U.S. patent application number 09/829000 was filed with the patent office on 2001-12-06 for airbag device.
Invention is credited to McCormick, David, Nanbu, Yuichi, Whang, David.
Application Number | 20010048218 09/829000 |
Document ID | / |
Family ID | 22730689 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010048218 |
Kind Code |
A1 |
Whang, David ; et
al. |
December 6, 2001 |
Airbag device
Abstract
An air bag device with improved initial restraining capability
includes an inflator that provides for shortening the starting time
for rising the pressure of an airbag and also the time required for
the pressure to reach the maximum value. The inflator includes a
propellant, an igniter for igniting the propellant, a combustion
chamber in which the propellant is burned, a filter chamber in
which a filter is accommodated, a partition separating the
combustion chamber and the filter chamber, communication orifices
formed in the partition for allowing the communication between the
combustion chamber and the filter chamber, and gas ports for
supplying inflating gas into an airbag, and further comprises
aluminum films which are broken and open the communication orifices
at a predetermined pressure inside the combustion chamber and
air-tightly close the communication orifices until the pressure
reaches the predetermined pressure.
Inventors: |
Whang, David; (Bloomfield
Hills, MI) ; Nanbu, Yuichi; (Tokyo, JP) ;
McCormick, David; (St. Clair Shores, MI) |
Correspondence
Address: |
Michael D. Kaminski
FOLEY & LARDNER
Suite 500
3000 K Street, N.W.
Washington
DC
20007-5109
US
|
Family ID: |
22730689 |
Appl. No.: |
09/829000 |
Filed: |
April 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60197771 |
Apr 14, 2000 |
|
|
|
Current U.S.
Class: |
280/737 ;
280/728.1; 707/E17.058 |
Current CPC
Class: |
B60R 21/232 20130101;
B60R 2021/2617 20130101; G06F 16/30 20190101; B60R 21/2644
20130101 |
Class at
Publication: |
280/737 ;
280/728.1 |
International
Class: |
B60R 021/16 |
Claims
What is claimed is:
1. An airbag device having an inflator comprising: a propellant; an
igniter for igniting the propellant; a combustion chamber in which
the propellant is burned; a filter chamber in which a filter is
positioned; a partition separating said combustion chamber and said
filter chamber; communication orifices formed in said partition for
allowing communication between said combustion chamber and said
filter chamber; gas ports for supplying inflating gas into an
airbag; and a closing mechanism configured to maintain said
communication orifices closed until the pressure of said combustion
chamber reaches a predetermined pressure.
2. The device of claim 1, wherein said closing mechanism includes
breakable members adapted to break at the predetermined
pressure.
3. The device of claim 1, wherein said closing mechanism is adapted
to open when the pressure of the combustion chamber is slightly
lower than a maximum combustion pressure of the propellant in the
combustion chamber.
4. The device of claim 3, wherein said closing mechanism is adapted
to open when said pressure of the combustion chamber reaches
approximately a lower limit of a variation range of a maximum
combustion pressure.
5. An airbag device having an inflator comprising: a propellant; an
igniter for igniting the propellant; a combustion chamber in which
the propellant is burned; a filter chamber in which a filter is
positioned; a partition separating said combustion chamber and said
filter chamber; communication orifices formed in said partition for
allowing communication between said combustion chamber and said
filter chamber; gas ports for supplying inflating gas into an
airbag, wherein said gas ports are formed in an outer periphery of
the inflator, away from said combustion chamber.
6. The device of claim 1, further comprising an airbag connected to
the inflator.
7. The device of claim 6, wherein said airbag has an gas inlet
facing to the gas ports of said inflator.
8. The device of claim 5, further comprising an airbag connected to
the inflator.
9. An airbag device having an elongated inflator comprising: a
propellant; an igniter for igniting the propellant; a combustion
chamber in which the propellant is burned; a filter chamber in
which a filter is positioned; a partition separating said
combustion chamber and said filter chamber; communication orifices
formed in said partition for allowing communication between said
combustion chamber and said filter chamber, wherein said combustion
chamber and said filter chamber are arranged in parallel in the
longitudinal direction of the inflator with said partition being
interposed therebetween; and gas ports for supplying inflating gas
into an airbag.
