Gas generator

Patent metadata

Field	Value
Publication number	US-10953843-B2
Application number	US-201716307194-A
Country	US
Kind code	B2
Filing date	May 16, 2017
Priority date	Jun 27, 2016
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A gas generator includes, an ignition device chamber arranged on a first end of a housing, a diffuser including a gas discharge port and closing a second end of the housing, a gas containing chamber disposed between the diffuser and the ignition device chamber, a first rupturable plate closing the ignition device chamber from the gas containing chamber, and a second rupturable plate closing the gas containing chamber from the diffuser, and a cup-shaped deflector disposed on a side of the second rupturable plate. The cup-shaped deflector includes a gas passage in a peripheral surface and a fragile section on at least one of a bottom surface and the peripheral surface, and is disposed with the bottom surface located on a side of the first rupturable plate, with an opening covering the second rupturable plate, and defines a gap between the peripheral surface and an inner surface of the housing.

First claim

The invention claimed is:

1. A gas generator, comprising:
an ignition device chamber arranged on a first end side of a cylindrical housing and closed by an ignition device provided with an igniter;
a diffuser including a gas discharge port and closing a second end side of the cylindrical housing opposite to the first end side in an axial direction;
a compressed gas containing chamber disposed between the diffuser and the ignition device chamber and containing therein a compressed gas as a gas source;
a first rupturable plate disposed closing off the ignition device chamber and the compressed gas containing chamber from one another, and a second rupturable plate disposed closing off the compressed gas containing chamber and the diffuser from one another; and
a cup-shaped deflector disposed on a side of the second rupturable plate and downstream of a gas flow with respect to the ignition device chamber, the first rupturable plate, and the compressed gas containing chamber; wherein
the cup-shaped deflector includes a gas passage in a peripheral surface section thereof, and a fragile section on at least one of a bottom surface section thereof and the peripheral surface section; and
the cup-shaped deflector is disposed with the bottom surface section located on a side where the first rupturable plate is disposed, the cup-shaped deflector has an opening covering the second rupturable plate, and defines a cylindrical gap between the peripheral surface section and an inner peripheral wall surface of the cylindrical housing.

2. The gas generator according to claim 1 , wherein
the cup-shaped deflector includes the gas passage in the peripheral surface section and the fragile section on the bottom surface section; and
the fragile section is constituted by a groove formed along a line connecting a starting point and an ending point located remote from each other so as not have a shortest distance (L), the groove having a total distance of from 2 L to 15 L.

3. The gas generator according to claim 1 , wherein
the cup-shaped deflector includes the gas passage and the fragile section in the peripheral surface section;
the gas passage is constituted by a plurality of elongated holes formed in a section between the bottom surface section and the opening, the plurality of elongated holes being formed at intervals in a circumferential direction; and
the fragile section is constituted by a plurality of peripheral walls remaining between the plurality of elongated holes in the circumferential direction.

4. The gas generator according to claim 3 , wherein
the cup-shaped deflector includes the gas passage and the fragile section in the peripheral surface section; and
a ratio (L 2 /L 1 ) of a length L 2 of the gas passage to a length L 1 from the opening to the bottom surface section of the cup-shaped deflector is from 0.5 to 0.9.

5. The gas generator according to claim 3 , wherein
a ratio D 2 /D 1 of an outer diameter D 2 of the cup-shaped deflector to an inner diameter D 1 of the cylindrical housing is from 0.5 to 0.8; and
the cylindrical gap defined between the peripheral surface section of the cup-shaped deflector and the inner peripheral wall surface of the cylindrical housing has a width defined as (D 1 −D 2 )/2.

