Airbag device

Abstract

To provide an airbag device which can inhibit an impact applied to an occupant by an airbag without increasing the number of components.SOLUTION: An airbag device 10 includes an airbag 50 including: a rear wall part 50a which receives an occupant M when inflation is completed; an upper wall part 50b extending along a windshield 8 of a vehicle 1; and a lower wall part 50c facing the upper wall part 50b in a vertical direction and having a recessed part 50c1 recessed upward. The folded airbag 50 has a rolled part 50kx3 where a rear wall part forming part 50k forming the rear wall part 50a is folded in a rolled manner, the rolled part 50kx3 being sandwiched in a vertical direction by a recessed part forming part 50r1 forming the recessed part 50c1 above an opening 50h. An upper wall part forming part 50p forming the upper wall part 50b is disposed above the recessed part forming part 50r1 sandwiching the rolled part 50kx3.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to an airbag device mounted in a vehicle. [Background technology]

[0002] An airbag device for protecting an occupant has been conventionally mounted on the instrument panel of a vehicle. The airbag device includes an airbag and an inflator that supplies inflation gas to the airbag. In response to a vehicle collision or the like, the airbag is supplied with inflation gas from the inflator, which causes the airbag to change from a folded state to an inflated state, and in the inflated state, it receives and protects the occupant.

[0003] Patent Document 1 also describes a configuration in which a flap is wrapped around the outer periphery of the airbag in a folded state. As a result, when the airbag inflates, the flap suppresses the airbag from inflating toward the occupant, and the deployment speed of the airbag toward the occupant is delayed. Therefore, even if the airbag starts to inflate when the occupant is close to the instrument panel, the impact that the occupant receives from the airbag is suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2006 / 003748 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration described in Patent Document 1, it is necessary to provide a flap to suppress the impact that the occupant receives from the airbag, which increases the number of parts and may adversely affect the ease of assembly.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an airbag device capable of reducing the impact that an occupant receives from an airbag without increasing the number of parts. [Means for solving the problem]

[0007] A representative configuration of an airbag device according to the present invention for solving the above problems is an airbag device mounted on a vehicle, which is folded and stored in an instrument panel of the vehicle, has an opening for allowing inflation gas to flow in, and is inflated by being supplied with inflation gas through the opening and is projected from the instrument panel toward an occupant, and comprises a rear wall portion that receives the occupant when inflation is complete, an upper wall portion that extends along the windshield of the vehicle and is connected to the rear wall portion at the rear, and a lower wall portion that faces the upper wall portion in the vertical direction and projects upward. and an inflator that supplies the inflation gas to the airbag, wherein the airbag in a folded state has a rear wall forming portion that forms the rear wall portion at the completion of inflation, the rear wall forming portion having a rolled-up portion that is rolled-up, the rolled-up portion being sandwiched from above and below by the recess forming portions that form the recess at the completion of inflation above the opening, and an upper wall forming portion that forms the upper wall portion at the completion of inflation is disposed above the recess forming portions that sandwich the rolled-up portion.

[0008] According to the present invention, in an airbag device, it is possible to reduce the impact that an occupant receives from an airbag without increasing the number of parts. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic perspective view of an instrument panel. [Diagram 2] FIG. 2 is a view of the area around the passenger seat of the vehicle as seen from the left side. [Diagram 3] FIG. 2 is a schematic cross-sectional view of the airbag device. [Figure 4]FIG. 2 is a plan view of a panel that constitutes the airbag. [Diagram 5] FIG. 2 is a plan view of the airbag in a pre-folded state. [Figure 6] FIG. 4 is a schematic diagram showing a state in which the airbag is folded. [Figure 7] FIG. 4 is a schematic diagram showing a state in which the airbag is folded. [Figure 8] FIG. 4 is a schematic diagram showing a state in which the airbag is folded. [Figure 9] FIG. 4 is a schematic diagram showing a state in which the airbag is folded. [Figure 10] FIG. 4 is a schematic diagram showing a state in which the airbag is folded. [Figure 11] FIG. 4 is a schematic diagram showing a state in which the airbag is folded. [Figure 12] 4 is a schematic diagram showing the corresponding relationship between each part of the airbag in a folded state and each part of the airbag when fully inflated. FIG. [Figure 13] 5A to 5C are schematic diagrams showing behavior of an airbag when it is inflated. [Figure 14] 5A to 5C are schematic diagrams showing behavior of an airbag when it is inflated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the overall configuration of an airbag device 10 according to one embodiment of the present invention will be described with reference to the drawings. In the following description, the left-right direction means the left and right directions of a vehicle 1 equipped with the airbag device 10, specifically the left and right directions as seen by an occupant M seated in the passenger seat 3. The front-rear direction means the front and rear directions of the vehicle 1, specifically the front and rear directions as seen by an occupant M seated in the passenger seat 3. The up-down direction means the vertical upward and downward directions. Note that the dimensions, materials, shapes, etc. of components in the following description are not intended to limit the scope of the present invention to only those unless otherwise specified.

