Gas generator for air bag

• US 7,467,588 B2
• Filed: 12/08/2003
• Issued: 12/23/2008
• Est. Priority Date: 12/09/2002
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Matsuda, Naoki, Hirooka, Masato
• Primary Examiner(s): Parsley; David J
• Application Number:
  US10/729,009
• Publication Number:
  US 20040144281A1
• Time in Patent Office: 1,842 Days
• Field of Search: 149/22, 149/36, 149/45, 149/61, 149/62, 280/741, 280/736, 280/740, 280/742, 264/3.1, 102530-531
• US Class Current: 102/530
• 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: C06C 9/00 Chemical contact igniters; Chemical lighters
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

A gas generator for an air bag, includes: a housing having a gas discharging hole; an ignition unit activated upon an impact, the ignition unit including at least one igniter and at least one transfer charge, the transfer charge being a mixture of a transfer charge power and a gas generating agent molded article, and the gas generating agent molded article generates a gas of at least 1.2 moles/100 g; and a combustion chamber accommodating a gas generating agent which is ignited and burnt to generate a combustion gas.

Claims

1. A gas generator for an air bag, comprising:

a housing having a gas discharging hole;

ignition means activated upon an impact, the ignition means including at least one igniter and at least one transfer charge, the at least one transfer charge being a mixture of a transfer charge powder and molded articles of a gas generating agent; and

a combustion chamber accommodating a gas generating agent which is ignited and burnt to generate a combustion gas, wherein

the ignition means includes a first igniter, a first transfer charge, a second igniter, and a second transfer charge, and when the first igniter and the second igniter are activated with a time difference, the second transfer charge combined with the second igniter which is activated with a delay includes only the molded articles of a gas generating agent, and

the molded articles of the gas generating agent in the combustion chamber include guanidine nitrate, basic copper nitrate, carboxymethyl cellulose sodium salt, and aluminum hydroxide, and have a combustion temperature of about 1200 to 1700°

C.

2. The gas generator for an air bag according to claim 1, wherein

the first transfer charge includes a mixture of a transfer charge powder and molded articles of a gas generating agent,

the second transfer charge includes only the molded articles of a gas generating agent, and

the second transfer charge is adapted to be activated after an activation of the first transfer charge.

3. The gas generator for an air bag according to claim 1, wherein the first transfer charge is a mixture of boron and niter.

4. The gas generator for an air bag according to claim 1, wherein the molded articles of the gas generating agent of the first transfer charge include nitroguanidine, strontium nitrate, and carboxymethyl cellulose sodium salt.

5. The gas generator for an air bag according to claim 1, wherein the molded articles of the gas generating agent of the first transfer charge include about 34.4 mass % of nitroguanidine, about 55.6 mass % of strontium nitrate, and about 10.0 mass % of carboxymethyl cellulose sodium salt.

6. The gas generator for an air bag according to claim 1, wherein the molded articles of the gas generating agent of the first transfer charge include nitroguanidine, and strontium nitrate.

7. The gas generator for an air bag according to claim 1, wherein the molded articles of the gas generating agent of the first transfer charge or the second transfer charge generate a gas of at least 1.2 moles/100 g.

8. The gas generator for an air bag according to claim 1, wherein the molded articles of the gas generating agent of the first transfer charge or the second transfer charge include carboxymethyl cellulose sodium salt.

9. The gas generator for an air bag according to claim 1, wherein the gas generating agent in the combustion chamber has the combustion temperature of about 1200 to 1700°

C.

10. The gas generator for an bag according to claim 4, wherein the molded articles of the gas generating agent of the first transfer charge has a combustion temperature of about 2200°

C.