U.S. patent application number 10/382642 was filed with the patent office on 2003-09-11 for side airbag apparatus.
Invention is credited to Koyama, Toru, Mabuchi, Satoshi, Naruse, Motoaki, Sato, Eiji, Tanase, Toshinori.
Application Number | 20030168836 10/382642 |
Document ID | / |
Family ID | 27767966 |
Filed Date | 2003-09-11 |
United States Patent
Application |
20030168836 |
Kind Code |
A1 |
Sato, Eiji ; et al. |
September 11, 2003 |
Side airbag apparatus
Abstract
A side airbag apparatus for vehicle has an airbag and an
inflator. An upper chamber, a lower chamber, and an intermediate
chamber are defined by a seam in the airbag. When the airbag is
deployed, the upper chamber corresponds to a shoulder of an
occupant, the lower chamber corresponds to a lumbar region of the
occupant, and the intermediate chamber corresponds to a thorax of
the occupant. The seam guides gas from the inflator to the upper
and lower chambers such that the upper and lower chambers are
substantially simultaneously inflated, and the intermediate chamber
is inflated after a delay. The thickness of the intermediate
chamber is less than the thicknesses of the upper and lower
chambers. As a result, the occupant of the vehicle is effectively
protected.
Inventors: |
Sato, Eiji; (Aichi-ken,
JP) ; Tanase, Toshinori; (Aichi-ken, JP) ;
Mabuchi, Satoshi; (Aichi-ken, JP) ; Koyama, Toru;
(Aichi-ken, JP) ; Naruse, Motoaki; (Aichi-ken,
JP) |
Correspondence
Address: |
POSZ & BETHARDS, PLC
11250 ROGER BACON DRIVE
SUITE 10
RESTON
VA
20190
US
|
Family ID: |
27767966 |
Appl. No.: |
10/382642 |
Filed: |
March 7, 2003 |
Current U.S.
Class: |
280/730.2 |
Current CPC
Class: |
B60R 21/23138 20130101;
B60R 21/235 20130101 |
Class at
Publication: |
280/730.2 |
International
Class: |
B60R 021/22 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 11, 2002 |
JP |
2002-065998 |
Mar 11, 2002 |
JP |
2002-065999 |
Jun 12, 2002 |
JP |
2002-171640 |
Jun 12, 2002 |
JP |
2002-171641 |
Jun 12, 2002 |
JP |
2002-171642 |
Jul 30, 2002 |
JP |
2002-220748 |
Claims
1. A side airbag apparatus used in a vehicle, comprising: an
airbag; an inflator, wherein the inflator supplies gas to the
airbag, thereby deploying the airbag between a body side portion of
the vehicle and a seat located in the passenger compartment of the
vehicle; an upper chamber and a lower chamber provided in the
airbag, wherein, when the airbag is deployed, the upper chamber is
located at a position that corresponds to a shoulder of an occupant
sitting on the seat and the lower chamber is located at a position
that corresponds to a lumbar region of the occupant; and a gas
guiding mechanism, wherein the gas guiding mechanism guides gas
from the inflator to the upper and lower chambers, thereby
substantially simultaneously inflating the upper and lower
chambers.
2. The side airbag apparatus according to claim 1, wherein the gas
guiding mechanism includes a seam that is formed by partially
sewing facing portions of the airbag to each other.
3. The side airbag apparatus according to claim 2, wherein the seam
defines the upper chamber and the lower chamber in the interior of
the airbag.
4. The side airbag apparatus according to claim 1, wherein the
airbag has an intermediate chamber between the upper chamber and
the lower chamber, wherein the intermediate chamber is located at a
position that corresponds to a thorax of the occupant, wherein the
gas guiding mechanism includes a gas introducing chamber into which
gas generated by the inflator is introduced, wherein the gas
guiding mechanism further includes at least one upper guiding hole,
at least one lower guiding hole, and at least one intermediate
guiding hole, wherein the upper, lower and intermediate guiding
holes correspond to the upper, lower and intermediate chambers,
respectively, and guide gas from the gas introducing chamber to the
corresponding chambers, respectively, and wherein the opening area
of the upper guiding hole and the opening area of the lower guiding
hole are each greater than the opening area of the intermediate
guiding hole.
5. The side airbag apparatus according to claim 1, wherein the gas
guiding mechanism includes an upper gas injection portion and a
lower gas injection portion provided in the inflator, and wherein
the upper and lower gas injection portions correspond to the upper
chamber and the lower chamber, respectively.
6. The side airbag apparatus according to claim 1, wherein the
airbag includes an upper airbag member having the upper chamber and
a lower airbag member having the lower chamber, wherein the airbag
members are independent from each other, and wherein the inflator
includes an upper inflator member corresponding to the upper airbag
member and a lower inflator member corresponding to the lower
airbag member.
7. The side airbag apparatus according to claim 1, wherein the
airbag has an intermediate portion located between the upper
chamber and the lower chamber, wherein the intermediate portion is
located at a position that corresponds to a thorax of the occupant,
and wherein, when the airbag is deployed, the thickness of the
intermediate portion is less than the thickness of the upper and
lower chambers in respect to a horizontal direction between the
occupant and the body side portion.
8. The side airbag apparatus according to claim 1, wherein the
airbag has an intermediate chamber located between the upper
chamber and the lower chamber, wherein the intermediate chamber is
located at a position that corresponds to a thorax of the occupant,
and wherein, when the airbag is deployed, bulging of the
intermediate chamber is limited such that the thickness of the
intermediate chamber is less than the thickness of the upper and
lower chambers in respect to a horizontal direction between the
occupant and the body side portion.
9. The airbag apparatus according to claim 1, wherein the airbag
has an intermediate chamber located between the upper chamber and
the lower chamber, wherein the intermediate chamber is located at a
position that corresponds to a thorax of the occupant, wherein the
side airbag apparatus further includes an internal pressure
adjusting mechanism to adjust the internal pressure of the
intermediate chamber to be lower than the internal pressures of the
upper and lower chambers when the airbag is deployed.
10. The side airbag apparatus according to claim 9, wherein
portions of the airbag that correspond to the upper chamber and the
lower chamber are configured to be less likely to leak gas than a
portion of the airbag that corresponds to the intermediate
chamber.
11. The side airbag apparatus according to claim 9, wherein the
internal pressure adjusting mechanism includes a vent hole formed
in a portion of the airbag that corresponds to the intermediate
chamber.
12. The side airbag apparatus according to claim 11, wherein the
location of the vent hole is determined such that the vent hole is
separated from the body side portion when the airbag is
deployed.
13. The side airbag apparatus according to claim 1, wherein the
airbag has an intermediate chamber located between the upper
chamber and the lower chamber, wherein the intermediate chamber is
located at a position that corresponds to a thorax of the occupant,
wherein the intermediate chamber has an opening communicated with
the upper and lower chambers, and wherein the opening is oriented
in a direction either toward or away from the inflator.
14. The side airbag apparatus according to claim 13, wherein a flow
guide is provided at the opening of the intermediate chamber, the
flow guide guiding gas toward the intermediate chamber.
15. The airbag apparatus according to claim 1, wherein the airbag
has an intermediate chamber located between the upper chamber and
the lower chamber, wherein the intermediate chamber is located at a
position that corresponds to a thorax of the occupant, wherein the
side airbag apparatus further includes a promoting mechanism,
wherein, when the inflator generates gas, the promoting mechanism
promotes inflation of the upper and lower chambers compared to
inflation of the intermediate chamber.
16. The airbag apparatus according to claim 1, wherein the airbag
has an intermediate chamber located between the upper chamber and
the lower chamber, wherein the intermediate chamber is located at a
position that corresponds to a thorax of the occupant, wherein the
side airbag apparatus further includes a delaying mechanism,
wherein, when the inflator generates gas, the delaying mechanism
delays inflation of the intermediate chamber compared to inflation
of the upper and lower chambers.
17. The side airbag apparatus according to claim 1, further
comprising a limiting mechanism, wherein, when the airbag is
deployed, the limiting mechanism partially limits inflation of the
airbag, thereby reducing the area of the airbag that contacts a
flank of the occupant.
18. The side airbag apparatus according to claim 17, wherein the
limiting mechanism includes a seam that is formed by partially
sewing facing portions of the airbag to each other.
19. The side airbag apparatus according to claim 18, wherein the
seam includes a vertical seam portion that extends perpendicular to
ribs of the occupant when the airbag is deployed.
20. The side airbag apparatus according to claim 19, wherein the
seam includes a lateral seam portion that extends perpendicular to
the vertical seam portion.
