Gas generator, airbag module, vehicle safety system and method for purifying a pyrotechnically produced gas

Patent metadata

Field	Value
Publication number	US-11273788-B2
Application number	US-201816607372-A
Country	US
Kind code	B2
Filing date	Apr 23, 2018
Priority date	Apr 25, 2017
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

The invention relates to a gas generator ( 10 ), particularly a pyrotechnical tube gas generator, with an axial longitudinal direction (L), comprising an ignition unit ( 20 ), a combustion chamber ( 30 ) axially mounted downstream from the ignition unit ( 20 ) and comprising a combustion chamber bottom ( 35 ) forming a combustion chamber outlet ( 36 ), and a filter chamber ( 70 ) that is axially mounted downstream of the combustion chamber ( 30 ). According to the invention, at least one guiding sleeve ( 50 ) and a front-side baffle plate ( 80 ) are formed in the filter chamber, a first end ( 51 ) of the guiding sleeve ( 50 ), on the side of the combustion chamber, being axially mounted downstream from the combustion chamber bottom ( 35 ), and a second end ( 53 ) of the guiding sleeve ( 50 ) being associated with the baffle plate ( 80 ), a first deflection section being formed on the baffle plate ( 80 ) and the guiding sleeve ( 50 ) which allows a gas flow to an outer side of the guiding sleeve ( 50 ) into an annular first discharge chamber ( 75 ).

First claim

The invention claimed is:

1. A pyrotechnical tube gas generator ( 10 ) with an axial longitudinal direction (L), comprising an ignition unit ( 20 ), a combustion chamber ( 30 ) mounted axially downstream of the ignition unit ( 20 ) comprising a combustion chamber bottom ( 35 ), and a filter chamber ( 70 ) that is mounted axially downstream of the combustion chamber ( 30 ), wherein in the filter chamber ( 70 ) a plate labyrinth filter system ( 150 ) is formed, the plate labyrinth filter system ( 150 ) including at least two plates ( 151 , 152 ) positioned axially downstream of each other, wherein the at least two plates ( 151 , 152 ) are aligned substantially perpendicularly to the axial longitudinal direction (L) of the gas generator ( 10 ) and substantially in parallel to the combustion chamber bottom ( 35 ), and wherein each of the at least two plates ( 151 , 152 ) has at least one through-opening, the through-openings of adjacent ones of the at least two plates ( 151 , 152 ) being arranged to be offset against each other in the radial direction, wherein the combustion chamber bottom ( 35 ) comprises a combustion chamber outlet ( 36 ) comprising at least one opening in the combustion chamber bottom ( 35 ), wherein all of the through-openings of a first plate ( 151 ) of the plate labyrinth filter system ( 150 ) arranged to be first in the axial longitudinal direction (L) being formed between the first plate ( 151 ) and an inner face ( 72 ) of a filter chamber outer casing ( 71 ).

2. The gas generator ( 10 ) according to claim 1 , wherein the first plate ( 151 ) of the at least two plates of the plate labyrinth filter system ( 150 ) has a circular portion ( 160 ) with circular segment portions ( 165 ) projecting laterally therefrom.

3. The gas generator ( 10 ) according to claim 2 , wherein the first plate includes a plurality of through-openings formed between the first plate ( 151 ) and the inner face ( 72 ) of the filter chamber outer casing ( 71 ), all of the through-openings of the first plate ( 151 ) being formed between the circular segment portions ( 165 ) of the first plate ( 151 ) and displaced radially outwardly in relation to the combustion chamber outlet ( 36 ).

4. The generator ( 10 ) according to claim 2 , wherein the number of circular segment portions ( 165 ) equals the number of through-openings of the first plate ( 151 ).

5. The gas generator ( 10 ) according to claim 2 , wherein the cross-section of the combustion chamber outlet ( 36 ) of the combustion chamber bottom ( 35 ) is smaller than the diameter of the circular portion ( 160 ) so that gas flowing into the filter chamber ( 70 ) through the combustion chamber outlet ( 36 ) first impacts on the circular portion ( 160 ) of the first plate ( 151 ) and then flows toward the through-openings of the first plate ( 151 ).

