Passenger-side airbag system

Abstract

To provide a passenger-side airbag system that can reliably protect the occupant with an airbag once it has fully inflated, even if the inflation patterns are configured differently. [Solution] The airbag 25 comprises a main bag portion 28 having an occupant side wall portion 40 that is connected to the storage portion side at the front end when inflation is complete and is positioned facing the occupant, and a sub-bag portion 45 that is connected to the main bag portion via a communication portion and can inflate to protrude rearward from the occupant side wall portion. A connecting member is provided inside the main bag portion to connect the sub-bag portion and the control mechanism. When the main bag portion is inflated while the connection between the connecting member and the control mechanism is maintained, the sub-bag portion is pulled into the main bag portion via the communication portion, and when the main bag portion is inflated while the connection between the connecting member and the control mechanism is released, the sub-bag portion inflates to protrude rearward from the occupant side wall portion.

Description

Technical Field

[0001] The present invention relates to a passenger seat airbag device that is disposed in front of a passenger sitting in the passenger seat and whose inflation shape of the airbag is controlled by a control mechanism.

Background Art

[0002] Conventionally, as a passenger seat airbag device that controls the inflation of an airbag by a control mechanism, the airbag has been configured to include a main bag portion and a sub-bag portion whose inflation is controlled by a control mechanism. In this conventional passenger seat airbag device, the sub-bag portion is disposed so as to cover the rear surface side of the main bag portion such that the upper end side and the lower end side are temporarily coupled to the main bag portion side by a temporary stitching portion, and the main bag portion and the sub-bag portion are interconnected via a valve mechanism connected to a control mechanism by a connecting member. When the connection between the connecting member and the control device is released, inflation gas flows into the sub-bag portion through the opened valve mechanism, and the sub-bag portion is configured to expand together with the main bag portion by releasing the temporary connection by the temporary stitching portions on both the upper and lower end sides. In a state where the connection between the connecting member and the control device is maintained, the valve mechanism is not opened, and only the main bag portion expands (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in conventional passenger-side airbag systems, the sub-bag is designed to inflate by allowing inflation gas to flow into it via a valve mechanism, releasing the temporary connection to the main bag at both the upper and lower ends. As a result, it is difficult to maintain a consistent timing for releasing the temporary connection (the timing at which the sutures break). In other words, variations occur in the inflation timing of the sub-bag, leaving room for improvement in ensuring stable protection of the occupant by the fully inflated airbag.

[0005] The present invention aims to solve the above-mentioned problems and to provide a passenger-side airbag system that can reliably protect the occupant with an inflated airbag, even if the inflation mode is configured differently. [Means for solving the problem]

[0006] The passenger-side airbag system according to the present invention comprises an airbag positioned in front of the occupant seated in the passenger seat, which folds and is stored in a storage compartment; an inflator that supplies inflation gas to the airbag; and a control mechanism that controls the inflation shape of the airbag. The airbag is made into a flexible, bag-like shape. The main bag section has a configuration in which, when inflation is complete, the front end is connected to the storage section at its periphery and has an inlet opening for allowing inflation gas to flow into the interior, and when inflation is complete, the rear end is provided with a crew side wall section positioned directly facing the crew member. A sub-bag section is connected to the main bag section and is configured to expand so as to protrude rearward from the occupant side wall section, and its expansion is controlled by a control mechanism. A passenger-side airbag system comprising the following configuration: The airbag is configured to include a connecting member that is positioned within the main bag section, with its base end connected to the inner circumferential surface of the sub-bag section, and its tip end connected to a control mechanism positioned near the air intake opening. The sub-bag section is connected to the main bag section via a connecting section, and when the main bag section inflates while maintaining its connection with the control mechanism of the connecting member, the sub-bag section is retracted into the main bag section via the connecting section. When the main bag section inflates while the connection with the control mechanism of the connecting member is released, the sub-bag section inflates so as to protrude rearward from the occupant side wall, and is configured to protect the occupant with its rear side when inflation is complete.

[0007] The passenger-side airbag system of the present invention comprises a main bag section and a sub-bag section whose inflation is controlled by a control mechanism. The sub-bag section, whose inflation is controlled by the control mechanism, is connected to the control mechanism by a connecting member. When the connection between the connecting member and the control mechanism is maintained, the sub-bag section is in a non-inflated state, retracted into the main bag section via a communication section. When the connection between the connecting member and the control mechanism is released, inflation gas is allowed to flow into the sub-bag section through the main bag section and the communication section, causing it to inflate so as to protrude rearward from the occupant side wall section located at the rear end of the main bag section. In other words, in the passenger-side airbag system of the present invention, the inflation of the sub-bag section is controlled solely by maintaining or releasing the connection between the control mechanism and the connecting member extending from the sub-bag section. Therefore, even when both the main bag section and the sub-bag section are inflated, variations in the inflation timing of the sub-bag section can be suppressed. Furthermore, in the passenger-side airbag device of the present invention, when inflation is completed while the connection between the connecting member and the control mechanism is maintained, the sub-bag portion is retracted into the main bag portion and not exposed to the outside, and the occupant can be accurately caught by the occupant side wall portion of the main bag portion once inflation is complete. When inflation is completed while the connection between the connecting member and the control mechanism is released, the occupant can be accurately caught by the rear surface of the sub-bag portion, which is inflated to protrude further back than the main bag portion.

[0008] Therefore, even if the passenger-side airbag device of the present invention has a configuration that allows for different inflation modes, the occupant can be reliably protected by the fully inflated airbag.

[0009] Furthermore, in the passenger-side airbag device of the present invention, the airbag is formed into a bag shape by joining the peripheral edges of a predetermined-shaped base material made of a flexible sheet body. The sub-bag section has substantially the same external shape and is configured to have a front wall section positioned on the front side, which becomes the occupant side wall section when fully inflated, and a rear wall section positioned on the rear side, opposite the front wall section. The occupant side wall is composed of two occupant side panel sections that are divided into two parts in the vertical or horizontal direction. In each occupant-side panel section, the front wall component, which constitutes half of the front wall section of the sub-bag section, is configured to protrude from the inner edge that forms the central region of the occupant-side wall section and is connected to one another. The outer shape of the rear panel portion that constitutes the rear wall portion of the sub-bag section is configured to be substantially the same as the shape of each front wall component portion of each crew-side panel portion when the inner edges are joined together and the front wall components are opened. It is preferable to form the connecting member so that it extends from two opposing points on the outer periphery of the sub-bag portion, in the direction along the division direction of the occupant side wall portion.

[0010] If the passenger-side airbag device is configured in this way, a sub-bag can be formed by joining the remaining edge of the front wall component and the outer peripheral edge of the rear panel at each occupant-side panel section, where the inner edges of the front and rear panels are joined together. In other words, in the passenger-side airbag device with the above configuration, the occupant-side wall section of the main bag and the sub-bag section can be formed by a planar joining operation, making it possible to manufacture the airbag simply. Furthermore, in the passenger-side airbag device with the above configuration, the sub-bag is formed by joining the outer peripheral edges of the front and rear side wall sections, which have substantially the same external shape, and the connecting member is formed to extend from the inner circumferential surface at two opposing locations on the outer peripheral edge of the sub-bag section, along the direction of division of the occupant-side wall section (i.e., approximately the center of the edge of each front wall component). Therefore, when the main bag is inflated while the connection between the connecting member and the control mechanism is maintained, the sub-bag is pulled by the connecting member, inverted as a whole, folded in half, and positioned within the main bag. In other words, while the connection between the connecting member and the control mechanism is maintained, the sub-bag does not take up much space within the main bag, and is positioned so as to recess forward from the occupant side wall in a pocket-like manner, with a slit-shaped opening formed from the area around the communication part on the occupant side wall. This does not affect the inflation shape of the main bag, and allows only the main bag to be inflated stably.

