Airbag system

Abstract

To provide an airbag system that can accurately protect occupants, even when configured to support the upper body and knees with an inflated airbag. [Solution] The passenger-side airbag device M is positioned in front of the occupant seated in the seat and includes an airbag 20 that folds and stores in a storage compartment 16. The airbag is configured to inflate to cover the front of the occupant from the knees to the upper body and includes an upper body protection section 21 that can protect the upper body and a knee protection section 72 that can protect the knees. The upper body protection section and the knee protection section are each separate bag-shaped units, connected to separate inflators 12L and 12R to allow inflation gas to flow into them, and are folded and stored in the storage compartment.

Description

Technical Field

[0001] The present invention relates to an airbag apparatus configured with an airbag that is disposed in front of an occupant seated on a seat and is folded and stored in a storage portion.

Background Art

[0002] Conventionally, as an airbag apparatus, there has been a passenger-side airbag apparatus disposed in front of a front passenger seat, configured such that the airbag protrudes from a storage portion disposed on the lower side of an instrument panel in front of the front passenger seat, and the inflated airbag protects the occupant seated in the front passenger seat from the knees to the upper body (for example, see Patent Document 1).

Prior Art Literature

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional airbag apparatus, the airbag is configured such that a knee protection region for receiving knees and an upper body protection region for receiving the upper body are integrally disposed. Therefore, for example, when the fully inflated airbag receives the knees prior to the upper body, inflation gas moves from the knee protection region to the upper body protection region side upon contact with the knees, so that the internal pressure required for knee protection may not be secured, and there is a risk that the knees cannot be properly protected.

[0005] The present invention solves the above-described problems, and an object of the present invention is to provide an airbag apparatus capable of properly protecting an occupant even in a configuration where the fully inflated airbag receives both the upper body and the knees.

Means for Solving the Problems

[0006] The airbag system according to the present invention is equipped with an airbag that is positioned in front of the occupant seated in the seat and folds up and is stored in a storage area. An airbag system configured such that the airbag inflates to cover the front of the occupant's body from the knees to the upper body, The airbag is configured to include an upper body protection section capable of protecting the upper body and a knee protection section capable of protecting the knees. The upper body protection section and the knee protection section are each separate bag-like structures connected to a separate inflator, allowing inflation gas to flow into them, and are folded and stored within a storage compartment.

[0007] In the airbag device of the present invention, the airbag is configured to inflate to cover the front of the occupant from the knees to the upper body. The upper body protection section, which can protect the upper body, and the knee protection section, which can protect the knees, are each separate bag-shaped components connected to separate inflators. Therefore, in the airbag device of the present invention, when the airbag is fully inflated, for example, when the knee protection section receives the knee before the upper body and upper body protection section come into contact, the movement of inflation gas from the knee protection section to the upper body protection section can be suppressed. This ensures that the appropriate internal pressure of the knee protection section is maintained, and the knee can be accurately protected by the knee protection section. Furthermore, in the airbag device of the present invention, although the upper body protection section and the knee protection section are connected to separate inflators, they are arranged in a single storage area when folded. Compared to the case where the knee protection airbag device and the upper body protection airbag device are separate units and each is attached to the vehicle body, the mounting space can be reduced, and the number of parts and assembly man-hours can also be reduced, thereby suppressing an increase in manufacturing costs.

[0008] Therefore, in the airbag system of the present invention, even if the configuration is such that the upper body and knees are supported by the fully inflated airbag, the occupant can be accurately protected.

[0009] Furthermore, in the airbag device of the present invention, if the upper body protection section and the knee protection section are folded together and stored in the storage section, it is preferable because the folding and storage operations can be performed more smoothly compared to the case where the upper body protection section and the knee protection section are folded separately and stored in the storage section.

[0010] Furthermore, in the airbag device with the above configuration, it is preferable that the knee protection portion is configured to allow inflation gas to flow into the interior via a gas flow path that is arranged to pass through the inside of the upper body protection portion when inflation is complete.

[0011] In an airbag system with this configuration, the gas passage located within the upper body protection section is inflated by the inflation gas discharged from the inflator for the knee protection section. In other words, the volume of the upper body protection section is set to be smaller by the amount of the gas passage section. Therefore, the upper body protection section can be inflated more quickly by the amount of the volume reduction. Furthermore, by inflating the knee protection section via the gas passage section that passes through the upper body protection section, it is possible to suppress the knee protection section and the upper body protection section from pressing against each other in or near the storage area when inflation is complete, thereby stabilizing the positional relationship between the knee protection section and the upper body protection section.

[0012] Specifically, the airbag system is configured to have its storage compartment located on the lower side of the instrument panel in front of the passenger seat. Upper body protection section, The device is configured to inflate by introducing expansion gas into its interior, causing it to protrude from the storage area towards the rear while expanding upward and forward. It is preferable to have a configuration in which the lower and upper expansion parts are connected at the periphery of the communication hole, with each being a separate bag-like structure, having a lower expansion part that is connected to the inflator and expands to protrude rearward from the storage area, and an upper expansion part that is connected to the lower expansion part via a communication hole and expands above the lower expansion part.

[0013] If the airbag system is configured as described above, in the initial stages of airbag inflation, the lower inflation section of the upper body protection unit first inflates by allowing inflation gas discharged from the inflator to flow into its interior, causing it to protrude backward from the storage area. Subsequently, the upper inflation section inflates by allowing inflation gas to flow into its interior through the communication hole. Therefore, even if the upper body protection unit is configured to inflate by protruding backward from the storage area while deploying forward and upward, it is possible to suppress the upper inflation section, which actually receives the occupant's upper body, from deploying in a way that causes it to protrude excessively towards the occupant, thereby effectively protecting the occupant's upper body.

[0014] Furthermore, in the airbag device with the above configuration, the knee protection portion is configured to include a left portion and a right portion that are positioned on the left and right sides of the lower inflation portion when inflation is complete. It is preferable to connect the left and right edges of the lower expansion section with the vicinity of the upper ends of each left and right section, respectively, using a lower restricting tether.

[0015] With the airbag system configured as described above, the lower restricting tether connects the upper edges of the left and right portions of the knee protection section to the left and right edges of the lower inflation section. This prevents gaps from forming between the left and right sides of the lower inflation section and the left and right portions of the knee protection section when the airbag is fully inflated. Therefore, when the knee protection section receives the occupant's knee when the airbag is fully inflated, it prevents the occupant's knee from entering the space between the left and right portions and the lower inflation section, allowing the left and right portions to effectively restrain the occupant's knee.

[0016] In the configuration where lower regulating tethers are installed, specifically, each lower regulating tether is positioned when the airbag has finished inflating. The upper left or upper right edge of the lower expansion portion is connected to the inner front edge of the left or right portion, and the front portion is disposed on the front side that faces the instrument panel. The lower left or right lower edge of the lower expansion section is connected to the inner rear edge of the left or right section, and the rear section is positioned on the rear side that faces the occupant. It is preferable to have a configuration that includes the following.