[0011] Fig. 1 is a schematic perspective view of an instrument panel 2 (hereinafter referred to as "instrument panel 2") of a vehicle 1. Fig. 2 is a diagram of the periphery of a passenger seat 3 of the vehicle 1 as viewed from the left side, showing the instrument panel 2 and the airbag device 10 in a cross section taken along the line AA shown in Fig. 1, and showing an airbag 50 and an occupant M at the time of complete inflation by a two-dot chain line. Fig. 3 is a schematic cross-sectional view of the airbag device 10.

[0012] As shown in Figs. 1 to 3, an airbag device 10 is mounted on an instrument panel 2 provided in front of a passenger seat 3 of a vehicle 1. The instrument panel 2 is held by a body (not shown) of the vehicle 1, and has a driver's seat side portion 2a located in front of a driver's seat (not shown), a passenger's seat side portion 2b located in front of the passenger seat 3, and a center portion 2c in front of a center console located between the driver's seat and the passenger seat 3. A monitor 4 (protruding member) capable of displaying images and videos is attached to a rear end surface 2b1 of the passenger's seat side portion 2b of the instrument panel 2. An upper portion of the monitor 4 is located at a position higher than an upper surface 2b2 of the instrument panel 2. In other words, the monitor 4 is attached to the instrument panel 2 so as to protrude upward from the instrument panel 2. The airbag device 10 is mounted on the passenger's seat side portion 2b, and protects an occupant M seated in the passenger seat 3.

[0013] The airbag device 10 includes an airbag 50, an inflator 14 that supplies inflation gas to the airbag 50, a case 15 that holds the airbag 50 and the inflator 14, and an airbag cover 20 that covers the upper part of the airbag 50 in a folded state.

[0014] The inflator 14 is a generally cylindrical member that generates inflation gas and has an outlet 14a at its upper portion for discharging the inflation gas. The inflator 14 also has a flange portion 14b that extends in the radial direction of the cylindrical shape from the surface where the outlet 14a is formed, as a portion that is connected to the case 15. The inflator 14 is electrically connected to a control device (not shown) by a lead wire (not shown), and is activated by an activation signal input from the control device via the lead wire to generate inflation gas.

[0015] The airbag 50 is a bag-shaped member, and is stored in a folded state inside the passenger seat side portion 2b of the instrument panel 2. An opening 50h (see FIG. 4) is formed on the underside of the airbag 50 in the folded state, through which the portion of the inflator 14 where the discharge port 14a is formed is inserted. In other words, the opening 50h is provided to allow the inflation gas discharged from the inflator 14 to flow into the airbag 50. A substantially rectangular annular retainer 12 for fixing the airbag 50 and the inflator 14 to the case 15 is also stored inside the airbag 50.

[0016] When inflation gas is supplied from the inflator 14 through the opening 50h, the airbag 50 inflates to close the gap between the instrument panel 2 and the windshield 8 of the vehicle 1. The airbag 50 at the time of full inflation includes a rear wall portion 50a arranged at the rear (directly in front of the occupant M) and configured to receive the occupant M moving forward, and an upper wall portion 50b arranged at the upper side, extending along the windshield 8 of the vehicle 1, and connected at the rear to an upper end portion 50a1 of the rear wall portion 50a. The airbag 50 at the time of full inflation also includes a lower wall portion 50c arranged at the lower side, facing the upper wall portion 50b in the vertical direction, and connected at the rear to a lower end portion 50a2 of the rear wall portion 50a, and a left wall portion 50d and a right wall portion 50e arranged at the left and right sides, respectively. The lower wall portion 50c is placed on the instrument panel 2 and the monitor 4 and supported by these members.

