JP2007176211A - Airbag, and airbag device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag which is capable of sufficiently and effectively constraining an occupant by the airbag, and reducing sewn portions, and rapidly broken. <P>SOLUTION: The capacity of the airbag is set to be relatively small at the initial inflation and development. Capacity control means 81, 82, 83, 84 are provided, which increases the capacity of the airbag 1 when the internal pressure of the inflated and developed airbag 1 reaches a predetermined value or over. During the initial inflation and development, a gas is filled in internal spaces 1a of the airbag on both sides of the capacity control means 81, 82, 83, 84. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of an airbag for receiving an occupant who is inflated and deployed by gas from an inflator or the like in an emergency such as a vehicle collision, and an airbag device including the airbag. .

  In an air bag device provided in a vehicle body fixing part such as a steering wheel in front of an automobile seat or a lower part of an instrument panel, in an emergency such as a vehicle collision, a reaction gas released from an inflator fixed to the vehicle body fixing part The airbag is inflated and catches the occupant moving forward.

  By the way, in the airbag used in such an airbag apparatus, the time required to complete the inflation and deployment at the time of initial inflation and deployment by shortening the speed of inflation and deployment at the time of initial inflation and deployment, The occupant is required to be softly received by the inflated airbag.

  As a conventional airbag that meets such demands, an exhaust port for exhausting gas that inflates the airbag is provided, and this exhaust port is first closed with a suture thread that reduces the capacity of the airbag by a predetermined amount. When the airbag is initially inflated and deployed, the airbag is inflated and deployed more quickly by being reduced in volume by the suture, and then the suture is broken by the internal pressure that rises after the completion of the initial inflation and deployment. There is known an airbag that expands the capacity of the bag and opens the exhaust port so that the gas in the airbag is discharged from the exhaust port and softly receives the occupant (see Patent Document 1).

  However, the airbag described in Patent Document 1 has a problem that the stitched portion by the shape regulating suture is considerably long, the sewing time becomes long, and a large amount of sewing thread is used. Further, since the stitched portion is long, there is a problem that the breaking time of the shape regulating suture also becomes long.

Therefore, there is an airbag in which the number of parts is reduced by reducing stitching of the base fabric as much as possible. (See Patent Document 2)
JP-A-8-119052 JP 2002-67849 A

  However, in the airbags described in Patent Document 1 and Patent Document 2, when the suture portion breaks after the initial inflating and deploying, a force for breaking only from one side of the suture portion is applied. The force for breaking was weak and it took time to break.

  The present invention has been made in view of such circumstances, and an object thereof is to restrain an occupant more effectively and more effectively with an airbag, reduce a stitched portion, and quickly break the occupant. It is to provide an air bag that can be used.

  In order to solve the above-mentioned problems, the invention of claim 1 is an air bag which is made of a base fabric formed in a bag shape and which is inflated and deployed by gas from an inflator. And a capacity control means for increasing the capacity of the airbag when the internal pressure of the inflated and deployed airbag exceeds a predetermined pressure, and the airbag inner space on both sides of the capacity control means during the initial inflation and deployment. And filling the gas.

  The capacity control means is a tear seam for sewing the base fabric, and the air seam breaks when the inner pressure of the airbag becomes equal to or higher than the predetermined pressure, whereby the air seam It is characterized by increasing the capacity of the bag.

  According to a third aspect of the present invention, the capacity control means includes a plurality of sets that can be set so that the capacities of the airbags are different from each other, and the plurality of capacity control means are sequentially set at different timings. The capacity is increased stepwise.

  According to a fourth aspect of the present invention, when the internal pressure of the airbag becomes equal to or higher than the predetermined pressure and the capacity control means increases the capacity of the airbag, the base fabric has the airbag inside the airbag. A vent hole is provided which communicates with the outside of the bag and discharges the gas inside the airbag to the outside of the airbag.

  In the invention according to claim 5, the airbag has an inner bag that is initially inflated and deployed inside the base fabric, and the capacity control means sets the capacity of the inner bag at the time of initial inflation and deployment. The capacity of the airbag is increased when the inner pressure of the inflated and deployed inner bag becomes equal to or higher than a predetermined pressure.

  The invention according to claim 6 is characterized in that the airbag has a positioning tab for positioning when the capacity control means is created.

  The invention of claim 7 comprises the airbag, an inflator for injecting gas into the airbag, a holding means for holding the airbag, and a cover means for covering the folded airbag. It is characterized by that.

  According to the airbag according to the present invention configured as described above, the capacity of the airbag is set to be relatively small at the time of initial inflation and deployment, and when the internal pressure of the airbag that has been inflated and deployed exceeds a predetermined pressure, Capacitance control means for increasing the capacity is provided, and gas is filled in the air bag interior space on both sides of the capacity control means at the time of initial inflation and deployment. At the same time, the subsequent inflation and deployment of the airbag can be speeded up.

  Further, the capacity control means is a tear seam for sewing the base fabric, and when the internal pressure of the airbag becomes a predetermined pressure or more, the tear seam breaks to increase the capacity of the airbag, thereby reducing the number of parts. The structure of the capacity control means can be simplified, and the capacity control means can be easily manufactured.

  Further, the capacity control means is composed of a plurality of air bag capacity that can be set differently, and since the plurality of capacity control means increase the air bag capacity stepwise at different timings, the initial inflation The capacity of the airbag during deployment can be further reduced, the airbag can be inflated and deployed more quickly during initial inflation and deployment, and the internal pressure of the airbag can be further effectively reduced. This makes it possible to restrain the occupant more appropriately.

  Further, when the inner pressure of the airbag becomes equal to or higher than the predetermined pressure and the capacity control means increases the capacity of the airbag, the base fabric communicates the interior of the airbag to the exterior of the airbag and causes the gas inside the airbag to be Since the vent hole to be discharged to the outside is provided, the internal pressure in the airbag can be effectively reduced, and the occupant can be more appropriately restrained by the airbag.

