Airbag device

Abstract

When inflation gas flows into the airbag (20) and the airbag (20) is inflated, the airbag (20) is inflated so as to protrude upward from a housing portion (16) provided on the upper surface (2) side of the instrument panel (1) and deploy rearward. An airbag is provided with: an airbag body (21); and an outer lacing portion (55) disposed on the outer peripheral surface side of the airbag body. The airbag main body has a recessed portion (35) recessed upward on the lower surface side of a region further forward than an occupant side wall portion (40) disposed on the rear surface side when the airbag main body is inflated. The outer lacing portion is disposed so as to connect the rear lower end (21c) side of the airbag main body after completion of inflation and the front edge (35a) side of the recessed portion, and is configured so that the rear lower end of the airbag main body after completion of inflation can be disposed close to the rear surface (3) of the instrument panel.

Description

Technical Field

[0001] The present invention relates to an airbag device having the following structure, namely, comprising: an airbag, which is arranged on the upper surface side of an instrument panel and can allow inflation gas to flow into the inside to inflate; an inflator, which supplies inflation gas to the airbag; and a storage portion, which stores the folded airbag and the inflator. Background Art

[0002] Currently, as an airbag device of this structure, there is a structure shown in Japanese Patent Gazette 2016-60390. The current airbag device is arranged in front of the passenger seat to protect the passenger sitting in the passenger seat. Regarding the passenger seat airbag device of this structure, when the inflator is working, the airbag folded and stored in the storage part expands from the storage part in a manner of protruding upward and unfolding toward the rear, thereby protecting the passenger sitting in the passenger seat. In detail, the front surface side of the inflated airbag is supported by the windshield arranged on the instrument panel and above the instrument panel, thereby protecting the passenger moving forward.

[0003] However, when an airbag device of this structure is installed in a vehicle of the type in which an instrument panel is arranged at a position far away from the front seat where the occupant sits, the volume of the airbag will be increased in order to stably support the occupant, resulting in a larger device and an increase in manufacturing cost. This is because the distance from the installation position of the airbag device to the occupant is large. Summary of the invention

[0004] An object of the present invention is to provide an airbag device that can be formed into a compact structure and reliably protect an occupant.

[0005] The airbag device of the present invention is formed into the structure shown below:

[0006] The airbag device is arranged on the upper surface side of the instrument panel.

[0007] The invention comprises: an airbag which can inflate by allowing inflation gas to flow into the inside; an inflator which supplies inflation gas to the airbag; and a storage portion which stores the folded airbag and the inflator.

[0008] The airbag is formed into a structure that, when the inflation gas discharged from the inflator flows into the inside and inflates, the airbag inflates so as to protrude upward from the storage portion and deploy backward, wherein:

[0009] The airbag comprises: an airbag body which is inflated by allowing an inflation gas to flow into the inside; and an outer tether portion which is arranged on the outer peripheral surface side of the airbag body and restricts the inflation completed shape of the airbag body.

[0010] The airbag body has a passenger side wall portion configured on the rear surface side when fully inflated to protect a passenger seated in the front seat, and has a recessed portion recessed upward in a manner that a gap is provided between the airbag body and the instrument panel on the lower surface side of the area further forward than the passenger side wall portion when fully inflated.

[0011] The outer tether portion is configured to connect the rear lower end side of the inflated airbag body and the front edge side of the recessed portion, so that the rear lower end of the inflated airbag body can be arranged close to the rear surface of the instrument panel.

[0012] With respect to the airbag device of the present invention, when the airbag is fully inflated, the inflated airbag body is configured to have a gap between the area on the front lower surface side and the instrument panel. However, the rear lower end side of the airbag body is connected to the front edge side of the recessed portion constituting the gap via the outer tie portion configured on the outer peripheral surface side of the airbag body, and is therefore configured to be close to the rear surface of the instrument panel when the inflation is completed. That is, with respect to the airbag device of the present invention, the airbag (airbag body) can be inflated in a partially recessed state in a manner that a gap is provided between the airbag and the instrument panel. Therefore, the volume can be reduced compared to an airbag having a structure without such a recessed portion. Moreover, the rear lower end side of the inflated airbag body is configured to be close to the rear surface of the instrument panel through the outer tie portion. In addition, the recessed portion formed in the airbag body is formed in an area closer to the front side than the passenger side wall portion that protects the passenger when the inflation is completed. Therefore, even with a structure having a recessed portion, the rear lower end side area of ​​the airbag body can be supported on the instrument panel, and the passenger moving forward can be stably supported by the passenger side wall portion. As a result, the airbag device of the present invention can suppress an increase in the volume of the airbag and an increase in the size of the device itself by appropriately setting the shape of the recessed portion formed in the airbag body even when the interior shape of the vehicle on which the airbag is installed is different.

[0013] Therefore, the airbag device of the present invention can be formed into a compact structure and can reliably protect the occupant.

[0014] In addition, regarding the airbag device of the present invention, the airbag main body is formed into the following structure:

[0015] That is, the instrument panel is expanded in such a manner that a protrusion that partially protrudes upward from the instrument panel is located in the concave portion.

[0016] The outer tether portion is preferably formed into a structure such that it is arranged close to the rear surface side of the projection when the airbag body is fully inflated.

