Gas generator

• US 20080257195A1
• Filed: 04/14/2008
• Published: 10/23/2008
• Est. Priority Date: 04/18/2007
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Original Assignee: Daicel Chemical Industries Limited (Daicel Corporation)
• Inventors: Nakayasu, Masayuki, Noma, Noriaki, Nikko, Takeo
• Granted Patent: US 8,011,303 B2
• Time in Patent Office: Days
• US Class Current: 102/530
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• 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

Abstract

The present invention provides a gas generator comprising:

• • a housing including a diffuser shell provided with a gas discharge port and a closure shell, a cylindrical filter disposed inside the housing, a first combustion chamber defined inside the cylindrical filter and a second combustion chamber defined inside the first combustion chamber;
  • the first combustion chamber having an enhancer chamber and a first gas generating agent stored outside the enhancer chamber,
  • the enhancer chamber, being defined by an enhancer chamber cup member and accommodating therein a first ignition device for igniting and combusting the first gas generating agent,
  • an enhancer cup member having, in the peripheral surface thereof, an enhancer hole for communicating the enhancer chamber with the first combustion chamber during activation;
  • the second combustion chamber having a through-hole for communicating the second combustion chamber with the first combustion chamber during activation,
  • the second combustion chamber being surrounded by a combustion chamber cup member disposed eccentrically to a central axis of the housing,
  • the second combustion chamber accommodating a second ignition device and a second gas generating agent therein; and
  • a top plate of the enhancer chamber cup member being positioned higher than a top plate of the combustion chamber cup member, the enhancer hole being positioned higher than the top plate of the combustion chamber cup member.

Claims

1. A gas generator comprising:

a housing including a diffuser shell provided with a gas discharge port and a closure shell, a cylindrical filter disposed inside the housing, a first combustion chamber defined inside the cylindrical filter and a second combustion chamber defined inside the first combustion chamber;

the first combustion chamber having an enhancer chamber and a first gas generating agent stored outside the enhancer chamber,

the enhancer chamber, being defined by an enhancer chamber cup member and accommodating therein a first ignition device for igniting and combusting the first gas generating agent,

an enhancer cup member having, in the peripheral surface thereof, an enhancer hole for communicating the enhancer chamber with the first combustion chamber during activation;

the second combustion chamber having a through-hole for communicating the second combustion chamber with the first combustion chamber during activation,

the second combustion chamber being surrounded by a combustion chamber cup member disposed eccentrically to a central axis of the housing,

the second combustion chamber accommodating a second ignition device and a second gas generating agent therein; and

a top plate of the enhancer chamber cup member being positioned higher than a top plate of the combustion chamber cup member, the enhancer hole being positioned higher than the top plate of the combustion chamber cup member.

2. The gas generator according to claim 1, wherein

the second ignition device comprises only an electric igniter, and

the combustion chamber cup member comprises a cylindrical member and a cover, an opening portion at one end of the cylindrical member is in contact with a bottom surface of the housing, the cover is placed on an opening portion on the other end side, and a protruding portion is provided in the center of the cover.

3. The gas generator according to claim 1, wherein

a ratio H₂/H₁ of a height (H₂) of the combustion chamber cup member to a height (H₁) of the enhancer chamber cup member is within a range of 0.3 to 0.9, and the height of the enhancer chamber cup member is equal to a height from a bottom surface to a ceiling surface of the housing.

4. The gas generator according to claim 1, wherein

the housing has a round planar shape, the filter has a round planar shape, the enhancer chamber cup member has a round planar shape, and the combustion chamber cup member has a circular arc planar shape, and

the combustion chamber cup member is disposed so that a curved portion thereof is positioned on the inner wall surface side of the filter, and a flat portion thereof is positioned on the side of the enhancer chamber cup member.

5. The gas generator according to claim 1, wherein

the housing has a round planar shape, the filter has a round planar shape, the enhancer chamber cup member has a round planar shape, and the combustion chamber cup member has a planar shape similar to a circular arc comprising a circumference and a concave curve, and

the combustion chamber cup member is disposed so that a curved portion thereof is positioned on the inner wall surface side of the filter, and a concave curved portion thereof is positioned on the side of the enhancer chamber cup member.

7. The gas generator according to claim 2, wherein

a ratio H₂/H₁ of a height (H₂) of the combustion chamber cup member to a height (H₁) of the enhancer chamber cup member is within a range of 0.3 to 0.9, and the height of the enhancer chamber cup member is equal to a height from a bottom surface to a ceiling surface of the housing.

8. The gas generator according to claim 2, wherein

the housing has a round planar shape, the filter has a round planar shape, the enhancer chamber cup member has a round planar shape, and the combustion chamber cup member has a circular arc planar shape, and

the combustion chamber cup member is disposed so that a curved portion thereof is positioned on the inner wall surface side of the filter, and a flat portion thereof is positioned on the side of the enhancer chamber cup member.

9. The gas generator according to claim 2, wherein

the housing has a round planar shape, the filter has a round planar shape, the enhancer chamber cup member has a round planar shape, and the combustion chamber cup member has a planar shape similar to a circular arc comprising a circumference and a concave curve, and

the combustion chamber cup member is disposed so that a curved portion thereof is positioned on the inner wall surface side of the filter, and a concave curved portion thereof is positioned on the side of the enhancer chamber cup member.

6. A gas generator, comprising:

a housing including a diffuser shell provided with a gas discharge port and a closure shell;

a cylindrical filter disposed within the housing and defining a first combustion chamber including therein a first gas generating agent;

an enhancer cup member provided within the first combustion chamber and defining an enhancer chamber accommodating therein a first ignition device for igniting and combusting the first gas generating agent, the enhancer cup member being provided with an enhancer hole formed in a peripheral surface thereof for communicating the enhancer chamber with the first combustion chamber during activation;

a combustion chamber cup member provided eccentrically to a central axis of the housing within the first combustion chamber, the combustion chamber cup member defining a second combustion chamber including therein a second ignition device and a second gas generating agent, and having a top plate and a through-hole for communicating the second combustion chamber with the first combustion chamber during activation, the combustion chamber cup member being provided such that the enhancer hole is positioned higher than the top plate.