Liquid cooled hybrid

• US 20100013201A1
• Filed: 07/17/2008
• Published: 01/21/2010
• Est. Priority Date: 07/17/2008
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Parkinson, David W., Smith, Bradley W., Cox, Matthew A., Parks, Brent A.
• Granted Patent: US 7,770,924 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/26017 a cooling agent being added to the inflation fluid
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

An inflator that includes a quantity of gas generant housed within a chamber. A liquid and a piston are also housed within another chamber. This chamber is sealed by a burst disk. The piston includes an opening. During deployment of the inflator, the burst disk is ruptured and the piston moves towards the distal end of the inflator. The movement of the piston hydraulically expels the liquid through the opening in the piston such that the liquid cools and contacts the gas formed by combustion of the gas generant.

Claims

1. An inflator comprising:

a quantity of gas generant housed within a gas generant chamber, the gas generant chamber having a constant volume;

an initiator to ignite the gas generant and form gas during deployment;

a chamber that houses a piston and a liquid, wherein the interior of the piston is sealed from the liquid, wherein during deployment the piston moves unsealing the interior of the piston from the liquid and hydraulically expelling the liquid through an opening in the piston such that the liquid contacts and cools the gas formed by combustion of the gas generant.

2. An inflator as in claim 1 wherein the gas formed by combustion of the gas generant and the liquid moving into the interior of the piston passes through an exit opening to allow passage to the exterior of the piston.

3. An inflator as in claim 1 wherein the inflator is filterless.

4. An inflator as in claim 1 further comprising more than one opening, wherein at least one of the openings is off-set from the flow of the gas, thereby allowing the liquid to more readily be hydraulically expelled through the openings.

5. An inflator as in claim 1 wherein the liquid hydraulically expelled through the opening vaporizes and mixes with the gas formed by combustion of the gas generant.

6. An inflator as in claim 5 wherein the liquid is vaporized and mixes with the gas in a mixing chamber.

7. An inflator as in claim 1, wherein the gas formed by combustion of the gas generant flows through a tortuous path prior to exiting the inflator.

8. An inflator as in claim 7 wherein the tortuous path has a right angle turn for capturing particulates entrained in the gas.

9. An inflator as in claim 7 wherein as the gas flows through the tortuous path, at least some particulates entrained in the gas are removed from the gas and deposited within the inflator.

10. An inflator as in claim 9 wherein the particulates are deposited at a capture area.

11. An inflator as in claim 1 further comprising one or more baffles.

12. An inflator as in claim 1 wherein the liquid contains water.

13. An inflator as in claim 1 wherein the liquid is housed in a chamber and sealed by a seal, further comprising a quantity of gas that is positioned proximate the liquid.

14. An inflator as in claim 13 wherein the seal is press fit and the seal is unsealed by movement of the piston.

15. An inflator as in claim 1 wherein the interior of the piston is sealed by a burst disk.

16. An inflator as in claim 1 wherein the impact area of the piston that contacts the liquid is smaller than the drive area that contacts the gas, wherein the pressure of the liquid is amplified and causes injection of the liquid due to the differences between the impact area and the drive area.

21. An inflator as in claim 1, further comprising one or more vent holes that relieve pressure in the inflator.

17. An inflator comprising:

a quantity of gas generant housed within a gas generant chamber, the gas generant chamber having a constant volume;

an initiator to ignite the gas generant and form gas during deployment;

a chamber that houses a piston and a liquid, wherein the interior of the piston is sealed from the liquid, wherein during deployment the piston moves and unseals the interior of the piston from the liquid and the movement of the piston hydraulically expels the liquid through an opening in the piston such that the liquid contacts, vaporizes, mixes with, and cools the gas formed by combustion of the gas generant, wherein the gas flows through a tortuous path, at least some particulates entrained in the gas are removed from the gas and deposited within the inflator.

18. An inflator as in claim 17 wherein the tortuous path has a right angle turn for capturing particulates entrained in the gas.

19. A method of cooling gas formed in an inflator, the inflator comprising a quantity of gas generant housed within a gas generant chamber having a constant volume, an initiator, and a piston chamber that houses a piston and a liquid, the method comprising:

igniting the gas generant to form gas;

unsealing an opening in the piston that was used to seal the piston chamber;

moving the piston to hydraulically expels the liquid through an opening in the piston such that the liquid contacts and cools the gas formed by combustion of the gas generant.

20. A method as in claim 19 wherein the liquid vaporizes and mixes with the gas, thereby operating to cool the gas, further comprising the step of having the liquid cooled gas exit the inflator.