Variable output inflator

• US 20080172157A1
• Filed: 01/16/2007
• Published: 07/17/2008
• Est. Priority Date: 01/16/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Fu, Yan, Hall, Ian Brewster, Simmons, Paul
• Granted Patent: US 7,748,737 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/01027 Safing sensors
• CPC Class Codes: B60R 2021/01218 control of expansion speed
• CPC Class Codes: B60R 2021/2636 The volume of gas being continuously adjustable
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: B60R 21/015 including means for detecting the presence or position of passengers, passenger seats or child seats , and the related safety parameters therefor, e.g. speed or timing of airbag inflation in relation to occupant position or seat belt use
• CPC Class Codes: B60R 21/26 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 Class Codes: B60R 21/268 using instantaneous release of stored pressurised gas B60R21/26005 takes precedence

Abstract

A method of inflating an airbag with a fluid includes sending a signal to open a first valve and opening the first valve. The method also includes directing a control pressure through the first valve and toward a second valve. The method further includes throttling the second valve in response to the control pressure. The throttling of the second valve produces a variable inflation mass flow rate of the fluid at a second valve outlet. Opening the first valve and closing the first valve are performed as a step function to achieve a desired predetermined variable inflation mass flow rate of the airbag.

Claims

1. A method of inflating an airbag with a fluid comprising:

sending a signal to open a first valve;

opening the first valve;

directing a control pressure through the first valve and toward a second valve; and

throttling the second valve in response to the control pressure, wherein the throttling of the second valve produces a variable inflation mass flow rate of the fluid at a second valve outlet, wherein opening the first valve and closing the first valve are performed as a step function to achieve a desired predetermined variable inflation mass flow rate of the airbag.

2. The method of claim 1, wherein an inlet to the first valve is in constant fluid communication with an inlet of the second valve.

3. The method of claim 1, wherein an inlet to the second valve is in constant fluid communication with the outlet of the second valve such that the second valve cannot prevent the fluid from flowing through the second valve.

4. The method of claim 1, wherein throttling the second valve includes switching the second valve from permitting the fluid to flow through a first predetermined effective flow area to permitting the fluid to flow through a second predetermined effective flow area and back to permitting the fluid to flow through a first predetermined effective flow area, wherein neither the first predetermined effective flow area and the second predetermined effective flow area are not equal to about zero.

5. The method of claim 1, further comprising detecting an inflation parameter and calculating a desired variable flow rate using the inflation parameter.

6. The method of claim 5, wherein the inflation parameter is one of a belt status, an occupant position, a pre-crash state, a post-crash state, and a vehicle dynamic parameter.

7. The method of claim 1, further comprising selecting an algorithm based upon a vehicle type, wherein the algorithm is used in the calculating a desired variable flow rate using the inflation parameter.

8. An apparatus for inflating an airbag comprising:

a control valve having a control valve inlet and a control valve outlet, wherein the control valve selectively provides a first predetermined flow area, wherein a fluid is selectively permitted to flow through the first predetermined flow area to produce a first predetermined mass flow rate at a first predetermined fluid pressure, wherein the control valve selectively provides a second predetermined flow area, and wherein the fluid is selectively permitted to flow through the second predetermined flow area to produce a second predetermined mass flow rate at a second predetermined fluid pressure;

a sensor for detecting an inflation parameter; and

a control module, wherein the control module will selectively switch the control valve between permitting the fluid to flow through the first predetermined effective flow area and permitting the fluid to flow through the second predetermined effective flow area to achieve a desired first variable mass flow rate at the outlet of the control valve, and wherein the desired first variable mass flow rate is selectively determined by the control module using the occupant parameter as an input to an algorithm.

9. The apparatus of claim 8, wherein the control module may selectively provide a second variable mass flow rate at the outlet of the control valve.

10. The apparatus of claim 8, wherein the control module will selectively switch the control valve from permitting the fluid to flow through the first predetermined effective flow area to permitting the fluid to flow through the second predetermined effective flow area and back to permitting the fluid to flow through the first predetermined effective flow area in less than about 5 milliseconds.

11. The apparatus of claim 8, wherein the control module further comprises a microprocessor to control the switching of the control valve based upon at least one inflation parameter.

12. The apparatus of claim 8, wherein the sensor detects one of a belt status, an occupant position, a pre-crash state, a post-crash state, and a vehicle dynamic parameter.

13. The apparatus of claim 8, further comprising a plurality of sensors for detecting a plurality of inflation parameters.

14. The apparatus of claim 8, wherein the control valve cannot provide a seal between the control valve inlet and the control valve outlet.

15. The apparatus of claim 8, wherein the control valve includes a solenoid valve and a ring valve.

16. A method of inflating an airbag with a fluid comprising:

sending a signal to open a first valve;

opening the first valve;

directing a control pressure through the first valve and toward a second valve;

detecting an inflation parameter, wherein the inflation parameter is one of a belt status, an occupant position, a pre-crash state, a post-crash state, and a vehicle dynamic parameter; and

switching the second valve from permitting the fluid to flow through a first predetermined effective flow area to permitting the fluid to flow through a second predetermined effective flow area and back to permitting the fluid to flow through a first predetermined effective flow area, wherein neither the first predetermined effective flow area and the second predetermined effective flow area are not equal to about zero.

17. The method of claim 16, wherein the first valve is a solenoid valve and the second valve is a ring valve.

18. The method of claim 16, further comprising determining a desired first variable mass flow rate based upon at least the inflation parameter.

19. The method of claim 17, further comprising selecting an algorithm based upon a vehicle type, wherein the algorithm is used in the determining a desired first variable mass flow rate.

20. The method of claim 16, wherein the detecting an inflation parameter includes sending a sensor input to a microprocessor.