[0017] If the airbag system is configured as described above, the lower regulating tether will connect the left or right side of the lower inflation section to the inner sides of each left and right section at two points separated front and rear. This lower regulating tether allows the knee protection section to inflate stably when the airbag is deployed and inflated. Specifically, the front section connects the inner front edge of the upper end of each left and right section of the knee protection section to the upper left or upper right edge of the lower inflation section. This prevents the knee protection section, which protrudes from the storage area, from inflating in a way that causes the upper ends of each left and right section to move away from the lower inflation section and tilt towards the occupant during the initial stages of airbag inflation. Furthermore, because the rear portion connects the inner rear edge of the upper end of each left and right portion of the knee protection section to the left or right lower edge of the lower inflation section, it is possible to suppress the upper end of each left and right portion from expanding outward to the left and right, separating from the lower inflation section, during the initial stages of airbag inflation. Therefore, in an airbag device with the above configuration, the lower regulating tether can stabilize the position of each left and right portion of the knee protection section (suppressing lateral movement during deployment), allowing the knee protection section to inflate quickly to broadly and accurately cover the front of the occupant's left and right knees, and the knee protection section (left and right portions) can more accurately restrain the occupant's knees. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic longitudinal cross-sectional view showing a passenger-side airbag system, which is one embodiment of the present invention, installed in a vehicle. [Figure 2] This is a schematic enlarged longitudinal cross-sectional view of the passenger-side airbag device according to the embodiment. [Figure 3] This is a schematic enlarged cross-sectional view of the passenger-side airbag device according to the embodiment. [Figure 4] This is a left side view showing a state where the airbag used alone in the passenger airbag device of the embodiment is inflated as a single unit. [Figure 5] This is a plan view of the airbag of Figure 4 viewed from above. [Figure 6] This is a rear view of the airbag of Figure 4 viewed from the rear. [Figure 7] This is a schematic longitudinal sectional view of the airbag of Figure 4 along the front-rear direction. [Figure 8] This is a schematic partial longitudinal sectional view along the left-right direction showing the part of the communication hole in the airbag of Figure 4. [Figure 9] This is a schematic partial transverse sectional view showing the part of the communication hole in the airbag of Figure 4. [Figure 10] This is a schematic partially enlarged longitudinal sectional view showing the part of the knee protection portion in the airbag of Figure 4. [Figure 11] This is a schematic partial transverse sectional view showing the part of the gas flow passage portion in the knee protection portion in the airbag of Figure 4. [Figure 12] This is a schematic partial longitudinal sectional view showing the part of the gas flow passage portion in the knee protection portion in the airbag of Figure 4. [Figure 13] This is a partial sectional view showing the part of the lower regulation tether that connects the left side portion of the knee protection portion and the lower inflatable portion in the airbag of Figure 4. [Figure 14] This is a plan view of a state where the base material constituting the upper inflatable portion in the upper body protection portion and the base material constituting the inner tether are arranged side by side in the airbag of Figure 4. [Figure 15] This is a plan view of a state where the base material constituting the lower inflatable portion in the upper body protection portion, the base material constituting the gas flow passage portion in the knee protection portion, and the base material constituting the flow regulating fabric are arranged side by side in the airbag of Figure 4. [Figure 16] This is a plan view of a state where the base materials constituting the protection main body portion in the knee protection portion are arranged side by side in the airbag of Figure 4. [Figure 17] These are a front view and a rear view of a pre-folded bag obtained by pre-folding the airbag of Figure 4. [Figure 18] Figure 4 is a schematic diagram showing the folding process for the airbag. [Figure 19] This is a schematic longitudinal cross-sectional view showing the completed inflation state of the passenger-side airbag device according to the embodiment. [Figure 20] This is a schematic, partially enlarged longitudinal cross-sectional view showing the knee protection portion of the passenger-side airbag device according to the embodiment when the airbag has finished inflating. [Figure 21] This is a schematic cross-sectional view showing the portion of the case of the passenger-side airbag device according to the embodiment when the airbag has finished inflating. [Figure 22] This is a plan view from above of an airbag, which is another embodiment of the present invention, in an inflated state. [Figure 23] Figure 22 is a schematic, enlarged longitudinal cross-sectional view along the anterior-posterior direction, showing the lower inflation portion of the upper body protection section and the knee protection section of the airbag. [Figure 24] Figure 22 is a partial cross-sectional view showing the front portion of the lower restrictive tether connecting the left side of the knee protection section and the lower inflation section of the airbag. [Figure 25] Figure 22 is a partial cross-sectional view showing the rear portion of the lower restrictive tether connecting the left side of the knee protection section and the lower inflation section of the airbag. [Figure 26] Figure 22 is a plan view of the airbag, showing the base material constituting the upper inflation section of the upper body protection part and the base material constituting the internal tether arranged side by side. [Figure 27] Figure 22 is a plan view of the airbag, showing the base material constituting the lower inflation section of the upper body protection section and the base material constituting the gas flow path section of the knee protection section side by side. [Figure 28] Figure 22 is a plan view of the airbag, showing the arrangement of the base materials that make up the protective body of the knee protection section. [Modes for carrying out the invention]

[0019] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In this embodiment, a passenger-side airbag device will be used as an example for the airbag device M. As shown in Figures 1 and 2, the passenger-side airbag device M of this embodiment (hereinafter abbreviated as "airbag device") is arranged on the rear surface 3 side of the lower part 1a side of the instrument panel (hereinafter abbreviated as "instrument panel") 1. In this embodiment, unless otherwise specified, the front-rear, up-down, and left-right directions correspond to the front-rear, up-down, and left-right directions of the vehicle.

[0020] As shown in Figures 1 to 3, the airbag device M comprises a case 16 as a storage area located at the lower part 1a of the instrument panel 1, an airbag 20 that is folded and stored in the case 16, two inflators 12L and 12R that supply inflation gas to the airbag 20, two retainers 13L and 13R for attaching the airbag 20 and each inflator 12L and 12R to the case 16, and an airbag cover 10 that covers the folded airbag 20.

[0021] The airbag cover 10 is formed to be connected to the instrument panel 1, is made of synthetic resin, and has a single door portion 10a that opens when the airbag 20 is deployed and inflated. In this embodiment, the door portion 10a is configured to open downward when pushed by the airbag 20. In addition, a connecting wall portion 10b that is connected to the case 16 is formed around the door portion 10a of the airbag cover 10 so as to protrude forward.

[0022] In this embodiment, the two inflators 12L and 12R are mounted side-by-side on the left and right sides of the case 16, respectively, on the bottom wall portion 16a, which will be described later. In this embodiment, the inflator 12L located on the left side supplies inflation gas G2 to the knee protection portion 72 of the airbag 20, which will be described later, and the inflator 12R located on the right side supplies inflation gas G1 to the upper body protection portion 21 of the airbag 20, which will be described later (see Figures 3, 19-21). The inflators 12L and 12R have the same configuration except for their different outputs, with the inflator 12R for the larger volume upper body protection portion 21 having a higher output than the inflator 12L for the knee protection portion 72. Each inflator 12L, 12R comprises a substantially cylindrical body portion 12a having a plurality of gas outlets 12b, and a flange portion 12c for attaching the inflators 12L, 12R to the case 16 (see Figure 3). In the airbag device M of this embodiment, each inflator 12L, 12R is attached to the front end side (bottom wall portion 16a) of the case 16 such that the axial direction of the body portion 12a is aligned with the front-rear direction. Each inflator 12L, 12R is electrically connected to an airbag operating circuit (not shown) by lead wires (not shown). In this embodiment, the inflators 12L, 12R are set to operate substantially simultaneously.

[0023] The case 16, which serves as the storage area, is a flat, roughly rectangular parallelepiped extending to the left and right, with a rectangular opening at its rear end. As shown in Figures 2 and 3, it comprises a roughly rectangular bottom wall portion 16a into which the inflators 12L and 12R are inserted and mounted from the front, and a peripheral wall portion 16b extending rearward from the outer edge of the bottom wall portion 16a to engage with the connecting wall portion 10b of the airbag cover 10. The case 16 is located on the lower 1a side of the instrument panel 1 (a position separated from the upper surface 2 of the instrument panel 1), specifically, above and in front of the knees K of an occupant MP seated in the passenger seat, with its axial direction aligned with the front-rear direction (horizontal direction) (see Figure 1). The opening at the rear end of the case 16 constitutes a protruding opening 17 into which the airbag 20, which inflates by allowing inflation gas to flow into it, can be projected towards the rear. In this embodiment, the airbag 20 and each inflator 12L, 12R are attached to the bottom wall 16a of the case 16 by fastening nuts 14 through the periphery of the intake openings 28L, 28R in the airbag 20 (described later), the bottom wall 16a of the case 16, and the flange portion 12c of each inflator 12L, 12R, using the bolts 13a of each retainer 13L, 13R disposed inside the airbag 20 as mounting means. The nuts 14 fasten these bolts 13a through the periphery of the intake openings 28L, 28R in the airbag 20, the bottom wall 16a of the case 16, and the flange portion 12c of each inflator 12L, 12R. This case 16 is connected to the vehicle body using a bracket (not shown).

[0024] The airbag 20 is formed from a flexible sheet body and, as shown in Figures 4-7, comprises a separate bag-shaped upper body protection section 21 and a knee protection section 72. The upper body protection section 21 is connected to the right inflator 12R and is configured to allow the inflation gas G1 discharged from the inflator 12R to flow into its interior, while the knee protection section 72 is connected to the left inflator 12L and is configured to allow the inflation gas G2 discharged from the inflator 12L to flow into its interior (see Figure 21). The upper body protection section 21 and the knee protection section 72 are completely separated and configured to prevent the inflation gas from moving between them once it has flowed inside. Furthermore, the lower inflation section 24 of the upper body protection section 21, which will be described later, and the knee protection section 72 are interconnected by lower regulating tethers 97L and 97R.

[0025] The upper body protection section 21 is positioned in front of the upper body MU of the crew member MP when inflation is complete, and as shown in Figures 4 to 7, it comprises an upper inflation section 38 and a lower inflation section 24, which are separate bag-shaped parts. The upper inflation section 38 and the lower inflation section 24 are connected to each other via a communication hole 50 and are joined at the periphery of the communication hole 50 (see Figures 7 to 9).

[0026] The lower expansion section 24 is a part that is connected to the inflator 12R and expands to protrude rearward from the case 16. The lower expansion section 24 has a roughly rectangular plate shape when fully expanded. The lower expansion section 24 comprises a left wall section 26 and a right wall section 27 that are arranged to face each other in the left-right direction when fully expanded, and a peripheral wall section 25 that connects the left wall section 26 and the right wall section 27 to form a region extending from front to back and up to down when fully expanded (see Figures 7 and 8). As described above, this lower expansion section 24 is connected to the knee protection section 72 by lower regulating tethers 97L and 97R. Specifically, the lower expansion section 24 is connected on its left and right edges, respectively, to the protective body section 73 of the knee protection section 72, which will be described later, and more specifically, to the vicinity of the upper ends 75a of the left side section 75L and the right side section 75R of the protective body section 73, which will be described later, by lower regulating tethers 97L and 97R.

