Rupturable plate and inflator using same

Patent metadata

Field	Value
Publication number	US-9827943-B2
Application number	US-201415023478-A
Country	US
Kind code	B2
Filing date	Oct 1, 2014
Priority date	Oct 22, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An inflator includes a rupturable plate in a circular shape for closing an opening of a pressurized gas-filled space. The rupturable plate has a fragile portion formed by grooves in a regular polygon on one surface, including first fragile portions formed by grooves forming a circumference of the regular polygon, and second fragile portions formed by grooves extending from all apexes of the regular polygon to a center thereof creating a plurality of triangles formed by the first fragile portions as a base and the second fragile portions as the remaining two sides. The depth (h1) of the first fragile portion is less than the depth (h2) of the second fragile portion whereby, when pressure is exerted on a rear surface opposite to the fragile portions, the second fragile portions will rupture as the first fragile portions bend.

First claim

The invention claimed is:

1. A rupturable plate in a circular shape for closing an opening of a pressurized gas-filled space in an inflator, comprising:
a fragile portion formed in the shape of a regular polygon on one surface of the rupturable plate, the fragile portion including,
first fragile portions formed by grooves forming a circumference of the regular polygon, and
second fragile portions formed by grooves extending from all apexes of the regular polygon to a center of the regular polygon;

a plurality of triangles formed by the first fragile portions as a base and the second fragile portions as the remaining two sides,
a depth (h1) of said first fragile portions and a depth (h2) of said second fragile portions satisfying the relationship h1<h2, and
wherein at the time of rupture, the rupturable plate receives a pressure on a rear surface opposite to the one surface provided with the fragile portion, and ruptures to a side of the one surface provided with the fragile portion.

2. The rupturable plate according to claim 1 , wherein
said rupturable plate has a thickness T, and
a ratio (h1/T) of the depth (h1) of said first fragile portions formed by the grooves to the thickness (T) of the rupturable plate is within a range of 0.05 to 0.50;
a ratio (h2/T) of the depth (h2) of said second fragile portions formed by the grooves to the thickness (T) of the rupturable plate is within a range of 0.20 to 0.60; and
the relationship of h1<h2 is satisfied.

3. An inflator charged with a pressurized gas as a gas source, comprising:
a gas outlet of the pressurized gas-filled space being closed with the rupturable plate according to claim 1 , the rupturable plate being attached such that the one surface provided with the fragile portion faces a side of the pressurized gas-filled space; and
a device for fracturing the rupturable plate.

4. An inflator, comprising:
a bottle filled with a pressurized gas; and
an ignition device unit mounted on an opening of the bottle, the ignition device unit having an ignition device and a piston that moves axially by activation of the ignition device, accommodated in an ignition device unit housing provided with a gas discharge port; and
the rupturable plate according to claim 1 closing between the bottle and the ignition device unit housing such that the one surface of the rupturable plate provided with the fragile portion faces the bottle and that the piston faces the surface of the rupturable plate opposite to the one surface provided with the fragile portion, the piston axially moving upon receiving a gas pressure generated by activation of the ignition device to collide with and rupture the rupturable plate.

5. A gas generator according to claim 4 , further comprising a diffuser chamber including a plurality of gas discharge ports formed in the ignition device unit housing; a convex partition wall separating an interior of the ignition device unit housing into a combustion chamber and the diffuser chamber, the convex partition wall having an outer circumferential wall which abuts against an inner circumferential surface of the ignition device unit housing, an annular support portion which has a fixing hole for supporting the piston that is positioned inside the diffuser chamber, and an inner circumferential wall which is provided with a plurality of through holes and joins the outer circumferential wall and the annular support portion.

6. An inflator, comprising:
a pressurized gas chamber having an outer shell formed by a cylindrical pressurized gas chamber housing and that is filled with pressurized gas;
a gas generator including an ignition device and a molded article of a gas generating agent accommodated in a gas generator housing which is connected to one end of the pressurized gas chamber;
a diffuser portion having a gas discharge port connected to the other end of the pressurized gas chamber;
a first rupturable plate closing a first communication path between the pressurized gas chamber and the gas generator;
a second rupturable plate closing a second communication path between the pressurized gas chamber and the diffuser portion,
at least one of the first rupturable plate and the second rupturable plate being the rupturable plate having a fragile portion according to claim 1 , and
wherein when the rupturable plate having the fragile portion is used as the first rupturable plate, the rupturable plate is attached with the one surface thereof provided with the fragile portion facing the pressurized gas chamber, and
when the rupturable plate having the fragile portion is used as the second rupturable plate, the rupturable plate is attached with the one surface thereof provided with the fragile portion facing the diffuser portion.

7. A rupturable plate according to claim 1 , wherein the grooves forming said first fragile portions and said second fragile portions are formed continuously.

8. A rupturable plate according to claim 1 , wherein the grooves forming said first fragile portions and said second fragile portions are formed discontinuously.

9. A rupturable plate according to claim 1 , wherein the grooves forming said first fragile portions are different in cross-sectional shape than the grooves forming said second fragile portions.

Assignees

• Daicel Corp

Inventors

• Kobayashi Tomoharu
• Yamazaki Masayuki

Classifications

• B60R21/274 Primary

  characterised by means to rupture or open the fluid source · CPC title

• B60R21/272 Primary

  with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators · CPC title

• B60R21/268

  using instantaneous release of stored pressurised gas {(B60R21/26005 takes precedence)} · CPC title

• B60R21/262

  Elongated tubular diffusers, e.g. curtain-type · CPC title