[0011] Furthermore, in the passenger-side airbag system with the above configuration, if the occupant-side panel is configured to divide the occupant-side wall into two sections on the left-right side, when the main bag is fully inflated while maintaining the connection between the connecting member and the control mechanism, the sub-bag, which is positioned in a pocket shape so as to be recessed forward from the occupant-side wall, will be positioned so that the slit-shaped opening at its rear end is roughly aligned vertically with the occupant-side wall. Therefore, if only the main bag is inflated, it is possible to protect the occupant's head by allowing it to enter this pocket-shaped area (the vertically aligned slit-shaped opening formed in the occupant-side wall). In addition, with such an airbag configuration, the vertical position of the sub-bag relative to the main bag (occupant-side wall) can be easily adjusted as needed by changing the vertical position of the front wall component relative to the occupant-side panel.

[0012] Furthermore, in the passenger-side airbag device with the above configuration, the airbag is stored in the storage compartment in a state where the pre-folded bag, which is formed by folding the front, back, left and right sides of the pre-folded bag so that the occupant side wall portion of the main bag portion is deployed to be approximately flat and positioned on the intake opening, is compressed. In the spare folding bag, it is preferable to configure the sub-bag section to be placed on the occupant side wall of the main bag section when it is unfolded flat so that the front and rear side walls overlap.

[0013] In a passenger-side airbag system with this configuration, the airbag is folded with the sub-bag portion exposed to the outside of the main bag portion and stored within the storage compartment. Therefore, when the airbag is inflated with the connection between the connecting member and the control mechanism released, the sub-bag portion is exposed to the rear side of the main bag portion, and inflation gas is introduced into the interior to inflate it, allowing the sub-bag portion to inflate quickly and smoothly. [Brief explanation of the drawing]

[0014] [Figure 1]It is a schematic diagram showing the vicinity where the passenger seat airbag device according to an embodiment of the present invention is mounted. [Figure 2] It is a schematic enlarged longitudinal sectional view in the front - rear direction of the airbag device of the embodiment. [Figure 3] It is a schematic enlarged longitudinal sectional view in the left - right direction of the airbag device of the embodiment. [Figure 4] It is a perspective view of the airbag used in the airbag device of the embodiment in a state where it is inflated alone, showing a state in which both the sub - bag portion and the gas discharge portion are retracted. [Figure 5] It is a schematic longitudinal sectional view along the front - rear direction of the airbag in FIG. 4. [Figure 6] It is a schematic cross - sectional view along the front - rear direction of the airbag in FIG. 4. [Figure 7] In the airbag of the embodiment, it is a schematic longitudinal sectional view along the front - rear direction showing the vicinity of the sub - bag portion in a state where the sub - bag portion is inflated. [Figure 8] In the airbag of the embodiment, it is a schematic cross - sectional view along the front - rear direction showing the vicinity of the sub - bag portion in a state where the sub - bag portion is inflated. [Figure 9] It is a plan view showing the base material constituting the airbag of the embodiment. [Figure 10] It is a plan view showing the remaining base material constituting the airbag of the embodiment. [Figure 11] It is a plan view and a bottom view showing the state where the airbag of the embodiment is pre - folded. [Figure 12] In the airbag device of the embodiment, it is a schematic longitudinal sectional view along the front - rear direction showing the state where the airbag has completed inflation in the small - volume mode. [Figure 13] In the airbag device of the embodiment, it is a schematic longitudinal sectional view along the front - rear direction showing the state where the airbag has completed inflation in the large - volume mode. [Figure 14] In the airbag device of the embodiment, it is a schematic cross - sectional view along the front - rear direction showing the state where the airbag has completed inflation in the small - volume mode. [Figure 15]This is a schematic cross-sectional view along the front-rear direction showing the state in which the airbag in the embodiment has completed inflation in large volume mode. [Figure 16] This is a schematic side view of the airbag device of the embodiment when the airbag has finished inflating, showing the state in small volume mode and the state in large volume mode. [Figure 17] This is a schematic rear view of the airbag device according to the embodiment, showing the state in which the airbag has completed inflation in small volume mode, as seen from the rear of the vehicle. [Figure 18] This is a schematic diagram illustrating how the occupant's head is supported by an airbag inflated in small volume mode. [Figure 19] This is a schematic perspective view showing an airbag, which is another embodiment of the present invention, in a state where it is inflated in small volume mode on its own. [Figure 20] Figure 19 is a plan view showing the base materials that make up the airbag. [Modes for carrying out the invention]

[0015] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The passenger-side airbag device M (hereinafter abbreviated as "airbag device") of the embodiment is a top-mount type, positioned inside the upper surface 2 of the instrument panel (hereinafter abbreviated as "instrument panel") 1 in front of the passenger-side PS in the vehicle, as shown in Figure 1. In this embodiment, unless otherwise specified, the front-rear, up-down, and left-right directions coincide with the front-rear, up-down, and left-right directions of the vehicle.

[0016] As shown in Figures 1-3, the airbag device M comprises a folded airbag 25, an inflator 8 that supplies inflation gas to the airbag 25, a case 12 as a storage area for housing and holding the airbag 25 and the inflator 8, a retainer 9 for attaching the airbag 25 and the inflator 8 to the case 12, an airbag cover 6 that covers the folded airbag 25, and two locking members 16L and 16R as a control mechanism for controlling the inflation state of the airbag 25. In this embodiment, the operation of the inflator 8 and the locking members 16L and 16R is controlled by the control device 110 shown in Figure 1.

[0017] As shown in Figure 1, the control device 110 receives electrical signals from a position detection sensor 111 that can detect the physique of the occupant MP seated in the passenger seat PS and the distance between the instrument panel 1 and the occupant MP (the position of the passenger seat PS relative to the instrument panel 1), a weight detection sensor 112 that can detect the weight of the occupant MP, and a collision detection sensor 113 that can detect the acceleration and direction of acceleration of the vehicle, etc., to activate the inflator 8 and control the operation of the locking members 16L and 16R so as to inflate the airbag 25 in a suitable inflation mode.

[0018] The airbag cover 6 is integrally formed with the instrument panel 1, which is made of synthetic resin, and is configured so that when the airbag 25 is deployed and inflated, the two front and rear door sections 6a and 6b are pushed open by the airbag 25. In addition, a connecting wall section 6c is formed around the door sections 6a and 6b of the airbag cover 6, which is connected to the case 12.

[0019] As shown in Figures 1-3, the inflator 8 comprises a substantially cylindrical main body 8a having a plurality of gas outlets 8b, and a flange portion 8c for attaching the inflator 8 to the case 12.

[0020] The case 12, which serves as the storage area, is formed in a roughly rectangular parallelepiped shape from sheet metal with a rectangular opening at its upper end. As shown in Figures 1-3, it includes a roughly rectangular bottom wall portion 13 into which the inflator 8 is inserted and mounted from below, and a peripheral wall portion 14 that extends upward from the outer edge of the bottom wall portion 13 and engages with the connecting wall portion 6c of the airbag cover 6. In this embodiment, the airbag 25 and the inflator 8 are connected to the bottom wall portion 13 of the case 12 by using the bolts 9a of the retainer 9, which are placed inside the airbag 25, as mounting means, passing through the periphery of the airbag 25's intake opening 35, the bottom wall portion 13 of the case 12, and the flange portion 8c of the inflator 8, and securing them with nuts 10. The bottom wall portion 13 of case 12 is wider on the left-right side, and at a position approximately in the center from left to right, there is an insertion hole (not shown in the figure) through which the main body portion 8a of the inflator 8 can be inserted, and an insertion hole (not shown) for inserting each bolt 9a of the retainer 9. In the bottom wall portion 13, through holes 13a and 13b are formed on both the left and right sides of the insertion hole for inserting the main body portion 8a of the inflator 8 (see Figures 2 and 3). The through hole 13a on the left side is for inserting the tip 100b side of the connecting member 100 that extends from the gas discharge portion 50 of the airbag 25, which will be described later. The through hole 13b on the right side is for inserting the tip 97b side of the connecting members 97L and 97R that extend from the sub-bag portion 45 of the airbag 25, which will be described later. In addition, a bracket (not shown) that is connected to the vehicle body side is provided on case 12.