[0017] If the airbag device is formed into such a structure, when the airbag device is mounted on a vehicle of a type in which a protrusion protrudes partially from the instrument panel, the arrangement of the recessed portion can also prevent the inflated airbag body from interfering greatly with the protrusion, and the inflation can be completed smoothly. In addition, in the airbag device of the above structure, the outer tether portion is arranged to approach the rear surface side of the protrusion when the inflation of the airbag body is completed. Therefore, when the passenger side wall portion receives the passenger, the outer tether portion is supported by the protrusion, and the reaction force can be ensured, and the passenger can be reliably protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic perspective view showing an instrument panel of a vehicle equipped with an airbag device for a passenger seat according to one embodiment of the present invention.

[0019] Figure 2 It is a schematic longitudinal sectional view showing a state in which the passenger seat airbag device according to the embodiment is mounted on a vehicle.

[0020] Figure 3 It is a schematic perspective view showing a state in which the airbag used in the airbag device for a passenger seat according to the embodiment is inflated as a single unit.

[0021] Figure 4 yes Figure 3 A schematic longitudinal cross-sectional view of an airbag roughly along the front-rear direction.

[0022] Figure 5 It will constitute Figure 3 A top view of the arrangement state of the substrates of the airbag.

[0023] Figure 6 It is composed Figure 3 An enlarged top view of the side wall panel of the air bag.

[0024] A in Figure 7 is Figure 3 FIG. 7B is a top view of the pre-folded airbag formed by folding the airbag, and FIG. 7C is a bottom view of the pre-folded airbag.

[0025] FIG. 8A is a top view of left and right reduced folded airbags formed by folding the preliminary folded airbag, and FIG. 8B is a bottom view of the left and right reduced folded airbags.

[0026] A to C in FIG. 9 represent Figure 3 8 is a schematic diagram of the folding process of the airbag, showing the front-to-back shrinking folding process (the process after A and B in FIG. 8 ).

[0027] A and B of FIG. 10 are schematic longitudinal sectional views showing an inflation process of the airbag in the airbag device for a passenger seat according to the embodiment.

[0028] A and B of FIG. 11 are schematic longitudinal sectional views showing the inflation process of the airbag in the airbag device for a passenger seat according to the embodiment, and show the process after B of FIG. 10 .

[0029] Fig.12 It is a schematic longitudinal sectional view showing a state in which the airbag is completely inflated in the airbag device for a passenger seat according to the embodiment.

[0030] Fig.13 This is a schematic rear view of the passenger seat airbag device according to the embodiment, showing a state in which the airbag is fully inflated, as viewed from the rear side of the vehicle. DETAILED DESCRIPTION

[0031] Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings. In the embodiment, an airbag device for a passenger seat (hereinafter referred to as "airbag device") M disposed in front of a passenger seat as a front seat will be described as an example. Figure 1 , 2 As shown, the airbag device M is configured as a top-mounted type disposed on the upper surface 2 side of an instrument panel (hereinafter abbreviated as "instrument panel") 1. In the embodiment, on the instrument panel 1 of the vehicle V equipped with the airbag device M, as shown in FIG. Figure 1 , 2 As shown in FIG. 1 , a monitor 5 is arranged as a protrusion on the rear surface side behind the area where the airbag device M is arranged. The monitor 5 is arranged so as to protrude upward from the instrument panel 1. Specifically, in the embodiment, the instrument panel 1 is formed into a structure in which the rear surface 3 is tilted slightly forward relative to the vertical direction. Furthermore, the monitor 5 is also arranged so as to be slightly tilted forward relative to the vertical direction in a manner substantially along the rear surface 3 of the instrument panel 1 (see FIG. 1 ). Figure 2 In addition, in the embodiment, the monitor 5 is formed to be slightly wider in the left-right direction than the airbag device M (more specifically, the airbag cover 10 described later) (see Figure 1 ), and is arranged in a position directly opposite to the passenger MP sitting in the front passenger seat (refer to Fig.13 ). In addition, in the embodiment, unless otherwise stated, the front-rear / up-down / left-right directions are consistent with the front-rear / up-down / left-right directions of the vehicle V.

[0032] like Figure 2 , 12 As shown, the airbag device M includes: a folded airbag 20; an inflator 12, which supplies inflation gas to the airbag 20; a housing 16 as a storage portion, which stores the folded airbag 20 and the inflator 12; a retaining member 13, which is used to install the airbag 20 and the inflator 12 on the housing 16; and an airbag cover 10, which covers the folded airbag 20.

[0033] In the embodiment, the airbag cover 10 is formed integrally with the synthetic resin instrument panel 1. The airbag cover 10 has two front and rear door portions 10a and 10b, which are configured to be opened by being pressed by the airbag 20 when the airbag 20 is deployed and expanded. In addition, a connecting wall portion 10c connected to the housing 16 is formed around the door portions 10a and 10b of the airbag cover 10.

[0034] like Figure 2 As shown, the inflator 12 includes: a substantially cylindrical main body portion 12 a having a plurality of gas discharge ports 12 b ; and a flange portion 12 c for mounting the inflator 12 on the housing 16 .

[0035] The housing 16 as the storage part is formed into a substantially rectangular parallelepiped shape made of a thin metal plate having a rectangular opening at the upper end. Figure 2 As shown, the housing 16 has: a bottom wall portion 16a in a substantially rectangular plate shape, into which the inflator 12 is inserted and installed from below; and a peripheral wall portion 16b, which extends upward from the outer peripheral edge of the bottom wall portion 16a and locks the connecting wall portion 10c of the airbag cover 10. In the case of the embodiment, the airbag 20 and the inflator 12 are mounted on the bottom wall portion 16a of the housing 16 using the bolts 13a of the retainer 13 disposed in the airbag 20 as a mounting unit. At this time, each bolt 13a penetrates the peripheral edge of the inflow opening 30 of the airbag 20, which will be described later, the bottom wall portion 16a of the housing 16, and the flange portion 12c of the inflator 12 and is fixed by the nut 14. In addition, a bracket (not shown) connected to the body side of the vehicle V is disposed on the bottom wall portion 16a of the housing 16.

