Airbag system

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 on a vehicle.

Background Art

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

[0003] Also, Patent Document 1 describes a configuration in which a flap is wound around an outer peripheral portion of an airbag in a folded state. Thereby, when the airbag inflates, the inflation toward the occupant side is suppressed by the flap, and the deployment speed of the airbag toward the occupant side is delayed. Therefore, even when the airbag starts to inflate in a state where the distance between the occupant and the instrument panel is small, the impact received by the occupant from the airbag is suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration described in Patent Document 1, it is necessary to provide a flap in order to suppress the impact received by the occupant from the airbag. Therefore, there is a possibility that the number of parts increases and the assembly workability is adversely affected.

[0006] Therefore, the present invention aims to provide an airbag device that can suppress the impact received by the occupant from the airbag without increasing the number of parts. [Means for solving the problem]

[0007] A typical configuration of the 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 the instrument panel of the vehicle, has an opening for introducing inflation gas, and is inflated by the supply of inflation gas through the opening and deployed from the instrument panel toward the occupant, and when inflation is complete, has a rear wall portion that catches the occupant, 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 portion that faces the upper wall portion in the vertical direction and extends upward The airbag comprises a lower wall portion having a recess that is recessed and connected to the rear wall portion at the rear, and an inflator that supplies the inflation gas to the airbag, wherein the folded airbag has a roll-fold portion in which the rear wall portion forming portion that forms the rear wall portion when inflation is complete is roll-folded, and the roll-fold portion is sandwiched from above and below by the recess-forming portion that forms the recess when inflation is complete above the opening, and above the recess-forming portion that sandwiches the roll-fold portion, the upper wall portion forming portion that forms the upper wall portion when inflation is complete is arranged.

[0008] According to the present invention, in an airbag system, the impact received by the occupant from the airbag can be suppressed without increasing the number of parts. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view of the instrument panel. [Figure 2] This is a view of the area around the passenger seat of the vehicle, seen from the left side. [Figure 3] This is a schematic cross-sectional view of an airbag system. [Figure 4]This is a plan view of the panels that make up the airbag. [Figure 5] This is a plan view of the airbag in its pre-folded state. [Figure 6] This is a schematic diagram showing how an airbag folds. [Figure 7] This is a schematic diagram showing how an airbag folds. [Figure 8] This is a schematic diagram showing how an airbag folds. [Figure 9] This is a schematic diagram showing how an airbag folds. [Figure 10] This is a schematic diagram showing how an airbag folds. [Figure 11] This is a schematic diagram showing how an airbag folds. [Figure 12] This is a schematic diagram showing the correspondence between the parts of an airbag in its folded state and the parts of an airbag when fully inflated. [Figure 13] This is a schematic diagram illustrating the behavior of an airbag during inflation. [Figure 14] This is a schematic diagram illustrating the behavior of an airbag during inflation. [Modes for carrying out the invention]

[0010] The following describes the overall configuration of an airbag device 10 according to one embodiment of the present invention, with reference to the drawings. In the following description, the left-right direction refers to the left and right directions of the vehicle 1 on which the airbag device 10 is installed, specifically the left and right directions as seen from the perspective of occupant M seated in the passenger seat 3. The front-rear direction refers to the front and rear directions of the vehicle 1, specifically the front and rear directions as seen from the perspective of occupant M seated in the passenger seat 3. The up-down direction refers to the upward and downward directions in the vertical direction. The dimensions, materials, shapes, etc. of the components in the following description are not intended to limit the scope of this invention to those unless specifically stated otherwise.

[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 view of the surroundings of the passenger seat 3 of the vehicle 1 as seen from the left side, showing a cross-section cut along the A-A cross-section of the instrument panel 2 and the airbag device 10 shown in FIG. 1, and the airbag 50 and the occupant M at the end of inflation are shown 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, the airbag device 10 is mounted on an instrument panel 2 provided in front of the passenger seat 3 of the 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 seat side portion 2b located in front of the passenger seat 3, and a central portion 2c in front of a center console located between the driver's seat and the passenger seat 3. A monitor 4 (a protruding member) capable of displaying images and videos is attached to the rear end surface 2b1 of the passenger seat side portion 2b of the instrument panel 2. The upper part of the monitor 4 is located at a position higher than the 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 seat side portion 2b and protects the occupant M sitting on the passenger seat 3.

