Airbag system

Abstract

To provide an air bag device capable of easily reducing a curvature radius of a recess formed in a lower wall of an air bag.SOLUTION: An air bag device 10 includes an air bag 50 having a rear wall part 50a that 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 recess 50c1 that is recessed upward. The air bag 50 has: an upstream chamber 50x to which inflation gas is supplied from an inflator 14 through an opening 50h; and a downstream chamber 50y that is sewn and connected to the upstream chamber 50x and to which inflation gas is supplied from the upstream chamber 50x through a communication opening 50j. The recess 50c1 is formed by an outer peripheral part of the upstream chamber 50x and an outer peripheral part of the downstream chamber 50y.SELECTED DRAWING: Figure 4

Description

Technical Field

[0005] , , ,

[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. <000001​​​​​​​​​​​​​​​​​​​​​​​​​However, in the configuration described in Patent Document 1, since the airbag is composed of a single chamber, the radius of curvature of the recess tends to be large due to the sewing process. When the radius of curvature of the recess is large in this way, if there are vehicle-side components mounted on the vehicle, such as monitors, around the recess, a gap is likely to occur between the inner wall of the recess and the vehicle-side components. Also, if there are no vehicle-side components, a gap is likely to occur between the two inner walls that make up the recess and face each other. In order to improve the occupant protection performance, it is desirable to have a configuration in which these gaps are made as small as possible so that the airbag can easily obtain reaction force from the monitor and the inner walls that make up the recess.

[0006] Therefore, the present invention aims to provide an airbag device that can easily reduce the radius of curvature of a recess formed in the lower wall of the airbag. [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 a first opening for introducing inflation gas, and is inflated by the supply of inflation gas through the first 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 recess that faces the upper wall portion in the vertical direction and is recessed upward, and rear The airbag comprises a lower wall portion connected to the rear wall portion, an airbag, and an inflator that supplies the inflation gas to the airbag, wherein the airbag has a first chamber to which the inflation gas is supplied from the inflator through the first opening, and a second chamber sewn to and connected to the first chamber, to which the inflation gas is supplied from the first chamber through a second opening that connects the first chamber and the second chamber, and the recess is formed by the outer periphery of the first chamber and the outer periphery of the second chamber.

[0008] According to the present invention, the radius of curvature of the recess formed in the lower wall of the airbag can be easily reduced in an airbag device. [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 schematic perspective view of the airbag when it is fully inflated. [Figure 5] This is a plan view of the panels that make up the airbag. [Figure 6] This is a view from the left side of the area around the passenger seat of a vehicle with the airbags inflated. [Figure 7] This is a view from the left side of the area around the passenger seat of a vehicle with the airbags inflated. [Figure 8] This is a view from the left side of the area around the passenger seat of a vehicle with the airbags inflated. [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] Figure 1 is a schematic perspective view of the instrument panel 2 (hereinafter referred to as "instrument panel 2") of vehicle 1. Figure 2 is a view of the area around the passenger seat 3 of vehicle 1 from the left side, showing the instrument panel 2 and the airbag device 10 in a cross-section cut along the AA section shown in Figure 1, with the outer shape of the airbag 50 and the outer shape of the occupant M when fully inflated indicated by dashed lines. Figure 3 is a schematic cross-sectional view of the airbag device 10.

[0012] As shown in Figures 1 to 3, the airbag system 10 is mounted on an instrument panel 2 located in front of the passenger seat 3 of the vehicle 1. The instrument panel 2 is held by the body of the vehicle 1 (not shown) and has a driver's side section 2a located in front of the driver's seat (not shown), a passenger side section 2b located in front of the passenger seat 3, and a central section 2c in front of the center console located between the driver's seat and the passenger seat 3. A monitor 4 (vehicle-side component) capable of displaying images and videos is attached to the rear end surface 2b1 of the passenger side section 2b of the instrument panel 2. The top of the monitor 4 is positioned higher than the top surface 2b2 of the instrument panel 2. In other words, the monitor 4 is mounted on the instrument panel 2 so as to protrude upward from the instrument panel 2. The airbag system 10 is mounted on the passenger side section 2b and protects the 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 top of the folded airbag 50.

