U.S. patent application number 09/725893 was filed with the patent office on 2001-06-14 for air bag and air bag device.
This patent application is currently assigned to TAKATA CORPORATION. Invention is credited to Ariyoshi, Katsuhiro.
Application Number | 20010003395 09/725893 |
Document ID | / |
Family ID | 18401717 |
Filed Date | 2001-06-14 |
United States Patent
Application |
20010003395 |
Kind Code |
A1 |
Ariyoshi, Katsuhiro |
June 14, 2001 |
Air bag and air bag device
Abstract
An air bag is formed of a panel portion with a gas introducing
port, a partition wall situated inside the panel portion for
partitioning an inside of the panel portion into a first chamber
located on a front side of an automobile and a second chamber
located on a rear side of the automobile, a gas passage situated
between the first chamber and the second chamber, and at least one
vent hole formed in the panel portion at the second chamber. An air
bag device includes, in addition to the air bag, a retainer for
retaining the air bag, an inflator for expanding the air bag, and a
lid for covering the retainer. In case a collision speed is small
or the passenger is relatively small, the passenger can be received
by the air bag with a soft touch. In case the collision speed is
large or the passenger is large, the passenger can be securely
received by the first and second chambers.
Inventors: |
Ariyoshi, Katsuhiro; (Tokyo,
JP) |
Correspondence
Address: |
KANESAKA AND TAKEUCHI
1423 Powhatan Street
Alexandria
VA
22314
US
|
Assignee: |
TAKATA CORPORATION
|
Family ID: |
18401717 |
Appl. No.: |
09/725893 |
Filed: |
November 30, 2000 |
Current U.S.
Class: |
280/729 ;
280/728.2 |
Current CPC
Class: |
B60R 21/233 20130101;
B60R 2021/23324 20130101; B60R 21/239 20130101 |
Class at
Publication: |
280/729 ;
280/728.2 |
International
Class: |
B60R 021/24; B60R
021/20 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 1999 |
JP |
11-349131 |
Claims
What is claimed is:
1. An air bag comprising: an air bag panel portion with a gas
introducing port, a partition wall situated inside the panel
portion for partitioning an inside of the panel portion into a
first chamber located on a front side of an automobile and having
the gas introducing port, and a second chamber located on a rear
side of the automobile, a gas passage situated between the first
chamber and the second chamber, and at least one vent hole formed
in the panel portion at the second chamber.
2. An air bag according to claim 1, further comprising a
reverse-flow preventing device situated between the first and
second chambers for allowing a gas to flow from the first chamber
to the second chamber and preventing the gas from flowing from the
second chamber to the first chamber.
3. An air bag according to claim 2, wherein said reverse-flow
preventing device is a valve made of a sheet, and has a hole in the
sheet overlapping the vent hole of the panel portion,
circumferential portions of the hole and the vent hole being sewed
together.
4. An air bag according to claim 1, wherein said gas passage is
provided on only a lower surface side of the panel portion, or on
only the lower surface side and two lateral sides of the panel
portion.
5. An air bag according to claim 1, wherein said second chamber has
a capacity greater than that of the first chamber.
6. An air bag according to claim 2, wherein said partition wall is
a flexible sheet having a main portion for separating the first and
second chambers, and a plurality of flaps extending from the main
portion, at least one of the flaps extending toward the second
chamber to form the reverse-flow preventing device between the flap
and a part of the panel portion situated adjacent thereto.
7. An air bag according to claim 6, wherein said flexible sheet has
upper, lower and two side flap portions, said upper flap portion
being fixed to the panel portion, and two side flap portions being
at least partly fixed to the panel portion.
8. An air bag according to claim 7, wherein said at least one vent
hole is formed in the side flap portion and the panel portion to
penetrate therethrough, said side flap and the panel portion being
fixed together around the at least one vent hole.
9. An air bag according to claim 8, wherein said lower flap portion
is disposed over the panel portion without being fixed thereto.
10. An air bag device comprising the air bag according to claim 1
and an inflator for supplying a gas into the air bag to expand the
same.