[0027] At the front end of the peripheral wall portion 25, two circular inlet openings 28L and 28R are arranged side by side on the left-right side, with their peripheries attached to the bottom wall portion 16a of the case 16 (see Figures 5, 11, and 15). These inlet openings 28L and 28R are for connecting the inflators 12L and 12R, and multiple (four in this embodiment) mounting holes 29L and 29R are formed around the periphery of each inlet opening 28L and 28R for inserting the bolts of the retainers 13L and 13R to attach the periphery of each inlet opening 28L and 28R to the bottom wall portion 16a of the case 16 (see Figures 5 and 15). In this embodiment, the inlet opening 28R on the right side is for connecting the inflator 12R, and the expansion gas G1 discharged from the inflator 12R flows into the lower expansion section 24 through this inlet opening 28R (see Figures 7, 19, and 21). The inlet opening 28L on the left side is for connecting the inflator 12L, and the gas passage section 85 of the knee protection section 72, described later, is arranged inside the lower expansion section 24 so as to cover the entire outer circumference of this inlet opening 28L (see Figures 10, 12, 20, and 21). Then, as shown in Figures 10, 20, and 21, the expansion gas G2 discharged from the inflator 12L flows into the knee protection section 72 through this inlet opening 28L. In other words, in the airbag 20 of this embodiment, the front end of the lower inflation section 24 is connected to the case 16 side by two inflow openings 28L and 28R, which are wide on both sides. However, the lower inflation section 24 allows the inflation gas G1 to flow into the interior only from the front right end region.

[0028] In the peripheral wall portion 25, on the left side of a position forward of the front-to-back center of the lower portion constituting the lower surface side of the lower expansion portion 24 (within the area of ​​the front lower portion 25c, adjacent to the inlet opening 28L), an opening 30 is formed in a circular shape, corresponding to the outlet hole 92 formed in the gas flow path portion 85 that allows expansion gas to flow out to the protective body portion 73 of the knee protection portion 72 (see Figures 10-12, 15). The area around this opening 30, along with the inlet opening 28L, is covered all around the outer circumference by the gas flow path portion 85. In addition, in the peripheral wall portion 25, an opening 31 constituting a communication hole 50 is formed at a position slightly backward of the front-to-back center of the upper portion constituting the upper surface side of the lower expansion portion 24 (the rear upper portion 25b, which is the upper surface side of the rear region 24b, described later) (see Figures 5, 7-9, 15). In this embodiment, the opening 31 is circular and two are arranged side by side on the left-right side. Furthermore, connecting pieces 35L and 35R, which constitute the lower restricting tethers 97L and 97R, are formed on the upper left and upper right edges (upper edges 26a and 27a of the left wall portion 26 and the right wall portion 27) of the lower expansion portion 24. Each connecting piece 35L and 35R is formed as a strip that is roughly aligned with the front-rear direction, at a position slightly forward of the center of the front-rear upper edge of the left wall portion 26 and the right wall portion 27 (see Figures 5 and 15). In this embodiment, the connecting pieces 35L and 35R are formed to protrude from near the boundary between the front upper portion 117a and the rear upper portion 117b of the outer peripheral edge 117L and 117R of the lower wall panels 116L and 116R, which will be described later and constitute the left wall portion 26 and the right wall portion 27 (see Figure 15).

[0029] The lower expansion section 24 comprises a front region 24a that is positioned inside the case 16 when inflation is complete, and a rear region 24b that is positioned behind the front region 24a and below the upper expansion section 38 when inflation is complete (see Figures 19 and 20). The inlet openings 28L and 28R and mounting holes 29L and 29R are located on the front end side of the front region 24a, the opening 30 constituting the outlet hole 92 is located on the lower surface side of the front region 24a, and the opening 31 constituting the communication hole 50 is located on the upper surface side of the rear region 24b (see Figures 5 and 7). In the airbag 20 of this embodiment, when the lower expansion section 24 is in an inflated state when mounted in a vehicle and viewed from the left and right sides, as shown in Figures 19 and 20, the front region 24a is positioned along the front-rear direction (horizontal direction), and the rear region 24b is positioned to be tilted upwards with respect to the front-rear direction (horizontal direction). In the front region 24a, when the expansion is complete while the unit is inflated on its own, the width dimension (width dimension in the left-right direction) is kept approximately constant throughout the entire front-to-rear area, and the thickness dimension is also kept approximately constant throughout the entire front-to-rear area (see Figures 4, 5, and 7). In the rear region 24b, the thickness dimension T1 when the expansion is complete (thickness dimension when the external shape when the expansion is complete is viewed from the left and right sides) is set to be larger than the thickness dimension T2 of the front region 24a when the expansion is complete (see Figure 4). Furthermore, the upper surface of this rear region 24b when the expansion is complete (the rear upper part 25b, which is the area in the peripheral wall 25 where the opening 31 constituting the communication hole 50 is located) is also tilted upwards with respect to the horizontal direction when the expanded state when mounted on a vehicle is viewed from the left and right sides (see Figure 20). The difference in thickness between the front region 24a and the rear region 24b, as well as the upward slope of the rear region 24b, are due to the external shape of the pair of left and right lower wall panels 116L and 116R (see Figure 15), which will be described later and constitute the left wall portion 26 and the right wall portion 27 in the lower expansion portion 24.

[0030] The rear upper portion 25b, which constitutes the upper surface of the rear region 24b, is positioned to be tilted upward relative to the rear in the horizontal direction when the airbag 20 is viewed from the left and right sides after inflation is complete in the vehicle-mounted state (see Figure 20). This rear region 24b is configured to support the rear lower end of the upper inflation portion 38 when inflation is complete, and the width dimension of the upper surface (rear upper portion 25b) in the left-right direction is configured to be approximately the same as the width dimension of the rear lower surface (rear portion 42b of the lower wall portion 42, which will be described later) of the upper inflation portion 38 (see Figure 6). Furthermore, in this embodiment, as shown in Figure 7, the rear region 24b is configured to be positioned such that when inflation is complete, the rear end 24ba is approximately the same as the rear end 38ba of the upper inflation portion 38 in the front-rear direction. Furthermore, the rear region 24b is shaped like a trapezoid, with its completed inflation shape narrowing downwards when viewed from the rear (see Figure 6). In the upper body protection portion 21 of the airbag 20 of this embodiment, the upper inflation portion 38 is also configured to narrow downwards when viewed from the rear, and the rear region 24b is configured such that the left and right edges of the completed inflation shape when viewed from the rear are connected to the outline of the upper inflation portion 38 (see Figure 6).

[0031] The upper inflatable section 38 is bag-shaped and communicates with the lower inflatable section 24 via a communication hole 50. This upper inflatable section 38 is a part that protects the upper body MU of the occupant MP seated in the passenger seat, and when fully inflated, it is positioned to close the space between the upper surface 2 of the instrument panel 1 and the front windshield 5 located above the instrument panel 1, and its rear lower side is supported by the lower inflatable section 24 (see Figure 19). As shown in Figures 4 to 7, the upper inflatable section 38 comprises a front wall section 39 and a rear wall section 40 that face each other in the front-rear direction when fully inflated, an upper wall section 41 and a lower wall section 42 that face each other in the up-down direction when fully inflated, and a left wall section 43 and a right wall section 44 that face each other in the left-right direction when fully inflated. Furthermore, in the upper body protection section 21 of the airbag 20 in this embodiment, the upper inflatable section 38 has a rear region 38b (the region on the rear wall section 40 side) that is positioned on the occupant MP side when the airbag 20 is fully inflated, which is wide from side to side to accurately protect the upper body MU of the occupant MP, while the front region 38a that is positioned on the front side is narrow from side to side (see Figure 5). In this embodiment, as shown in Figure 5, the width dimension of the front region 38a in the left-right direction when inflation is fully inflated is set to be smaller than the width dimension of the front region 24a in the left-right direction of the lower inflatable section 24.

[0032] In the upper inflatable section 38, the rear wall section 40 is positioned to substantially follow the vertical direction in front of the upper body MU of the occupant MP seated in the passenger seat when the airbag 20 has finished inflating, and is the part that receives and protects the upper body MU of the occupant MP as it moves forward. The width dimensions of the rear wall section 40 are set to dimensions that can receive and protect the upper body MU of the occupant MP. Specifically, the outer shape of the rear wall section 40 when viewed from the rear is a substantially inverted trapezoid shape, with the upper part being wider from left to right and narrowing towards the lower end (see Figure 6). The upper wall section 41 is positioned at a downward slope when the airbag 20 has finished inflating, and is the part that comes into contact with the front windshield 5. The front part 42a of the lower wall section 42 is the part that comes into contact with the upper surface 2 of the instrument panel 1 when the airbag 20 has finished inflating (see Figure 19). The rear portion 42b of the lower wall portion 42 is positioned one level below the front portion 42a when the airbag 20 has finished inflating, and is positioned in contact with the rear upper portion 25b of the peripheral wall portion 25 of the lower inflation portion 24 (see Figure 19). The front wall portion 39 is positioned substantially along the vertical direction so as to connect the front end of the upper wall portion 41 and the front end of the front portion 42a of the lower wall portion 42. In the airbag 20 (upper body protection portion 21) of this embodiment, the front wall portion 39 (front end 38aa when the upper inflation portion 38 has finished inflating) is configured to be positioned in front of the front end (inlet opening 28L, 28R) of the lower inflation portion 24. That is, when the airbag 20 has finished inflating, the upper inflation portion 38 is configured so that its front end 38aa is positioned in front of the case 16, as shown in Figure 19. The left wall 43 and the right wall 44 have vent holes 46 that open in a roughly circular shape to exhaust excess expansion gas that has flowed into the upper expansion section 38. Each vent hole 46 is located near the front upper edge of the left wall 43 and the right wall 44 (a position in front of the internal tether 55, which will be described later, and within the front region 38a of the upper expansion section 38).

