Adaptive output fluid fueled airbag inflator

• US 5,857,699 A
• Filed: 02/25/1997
• Issued: 01/12/1999
• Est. Priority Date: 02/25/1997
• Status: Expired due to Fees

• Current Assignee: Morton International Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Smith, Bradley W., Green, David J., Rink, Karl K., Mossi, G. Dean
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US08/810,118
• Time in Patent Office: 686 Days
• Field of Search: 280/741, 280/736, 280/737, 280/735
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2725 using a fluid fuel gas generator
• CPC Class Codes: B60R 21/01526 using piezoelectric elements
• 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

Abstract

An improvement in an airbag system for a motor vehicle relating to an adaptive output fluid fueled airbag inflator and method of operation thereof are provided. Such an inflator, in addition to a stored gas chamber, a combustion chamber wherein, upon actuation, a first fluid fuel and an oxidant are burned, and a first initiator device for initiating the combustion of the first fuel and the at least one oxidant, includes a combination of a fluid fuel container, which holds a supply of a second fluid fuel, and a second initiator device for initiating the combustion of the second fuel. Various selected performance levels can be obtained through the proper selection, actuation and sequencing of actuation of the initiator devices and burning of fuels contained within the inflator.

Claims

1. An adaptive output inflator apparatus for inflating an inflatable device, said apparatus comprising:

a first chamber wherein a supply of a first fuel in the form of a fluid and at least one oxidant are burned to produce combustion products including hot combustion gas and to increase the temperature and pressure within said first chamber, said first chamber adapted to open when a predetermined increase in pressure within said first chamber is realized, whereby at least a portion of the hot combustion gas is released from said first chamber,

a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said first chamber, the hot combustion gas released from said first chamber mixing with the pressurized stored gas to produce inflation gas and to increase the temperature and pressure within said second chamber, said second chamber adapted to open when a predetermined increase in pressure within said second chamber is realized after the hot combustion gas released from said first chamber mixes with the pressurized stored gas to produce the inflation gas, whereby at least a portion of the inflation gas is released from said second chamber to inflate the inflatable device,

a first initiator device for initiating the combustion of the first fuel and the at least one oxidant, and

a combination including,

a second container containing a supply of a second fuel in the form of a fluid, said second container adapted to open to be in fluid communication with said first chamber, and

a second initiator device for initiating the combustion of the second fuel and the at least one oxidant.

2. The apparatus of claim 1 additionally comprising a first container containing the supply of the first fuel in the form of a fluid, said first container adapted to open to be in fluid communication with said first chamber.

3. The apparatus of claim 2 wherein said first initiator device produces a discharge whereby said first container is opened to release at least a portion of the supply of the first fuel therefrom into said first chamber.

4. The apparatus of claim 2 wherein at least one of said first and said second containers holds the supply of fuel thereof free of combustion oxidant.

5. The apparatus of claim 1 wherein the second fuel and a second oxidant are stored together within said second container.

6. The apparatus of claim 5 wherein the second fuel and the second oxidant are stored together within said second container as a single material.

7. The apparatus of claim 6 wherein the single material comprises a hydroxyl ammonium nitrate-based liquid monopropellant.

8. In an airbag system for a motor vehicle, the system comprising at least one airbag module containing at least one inflatable airbag and sensor means for sensing at least one airbag system operating condition selected from the group of ambient temperature, occupant presence, seat belt usage and deceleration of the motor vehicle, the improvement comprising:

an adaptive output airbag inflator, coupled to the at least one airbag module, for generating an adaptive output of inflation gas to the airbag module, said adaptive output airbag inflator comprising;

a first chamber wherein a supply of a first fuel in the form of a fluid and at least one oxidant are burned to produce combustion products including hot combustion gas and to increase the temperature and pressure within said first chamber, said first chamber adapted to open when a predetermined increase in pressure within said first chamber is realized, whereby at least a portion of the hot combustion gas is released from said first chamber,