[0036] In the case of implementation, such as Figure 3 , 4 As shown, the airbag 20 includes: an airbag body 21 that is inflated by allowing inflation gas to flow into the inside; front and rear tethers 45 that are arranged in the airbag body 21; and an outer tether portion 55 that is arranged on the outer peripheral surface side of the airbag body 21. The front and rear tethers 45 are inner tethers that restrict the inflated shape of the airbag body 21. The outer tether portion 55 is a member that restricts the inflated shape of the airbag body 21.

[0037] like Fig.12 As shown in FIG. 1 , the airbag body 21 is formed into a structure such that, when the airbag body 21 is fully inflated, it can be configured to block the space between the upper surface 2 of the instrument panel 1 and the windshield 7 above the instrument panel 1. Specifically, Figure 3 , 4As shown, the airbag body 21 has an outer shape when fully inflated, that is, a substantially quadrangular pyramid shape with the top disposed at the front end side and the lower surface side being greatly recessed upward. The airbag body 21 has: a passenger side wall portion 40, which is disposed at the rear side (rear surface side) that becomes the passenger MP side when fully inflated; and a peripheral wall portion 23, which extends from the peripheral edge of the passenger side wall portion 40 and converges to the front end side mounted on the housing 16 side.

[0038] The peripheral wall portion 23 is a portion that is configured to mainly block the upper surface 2 of the instrument panel 1 and the windshield 7 above the instrument panel when the airbag 20 (airbag body 21) is fully inflated. The peripheral wall portion 23 includes an upper wall portion 24 and a lower wall portion 25 that are configured to face each other in the vertical direction, and a left wall portion 26 and a right wall portion 27 that are configured to face each other in the left-right direction when the inflation is completed. An inflow opening 30 is formed near the front end 25a of the lower wall portion 25 at a position approximately in the center in the left-right direction. The inflow opening 30 is a portion that allows the inflation gas to flow into the interior and is mounted on the bottom wall portion 16a of the housing 16 in an approximately circular opening. A plurality of (four in the embodiment) mounting holes 31 are formed on the periphery of the inflow opening 30. Each mounting hole 31 is a portion for inserting the bolt 13a of the retainer 13 and mounting the periphery of the inflow opening 30 on the bottom wall portion 16a of the housing 16. The left wall 26 and the right wall 27 are provided with vent holes 33 opening in a substantially circular shape for discharging the excess inflation gas flowing into the airbag body 21. Each vent hole 33 is disposed in the left wall 26 and the right wall 27 at a position above and behind a region where a recess 35 described later is disposed.

[0039] In addition, regarding the airbag body 21 of the embodiment, the lower wall portion 25 is configured to be curved when viewed from the left-right direction so that the middle portion of the front and rear is located at the top. In addition, the curved shape of the lower wall portion 25 is configured to extend over substantially the entire range in the left-right direction (i.e., substantially the entire range in the left-right direction of the airbag body 21) (see Figure 3 , 4). In the embodiment, the airbag body 21 is formed into a structure having a recessed portion 35 recessed upward in the area on the lower surface side due to the curved shape of the lower wall portion 25. In detail, the recessed portion 35 is formed at a substantially central position in the front and rear direction when the airbag body 21 is viewed from the left and right sides when inflation is complete. In other words, the recessed portion 35 is separated from the passenger side wall portion 40 disposed on the rear surface side of the airbag body 21 in the front and rear direction, and is formed on the lower surface side of the area further to the front side than the passenger side wall portion 40. As described above, the recessed portion 35 is continuously formed over substantially the entire left and right range of the airbag body 21 in such a manner that the recessed shape is the same. That is, by configuring the recessed portion 35, a gap is provided between the airbag body 21 and the instrument panel 1 over the entire left and right range when inflation is complete. In addition, when inflation of the airbag 20 is complete, the recessed portion 35 is configured at a position corresponding to the monitor 5 protruding upward on the rear surface 3 side of the instrument panel 1 (refer to Fig.12 ) In other words, the airbag body 21 is configured to bypass the monitor 5 due to the recessed portion 35 when inflation is complete.

[0040] The passenger side wall portion 40 is disposed at a position further rearward than the monitor 5 on the rear end 21b side of the airbag body 21 when the airbag body 21 is fully inflated. In addition, the passenger side wall portion 40 is disposed substantially in the vertical direction so as to face the passenger MP sitting in the front passenger seat when the airbag body 21 is fully inflated (see FIG. Fig.12 ). Specifically, Fig.13 As shown, the passenger side wall portion 40 is configured in such a manner that the outer shape when fully inflated is formed into a substantially rectangular shape with a large width in the vertical direction, and can cover the front of the upper body of the passenger MP in a wide range. In the case of the embodiment, the passenger side wall portion 40 is configured to cover the vehicle rear side of the monitor 5 over the entire surface (see Fig.12 , 13 ). The lower end 40a side of the passenger side wall portion 40 is located below the monitor 5 when the inflation is complete. The width dimension of the passenger side wall portion 40 in the left-right direction is set to be larger than the width dimension of the monitor 5 in the left-right direction. In addition, in the embodiment, when the inflation is complete, the airbag body 21 makes the upper surface side (upper wall portion 24 side) contact the windshield 7.