6. The gas generator ( 10 ) according to claim 2 , wherein a second plate ( 152 ) of the plate labyrinth filter system ( 150 ) is ring-shaped with only one through-opening, the one through-opening of the second plate ( 152 ) being arranged centrally on the second plate ( 152 ), a diameter of the central through-opening of the second plate ( 152 ) being smaller than a diameter of the circular portion ( 160 ) of the first plate ( 151 ).

7. The gas generator ( 10 ) according to claim 1 , wherein in the combustion chamber ( 30 ) a combustion chamber screen ( 60 ) is arranged which is mounted axially upstream, with respect to the longitudinal direction (L) of the gas generator, of the filter chamber ( 70 ), the combustion chamber screen ( 60 ) being in the form of a sleeve having radial openings ( 61 ).

8. The gas generator ( 10 ) according to claim 1 , further comprising a helical vane arranged axially upstream of the labyrinth filter system ( 150 ).

9. An airbag module comprising a gas generator ( 10 ), an airbag inflatable by the gas generator ( 10 ) and a fastening device for attaching the airbag module to a vehicle, wherein the gas generator ( 10 ) is configured according to claim 1 .

10. A vehicle safety system for protecting a person such as a vehicle occupant or a pedestrian, comprising a gas generator ( 10 ), an airbag inflatable by the gas generator ( 10 ) as part of an airbag module, and an electronic control unit by means of which the gas generator ( 10 ) can be activated when a trigger situation is given, wherein the gas generator ( 10 ) is configured according to claim 1 .

11. The gas generator ( 10 ) according to claim 2 , wherein the circular portion ( 160 ) is free from through-openings so that gas flowing into the filter chamber ( 70 ) through the combustion chamber outlet ( 36 ) first impacts on the circular portion ( 160 ) of the first plate ( 151 ) and then flows toward the through-openings of the first plate ( 151 ).

12. The gas generator ( 10 ) according to claim 1 , wherein the first plate ( 151 ) has a central portion ( 160 ) intersecting a central longitudinal axis (A) of the gas generator ( 10 ), the central portion ( 160 ) being free from through-openings so that all of the through-openings of the first plate ( 151 ) are formed between the central portion ( 160 ) and the inner face ( 72 ) of the filter chamber outer casing ( 71 ).

13. The gas generator ( 10 ) according to claim 1 , wherein a second plate ( 152 ) of the plate labyrinth filter system ( 150 ) arranged to be second in the axial longitudinal direction (L) is ring-shaped with only one through-opening, the one through-opening of the second plate ( 152 ) being arranged centrally on the second plate ( 152 ).

14. The gas generator ( 10 ) according to claim 13 , wherein gas flowing into the filter chamber ( 70 ) through the combustion chamber outlet ( 36 ) first travels along a central longitudinal axis (A) of the gas generator ( 10 ), then travels parallel to, and radially spaced apart from, the central longitudinal axis (A) through the at least one through-opening of the first plate ( 151 ), and then travels along the central longitudinal axis (A) through the central through-opening of the second plate ( 152 ).

15. The gas generator ( 10 ) according to claim 13 , wherein the first plate ( 151 ) has a central portion ( 160 ) that is free from through-openings, all of the through-openings of the first plate ( 151 ) being formed between the central portion ( 160 ) and the inner face ( 72 ) of the filter chamber outer casing ( 71 ), the central portion ( 160 ) of the first plate ( 151 ) having a larger diameter than a dimeter of the central through-opening of the second plate ( 152 ).

Assignees

• Trw Airbag Sys Gmbh

Inventors

• Bendel Elmar
• Esau Anja
• Last Detlef
• Jung Christian
• Wei Ning

Classifications

• B60R21/2644

  using only solid reacting substances, e.g. pellets, powder · CPC title

• B60R2021/26076

  characterised by casing · CPC title

• B60R21/2646 Primary

  the reacting substances being supported by the inflatable member walls, or by a flexible support within it · CPC title

• B60R2021/2648

  comprising a plurality of combustion chambers or sub-chambers · CPC title

• B60R2021/26064

  characterised by auto-ignition means · CPC title