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

[0014] The inflater 14 is a substantially cylindrical member that generates inflation gas, and has an ejection port 14a for ejecting inflation gas at the upper part. Further, the inflater 14 includes a flange portion 14b that extends in the radial direction of the cylindrical shape from the surface where the ejection port 14a is formed as a portion connected to the case 15. The inflater 14 is electrically connected by a control device (not shown) and a lead wire (not shown), and operates to generate inflation gas when an operation signal is input from the control device via the lead wire.

[0015] The airbag 50 is a bag-shaped member and is stored inside the passenger seat side portion 2b of the instrument panel 2 in a folded state. An opening 50h (see FIG. 4) for inserting a portion where the discharge port 14a of the inflater 14 is formed is formed on the lower surface of the airbag 50 in the folded state. That is, the opening 50h is provided to allow the inflation gas discharged from the inflater 14 to flow into the airbag 50. Further, inside the airbag 50, a substantially square-ring-shaped retainer 12 for fixing the airbag 50 and the inflater 14 to the case 15 is accommodated.

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

[0017] Furthermore, a recess 50c1 is formed near the monitor 4 on the lower wall portion 50c of the airbag 50, in order to avoid interference with the monitor 4. The shape of the recess 50c1 is a roughly downward V-shape when viewed from the left or right direction. The recess 50c1 is formed by an inner wall 50c1a (first inner wall) that extends diagonally upward from the front to the rear, and an inner wall 50c1b (second inner wall) that extends diagonally downward from the rear end of the inner wall 50c1a toward the rear, with the transition portion from the inner wall 50c1a to the inner wall 50c1b being the bottom portion 50c1c. Since the recess 50c1 is recessed upward, the bottom portion 50c1c is the upper end of the recess 50c1. When the airbag 50 has finished inflating, the monitor 4 is positioned inside the recess 50c1.

[0018] Case 15 comprises a roughly rectangular plate-shaped bottom wall portion 15a and a roughly square cylindrical side wall portion 15b extending upward from the outer edge of the bottom wall portion 15a, and is connected to the body of vehicle 1 by a bracket (not shown). The upper ends of the front and rear side wall portions 15b are each formed into hook-shaped portions 15b1. Multiple hook portions 15b1 are provided on the front and rear side wall portions 15b, arranged in a left-right direction. In addition, an insertion hole (not shown) is formed in the bottom wall portion 15a 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 a retainer 12 provided inside the airbag 50. Specifically, the periphery of the opening 50h of the airbag 50 is held between the lower surface of the retainer 12 and the upper surface of the bottom wall 15a of the case 15. Also, the upper surface of the flange portion 14b of the inflator 14 is pressed against the lower surface of the bottom wall 15a of the case 15. In this state, 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 portion 14b of the inflator 14, and nuts 13 are fastened. In this way, 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 top of the folded airbag 50, and when the airbag 50 inflates, a portion of the cover 20 ruptures to form an opening 60, allowing the airbag 50 to be deployed through the opening 60. The airbag cover 20 is made of synthetic resin and consists of a base material 21 and a connecting part 22 connected to the back surface of the base material 21 by screws or the like. The base material 21 is a component of the instrument panel 2 and extends to the driver's side portion 2a and the central portion 2c. In other words, the instrument panel 2 also serves as a part of the airbag cover 20.

[0021] The connecting portion 22 extends substantially horizontally along the base material 21 and has a top surface portion 22a connected to the back surface of the base material 21, and a substantially rectangular cylindrical side wall portion 22b extending downward from the top surface portion 22a and positioned adjacent to the side wall portion 15b of the case 15. The front and rear side wall portions 22b have a plurality of engagement holes 22b1 into which a plurality of hook portions 15b1 formed on the side wall portion 15b of the case 15 engages. The airbag cover 20 and the case 15 are connected when the hook portions 15b1 catch and engage with these engagement holes 22b1.

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

[0023] Next, the operation of the airbag device 10 when it is activated will be explained. First, when a collision of the vehicle 1 or the like is detected by a sensor (not shown), an activation signal is input to the inflator 14 from a control device (not shown), and the inflator 14 activates to generate inflation gas. As a result, the inflation gas flows into the airbag 50, and the airbag 50 begins to inflate.

[0024] Next, as the airbag 50 inflates, it comes into contact with the top surface 22a of the connecting portion 22 of the airbag cover 20. As the airbag 50 inflates further, it pushes the top surface 22a upward, and the pressure from the airbag 50 causes the top surface 22a to rupture, starting from the fragile recess 22a1, and consequently the portion of the base material 21 connected to the top surface 22a ruptures.