a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said first chamber, the hot combustion gas released from said first chamber mixing with the pressurized stored gas to produce inflation gas and to increase the temperature and pressure within said second chamber, said second chamber adapted to open when a predetermined increase in pressure within said second chamber is realized after the hot combustion gas released from said first chamber mixes with the pressurized stored gas to produce the inflation gas, whereby at least a portion of the inflation gas is released from said second chamber to inflate the inflatable device,

a first initiator device for initiating the combustion of the first fuel and the at least one oxidant, and

a combination including,

a second container for holding a supply of a second fuel in the form of a fluid, said second container adapted to open to be in fluid communication with said first chamber, and

a second initiator device for initiating the combustion of the second fuel and the at least one oxidant;

wherein, upon receipt by the module of a first level output signal from the sensor means, said first initiator device is actuated to initiate the combustion of the first fuel and the supply of the second fuel is retained in said second container, and

wherein, upon receipt by the module of a third level output signal from the sensor means, both said first initiator device and said second initiator device are actuated to initiate the combustion of the first fuel and the second fuel, respectively.

9. The airbag system of claim 8 wherein, upon receipt by the module of a second level output signal from the sensor means, said second initiator device is actuated only after the passage of a predetermined interval of time subsequent to actuation of said first initiator device.

10. The airbag system of claim 8 additionally comprising a first container for holding the supply of the first fuel, said first container adapted to open to be in fluid communication with said first chamber.

11. The airbag system of claim 10 wherein said first initiator device produces a discharge whereby said first container is opened to release the first fuel therefrom into said first chamber.

12. The airbag system of claim 10 wherein at least one of said first and said second containers holds the supply of fuel thereof free of combustion oxidant.

13. The airbag system of claim 8 wherein the second fuel and a second oxidant are stored together within said second container.

14. The airbag system of claim 13 wherein the second fuel and the second oxidant are stored together within said second container as a single material.

15. The airbag system of claim 14 wherein the single material comprises a hydroxyl ammonium nitrate-based liquid monopropellant.

16. A method of operation of an adaptive output airbag inflator in an airbag system for a motor vehicle, the system comprising at least one airbag module containing at least one inflatable airbag and sensor means for sensing at least one airbag operating condition selected from the group of ambient temperature, occupant presence, seat belt usage and deceleration of the motor vehicle, the airbag inflator having:

a first chamber wherein a supply of a first fuel in the form of a fluid and at least one oxidant are burned to produce combustion products including hot combustion gas and to increase the temperature and pressure within the first chamber, the first chamber opening when a predetermined increase in pressure within the first chamber is realized, whereby at least a portion of the hot combustion gas is released from the first chamber,

a second chamber containing a supply of pressurized stored gas, the second chamber in fluid communication with the first chamber upon the opening of the first chamber, the hot combustion gas released from the first chamber mixing with the pressurized stored gas to produce inflation gas and to increase the temperature and pressure within said second chamber, said second chamber opening when a predetermined increase in pressure within the second chamber is realized after the hot combustion gas released from the first chamber mixes with the pressurized stored gas to produce the inflation gas, whereby at least a portion of the inflation gas is released from the second chamber to inflate the inflatable device,

a first initiator device for initiating the combustion of the first fuel and the at least one oxidant, and

a combination including,

a second container holding a supply of a second fuel in the form of a fluid, the second container adapted to open to be in fluid communication with the first chamber, and

a second initiator device for initiating the combustion of the second fuel,

wherein;

1) in response to receipt by the module of a first level output signal from the sensor means, said method comprises the steps of;

burning the first fuel and the at least one oxidant in the first chamber to produce combustion products including hot combustion gas and increasing the temperature and pressure within the first chamber,

opening the first chamber when a predetermined increase in pressure within the first chamber is realized to release hot combustion gas from the first chamber into the second chamber,

mixing the released hot combustion gas with the pressurized stored gas in the second chamber to produce inflation gas,

opening the second chamber when a predetermined increase in pressure within the second chamber is realized after the hot combustion gas released from the first chamber has mixed with the pressurized stored gas to produce the inflation gas to release at least a portion of the inflation gas from the second chamber to inflate the inflatable device; and