[0021] As shown in Figure 3, locking members 16L and 16R, which serve as control mechanisms, are provided on the lower side of the bottom wall portion 13, near the through holes 13a and 13b (i.e., on both the left and right sides of the inflator 8). Each locking member 16L and 16R locks the tip ends 97b and 100b of the connecting members 97L, 97R, and 100, which are provided on the airbag 25. Since they have the same configuration except for the difference in their operating timing, we will explain using the left locking member 16L as an example. As shown in Figure 2, the locking member 16L includes a locking pin 17L that is inserted into a locking hole 101 formed on the tip 100b side of the connecting member 100 to lock the tip 100b side of each connecting member 100, an actuator 18L that is attached to the lower surface of the bottom wall portion 13 and operates to retract the locking pin 17L, and a support bracket 19L that is configured to extend downward from the bottom wall portion 13 at the tip side of the locking pin 17L and to support the tip side of the locking pin 17L. The actuator 18L is configured to operate to retract the locking pin 17L in response to an operation signal from the control device 110. When the actuator 18L operates to retract the locking pin 17L, the locking pin 17L transitions from a state in which it is locked to the tip 100b side of the connecting member 100 to a state in which it is released. As the actuator 18L, any actuator that can move the locking pin 17L by an electrical signal from the control device 110 can be used, such as a piston cylinder that utilizes fluid pressure including hydraulic, water, pneumatic, or inflatable gas pressure, a motor that utilizes such fluid pressure or electricity, an electromagnetic solenoid, or a spring that utilizes the biasing force during restoration. When the actuator 18L is not in operation, the locking pin 17L is supported at the tip end 100b of the connecting member 100 by a support bracket 19L to prevent it from coming loose from the locking pin 17L when locked.

[0022] As shown in Figures 4 to 8, the airbag 25 comprises a bag body 26 having a main bag section 28 and a sub-bag section 45, a gas discharge section 50 provided in the main bag section 28, tethers 60, 66L, 66R, 71, 72 arranged inside the bag body 26 to restrict the completed inflation shape of the main bag section 28 and the sub-bag section 45, connecting members 97L, 97R arranged to extend from the sub-bag section 45, and a connecting member 100 arranged to extend from the gas discharge section 50.

[0023] The bag body 26 is a bag-like structure formed from a flexible sheet material, and comprises a main bag section 28 and a sub-bag section 45 whose expansion is controlled by a locking member 16R acting as a control mechanism.

[0024] The main bag section 28 is positioned to close the space between the upper surface 2 of the instrument panel 1 and the windshield 4 above the instrument panel 1 when inflation is complete. As shown in Figures 4-6, the outer shape when inflation is complete is a roughly square pyramidal shape with the top positioned towards the front. The main bag section 28 includes an occupant side wall section 40 located on the rear end 28b side when inflation is complete, and a tapered peripheral wall section 29 that extends forward from the periphery of the occupant side wall section 40 and converges towards the front end.

[0025] The peripheral wall portion 29 is positioned to primarily block the space between the upper surface 2 of the instrument panel 1 and the windshield 4 above the instrument panel 1 when the airbag 25 has finished inflating. It comprises an upper wall portion 30 and a lower wall portion 31 that are positioned opposite each other in the vertical direction, and a left wall portion 32 and a right wall portion 33 that are positioned opposite each other in the horizontal direction. Near the front end of the lower wall portion 31 of the peripheral wall portion 29, which is near the front end 28a of the main bag portion 28 when inflation is complete, an inlet opening 35 is formed, which is roughly circular in shape to allow inflation gas to flow into the interior, and whose periphery is attached to the bottom wall portion 13 of the case 12. Multiple (four in this embodiment) mounting holes 36 are formed on the periphery of the inlet opening 35 for inserting the bolts 9a of the retainer 9 to attach the periphery of the inlet opening 35 to the bottom wall portion 13 (see A in Figures 9 and 11). To the left of the inlet opening 35, as shown in Figures 9 and 11, B, a slit-shaped through hole 37L is formed, through which the tip 100b of the connecting member 100 extending from the gas discharge section 50 can be inserted, and which is substantially aligned in the left-right direction. To the right of the inlet opening 35, a slit-shaped through hole 37R is formed, through which the tip 97b of the connecting members 97L and 97R extending from the sub-bag section 45 can be inserted, and which is substantially aligned in the left-right direction (see Figures 9 and 11, A). In addition, vent holes 38, 38 are formed in the left wall section 32 and the right wall section 33 of the peripheral wall section 29, opening in a substantially circular shape, for exhausting excess expansion gas that has flowed into the bag body 26 (see Figures 4 and 5).

[0026] The occupant side wall portion 40 is positioned directly opposite the occupant MP seated in the passenger seat PS when the main bag portion 28 is fully inflated, and is arranged along a substantially vertical direction on the rear end 28b side of the main bag portion 28 which is on the occupant MP side (see A in Figures 12 and 16). The external shape of the occupant side wall portion 40 when viewed from the rear when the inflation is complete is a substantially rectangular shape that is wide vertically, as shown in Figure 17.

[0027] The sub-bag section 45, whose inflation is controlled by a locking member 16R acting as a control mechanism, is connected to the main bag section 28 via a communication section 42. When the entire bag body 26 is inflated (when the airbag 25 has finished inflating with the locking member 16R releasing the locking of the tips 97b of the connecting members 97L and 97R, i.e., when the airbag 25 has finished inflating in large volume mode), the sub-bag section 45 is configured to protrude rearward from the occupant side wall section 40 (see Figures 13 and 15). In the embodiment, as shown in Figures 7 and 8, the inflated shape of the sub-bag section 45 is approximately disc-shaped. When the airbag 25 has finished inflating in large volume mode, the left and right centers are positioned approximately to coincide with the left and right centers of the occupant side wall section 40, and the top and bottom centers are positioned slightly below the top and bottom centers of the occupant side wall section 40, so that it protrudes rearward from the occupant side wall section 40. In detail, the outer diameter of the sub-bag section 45 is set to be slightly smaller than the width of the occupant side wall section 40 in the left-right direction. The sub-bag section 45 has an outer shape that is approximately the same (approximately circular) and has a front side wall section 46 that is located on the front side which becomes the occupant side wall section 40 side when inflation is complete, and a rear side wall section 47 that is located on the rear side (occupant MP side) opposite the front side wall section 46, so that the rear side wall section 47 which constitutes the rear side when inflation is complete can protect the occupant MP. The main bag section 28 and the sub-bag section 45 are in communication with each other via a communication section 42, as shown in Figures 7 and 8. In the airbag 25 of this embodiment, the communication section 42 is composed of boundary sections 91L and 91R between the main body sections 89L and 89R and the front wall components 90L and 90R in the rear left panel section 88L and rear right panel section 88R, which will be described later (see Figures 7, 8, and 10).

[0028] The base portion 97a of the connecting members 97L and 97R is connected to the left edge 45a and right edge 45b on the inner circumferential surface side of the sub-bag portion 45 (see Figures 7 and 8). The tip 97b of these connecting members 97L and 97R is locked to a locking member 16R, which serves as a control mechanism and is located on the bottom wall portion 13 side of the case 12 (see Figures 6, 12, and 14). When the main bag section 28 is inflated while the connection between the connecting members 97L, 97R and the locking member 16R is maintained (when the airbag 25 is inflated in small volume mode), the sub-bag section 45 is positioned to be retracted into the main bag section 28 via the communication section 42 (see A in Figures 4-6, 12, 14, 16). When the main bag section 28 is inflated while the connection between the connecting members 97L, 97R and the locking member 16R is released (when the airbag 25 is inflated in large volume mode), the sub-bag section 45 is configured to inflate so as to protrude rearward from the occupant side wall section 40 (see B in Figures 7, 8, 13, 15, 16). In detail, when the airbag 25 has completed inflation (when only the main bag section 28 is inflated and the airbag 25 is inflated in small volume mode), the sub-bag section 45 is pulled forward by the connecting members 97L and 97R on its left edge 45a and right edge 45b sides, causing it to invert and fold in half on the left-right side, so that it is positioned within the main bag section 28 so as to be roughly aligned in the front-rear direction (see Figures 5, 6, 12, and 14). In other words, in the airbag 25 of this embodiment, when inflated in small volume mode, the sub-bag portion 45 is positioned so as to be recessed forward in a pocket shape, with a slit-shaped opening formed from the area surrounding the communication portion 42 in the occupant side wall portion 40 (see Figure 18). To put it another way, when inflated in small volume mode, as shown in Figures 4 and 17, the communication portion 42 is exposed in a slit shape on the occupant side wall portion 40 of the main bag portion 28 after inflation is complete. More specifically, in this embodiment, the slit-shaped communication portion 42 is positioned approximately along the vertical direction at a location approximately in the center of the occupant side wall portion 40 in all directions.

