Gas generator

• US 20050225064A1
• Filed: 02/06/2003
• Published: 10/13/2005
• Est. Priority Date: 02/06/2002
• Status: Active Grant

• Current Assignee: Nippon Kayaku Company Limited
• Original Assignee: Nippon Kayaku Company Limited
• Inventors: Kawakami, Tameo, Saito, Tetsuo, Sato, Eishi, Dosai, Takayoshi, Suehiro, Akihiko
• Granted Patent: US 7,516,983 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

A gas generator comprising a housing (3) made of metal and having an initiator shell (1) and a closure shell (2), (a) combustion chamber(s) (5, 5a, 5b) formed in the housing (3) and packed with gas generant (4) that generates high temperature gas by burning, (a) filter member(s) (6, 6a, 6b) arranged around the combustion chamber(s) (5, 5a, 5b), (an) igniter device(s) (7, 7a, 7b) put in the housing (3) for igniting and burning the gas generant (4) in the combustion chamber(s) (5, 5a, 5b), and a plurality of gas discharge holes (8) formed at the housing (3), for discharging gas generated in the combustion chamber(s) (5, 5a, 5b), wherein either or both of the initiator shell (1) and the closure shell (2) forming the housing (3) has a head portion (14, 10) of a semispherical form or an oval semispherical form and a cylindrical portion (13, 9) of a diameter (D) formed continuously from the head portion (14, 10), and wherein a ratio H/D between the diameter D of the cylindrical portion (13, 9) and a distance H between bottoms of the head portions (14, 10) of the initiator shell (1) and closure shell (2) is in the range of 0.4-1.3.

Claims

1. A gas generator comprising a housing (3) made of metal and having an initiator shell (1) and a closure shell (2), (a) combustion chamber(s) (5, 5a, 5b) formed in the housing (3) and packed with gas generant (4) that generates high temperature gas by burning, (a) filter member(s) (6, 6a, 6b) arranged around the combustion chamber(s) (5, 5a, 5b), (an) igniter device(s) (7, 7a, 7b) put in the housing (3) for igniting and burning the gas generant (4) in the combustion chamber(s) (5, 5a, 5b), and a plurality of gas discharge holes (8) formed at the housing (3) for discharging gas generated in the combustion chamber(s) (5, 5a, 5b), wherein

either or both of the initiator shell (1) and the closure shell (2) forming the housing (3) has a head portion (14, 10) of a semispherical form or an oval semispherical form and a cylindrical portion (13, 9) of a diameter (D) formed continuously from the head portion (14, 10), and wherein

a ratio H/D between the diameter D of the cylindrical portion (13, 9) and a distance H between bottoms of the head portions (14, 10) of the initiator shell (1) and closure shell (2) is in the range of 0.6-1.3.

2. The gas generator according to claim 1, wherein a ratio d₁/d₂ between a minor axis d₁ and a major axis d₂ of the head portion (14, 10) of the initiator shell (1) and closure shell (2) is in the range of 1-0.02.

3. The gas generator according to claim 1, wherein the head portion (14, 10) has a cross section of a generally semicircular shape or a generally semi-elliptical shape formed with at least three continuously extending straight lines.

4. The gas generator according to claim 1, wherein the head portion (10) has a semi-spherical form having a curvature radius R, and a ratio D/R between the diameter D of the cylindrical portion (9) and the curvature radius R is in the range of 0.3-2.

5. The gas generator according to any one of claims 1 to 4, wherein the diameter D is a diameter D₁ between outside surface of the closure shell (2).

6. The gas generator according to claim 1, wherein the cylindrical portion (9) formed in the closure shell (2) has a height h in the range of 5-30 mm.

7. The gas generator according to claim 1, wherein the filter member (6) is formed so that a portion thereof around the gas discharge holes (8) is thicker than at either of an upper end portion thereof and a lower end portion thereof.

8. The gas generator according to claim 1, wherein the gas discharge holes (8) are arranged in zigzag on a surface of the housing (3).

