Hybrid inflator

• US 6,808,204 B1
• Filed: 06/13/2001
• Issued: 10/26/2004
• Est. Priority Date: 10/01/1999
• Status: Expired due to Term

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Hirata, Norimasa, Yamazaki, Masayuki, Katsuda, Nobuyuki
• Primary Examiner(s): Fleming, Faye M.
• Application Number:
  US09/857,891
• Time in Patent Office: 1,231 Days
• Field of Search: 280/740, 280/741, 280/742, 280/736, 280/735
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators
• CPC Class Codes: C06D 5/00 Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets explosive compositions containing an oxidizer, fuels for rocket engines intended for reaction with an oxidant other than air C06B
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

A hybrid inflator which is made more compact and lighter is provided. An excessive internal pressure increase at a time of activation is prevented by setting a molar ratio (A/B) between a pressurized medium (A moles) charged in a housing 102 and an amount of a gas (B moles) generated due to combustion of a gas generating agent 122 to 8/2 to 1/9.

Claims

1. A hybrid inflator for an inflating-type safety system of vehicles provided with an air bag, comprising:

an inflator housing containing pressurized medium therein, and having a gas exit opening closed by a rupturable disk and provided in a vicinity of a first end portion of the inflator housing;

a gas generator installed in the inflator housing and attached to a second end portion of the inflator housing opposing said first end portion with respect to a longitudinal direction of the inflator housing, said gas generator having at least one gas generating chamber and a plurality of ports formed only along a longitudinally axial direction of the gas generator in a circumferential wall thereof extending along the longitudinally axial direction to establish a fluid communication between the gas generating chamber and an interior of the inflator housing;

gas generating agent provided inside the gas generating chamber, the gas generating agent being a mixture of at least a fuel, an oxidizing agent, and a slug-forming agent, for generating a predetermined amount (B) of combustion gas by combustion thereof, a molar ratio (A/B) between an amount (A moles) of the pressurized medium and the amount (B moles) of a gas generated due to combustion of the gas generating agent is between 8/2 and 1/9; and

an ignition unit connected to the gas generator and adapted to ignite the gas generating agent.

2. A hybrid inflator according to claim 1, wherein the ratio A/B is 8/2 to 3/7.

3. A hybrid inflator according to claim 1, wherein the fuel is guanidine derivatives.

4. A hybrid inflator according to claim 1, wherein the fuel is a non-azide organic compound except the nitramine compounds.

5. A hybrid inflator according to claim 1, wherein a pressure index of the gas generating agent is less than 0.8.

6. A hybrid inflator according to claim 1, wherein a weight ratio (a/b) between a weight (a) of the pressurized medium and a weight (b) of the gas generating agent is 0.1 to 7.

7. A hybrid inflator according to claim 1, wherein the inflator housing is made of high strength steel.

8. A hybrid inflator according to claim 7, wherein the high strength steels has a tensile strength of being not less than 60 kg/mm2.

9. A hybrid inflator according to claim 1, wherein the gas generating agent is kept under a normal pressure atmosphere.

10. A hybrid inflator according to claim 1, wherein the gas generating agent is formed in a perforated cylindrical shape.

11. A hybrid inflator for an inflating-type safety system of vehicles provided with an air bag, comprising:

an inflator housing containing a pressurized medium therein that includes an inert gas and no oxygen, said inflator housing having a gas exit opening closed by a rupturable disk and provided in a vicinity of a first end portion of the inflator housing;

a gas generator installed in the inflator housing and attached to a second end portion of the inflator housing opposing said first end portion with respect to a longitudinal direction of the inflator housing, said gas generator having at least one gas generating chamber and a plurality of ports formed only along a longitudinally axial direction of the gas generator in a circumferential wall thereof extending along the longitudinally axial direction to establish a fluid communication between the gas generating chamber and an interior of the inflator housing;

a gas generating agent provided in the gas generating chamber, the gas generating agent being a mixture of at least a fuel, an oxidizing agent, and a slug-forming agent, a molar ratio (A/B) between an amount (A moles) of the pressurized medium and an amount (B moles) of a gas generated due to combustion of the gas generating agent being between 8/2 and 1/9; and

an ignition unit connected to the gas generator and adapted to ignite the gas generating agent.

