JP2019034593A - Air belt - Google Patents

Abstract

To provide an air belt capable of finely maintaining a flat band state of a webbing when an airbag develops.SOLUTION: An air belt 10 is equipped with an air bag 20 which is disposed between a webbing 11 and an occupant when used, and is expandable; and a bag cover 40 which stores the air bag 20 in a folded state. The bag cover 40 is provided with a tear portion 41 that becomes a breakage start point when the airbag 20 actuates, along one end portion in a width direction. The airbag 20 has a center portion 34 overlapped with the webbing 11 in a developed state, and a pair of folded portions 35 and 36 respectively disposed on both sides in a width direction from the center portion 34 and folded back to the center portion 34 along an insertion direction of the webbing 11 when stored in the back cover 40. At least one of the pair of the folded portions is folded back to the opposite side to the webbing 11 over the center portion 34.SELECTED DRAWING: Figure 8

Description

  The present disclosure relates to an air belt.

  An air belt is known in which an airbag that inflates and deploys to a webbing of a seat belt device is attached. In the airbag, for example, as described in Patent Document 1, the airbag is folded in the width direction so as to be wound around the webbing, so that the airbag is shortened in the width direction to form a storage state.

JP 2013-184559 A

  In the conventional airbag storage structure, the airbag is disposed so as to surround the entire circumference of the webbing. The folded airbag is covered by the bag cover, but in the process of breaking the bag cover when inflated, the airbag inflates to the internal webbing side and compresses the webbing from all directions. It can be considered that the webbing is crushed in the width direction and a flat belt state cannot be maintained.

  An object of this indication is to provide the air belt which can maintain the flat belt state of webbing well at the time of air bag deployment.

  An air belt according to an aspect of an embodiment of the present invention includes an inflatable airbag that is disposed so as to be sandwiched between a webbing and an occupant during use, and a bag cover that accommodates the airbag in a folded state. The bag cover is provided with a tear portion that is a starting point of breakage when the airbag is operated along one end in the width direction of the webbing, and the airbag is unfolded with the webbing. An overlapping central portion, and a pair of folded portions disposed on both sides of the webbing in the width direction from the central portion and folded back toward the central portion along the webbing insertion direction when stored in the bag cover. Then, at least one of the pair of folded portions is folded to the opposite side of the webbing with the central portion interposed therebetween.

  According to the present disclosure, it is possible to provide an air belt that can favorably maintain a flat belt state of the webbing when the airbag is deployed.

It is a perspective view showing typically an example of composition of a seat belt device. It is sectional drawing of the tongue of the seatbelt apparatus shown in FIG. 1, and an air belt vicinity. It is an upper section showing an example of the upper connection structure part of an air belt. It is a figure which shows the sewing state of the airbag which concerns on this embodiment. It is a figure which shows the folding state of the webbing sliding direction of an airbag. It is a figure which shows the 1st step of the folding procedure of the webbing width direction of the airbag in 1st Embodiment. It is a figure which shows the 2nd step of the folding procedure of the webbing width direction of the airbag in 1st Embodiment. It is a figure which shows the 3rd step of the folding procedure of the webbing width direction of the airbag in 1st Embodiment. It is a figure which shows the state by which the airbag in 1st Embodiment was folded. It is a schematic diagram which shows the initial state at the time of expansion | deployment of the airbag in 1st Embodiment (folded state). It is a schematic diagram which shows the 1st step at the time of expansion | deployment of the airbag in 1st Embodiment. It is a schematic diagram which shows the 2nd stage at the time of expansion | deployment of the airbag in 1st Embodiment. It is a schematic diagram which shows the 3rd stage at the time of expansion | deployment of the airbag in 1st Embodiment. It is a figure which shows the 1st step of the folding procedure of the webbing width direction of the airbag in 2nd Embodiment. It is a figure which shows the 2nd step of the folding procedure of the webbing width direction of the airbag in 2nd Embodiment. It is a schematic diagram which shows the initial state (folded state) at the time of expansion | deployment of the airbag in 2nd Embodiment. It is a schematic diagram which shows the 1st step at the time of expansion | deployment of the airbag in 2nd Embodiment. It is a schematic diagram which shows the 2nd stage at the time of expansion | deployment of the airbag in 2nd Embodiment. It is a schematic diagram which shows the 3rd stage at the time of expansion | deployment of the airbag in 2nd Embodiment. It is a schematic diagram which shows the 4th step at the time of expansion | deployment of the airbag in 2nd Embodiment. It is a figure which shows the folding state of the webbing width direction of the airbag in 3rd Embodiment. It is a figure which shows the modification of 3rd Embodiment.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

[First Embodiment]
The first embodiment will be described with reference to FIGS. First, an overall configuration of a seat belt apparatus 100 to which an air belt according to the present embodiment is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view schematically showing an example of the configuration of the seat belt device 100. 2 is a cross-sectional view of the vicinity of the tongue 4 and the air belt 10 of the seat belt device 100 shown in FIG.