[0017] In addition, a recess 50c1 recessed upward is formed in the vicinity of the monitor 4 in the lower wall portion 50c of the airbag 50 to avoid interference with the monitor 4. The shape of the recess 50c1 is a downward approximately V-shape when viewed from the left-right direction. The recess 50c1 is formed by an inner wall 50c1a (first inner wall) extending obliquely upward from the front to the rear, and an inner wall 50c1b (second inner wall) extending obliquely downward from the rear end of the inner wall 50c1a to the rear, and the transition portion from the inner wall 50c1a to the inner wall 50c1b is the bottom portion 50c1c. Since the recess 50c1 recesses upward, the bottom portion 50c1c is the upper end portion of the recess 50c1. When the airbag 50 is fully inflated, the monitor 4 is disposed inside the recess 50c1.

[0018] The case 15 includes a bottom wall portion 15a in the shape of a substantially rectangular plate, and side wall portions 15b in the shape of a substantially square cylinder extending upward from the outer edge of the bottom wall portion 15a, and is connected to the body of the vehicle 1 by a bracket (not shown). The upper ends of the front and rear side wall portions 15b each form a hook-shaped hook portion 15b1. A plurality of hook portions 15b1 are provided on the front and rear side wall portions 15b so as to be aligned in the left-right direction. The bottom wall portion 15a also has an insertion hole (not shown) through which the inflator 14 is inserted.

[0019] The airbag 50 and the inflator 14 are fixed to the bottom wall 15a of the case 15 via the retainer 12 provided inside the airbag 50. Specifically, the periphery of the opening 50h of the airbag 50 is sandwiched between the lower surface of the retainer 12 and the upper surface of the bottom wall 15a of the case 15. The upper surface of the flange 14b of the inflator 14 is pressed against the lower surface of the bottom wall 15a of the case 15. In this state, the bolts 5 are inserted through screw holes formed in the periphery of the opening 50h of the airbag 50, the bottom wall 15a of the case 15, and the flange 14b of the inflator 14, respectively, and the nuts 13 are fastened. In this manner, the airbag 50 and the inflator 14 are fixed to the bottom wall 15a of the case 15.

[0020] The airbag cover 20 covers the upper part of the airbag 50 in a folded state, and when the airbag 50 inflates, a part of the airbag cover 20 breaks to form an opening 60 through which the airbag 50 is deployed. The airbag cover 20 is made of synthetic resin, and is composed of a base material 21 and a connecting part 22 connected to the back surface of the base material 21 by a screw or the like. The base material 21 is a member that constitutes the instrument panel 2, and extends to the driver's seat side part 2a and the central part 2c. In other words, the instrument panel 2 also serves as a part of the airbag cover 20.

[0021] The connecting portion 22 extends in a substantially horizontal direction along the base material 21 and has a top surface portion 22a connected to the rear surface of the base material 21, and a substantially rectangular tubular side wall portion 22b extending downward from the top surface portion 22a and disposed adjacent to the side wall portion 15b of the case 15. The front and rear side wall portions 22b are formed with a plurality of engagement holes 22b1 with which the plurality of hook portions 15b1 formed on the side wall portion 15b of the case 15 are respectively engaged. The airbag cover 20 and the case 15 are connected by the hook portions 15b1 being caught and engaged in the engagement holes 22b1.

[0022] A recess 22a1 is formed in the approximate center of the back surface of the top surface 22a in the front-rear direction, where the thickness is reduced. The front portion of the recess 22a1 in the top surface 22a is a door portion 22a2 that rotates upward about a corner 22a4 formed between the recess 22a1 and the front side wall portion 22b when the airbag 50 is inflated. Similarly, the rear portion of the recess 22a1 in the top surface 22a is a door portion 22a3 that rotates upward about a corner 22a5 formed between the recess 22a1 and the rear side wall portion 22b when the airbag 50 is inflated.

