WO2018229101A1 - Pyrotechnical gas generator for an airbag. - Google Patents

Pyrotechnical gas generator for an airbag. Download PDF

Info

Publication number
WO2018229101A1
WO2018229101A1 PCT/EP2018/065609 EP2018065609W WO2018229101A1 WO 2018229101 A1 WO2018229101 A1 WO 2018229101A1 EP 2018065609 W EP2018065609 W EP 2018065609W WO 2018229101 A1 WO2018229101 A1 WO 2018229101A1
Authority
WO
WIPO (PCT)
Prior art keywords
casing
gas generator
pyrotechnical
gas ejection
gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2018/065609
Other languages
French (fr)
Inventor
Frédéric MARLIN
Clément BENILLAN
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ArianeGroup SAS
Original Assignee
ArianeGroup SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ArianeGroup SAS filed Critical ArianeGroup SAS
Priority to US16/621,913 priority Critical patent/US11135994B2/en
Priority to CN201880039598.1A priority patent/CN110753643B/en
Publication of WO2018229101A1 publication Critical patent/WO2018229101A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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
    • 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
    • B60R2021/26029—Ignitors
    • 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
    • B60R2021/2642—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 comprising a plurality of combustion chambers or sub-chambers

Definitions

  • the invention relates to an inflator, and in particular to a pyrotechnical gas generator designed to inflate the bag of an airbag.
  • the present invention further relates to an airbag device having such an inflator.
  • An inflator for use in an airbag device for a passenger seat generally comprises a cylindrical casing having holes for discharging gas disposed on the peripheral surface thereof, propellant filled in the casing, booster for causing gas evolution of the propellant, an electrical igniter for igniting the booster, and auto ignition material having a lower firing temperature than the firing temperature of the booster.
  • the casing is generally made of steel or stainless steel.
  • the current nozzles used in the inflators to provide gas jets are generally round holes made in the steel casing, sealed by a film, and which usually have diameters between 2 mm and 4 mm for frontal disc shape inflators.
  • the number of holes is usually between 4 to 16.
  • the cylindrical inflator of this type is sometimes used for an airbag device for a driver seat.
  • the filtering device In the field of devices for automotive applications, constructors are always looking after new solutions which can bring weight and cost decrease.
  • the filtering device In an inflator, the filtering device represents an non-negligible part of its total weight.
  • the filtering device used in a pyrotechnical gas generator has currently three main functions which are:
  • Some low burning temperature compositions are used in pyrotechnical gas generators to reduce their total weight as they can exhibit an exhaust gas temperature and an aggressiveness of the jets allowing a significant decrease in the size, and thus the weight, or even a cancellation of the filtering device in the inflator. Indeed, the low burning temperature compositions allows decreasing the burning temperatures and improve the slagging effect with less particles.
  • compositions are not sufficient on their own to meet all the requirements allowing the removal of the filtering device in a pyrotechnical gas generator designed to be used in an airbag.
  • the invention aims to solve the aforementioned problems, by providing a pyrotechnical gas generator for an airbag with a reduced weight, and furthermore, providing a light pyrotechnical gas generator with a maximized output gas flow and a minimized jet's aggressiveness.
  • a pyrotechnical gas generator comprising at least one pyrotechnical charge, at least one ignitor, and a cylindrical casing enclosing said at least one charge and said at least one ignitor, said cylindrical casing having an axial direction and a radial direction and comprising an annular wall extending along said axial direction, and gas ejection holes arranged on said annular wall for letting the inside of the casing to communicate with the outside of the casing.
  • each gas ejection hole extends in a output plan forming a nonzero angle with a tangential plan which is tangent to said annular wall at said gas ejection hole.
  • the energy delivered in the radial direction is reduced and therefore the energy is smoothen.
  • each gas ejection hole comprises a notch extending along said axial direction and the casing is stamped on one same side of each notch.
  • the casing comprises more than sixteen gas ejection holes arranged homogeneously around said annular wall.
  • gas ejection holes i.e. nozzles
  • the great number of gas ejection holes allows to smoothen the energy homogeneously on a higher area and increase the flow of gas delivered by the gas generator while maintaining a low radial aggression of the gas jets.
  • the notch of each gas ejection hole has a length less than or equal to 1 mm .
  • the small size of the notch first, allows reducing the energy delivered by each hole, and, second, enables the gas ejection hole to act as a filter for big particles which could make pin holes in the bag of an airbag cooperating such a gas generator.
  • the casing can therefore integrate the function of a filtering device, thus reducing the total weight of the pyrotechnical gas generator as a separate filtering device is no longer needed.
  • the gas ejection holes are arranged on several rings running along the annular wall.