  Further, the airbag has an inner bag that is initially inflated and deployed inside the base fabric, and the capacity control means sets the capacity of the inner bag to be smaller than the capacity of the entire airbag at the time of initial inflation and deployment, and is inflated and deployed. When the inner pressure of the inner bag becomes equal to or higher than the predetermined pressure, the capacity of the airbag is increased. Therefore, the operation of the capacity control means can be overlapped with the inner bag, and the tear seam can be efficiently ruptured by the high-pressure inflation of the inner bag.

  Further, since the airbag has a positioning tab that is positioned when the capacity control means is created, the position of the airbag is not shifted when the capacity control means is created, and the deviation of the airbag during inflation and deployment can be reduced. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first example of an embodiment of an airbag according to the present invention, FIG. 1 (a) shows a passenger-side base fabric of the airbag of the first example, and FIG. 1 (b) shows the first example. It is a figure which shows the attachment side base fabric of the airbag of an example. In the figure, 1 is an air bag, 11 is a first capacity limiting portion, 2 is an air bag occupant side base fabric, 3 is an air bag mounting side base fabric, 4 is an inflator insertion hole, 5 is a mounting hole, and 6 is a vent. Hole, 7 is a sewing part, 21 is a passenger side first folding part, 211 is a passenger side first folding line, 212 is a passenger side second folding line, 31 is a mounting side first folding part, 311 is a mounting side first folding line , 312 is a second broken line on the attachment side, and 81 is a first tear seam as an example of a capacity control means.

  The airbag of the first example is formed in a circular occupant-side base fabric 2 shown in FIG. 1A facing the occupant and the same size as the occupant-side base fabric 2, and a steering wheel or an instrument panel It is comprised from the circular attachment side base fabric 3 shown in FIG.1 (b) attached to the inflator 110 (refer FIG. 14) fixed to vehicle bodies, such as.

  The occupant side base fabric 2 and the attachment side base fabric 3 have a first capacity limiting portion 11. The first capacity limiting unit 11 includes first folded portions 21 and 31 and a first tear seam 81, and the first folded portion includes first folded lines 211 and 311 and second folded lines 212 and 312. There are three. The detailed structure will be described when explaining FIG.

  In addition, a circular inflator insertion hole 4 into which a part of the inflator is inserted is formed at the center of the attachment-side base fabric 3, and a predetermined number (four in the illustrated example) is attached around the periphery. Holes 5 are formed at equal intervals in the circumferential direction. Further, between the inflator insertion hole 4 of the occupant side fabric 2 and the outer peripheral edge, a predetermined number (two in the illustrated example) of vent holes (two in the illustrated example) for discharging gas in the airbag when the occupant hits the airbag. (Corresponding to the discharge hole of the present invention) 6 is drilled. The inflator insertion hole 4, the attachment hole 5 and the vent hole 6 are the same as the well-known inflator insertion hole, the well-known attachment hole and the well-known vent hole of the conventional driver airbag, respectively. Reference numeral 7 denotes a sewing portion that stitches the occupant side base fabric 2 and the attachment side base fabric 3 together.

  FIG. 2 is a view of the airbag of the first example from the occupant side before inflation, before the first tear seam break or after a partial break, and after the first tear seam is completely broken, and FIG. 3 is a cross-sectional view of each cross section of FIG. A state diagram is shown. 2 (a) is an airbag before inflation, FIG. 2 (b) is an airbag before the first tear seam is broken or partially broken, and FIG. 2 (c) is an airbag after the first tear seam is completely broken. 3A is a cross-sectional view taken along the line AA in FIG. 2A, FIG. 3B is a cross-sectional view taken along the line BB in FIG. 2B, and FIG. It is CC sectional drawing of (c).

  FIG. 2 (a) shows that the occupant side base fabric 2 and the attachment side base fabric 3 are stitched together by a stitching portion 7, and the airbag 1 of the first example before the inflation in which the first capacity limiting portion 11 is installed is seen from the occupant side. FIG. The two occupant-side base fabrics 2 and the attachment-side base fabrics 3 are overlapped with each other, and their peripheral portions are sewn together with the peripheral portions of these base fabrics 2 and 3 with the stitching portion 7 shown in FIG. By doing so, it is formed in a bag shape, and is inverted so that the inside becomes the outside and the outside becomes the inside. In that case, after the airbag 1 is inflated, the stitching portion 7 is set to a stitching strength that does not break even when the internal pressure of the airbag 1 rises due to the occupant hitting it.

  FIG. 3A is a cross-sectional view taken along the line AA of FIG. 2A, and the first capacity limiting portion 11 of the airbag 1 of the first example in which the occupant side base fabric 2 and the attachment side base fabric 3 are stitched together. FIG. The occupant side base fabric 2 and the attachment side base fabric 3 of the airbag are folded along a plurality of first fold lines 211 and 311 and second fold lines 212 and 312 in a substantially radial manner, whereby the first folded portions 21 and 31 are folded. Are formed, and the base portions of the first folded portions 21 and 31 are stitched together by first tear seams 81 extending in parallel to the first broken lines 211 and 311 and the second folded lines 212 and 312, respectively. The stitching by the first tear seam 81 is set to a stitching strength at which the airbag 1 is inflated and deployed and is broken by the internal pressure of the airbag 1 raised to a predetermined pressure or more. By the first tear seam 81 and the first folded portions 21 and 31, the volume of the airbag 1 is set to a small volume before or after the suture is broken, and after the whole suture is broken, The first capacity restriction unit 11 is configured to set the capacity to a large capacity (the total capacity of the airbag). Needless to say, the stitching strength at the stitching portions 7 at the peripheral edge portions of the base fabrics 2 and 3 is set to a size that prevents the stitching from being broken by the increased internal pressure of the airbag 1.

