Airbag device

Abstract

Provided is an airbag device that comprises an airbag deploying from a roof portion of a cabin and that can appropriately protect an occupant.　The air bag protects the occupant by expanding in front of the occupant in the cabin. The airbag includes a main chamber 17 that deploys downward from the roof portion of a vehicle, and a protruding portion that deploys so as to protrude toward the front of the vehicle at a lower part of the main chamber 17. The protruding portion can be a sub-chamber 18 provided so as to be in fluid communication with the main chamber 17, and the sub-chamber 18 is expanded and deployed by gas flowing in from the main chamber 17 through a vent hole 22. When viewed from the side direction of the vehicle, the vent hole 22 is located below the center C1 of the main chamber 17 in a longitudinal direction L1.

Description

Airbag device

[0001] The present invention relates to an airbag device for protecting occupants in a vehicle, and more particularly to an airbag device including an airbag that deploys into the vehicle interior from a roof portion of the vehicle interior.

[0002] It is well known that vehicles are equipped with one or more types of airbags to protect occupants in the event of a vehicle accident. Airbags come in a variety of forms, including a driver's airbag that inflates near the center of the steering wheel to protect the driver, a passenger airbag that inflates from the instrument panel to protect the front passenger, a curtain airbag that inflates downward inside the vehicle window to protect occupants in the event of a lateral impact or a rollover or overturning accident, and a side airbag that inflates on the side of the seat to protect occupants in the event of a lateral impact.

[0003] In recent years, advances in autonomous driving technology (level) have led to increased freedom in vehicle interior design. Under these circumstances, airbags deployed from the steering wheel or instrument panel may not adequately protect occupants. Therefore, methods have been proposed in which airbags are deployed from the roof of the vehicle interior, as disclosed in Patent Documents 1 and 2.

[0004] However, the inventions disclosed in Patent Documents 1 and 2 may not be able to properly restrain the occupant depending on the physique and seated posture of the occupant. For example, if the seat is set to the forward-most position, there is a risk that the occupant's head may collide with the instrument panel or the like before the airbag reaches the occupant.

[0005] European Patent Publication No. 2,686,206 U.S. Patent Publication No. 6,460,878

[0006] The present invention has been made in consideration of the above-described circumstances, and has an object to provide an airbag device that is equipped with an airbag that deploys from the roof portion of the vehicle compartment and can adequately protect occupants.

[0007] In order to solve the above problems, the present invention provides an airbag device equipped with an airbag that protects an occupant by deploying in front of the occupant inside a vehicle cabin, the airbag including: a main chamber that deploys downward from a roof portion of the vehicle; and a protrusion that deploys from a lower portion of the main chamber so as to protrude in front of the vehicle.

[0008] Here, "downward from the roof of the vehicle" includes, for example, a configuration in which a folded airbag is housed inside the roof lining and when the airbag device is activated, a part of the roof lining breaks and deploys into the vehicle cabin, but does not exclude a configuration in which the folded airbag is installed outside the roof lining (toward the vehicle cabin).

[0009] In the present invention as described above, the main chamber is provided with a main chamber that deploys downward from the roof inside the vehicle cabin, allowing the main chamber to deploy quickly in a position close to the occupants. Also, by providing a protrusion that deploys in a manner that protrudes forward of the vehicle at the bottom of the main chamber, the protrusion quickly comes into contact with the instrument panel or the like, and can obtain a reaction force from the instrument panel or the like, leading to a stable deployment behavior of the main chamber.

[0010] The present invention is most effective when used as an airbag device for a passenger seat where there is a large space in front of the occupant. When the airbag device according to the present invention is used to protect the driver, for example, an airbag that deploys from the steering wheel is omitted, and the protruding portion that deploys in front of the main chamber may come into contact with the steering wheel. Furthermore, when the airbag device according to the present invention is used for a rear seat, the airbag deploys from the roof of the rear seat of the vehicle, and the protruding portion comes into contact with the lower part of the backrest of the front seat.

[0011] The protrusion may be a sub-chamber provided to be fluidly connected to the main chamber, and may be configured to be inflated and deployed by gas flowing from the main chamber via a first vent.

[0012] When viewed from the side of the vehicle, the first vent may be configured to be located below the center of the main chamber in the longitudinal direction, where the "longitudinal direction" may also be roughly defined as the up-down direction.

[0013] In this way, by providing the first vent that connects the main chamber and sub-chamber at a lower position, the deployment position of the sub-chamber is lowered, allowing the sub-chamber to quickly come into contact with the instrument panel, etc. Furthermore, the sub-chamber will deploy in a position close to the knees of the occupant, which is expected to have the same effect as a knee airbag in protecting the occupant's lower legs.