[0033] In the rear portion 42b of the lower wall portion 42 (the area on the lower surface side of the rear region 38b of the upper expansion portion 38, which is supported by the lower expansion portion 24 when inflation is complete), an opening 47 constituting a communication hole 50 is formed, corresponding to the opening 31 formed in the rear upper portion 25b of the peripheral wall portion 25 of the lower expansion portion 24 (see Figures 5, 7, 8, 14). The opening 47 is circular and two are arranged side by side on the left-right side. That is, in the upper body protection portion 21 of the airbag 20 of this embodiment, two communication holes 50 that connect the upper expansion portion 38 and the lower expansion portion 24 are arranged side by side on the left-right side. In detail, when the airbag 20 is inflated, the communication holes 50 are formed at two locations symmetrically on the left and right sides with respect to the center of the left and right sides of the airbag 20 (see Figures 5, 8).

[0034] The upper expansion portion 38 and the lower expansion portion 24 are interconnected by sewing the rear portion 42b of the lower wall portion 42 and the rear upper portion 25b of the peripheral wall portion 25 together using sutures at the periphery of the communication hole 50 (the periphery of each opening 31, 47). In this embodiment, the suture portion 51 connecting the upper expansion portion 38 and the lower expansion portion 24 (the rear portion 42b and the rear upper portion 25b) is formed in a double layer so as to surround the two communication holes 50 around their entire circumference, as shown in Figure 9. More specifically, in the suture portion 51, the inner portion 51a, which is positioned on the inside, is oval-shaped with a wide width on both sides so as to surround the two communication holes 50. The outer portion 51b, positioned on the outside, surrounds the inner portion 51a and is roughly rectangular in shape, such that the front region (the region in front of the communication hole 50) when inflation is complete is further away from the inner portion 51a than the rear region. More specifically, the width dimension of the outer portion 51b in the left-right direction is set to be slightly narrower than the width dimension in the left-right direction of the rear portion 42b of the lower wall portion 42 in the upper inflation portion 38 and the rear upper portion 25b of the peripheral wall portion 25 in the lower inflation portion 24 (see Figures 8 and 9). In other words, in the upper body protection portion 21 of the airbag 20 of this embodiment, the upper inflation portion 38 and the lower inflation portion 24 are interconnected by joining the rear portion 42b of the lower wall portion 42 and the rear upper portion 25b of the peripheral wall portion 25, which constitute the periphery of the communication hole 50, by suture portions 51 over substantially the entire left and right sides. To put it another way, in the upper body protection section 21 of the embodiment, the rear portion 42b of the lower wall portion 42 of the upper inflatable section 38 and the rear upper portion 25b of the peripheral wall portion 25 of the lower inflatable section 24 are sewn together and integrated at the front region that forms the periphery of the communication hole 50. When the airbag 20 is fully inflated during vehicle installation, the rear portion 42b and the rear upper portion 25b are positioned at an upward and backward angle relative to the horizontal direction (see Figure 20).

[0035] In the upper body protection section 21 of the airbag 20 of this embodiment, an internal tether 55 that restricts the completed inflation shape of the upper inflation section and a flow straightening cloth 63 that can straighten the inflation gas G1 flowing into the upper inflation section 38 are provided inside the upper inflation section 38 (see Figure 7).

[0036] The internal tether 55 is, in detail, disposed within the rear region 38b of the upper expansion section 38. In this embodiment, it has a left-right connecting section 56 that connects the left wall section 43 and the right wall section 44, and a front-rear connecting section 57 that connects the left-right connecting section 56 and the rear wall section 40. When viewed from the vertical direction, it has a flattened, approximately Y-shape (see Figure 5). The left-right connecting section 56 is formed from a flexible, strip-shaped sheet body. Both ends are joined at a position slightly behind the front-rear center of the left wall section 43 and the right wall section 44, and near the vertical center, with the width direction approximately aligned with the vertical direction. When the expansion of the upper expansion section 38 is complete, it is bent and positioned so that the left-right center is slightly behind. In this embodiment, the left-right connecting section 56 is constructed by arranging two tether base materials 59, 59, as shown in Figure 14, side by side on the left-right side (see Figure 5). The front-rear connecting portion 57 is positioned to connect the left and right centers of the left and right connecting portions 56 and the approximate center of the top, bottom, left, and right of the rear wall portion 40. It is formed from a flexible, strip-shaped sheet body, and is positioned so that its width is approximately aligned with the vertical direction, and when the expansion of the upper expansion portion 38 is complete, it is positioned approximately along the front-rear direction. In this embodiment, the front-rear connecting portion 57 is configured such that the rear end, which is connected to the rear, is slightly wider than the front end, which is connected to the left and right connecting portions 56 (see Figure 7). The internal tether 55 is positioned to suppress excessive outward protrusion of the left wall portion 43 and the right wall portion 44 in the upper inflation portion 38, and excessive rearward protrusion of the rear wall portion 40, when the airbag 20 is deployed and inflated. It also regulates the separation distance between the left wall portion 43 and the right wall portion 44 when inflation is complete, and regulates excessive rearward protrusion of the rear wall portion 40 (regulating the separation distance between the left and right connecting portions 56 and the rear wall portion 40).

[0037] The rectifying cloth 63 is arranged inside the upper expansion section 38 so as to cover the area around the communication hole 50 (specifically, above the communication hole 50) (see Figures 7 and 8). This rectifying cloth 63 is configured to rectify the expansion gas G1 flowing into the interior through the communication hole 50, and is specifically configured to rectify the expansion gas G1 flowing in from the communication hole 50 so that it flows outwards to the left and right and forward. The rectifying cloth 63 is constructed to cover the area above the communication hole 50 by sewing its front edge 63a and rear edge 63b to the rear portion 42b of the lower wall 42 of the upper expansion section 38, respectively, in front of and behind the communication hole 50, and has openings 65, 65 for gas outflow at the left end 63c and the right end 63d, respectively. Furthermore, in the rectifying cloth 63, a gas outlet hole 66 is provided in the front region 63e, which is located at the front, allowing the expansion gas G1 to flow out. In this embodiment, the gas outlet hole 66 is provided as a single circular opening in the center of the front region 63e, which will be described later, that constitutes the rectifying cloth 63 (see Figure 15). In this embodiment, the rectifying cloth 63 is composed of a front member 68 and a rear member 69 as shown in Figure 15. The front member 68 and the rear member 69 are set to have substantially the same external shape, and the rectifying cloth 63 is constructed by sewing the upper edges 68a and 69a to each other and sewing the lower edges 68b and 69b to the rear portion 42b of the lower wall portion 42, respectively. The upper edges 68a and 69a of the front member 68 and the rear member 69 are formed in an arc shape that protrudes upward from the center.

[0038] Furthermore, in the upper body protection portion 21 of the airbag 20 of this embodiment, the separation distance D1 (see Figure 4) between the front end (intake opening 28L, 28R) of the lower inflation portion 24 and the front portion 42a of the lower wall portion 42 of the upper inflation portion 38, when viewed from the left or right side in a state where the airbag is inflated on its own, is set to be smaller than the separation distance D2 (see Figure 2) between the intake opening (i.e., the front end of the case 16) of the airbag 20 when it is mounted in a vehicle and viewed from the left or right side, and the front portion of the lower wall portion 42 of the upper inflation portion 38 (i.e., the upper surface 2 of the instrument panel 1).

[0039] In this embodiment, the knee protection section 72 includes a protective body section 73 that expands to protrude below the upper body protection section 21, and a gas passage section 85 that allows expansion gas G2 to flow into the protective body section 73. As described above, the knee protection section 72 is connected to the lower expansion section 24 by lower restricting tethers 97L and 97R.

[0040] In this embodiment, the protective body 73 deploys so as to protrude downward from the case 16 when the airbag 20 is deployed and inflated. The protective body 73 is configured to cover the front of the left and right knees K of the occupant MP when inflation is complete. In detail, its external shape is configured as a roughly U-shaped plate that is positioned from the area below the upper body protective body 21 (lower inflation section 24) to the left and right lateral areas of the lower inflation section 24 when the airbag 20 is viewed from the rear when inflation is complete (see Figures 4-7). That is, the protective body 73 is positioned in the area from below the case 16 to the left and right lateral areas when the airbag 20 is complete. The protective body 73 includes a central section 74 positioned below the lower inflation section 24 when inflation is complete, and a left section 75L and a right section 75R positioned along the vertical direction to the left and right of the lower inflation section 24 when inflation is complete. The protective body 73 is configured to be positioned along the rear surface 3 of the instrument panel 1 when the airbag 20 has finished inflating, and the left portion 75L and the right portion 75R are configured so that their upper ends 75a are positioned to coincide with the upper surface of the lower inflation portion 24 (see Figure 20). The protective body 73 also includes a front wall portion 77 positioned on the instrument panel 1 side when inflation is complete, a rear wall portion 78 positioned on the occupant MP side, and a connecting wall portion 79 that constitutes the upper end region when inflation is complete and is connected to the upper body protection portion 21 (specifically the lower inflation portion 24) (see Figure 10). The front wall portion 77 and the rear wall portion 78 have an outer shape that is approximately the same, a roughly U-shape (see Figure 16). The connecting wall portion 79 extends from the upper surface of the central portion 74 to the inner surfaces of the left portion 75L and the right portion 75R (see Figures 10 and 11), and is elongated in the left-right direction (see Figure 16). The protective body portion 73 is formed into a bag shape by connecting the outer edges 77a and 78a of the front wall portion 77 and the rear wall portion 78 to each other (and the outer edges 120a of the main body panel 120, which will be described later), and connecting the inner edges 77b and 78b of the front wall portion 77 and the rear wall portion 78 to the front edge 79a and rear edge 79b of the connecting wall portion 79 (and the inner edge 120b of the main body panel 120 and the front edge 121a and rear edge 121b of the connecting wall panel 121, which will be described later).