[0029] The connecting members 97L and 97R, which are arranged to extend from the sub-bag portion 45 and connect the sub-bag portion 45 to the locking member 16R, are separate from the bag body 26 and are made of a flexible, strip-shaped fabric material. In this embodiment, the connecting members 97L and 97R are arranged as a pair, left and right, extending from the left edge 45a and right edge 45b on the inner circumferential surface side of the sub-bag portion 45, respectively (see Figure 8). The base portion 97a of each connecting member 97L and 97R is sewn to the left edge 45a and right edge 45b on the inner circumferential surface side of the sub-bag portion 45 (i.e., approximately in the center of the outer circumferential edge 90a of each front wall component 90L and 90R, which will be described later). A locking hole 98 is formed at the tip 97b side of each connecting member 97L and 97R, through which the locking pin 17R of the locking member 16R can be inserted (see Figure 10). In this embodiment, the connecting members 97L and 97R are sewn together at an intermediate point, as shown in Figure 8. The length of these connecting members 97L and 97R is set to such a length that, when the airbag 25 inflates with the locking pin 17R inserted through the locking hole 98 and the locking with the locking pin 17R maintained, the entire sub-bag portion 45 is kept inside the main bag portion 28 (restricting the protrusion of the sub-bag portion 45 from the main bag portion 28).

[0030] In this embodiment, the gas discharge section 50 is located on the left wall 32 side of the main bag section 28. Specifically, it is located on the left wall 32 at a position behind the vent hole 38 and the left and right tethers 71 (more precisely, near the rear upper end of the left wall 32) (see Figure 5). This gas discharge section 50 is integrally formed with the main bag section 28 (bag body 26), and its external shape in a side view when laid flat is a roughly trapezoidal shape that narrows towards the tip 50a (see Figure 5). The gas discharge section 50 is configured such that the tip 100b of the connecting member 100 extending from the tip 50a side is locked to a locking member 16L located on the bottom wall 13 side of the case 12. When the main bag section 28 expands while the connection between the connecting member 100 and the locking member 16L is maintained, the gas discharge section 50 remains retracted into the main bag section 28 (see B in Figures 13, 15, and 16). When the main bag section 28 expands while the connection between the connecting member 100 and the locking member 16L is released, the gas discharge section 50 is released from being retracted into the main bag section 28 and protrudes from the main bag section 28 (see A in Figures 12, 14, and 16). In detail, the gas discharge section 50 is formed by extending from the front portion 32a and the rear portion 32b of the left wall portion 32 of the main bag portion 28, and is constructed by joining the outer edges of two side wall portions 52 and 53, which have substantially the same external shape. Approximately circular openings 52a and 53a are formed at the lower position near the tip of each side wall portion 52 and 53. These openings 52a and 53a constitute exhaust holes 55 that can exhaust the expansion gas G to the outside when the main bag portion 28 is protruding (see Figures 14 and 16).

[0031] The connecting member 100, which is arranged to extend from the gas discharge section 50 and connects the gas discharge section 50 to the locking member 16L, is separate from the bag body 26 and is made of a flexible strip of fabric. The base part 100a of the connecting member 100 is sewn (joined) to the tip 50a of the gas discharge section 50 (see Figures 5 and 6), and the tip 100b has a locking hole 101 through which the locking pin 17L of the locking member 16L can be inserted (see Figure 9). The length of this connecting member 100 is set to a length that allows the main bag section 28 to expand without hindrance even when the main bag section 28 expands while the locking pin 17L is inserted through the locking hole 101 and the locking with the locking pin 17L is maintained. In the airbag device M of this embodiment, when the main bag portion 28 inflates while the connection between the connecting member 100 and the locking member 16L is maintained, the main bag portion 28 inflates with the gas discharge portion 50 retracted into the main bag portion 28 by the connecting member 100. The gas discharge portion 50 is positioned such that the side walls 52 and 53 around the exhaust hole 55 are pressed against each other by the internal pressure of the expansion gas flowing into the main bag portion 28, thereby suppressing the opening of the exhaust hole 55 (see Figure 15). Furthermore, when the main bag portion 28 inflates with the connection between the connecting member 100 and the locking member 16L released, the gas discharge portion 50 is released from being retracted into the main bag portion 28 and is reversed relative to the main bag portion 28, causing it to protrude from the main bag portion 28 and open the exhaust hole 55 (see Figure 14).

[0032] The tethers positioned inside the main body 26 of the bag include front and rear tethers 60, 66L, and 66R, and left and right tethers 71 and 72.

[0033] The front and rear tethers 60 are arranged within the main bag section 28. In this embodiment, they are arranged to connect the left and right sides of the inner circumferential surface of the communication section 42, which connects the main bag section 28 and the sub-bag section 45, with the front end 28a side of the main bag section 28. In this embodiment, the front and rear tethers 60 are configured to connect a front portion 61 extending from the periphery of the inflow opening 35 with two rear portions 62L and 62R extending from the left inner surface and right inner surface of the communication section 42, respectively (see Figures 5, 6, 12-15). In this embodiment, the front portion 61 is formed by folding a part of the strip-shaped material 64 for the front portion shown in Figure 9, so that the rear edge follows the vertical direction. Each rear portion 62L and 62R has an outer shape that is roughly trapezoidal, expanding vertically towards the rear end 62b (see Figure 9). Each rear section 62L, 62R is connected at its front end 62a to the rear end 61a of the front section 61, and at its rear end 62b to the left inner side or right inner side of the communication section 42. Specifically, the rear ends 62b of each rear section 62L, 62R in the front and rear tethers 60 are sewn to the boundary sections 91L, 91R between the main body sections 89L, 89R of the rear left panel section 88L and the rear right panel section 88R (described later as occupant-side panel sections) and the front wall components 90L, 90R, so as to form suture sections 63L, 63R (see Figures 7, 8, 10, 15). These front and rear tethers 60 connect the area near the center (communication section 42) of the occupant side wall 40 in the upper, lower, left, and right directions when the main bag section 28 has finished inflating, to the peripheral area of ​​the intake opening 35. They are arranged to suppress excessive rearward protrusion of the occupant side wall 40 during the initial stages of airbag inflation and to suppress rearward movement of the occupant side wall 40 when inflation is complete (increase in the separation distance between the area near the intake opening 35 and the occupant side wall 40).