21. A side airbag apparatus used in a vehicle, comprising: an
airbag; an inflator, wherein the inflator supplies gas to the
airbag, thereby deploying the airbag between a body side portion of
the vehicle and a seat located in the passenger compartment of the
vehicle; an upper deploying portion, a lower deploying portion, and
an intermediate portion provided in the airbag, wherein, when the
airbag is deployed, the upper deploying portion is located at a
position that corresponds to a shoulder of an occupant sitting on
the seat, the lower deploying portion is located at a position that
corresponds to a lumbar region of the occupant, and the
intermediate portion is located at a position that corresponds to a
thorax of the occupant; and a limiting mechanism, wherein, when the
airbag is deployed, the limiting mechanism limits bulging of the
intermediate portion such that the thickness of the intermediate
portion is less than the thickness of the upper and lower deploying
portions in respect to a horizontal direction between the occupant
and the body side portion.
22. The side airbag apparatus according to claim 21, wherein the
limiting mechanism includes a seam that is formed by partially
sewing facing portions of the airbag to each other.
23. The side airbag apparatus according to claim 21, wherein the
limiting mechanism includes a constriction portion formed in a part
of the airbag that corresponds to the intermediate portion.
24. The side airbag apparatus according to claim 23, wherein the
portion of the airbag that corresponds to the constriction portion
is formed of a material that has a less stretchability compared to
materials of which the upper and lower deploying portions are
formed.
25. A side airbag apparatus used in a vehicle, comprising: an
airbag; an inflator, wherein the inflator supplies gas to the
airbag, thereby deploying the airbag between a body side portion of
the vehicle and a seat located in the passenger compartment of the
vehicle; an upper chamber, a lower chamber, and an intermediate
chamber provided in the airbag, wherein, when the airbag is
deployed, the upper chamber is located at a position that
corresponds to a shoulder of an occupant sitting on the seat, the
lower chamber is located at a position that corresponds to a lumbar
region of the occupant, and the intermediate chamber is located at
a position that corresponds to a thorax of the occupant; and a
promoting mechanism, wherein, when the inflator generates gas, the
promoting mechanism promotes inflation of the upper and lower
chambers compared to inflation of the intermediate chamber.
26. The side airbag apparatus according to claim 25, wherein the
promoting mechanism includes a seam that is formed by partially
sewing facing portions of the airbag to each other.
27. The side airbag apparatus according to claim 25, wherein the
promoting mechanism includes a breakable fastener member, and
wherein, prior to deployment of the airbag, the breakable fastener
member fastens the airbag at a portion corresponding to the
intermediate chamber.
28. The side airbag apparatus according to claim 25, further
comprising a case for accommodating the airbag prior to deployment,
wherein the case has an opening through which the airbag protrudes
when deployed and a cover covering the opening, wherein a
perforation is formed in the cover, and wherein the breaking
strength of the perforation is weaker in a portion corresponding to
the upper chamber and the lower chamber than in a portion
corresponding to the intermediate chamber.
29. The side airbag apparatus according to claim 25, further
comprising a case for accommodating the airbag prior to deployment,
wherein the case has an opening through which the airbag protrudes
when deployed and a cover covering the opening, wherein a slit is
formed in the cover, the slit being sealed with a plurality of
sealing members, and wherein the sealing members are formed and
arranged such that a force required for opening the slit against
the sealing force of the sealing members is weaker in portions
corresponding to the upper chamber and the lower chamber than in a
portion corresponding to the intermediate chamber.
30. A side airbag apparatus used in a vehicle, comprising: an
airbag; an inflator, wherein the inflator supplies gas to the
airbag, thereby deploying the airbag between a body side portion of
the vehicle and a seat located in the passenger compartment of the
vehicle; an upper chamber, a lower chamber, and an intermediate
chamber provided in the airbag, wherein, when the airbag is
deployed, the upper chamber is located at a position that
corresponds to a shoulder of an occupant sitting on the seat, the
lower chamber is located at a position that corresponds to a lumbar
region of the occupant, and the intermediate chamber is located at
a position that corresponds to a thorax of the occupant; and a
delaying mechanism, wherein, when the inflator generates gas, the
delaying mechanism delays inflation of the intermediate chamber
compared to inflation of the upper and lower chambers.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an airbag apparatus having
an airbag that is deployed at a side of an occupant of a vehicle
when an impact of a force greater than a predetermined value is
applied to a side of the vehicle body due to a side collision.
[0002] Such side airbag apparatuses have been disclosed in, for
example, Japanese Laid-Open Patent Publication No. 2000-177527
(first prior art), Japanese Laid-Open Patent Publication No.
2000-280853 (second prior art), and U.S. Pat. No. 5,112,079 (third
prior art).
[0003] In the first prior art, a side airbag apparatus 542 is
mounted in a backrest 541a of a vehicle seat 541 as shown in FIG.
34. The interior of an airbag 543 of the side airbag apparatus 542
is divided by a dividing seam 544 into a first chamber 545 and a
second chamber 546. The first chamber 545 inflates at a side of the
thorax Pc of an occupant P sitting on the vehicle seat 541. The
second chamber 546 inflates at a side of the lumbar region Ph of
the occupant P.
[0004] The side airbag apparatus 542 has a gas generator 547 for
deploying the airbag 543. A pre-chamber 548 is located about the
gas generator 547. The pre-chamber 548 is connected to the first
chamber 545 through first small holes 549 and to the second chamber
546 through second small holes 550. The total opening area of the
first small holes 549 is less than the total opening area of the
second small holes 550.
[0005] When an impact of a force that is greater than a
predetermined value is applied to the side of the vehicle body due
to a side collision, the gas generator 547 generates gas, which is
first supplied to the pre-chamber 548. The gas is then supplied to
the first and second chambers 545, 546 through the first and second
small holes 549, 550 of different total opening areas at different
flow rates. Due to the difference of the gas flow rates, the first
and second chambers 545, 546 are inflated such that the internal
pressure of the first chamber 545 is lower than the internal
pressure of the second chamber 546.
[0006] In the second prior art also, a side airbag apparatus 642 is
mounted in a backrest 641a of a vehicle seat 641 as shown in FIG.
35. The interior of an airbag 643 of the side airbag apparatus 642
is divided into a first deployment region 652 and a second
deployment region 653 by a substantially vertical dividing wall
651. The first deployment region 652 inflates at a position that is
at rear of an arm Pa of the occupant P. The second deployment
region 653 inflates to contact the arm Pa. During a side collision,
a gas generator 647 generates gas, which immediately inflates the
first deployment region 652 from the lower part to the upper part.
After a delay, the second deployment region 653 is inflated from
the lower part to the upper part.
[0007] The third prior art discloses a side airbag apparatus having
a large airbag. This airbag is deployed to cover a large area
including the head and the lumbar region of an occupant.
[0008] In the first prior art, the first chamber 545, which
corresponds to the thorax Pc of the occupant P is inflated with a
pressure that is lower than that of the second chamber 546, which
corresponds to the lumbar region Ph. Therefore, the thorax Pc,
which is relatively vulnerable to impacts, is more softly received
compared to the lumbar region Ph. Therefore, the impact of a side
collision is not greatly applied to the thorax. However, since the
internal pressure of the first chamber 545 corresponding to the
thorax Pc is relatively low, if the body side portion of the
vehicle is greatly deformed inward of the passenger compartment due
to a side collision, the thorax Pc might not be sufficiently
protected.
[0009] In the second prior art, the vertically extending first and
second deployment regions 652, 653 are inflated substantially with
the same pressure. Therefore, the part of the body of the occupant
P from a shoulder Ps to the lumbar region Ph is uniformly contacts
the inflated airbag 643. Therefore, like the first prior art, the
thorax Pc might not be sufficiently protected.
[0010] The third prior art discloses the largely deployable airbag
that simply protects the body of an occupant over a large area, but
does not disclose any deployment modes of the airbag to correspond
to specific parts of the occupant's body. Therefore, the third
prior art is not expected to effectively protect occupants by
taking the characteristics of a human body into consideration.
SUMMARY OF THE INVENTION
[0011] Accordingly, it is an objective of the present invention to
provide a side airbag apparatus that effectively protects
occupants.
[0012] To achieve the foregoing and other objectives and in
accordance with the purpose of the present invention, a side airbag
apparatus used in a vehicle is provided. The apparatus includes an
airbag, an inflator, and a gas guiding mechanism. The inflator
supplies gas to the airbag, thereby deploying the airbag between a
body side portion of the vehicle and a seat located in the
passenger compartment of the vehicle. An upper chamber and a lower
chamber are provided in the airbag. When the airbag is deployed,
the upper chamber is located at a position that corresponds to a
shoulder of an occupant sitting on the seat and the lower chamber
is located at a position that corresponds to a lumbar region of the
occupant. The gas guiding mechanism guides gas from the inflator to
the upper and lower chambers, thereby substantially simultaneously
inflating the upper and lower chambers.