Description
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
[0001] The invention relates to an air bag for protecting a
passenger in a vehicle, such as an automobile, at an emergency
time, i.e. a collision, and an air bag device including the air
bag. More particularly, it relates to an air bag having a plurality
of chambers therein, and an air bag device thereof.
[0002] An air bag device, as well known, is a device for expanding
an air bag for receiving a passenger therewith at a collision time
of an automobile or the like. The air bag is provided with a vent
hole, and when the passenger hits the expanded air bag very hard, a
gas in the air bag gradually flows out through the vent hole to
absorb an impact.
[0003] In case an automobile speed and a physical structure of a
passenger are different, a kinetic energy to a forward direction of
the passenger is also varied. Thus, an air bag device satisfying
the following items (1) and (2) is ideal.
[0004] (1) In case the kinetic energy to the forward direction of
the passenger is large, it is preferable that a bag resistance is
made large, and energy absorbing stroke and time are made long;
and
[0005] (2) In case the kinetic energy to the forward direction of
the passenger is relatively small, it is necessary to expand a bag
to provide a small resistance against the passenger.
[0006] Japanese Utility Model Publication (KOKAI) No. 2-132555
discloses an air bag device, wherein an air bag is partitioned into
two chambers separated in the vertical direction, a gas is
introduced into an upper chamber through a lower chamber, and vent
holes are provided to the upper side chamber. In the air bag
device, at a time of collision of an automobile, first, a chest
portion of the passenger is received by a first chamber having a
high inner pressure, and then, a head portion of the passenger is
received by a second chamber having a weak inner pressure. The air
bag can not attain the above items (1) and (2).
[0007] It is an object of the invention to provide an air bag
device, wherein when a passenger hits an air bag at a relatively
low speed, the passenger is received by the air bag with a
relatively soft touch, and in case the passenger hits the air bag
at a relatively high speed, the passenger is securely received by
the air bag at two stages.
[0008] Further objects and advantages of the invention will be
apparent from the following description of the invention.
SUMMARY OF THE INVENTION
[0009] In the present invention, an air bag includes a gas
introducing port, a partition wall for partitioning the air bag
into a first chamber having the gas introducing port and disposed
on a forward side of an automobile and a second chamber disposed on
a rear side thereof, a gas passage for communicating between the
first chamber and the second chamber, and a vent hole disposed at
the second chamber. An air bag device includes, in addition to the
air bag, a gas generator for supplying gas to the air bag.
[0010] In the air bag as described above, when the gas generator is
operated at a time of collision of the automobile or the like,
first, the first chamber expands, and then the second chamber is
expanded by the gas passing through the gas passage. In case the
passenger hits the expanded air bag, the gas gradually flows out
through the vent hole from the second chamber, so that an impact
energy is absorbed and the passenger is received by the second
chamber with a relatively soft touch. Thus, when the passenger hits
the air bag with a small speed, the passenger can be sufficiently
received with only a gas flow-out from the second chamber.
[0011] In case the passenger hits the air bag with a high speed, a
body of the passenger also presses the first chamber from the
second chamber side through the partition wall. The gas in the
first chamber flows into the second chamber through the gas passage
and flows out through the vent hole. Since a gas flow-out
resistance at this time is large, the passenger can be securely
received by the first chamber. Of course, since the gas in the
first chamber is drawn into the second chamber, the impact energy
of the passenger is absorbed.
[0012] As described above, since the air bag is partitioned into
the first and second chambers, the passenger can be received with
different impact absorbing characteristics at two stages.
Incidentally, the air bag may be partitioned into first, second and
third chambers or more than that.
[0013] In the present invention, it is preferable to provide a gas
reverse-flow preventing device for preventing the gas from
reversely flowing from the second chamber to the first chamber.
With the gas reverse-flow preventing device, in case the second
chamber is pressed by the passenger, a gas-reverse flow from the
second chamber to the first chamber can be prevented, and a gas
flow quantity for flowing out from the second chamber through the
vent hole can be rationalized to thereby properly absorb the impact
energy of the passenger.
[0014] The gas reverse-flow preventing device is a valve formed of
a sheet. The vent hole penetrates through the sheet constituting
the valve. A circumference of the vent hole provided on the sheet
may be united to the air bag. Thus, when the gas in the first
chamber flows out from the vent hole through the second chamber, a
flow resistance becomes large and the passenger can be sufficiently
received by the first chamber.