[0014] The inflator 14 is a substantially cylindrical member that generates expansion gas and has an outlet 14a at its top for discharging the expansion gas. The inflator 14 also has a flange portion 14b that extends radially from the surface where the outlet 14a is formed, as a part that connects to the case 15. The inflator 14 is electrically connected to a control device (not shown) and lead wires (not shown), and operates to generate expansion gas when an operating signal is input from the control device via the lead wires.

[0015] The airbag 50 is a bag-shaped component that, when folded, is stored inside the passenger-side portion 2b of the instrument panel 2. On the lower surface of the folded airbag 50, there is an opening 50h (see Figure 4) for inserting the portion where the discharge port 14a of the inflator 14 is formed. In other words, the opening 50h is provided to allow the inflation gas released from the inflator 14 to flow into the airbag 50. Inside the airbag 50, there is also a roughly rectangular annular retainer 12 for fixing the airbag 50 and the inflator 14 to the case 15.

[0016] When inflation gas is supplied to the airbag 50 from the inflator 14 through the opening 50h, the airbag 50 inflates to seal the space between the instrument panel 2 and the windshield 8 of the vehicle 1. When fully inflated, the airbag 50 has a rear wall portion 50a positioned at the rear (immediately in front of the occupant M) and configured to catch the occupant M as it moves forward, and an upper wall portion 50b positioned above, extending along the windshield 8 of the vehicle 1 and connected to the upper end 50a1 of the rear wall portion 50a at the rear. Furthermore, when fully inflated, the airbag 50 has a lower wall portion 50c positioned below, facing the upper wall portion 50b in the vertical direction and connected to the lower end 50a2 of the rear wall portion 50a at the rear, and a left wall portion 50d and a right wall portion 50e positioned on the left and right sides, respectively. The lower wall portion 50c is placed on top of the instrument panel 2 and the monitor 4 and supported by these components.

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

[0018] The case 15 includes a substantially rectangular - plate - shaped bottom wall portion 15a and a substantially square - cylindrical side wall portion 15b that extends 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 end portions of the front and rear side wall portions 15b are respectively hook - shaped hook portions 15b1. A plurality of hook portions 15b1 are provided on the front and rear side wall portions 15b so as to be arranged in the left - right direction. Further, an insertion hole (not shown) through which the inflator 14 is inserted is formed in the bottom wall portion 15a.

[0019] The airbag 50 and the inflator 14 are fixed to the bottom wall portion 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 sandwiched between the lower surface of the retainer 12 and the upper surface of the bottom wall portion 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 portion 15a of the case 15. In this state, bolts 5 are inserted into screw holes formed in the periphery of the opening 50h of the airbag 50, the bottom wall portion 15a of the case 15, and the flange portion 14b of the inflator 14, respectively, and nuts 13 are fastened. In this way, the airbag 50 and the inflator 14 are fixed to the bottom wall portion 15a of the case 15.

[0020] The airbag cover 20 covers the upper part of the folded airbag 50, and when the airbag 50 inflates, a part of it breaks to form an opening 60, and the airbag 50 is drawn out from the opening 60. The airbag cover 20 is formed of a synthetic resin and is composed of a base material 21 and a connecting portion 22 connected to the back surface of the base material 21 by screws or the like. The base material 21 is a member constituting the instrument panel 2 and extends to the driver's seat 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 in a substantially horizontal direction 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 square cylindrical 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. A plurality of engaging holes 22b1 are formed in the front and rear side wall portions 22b, and a plurality of hook portions 15b1 formed in the side wall portion 15b of the case 15 are respectively engaged with the engaging holes 22b1. The airbag cover 20 and the case 15 are connected by the hook portion 15b1 being caught and engaged in the engaging hole 22b1.

[0022] A recess 22a1 that is recessed so as to have a thin wall thickness is formed at a substantially central portion in the front-rear direction on the back surface of the top surface portion 22a. Further, the front side portion of the recess 22a1 in the top surface portion 22a becomes a door portion 22a2 that rotates upward around a corner portion 22a4 formed between the front side wall portion and the airbag 50 when the airbag 50 inflates. Similarly, the rear side portion of the recess 22a1 in the top surface portion 22a becomes a door portion 22a3 that rotates upward around a corner portion 22a5 formed between the rear side wall portion and the airbag 50 when the airbag 50 inflates.