[0013] The present invention also provides another side airbag
apparatus used in a vehicle. The apparatus includes an airbag, an
inflator, and a limiting mechanism. The inflator supplies gas to
the airbag, thereby deploying the airbag between a body side
portion of the vehicle and a seat located in the passenger
compartment of the vehicle. A upper deploying portion, a lower
deploying portion, and an intermediate portion are provided in the
airbag. When the airbag is deployed, the upper deploying portion is
located at a position that corresponds to a shoulder of an occupant
sitting on the seat, the lower deploying portion is located at a
position that corresponds to a lumbar region of the occupant, and
the intermediate portion is located at a position that corresponds
to a thorax of the occupant. When the airbag is deployed, the
limiting mechanism limits bulging of the intermediate portion such
that the thickness of the intermediate portion is less than the
thickness of the upper and lower deploying portions in respect to a
horizontal direction between the occupant and the body side
portion.
[0014] In another aspect of the present invention, another side
airbag apparatus used in a vehicle is provided. The apparatus
includes an airbag, an inflator, and a promoting mechanism. The
inflator supplies gas to the airbag, thereby deploying the airbag
between a body side portion of the vehicle and a seat located in
the passenger compartment of the vehicle. An upper chamber, a lower
chamber, and an intermediate chamber are provided in the airbag.
When the airbag is deployed, the upper chamber is located at a
position that corresponds to a shoulder of an occupant sitting on
the seat, the lower chamber is located at a position that
corresponds to a lumbar region of the occupant, and the
intermediate chamber is located at a position that corresponds to a
thorax of the occupant. When the inflator generates gas, the
promoting mechanism promotes inflation of the upper and lower
chambers compared to inflation of the intermediate chamber.
[0015] In a further aspect of the present invention, another side
airbag apparatus used in a vehicle is provided. The apparatus
includes an airbag, an inflator, and a delaying mechanism. The
inflator supplies gas to the airbag, thereby deploying the airbag
between a body side portion of the vehicle and a seat located in
the passenger compartment of the vehicle. An upper chamber, a lower
chamber, and an intermediate chamber are provided in the airbag.
When the airbag is deployed, the upper chamber is located at a
position that corresponds to a shoulder of an occupant sitting on
the seat, the lower chamber is located at a position that
corresponds to a lumbar region of the occupant, and the
intermediate chamber is located at a position that corresponds to a
thorax of the occupant. When the inflator generates gas, the
delaying mechanism delays inflation of the intermediate chamber
compared to inflation of the upper and lower chambers.
[0016] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0018] FIG. 1 is a cross-sectional view illustrating a side airbag
according to a first embodiment of the present invention;
[0019] FIG. 2 is an enlarged partial cross-sectional view taken
along line 2-2 of FIG. 1;
[0020] FIG. 3 is an enlarged partial cross-sectional view taken
along line 3-3 of FIG. 1;
[0021] FIG. 4 is a graph showing pressure changes when the chambers
of FIG. 1 are inflated;
[0022] FIG. 5 is a cross-sectional view illustrating a side airbag
according to a second embodiment of the present invention;
[0023] FIG. 6 is an enlarged partial cross-sectional view taken
along line 6-6 of FIG. 5;
[0024] FIG. 7 is a cross-sectional view illustrating a side airbag
according to a third embodiment of the present invention;
[0025] FIG. 8 is a cross-sectional view illustrating a side airbag
according to a fourth embodiment of the present invention;
[0026] FIG. 9 is a cross-sectional view illustrating a side airbag
according to a fifth embodiment of the present invention;
[0027] FIG. 10 is a cross-sectional view illustrating a side airbag
according to a sixth embodiment of the present invention;
[0028] FIG. 11 is a cross-sectional view illustrating a side airbag
according to a seventh embodiment of the present invention;
[0029] FIG. 12 is an enlarged partial cross-sectional view taken
along line 12-12 of FIG. 11;
[0030] FIG. 13 is an enlarged front view illustrating the inflator
provided in the side airbag apparatus shown in FIG. 11;
[0031] FIG. 14 is a plan view showing the inflator of FIG. 13;
[0032] FIG. 15 is a cross-sectional view illustrating a side airbag
apparatus according to an eighth embodiment of the present
invention;
[0033] FIG. 16 is a cross-sectional view illustrating a side airbag
apparatus according to a ninth embodiment of the present
invention;
[0034] FIG. 17 is an enlarged partial cross-sectional view taken
along line 17-17 of FIG. 16;
[0035] FIG. 18 is a cross-sectional view illustrating a
modification of the side airbag apparatus according to the ninth
embodiment;
[0036] FIG. 19 is a cross-sectional view illustrating a side airbag
apparatus according to a tenth embodiment of the present
invention;
[0037] FIG. 20 is an enlarged partial cross-sectional view taken
along line 20-20 of FIG. 19;
[0038] FIG. 21 is a cross-sectional view illustrating a side airbag
apparatus according to an eleventh embodiment of the present
invention;
[0039] FIG. 22 is an enlarged partial cross-sectional view taken
along line 22-22 of FIG. 21;
[0040] FIG. 23 is a cross-sectional view illustrating a side airbag
apparatus according to a twelfth embodiment of the present
invention;
[0041] FIG. 24 is a cross-sectional view illustrating a side airbag
apparatus according to a thirteenth embodiment of the present
invention;
[0042] FIG. 25 is a cross-sectional view illustrating a side airbag
apparatus according to a fourteenth embodiment of the present
invention;
[0043] FIG. 26 is a front view showing the side airbag apparatus
shown in FIG. 25;
[0044] FIGS. 27(a) and 27(b) are enlarged partial cross-sectional
views showing an example of perforations;
[0045] FIGS. 28(a) and 28(b) are enlarged partial cross-sectional
views showing another example of perforations;
[0046] FIGS. 29(a) and 29(b) are enlarged partial cross-sectional
views showing a further example of perforations;
[0047] FIG. 30 is a cross-sectional view illustrating a side airbag
apparatus according to a fifteenth embodiment of the present
invention;
[0048] FIG. 31 is an enlarged partial cross-sectional view taken
along line 31-31 of FIG. 30;
[0049] FIGS. 32(a) and 32(b) are enlarged partial cross-sectional
views showing the arrangement of pairs of engaging hook and
engaging eyes;
[0050] FIG. 33 is a cross-sectional view illustrating a side airbag
apparatus according to a sixteenth embodiment of the present
invention;
[0051] FIG. 34 is a cross-sectional view illustrating a prior art
side airbag apparatus; and
[0052] FIG. 35 is a cross-sectional view illustrating another prior
art side airbag apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] A first embodiment of the present invention will now be
described with reference to FIGS. 1 to 4.
[0054] FIGS. 1 to 3 show a side airbag apparatus 13 provided in a
left front seat 11 in a vehicle passenger compartment. The front
seat 11 includes a seat portion 11a and a backrest 11b. A case 14
accommodating the side airbag apparatus 13 is embedded in the left
portion of the backrest 11b to correspond to a door 12, which
consists part of a side portion of the vehicle body. Although only
the left front seat 11 is illustrated in the drawings, a right
front seat has a similar airbag apparatus in its right portion.
[0055] The side airbag apparatus 13 includes a gas generator, which
is an inflator 15, and an airbag 16. The inflator 15 is fixed in
the case 14. The airbag 16 covers the inflator 15. The inflator 15
has a case and gas generation agent (not shown) in the case. The
gas generation agent generates gas to deploy the airbag 16. Gas
portion is formed at a lower portion of the inflator 15. In this
embodiment, the gas portion is a plurality of gas ports 15a.
[0056] The inflator 15 is electrically connected to an impact
sensor (not shown) that detects the magnitude of impact applied to
the body side portion. When an object, such as another vehicle,
collides with the body side portion, that is, during a side
collision, if an impact having a magnitude that is greater than a
predetermined value is applied to the body side portion, a control
circuit (not shown) sends driving current to the inflator 15 based
on detection signal from the impact sensor. Ignition based on the
driving current causes the gas generating agent in the inflator 15
to generate gas. The gas is in turn injected from the gas ports 15a
into the airbag 16.
[0057] As shown in FIGS. 2 and 3, the airbag 16 has a pair of
ground fabric sheets 16a, 16b made of, for example, woven cloth.
The ground fabric sheets 16a, 16b are sewn together at the
periphery to form the airbag 16. Normally, the airbag 16 is
accommodated in the case 14 in a folded state.
[0058] When the inflator 15 generates gas, the airbag 16 is
deployed into the space between the door 12 and the front seat 11
to spread over the torso of an occupant P sitting on the front seat
11 from a shoulder Ps to a lumbar region Ph.