  In FIG. 2 and subsequent figures, the X direction, the Y direction, and the Z direction are directions perpendicular to each other. The Z direction is a sliding direction of the webbing 11 passing through the webbing guide 30 of the air belt 10. In the following description, the Z positive direction side is expressed as “the upper end side of the webbing guide 30”, “the upper end side of the airbag 20”, “the rear end side of the tongue 4”, and the Z negative direction side is expressed as “the webbing guide 30”. "The lower end side of", "the lower end side of the airbag 20," "the front end side of the tongue 4", etc. The X direction is a direction perpendicular to the main surface of the webbing 11. The Y direction is the width direction of the webbing 11.

  A seat belt device 100 shown in FIG. 1 is installed in a seat 1 of a vehicle. The seat belt device 100 includes a retractor 2, a webbing 11, an air belt 10, a shoulder anchor 7, a tongue 4 and a buckle 9.

  The webbing 11 drawn out from the retractor 2 is drawn around the shoulder anchor 7 and folded back by the tongue 4. The end of the webbing 11 is fixed to the anchor plate 6. The anchor plate 6 is fixed to a fixing portion (not shown) of the seat or the vehicle body via the fixing bolt 5.

  The seat 1 is, for example, a front seat such as a driver seat or a passenger seat. The seat 1 may be a rear seat.

  In this embodiment, the retractor 2 is installed on the B pillar. However, the retractor 2 may be installed in a vehicle body side portion such as a B-pillar, a C-pillar, or a tray behind the rear seat corresponding to the position of the seat 1. Further, the retractor 2 may be installed inside the seat 1 (for example, inside the seat back 1B).

  An air belt 10 is attached to the shoulder anchor 7 side of the tongue 4 slidably attached to the webbing 11. The tongue 4 includes a gas supply pipe 4a and a tongue plate 4b. The gas supply pipe 4a is a metal cylindrical body, and a gas introduction port at the lower end portion of the airbag 20 shown in FIG. 4 and the like shown below through a gas supply path in the tongue 4 communicating with the gas supply pipe 4a. 21 communicates.

  As shown in FIG. 2, the front end side of the tongue plate 4b of the tongue 4 is provided with a latch hole 4c into which the latch member in the buckle 9 engages when the tongue plate 4b is inserted into the buckle 9. . The rear end side of the tongue plate 4b is embedded in the resin mold 4d. An insertion port 4e for the webbing 11 is provided in the resin mold 4d.

  As shown in FIG. 1, the buckle 9 to which the tongue 4 is attached and detached is fixed to a seat or a fixing portion (not shown) of the vehicle body via a bracket 9a via a fixing member such as a bolt. The buckle 9 is formed with a tongue plate support hole 9b and a gas supply pipe connection hole 9c. When the tongue 4 is attached, the tongue plate 4b and the gas supply pipe 4a are inserted into the holes 9b and 9c of the buckle 9, respectively. The A gas outlet (not shown) of the inflator 16 installed in the buckle 9 communicates with the gas supply pipe connection hole 9c into which the gas supply pipe 4a is inserted. At the time of a collision or the like, gas is ejected from the gas ejection port of the inflator 16 due to the reaction of the igniter in the inflator 16, and the air belt 10 expands along the webbing 11 as shown by a two-dot chain line 10 'in FIG.

  As shown in FIG. 2, the air belt 10 includes a webbing guide 30 through which the webbing 11 is inserted, an inflatable airbag 20 extending along the webbing guide 30, and a bag cover 40 that covers a folded body of the airbag 20. Prepare. The air belt 10 includes a lower connecting structure 50 that connects the lower ends of the webbing guide 30 and the bag cover 40 to the tongue 4, and an upper connection that connects the upper ends of the airbag 20, the webbing guide 30, and the bag cover 40. The structure part 51 (connection structure part) is provided.

