JP4566629B2 - Airbag device - Google Patents

Description

  The present invention relates to an air bag including a first air chamber for protecting a lumbar region or a chest having an inflator and a second air chamber for protecting a head for introducing gas of the inflator from the first air chamber. In particular, the present invention relates to an airbag device that can be easily deployed even in a limited space and can easily guide gas to a head protecting portion in a second air chamber.

An air bag is used to protect the occupant during a side collision, but the lumbar part of the occupant sitting on the seat first hits the door and receives an impact, and then the chest part collides with the door. It has been known.
By the way, in the old days, the airbag device for side collision countermeasures inflates the entire one airbag uniformly. However, if this configuration is used to sufficiently absorb the energy at the side collision, In particular, it is not suitable for protecting only the waist first, and is not sufficient as a countermeasure against side collision.

Therefore, the airbag of the side collision airbag device is integrally configured to have two air chambers, a lower airbag corresponding to the occupant side waist and an upper airbag corresponding to the occupant side chest. There is known a system in which a pressure control valve is provided in a partition wall between an upper airbag and a lower airbag so that the lower airbag is inflated before the upper airbag (see Patent Document 1).
In this side collision airbag device, the side collision airbag deployed from the side of the seat cushion is first inflated to the height of the occupant's waist to protect the occupant's waist and then to the height of the chest. Expand.

However, when using side impact airbags, considering not only the waist and chest but also the head, for example, the waist should reach a peak pressure by 4 ms after deployment of the side impact airbag, and then quickly depressurize. In fact, it is necessary to weaken the repulsive force of the side impact airbag on the waist, while the head needs to keep the peak value firmly even if it exceeds 12 ms. It is necessary to make a difference in pressure after inflation according to not only the timing of inflation of the collision airbag but also the body part. However, the conventional one cannot make a difference in pressure between the upper and lower airbags.
Therefore, in this configuration, there is a problem that the pressure cannot be adjusted to an optimum value according to the body part after the side collision airbag is inflated.

Therefore, a partition wall provided with a communication portion is provided inside the bag body of the airbag device, and the bag body is vertically divided into first and second chambers, and both edges of the thin film are formed on the upper surface of the partition wall so as to cover the communication portion. When a check valve having a fixed configuration is provided and the gas in the lower chamber flows into the upper chamber, the intermediate portion of the check valve is moved upward by the pressure of the gas flowing into the upper chamber from the lower chamber through the communication portion. The check valve is released by expanding in an arc shape, and the gas in the lower chamber flows into the upper chamber.However, when the gas outflow pressure from the upper chamber to the lower chamber is applied, the communication portion is opened by the intermediate portion of the check valve. There has been proposed an airbag device that is closed to prevent gas from flowing out from the upper chamber to the lower chamber (see Patent Document 2).
However, in this airbag device, a check valve must be prepared separately and fixed to a partition wall that can be attached to the airbag device, the number of parts is increased, and a communication portion is secured in a shape that requires a small gas passage. There are problems such as being unable to do so.

By the way, in this conventional airbag, since the upper chamber is simply formed in a bag shape, the gas from the inflator diffuses throughout the upper chamber when the airbag is inflated, so that the occupant's head is reliably protected. When trying to do so, a large amount of gas must flow into the upper chamber in a short time. Further, when the gap between the occupant and the door trim or the side wall is narrow, the gas flow from the occupant's chest (or waist) to the head is restricted when the airbag is inflated, so that the deployment of the airbag to the head is delayed. In addition, the pressure increase due to the narrowing of the gas flow may cause the airbag to be partially damaged or partially hit the passenger.
Japanese Patent No. 2933894 (paragraph number “0022”) Japanese Patent Laid-Open No. 10-10087 (paragraph numbers “0021” and “0022” and FIG. 1)

The present invention has been made to solve these problems, and its purpose is to move from the chest (or waist) to the head when the airbag is inflated even when the gap between the door trim and the occupant is narrow. The head protection area is first inflated in the second air chamber of the airbag at the time of collision with a relatively small amount of gas so that the passenger's head can be efficiently protected with a relatively small amount of gas. In addition, even when the airbag is constricted between the occupant and the door trim, the gas pressure is prevented from excessively rising, thereby protecting the occupant safely and reliably.
A second object is to obtain an airbag device having these functions with a simple configuration.

