JP5973836B2 - Vehicle airbag - Google Patents

Description

  The present invention relates to a vehicle airbag that can suppress thermal damage without increasing rigidity when it has both a check valve function and a function of changing the inflow direction of an inflator gas.

  A vehicle airbag may include a check valve for the purpose of preventing the inflator gas jetted into the airbag body from flowing backward. The “side impact airbag device” of Patent Document 1 aims to provide a side impact airbag device capable of maintaining the gas pressure in the lower chamber at a sufficiently high pressure for a long time. A sheet-like material such as a resin sheet is formed into a bag shape, and the inside is partitioned into a lower lower chamber and an upper upper chamber by a seam. There is a vent hole in the upper room. The rear end of the seam is slightly separated from the rear edge of the airbag, and a check valve is provided at a separation portion between the seam and the rear edge of the airbag. The check valve has a cylindrical shape, and a rod-shaped gas generator is disposed therein. This gas generator is arranged so that its longitudinal direction is the vertical direction. The check valve is formed by overlapping two sheets and stitching both sides with seams, and prevents gas from flowing out from the lower chamber to the upper chamber.

  The “check valve and airbag for airbag” disclosed in Patent Document 2 aims to prevent a backflow of fluid connection between two chambers formed in an airbag of an automobile occupant restraint system. A connection hose is provided between the first chamber and the second chamber as a check valve for the bag, and an inner cloth is disposed in the connection hose. The connecting hose is divided into a fluid passage between the first chamber and the second chamber and a pressure chamber connected to the second chamber by the inner cloth. When the internal pressure of the second chamber is lower than the internal pressure of the first chamber, the inner cloth opens the fluid passage, and when the internal pressure of the second chamber is higher, the inner passage acts on the fluid passage by the internal pressure acting on the pressure chamber. Close.

Japanese Patent Laid-Open No. 2004-256017 JP 2001-63502 A

  The background art includes a cylindrical check valve and a connection hose with a check valve as means for circulating the inflator gas from one chamber to the other chamber. Inflator gas circulates through these check valves and connecting hoses. Inflator gas is hot.

  When changing the outflow direction of the inflator gas, a portion for changing the direction of gas flow is set in the connecting hose or the like by bending or the like. The inflator gas hits this part directly when circulating through the connecting hose and the like. When the direct hit of the high-temperature inflator gas is received, the direction change portion is damaged. If damage occurs, the function of the check valve may be impaired.

  For the purpose of reducing damage, it is conceivable to provide a reinforcing cloth at a site that is directly hit by the inflator gas. When the reinforcing cloth is provided, the rigidity of the connection hose and the like is increased, the flexibility is lowered, and it is difficult to deform. The action of the check valve depends on the flexibility of the connecting hose and the like. It is conceivable that the function of the check valve is lowered when the flexibility is lowered and the deformation becomes difficult.

  The present invention was devised in view of the above-described conventional problems, and suppresses thermal damage without increasing rigidity when the check valve function and the function of changing the outflow direction of the inflator gas are combined. An object of the present invention is to provide a vehicle airbag that can be used.

  The vehicle airbag according to the present invention has an airbag main body having a plurality of chambers, an inflator for injecting inflator gas into the airbag main body, and a structure in which the inflator gas flows from the inflator into any one of the chambers. In a vehicle airbag, a duct made of a foldable material is provided at a portion where the inflator gas flows into the chamber, and the inflow direction of the inflator gas is changed at the end of the gas outflow side of the duct. A folded portion formed by folding a part of the duct toward the inside of the duct, and a divided portion where the duct is divided so as to face the folded portion, and the folded portion of the chamber into which the inflator gas flows It is characterized by being blocked in accordance with an increase in internal pressure.

  It is desirable that the folded portion is formed by mountain-folding inwardly into the duct with a pair of folded portions as a base, and a leading end portion of the folded portion directed toward the divided portion, and the pair of folded portions joined together. It is preferable that the folded portion is further formed by valley-folding the distal end portion of the folded portion with a pair of second folded portions as a base, and joining the second folded portions.

  Alternatively, the folded portion has a pair of folded portions as the base, and the folded tip is folded inward into the duct with the folded portion directed toward the divided portion, and a joining portion is formed between the folded portion and the tip portion. It is desirable that

  In the vehicle airbag according to the present invention, when both the check valve function and the function of changing the outflow direction of the inflator gas are provided, thermal damage can be suppressed without increasing rigidity.