  FIG. 2B is a view of the airbag 1 of the first example from the occupant side before the first tear seam 81 is broken after being inflated. After expansion, before the first tear seam 81 breaks or after partial breakage, the first volume limiting portion 11 forms a small-capacity airbag 1 having a slightly smaller diameter. In addition, a plurality of recessed stitching lines of the first capacity limiting portion 11 formed by stitching the first tear seam 81 are radially formed on the surface of the passenger-side base fabric 2 of the small-capacity airbag 1.

  FIG.3 (b) is BB sectional drawing of FIG.2 (b). The air bag 1 after the first tear seam 81 after inflating and before or after the partial breakage is already filled with gas in the air bag 1 internal space 1a on both sides of the first tear seam 81, and the thickness is uniform over a wide range. ing. Further, as shown by the arrow in FIG. 3B, the first tear seam 81 is applied with a force to tear from at least four directions.

  FIG. 2C is a view of the airbag 1 of the first example after the first tear seam 81 is completely broken, as viewed from the passenger side, and FIG. 3C is a cross-sectional view taken along the line C-C in FIG. It is. After the first tear seam 81 is broken, the airbag 1 is completely broken by the first tear seam 81 of the first capacity limiting portion 11 and the base fabrics 2 and 3 are formed as shown in FIGS. 2 (c) and 3 (c). All the first folded portions 21, 31 that have been stretched and located in the airbag 1 appear on the surface in a state where they are not folded as a part of the base fabrics 2, 3, and the folding disappears.

  In the airbag 1 of the first example configured as described above, the inflator is activated in the event of an emergency to generate gas from the state shown in FIGS. 2 (a) and 3 (a). The small-capacity airbag 1 is inflated and deployed, and as shown in FIGS. 2B and 3B, the small-capacity airbag 1 is completely inflated before the first tear seam 81 is broken or partially broken. It will be in the state. Since the capacity of the airbag 1 at the time of initial inflation and deployment is relatively small by the first capacity restriction unit 11, the airbag 1 is inflated more quickly. In addition, the air bag interior spaces on both sides of the first tear seam 81 are already filled with gas, and the thickness is uniform over a wide range.

  Next, when the airbag 1 further tries to inflate, all the first tear seams 81 are torn and the deployment ends as shown in FIGS. 2 (c) and 3 (c). At this time, since the force is applied to the first tear seam 81 from at least four directions as indicated by the arrows in FIG. 3B, the first tear seam 81 can be efficiently torn. Further, since the first tear seam 81 is arranged substantially radially with respect to the inflator insertion hole 4 as shown in FIGS. 2 (a) and 2 (b), the expansion force due to the gas spreads from the center to the outer peripheral direction. In this case, the tearing point can be concentrated and the first tear seam 81 can be further efficiently torn.

  FIG. 4 shows a second example of the embodiment of the airbag 1 according to the present invention, FIG. 4 (a) shows a passenger side base fabric 2 of the airbag of the second example, and FIG. It is a figure which shows the attachment side base fabric 3 of the airbag 1 of a 2nd example. In the figure, 12 is a second capacity limiting portion, 22 is an occupant side second folding portion, 221 is an occupant side first fold line, 222 is an occupant side second fold line, 223 is an occupant side third fold line, and 32 is an attachment side first fold line. Two folded portions, 321 is a first folding line on the mounting side, 322 is a second folding line on the mounting side, 323 is a third folding line on the mounting side, and 82 is a second tear seam as an example of capacity control means. In addition, this 2nd example folds the thing similar to the 1st folding parts 21 and 31 of the airbag 1 of a 1st example further by the 3rd folding lines 223 and 323, and a base fabric with the 2nd folding parts 22 and 32 The second capacity limiting portion 12 is formed by stitching 2 and 3 with the second tear seam 82, and the details will be described with reference to FIG. The same components as those in the first example described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 5 is a view of the airbag of the second example from the occupant side before inflating, before breaking the second tear seam or after partially breaking, and after breaking the second tear seam completely, and FIG. 6 is a cross-sectional view of each cross section of FIG. A state diagram is shown. FIG. 5 (a) shows that the occupant side base fabric 2 and the attachment side base fabric 3 are stitched together by the stitching portion 7, and the airbag 1 of the second example before the inflation in which the second capacity limiting portion 12 is installed is seen from the occupant side. FIG. 5 (b) is a view of the airbag 1 of the second example from the occupant side before or after the second tear seam 82 breaks after inflating, and FIG. 5 (c) is the second tear seam. 82 is a view of the airbag 1 of the second example after being completely broken, as viewed from the passenger side. FIG. 6 (a) is a sectional view taken along the line DD of FIG. 5 (a), and FIG. (B) EE sectional drawing and FIG.6 (c) are FF sectional drawings of FIG.5 (c).

  Fig.5 (a) is the figure which looked at the airbag 1 of the 2nd example before inflation from the passenger | crew side. As in the first example, the occupant-side base fabric 2 and the attachment-side base fabric 3 are stitched together by the stitching portion 7 and the second capacity limiting portion 12 is installed. Moreover, in this figure, the 2nd folding parts 22 and 32 and the 2nd tear seam 82 which comprise the 2nd capacity | capacitance restriction | limiting part 12 are extended radially.

  6A is a cross-sectional view taken along the line DD in FIG. 5A, and the second capacity limiting portion 12 of the airbag 1 of the first example in which the occupant side base fabric 2 and the attachment side base fabric 3 are stitched together. FIG. The second capacity limiting unit 12 includes second folded portions 22 and 32 and a second tear seam 82, and the second folded portions 22 and 32 include the first broken lines 221 and 321, the second folded lines 222 and 322, and the third. It consists of broken lines 223 and 323. The occupant-side base fabric 2 and the attachment-side base fabric 3 of the airbag 1 are folded along the first fold lines 221, 321, the second fold lines 222, 322, and the third fold lines 223, 323 in a radial manner. Two folded portions 22 and 32 are formed. Between the first broken lines 221 and 321 and the third folded lines 223 and 323 of the folded portions 22 and 32 and the base fabrics 2 and 3 are the first folded lines 221 and 321, The second tear seams 82 and 322 and the third tear lines 223 and 323 are respectively stitched by second tear seams 82 extending in parallel. The suturing by the second tear seam 82 is set to a suturing strength at which the air bag 1 is inflated and deployed and is broken by the internal pressure of the air bag 1 that has risen above a predetermined pressure.