10. The device of claim 9, further comprising an airbag connected
to the inflator.
11. The device of claim 9, wherein said filter chamber includes
projecting portions on both ends thereof in the longitudinal
direction so that said filter chamber is longer than said
combustion chamber, and wherein connecting portions are formed on
the ends of said projecting portions for connecting to the
airbag.
12. The airbag device of claim 11 further comprising an airbag
connected to the connecting portions of the inflator.
13. The device of claim 9, wherein said filter chamber and said
combustion chamber are arranged to be offset from each other in the
longitudinal direction with the partition being interposed
therebetween so that said filter chamber and said combustion
chamber project in the opposite directions to each other, and
wherein the inflator further comprises a connecting portion formed
on the end of the projecting portion of said filter chamber.
14. The device of claim 13, further comprising an airbag connected
to the connecting portion of the inflator.
15. An airbag device having an inflator comprising: a propellant;
an igniter for igniting the propellant; a combustion chamber in
which the propellant is burned; a filter chamber in which a filter
is positioned, wherein said filter is disk shaped and has one
surface of said filter arranged adjacent to said partition; a
partition separating said combustion chamber and said filter
chamber; communication orifices formed in said partition for
allowing communication between said combustion chamber and said
filter chamber; and gas ports for supplying inflating gas into an
airbag.
16. The airbag device of claim 15 further comprising an airbag
connected to the inflator.
17. An airbag device having an inflator comprising: a propellant;
an igniter for igniting the propellant; a combustion chamber in
which the propellant is burned; a filter chamber in which a filter
is positioned, wherein said filter has a hollow cylindrical
configuration and said combustion chamber is formed in the hollow
portion of said filter; a partition separating said combustion
chamber and said filter chamber; communication orifices formed in
said partition for allowing communication between said combustion
chamber and said filter chamber; and gas ports for supplying
inflating gas into an airbag.
18. The device of claim 17, further comprising an airbag connected
to the inflator.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit
of U.S. Provisional Patent Application Ser. No. 60/197,771 filed
Apr. 14, 2000. The foregoing provisional application is
incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an airbag device having an
inflator which generates gas for inflating and deploying an airbag.
More particularly, the invention relates to a device having an
inflator of a type that a combustion chamber and a filter chamber
are separately provided.
[0003] Regardless of the type of airbags (e.g. driver airbags,
front-passenger airbags, side impact airbags, and curtain airbags),
conventional pyrotechnic inflators generally fall into the
following two types: a type wherein the propellant and a filter are
housed in one chamber (for example, a one-chamber type as disclosed
in W09908907); and a type where these components are housed in
respective separate chambers (for example, a two-chamber type as
disclosed in DE2981 91 68U1). That is, the one-chamber type
inflator has one chamber in which propellant and a filter are
housed. The two-chamber type inflator comprises a combustion
chamber in which propellant is filled, a filter chamber in which a
filter is housed, and a partition provided between the combustion
chamber and the filter chamber wherein the partition is formed with
a hole for allowing the communication between the combustion
chamber and the filter chamber from the initiation of combustion
until the combustion pressure reaches the maximum value. The
combustion gas starts to flow into the filter chamber at the
initiation of combustion. This inflow of gas causes a little delay
to rise the combustion pressure to the maximum value. Further, the
delay slows the speed of combustion.
[0004] It is desired to shorten the starting timing of rising the
inner pressure of an airbag and to shorten the time period required
from the start of rising of the inner pressure until the inner
pressure reaches the maximum value, for improving the initial
restraining capability of an airbag device.
[0005] It is desired to provide an inflator which has an increased
degree of freedom of design for positioning a gas port.
[0006] It is desired to provide an inflator which provides for an
increased degree of freedom of design for easily changing its
profile to be suitable for any housing space.