[0041] The protective body portion 73 is connected to the lower expansion portion 24 by sewing the area near the center of the connecting wall portion 79 (the area on the upper side of the central portion 74) to the front lower portion 25c of the peripheral wall portion 25 of the lower expansion portion 24 using suture thread. The suture portion 82 connecting the protective body portion 73 and the lower expansion portion 24 (the connecting wall portion 79 and the front lower portion 25c) is shaped like a roughly elongated oval extending in the left-right direction, and is formed to surround the entire circumference of the opening 30 formed in the front lower portion 25c corresponding to the outflow hole 92 (see Figures 11, 12, 15, and 16). The suture portion 82 is arranged over almost the entire left and right sides of the front lower portion 25c (see Figures 11 and 15). In the region surrounded by the sutured portion 82 in the connecting wall portion 79, an opening 83 constituting the outflow hole 92 is formed corresponding to the opening 30 (see Figures 12 and 16). On the inner edge 75b side of the left portion 75L and the right portion 75R of the protective body portion 73, connecting pieces 84L and 84R constituting the lower restricting tethers 97L and 97R are formed corresponding to the connecting pieces 35L and 35R formed in the lower expansion portion 24 (see Figure 16). Each connecting piece 84L and 84R is formed at a position on the inner edge 75b side (more specifically, the inner edge 78b side near the upper end 75a of the left portion 75L and the right portion 75R) In this embodiment, the connecting pieces 84L and 86R are formed on the inner edge 120b side of the region constituting the rear wall portion 78 in the main body panel 120 that constitutes the region between the front wall portion 77 and the rear wall portion 78 of the protective main body portion 73 of the knee protection portion 72 (see Figure 16).

[0042] The gas passage section 85 is positioned within the lower expansion section 24 of the upper body protection section 21 to connect the inlet opening 28R and the protective body section 73. It extends rearward from the periphery of the inlet opening 28R so as to cover the inlet opening 28R, and has an outlet hole 92 at its tip for releasing the expansion gas G2 into the protective body section 73. It is roughly cylindrical in shape (see Figures 10-12). More specifically, the gas passage section 85 has an upper wall section 86 and a lower wall section 87 that are positioned opposite each other in the vertical direction when the airbag 20 has completed inflation (see Figures 10 and 12). The upper wall section 86 and the lower wall section 87 have the same external shape and are elongated oval in shape extending in the front-rear direction (see Figure 15). The gas passage section 85 is formed into a cylindrical shape by connecting the outer edges of the upper wall section 86 and the lower wall section 87 around its entire circumference. Openings 88 and 89 are formed on the front end of the lower wall portion 87, corresponding to the inlet opening 28L and the mounting hole 29L, and an outlet hole 92 is formed as a circular opening on the rear end of the lower wall portion 87 (see Figures 10 and 15). The gas flow path portion 85 is attached to the inner circumferential surface of the lower expansion portion 24 and is connected to the protective body portion 73, by sewing (joining) the periphery of the opening 88 in the lower wall portion 87 to the periphery of the inlet opening 28L in the peripheral wall portion 25 of the lower expansion portion 24 so as to form a suture portion 94, and by sewing (joining) the periphery of the outlet hole 92 to the periphery of the opening 83 formed in the connecting wall portion 79 and the periphery of the opening 30 formed in the front lower part 25c of the peripheral wall portion 25 of the lower expansion portion 24 so as to form a suture portion 95.

[0043] The lower restrictive tethers 97L and 97R connecting the lower inflatable portion 24 of the upper body protection portion 21 and the knee protection portion 72 are composed of connecting pieces 35L and 35R that extend from the lower inflatable portion 24 and connecting pieces 84L and 84R that extend from the knee protection portion 72, as described above (see Figure 13). In detail, the lower restrictive tethers 97L and 97R are formed by sewing (joining) the ends of the connecting pieces 35L and 35R and the connecting pieces 84L and 84R together. In detail, the connecting pieces 35L and 35R formed on the lower inflatable portion 24 side are formed to extend from the upper left edge and upper right edge (upper edges 26a and 27a of the left wall portion 26 and right wall portion 27) of the lower inflatable portion 24. The connecting pieces 84L and 84R formed on the knee protection portion 72 are formed to extend from the inner edge 75b side (more specifically, the inner edge 78b side of the rear wall portion 78) at a position near the upper end 75a of the left portion 75L and right portion 75R of the protective body portion 73. In other words, in this embodiment, the lower regulating tethers 97L and 97R are arranged to connect the left upper edge side or the right upper edge side (the upper edges 26a and 27a sides of the left wall portion 26 and right wall portion 27) of the lower inflation portion 24 with the inner rear edge side near the upper end 75a of the left portion 75L or right portion 75R when the airbag 20 has finished inflating.

[0044] In the airbag 20 of this embodiment, the upper inflatable section 38 and lower inflatable section 24 of the upper body protection section 21, and the protective main body section 73 of the knee protection section 72 are each constructed in a bag shape by joining the periphery edges of a predetermined shape base material (base fabric). The upper inflatable section 38 is composed of one upper peripheral wall panel 100 and a pair of left and right upper wall panels 106L and 106R (see Figure 14). The lower inflatable section 24 is composed of one lower peripheral wall panel 110 and a pair of left and right lower wall panels 116L and 116R (see Figure 15). The protective main body section 73 is composed of a main body panel 120 and a connecting wall panel 121 (see Figure 16). In addition, the gas flow path section 85 in the knee protection section 72 is composed of one flow path section panel 125 as shown in Figure 15.

[0045] The upper peripheral wall panel 100 constitutes the upper wall portion 41, rear wall portion 40, lower wall portion 42, and front wall portion 39 of the upper expansion portion 38. As shown in Figure 14, the upper peripheral wall panel 100 has an outer shape that is roughly symmetrical and roughly strip-shaped. Lower rear components 102A and 102B, which constitute the rear portion 42b of the lower wall portion 42 (the peripheral portion of the communication hole 50), are arranged at both ends. Between these lower rear components 102A and 102B, a narrow portion 103, which constitutes the portion from the front portion 42a of the lower wall portion 42 through the front wall portion 39 to the front of the upper wall portion 41, and a wide portion 104, which constitutes the region from the rear of the upper wall portion 41 to the rear wall portion 40, are arranged in series.

[0046] The left and right upper wall panels 106L and 106R constitute the left wall portion 43 and the right wall portion 44 that face each other in the left-right direction when the expansion is complete in the upper expansion portion 38, and their external shapes are symmetrical (see Figure 14). At the outer edges 107L and 107R of the upper wall panels 106L and 106R, the lower front portion 107a that constitutes the left or right edge of the front portion 42a of the lower wall portion 42 and the lower rear portion 107b that constitutes the left or right edge of the rear portion 42b of the lower wall portion 42 are formed to be approximately parallel while having a step difference.

[0047] The upper expansion portion 38 is formed into a bag shape by overlapping the lower rear components 102A and 102B of the upper periphery wall panel 100, sewing the front and rear edges 100a and 100b together, and sewing the left edge 100c and right edge 100d of the upper periphery wall panel 100 to the outer edges 107L and 107R of the upper wall panels 106L and 106R, respectively.

[0048] The lower peripheral wall panel 110 constitutes the peripheral wall portion 25 in the lower expansion portion 24, and as shown in Figure 15, its outer shape is roughly symmetrical and roughly strip-shaped. The lower peripheral wall panel 110 has front end components 112A and 112B at both ends, which constitute the front end region of the peripheral wall portion 25 (the peripheral portion of the inflow openings 28L and 28R). Between these front end components 112A and 112B, a rear upper surface component 113, which constitutes the rear upper portion 25b of the peripheral wall portion 25 (the peripheral portion of the communication hole 50), and a lower surface component 114, which constitutes the region from the rear end to the bottom of the peripheral wall portion 25, are arranged in series. The lower surface component 114 is configured to be narrow in the intermediate portions between the front and rear.

[0049] The left and right pair of lower wall panels 116L and 116R constitute the left wall portion 26 and the right wall portion 27 that face each other in the left-right direction when the expansion is complete in the lower expansion portion 24, and their external shapes are symmetrical (see Figure 15). Connecting pieces 35L and 35R that constitute the lower regulating tethers 97L and 97R are provided on each lower wall panel 116L and 116R. At the outer peripheral edges 117L and 117R of the lower wall panels 116L and 116R, the front upper portion 117a, which constitutes the upper edge of the front region 24a (the left or right edge of the front upper portion 25a of the peripheral wall portion 25), and the rear upper portion 117b, which constitutes the upper edge of the rear region 24b (the left or right edge of the rear upper portion 25b of the peripheral wall portion 25), are arranged to intersect at an obtuse angle. Furthermore, the front upper portion 117a is slightly inclined upward towards the rear with respect to the front lower portion 117c, which forms the lower edge of the front region 24a. That is, the rear upper portion 117b of the outer peripheral edges 117L and 117R is inclined upward towards the rear with respect to the front upper portion 117a. In the outer peripheral edges 117L and 117R of the lower wall panels 116L and 116R, the rear lower portion 117d, which forms the lower edge of the rear region 24b, is arranged to curve downwards with respect to the rear upper portion 117b, which is formed in a substantially straight line.