[0041] The front and rear tethers 45 as the internal tethers arranged in the airbag body 21 are arranged to connect the approximate center of the left and right sides of the passenger side wall portion 40 to the front end 21a side of the airbag body 21. The front and rear tethers 45 are arranged to limit the excessive rearward protrusion of the passenger side wall portion 40 at the initial stage of inflation and to limit the position of the passenger side wall portion 40 (the separation distance relative to the portion around the inflow opening 30) when inflation is completed. In the case of the embodiment, the front and rear tethers 45 are configured to connect the front side portion 46 extending from the periphery of the inflow opening 30 and the rear side portion 47 extending from the passenger side wall portion 40 side (see Figure 3 , 4 In the embodiment, the front part 46 is configured to Figure 5 The strip-shaped front part material 49 shown is partially folded into two parts. The outer shape of the rear part 47 is formed into a trapezoidal shape with a small width until the front end side connected to the front part 46. The rear part 47 is sewn to the substantially central position of the left and right sides of the passenger side wall portion 40 so that the rear edge is along the up-down direction.

[0042] The outer tether portion 55 is arranged on the outer peripheral surface side of the airbag body 21 so as to connect the rear lower end 21c side of the airbag body 21 when the inflation is complete (specifically, the vicinity of the rear end 25b of the lower wall portion 25) and the front edge 35a side of the recess 35 (the area behind the inflow opening 30). In the embodiment, when the airbag 20 (airbag body 21) is inflated as a single body, as shown in FIG. Figure 4 As shown, the outer tie portion 55 is arranged to cross the recessed portion 35. In addition, when the expansion is completed in the vehicle-mounted state, as shown in FIG. Fig.12 As shown, the outer tie portion 55 is arranged close to the rear side of the monitor 5 in a manner roughly along the rear surface 5a. The outer tie portion 55 is used to limit the rear lower end 21c side of the airbag body 21 (the area on the side of the lower end 40a of the passenger side wall portion 40) from excessively expanding in a manner convex toward the rear and lower when the airbag body 21 is deployed and inflated, and when the airbag body 21 is fully inflated, the rear lower end 21c side of the airbag body 21 can be arranged to be close to the rear surface 3 of the instrument panel 1. In detail, the outer tie portion 55 is connected so that the upper end 55a (one end) when the inflation is complete is connected to the front edge 35a side of the recessed portion 35. The upper end 55a of the outer tie portion 55 is connected to a portion located near the upper end 5b of the monitor 5 in the fully inflated state when the airbag body 21 is mounted on the vehicle (refer to Fig.12 The other end (lower end 55b) of the outer tether portion 55 is connected to the vicinity of the rear edge 35b of the recessed portion 35 and to a position above the lower edge 21d of the airbag body 21 when inflation is complete (near the rear end 25b of the lower wall portion 25) (see Figure 4 ). In detail, regarding the airbag body 21 in the fully inflated state when mounted on the vehicle, as shown in FIG. Fig.12As shown, the lower end 55b of the outer tie portion 55 is connected to a position below the monitor 5 and arranged close to the rear surface 3 of the instrument panel 1. The length dimension L1 of the outer tie portion 55 (see Figure 4 ) is set to the following length dimension L2 (see Figure 5 ) are substantially the same. The length dimension L2 refers to the length of the connection portion 77F, 77B (refer to Figure 5 ) is connected to each other by the length L2 of the straight line connecting the points P1 and P2 corresponding to each other, and the connection predetermined portions 77F and 77B respectively connect the two ends (upper end 55a and lower end 55b) of the outer tie portion 55 of the side wall panel 68 in a flatly unfolded state. In addition, the width dimension of the outer tie portion 55 is set to be substantially equal to the width dimension of the lower wall portion 25. In detail, the width dimension of the outer tie portion 55 is set to be slightly smaller than the width dimension of the lower wall portion 25 (the width dimension of the peripheral wall panel 63 described later) (refer to Figure 5 As described above, when the airbag body 21 is installed in the vehicle and the airbag body 21 is fully inflated, the outer tether portion 55 is arranged so that the lower end 55b is located below the monitor 5. That is, when the airbag body 21 is fully inflated, the outer tether portion 55 covers the rear surface 5a side of the monitor 5 over a wide range of substantially the entire range of the upper, lower, left, and right sides. Figures 3 to 5 As shown, the outer tether portion 55 is formed by connecting two tether base materials 57 and 57 in series.

[0043] The airbag body 21 is formed into a bag shape by bonding the peripheries of base materials (base fabrics) of a predetermined shape to each other. Figure 5 As shown, the airbag body 21 is composed of two peripheral wall panels 60 and 63 and two side wall panels 68L and 68R.

[0044] The peripheral wall panel 60 mainly constitutes a portion extending from the area on the front end 25a side of the lower wall portion 25 through the upper wall portion 24 to the passenger side wall portion 40. Figure 5 As shown, the peripheral wall panel 60 is formed into a substantially strip-shaped outer shape that is approximately bilaterally symmetrical. At one end of the peripheral wall panel 60, a mounting side portion 61 is disposed that forms the area surrounding the inlet opening 30. The peripheral wall panel 63 mainly forms the lower wall portion 25. Figure 5 As shown, the peripheral wall panel 63 is formed into a substantially strip-shaped outer shape that is substantially bilaterally symmetrical. A mounting side portion 64 that constitutes the area surrounding the inlet opening 30 is also arranged on one end side of the peripheral wall panel 63. The side wall panels 68L and 68R respectively constitute the left wall portion 26 and the right wall portion 27, and are formed into a left and right pair whose outer shape is substantially bilaterally symmetrical.

