Gas generator for restraining device of vehicle

• US 8,720,944 B2
• Filed: 01/14/2010
• Issued: 05/13/2014
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Kobayashi, Tomoharu, Matsuda, Naoki
• Primary Examiner(s): Dickson, Paul N
• Assistant Examiner(s): Wilhelm, Timothy
• Application Number:
  US13/059,788
• Publication Number:
  US 20110193330A1
• Time in Patent Office: 1,580 Days
• Field of Search: 280/736, 280/741, 102/530, 102/531
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

A gas generator includes,

• • a housing having a circumferential wall, a first end, and a second end, an
  • inner tube member disposed in the housing, an outer space thereof being a combustion chamber,
  • an outer circumference cylindrical member being such that one end opening abuts against a bottom plate of the second end,
  • an annular porous member provided between the outer circumference cylindrical member and the cup-shaped inner tube member so as to form a space above the combustion chamber,
  • a gas discharge path formed between the outer circumference cylindrical member and an inner wall surface of the circumferential wall portion of the housing;
  • a communicating portion communicating the space and the gas discharge path, and being provided in the other end opening of the outer circumference cylindrical member; and
    a total cross-sectional area of the gas discharge port being smaller than a smallest cross-sectional area of a gas pathway.

Claims

1. A gas generator for a restraining device of a vehicle comprising:

a housing forming an outer shell container of the gas generator, and having a circumferential wall portion which is provided with a gas discharge port, a first end, and a second end, opposite to the first end, the first end and the second end being both closed;

a cup-shaped inner tube member disposed in the housing so that an opening end portion thereof is located in a side of a bottom plate of the second end, an inside of the cup-shaped inner tube member being an ignition chamber accommodating an ignition device, an outer space of the cup-shaped inner tube member being a combustion chamber charged with a gas generating agent, the inner tube member defining an inner circumferential surface of the combustion chamber;

an annular porous member defining an upper surface of the combustion chamber and being provided such that a space is formed between the annular porous member and the bottom plate of the first end of the housing, the annular porous member having a plurality of holes that allows communication between the combustion chamber and the space,

a gas passage extending in a radial direction of the housing and defined by a concave surface and a convex surface disposed in the space such that an inner circumferential of the concave surface and the convex surface is placed with a distance from the cup-shaped member;

a step portion defining a gas discharge path connecting the space and gas discharge port;

a communicating portion communicating the space and the gas discharge path and being open prior to activation of the gas generator; and

a total cross-sectional area of the gas discharge port being smaller than a total opening area of the plurality of holes of the annular porous member;

a cross-sectional area of the communicating portion; and

a cross-sectional area of the space.

2. The gas generator for a restraining device of a vehicle according to claim 1, wherein the annular porous member has a first annular planar portion having the plurality of holes, a first annular outside wall surface portion formed on an outer circumference of the first annular planar portion, and a first annular inside wall surface portion formed on an inner circumference of the first annular planar portion and on the same side as the first annular outside wall surface portion.

3. The gas generator for a restraining device of a vehicle according to claim 1, wherein the annular porous member has a first annular planar portion having the plurality of holes, a first annular outside wall surface portion formed on an outer circumference of the first annular planar portion, and a first annular inside wall surface portion formed on an inner circumference of the first annular planar portion and on a side opposite to the first annular outside wall surface portion.

4. The gas generator for a restraining device of a vehicle according to claim 1, wherein the concave surface and the convex surface is formed by a gas collision member,

the outer circumferential side of the gas passage is sealed in one of the concave surface or the convex surface by an outside wall surface formed on an outer circumferential portion thereof, and

combustion gas from the combustion chamber collides with the gas collision member after passing through the plurality of holes of the annular porous member, and is discharged to the gas discharge path through the gas passage that is not sealed.