[0050] The lower expansion portion 24 is formed into a bag shape by overlapping the front end components 112A and 112B of the lower peripheral wall panel 110, sewing the front and rear edges 110a and 110b together, and sewing the left edge 110c and right edge 110d of the lower peripheral wall panel 110 to the outer edges 117L and 117R of the lower wall panels 116L and 116R, respectively.

[0051] The main body panel 120 constitutes the area between the front wall portion 77 and the rear wall portion 78 of the protective main body portion 73 of the knee protection portion 72. As shown in Figure 16, it is a roughly rectangular ring shape with the front wall portion 77 and the rear wall portion 78 connected to each other at their upper ends. Connecting pieces 84L and 84R, which constitute the lower regulating tethers 97L and 97R, are arranged on the inner edge 120b side of the area constituting the rear wall portion 78 of the main body panel 120. The connecting wall panel 121 constitutes the area of ​​the connecting wall portion 79 of the protective main body portion 73 and is a roughly wide, strip-shaped panel. Specifically, as shown in Figure 16, the connecting wall panel 121 has a constant width dimension for the central side portion that constitutes the upper surface side of the central portion 74, and the width dimension of the left end region and the right end region gradually decreases towards the edges. The protective body portion 73 of the knee protection portion 72 is formed into a bag shape by folding the main body panel 120 in half, sewing the outer edges 120a together, and sewing the inner edges 120b to the front edge 121a and rear edge 121b of the connecting wall panel 121, respectively. The flow channel panel 125 that constitutes the gas flow channel portion 85 of the knee protection portion 72 has a shape in which an upper wall portion 86 and a lower wall portion 87 are arranged side by side on the left and right (see Figure 15). The gas flow channel portion 85 is formed into a bag shape by folding this flow channel panel 125 in half and joining the corresponding outer edges 125a together.

[0052] In the embodiment, as shown in Figures 14 to 16, the upper perimeter wall panel 100, upper side wall panels 106L, 106R, lower perimeter wall panel 110, lower side wall panels 116L, 116R, main body panel 120, connecting wall panel 121, and flow path panel 125 that constitute the airbag 20, the left and right connecting parts 56 (tether base materials 59, 59) and front and rear connecting parts 57 that constitute the internal tether 55, and the front side member 68 and rear side member 69 that constitute the rectifying cloth 63 are each formed from a flexible woven fabric made of polyester yarn, polyamide yarn, etc.

[0053] Next, the installation of the airbag device M of the embodiment into a vehicle will be described. First, the airbag 20 is folded so that it can be stored in the case 16 with the retainers 13L and 13R stored inside. The airbag 20 is folded so that the width dimensions in the front / back (up / down) and left / right directions are reduced from the state of the spare folded bag 130 as shown in Figures 17A and B. As shown in Figures 17A and B, the spare folded bag 130 is in a state where the upper inflatable part 38 and lower inflatable part 24 of the upper body protection part 21 and the protective body part 73 of the knee protection part 72 are laid flat and overlapped with each other. Specifically, in the spare folding bag 130, the upper inflatable portion 38 is folded in the areas of the upper wall portion 41, lower wall portion 42, left wall portion 43, and right wall portion 44, with folds made in these areas, so that the rear wall portion 40 is laid flat over almost the entire area and overlapped with the front wall portion 49, thereby forming the upper portion 131. In the knee protection portion 72, the protective main body portion 73 is arranged so that the front wall portion 77 and the rear wall portion 78 are laid flat and overlapped, thereby forming the lower portion 132. The lower inflatable portion 24 is folded in half in the front-rear direction, so that the front area is laid over the front wall portion 77 of the protective main body portion 73, and the rear area is laid over the rear wall portion 78 of the protective main body portion 73.

[0054] First, the spare folding bag 130 is formed by rolling the lower portion 132 from the lower edge 132a towards the front wall portion 77 to form the lower roll folding portion 135, and this lower roll folding portion 135 is placed on top of the inflow openings 28L and 28R (see Figure 17B and Figure 18A). At this time, the protective main body portion 73 and a part of the lower expansion portion 24 of the upper body protective portion 21 are folded together. Next, the upper portion 131 is formed by rolling it from the upper edge 131a towards the front wall portion 39 to form the upper roll folding portion 136, and this upper roll folding portion 136 is placed on top of the lower roll folding portion 135 to form the upper and lower reduced folding bag 138 (see Figure 18B and C). In this vertically retractable folding bag 138, by folding the left end 135a and the right end 135b of the lower roll folding portion 135 so that they overlap onto the upper roll folding portion 136, the upper body protection portion 21 and the knee protection portion 72 (protective main body portion 73) are folded together, completing the folding of the airbag 20 and forming the folded complete body 140 (see Figures 18C and 18D).

[0055] The folded body 140 formed in this manner is wrapped with a tearable wrapping sheet (not shown) to prevent it from collapsing. The folded body 140 is then housed in the case 16 with each bolt 13a protruding from the bottom wall 16a. Next, the main body 12a of each inflator 12L, 12R is inserted into the case 16 from below the bottom wall 16a (from the front when mounted in a vehicle), and the bolts 13a of the retainers 13L, 13R protruding from the bottom wall 16a are inserted through the flange portions 12c of each inflator 12L, 12R. After that, nuts 14 are fastened to each bolt 13a protruding from the flange portions 12c of each inflator 12L, 12R, thereby attaching the folded airbag 20 and inflators 12L, 12R to the case 16.

[0056] Subsequently, the peripheral wall portion 16b of the case 16 is locked to the connecting wall portion 10b of the airbag cover 10 on the instrument panel 1 mounted on the vehicle, a bracket (not shown) provided on the case 16 is fixed to the vehicle body, and the inflators 12L and 12R are electrically connected to an airbag operating circuit (not shown), thereby enabling the airbag device M to be mounted on the vehicle.

[0057] In the airbag device M of this embodiment, after being installed in the vehicle, when inflation gas is discharged from the gas outlets 12b of each inflator 12L, 12R, the airbag 20 inflates by allowing the inflation gas to flow into it, causing it to push open the door portion 10a of the airbag cover 10. The airbag 20 then protrudes rearward from the case 16 through the protruding opening 17 of the case 16 formed by pushing open the door portion 10a of the airbag cover 10, and expands vertically, completing the inflation as shown by the dashed line in Figure 1 and in Figure 19. In detail, in the airbag device M of this embodiment, each inflator 12L, 12R is configured to operate almost simultaneously, and the knee protection portion 72 completes its inflation before the upper body protection portion 21.

[0058] In the airbag device M of this embodiment, the airbag 20 is configured to inflate to cover the front of the occupant MP from the knee K to the upper body MU. The upper body protection section 21, which can protect the upper body MU, and the knee protection section 72, which can protect the knee K, are each made into separate bags and connected to separate inflators 12L and 12R. Therefore, in the airbag device M of this embodiment, when the airbag 20 is fully inflated, for example, when the knee protection section 72 (protective main body section 73) receives the knee K prior to contact between the upper body MU and the upper body protection section 21 (upper inflation section 38), the movement of inflation gas from the knee protection section 72 to the upper body protection section 21 can be suppressed. This ensures that the appropriate internal pressure of the knee protection section 72 is maintained, and the knee K can be accurately protected by the knee protection section 72. Furthermore, although the airbag device M of this embodiment is configured such that the upper body protection section 21 and the knee protection section 72 are connected to separate inflators 12L and 12R, they are arranged in a folded state within a single storage case 16. Compared to the case where the knee protection airbag device and the upper body protection airbag device are separate and mounted on the vehicle body, the mounting space can be reduced, and the number of parts and assembly man-hours can also be reduced, thus suppressing an increase in manufacturing costs.

[0059] Therefore, in the airbag device M of this embodiment, even if the configuration is such that the upper body MU and knees K are supported by the inflated airbag 20, the occupant MP can be accurately protected.

[0060] Furthermore, in the airbag device M of this embodiment, the upper body protection section 21 and the knee protection section 72 are folded together and stored in the case 16. Therefore, compared to the case in which the upper body protection section and the knee protection section are folded separately and stored in the storage section (case), the folding and storage operations can be performed more smoothly.