  • Arranging the gas ejection holes on several rings allows increasing the number of holes and thus increasing the flow of gas delivered.
  • the casing is made of a thin sheet of metal and each gas ejection hole comprises some least resistance lines along which the hole will preferably deform or tear itself to enlarge the opening in case of a too high pressure difference between inside and outside the casing.
  • the casing's resistance between two adjacent gas ejection holes along the axial direction is less than a threshold so that the casing can be slightly torn up in case of overpressure to increase the gas ejection holes area and decrease the pressure, thus limiting the risks of explosion of the casing.
  • an airbag assembly comprising a bag and a pyrotechnical gas generator as defined here above and acting as an inflator, said bag being sealed around said pyrotechnical gas generator in an air tight manner.
  • FIG. 1 shows schematically a view in section of an airbag assembly comprising a bag and a pyrotechnical gas generator according to an embodiment of the invention
  • FIG. 2 shows a view in perspective of the casing of the pyrotechnical gas generator of figure 1;
  • FIG. 3 shows a zoomed in view of a portion III of the gas ejection hole of the casing of figure 2;
  • Figure 4 represents a section view according to a plan IV of Figure 3.
  • figure 1 is schematically presented a view in section of an airbag assembly comprising a bag 10 and a pyrotechnical gas generator 1 according to an embodiment of the invention.
  • the bag 10 is attached to the pyrotechnical gas generator 1 in an airtight manner.
  • the pyrotechnical gas generator 1, or inflator has a cylindrical casing 2 made of metal such as steel or stainless steel.
  • the inside of the casing 2 defines a first chamber 11.
  • the pyrotechnical gas generator 1 further comprises a first cylindrical partition 3 and a second cylindrical partition 4.
  • the inside of the first cylindrical partition 3 defines a second chamber 12 and the inside of the second cylindrical partition 4 defines an ignition chamber 13.
  • the first chamber 11 is thus defined by the space left inside the casing 2 once the two cylindrical partitions 3 and 4 have been inserted in the casing 2.
  • the second partition wall 4 defining the ignition chamber 13 is perforated in order to communicate with the first chamber 11.
  • the casing 2 is cylindrical with an annular surface 20 extending along the axial direction DA and defining a tube.
  • the annular surface 20 extends along the axial direction D A from a top wall 25 extending in the radial direction D R .
  • the annular surface 20 comprises a plurality of gas ejection openings, or nozzles, 7 for allowing gas to spout from the first chamber 11 of the casing 2 and inflate the bag 10.
  • each nozzle 7 is made by, first, cutting a notch 70 into the annular surface, the notch 70 extending along said axial direction D A , and, second, stamping the casing 2 on one side of the notch 70, the stamping 75 being made from the inside of the casing 2 to deform the casing 2 towards the outside, i.e. away from the axial centre of the casing 2.
  • the stamping 75 is made on the same side of each notch 70 for every nozzle 7.
  • the notch 70 and the stamping 75 cooperate to define an output section of the nozzle 7 extending in a first plan P comprising the axial direction D A , the first plan P forming a nonzero angle a with a second plan T which is tangent to the annular wall 20 at the notch 70 and comprises the axial direction D A .
  • the first plan P and the second plan T both comprise the axial direction D A but are distinct from each other, thus forming an angle a which cannot have a value equal to zero or 180°.
  • the non-zero angle a formed by the first and second plans P and T ensures that the gaz jet ejected from the nozzle is not purely radial, i.e. is not directed only along the radial direction D R , but comprises a tangential component, i.e. comprises a radial component and a tangential component, thus reducing the aggressiveness of the jet on the bag.
  • the angle a formed by the first and the second plans P and T is strictly superior to 90°, and in particular slightly superior to 90°, for example between 92° and 100°.
  • the casing 2 comprises forty-four nozzles 7 arranged on two rings 8 and 9 running around the annular wall 20 at two different positions along the axial direction D A .
  • Each notch 70 of each nozzle 7 has a length of 0.5 mm.
  • the nozzles 7 thus integrate the gas ejection function together with the filtering function for big particles which could make pin holes in the bag of an airbag cooperating such a gas generator 1.
  • the casing's resistance between two adjacent nozzles 7 along the axial direction D A is less than a threshold so that the casing can be slightly torn up in case of overpressure to increase the nozzles area and decrease the pressure, thus limiting the risks of explosion of the casing 2.
  • the casing 2 is an external casing configured to be directly in contact with the external environment of the pyrotechnical gas generator 1, i.e. the most external casing of the pyrotechnical gas generator 1.
  • the casing 2 is thus the most external casing of the gas generator 1, and is regarding the bag 10 of the airbag assembly, no other element, such as another casing or a filter for example, being positioned between the casing 2 and the bag 10.
  • the invention provides thus a pyrotechnical gas generator for airbag, and an airbag, with a reduced weight and a maximized output gas flow and a minimized jet's aggressiveness.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Air Bags (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Abstract