According to the first aspect of the present invention, there is provided an airbag formed by stitching a front-side base fabric and a back-side base fabric, a first air chamber and a head-protecting portion for protecting a waist or a chest provided in the airbag. a second air chamber of sandwiches a sheet of base fabric between the front and back of the base fabric are formed by sewing together with these, the second air chamber and the first air chamber a diffuser for a gas distributor interposed between, are disposed in the diffuser, the inflator for supplying gas to the air bag, the provided diffuser, the first distribution gas by the diffuser and the second It has the first and second communication holes for introducing into the air chamber, wherein the first and second communicating holes, said to be able to introduce the gas from the inflator to the respective air chamber Installed in the first and second air chambers Is and wherein said provided second air chamber second communication hole is opened directed upward so that it can be introduced toward the gas upwards, further wherein the second air the chamber, provided with a first tether for guiding the gas blown into the air chamber from the second communicating hole from the back of the head protection area of the airbag in such a way as to wrap around the front, the second communicating hole and between said first tether, is an air bag device characterized by gaps for releasing a portion of the gas to the front of the second air chamber are formed.
The invention of claim 2 is the airbag device according to claim 1, wherein the first tether, wherein the front and back of the base fabric constituting the second air chamber from the vicinity of the second communication holes The airbag device is formed by stitching upward from the second air chamber.
The invention according to claim 3, in the airbag device according to claim 1 or 2, the gap to escape a part of the gas in front of the second air chamber, said first tether, said at a position spaced a predetermined distance below the first tether, is an air bag device characterized by being formed by a second tether formed by stitching the front and back of the base fabric constituting the second air chamber .
A fourth aspect of the present invention, in the airbag device according to any one of claims 1 to 3, the tether is provided to the occupant's shoulder protection area of the second air chamber, the shoulder protection region of the air bag an air bag device characterized by the thickness when inflated and regulations thinner than the head protection area.
The invention of claim 5 is the airbag device according to any one of claims 1 to 4, wherein the second communication hole for distributing the gas from the inflator to the second air chamber, the diffuser When the internal pressure becomes smaller than the internal pressure of the second air chamber, the airbag device is closed by the pressure difference.
The invention of claim 6 is the airbag device according to any one of claims 1 to 5, wherein the first communication hole is an air bag system, characterized in that less than the second communication hole .
According to a seventh aspect of the invention, in the airbag device according to any one of claims 1 to 6, and an exhaust port is provided near an end opposite to the inflator of the first air chamber, said an air bag device characterized by a gas jet from the inflator by flowing out of the exhaust port to adjust the pressure of the first air chamber.

"Action"
1. According to the present invention, the first tether for guiding the gas blown out from the second communication hole so as to go around from the rear to the front of the head protection region is provided in the second air chamber for protecting the head. Therefore, the inflation gas inflates the second air chamber of the airbag sequentially from the rear of the head of the occupant toward the front along the tether. Further, the width of the airbag is suppressed by the tether, and the head protection area is reliably inflated with a relatively small amount of gas.
2. A gap is formed at the lower end of the first tether in the vicinity of the second communication hole to allow a part of the inflation gas to escape. Even if the airbag is narrowed between the occupant and the side wall (door trim), the gap is removed from the gap. Excessive pressure rise is suppressed by gas outflow.
3. When the internal pressure of the diffuser becomes lower than the internal pressure of the second air chamber during inflation of the airbag, the communication hole is blocked by the pressure difference, so that the first and second air chambers are shut off, The pressure in the second air chamber is maintained. That is, it is possible to reliably protect the head by setting the air chambers having different pressure characteristics between the first air chamber and the second air chamber.

