direction with intervals formed thereon and projected inwardly, the cylindrical housing further including a plurality of gas discharging ports;

a partition wall provided within the cylindrical housing and separating the combustion chamber into a first combustion chamber and a second combustion chamber, the partition wall being fixed to the cylindrical housing by the two rows of plurality of projections;

an ignition device provided within each of the first combustion chamber and the second combustion chamber;

a gas generating agent provided within the first combustion chamber and the second combustion chamber; and

a retainer press-inserted into the first combustion chamber, the retainer including a peripheral wall section including a first peripheral wall and a second peripheral wall, having a diameter larger than the first peripheral wall, that abuts an inner circumferential surface of the cylindrical housing, such that the first combustion chamber is sealed from the second combustion chamber.

11. The gas generator according to claim 10, wherein the first combustion chamber is actuated prior to the second combustion chamber.

12. The gas generator according to claim 10, wherein the retainer has a disk section, formed integrally with the first peripheral wall, that abuts against the partition wall.

13. The gas generator according to claim 10, further comprising;

a filter disposed in the first combustion chamber, the filter being supported and positioned by a first protrusion formed in the retainer.

14. The gas generator according to claim 10, wherein a flame transmission tube for transmitting ignition energy generated from the ignition device is disposed in the first combustion chamber, and

an opening portion at one end of the flame transmission tube is closed by the ignition device, and an opening portion at the other end of the flame transmission tube abuts against and is closed by the retainer and positioned by a second protrusion provided in the retainer.

15. The gas generator according to claim 10, wherein the retainer has a disk section and a protruding section formed integrally with the peripheral wall section, the protruding section including an inner annular protruding section and an outer annular protruding section, and the disk section including a first disk portion surrounded by the inner annular protruding section, a second disk section defined between the inner annular protruding section and the outer annular protruding section, and a third disk section defined between the outer annular protruding section and the first peripheral wall.

16. The gas generator according to claim 15, further comprising;

a cylindrical filter disposed in the combustion chamber, one end of the cylindrical filter being supported and positioned by being inserted in the third disk section.

17. The gas generator according to claim 15, further comprising;

a flame transmission tube for transmitting ignition energy generated from the ignition device is disposed in the combustion chamber,

wherein an opening portion at one end of the flame transmission tube is connected to the ignition device, and an opening portion at the other end of the flame transmission tube is supported and position by being inserted in the first disk portion.