[0025] Next, the pressure from the airbag 50 deforms the corners 22a4 and 22a5 of the top surface 22a, causing the door sections 22a2 and 22a3 of the top surface 22a, along with the broken base material 21, to be pushed upward by the airbag 50 and rotate upward, thereby forming the opening 60. The dashed line shown in Figure 3 indicates the state in which the door sections 22a2 and 22a3 of the top surface 22a and the base material 21 have rotated upward. The airbag 50 is then deployed from this opening 60 towards the occupant M seated in the passenger seat 3, and the airbag 50 completes its inflation. Subsequently, the occupant M, moving forward, is caught and protected by the inflated airbag 50.

[0026] Next, the detailed configuration of the airbag 50 will be described. Figure 4 is a plan view of the panels constituting the airbag 50. As shown in Figure 4, the airbag 50 is formed into a bag shape by joining the periphery of three panels: a main panel 51 which constitutes the rear wall portion 50a, the upper wall portion 50b, and the lower wall portion 50c; a left panel 52 which constitutes the left wall portion 50d; and a right panel 53 which constitutes the right wall portion 50e. In addition, tethers 54 to 57 are attached to the inner circumferential surfaces of the main panel 51, the left panel 52, and the right panel 53 to define the shape of the airbag 50 when inflation is complete. In this embodiment, the main panel 51, the left panel 52, the right panel 53, and the tethers 54 to 57 are formed from a 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 sutured to the seam 54x1 near one end 54a of the tether 54, and then the seam 51x6 of the main panel 51 is sutured to the seam 55x1 near one end 55a of the tether 54. Next, the seam 52x2 of the left panel 52 is sutured to the seam 55x1 near one end 55a of the tether 55, and then the seam 53x2 of the right panel 53 is sutured 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 together, and the suture portion 51x1 near the end 51a and the suture portion 51x2 near the other end 51b are sutured together. At this time, the main panel 51 is curved so that the tethers 54 and 55 sutured to the main panel 51 are positioned on the outside. As a result, the main panel 51 becomes a cylindrical shape with openings on the left and right sides.

[0029] Next, the left panel 52 is placed in the left opening to close the opening, and the suture portion 51x3 near one end 51c in the width direction of the main panel 51 is sutured to the suture portion 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 to close the opening, and the suture portion 51x4 near the other end 51d in the width direction of the main panel 51 is sutured to the suture portion 53x1 near the periphery 53a of the right panel 53.

[0030] Next, the other ends of tethers 54-57, one end of which is attached to the main panel 51, the left panel 52, and the right panel 53, are connected to each other. Specifically, the stitching 54x2 near the other end 54b of tether 54 sewn to the main panel 51 is joined to the stitching 55x2 near the other end 55b of tether 55, the stitching 56x2 near the other end 56b of tether 56 sewn to the left panel 52 is joined to the stitching 57x2 near the other end 57b of tether 57 sewn to the right panel 53. After that, the integrated main panel 51, left panel 52, and right panel 53 are turned inside out so that tethers 54-57 are positioned on the inside. In this way, the airbag 50 is formed in its pre-folded state.

[0031] Next, the method for folding the airbag 50 will be explained. Figure 5 is a plan view of the airbag 50 in a pre-folded state, and Figure 5B shows the same state as Figure 5A but reversed. Figures 6 to 11 are schematic diagrams showing how the airbag 50 is folded.

[0032] As shown in Figure 5, the worker performing the folding first pre-folds the airbag 50 at a predetermined position so that the rear wall forming portion 50k, which will form the rear wall portion 50a when the airbag 50 is fully inflated, becomes flat. The worker then places the pre-folded airbag 50 on a folding stand (not shown) with the rear wall forming portion 50k facing upwards (Figure 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 positioned downwards. In addition, 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 positioned upwards, but are mostly positioned downwards. The recess forming portion 50r1 which forms the recess 50c1 when the airbag 50 is fully inflated consists 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 portion 50c1c of the recess 50c1. Due to the partial folding of the lower wall forming portion 50r, the inner wall forming portions 50r1a and 50r1b are arranged to overlap vertically above the opening 50h.

