Method and airbag inflation apparatus employing magnetic fluid

• US 7,007,972 B1
• Filed: 03/10/2003
• Issued: 03/07/2006
• Est. Priority Date: 03/10/2003
• Status: Active Grant

• Current Assignee: Materials Modification Inc.
• Original Assignee: Materials Modification Inc.
• Inventors: Radhakrishnan, Ramachandran, Kotha, Sanjay, Sudarshan, Tirumalai S.
• Primary Examiner(s): Dunn, David R.
• Application Number:
  US10/383,779
• Time in Patent Office: 1,093 Days
• Field of Search: 280/741, 280/742, 280/736, 280/735, 280/737, 137/807, 137/827, 137/909, 137/251.1, 137/315.03
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/2636 The volume of gas being continuously adjustable
• 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: Y10S 137/909 Magnetic fluid valve
• CPC Class Codes: Y10T 137/2082 Utilizing particular fluid

Abstract

An airbag inflation apparatus includes a chamber for generating a gas to inflate an airbag. A valve, including a magnetic fluid and a source of magnetic field, preferably an electromagnet, is associated with the chamber for regulating the flow of the gas into the airbag. A sensor determines and feeds occupant information to the sensor.

Claims

1. An airbag inflation apparatus, comprising:

a) a chamber for generating a gas to inflate an airbag;

b) a valve operably connected to said chamber for regulating the flow of the gas into the airbag;

c) said valve including a magnetic fluid and a source of magnetic field;

d) said magnetic fluid comprising core particles of a magnetic material;

e) said core particles comprising first and second successive coatings; and

f) a sensor for determining and feeding occupant information to said valve.

2. The airbag inflation apparatus of claim 1, wherein:

a) said core particles have an average diameter of about 1 nm to 10 μ

m.

3. The airbag inflation apparatus of claim 2, wherein:

a) said core particles have an average diameter of about 1 nm to 5 μ

m.

4. The airbag inflation apparatus of claim 3, wherein:

a) said core particles have an average diameter of about 10 nm to 1 μ

m.

5. The airbag inflation apparatus of claim 1, wherein:

a) said magnetic material is selected from the group consisting of iron, iron oxide, cobalt, cobalt oxide, nickel, nickel oxide, an alloy, and a combination thereof.

6. The airbag inflation apparatus of claim 1, wherein:

a) said first coating comprises a coating of a surfactant; and

b) said second coating comprises a coating of a material selected from the group consisting of a ceramic material, a metallic material, a polymer material, and a combination thereof.

7. The airbag inflation apparatus of claim 6, wherein:

a) said surfactant is selected from the group consisting of polyethylene glycol, lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

8. The airbag inflation apparatus of claim 7, wherein:

a) said second coating is selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, polyethylene glycol, polystyrene, dextran, and a combination thereof.

9. The airbag inflation apparatus of claim 2, wherein:

a) said core particles are dispersed in a carrier fluid.

10. The airbag inflation apparatus of claim 9, wherein:

a) said carrier fluid comprises a water-based or an oil-based carrier fluid.

11. The airbag inflation apparatus of claim 9, wherein:

a) said carrier fluid is selected from the group consisting of water, hydraulic oil, mineral oil, silicone oil, biodegradable oil, and a combination thereof.

12. The airbag inflation apparatus of claim 9, wherein:

a) the fraction of said core particles is about 1–

95% by weight of said magnetic fluid.

13. The airbag inflation apparatus of claim 2, wherein:

a) said core particles comprise a general shape selected from the group consisting of spherical, needle-like, cubic, irregular, cylindrical, diamond, oval, and a combination thereof.

14. The airbag inflation apparatus of claim 1, wherein:

a) the occupant information comprises weight and position data for an occupant.

15. An airbag inflation apparatus, comprising:

a) a chamber for generating a gas to inflate an airbag;

b) a valve operably connected to said chamber for regulating the flow of the gas;

c) said valve including a magnetic fluid and a source of magnetic field;

d) a first sensor for determining and feeding a probable collision information to said valve;

e) a second sensor for determining and feeding occupant information to said valve;

f) said magnetic fluid comprising core particles of a magnetic material;

g) said core particles comprising first and second successive coatings; and

h) wherein said source of magnetic field produces a magnetic field for regulating the flow of the gas through said valve based on the information from said first and second sensors.

16. The airbag inflation apparatus of claim 15, wherein:

a) said core particles have an average diameter of about 1 nm to 10 μ

m.

17. The airbag inflation apparatus of claim 16, wherein:

a) said core particles have an average diameter of about 1 nm to 5 μ

m.

18. The airbag inflation apparatus of claim 17, wherein:

a) said core particles have an average diameter of about 10 nm to 1 μ

m.

19. The airbag inflation apparatus of claim 15, wherein:

a) said magnetic material is selected from the group consisting of iron, iron oxide, cobalt, cobalt oxide, nickel, nickel oxide, an alloy, and a combination thereof.