[0045] In the airbag body 21 of the embodiment, the concave shape of the concave portion 35 is formed by the outer shape of the side wall panels 68L and 68R constituting the left wall portion 26 and the right wall portion 27. Specifically, the concave shape of the concave portion 35 is formed by the shape of the curved portions 70L and 70R constituting a part of the outer edges 69L and 69R of the side wall panels 68L and 68R. In the embodiment, as described later, if the outer edges 69L and 69R of the side wall panels 68L and 68R are sewn to the edges 60c, 60d, 63c and 63d of the corresponding peripheral wall panels 60 and 63, the airbag body 21 having the concave portion 35 can be shaped.

[0046] The side wall panel 68L constituting the left wall portion 26 is described in detail as an example. In the area on the front lower end side of the outer edge 69L (69) of the side wall panel 68L (68), a curved portion 70L (70) connecting three arcs is formed (see Figure 6 ). The front arc portion 73 and the rear arc portion 74 arranged on the front and rear sides are formed into an approximately arc shape convex toward the outside (downward or forward). The central arc portion 75 arranged in the middle is formed into an approximately arc shape convex toward the inside, and is formed to connect the front arc portion 73 and the rear arc portion 74. Regarding the side wall panel 68, the area of ​​the peripheral edge of the front arc portion 73 constitutes an area near the front lower end of the left wall portion 26 and is on the side of the inflow opening 30. Regarding the side wall panel 68, the area on the side of the rear portion 74b of the rear arc portion 74 constitutes an area near the rear lower end of the left wall portion 26 and is near the lower end 40a of the passenger side wall portion 40. Moreover, regarding the side wall panel 68, the area of ​​the peripheral edge of the portion from the central arc portion 75 to the front portion 74a of the rear arc portion 74 constitutes an area near the left edge of the recess 35 in the left wall portion 26. In the embodiment, the central angle α of the central arc portion 75 is set to about 230° (see FIG. 1 ), while the side wall panel 68 is flatly developed. Figure 6 ). More specifically, in the embodiment, the radius r of the central arc portion 75 is set to about 80 mm (see Figure 6 ). In addition, the separation distance D at the closest position of the front arc portion 73 and the rear arc portion 74 (refer to Figure 6 ), is set to be larger than the radius r of the central side arc portion 75, and is set to be about 125 mm. The radius dimensions of both the front side arc portion 73 and the rear side arc portion 74 are set to be larger than the central side arc portion 75. Moreover, with respect to the airbag body 21 of the embodiment, specifically, at the curved portion 70, the outer shape of the central side arc portion 75 and the area (front side portion 74a) in front of the rear side arc portion 74 connected to the central side arc portion 75 determines the outer shape of the recessed portion 35 when inflation is complete (the shape of the recessed gap formed between the airbag body 21 and the instrument panel 1 when inflation is complete).

[0047] In an embodiment, the peripheral wall panels 60, 63, the side wall panels 68L, 68R, the material 49 for the front portion of the front and rear tethers 45, the rear portion 47, and the tether base materials 57, 57 constituting the outer tether portion 55, which constitute the airbag body 21, are respectively formed of flexible woven fabrics composed of polyester threads, polyamide threads, etc.

[0048] Next, the manufacture of the airbag 20 of the embodiment will be described. The one end sides of the tether base materials 57, 57 constituting the outer tether portion 55 are sewn to the outer surface side of the peripheral wall panel 63 in advance. In addition, the rear side portion 47 constituting the front and rear tethers 45 is sewn to the inner surface side of the region constituting the passenger side wall portion 40 of the peripheral wall panel 60 in advance. First, the mounting side portions 61, 64 formed on the peripheral wall panels 60, 63 are overlapped with each other, and the edge portion 60a of the peripheral wall panel 60 is sewn to the peripheral wall panel 63. Similarly, the edge portion 63a of the peripheral wall panel 63 is sewn to the peripheral wall panel 60. Next, the front side portion material 49 constituting the front and rear tethers 45 is overlapped with the mounting side portions 61, 64, and the mounting side portions 61, 64 and the front side portion material 49 are sewn to the portion that becomes the peripheral edge of the inlet opening 30. Next, the inlet opening 30 and the mounting hole 31 are opened at the portion of the mounting side portions 61, 64. Then, the corresponding edges 60b, 63b of the peripheral wall panels 60, 63 are sewn together by sewing threads. Next, the outer edge 69L of the side wall panel 68L and the edges 60c, 63c of the peripheral wall panels 60, 63 are sewn together. Similarly, the outer edge 69R of the side wall panel 68R and the edges 60d, 63d of the peripheral wall panels 60, 63 are sewn together to form a bag-shaped airbag body 21. The airbag body 21 is turned over by using the inlet opening 30. Then, the ends are sewn together in a manner that the front side portion 46 and the rear side portion 47 are pulled out from the inlet opening 30 to form the front and rear tethers 45. If the ends of the tether base materials 57, 57 are sewn together to form the outer tether portion 55, the airbag 20 can be manufactured.