According to the present invention, the following effects can be obtained.
1. When the airbag is deployed, the first tether guides the gas, and the airbag is deployed from the rear of the head. Therefore, the deployment of the airbag is hardly affected by the gap between the occupant and the side wall, and can be quickly deployed with a small amount of low-pressure gas. . Even if the gas flow path is constricted by the occupant and the side wall, part of the gas can escape to the front part of the second air chamber, and an abnormal increase in pressure can be prevented.
2. When the airbag is deployed, the gas rises in the tubular passage formed by the tether and flows so as to wrap around the head protection area from the rear to the front, so it is quickly deployed in the head protection area with a relatively small amount of gas. Can protect the head.
Further, since the tether is formed by stitching the front and back base fabrics together when the airbag is sewn, a gas introduction path can be formed simultaneously with the stitching of the airbag, and the manufacturing cost can be reduced.
3. Since there is a gap between the second communication hole of the second air chamber of the airbag and the first tether, even if the airbag is constricted between the occupant and the door trim, the gas is Since the gas can escape through the gap, there is no possibility that the gas that has been overpressured due to the narrowing directly hits the head or damages the airbag.
4). When the airbag is inflated, the thickness of the shoulder protection region is regulated by the tether to be thinner than the head protection region, so even if the space between the occupant and the side wall is narrow, it is not affected by the gap between the occupant and the side wall. The inflation gas from the inflator can be smoothly sent to the head protection area.
5). Since the diffuser can serve as a valve, the valve function can be easily provided even in a narrow gas flow path, and the number of parts can be reduced, thereby reducing the cost.

A side collision airbag apparatus according to an embodiment of the airbag apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view for explaining the overall configuration of a side collision airbag device.
As shown in the figure, the airbag 10 of the side impact airbag device 1 is composed of a synthetic fiber fabric such as polyamide, polyester, etc. with a resin coating usually used for airbags, and a base fabric 10a on the front and back sides. 10b is sewn with a suture line 10c along the entire periphery thereof, and is further laterally separated by another suture line 10d branched from the suture line 10c for sewing the front and back base fabrics 10a and 10b. It is divided into a lower air chamber 12 for protecting the lumbar region or the chest that is the first air chamber that extends, and an upper air chamber 14 that is the second air chamber for protecting the head that is narrower than that and extends vertically. ing.

  In the lower air chamber 12, a single base cloth having a predetermined length and width is bent at the left end in FIG. 1, and both ends thereof are sandwiched between the base cloths 10a and 10b and stitched together. The formed diffuser 30 is arranged. The diffuser 30 is preferably a cloth having a higher heat resistance than the base cloths 10a and 10b, and rectifies at least a part of the jet flow when gas is ejected from the inflator 20 disposed therein. Further, in the present embodiment, two vent holes (exhaust ports) 16 are provided near the right end of the lower air chamber 12 in the drawing. The vent hole 16 is for absorbing a passenger's impact by releasing the pressure in the lower air chamber when the lower air chamber is inflated.

  In the upper air chamber 14, a first tether 50 is provided substantially parallel to the left end side of the upper air chamber 14 in FIG. The first tether 50 is formed by stitching the front and back base fabrics forming the airbag into, for example, an ellipse as shown in the figure, and between the upper end of the first tether 50 and the upper end of the airbag. A gap G1 serving as a gas flow path is formed. Further, the first tether 50 forms a tubular passage 14a extending upward from a portion communicating with the lower air chamber 12 along the left end portion of the airbag 10 in FIG. The Further, a second tether 52 formed by stitching the front and back base fabrics in the same manner as the first tether 50 is provided on the lower end side of the first tether 50, that is, in the vicinity of the partition 40 of the diffuser 30. A gap G2 is formed between the tether 50 and the tether 50. The gap G2 functions as an escape hole for the pressurized gas when the inflating airbag is constricted in the gap when the gap between the passenger and the door trim is small. Thereby, it can avoid that the pressurized gas hits a passenger | crew's head directly.