[0034] The front and rear tethers 66L and 66R are arranged within the sub-bag section 45, and two of them are arranged on the left-right side to connect the rear wall section 47 and the front wall section 46 (specifically, the left inner side or right inner side of the communication section 42) of the sub-bag section 45. In this embodiment, the front and rear tethers 66L and 66R are composed of a base material 67 for the front and rear tethers as shown in Figure 10. The front and rear tether base material 67 comprises a circular attachment portion 68 and strip-shaped tether components 69L and 69R extending from the attachment portion 68 to the left and right. The attachment portion 68 is positioned so that its center coincides with the center of the rear side wall portion 47, and its outer edge 68a is sewn to the rear side wall portion 47. The tips 69a of each tether component 69L and 69R are sewn together with the rear ends 62b of the rear portions 62L and 62R of the front and rear tethers 60 and the sewn portions 63L and 63R, thereby connecting to the left inner side or right inner side of the communication portion 42. These front and rear tethers 66L and 66R (tether components 69L and 69R of the front and rear tether base material 67) are positioned inclined with respect to the front-to-back direction so that their front ends are located outward to the left and right when the sub-bag portion 45 is viewed from the top and bottom when inflation is complete (see Figure 8). These front and rear tethers 66L and 66R are provided to suppress excessive rearward protrusion of the rear side wall portion 47 of the sub-bag portion 45 during the initial stages of inflation of the airbag 25 in large volume mode, and to suppress rearward movement of the rear side wall portion 47 (increase in the separation distance between the front side wall portion 46 and the rear side wall portion 47) when inflation is complete.

[0035] In this embodiment, the left and right tethers 71 and 72 are positioned in two locations within the main bag section 28, above and below the front and rear tethers 60, as shown in Figures 5 and 6. They connect the left wall section 32 and the right wall section 33, respectively, and are positioned roughly along the left-right direction when the main bag section 28 is fully inflated. The left and right tethers 71, positioned on the upper side, are composed of two strip-shaped tether base materials 73 and 73 (see Figure 9). Although detailed illustrations are omitted, they are formed by sewing the center of the strip-shaped tether base materials 73 and 73, with their width roughly aligned along the front-rear direction, to the left wall section 32 or the right wall section 33, and sewing the ends together in a four-layer overlap. The left and right tethers 72 positioned on the lower side are also composed of two strip-shaped tether base materials 74, 74 (see Figure 9). Although detailed illustrations are omitted, they are formed by sewing one end of each tether base material 74, 74, with its width roughly aligned in the vertical direction, to the left wall portion 32 or the right wall portion 33, and sewing the other ends to each other. These left and right tethers 71, 72 are arranged to suppress excessive separation between the left wall portion 32 and the right wall portion 33 during the initial stages of expansion, and to suppress an increase in the width dimension of the main bag portion 28 in the left-right direction (the distance between the left wall portion and the right wall portion) when expansion is complete.

[0036] In the airbag 25, the bag body 26 and the gas discharge section 50 are formed into an integrated bag shape by joining the periphery of a predetermined shape base material. In this embodiment, as shown in Figures 9 and 10, the bag body 26 and the gas discharge section 50 consist of a left panel section 75, a right panel section 85, a rear left panel section 88L, a rear right panel section 88R, and a rear panel section 94, which serve as occupant-side panel sections.

[0037] The left panel section 75 and the right panel section 85 mainly constitute the area of ​​the peripheral wall section 29 of the main bag section 28. Specifically, they divide the peripheral wall section 29 into two parts in the left-right direction, forming the left and right areas, respectively. The left panel section 75 constitutes the left area of ​​the peripheral wall section 29 and the gas discharge section 50. Specifically, it extends from the left half of the upper wall section 30 of the peripheral wall section 29, through the left wall section 32, to the left half of the lower wall section 31. The right panel section 85 constitutes the right area of ​​the peripheral wall section 29. Specifically, it extends from the right half of the upper wall section 30 of the peripheral wall section 29, through the right wall section 33, to the right half of the lower wall section 31. The left panel section 75 and the right panel section 85 each have protrusions 77 and 86 that constitute the peripheral area of ​​the inlet opening 35. As shown in Figure 9, the left panel section 75 is divided into two parts in the front-rear direction, comprising a front section 76 and a rear section 80. The front section 76 includes a protruding portion 77 that forms the peripheral area of ​​the inlet opening 35, and a discharge section component 78 that forms the side wall 52 of the gas discharge section 50 is partially projected on the rear upper edge 76c side. The rear section 80 has a discharge section component 81 that forms the side wall 53 of the gas discharge section 50 partially projected on the front edge 80b side. The outer shape of the right panel section 85 is substantially the same as that of the left panel section 75 when the rear upper edge 76c of the front section 76 and the front edge 80b of the rear section 80 are sewn together.

[0038] The rear left panel section 88L and the rear right panel section 88R, as occupant-side panel sections, mainly constitute the occupant-side wall section 40 of the main bag section 28, and are configured to divide the occupant-side wall section 40 into two parts on the left-right side. In detail, as shown in Figure 10, the rear left panel section 88L comprises a main body section 89L that constitutes the left side region of the occupant-side wall section 40, and a front wall component section 90L that is formed to protrude from the inner edge 89a of the main body section 89L (the edge that constitutes the central region of the occupant-side wall section 40). The front wall component section 90L constitutes the front side wall section 46 of the sub-bag section 45 and is formed to partially protrude from the inner edge 89a of the main body section 89L. In detail, the front wall component section 90L constitutes the left half region of the front side wall section 46 of the sub-bag section 45, and its outer shape is approximately semicircular. In the embodiment of the airbag 25, the boundary portion 91L between the main body portion 89L and the front wall component portion 90L in the rear left panel portion 88L constitutes a communication portion 42 that connects the main bag portion 28 and the sub-bag portion 45. The outer edge 89b of the main body portion 89L in the rear left panel portion 88L substantially matches the rear lower edge 76d and rear edge 80c of the left panel portion 75 in terms of external shape. In this embodiment, the rear left panel portion 88L and the rear right panel portion 88R are symmetrical, so for the rear right panel portion 88R, the letter "R" is added to the end of the same reference numeral, and a detailed explanation is omitted. The rear panel portion 94 constitutes the rear side wall portion 47 of the sub-bag portion 45, and its external shape is circular. In other words, the rear panel section 94 is configured to have an external shape that is substantially the same as the shape of the front wall components 90L and 90R of the rear left panel section 88L and rear right panel section 88R when the inner edges 89a, 89a are joined together and the front wall components 90L and 90R are opened.

[0039] In this embodiment, the left panel section 75 (front section 76, rear section 80), right panel section 85, rear left panel section 88L, rear right panel section 88R, and rear panel section 94, which constitute the bag body 26 and the gas discharge section 50, and the front section material 64, rear section 62L, 62R, front and rear tether base material 67, tether base material 73, 74, which constitute the front and rear tethers 60, 66L, 66R and left and right tethers 71, 72, are each formed from a flexible woven fabric made of polyester yarn, polyamide yarn, etc. In this embodiment, the connecting members 97L, 97R, and 100 are also formed from a flexible woven fabric made of polyester yarn, polyamide yarn, etc., similar to the bag body 26.

[0040] The bag body 26 of the embodiment is formed into a bag shape having a gas discharge section 50 by sewing (joining) the corresponding edges of the left panel section 75 (front section 76, rear section 80), the right panel section 85, the rear left panel section 88L, the rear right panel section 88R, and the rear panel section 94 together using suture thread. The front section 76 and the rear section 80 of the left panel section 75 are sewn together, along with the corresponding rear upper edge 76c and front edge 80b, including the outer peripheral edges 78a and 81a of the discharge section components 78 and 81. The upper edges 76a and 80a of the front section 76 and the rear section 80 of the left panel section 75 are sewn together with the upper edge 85a of the right panel section 85. The lower edge 76b of the front section 76 of the left panel section 75 is sewn together with the lower edge 85b of the right panel section 85. The rear lower edge 76d of the front portion 76 and the rear edge 80c of the rear portion 80 of the left panel portion 75 are sewn to the outer edge 89b of the main body portion 89L of the rear left panel portion 88L. The rear edge 85c of the right panel portion 85 is sewn to the outer edge 89b of the main body portion 89R of the rear right panel portion 88R. The inner edge 89a of the main body portion 89L of the rear left panel portion 88L is sewn to the inner edge 89a of the main body portion 89R of the rear right panel portion 88R. The outer peripheral edge 90a of the front wall component 90L of the rear left panel portion 88L is sewn to the left half of the outer peripheral edge 94a of the rear panel portion 94, and the outer peripheral edge 90a of the front wall component 90R of the rear right panel portion 88R is sewn to the right half of the outer peripheral edge 94a of the rear panel portion 94.

