GAS GENERATOR FOR RESTRAINING DEVICE OF VEHICLE

• US 20110193330A1
• Filed: 01/14/2010
• Published: 08/11/2011
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Kobayashi, Tomoharu, Matsuda, Naoki
• Granted Patent: US 8,720,944 B2
• Time in Patent Office: Days
• 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

The present invention provides a gas generator including,

• • a housing having a circumferential wall including a gas discharge port, a first end, and a second end,
  • a inner tube member disposed in the housing, an outer space thereof defines a combustion chamber charged with a gas generating agent,
  • an outer circumference cylindrical member provided within the housing 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 (A₁) of the gas discharge port being smaller than a smallest cross-sectional area (A₂) of a gas pathway (A₁<A₂).

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 outer circumference cylindrical member provided within the housing for defining an outer circumferential surface of the combustion chamber such that one end opening thereof abuts against a bottom plate of the second end of the housing,

an annular porous member defining an upper surface of the combustion chamber and being provided between the outer circumference cylindrical member and the cup-shaped inner tube member such that a space is formed between the annular porous member and the bottom plate of the first end of the housing,

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 portion of the outer circumference cylindrical member; and

a total cross-sectional area (A₁) of the gas discharge port being smaller than a smallest cross-sectional area (A₂) of a gas pathway extending from the combustion chamber to the gas discharge port and allowing combustion gas of the gas generating agent pass therethrough (A₁<

A₂).

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 a 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 a 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 3, wherein a gas collision member is disposed on the porous member in the space,

the gas collision member has concave and convex surfaces forming a gas pathway, the outer circumferential side of the gas pathway is sealed in one of the concave surface or 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 holes of the annular porous member, and is discharged to the gas discharge path through the gas pathway that is not sealed.

5. The gas generator for a restraining device of a vehicle according to claim 1, wherein the gas discharge ports are formed closer to the or 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.

6. The gas generator for a restraining device of a vehicle according to claim 1, which does not comprise a filter for cooling and filtering the combustion gas generated by combustion of the gas generating agent.