2) in response to receipt by the module of a third level output signal from the sensor means, said method comprises the steps of;

burning the first fuel and the at least one oxidant in the first chamber to produce combustion products including hot combustion gas and increasing the temperature and pressure within the first chamber,

releasing the second fuel into the first chamber from the second container,

burning the second fuel and an oxidant in the first chamber to produce additional combustion products including additional hot combustion gas, the burning of the first fuel and the burning of the second fuel increasing the temperature and pressure within the first chamber,

opening the first chamber when a predetermined increase in pressure in the first chamber is realized to release hot combustion gas from the first chamber into the second chamber,

mixing the released hot combustion gas with the pressurized stored gas in the second chamber to produce inflation gas,

opening the second chamber when a predetermined increase in pressure within the second chamber is realized,

releasing combustion products produced from the combustion of the first fuel and additional combustion products produced from the combustion of the second fuel and the at least one oxidant from the first chamber into the second chamber,

mixing at least the released combustion products with the pressurized stored gas in the second chamber to produce inflation gas,

opening the second chamber when a predetermined increase in pressure within the second chamber is realized to release at least a portion of the inflation gas from the second chamber to inflate the inflatable device.

17. The method of claim 16 wherein the supply of the first fuel is initially held in a first container and wherein in response to receipt by the module of either a first or a third level output signal from the sensor means, the method additionally comprises the step of releasing the first fuel from the first container into the first chamber whereby said burning of the first fuel and the at least one oxidant in the first chamber occurs.

18. The method of claim 16 wherein, upon receipt by the module of a second level output signal from the sensor means, said method comprises the steps of:

burning the first fuel and the at least one oxidant in the first chamber to produce combustion products including hot combustion gas and increasing the temperature and pressure within the first chamber,

releasing the second fuel into the first chamber from the second container only after the passage of a predetermined interval of time subsequent to the initiation of the burning of the first fuel and oxidant in the first chamber,

burning the second fuel in the first chamber to produce additional combustion products including additional hot combustion gas, the burning of the first fuel and the burning of the second fuel increasing the temperature and pressure within the first chamber,

opening the first chamber when a predetermined increase in pressure in the first chamber is realized to release hot combustion gas from the first chamber into the second chamber,

mixing the released hot combustion gas with the pressurized stored gas in the second chamber to produce inflation gas,

opening the second chamber when a predetermined increase in pressure within the second chamber is realized,

releasing combustion products produced from the combustion of the first fuel and additional combustion products produced from the combustion of the second fuel from the first chamber into the second chamber,

mixing at least the released combustion products with the pressurized stored gas in the second chamber to produce inflation gas,

opening the second chamber when a predetermined increase in pressure within the second chamber is realized to release at least a portion of the inflation gas from the second chamber to inflate the inflatable device.

19. The method of claim 18 wherein, upon receipt by the module of a second level output signal from the sensor means, said opening of the first chamber precedes said releasing of the second fuel into the first chamber from the second container.

20. The method of claim 19 wherein prior to said releasing of the second fuel into the first chamber from the second container, the second container additionally contains a supply of a second oxidant.

21. The method of claim 20 wherein prior to said releasing of the second fuel into the first chamber from the second container, the second container contains the second fuel and the second oxidant as a single material.

22. The method of claim 21 wherein the single material comprises a hydroxyl ammonium nitrate-based liquid monopropellant.

23. The method of claim 22 wherein the supply of the first fuel is initially held in a first container and wherein in response to receipt by the module of either a first, second or third level output signal from the sensor means, the method additionally comprising the step of releasing the first fuel from the first container into the first chamber whereby said burning of the first fuel occurs.