[0023] Next, the 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, and the inflator 14 operates to generate inflation gas. As a result, the inflation gas flows into the airbag 50, and the airbag 50 starts 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 explained. Figure 4 is a schematic perspective view of the airbag 50 when inflation is complete. Figure 5 is a plan view of the panels that make up the airbag 50. Figure 6 is a view from the left side of the area around the passenger seat 3 of vehicle 1 when the airbag 50 is inflated, and the outline of occupant M is shown by a dashed line.

[0027] As shown in Figure 4, the airbag 50 consists of two chambers: an upstream chamber 50x (first chamber) having an opening 50h (first opening) through which inflation gas is supplied from the inflator 14; and a downstream chamber 50y (second chamber) through a communication port 50j (second opening) inside the airbag 50, through which inflation gas is supplied from the upstream chamber 50x. That is, the inflation gas generated in the inflator 14 first flows into the upstream chamber 50x, which is located upstream in the direction of the inflation gas flow in the airbag 50, and then flows into the downstream chamber 50y, which is located downstream. The upstream chamber 50x and the downstream chamber 50y are formed separately, and they are connected by the downstream chamber 50y being sutured to the upstream chamber 50x.

[0028] Furthermore, when the airbag 50 has finished inflating, the upstream chamber 50x is located on the front side of the vehicle 1 and constitutes a part of the upper wall 50b, a part of the lower wall 50c, a part of the left wall 50d, and a part of the right wall 50e. The downstream chamber 50y is located on the rear side of the vehicle 1 and constitutes a part of the upper wall 50b, a part of the lower wall 50c, a part of the left wall 50d, a part of the right wall 50e, and the entirety of the rear wall 50a. When the airbag 50 has finished inflating, the upstream chamber 50x and the downstream chamber 50y are located adjacent to each other in the front-rear direction.

[0029] Furthermore, the outer periphery of the upstream chamber 50x constitutes the inner wall 50c1a of the recess 50c1 provided in the lower wall portion 50c of the airbag 50. The outer periphery of the downstream chamber 50y constitutes the inner wall 50c1b of the recess 50c1. In this way, the recess 50c1 of the airbag 50 is formed by the outer periphery of the upstream chamber 50x and the outer periphery of the downstream chamber 50y.

[0030] As shown in Figure 5, the airbag 50 is formed from an upstream main panel 61, an upstream left panel 62, and an upstream right panel 63 for forming the upstream chamber 50x, and a downstream main panel 64, a downstream left panel 65, and a downstream right panel 66 for forming the downstream chamber 50y, as well as tethers 67 and 68. The tethers 67 and 68 are provided inside the airbag 50 and define the shape of the airbag 50 when inflation is complete. In this embodiment, each of these panels (61-66) and the tethers 67 and 68 are formed from a flexible woven fabric made of polyester yarn, polyamide yarn, or the like.

[0031] The upstream main panel 61, the downstream main panel 64, and the tether 68 are provided with through holes 61h, 64h, and 68h for forming a communication opening 50j (Figure 4). The through holes 61h, 64h, and 68h are elongated holes with a larger opening area than a perfect circle in order to allow air to pass through easily when the airbag 50 inflates, and as a result the communication opening 50j is also an elongated hole. When forming the airbag 50, first the suture portions 61x5, 64x5, and 68x1 around the edges of these through holes 61h, 64h, and 68h are sutured together. Next, the suture portion 68x2 of the tether 68 and the suture portion 67x2 of the tether 67 are sutured together, and the suture portion 67x1 of the tether 67 and the suture portion 64x6 of the downstream main panel 64 are sutured together.

[0032] Next, the upstream main panel 61 is curved so that one end 61a and the other end 61b in the longitudinal direction of the upstream main panel 61 are brought closer together, and the suture portion 61x1 near the end 61a and the suture portion 61x2 near the other end 61b are sutured together. At this time, the upstream main panel 61 is curved so that the tethers 67 and 68 are positioned on the outside. As a result, the upstream main panel 61 becomes a cylindrical shape with openings on the left and right sides.