[0015] In the present invention, it is preferable that the gas
passage is disposed only on an under surface side of the air bag,
or on both sides and the under surface side of the air bag. Thus,
when the gas flows into the second chamber from the first chamber,
the gas mainly enters a lower side of the second chamber to thereby
start expanding the second chamber from the lower side. As a
result, a passenger facing surface of the air bag expands to
approach the passenger from the lower side thereof.
[0016] In the present invention, it is preferable that the capacity
of the second chamber is larger than that of the first chamber, so
that most part of the impact is absorbed by the second chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of an air bag according to the
present invention;
[0018] FIG. 2 is a seeing-through inner perspective view of the air
bag of the invention;
[0019] FIG. 3 is a sectional view taken along line 3-3 in FIG.
1;
[0020] FIG. 4 is a sectional view taken along line 4-4 in FIG.
3;
[0021] FIG. 5 is a sectional view taken along line 5-5 in FIG.
3;
[0022] FIG. 6 is a sectional view taken along line 6-6 in FIG. 3;
and
[0023] FIG. 7 to FIG. 12 are explanatory views for explaining an
air bag expanding operation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] Hereunder, with reference to the accompanying drawings, an
embodiment of an air bag according to the present invention is
explained. FIG. 1 is a perspective view of an embodiment of an air
bag for a front passenger seat according to the invention; FIG. 2
is a seeing-through inner perspective view of the air bag for the
front passenger seat according to the invention; FIG. 3 is a
sectional view taken along line 3-3 in FIG. 1; FIG. 4 to FIG. 6 are
sectional views taken along lines 4-4 to 6-6 in FIG. 3; and FIG. 7
to FIG. 12 are explanatory views of air bag expanding
operations.
[0025] The air bag device includes a retainer 1 having a container
shape, a front surface of which is open; an air bag 2 housed in the
retainer 1; an inflator, i.e. gas generator, 3 for expanding the
air bag 2; and a lid, not shown, for covering the front surface of
the retainer 1. An edge portion of a gas introducing port 4 of the
air bag 2 is attached to the retainer 1.
[0026] The air bag 2 has an outer or panel portion structured by a
pair of side panels 5, and a front panel 6 formed of an upper
surface, a passenger facing surface and a lower surface of the air
bag 2 and surrounding outer circumferences of the side panels 5.
The air bag 2 has a gas introduction port 4 at an end portion
thereof.
[0027] The air bag 2 is divided into a first chamber 11 on a side
of gas introducing port 4 and a second chamber 12 on a side facing
a passenger by a partition wall 10 formed of a cloth or sheet
extending in a vertical direction.
[0028] An entire upper side or flap of the partition wall 10 is
sewed together with an upper surface of the air bag 2. Between the
air bag 2 and both sides of the partition wall 10 and between the
air bag 2 and a lower side of the partition wall 10, there are
provided gas passages 13, 14, 15 communicating the first chamber 11
with the second chamber 12.
[0029] To prevent the reverse flow of the gas having passed through
the gas passages 13, 14, 15, there are provided check valves 16,
17, 18 made of cloths or flaps. Base end sides of the respective
check valves 16, 17, 18 are connected to the partition wall 10, and
free end sides thereof extend into the second chamber 12.
[0030] The check valves 16, 17 on the both sides of the partition
wall 10 face both side panels 5, respectively, and vent holes 19
are provided to pass through the check valves 16, 17 and the both
side panels 5, respectively. The check valves 16, 17 are sewed
together with the side panels 5 at circumferential portions of the
respective vent holes 19 in a circular shape.
[0031] Incidentally, the partition wall 10 is disposed at a portion
relatively close to the gas introducing port 4 so that even if the
passenger hits the air bag very hard, the passenger does not
substantially contact the partition wall 10. A capacity of the
second chamber is larger than that of the first chamber.
[0032] Operations of the air bag device with the air bag thus
structured are explained with reference to FIGS. 7 to 12.