SUMMARY OF THE INVENTION
[0007] In order to solve the above-described problems, an inflator
of the present invention comprises: a propellant, an igniter for
igniting the propellant, a combustion chamber in which the
propellant is burned, a filter chamber in which a filter is
accommodated, a partition separating the combustion chamber and the
filter chamber, communication orifices formed in the partition for
allowing the communication between the combustion chamber and the
filter chamber, and gas ports for supplying inflating gas into an
airbag, and further comprising a closing mechanism which provides
for an air tight closure at the communication orifices until the
inner pressure of the combustion chamber reaches a predetermined
pressure.
[0008] According to this structure, the combustion chamber is
closed so that the pressure in the combustion chamber rises
quickly. The closing mechanism releases when the pressure reaches
the predetermined pressure, thereby reducing the delay in the start
of rising the inner pressure of an airbag, shortening the time
period required from the start of rising of the inner pressure
until the inner pressure reaches the maximum value, and thus
improving the initial restraining capability of an airbag
device.
[0009] The inflator of the present invention is characterized in
that the closing mechanism breakable members which can be broken at
the predetermined pressure. According to this structure,
inexpensive breakable members such as aluminum film can be employed
as the closing mechanism or means.
[0010] The inflator of the present invention is further
characterized in that the predetermined pressure is slightly lower
than the maximum combustion pressure of the propellant in the
combustion chamber. According to this structure, the reliability of
releasing action of the closing mechanism can be improved because
the action is not affected by variation in the maximum combustion
pressure due to individual differences of the propellant.
[0011] The inflator of the present invention is characterized in
that the predetermined pressure is a value around the lower limit
of a variation range of the maximum combustion pressure. According
to this structure, the reliability of releasing action of the
closing mechanism can be improved because the action is not
affected by variation in the maximum combustion pressure due to
individual differences of the propellant.
[0012] An airbag device according to the present invention may
include: a propellant, an igniter for igniting the propellant, a
combustion chamber in which the propellant is burned, a filter
chamber in which a filter is accommodated, a partition separating
the combustion chamber and the filter chamber, communication
orifices formed in the partition for allowing communication between
the combustion chamber and the filter chamber, and gas ports for
supplying inflating gas into an airbag, and is characterized in
that the gas ports can be formed at any places in the outer
periphery of the inflator, except a portion adjacent to the
combustion chamber.
[0013] According to this structure, the gas ports may be formed in
almost all outer periphery adjacent to the filter chamber, thus
increasing the degree of freedom of design for positioning gas
ports. In addition, the filter can be used as heat-absorbing
mechanism through its entire surface, thus improving the
endothermic effect of the filter.
[0014] An airbag device of the present invention is characterized
by comprising an airbag connected to the aforementioned inflator.
According to this structure, an airbag device can be obtained which
has excellent rising characteristics of the inner pressure of the
airbag.
[0015] The airbag device of the present invention is characterized
in that the airbag has a gas inlet facing to the gas ports of the
aforementioned inflator. According to this structure, the gas inlet
of the airbag is disposed to face to the gas ports so as to cope
with multidirectional or bidirectional gas spouted out
simultaneously from the gas ports of the inflator of this type,
thereby effectively introducing the inflating gas of the inflator
of this type into the airbag. This structure can speed up the
initial deployment of the airbag or can deploy multiple areas of
airbags at once.
[0016] In an alternative embodiment, an inflator of the present
invention may comprise: a propellant, an igniter for igniting the
propellant, a combustion chamber in which the propellant is burned,
a filter chamber in which a filter is positioned, a partition
separating the combustion chamber and the filter chamber,
communication orifices formed in the partition for allowing the
communication between the combustion chamber and the filter
chamber, and gas ports for supplying inflating gas into an airbag,
and wherein the combustion chamber and the filter chamber are
arranged in parallel in the longitudinal direction with the
partition being interposed therebetween.
[0017] According to this structure, the inflator can be made to be
short in the longitudinal direction and thin in the thickness so
that the inflator can be suitably used in such a case to be housed
in a limited space such as an A-pillar, a B-pillar, a C-pillar, and
a space behind a garnish. By arranging the combustion chamber and
the filter chamber to be offset in parallel or making the filter
chamber longer than the combustion chamber in the longitudinal
direction, the projecting portion of the filter chamber can be
effectively used as a connecting portion with the airbag. Ends of
the projecting portion can be provided with gas ports.