  The webbing guide 30 is a flat and elongated cylindrical member through which the webbing 11 is movably inserted in the sliding direction, and is formed of a resin material such as polyurethane resin or silicone elastomer. The airbag 20 is disposed outside the webbing guide 30 in a state where the airbag 20 is elongated in the insertion direction of the webbing 11.

  A binding structure on the upper end side (shoulder anchor side) of the airbag 20, the webbing guide 30, and the bag cover 40 will be described with reference to FIG.

  FIG. 3 is a top sectional view showing an example of the upper connection structure 51 of the air belt 10. As shown in FIGS. 2 and 3, the airbag 20 and the webbing guide 30 are surrounded by a bag cover 40. 2 and 3, for convenience of illustration, the airbag 20 is disposed on both sides of the webbing guide 30 and the webbing 11 in the X direction, and the airbag 20 is illustrated as being wound around the entire circumference of the webbing 11. However, in the present embodiment, as will be described later, the airbag 20 is arranged so as to be folded from the webbing 11 to the X positive direction side (occupant side).

  The webbing guide 30 and the bag cover 40 are provided with small holes 30 a and 40 a at positions overlapping the small holes 22 a of the projecting piece 22 of the airbag 20.

  A mouse inner 60 is inserted from the upper end of the webbing guide 30. The mouse inner 60 includes a flat annular portion 61 that is inserted into the webbing guide 30, a small-diameter cylindrical fitting seat 62 that protrudes from the flat annular portion 61, and a flange portion 63 that continues to the rear end portion of the flat annular portion 61. Etc. The fitting seat 62 includes a first fitting seat that protrudes from the first flat surface of the flat annular portion 61, and a second flat surface of the flat annular portion 61 (the flat surface on the opposite side of the first flat surface). And a second fitting seat projecting from the second fitting seat.

  The mouse outer 70 made of synthetic resin fits outside the mouse inner 60. The mouse outer 70 includes a flat cylindrical flat annular portion 71, an end portion 72 provided on one end side of the flat annular portion 71, a webbing insertion port 73 provided in the end portion 72, and an edge portion of the webbing insertion port 73. A convex wall 74 projecting into the flat annular portion 71 from the top.

  When the mouse inner 60 and the mouse outer 70 are connected, the webbing guide 30, the protruding piece 22 of the airbag 20, and the bag cover 40 are sandwiched between the mouse inner 60 and the mouse outer 70. For example, the mouse inner 60 and the mouse outer 70 are connected by the push pin 75 being pushed toward the fitting seat 62 in a state where the mouse outer 70 is fitted to the outside of the mouse inner 60. The connection structure between the mouse inner 60 and the mouse outer 70 is not limited to the structure using the push pin 75, and may be a structure using a fastening member such as a screw or a rivet, or may be a structure by bonding such as adhesion or welding. The push pin 75 may be a portion formed integrally with the mouse outer 70.

  As described above, the upper end side of the airbag 20, the webbing guide 30, and the bag cover 40 is sandwiched between the mouse inner 60 and the mouse outer 70, and their mating surfaces (end surfaces) are surrounded by the mouse inner 60 and the mouse outer 70. Therefore, foreign matter is prevented from entering between the airbag 20 and the bag cover 40.

  A fitting seat 62 is inserted into each of the small holes 22a, 30a, 40a of the airbag 20, the webbing guide 30, and the bag cover 40. Thereby, the airbag 20, the webbing guide 30, and the bag cover 40 are connected to each other by the upper connection structure portion 51. Therefore, the connection strength between the airbag 20, the webbing guide 30, and the bag cover 40, the mouse inner 60, and the mouse outer 70 is also high. In FIG. 3, the connection structure of the airbag 20, the webbing guide 30, and the bag cover 40 by the fitting seat 62 is illustrated only on the first and second flat surfaces of the flat annular portion 61, but this embodiment Then, a similar pair of connection structures are also provided in the width direction (Y direction). That is, a total of four connecting portions 52a to 52d are provided on the outer peripheral surface of the upper connecting structure portion 51 (see FIG. 10 and the like).