[0041] Next, the installation of the airbag device M of the embodiment into a vehicle will be described. First, the airbag 25 is folded so that it can be stored inside the case 12 with the retainer 9 stored inside. Although detailed illustrations are omitted, the airbag 25 is folded from the state of the pre-folded bag 120 as shown in Figures 11A and 11B, so as to reduce the width dimensions in the front, back, left, and right. In the pre-folded bag 120, which is a pre-folded airbag 25 (bag body 26), as shown in Figures 11A and B, the occupant side wall portion 40 is unfolded to be nearly flat, and the occupant side wall portion 40 is brought closer to the intake opening 35 (positioned on the intake opening 35), and a valley fold is made in the peripheral wall portion 29 to fold the main bag portion 28. The sub-bag portion 45, which is unfolded flat with the front side wall portion 46 and the rear side wall portion 47 overlapping, is placed on top of the occupant side wall portion 40 of the main bag portion 28. In other words, in the airbag 25 of this embodiment, in the state of the pre-folded bag 120, the sub-bag portion 45 is not inserted into the main bag portion 28, but is exposed from the main bag portion 28 and is placed on top of the main bag portion 28. Then, the spare folding bag 120 is folded to reduce its width in all directions, and the area around the resulting folded body is wrapped with a tearable wrapping sheet (not shown) to prevent it from collapsing. At this time, the tip 97b side of the connecting members 97L and 97R extending from the sub-bag section 45 and the tip 100b side of the connecting member 100 extending from the gas discharge section 50 are made to protrude from the insertion holes 37L and 37R formed in the bag body 26, respectively. The folded airbag 25 is then stored in the case 12, which has the locking members 16L and 16R attached in advance, with the bolt 9a protruding from the bottom wall section 13. Then, the locking pin 17L of the locking member 16L is inserted through the locking hole 101 of the connecting member 100 that protrudes from the through hole 13a formed in the bottom wall portion 13, and the tip of the locking pin 17L is supported by the support bracket 19L, thereby locking the tip 100b side of the connecting member 100 to the locking member 16L. Similarly, the tip 97b side of the connecting members 97L and 97R that protrude from the through hole 13b of the bottom wall portion 13 is locked to the locking member 16R.Next, the main body 8a of the inflator 8 is inserted into the case 12 from below the bottom wall 13, and the bolts 9a of the retainer 9 protruding downward from the bottom wall 13 are inserted through the flange portion 8c of the inflator 8. After that, nuts 10 are fastened to each bolt 9a protruding from the flange portion 8c of the inflator 8, thereby attaching the folded airbag 25 and the inflator 8 to the case 12.

[0042] Subsequently, the peripheral wall portion 14 of the case 12 is locked to the connecting wall portion 6c of the airbag cover 6 on the instrument panel 1 mounted on the vehicle, a bracket (not shown) provided on the case 12 is fixed to the vehicle body, and the inflator 8 and the locking members 16L and 16R are electrically connected to the control device 110, thereby enabling the airbag device M to be mounted on the vehicle.

[0043] After the airbag device M is installed in the vehicle, if a frontal collision is detected, the control device 110 outputs an activation signal to the inflator 8, causing the inflator 8 to discharge inflation gas from the gas outlet 8b, which inflates the airbag 25 by allowing the inflation gas to flow into it, causing it to push open the door portions 6a and 6b of the airbag cover 6. The airbag 25 then protrudes upward from the case 12 through the opening formed by pushing open the door portions 6a and 6b of the airbag cover 6, and expands while protruding toward the rear of the vehicle, completing its inflation so as to seal the space between the upper surface 2 of the instrument panel 1 and the windshield 4 above the instrument panel 1, as shown by the dashed line in Figure 1 and A, B, and 17 in Figures 12, 13, and 16.

[0044] In the airbag device M of this embodiment, the airbag 25 comprises a main bag section 28 and a sub-bag section 45 whose inflation is controlled by a locking member 16R acting as a control mechanism. The sub-bag section 45, whose inflation is controlled by the locking member 16R acting as a control mechanism, is connected to the locking member 16R by connecting members 97L and 97R. When the connection between the connecting members 97L and 97R and the locking member 16R is maintained, the sub-bag section 45 is in a non-inflated state, retracted into the main bag section 28 via the communication section 42. When the connection between the connecting members 97L and 97R and the locking member 16R is released, inflation gas is allowed to flow into the main bag section 28 via the communication section 42, causing the sub-bag section 45 to inflate so as to protrude rearward from the occupant side wall section 40 located on the rear end side of the main bag section 28. In other words, in the airbag device M of the embodiment, the inflation of the sub-bag portion 45 is controlled solely by maintaining or releasing the connection between the locking member 16R, which acts as a control mechanism, and the connecting members 97L, 97R extending from the sub-bag portion 45. Therefore, even when the sub-bag portion 45 is inflated in addition to the main bag portion 28, variations in the inflation timing of the sub-bag portion 45 can be suppressed. Furthermore, in the airbag device M of the embodiment, when inflation is completed with the connection between the connecting members 97L, 97R and the locking member 16R maintained, the sub-bag portion 45 is retracted into the main bag portion 28 and not exposed to the outside, and the occupant MP can be accurately received by the occupant side wall portion 40 of the main bag portion 28 after inflation is complete. When inflation is completed with the connection between the connecting members 97L, 97R and the locking member 16R released, the occupant MP can be accurately received by the rear surface (rear side wall portion 47) of the sub-bag portion 45, which is inflated to protrude behind the main bag portion 28.

[0045] Therefore, in the airbag device M of the embodiment, even if the inflation modes are configured differently, the occupant MP can be reliably protected by the airbag 25 once it has completed inflation.

[0046] Specifically, in the airbag device M of the embodiment, when the control device 110, which receives signals from predetermined sensors 111, 112, and 113, detects, for example, the seating of a small occupant MP1, or detects that occupant MP is seated in a position close to the instrument panel 1, the airbag 25 inflates with an operating signal output to the actuator 18L of the locking member 16L almost simultaneously with the operation of the inflator 8. That is, no operating signal is output to the actuator 18R of the locking member 16R, and the airbag 25 inflates while maintaining the connection between the connecting members 97L, 97R extending from the sub-bag section 45 and the locking member 16R, and in small volume mode, only the main bag section 28 completes inflation (see A, 17 in Figures 12, 14, and 16). At this time, the operation of the actuator 18L releases the connection between the connecting member 100 extending from the gas discharge section 50 and the locking member 16L, allowing excess expansion gas G to be exhausted from the gas discharge section 50 protruding from the main bag section 28. As a result, the occupant side wall section 40 of the main bag section 28, which is expanding while the excess expansion gas G is being discharged from the gas discharge section 50, can accurately support a small occupant MP1 or an occupant MP seated close to the instrument panel 1.

[0047] Conversely, if the control device 110 detects, for example, the presence of a large occupant MP2 or the presence of occupant MP seated away from the instrument panel 1, the airbag device M of this embodiment will inflate the airbag 25 at approximately the same time as the inflator 8 is activated, with an activation signal output to the actuator 18R of the locking member 16R. In other words, the airbag 25 will inflate with the connection between the connecting members 97L and 97R extending from the sub-bag section 45 and the locking member 16R released, and the main bag section 28 and the sub-bag section 45 will complete their inflation in a large-volume mode (see Figures 13, 15, and 16B). In this case, no activation signal is output to the locking member 16L, and the airbag 25 inflates while maintaining the connection between the connecting member 100 extending from the gas discharge section 50 and the locking member 16L. The gas discharge section 50 is then retracted into the main bag section 28, maintaining the closed state of the exhaust port 55. This suppresses excessive exhaust of the inflation gas G, maintaining the internal pressure between the main bag section 28 and the sub-bag section 45. The rear side wall 47 of the sub-bag section 45, which protrudes further back than the occupant side wall 40, can accurately catch large occupants MP2 or occupants MP seated away from the instrument panel 1.

