Cylindrical filter for gas generator

• US 8,672,350 B2
• Filed: 05/27/2011
• Issued: 03/18/2014
• Est. Priority Date: 06/08/2010
• Status: Active Grant

• Current Assignee: Daicel Chemical Industries Limited
• Original Assignee: Daicel Chemical Industries Limited
• Inventors: Hatomoto, Atsushi
• Primary Examiner(s): Dickson, Paul
• Assistant Examiner(s): FRISBY, KEITH J
• Application Number:
  US13/117,504
• Publication Number:
  US 20110300030A1
• Time in Patent Office: 1,026 Days
• Field of Search: 280/741, 280/736, 555/26, 555/25, 298/966.2, 299/02, 102/530, 102/531
• US Class Current: 280/741
• CPC Class Codes: B01D 2275/105 Wound layers
• CPC Class Codes: B01D 2279/10 for air bags, e.g. inflators therefor
• CPC Class Codes: B01D 39/12 of wire gauze; of knitted wire; of expanded metal
• CPC Class Codes: B01D 46/2403 characterised by the physical shape or structure of the filtering element
• CPC Class Codes: B01D 46/528 using wound sheets B01D46/527 takes precedence
• CPC Class Codes: B60R 2021/26011 using a filter through which the inflation gas passes
• CPC Class Codes: Y10T 29/49604 Filter

Abstract

A cylindrical filter for a gas generator includes, a plurality of layers made of a porous metal plate in which a compressive strength (S1) of a predetermined region in at least one end in the height direction is set smaller than a compressive strength (S2) of a portion other than the S1 region, the porous metal plate being selected from the group consisting of expanded metal, metal lath, and perforated metal, and the S1 region corresponding to a region of 5 to 20% in length from both ends with respect to the overall height.

Claims

1. A cylindrical filter for a gas generator, comprising:

a porous metal plate forming a plurality of layers, the porous metal plate having, throughout an entire length thereof, a predetermined region S1 in at least one end in a height direction and a region S2 other than the region S1, the predetermined region S1 being provided with first holes, and the region S2 being provided with second holes, a compression strength of the predetermined region S1 being smaller than that of the region S2, the porous metal plate being configured to be provided within a gas generator housing so as to be press-contacted and fixed between a top plate and a bottom plate of the gas generator housing such that the region S1 is squashed in an axial direction and the region S2 retains an original shape,

the porous metal plate being selected from a group consisting of expanded metal, metal lath, and perforated metal, and

the predetermined region S1 corresponding to a region of 5 to 20% in length from both ends with respect to an overall height.

2. The cylindrical filter for a gas generator according to claim 1, wherein a difference between the compressive strengths in the regions S1 and S2 is a difference due to an opening area of the first holes per unit area in the region S1 being set greater than an opening area of the second holes per unit area in the region S2.

3. The cylindrical filter for a gas generator according to claim 1, wherein

a difference between the compressive strengths in the regions S1 and S2 is a difference due to;

an opening area of the first holes per unit area in the region S1 being set greater than an opening area of the second holes per unit area in the region S2, and

a thickness in the region Si being set smaller than a thickness in the region S2.

4. The cylindrical filter for a gas generator according to claim 1, wherein a difference between the compressive strength in the regions S1 and S2 is a difference due to a thickness in the region S1 being set smaller than a thickness in the region S2.

5. The cylindrical filter for a gas generator according to claim 1, wherein the porous metal plate is rolled a plurality of times so as to form a cylindrical shape and a rolling end is welded and fixed.

6. A gas generator, comprising:

the gas generator housing;

a solid gas generating agent as a gas source provided within the gas generator housing; and

the cylindrical filter according to claim 1, disposed in the gas generator housing, wherein

at least one end of the cylindrical filter makes a direct contact with an inner wall surface of at least one of the top plate and the bottom plate of the gas generator housing.

7. A cylindrical filter for a gas generator, comprising:

a porous metal plate forming a plurality of layers, the porous metal plate having, throughout an entire longitudinal length thereof, a predetermined region S1 in at least one end in a height direction and a region S2 other than the region S1, such that the predetermined region S1 has a compressive strength smaller than a compressive strength of the region S2, the porous metal plate being configured to be provided within a gas generator housing so as to be press-contacted and fixed between a top plate and a bottom plate of the gas generator housing such that the region S1 is squashed in an axial direction and the region S2 retains an original shape,

the porous metal plate being selected from a group consisting of expanded metal, metal lath, and perforated metal, and

the predetermined region S1 corresponding to a region of 5 to 20% in length from both ends with respect to an overall height.