U.S. patent application number 10/715478 was filed with the patent office on 2004-07-22 for initiator and gas generator.
This patent application is currently assigned to Takata Corporation. Invention is credited to Amano, Junya, Nishina, Takuma.
Application Number | 20040141279 10/715478 |
Document ID | / |
Family ID | 32599331 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040141279 |
Kind Code |
A1 |
Amano, Junya ; et
al. |
July 22, 2004 |
Initiator and gas generator
Abstract
An initiator and gas generator using the initiator. An initiator
includes a conductive header, a reactant disposed on one side of
the header, a cover member for covering the reactant, an electrode
pin extending through the header to protrude from the other side of
the header, and insulated from the header, a heating member
provided between the one side of the header and the electrode pin
so as to generate heat by the application of electricity, a
cylindrical terminal protruding from the other side of the header
coaxially with the electrode pin, and a connector-retaining portion
provided at a leading end of the cylindrical terminal. The
electrode pin and the cylindrical terminal are coaxial, the
initiator can be mounted in an initiator housing in whatever
direction it points, and the efficiency in mounting the initiator
in the initiator housing is high. The size of the connector is also
reduced.
Inventors: |
Amano, Junya; (Gotenba-shi,
JP) ; Nishina, Takuma; (Hikone, JP) |
Correspondence
Address: |
FOLEY AND LARDNER
SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
Takata Corporation
|
Family ID: |
32599331 |
Appl. No.: |
10/715478 |
Filed: |
November 19, 2003 |
Current U.S.
Class: |
361/247 |
Current CPC
Class: |
F42B 3/103 20130101;
F42B 3/26 20130101 |
Class at
Publication: |
361/247 |
International
Class: |
F23Q 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 21, 2003 |
JP |
2003-12497 |
Aug 20, 2003 |
JP |
2003-296486 |
Claims
What is claimed is:
1. An initiator comprising: a conductive header; a reactant
disposed on one side of the header; a cover member for covering the
reactant; an electrode pin extending through the header to protrude
from the other side of the header, the electrode pin being
insulated from the header; a heating member provided between the
one side of the header and the electrode pin so as to generate heat
by the application of electricity; a cylindrical terminal
protruding from the other side of the header coaxially with the
electrode pin; and a connector-retaining portion provided at a
leading end of the cylindrical terminal.
2. An initiator according to claim 1, wherein the
connector-retaining portion is an outward flange provided at the
leading end of the cylindrical terminal.
3. An initiator according to claim 1, wherein the heating member is
a bridge wire.
4. An initiator comprising: a conductive header; a reactant
disposed on one side of the header; a cover member for covering the
reactant; an electrode pin extending through the header to protrude
from the other side of the header, the electrode pin being
insulated from the header; a heating member provided between the
one side of the header and the electrode pin so as to generate heat
by the application of electricity; and; a connector-retaining
portion provided at a leading end of the electrode pin.
5. An initiator according to claim 4, wherein the
connector-retaining portion is shaped like a cone that decreases in
diameter toward a leading end thereof.
6. An initiator according to claim 4, wherein the heating member is
a bridge wire.
7. A gas generator comprising: a gas-generating agent; and an
initiator; wherein the initiator comprises a conductive header; a
reactant disposed on one side of the header; a cover member for
covering the reactant; an electrode pin extending through the
header to protrude from the other side of the header, the electrode
pin being insulated from the header; a heating member provided
between the one side of the header and the electrode pin so as to
generate heat by the application of electricity; a cylindrical
terminal protruding from the other side of the header coaxially
with the electrode pin; and a connector-retaining portion provided
at a leading end of the cylindrical terminal; wherein the initiator
causes the gas-generating agent to start a gas-generating
reaction.
8. An initiator comprising: an electrode pin; and a cylindrical
terminal; wherein the electrode pin and cylindrical terminal are
coaxial; and; wherein the initiator may be mounted in a housing in
any direction.
9. An initiator according to claim 8 further comprising an outward
flange at the leading end of the cylindrical terminal for retaining
a connector.
10. An initiator comprising only one electrode pin; thereby
allowing the initiator to be easily attached to a connector.
11. An initiator according to claim 10, wherein the pin includes a
cone shaped connector-retaining portion that decreases toward a
leading end of the pin.
12. An initiator for an airbag gas generator comprising only a
single electrical conducting pin configured to connect to a
connector having only a single pin jack.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an initiator suitably
incorporated in a gas generator in an air bag device, a seat-belt
pretensioner, and the like, and to a gas generator having the
initiator.
[0002] In air bag devices provided in high-speed moving bodies such
as automobiles, an air bag is quickly inflated by a gas generator
called an inflator. The gas generator contains a gas-generating
agent, and an initiator for causing the gas-generating agent to
start a gas-generating reaction. Conventionally, the initiator
includes a reactant, and a filament-shaped bridge wire serving as a
heating resistor that causes the reactant to start a reaction, as
described in Japanese Unexamined Patent Application Publication No.