  FIG. 5B is a view of the airbag 1 of the second example from the occupant side before the second tear seam break after inflating or after a partial break. After inflating, before the second tear seam 82 breaks or after partial breakage, the second capacity limiting portion 12 forms a small-capacity airbag 1 with a slightly smaller diameter. Further, on the surface of the passenger-side base fabric 2 of the small-capacity airbag 1, three recessed lines and second tear seams 82 formed by the second folded portions 22 and 32 are formed radially.

  FIG.6 (b) is EE sectional drawing of FIG.5 (b). The air bag 1 after the inflation and before the tear break or after the partial break has already been filled with gas in the air bag 1 internal space 1a on both sides of the second tear seam 82, and has a uniform thickness over a wide range. In addition, as shown by the arrow in FIG. 6B, the second tear seam 82 is applied with a force for tearing from at least six directions.

  FIG. 5C is a view of the airbag 1 of the second example after the second tear seam is completely broken, as viewed from the occupant side, and FIG. 6C is a cross-sectional view taken along the line F-F in FIG. is there. After the second tear seam 82 breaks, the airbag 1 is completely broken by the second tear seam 82 of the second capacity limiting portion 12 so that the base fabrics 2 and 3 are formed as shown in FIGS. 5 (c) and 6 (c). All the second folded portions 22 and 32 that have been stretched and located in the airbag 1 appear on the surface in a state where they are not folded as a part of the base fabrics 2 and 3, and the folding disappears.

  The airbag 1 of the second example configured as described above operates in the same manner as the first example. However, when the second tear seam 82 is torn, a force is applied to the second tear seam 82 from at least six directions as indicated by the arrows in FIG. 6B, so that the second tear seam 82 can be more efficiently torn. Can do.

  FIG. 7 shows a third example of the embodiment of the airbag 1 according to the present invention, FIG. 7 (a) shows a passenger side base fabric 2 of the airbag of the third example, and FIG. It is a figure which shows the attachment side base fabric 3 of the airbag 1 of a 3rd example. In the figure, 13 is a third capacity limiting section, 14 is a fourth capacity limiting section, 15 is a fifth capacity limiting section, 23 is a passenger side third folding section, 231 is a passenger side first folding line, and 232 is a passenger side first folding line. Two folding lines, 33 is a mounting side third folding portion, 331 is a mounting side first folding line, 332 is a mounting side second folding line, 83 is a third tear seam as an example of a capacity control means, 83a is an inner third tear seam, 83b Indicates the outer third tear seam. The same components as those in the first example described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the third example, the occupant-side base fabric 2 and the attachment-side base fabric 3 have three patterns of third to fifth capacity limiting portions 13, 14, 15. The third capacity limiting unit 13 includes first folded portions 21 and 31, a first tear seam 81, and a third tear seam 83, and the first folded portion includes first folded lines 211 and 311 and second folded lines 212 and 312. Consists of. The fourth capacity limiting unit 14 includes third folded portions 23 and 33 and a third tear seam 83, and the third folded portion includes first broken lines 231 and 331 and second folded lines 232 and 332. The fifth capacity limiting unit 15 includes first folded portions 21 and 31 and a third tear seam 83, and the first folded portion includes first broken lines 211 and 311 and second folded lines 212 and 312. In the third example, five third to fifth capacity limiting portions 13, 14, and 15 are provided substantially radially. The detailed structure will be described when explaining FIG.

  The occupant-side base fabric 2 and the attachment-side base fabric 3 of the airbag 1 are folded along a plurality of first fold lines 211, 311 and second fold lines 212, 312 in a substantially radial manner, whereby the first folded portion 21, 31 is formed, and the base portions of the first folded portions 21 and 31 are stitched together by first tear seams 81 extending in parallel to the first broken lines 211 and 311 and the second folded lines 212 and 312, respectively. In addition, as the third tear seam 83, two stitches of the first broken line 211, 311, the second folded line 212, 312, and the inner third tear seam 83 a and the outer third tear seam 83 b orthogonal to the first tear seam 81 are sewn. Yes.

  Furthermore, the airbag 1 has a fourth capacity limiting unit 14 and a fifth capacity limiting unit 15 on the base fabrics 2 and 3, respectively. The fourth capacity restriction unit 14 includes third folding portions 23 and 33 and a third tear seam 83. The third folded portions 23 and 33 are formed in a substantially fan shape by being folded along the first folded lines 231 and 331 and the V-shaped second folded lines 232 and 332, and in the third folded portions 23 and 33, They are stitched together by an inner third tear seam 83a and an outer third tear seam 83b as third tear seams 83 extending substantially perpendicular to the first broken lines 221 and 321 and extending to the second bent lines 232 and 332, respectively. The fifth capacity restriction unit 15 includes first folding portions 21 and 31 and a third tear seam 83. The first folded portions 21 and 31 are formed in the same manner as in the first example, and the third tear seam 83 extends substantially up to the second folded lines 212 and 312 in the first folded portion 21 so as to be substantially orthogonal to the first folded lines 211 and 311. The inner second tear seam 83a and the outer third tear seam 83b as the tear seam 83 are respectively stitched. The stitching by the first tear seam 81 and the third tear seam 83 is set to a stitching strength at which the airbag 1 is inflated and deployed and is broken by the internal pressure of the airbag 1 raised to a predetermined pressure or more.