  In the upper air chamber 14, a third tether 54 is formed in the shoulder protection region of the occupant on the lower right side of the first tether 50 in FIG. The third tether 54 suppresses the thickness of the airbag in the shoulder protection region. In other words, by suppressing the thickness of the shoulder protection area of the occupant of the airbag, the airbag can be smoothly deployed even when the distance between the occupant's shoulder and the door trim is narrow.

FIG. 2 is an enlarged view of the partition 40 in FIG.
As shown in the figure, a base fabric having a predetermined width and length is folded at this portion, and the folded portion 40a is turned upward, that is, the direction opposite to the direction of the inflator 20, and the lower end portion 40c and both side end portions 40b are airbags. A partition 40 is formed by stitching together with the base fabrics 10a and 10b on the front side and the back side constituting the base 10.
In the folded upper edge portion of the partition portion 40, a second communication hole 40e (see, for example, FIG. 3A) described later for introducing the gas from the inflator 20 into the upper air chamber 14 is provided in this embodiment. Two are formed side by side.

FIG. 3 is a cross-sectional view of the partition portion in FIG. 1 as seen in a plane orthogonal to FIG.
FIG. 3A shows a state in which the pressure in the lower air chamber 12 is higher than that in the upper air chamber 14 at the beginning of the operation of the inflator 20, and in this state, the partition surface is outside by the pressure on the lower air chamber 12 side. Therefore, the second communication hole 40e of the partition 40 is opened, and gas flows from the lower air chamber 12 toward the upper air chamber 14.

  FIG. 3B shows a state in which the pressures of the upper air chamber 14 and the lower air chamber 12 are balanced. In this state, the pressure of the inner and outer surfaces of the partition wall is balanced, so that the gas moves through the second communication hole 40e. Never do. For example, it is in this state when the inflator 20 is not operating.

FIG. 3C shows a state in which, after the pressure in the lower air chamber reaches the maximum pressure, the pressure rapidly decreases and the pressure in the upper air chamber becomes higher than the pressure in the lower air chamber. In this state, the partition surface of the partition portion 40 receives pressure from the outside due to the pressure inside the upper air chamber, and the partition surfaces are brought into close contact with each other. Therefore, the second communication hole 40e of the partition portion 40 is closed and the air chambers 12, 14 is blocked. That is, the partition 40 functions as a check valve.
Reference numeral 40 d denotes a tether, and an upper edge portion folded back in front of the partitioning portion 40 is coupled to one base fabric constituting the airbag 10. The tether 40d is for preventing the inversion when the pressure in the upper air chamber becomes higher than the pressure in the lower air chamber, and all parts other than the folded portion are sewn to the base fabric of the airbag. In this embodiment, it can be omitted.

Next, the operation of the side collision airbag apparatus 1 according to this embodiment will be described.
The airbag device 1 for side collision according to the present embodiment is housed in an appropriate position such as a cushion material of a vehicle seat, for example, and when an impact due to a collision is applied to the side surface of the vehicle, this is detected by an impact sensor (not shown). Is detected and an initiation signal is sent to the inflator to deploy the airbag. The inflator ejects gas in response to the initiation signal.

  Here, the gas ejected from the inflator 20 is rectified by the diffuser 30 and sprayed into the upper air chamber through the second communication hole 40e provided in the partition 40 facing the upper air chamber 14, and a part of the gas is injected into the first air chamber. The lower air chamber 12 is expanded by being injected into the lower air chamber 12 through the first communication hole 30b smaller than the second communication hole 40e. The gas introduced into the upper air chamber 14 rises toward the head protection region in the tubular passage 14a which is a relatively narrow gas conduction path formed by the first tether 50, and the airbag is Rapidly inflates from the back side of the head to the front to support and protect the head in a stable state. Further, since the third tether 54 is provided in the shoulder protection region of the occupant, the thickness of the portion is regulated to be narrower than the head protection region. Therefore, even when the gap between the passenger and the door trim or the side wall is narrow, the head protection area of the airbag can be quickly inflated and deployed with a relatively small amount of inflation gas, and the entire upper air chamber 14 can be smoothly deployed. Done.

