Method of making gas generator for air bag and air bag system

• US 6,334,245 B2
• Filed: 05/15/2001
• Issued: 01/01/2002
• Est. Priority Date: 08/12/1997
• Status: Expired due to Fees

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Tomiyama, Shogo, Katsuda, Nobuyuki
• Primary Examiner(s): ROSENBAUM, IRENE CUDA
• Application Number:
  US09/854,529
• Publication Number:
  US 20010018802A1
• Time in Patent Office: 231 Days
• Field of Search: 294/551, 294/62, 294/64, 294/69, 298/901.24, 280/731, 280/733, 280/740, 280/741
• US Class Current: 29/462
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: Y10T 29/49229 Prime mover or fluid pump making
• CPC Class Codes: Y10T 29/49412 with assembly, disassembly or composite article making
• CPC Class Codes: Y10T 29/49892 Joining plate edge perpendicularly to frame
• CPC Class Codes: Y10T 29/49895 Associating parts by use of aligning means [e.g., use of a drift pin or a "fixture"]
• CPC Class Codes: Y10T 29/49904 Assembling a subassembly, then assembling with a second subassembly

Abstract

An air bag gas generator has a cylindrical member that permits reliable welding of the cylindrical member with an inner surface of a ceiling portion of a housing even if the welding surface is slightly misaligned. It furthermore permits welding in such a manner (a more stable manner) that unsteadiness does not occur in the area where the inner surface of the ceiling portion of the housing and the inner cylindrical member abuts. In the air bag gas generator, which includes the inner cylindrical member in the housing, the inner cylindrical member has a peripheral wall portion bent to form a flattened surface portion as an extension of the one of that cylindrical member where it joins the inner surface of the ceiling portion.

Claims

1. A method of manufacturing an airbag gas generator including a housing having a diffuser shell provided with a gas discharge port, comprising;

providing an inner cylindrical member having a peripheral wall, said inner cylindrical member having open ends;

bending the peripheral wall at a portion adjacent to one of the open ends to form a flat surface that extends at an angle with respect to the peripheral wall;

placing said inner cylindrical member onto an inner surface of the diffuser shell such that the flat surface is in contact with the inner surface;

attaching said inner cylindrical member to an inner surface by welding said flat portion and the diffuser shell;

providing a plate member around said inner cylindrical member, the plate member including a first circular portion defining a central hole and a circumferential wall portion formed at an outer edge of the first circular portion;

positioning said plate member by engaging said central hole with at least one of the peripheral wall and an outer circumference of said flat portion;

providing a cylindrical coolant member for at least one of cooling and filtering combustion gas generated when the gas generator operates; and

positioning said cylindrical coolant member by engaging an inner circumferential surface of said cylindrical coolant member with an outer circumference of the circumferential wall portion.

2. The method of manufacturing the gas generator of claim 1, wherein the diffuser shell includes a second circular portion and said inner cylindrical member attaching step further includes the step of,

attaching said inner cylindrical member such that a longitudinal axis of the inner cylindrical member matches a longitudinal axis of the diffuser shell.

3. The method of manufacturing the gas generator of claim 1, wherein said inner cylindrical member attaching step further includes the step of,

attaching said inner cylindrical member to the inner surface by an electron beam welding.

4. The method of manufacturing the gas generator of claim 1, wherein said inner cylindrical member providing step further includes the step of,

providing said inner cylindrical member formed by pressing a stainless steel plate.

5. The method of manufacturing the gas generator of claim 1, wherein said attaching step further includes the step of,

projecting a welding beam from an outside of the diffuser shell and using said flat surface as a welding area.

6. The method of manufacturing the gas generator of claim 1, wherein said cylindrical coolant member has an upper end and an upper opening that oppose the inner surface, and said plate member providing step further includes the step of,

providing said plate member in an upper portion of said cylindrical coolant member for closing the upper opening and preventing the combustion gas from by-passing between the upper end and the inner surface.

7. The method of manufacturing the gas generator of claim 1, wherein said plate member providing step further includes the step of,

providing said plate member for preventing, within said housing, a movement of said cylindrical coolant member in a radial direction with respect to the housing.

8. The method of manufacturing the gas generator of claim 1, wherein said plate member providing step further includes the step of,

providing said plate member including the first circular portion formed integrally with the circumferential wall portion.