12. A hybrid inflator according to claim 11, wherein the ratio A/B is 8/2 to 3/7.

13. A hybrid inflator according to claim 11, wherein the fuel is guanidine derivative.

14. A hybrid inflator according to claim 11, wherein the fuel is a non-azide organic compound except the nitramine compounds.

15. A hybrid inflator according to claim 11, wherein a pressure index of the gas generating agent is less than 0.8.

16. A hybrid inflator according to claim 11, wherein a weight ratio (a/b) between a weight (a) of the pressurized medium and a weight (b) of the gas generating agent is 0.1 to 7.

17. A hybrid inflator for an inflating-type safety system of vehicles provided with an air bag, comprising:

an inflator housing containing a pressurized medium including an inert gas therein and having a gas exit opening closed by a rupturable disk and provided in a vicinity of a first end portion of the inflator housing, the pressurized medium containing no oxygen;

a gas generating agent including a fuel, an oxidizing agent, and a slug-forming agent;

a gas generator installed in the inflator housing and attached to a second end portion of the inflator housing opposing said first end portion with respect to a longitudinal direction of the inflator housing, said gas generator having at least one gas generating chamber that contains the gas generating agent and having a plurality of ports formed only along a longitudinally axial direction of the gas generator in a circumferential wall thereof extending along the longitudinally axial direction to establish a fluid communication between the gas generating chamber and an interior of the inflator housing; and

an ignition means chamber connected to the gas generator and including an ignition unit adapted to ignite the gas generating agent.

18. A hybrid inflator for an inflating-type safety system of vehicles provided with an air bag, comprising:

an inflator housing containing a pressurized medium including an inert gas and no oxygen, said inflator having a gas exit opening closed by a rupturable disk and provided in a vicinity of a first end portion of the inflator housing;

a gas generating agent, comprising a fuel, an oxidizing agent, and a slug-forming agent, said gas generating agent having a pressure index of less than 0.8;

a gas generator installed in the inflator housing and attached to a second end portion of the inflator housing opposing said first end portion with respect to a longitudinal direction of the inflator housing, said gas generator having at least one gas generating chamber for storing a gas generating agent and having a plurality of ports formed only along a longitudinally axial direction of the gas generator in a circumferential wall thereof extending along the longitudinally axial direction to establish a fluid communication between the gas generating chamber and an interior of the inflator housing; and

an ignition means changer connected to the gas generator and including an ignition unit adapted to ignite the gas generating agent.

19. An air bag apparatus, comprising:

an activating signal outputting unit that includes an impact sensor for detecting an impact and a control unit, and

a module case containing an air bag and a hybrid inflator, said hybrid inflator including,

an inflator housing containing pressurized medium therein and having a gas exit opening closed by a rupturable disk and provided in a vicinity of a first end portion of the inflator housing,

a gas generator installed in the inflator housing and attached to a second end portion of the inflator housing opposing said first end portion with respect to a longitudinal direction of the inflator housing, said gas generator having at least one gas generating chamber and having a plurality of ports formed only along a longitudinally axial direction of the gas generator in a circumferential wall thereof extending along the longitudinally axial direction to establish a fluid communication between the gas generating chamber and an interior of the inflator housing;

a gas generating agent provided in the gas generating chamber, the gas generating agent being a mixture of at least a fuel, an oxidizing agent, and a slug-forming agent, for generating a predetermined amount (B) of combustion gas by combustion thereof, a molar ratio (A/B) between an amount (A moles) of the pressurized medium and the amount (B moles) of a gas generated due to combustion of the gas generating agent is between 8/2 and 1/9, and

an ignition unit connected to the gas generator and adapted to ignite the gas generating agent.