  FIG. 8 shows a view of the airbag of the third example as seen from the occupant side before inflation, before tear seam breakage or after partial breakage, and after full tear seam breakage. FIG. 8A shows a third example before expansion in which the occupant-side base fabric 2 and the attachment-side base fabric 3 are stitched together by the stitching portion 7 and the third to fifth capacity limiting portions 13, 14, 15 are installed. FIG. 8B is a view of the airbag 1 of the third example before and after the first tear seam 81 is broken or partially broken after the inflation, and FIG. FIG. 8C is a view of the airbag 1 of the third example before or after the third tear seam 83 is broken. FIG. 8D is a diagram of the third example after the first tear seam 81 is completely broken. It is the figure which looked at the airbag 1 from the passenger | crew side.

  FIG. 8A is a view of the airbag 1 of the third example before being inflated as seen from the passenger side. The shape is the same as that of the first example except that there are five capacity limiting portions 10.

  FIG. 8B is a view of the airbag 1 of the third example as seen from the occupant side before the tear seam break after inflating or after a partial break. After inflating, before tear seam breakage or after partial breakage, the third to fifth capacity restriction portions 13, 14, 15 form a small-capacity airbag 1 having a slightly smaller diameter. Further, on the surface of the passenger-side base fabric 2 of the small-capacity airbag 1, the third to fifth capacity limiting portions 13, 14, 15 by the first folded portions 21, 31 and the third folded portions 23, 33 are provided. Indented lines and first tear seams 81 are formed radially. In this state, gas is already filled in the air bag 1 internal space on both sides of the first tear seam 81, and the thickness is uniform over a wide range.

  FIG. 8C is a view of the airbag 1 of the third example before or after the third tear seam 83 is broken, as viewed from the passenger side. Before or after the third tear seam 83 breaks, the airbag 1 is partially broken by stitching by the first tear seam 81 of the third capacity restricting portion 13 and the base fabrics 2 and 3 are formed as shown in FIG. A part of the first folded portions 21 and 22, the first folded portions 21 and 31, and the third folded portions 23 and 33 that have been stretched and located in the airbag 1 are part of the base fabrics 2 and 3. Appears on the surface in a non-folding state. Since the third tear seam 83 has an inner third tear seam 83a and an outer third tear seam 83b, the airbag 1 is deployed in stages when they tear.

  FIG. 8 (d) is a view of the airbag 1 of the third example after the tear seam is completely broken as viewed from the passenger side. After the break of the third tear seam 83, the airbag 1 is fully broken by the first tear seam 81 of the third capacity restricting portion 13, and the base fabrics 2, 3 are stretched as shown in FIG. The first folded portions 21, 22 and the third folded portions 23, 33 of the third to fifth capacity limiting portions 13, 14, 15 located in the airbag 1 are part of the base fabrics 2, 3. Appears on the surface in a non-folding state and the fold-up disappears.

  In the airbag 1 of the third example configured as described above, the first tear seam 81 operates in the same manner as in the first example. However, when the third tear seam 83 tears, it develops in stages.

  As described above, according to the airbag 1 of the third example, in addition to the effects of the airbag 1 of the first example, there is the third tear seam 83. Can be set more gradually in stages by breaking at different timings.

  FIG. 9 shows a fourth example of the embodiment of the airbag 1 according to the present invention, FIG. 9A shows the passenger side base fabric 2 of the airbag of the fourth example, and FIG. It is a figure which shows the attachment side base fabric 3 of the airbag 1 of a 4th example. In the figure, 16 is a sixth capacity limiting unit, 84 is a fourth tear seam as an example of capacity control means, 84a is an inner fourth tear seam, and 84b is an outer fourth tear seam. The same components as those in the first example described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The sixth capacity limiting unit 16 includes a third folded portion 23 and a fourth tear seam 84 similar to those in the third example. The fourth tear seam 84 has an inner fourth tear seam 84a and an outer fourth tear seam 84b, and the inner fourth tear seam 84a and the outer fourth tear seam 84b are along the second fold lines 232 and 332 of the third folded portion 23, respectively. Arranged and substantially V-shaped. The base fabrics 2 and 3 have the first capacity limiting section 11 in addition to the sixth capacity limiting section 16 and are arranged radially.

  FIG. 10 is a view of the airbag of the fourth example viewed from the occupant side before inflation, before tear break, or after partial tear break, and after tear tear completely, and FIG. 11 shows a state diagram of each cross section of FIG. . FIG. 10A shows a fourth example before expansion in which the occupant-side base fabric 2 and the attachment-side base fabric 3 are stitched together by the stitching portion 7 and the first capacity limiting portion 11 and the sixth capacity limiting portion 16 are installed. FIG. 10B is a diagram of the airbag 1 of the fourth example after the first tear seam 81 and the fourth tear seam 84 after inflating or after the partial tearing, viewed from the occupant side. FIG. 10 (c) is a view of the airbag 1 of the fourth example after the first tear seam 81 and the fourth tear seam 84 are all broken, as viewed from the passenger side. FIG. 11 (a) is a perspective view of FIG. ) Is a cross-sectional view taken along line GG, FIG. 11B is a cross-sectional view taken along line H-H in FIG. 10B, and FIG. 11C is a cross-sectional view taken along line II in FIG.

  Fig.10 (a) is the figure which looked at the airbag 1 of the 4th example before inflation from the passenger | crew side, and Fig.11 (a) is GG sectional drawing of Fig.10 (a). FIG. 10A is the same as FIG. 2, but FIG. 11A is sewn at two locations of an inner fourth tear seam 84 a and an outer fourth tear seam 84 b as the fourth tear seam 84. In addition, a predetermined number (one in the illustrated example) of vent holes 6 are formed in the attachment-side base fabric 3 between the outer fourth tear seams 84b. In this manner, the two base fabrics 2 and 3 stitched in a bag shape are reversed in the same manner as in the first example, and a small-capacity airbag 1 is formed as shown in FIG. The The configuration of the first capacity limiting unit other than the sixth capacity limiting unit 16 of the airbag 1 of the fourth example is the same as that of the first example.