20. The airbag inflation apparatus of claim 15, wherein:

a) said first coating comprises a coating of a surfactant; and

b) said second coating comprises a coating of a material selected from the group consisting of a ceramic material, a metallic material, a polymer material, and a combination thereof.

21. The airbag inflation apparatus of claim 20, wherein:

a) said surfactant is selected from the group consisting of polyethylene glycol, lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

22. The airbag inflation apparatus of claim 21, wherein:

a) said second coating is selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, polyethylene glycol, polystyrene, dextran, and a combination thereof.

23. The airbag inflation apparatus of claim 16, wherein:

a) said core particles are dispersed in a carrier fluid.

24. The airbag inflation apparatus of claim 23, wherein:

a) said carrier fluid comprises a water-based or an oil-based carrier fluid.

25. The airbag inflation apparatus of claim 23, wherein:

a) said carrier fluid is selected from the group consisting of water, hydraulic oil, mineral oil, silicone oil, biodegradable oil, and a combination thereof.

26. The airbag inflation apparatus of claim 23, wherein:

a) the fraction of said core particles is about 1–

95% by weight of said magnetic fluid.

27. The airbag inflation apparatus of claim 16, wherein:

a) said core particles comprise a general shape selected from the group consisting of spherical, needle-like, cubic, irregular, cylindrical, diamond, oval, and a combination thereof.

28. The airbag inflation apparatus of claim 15, wherein:

a) the occupant information comprises weight and position data for an occupant.

29. A method of regulating the flow of inflation gas into an airbag, comprising the steps of:

a) generating a gas for passing through a valve connected to an airbag;

b) determining and feeding occupant information to the valve, the valve comprising a magnetic fluid including core particles of a magnetic material, the core particles comprising first and second successive coatings;

c) producing a magnetic field based on an occupant information; and

d) applying the magnetic field to the magnetic fluid to vary the viscosity thereof for thereby regulating the flow of the gas through the valve.

30. The method of claim 29, wherein:

the value of the magnetic field can be zero or more.

31. The method of claim 29, wherein:

the occupant information comprises weight and position data for an occupant.

32. The method of claim 29, wherein:

the first coating comprises a coating of a surfactant; and

the second coating comprises a coating of a material selected from the group consisting of a ceramic material, a metallic material, a polymer material, and a combination thereof.

33. The method of claim 32, wherein:

the surfactant is selected from the group consisting of polyethylene glycol, lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof.

34. The method of claim 33, wherein:

the second coating is selected from the group consisting of silica, gold, silver, platinum, steel, cobalt, carbon, polyethylene glycol, polystyrene, dextran, and a combination thereof.

35. The method of claim 29, wherein:

the core particles are dispersed in a carrier fluid.

36. The method of claim 35, wherein:

the carrier fluid comprises a water-based or an oil-based carrier fluid.

37. The method of claim 35, wherein:

the carrier fluid is selected from the group consisting of water, hydraulic oil, mineral oil, silicone oil, biodegradable oil, and a combination thereof.

38. The method of claim 35, wherein:

the fraction of the core particles is about 1–

95% by weight of the magnetic fluid.

39. The method of claim 29, wherein:

the core particles comprise a general shape selected from the group consisting of spherical, needle-like, cubic, irregular, cylindrical, diamond, oval, and a combination thereof.

40. An airbag inflation apparatus, comprising:

a) a chamber for generating a gas to inflate an airbag;

b) a valve operably connected to said chamber for regulating the flow of the gas into the airbag;

c) said valve including a magnetic fluid and a source of magnetic field;

d) said magnetic fluid comprising core particles of a magnetic material;

e) said core particles comprising a coating of a surfactant selected from the group consisting of polyethylene glycol, lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof; and

f) a sensor for determining and feeding occupant information to said valve.

41. An airbag inflation apparatus, comprising:

a) a chamber for generating a gas to inflate an airbag;

b) a valve operably connected to said chamber for regulating the flow of the gas;

c) said valve including a magnetic fluid and a source of magnetic field;

d) a first sensor for determining and feeding a probable collision information to said valve;

e) a second sensor for determining and feeding occupant information to said valve;

f) said magnetic fluid comprising core particles of a magnetic material;

g) said core particles comprising a coating of a surfactant selected from the group consisting of polyethylene glycol, lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof; and

h) wherein said source of magnetic field produces a magnetic field for regulating the flow of the gas through said valve based on the information from said first and second sensors.

42. A method of regulating the flow of inflation gas into an airbag, comprising the steps of:

a) generating a gas for passing through a valve connected to an airbag;

b) determining and feeding occupant information to the valve, the valve comprising a magnetic fluid including core particles of a magnetic material coated with a surfactant selected from the group consisting of polyethylene glycol, lecithin, oleic acid, non-ionic acetylenic diol, and a combination thereof;

c) producing a magnetic field based on an occupant information; and

d) applying the magnetic field to the magnetic fluid to vary the viscosity thereof for thereby regulating the flow of the gas through the valve.