Pyrotechnical gas generator for an airbag

Patent metadata

Field	Value
Publication number	US-2020122680-A1
Application number	US-201816621913-A
Country	US
Kind code	A1
Filing date	Jun 13, 2018
Priority date	Jun 13, 2017
Publication date	Apr 23, 2020
Grant date	—

Abstract

A pyrotechnical gas generator includes at least one pyrotechnical charge, at least one ignitor, and a cylindrical casing enclosing the at least one charge and the at least one ignitor, the cylindrical casing having an axial direction and a radial direction and including an annular wall extending along the axial direction of the casing, and gas ejection holes arranged on the annular wall. Each gas ejection hole extends in a output plan forming a non-zero angle with a tangential plan which is tangent to the annular wall at the gas ejection hole.

First claim

1 . 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 of said casing, and gas ejection holes arranged on said annular wall,
wherein said cylindrical casing defines a chamber comprising a cylindrical partition defining an ignition chamber enclosing an ignition load and an ignitor, and each gas ejection hole extends in a output plan forming a non-zero angle with a tangential plan which is tangent to said annular wall at said gas ejection hole.

2 . The pyrotechnical gas generator according to claim 1 , wherein the output plan forms an angle with the tangential plan which is strictly superior to 90°.

3 . The pyrotechnical gas generator according to claim 1 , wherein each gas ejection hole comprises a notch extending along said axial direction and the casing is stamped on one same side of each notch.

4 . The pyrotechnical gas generator according to claim 1 , wherein the casing comprises more than sixteen gas ejection holes arranged homogeneously around said annular wall.

5 . The pyrotechnical gas generator according to claim 1 , wherein the notch of each gas ejection hole has a length less than or equal to 1 mm.

6 . The pyrotechnical gas generator according to claim 1 , wherein the gas ejection holes are arranged on several rings running along the annular wall.

7 . The pyrotechnical gas generator according to claim 1 , wherein 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 deform or tear itself to enlarge the opening in case of a high pressure difference between inside and outside the casing.

8 . The pyrotechnical gas generator according to claim 3 , wherein the casing's resistance between two adjacent gas ejection holes along the axial direction is less than a threshold.

9 . The pyrotechnical gas generator according to claim 1 , wherein said cylindrical casing is an external casing configured to be directly in contact with the external environment of the pyrotechnical gas generator.

10 . An airbag assembly comprising a bag and a pyrotechnical gas generator according to claim 1 acting as an inflator, said bag being sealed around said pyrotechnical gas generator in an air tight manner.

Assignees

• Arianegroup Sas

Inventors

• Marlin Frédéric
• Benillan Clément

Classifications

• B60R21/264 Primary

  using instantaneous generation of gas, e.g. pyrotechnic (B60R21/268 takes precedence) · CPC title

• B60R2021/26029

  Ignitors · CPC title

• B60R2021/2642

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