  FIG. 10 (b) is a view of the airbag 1 of the fourth example from the occupant side before or after the tear seam breaks after inflation, and has the same shape as FIG. 2 showing the first example. .

  FIG.11 (b) is HH sectional drawing of FIG.10 (b). The airbag 1 after the inflated tear seam break or after a partial break has already been filled with gas in the air bag 1 internal space 1a on both sides of the inner fourth tear seam 84a, and the thickness is uniform over a wide range. . Further, as shown by the arrow in FIG. 11B, the fourth tear seam 84 is applied with a force for tearing from at least six directions.

  FIG. 10C is a view of the airbag 1 of the fourth example after the tear seam is completely broken, as viewed from the occupant side, and FIG. 11C is a cross-sectional view taken along the line II of FIG. After tearing the tear seam, the airbag 1 is completely broken by the first tear seam 81 of the first capacity restricting portion 11 and the fourth tear seam 84 of the sixth capacity restricting portion 16 as shown in FIGS. 10 (c) and 11 (c). As shown, the base fabrics 2 and 3 are stretched, and the first tear seam 81 of the first capacity limiter 11 and the first folded portions 21 and 31 of the sixth capacity limiter 16 located in the airbag 1 are shown. And the 3rd fold-up parts 23 and 33 appear on the surface in the state which does not fold as a part of the base fabrics 2 and 3, and fold-up disappears.

  Thereafter, all of the stitches by the outer fourth tear seam 84a are broken, and the vent hole 6 located in the outer fourth tear seam 84a appears on the surface. Therefore, the inside of the airbag 1 passes through these vent holes 6. Communicate with the outside. Then, since the gas in the airbag 1 is discharged outside through the vent hole 6, the internal pressure of the airbag 1 is further reduced, and the occupant is softly received and restrained by the airbag.

  The airbag 1 of the fourth example configured as described above operates in the same manner as the first example. However, when the fourth tear seam 84 is torn, a force is applied to the fourth tear seam 84 from at least six directions as indicated by arrows in FIG. 10B, so that the tear seam can be torn more efficiently.

  Further, the capacity is set to be relatively small at the time of initial inflation and deployment, and the vent hole 6 is hidden, so that the airbag 1 is inflated and deployed without leaking the gas introduced into the airbag 1 to the outside. Therefore, the airbag 1 can be inflated and deployed more quickly. Thereafter, since the gas in the airbag 1 is discharged from the vent hole 6 to the outside, the internal pressure of the airbag 1 can be efficiently reduced. Accordingly, the occupant can be more effectively and sufficiently restrained by the airbag.

  Further, since the plurality of tear seams of the inner fourth tear seam 84a and the outer fourth tear seam 84b are stitched as the fourth tear seam 84, the inflation speed of the airbag 1 can be easily set.

  If the internal pressure of the airbag 1 that has risen as a result of the occupant advancing by inertia and hitting the airbag 1 that has completed initial inflation and deployment becomes equal to or higher than the breaking pressure of the inner fourth tear seam 84a, the inner fourth tear seam is generated by this inner pressure. The intermediate volume airbag 1 surrounded by the outer fourth tear seam 84b is formed, and the capacity of the airbag 1 is increased by a first predetermined amount, the internal pressure of the airbag 9 is decreased, and the occupant's air The first stage of absorption mitigation against the impact at the time of bag contact is performed, and if the passenger's further contact with the airbag 1 is further increased due to further inertial movement of the passenger, the internal pressure of the airbag 1 once lowered increases again. When the internal pressure becomes equal to or higher than the breaking pressure of the outer fourth tear seam 84b, all the stitches by the outer fourth tear seam 84b are broken by this inner pressure, and the large-capacity airbag 1 It may be formed.

  As a result, the capacity of the airbag 1 is further increased by a second predetermined amount (> first predetermined amount), and the internal pressure of the airbag 1 is greatly decreased again from the previous time, so that the occupant can be received more softly by the airbag. . Further, when the stitching by the outer fourth tear seam 84b is broken, the vent hole 6 located between the outer fourth tear seams 84b also appears on the surface, so that the inside of the airbag 1 is interposed through these vent holes 6. Communicate with the outside. Then, since the gas in the airbag 1 is discharged to the outside through the vent hole 6, the internal pressure of the airbag 1 can be further reduced more quickly, and the occupant can be received more effectively and softly by the airbag. it can. Other functions and effects of the airbag 9 of the fourth example are the same as those of the first example. Note that the stitching strengths of the inner and outer fourth tear seams 84a and 84b can be set to be the same or different.

  FIG. 12 shows a fifth example of a concentric two-layer airbag. In the figure, 9 is an inner bag. The inner bag 9 is a bag provided inside the airbag 1 and is a portion that expands during initial expansion before the entire airbag 1 is expanded. The structure of the capacity limiting portion of the fifth example is the same as that of the fourth example, but the base fabrics 2 and 3 and the inner bag 9 of the airbag 1 are both connected to the first tear seam 81 and the fourth tear seam 84. It differs in that it is sewn with. By adopting such a structure, the trigger portion at the time of breakage of the first tear seam 81 and the fourth tear seam 84 is overlapped with the inner bag 9, and the tear seam is efficiently torn by the high-pressure expansion of the inner bag 9. be able to.

  FIG. 13 shows an airbag of a sixth example. In the figure, reference numeral 10 denotes a positioning tab. In the airbag 1 of the sixth example, a positioning tab 10 is provided on the occupant side base fabric 2 or the attachment side base fabric 3. The positioning tab 10 is disposed symmetrically with respect to a bending line L at least when sewing the base fabrics 2 and 3. By setting it as such a structure, the 1st tear seam 81 and the 4th tear seam 84 can be sewn in an exact position.

