Airbag device for a vehicle

• US 20040212180A1
• Filed: 05/17/2004
• Published: 10/28/2004
• Est. Priority Date: 11/17/2001
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Strutz, Torsten, Schoft, Axel
• Granted Patent: US 6,945,560 B2
• Time in Patent Office: Days
• US Class Current: 280/735
• CPC Class Codes: B60R 2021/01211 Expansion of air bags
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/01526 using piezoelectric elements
• CPC Class Codes: B60R 21/01528 mounted on the bag

Abstract

An airbag device for a vehicle includes an airbag and a sensor element located on the side of the airbag which moves towards the vehicle occupant. The sensor element is formed of sensor strips which transmit sensed pressure changes in the form of a sensor signal to a control device. The amount of gas supplied by a filling device can be controlled in response to the sensor signal. The sensor element has resistor elements forming a matrix-type grid of spaced apart contact regions of the resistor elements. An electric resistance in a contact region of two resistor elements is dependent on the force or pressure load of the contact region. A voltage can be applied to least one of the resistor elements at least in one of the contact regions via an electrically conductive element which is in electrical contact with a resistor element at the contact region.

Claims

1. An airbag device for a vehicle, comprising:

an airbag configured to advance into a passenger compartment when being inflated, said airbag having a side moving toward an occupant when being inflated;

a filling device configured to inflate said airbag with gas;

a control device operatively connected to said filling device, said control device controlling said filling device via a control signal;

at least one sensor element disposed on said side of said airbag moving toward the occupant when being inflated, said at least one sensor element being responsive to local pressure changes, said at least one sensor element passing sensed pressure changes as a sensor signal to said control device;

said at least one sensor element being formed of sensor strips crossing over one another, said sensor strips being resistor elements and being configured to detect pressure changes;

said resistor elements forming a matrix grid with rows and columns of spaced apart contact regions of said resistor elements;

a respective one of said contact regions of corresponding two of said resistor elements having a respective electrical resistance dependent on one of a force loading and a pressure loading of said respective one of said contact regions;

an electrically conductive element in electrical contact with one of said resistor elements at one of said contact regions, said electrically conductive element applying a voltage to said one of said resistor elements at said one of said contact regions, said electrically conductive element having a lower resistance than said one of said resistor elements; and

said filling device being controlled such that a quantity of gas supplied by said filling device can be controlled in response to a sensor signal supplied by said resistor elements detecting an advancing movement of said airbag.

2. The airbag device according to claim 1, wherein:

a first set of said sensor strips are first sensor strips extending substantially parallel to one another and being spaced apart from one another;

a second set of said sensor strips are second sensor strips extending substantially parallel to one another and being spaced apart from one another; and

said second sensor strips cross over said first sensor strips.

3. The airbag device according to claim 2, wherein said second sensor strips cross over said first sensor strips such that crossing-over points are defined and such that gaps are formed adjacent said crossing-over points.

4. The airbag device according to claim 3, wherein said first sensor strips are spaced apart from one another by a substantially same distance and said second sensor strips are spaced apart from one another by a substantially same distance such that said gaps form a regular pattern.

5. The airbag device according to claim 3, wherein said first sensor strips are offset through 900 with respect to said second sensor strips such that said gaps are substantially rectangular gaps.

6. The airbag device according to claim 1, wherein:

at least one fabric layer forms an airbag outer skin and at least a further fabric layer forms an airbag inner skin; and

said airbag has an airbag impact region, said airbag outer skin and said airbag inner skin are provided at least in said airbag impact region on both sides of said sensor strips such that said airbag outer skin and said airbag inner skin cover said sensor strips in said airbag impact region and said sensor strips are accommodated between said airbag outer skin and said airbag inner skin.

7. The airbag device according to claim 6, wherein said airbag is a one-piece-woven airbag with an airbag fabric, and said sensor strips are woven into said airbag fabric.

8. The airbag device according to claim 7, wherein said sensor strips are woven between two layers of said airbag fabric of said one-piece-woven airbag.

9. The airbag device according to claim 7, wherein said sensor strips are woven between two layers of said airbag fabric of said one-piece-woven airbag such that said two layers form pockets.

10. The airbag device according to claim 8, wherein:

a first set of said sensor strips are first sensor strips extending substantially parallel to one another and being spaced apart from one another;

a second set of said sensor strips are second sensor strips extending substantially parallel to one another and being spaced apart from one another;

said second sensor strips cross over said first sensor strips;

said second sensor strips cross over said first sensor strips such that crossing-over points are defined and such that gaps are formed adjacent said crossing-over points; and

said two layers of said airbag fabric of said one-piece-woven airbag are woven together at least at one of said gaps adjacent to said crossing-over points.