[0059] A seam 17 is formed in a section of the airbag 16 that is
substantially center in the vertical direction. The seam 17 is
formed by sewing the ground fabric sheets 16a, 16b and is
substantially laterally U-shaped as viewed from the side. The seam
17 defines an upper chamber 18, a lower chamber 19, and an
intermediate chamber 20. The intermediate chamber 20 is located
between the upper chamber 18 and the lower chamber 19 and functions
as an intermediate portion. The intermediate chamber 20 is
surrounded by the seam 17 on three sides. The airbag 16 has a gas
passage 21 formed between the edge of the airbag 16 and the seam
17. The gas passage 21 is located at a side of the airbag 16
opposite from the inflator 15, in other words, at a side opposite
from the opening of the intermediate chamber 20.
[0060] As shown by arrows in FIG. 1, gas injected from the gas
ports 15a of the inflator 15 is first guided to the lower chamber
19. The gas is then guided to the upper chamber 18 from the lower
chamber 19 along the seam 17 via the gas passage 21. Thereafter,
the gas in the upper chamber 18 is guided to the intermediate
chamber 20 while bypassing the upper edge of the seam 17.
Therefore, as obvious from FIG. 4, the lower chamber 19 is first
inflated (at a position corresponding to the lumbar region Ph of
the occupant P). Substantially simultaneously, the upper chamber 18
is inflated (at a position corresponding to the shoulder Ps of the
occupant P). Thereafter, the intermediate chamber 20 is inflated
(at a position corresponding to the thorax Pc of the occupant P).
The seam 17 has a gas guiding function and guides gas to
substantially simultaneously inflate the upper and lower chambers
18, 19. The seam 17 has a function to promote the inflation of the
upper and lower chambers 18, 19, or a function to delay the
inflation of the intermediate chamber 20.
[0061] A vent hole 22 is formed at a part of the airbag 16,
specifically, at the part corresponding to the intermediate chamber
20. The vent hole 22 discharges gas from the interior of the
intermediate chamber 20.
[0062] When forming the laterally U-shaped seam 17, the ground
fabric sheets 16a, 16b are sewed such that the portions of the
ground fabric sheets 16a, 16b surrounded by the seam 17 are
strained. Therefore, the thickness (horizontal measurement) of the
intermediate chamber 20 is less than those of the upper chamber 18
and the lower chamber 19 as shown in FIG. 2 when the airbag 16 is
deployed. That is, the seam 17 functions to limit bulging of the
intermediate chamber 20. As obvious from FIG. 4, the vent hole 22
formed in a part corresponding to the intermediate chamber 20
adjusts the internal pressure of the intermediate chamber 20 to be
lower than those of the upper and lower chambers 18, 19. The vent
hole 22 thus has an internal pressure adjusting function.
[0063] Various conditions, such as the pressure of gas supplied
form the inflator 15 to the airbag 16 and the size of the vent hole
22, are determined such that the internal pressures of the chambers
18 to 20 are in predetermined appropriate ranges. Specifically, the
conditions are determined such that the internal pressures of the
upper and lower chambers 18, 19 are in a range from 150 to 200 kilo
pascals (kPa), and the internal pressure of the intermediate
chamber 20 is in a range from 50 to 100 kilo pascals (kPa). The
internal pressure of the intermediate chamber 20 is preferably
equal to or less than the lower one of the internal pressures of
the upper chamber 18 and the lower chamber 19. When the internal
pressures in the upper and lower chambers 18, 19 are equal to each
other, the internal pressure of the intermediate chamber 20 is
preferably equal to or less than a half of the internal pressures
in the upper and lower chambers 18, 19.
[0064] Various conditions such as the location and the size of the
seam 17 are determined such that the thicknesses of the chambers 18
to 20 are in the following ranges. That is, the conditions are
determined such that the thicknesses of the upper and lower
chambers 18, 19 are in a range from 150 mm to 200 mm, and the
thickness of the intermediate chamber 20 is in a range from 50 mm
to 130 mm. If the thicknesses of the upper and lower chambers 18,
19 are equal to each other, the thickness of the intermediate
chamber 20 is preferably a quarter to a third of the thicknesses of
the upper and lower chambers 18, 19. If the thicknesses of the
upper and lower chambers 18, 19 are different from each other, the
thickness of the intermediate chamber 20 is preferably a quarter to
a third of the thicknesses of thinner one of the upper and lower
chambers 18, 19. The above presented values of the thicknesses of
the chambers 18 to 20 are values in a condition where no external
load is applied to the airbag 16.
[0065] Various conditions, such as the configuration of the
inflator 15 and the position of the seam 17, are determined such
that the internal pressures of the chambers 18 to 20 reach
specified internal pressures (internal pressures allowing the
airbag 16 to function properly) within a predetermined period,
which is discussed below, after the impact sensor detects an
impact. Specifically, the conditions are determined such that the
internal pressures of the upper and lower chambers 18, 19 reach the
specified internal pressure within five to ten milliseconds, and
the internal pressure of the intermediate chamber 20 reaches the
specified internal pressure within seven to twelve milliseconds. If
the internal pressures in the upper and lower chambers 18, 19
substantially simultaneously reach the specified pressure, the
period required for the internal pressure of the intermediate
chamber 20 reach the specified pressure is preferably longer than
the period for the upper and lower chambers 18, 19 by about 20%.
Also, if the internal pressures in the upper and lower chambers 18,
19 reach the specified pressure at different times, the period
required for the internal pressure of the intermediate chamber 20
reach the specified pressure is preferably longer than the period
for the longer one of the period for the upper and lower chambers
18, 19 by about 20%.
[0066] The above presented values of the internal pressures, the
thicknesses, and the periods to reach the specified internal
pressures of the chambers 18 to 20 are values in a condition where
no external load is applied to the airbag 16, or values when the
airbag 16 is statically deployed.
[0067] An operation of the side airbag apparatus 13 will now be
described.
[0068] When an impact the magnitude of which is greater than a
predetermined value is applied to the body side portion due to a
collision of an object, such as another vehicle, to the body side
portion, the inflator 15 generates gas. The gas is then supplied to
the lower chamber 19 of the airbag 16 through the gas ports 15a.
The gas is also guided to the upper chamber 18 through the gas
passage 21 and thereafter is guided to the intermediate chamber 20.
As a result, as shown in FIG. 4, the upper chamber 18 corresponding
to the shoulder Ps of the occupant and the lower chamber 19
corresponding to the lumbar region Ph of the occupant P are
substantially simultaneously inflated. Thereafter, the intermediate
chamber 20 corresponding to the thorax Pc is inflated.
[0069] As shown in FIG. 2, the thickness of the inflated
intermediate chamber 20 is less than those of the inflated upper
and lower chambers 18, 19. Therefore, a space S is created between
the thorax Pc of the occupant P and the part of the airbag 16
forming the intermediate chamber 20. In this state, the parts of
the airbag 16 forming the upper and lower chambers 18, 19 push the
shoulder Ps and the lumbar region Ph of the occupant P inward of
the passenger compartment. The airbag 16 therefore moves the
occupant P inward of the compartment and protects the thorax Pc
while absorbing the impact due to a side collision. Thus, even if
the body side portion significantly bulges inward, the occupant P
is separated from the body side portion prior to the deformation of
the body side portion, and an impact to the thorax Pc is reduced.
The thorax Pc is therefore effectively protected.
[0070] This embodiment therefore has the following advantages. (1)
The airbag 16 has the upper chamber 18 corresponding to the
shoulder Ps of the occupant P on the front seat 11 and the lower
chamber 19 corresponding to the lumbar region Ph of the occupant P.
When an impact of a magnitude greater than a predetermined value is
applied to the body side portion due to a side collision, gas
generated by the inflator 15 is substantially simultaneously
supplied to the upper chamber 18 and the lower chamber 19.
Therefore, the upper chamber 18 corresponding to the shoulder Ps of
the occupant P and the lower chamber 19 corresponding to the lumbar
region Ph are substantially simultaneously inflated. Thus, even if
the body side portion is greatly deformed inward, the shoulder Ps
and the lumbar region Ph, which are relatively impervious to
impacts, are substantially simultaneously pushed by the airbag 16.
This moves the occupant P inward of the passenger compartment.
Accordingly, the side airbag apparatus 13 effectively protects the
occupant P from impacts due to side collisions while sufficiently
protecting the thorax Pc.
[0071] (2) The airbag 16 has the intermediate chamber 20
corresponding to the thorax Pc of the occupant P between the upper
chamber 18 and the lower chamber 19. When the airbag 16 is
deployed, bulging of the intermediate chamber 20 is limited by the
seam 17 such that the thickness of the intermediate chamber 20 is
less than those of the upper and lower chambers 18, 19. This
prevents the thorax Pc from receiving a great impact and thus
improves the protection for the occupant P.
[0072] (3) When the airbag 16 is deployed, the inflation of the
upper and lower chambers 18, 19 is promoted by a greater degree
than the inflation of the intermediate chamber 20, and the upper
and lower chambers 18, 19 are inflated more rapidly than the
intermediate chamber 20. Therefore, during a side collision, the
airbag 16 first pushes the shoulder Ps and the lumbar region Ph and
then protects the thorax Pc. Therefore, the thorax Pc is more
effectively protected.
