JP4504116B2 - Airbag device - Google Patents

Description

  The present invention provides a first air chamber for protecting a chest (waist) provided with an inflator and a second air chamber for protecting a head for introducing gas of the inflator from the first air chamber. More particularly, 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 protection region 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 with a fixed configuration is provided, and the gas in the lower chamber flows into the upper chamber, the intermediate portion of the check valve moves upward due to the pressure of the gas flowing into the upper chamber from the lower chamber through the communicating portion. The check valve is released and the check valve is released, and the gas in the lower chamber flows into the upper chamber, but when the gas outflow pressure from the upper chamber to the lower chamber is applied, the communication portion is connected by the intermediate portion of the check valve. An air bag apparatus has been proposed in which the gas is blocked 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 separately prepared and fixed to a partition wall of a size that can be attached, and the number of parts increases, 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 smoothly deploy the chest 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, which is the upper air chamber of the airbag, at the time of collision with a relatively small amount of gas so that the head of the occupant can be efficiently protected. 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 a first air chamber for protecting a lumbar region or a chest, a second air chamber for protecting a head portion, and a gas from an inflator interposed between the first and second air chambers. Respectively, a first and a second communication hole for introducing the gas distributed by the diffuser into the first and second air chambers, and the second communication chamber. A first tether for guiding the gas blown out from the hole so as to wrap around from the rear to the front of the airbag head protection area, and is located below the head protection area and above the waist or chest protection area The shoulder protection area is provided with a thickness regulating portion for regulating the thickness of the shoulder protection area by stitching the front and back base fabrics of the airbag together, and the opening area of the first communication hole is the second area. It is characterized by being formed smaller than the opening area of the communication hole. It is an air bag device to.
According to a second aspect of the present invention, in the airbag device according to the first aspect, the second tether is disposed with a gap between the second tether and the first tether at a position adjacent to the second communication hole. The airbag device is characterized in that gas can flow into the shoulder protection region through the gap.
According to a third aspect of the invention, there is provided the airbag apparatus according to the second aspect, wherein the second tether is formed by sewing base fabrics on the front and back of the airbag in a circular shape. is there.
According to a fourth aspect of the present invention, in the airbag device according to any one of the first to third aspects, the communication hole for distributing the gas from the inflator to the second air chamber has an internal pressure of the diffuser of the second When the air pressure becomes smaller than the internal pressure of the air chamber, the air bag device is closed by the pressure difference.
According to a fifth aspect of the present invention, in the airbag device according to any one of the first to fourth aspects, an exhaust port is provided at an end of the first air chamber opposite to the inflator, and a jet of gas from the inflator The air bag apparatus is characterized in that the pressure in the first air chamber is adjusted by flowing out the air to the outside .
According to a sixth aspect of the present invention, in the airbag device according to any one of the first to fifth aspects, a first air chamber is provided at a side portion of the diffuser, and a second air chamber is provided at an upper portion thereof. The airbag device is characterized by that .

According to the present invention, the following effects can be obtained.
1. When the airbag is deployed, the head 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 the gas is smoothly supplied to the head protection area. Can be sent in.
Also, when the airbag is inflated, the thickness of the shoulder protection area is regulated by the tether to be thinner than the head protection area, so even if the space between the occupant and the side wall is narrow, the gap between the occupant and the side wall is affected. Instead, the inflation gas from the inflator can be smoothly sent to the head protection area.
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.
3. Even when the gas flow path is constricted between the occupant and the side wall when the inflator is inflated and deployed, a part of the gas can escape to the body part and an abnormal increase in pressure can be prevented.
4). In the present invention, since the tether is formed by stitching the front and back base fabrics together when sewing the airbag, a gas introduction path can be formed simultaneously with the stitching of the airbag, and the manufacturing cost can be reduced.
5). Since there is a gap between the second communication hole of the airbag and the first tether, gas can escape through the gap even when the airbag is narrowed between the occupant and the door trim. Therefore, there is no possibility that the gas that has become an overpressure state due to constriction hits the head directly or damages the airbag.
6). 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 and the cost can be reduced.

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. A lower air chamber 12 for protecting the chest (or lumbar region) 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. It is divided.