11. The airbag device according to claim 6, wherein:

a first set of said sensor strips are first sensor strips extending substantially parallel to one another and being spaced apart from one another;

a second set of said sensor strips are second sensor strips extending substantially parallel to one another and being spaced apart from one another;

said second sensor strips cross over said first sensor strips such that crossing-over points are defined and such that gaps are formed adjacent said crossing-over points; and

seams are provided such that said at least one fabric layer and said further fabric layer disposed on opposite sides of said sensor strips are stitched together and such that said gaps form passage openings for said seams.

12. The airbag device according to claim 11, wherein said seams hold said sensor strips in a given position.

13. The airbag device according to claim 12, wherein:

said first and second sensor strips cross over one another such that a plurality of rows of gaps is formed, said rows of gaps extend substantially parallel to one another and are spaced apart from one another; and

said at least one fabric layer and said further fabric layer are stitched together along at least a part of said rows of gaps.

14. The airbag device according to claim 13, wherein said seams define a stitching direction, and said seams cross under a first part of said first sensor strips and cross over a second part of said first sensor strips as seen in the stitching direction.

15. The airbag device according to claim 13, wherein said seams define a stitching direction, and said seams cross under a first part of said second sensor strips and cross over a second part of said second sensor strips as seen in the stitching direction.

16. The airbag device according to claim 14, wherein said seams, as seen from one of said gaps to an adjacent one of said gaps, alternately cross over and under said first sensor strips.

17. The airbag device according to claim 15, wherein said seams, as seen from one of said gaps to an adjacent one of said gaps, alternately cross over and under said second sensor strips.

18. The airbag device according to claim 11, wherein said seams run parallel to said first sensor strips.

19. The airbag device according to claim 11, wherein said seams run parallel to said second sensor strips.

20. The airbag device according to claim 11, wherein said seams run transversely alternately over and under said crossing-over points where said first and second sensor strips cross one another.

21. The airbag device according to claim 2, including a control line connecting said first sensor strips to said control device.

22. The airbag device according to claim 21, wherein said first sensor strips are of substantially equal length and each of said first sensor strips has an end region connected to said control line.

23. The airbag device according to claim 2, including a control line connecting said second sensor strips to said control device.

24. The airbag device according to claim 23, wherein said second sensor strips are of substantially equal length and each of said second sensor strips has an end region connected to said control line.

25. The airbag device according to claim 1, wherein said electrically conductive element is a strip-shaped element disposed along one of said rows of said contact regions of said resistor elements.

26. The airbag device according to claim 1, wherein said electrically conductive element is a strip-shaped element disposed along one of said columns of said contact regions of said resistor elements.

27. The airbag device according to claim 1, wherein said electrically conductive element is a strip-shaped element disposed along one of said resistor elements and is in contact with said one of said resistor elements.

28. The airbag device according to claim 1, wherein said electrically conductive element is an electrically conductive fiber embedded in one of said resistor elements.

29. The airbag device according to claim 28, wherein said one of said resistor elements has a given length, and said electrically conductive fiber extends over at least part of said given length of said one of said resistor elements.

30. The airbag device according to claim 29, wherein said electrically conductive fiber extends in a meander pattern in said one of said resistor elements.

31. The airbag device according to claim 1, wherein an element formed of a poorly conductive material is disposed between two of said resistor elements at one of said contact regions of said resistor elements.

32. The airbag device according to claim 31, wherein said one of said contact regions has a given area, and said element formed of poorly conductive material entirely covers said given area of said one of said contact regions.

33. The airbag device according to claim 1, wherein elements formed of a poorly conductive strip-shaped material are disposed between respective two of said resistor elements at respective ones of said contact regions of said resistor elements and extend along respective ones of said resistor elements.

34. The airbag device according to claim 1, including:

a layer disposed between a first and a second group of said resistor elements, said first group of said resistor elements being disposed along said rows, said second group of said resistor elements being disposed along said columns;

said layer having insulating column regions, insulating row regions, and poorly conductive elements delimited by said insulating column regions and by said insulating row regions such that said poorly conductive elements form a chessboard pattern; and

said poorly conductive elements being disposed between said resistor elements at said contact regions of said resistor elements.

35. The airbag device according to claim 1, including:

a fabric, said matrix grid being disposed in said fabric; and

electrodes fastened to said fabric, said electrodes being disposed in rows and columns and being in contact with said electrically conductive element and further electrically conductive elements.

36. The airbag device according to claim 1, wherein at least some of said resistor elements disposed in said rows and said columns are integrated in a sheet configuration, said sheet configuration has insulating regions separating said at least some of said resistor elements from one another.

37. The airbag device according to claim 1, wherein said airbag is a motor vehicle airbag.