1 is a partially broken perspective view showing a preferred embodiment of a vehicle airbag according to the present invention. It is a principal part expansion perspective view of the duct integrated in the vehicle airbag shown in FIG. It is explanatory drawing explaining the assembly process of the duct shown in FIG. It is a principal part expansion perspective view explaining the check valve function of the duct shown in FIG. It is a principal part expansion perspective view of the duct applied to the 1st modification of the vehicle airbag which concerns on this invention. It is a principal part expansion perspective view of the duct applied to the 2nd modification of the vehicle airbag which concerns on this invention. It is explanatory drawing explaining the assembly process of the duct shown in FIG. It is explanatory drawing explaining the duct applied to the 3rd modification of the vehicle airbag which concerns on this invention.

  Hereinafter, preferred embodiments of a vehicle airbag according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a partially broken perspective view of a vehicle airbag 1 according to the present embodiment, FIG. 2 is an enlarged perspective view of a main part of a duct 2 incorporated in the vehicle airbag 1, and FIG. 3 is shown in FIG. 4 is an explanatory view for explaining the assembly process of the duct 2, and FIG. 4 is an enlarged perspective view of a main part for explaining the check valve function of the duct 2 shown in FIG.

  In the present embodiment, a side airbag that is deployed and inflated in a gap between an occupant side portion and a vehicle body side portion will be described as an example. However, it is needless to say that any airbag can be used.

  As is well known in the art, the airbag body 3 that is deployed and inflated by the inflator gas that is ejected is formed in the form of a bag. The airbag body 3 in the illustrated example is formed by joining two base fabrics 4 having flexibility at a joining portion S1 along their outer peripheral edges. Of course, any method known in the art may be used for forming the airbag body 3.

  A plurality of chambers 5 and 6 are provided inside the airbag body 3. The plurality of chambers 5 and 6 are defined by a partition member 7 having flexibility. The outer peripheral edge of the partition wall member 7 is joined to the inner surface of the airbag body 3 by the joining portion S2, and the chambers 5 and 6 are partitioned airtightly.

  In the present embodiment, the partition member 7 shows the case where the interior of the airbag body 3 is divided up and down to form the upper chamber 5 and the lower chamber 6, but in addition, the front and rear partitions, the left and right partitions, etc. The interior of the airbag body 3 may be partitioned in any way. Moreover, although the case where the two chambers 5 and 6 are formed in the airbag main body 3 by one partition member 7 is illustrated, three or more chambers may be formed.

  The partition member 7 is formed with a through hole 8 that allows the chambers 5 and 6 to communicate with each other. The through hole 8 of the partition wall member 7 is provided with a hollow cylindrical duct 2 formed of a foldable material. The upper end opening 2 a of the duct 2 is located inside the upper chamber 5, and the lower end opening 2 b of the duct 2 is located inside the lower chamber 6. The duct 2 communicates the upper chamber 5 and the lower chamber 6. The outer periphery of the duct 2 is airtightly joined to the through hole 8 at the joint S3. Further, the duct 2 is integrally joined at one side edge to the airbag body 3 at the joint S1.

  Inside the duct 2, an inflator 9 having a gas ejection hole 9a for ejecting inflator gas is provided. The inflator 9 of this embodiment is formed in a cylinder shape that is long in the vertical direction along the length direction of the duct 2. The gas ejection hole 9a of the inflator 9 is disposed so as to be located on the lower chamber 6 side.

  A hollow cylindrical diffuser 12 surrounding the outer periphery of the inflator 9 is further provided inside the duct 2 so as to cover the gas ejection holes 9a. The diffuser 12 rectifies and distributes the inflator gas ejected from the gas ejection holes 9a upward and downward in the duct 2. The distributed inflator gas flows out from the lower end opening 12a of the diffuser 12 into the lower chamber 6 through the lower end opening 2b of the duct 2, and at the same time, from the upper end opening 12b of the diffuser 12, the upper end opening 2a of the duct 2. It flows out into the upper chamber 5 via.

  While the lower end opening 12a of the diffuser 12 is positioned below the inflator 9, the upper end opening 12b is positioned around the inflator 9, so that the inflator gas ejected from the diffuser 12 is transmitted from the lower end opening 12a to the inflator 9. The gas flows out vigorously at a high gas pressure G1 without being obstructed by the gas flow, whereas the gas flows out from the upper end opening 12b at a low gas pressure G2 (<G1) due to the throttling action of the inflator 9. Thereby, the internal pressure of the lower chamber 6 into which the inflator gas G1 having a high gas pressure flows becomes higher than the internal pressure of the upper chamber 5 into which the inflator gas G2 having a low gas pressure flows.