[0014] When viewed from the side of the vehicle, the sub-chamber may be configured to deploy in a direction generally perpendicular to the longitudinal direction of the main chamber in the deployed state.

[0015] By expanding the sub-chamber in a direction generally perpendicular to the longitudinal direction of the main chamber, the reaction force that the sub-chamber receives from the instrument panel or the like can be efficiently transmitted to the main chamber.

[0016] The protrusion may be integrally formed with the main chamber, where "integrally formed" means formed as the same chamber, excluding the case where the main chamber and the protrusion are formed by connecting two different chambers.

[0017] The main chamber may be configured to deploy with a lower portion inclined relative to the vertical direction toward the occupant.

[0018] By deploying the main chamber with its lower portion inclined toward the occupant relative to the vertical direction, the main chamber comes into contact with the occupant more quickly than if it were simply inflated and deployed vertically, allowing the occupant to be restrained earlier.

[0019] The main chamber may have a bend near its upper end.

[0020] Bending the upper end of the main chamber makes it easy to adjust the starting point for deployment of the main chamber. For example, by positioning the bent portion forward of the boundary between the roof lining and windshield, the bent portion can receive the reaction force from the windshield, helping to ensure that the main chamber deploys toward the occupants.

[0021] The airbag may further include a horizontal chamber connected to the upper end of the main chamber and inflating and deploying along the roof portion, and the main chamber may be configured to inflate and deploy by gas flowing in from the horizontal chamber.

[0022] The horizontal chamber may be formed as a separate chamber from the main chamber, and inflation gas may flow from the horizontal chamber to the main chamber through a second vent.

[0023] The device may further include at least two tethers connected to the inner surface of the main chamber to restrict deployment of the main chamber in the front-to-rear direction.

[0024] The at least two tethers include an upper tether and a lower tether, and can be configured so that, when the airbag is deployed, the rear ends of the upper tether and the lower tether are positioned above and below the head of an occupant (THOR, AM50 dummy developed by the National Highway Traffic Safety Administration (NHTSA); 50th male (50% adult male dummy, height approximately 175 cm, weight approximately 78 kg) dummy and AF05 dummy (5% adult female dummy), or Hybrid III 5th female (5% adult female dummy, height approximately 145 cm, weight approximately 49 kg)). In the present invention, "occupant" refers to a dummy having a predetermined physique based on the above definition.

[0025] By configuring the rear ends of the upper and lower tethers to be located above and below the occupant's head, the occupant's head will be located between the two rear ends of the tethers when viewed from the side of the vehicle. This reduces the probability that the occupant's head will come into contact with the tether connecting part, which is harder than the cushion part, making it possible to softly support the occupant's head.

[0026] The length of the upper tether may be shorter than the length of the lower tether.

[0027] When viewed from the side of the vehicle, the upper tether may be provided so as to slope upward from the front to the rear, and the lower tether may be provided so as to slope downward from the front to the rear.

[0028] In the specification, claims and drawings of this application, "front" means the front of the vehicle (direction of travel), "rear" means the rear of the vehicle (opposite the direction of travel), "right" means the right side as viewed in the direction of travel, "left" means the left side as viewed in the direction of travel, and "vehicle width direction" means the left-right direction.

[0029] Fig. 1 is a side view showing the interior of a vehicle equipped with an airbag device according to the present invention. Fig. 2 is a side view showing the deployed state of an airbag according to a first embodiment of the present invention. Figs. 3(A) and 3(B) are cross-sectional views showing the initial deployed state (A) and the fully deployed state (B) of the airbag according to the first embodiment of the present invention. Fig. 4 is a side view showing the deployed state of an airbag according to a second embodiment of the present invention. Fig. 5 is a side view showing the deployed state of an airbag according to a third embodiment of the present invention.

[0030] Hereinafter, a passenger airbag device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, experimental dummies are used as the reference for occupants P0 and P1, but it goes without saying that the device functions similarly for actual occupants (humans). Occupant P0 corresponds to a THOR AM50 dummy, and occupant P1 corresponds to a THOR AF05 dummy.

[0031] Fig. 1 is a side view showing the interior of a vehicle equipped with an airbag device according to the present invention. Fig. 2 is a side view showing the deployed state of an airbag according to a first embodiment. The embodiments shown in Figs. 1 to 5 are all assumed to be airbag devices for a passenger seat, and an instrument panel 20 is disposed in front of the occupant.