5. The gas generator for a restraining device of a vehicle according to claim 4,

wherein the gas collision member further includes an annular outside wall surface formed on an outer circumferences of the concave surfaced and the convex surface, and

wherein the gas collision member is disposed on the porous member in the space such that the annular outside wall surface abuts against an outer circumference cylindrical member defining an outer circumferential surface of the combustion chamber.

6. The gas generator for a restraining device of a vehicle according to claim 1, wherein the gas discharge ports are formed closer to the second end of the housing than the communicating portion, the housing comprises a closure shell and a diffuser shell having the gas discharge port in a side surface portion of the diffuser shell, and the opening end of the diffuser shell has a flange portion extending from the side surface portion to the outside in the radial direction, and the flange portion exists on an imaginary straight line connecting the communication portion to the gas discharge ports.

7. A gas generator for a restraining device of a vehicle comprising:

a housing forming an outer shell container of the gas generator, and having a circumferential wall portion which is provided with a gas discharge port, a first end, and a second end, opposite to the first end, the first end and the second end being both closed;

a cup-shaped inner tube member disposed in the housing so that an opening end portion thereof is located in a side of a bottom plate of the second end, an inside of the cup-shaped inner tube member being an ignition chamber accommodating an ignition device, an outer space of the cup-shaped inner tube member being a combustion chamber charged with a gas generating agent, the inner tube member defining an inner circumferential surface of the combustion chamber;

an annular porous member defining an upper surface of the combustion chamber and being provided such that a space is formed between the annular porous member and the bottom plate of the first end of the housing, the annular porous member having a plurality of holes that allows communication between the combustion chamber and the space;

a gas passage extending in a radial direction of the housing and defined by a concave surface and a convex surface disposed in the space such that an inner circumferential of the concave surface and the convex surface is placed with a distance from the cup-shaped inner tube member;

a step portion defining a gas discharge path connecting the space and gas discharge port;

a communicating portion communicating the space and the gas discharge path and being open prior to activation of the gas generator.

8. A gas generator for a restraining device of a vehicle comprising:

a housing forming an outer shell container of the gas generator, and having a circumferential wall portion which is provided with a gas discharge port, a first end, and a second end, opposite to the first end, the first end and the second end being both closed;

a cup-shaped inner tube member disposed in the housing so that an opening end portion thereof is located in a side of a bottom plate of the second end, an inside of the cup-shaped inner tube member being an ignition chamber accommodating an ignition device, an outer space of the cup-shaped inner tube member being a combustion chamber charged with a gas generating agent, the inner tube member defining an inner circumferential surface of the combustion chamber;

an annular porous member defining an upper surface of the combustion chamber and being provided such that a space is formed between the annular porous member and the bottom plate of the first end of the housing, the annular porous member having a plurality of holes that allows communication between the combustion chamber and the space,

a gas discharge path connecting the space and gas discharge port;

a communicating portion communicating the space and the gas discharge path and being open prior to activation of the gas generator; and

a total cross-sectional area of the gas discharge port being smaller than a total opening area of the plurality of holes of the annular porous member;

a cross-sectional area of the communicating portion; and

a cross-sectional area of the space,

wherein a gas collision member is disposed on the porous member in the space,

the gas collision member has a concave surface and a convex surface forming a gas pathway, the outer circumferential side of the gas pathway is sealed in one of the concave surface or the convex surface by an outside wall surface formed on an outer circumferential portion thereof, and

combustion gas from the combustion chamber collides with the gas collision member after passing through the plurality of holes of the annular porous member, and is discharged to the gas discharge path through the gas pathway that is not sealed.

9. The gas generator for a restraining device of a vehicle according to claim 8, wherein the gas discharge ports are formed closer to the second end of the housing than the communicating portion, the housing comprises a closure shell and a diffuser shell having the gas discharge port in a side surface portion of the diffuser shell, and the opening end of the diffuser shell has a flange portion extending from the side surface portion to the outside in the radial direction, and the flange portion exists on an imaginary straight line connecting the communication portion to the gas discharge ports.