[0073] (4) The airbag 16 is formed of the facing pair of the ground
fabric sheets 16a, 16b. The function to guide gas to the chambers
18 to 20, the function to limit bulging of the intermediate chamber
20, and the function to promote the inflation of the upper and
lower chambers 18, 19 are realized by the seam 17, which is formed
by sewing the ground fabric sheets 16a, 16b to each other.
Therefore, there is no necessity for providing parts dedicated for
these functions. This reduces the number of parts and simplifies
the structure. The airbag 16 can be thus manufactured at low
costs.
[0074] A second embodiment of the present invention will now be
described with reference to FIGS. 5 and 6. The differences from the
first embodiment shown in FIGS. 1 to 4 will mainly be
discussed.
[0075] In the second embodiment, a wide seam 17A is formed in a
section of the airbag 16 that is substantially center in the
vertical direction. The wide seam 17A is formed by sewing the
ground fabric sheets 16a, 16b. The wide seam 17A extends
substantially horizontally to define an upper chamber 18 and a
lower chamber 19 in the airbag 16. The wide seam 17A has a gas
guiding function and guides gas to substantially simultaneously
inflate the upper and lower chambers 18, 19. The wide seam 17A also
functions to limit bulging of the intermediate portion of the
airbag 16. As shown by arrows in FIG. 5, gas injected from the gas
ports 15a of the inflator 15 is first guided to the lower chamber
19. The gas is then guided to the upper chamber 18 from the lower
chamber 19 along the wide seam 17A via the gas passage 21. The gas
is substantially simultaneously guided into the upper and lower
chambers 18, 19.
[0076] When the airbag 16 is deployed, the upper chamber 18 and the
lower chamber 19 are inflated at positions corresponding to the
shoulder Ps and the lumbar region Ph of the occupant P,
respectively. At this time, the position of the wide seam 17A
between the chambers 18, 19 corresponds to the thorax Pc. In this
case, since the thickness of the wide seam 17A is less than those
of the chambers 18, 19 as shown in FIG. 6, a space S is created
between the wide seam 17A and the thorax Pc. Therefore, as in the
first embodiment, the shoulder Ps and the lumbar region Ph of the
occupant P are substantially simultaneously pushed by the airbag
16, which moves the occupant P inward of the passenger compartment.
Therefore, the side airbag apparatus 13 of the second embodiment
effectively absorbs the impact due to a side collision while
protecting the thorax Pc.
[0077] Accordingly, in addition to the advantages (1), (2) and (4)
of the first embodiment, the second embodiment has the following
advantage.
[0078] The function for guiding gas to the chambers 18, 19 and the
function for limiting bulging of the intermediate portion of the
airbag 16 are realized by the wide seam 17A, which is formed by
sewing the ground fabric sheets 16a, 16b between the upper chamber
18 and the lower chamber 19. The wide seam 17A has a simple shape
and only linearly extends. Therefore, the manufacture of the airbag
16 is simplified and the costs are reduced. When the airbag 16 is
deployed, the wide seam 17A, which is significantly thinner than
the chambers 18, 19, corresponds to the thorax Pc of the occupant P
between the upper chamber 18 and the lower chamber 19. Therefore,
the thorax Pc is effectively protected.
[0079] A third embodiment of the present invention will now be
described with reference to FIG. 7. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0080] In the third embodiment, as shown in FIG. 7, the airbag 16
has two seams 17, which are formed by sewing the ground fabric
sheets 16a, 16b to each other. The seams 17 are spaced vertically
by a predetermined distance. The seams 17 define an upper chamber
18, a lower chamber 19, and an intermediate chamber 20 in the
airbag 16. When forming each seam 17, the ground fabric sheets 16a,
16b are sewed such that the intermediate sections of the ground
fabric sheets 16a, 16b are strained. Thus, when the airbag 16 is
deployed, the intermediate chamber 20 is thinner than the upper and
lower chambers 18, 19. That is, the seams 17 function to limit
bulging of the intermediate chamber 20. The thicknesses of the
chambers 18 to 20 are represented by the measurements along a
direction perpendicular to the surface of the sheet of FIG. 7. A
cover 24 is located about the inflator 15. The cover 24 defines an
introducing chamber 25 into which gas injected from the gas ports
15a of the inflator 15 is guided.
[0081] First guiding holes 26A, second guiding holes 26B, and third
guiding holes 26C are formed in the cover 24 to correspond to the
chambers 18, 19, and 20, respectively. The cover 24 defining the
introducing chamber 25 and the guiding holes 26A to 26C formed in
the cover 24 have a gas guiding function. The guiding holes 26A to
26C function to promote inflation of the upper and lower chambers
18, 19. Gas is introduced into the chambers 18, 19, 20 from the
introducing chamber 25 through the corresponding guiding holes 26A
to 26C, respectively. The total opening area of the first guiding
hole 26A corresponding to the upper chamber 18 and the total
opening area of the second guiding hole 26B corresponding to the
lower chamber 19 are greater than the total opening area of the
third guiding holes 26C corresponding to the intermediate chamber
20. Therefore, the upper and lower chambers 18, 19 are
simultaneously inflated. Then, the intermediate chamber 20 is
inflated after a delay. Further, the thickness of the intermediate
chamber 20 when inflated is less than those of the upper and lower
chambers 18, 19 when inflated.
[0082] Thus, the third embodiment has substantially the same
advantages as the first embodiment. In this embodiment, a vent hole
like the vent hole 22 shown in FIG. 1 may be provided at a portion
of the airbag 16 that corresponds to the intermediate chamber
20.
[0083] A fourth embodiment of the present invention will now be
described with reference to FIG. 8. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0084] In the fourth embodiment, a seam 17 of an airbag 16 is
substantially G-shaped as shown in FIG. 8. The seam 17 defines an
upper chamber 18, a lower chamber 19, and an intermediate chamber
20 in the airbag 16. The seam 17 functions to limit bulging of the
intermediate chamber 20. An inflator 15 has two gas ports 15a,
which are vertically spaced. Gas is injected from the gas ports 15a
at the same time. The seam 17 and the vertically spaced gas ports
15a have a gas guiding function and a function to promote inflation
of the upper and lower chambers 18, 19. The seam 17 and the gas
ports 15a guide gas to substantially simultaneously inflate the
upper and lower chambers 18, 19, and then inflate the intermediate
chamber 20.
[0085] Accordingly, in addition to the advantages of the first
embodiment, the fourth embodiment has the following advantage.
[0086] The inflator 15 has the upper gas port 15a corresponding to
the upper chamber 18 and the lower gas port 15a corresponding to
the lower chamber 19. Therefore, the difference between the time
required for inflating the upper chamber 18 and the time required
for inflating the lower chamber 19 is reduced.
[0087] In this embodiment, a vent hole like the vent hole 22 shown
in FIG. 1 may be provided at a portion of the airbag 16 that
corresponds to the intermediate chamber 20.
[0088] A fifth embodiment of the present invention will now be
described with reference to FIG. 9. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0089] In the fifth embodiment, an airbag 16 has an upper airbag
member 16A and a lower airbag member 16B. The upper airbag member
16A has an upper chamber 18, and the lower airbag member 16B has a
lower chamber 19. The airbag members 16A and 16B are independent
from each other. The upper airbag member 16A corresponds to a
shoulder Ps of an occupant P, and the lower airbag member 16B
corresponds to a lumbar region Ph of the occupant P. The airbag
members 16A, 16B are arranged vertically with a predetermined space
in between in a case 14. Two inflators 15A, 15B are separately
provided in the case 14 to correspond to the airbag members 16A,
16B, respectively. Each of the inflators 15A, 15B supplies gas to
the corresponding one of the airbag members 16A, 16B. The separate
inflators 15A, 15B have a gas guiding function, and guide gas to
simultaneously inflate the airbag members 16A, 16B.
[0090] Accordingly, in addition to the advantage (1) of the first
embodiment, the fifth embodiment has the following advantage.
[0091] The upper airbag member 16A having the upper chamber 18 and
the lower airbag member 16B having the lower chamber 19 are
independent from each other. The independent inflators 15A, 15B
correspond to the different airbag members 16A, 16B, respectively.
Thus, there is no need to divide the interior of a single airbag
into several chambers with, for example, seams. This simplifies the
structure and manufacture of the airbag 16. The upper airbag member
16A and the lower airbag member 16B are simultaneously deployed
without a time difference. Further, a wide space is created at a
part corresponding to the thorax Pc of an occupant P between the
airbag members 16A, 16B. The thorax Pc is therefore effectively
protected.