[0032] As shown in Figure 1, an airbag device 14 according to the present invention protects occupants (P0, P1) seated in a seat 11 in a vehicle interior 10, and is housed in a roof portion 12. The airbag device 14 includes an inflator 16 that generates inflation gas, and airbags 17, 18 that are inflated and deployed by the inflation gas released from the inflator 16 (see Figure 2). The inflator 16 and airbags 17, 18 are housed in a housing 15. Note that the housing 15 is not an essential component, and the airbags 17, 18 and inflator 16 may also be held in place by wrapping cloth or straps.

[0033] The airbag device 14 is often installed inside the roof lining (not shown), but can also be installed outside the roof lining. The airbag device 14 can also be located near the boundary between the windscreen (front glass) 24 and the roof lining, for example, behind a sun visor (not shown).

[0034] 2, the airbags 17, 18 are configured to protect the occupants P0, P1 by deploying from the roof portion 12 of the vehicle in front of the occupants P0, P1 within the vehicle interior 10. The airbags 17, 18 include a main chamber 17 that deploys downward and a sub-chamber 18 that deploys below the main chamber 17 and protrudes forward of the vehicle. The sub-chamber 18 can also be referred to as a protrusion.

[0035] The main chamber 17 and the sub-chamber 18 are formed into bags using separate base fabrics and are connected by sewing around the vent hole 22. The vent hole 22 corresponds to the first vent. Inflation gas flows from the main chamber 17 to the sub-chamber 18.

[0036] When viewed from the side of the vehicle, the vent hole 22 is located below the center C1 of the main chamber in the longitudinal direction L1. By providing the vent hole 22, which connects the main chamber 17 and the sub-chamber 18, at a lower position in this way, the deployment position of the sub-chamber 18 is lowered, allowing the sub-chamber 18 to quickly come into contact with the instrument panel 20, etc. Furthermore, the sub-chamber 18 deploys close to the knees of the occupant, which is expected to have the same effect as a knee airbag in protecting the occupant's lower legs.

[0037] The sub-chamber 18 is configured to deploy in a direction L2 that is generally perpendicular to the longitudinal direction L1 of the deployed main chamber 17. This allows the reaction force that the sub-chamber 18 receives from the instrument panel 20 and the like to be efficiently transmitted to the main chamber 17.

[0038] The main chamber 17 is configured to deploy with its lower portion inclined toward the occupant in the vertical direction (UD direction), which allows the main chamber 17 to come into contact with the occupant, particularly the abdomen, more quickly than if the main chamber 17 were to simply inflate and deploy in the vertical direction (UD direction).

[0039] A horizontal chamber 28 that inflates and deploys along the roof portion 12 is provided at the upper end of the main chamber 17, and the inflator 16 is housed inside the horizontal chamber 28. The main chamber 17 is inflated and deployed by gas that flows in from the horizontal chamber 28.

[0040] A bent portion 26 is formed at the boundary between the main chamber 17 and the horizontal chamber 28. By bending the main chamber 17 near its upper end, it is possible to easily adjust the starting point of the deployment direction of the main chamber 17. For example, by positioning the bent portion 26 forward of the boundary between the roof lining (12) and the windshield 24, the upper surface of the bent portion 26 receives a reaction force from the windshield 24, causing the main chamber 17 to inflate and deploy in a direction intersecting the windshield 24. This makes it easier for the main chamber 17 to deploy in a direction roughly perpendicular or perpendicular to the windshield 24. As a result, it is possible to reliably control the deployment direction L1 of the main chamber 17.

[0041] Two tethers (an upper tether 30 and a lower tether 32) that restrict deployment of the main chamber 17 in the fore-and-aft direction are connected to the inner surface of the main chamber 17. The front ends (30a, 32a) of these tethers 30, 32 are connected by sewing to the inside of the front surface of the main chamber 17, and the rear ends (30b, 32b) are connected by sewing to the inside of the back surface (rear surface) of the main chamber 17. The rear ends (30b, 32b) of the upper tether 30 and the lower tether 32 are positioned above and below the heads of occupants P0 and P1.

[0042] By configuring the rear ends (30b, 32b) of the upper tether 30 and the lower tether 32 to be positioned above and below the heads of the occupants P0 and P1, when viewed from the side of the vehicle, the occupant's head is positioned between the two rear ends 30b, 32b of the tethers 30, 32. Therefore, the occupant's head is less likely to come into contact with the tether connecting parts (30b, 32b), which are harder than the cushion parts, and the occupant's head can be gently received.