2000-292099, and U.S. Pat. No. 5,404,263 (both incorporated by
reference). A connector-retaining portion is provided in the rear
of the initiator to retain a connector for the application of
electricity as described in Japanese Unexamined Patent Application
Publication No. 2001-165600 (incorporated by reference),
[0003] An example of a known initiator will be described with
reference to FIG. 3.
[0004] An initiator 10 includes a substantially cylindrical cup 12
having a closed end and an open rear end. A reactant 14 is
contained in the cup 12. The rear of the cup 12 is closed by a
header 16. The leading end of an electrode pin 18 extending through
the header 16 lies inside the cup 12.
[0005] A bridge wire 22 is provided between the leading end of the
electrode pin 18 and the header 16. Both ends of the bridge wire 22
are welded, respectively, to the electrode pin 18 and the header
16. The bridge wire 22 is in contact with the reactant 14 inside
the cup 12.
[0006] The electrode pin 18 and the header 16 are spaced with an
insulating material 19, such as glass, therebetween so as not to be
in electric contact with each other.
[0007] An electrode pin (ground pin) 20 protrudes from the header
16. A resin mold 24 is formed to surround the header 16 and the
bottoms of the electrode pins 18 and 20, and a substantially
annular collar 26 is combined with the resin mold 24.
[0008] The collar 26 has a hole 32 in which a connector 30 is to be
inserted. A retaining recess 34 is provided on an inner peripheral
surface at the entrance of the hole 32 so as to retain the
connector 30. A retaining projection 36 is provided on a side face
of the connector 30 so as to engage with the retaining recess 34.
Pin jacks 18j and 20j in which the electrode pins 18 and 20 are to
be inserted are provided on a leading end face of the connector 30.
In order to cause the connector 30 to point in one direction, the
resin mold 24 has a D-shaped projection 24D, and a D-shaped recess
30D in which the projection 24D is to be fitted is provided on the
leading end face of the connector 30. The projection 24D and the
recess 30D are sometimes T-shaped, instead of being D-shaped.
[0009] In an emergency such as a car collision, a voltage is
applied from a battery to the bridge wire 22 through the electrodes
18 and 20. In response thereto, the bridge wire 22 generates heat,
and the reactant 14 is ignited to start a reaction. High-pressure
gas and heat are generated by the reaction of the reactant 14, and
a gas-generating agent in a gas generator causes a gas-generating
reaction. With the reaction, the cup 12 is broken, and hot gas or
the like is emitted.
[0010] For example, the reactant includes a first reactant composed
of a mixture of lead styphnate and aluminum powder disposed to
surround the bridge wire 22, and a second reactant composed of
BKNO3 or gunpowder disposed to surround the first reactant. The
first reactant rapidly reacts to generate heat, and the second
reactant starts to react in response to the heat from the first
reactant, thereby producing high-pressure hot gas and fine
particles.
[0011] Since the above-described known initiator 10 has two pins,
it needs to be mounted in an initiator housing so that the rotation
angles of the initiator housing and the initiator precisely
coincide with each other, and this makes mounting operation
difficult.
[0012] For such a reason, the production cost of the known
initiator is mostly high.
[0013] Furthermore, the two electrode pins 18 and 20 are arranged
side by side with a predetermined distance therebetween, the width
of the connector 30 is large.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to overcome the above
problems, and to provide an initiator that can be easily produced
at a low production cost and that can reduce the size of a
connector, and a gas generator using the initiator.
[0015] An initiator of the present invention includes a conductive
header, a reactant disposed on one side of the header, a cover
member for covering the reactant, an electrode pin extending
through the header to protrude from the other side of the header,
and insulated from the header, a heating member provided between
the one side of the header and the electrode pin so as to generate
heat by the application of electricity, a cylindrical terminal
protruding from the other side of the header coaxially with the
electrode pin, and a connector-retaining portion provided at a
leading end of the cylindrical terminal.
[0016] In such an initiator, since the electrode pin and the
cylindrical terminal are coaxial, the initiator can be mounted in
an initiator housing in whatever direction it points, and the
efficiency in mounting the initiator in the initiator housing is
high,
[0017] Since the electrode pin and the cylindrical terminal are
coaxially arranged, the size of the connector can be reduced.
[0018] At the connector-retaining portion, an outward flange may be
provided at the leading end of the cylindrical terminal. This
structure is simple and is easily formed,
[0019] An initiator of another embodiment of the present invention
includes a conductive header, a reactant disposed on one side of
the header, a cover member for covering the reactant, an electrode
pin extending through the header to protrude from the other side of
the header, and insulated from the header, a heating member
provided between the one side of the header and the electrode pin
so as to generate heat by the application of electricity, and a
connector-retaining portion provided at a leading end of the
electrode pin.