[0048] Furthermore, in the airbag device M of this embodiment, the occupant side wall portion 40 of the main bag portion 28 is composed of two occupant side panel portions (rear left panel portion 88L, rear right panel portion 88R) which are divided into two on the left and right sides. In each rear left panel portion 88L and rear right panel portion 88R, front wall components 90L and 90R, which constitute half the area of ​​the front side wall portion 46 of the sub-bag portion 45, are formed protruding from the edges (inner edges 89a of the main body portions 89L and 89R) that constitute the central area of ​​the occupant side wall portion 40 and are connected to each other. In addition, the rear panel portion 94 that constitutes the rear side wall portion 47 of the sub-bag portion 45 is configured to have an outer shape that is substantially the same as the shape of each front wall component 90L and 90R in each rear left panel portion 88L and rear right panel portion 88R when the inner edges 89a, 89a are connected to each other and the front wall components 90L and 90R are opened. Therefore, in the rear left panel section 88L and rear right panel section 88R, with the corresponding inner edges 89a, 89a joined together, by joining the outer peripheral edge 90a of the front wall components 90L, 90R and the outer peripheral edge 94a of the rear panel section 94, the occupant side wall section 40 of the main bag section 28 can be formed, and at the same time, the sub-bag section 45 can be formed. In other words, in the airbag 25 of this embodiment, the occupant side wall section 40 of the main bag section 28 and the sub-bag section 45 can be formed by planar joining work, so the airbag 25 can be manufactured simply. In the airbag 25 of this embodiment, in addition to the sub-bag section 45, the entire main bag section 28 can also be manufactured by planar joining work, so the increase in manufacturing costs can be suppressed and it can be manufactured at a low cost.

[0049] Furthermore, in the airbag device M of this embodiment, the sub-bag portion 45 is formed by connecting the outer edges of the front wall portion 46 and the rear wall portion 47, which have substantially the same outer shape. The connecting members 97L and 97R are formed to extend from the inner circumferential surface of the left edge 45a and the right edge 45b (i.e., positions that are approximately in the center of the outer edge 90a of each front wall component 90L and 90R), which are two opposing locations on the outer edge of the sub-bag portion 45 in the direction along the division direction of the occupant side wall portion 40. Therefore, when the main bag portion 28 inflates while the connection between the connecting members 97L and 97R and the locking member 16R is maintained, the sub-bag portion 45 is pulled by the connecting members 97L and 97R, inverted as a whole, folded in half, and positioned within the main bag portion 28. In other words, when the connection between the connecting members 97L and 97R and the locking member 16R is maintained, the sub-bag section 45 does not take up much space within the main bag section 28. A slit-shaped opening formed from the area surrounding the communication section 42 is positioned in the occupant side wall section 40, and the sub-bag section 45 is positioned to recess forward in a pocket-like manner from the occupant side wall section 40. This does not affect the expansion shape of the main bag section 28, and allows only the main bag section 28 to expand stably.

[0050] Furthermore, in the airbag device M of the embodiment, the airbag 25 is stored in the case 12 in a folded state, where the front, rear, left, and right sides of the spare folding bag 120 are compressed. In the spare folding bag 120, the sub-bag portion 45 is positioned on the occupant side wall portion 40 of the main bag portion 28 in a state where it is unfolded flat so that the front side wall portion 46 and the rear side wall portion 47 overlap. In other words, in the airbag device M of the embodiment, the airbag 25 is folded with the sub-bag portion 45 exposed to the outside of the main bag portion 28 and stored in the case 12. Therefore, when the airbag 24 is inflated with the connection between the connecting members 97L, 97R and the locking member 16R released, the sub-bag portion 45 is exposed to the rear side of the main bag portion 28, and inflation gas flows into the interior to inflate it, allowing the sub-bag portion 45 to inflate quickly and smoothly. If these points are not taken into consideration, the airbag can be folded with the sub-bag section tucked inside the main bag section.

[0051] Furthermore, in this embodiment, since the airbag 25 is folded and stored in the case 12 with the sub-bag portion 45 exposed to the outside of the main bag portion 28, when the main bag portion 28 inflates while the connection between the connecting members 97L, 97R and the locking member 16R is maintained, the sub-bag portion 45 is drawn into the main bag portion 28 via the communication portion 42 as the main bag portion 28 inflates (the occupant side wall portion 40 moves backward). In the airbag 25 of this embodiment, the boundary portions 91L, 91R of the rear left panel portion 88L and the rear right panel portion 88R that constitute the communication portion 42 have a width dimension that is slightly smaller than the outer diameter dimension of the front wall components 90L, 90R, and are set to approximately the same dimensions. In other words, the length dimension of the communication portion 42 when it is laid flat is approximately the same as the outer diameter dimension of the sub-bag portion 45. Therefore, when expanding in small volume mode, the sub-bag section 45, which is pulled by the connecting members 97L and 97R, is prevented from partially getting caught on the connecting section 42, allowing it to be smoothly inserted into the main bag section 28.

[0052] Furthermore, in the airbag device M of this embodiment, the occupant-side panel sections (rear left panel section 88L, rear right panel section 88R) are configured to divide the occupant-side wall section 40 into two parts on the left-right side. Therefore, when the main bag section 28 is fully inflated while maintaining the connection between the connecting members 97L, 97R and the locking member 16R, the sub-bag section 45, which is positioned in a pocket shape so as to be recessed forward from the occupant-side wall section 40, is positioned so that the slit-shaped opening at the rear end is roughly aligned vertically with the occupant-side wall section 40 (see Figure 17). As a result, when only the main bag section 28 is inflated, as shown in Figure 18, it is possible to protect the occupant MP's head MH by allowing it to enter this pocket-shaped area (the vertically aligned slit-shaped opening formed in the occupant-side wall section 40). Furthermore, in the airbag 25 of this embodiment, the vertical position of the sub-bag portion 45 relative to the main bag portion 28 (occupant side wall portion 40) can be easily adjusted as needed by changing the vertical position of the front wall components 90L and 90R relative to the main body portions 89L and 89R of the rear left panel portion 88L and rear right panel portion 88R.

[0053] If these points are not taken into consideration, an airbag 25A with the configuration shown in Figure 19 may be used. This airbag 25A has substantially the same configuration as the aforementioned airbag 25, except that the occupant side wall portion 40A is divided into two parts vertically, consisting of two rear upper panel portions 130 and rear lower panel portions 135 (occupant side panel portions). For identical components, the letter A is added to the end of the same figure reference numeral, and detailed explanations are omitted. Note that the airbag 25A does not have front and rear tethers, and the connecting members 97U and 97D extending from the sub-bag portion 45A are connected at their base portion 97a to the upper edge 45c and lower edge 45d on the inner circumferential surface side of the sub-bag portion 45A (see Figure 20).

[0054] As shown in Figures 19 and 20, the rear upper panel section 130 and rear lower panel section 135, which serve as the occupant-side panel sections, mainly constitute the occupant side wall section 40A of the main bag section 28A, and are configured to divide the occupant side wall section 40A into two parts in the vertical direction. The rear upper panel section 130 comprises a main body section 131 that constitutes the upper region of the occupant side wall section 40A, and a front wall component section 132 that is formed to protrude from the lower edge 131c of the main body section 131 (the inner edge that constitutes the central region of the occupant side wall section 40A). The front wall component section 132 constitutes the upper half of the front side wall section 46A of the sub-bag section 45A, and its outer shape is approximately semicircular. The rear lower panel section 135 comprises a main body section 136 that constitutes the lower region of the occupant side wall section 40A, and a front wall component section 137 that is formed to protrude from the upper edge 136a of the main body section 136 (the inner edge that constitutes the central region of the occupant side wall section 40A). The front wall component section 137 constitutes the lower half of the front side wall section 46A of the sub-bag section 45A, and its outer shape is approximately semicircular. In the airbag 25A as well, the boundary portion 133 between the main body section 131 and the front wall component section 132 in the rear upper panel section 130, and the boundary portion 138 between the main body section 136 and the front wall component section 137 in the rear lower panel section 135, constitute a connecting portion 42A that connects the main bag section 28A and the sub-bag section 45A.