[0049] Next, the mounting of the airbag device M on the vehicle V will be described. First, the bolt 13a is made to protrude from the mounting hole 31, and the airbag 20 is folded in such a manner that it can be stored in the housing 16 from the state in which the retainer 13 is stored inside. In the embodiment, as shown in FIGS. 7 to 9, from the state of the pre-folded airbag 80 after pre-folding, the airbag 20 is folded through a left-right reduction folding process of reducing the width dimension on the left-right direction side and a front-back reduction folding process of reducing the width dimension on the front-back direction side. And, the airbag 20 is stored in the housing 16 in the state of the folded folded body 88. Specifically, first, the passenger side wall portion 40 is unfolded approximately flat, and the passenger side wall portion 40 is brought close to the inflow opening 30 side, and a concave fold is applied to the region of the peripheral wall portion 23 to form the pre-folded airbag 80 shown in A and B of FIG. 7. With respect to the preliminary folded airbag 80, a part of the lower wall portion 25 is folded in by applying a concave fold, and the outer tether portion 55 is arranged on the lower wall portion 25 in a flatly unfolded state (refer to B of FIG. 7 ). Next, with respect to the preliminary folded airbag 80, the left and right edge sides of the inflow opening 30 are folded by rolling toward the passenger side wall portion 40, respectively, to form the left and right reduced folded airbags 82 shown in A and B of FIG. 8 . Then, the front and rear reduced folding is performed. Specifically, with respect to the rear side portion 83 of the left and right reduced folded airbags 82 that is further to the rear side than the inflow opening 30, the rear edge 83a is rolled toward the peripheral wall portion 23 side to form a folded portion 86 (refer to A of FIG. 9 ). The folded portion 86 is turned over and placed above the inflow opening 30 (refer to B of FIG. 9 ). Then, regarding the left and right deflated and folded airbags 82, if the front side portion 84 on the front side of the inflow opening 30 is folded back so as to be placed on the upper side of the folded portion 86, a folded body 88 that can be housed in the housing 16 can be formed as shown in FIG. 9C.

[0050] The folded airbag 20 (folded body 88) is wrapped around by a breakable packaging sheet (reference numeral omitted) so as not to be loose. Then, the bolts 13a are protruded from the bottom wall 16a and the folded body 88 is stored in the housing 16. Moreover, the main body 12a of the inflator 12 is inserted into the housing 16 from below the bottom wall 16a. At this time, the bolts 13a of the retainer 13 protruding downward from the bottom wall 16a are inserted into the flange 12c of the inflator 12. If the nuts 14 are fastened to the bolts 13a protruding from the flange 12c, the folded airbag 20 and the inflator 12 can be mounted on the housing 16. Then, the peripheral wall 16b of the housing 16 is locked to the connecting wall 10c of the airbag cover 10 mounted on the instrument panel 1 of the vehicle V. The bracket (not shown) provided on the housing 16 is fixed to the body side of the vehicle V. The airbag device M can be mounted on the vehicle V by electrically connecting the inflator 12 to a control device (not shown).

[0051] After the airbag device M is mounted on the vehicle V, if the inflation gas is discharged from the gas outlet 12b of the inflator 12, the inflation gas flows into the interior to inflate the airbag 20, and the door portions 10a, 10b of the airbag cover 10 are pressed to open them. Then, the airbag 20 protrudes upward from the housing 16 through the opening of the housing 16 formed to open the door portions 10a, 10b of the airbag cover 10, and protrudes toward the rear side of the vehicle and expands. Then, as Fig.12 As shown, the airbag 20 is inflated in a manner that blocks the space between the upper surface 2 of the instrument panel 1 and the windshield 7 above the instrument panel.

[0052] Furthermore, regarding the airbag device M of the embodiment, when the airbag 20 is fully inflated, the inflated airbag body 21 is arranged in the area on the front lower surface side in a manner that a gap is provided between the airbag 20 and the instrument panel 1. However, the rear lower end 21c side of the airbag body 21 is connected to the front edge 35a side of the recessed portion 35 constituting the gap via the outer tether portion 55 arranged on the outer peripheral surface side of the airbag body 21, and is therefore arranged close to the rear surface 3 of the instrument panel 1 when the inflation is completed. That is, regarding the airbag device M of the embodiment, the airbag 20 (airbag body 21) can be inflated in a partially recessed state in a manner that a gap is provided between the airbag 20 and the instrument panel 1. Therefore, the volume can be reduced compared to an airbag having a structure without such a recessed portion. Furthermore, the rear lower end 21c side of the inflated airbag body 21 is arranged close to the rear surface 3 of the instrument panel 1 via the outer tether portion 55. In addition, the recessed portion 35 formed in the airbag body 21 is formed in an area that is closer to the front side than the passenger side wall portion 40 that protects the passenger when the inflation is completed. Therefore, even with the structure having the recessed portion 35, the area on the side of the rear lower end 21c of the airbag body 21 can be supported on the instrument panel 1, and the passenger moving forward can be stably received by the passenger side wall portion 40. As a result, with respect to the airbag device M of the embodiment, even when the shape of the interior of the vehicle to be installed is different, by appropriately setting the shape of the recessed portion 35 formed in the airbag body 21, it is possible to suppress the volume of the airbag 20 from increasing, and also suppress the size of the device itself from increasing.

[0053] Therefore, the airbag device M of the embodiment can be formed into a compact structure and can reliably protect the occupant.