  Further, when the gap between the occupant and the door trim or the side wall is particularly narrow, the airbag that is inflated and deployed may be constricted, and the pressure of the inflation gas may increase excessively. A gap G2 is formed between the lower end of the tether 50 and the upper end of the second tether 52, and a part of the inflation gas passes through the gap G2 and the front portion of the first tether in the second air chamber. Therefore, even in such a case, it is possible to prevent the inflation gas pressure from rising abnormally and damaging a part of the airbag or hitting the occupant directly.

  Here, a vent hole 16 is provided in the vicinity of the end of the lower air chamber 12 opposite to the inflator 20 of the airbag 10, and a gas jet from the inflator 20 flows out of the vent hole 16 to the outside. The pressure in the lower air chamber 12 is adjusted so that the occupant's waist (chest) can be effectively protected. This is to protect the lower back (chest) by rapidly reducing the repulsive force against the lower back by rapidly reducing the pressure in the lower chamber by injecting gas from the inflator 20 when a side collision occurs. is there.

On the other hand, on the upper air chamber 14 side, since the pressure in the lower air chamber is higher than the pressure in the upper air chamber at the beginning of the operation of the inflator 20, and the gas flows in by the diffuser, the gas in the inflator 20 is flown as shown in FIG. 3A. A part of the jet is introduced into the upper air chamber 14 through the second communication hole 40e of the partition 40, and the upper air chamber 14 expands.
As described above, the gas introduced into the upper air chamber 14 first flows upward along the tubular passage 14a of the upper air chamber 14, and the gap G1 between the first tether 50 and the upper end of the air bag. It flows so as to wrap around forward from the rear side of the head of the occupant, and then flows downward from the front. Therefore, the upper air chamber 14 first inflates in order from the rear to the front along the occupant's arm from the portion in contact with the lower air chamber 12 and further along the shoulder from the shoulder. In other words, when a side collision occurs, the occupant's waist is protected first, and then the protection area is expanded in order from the shoulder to the temporal region along the arm, so the occupant's waist, arm, and head are fixed in this order. The safest and most secure.

  In the meantime, the pressure introduced into the upper air chamber 14 acts on the partition 40 from the outside, and the gas pressure from the lower air chamber 12 side acts from the inside. As described above, the lower air chamber As long as the inner pressure continues to be higher than the pressure outside the partition, or as long as the gas from the inflator 20 is rectified by the diffuser and flows in, the gas continues to flow from the lower air chamber 12 side to the upper air chamber 14 side. .

In this state, when the gas pressure in the lower air chamber 12 drops and the gas from the inflator 20 stops flowing, the relationship between the gas pressures acting on the inside and outside of the partition portion is reversed, that is, outside the partition portion, that is, the upper air chamber. Since the pressure acting from the inside is relatively higher than the pressure acting on the inner side surface of the partition portion, that is, the pressure in the lower air chamber 12, the inside of the partition portion is crushed and both side walls are brought into close contact with each other. 40e is closed (see FIG. 3C).
As a result, the pressure in the upper air chamber 14 is maintained at a substantially predetermined maximum value, so that it is lighter than the waist (chest), and thus the head that needs to be kept fixed for a long time can be sufficiently protected. .

FIG. 4 is a view similar to FIG. 1 showing another embodiment of the present invention.
The difference from the side collision airbag apparatus shown in FIG. 1 is that the partition 40 ′ is integrally formed with the diffuser 30 ′, thereby further reducing the number of parts. The other configuration is the same as that shown in FIG. 1, and the same reference numerals with “′” are given to the same parts.
In actual production, if the partition portion 40 ′ and the diffuser 30 ′ are formed integrally, it is impossible to sew both the front and back surfaces of the bag body of the airbag device. Therefore, in this embodiment, the upper end portion of the diffuser 30 ′. Although 30'a is fitted and integrated in the partition part 40 ', the present invention employs a fixing means other than sewing, for example, adhesion or the like, so that the front and back of the bag body of the airbag device can be used. It also includes mounting on both sides as a single unit.