[0092] A sixth embodiment of the present invention will now be
described with reference to FIG. 10. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0093] In the sixth embodiment, a seam 17 has the same functions as
that in the first embodiment. Also, an intermediate chamber 20 is
defined by the seam 17. The intermediate chamber 20 has an opening
20a that opens frontward of the vehicle, or at the side opposite
from an inflator 15. The seam 17 has flow guides 20b located at the
upper and lower edges of the opening 20a. The flow guides 20b guide
gas to the interior of the intermediate chamber 20. One of the
ground fabric sheets 16a, 16b has a vent hole 22 at a part
corresponding to the intermediate chamber 20.
[0094] Accordingly, in addition to the advantages of the first
embodiment, the sixth embodiment has the following advantages.
[0095] Gas from the inflator 15 passes through the upper and lower
chambers 18, 19 before entering the intermediate chamber 20.
Therefore, after the upper and lower chambers 18, 19 are
substantially simultaneously inflated; the intermediate chamber 20
is inflated with a little delay. Also, the internal pressure in the
upper and lower chambers 18, 19 is higher than that of the
intermediate chamber 20. The thorax Pc is therefore effectively
protected.
[0096] The flow guides 20b smooth the flow of gas into the
intermediate chamber 20. This prevents the inflation of the
intermediate chamber 20 from being excessively delayed and allows
the intermediate chamber 20 to be inflated at a proper timing.
[0097] Gas is readily discharged from the intermediate chamber 20
through the vent hole 22. This prevents the internal pressure of
the intermediate chamber 20 from being excessively high. The thorax
Pc is therefore effectively protected.
[0098] The flow guides 20b may be provided on the seam 17 of FIG. 1
or on the seam 17 of FIG. 8.
[0099] A seventh embodiment of the present invention will now be
described with reference to FIGS. 11 to 14. The differences from
the first embodiment shown in FIGS. 1 to 4 will mainly be
discussed.
[0100] In the seventh embodiment, a seam 17 having a gas guiding
function is substantially V-shaped as shown in FIGS. 11 and 12. The
seam 17 defines an upper chamber 18, a lower chamber 19, and an
intermediate chamber 20 in the airbag 16. A reinforcing fabric
sheet 28A is layered on and sewed to portions of the inner sides of
the ground fabric sheets 16a, 16b that correspond to the upper
chamber 18. A reinforcing fabric sheet 28B is layered on and sewed
to portions of the inner sides of the ground fabric sheets 16a, 16b
that correspond to the lower chamber 19. The reinforcing fabric
sheets 28A, 28B have internal pressure adjusting function and gas
leak preventing function.
[0101] Walls that define the upper chamber 18 and the lower chamber
19 each have a double structure. When the airbag 16 is deployed,
the reinforcing fabric sheets 28A, 28B prevent gas supplied to the
upper and lower chambers 18, 19 from leaking. As a result, as in
the case shown in FIG. 4 of the first embodiment, the internal
pressure of the intermediate chamber 20 is lower than the internal
pressures of the upper and lower chambers 18, 19 when the airbag 16
is deployed.
[0102] In the seventh embodiment, an inflator 15 is accommodated in
a cylindrical metal case 29 as shown in FIGS. 13 and 14. The
cylindrical metal case 29 is fixed to a frame 32 of the front seat
11 with bolts 30 and nuts 31 at upper and lower sections. The
cylindrical metal case 29 has a substantially U-shaped stopper
portion 29b at an end. The stopper portion 29b is located at a side
opposite from the gas ports 15a of the inflator 15. When the
inflator 15 is inserted into the cylindrical metal case 29, the
stopper portion 29b is bent as shown by chain two-dot lines in FIG.
14 to prevent the inflator 15 from coming off the cylindrical metal
case 29.
[0103] Accordingly, in addition to the advantages of the first
embodiment, the seventh embodiment has the following advantage.
[0104] With a simple structure in which the reinforcing fabric
sheets 28A, 28B are provided at portions corresponding to the upper
chamber 18 and the lower chamber 19, gas is prevented from leaking
from the upper and lower chambers 18, 19. The prevention of gas
leak sets the internal pressure of the intermediate chamber 20
corresponding to the thorax Pc of the occupant P lower than the
internal pressures of the upper and lower chambers 18, 19. The
thorax Pc is therefore effectively protected.
[0105] Instead of the reinforcing fabric sheets 28A, 28B, the parts
of the ground fabric sheets 16a, 16b that correspond to the upper
and lower chambers 18, 19 may be formed with a material having a
less gas leakage characteristics than the material for the part
corresponding to the intermediate chamber 20.
[0106] An eighth embodiment of the present invention will now be
described with reference to FIG. 15. The differences from the
seventh embodiment shown in FIGS. 11 to 14 will mainly be
discussed.
[0107] In the eighth embodiment, the reinforcing fabric sheets 28A,
28B of the seventh embodiment are omitted. Instead, a coating layer
34 is formed on at least one of the surfaces of the ground fabric
sheets 16a, 16b at a portion corresponding to the upper chamber 18.
A coating layer 34 is formed on at least one of the surfaces of the
ground fabric sheets 16a, 16b at a portion corresponding to the
lower chamber 19. The coating layers 34 are made, for example, of
silicone rubber. Each coating layer 34 prevents gas from leaking
from the corresponding chambers 18, 19. That is, in this
embodiment, the coating layers 34 having an internal adjusting
function and a leak prevention function are provided instead of the
reinforcing fabric sheets 28A, 28B.
[0108] Therefore, the simple structure of the coating layers 34
sets the internal pressure of the intermediate chamber 20 lower
than those of the upper and lower chambers 18, 19. Thus, as in the
seventh embodiment, the thorax Pc is effectively protected with the
simply structured airbag 16.
[0109] A ninth embodiment of the present invention will now be
described with reference to FIGS. 16 and 17. The differences from
the seventh embodiment shown in FIGS. 11 to 14 will mainly be
discussed.
[0110] In the ninth embodiment, the airbag 16 has a vent hole 22 in
addition to the structure of the seventh embodiment. As shown in
FIGS. 16 and 17, the vent hole 22 opens to the outside and is
located at a part that corresponds to the intermediate chamber 20.
Specifically, the vent hole 22 corresponds to a part where gas from
the inflator 15 reaches last. The reinforcing fabric sheets 28A,
28B shown in FIGS. 16 and 17 may be omitted. When the airbag 16 is
deployed, the vent hole 22 is spaced from the inner side of the
door 12 forming the body side portion by a predetermined distance
L. The distance L is determined such that the vent hole 22 is
sufficiently separated from the inner side of the door 12 when the
airbag 16 is deployed. The vent hole 22 has an internal pressure
adjusting function. That is, when the airbag 16 is deployed, the
vent hole 22 discharges gas from the intermediate chamber 20 to the
outside so that the internal pressure of the intermediate chamber
20 is lower than those of the upper and lower chambers 18, 19.
[0111] Therefore, the ninth embodiment has the same advantages as
the seventh and eighth embodiments. Also, since the vent hole 22 is
spaced from the inner side of the door 12 when the airbag 16 is
deployed, the vent hole 22 is not closed by the door 12.
Accordingly, the internal pressure of the intermediate chamber 20
is effectively lowered.
[0112] In lieu of the vent hole 22 of the ninth embodiment, a
perforation 36 may be formed at a part corresponding to the
intermediate chamber 20 of the airbag 16 as shown in FIG. 18. When
the internal pressure of the intermediate chamber 20 reaches a
predetermined value, the perforation 36 breaks to form a vent hole
22. In this case, the amount of gas discharged through the vent
hole 22 is changed in accordance with the internal pressure of the
intermediate chamber 20. The internal pressure of the intermediate
chamber 20 is therefore appropriately controlled. In the subsequent
embodiments also, the vent hole 22 may be changed to a perforation
as the perforation 36 shown in FIG. 18.
[0113] A tenth embodiment of the present invention will now be
described with reference to FIGS. 19 and 20. The differences from
the first embodiment shown in FIGS. 1 to 4 will mainly be
discussed.
[0114] In the tenth embodiment, as shown in FIGS. 19 and 20, the
airbag 16 has a V-shaped seam 17. A bag-like flow adjuster fabric
sheet 35 is sewed to the inside of the airbag 16 below the V-shaped
seam 17. The flow adjuster fabric sheet 35 opens downward. An upper
chamber 18 that corresponds to a shoulder Ps of an occupant P is
defined above the seam 17. A lower chamber 19 that corresponds to
the lumbar region Ph of the occupant P is defined below the flow
adjuster fabric sheet 35. An intermediate chamber 20 is defined
between the flow adjuster fabric sheet 35 and the seam 17. The
intermediate chamber 20 corresponds to the thorax Pc of the
occupant P. The flow adjuster fabric sheet 35 has an internal
pressure adjusting function. When the airbag 16 is deployed, the
flow adjuster fabric sheet 35 adjusts the internal pressure in the
intermediate chamber 20 to be lower than the internal pressure of
the lower chamber 19.
