Outwardly deploying airbag system

• US 20060091661A1
• Filed: 10/04/2005
• Published: 05/04/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Joyson Safety Systems Japan K.K.
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Takimoto, Takayuki
• Granted Patent: US 7,559,564 B2
• Time in Patent Office: Days
• US Class Current: 280/742
• CPC Class Codes: B60R 2021/26058 using a combination of inflators
• CPC Class Codes: B60R 21/239 characterised by their venting means
• CPC Class Codes: B60R 21/36 using airbags

Abstract

An outwardly deploying airbag system can maintain the internal pressure of an airbag for a required period without vainly increasing the maximum internal pressure of the airbag during inflation. When a sensor detects a collision with a pedestrian, an inflator performs a first gas injection step. An airbag is thereby deployed into a final deployment shape. Subsequently, when the internal pressure of the airbag falls to a predetermined pressure because of leakage of gas through vent holes, and a sensor predicts or detects a collision with a pedestrian, the inflator performs a second gas injection step. Consequently, the internal pressure of the airbag remains high for a long period, and the airbag sufficiently absorbs an impact whenever the pedestrian hits the airbag. The pressure and amount of gas injected in the first gas injection step can be made smaller than in related art, and the required airbag strength is reduced.

Claims

1. An airbag system for a vehicle, the airbag system comprising:

an airbag mounted to the vehicle to be deployed along an outer surface thereof; and

at least one inflator that injects inflation gas into the airbag in different stages during deployment of the airbag along the vehicle outer surface.

2. The airbag system of claim 1, wherein the at least one inflator injects inflation gas in a first stage with the airbag being inflated to a predetermined, final deployment shape, and a second stage a predetermined time after initiation of the first stage.

3. The airbag system of claim 1, wherein the at least one inflator is operable to initiate gas injection in a subsequent gas injection stage after a previous gas injection stage and upon pressure in the airbag falling to a predetermined pressure.

4. The airbag system of claim 1, wherein the airbag has gas leak means for leaking gas out from the airbag so that injection of inflation gas by the at least one inflator in different stages develops a maximum pressure in the airbag that is kept to a minimum for reducing impact forces with the airbag.

5. The airbag system of claim 1, wherein the airbag has gas leak means for leaking gas out from the airbag so that injection of inflation gas by the at least one inflator in different stages keeps pressure in the airbag in a predetermined range for providing cushioned impact therewith.

6. The airbag system of claim 1, wherein the airbag has an internal pressure that is maintained above a predetermined minimum pressure for a maximized time period by the injection of inflation gas in different stages by the at least one inflator.

7. The airbag system of claim 1, wherein the at least one inflator comprises a single, multi-stage inflator or a plurality of inflators.

8. An airbag system comprising:

an airbag; and

at least one inflator for performing first and second gas injection steps with the second step being initiated upon internal pressure in the airbag falling to a predetermined pressure.

9. The airbag system of claim 8, wherein the airbag has gas leak means for leaking gas out from the airbag so that a maximum pressure developed in the airbag is kept to a level that provides an optimum cushioned impact therewith.

10. The airbag system of claim 8, wherein the airbag has gas leak means for leaking gas out from the airbag so that the gas injection steps are operable to keep pressure in the airbag in a predetermined range sufficient for absorbing impact therewith.

11. The airbag system of claim 8, wherein the inflator is operable to initiate the second gas injection step approximately 70 msec to approximately 120 msec after initiation of the first gas injection step.

12. The airbag system of claim 8, wherein the airbag has one of vent holes, stitches and breathable cloth for leaking gas therefrom.

13. An external airbag deployment system for a vehicle with an exterior, the external airbag deployment system comprising:

an airbag; and

at least one inflator connected to the airbag for inflating the airbag with an initial gas injection and at least one subsequent gas injection distinct from, and injected after, the initial gas injection for increasing the amount of time the pressure in the airbag remains above a predetermined level.

14. The deployment system of claim 13, wherein the airbag has a final deployment shape with the initial gas injection inflating the airbag to the final deployment shape.

15. The deployment system of claim 13, wherein the initial gas injection being provided for producing a maximum internal pressure inside the airbag, and wherein the at least one subsequent gas injection being provided to occur when the pressure inside the airbag is falling from the maximum internal pressure.

16. A method of deploying an airbag, the method comprising:

injecting the airbag with inflation gas in a first inflation stage;

leaking gas out from the airbag; and

injecting the airbag with inflation gas in a second inflation stage when pressure in the airbag falls to a predetermined pressure due to the leakage of gas therefrom.

17. The method of claim 16 including deploying the airbag along an external surface of a vehicle.

18. The method of claim 16, wherein gas is leaked out from the airbag so that a maximum pressure in the airbag is optimized for cushioned impact therewith.

19. The method of claim 16, wherein the airbag gas injection in the first inflation stage includes inflating the airbag to a final deployment shape thereof.

20. The method of claim 16, wherein injecting inflation gas in the first and second stage and leaking gas includes keeping pressure in an optimum pressure range in the airbag for a sufficient time period for impact therewith.