  The duct 2 will be described with reference to FIG. 2 and FIG. 3 showing an example of an assembly process. The upper end opening 2a and the lower end opening 2b of the duct 2 are end portions on the gas outflow side of the inflator gas. In the present embodiment, the lower end opening 2b of the duct 2 has a function of changing the outflow direction of the inflator gas. The outflow direction changing function may be provided in the upper end opening 2a, or may be provided in both the upper end opening 2a and the lower end opening 2b.

  As shown in FIG. 3A, the duct 2 is formed from, for example, a single duct-forming base fabric 10. As shown in FIG. 3B, the duct-forming base fabric 10 is folded in two along the longitudinal fold line F1. Thereby, the overlapping edge X is formed along the vertical direction on the opposite side of the vertical folding line F1. A lower portion of the overlapping edge X forms a divided portion Y that becomes the lower end opening 2b as described later.

  Next, as shown in FIG. 3C, at the position of the vertical fold line F1 at the lower part of the duct 2, the part of the duct 2 is folded back so as to be folded inward toward the overlapping edge X toward the inside of the duct 2. The folded portion P is formed. When the folded portion P is formed, the lower portion (divided portion Y) of the overlapping edge X faces the folded portion P. By forming the folded portion P, four duct forming base fabrics 10 are stacked on the lower portion of the duct 2 as shown in FIGS. 3 (c) and 3 (d).

  Specifically, when the folding portion P is formed at the position of the vertical folding line F1, a pair of folding points F2 are formed in an oblique direction from the vertical folding line F1 position toward the overlapping edge X. Using the folded portion F2 as a base, the tip portion Z of the folded portion P is mountain-folded inward of the duct 2 toward the divided portion Y.

  As a result, a structure is obtained in which four duct-forming base fabrics 10 are stacked in the lower part of the duct 2 in a triangular shape. Next, as shown in FIGS. 3E and 3F, the pair of folded portions F2 are joined together at the joining portion S4. That is, the pair of folded portions F2 in the oblique direction are collectively joined at the joint S4 in a stack of four sheets. Further, the overlapping edge X is joined to the upper portion of the folded portion P by the joining portion S5.

  Thereby, as shown in FIG.2 and FIG.3 (g), the location which is not joined by joining part S5 among the overlapping edge X becomes the division part Y, and the lower end opening part 2b of the duct 2 by this division part Y Is formed.

  The divided portion Y is formed sideways on the side edge of the duct 2. The inflator gas flowing downward from the duct 2 flows out from the lower end opening 2b formed laterally by the folded portion P and the divided portion Y into the lower chamber 6 with the outflow direction being changed in the lateral direction. Thereby, the outflow direction changing function of the inflator gas is exhibited.

  In addition, the duct 2 is formed of a foldable material as shown in FIG. 4, and the folded portion P is crushed and the divided portion Y is blocked as the internal pressure increases in the lower chamber 6. Thus, the function of a check valve that seals the lower end opening 2b of the duct 2 is exhibited. The upper end opening 2a is formed upward by joining the overlapping edge X of the duct 2 along the length direction of the duct 2 at the joining portion S5.

  The operation of the vehicle airbag 1 according to this embodiment will be described. When the inflator 9 is activated, the inflator gas ejected from the gas ejection holes 9a flows out upward and downward in the duct 2 by the rectification and distribution action by the diffuser 12, and then flows out from the upper end opening 12b and the lower end opening 12a.

  The inflator gas going upward flows upward into the upper chamber 5 from the upper end opening 2a, and the upper portion of the airbag body 3 is expanded and inflated upward. The inflator gas going downward collides with the folded portion P at the lower part of the duct 2, the outflow direction is changed from the lower end opening 2 b formed by the divided portion Y, and flows into the lower chamber 6 sideways. Thereby, the lower part of the airbag body 3 is deployed and inflated forward from the seat on which the occupant is seated toward the front instrument panel.

  As described above, the internal pressure of the lower chamber 6 into which the inflator gas G1 having a high gas pressure flows is higher than the internal pressure of the upper chamber 5 into which the inflator gas G2 having a low gas pressure flows. In response to the rise, the folded portion P is crushed and the divided portion Y is closed, whereby the duct 2 can function as a check valve.

  In the vehicle airbag 1 according to the present embodiment, a duct 2 formed of a foldable material is provided at a portion where the inflator gas flows into the lower chamber 6, and the outflow direction of the inflator gas is set at the lower end opening 2 b of the duct 2. In order to change, a folded portion P where the lower portion of the duct 2 is folded back toward the inside of the duct 2 and a divided portion Y where the duct 2 is divided facing the folded portion P are provided. Thereby, the outflow direction of the inflator gas going downward can be changed sideways.

