WO1995001946A1 - Gas generator - Google Patents
Gas generator Download PDFInfo
- Publication number
- WO1995001946A1 WO1995001946A1 PCT/US1994/006961 US9406961W WO9501946A1 WO 1995001946 A1 WO1995001946 A1 WO 1995001946A1 US 9406961 W US9406961 W US 9406961W WO 9501946 A1 WO9501946 A1 WO 9501946A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- propellant
- shock wave
- housing
- igniter
- grains
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
- B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
- B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
- B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
- B60R21/264—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic
- B60R21/2644—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
- B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
- B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
- B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
- B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
- B60R21/264—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic
- B60R21/2644—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder
- B60R2021/2648—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder comprising a plurality of combustion chambers or sub-chambers
Definitions
- the present invention generally relates to gas generators or inflators for use in vehicle occupant restraint systems.
- the onset rate of pressurization of an automobile airbag is subject to strict requirements to avoid injury to an out of position vehicle occupant.
- An aggressive, uncontrolled onset rate of pressurization is undesirable since excessively rapid inflation of the air bag may impact against the occupant.
- Essential to the concept of the present invention is the discovery that propellant grains adjacent to the igniter of the inflator are susceptible to crushing or fragmentation due to a shock wave developed by the igniter resulting in a significant increase in the onset rate of gas production.
- the aforesaid problem is solved, in accordance with the present invention, by utilizing a shock wave barrier in closely spaced relation to the igniter that attenuates the shock wave so as to minimize crush or fragmentation of the propellant grains without introducing time lapse to first gas production.
- a gas generator comprises an elongated cylindrical housing having a central axis and a plurality of gas discharge apertures spaced longitudinally in a side wall thereof; an elongated cylindrical propellant tube in the housing in coaxial relation thereto and having a plurality of longitudinally spaced apertures in a sidewall thereof and an open end; a cylindrical igniter at one end of the housing for igniting a propellant and having a central axis coaxially related to the axis of the housing and a discharge end aligned with and communicating with the open end of the propellant tube; a propellant charge in the propellant tube comprising a plurality of propellant grains; and a circular shock wave attenuation disc in the propellant tube disposed within the propellant grains so as to divide the grains into first and second longitudinally spaced portions.
- the shock wave attenuation disc is spaced from the discharge end of the igniter from approximately 10 mm to approximately 50 mm and extends at a right angle to the central axis of the housing.
- the shock wave attenuation disc further has a plurality of apertures therein extending parallel to the axis of the housing in a radially dispersed array, whereby a flame front emanating from the igniter is free to move through the first portion of the propellant grains, thence through the apertures in the shock wave disk, thence through the second portion of the propellant grains, but a shock wave emanating from the igniter is attenuated by the shock wave attenuation disc to preclude fragmentation of the second portion of the propellant grains.
- Fig. 1 is a cross-sectional view of an inflator having the shock wave barrier of the invention
- Fig. 2 is a view taken in the direction of the arrow 2 of Fig. 1; and Fig. 3 is a graph of comparative inflator pressure curves.
- a gas generator or inflator 10 for an automobile airbag in accordance with an exemplary constructed embodiment of the invention, comprises a housing 12, for example, an aluminum forging provided with a plurality of gas discharge orifices 14.
- the housing 12 has an integral closure 16 at one end and is open at the opposite end 18 for the acceptance of an end closure 20.
- the end closure 20 has a central bore 22 for the acceptance of a conventional igniter 24.
- the igniter 24 is provided with a pair of electrical conductors 26 and 28 to facilitate electric ignition of an explosive charge contained therein.
- a cylindrical propellant tube 30 has one end portion 32 supported on the end closure 20 and an opposite end portion 34 supported by the closed end portion 16 of the housing 12. grains so as to divide the grains into first and second longitudinally spaced portions.
- the shock wave attenuation disc is spaced from the discharge end of the igniter from approximately 10 mm to approximately 50 mm and extends at a right angle to the central axis of the housing.
- the shock wave attenuation disc further has a plurality of apertures therein extending parallel to the axis of the housing in a radially dispersed array, whereby a flame front emanating from the igniter is free to move through the first portion of the propellant grains, thence through the apertures in the shock wave disk, thence through the second portion of the propellant grains, but a shock wave emanating from the igniter is attenuated by the shock wave attenuation disc to preclude fragmentation of the second portion of the propellant grains.
- Fig. 1 is a cross-sectional view of an inflator having the shock wave barrier of the invention
- Fig. 2 is a view taken in the direction of the arrow 2 of Fig. 1; and Fig. 3 is a graph of comparative inflator pressure curves.
