Inflator

• US 20040066024A1
• Filed: 06/05/2003
• Published: 04/08/2004
• Est. Priority Date: 06/05/2002
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Iwai, Yasunori, Tokuda, Masakazu, Shioji, Hiroshi
• Granted Patent: US 7,052,039 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• 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 in which a flow amount of a pressurized gas can be kept almost constant.

Fragments produced by rupture of a first rupturable plate 22 are arrested around a top 20b of an inner surface of a filter 20, and the remaining portion of the inner surface does not contact with fragments. Therefore, since a gas flow does is not blocked by the fragments, a flow amount of a pressurized gas can be kept almost constant.

Claims

1. An inflator comprising an inflator housing which has an opening portion and is charged with a pressurized gas, a diffuser portion which is provided in the opening portion side of the inflator housing and has a gas discharging port for discharging outside a pressurized gas flowing from the opening portion at activation, and a first rupturable plate closing a pressurized gas flow path between the diffuser portion and the gas discharging port, wherein

a filter is disposed between the first rupturable plate and the gas discharging port, the filter comprises a flat plate with many holes except for a wire mesh and a surface of the filter in the first rupturable plate side has a concave portion and a convex portion.

2. An inflator according to claim 1, wherein the convex portion of the filter is formed continuously and the concave portion thereof forms a groove.

3. An inflator according to claim 1 or 2, wherein the convex portion of the filter is formed continuously and the concave portion thereof forms a single or double or more concentric grooves.

4. An inflator according to claim 1, wherein the convex portion of the filter includes plural independent projections.

5. An inflator according to claim 1 or 2, wherein a flow amount of the pressurized gas is adjusted by the many holes formed in the filter.

6. An inflator comprising an inflator housing which has an opening portion and is charged with a pressurized gas, a diffuser portion which is provided in the opening portion side of the inflator housing and has a gas discharging port for discharging outside a pressurized gas flowing from the opening portion at activation, and a first rupturable plate closing a pressurized gas flow path between the diffuser portion and the gas discharging port, wherein

a screen is disposed between the first rupturable plate and the gas discharging port, a filter is disposed to contact the screen, the filter is porous and have a sectional configuration of an arc shape, and the filter is disposed such that an opening portion thereof is directed to the first rupturable plate side and a spherical surface thereof contacts with the screen.

8. An inflator according to claim 6 or 7, wherein plural independent projections, or one or two or more grooves are formed on a surface of the filter in the first rupturable plate side.

9. An inflator according to claim 6 or 7, wherein the filter has an extension portion extended from an peripheral edge of the opening portion, and the extension portion is formed such that the more it is extended from the peripheral edge of the opening portion, the smaller an outer diameter of the extension portion becomes than the outer diameter of the peripheral edge of the opening portion in the filter portion.

10. An inflator according to claim 6 or 7, wherein a combustion chamber which accommodates a solid gas generating agent for generating a combustion gas is provided inside the inflator housing, and a second rupturable plate closes between the combustion chamber and a space charged with the pressurized gas.

11. An inflator according to claim 10, wherein the combustion chamber is provided at an end portion of the inflator housing, and an igniter is disposed in the combustion chamber.

12. An inflator according to claim 6 or 7, wherein many openings are formed in the screen, and a flow amount of the pressurized gas is adjusted by the openings.

7. An inflator comprising an inflator housing which has an opening portion and is charged with a pressurized gas, a diffuser portion which is provided in the opening portion side of the inflator housing and has a gas discharging port for discharging outside a pressurized gas flowing from the opening portion at activation, and a first rupturable plate closing a pressurized gas flow path between the diffuser portion and the gas discharging port, wherein

a screen is disposed between the first rupturable plate and the gas discharging port, a filter is disposed to contact the screen, the filter is porous and have a sectional configuration of an arc shape, and the filter is disposed in a state that a spherical surface thereof is directed to the first rupturable plate side and a peripheral edge of an opening portion thereof contacts with the screen.

13. A filter for an inflator used in an inflator for using a pressurized gas to inflate a body to be inflated and preventing foreign matters from entering the body to be inflated, wherein the filter comprises a porous flat plate except for a wire mesh, and a surface of the filter facing a pressurized gas flow has a concave portion and a convex portion.

14. An inflator comprising an inflator housing which has an opening portion and is charged with a pressurized gas, a diffuser portion which is provided in the opening portion side of the inflator housing and has a gas discharging port for discharging outside a pressurized gas flowing from the opening portion at activation, and a first rupturable plate closing a pressurized gas flow path between the diffuser portion and the gas discharging port, wherein

a filter is provided in a gas flow path inside the diffuser portion,

the filter is formed in a cap-like shape having one end portion closed and the other end portion opened, plural communication holes are formed in a side wall portion of the filter apart from the opened end portion of the filter, and the filter is disposed such that the closed end portion of the filter is directed to the first rupturable plate and the end portion of the filter on the opened side contacts with a wall portion provided with the gas discharging port.

15. An inflator according to claim 14, wherein the filter is welded to a wall portion having the gas discharging port of the diffuser portion.

16. An inflator according to claim 14 or 15, wherein the filter is formed with an expanded portion obtained by further expanding outwardly the opening side of the side wall portion of the filter.

17. An inflator according to claim 16, wherein the communication holes are formed at a portion in the side wall portion excluding the expanded portion.

18. An inflator according to claim 16, wherein the expanded portion is formed in a shirt shape gradually expanded outwardly toward the opened end portion of the filter.

19. An inflator comprising an inflator housing which has an opening portion and is charged with a pressurized gas, a diffuser portion which is provided in the opening portion side of the inflator housing and has a gas discharging port for discharging outside a pressurized gas flowing from the opening portion at activation, and a first rupturable plate closing a pressurized gas flow path between the diffuser portion and the gas discharging port, wherein

a filter is provided in a gas flow path inside the diffuser portion,

the filter is formed in a cap-like shape having one end portion closed and the other end portion opened, plural communication holes are formed in a side wall portion of the filter apart from the closed end portion of the filter, and an expanded portion is formed by further expanding the opened side of the filter outwardly and the filter is arranged such that the opened end portion is directed to the first rupturable plate and the expanded portion is fitted to a step portion provided in the diffuser portion.

20. An inflator according to claim 19, wherein a continuous projection is formed on a wall surface having the gas discharging port inside the diffuser portion.

21. An inflator according to claim 19 or 20, wherein the filter is press-fitted in or welded to the step portion.