9. The gas generator according to claim 1, wherein the igniter device (7) comprises an inner cylinder (16) having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the inner cylinder (16), and an igniter (18) placed in contact with the enhancer agent (17).

10. The gas generator according to claim 1, wherein the igniter device (7) comprises an inner cylinder (16) having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the inner cylinder (16), and an igniter (18) placed in contact with the enhancer agent (17), and wherein the enhancer holes (15) are arranged in zigzag on a surface of the inner cylinder (16).

11. The gas generator according to claim 1, wherein the igniter device (7) comprises an inner cylinder (16) having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the inner cylinder (16), and an igniter (18) placed in contact with the enhancer agent (17), and wherein the each enhancer hole (15) is formed on a surface of cylindrical portion of the inner cylinder (16) in the form of a slot long along an axial direction thereof.

12. The gas generator according to claim 1, wherein the igniter device (7) comprises an inner cylinder (16) having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the inner cylinder (16), and an igniter (18) placed in contact with the enhancer agent (17), and wherein the enhancer holes (15) are arranged in zigzag on a surface of a cylindrical portion of the inner cylinder (16) in the form of slots along an axial direction thereof respectively.

29. The gas generator according to any one of claims 1 to 28, wherein the gas generant is in the form of a hollow body closed at both ends.

30. The gas generator according to any one of claims 1 to 29, which is designed for a passenger'"'"'s seat.

31. A passenger'"'"'s seat airbag module to which the gas generator according to any one of claims 1 to 30 is fixed through a flanged portion (12).

32. A passenger'"'"'s seat airbag module according to claim 31, in which a single gas generator exists.

13. A gas generator comprising a housing (3) made of metal and having an initiator shell (1) and a closure shell (2), a combustion chamber (5) formed in the housing (3) and packed with gas generant (4) that generates high temperature gas by burning, a partition plate (30) for partitioning the combustion chamber (5) into two tiered chambers, a first filter member (6a) and a second filter member (6b) arranged around the first partitioned combustion chamber (5a) and the second partitioned combustion chamber (5b) respectively, a first igniter device (7a) and a second igniter device (7b) put in the initiator shell (1) for igniting and burning the gas generant (4) packed in the first partitioned combustion chamber (5a) and the second partitioned combustion chamber (5b) respectively, and a plurality of gas discharge holes (8) formed in the housing (3) for discharging gas generated in the first partitioned combustion chamber (5a) and the second partitioned combustion chamber (5b), wherein

either or both of the initiator shell (1) and the closure shell (2) forming the housing (3) has a head portion (14, 10) of a semispherical form or an oval semispherical form and a cylindrical portion (13, 9) of a diameter D formed continuously from the head portion (14, 10), and wherein

a ratio H/D between the diameter D of the cylindrical portion (13, 9) and a distance H between bottoms of the head portions (14, 10) of the initiator shell (1) and closure shell (2) is in the range of 0.6-1.3.

14. The gas generator according to claim 13, wherein a ratio d₁/d₂ between a minor axis d₁ and a major axis d₂ of the head portion (14, 10) of the initiator shell (1) and closure shell (2) is in the range of 1-0.02.

15. The gas generator according to claim 13, wherein the head portion (14, 10) has a cross section of a generally semicircular shape or a generally semi-elliptical shape formed with at least three continuously extending straight lines.

16. The gas generator according to claim 13, wherein the head portion (10) has a semi-spherical form having a curvature radius R, and a ratio D/R between the diameter D of the cylindrical portion (9) and the curvature radius R is in the range of 0.3-2.

17. The gas generator according to any one of claims 13 to 16, wherein the diameter D is a diameter D₁ between outer sides of the closure shell (2).

18. The gas generator according to claim 13, wherein the cylindrical portion (9) has a height h in the range of 5-30 mm.

19. The gas generator according to claim 13, wherein the filter member (6) is formed so that a portion thereof around the gas discharge holes (8) is thicker than either of an upper end portion thereof and a lower end portion thereof.