[0115] Therefore, the tenth embodiment has substantially the same
advantages as the seventh to ninth embodiments. In this embodiment,
a vent hole like the vent hole 22 shown in FIG. 1 or a perforation
like the perforation 36 shown in FIG. 18 may be provided at a
portion of the airbag 16 that corresponds to the intermediate
chamber 20
[0116] An eleventh embodiment of the present invention will now be
described with reference to FIGS. 21 and 22. The differences from
the first embodiment of FIGS. 1 to 4 will mainly be discussed.
[0117] In the eleventh embodiment, as shown in FIGS. 21 and 22, the
interior of the airbag 16 is not divided. That is, a single chamber
is defined in the airbag 16. When the airbag 16 is deployed, the
airbag 16 has an upper deployment portion 127 corresponding to a
shoulder Ps of an occupant P, a lower deployment portion 128
corresponding to a lumbar region Ph of the occupant P, and an
intermediate deployment portion 129 corresponding to the thorax Pc
of the occupant P.
[0118] A constricted portion 130 is formed in the intermediate
deployment portion 129 at a side in the direction of thickness. The
constricted portion 130 corresponds to the thorax Pc of the
occupant P. The constricted portion 130 limits bulging of the
intermediate deployment portion 129. Therefore, as shown in FIG.
22, the thickness of the intermediate deployment portion 129 is
less than those of the upper and lower deployment portions 127,
128. As shown in FIG. 21, the width (lateral measurement as viewed
in FIG. 21) of the upper deployment portion 127 is greater than
those of the lower and intermediate deployment portions 128, 129.
The constricted portion 130 is formed, for example, by using wefts
having a small stretchability for the portion corresponding to the
intermediate deployment portion 129 of the ground fabric sheet 16b
at the side of the occupant P. That is, the wefts with a small
stretchability function to limit bulging of the intermediate
deployment portion 129.
[0119] When the airbag 16 is deployed, bulging of the intermediate
deployment portion 129 is limited by the constricted portion 130 as
shown in FIG. 22. The thickness of the upper deployment portion 127
and the lower deployment portion 128 is greater than that of the
intermediate deployment portion 129. At the same time, as shown in
FIG. 21, the upper deployment portion 127 is wider than the lower
deployment portion 128 and the intermediate deployment portion 129.
Thus, the shoulder Ps and the lumbar region Ph of the occupant P
are substantially simultaneously pushed at two points by the airbag
16. This presses the occupant P inwardly. Accordingly, the airbag
16 reduces the impact due to a side collision while protecting the
thorax Pc.
[0120] Accordingly, in addition to the advantage (2) of the first
embodiment, the eleventh embodiment has the following
advantages.
[0121] Bulging of the intermediate portion 129 is limited simply by
forming the constricted portion 130 at the side of the intermediate
deployment portion 129 of the airbag 16. Therefore, there is no
necessity for providing parts dedicated for limiting the bulging of
the intermediate deployment portion 129. This reduces the number of
parts and simplifies the structure. The airbag 16 can be thus
manufactured at low costs.
[0122] The width of the upper deployment portion 127 is greater
than those of the lower and intermediate deployment portion 128,
129. Therefore, when the airbag 16 is deployed, the wide upper
deployment portion 127 effectively contacts the shoulder Ps of the
occupant P, which readily moves the occupant P inward of the
passenger compartment.
[0123] A twelfth embodiment of the present invention will now be
described with reference to FIG. 23. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0124] In the twelfth embodiment, as shown in FIG. 23, the airbag
16 has two seams 17A, 17B, which are formed by sewing the ground
fabric sheets 16a, 16b to each other. The seams 17A, 17B are
located at an intermediate section in the vertical direction of the
airbag 16. The seams 17A, 17B extend vertically and are spaced from
each other in the width direction (lateral direction as viewed in
FIG. 23) of the airbag 16. The seams 17A, 17B define an upper
chamber 18, a lower chamber 19, and an intermediate chamber 20 in
the airbag 16. That is, the upper chamber 18 is defined above the
seams 17A, 17B. The lower chamber 19 is defined below the seams
17A, 17B. The intermediate chamber 20 is defined between the seams
17A and 17B. The first seam 17A, which is closer to the inflator
15, is vertically longer than the second seam 17B, which is farther
from the inflator 15. The first seam 17A has a function to promote
the inflation of the upper and lower chambers 18, 19 in the
vertical direction, or a function to delay the inflation of the
intermediate chamber 20. The first seam 17A also has a function to
simultaneously guide gas to the upper and lower chambers 18,
19.
[0125] The inflator 15 has upper gas ports 15a and lower gas ports
15a at an upper portion and a lower portion of the inflator 15,
respectively. Gas is injected from the upper and lower gas ports
15a at the same time. Gas injected from the upper gas ports 15a is
guided to the upper chamber 18 along the first seam 17A and then
supplied to the intermediate chamber 20. On the other hand, gas
injected from the lower gas ports 15a is guided to the lower
chamber 19 along the first seam 17A and then supplied to the
intermediate chamber 20. Therefore, after the upper and lower
chambers 18, 19 are simultaneously inflated, the intermediate
chamber 20 is inflated after a delay.
[0126] Thus, the twelfth embodiment has substantially the same
advantages as the first embodiment.
[0127] A thirteen embodiment of the present invention will now be
described with reference to FIG. 24. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0128] In the thirteenth embodiment, a fastener fabric sheet 229
made of flame-resistant nonwoven fabric is wrapped about the folded
airbag 16 (see the solid lines) as shown in FIG. 24. The fastener
fabric sheet 229 has a function to promote the inflation of the
upper and lower chambers 18, 19 in the vertical direction, or a
function to delay the inflation of the intermediate chamber 20. A
perforation 230 is formed at a part of the fastener fabric sheet
229 at a position opposite from the inflator 15. The perforation
230 breaks when the airbag 16 is deployed. In this embodiment, the
seam 17 shown in FIG. 1 may be either provided or omitted.
[0129] When gas is supplied from the inflator 15 to the interior of
the airbag 16, the upper and lower chambers 18, 19 are inflated as
shown by chain double-dashed lines in FIG. 24 with the intermediate
portion of the airbag 16 tied with fastener fabric sheet 229.
Thereafter, due to an increase of the internal pressure of the
airbag 16, the fastener fabric sheet 229 is torn along the
perforation 230, which releases the intermediate portion of the
airbag 16. Then, as shown by chain two-dashed lines in FIG. 24, the
intermediate chamber 20 is inflated after a little delay.
[0130] Accordingly, in addition to the advantages of the first
embodiment, the thirteenth embodiment has the following
advantage.
[0131] The inflation of the upper and lower chambers 18, 19 are
promoted simply providing the fastener fabric sheet 229 about the
intermediate portion of the airbag 16. Therefore, the inflation of
the upper and lower chambers 18, 19 is readily improved while
minimizing the increase in the number of parts and complication of
the structure. In other words, the inflation of the intermediate
chamber 20 is reliably delayed.
[0132] A fourteenth embodiment of the present invention will now be
described with reference to FIGS. 25 to 29(b). The differences from
the first embodiment shown in FIGS. 1 to 4 will mainly be
discussed.
[0133] In the fourteenth embodiment, a case 14 for accommodating
the folded airbag 16 has a breakable cover 131 as shown in FIGS. 25
and 26. The breakable cover 131 is located at a side opposite from
the inflator 15. In other words, the case 14 has an opening 14a for
projecting the airbag 16 and the breakable cover 131 covering the
opening 14a. A vertically extending perforation 132 is formed in
the lateral center of the breakable cover 131. The breaking
strength of the perforation 132 is weaker in first portions s1
corresponding to the upper and lower chambers 18, 19 of the airbag
16 than in a second portion s2 corresponding to the intermediate
chamber 20. The perforation 132 has a function to promote the
inflation of the upper and lower chambers 18, 19 in the vertical
direction, or a function to delay the inflation of the intermediate
chamber 20. In this embodiment, the seam 17 shown in FIG. 1 may be
either provided or omitted.
[0134] To differentiate the breaking strength of the perforation
132 between the first portions s1 and the second portion s2, the
airbag 16 may be configured as followings. In an example shown in
FIGS. 27(a) and 27(b), a pitch p1 of the perforation 132 in the
first portions s1 is smaller than a pitch p2 in the second portion
s2. In an example shown in FIGS. 28(a) and 28(b), a width w1 of the
perforation 132 in the first portions s1 is wider than a width w2
in the second portion s2. In an example shown in FIGS. 29(a) and
29(b), a depth d1 of the perforation 132 at the first portions s1
is deeper than a depth d2 in the second portion s2.