  The folded portion P that exerts the function of changing the inflow direction of the inflator gas is directly hit by the high-temperature inflator gas, but the duct forming base fabric 10 is overlapped by the folding, so that the reinforcing fabric is separately joined. In comparison, thermal damage due to high-temperature inflator gas can be suppressed without increasing rigidity.

  In the present embodiment, the folded portion P is formed by folding the tip end portion Z of the folded portion inward of the duct 2 with the pair of folded portions F2 as a base portion toward the divided portion Y, and joining the pair of folded portions F2 together. Has been. As a result, the inflator gas hits directly when the folded tip portion Z is mountain-folded, there is no joint portion, and the duct-forming base fabric 10 overlaps when the mountain fold is flattened. On the other hand, the joint portion S4 that is the folded portion P and joins the pair of folded portions F2 to form the duct 2 is covered with the folded portion P, so that direct hit of the inflator gas can be avoided.

  Therefore, the function of changing the inflow direction of the inflator gas is provided, and thermal damage due to direct hitting of the inflator gas can be reduced.

  Since the duct 2 is formed of a material that can be bent, the folded portion P is crushed in multiple as the internal pressure of the lower chamber 6 increases, and the divided portion Y is blocked, thereby opening the lower end opening 2b of the duct 2. The function of the check valve for blocking can be exhibited.

  Therefore, the inflator gas flows backward from the lower chamber 6 partitioned by the partition wall member 7 toward the upper chamber 5 and the inflator gas flows from the upper chamber 5 toward the lower chamber 6. 1 can be properly expanded and inflated as set.

  As described above, the vehicle airbag 1 according to the present embodiment suppresses thermal damage without increasing rigidity when both the check valve function and the function of changing the inflow direction of the inflator gas are provided. can do.

  FIG. 5 shows a first modification of the above embodiment. FIG. 5 is an enlarged perspective view of a main part of the duct 2. In the first modification, the folded portion P is further folded at the tip Z of the folded portion P with the second folded portion F3 set at the middle in the vertical direction of the folded portion P as a base, and the second folded portions F3 are individually set. Individually formed by joining at the joint S6.

  The starting point inside the duct 2 of the second folding point F3 is preferably set in the vicinity of the position of the vertical folding line F1 of the folding point F2. Thereby, it can fold stably.

  Even in the first modification, it is a matter of course that the same operational effects as the above-described embodiment can be obtained. By folding the folded portion P in the valley, the flow of the inflator gas can be guided, and the inflator gas can smoothly flow out from the lower end opening 2b. Further, the folded portion P can be smoothly and accurately collapsed by the second folded portion F3, and the check valve function can be exhibited quickly and reliably.

  6 and 7 show a second modification of the above embodiment. FIG. 6 is an enlarged perspective view of a main part of the duct 2, and FIG. 7 is an explanatory diagram for explaining an assembly process of the duct 2 shown in FIG. 6. The processes from FIG. 6A to FIG. 6D are the same as in the above embodiment.

  In the second modified example, as shown in FIGS. 6E and 6F, instead of the joint portion S4, a joint portion S7 is set between each folded portion F2 and the leading end portion Z of the folded portion. Join. That is, unlike the above-described embodiment, the configuration is different from the configuration in which the folded portion F2 is joined together at the joint S4. In this modified example, the joint portion S7 is set in the vicinity of each folded portion F2 and formed at two locations. Thereby, in the 2nd modification, as shown in Drawing 6 and Drawing 7 (g), return part F2 is divided into two forks, and return part P without return tip part Z is formed.

  Also in the second modification, a portion of the overlapping edge X that is not joined at the joining portion S5 becomes the divided portion Y, and the lower end opening 2b is formed by the divided portion Y. The divided portion Y is formed sideways on the side edge of the duct 2. The inflator gas flowing downward in the duct 2 flows out from the lower end opening 2b formed laterally by the folded portion P and the divided portion Y into the lower chamber 6 with the outflow direction changed in the lateral direction. Thereby, the outflow direction changing function of the inflator gas is exhibited.

  In addition, the duct 2 functions as a check valve that seals the lower end opening 2b of the duct 2 by collapsing the folded portion P and closing the divided portion Y in accordance with the increase in internal pressure in the lower chamber 6. Is demonstrated. Even in the second modified example, it is a matter of course that the same operational effects as those of the above-described embodiment and modified example can be obtained.

  In the second modified example, unlike the above-described embodiment and the first modified example in which the folded portions F2 are joined together, the joining portion S7 of the folded portions F2 is separated from the left and right, so that the opening ratio of the lower end opening 2b is increased. And the inflator gas can flow out smoothly.