[0020] Since the initiator has only one electrode pin, it can be
mounted in an initiator housing in whatever direction the connector
points, and the efficiency in mounting the initiator in the
initiator housing is high. Moreover, the size of the connector can
be reduced
[0021] In a case in which the connector-retaining portion is shaped
like a cone that decreases in diameter toward its leading end, the
structure is simple and is easily formed.
[0022] In the present invention, a bridge wire is suitable as the
heating member for generating heat by the application of
electricity. The bridge wire is inexpensive, and the initiator can
be produced easily. However, the heating member is not limited to
the bridge wire.
[0023] A gas generator of the present invention includes a
gas-generating agent, and the above initiator of the present
invention that causes the gas-generating agent to start a
gas-generating reaction.
[0024] The present invention provides an initiator that can be
easily produced at a low production cost and that can reduce the
size of a connector, and a gas generator using the initiator.
[0025] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and exemplary only, and are not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and other features, aspects, and advantages of the
present invention will become apparent from the following
description, appended claims, and the accompanying exemplary
embodiments shown in the drawings, which are briefly described
below.
[0027] FIG. 1 is a cross-sectional view of an initiator.
[0028] FIG. 2 is a cross-sectional view of an initiator according
to another embodiment of the present invention.
[0029] FIG. 3 is a cross-sectional view of a known initiator.
DETAILED DESCRIPTION
[0030] Embodiments of the present invention will be described below
with reference to the drawings. FIGS. 1 and 2 are cross-sectional
views of initiators according to the embodiments of the present
invention.
[0031] In an initiator 50 shown in FIG. 1, a cup 52 and a header 54
fitted in an entrance of the cup 52 constitute a casing 56. The
casing 56 is filled with a reactant 58. In this embodiment, the cup
52 is shaped like a circular container made of SUS304 or the like,
A body of the header 54 is shaped like a disc made of an
anticorrosion metal such as SUS304, and an outer peripheral surface
thereof is fixed to an inner peripheral surface of the cup 52, for
example, by welding.
[0032] A cylindrical terminal 54A protrudes from the center of an
outer surface of the disc-shaped body of the header 54. A
connector-retaining portion 54a shaped like an outward flange
(thick flange) is provided at the leading end of the cylindrical
terminal 54A. The cylindrical terminal 54A is formed integrally
with the disc-shaped body of the header 54.
[0033] A hole 60 extends from a leading end face of the cylindrical
terminal 54A to an inward surface of the header 54 (surface facing
the interior of the casing 56)
[0034] An electrode pin 62 coaxially extends through the hole 60.
The electrode pin 62 is fixed to the header 54 with an insulating
fixing material 66, such as glass, therebetween so as not to touch
the header 54. The leading end of the pin 62 protrudes outward from
the cylindrical terminal 54A. Inside the casing 56, a bridge wire
68 is provided between the surface of the header 54 inside the cup
52, and an end face of the electrode pin 62.
[0035] An outer surface of the cup 52 is covered with a resin cover
52a made of nylon, polypropylene, or the like. A rear side of the
cup 52 and a rear end face of the header 54 are covered with a
resin mold 70 made of nylon, polybutylene terephthalate, or the
like. The cylindrical terminal 54A extends outward through the
resin cover 70. A ground terminal of a connector contacts the
leading end of the cylindrical terminal 54A.
[0036] A reactant 58 is contained in a casing 56 of an initiator
50. An electrode pin 62 is fitted in a hole 66 of a header 54 and
is fixed by glass or the like. A bridge wire 68 is provided between
the electrode pin 62 and the header 54. A cylindrical terminal 54A
protrudes from the header 54, and the electrode pin 62 extends
through the cylindrical terminal 54A. A connector-retaining portion
54a is provided at the leading end of the cylindrical terminal
54A.
[0037] The reactant 58 may be composed of only a first reactant
(ignition agent), or may be composed of a mixture of the first
reactant and a second reactant (oxidizer particles). Although not
particularly limited, the first reactant includes, for example, a
single metal, such as Mg, Zr, Ti, W, B, Si, C, Be, Li, Al, V,
CaC.sub.2, Ca, Ce, or La, or an alloy or compound of them. Although
not particularly limited, the second reactant includes, for
example, KClO.sub.4, KCLO.sub.3, Kb.sub.4, NH.sub.4ClO.sub.4,
NH.sub.4NO.sub.3, KNO.sub.3, Fe.sub.2O.sub.3, Fe.sub.3O.sub.4,
Sr(NO.sub.3).sub.2, CuO, or NiO.