[0018] An airbag device of the present invention is characterized
by comprising an airbag which can be connected to the connecting
portion of the aforementioned inflator. According to this
structure, a curtain airbag device or a side impact airbag device
can be obtained which has excellent rising characteristics of the
inner pressure of the airbag.
[0019] In another alternative embodiment, the inflator of the
present invention is characterized in that the filter chamber has
projecting portions on both ends thereof in the longitudinal
direction so that the filter chamber is longer than the combustion
chamber, and further has connecting portions formed on the ends of
the projecting portions which can be connected to the airbag.
According to this structure, since gas can be supplied to the
airbag through gas ports facing in directions opposite to each
other, the deployment of the airbag can be started at two locations
at the same time, thus speeding up the deployment of the airbag. It
is effective for deploying an airbag having a wide areas such as a
curtain airbag. An airbag device of the present invention may
include an airbag which can be connected to the connecting portions
of the aforementioned inflator.
[0020] According to this structure, a curtain airbag device can be
obtained which has excellent rising characteristics of the inner
pressure of the airbag. Since gas spouted out in the opposite
directions can be effectively introduced into the airbag at the
same time i.e. bidirectional gas can be supplied simultaneously
into the airbag, the gas can quickly fill the entire airbag, thus
speeding up the deployment of the airbag.
[0021] In yet another alternative embodiment, the inflator of the
present invention is characterized in that the filter chamber and
the combustion chamber are arranged to be offset from each other in
the longitudinal direction with the partition being interposed
therebetween so that the filter chamber and the combustion chamber
project in the opposite directions to each other, and further has a
connecting portion formed on the end of the projecting portion of
the filter chamber. According to this structure, when this inflator
is used for a curtain airbag, for example, the inflator has
advantages that it can be made shorter than a conventional inflator
and that the projecting portion can be used as a connecting portion
with the airbag. It is especially advantageous in a case that the
inflator is connected to the curtain airbag around the A-pillar,
the B-pillar, or the C-pillar.
[0022] An airbag device of the present invention includes an airbag
which can be connected to the connecting portion of the
aforementioned inflator. According to this structure, a curtain
airbag device can be obtained which has excellent rising
characteristics of the inner pressure of the airbag and of which
inflator can be housed in a long curved limited space such as a
A-pillar and a C-pillar.
[0023] In an alternative embodiment, an inflator of the present
invention may comprise: a propellant, an igniter for igniting the
propellant, a combustion chamber in which the propellant is burned,
a filter chamber in which a filter is positioned, a partition
separating the combustion chamber and the filter chamber,
communication orifices formed in the partition for allowing
communication between the combustion chamber and the filter
chamber, and gas ports for supplying inflating gas into an airbag,
and is characterized in that the filter is substantially formed in
a thick disk-like configuration wherein one surface of the filter
is arranged adjacent to the combustion chamber via the
partition.
[0024] According to this structure, since the gas ports can be
formed in the top surface in addition to the side surface of the
inflator, the airbag can be controlled to be deployed in a desired
condition (for instance, a front portion of the airbag is deployed
prior to the other portion). It is especially advantageous in a
case that the inflator is used for a driver airbag. An airbag
device of the present invention may include an airbag connected to
the aforementioned inflator. According to this structure, a driver
airbag device can be obtained which has excellent rising
characteristics of the inner pressure of the airbag. Since the gas
ports can be formed in the top surface in addition to the side
surface of the inflator, a driver airbag device can be obtained in
which a front portion of the airbag can be initially deployed by
gas spouted out through the gas ports of the top surface so that it
is suitable for early restraint.