  The configuration of the airbag 20 according to the present embodiment will be described with reference to FIGS. FIG. 4 is a diagram illustrating a sewing state of the airbag 20 according to the present embodiment. FIG. 5 is a view showing a folded state of the airbag 20 in the webbing sliding direction. FIG. 6 is a diagram illustrating a first stage of a folding procedure of the airbag 20 in the webbing width direction according to the first embodiment. FIG. 7 is a diagram illustrating a second stage of the folding procedure of the airbag 20 in the webbing width direction according to the first embodiment. FIG. 8 is a diagram illustrating a third stage of the folding procedure of the airbag 20 in the webbing width direction according to the first embodiment. FIG. 9 is a view showing a state in which the airbag 20 in the first embodiment is folded. 3 to 9, (a) is a plan view of each state, and (b) schematically shows a cross section along the cutting line in the webbing sliding direction (Z direction) in each figure (a). It is a figure, (c) is a figure which shows typically the cross section along the cutting line of the webbing width direction (Y direction) in each figure (a).

  As shown in FIG. 4, the airbag 20 includes a gas inlet 21 on the lower end side (the tongue 4 side). The airbag 20 extends elongated along the webbing 11. A projecting piece 22 is provided on the upper end side (shoulder anchor 7 side) of the airbag 20. A small hole 22 a is provided in the projecting piece 22.

  The airbag 20 is manufactured in the shape of an elongated bag by overlapping two elongated base fabrics 20 a and 20 b and stitching the peripheral edges thereof with a suture thread 23.

  A slit 24 for passing the webbing guide 30 from the base fabric 20a side of the airbag 20 to the opposite base fabric 20b side is provided on the lower end side (the tongue 4 side) from the middle in the longitudinal direction of the airbag 20. ing. Sutures with a suture thread 25 are applied so as to sew the base fabrics 20a and 20b around the slit 24.

  A plurality of loop portions 26 </ b> A, 26 </ b> B, 26 </ b> C, and 26 </ b> D for passing the webbing guide 30 are provided at intervals from the vicinity of the middle in the longitudinal direction of the airbag 20 to the upper end side (projection piece portion 22 side). The loop portions 26A, 26B, 26C, and 26D are formed of cloth pieces. Both side portions of each of the loop portions 26A, 26B, 26C, and 26D are sewn to the base fabric 20a of the airbag 20 with sutures. In the present embodiment, a configuration including four loop portions 26A, 26B, 26C, and 26D is illustrated, but the number of loop portions is not limited thereto.

  In the longitudinal direction of the airbag 20, the portion on the upper end side (one side in the webbing insertion direction) from the lowermost loop portion 26 </ b> A is an inflating portion 31 that inflates in the X direction when the airbag 20 is activated. A portion of the airbag 20 on the lower end side (the other side in the webbing insertion direction) from the loop portion 26 </ b> A is a non-inflatable portion 32 that does not inflate in the X direction even when the airbag 20 is activated.

  As shown in FIG. 5, the airbag 20 includes a folded portion 33 in which the inflatable portion 31 is folded in a bellows shape along a plurality of folded lines along a direction orthogonal to the insertion direction when stored. For example, as shown in FIG. 5, the folding portion 33 includes two webbing side folding portions F <b> 11 and F <b> 12 and two passenger side folding portions F <b> 21 and F <b> 22 in order from the lower end side (X negative direction side). The webbing-side folded portions F11 and F12 are formed to protrude from the airbag 20 to the webbing 11 side (X negative direction side). The occupant side folding portions F21 and F22 are formed so as to protrude from the airbag 20 to the occupant side (the X positive direction side) opposite to the webbing 11 side.

  As shown in FIG. 5, the airbag 20 in which the folded portion 33 is formed becomes an intermediate folded body having a reduced overall length by being folded back a plurality of times on the protruding piece portion 22 side. The extending direction of the folding line at this time is the width direction orthogonal to the longitudinal direction of the airbag 20.

  After the intermediate folded body shown in FIG. 5, it is folded in the webbing width direction by the procedure of FIGS. As shown in FIG. 5, the intermediate folded body is disposed along the webbing width direction, the central part 34 that overlaps the webbing 11 when deployed in the width direction, and the both sides of the webbing 11 from the central part 34 in the width direction. The pair of folded portions 35 and 36 are folded back toward the central portion 34 along the insertion direction of the webbing 11 when stored in the bag cover 40.