A pyrotechnical gas generator (1) comprising at least one pyrotechnical charge, at least one ignitor (5, 6), and a cylindrical casing (2) enclosing said at least one charge and said at least one ignitor (5, 6), said cylindrical casing (2) having an axial direction (DA) and a radial direction (DR) and comprising an annular wall (20) extending along said axial direction (DA) of said casing (2), and gas ejection holes (7) arranged on said annular wall (20). Each gas ejection hole (7) extends in a output plan (P) forming a non-zero angle (a) with a tangential plan (T) which is tangent to said annular wall (20) at said gas ejection hole (7).

Description

Title of the invention
Pyrotechnical gas generator for an airbag. Background of the invention
The invention relates to an inflator, and in particular to a pyrotechnical gas generator designed to inflate the bag of an airbag. The present invention further relates to an airbag device having such an inflator.
An inflator for use in an airbag device for a passenger seat generally comprises a cylindrical casing having holes for discharging gas disposed on the peripheral surface thereof, propellant filled in the casing, booster for causing gas evolution of the propellant, an electrical igniter for igniting the booster, and auto ignition material having a lower firing temperature than the firing temperature of the booster. The casing is generally made of steel or stainless steel.
The current nozzles used in the inflators to provide gas jets are generally round holes made in the steel casing, sealed by a film, and which usually have diameters between 2 mm and 4 mm for frontal disc shape inflators. The number of holes is usually between 4 to 16. As gas is generated by the propellant, the film is broken by the gas pressure. The cylindrical inflator of this type is sometimes used for an airbag device for a driver seat.
In the field of devices for automotive applications, constructors are always looking after new solutions which can bring weight and cost decrease. In an inflator, the filtering device represents an non-negligible part of its total weight.
The filtering device used in a pyrotechnical gas generator has currently three main functions which are:
- decreasing the gas temperature so that the exhaust gas does not damage the bag,
- avoiding having particles emitted by the inflator which can make pin holes in the bag, and,
- keeping slag and particles inside the inflator to meet solid effluents expected level. Some low burning temperature compositions are used in pyrotechnical gas generators to reduce their total weight as they can exhibit an exhaust gas temperature and an aggressiveness of the jets allowing a significant decrease in the size, and thus the weight, or even a cancellation of the filtering device in the inflator. Indeed, the low burning temperature compositions allows decreasing the burning temperatures and improve the slagging effect with less particles.
However, these compositions are not sufficient on their own to meet all the requirements allowing the removal of the filtering device in a pyrotechnical gas generator designed to be used in an airbag.
Object and summary of the invention
The invention aims to solve the aforementioned problems, by providing a pyrotechnical gas generator for an airbag with a reduced weight, and furthermore, providing a light pyrotechnical gas generator with a maximized output gas flow and a minimized jet's aggressiveness.
This goal is reached thanks to a pyrotechnical gas generator comprising at least one pyrotechnical charge, at least one ignitor, and a cylindrical casing enclosing said at least one charge and said at least one ignitor, said cylindrical casing having an axial direction and a radial direction and comprising an annular wall extending along said axial direction, and gas ejection holes arranged on said annular wall for letting the inside of the casing to communicate with the outside of the casing.
According to a general feature of this pyrotechnical gas generator, each gas ejection hole extends in a output plan forming a nonzero angle with a tangential plan which is tangent to said annular wall at said gas ejection hole.
Having an output section forming a non-zero angle with a tangential plan provides the gas jet with a tangential component, thus reducing the aggressiveness of the gas jet on the parts of an object cooperating with the gas generator close to the gas generator.