[0054] In addition, the airbag device M of the embodiment is mounted on a vehicle V in which a monitor 5 is configured as a protruding portion and partially protrudes upward from the instrument panel 1, and the monitor 5 is configured to the rear of the mounting area of ​​the airbag device M. However, the airbag body 21 is formed to be able to expand so that the monitor 5 configured to partially protrude upward from the instrument panel 1 is located in the recessed portion 35. Therefore, with such a structure mounted on the vehicle V, it is also possible to suppress the inflated airbag body 21 from interfering greatly with the monitor 5 as a protruding object, and the expansion can be completed smoothly. The deployment operation of the airbag 20 (airbag body 21) of the airbag device M of the embodiment will be described in detail below. The airbag body 21 allows the inflation gas to flow into the inside, and when inflated, it first protrudes upward from the outer shell 16, and is deployed in a manner that the folded portion 86 protrudes toward the rear and eliminates the fold. As shown in A and B of FIG. 10, the folded portion 86 protrudes toward the rear in a manner that passes over the monitor 5, and then is deployed in a large range in the vertical direction in a manner that eliminates the fold. At this time, the airbag body 21 bypasses the monitor 5 by using the recess 35 (so that the monitor 5 enters the recess 35), and expands in a manner that the passenger side wall portion 40 is expanded in a large range in the vertical direction at a position behind the monitor 5 (refer to A of FIG. 11). In addition, the lower end 40a side of the passenger side wall portion 40 (the rear lower end 21c side when the inflation of the airbag body 21 is completed) is connected to the area on the front edge 35a side of the recess 35 (the part located near the upper end 5b of the monitor 5) by the outer tie portion 55. Therefore, the passenger side wall portion 40 is suppressed from excessively protruding backward and downward. In other words, the airbag body 21 is suppressed from protruding backward and downward when it is deployed and inflated by the outer tie portion 55. As a result, the airbag body 21 is inflated while being restrained from swinging greatly in the vertical direction. Moreover, the passenger side wall portion 40 is suppressed from swinging in the vertical direction, and is maintained in a state of being expanded widely in the vertical direction, and is deployed in a manner toward the rear (refer to A and B of FIG. 11). Therefore, the airbag body 21 is inflated while suppressing a large swing in the vertical direction, and the rear of the monitor 5 can be quickly covered by the passenger side wall portion 40. Fig.12 As shown, the outer tether portion 55 is disposed close to the rear surface 5a side of the monitor 5. Therefore, when the passenger side wall portion 40 receives the occupant MP, the outer tether portion 55 is supported by the monitor 5, thereby ensuring a reaction force and reliably protecting the occupant MP.

[0055] As described above, regarding the airbag device M of the embodiment, the outer shape of the recess 35 of the airbag body 21 is determined by the shape of the curved portion 70 (70L, 70R) provided on the side wall panel 68 (68L, 68R). Moreover, in the embodiment, the curved portion 70 is configured to connect three arcs in a state where the side wall panel 68 is flatly unfolded. In the curved portion 70, the central side arc portion 75 arranged in the middle constitutes the most depressed area of ​​the recess 35, and the central side arc portion 75 is formed into an approximate arc shape with a radius r set to about 80 mm and a center angle α set to about 230°. That is, the central side arc portion 75 is formed into a shape that is gently curved and greatly depressed. Moreover, the area (front side portion 74a) from the central side arc portion 75 to the front side of the rear side arc portion 74 is formed into a shape that is connected by bending in an S-shape. In addition, in the curved portion 70, the separation distance D at the closest position of the front arc portion 73 and the rear arc portion 74 is greater than the radius r of the central arc portion 75 and is set to about 125 mm. That is, the recessed portion 35 defined by the outer shape of the curved portion 70 of the side wall panel 68 is formed so that when the airbag body 21 is fully inflated, the lower end side is opened widely in the front-to-back direction, and the expanded state in the front-to-back direction is maintained and the upper side is greatly recessed. Therefore, it is formed in the following manner, that is, assuming that the structure is formed in which the outer tether portion is not provided in the airbag body, the airbag body is deployed in a manner bypassing the monitor due to the recessed portion, but the part of the airbag body arranged behind the recessed portion (the area on the lower end side of the passenger side wall portion) protrudes greatly to the rear. This is because the recessed portion is formed so that the lower end side (the lower surface side of the airbag body) is opened widely in the front-to-back direction. In addition, when the outer tether portion is not provided, the airbag body is deployed in such a manner that the area curved in an approximately S-shape from the rear side of the central side arc portion constituting the periphery of the recessed portion to the front side of the rear side arc portion is extended into the S-shape. When the outer tether portion is not provided, the airbag body is deployed in such a manner that the area on the rear lower end side of the airbag body, that is, the area on the lower end side of the passenger side wall portion further protrudes rearward and downward to a desired extent. With regard to the airbag device M of the embodiment, the outer tether portion 55 is arranged on the airbag body 21. Therefore, even with the structure having the recessed portion 35 that is widely opened in the front-to-back direction and is greatly recessed (deeply recessed) upward, when the airbag body 21 is deployed and expanded, it is possible to reliably restrict the area on the rear lower end 21c side of the airbag body 21 (the area on the lower end 40a side of the passenger side wall portion 40) from protruding rearward and downward to a large extent.