  In the present embodiment, one folded portion 36 of the pair of folded portions 35, 36 is disposed on the X positive direction side (lower side in FIG. 5A), and the other folded portion 35 is disposed on the X negative direction side (FIG. 5). The central portion 34 and the folded portions 35 and 36 are divided by folded lines along the longitudinal direction (Z direction) of the airbag 20. In the present embodiment, The side on which the folded portion 36 is disposed is the side on which the tear portion 41 (see FIG. 10 and the like) of the bag cover 40 is disposed, and is denoted as “the tear side” in FIGS.

  First, as shown in FIG. 6, the edge 37 on the upper connecting structure 51 side of the other folded portion 35 on the opposite side to the tear portion 41 is folded diagonally to the opposite side to the central portion 34 with the webbing 11 interposed therebetween. At this time, the folding is performed so that the edge 37 is disposed on the central portion 34.

  Next, as shown in FIG. 7, the other folded portion 35 on the opposite side to the tear portion 41 is folded to the opposite side to the webbing 11 with the central portion 34 interposed therebetween. Thereby, the webbing side folding part 38 is formed so that a part (part including the edge 37) of the other folded part 35 on the upper connection structure part 51 side remains on the webbing 11 side.

  Next, as shown in FIG. 8, one folded portion 36 is folded to the opposite side of the webbing 11 with the central portion 34 sandwiched in the same manner as the other folded portion 35. As a result, one folded portion 36 on the tear portion 41 side of the pair of folded portions is disposed outside the other folded portion 35. As a result, the airbag 20 as a whole becomes an elongated folded body having a substantially equal width. The width of the folded body in the Y direction is a width in which the webbing 11 and the webbing guide 30 can be inserted.

  Next, as shown in FIG. 9, the webbing guide 30 is inserted between the loop portions 26 </ b> A to 26 </ b> D of the folded body and the base fabric 20 a in the direction connecting the slit 24 and the protruding piece portion 22. Although not shown in FIG. 9, the webbing 11 is inserted through the webbing guide 30. As shown in FIG. 9, the webbing guide 30 that passes through the loop portions 26 </ b> A to 26 </ b> D along the base fabric 20 a is drawn from the base fabric 20 a side to the base fabric 20 b side through the slit 24, and the gas introduction port 21. Extends to the vicinity. The webbing guide 30 extends continuously from the lower end of the bag cover 40 to the other end.

  The webbing guide 30 and the folded body of the airbag 20 are inserted into the bag cover 40 as shown in FIG. The bag cover 40 is an example of a flat and elongated cylindrical cover. The bag cover 40 is provided with a tear portion 41 that is a starting point of breakage when the airbag 20 is operated along one end portion in the width direction of the webbing 11 (see FIG. 10 and the like). The tear portion 41 is sewn with a suture thread that is cut by the inflation pressure of the airbag 20. In the present embodiment, the overall lengths of the webbing guide 30 and the bag cover 40 are substantially equal, and the positions of the lower end and the upper end of the webbing guide 30 and the bag cover 40 are substantially the same.

  FIGS. 10-13 is a schematic diagram for demonstrating the effect by the folding structure of the airbag 20 of 1st Embodiment. FIG. 10 is a schematic diagram showing an initial state (folded state) when the airbag 20 according to the first embodiment is deployed. FIG. 11 is a schematic diagram illustrating a first stage when the airbag 20 is deployed in the first embodiment. FIG. 12 is a schematic diagram showing a second stage when the airbag 20 is deployed in the first embodiment. FIG. 13 is a schematic diagram illustrating a third stage during deployment of the airbag 20 according to the first embodiment. 10A to 13A, FIG. 10A is a plan view of the air belt 10 viewed from the X positive direction side, and FIG. 10B schematically illustrates a cross-sectional view of the air belt 10 in the Z direction.

  As shown in FIG. 10, in the initial state (folded state) during deployment, the airbag 20 is housed inside the bag cover 40 as the folded body shown in FIG. That is, the pair of folded portions 35 and 36 are both folded back on the opposite side to the webbing 11 with the central portion 34 interposed therebetween, and the folded portion 36 on the tear portion 41 side is disposed outside. Further, a part including the edge 37 on the upper connecting structure 51 side of the folded portion 35 is a webbing-side folded portion 38 between the bag cover 40 and the webbing 11 on the side opposite to the folded portions 35 and 36. Has been placed.