[0055] In this airbag 25A, the bag body 26A is also formed into a bag shape with a gas discharge section 50A by sewing (joining) the corresponding edges of the left panel section 75A (front section 76A, rear section 80A), the right panel section 85A, the rear upper panel section 130, the rear lower panel section 135, and the rear panel section 94A together using sutures. In the rear upper panel section 130, the main body section 131 is sewn together at the upper inner left edge 131a and the upper inner right edge 131b. The lower edge 131c (inner edge) of the main body section 131 is sewn to the upper edge 136a (inner edge) of the main body section 136 in the rear lower panel section 135. The left edge 131d of the main body portion 131 is sewn together with the left edge 136b of the main body portion 136 in the rear lower panel portion 135 to the rear lower edge 76d of the front portion 76A and the rear edge 80c of the rear portion 80A in the left panel portion 75A. The right edge 131e of the main body portion 131 is sewn together with the right edge 136c of the main body portion 136 in the rear lower panel portion 135 to the rear edge 85c of the right panel portion 85A. The outer peripheral edge 132a of the front wall component 132 is sewn to the upper half of the outer peripheral edge 94a of the rear panel portion 94A, and the outer peripheral edge 137a of the front wall component 137 is sewn to the lower half of the outer peripheral edge 94a of the rear panel portion 94A.

[0056] Even with this configuration of airbag 25A, the occupant side wall portion 40A of the main bag portion 28A and the sub-bag portion 45A can be formed by planar joining operations, thus enabling the airbag 25A to be manufactured simply. In the above configuration of airbag 25A, the entire main bag portion 28A can also be manufactured by planar joining operations, thus suppressing increases in manufacturing costs and enabling inexpensive manufacturing.

[0057] Furthermore, in the airbag 25A with the above configuration, the sub-bag portion 45A is formed by connecting the outer edges of the front wall portion 46A and the rear wall portion 47A, which have substantially the same outer shape. The connecting members 97U and 97D are formed to extend from the inner circumferential surface of the upper edge 45c and lower edge 45d (i.e., positions that are approximately in the center of the outer edges 132a and 137a of the respective front wall components 132 and 137) which are two opposing locations on the outer edge of the sub-bag portion 45A in the direction along the division direction of the occupant side wall portion 40A. Therefore, when the main bag portion 28A is inflated while the connecting members 97U and 97D are connected to a locking member (not shown), the sub-bag portion 45A is pulled by the connecting members 97U and 97D, inverted as a whole, folded in half, and positioned within the main bag portion 28A. In other words, when the connection between the connecting members 97U and 97D and the locking member is maintained, the sub-bag section 45A does not take up much space within the main bag section 28A. A slit-shaped opening formed from the area surrounding the communication section 42A is positioned along the left-right direction on the occupant side wall section 40A, and the sub-bag section 45A is positioned to recess forward from the occupant side wall section 40A in a pocket-like manner. This does not affect the expansion shape of the main bag section 28A, and allows only the main bag section 28A to expand stably.

[0058] In this embodiment, the airbags 25 and 25A are configured to have gas exhaust sections 50 and 50A that can release inflation gas, and their opening and closing are controlled by a locking member 16L acting as a control mechanism, thereby adjusting the internal pressure upon completion of inflation. Therefore, the airbags can support the occupant with appropriate internal pressure, both in the small-volume inflation mode where only the main bag sections 28 and 28A are inflated, and in the large-volume inflation mode where both the main bag sections 28 and 28A and the sub-bag sections 45 and 45A are inflated. Of course, these gas exhaust sections are not essential, and airbags without gas exhaust sections may also be used. [Explanation of symbols]

[0059] 1…Instrument panel, 6…Airbag cover, 8…Inflator, 12…Case (storage area), 16L, 16R…Locking member (control mechanism), 25, 25A…Airbag, 28, 28A…Main bag section, 35…Inlet opening, 40, 40A…Occupant side wall section, 42, 42A…Communication section, 45, 45A…Sub-bag section, 88L…Rear left panel section (occupant side panel section), 88R…Rear right panel section (occupant side panel section), 89L, 89R…Main body section, 89a…Inner edge, 9 0L, 90R... Front wall component, 94, 94A... Rear panel, 97L, 97R, 97U, 97D... Connecting member, 97a... Base, 97b... Tip, 110... Control device, 120... Spare folding bag, 130... Rear upper panel (occupant side panel), 131... Main body, 131c... Lower edge (inner edge), 132... Front wall component, 135... Rear lower panel (occupant side panel), 136... Main body, 136a... Upper edge (inner edge), 137... Front wall component, MP... Occupant, PS... Passenger seat, M... Passenger side airbag device.

Claims

1. It comprises an airbag positioned in front of the passenger seated occupant, which folds up and is stored in a storage compartment, an inflator that supplies inflation gas to the airbag, and a control mechanism that controls the inflation shape of the airbag, The aforementioned airbag is in the shape of a flexible bag, The main bag section has a configuration in which, when inflation is complete, the front end is provided with an inlet opening connected to the storage section at its periphery to allow the inflation gas to flow into the interior, and when inflation is complete, the rear end is provided with a crew side wall section positioned directly facing the crew member. A sub-bag section is connected to the main bag section and is configured to expand so as to protrude rearward from the occupant side wall section, and its expansion is controlled by the control mechanism, A passenger-side airbag system comprising the following configuration: The airbag is configured to include a connecting member, which is positioned within the main bag section, with its base end connected to the inner circumferential surface of the sub-bag section, and its tip end connected to the control mechanism positioned near the intake opening. A passenger-side airbag device characterized in that the sub-bag portion is connected to the main bag portion via a communication portion, and when the main bag portion is inflated while the connection of the connecting member with the control mechanism is maintained, the sub-bag portion is retracted into the main bag portion via the communication portion, and when the main bag portion is inflated while the connection of the connecting member with the control mechanism is released, the sub-bag portion inflates so as to protrude rearward from the occupant side wall portion, and is configured to protect the occupant with its rear side when inflation is complete.

2. The airbag is formed into a bag shape by joining the periphery of a predetermined-shaped base material made of a flexible sheet body together. The sub-bag portion has substantially the same external shape and includes a front wall portion positioned on the front side which becomes the occupant side wall portion when inflation is complete, and a rear wall portion positioned on the rear side opposite the front wall portion. The aforementioned occupant side wall is composed of two occupant side panel sections that are divided into two parts in the vertical direction or the left-right direction. Each of the occupant-side panel sections is configured to form the central region of the occupant-side wall section and is connected to the inner edge, with the front wall section, which forms half the region of the front side wall section of the sub-bag section, positioned to protrude from the inner edge. The rear panel portion constituting the rear side wall portion of the sub-bag portion is configured such that its external shape is substantially the same as the shape of the front wall components of each occupant-side panel portion when they are opened and their inner edges are joined together. The passenger-side airbag device according to claim 1, characterized in that the connecting member is formed to extend from two opposing locations on the outer peripheral edge of the sub-bag portion, in a direction along the division direction of the occupant side wall portion.

3. The passenger-side airbag device according to claim 2, characterized in that the occupant-side panel portion is configured to divide the occupant-side wall portion into two parts in the left-right direction.

4. The airbag is stored in the storage compartment in a folded state, where the front, back, left, and right sides of the pre-folded bag are folded down so that the occupant side wall portion of the main bag portion is laid flat and positioned on the intake opening, The passenger-side airbag device according to claim 2 or 3, characterized in that the spare folding bag is positioned on the occupant side wall of the main bag in a state where the sub-bag portion is laid flat so that the front side wall portion and the rear side wall portion overlap.

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