[0038] A connector (not shown in FIG. 1) is attached to the
initiator 50 from the upper side of FIG. 1. The connector has a pin
jack in which the electrode pin 62 is to be inserted, and a hole in
which the cylindrical terminal 54A is to be inserted A chuck
portion is provided on an inner surface of the hole to engage with
the connector-retaining portion 54a. When the cylindrical terminal
54A is inserted in the hole to a predetermined depth, the chuck
portion is retained by the connector-retaining portion 54a, thereby
preventing the connector from falling off.
[0039] In the initiator 50 having such a configuration, when a
voltage is applied between the electrode pin 62 and the cylindrical
terminal 54A, the bridge wire 68 generates heat, the reactant 58
starts to react, and a high-pressure and hot gas containing fine
particles is generated. In a case in which the reactant 58 contains
oxidizer particles, the reaction is accelerated because metal
particles quickly causes an oxidation reaction and generates heat
by an oxidizing action of the oxidizer particles.
[0040] In the initiator 50, since the electrode pin 62 and the
cylindrical terminal 54A are coaxial, the connector can be fitted
on the cylindrical terminal 54A in whatever direction around the
pin jack it points. Moreover, since the electrode pin 62 and the
cylindrical terminal 54A are coaxial, the connector may be small,
In addition, the initiator 50 can be produced easily
[0041] In an initiator 80 shown in FIG. 2, a cup 82 and a header 84
fitted in an entrance of the cup 82 constitute a casing 86. The
casing 86 is filled with a reactant 88. In this embodiment, the cup
82 is shaped like a circular container made of SUS.sub.330.sub.4 or
the like. The header 84 is a substantially cylindrical member made
of SUS.sub.330.sub.4 or the like, and having a small-diameter
portion 84a and a large-diameter portion 84b. An outer peripheral
surface of the small-diameter portion 84a is fixed to an inner
peripheral surface of the cup 82, for example, by welding.
[0042] A hole 90 is provided in the center of the header 84 to
extend therethrough in the axial direction of the cylinder.
[0043] An electrode pin 92 extends through the hole 90. The pin 92
is fixed to the header 84 with an insulating fixing material 96,
such as glass, therebetween so as not to touch the header 84. The
leading end of the pin 92 protrudes outward from the header 84.
[0044] A frusto-conical connector-retaining portion 92a that tapers
off toward the leading end is provided integrally with the leading
end of the electrode pin 92. The base end of the
connector-retaining portion 92a has a diameter larger than the
diameter of the electrode pin 92.
[0045] A bridge wire 98 is provided between an end face of the
header 84 inside the cup 82, and an end face of the electrode pin
92.
[0046] An outer surface of the cup 82 is covered with a resin cover
82a made of nylon, polypropylene, or the like. A rear side of the
cup 82 and a rear end face of the header 84 are covered with a
resin mold 100 made of nylon, polybutylene terephthalate, or the
like. Almost the center of an outer end face of the header 84 is
not covered with the resin mold 100. A ground terminal of a
connector contacts the exposed face of the header 84.
[0047] A connector (not shown) is attached to the initiator 80 from
the upper side in FIG. 2. The connector has a pin jack in which the
electrode pin 92 is to be inserted. A chuck portion is provided in
the innermost portion of the pin jack to engage with the
connector-retaining portion 92a. When the electrode pin 92 is
inserted in the pin jack to a predetermined depth, the chuck
portion engages with the connector-retaining portion 92a, thereby
preventing the connector from falling off.
[0048] In the initiator 80 having such a configuration, when a
voltage is applied between the electrode pin 92 and the header 84,
the bridge wire 98 generates heat, the reactant 88 starts to react,
and a high-pressure hot gas containing fine particles is
generated.
[0049] In the initiator 80 shown in FIG. 2, only one electrode pin
92 protrudes from the header 84, and the connector can be attached
to the initiator 80 in whatever direction around the electrode pin
92 it points. Moreover, the connector may be small. In addition,
the initiator 80 can be produced easily.
[0050] The initiator of the present invention is applicable to
various gas generators. The gas generators may be incorporated in
various air bag devices, such as a driver's seat air bag, a
passenger's seat air bag, a rear-seat air bag, a side air bag, a
head-protection air bag, and a pedestrian-protection air bag, and
in seat-belt pretensioners.
[0051] The priority applications, Japanese Patent Application No.
2003-12497, filed on Jan. 21, 2003 and Japanese Patent Application
No. 2003-296486, filed on Aug. 20, 2003, including the
specification, drawings, claims and abstract, are incorporated
herein by reference in their entirety.
[0052] Given the disclosure of the present invention, one versed in
the art would appreciate that there may be other embodiments and
modifications within the scope and spirit of the invention.
Accordingly, all modifications attainable by one versed in the art
from the present disclosure within the scope and spirit of the
present invention are to be included as further embodiments of the
present invention. The scope of the present invention is to be
defined as set forth in the following claims.
* * * * *