[0056] In addition, regarding the airbag device M of the embodiment, the outer tether portion 55 that restricts the inflated shape of the airbag body 21 is set so that the length dimension L1 is substantially the same as the length dimension L2 of the straight line connecting the points P1 and P2 corresponding to the connection planned portions 77F and 77B that connect the two ends of the outer tether portion 55, respectively, in the state where the side wall panel 68 is flatly deployed. That is, in the embodiment, the outer tether portion 55 can restrict the movement (excessive bulging toward the rear and lower side) of the area on the side of the rear lower end 21c of the airbag body 21 during inflation, but is not formed into a structure that excessively pulls the area on the side of the rear lower end 21c of the airbag body 21 forward when the airbag 20 is fully inflated. Therefore, the deformation of the airbag body 21 when the inflation is completed can be suppressed by the excessive pulling of the outer tether portion 55, and the occupant can be stably protected by the inflated airbag body 21.

[0057] In addition, the recessed portion may not be constituted by such a bent portion. For example, by arranging a bent portion that is not a bent portion but is bent at an acute angle at the same position of the side wall panel, a recessed portion can also be formed. However, if the manufacturing cost of the airbag body (the ease and speed of the sewing operation of the side wall panel and the peripheral wall panel) is taken into consideration, it is preferred to arrange a bent portion that is bent more gently as in the embodiment compared to the bent portion that is bent at an acute angle. That is, with respect to the airbag used in the airbag device of the embodiment, the sewing operation of the airbag body is easy, the increase in manufacturing man-hours and costs can be suppressed, and even if the airbag is mounted on a vehicle equipped with a monitor that protrudes locally between the occupants, the occupants can be reliably protected when the inflation is completed.

[0058] In addition, regarding the airbag 20 of the embodiment, the outer tie portion 55 is formed into a wide belt-like shape with a width dimension set to be substantially equal to the width dimension of the lower wall portion 25 of the airbag body 21, and one is arranged. The outer shape and the number of arrangements of the outer tie portion are not limited to the embodiment. For example, as the outer tie portion, a structure in which a plurality of structures formed into narrow belt-like shapes or a structure composed of a rope-like body are arranged side by side in the left and right directions may be formed.

[0059] In addition, in the embodiment, the airbag device for the passenger seat arranged in front of the passenger seat is described as an example, but the present invention is not limited to the airbag device for the passenger seat. For example, the present invention can be applied to the airbag device for the driver's seat of the type having an airbag mounted in front of the steering wheel of the instrument panel and inflated in a manner to cover the rear surface of the steering wheel. In the case of the airbag device for the driver's seat of such a structure, even if the steering wheel is configured to protrude upward from the instrument panel, the rear surface side of the steering wheel as a protrusion can be smoothly covered by the inflated airbag, and the driver can be reliably protected.

Claims

1. An airbag device (M), arranged on the upper surface (2) side of an instrument panel (1), The airbag device (M) comprises: an airbag (20) capable of inflating by allowing inflation gas to flow into the airbag; an inflator (12) for supplying inflation gas to the airbag; and a storage portion (16) for storing the folded airbag and the inflator. The airbag is formed into a structure that, when the inflation gas discharged from the inflator flows into the inside and inflates, the airbag inflates so as to protrude upward from the storage portion and deploy backward, wherein: The airbag comprises: an airbag body (21) which is inflated by allowing inflation gas to flow into the inside; and an outer tether portion (55) which is arranged on the outer peripheral surface side of the airbag body to restrict the inflation completed shape of the airbag body. The airbag body is provided with a passenger side wall portion (40) capable of protecting a passenger (MP) sitting in a front seat on the rear surface side when the airbag body is fully inflated, and has a recessed portion (35) recessed upward in a manner that a gap is provided between the airbag body and the instrument panel on the lower surface side of the area further forward than the passenger side wall portion when the airbag body is fully inflated. The outer strap portion is constructed so as to connect the rear lower end (21c) side of the airbag body when inflation is complete and the front edge (35a) side of the recessed portion, so that the rear lower end of the airbag body when inflation is complete can be configured to be close to the rear surface (3) of the instrument panel.

2. The airbag device (M) according to claim 1, wherein: The airbag body (21) is formed into a structure that expands in such a manner that a protrusion (5) configured to protrude upward from the instrument panel (1) is located in the recess (35). The outer strap portion (55) is configured to be close to the rear surface side of the projection when the airbag body is fully inflated.

3. The airbag device (M) according to claim 1, wherein: The airbag body (21) comprises: The passenger side wall portion (40); and a peripheral wall portion (23) extending from the peripheral edge of the passenger side wall portion and configured to seal between the upper surface (2) of the instrument panel (1) and the windshield (7) above the instrument panel when the airbag body is fully inflated, The peripheral wall portion includes a left wall portion (26) and a right wall portion (27) which are opposite to each other in the left-right direction. The left wall portion and the right wall portion are composed of a pair of side wall panels (68L, 68R) formed in a left-right symmetrical shape. Each of the side wall panels has a curved portion (70L, 70R) at an outer edge (69L, 69R) that defines an outer shape of the recess (35).

4. The airbag device (M) according to claim 3, wherein: The length dimension of the outer tie portion (55) is set to be the same as the length dimension of a straight line connecting points (P1, P2) corresponding to predetermined connection portions (77F, 77B), and the predetermined connection portions (77F, 77B) are used to respectively connect the two ends of the outer tie portion (55) in the side wall panels (68L, 68R) in a flatly unfolded state.

5. The airbag device (M) according to claim 2, wherein: The protrusion (5) is a monitor (5) configured to protrude from the instrument panel (1).

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