- a gas generator or inflator 10 for an automobile airbag in accordance with an exemplary constructed embodiment of the invention, comprises a housing 12, for example, an aluminum forging provided with a plurality of gas discharge orifices 14.
- the housing 12 has an integral closure 16 at one end and is open at the opposite end 18 for the acceptance of an end closure 20.
- the end closure 20 has a central bore 22 for the acceptance of a conventional igniter 24.
- the igniter 24 is provided with a pair of electrical conductors 26 and 28 to facilitate electric ignition of an explosive charge contained therein.
- a cylindrical propellant tube 30 has one end portion 32 supported on the end closure 20 and an opposite end portion 34 supported by the closed end portion 16 of the housing 12.
- the propellant tube 30 is provided with a plurality of relatively small apertures 36 such that approximately 25-40% of the tube 30 is open.
- the apertures 36 in the constructed embodiment of the invention, are 1.6 mm ( «.063 in) in diameter.
- the inside of the propellant tube 30 is provided with a burst foil 38 which controls pressure buildup and flame front propagation through a plurality of propellant grains 40 disposed internally of the propellant tube 30.
- the propellant tube 30 is surrounded by a slagging screen 42 comprising one or more layers of 20 mesh wire having a wire diameter of .58 mm ( «.023 in).
- a baffle tube 44 is telescoped about the propellant tube 30 in radially spaced relation to the slagging screen 42 thereon, so as to define a plenum 46 radially outwardly from the screen 42.
- the baffle tube 44 is provided with a plurality of relatively large apertures 48 and is surrounded by a final filter screen 50.
- conventional propellant grains 40 of the aforesaid dimension may be fragmented or crushed by a shock wave from the igniter 24.
- the propellant grains 40 are reduced to relatively small particles by crushing, combustion is accelerated resulting in a rapid and sometimes uncontrolled and excessive pressure rise.
- the aforesaid problem is solved by introducing a shock wave barrier 60 in closely spaced relation to the igniter 24, for example 10-50 mm from the exit nozzle 62 of igniter 24.
- the barrier 60 has a plurality of apertures 64 therein that permit passage of a flame front yet attenuate the shock wave produced by the igniter 24 thereby gases produced by combustion of the propellant grains 40 while maintaining ignition efficiency.
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Air Bags (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69402521T DE69402521T2 (en) | 1993-07-07 | 1994-06-20 | GAS GENERATOR |
EP94921336A EP0662935B1 (en) | 1993-07-07 | 1994-06-20 | Gas generator |
DE0662935T DE662935T1 (en) | 1993-07-07 | 1994-06-20 | GAS GENERATOR. |
JP50403795A JP3615761B2 (en) | 1993-07-07 | 1994-06-20 | Gas generator |
KR1019950700882A KR950702948A (en) | 1993-07-07 | 1994-06-20 | Gas generator |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/087,985 | 1993-07-07 | ||
US08/087,985 US5345875A (en) | 1993-07-07 | 1993-07-07 | Gas generator |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1995001946A1 true WO1995001946A1 (en) | 1995-01-19 |
Family
ID=22208431
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1994/006961 WO1995001946A1 (en) | 1993-07-07 | 1994-06-20 | Gas generator |
Country Status (7)
Country | Link |
---|---|
US (1) | US5345875A (en) |
EP (1) | EP0662935B1 (en) |
JP (1) | JP3615761B2 (en) |
KR (1) | KR950702948A (en) |
CA (1) | CA2141666A1 (en) |
DE (2) | DE662935T1 (en) |
WO (1) | WO1995001946A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2719531A1 (en) * | 1994-05-04 | 1995-11-10 | Breed Automotive Tech | Inflation device for passenger side air bags. |
EP0776796A3 (en) * | 1995-11-30 | 1997-12-10 | HS Technik und Design Technische Entwicklungen GmbH | Pyrotechnic gas generator |