20. The gas generator according to claim 13, wherein the gas discharge holes (8) are arranged in zigzag on a surface of the housing (3).

21. The gas generator according to claim 13, wherein the first igniter device (7a) and the second igniter device (7b) comprise first and second inner cylinders (16a), (16b) each having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the first inner cylinder (16a) and the second inner cylinder (16b), and a first igniter (18a) and a second igniter (18b) both being placed in contact with the enhancer agent (17), respectively.

22. The gas generator according to claim 13, wherein the first igniter device (7a) and the second igniter device (7b) comprise first and second inner cylinders (16a), (16b) each having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the first inner cylinder (16a) and the second inner cylinder (16b), and a first igniter (18a) and a second igniter (18b) both being placed in contact with the enhancer agent (17), respectively, and wherein

the enhancer holes (15) are arranged in zigzag on surfaces of the first inner cylinder (16a) and the second inner cylinder (16b) respectively.

23. The gas generator according to claim 13, wherein the first igniter device (7a) and the second igniter device (7b) comprise first and second inner cylinders (16a), (16b) each having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the first inner cylinder (16a) and the second inner cylinder (16b), and a first igniter (18a) and a second igniter (18b) both being placed in contact with the enhancer agent (17), respectively, wherein

the enhancer hole (15) is formed on surfaces of cylindrical portions of the first inner cylinder (16a) and the second inner cylinder (16b) in the form of a slot long along axial directions thereof.

24. The gas generator according to claim 13, wherein the first igniter device (7a) and the second igniter device (7b) comprise first and second inner cylinders (16a), (16b) each having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the first inner cylinder (16a) and the second inner cylinder (16b), and a first igniter (18a) and a second igniter (18b) both being placed in contact with the enhancer agent (17), respectively, wherein

the enhancer holes (15) are arranged in zigzag on surfaces of the first inner cylinder (16a) and the second inner cylinder (16b), and wherein

either of the first inner cylinder (16a) and the second inner cylinder (16b) is has a height enough to be located in the second combustion chamber (5b) which is an upper side chamber of the two partitioned chambers.

25. The gas generator according to claim 13, wherein the first igniter device (7a) and the second igniter device (7b) comprise first and second inner cylinders (16a), (16b) each having a base and a plurality of enhancer holes (15) therearound, enhancer agent (17) packed in the first inner cylinder (16a) and the second inner cylinder (16b), and a first igniter (18a) and a second igniter (18b) both being placed in contact with the enhancer agent (17), respectively, wherein

the enhancer holes (15) which are formed at either of the first inner cylinder (16a) and the second inner cylinder (16b) in the form of a cylinder having an extended axis, are formed to open only in the second combustion chamber (5b) which is located on an upper side of the two partitioned chambers.

26. The gas generator according to claim 13, wherein the partition plate (30) is held in sandwich relation between the initiator shell (1) and the closure shell (2).

27. A gas generator comprising a housing (3) made of metal and having an initiator shell (1) and a closure shell (2), a combustion chamber (5) formed in the housing (3) and packed with gas generant (4) that generates high temperature gas by burning, a filter member (6) arranged around the combustion chamber (5), an igniter device (7) put in the housing (3) for igniting and burning the gas generant (4) in the combustion chamber (5), and a plurality of gas discharge holes (8) formed at the housing (3) for discharging gas generated in the combustion chamber (5), wherein the housing (3) has a generally spherical form.

28. A gas generator comprising a housing (3) made of metal and having an initiator shell (1) and a closure shell (2), a combustion chamber (5) formed in the housing (3) and packed with gas generant (4) that generates high temperature gas by burning, a filter member (6) arranged around the combustion chamber (5), an igniter device (7) put in the housing (3) for igniting and burning the gas generant (4) in the combustion chamber (5), and a plurality of gas discharge holes (8) formed at the housing (3) for discharging gas generated in the combustion chamber (5), wherein

the housing (3) has a generally oval spherical form.