[0034] First, the worker roll-folds the left end 50k1 of the rear wall forming section 50k towards the center in a left-right direction so that the width of the rear wall forming section 50k is narrowed in the left-right direction, thereby forming the left roll-folded section 50kx1 (Figure 6A). At this time, the worker roll-folds so that the left roll-folded section 50kx1 is positioned on the upper side, and repeats the roll-folding until the right end of the left roll-folded section 50kx1 is positioned near the center of the rear wall forming section 50k (Figure 6B). At this point, the left wall forming section 50q and the upper wall forming section 50p are located on the left rear surface of the rear wall forming section 50k, so these parts are also roll-folded together with the rear wall forming section 50k during the roll-folding process. The left-right direction referred to here corresponds to the left-right direction of the rear wall section 50a when expansion is complete.

[0035] Next, the worker roll-folds the right end portion 50k2 of the rear wall forming portion 50k towards the center in a left-right direction so that the width of the rear wall forming portion 50k is narrowed in the left-right direction, thereby forming the right roll-fold portion 50kx2 (Figure 7A). At this time, the worker roll-folds so that the right roll-fold portion 50kx2 is positioned on the upper side, and repeats the roll-folding until the left end of the right roll-fold portion 50kx2 is positioned near the center of the rear wall forming portion 50k (Figure 7B). At this point, the right wall forming portion 50s and the upper wall forming portion 50p are located on the right rear surface of the rear wall forming portion 50k, so these portions are also roll-folded together with the rear wall forming portion 50k during the roll-folding process. The left-right direction referred to here corresponds to the left-right direction of the rear wall portion 50a when expansion is complete.

[0036] Next, with the opening 50h still facing downwards, the worker reverses the front and back of the rear wall forming section 50k, starting from the bottom forming section 50r1c of the recess forming section 50r1, so that the left roll folding section 50kx1 and the right roll folding section 50kx2 of the rear wall forming section 50k, which are positioned on the upper side, are positioned on the lower side. As a result, the airbag 50 changes from the state shown in Figure 8A to the state shown in Figure 8B. In the state shown in Figure 8B, the inner wall forming section 50r1a, the inner wall forming section 50r1b, and the bottom forming section 50r1c that constitute the recess forming section 50r1 are all positioned facing upwards. In addition, the inner wall forming section 50r1a is positioned above the opening 50h.

[0037] Next, the worker forms a roll-folded portion 50kx3 by rolling the rear wall forming portion 50k, which has been roll-folded in the left-right direction, in the up-down direction so that its lower end portion 50k3 is close to the opening 50h (Figures 9A and 9B). In other words, the worker forms a roll-folded portion 50kx3 by rolling the left roll-folded portion 50kx1 and the right roll-folded portion 50kx2 toward the opening 50h so that their width in the up-down direction becomes narrower. At this time, the worker continues the roll-folding until the roll-folded portion 50kx3 is positioned above the opening 50h (Figures 10A, 10B, and 11A). The lower end portion 50k3 of the rear wall forming portion 50k here corresponds to the lower end portion 50a2 of the rear wall portion 50a when expansion is complete. The up-down direction corresponds to the up-down direction of the rear wall portion 50a when expansion is complete.

[0038] In this state, where the roll folding portion 50kx3 shown in Figure 11A is positioned above the opening 50h, the roll folding portion 50kx3 is held in place from above and below by the recess forming portion 50r1. That is, during the process of rolling the rear wall forming portion 50k in the vertical direction, the roll folding portion 50kx3 is first placed on the inner wall forming portion 50r1b of the recess forming portion 50r1 (Figure 10B). Subsequently, the roll folding portion 50kx3 placed on the inner wall forming portion 50r1b is roll-folded together with the inner wall forming portion 50r1b using the bottom forming portion 50r1c as a fold, and the roll folding portion 50kx3 encompassing the inner wall forming portion 50r1b is placed on the inner wall forming portion 50r1a (Figure 11A). In this way, the roll folding portion 50kx3 is positioned between the inner wall forming portion 50r1a and the inner wall forming portion 50r1b in the vertical direction. In other words, the roll-fold portion 50kx3 is held from above and below by the recess-forming portion 50r1. Alternatively, when the airbag 50 is folded, the rear wall portion 50a, which is roll-folded in the vertical and horizontal directions when inflation is complete, is stored in the recess 50c1 of the lower wall portion 50c when inflation is complete.

[0039] Subsequently, the worker folds the upper wall forming section 50p and places it on top of the recess forming section 50r1, which is holding the roll folding section 50kx3 from above and below (Figure 11B). This positions the upper wall forming section 50p above the recess forming section 50r1 that is holding the roll folding section 50kx3. Finally, the worker folds the upper wall forming section 50p back so that it forms a rectangle when viewed from above (Figure 11C). In this way, the worker completes folding the airbag 50.