[0023] Next, an operation of the airbag device 10 during operation will be described. First, when a collision or the like of the vehicle 1 is detected by a sensor (not shown), an operation signal is input from a control device (not shown) to the inflator 14, which operates to generate inflation gas. This causes the inflation gas to flow into the airbag 50, and the airbag 50 begins to inflate.

[0024] Next, as the airbag 50 inflates, the airbag 50 comes into contact with the top surface portion 22a of the connecting portion 22 of the airbag cover 20. When the airbag 50 further inflates, the airbag 50 pushes the top surface portion 22a upward, and the top surface portion 22a breaks starting from the weak recessed portion 22a1 due to the pressing force of the airbag 50, and accordingly the portion of the base material 21 connected to the top surface portion 22a breaks.

[0025] Next, the corners 22a4 and 22a5 of the top surface 22a are deformed by the pressure from the airbag 50, and the door parts 22a2 and 22a3 of the top surface 22a are pushed up by the airbag 50 together with the broken base material 21 and rotate upward, forming an opening 60. The two-dot chain line shown in FIG. 3 indicates the state in which the door parts 22a2 and 22a3 of the top surface 22a and the base material 21 rotate upward. The airbag 50 is deployed from this opening 60 toward the occupant M seated in the passenger seat 3, and the airbag 50 completes its inflation. The occupant M, who moves forward, is then received by the inflated airbag 50 and protected.

[0026] Next, a detailed configuration of the airbag 50 will be described. FIG. 4 is a plan view of the panels constituting the airbag 50. As shown in FIG. 4, the airbag 50 is formed into a bag shape by joining the peripheries of three panels, namely, a main panel 51 constituting the rear wall portion 50a, the upper wall portion 50b, and the lower wall portion 50c, a left panel 52 constituting the left wall portion 50d, and a right panel 53 constituting the right wall portion 50e. In addition, tethers 54 to 57 for defining the shape of the airbag 50 when it is fully inflated are attached to the inner periphery of the main panel 51, the left panel 52, and the right panel 53. In this embodiment, the main panel 51, the left panel 52, the right panel 53, and the tethers 54 to 57 are formed of flexible woven fabric made of polyester yarn, polyamide yarn, or the like.

[0027] When forming the airbag 50 with these panels, first, the seam 51x5 of the main panel 51 is sewn to the seam 54x1 near one end 54a of the tether 54, and then the seam 51x6 of the main panel 51 is sewn to the seam 55x1 near one end 55a of the tether 54. Next, the seam 52x2 of the left panel 52 is sewn to the seam 55x1 near one end 55a of the tether 55, and then the seam 53x2 of the right panel 53 is sewn to the seam 56x1 near one end 56a of the tether 56.

[0028] Next, the main panel 51 is curved so that one end 51a and the other end 51b in the longitudinal direction of the main panel 51 are brought closer to each other, and a sewn portion 51x1 near the one end 51a and a sewn portion 51x2 near the other end 51b are sewn together. At this time, the main panel 51 is curved so that the tethers 54, 55 sewn to the main panel 51 are disposed on the outside. As a result, the main panel 51 becomes a cylinder that is open on the left and right sides.

[0029] Next, the left panel 52 is placed in the left opening so as to close the opening, and a seam 51x3 near one end 51c of the main panel 51 in the width direction is sewn together with a seam 52x1 near the periphery 52a of the left panel 52. Similarly, the right panel 53 is placed in the right opening of the main panel 51 so as to close the opening, and a seam 51x4 near the other end 51d of the main panel 51 in the width direction is sewn together with a seam 53x1 near the periphery 53a of the right panel 53.

[0030] Next, the other ends of the tethers 54 to 57, one end of which is connected to the main panel 51, the left panel 52, and the right panel 53, are connected to each other. That is, a stitched portion 54x2 near the other end 54b of the tether 54 sewn to the main panel 51, a stitched portion 55x2 near the other end 55b of the tether 55, a stitched portion 56x2 near the other end 56b of the tether 56 sewn to the left panel 52, and a stitched portion 57x2 near the other end 57b of the tether 57 sewn to the right panel 53 are sewn together. Thereafter, the integrated main panel 51, the left panel 52, and the right panel 53 are turned inside out so that the tethers 54 to 57 are disposed on the inside. In this manner, the airbag 50 in a state before being folded is formed.