[0135] When gas is supplied to the airbag 16 from the inflator 15,
the inflating pressure of the airbag 16 first breaks the breakable
cover 131 at a part corresponding to the first portions s1 along
the perforation 132. Then, as shown by chain double-dashed lines in
FIG. 25, the upper and lower chambers 18, 19 are inflated outward
of the case 14. Thereafter, the part corresponding to the second
portion s2 of the breakable cover 131 is torn along the perforation
132. As shown by chain double-dashed line in FIG. 25, the
intermediate chamber 20 is inflated after a delay.
[0136] Accordingly, in addition to the advantages of the first
embodiment, the fourteenth embodiment has the following
advantage.
[0137] The inflation of the upper and lower chambers 18, 19 is
readily improved simply by forming the perforation 132 with varied
breaking strength in the breakable cover 131 of the case 14
accommodating the airbag 16. In other words, the inflation of the
intermediate chamber 20 is reliably delayed. Therefore, the
increase in the number of parts and the complication of the
structure are minimized.
[0138] To differentiate the breaking strength of the perforation
132 between the first portions s1 and the second portion s2, the
length of each hole in the first portion s1 may be greater than
that in the second portion s2. Alternatively, to differentiate the
breaking strengths of the first portions s1 and the second portion
s2 from each other, two or more elements of the pitch, the width,
the depth, and the hole length may be varied.
[0139] A fifteenth embodiment of the present invention will now be
described with reference to FIGS. 30 to 32(b). The differences from
the fourteenth embodiment shown in FIGS. 30 to 32 will mainly be
discussed.
[0140] In the fifteenth embodiment, the breakable cover 131 of the
case 14 has a vertically extended slit 131a instead of the
perforation 132 as shown in FIGS. 30 and 31. The breakable cover
131 is divided into a pair of pieces by the vertically extended
slit 131a. Hooks 133 are arranged on one of the pieces. Eyes 134
are arranged on the other one of the pieces. Each eye 134
corresponds to one of the hooks 133. Each hook 133 is engaged with
the corresponding eye 134. The opening 14a is closed by engaging
the hooks 133 with the eyes 134 with the folded airbag 16
accommodated in the case 14. The hooks 133 and the eyes 134 have a
function to maintain the opening 14a closed with the breakable
cover 131. The hooks 133 and the eyes 134 have a function to
promote the inflation of the upper and lower chambers 18, 19 in the
vertical direction, or a function to delay the inflation of the
intermediate chamber 20.
[0141] When gas is supplied to the airbag 16 from the inflator 15,
the inflating pressure of the airbag 16 disengages the hooks 133
from the eyes 134. Accordingly, the breakable cover 131 opens the
opening 14a at the vertically extended slit 131a. As shown in FIG.
32(a), a pitch of the hooks 133 and the eyes 134 is represented by
p3 at the first portions s1 that corresponds to the upper and the
lower chambers 18, 19. As shown in FIG. 32(b), a pitch of the hooks
133 and the eyes 134 is represented by p4 at a second portion s2
that corresponds to the intermediate chamber 20. In this
embodiment, the pitch p3 at the first portion s1 is greater than
the pitch p4 at the second portion s2. Therefore, the force
required for opening the opening 14a against the engaging force of
the hooks 133 and the eyes 134 (opening strength) is weaker in the
first portions s1 than in the second portion s2.
[0142] When gas is supplied to the airbag 16 from the inflator 15,
the inflating pressure of the airbag 16 first disengages the hooks
133 from the eyes 134 in the first portions s1. Accordingly, the
upper and lower chambers 18, 19 are inflated outward of the case
14. Thereafter, the hooks 133 and the eyes 134 are disengaged from
each other in the second portion s2, which inflates the
intermediate chamber 20 after a delay.
[0143] Therefore, according to the fifteenth embodiment, the
inflation of the upper and lower chambers 18, 19 is readily
promoted simply by forming the hooks 133 and the eyes 134 at
varying pitch in the breakable cover 131 of the case 14
accommodating the airbag 16. In other words, the inflation of the
intermediate chamber 20 is reliably delayed. This embodiment
therefore has the same advantages as the fourteenth embodiment.
[0144] A sixteenth embodiment of the present invention will now be
described with reference to FIG. 33. The differences from the first
embodiment shown in FIGS. 1 to 4 will mainly be discussed.
[0145] In the sixteenth embodiment, a seam 17 of an airbag 16 is
formed to be T-shaped as shown in FIG. 33. The seam 17 has a
vertical seam portion 17a and a lateral seam portion 17b. When the
airbag 16 is deployed, the vertical seam portion 17a extends
vertically at a center of the airbag 16 in a vehicle moving
direction (lateral direction as viewed in FIG. 33). The lateral
seam portion 17b is connected to the lower end of the vertical seam
portion 17a and extends laterally. A front guiding seam portion 17c
is provided at the front end of the lateral seam portion 17b. A
rear guiding seam portion 17d is provided at the rear end of the
lateral seam portion 17b. The front guiding seam portion 17c is
spaced from the front edge of the airbag 16 by a predetermined
distance and extends substantially parallel to the front edge of
the airbag 16. The rear guiding seam portion 17d is located at a
position corresponding to the gas ports 15a of the inflator 15 and
extends slantly to guide gas injected from the gas ports 15a to a
part below the lateral seam portion 17b.
[0146] When the airbag 16 is deployed, the vertical seam 17a
extends perpendicular to the direction in which the ribs Pr of the
occupant P extend. That is, the vertical seam portion 17a is an
intersecting portion that intersects the ribs Pr of the occupant P.
The seam 17 partially limits the inflation of the central portion
of the airbag 16 such that the area of the airbag 16 contacting the
occupant P is less in the flank of the occupant than in the
shoulder Ps and the lumbar region Ph. The flank refers to a part
including the thorax Pc and the abdomen. In FIG. 33, the ribs Pr of
the occupant P are schematically shown. A vent hole (not shown) is
formed in a part of the airbag 16 to discharge gas from the
interior.
[0147] When the airbag 16 is deployed, the seam 17 partially limits
the inflation of the airbag 16. As a result, the degree of
inflation of the part of the airbag 16 that corresponds to the
flank of the occupant P is less than the degree of inflation of the
part of the airbag 16 that corresponds to the shoulder Ps and the
lumbar region Ph. The difference in the inflation degrees causes
the area of the airbag 16 contacting the flank to be less than the
area of the airbag 16 contacting the shoulder Ps and the lumbar
region Ph. Therefore, even if the internal pressure of the airbag
16 is uniform, the reaction force of the airbag 16 applied to the
flank is reduced where the contacting area of the airbag 16 is
small. Therefore, constraining force applied to the flank is less
than constraining force applied to the shoulder Ps and the lumbar
region Ph. That is, although the impact on the flank is reduced,
the shoulder Ps and the lumbar region Ph are sufficiently
constrained by the airbag 16. As a result, the entire body of the
occupant P including the flank is effectively protected.
[0148] When the airbag 16 is deployed, the vertical seam portion
17a intersects with the ribs Pr of the occupant P. Therefore, the
contacting area of the airbag 16 is reduced over all the ribs Pr,
or over the entire flank. The occupant is thus effectively
protected. If the vertical seam portion 17a is narrow and parallel
to the ribs Pr, the contacting area of the airbag 16 is reduced
only at one of the ribs Pr that corresponds to the vertical seam
portion 17a. In this case, the contacting area of the airbag 16 of
parts that do not correspond to the vertical seam portion 17a is
not reduced.
[0149] The seam 17 has the vertical seam portion 17a extending
vertically and the lateral seam portion 17b extending laterally.
The vertical seam portion 17a and the lateral seam portion 17b
cooperate to effectively limit the inflation of a part of the
airbag 16 corresponding to the flank in a wide region. The lateral
seam portion 17b guides the flow of gas to quickly deploy the
airbag 16 despite the vertical seam portion 17a. The guiding seam
portions 17c, 17d at the ends of the lateral seam portion 17b
smoothly guide gas from the gas ports 15a at the lower portion of
the inflator 15 to the upper portion of the airbag 16 through the
section below the lateral seam portion 17b, thereby rapidly deploys
the airbag 16.
[0150] The operation and the advantages of this embodiment are
realized in some of the preceding embodiments, for example, in the
side airbag apparatus having the V-shaped seam 17 shown in FIG.
11.
[0151] The above described embodiments may be modified as
follows.
[0152] To make the internal pressure of the intermediate chamber 20
lower than those of the upper and lower chambers 18, 19, the
cross-sectional area of the gas passage from the inflator 15 to the
intermediate chamber 20 may be restricted.
[0153] Instead for forming the airbag by sewing the ground fabric
sheets 16a, 16b, the airbag may be formed with a single hollow
weave.
[0154] Instead of woven cloth, the airbag may be formed with other
materials, such as nonwoven fabric or synthetic resin sheets.
[0155] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
* * * * *