[0061] Furthermore, in the airbag device M of this embodiment, the knee protection section 72 (protective body section 73) is configured to receive inflation gas through a gas passage section 85, which is arranged to pass through the inside of the upper body protection section 21 (lower inflation section 24) when inflation is complete. The gas passage section 85 located inside the upper body protection section 21 (lower inflation section 24) is inflated by the inflation gas G2 discharged from the inflator 12L for the knee protection section. In other words, the volume of the upper body protection section 21 is set to be smaller by the amount of the gas passage section 85. Therefore, in the airbag device M of this embodiment, the upper body protection section 21 can be inflated quickly by the amount of the volume reduction. Furthermore, by inflating the knee protection section 72 (protective main body section 73) via the gas passage section 85 that passes through the upper body protection section 21, it is possible to suppress the protective main body section 73 (knee protection section 72) and the upper body protection section 21 (lower inflatable section 24) from pressing against each other inside or near the case 16 when inflation is complete, and it is also possible to stabilize the positional position of the protective main body section 73 (knee protection section 72) and the upper body protection section 21 (lower inflatable section 24). If these points are not taken into consideration, a knee protection section may be used that does not have a gas passage section that passes through the inside of the upper body protection section, but is instead directly connected to the inflator on the outside of the upper body protection section.

[0062] Furthermore, in the airbag device of this embodiment, the case 16, which serves as the storage area, is located on the lower side 1a of the instrument panel 1 in front of the passenger seat, and the upper body protection section 21 is configured to inflate by allowing inflation gas to flow into it, protruding from the case 16 toward the rear and expanding toward the front and upward. The upper body protection section 21 is configured as a separate bag-like structure and has a lower inflation section 24 that is connected to the inflator 12R and inflates so as to protrude toward the rear of the case 16, and an upper inflation section 38 that is connected to the lower inflation section 24 via a communication hole 50 and inflates above the lower inflation section 24. The lower inflation section 24 and the upper inflation section 38 are connected by joining them at the periphery of the communication hole 50. Therefore, in the airbag device M of this embodiment, during the initial inflation of the airbag 20, the lower inflation section 24 of the upper body protection section 21 first inflates by allowing the inflation gas G1 discharged from the inflator 12R to flow into its interior, causing it to protrude rearward from the case 16. Subsequently, the upper inflation section 38 inflates by allowing the inflation gas G1 to flow into its interior through the communication hole 50. Therefore, even if the upper body protection section 21 is configured to inflate so as to protrude rearward from the case 16 and deploy forward and upward, it is possible to suppress the upper inflation section 38, which actually receives the upper body MU of the occupant MP, from deploying so as to protrude excessively toward the occupant MP, thereby accurately protecting the upper body MU of the occupant MP. If these points are not taken into consideration, even if the configuration is such that it protrudes rearward from the storage area, the upper body protection section may be an integrated configuration without being divided into a lower inflation section and an upper inflation section.

[0063] In particular, in the airbag device M of the embodiment, the upper inflatable portion 38 of the upper body protection portion 21 is configured such that, upon completion of inflation, its front lower surface (front portion 42a of the lower wall portion 42) abuts against the instrument panel 1, its upper surface (upper wall portion 41) abuts against the front windshield 5 located above the instrument panel 1, and the rear lower surface region (rear portion 42b of the lower wall portion 42) that forms the periphery of the communication hole 50 is supported by the lower inflatable portion 24. The lower inflatable portion 24 has a rear end region (rear region 24b) that is thicker than the front end region (front region 24a) located on the case 16 side when inflation is complete, and the upper surface (rear upper portion 25b of the peripheral wall portion 25) that supports the rear lower surface of the upper inflatable portion 38 is inclined upward with respect to the horizontal direction when viewed from the left and right sides when inflation is complete. Therefore, when the upper expansion portion 38 expands, the surface of the lower expansion portion 24 on the upper expansion portion 38 side (the area forming the periphery of the communication hole 50), which has almost completed its expansion, is inclined upward towards the rear. This causes it to push the upper expansion portion 38 forward and upward, allowing the expanding upper expansion portion 38 to quickly come into contact with the front windshield 5 and the upper surface 2 of the instrument panel 1. Furthermore, when the airbag 20 has completed its expansion, the lower expansion portion 24, which supports the rear lower side of the upper expansion portion 38, has an upper surface in contact with the upper expansion portion 38 that is inclined upward towards the rear with respect to the horizontal direction. This inclination of the upper surface of the lower expansion portion 24 causes a force to act on the upper expansion portion 38, which has completed its expansion, causing it to tilt downward towards the front (pointing the front end 38aa downward). As a result, the upper expansion portion 38 is pressed against the upper surface 2 of the instrument panel 1, particularly in the area on the front end 38aa side when it is completed. Therefore, the front lower surface of the upper expansion portion 38 can be stably brought into contact with the upper surface 2 of the instrument panel 1 over its entire front-to-rear area.

[0064] Furthermore, in the airbag device M of this embodiment, the lower inflatable section 24 is made of a separate bag from the upper inflatable section 38. Therefore, when inflation is complete, the upper inflatable section 38 can be supported by bringing the peripheral areas of the communication hole 50 into contact with each other. In addition, since the rear end region (rear region 24b) of the lower inflatable section 24 is thicker than the front end region (front region 24a), the rear lower surface of the upper inflatable section 38 can be stably supported by this thicker rear region 24b, and the upper inflatable section 38 can be prevented from moving in a way that causes it to collapse downward and rearward before the occupant is caught. In other words, even if the airbag device M of the embodiment is configured to house the airbag 20 on the lower 1a side of the instrument panel 1 and inflate the upper body protection portion 21 so as to protrude rearward and expand forward and upward, the upper inflatable portion 38 of the upper body protection portion 21 can be rapidly inflated so as to come into contact with the upper surface 2 of the instrument panel 1 and the front windshield 5. Furthermore, the contact state with the upper surface 2 of the instrument panel 1 can be stably maintained when the upper inflatable portion 38 is fully inflated, and any movement of the upper inflatable portion 38 that would cause it to collapse downward and rearward after inflation is complete can also be suppressed. As a result, the upper body MU of the occupant MP can be stably protected by the upper inflatable portion 38, which is supported by the upper surface 2 of the instrument panel 1, the front windshield 5 and the lower inflatable portion 24.

[0065] Furthermore, in the upper body protection portion 21 of the airbag 20 of this embodiment, the separation distance D1 (see Figure 4) between the front end (intake opening 28L, 28R) of the lower inflation portion 24 and the front portion 42a of the lower wall portion 42 of the upper inflation portion 38, when viewed from the left and right sides in a state where the airbag is inflated on its own, is set to be smaller than the separation distance D2 (see Figure 2) between the intake opening 28L, 28R (i.e., the front end of the case 16) and the front portion 42a of the lower wall portion 42 of the upper inflation portion 38 (i.e., the upper surface 2 of the instrument panel 1) when viewed from the left and right sides in a vehicle-mounted state of the airbag 20. In other words, in this embodiment, when the airbag is installed in the vehicle, it inflates by widening the gap between the lower inflatable portion 24 and the upper inflatable portion 38, causing the upper inflatable portion 38 to press its front lower surface (front portion 42a of the lower wall portion 42) strongly against the upper surface 2 of the instrument panel 1 (to strongly interfere with it), thereby completing the inflation. As a result, the contact state with the upper surface 2 of the instrument panel 1 can be stably maintained when the inflation of the upper inflatable portion 38 is complete.

[0066] Furthermore, in the airbag device M of this embodiment, the knee protection portion 72 is configured such that the area near the upper end 75a of the left portion 75L and the right portion 75R, which are located on the left and right sides of the lower inflation portion 24, and the left and right edges (left wall portion 26 and right wall portion 27) of the lower inflation portion 24 are connected by lower restricting tethers 97L and 97R, respectively. Therefore, when the airbag 20 is fully inflated, it is possible to suppress the formation of a gap between the left and right sides of the lower inflation portion 24 and the left portion 75L and the right portion 75R of the knee protection portion 72. As a result, when the airbag 20 is fully inflated, when the knee protection portion 72 receives the occupant MP's knee K, it is possible to suppress the occupant MP's knee K from entering between the left portion 75L and the right portion 75R and the lower inflation portion 24, and the left portion 75L and the right portion 75R can effectively restrain the occupant MP's knee K.

[0067] Furthermore, the airbag 20A can also be configured as shown in Figure 22. As shown in Figures 22 to 28, the airbag 20A has a similar configuration to the aforementioned airbag 20, although its shape is slightly different except for the lower restrictive tethers 150L and 150R that connect the knee protection portion 72A and the lower inflatable portion 24A of the upper body protection portion 21A. Therefore, for components other than the lower restrictive tethers 150L and 150R, the letter "A" is added to the end of the same reference numeral, and a detailed explanation is omitted.

[0068] In the airbag 20A, the lower restrictive tethers 150L and 150R that connect the knee protection portion 72A and the lower inflatable portion 24A of the upper body protection portion 21A include a front portion 151L and 151R that is located on the front side facing the instrument panel when the airbag 20A is fully inflated, and a rear portion 156L and 156R that is located on the rear side facing the occupant (see Figure 23).

