Inflator

• US 20030168841A1
• Filed: 08/26/2002
• Published: 09/11/2003
• Est. Priority Date: 02/26/2001
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Iwai, Yasunori, Nakayasu, Masayuki, Katsuda, Nobuyuki, Goto, Yuzo
• Granted Patent: US 7,222,880 B2
• Time in Patent Office: Days
• US Class Current: 280/740
• CPC Class Codes: B60R 2021/2612 Gas guiding means, e.g. ducts
• CPC Class Codes: B60R 2021/2617 Curtain bag nozzles
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• CPC Class Codes: B60R 21/268 using instantaneous release of stored pressurised gas B60R21/26005 takes precedence
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

The present invention provides an inflator whose manufacturing process is facilitated.

An opening portion 14 of the inflator housing 12 and a diffuser portion 20 are connected by welding, and an inflow portion 42 of a gas discharging port 40 is press-fitted in and connected to a first gas discharging hole 22 of the diffuser portion 20.

Claims

1. An inflator comprising an inflator housing in which a pressurized medium is charged and one end is provided with an opening portion, a diffuser portion which is fixed to the opening portion of the inflator housing and is provided with a gas discharging hole for discharging the pressurized medium flowing from the opening portion to the outside at a time of actuation, a rupturable plate closing an outflow path for the pressurized medium between the diffuser portion and the opening portion of the inflator housing, an igniter provided in the diffuser portion to serve as rupturing means for the rupturable plate, and a gas discharging port connected to the gas discharging hole of the diffuser portion to serve as a discharging path for the pressurized medium,

wherein the gas discharging hole of the diffuser portion and the gas discharging port are connected by press-fitting an inflow portion for the pressurized medium of the gas discharging port into the gas discharging hole.

2. An inflator according to claim 1, wherein a connecting portion between the gas discharging hole of the diffuser portion and the gas discharging port is fastened from outside with a fastening means.

3. An inflator according to claim 1 or 2, wherein a connecting portion between the gas discharging hole of the diffuser portion and the gas discharging port is fastened by a metallic band winding around the connecting portion from outside.

24. An inflator according to any one of claims 1 to 23, wherein the gas discharging port is mounted such that the axial direction of the gas discharging port and the axial direction of the inflator housing are parallel to each other.

25. An inflator according to any one of claims 1 to 12 and 22 to 24, wherein the gas discharging port comprises a cylindrical member having one end closed and the other end provided with an opening portion, and the pressurized medium flows out from the opening portion.

26. An inflator according to any one of claims 1 to 25, wherein the rupturable plate is attached to the opening portion of the inflator housing or the diffuser portion.

29. An air bag apparatus provided with an activation signal-outputting means comprising an impact sensor and a control unit, and a module case accommodating an inflator according to any one of claims 1 to 26 and an air bag.

4. An inflator comprising an inflator housing in which a pressurized medium is charged and one end is provided with an opening portion, a diffuser portion which is fixed to the opening portion of the inflator housing and is provided with a gas discharging hole for discharging the pressurized medium flowing from the opening portion to the outside at a time of actuation, a rupturable plate closing an outflow path for the pressurized medium between the diffuser portion and the opening portion of the inflator housing, an igniter provided in the diffuser portion to serve as rupturing means for the rupturable plate, and a gas discharging port connected to the gas discharging hole of the diffuser portion to serve as a discharging path for the pressurized medium,

wherein the gas discharging hole of the diffuser portion and the gas discharging port are connected by a resistance-welding.

5. An inflator comprising an inflator housing in which a pressurized medium is charged and one end is provided with an opening portion, a diffuser portion which is fixed to the opening portion of the inflator housing and is provided with a gas discharging hole for discharging the pressurized medium flowing from the opening portion to the outside at a time of actuation, a rupturable plate closing an outflow path for the pressurized medium between the diffuser portion and the opening portion of the inflator housing, an igniter provided in the diffuser portion to serve as rupturing means for the rupturable plate, and a gas discharging port connected to the gas discharging hole of the diffuser portion to serve as a discharging path for the pressurized medium,

wherein a screen having a plurality of outflow holes through which the pressurized medium passes is disposed in the gas discharging port.

6. An inflator according to claim 5, wherein the screen comprises a cylindrical member having one end open and the other end closed, and a plurality of the outflow holes are provided to a peripheral surface thereof.

7. An inflator according to claim 5 or 6, wherein the screen is arranged such that its axial direction is coincident with the axial direction of the gas discharging port.

8. An inflator according to any one of claims 5 to 7, wherein the screen has a flange portion at a peripheral edge of the opening portion of the one end and is mounted such that a flange portion contacts a step portion formed at an inner wall surface of the gas discharging port.