EP1671856A1 (en) * | 2004-12-20 | 2006-06-21 | Daicel Chemical Industries, Ltd. | Gas generator for air bag |
US7520530B2 (en) | 2004-12-20 | 2009-04-21 | Daicel Chemical Industries, Ltd. | Gas generator for air bag |
Families Citing this family (30)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69324606T2 (en) * | 1992-08-28 | 1999-08-26 | Honda Giken Kogyo K.K. | Gas generator for inflating a gas cushion |
DE4324554B4 (en) * | 1993-07-22 | 2006-03-02 | Delphi Technologies, Inc. (n.d.Ges.d. Staates Delaware), Troy | Gas generator, in particular for an airbag |
US5454593A (en) * | 1993-08-02 | 1995-10-03 | Morton International, Inc. | Metal igniter tube boot with permanent retention system |
US5725834A (en) * | 1995-04-07 | 1998-03-10 | Daicel Chemical Industries, Ltd. | Chemical oxygen generator |
US5585597A (en) * | 1995-05-15 | 1996-12-17 | Trw Vehicle Safety Systems Inc. | Air bag inflator |
US5533754A (en) * | 1995-05-31 | 1996-07-09 | Trw Vehicle Safety Systems Inc. | Air bag inflator |
US5628528A (en) * | 1995-07-06 | 1997-05-13 | Automotive Systems Laboratory, Inc. | Dual chamber nonazide gas generator |
US5609361A (en) * | 1995-08-24 | 1997-03-11 | Trw Vehicle Safety Systems Inc. | Inflation fluid container and initiator with press-fit fluid seal |
US5622380A (en) * | 1995-09-21 | 1997-04-22 | Automotive Systems Laboratory, Inc. | Variable nonazide gas generator having multiple propellant chambers |
US5645298A (en) * | 1996-01-05 | 1997-07-08 | Trw Inc./Trw Vehicle Safety Systems, Inc. | Inflator for an inflatable vehicle occupant protection device |
US5593181A (en) * | 1996-03-15 | 1997-01-14 | Morton International, Inc. | Generant wafer core ignition system for passenger side airbag inflator |
US5829785A (en) * | 1996-03-26 | 1998-11-03 | Morton International, Inc. | Internal structure for a two-walled inflator |
CA2233466C (en) | 1996-08-12 | 2002-05-14 | Thomas & Betts International, Inc. | Orientationless squib connector assembly for automotive air bag assemblies |
US5727813A (en) * | 1996-08-21 | 1998-03-17 | Automotive Systems Laboratory, Inc. | Air bag inflator |
US5700973A (en) * | 1996-11-13 | 1997-12-23 | Automotive Systems Laboratory, Inc. | Gas inflator having aluminum bead filter |
US5738373A (en) * | 1996-11-13 | 1998-04-14 | Automotive Systems Laboratory, Inc. | Gas inflator with ceramic foam balls |
US5808232A (en) * | 1996-11-13 | 1998-09-15 | Automotive Systems Laboratory, Inc. | Gas inflator having aluminum or alumina bead filter |
US5806888A (en) * | 1997-01-16 | 1998-09-15 | Automotive Systems Laboratory, Inc. | Air bag inflator |
DE69824907T2 (en) * | 1997-03-24 | 2004-11-04 | Daicel Chemical Industries, Ltd., Sakai | Gas generating tablets and gas generator |
US6562161B1 (en) | 1997-03-24 | 2003-05-13 | Daicel Chemical Industries, Ltd. | Gas generating compositions for air bag |
US5944343A (en) * | 1997-08-21 | 1999-08-31 | Automotive Systems Laboratory, Inc. | Miniature inflator |
US6276953B1 (en) | 1997-12-04 | 2001-08-21 | Thoma & Betts International, Inc. | Orientationless squib connector assembly for automotive air bag assemblies |
JP2963086B1 (en) * | 1997-12-26 | 1999-10-12 | ダイセル化学工業株式会社 | Gas generator and airbag device for airbag |
US6454299B2 (en) * | 2000-04-14 | 2002-09-24 | Takata Corporation | Airbag device |
US7527289B2 (en) * | 2004-02-25 | 2009-05-05 | Daicel Chemical Industries, Ltd. | Gas generator for an air bag |
US7140638B2 (en) * | 2004-04-06 | 2006-11-28 | Trw Vehicle Safety Systems, Inc. | Inflator filter retainer |
FR2890022B1 (en) * | 2005-09-01 | 2007-10-12 | Livbag Soc Par Actions Simplif | PYROTECHNIC GAS GENERATOR COMPRISING MEANS FOR TEMPORARILY STORING A PART OF GASES |
WO2010084899A1 (en) * | 2009-01-22 | 2010-07-29 | 株式会社オートリブニチユ | Gas generator for airbag device |