Incidentally, in order to make the drawings easily understandable,
in FIGS. 7-12, the vent holes 19 are disposed away from the check
valves 16, 17.
[0033] When a collision of an automobile is detected, the inflator
3 starts to eject a gas. The gas, as shown in FIG. 7, first expands
the first chamber 11, and then expands the second chamber 12
through the gas passages 13, 14, 15 as shown in FIG. 8. At this
time, the check valves 16, 17, 18 allow the gas to flow into the
second chamber 12 through the gas passages 13, 14, 15.
[0034] When a pressure in the second chamber 12 becomes a positive
or appropriate pressure, as shown in FIG. 9, the check valves 16-18
are closed by the pressure.
[0035] As shown in FIG. 10, in case the passenger hits the expanded
air bag 2, first, the gas in the second chamber 12 flows out
through the vent holes 19, and an impact energy is absorbed.
Although the pressure in the second chamber 12 is raised because of
the passenger hitting the air bag, the check valves 16 to 18 remain
closed, so that the reverse flow of the gas from the second chamber
12 to the first chamber 11 is prevented. The gas in the second
chamber 12 flows outside the air bag 2 solely through the vent
holes 19 to thereby absorb the impact energy of the passenger.
[0036] In case a collision speed of the automobile is small or the
passenger is relatively small, the passenger is stopped at a state
shown in FIG. 10 or right before a state shown in FIG. 11. During
this period, since the gas in the second chamber 12 relatively
easily flows out through the vent holes 19, the passenger is
received by the second chamber 12 with a relatively soft touch.
[0037] In case the collision speed of the automobile is relatively
large or the passenger is large, the passenger is further moved
forward from the state shown in FIG. 10, and abuts against the
partition wall 10, as shown in FIG. 11, to press the first chamber
11, too. Thus, an inner pressure in the first chamber 11 becomes
higher than an inner pressure in the second chamber 12 to thereby
open the check valves 16, 17, 18, so that the gas in the first
chamber 11 flows out from the vent holes 19 through the second
chamber 12. Thus, the impact energy of the passenger is further
absorbed. Incidentally, since the gas in the first chamber 11
passes through the narrow gas passages 13, 14, 15, and further
enters the check valves 16, 17, 18 to reach the vent holes 19, an
exhausting speed of the gas in the first chamber 11 is smaller than
that of the gas in the second chamber 12 as shown in FIG. 10.
Therefore, the speed for crushing the first chamber 11 is small to
thereby positively receive the passenger thereat.
[0038] As described hereinabove, according to the air bag, the
impact energy of the passenger can be sufficiently absorbed. Also,
in case the collision speed is small or the passenger is relatively
small, the passenger can be softly received by the air bag. Also,
in case the collision speed is large or the passenger is large, the
passenger can be securely received by the air bag.
[0039] In the present embodiment, the gas passages 13, 14, 15 are
disposed on both sides and the lower surface side of the air bag 2,
the lower side of the second chamber 12 starts expanding first, and
a forward edge surface, i.e. passenger facing surface, of the air
bag 2 expands in an inclined state. Incidentally, the gas passage
may be provided only at the lower surface of the air bag 2.
[0040] In the present embodiment, since the vent holes 19 are
provided to the check valves 16, 17, the exhausting speed of the
gas from the first chamber 11 can be sufficiently made small. Also,
since the check valves 16, 17 are sewed together with the side
panels 5 around the vent holes 19, the check valves 16, 17 are
positively positioned on the sides of the second chamber 12.
[0041] The air bag and the air bag device of the above embodiment
are for the front passenger seat. However, the present invention
can be also applied to a driver's seat air bag and rear seat air
bags.
[0042] As described above, according to the present invention, the
passenger can be received at plural stages with different impact
absorbing characteristics. The impact energy of the passenger can
be sufficiently absorbed. Also, in case the collision speed is
small or the passenger is relatively small, the passenger can be
softly received by the air bag. Further, in case the collision
speed is large or the passenger is large, the passenger can be
securely received at two stages.
[0043] While the invention has been explained with reference to the
specific embodiments of the invention, the explanation is
illustrative and the invention is limited only by the appended
claims.
* * * * *