[0031] Next, a method for folding the airbag 50 will be described. Fig. 5 is a plan view of the airbag 50 in a pre-folded state, and Fig. 5B shows the state obtained by inverting Fig. 5A. Figs. 6 to 11 are schematic diagrams showing how the airbag 50 is folded.

[0032] 5, the worker performing the folding first performs a pre-fold by folding a predetermined position of the airbag 50 so that the rear wall forming portion 50k that forms the rear wall portion 50a when the airbag 50 is fully inflated will be flat. The worker also places the pre-folded airbag 50 on a folding table (not shown) so that the rear wall forming portion 50k faces upward (FIG. 5B).

[0033] At this time, the opening 50h of the airbag 50, the left wall forming portion 50q which forms the left wall portion 50d when the airbag 50 is fully inflated, and the right wall forming portion 50s which forms the right wall portion 50e are disposed downward. The upper wall forming portion 50p which forms the upper wall portion 50b when the airbag 50 is fully inflated and the lower wall forming portion 50r which forms the lower wall portion 50c when the airbag 50 is fully inflated are also partially folded back and disposed upward, but most of them are disposed downward. The recess forming portion 50r1 which forms the recess 50c1 when the airbag 50 is fully inflated is composed of an inner wall forming portion 50r1a (first inner wall forming portion) which forms the inner wall 50c1a, an inner wall forming portion 50r1b (second inner wall forming portion) which forms the inner wall 50c1b, and a bottom forming portion 50r1c which forms the bottom 50c1c of the recess 50c1. Since the lower wall forming portion 50r is partially folded back, the inner wall forming portions 50r1a and 50r1b are disposed so as to overlap in the vertical direction above the opening 50h.

[0034] First, the worker rolls the left end 50k1 of the rear wall forming portion 50k toward the center in the left-right direction so that the width of the rear wall forming portion 50k in the left-right direction becomes narrower, forming the left rolled fold portion 50kx1 (FIG. 6A). At this time, the worker rolls the left rolled fold portion 50kx1 so that it is located on the upper side, and repeats the roll folding until the right end of the left rolled fold portion 50kx1 is located near the center of the rear wall forming portion 50k (FIG. 6B). Here, the left wall forming portion 50q, the upper wall forming portion 50p, etc. are located on the left back surface of the rear wall forming portion 50k, so that these portions are also roll-folded together with the rear wall forming portion 50k in accordance with the above-mentioned roll folding. The left-right direction here refers to the direction corresponding to the left-right direction of the rear wall portion 50a when inflation is completed.

[0035] Next, the worker rolls the right end 50k2 of the rear wall forming portion 50k toward the center in the left-right direction so that the width of the rear wall forming portion 50k in the left-right direction becomes narrower, forming the right rolled fold portion 50kx2 (FIG. 7A). At this time, the worker rolls the right rolled fold portion 50kx2 so that it is located on the upper side, and repeats the roll folding until the left end of the right rolled fold portion 50kx2 is located near the center of the rear wall forming portion 50k (FIG. 7B). Since the right wall forming portion 50s and the upper wall forming portion 50p are located on the right back surface of the rear wall forming portion 50k, these portions are also rolled together with the rear wall forming portion 50k in accordance with the above roll folding. The left-right direction here refers to the direction corresponding to the left-right direction of the rear wall portion 50a when inflation is completed.

[0036] Next, the worker turns the rear wall forming portion 50k upside down, starting from the bottom forming portion 50r1c of the recess forming portion 50r1, so that the left rolled fold 50kx1 and the right rolled fold 50kx2 of the rear wall forming portion 50k arranged on the upper side are arranged on the lower side, while keeping the opening 50h facing downward. This causes the airbag 50 to change from the state shown in FIG. 8A to the state shown in FIG. 8B. In the state shown in FIG. 8B, the inner wall forming portion 50r1a, the inner wall forming portion 50r1b, and the bottom forming portion 50r1c that constitute the recess forming portion 50r1 are all arranged facing upward. Also, the inner wall forming portion 50r1a is arranged above the opening 50h.