The energy delivered in the radial direction is reduced and therefore the energy is smoothen.
In a preferred embodiment of the pyrotechnical gas generator, the output plan forms an angle with the tangential plan which is strictly superior to 90°. In a first aspect of the pyrotechnical gas generator, each gas ejection hole comprises a notch extending along said axial direction and the casing is stamped on one same side of each notch.
Realising the gas ejection holes with a notch and a stamping on one side simplifies to a minimum the production of the holes.
In a second aspect of the pyrotechnical gas generator, the casing comprises more than sixteen gas ejection holes arranged homogeneously around said annular wall.
The great number of gas ejection holes, i.e. nozzles, allows to smoothen the energy homogeneously on a higher area and increase the flow of gas delivered by the gas generator while maintaining a low radial aggression of the gas jets.
In a third aspect of the pyrotechnical gas generator, the notch of each gas ejection hole has a length less than or equal to 1 mm .
The small size of the notch, first, allows reducing the energy delivered by each hole, and, second, enables the gas ejection hole to act as a filter for big particles which could make pin holes in the bag of an airbag cooperating such a gas generator.
The casing can therefore integrate the function of a filtering device, thus reducing the total weight of the pyrotechnical gas generator as a separate filtering device is no longer needed.
In a fourth aspect of the pyrotechnical gas generator, the gas ejection holes are arranged on several rings running along the annular wall.
Arranging the gas ejection holes on several rings allows increasing the number of holes and thus increasing the flow of gas delivered.
In a fifth aspect of the pyrotechnical gas generator, the casing is made of a thin sheet of metal and each gas ejection hole comprises some least resistance lines along which the hole will preferably deform or tear itself to enlarge the opening in case of a too high pressure difference between inside and outside the casing.
In a sixth aspect of the pyrotechnical gas generator, the casing's resistance between two adjacent gas ejection holes along the axial direction is less than a threshold so that the casing can be slightly torn up in case of overpressure to increase the gas ejection holes area and decrease the pressure, thus limiting the risks of explosion of the casing.
In another object of the invention, it is proposed an airbag assembly comprising a bag and a pyrotechnical gas generator as defined here above and acting as an inflator, said bag being sealed around said pyrotechnical gas generator in an air tight manner.
Brief description of the drawings
The invention will be better understood by reading here after, as examples and in a non-limitative way, in reference to the enclosed drawings on which:
- Figure 1 shows schematically a view in section of an airbag assembly comprising a bag and a pyrotechnical gas generator according to an embodiment of the invention;
- Figure 2 shows a view in perspective of the casing of the pyrotechnical gas generator of figure 1;
- Figure 3 shows a zoomed in view of a portion III of the gas ejection hole of the casing of figure 2;
- Figure 4 represents a section view according to a plan IV of Figure 3.
Detailed description of the embodiments
The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non- limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated.
The term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.
Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.
In figure 1 is schematically presented a view in section of an airbag assembly comprising a bag 10 and a pyrotechnical gas generator 1 according to an embodiment of the invention.
The bag 10 is attached to the pyrotechnical gas generator 1 in an airtight manner.
The pyrotechnical gas generator 1, or inflator, has a cylindrical casing 2 made of metal such as steel or stainless steel. The inside of the casing 2 defines a first chamber 11.
The pyrotechnical gas generator 1 further comprises a first cylindrical partition 3 and a second cylindrical partition 4. The inside of the first cylindrical partition 3 defines a second chamber 12 and the inside of the second cylindrical partition 4 defines an ignition chamber 13. The first chamber 11 is thus defined by the space left inside the casing 2 once the two cylindrical partitions 3 and 4 have been inserted in the casing 2. The second partition wall 4 defining the ignition chamber 13 is perforated in order to communicate with the first chamber 11.