[0033] Next, the upstream left panel 62 is positioned in the opening on the left side of the upstream main panel 61 so as to close this opening, and the suture portion 61x3 near one end 61c in the width direction of the upstream main panel 61 is sutured to the suture portion 62x1 near the periphery 62a of the upstream left panel 62. Similarly, the upstream right panel 63 is positioned in the opening on the right side of the upstream main panel 61 so as to close this opening, and the suture portion 61x4 near the other end 61d in the width direction of the upstream main panel 61 is sutured to the suture portion 63x1 near the periphery 63a of the upstream right panel 63. Note that the suture portion 62x1 of the upstream left panel 62 is not present all around, and a portion of it is an outer suture portion 62x2. Similarly, the suture portion 63x1 of the upstream right panel 63 is not present all around, and a portion of it is an outer suture portion 63x2. The outer suture sections 62x2 and 63x2 are not sutured at this stage, but are sutured from the outside of the airbag 50 at the end.

[0034] Next, the downstream main panel 64 is curved so that one end 64a and the other end 64b in the longitudinal direction of the downstream main panel 64 are brought closer together, and the suture portion 64x1 near the end 64a and the suture portion 64x2 near the other end 64b are sutured together. At this time, the downstream main panel 64 is curved so that the tethers 67 and 68 are positioned on the outside. As a result, the downstream main panel 64 becomes a cylindrical shape with openings on the left and right sides.

[0035] Next, the downstream left panel 65 is positioned in the left opening of the downstream main panel 64 so as to close this opening, and the suture portion 64x3 near one end 64c in the width direction of the downstream main panel 64 is sutured to the suture portion 65x1 near the periphery 65a of the downstream left panel 65. Similarly, the downstream right panel 66 is positioned in the right opening of the downstream main panel 64 so as to close this opening, and the suture portion 64x4 near the other end 64d in the width direction of the downstream main panel 64 is sutured to the suture portion 66x1 near the periphery 66a of the downstream right panel 66. Note that the suture portion 65x1 of the downstream left panel 65 is not present all around, and a portion of it is an outer suture portion 65x2. Similarly, the suture portion 66x1 of the downstream right panel 66 is not present all around, and a portion of it is an outer suture portion 66x2. The outer suture sections 65x2 and 66x2 are not sutured at this stage, but are sutured from the outside of the airbag 50 at the end.

[0036] Next, the integrated panels (61-66) and tethers 67 and 68 are turned inside out, starting from the unsewn outer seams 62x2, 63x2, 65x2, and 66x2, so that the tethers 67 and 68 are positioned on the inside. Finally, the seams around the upstream main panel 61 (61x1, 61x2), the seams around the downstream main panel 64 (64x1, 64x2), and the outer seams 62x2, 63x2, 65x2, and 66x2 are sewn together linearly from the outside of the airbag 50 so that the airbag 50 is sealed. In this way, the airbag 50 is formed.

[0037] By forming the airbag 50 in this way by sewing together the upstream chamber 50x and the downstream chamber 50y, and by forming a recess 50c1 with their outer periphery, the following effects are achieved. That is, if the airbag 50 were to be formed in a single chamber, in order to sew the recess 50c1, it would be necessary to operate the sewing machine or needle along the curve of the recess 50c1. Therefore, if the radius of curvature of the recess 50c1 is small, it becomes necessary to make sharp turns of the sewing machine during the sewing process, which increases the likelihood of sewing errors. On the other hand, if the radius of curvature of the recess 50c1 is increased to suppress sewing errors, gaps are more likely to form between the inner walls 50c1a and 50c1b of the recess 50c1 and the monitor 4, making it difficult for the airbag 50 to receive reaction force from the monitor 4.

[0038] In contrast, as in this embodiment, the airbag 50 is formed by sewing together an upstream chamber 50x and a downstream chamber 50y, and a recess 50c1 is formed by the outer periphery of these chambers. As a result, the radius of curvature of the recess 50c1 can be set simply by adjusting the positional relationship between the upstream chamber 50x and the downstream chamber 50y, making it possible to easily form a recess 50c1 with a small radius of curvature without making sharp turns with a sewing machine or the like. Therefore, as shown in Figure 6, the gap S1 between the inner walls 50c1a, 50c1b of the recess 50c1 and the monitor 4 can be reduced, making it easier for the airbag 50 to receive reaction force from the monitor 4 and improving the protection performance of the occupant M.