[0037] Next, the worker forms the rolled fold 50kx3 by vertically rolling the rear wall forming portion 50k that has been rolled in the left-right direction so that its lower end 50k3 is close to the opening 50h (FIGS. 9A and 9B). In other words, the worker forms the rolled fold 50kx3 by rolling the left rolled fold 50kx1 and the right rolled fold 50kx2 toward the opening 50h so that their vertical widths become narrower. At this time, the worker performs the roll folding until the rolled fold 50kx3 is positioned above the opening 50h (FIGS. 10A, 10B, and 11A). The lower end 50k3 of the rear wall forming portion 50k here is a portion that corresponds to the lower end 50a2 of the rear wall 50a when inflation is complete. The vertical direction is a direction that corresponds to the vertical direction of the rear wall 50a when inflation is complete.

[0038] Here, in a state where the roll-folded portion 50kx3 shown in FIG. 11A is disposed above the opening 50h, the roll-folded portion 50kx3 is sandwiched from the top and bottom by the recessed portion forming portion 50r1. That is, in the process of vertically rolling the rear wall forming portion 50k, the roll-folded portion 50kx3 is first placed on the inner wall forming portion 50r1b of the recessed portion forming portion 50r1 (FIG. 10B). Then, the roll-folded portion 50kx3 placed on the inner wall forming portion 50r1b is roll-folded together with the inner wall forming portion 50r1b at the bottom forming portion 50r1c as a fold, and the roll-folded portion 50kx3 including the inner wall forming portion 50r1b is placed on the inner wall forming portion 50r1a (FIG. 11A). In this way, the roll-folded portion 50kx3 is disposed between the inner wall forming portion 50r1a and the inner wall forming portion 50r1b in the vertical direction. In other words, the rolled fold 50kx3 is sandwiched from above and below by the recess forming portion 50r1. From another perspective, when the airbag 50 is in a folded state, the rear wall portion 50a at the time of completion of inflation that is rolled in the up-down and left-right directions is stored in the recess 50c1 of the lower wall portion 50c at the time of completion of inflation.

[0039] Thereafter, the worker folds the upper wall forming portion 50p and places the upper wall forming portion 50p on the recess forming portion 50r1 that is holding the rolled folded portion 50kx3 from above and below (FIG. 11B). As a result, the upper wall forming portion 50p is disposed above the recess forming portion 50r1 that is holding the rolled folded portion 50kx3. Finally, the worker folds back the upper wall forming portion 50p so that the upper wall forming portion 50p has a rectangular shape when viewed from above (FIG. 11C). In this manner, the worker completes the folding of the airbag 50.

[0040] 12 is a schematic diagram showing the relationship between the rear wall forming portion 50k, the upper wall forming portion 50p, and the lower wall forming portion 50r of the airbag 50 in the folded state and the rear wall forming portion 50k, the upper wall forming portion 50p, and the lower wall forming portion 50r of the airbag 50 at the completion of inflation. FIG. 12A shows the airbag 50 in a cross section in the folded state, and FIG. 12B shows the airbag 50 in a cross section at the completion of inflation. The airbag 50 in the folded state is covered by a folding prevention panel (not shown) and fixed to the case 15. The folding prevention panel covers the airbag 50 in the folded state except for the periphery of the opening 50h, and breaks and separates from the airbag 50 as the airbag 50 inflates.

[0041] The airbag 50 folded in this manner is inflated in the following manner when inflation gas is supplied from the inflator 24. That is, as shown in Fig. 13A, first, the upper wall forming portion 50p located at the uppermost position above the opening 50h jumps upward and contacts the windshield 8. At this time, the roll fold portion 50kx3 of the rear wall forming portion 50k is hardly unfolded.

[0042] 13B, when inflation gas is further supplied to the airbag 50, the upper wall forming portion 50p inflates so as to spread rearward along the windshield 8. At this time, the roll-folded portion 50kx3 of the rear wall forming portion 50k inflates rearward and downward, that is, in a rearward and diagonally downward direction, while gradually unfolding.

