Gas generator

• US 8,459,187 B2
• Filed: 09/18/2009
• Issued: 06/11/2013
• Est. Priority Date: 09/19/2008
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Nakayasu, Masayuki, Kinoshita, Gen
• Primary Examiner(s): Lee, Benjamin P
• Application Number:
  US12/562,662
• Publication Number:
  US 20100071580A1
• Time in Patent Office: 1,362 Days
• Field of Search: 102/367, 102/530, 102/531, 102/282, 280/741, 280/736
• US Class Current: 102/530
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• CPC Class Codes: B60R 21/263 using a variable source, e.g. plural stage or controlled output hybrid inflators B60R21/272
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

A gas generator includes a housing having a gas discharge port, a combustion chamber cup member disposed, in the housing, such that an opening portion thereof covers a bottom surface of the housing, the combustion chamber cup member having a communication hole at least a portion of its peripheral wall surface thereof, a metallic cover member covering the peripheral wall surface provided with the communication hole, and a combustion chamber being formed inside the combustion chamber cup member and accommodating a gas generating agent and an igniter therein, at the time of activation, the cover member expanding and deforming mainly in the radial direction to form a gap between the peripheral wall surface of the combustion cup member and the metallic cover member, which serves as a gas channel leading to the combustion chamber and the outside of the combustion chamber.

Claims

1. A gas generator, comprising:

a housing having a gas discharge port,

a combustion chamber cup member disposed, in the housing, such that an opening portion thereof covers a bottom surface of the housing, the combustion chamber cup member having a communication hole at least at a single portion in its peripheral wall surface thereof,

a cover member covering an outer peripheral wall surface of the combustion chamber cup member including the communication hole, and including an enlarged-diameter portion at least at a peripheral edge of the opening portion facing a housing bottom surface, and a fragile portion formed in the enlarged diameter portion at a position opposing the communication hole in the radial direction, and

a first combustion chamber formed inside the combustion chamber cup member and accommodating a first gas generating agent and a first igniter therein,

at the time of activation, the cover member expanding and deforming mainly in the radial direction to form a gap between the peripheral wall surface of the combustion cup member and the cover member, which serves as a gas channel communicating the first combustion chamber and the outside of the first combustion chamber.

2. The gas generator according to claim 1, wherein the fragile portion of the cover member is formed by a linear cut which runs through or does not run through in the thickness direction.

3. The gas generator according to claim 1, wherein the cover member is a metallic cover member.

4. The gas generator according to claim 1, further comprising:

a second combustion chamber including a second gas generating material, and provided within the housing and outside of the combustion chamber cup member; and

a second igniter provided in the second chamber,

wherein when the first gas generating agent is first burnt, the cover member expands and deforms causing the first combustion chamber and the second combustion chamber to communicate with each other, but when the second gas generating agent burns first, the cover member does not deform.

5. A gas generator, comprising:

a housing having a gas discharge port;

a combustion chamber cup member disposed, in the housing, such that an opening portion thereof covers a bottom surface of the housing, the combustion chamber cup having a communication hole at least at a portion of its peripheral wall surface thereof;

a cover member covering an outer peripheral wall surface of the combustion chamber cup member including the communication hole; and

a first combustion chamber formed inside the combustion chamber cup member and accommodating a first gas generating agent and a first igniter therein,

at the time of activation, the cover member expanding and deforming mainly in the radial direction to form a gap between the peripheral wall surface of the combustion cup member and the cover member, which serves as a gas channel communicating the first combustion chamber and the outside of the first combustion chamber,

wherein the combustion chamber cup member has two communication holes,

and the cover member has an enlarged-diameter portion at least at a peripheral edge of the opening portion facing the housing bottom surface, and two fragile portions are provided in the enlarged-diameter portion,

the communication holes and the fragile portions are formed equiangularly at four portions in the circumferential direction, and

the communication holes are formed at opposing positions to each other in the radial direction, and the fragile portions are formed at opposing positions to each other in the radial direction, such that the communication holes and the fragile portions do not overlap.

6. The gas generator according to claim 5, wherein the fragile portion of the cover member is formed by a linear cut which runs through or does not run through in the thickness direction.

7. The gas generator according to claim 5, further comprising:

a second combustion chamber including a second gas generating material, and provided within the housing and outside of the combustion chamber cup member; and

a second igniter provided in the second chamber,

wherein when the first gas generating agent is first burnt, the cover member expands and deforms causing the first combustion chamber and the second combustion chamber to communicate with each other, but when the second gas generating agent burns first, the cover member does not deform.

8. A gas generator, comprising:

a housing having a gas discharge port,

a combustion chamber cup member disposed, in the housing, such that an opening portion thereof covers a bottom end surface of the housing,

the combustion chamber cup member having a communication hole at least at a portion of its peripheral wall surface thereof,

a cover member including a bottom surface, an opening portion opposing the bottom surface, and a peripheral surface and covering the peripheral wall surface including the communication hole, and the cover member having a fragile portion at least at a peripheral edge of the opening portion facing the bottom end surface of the housing and the fragile portion extending from the peripheral edge only in an axial direction of the housing so as not to reach the bottom surface, the fragile portion being provided at a position that does not overlap the communication hole, and

a first combustion chamber formed inside the combustion chamber cup member and accommodating a first gas generating agent and a first igniter therein,

at the time of activation, the cover member expanding and deforming mainly in the radial direction such that the peripheral surface of the cover member, separated along the fragile portion including the peripheral edge, forms a gap between the peripheral wall surface of the combustion cup member and the cover member, which serves as a gas channel communicating the first combustion chamber and the outside of the first combustion chamber.

9. The gas generator according to claim 8, wherein the cover member is a metallic cover member.

10. The gas generator according to claim 8, further comprising:

a second combustion chamber including a second gas generating material, and provided within the housing and outside of the combustion chamber cup member; and

a second igniter provided in the second chamber,

wherein when the first gas generating agent is first burnt, the cover member expands and deforms causing the first combustion chamber and the second combustion chamber to communicate with each other, but when the second gas generating agent burns first, the cover member does not deform.

11. The gas generator according to claim 8, wherein the cover member has an enlarged-diameter portion at a peripheral edge of the opening portion, and has the fragile portion at least in the enlarged-diameter portion.

12. The gas generator according to claim 8, wherein the fragile portion is formed by a linear cut which runs through or does not run through the thickness direction.