Filled in the first and second chambers 11 and 12 are gas generant for generating gases, respectively, and filled in the ignition chamber 13 is an ignition load. The second chamber 12 and the ignition chamber 13 are both provided with ignitors 5, 6. The electrical ignitors 5 and 6 have a wire generating heat by electricity and explosive. When the wire is turned on an electric current, the ignitor is fired and thereby the generant or the ignition load is ignited so that the generant initiates the gas evolution. As illustrated on Figure 2 which shows a view in perspective of the casing 2 of the pyrotechnical gas generator 1 of figure 1, the casing 2 is cylindrical with an annular surface 20 extending along the axial direction DA and defining a tube. The annular surface 20 extends along the axial direction DA from a top wall 25 extending in the radial direction DR.
The annular surface 20 comprises a plurality of gas ejection openings, or nozzles, 7 for allowing gas to spout from the first chamber 11 of the casing 2 and inflate the bag 10.
As illustrated on figure 2 and on figure 3 which is a zoom of part III of figure 2, each nozzle 7 is made by, first, cutting a notch 70 into the annular surface, the notch 70 extending along said axial direction DA, and, second, stamping the casing 2 on one side of the notch 70, the stamping 75 being made from the inside of the casing 2 to deform the casing 2 towards the outside, i.e. away from the axial centre of the casing 2. The stamping 75 is made on the same side of each notch 70 for every nozzle 7.
As illustrated on figure 4 which represents a section view according to a plan IV comprising the radial direction DR and perpendicular to the axial direction DA of the casing 2, the notch 70 and the stamping 75 cooperate to define an output section of the nozzle 7 extending in a first plan P comprising the axial direction DA, the first plan P forming a nonzero angle a with a second plan T which is tangent to the annular wall 20 at the notch 70 and comprises the axial direction DA. In other words, the first plan P and the second plan T both comprise the axial direction DA but are distinct from each other, thus forming an angle a which cannot have a value equal to zero or 180°. The non-zero angle a formed by the first and second plans P and T ensures that the gaz jet ejected from the nozzle is not purely radial, i.e. is not directed only along the radial direction DR, but comprises a tangential component, i.e. comprises a radial component and a tangential component, thus reducing the aggressiveness of the jet on the bag.
In a preferred embodiment, the angle a formed by the first and the second plans P and T is strictly superior to 90°, and in particular slightly superior to 90°, for example between 92° and 100°.
In the embodiment illustrated on figures 2 and 3, the casing 2 comprises forty-four nozzles 7 arranged on two rings 8 and 9 running around the annular wall 20 at two different positions along the axial direction DA. Each notch 70 of each nozzle 7 has a length of 0.5 mm.
The nozzles 7 thus integrate the gas ejection function together with the filtering function for big particles which could make pin holes in the bag of an airbag cooperating such a gas generator 1.
In this embodiment, the casing's resistance between two adjacent nozzles 7 along the axial direction DA is less than a threshold so that the casing can be slightly torn up in case of overpressure to increase the nozzles area and decrease the pressure, thus limiting the risks of explosion of the casing 2.
The casing 2 is an external casing configured to be directly in contact with the external environment of the pyrotechnical gas generator 1, i.e. the most external casing of the pyrotechnical gas generator 1. In the airbag assembly of figure 1, the casing 2 is thus the most external casing of the gas generator 1, and is regarding the bag 10 of the airbag assembly, no other element, such as another casing or a filter for example, being positioned between the casing 2 and the bag 10.
The invention provides thus a pyrotechnical gas generator for airbag, and an airbag, with a reduced weight and a maximized output gas flow and a minimized jet's aggressiveness.