[0025] In yet another alternative embodiment, an inflator of the
present invention may comprise: a propellant, an igniter for
igniting the propellant, a combustion chamber in which the
propellant is burned, a filter chamber in which a filter is
positioned, a partition separating the combustion chamber and the
filter chamber, communication orifices formed in the partition for
allowing the communication between the combustion chamber and the
filter chamber, and gas ports for supplying inflating gas into an
airbag, and is characterized in that the filter is substantially
formed in a hollow cylindrical configuration and the combustion
chamber is formed in the hollow portion of the filter via the
partition.
[0026] According to this structure, this inflator can be employed
as an inflator for a front passenger airbag. Therefore, an inflator
for a front passenger airbag can be obtained which can provide
excellent rising characteristics of inner pressure of the airbag.
In case that the inflator is used for a front passenger airbag, the
gas ports can be positioned at any places in a wide side surface
and portions of ends of the cylindrical portion, thereby increasing
the degree of freedom of design for positioning gas ports.
[0027] An airbag device of the present invention may include an
airbag connected to the aforementioned inflator.
[0028] According to this structure, a front passenger airbag device
can be obtained which has excellent rising characteristics of the
inner pressure of the airbag. The airbag device is suitable for a
curtain airbag, a side impact airbag, a front-passenger airbag, or
a driver airbag, of which profile is compact, which has an
increased degree of freedom of design for positioning a gas port
and setting the flow of gas.
[0029] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only, and are not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] 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.
[0031] FIGS. 1(A)-1(C) show the structure of a first embodiment of
an inflator according to the present invention wherein FIG. 1 (A)
is an exploded perspective view, FIG. 1 (B) is a perspective
sectional view taken along A-A of FIG. (A), and FIG. 1 (C) is a
partially enlarged view of a range circled in FIG. 1 (B).
[0032] FIG. 2 is a view showing a second embodiment of the inflator
according to the present invention.
[0033] FIG. 3 is a view showing a third embodiment of the inflator
according to the present invention.
[0034] FIGS. 4(A), 4(B) show a fourth embodiment of the inflator
according to the present invention wherein FIG. 4(A) is a sectional
view taken along B-B of FIG. 4(B) and FIG. 4(B) is a perspective
view showing the contour of the inflator of this embodiment.
[0035] FIGS. 5(A), 5(B) show a fifth embodiment of the inflator
according to the present invention wherein FIG. 5(A) is a
perspective view showing the contour of the inflator of this
embodiment for use of a front passenger airbag and FIG. 5(B) is a
sectional view taken along C-C of FIG. 5 (A).
DETAILED DESCRIPTION
[0036] Hereinafter, embodiments of the present invention will be
described with reference to the attached drawings. It should be
understood that the sizes, shapes, positional relation of
respective components are schematically shown just for
understanding the invention and that the numerical conditions
stated in the following are just illustrative examples.
[0037] FIGS. 1(A)-1(C) show the structure of a first embodiment of
an inflator according to the present invention wherein FIG. 1 (A)
is an exploded perspective view, FIG. 1 (B) is a perspective
sectional view taken along A-A of FIG. 1 (A), and FIG. 1 (C) is a
partially enlarged view of a range circled in FIG. 1 (B).
[0038] An inflator 100 of this embodiment is of a type for use of a
curtain airbag and is formed in a thin box-like configuration. The
inflator may include the following components:
[0039] 1) a body 1 composing a casing of the inflator 100;
[0040] 2) a propellant combustion chamber 1 a formed inside the
body 1;
[0041] 3) a propellant opening 1d formed in one side surface of the
body 1 to be connected to the propellant combustion chamber 1a;
[0042] 4) a filter chamber 1b formed inside the body 1;
[0043] 5) a filter opening 1e formed in the side surface of the
body to be connected to the filter chamber 1b;
[0044] 6) a partition 1f for separating the propellant combustion
chamber 1a and the filter chamber 1b from each other;
[0045] 7) a plurality of first orifices formed in the partition 1f
to allow the communication between the propellant combustion
chamber 1 a and the filter chamber 1b;
[0046] 8) first shims 11 for air-tightly closing the first orifices
10, respectively;
[0047] 9) a booster 2 in which booster propellant 5 is filled and
which is sealed by an initiator 3;
[0048] 10) propellant 4 disposed in the propellant combustion
chamber ia;
[0049] 11) a filter 6 disposed in the filter chamber 1b;
[0050] 12) a plurality of second orifices 7 formed in one side
surface of the body 1;
[0051] 13) second shims 11 a for air-tightly closing the openings
of the second orifices 7;
[0052] 14) a fixing ring 8 to be threaded in the propellant opening
1b for sealing and fixing the propellant 4 and the booster 2;
and
[0053] 15) a cap 9 for covering the filter opening 1e in which the
filter 6 is inserted.