  The bag cover 40 accommodates the folded body of the airbag 20, and one side in the width direction is sewn to form a tear portion 41. The airbag 20 and the bag cover 40 are connected by an upper connection structure portion 51 at the upper end portions thereof. The upper connecting structure 51 is connected to the airbag 20 and the bag cover 40 at a total of four locations including a pair of main surfaces and side surfaces at both ends of these main surfaces. Of the four connecting portions, the portion provided on the main surface on the webbing 11 side (the X positive direction side) is the connecting portion 52a, and the portion provided on the opposite main surface is the connecting portion 52b. What is provided on the side surface on the opposite side (Y positive direction side) is the connecting portion 52c, and what is provided on the side surface on the tear portion 41 side (Y negative direction side) is the connecting portion 52d.

  Next, as shown in FIG. 11, when the airbag 20 is started to be deployed and gas is supplied to the airbag 20, the folded portion 36 that is folded outward is first of the pair of folded portions 35 and 36. It begins to expand first. Since the folded portion 36 is on the side of the tear portion 41 of the bag cover 40 as described above, when the folded portion 36 expands, the tear portion 41 is immediately broken and the folded portion 36 expands to the outside. At the same time as the tear portion 41 breaks, the coupling of the connecting portion 52d on the tear portion 41 side is separated.

  Next, as shown in FIG. 12, the folded portion 35 that has been folded inward begins to expand. Thereby, the coupling | bonding of the connection parts 52b and 52c is isolate | separated. At this time, the webbing-side folded portion 38 that has been folded to the webbing 11 side also expands. The webbing side folding portion 38 is inflated so as to push the main surface of the webbing 11 of the airbag outward so as to be deployed from the folded state as indicated by an arrow in FIG. Thereby, the coupling | bonding of the connection part 52a provided in this main surface is also isolate | separated.

  And as shown in FIG. 13, when the expansion | swelling of the width direction of the airbag 20 is completed, all the coupling | bonding of the connection parts 52a-52d with the upper connection structure part 51 will be isolate | separated, and the upper connection structure part 51, the bag cover 40, and Debinding of is completed. Thereby, the airbag 20 can operate | move smoothly, without receiving resistance of the bag cover 40 etc. at the time of expansion | swelling (extension) to the longitudinal direction (sliding direction of the webbing 11) of the airbag 20 after that.

  As described above, according to the air belt 10 of the first embodiment, both of the pair of folded portions 35 and 36 of the airbag 20 are folded back to the opposite side to the webbing 11 when folded. Thereby, since the airbag 20 does not wrap the webbing 11 in the folded state, the webbing 11 is not crushed from both sides in the width direction due to the inflation of the airbag 20, and the normal state (flatness) of the webbing 11 when the airbag 20 is deployed. Can be maintained satisfactorily.

  Further, in the air belt 10 of the first embodiment, the folded portion 36 on the tear portion 41 side of the pair of folded portions 35, 36 of the airbag 20 is folded so as to be disposed outside the other folded portion 35. Thereby, when the airbag 20 is deployed, the folded portion 36 on the side of the tear portion 41 is first inflated, so that the tear portion 41 can be broken at the initial stage of the inflation process of the airbag 20 and the airbag 20 can be deployed smoothly. Can do.

  Further, in the airbag 10 of the first embodiment, the airbag 20 is folded so that the webbing-side folded portion 38 is disposed on the side opposite to the pair of folded portions 35 and 36. Thereby, when the airbag 20 is deployed, the bag cover 40 can be pushed out in the direction opposite to the pair of folded portions 35 and 36, and the connection with the bag cover 40 can be released more smoothly.

  In the air belt 10 of the first embodiment, the tear portion 41 of the bag cover 40 is preferably disposed on the lower side when the webbing 11 is attached to the occupant. That is, the Y negative direction side where the tear portion 41 of the bag cover 40 is provided is lower than the Y positive direction side. Thereby, it can suppress that webbing 11 slips to a crew member at the time of deployment of air bag 20, and webbing 11 can be made hard to come off from a crew member's shoulder.

  In addition, the formation procedure of the webbing side folding part 38 is not limited to the procedure shown in FIGS. The webbing-side folded portion 38 is a final folded body of the airbag 20 as long as the edge 37 on the upper connecting structure 51 side of the folded portion 35 is disposed within the width of the central portion 34 and the webbing 11. Good. For example, the webbing-side folding part 38 can be formed by a procedure in which the folding part 35 is first folded back to the opposite side of the webbing 11 and then the edge 37 is folded back obliquely.

