Multistage inflating-type hybrid inflator

• US 20030071447A1
• Filed: 08/21/2002
• Published: 04/17/2003
• Est. Priority Date: 08/21/2001
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Ogawa, Akihisa, Yamazaki, Masayuki, Iwai, Yasunori, Ryobo, Eiichi
• Granted Patent: US 6,860,510 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 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

A multistage inflating-type hybrid inflator in which a malfunction does not occur is provided.

When a first gas generating chamber 130 is first burnt, a combustion gas flowed out of first communication holes 136 advances in a direction towards an inner wall of an inflator housing 102 but it does not flow in a direction towards a second gas generating chamber 140. For this reason, the malfunction of the second gas generating chamber 140 cannot occur due to heat energy of the combustion gas.

Claims

1. A multistage inflating-type hybrid inflator comprising an inflator housing, two gas generating chambers provided with an gas generating agent which is accommodated in the inflator housing, an ignition chamber provided with an igniter which is connected to the two gas generating chambers, a diffuser portion connected to the inflator housing and provided with a gas discharging port, a pressurized medium charged inside the inflator housing, and a principal rupturable plate closing between the inflator housing and the diffuser portion, wherein

the first gas generating chamber and the second gas generating chamber are arranged radially in parallel with each other to be spaced from each other, the respective chambers are provided with one or two or more first communication holes which communicate the first gas generating chamber with the inflator housing and one or two or more second communication holes which communicate the second gas generating chamber with the inflator housing,

at least one of the opening direction of the first communication holes and the axial position of the first communication holes is adjusted so that heat energy generated in the first gas generating chamber is prevented from flowing into the second gas generating chamber to ignite the gas generating agent therein.

2. A multistage inflating-type hybrid inflator as claimed in claim 1, wherein the opening direction of the first communication holes is the radial direction, and is not opposite to the second gas generating chamber but opposite to an inner wall of the inflator housing.

3. A multistage inflating-type hybrid inflator as claimed in claim 1, wherein the opening direction of the first communication holes is the axial direction.

4. A multistage inflating-type hybrid inflator as claimed in claim 1 or 2, wherein the first communication holes and one or two or more second communication holes are opened radially, and the axial longitudinal positions of the former holes and that of the latter holes are different from each other.

5. A multistage inflating-type hybrid inflator as claimed in any one of claims 1 to 4, wherein the opening direction of part or all of the second communication holes face an inner wall of the inflator housing.

6. A multistage inflating-type hybrid inflator as claimed in any one of claims 1 to 5, wherein the first gas generating chamber and the second gas generating chamber are formed such that axial lengths thereof are different from each other.

7. A multistage inflating-type hybrid inflator as claimed in any one of claims 1 to 6, wherein at least one of the first gas generating chamber and the second gas generating chamber is closed at its axial one end portion by a retainer, and the retainer is fixed by crimping the axial end portion of the gas generating chamber.

8. An air bag system provided with an activation signal-outputting means comprising an impact sensor and a control unit, and a module case in which a multistage inflating-type hybrid inflator as claimed in any one of claims 1 to 7 and an air bag are accommodated.