[0043] Next, as shown in Fig. 14A, when inflation gas is further supplied to the airbag 50, the upper wall forming portion 50p is fully deployed. At this time, the rolled fold 50kx3 of the rear wall forming portion 50k is unfolded and expands downward. After that, as shown in Fig. 14B, when inflation gas is further supplied to the airbag 50, the rear wall forming portion 50k is fully deployed and the fold of the rolled fold 50kx3 is unfolded, and the airbag 50 completes its inflation.

[0044] In this embodiment, in the airbag 50 in the folded state, the rolled fold 50kx3 of the rear wall forming portion 50k is sandwiched from above and below by the recess forming portion 50r1 above the opening 50h. Also, the upper wall forming portion 50p is disposed above the recess forming portion 50r1 that sandwiches the rolled fold 50kx3. This suppresses the impact that the occupant M receives from the airbag 50 even if the airbag 50 is inflated while the distance between the occupant M and the instrument panel 2 is short.

[0045] That is, if the recess 50c1 does not exist, the recess forming portion 50r1 does not exist either, and therefore the rolled folded portion 50kx3 cannot be sandwiched from above and below by the recess forming portion 50r1. Therefore, in order to arrange the rolled folded portion 50kx3 above the opening 50h, it is necessary to break a part of the fold, such as by folding back the final part of the fold of the rolled folded portion 50kx3 in the direction opposite to the roll direction. In this case, when the airbag 50 is inflated, the broken part of the fold unfolds at an early stage, and thus the entire fold of the rolled folded portion 50kx3 is likely to be unfolded early. If the fold of the rolled folded portion 50kx3 is largely unfolded at a stage before the upper wall forming portion 50p spreads rearward to some extent (for example, the stage shown in FIG. 13A, etc.), the rolled folded portion 50kx3 is likely to spread rearward. Therefore, when the airbag 50 is inflated when the distance between the occupant M and the instrument panel 2 is short, the occupant M collides with the rear wall forming portion 50k spreading rearward, and the occupant M is likely to receive an impact from the airbag 50. Furthermore, if the upper wall forming portion 50p is not disposed above the recess forming portion 50r1 that holds the rolled fold 50kx3, the timing at which the upper wall forming portion 50p spreads rearward is delayed. Therefore, the fold of the rolled fold 50kx3 is likely to be largely unfolded before the upper wall forming portion 50p spreads rearward to a certain extent, and the occupant M is likely to receive an impact from the airbag 50 as described above.

[0046] In contrast, in this embodiment, the rolled folding portion 50kx3 is sandwiched from above and below by the recessed portion forming portion 50r1, so that the rolled folding portion 50kx3 can be disposed above the opening 50h without collapsing the final folded portion of the rolled folding portion 50kx3. Therefore, when the airbag 50 inflates, the folding of the rolled folding portion 50kx3 is suppressed from being unfolded early, and the timing at which the folding of the rolled folding portion 50kx3 is unfolded can be delayed. In addition, since the upper wall portion forming portion 50p is disposed above the recessed portion forming portion 50r1 that sandwiches the rolled folding portion 50kx3, the upper wall portion forming portion 50p can be deployed backward early. Due to these actions, the rolled folding portion 50kx3 becomes easier to unfold at a stage where the upper wall portion forming portion 50p spreads backward to a certain extent, so that the rolled folding portion 50kx3 easily spreads downward. Therefore, even if the airbag 50 is inflated when the distance between the occupant M and the instrument panel 2 is close, a strong collision between the rear wall forming portion 50k and the occupant M is suppressed, thereby reducing the impact that the occupant M receives from the airbag 50.

[0047] In this embodiment, the positional relationship between the opening 50h, the rolled fold 50kx3, the recess forming portion 50r1, and the upper wall forming portion 50p of the airbag 50 in the folded state is set as described above without providing any additional members, thereby suppressing the impact that the occupant M receives from the airbag 50. Therefore, according to the airbag device 10 of this embodiment, it is possible to suppress the impact that the occupant M receives from the airbag 50 without increasing the number of parts.