  Contrary to the first embodiment, the folded portion 35 opposite to the tear portion 41 of the pair of folded portions 35, 36 of the airbag 20 is disposed outside the folded portion 36 on the tear portion 41 side. May be folded.

[Second Embodiment]
A second embodiment will be described with reference to FIGS. FIG. 14 is a diagram illustrating a first stage of a folding procedure of the airbag 20 in the webbing width direction according to the second embodiment. FIG. 15 is a diagram illustrating a second stage of the folding procedure of the airbag 20 in the webbing width direction according to the second embodiment.

  As shown in FIGS. 14 and 15, the second embodiment differs from the first embodiment in that the webbing side folding portion 38 is not formed in the folding procedure of the airbag 20 in the webbing width direction.

  After the intermediate folded body shown in FIG. 5, the folded portion 35 is not folded diagonally as shown in FIG. 6, and the other folded portion 35 on the side opposite to the tear portion 41 has the central portion 34 as shown in FIG. 14. It is folded back to the opposite side of the webbing 11 with the pinch.

  Next, as shown in FIG. 15, one folded portion 36 is folded to the opposite side of the webbing 11 with the central portion 34 sandwiched in the same manner as the other folded portion 35. One folded portion 36 on the tear portion 41 side of the pair of folded portions is disposed outside the other folded portion 35. As a result, an elongated folded body having a substantially equal width as a whole is obtained. The width of the folded body in the Y direction is a width in which the webbing 11 and the webbing guide 30 can be inserted.

  Thereafter, as shown in FIG. 9, the webbing guide 30 is inserted between the loop portions 26 </ b> A to 26 </ b> D of the folded body and the base fabric 20 a in the direction connecting the slit 24 and the projecting piece portion 22. .

  FIGS. 16-20 is a schematic diagram for demonstrating the effect by the folding structure of the airbag 20 of 2nd Embodiment. FIG. 16 is a schematic diagram illustrating an initial state (folded state) when the airbag 20 according to the second embodiment is deployed. FIG. 17 is a schematic diagram illustrating a first stage when the airbag 20 according to the second embodiment is deployed. FIG. 18 is a schematic diagram illustrating a second stage when the airbag 20 according to the second embodiment is deployed. FIG. 19 is a schematic diagram illustrating a third stage during deployment of the airbag 20 in the second embodiment. FIG. 20 is a schematic diagram illustrating a fourth stage when the airbag 20 according to the second embodiment is deployed. 16 to 20, (a) schematically shows a front view of the air belt, and (b) schematically shows a cross-sectional view of the air belt.

  As shown in FIG. 16, in the initial state (folded state) at the time of deployment, the airbag 20 is housed inside the bag cover 40 as a folded body shown in FIG. 15. The bag cover 40 accommodates the folded body of the airbag 20, and one side in the width direction is sewn to form a tear portion 41. As in the first embodiment, the airbag 20 and the bag cover 40 are connected to the upper connection structure portion 51 by the connection portions 52a to 52d at the four upper ends.

  Next, as shown in FIG. 17, when deployment of the airbag 20 is started and gas is started to be supplied to the airbag 20, the folded portion 36 that is folded outward is first of the pair of folded portions 35 and 36. It begins to expand first. Since the folded portion 36 is on the side of the tear portion 41 of the bag cover 40 as described above, when the folded portion 36 expands, the tear portion 41 is immediately broken and the folded portion 36 expands to the outside. At the same time as the tear portion 41 breaks, the coupling of the connecting portion 52d on the tear portion 41 side is separated.

  Next, as shown in FIG. 18, the folded portion 35 that has been folded inward starts to expand. Thereby, the coupling | bonding of the connection parts 52b and 52c is isolate | separated.

  As shown in FIG. 19, even if the expansion in the width direction is completed, the connection of the connecting portion 52a provided on the main surface on the webbing 11 side remains, but as shown in FIG. 20, the airbag 20 is deployed in the longitudinal direction. As a result, the coupling of the coupling portion 52a is separated, and the coupling release between the upper coupling structure 51 and the bag cover 40 is completed.