  Since the inflator gas directly hits the folded portion P having no joint portion, the joint portion F7 can be prevented from being thermally damaged. When the internal pressure of the lower chamber 6 rises, the folded portion P becomes a pressure receiving surface and is easily crushed. Therefore, the lower end opening 2b can be appropriately closed to prevent the inflator gas from flowing backward.

  FIG. 8 shows a third modification of the above embodiment. FIGS. 8A and 8B show an example of an assembly process of the duct 2 according to the third modification, and FIG. 8C shows a duct forming base fabric 11 used for different assembly.

  In the second modified example of FIG. 7, the joint portion S7 is set in the vicinity of the folded portion F2, but in this case, the lower end opening 2b has a very large opening ratio. Therefore, when reducing the aperture ratio, as shown in FIG. 8A, it is desirable to set the joint portion S7 closer to the distal end portion Z side than the bent portion F2. In this case, as shown in FIG.8 (b), it is preferable to cut off the surplus part Q outside a junction part S7.

  FIG. 8C shows a case where the surplus portion Q is cut from the duct forming base fabric 11 along the cutting line C in advance. Even in this case, the duct 2 having a small opening ratio of the lower end opening 2b can be formed.

  By reducing the opening ratio of the lower end opening 2b, it is possible to ensure a check valve action that is faster than when the opening ratio is large. Even in the third modified example, it is a matter of course that the same operational effects as those of the above-described embodiment and modified example can be obtained.

  In the above embodiment and each modified example, the description has been given using the side airbag that is deployed and inflated between the occupant and the vehicle body side part, but a so-called front airbag that is deployed and inflated from the front to the rear of the occupant. Of course, the present invention may be applied to a so-called curtain airbag that expands and inflates downward from the ceiling.

  Of course, the joining portions S1 to S7 described in the above embodiment may be formed by any conventionally known joining method such as sewing, adhesion, welding, and knitting.

  In addition, in the present embodiment, the case where the gas ejection hole 9a of the inflator 9 is provided on the lower chamber 6 side and the lower end opening 12a of the diffuser 12 is positioned below the inflator 9 has been described as an example. Thus, the gas ejection hole 9 a of the inflator 9 may be provided on the upper chamber 5 side, and the upper end opening 12 b of the diffuser 12 may be positioned above the inflator 9. In this case, the internal pressure of the upper chamber 5 into which the inflator gas G1 having a high gas pressure flows is higher than the internal pressure of the lower chamber 6 into which the inflator gas G2 having a low gas pressure flows. The folded portion P and the divided portion Y may be provided on the (upper chamber side).

  The vehicle airbag 1 described above is a preferred example of the present invention, and other embodiments can be implemented or performed by various methods. In particular, the present invention is not limited to the detailed shape, size, configuration, and the like of the components shown in the accompanying drawings unless otherwise stated in the present specification. In addition, expressions and terms used in the present specification are for the purpose of explanation, and are not limited thereto unless otherwise specified.

DESCRIPTION OF SYMBOLS 1 Vehicle airbag 2 Duct 2a Upper end opening 2b Lower end opening 3 Airbag main body 5 Upper chamber 6 Lower chamber 8 Through hole 9 Inflator F2 Folding place F3 Second folding part P Folding part S4, S6, S7 Joint Y Part Z Folding tip

Claims (4)

An airbag main body having a plurality of chambers, an inflator for injecting inflator gas into the airbag main body, and a vehicle airbag having a structure in which the inflator gas flows into any one of the chambers from the inflator,
In the part where the inflator gas flows into the chamber, a duct made of a foldable material is provided,
A folded portion formed by folding a part of the duct inwardly toward the inside of the duct so as to change the outflow direction of the inflator gas at an end portion on the gas outflow side of the duct, and facing the folded portion. Has a divided part,
The vehicle airbag according to claim 1, wherein the folded portion is sealed in response to an increase in internal pressure of the chamber into which inflator gas flows.   The folded portion is formed by mountain-folding inwardly into the duct with a pair of folded portions as a base, with a leading end portion of the folded portion directed toward the dividing portion, and the pair of folded portions being joined together. The vehicle airbag according to claim 1.   The vehicle according to claim 2, wherein the folded portion is further formed by valley-folding the tip end portion of the folded portion with a pair of second folded portions as a base portion and joining the second folded portions. Airbags.   The folded portion has a pair of folded portions as a base portion, and a folded tip is folded inwardly into the duct toward the divided portion, and a joint portion is formed between the folded portion and the tip portion. The vehicle airbag according to claim 1.

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