The present invention has been described by taking the side collision airbag device as an example. However, the present invention is not necessarily limited thereto, and the air chamber is described as being composed of an upper air chamber and a lower air chamber. The chambers are not necessarily upper and lower air chambers, but may be front and rear air chambers, for example.
The number of the second air chamber of the present invention is not necessarily limited to one, and a plurality of the air chambers may be provided between the air chambers as necessary.

It is a schematic sectional drawing for demonstrating the whole structure of one Embodiment of the airbag apparatus of this invention. It is an enlarged view of the partition part of FIG. 3A is a cross-sectional view of the partition portion of FIG. 1 in a plane orthogonal to the plane of FIG. 1, FIG. 3A shows a state in which the pressure in the lower air chamber is higher than that in the upper air chamber, and FIG. FIG. 3C shows a state where the pressure in the upper air chamber is higher than the pressure in the lower air chamber. It is a schematic sectional drawing for demonstrating the whole structure of another embodiment of the airbag apparatus of this invention.

DESCRIPTION OF SYMBOLS 1, 1 '... Airbag apparatus, 10, 10' ... Airbag, 10a, 10a ', 10b, 10b' ... Base fabric, 12, 12 '... Lower air chamber, 14, 14 '... upper air chamber, 16, 16' ... vent hole, 20, 20 '... inflator, 30, 30' ... diffuser, 30b, 30b '... first communication hole, 40 , 40 '... partitioning part, 40e, 40e' ... second communication hole, 50, 50 '... first tether, 52, 52' ... second tether, 54, 54 ' ... Third tether.

Claims (7)

An airbag formed by stitching the base fabric on the front side and the base fabric on the back side;
A first air chamber for protecting a lumbar region or a chest and a second air chamber for protecting a head portion provided on the airbag;
Sandwiching a sheet of base fabric between the front and back of the base fabric are formed by sewing together with these, gas distribution interposed between said second air chamber and the first air chamber With a diffuser,
Disposed within said diffuser, an inflator for supplying gas to the airbag,
Provided in the diffuser has a first and second communication holes for introducing the distributed gas into the first and second air chamber by said diffuser,
Said first and second communication holes, the gas is provided to each of the first and second air chamber to be able to introduce the to the respective air chamber from the inflator, the second air wherein provided in the chamber the second communication hole is opened directed upward so that it can be introduced toward the gas upwards, the further the second air chamber, communicating the second provided with a first tether for guiding the gas blown into the gas chamber from the hole from the back of the head protection area of the airbag in such a way as to wrap around the front, between the first tether and the second communicating hole the airbag apparatus characterized by gaps for releasing a portion of the gas to the front of the second air chamber are formed. In the airbag apparatus described in Claim 1,
Said first tether are those formed by sewing toward the front and back of the base fabric constituting the second air chamber above the second air chamber from the vicinity of the second communication holes An airbag device characterized by the above. In the airbag apparatus described in Claim 1 or 2,
Clearance for releasing a portion of the gas to the front of the second air chamber, said first tether, at a position spaced a predetermined distance below the first tether, the second air chamber An airbag device formed by a second tether formed by stitching the front and back base fabrics to be formed. In the airbag apparatus as described in any one of Claim 1 thru | or 3,
Wherein the shoulder protection region of the occupant in the second air chamber provided tether airbag device thickness when inflated of the shoulder protection region of the airbag, characterized in that the regulating thinner than the head protection area. In the airbag apparatus as described in any one of Claim 1 thru | or 4,
It said second communication hole for distributing the gas from the inflator to the second air chamber, when the internal pressure of the diffuser is smaller than the internal pressure of the second air chamber, it is closed by the pressure difference An airbag device characterized by the above. In the airbag apparatus as described in any one of Claim 1 thru | or 5,
Said first communicating hole airbag apparatus characterized by less than the second communication hole. In the airbag apparatus described in any one of Claims 1 thru | or 6,
Wherein and exhaust port is provided near an end opposite the first of said inflator air chambers, to adjust the pressure of the first air chamber gas jet from the inflator by flowing out of the exhaust port An airbag device characterized by that.

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