  Thus, also by the air belt 10 of 2nd Embodiment, when both of a pair of folding | returning parts 35 and 36 of the airbag 20 are a folding state similarly to 1st Embodiment, it is folded back to the webbing 11 and the other side. Thereby, since the airbag 20 does not wrap the webbing 11 in the folded state, the webbing 11 is not crushed from both sides in the width direction due to the expansion of the airbag 20, and the airbag 20 is deployed as in the first embodiment. Sometimes the flat state of the webbing 11 can be maintained well.

  Contrary to the second embodiment, the folded portion 35 opposite to the tear portion 41 of the pair of folded portions 35, 36 of the airbag 20 is disposed outside the folded portion 36 on the tear portion 41 side. May be folded.

[Third Embodiment]
A third embodiment will be described with reference to FIGS. FIG. 21 is a diagram illustrating a folded state of the airbag 20 in the webbing width direction according to the third embodiment.

  As shown in FIG. 21, in the third embodiment, of the pair of folded portions 35, 36 of the airbag 20, only the folded portion 35 opposite to the tear portion 41 of the bag cover 40 is webbed with the central portion 34 interposed therebetween. 11 is different from the first and second embodiments in that it is folded back to the opposite side.

  As shown in FIG. 21, the folded portion 36 on the tear portion 41 side is folded toward the webbing 11 with the center portion 34 interposed therebetween. That is, the airbag 20 is folded in a substantially S shape when viewed from the webbing sliding direction, with the folding direction of the pair of folded portions 35 and 36 being opposite.

  Even with such a folding structure, the webbing 11 is sandwiched between the airbags 20 from both sides in the width direction and is not folded in the folded state, so that the webbing 11 may be crushed from both sides in the width direction by the inflation of the airbag 20. In addition, as in the first and second embodiments, the flat belt state of the webbing 11 can be favorably maintained when the airbag 20 is deployed.

  FIG. 22 is a diagram illustrating a modification of the third embodiment. In the folding structure of the third embodiment, only one of the pair of folded portions 35 and 36 of the airbag 20 needs to be folded to the opposite side of the webbing 11 with the central portion 34 interposed therebetween, as shown in FIG. In contrast to FIG. 21, only the folded portion 36 on the tear portion 41 side of the bag cover 40 may be folded to the opposite side to the webbing 11 with the central portion 34 interposed therebetween.

  The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Those in which those skilled in the art appropriately modify the design of these specific examples are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each of the specific examples described above and their arrangement, conditions, shape, and the like are not limited to those illustrated, and can be changed as appropriate. Each element included in each of the specific examples described above can be appropriately combined as long as no technical contradiction occurs.

DESCRIPTION OF SYMBOLS 10 Airbelt 11 Webbing 20 Airbag 34 Center part 35,36 Folding part 37 Edge part 38 Webbing side folding part 40 Bag cover 41 Tear part 51 Upper connection structure part (connection structure part)

Claims (6)

An inflatable airbag arranged and sandwiched between the webbing and the occupant in use;
A bag cover that accommodates the airbag in a folded state,
In the bag cover, a tear portion that becomes a breakage starting point when the airbag is operated is provided along one end portion in the width direction of the webbing,
The airbag is
A central portion that overlaps with the webbing in the unfolded state, and is disposed on both sides in the width direction of the webbing from the central portion, and is folded back toward the central portion along the insertion direction of the webbing when stored in the bag cover. A pair of folded portions,
At least one of the pair of folded portions is folded to the opposite side of the webbing across the central portion;
Air belt. Both of the pair of folded portions are folded back to the opposite side of the webbing across the central portion.
The air belt according to claim 1. Of the pair of folded portions when stored in the bag cover, one folded portion on the tear portion side is disposed outside the other folded portion.
The air belt according to claim 2. A connecting structure for connecting the bag cover and the end of the airbag on the opposite side of the tongue from the webbing insertion direction;
The airbag is formed such that, when stored in the bag cover, a part of the pair of folded portions on the side of the connecting structure portion of the other folded portion on the side opposite to the tear portion remains on the webbing side. A webbing side fold
The air belt according to claim 2 or 3. The webbing-side folded part is configured to fold the edge of the other folded part on the side of the connecting structure part obliquely to the opposite side of the central part across the webbing, and the edge is above the central part Formed by being placed,
The air belt according to claim 4. The tear portion is disposed on the lower side when the webbing is mounted on an occupant.
The air belt according to any one of claims 1 to 5.

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