Claims

1. A pyrotechnical gas generator (1) comprising at least one pyrotechnical charge, at least one ignitor (5, 6), and a cylindrical casing (2) enclosing said at least one charge and said at least one ignitor (5, 6), said cylindrical casing (2) having an axial direction (DA) and a radial direction (DR) and comprising an annular wall (20) extending along said axial direction (DA) of said casing (2), and gas ejection holes (7) arranged on said annular wall (20),
characterized in that said cylindrical casing (2) defines a chamber (11) comprising a cylindrical partition (4) defining an ignition chamber (13) enclosing an ignition load and an ignitor (5), and
each gas ejection hole (7) extends in a output plan (P) forming a non-zero angle (a) with a tangential plan (T) which is tangent to said annular wall (20) at said gas ejection hole (7).
2. The pyrotechnical gas generator (1) according to claim 1, the output plan (P) forms an angle (a) with the tangential plan (T) which is strictly superior to 90°.
3. The pyrotechnical gas generator (1) according to any of claims 1 or 2,wherein each gas ejection hole (7) comprises a notch (70) extending along said axial direction (DA) and the casing (2) is stamped on one same side of each notch (7).
4. The pyrotechnical gas generator (1) according to any of claims 1 to 3, wherein the casing (2) comprises more than sixteen gas ejection holes (7) arranged homogeneously around said annular wall (20).
5. The pyrotechnical gas generator (1) according to any of claims 1 to 4, wherein the notch (70) of each gas ejection hole (7) has a length less than or equal to 1 mm.
6. The pyrotechnical gas generator (1) according to any of claims 1 to 5, wherein the gas ejection holes (7) are arranged on several rings (8, 9) running along the annular wall (20).
7. The pyrotechnical gas generator (1) according to any of claims 1 to 6, wherein the casing (2) is made of a thin sheet of metal and each gas ejection hole (7) comprises some least resistance lines along which the hole (7) will preferably deform or tear itself to enlarge the opening in case of a high pressure difference between inside and outside the casing (2).
8. The pyrotechnical gas generator (1) according to claim 3 in combination with any of claims 2 and 4 to 7, wherein the casing's resistance between two adjacent gas ejection holes (7) along the axial direction (DA) is less than a threshold.
9. The pyrotechnical gas generator according to any of claims 1 to 8, wherein said cylindrical casing (2) is an external casing configured to be directly in contact with the external environment of the pyrotechnical gas generator (1).
10. An airbag assembly comprising a bag (10) and a pyrotechnical gas generator (1) according to any of claims 1 to 9 acting as an inflator, said bag (10) being sealed around said pyrotechnical gas generator (10) in an air tight manner.
PCT/EP2018/065609 2017-06-13 2018-06-13 Pyrotechnical gas generator for an airbag. Ceased WO2018229101A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US16/621,913 US11135994B2 (en) 2017-06-13 2018-06-13 Pyrotechnical gas generator for an airbag
CN201880039598.1A CN110753643B (en) 2017-06-13 2018-06-13 Pyrotechnic gas generator for an airbag

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP17305719.1A EP3415377B1 (en) 2017-06-13 2017-06-13 Pyrotechnical gas generator for an airbag
EP17305719.1 2017-06-13

Publications (1)

Publication Number Publication Date
WO2018229101A1 true WO2018229101A1 (en) 2018-12-20

Family

ID=59215673

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2018/065609 Ceased WO2018229101A1 (en) 2017-06-13 2018-06-13 Pyrotechnical gas generator for an airbag.

Country Status (4)

Country Link
US (1) US11135994B2 (en)
EP (1) EP3415377B1 (en)
CN (1) CN110753643B (en)
WO (1) WO2018229101A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6504963B2 (en) * 2015-08-05 2019-04-24 株式会社ダイセル Closed structure of cylindrical housing opening and gas generator

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19505580A1 (en) * 1995-02-18 1996-08-22 Dynamit Nobel Ag Gas generator in sheet metal construction for a motor vehicle occupant protection device
DE19716652A1 (en) * 1997-04-21 1998-10-22 Wilhelm Biemold Centrifugal separator
WO2015042126A1 (en) * 2013-09-19 2015-03-26 Key Safety Systems Inc. Inflator with flow wash strainer
US20150128799A1 (en) * 2013-11-12 2015-05-14 Autoliv Asp, Inc. Airbag inflation systems and methods