  In addition, in order to improve the strength of the vent hole 6, a vent hole cloth disposed around the vent hole 6 is fixed to the outer surface of the attachment side base fabric 3 of the airbag 1, and a positioning tab is formed on a part of the vent hole cloth. 10 may be arranged symmetrically on the folding line L during sewing.

  Although the first to sixth examples have been described as the embodiment of the airbag 1 of the present invention, the present invention is not limited to this, and the first to sixth capacity limiting portions 11, 12, 13, 14, 15, and 16 may be applied in various combinations. Similarly, the capacity limiting unit 10 is applied to the first to fourth folded portions 21, 22, 23, 31, 32, 33 in various combinations of the first to fourth tear seams 81, 82, 83, 84, respectively. May be.

  As described above, the airbag 1 of the present embodiment has the capacity limiting portions 11, 12, 13, 14, 15, 16 formed by stitching with the tear seams 81, 82, 83, 84. Can be constructed simply by stitching, the number of parts is small, the structure can be simplified, and the manufacturing can be facilitated. Further, since the capacity of the airbag 1 at the time of initial inflation and deployment is relatively small due to the capacity limiting portions 11, 12, 13, 14, 15, and 16, the airbag 1 is inflated more quickly. Further, since gas is contained in almost the entire area of the airbag 1 before the tear seams 81, 82, 83, and 84, or at the time of initial inflation and deployment after a partial break, the thickness is quickly uniform over a wide range.

  Further, since forces are applied to the tear seams 81, 82, 83, 84 from at least four directions, the tear can be reliably torn. Further, since the tear seams 81, 82, 83, 84 are disposed substantially radially with respect to the inflator insertion hole 4, the tear seams 81, 82, 83, 84 are broken while concentrating the breaking points when the expansion force due to the gas spreads from the center to the outer circumferential direction. The tear seams 81, 82, 83, 84 can be reliably torn.

  Of the plurality of tear seams 81, 82, 83, 84, the stitching strengths of some of the tear seams 81, 82, 83, 84 and the stitching strengths of the remaining tear seams 81, 82, 83, 84 are set differently. You can also In this way, the airbag 1 can be inflated and deployed in stages.

  Further, tearing of the tear seams 81, 82, 83, 84 may occur when the occupant moves forward due to its inertia and hits the airbag 1 in which the initial inflation and deployment has been completed, and the internal pressure of the airbag 1 increases.

  FIG. 14 is a longitudinal sectional view of an airbag device to which the airbag of this embodiment is applied. The airbag apparatus 100 includes an inflator 110, an airbag 1 that is inflated by gas from the inflator 110, a retainer 101 as an example of a holding unit that holds the inflator 110 and the airbag 1, and a folded airbag 1. And a module cover 102 as an example of cover means attached to the retainer 101 so as to cover the container.

  The airbag 1 includes a front surface composed of an occupant-side base fabric 2 that faces a vehicle occupant and the like when inflated, and a rear side composed of an attachment-side base fabric 3 that is attached to a retainer 101 together with an inflator 110 on the opposite side. The rear surface has an inflator insertion hole 4 into which the inflator 110 is inserted.

  The retainer 101 includes a main plate portion 101a and leg piece portions 101b bent downward from the peripheral edge portion of the main plate portion 101a. An inflator insertion port 101c is provided at the center of the main plate portion 101a. The leading side of the inflator 110 is inserted into the inflator insertion port 101c from the back side of the main plate portion 101a. The inflator insertion hole 4 of the airbag 1 is overlapped on the peripheral edge portion of the inflator insertion port 101 c and fixed by the attachment ring 103. A leading side of the inflator 110 is disposed in the airbag 1 through the inflator insertion hole 4.

  A bolt (stud bolt) 103a protrudes from the mounting ring 103, and the bolt 103a extends to the mounting holes 5 around the inflator insertion hole 4 and the inflator insertion port 101c and the insertion holes 112a of the flange 112. The air bag 1 and the inflator 110 are fixed to the retainer 101 by being inserted and extending to the back side of the flange 112 and the nut 103b being fastened to the bolt 103a.

  The airbag device 100 is configured by folding the airbag 1 and mounting the module cover 102 so as to cover the folded body of the airbag 1.

  In this embodiment, a leg piece 102a is erected downward from the back surface of the module cover 102, and the leg piece 102a is fixed to the leg piece 101b of the retainer 101 by a fixing tool 102b such as a rivet. Has been. The module cover 102 is configured to be pushed and cleaved by the airbag 1 when the airbag 1 is inflated. Reference numeral 102c indicates a tear line that induces this cleavage.

  In the airbag apparatus 100 having such a configuration, when a vehicle collision is detected, the inflator 110 is activated to generate gas. This gas is ejected into the airbag 1 from the gas ejection hole 111 of the inflator 110, and the airbag 1 is inflated. The airbag 1 inflates and deploys the module cover 102 so as to face the vehicle occupant and the like and restrains the vehicle occupant and the like.

  According to the airbag according to the present invention, the capacity control is performed such that the capacity of the airbag is set to be relatively small at the time of initial inflation and deployment, and the capacity of the airbag is increased when the internal pressure of the airbag that has been inflated and deployed exceeds a predetermined pressure. Since the air bag interior space on both sides of the capacity control means is filled with gas at the time of initial inflation and deployment, when the airbag is initially inflated and deployed, the thickness quickly becomes uniform over a wide range, and the subsequent air The bag can be inflated and deployed quickly.

  Further, the capacity control means is a tear seam for sewing the base fabric, and when the internal pressure of the airbag becomes a predetermined pressure or more, the tear seam breaks to increase the capacity of the airbag, thereby reducing the number of parts. The structure of the capacity control means can be simplified, and the capacity control means can be easily manufactured.