9. An inflator according to any one of claims 5 to 8, wherein a relationship between a length L from a closed end surface of the screen to the outflow hole nearest the closed end surface and a diameter D of the rupturable plate satisfies an expression:

L≧

D/2.

10. An inflator according to claim 9, wherein the length L is 3 to 8 mm.

11. An inflator according to any one of claims 5 to 10, wherein a diameter of the outflow hole provided to the screen is 0.5 to 2 mm.

12. An inflator according to any one of claims 5 to 11, wherein a total opening area of a plurality of the outflow holes provided to the screen is 20 to 1000 mm².

13. An inflator comprising an inflator housing in which a pressurized medium is charged and one end is provided with an opening portion, a diffuser portion which is fixed to the opening portion of the inflator housing and is provided with a gas discharging hole for discharging the pressurized medium flowing from the opening portion to the outside at a time of actuation, a rupturable plate closing an outflow path for the pressurized medium between the diffuser portion and the opening portion of the inflator housing, an igniter provided in the diffuser portion to serve as rupturing means for the rupturable plate, and a cylindrical gas discharging port connected to the gas discharging hole of the diffuser portion to serve as a discharging path for the pressurized medium,

wherein the gas discharging port has two or more opening portions only on a side surface, at least two of the two or more opening portions are positioned symmetrically in the widthwise direction or positioned similarly thereto, and a screen with a plurality of outflow holes is arranged inside the gas discharging port at the position where the opening portion is provided.

14. An inflator according to claim 13, wherein the screen comprises a one-layered or multiple layered cylinder made of a punching metal, a plain-stitched wire mesh or the similar member.

15. An inflator according to claim 13 or 14, wherein the pressurized medium is discharged from the gas discharging hole of the diffuser portion and flows out from the opening portions provided to the side surface of the gas discharging port via the screen in the gas discharging port at the time of actuation of the inflator and an opening area (A1) of the gas discharging hole is smaller than a total opening area (A2) of holes of the screen facing the opening portions.

16. An inflator according to claim 15, wherein A1/A2 is 0.1 to 0.95.

17. An inflator according to any one of claims 13 to 16, wherein the screen is arranged such that its axial direction is coincident with the axial direction of the gas discharging port.

18. An inflator according to any one of claims 13 to 17, wherein a relationship between a length L1 from a closed end surface of the gas discharging port to the opening portion nearest the closed end surface and a diameter D of the rupturable plate satisfies an expression:

L1≧

D/2.

19. An inflator according to any one of claims 13 to 18, wherein, when the inflator is connected to an air bag, the gas discharging port has a convex portion provided, continuously in the circumferential direction or at intervals, on an outer surface in the part from the at least two openings on the side surface to a portion where the air bag is connected.

20. An inflator according to claim 19, wherein the convex portion is provided near the opening portion.

21. An inflator according to any one of claims 13 to 18, wherein, when the inflator is connected to an air bag, the gas discharging port has a convex portion provided with a screw portion on a top surface continuously in the circumferential direction between the at least two openings on the side surface and a portion where the air bag is connected.

27. A connecting method of an air bag and the inflator according to claim 21, wherein the air bag has, at an opening, a cylindrical mouthpiece which is provided with a screw portion on the inner surface, the gas discharging port is inserted into the mouthpiece, and the air bag and the inflator are connected by screwing the screw portion on the convex portion of the gas discharging port into the screw portion of the mouthpiece.

28. A connecting method according to claim 27, wherein the mouthpiece has such a length that the screw portion of the convex portion can be screwed into the mouthpiece and that part or the whole of the opening portion provided to the side surface of the gas discharging port is covered with the mouthpiece in the axial direction.

22. An inflator comprising an inflator housing in which a pressurized medium is charged and one end is provided with an opening portion, a diffuser portion which is fixed to the opening portion of the inflator housing and is provided with a gas discharging hole for discharging the pressurized medium flowing from the opening portion to the outside at a time of actuation, a rupturable plate closing an outflow path for the pressurized medium between the diffuser portion and the opening portion of the inflator housing, an igniter provided in the diffuser portion to serve as rupturing means for the rupturable plate, and a gas discharging port connected to the gas discharging hole of the diffuser portion to serve as a discharging path for the pressurized medium,

wherein the igniter disposed in the diffuser portion is fitted in from an opening portion at one end of the diffuser portion toward the rupturable plate.

23. An inflator according to claim 22, wherein the igniter disposed in the diffuser portion is fixed by being crimped at a peripheral edge of the opening portion at the one end of the diffuser portion.