[0040] Figure 12 is a schematic diagram showing the correspondence between the rear wall forming portion 50k, the upper wall forming portion 50p, and the lower wall forming portion 50r of the folded airbag 50 and the rear wall forming portion 50k, upper wall forming portion 50p, and lower wall forming portion 50r of the airbag 50 when inflation is complete. Figure 12A shows a cross-section of the folded airbag 50, and Figure 12B shows a cross-section of the airbag 50 when inflation is complete. The folded airbag 50 is covered by a folding prevention panel (not shown) and fixed to the case 15. The folding prevention panel covers the portion of the folded airbag 50 other than the area around the opening 50h, and ruptures and separates from the airbag 50 as the airbag 50 inflates.

[0041] When inflation gas is supplied from the inflator 24, the folded airbag 50 inflates in the following manner. That is, as shown in Figure 13A, first the upper wall forming portion 50p, which is located at the uppermost position above the opening 50h, pops out upward and contacts the windshield 8. At this time, the folds of the rolled fold portions 50kx3 of the rear wall forming portion 50k are hardly released.

[0042] Next, as shown in Figure 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 rolled fold portion 50kx3 of the rear wall forming portion 50k inflates so as to spread rearward and downward, that is, diagonally downward, while gradually unfolding the fold.

[0043] Next, as shown in Figure 14A, when inflation gas is further supplied to the airbag 50, the upper wall forming portion 50p is fully deployed. At this time, the roll-fold portion 50kx3 of the rear wall forming portion 50k expands downwards while the fold is released. Then, as shown in Figure 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 roll-fold portion 50kx3 is released, and the airbag 50 completes its inflation.

[0044] In this embodiment, in the folded state of the airbag 50, the roll-fold portion 50kx3 of the rear wall forming portion 50k is sandwiched from above and below by the recess forming portion 50r1 above the opening 50h. Furthermore, the upper wall forming portion 50p is positioned above the recess forming portion 50r1 that sandwiches the roll-fold portion 50kx3. As a result, even if the airbag 50 inflates when the distance between the occupant M and the instrument panel 2 is short, the impact received by the occupant M from the airbag 50 is suppressed.

[0045] In other words, if the recess 50c1 does not exist, the recess forming portion 50r1 also does not exist, and therefore the roll folding portion 50kx3 cannot be clamped from above and below by the recess forming portion 50r1. For this reason, in order to position the roll folding portion 50kx3 above the opening 50h, it becomes necessary to break up part of the fold, such as folding the final part of the fold of the roll folding portion 50kx3 in the opposite direction to the roll direction. In this case, when the airbag 50 inflates, the part of the broken fold will unfold at an earlier stage, and this will make it easier for the fold of the entire roll folding portion 50kx3 to be released earlier. If the fold of the roll folding portion 50kx3 is largely released at a stage before the upper wall forming portion 50p spreads to the rear to a certain extent (for example, at the stage shown in Figure 13A), the roll folding portion 50kx3 will spread more easily toward the rear. Therefore, when the airbag 50 inflates with the distance between the occupant M and the instrument panel 2 close, the rear wall forming portion 50k that spreads to the rear will collide with the occupant M, making it easier for the occupant M to be hit by the airbag 50. Furthermore, if the upper wall forming portion 50p is not positioned above the recess forming portion 50r1 that clamps the roll folding portion 50kx3, the timing of the upper wall forming portion 50p expanding backward is delayed. As a result, the fold of the roll folding portion 50kx3 is more likely to be largely released before the upper wall forming portion 50p expands backward to a certain extent, and as described above, the occupant M is more likely to be impacted by the airbag 50.

[0046] In contrast, in this embodiment, the roll folding portion 50kx3 is held between the recess-forming portion 50r1 from above and below, so that the roll folding portion 50kx3 can be positioned above the opening 50h without disturbing the final part of the fold of the roll folding portion 50kx3. Therefore, when the airbag 50 inflates, the premature unfolding of the fold of the roll folding portion 50kx3 is suppressed, and the timing of the unfolding of the roll folding portion 50kx3 can be delayed. Furthermore, since the upper wall forming portion 50p is positioned above the recess-forming portion 50r1 that holds the roll folding portion 50kx3, the upper wall forming portion 50p can be deployed backward at an early stage. Due to these effects, once the upper wall forming portion 50p has spread to a certain extent backward, it becomes easier to deploy the roll folding portion 50kx3, so that the roll folding portion 50kx3 tends to spread downward. Therefore, even if the airbag 50 inflates while the distance between the occupant M and the instrument panel 2 is short, a strong collision between the rear wall forming part 50k and the occupant M is suppressed, thereby reducing the impact that the occupant M receives from the airbag 50.