  Further, the capacity control means is composed of a plurality of air bag capacity that can be set differently, and since the plurality of capacity control means increase the air bag capacity stepwise at different timings, the initial inflation The capacity of the airbag during deployment can be further reduced, the airbag can be inflated and deployed more quickly during initial inflation and deployment, and the internal pressure of the airbag can be further effectively reduced. This allows the occupant to be received more softly and restrained more appropriately.

  Further, when the inner pressure of the airbag becomes equal to or higher than the predetermined pressure and the capacity control means increases the capacity of the airbag, the base fabric communicates the interior of the airbag to the exterior of the airbag and causes the gas inside the airbag to be Since the vent hole to be discharged to the outside is provided, the internal pressure in the airbag can be effectively reduced, and the occupant can be received more softly by the airbag.

  Further, the airbag has an inner bag that is initially inflated and deployed inside the base fabric, and the capacity control means sets the capacity of the inner bag to be smaller than the capacity of the entire airbag at the time of initial inflation and deployment, and is inflated and deployed. When the inner pressure of the inner bag becomes equal to or higher than a predetermined pressure, the capacity of the air bag is increased. Therefore, the operation of the capacity control means can be overlapped with the inner bag, and the tear seam can be efficiently torn by the high pressure expansion of the inner bag. .

  Further, since the airbag has a positioning tab that is positioned when the capacity control means is created, the position of the airbag is not shifted when the capacity control means is created, and the deviation of the airbag during inflation and deployment can be reduced. .

The figure which shows the 1st example of embodiment of the airbag concerning this invention The figure which shows the inflation process of the airbag of a 1st example The figure which shows the cross section of the expansion process of the airbag of the 1st example The figure which shows the 2nd example of embodiment of the airbag concerning this invention. The figure which shows the expansion | swelling process of the airbag of a 2nd example The figure which shows the cross section of the expansion process of the airbag of the 2nd example The figure which shows the 3rd example of embodiment of the airbag concerning this invention. The figure which shows the inflation process of the airbag of the 3rd example The figure which shows the 4th example of embodiment of the airbag concerning this invention The figure which shows the expansion process of the airbag of a 4th example The figure which shows the cross section of the expansion process of the airbag of a 4th example The figure which shows the 5th example of embodiment of the airbag concerning this invention. The figure which shows the 6th example of embodiment of the airbag concerning this invention. The figure which shows the airbag apparatus provided with the airbag concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air bag, 11 ... 1st capacity | capacitance restriction | limiting part, 12 ... 2nd capacity | capacitance restriction | limiting part, 13 is a 3rd capacity | capacitance restriction | limiting part, 14 is a 4th capacity | capacitance restriction | limiting part, 15 is a 5th capacity | capacitance restriction part, 16 is a 6th capacity | capacitance Restriction part, 2 ... passenger side base fabric of airbag, 21 ... passenger side first folding part, 22 ... passenger side second folding part, 23 ... passenger side third folding part, 24 ... passenger side fourth folding part Overlapping part, 211, 221, 231, 241 ... first fold line on occupant side, 212, 222, 232, 242 ... second fold line on occupant side, 223 ... third fold line on occupant side, 3 ... base fabric for attachment side of airbag, 31 ... Mounting side first folded part, 32 ... Mounting side second folded part, 33 ... Mounting side third folded part, 34 ... Mounting side fourth folded part, 311, 321, 331, 341 ... Mounting side first One broken line, 312, 322, 332, 342 ... installation side second broken line, 323 ... installation 3rd broken line, 4 ... inflator insertion hole, 5 ... mounting hole, 6 ... vent hole, 7 ... sewing part, 81 ... first tear seam (capacity control means), 82 ... second tear seam (capacity control means), 83 ... first Three tear seams (capacity control means), 83a ... inner third tear seam, 83b ... outer third tear seam, 84 ... fourth tear seam (capacity control means), 84a ... inner fourth tear seam, 84b ... outer fourth tear seam, 9 ... inner Bag 10 Positioning tab 100 Air bag device 101 Retainer (holding means) 102 Module cover (cover means) 103 Mounting ring 110 Inflator 111 Gas ejection hole 112 Flange

Claims (7)

  In an airbag comprising a base fabric formed in a bag shape and inflated and deployed by gas from an inflator, the capacity was set to be relatively small at the time of initial inflation and deployment, and the inner pressure of the airbag that was inflated and deployed became a predetermined pressure or more. In this case, a capacity control means for increasing the capacity of the airbag is provided, and the air bag interior space on both sides of the capacity control means is filled with the gas during the initial inflation and deployment.   The capacity control means is a tear seam for sewing the base fabric, and the capacity of the airbag is increased by breaking the tear seam when the internal pressure of the airbag becomes equal to or higher than the predetermined pressure. The airbag according to claim 1.   The capacity control means comprises a plurality of sets that can be set so that the capacities of the airbags are different from each other, and the capacity control means increases the capacity of the airbag step by step at different timings. The airbag according to claim 1 or 2, wherein the airbag is characterized.   When the inner pressure of the airbag becomes equal to or higher than the predetermined pressure and the capacity control means increases the capacity of the airbag, the base fabric communicates the interior of the airbag with the exterior of the airbag. The airbag according to any one of claims 1 to 3, further comprising a vent hole for discharging an internal gas to the outside of the airbag.   The airbag has an inner bag that is initially inflated and deployed inside the base fabric, and the capacity control means sets the capacity of the inner bag to be smaller than the capacity of the entire airbag during initial inflation and deployment, The airbag according to any one of claims 1 to 4, wherein a capacity of the airbag is increased when an inner pressure of the inflated and deployed inner bag becomes equal to or higher than a predetermined pressure.   The airbag according to any one of claims 1 to 5, wherein the airbag has a positioning tab that is positioned when the capacity control means is created. The said airbag, the inflator which injects gas in the said airbag, the holding means holding the said airbag, and the cover means which covers the said folded airbag are provided. The airbag apparatus in any one of Claim 6.

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