6. The gas generator according to claim 1 , wherein
the cup-shaped deflector includes the gas passage and the fragile section in the peripheral surface section;
the gas passage is constituted by a plurality of rectangular holes formed in a section between the bottom surface section and the opening, the plurality of rectangular holes being formed at intervals in a circumferential direction and each of the plurality of rectangular holes having a width W 1 ;
the fragile section is constituted by a plurality of peripheral walls remaining between the plurality of rectangular holes in the circumferential direction, each of the plurality of peripheral walls having a width W 2 ; and
the width W 1 of the plurality of rectangular holes and the width W 2 of the plurality of peripheral walls constituting the fragile section satisfy a relationship W 1 >W 2 .

7. The gas generator according to claim 6 , wherein
the cup-shaped deflector includes the gas passage and the fragile section in the peripheral surface section; and
a ratio (L 2 /L 1 ) of a length L 2 of the gas passage to a length L 1 from the opening to the bottom surface section of the cup-shaped deflector is from 0.5 to 0.9.

8. The gas generator according to claim 1 , wherein
the cup-shaped deflector includes the gas passage and the fragile section in the peripheral surface section;
the gas passage is constituted by a plurality of elongated holes formed in a section between the bottom surface section and the opening, the plurality of elongated holes being formed at intervals in a circumferential direction and each of the plurality of elongated holes having a maximum width (short-axis length) W 11 at a longitudinally intermediate portion;
the fragile section is constituted by a plurality of peripheral walls remaining between the plurality of elongated holes in the circumferential direction, each of the plurality of peripheral walls having a minimum width W 12 at the longitudinally intermediate portion of the plurality of elongated holes; and
a relationship W 12 /W 11 <0.5 is satisfied.

9. The gas generator according to claim 6 , wherein
a ratio D 2 /D 1 of an outer diameter D 2 of the cup-shaped deflector to an inner diameter D 1 of the cylindrical housing is from 0.5 to 0.8; and
the cylindrical gap defined between the peripheral surface section of the cup-shaped deflector and the inner peripheral wall surface of the cylindrical housing has a width defined as (D 1 −D 2 )/2.

10. A gas generator, comprising:
a cylindrical housing closed at a first end side by an ignition device provided with an igniter,
a diffuser including a gas discharge port and closing a second end side of the cylindrical housing opposite to the first end side in an axial direction;
a combustion chamber disposed between the diffuser and the ignition device and containing therein a gas generating agent as a gas source;
a sealing member disposed closing off the combustion chamber and the diffuser from one another; and
a cup-shaped deflector disposed on a side of the sealing member and downstream of a gas flow with respect to the combustion chamber; wherein
the cup-shaped deflector includes a gas passage in a peripheral surface section thereof, and a fragile section on at least one of a bottom surface section thereof and the peripheral surface section; and
the cup-shaped deflector is disposed with the bottom surface section located on the first end side, the cup-shaped deflector has an opening covering the sealing member, and defines a cylindrical gap between the peripheral surface section and an inner peripheral wall surface of the cylindrical housing.

11. The gas generator according to claim 10 , wherein
the cup-shaped deflector includes the gas passage in the peripheral surface section and the fragile section on the bottom surface section; and
the fragile section is constituted by a groove formed along a line connecting a starting point and an ending point located remote from each other so as not have a shortest distance (L), the groove having a total distance of from 2 L to 15 L.

12. The gas generator according to claim 10 , wherein
the cup-shaped deflector includes the gas passage and the fragile section in the peripheral surface section;
the gas passage is constituted by a plurality of elongated holes formed in a section between the bottom surface section and the opening, the plurality of elongated hole

Assignees

• Daicel Corp

Inventors

• Ukita Shinichiro
• Kobayashi Tomoharu

Classifications

• B60R21/268 Primary

  using instantaneous release of stored pressurised gas {(B60R21/26005 takes precedence)} · CPC title

• B60R21/26

  characterised by the inflation fluid source or means to control inflation fluid flow {(arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10)} · CPC title

• B60R21/261

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

• B60R21/272 Primary

  with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators · CPC title

• B60R2021/26029

  Ignitors · CPC title