[0054] The detail of the inflator of this embodiment will now be
described with reference to FIGS. 1(A)-1(C).
[0055] The body 1 is made by molding the contour of the body 1,
drilling or forming the propellant combustion chamber 1a and the
filter chamber 1b, drilling or forming the first orifices 10 in the
partition 1f from through an outside wall of the body 1 and the
propellant combustion chamber 1a wherein drilled holes in the
outside wall of the body 1 should be filled by filler, and drilling
or forming the second orifices 7 in another outside wall of the
body 1. The closing mechanism may include first shims 11 (see FIG.
1(C)) for air-tightly closing the first orifices 10 are breakable
members as closing mechanism or means, e.g. aluminum films. The
first shims 11 are attached to the openings of the first orifices
10 by, for example, heat-resisting adhesives. The strength and the
thickness of the first shims 11 are selected that the first shims
11 break at a time when the combustion pressure in the propellant
combustion chamber 1a reaches a predetermined pressure. Ideally,
the predetermined pressure in this case is the maximum combustion
pressure of the propellant. However, since the maximum combustion
pressure may vary due to individual differences of the propellant
and the strength of the aluminum films may also vary due to
individual differences of the aluminum films, the predetermined
pressure should be set slightly lower than the maximum combustion
pressure. It should be noted that the closing mechanism are not
limited to the breakable members and may be any mechanism, means or
device capable of opening the orifices according to the
predetermined pressure. For example, electric opening mechanism
which senses the predetermined pressure by a sensor and opens the
first orifices 10 may be employed as the closing mechanism. The
breakable members may include shims and may be made of other metal
such as copper and iron besides aluminum which can be broken at the
predetermined pressure.
[0056] The second shims 11a air-tightly closing the second orifices
7 are for example aluminum films and are attached to the openings
of the second orifices 7 by for example heat-resisting adhesives.
Since the main purpose of the second shims 7 is to seal the second
orifices 7 for preventing water and/or foreign matters from
entering into the filter chamber 1b, the strength and the thickness
of the second shims 11a are set in such a manner that the second
shims 11 are broken at such slight combustion pressure as not to
delay the timing of inflating gas sporting through the second
orifices 7.
[0057] Disposed at a lower end of the initiator 3 is a terminal 3a
which is connected to an airbag harness not shown.
[0058] Hereinafter, the actions of the inflator of this embodiment
will be described. As the terminal 3a receives an ignition signal
of the airbag at the event of a vehicle collision, the initiator 3
is triggered to ignite the propellant 5 so that high-temperature
gas spouts out of orifices 2a formed in the booster 2 into the
propellant combustion chamber 1a. Accordingly, the propellant 4 in
the propellant combustion chamber 1a is ignited to generate gas for
inflating the airbag. Since the first orifices 10 are closed by the
first shims 11, the inflating gas is prevented from flowing out of
the propellant combustion chamber 1a so that the pressure in the
propellant combustion chamber 1a is risen earlier as compared to
the conventional one. As the pressure in the propellant combustion
chamber 1a reaches the predetermined pressure (preferably, slightly
lower than the maximum combustion pressure, and most preferably a
value around the lower limit of a variation range of the maximum
combustion pressure), the first shims 11 are broken so that the
inflating gas spouts into the filter chamber 1b through the first
orifices 10. The second shims 11a are immediately broken so that
the inflating gas spouts into the airbag through the second
orifices 7. In this case, since the second shims 11a can be broken
at slight combustion pressure, the second shims 11a block little
the spout of the inflating gas.