[0039] In this embodiment, a configuration in which the airbag device 10 is mounted on a vehicle 1 having a monitor 4 has been described, but the present invention is not limited to this. That is, the same effects as described above can be obtained even if the airbag device 10 is mounted on a vehicle 1 that does not have a monitor 4 as shown in Figure 7, or on a vehicle 1 in which the monitor 4 is located in a position where it is unlikely to interfere with the airbag 50. In other words, in such a configuration, if the radius of curvature of the recess 50c1 is large, a gap is likely to occur between the inner walls 50c1a and 50c1b of the recess 50c1, making it difficult for the airbag 50 to obtain the reaction force generated by the contact between the inner walls 50c1a and 50c1b. In contrast, with the airbag device 10 of this embodiment, the gap S2 (Figure 7) between the inner walls 50c1a and 50c1b of the recess 50c1 can be reduced, so that the airbag 50 can obtain the reaction force generated by the contact between the inner walls 50c1a and 50c1b, thereby improving the protective performance of the occupant M.

[0040] Furthermore, although this embodiment describes a configuration in which the upstream chamber 50x and the downstream chamber 50y are positioned adjacent to each other in the front-rear direction when the airbag 50 has finished inflating, the present invention is not limited to this. That is, as shown in Figure 8, the same effects as described above can be obtained even if the upstream chamber 50x and the downstream chamber 50y are positioned adjacent to each other in the vertical direction when the airbag 50 has finished inflating. Note that the configuration shown in Figure 8 is achieved by making the upstream chamber 50x larger and the downstream chamber 50y smaller compared to the configurations shown in Figures 1 to 7. The positional relationship between the upstream chamber 50x and the downstream chamber 50y is determined according to the positional relationship between the airbag 50 and other components of the vehicle 1, etc.

[0041] 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 to this, and a configuration in which a recess 50c1 is provided in the lower wall portion 50c of the airbag 50 to avoid interference with other members that protrude upward from the instrument panel 2 is also possible. In addition, the same effects can be obtained by mounting the airbag device 10 on the driver's side portion 2a in front of the driver's seat on the instrument panel 2, and providing a recess 50c1 in the lower wall portion 50c of the airbag 50 to avoid interference with vehicle side members such as the steering wheel of the vehicle 1 located behind the instrument panel 2. [Explanation of Symbols]

[0042] 1...Vehicle, 2...Instrument panel, 4...Monitor (vehicle side component), 8...Windshield, 10...Airbag device, 14...Inflator, 50...Airbag, 50a...Rear wall, 50b...Upper wall, 50c...Lower wall, 50c1...Recess, 50c1a...Inner wall (first inner wall), 50c1b...Inner wall (second inner wall), 50h...Opening (first opening), 50j...Communication port (second opening), 50x...Upstream chamber (first chamber), 50y...Downstream chamber (second chamber), 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 a first opening for introducing inflation gas, and inflates when inflation gas is supplied through the first 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; a lower wall portion that faces the upper wall portion in the vertical direction and has a recess that is recessed upward and is connected to the rear wall portion at the rear; and a left wall portion and a right wall portion, respectively, located on the left and right sides, respectively. An inflator that supplies the inflation gas to the airbag, Equipped with, The aforementioned airbag, A first chamber from which the expansion gas is supplied from the inflator through the first opening, A second chamber is sutured and connected to the first chamber, and the expansion gas is supplied from the first chamber through a second opening that connects the first chamber and the second chamber. The recess is formed by the outer periphery of the first chamber and the outer periphery of the second chamber, The first chamber and the second chamber are each formed from separate, flexible panels and are arranged adjacent to each other in the front-rear direction when the airbag has finished inflating. An airbag device characterized in that the outer periphery of the first chamber constitutes a first inner wall in the recess, and the outer periphery of the second chamber constitutes a second inner wall facing the first inner wall in the recess.

2. The airbag device according to claim 1, characterized in that the second opening is an elongated hole.

3. The airbag device according to claim 1 or 2, characterized in that, when the airbag has finished inflating, a vehicle-side member mounted on the vehicle is positioned inside the recess.

4. The airbag device according to claim 3, characterized in that the vehicle-side member is a monitor attached to the instrument panel and displays an image.

5. The airbag device according to claim 3, characterized in that the vehicle-side member is a steering wheel.

Images