[0048] In this embodiment, the roll-folded portion 50kx3 is formed by rolling the rear wall forming portion 50k in the vertical and horizontal directions, but the present invention is not limited to this. That is, the roll-folded portion 50kx3 may be formed by at least rolling the rear wall forming portion 50k in the vertical direction. That is, the same effect as above can be obtained by, for example, folding the rear wall forming portion 50k in the horizontal direction as an accordion-folded portion, and then rolling the folded rear wall forming portion 50k in the vertical direction to form the roll-folded portion 50kx3.

[0049] In addition, in the present embodiment, a configuration has been described in which the airbag 50 in a folded state is fixed to the case 15 while being covered with a panel for preventing collapse. However, if the airbag 50 is not likely to collapse due to its shape retention or the like, the airbag 50 may be fixed to the case 15 without providing a panel for preventing collapse. However, by covering the airbag 50 with a panel for preventing collapse as in the present embodiment, it is possible to not only prevent collapse but also to delay the deployment of the rolled fold portion 50kx3, so that a configuration in which a panel for preventing collapse is provided is preferable.

[0050] In the present embodiment, the configuration in which the recess 50c1 is provided in the lower wall portion 50c of the airbag 50 to avoid interference between the airbag 50 and the monitor 4 has been described, but the present invention is not limited to this. That is, the recess 50c1 may be provided in the lower wall portion 50c of the airbag 50 to avoid interference with other protruding members such as instruments and other resin members protruding upward from the instrument panel 2. In addition, the recess 50c1 may be provided in the lower wall portion 50c of the airbag 50 to avoid interference with other members disposed behind the instrument panel 2. In addition, the recess 50c1 may be provided in the airbag 50 not for the purpose of avoiding interference between the airbag 50 and other members, but for the purpose of sandwiching the rolled folded portion 50kx3 from above and below by the recess forming portion 50r1. [Explanation of symbols]

[0051] Reference Signs List 1...vehicle, 2...instrument panel, 4...monitor (protruding member), 8...windshield, 10...airbag device, 14...inflator, 50...airbag, 50a...rear wall portion, 50b...upper wall portion, 50c...lower wall portion, 50c1...recess, 50c1a...inner wall (first inner wall), 50c1b...inner wall (second inner wall), 50h...opening, 50k...rear wall forming portion, 50kx3...roll folded portion, 50p...upper wall forming portion, 50r1...recess forming portion, 50r1a...inner wall forming portion (first inner wall forming portion), 50r1b...inner wall forming portion (second inner wall forming portion), M...occupant

Claims

1. In an airbag device mounted in a vehicle, an airbag that is folded and stored in an instrument panel of the vehicle, has an opening for allowing inflation gas to flow in, and is inflated by being supplied with inflation gas through the opening and projected from the instrument panel toward an occupant, the airbag comprising: a rear wall that receives an occupant when inflation is complete; an upper wall that extends along a windshield of the vehicle and is connected to the rear wall at a rear end; and a lower wall that faces the upper wall in the vertical direction, has a recess that is recessed upward, and is connected to the rear wall at a rear end; an inflator for supplying the inflation gas to the airbag; Equipped with The airbag device is characterized in that the airbag in a folded state has a rolled-up portion in which a rear wall forming portion that forms the rear wall portion when inflation is complete is rolled up, and has a rolled-up portion that is sandwiched from above and below by a recess forming portion that forms the recess when inflation is complete above the opening, and an upper wall forming portion that forms the upper wall portion when inflation is complete is disposed above the recess forming portions that sandwich the rolled-up portion.

2. When the airbag is fully inflated, the recess includes a first inner wall and a second inner wall that faces the first inner wall in a front-rear direction, 2. The airbag device according to claim 1, wherein, when the airbag is in a folded state, the rolled folded portion is sandwiched from above and below by a first inner wall forming portion that forms the first inner wall when inflation is completed, and a second inner wall forming portion that forms the second inner wall when inflation is completed.

3. 3. The airbag device according to claim 1, wherein a protruding member that is mounted on the vehicle and protrudes upward from the instrument panel is disposed inside the recess when the airbag is fully inflated.

4. 4. The airbag device according to claim 3, wherein the protruding member is a monitor for displaying an image.

Images