[0059] Since the actions of other embodiments are the same as those
of this embodiment, the description about the actions of the other
embodiment can be understood as discussed above. In addition, the
description of parts similar or corresponding to the parts of this
embodiment applies to the embodiments discussed below.
[0060] FIG. 2 is a view showing a second embodiment of the inflator
according to the present invention, illustrating a case where the
inflator of this embodiment is connected to a central portion
(B-pillar) of a curtain airbag.
[0061] An inflator 100 of this embodiment is of a type for use of a
curtain airbag. The inflator 100 of this embodiment is different
from that of the first embodiment because the portion of the body 1
covering the filter chamber 1b projects in the right and left
directions to be longer than the portion of the body 1 covering the
propellant combustion chamber 1a. In addition, the second orifices
7 are formed in the ends of two projecting portions. Both ends of
the filter chamber 1b are extended in the longitudinal direction
such that the both ends project from the propellant combustion
chamber 1a to form cylindrical projecting portions 1g. The second
orifices 7 are formed in the ends of the projecting portions 1g.
The projecting portions 1g are inserted into connecting portions
13a of a curtain airbag 13 as shown in FIG. 2 and are fastened by
bands 12 to provide an air-tight connection.
[0062] According to this structure of the inflator, the length of
the inflator can be shortened in the longitudinal direction and the
thickness of the inflator can also be reduced. Therefore, the
inflator 100 can be connected to the airbag 13 structured as shown
in FIG. 2 around the B-pillar and can be compactly accommodated
behind a garnish around the B-pillar. Gas spouts are provided to
inflate the airbag 13 through the two connecting portions 13a,
thereby efficiently deploying the airbag 13 and thus speeding up
the initial deployment of the airbag.
[0063] FIG. 3 is a view showing a third embodiment of the inflator
according to the present invention, illustrating a case that the
inflator of this embodiment is connected to a curtain airbag around
a A-pillar or a C-pillar.
[0064] An inflator 100 of this embodiment is of a type for use of a
curtain airbag. The inflator 100 of this embodiment is different
from that of the first embodiment because the portion of the body 1
covering the propellant combustion chamber 1a and the portion of
the body 1 covering the filter chamber 1b are arranged to be offset
from each other in the longitudinal direction as shown in FIG. 3.
An end portion (projecting portion 1g in FIG. 3) of the range
covering the filter chamber 1b is formed in a cylindrical
configuration to have such a size as to be connected to a pipe 14
of the airbag 13, and the second orifices 7 are formed in the end
thereof.
[0065] As structured above, the length and the width of the
inflator can be adjusted to desired values just by changing the
shifting length.
[0066] According the structure of the inflator, for example in a
case shown in FIG. 3, the length and the width of the inflator can
be freely set to have such a size and configuration as to be
accommodated in the A-pillar or the C-pillar.
[0067] FIGS. 4(A), 4(B) show a fourth embodiment of the inflator
according to the present invention wherein FIG. 4(A) is a sectional
view taken along B-B of FIG. 4(B) and FIG. 4(B) is a perspective
view showing the contour of the inflator of this embodiment.
[0068] An inflator 100 of this embodiment is of a type for use of a
driver airbag. In this embodiment, a body 1 comprises an upper body
1k defining the filter chamber 1b and a lower body 1j defining a
propellant combustion chamber 1a which are structured to be fitted
to each other as shown in FIG. 4(A). As shown in FIG. 4(B), second
orifices 7 are formed in a side surface 1kb and a top surface 1ka
of the upper body 1k as shown in FIG. 4(B). Each second shim 11a is
air-tightly attached to each of the second orifices 7 from the
inside. A thick disk-like filter 6 is disposed inside of the upper
body 1k for covering the inside of the upper body 1 and a disk-like
partition 1f is air-tightly fixed by welding to close the upper
body 1k. The partition 1f is formed with first orifices 10. All of
openings of the first orifices 10 facing the lower body 1j are
air-tightly closed with first shims 11. The lower body 1j is formed
with a hole 1jc at a central portion thereof for the attachment of
a booster 2. The booster 2 is fixed to the hole 1jc by welding to
provide an air-tight connection. Inside the booster 2, a booster
propellant 5 and an initiator 3 are disposed. Further, a propellant
4 is disposed inside the lower body 1j to surround the booster 2.