DE102012021204A1 (en) * | 2012-10-30 | 2014-04-30 | Trw Airbag Systems Gmbh | Combustor screen, in particular for a gas generator, gas generator, gas bag module, vehicle safety system and method for producing a combustion chamber screen |
DE102014016521A1 (en) | 2014-11-10 | 2016-05-12 | PYRAFOR GmbH | Pyrotechnic gas generator |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US34615A (en) * | 1862-03-04 | Improvement in cartridges for fire-arms | ||
US2529791A (en) * | 1945-11-26 | 1950-11-14 | Ici Ltd | Power gas generating cartridge |
US3726220A (en) * | 1971-06-01 | 1973-04-10 | Us Army | Cartridge |
US3797854A (en) * | 1971-06-14 | 1974-03-19 | Rocket Research Corp | Crash restraint air generating inflation system |
US4530516A (en) * | 1984-07-09 | 1985-07-23 | Morton Thiokol Inc. | Aluminum inflator with steel center-tie |
US5009855A (en) * | 1988-10-17 | 1991-04-23 | Bayern-Chemie Gesellschaft Fuer Flugchemische Antriebe Mbh | Gas generator for inflating a safety bag |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3972545A (en) * | 1975-03-10 | 1976-08-03 | Thiokol Corporation | Multi-level cool gas generator |
US4899663A (en) * | 1989-02-15 | 1990-02-13 | Automotive Systems Laboratory, Inc. | Percussion initiated inflator assembly |
DE4005768A1 (en) * | 1990-02-23 | 1991-08-29 | Bayern Chemie Gmbh Flugchemie | Cylindrical gas generator for vehicle airbag - incorporates two chambers enclosed by filter |
DE4019677A1 (en) * | 1990-06-20 | 1992-01-09 | Bayern Chemie Gmbh Flugchemie | Gas generator for airbag system - operates in two stages to minimise bag kinetic energy |
-
1993
- 1993-07-07 US US08/087,985 patent/US5345875A/en not_active Expired - Fee Related
-
1994
- 1994-06-20 JP JP50403795A patent/JP3615761B2/en not_active Expired - Fee Related
- 1994-06-20 WO PCT/US1994/006961 patent/WO1995001946A1/en active IP Right Grant
- 1994-06-20 DE DE0662935T patent/DE662935T1/en active Pending
- 1994-06-20 CA CA002141666A patent/CA2141666A1/en not_active Abandoned
- 1994-06-20 KR KR1019950700882A patent/KR950702948A/en not_active Application Discontinuation
- 1994-06-20 DE DE69402521T patent/DE69402521T2/en not_active Expired - Fee Related
- 1994-06-20 EP EP94921336A patent/EP0662935B1/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US34615A (en) * | 1862-03-04 | Improvement in cartridges for fire-arms | ||
US2529791A (en) * | 1945-11-26 | 1950-11-14 | Ici Ltd | Power gas generating cartridge |
US3726220A (en) * | 1971-06-01 | 1973-04-10 | Us Army | Cartridge |
US3797854A (en) * | 1971-06-14 | 1974-03-19 | Rocket Research Corp | Crash restraint air generating inflation system |
US4530516A (en) * | 1984-07-09 | 1985-07-23 | Morton Thiokol Inc. | Aluminum inflator with steel center-tie |
US5009855A (en) * | 1988-10-17 | 1991-04-23 | Bayern-Chemie Gesellschaft Fuer Flugchemische Antriebe Mbh | Gas generator for inflating a safety bag |
Non-Patent Citations (1)
Title |
---|
See also references of EP0662935A4 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2719531A1 (en) * | 1994-05-04 | 1995-11-10 | Breed Automotive Tech | Inflation device for passenger side air bags. |
EP0776796A3 (en) * | 1995-11-30 | 1997-12-10 | HS Technik und Design Technische Entwicklungen GmbH | Pyrotechnic gas generator |
EP1671856A1 (en) * | 2004-12-20 | 2006-06-21 | Daicel Chemical Industries, Ltd. | Gas generator for air bag |
US7520530B2 (en) | 2004-12-20 | 2009-04-21 | Daicel Chemical Industries, Ltd. | Gas generator for air bag |
Also Published As
Publication number | Publication date |
---|---|
KR950702948A (en) | 1995-08-23 |
EP0662935B1 (en) | 1997-04-09 |
DE662935T1 (en) | 1996-01-04 |
JPH08501273A (en) | 1996-02-13 |
US5345875A (en) | 1994-09-13 |
JP3615761B2 (en) | 2005-02-02 |
DE69402521D1 (en) | 1997-05-15 |
CA2141666A1 (en) | 1995-01-19 |
DE69402521T2 (en) | 1997-09-11 |
EP0662935A4 (en) | 1996-04-10 |
EP0662935A1 (en) | 1995-07-19 |
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