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3602526A (en) * 1968-11-12 1971-08-31 Eaton Yale & Towne Vehicle safety assembly having inflatable confinement
US4178017A (en) * 1974-11-20 1979-12-11 Nissan Motor Company, Limited Safety bag inflation apparatus with extendible guard member against contact of bag with heated gas generator
US5584506A (en) * 1995-12-18 1996-12-17 Trw Inc. Filter assembly for an air bag inflator
US6149192A (en) * 1998-08-11 2000-11-21 Trw Inc. Inflator having gas deflector flanges
US6183007B1 (en) * 1998-12-15 2001-02-06 Trw Vehicle Safety Systems Inc. Thrust-neutral inflator manifold
WO2002051673A1 (en) * 2000-12-26 2002-07-04 Nippon Kayaku Kabushiki-Kaisha Gas generator
US20040155444A1 (en) * 2002-12-09 2004-08-12 Naoki Matsuda Gas generator for air bag
US6871872B2 (en) * 2003-05-09 2005-03-29 Key Safety Systems, Inc. Air bag module diffuser
US8142534B2 (en) * 2006-12-20 2012-03-27 Tk Holdings, Inc. Gas generating system
DE102007033344A1 (en) * 2007-07-16 2009-05-07 Takata-Petri Ag Gas generator for a vehicle occupant protection device and method for removing solids and liquid burnt residues in a gas stream
JP5090100B2 (en) * 2007-08-09 2012-12-05 豊田合成株式会社 Inflator
US7874575B2 (en) * 2007-08-10 2011-01-25 Toyoda Gosei Co., Ltd. Airbag apparatus
JP5436036B2 (en) * 2009-05-12 2014-03-05 株式会社ダイセル Gas generator
US7938443B1 (en) * 2010-08-20 2011-05-10 Autoliv Asp, Inc. Shipping-safe inflator for an airbag module
US8297653B2 (en) * 2011-03-18 2012-10-30 Autoliv Asp, Inc. Pyrotechnic inflator with composite overwrap
JP5638996B2 (en) * 2011-03-30 2014-12-10 株式会社ダイセル Gas generator for personnel restraint system
JP2012240552A (en) * 2011-05-19 2012-12-10 Honda Motor Co Ltd Inflator for airbag apparatus
CN204279333U (en) * 2014-11-28 2015-04-22 东方久乐汽车安全气囊有限公司 A kind of safe automobile air bag firework type gas generator
KR20190137784A (en) * 2017-02-16 2019-12-11 제트에프 패시브 세이프티 시스템즈 유에스 인코포레이티드 Inflator Filter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19505580A1 (en) * 1995-02-18 1996-08-22 Dynamit Nobel Ag Gas generator in sheet metal construction for a motor vehicle occupant protection device
DE19716652A1 (en) * 1997-04-21 1998-10-22 Wilhelm Biemold Centrifugal separator
WO2015042126A1 (en) * 2013-09-19 2015-03-26 Key Safety Systems Inc. Inflator with flow wash strainer
US20150128799A1 (en) * 2013-11-12 2015-05-14 Autoliv Asp, Inc. Airbag inflation systems and methods

Also Published As

Publication number Publication date
US11135994B2 (en) 2021-10-05
CN110753643A (en) 2020-02-04
EP3415377B1 (en) 2020-07-22
EP3415377A1 (en) 2018-12-19
US20200122680A1 (en) 2020-04-23
CN110753643B (en) 2023-01-03

Similar Documents

Publication Publication Date Title
US5628528A (en) Dual chamber nonazide gas generator
CA2203520C (en) Variable nonazide gas generator having multiple propellant chambers
JP3830897B2 (en) 2-chamber inflator
JP3022961B2 (en) Hot gas generator for vehicle safety
US6379627B1 (en) Gas generator
JP5770978B2 (en) Gas generator
EP1266807B1 (en) Gas generator
WO2001096153A1 (en) Gas generator for multi-stage air bag
US20190176745A1 (en) Gas generator
JP2017210006A (en) Gas generator
CN110139781A (en) Inflator
CN1328091C (en) Gas generator
JP4190353B2 (en) Multistage ignition gas generator
US11135994B2 (en) Pyrotechnical gas generator for an airbag
EP1790539B1 (en) Gas generating device for air bag
JP2006160251A (en) Gas generator
US6007098A (en) Low cost pyrotechnic inflator
JP2007314102A (en) Gas generator
JP7745448B2 (en) Gas generator and airbag device
US20200254962A1 (en) Gas generator
JP2023176476A (en) gas generator
JP7270793B2 (en) gas generator
WO2004052693A1 (en) Gas generator for air bag
JP3857892B2 (en) Double chamber inflator
JP2005008093A (en) Gas generator for airbag

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18729445

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18729445

Country of ref document: EP

Kind code of ref document: A1