The upper body 1k and the lower body 1j structured as described
above are fitted and connected to each other air-tightly by
welding. The other details of the structure are substantially
similar those of the first embodiment.
[0069] According to the structure of the inflator, the second
orifices 7 can be formed freely at any places of the side surface
1kb and the top surface 1ka of the upper body 1k. Therefore, for
example, it can be possible to form the gas ports in the top
surface 1ka as shown in FIG. 4(B) that was impossible in prior art,
thereby increasing the degree of freedom of design for positioning
the second orifices 7.
[0070] FIGS. 5(A), 5(B) show a fifth embodiment of the inflator
according to the present invention wherein FIG. 5(A) is a
perspective view showing the contour of the inflator of this
embodiment for use of a front passenger airbag and FIG. 5(B) is a
sectional view taken along C-C of FIG. 5 (A).
[0071] An inflator 100 of this embodiment comprises, as shown in
FIG. 5(B), a cylindrical body 1 of which one end is open and the
other end is closed. A partition 1f is provided for separating the
inside of the body 1 into a filter chamber 1b and a propellant
combustion chamber 1a, a tubular filter 6 having such a size as to
be just fitted to the filter chamber 1b is fitted into the filter
chamber 1b. A propellant 4 is stored in the propellant combustion
chamber 1a. A booster 2 is disposed to seal the propellant
combustion chamber 1a. A lid 20 is provided for air-tightly sealing
the filter chamber 1b and fixing the booster 2. The partition 1f is
formed with first orifices 1 0 of which openings are attached with
and airtightly closed by first shims 11 from the inside. The side
surface of the cylindrical body 1 is formed with second orifices 7
of which openings are attached and air-tightly closed by second
shims 11a from the inside. Inside of the booster 2, a booster
propellant 5 and an initiator 3 are airtightly accommodated. The
other details of the structure are the same as those of the fourth
embodiment.
[0072] According to the aforementioned structure of the inflator,
the second orifices 7 can be formed freely at any places of the
side surface of the inflator 100 for the use of the front passenger
airbag, thereby increasing the degree of freedom of design for
positioning the second orifices 7.
[0073] It should be understood that the present invention is not
limited to the aforementioned embodiments and can be applied to
another inflator for a side impact airbag, a knee-protecting
airbag, or a foot-protecting airbag.
[0074] Though the embodiments are described by using the inflator
having one filter and one combustion chamber, the present invention
is not limited thereto and the inflator may have a plurality of
filters and/or a plurality of combustion chambers.
[0075] As described above, the airbag device of the present
invention has an inflator which is provided with a closing
mechansim at communication orifices of a partition separating a
combustion chamber and a filter chamber which can be broken at a
predetermined pressure and air-tightly close the communication
orifices until the pressure reaches the predetermined pressure so
that the gas pressure in the combustion chamber is risen quickly
and the combustion in the combustion chamber is speeded up, thereby
shortening the starting timing of rising the inner pressure of an
airbag and shortening the time period required from the start of
rising of the inner pressure until the inner pressure reaches the
maximum value. Therefore, the present invention can provide an
airbag device having excellent rising characteristics of the inner
pressure of the airbag, i.e. excellent initial restraining
capability.
[0076] Since a filter is disposed to cover an inner surface not
facing the partition of the filter chamber, an area covered by the
filter is increased, thereby increasing the degree of freedom of
design for positioning gas ports.
[0077] Since the combustion chamber and the filter chamber are
arranged in parallel in the longitudinal direction with the
partition being interposed therebetween, the inflator can be made
to be short in the longitudinal direction and thin in the
thickness. Therefore, the present invention can provide an airbag
device comprising an inflator having an increased degree of freedom
of design for easily changing its profile to be suitable for any
housing space.
[0078] 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.
* * * * *