[0069] The anterior portions 151L and 151R are composed of anteromedial connecting pieces 153L and 153R that extend from the lower expansion portion 24A, and anterolateral connecting pieces 154L and 154R that extend from the knee protection portion 72A (see Figures 23 and 24). The anteromedial connecting pieces 153L and 153R formed on the lower expansion portion 24A side are, in detail, formed to extend from the left upper edge side and the right upper edge side of the lower expansion portion 24A (the upper edges 26a and 27a sides of the left wall portion 26A and the right wall portion 27A) (see Figures 23 and 24). Specifically, the anterior medial connecting pieces 153L and 153R are formed to protrude from near the boundary between the anterior upper portion 117a and the posterior upper portion 117b of the outer peripheral edges 117AL and 117AR of the lower wall panels 116AL and 116AR, which will be described later and constitute the left wall portion 26A and the right wall portion 27A (see Figure 27). The anterior lateral connecting pieces 154L and 154R formed on the knee protection portion 72A side are formed to extend from the inner anterior edge 75ba side (more specifically, the inner edge 77b side of the anterior wall portion 77A) at a position near the upper end 75a of the left portion 75AL and right portion 75AR of the protective body portion 73A. Specifically, the anterior-lateral connecting pieces 154L and 154R are formed on the inner edge 120b side of the area constituting the anterior wall portion 77A in the main body panel 120A that constitutes the area between the anterior wall portion 77A and the posterior wall portion 78A of the protective main body portion 73A of the knee protection portion 72A (see Figure 28). The anterior portions 151L and 151R are formed by sewing (joining) the tips of the anterior-medial connecting pieces 153L and 153R and the anterior-lateral connecting pieces 154L and 154R to each other (see Figures 23 and 24).

[0070] The posterior portions 156L and 156R are composed of posteromedial connecting pieces 158L and 158R that extend from the lower expansion portion 24A, and posterolateral connecting pieces 159L and 159R that extend from the knee protection portion 72A (see Figures 23 and 24). The posteromedial connecting pieces 158L and 158R formed on the lower expansion portion 24A side are, in detail, formed to extend from the left lower edge side and the right lower edge side of the lower expansion portion 24A (the lower edges 26b and 27b sides of the left wall portion 26A and the right wall portion 27A) (see Figures 23 and 24). Specifically, the posteromedial connecting pieces 158L and 158R are formed to protrude from the area located on the lower side of the peripheral wall 25A when the expansion is complete, at the left edge 110c and right edge 110d of the lower peripheral wall panel 110A that constitutes the peripheral wall 25A in the lower expansion portion 24A (see Figure 27). The posteromedial connecting pieces 159L and 159R formed on the knee protection portion 72A side are formed to extend from the inner rear edge 75bb side (more specifically, the inner edge 78b side of the rear wall portion 78A) at a position near the upper end 75a of the left portion 75AL and right portion 75AR of the protective body portion 73A. Specifically, the posterolateral connecting pieces 159L and 159R are formed on the inner edge 120b side of the region constituting the rear wall 78A in the main body panel 120A that constitutes the region between the anterior wall 77A and the rear wall 78A of the protective main body 73A of the knee protection part 72A (see Figure 28). The rear portions 156L and 156R are formed by sewing (joining) the tips of the posteromedial connecting pieces 158L and 158R and the posterolateral connecting pieces 159L and 159R to each other (see Figures 23 and 24).

[0071] When the airbag 20A is fully inflated, the front portions 151L, 151R and rear portions 156L, 156R of the lower restricting tethers 150L, ​​150R are positioned at a distance from each other, connecting the knee protection portion 72A and the lower inflation portion 24A of the upper body protection portion 21A, respectively. Specifically, the front portions 151L, 151R are positioned on the upper left edge side or the upper right edge side (upper edges 26a, 27a of the left wall portion 26A and right wall portion 27A) of the lower inflation portion 24A. The front portion 151R (151L) is connected to the inner front edge 75ba side of the left portion 75AL or the right portion 75AR of the knee protection portion 72A and positioned on the front side (instrument panel side), while the rear portions 156L and 156R are connected to the left lower edge or right lower edge side of the lower expansion portion 24A (lower edges 26b and 27b sides of the left wall portion 26A and the right wall portion 27A) and the inner rear edge 75bb side of the left portion 75AL or the right portion 75AR of the knee protection portion 72A and positioned on the rear side (occupant side) (see Figure 23). In practice, as shown in Figure 23, the front portion 151R (151L) is twisted and positioned in front of and above the rear portion 156R (156L).

[0072] When using an airbag 20A with this configuration, the lower regulating tethers 150L and 150R connect the left or right side of the lower inflatable section 24A to the inner surfaces of the left portion 75AL and the right portion 75AR of the knee protection section 72A at two points separated front and rear. These lower regulating tethers 150L and 150R allow the knee protection section 72A to be stably inflated when the airbag 20A is deployed and inflated. Specifically, the front portions 151L and 151R connect the inner front edge 75ba side of the upper end 75a side of each left portion 75AL and right portion 75AR of the knee protection portion 72A to the upper left edge side or the upper right edge side (upper edges 26a and 27a sides of the left wall portion 26A and right wall portion 27A) of the lower inflation portion 24A. As a result, in the initial stages of inflation of the airbag 20A, the knee protection portion 72A protruding from the case (not shown) can be prevented from inflating in such a way that the upper end 75a side of each left portion 75AL and right portion 75AR is separated from the lower inflation portion 24A and tilts toward the occupant. Furthermore, the rear portions 156L and 156R connect the inner rear edge 75bb side of the upper end 75a side of each left portion 75AL and right portion 75AR of the knee protection portion 72A to the left lower edge side or the right lower edge side (lower edges 26b and 27b sides of the left wall portion 26A and right wall portion 27A) of the lower inflation portion 24A. This also prevents the upper end 75a side of each left portion 75AL and right portion 75AR from expanding outward to the left and right, separating from the lower inflation portion 24A, during the initial inflation of the airbag 20A. Therefore, in an airbag system using an airbag 20A with this configuration, the lower restricting tethers 150L and 150R stabilize the positions of the left portion 75AL and the right portion 75AR of the knee protection section 72A (suppressing lateral movement during deployment), allowing the knee protection section 72A to inflate quickly and accurately cover a wide area in front of the occupant's left and right knees, and enabling the knee protection section 72A (left portion 75AL, right portion 75AR) to more accurately restrain the occupant's knees.

[0073] In the airbag device M of this embodiment, the two inflators 12L and 12R are configured to operate almost simultaneously, but the operating timing of the two inflators may be configured to be different as needed. Also, in this embodiment, the two inflators 12L and 12R are arranged side by side on the left-right side and attached to the bottom wall 16a of the case 16, but the arrangement of the two inflators is not limited to this embodiment. The two inflators may be arranged side by side on the up-down side, or side by side on an oblique side.

[0074] Furthermore, although the embodiments describe a passenger-side airbag system for protecting an occupant seated in the passenger seat as an example, the airbag system to which the present invention can be applied is not limited to a passenger-side airbag system. The present invention can also be applied to airbag systems located in front of the driver's seat or in front of the rear seats. [Explanation of Symbols]

[0075] 1…Instrument panel, 1a…Lower part, 10…Airbag cover, 12L,12R…Inflator, 16…Case (storage area), 20,20A…Airbag, 21,21A…Upper body protection section, 24,24A…Lower inflation section, 28L,28R…Inlet opening, 38…Upper inflation section, 50…Communication hole, 72,72A…Knee protection section, 73,73A…Protection Main body, 75L, 75AL...left side, 75R, 75AR...right side, 75a...upper end, 85...gas passage section, 92...outlet, 97L, 97R...lower regulating tether, 150L, ​​150R...lower regulating tether, 151l, 151R...front section, 156L, 156R...rear section, MP...occupant, MU...upper body, K...knee, M...passenger side airbag system (airbag system).

Claims

1. It is equipped with an airbag positioned in front of the seated occupant, which folds and stores in a storage compartment. An airbag system configured such that the airbag inflates to cover the front of the occupant from the knees to the upper body, The airbag is configured to include an upper body protection section capable of protecting the upper body and a knee protection section capable of protecting the knees. An airbag device characterized in that the upper body protection portion and the knee protection portion are each separate bag-shaped components, connected to a separate inflator to allow inflation gas to flow into them, and are folded and stored within the storage portion.

2. The airbag device according to claim 1, characterized in that the upper body protection portion and the knee protection portion are folded together and stored within the storage portion.

3. The airbag device according to claim 1 or 2, characterized in that the knee protection portion is configured to allow inflation gas to flow into the interior of the upper body protection portion via a gas passage portion that is arranged to pass through the interior of the upper body protection portion when inflation is complete.

4. The aforementioned storage compartment is configured to be located on the lower side of the instrument panel in front of the passenger seat. The aforementioned upper body protection part, The expansion gas is introduced into the interior, causing it to expand so as to protrude rearward from the storage area while expanding forward and upward. The airbag device according to claim 1, comprising a lower expansion section that is connected to the inflator and expands to protrude rearward from the storage area, and an upper expansion section that is connected to the lower expansion section via a communication hole and expands above the lower expansion section, and the lower expansion section and the upper expansion section are connected by joining them at the peripheral edge of the communication hole.

5. The knee protection portion is configured to include a left portion and a right portion, which are positioned on the left and right sides of the lower expansion portion when inflation is complete. The airbag device according to claim 4, characterized in that the left and right edges of the lower inflatable portion and the vicinity of the upper ends of the respective left and right portions are connected by a lower restricting tether.

6. Each of the aforementioned lower restricting tethers, when the airbag has finished inflating, The upper left edge or upper right edge of the lower expansion portion and the inner front edge of the left portion or the right portion are connected to a front portion that is disposed on the front side of the instrument panel, The lower left or right lower edge of the lower expansion portion is connected to the inner rear edge of the left or right portion, and the rear portion is disposed on the rear side that is on the occupant side. The airbag device according to claim 5, characterized by comprising the features.

Images