[0047] Furthermore, in this embodiment, without providing any separate components, the impact received by the occupant M from the airbag 50 is suppressed by setting the positional relationship of the opening 50h, roll folding portion 50kx3, recess forming portion 50r1, and upper wall forming portion 50p of the folded airbag 50 to the above-described relationship. Therefore, according to the airbag device 10 of this embodiment, the impact received by the occupant M from the airbag 50 can be suppressed without increasing the number of parts.

[0048] In this embodiment, a configuration in which the roll-folded portion 50kx3 is formed by roll-folding the rear wall forming portion 50k in the vertical and horizontal directions has been described, but the present invention is not limited to this. That is, the roll-folded portion 50kx3 only needs to be formed by roll-folding the rear wall forming portion 50k in the vertical direction. In other words, for example, the same effect as above can be obtained by accordion-folding the rear wall forming portion 50k in the horizontal direction, and then roll-folding the accordion-folded rear wall forming portion 50k in the vertical direction to form the roll-folded portion 50kx3.

[0049] Furthermore, in this embodiment, a configuration has been described in which the folded airbag 50 is covered with a panel to prevent collapse and then fixed to the case 15. However, if the airbag 50 is not easily collapsed due to its shape retention properties, etc., the airbag 50 may be fixed to the case 15 without a panel to prevent collapse. However, as in this embodiment, covering the airbag 50 with a panel to prevent collapse not only prevents collapse but also delays the deployment of the roll-fold portion 50kx3, so it is preferable to provide a panel to prevent collapse.

[0050] Furthermore, although this embodiment describes a configuration in which a 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, the present invention is not limited thereto. That is, the airbag 50 may be configured to have a recess 50c1 in the lower wall portion 50c to avoid interference with other protruding members such as instruments or other resin members that protrude upward from the instrument panel 2. Also, the airbag 50 may be configured to have a recess 50c1 in the lower wall portion 50c to avoid interference with other members positioned behind the instrument panel 2. Furthermore, the airbag 50 may be configured to have a recess 50c1 not for the purpose of avoiding interference between the airbag 50 and other members, but to clamp the roll folding portion 50kx3 from above and below by the recess forming portion 50r1. [Explanation of symbols]

[0051] 1...Vehicle, 2...Instrument panel, 4...Monitor (protruding member), 8...Windshield, 10...Airbag device, 14...Inflator, 50...Airbag, 50a...Rear wall section, 50b...Upper wall section, 50c...Lower wall section, 50c1...Recess, 50c1a...Inner wall (first inner wall), 50c1b...Inner wall (second inner wall), 50h...Opening, 50k...Rear wall section forming section, 50kx3...Roll folding section, 50p...Upper wall section forming section, 50r1...Recess section forming section, 50r1a...Inner wall section forming section (first inner wall section), 50r1b...Inner wall section forming section (second inner wall section), M...Occupant

Claims

1. In an airbag system installed in a vehicle, An airbag that folds and stores in the instrument panel of the vehicle, has an opening for supplying inflation gas, and inflates when inflation gas is supplied through the opening and is deployed from the instrument panel toward the occupant, comprising: a rear wall portion that catches 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, has a recess that is recessed upward, and is connected to the rear wall portion at the rear; An inflator that supplies the inflation gas to the airbag, Equipped with, The airbag device is characterized in that, in its folded state, the rear wall forming portion that forms the rear wall portion when inflation is complete is a roll-folded portion, and the roll-folded portion is sandwiched from above and below by a recess forming portion that forms the recess when inflation is complete, above the opening, and above the recess forming portion that sandwiches the roll-folded portion, an upper wall forming portion that forms the upper wall portion when inflation is complete is arranged.

2. When the airbag has finished inflating, the recess comprises a first inner wall and a second inner wall facing the first inner wall in the front-rear direction. The airbag device according to claim 1, characterized in that, when the airbag is folded, the roll folding portion is held from above and below by a first inner wall forming portion that forms the first inner wall when inflation is complete and a second inner wall forming portion that forms the second inner wall when inflation is complete.

3. The airbag device according to claim 1 or 2, characterized in that, when the airbag has finished inflating, a protruding member mounted on the vehicle and projecting upward from the instrument panel is arranged inside the recess.

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

Images