  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 has a first communication hole 30b for distributing gas from the inflator to the lower air chamber 12. The first communication hole 30b has a smaller opening area than the second communication hole 40e, and the diffuser 30 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 releasing the pressure in the lower air chamber during the expansion of the lower air chamber and absorbing the occupant's impact.

  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, on the lower end side of the tether 50, that is, in the vicinity of the partition portion 40 of the diffuser 30, a second tether 52 formed by stitching the base fabrics of the front and back, for example, in a circular shape in the same manner as the first tether 50, A gap G <b> 2 is formed between the first tether 50 and the first 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, as shown in FIG. 1, in the shoulder protection area of the occupant on the diagonally lower right side of the first tether 50, a base fabric on the front and back is also sewn in a circular shape, for example. A tether 54 is formed. 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 thinly, even if the distance between the occupant's shoulder and the door trim is narrow, or even if the amount of gas injected from the inflator is relatively small The air bag can be deployed smoothly.

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.

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. In this state, the partition surface is moved outward by the pressure on the lower air chamber 12 side. Since the force to expand is applied, 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.

  FIG. 3B shows a state in which the pressures in the upper air chamber 14 and the lower air chamber 12 are in equilibrium. In this state, the pressure on the inner and outer surfaces of the partition wall is balanced, so that the gas moves through the second communication hole 40e. There is nothing. 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 directed to the upper air chamber 14 and is ejected into the upper air chamber through the second communication hole 40e provided in the partition 40, and a part of the gas is The lower air chamber 12 is expanded by being ejected 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 opposite to the inflator 20 of the lower air chamber 12 of the airbag 10, that is, at the front end thereof, and a gas jet from the inflator 20 is directed to the outside from the vent hole 16. The pressure in the lower air chamber 12 flows out and is adjusted so as to effectively protect the occupant's lower back (chest). 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, as shown in FIG. 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 possible to sufficiently protect the head that is lighter than the waist and therefore needs to be kept fixed for a long time.

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. 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 is also included to be attached to both sides as a unit.

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' ... Exhaust port, 20, 20 '... Inflator, 30, 30' ... Diffuser, 30b, 30b '... First communication hole, 40 , 40 '... partitioning part, 40e, 40e' ... second communication hole, 50 ... first tether, 52 ... second tether, 54 ... third tether.

Claims (6)

A first air chamber for protecting the lumbar region or the chest, a second air chamber for protecting the head portion, and a diffuser interposed between them to distribute gas from the inflator to the first and second air chambers, respectively. First and second communication holes for introducing the gas distributed by the diffuser into the first and second air chambers;
A first tether that is provided in the second air chamber and guides the gas blown out from the second communication hole so as to go around from the rear of the airbag head protection area to the front; In the shoulder protection area located below the protection area and above the waist or chest protection area, a thickness regulating portion for regulating the thickness of the shoulder protection area is provided by stitching the base fabrics on the front and back of the airbag together. The airbag device is characterized in that an opening area of the first communication hole is smaller than an opening area of the second communication hole. In the airbag apparatus described in Claim 1,
The second tether is disposed at a position adjacent to the second communication hole with a gap between the first tether and allows gas to flow into the shoulder protection region through the gap. Air bag device. In the airbag apparatus described in Claim 2,
The airbag device according to claim 2, wherein the second tether is formed by sewing base fabrics on the front and back of the airbag into a circular shape. In the airbag apparatus as described in any one of Claim 1 thru | or 3,
The communication hole for distributing the gas from the inflator to the second air chamber is closed by the pressure difference when the internal pressure of the diffuser becomes smaller than the internal pressure of the second air chamber. apparatus. In the airbag apparatus as described in any one of Claim 1 thru | or 4,
An air bag device characterized in that an exhaust port is provided at an end of the first air chamber opposite to the inflator, and a gas jet from the inflator flows out to adjust the pressure in the first air chamber. . In the airbag apparatus as described in any one of Claim 1 thru | or 5,
The airbag apparatus according to claim 1, wherein a first air chamber is provided at a side portion of the diffuser and a second air chamber is provided at an upper portion thereof .

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