[0043] The length of the upper tether 30 is shorter than the length of the lower tether 32. When viewed from the side of the vehicle, the upper tether 30 is provided so as to slope upward from the front to the rear, and the lower tether 32 is provided so as to slope downward from the front to the rear.

[0044] By providing the upper tether 30 so as to slope upward from the front to the rear, and providing the lower tether 32 so as to slope downward from the front to the rear, it is possible to form a wider area on the surface of the inflated main chamber 17 that restrains the occupant, where the occupant's head can be softly received without coming into contact with the tether connecting portions (30b, 32b), as shown in Figure 2. Although the head positions of occupant P0 corresponding to an adult male dummy and occupant P1 corresponding to an adult female dummy are different, the head of either occupant can be reliably restrained in the area between the rear end 30b of the upper tether 30 and the rear end 32b of the lower tether 32.

[0045] 3A and 3B are cross-sectional views showing the airbag according to the first embodiment in an initial deployment state (A) and a fully deployed state (B). Note that tethers and other components are omitted from Fig. 3 to clearly illustrate the deployment behavior of the airbags 17 and 18. The airbags 17 and 18 are housed in a housing 15 in a folded state, and when a collision is detected and the airbag device 14 is activated, a portion of the roof lining breaks, causing the airbags to deploy into the vehicle cabin.

[0046] As shown in Figure 3A, in the initial stage, the main chamber 17 first deploys diagonally downward from the roof of the vehicle interior. At this time, the bent portion 26 comes into contact with the inner surface of the windshield 24 and can receive the reaction force from the windshield. Furthermore, because the main chamber 17 deploys quickly at a position close to the occupant, the main chamber 17 reliably restrains the occupant from moving forward.

[0047] Next, as shown in Figure 3(B), the inflation gas filled in the main chamber 17 flows into the sub-chamber 18 through the vent hole 22. This causes the sub-chamber 18 to deploy forward. The sub-chamber 18 quickly comes into contact with the instrument panel 20 and receives a reaction force from the instrument panel 20, stabilizing the deployment behavior of the sub-chamber 18 and the main chamber 17.

[0048] Second Embodiment Fig. 4 is a side view showing the deployed state of an airbag according to a second embodiment of the present invention. Components that are the same as or correspond to those in the first embodiment described above are given the same reference numerals, and redundant explanations will be omitted. In this embodiment, a protrusion 118 is formed integrally with the main chamber 117 so as to deploy in a manner that protrudes forward of the vehicle from a lower portion of the main chamber 117. In other words, the main chamber 117 and the protrusion 118 are formed as a single chamber, and are not structured to connect two different chambers.

[0049] As in the first embodiment, the main chamber 117 is configured to deploy with its lower portion inclined relative to the vertical direction (U-D direction) toward the occupant. A horizontal chamber 128 is provided at the upper end of the main chamber 117, and is continuous with the main chamber 117 and inflates and deploys along the roof portion 12. The inflator 16 is housed inside the horizontal chamber 128. The main chamber 117 is inflated and deployed by gas flowing in from the horizontal chamber 128.

[0050] A bent portion 126 is formed at the boundary between the main chamber 117 and the horizontal chamber 128. The basic structure and function of the bent portion 126 are similar to those of the bent portion 26 in the first embodiment.

[0051] Two tethers (upper tether 130 and lower tether 132) that regulate the deployment of the main chamber 117 in the front-to-rear direction are connected to the inner surface of the main chamber 117. The front ends (130a, 132a) of these tethers 130, 132 are connected by sewing to the inside of the front surface of the main chamber 117, and the rear ends (130b, 132b) are connected by sewing to the inside of the back surface (rear surface) of the main chamber 117. The basic structure and function of the upper tether 130 and the lower tether 132 are similar to the tethers 30, 32 in the first embodiment.

[0052] In this embodiment, the airbags 117, 118 are stored in a folded state within the housing 15, and when a collision is detected and the airbag device is activated, a portion of the roof lining breaks and the airbags are deployed into the vehicle cabin.

[0053] In the initial stage of airbag deployment, the main chamber 117 first deploys diagonally downward from the roof of the vehicle interior. Simultaneously with or slightly after the deployment of the main chamber 117, the protrusion 118 deploys forward.

[0054] 5 is a side view showing the deployed state of an airbag according to a third embodiment of the present invention. Components identical to or corresponding to those in the first and second embodiments are designated by the same reference numerals, and redundant explanations will be omitted.

[0055] This embodiment is an arrangement of the first embodiment described above, and a horizontal chamber 228 that is connected to the upper end of the main chamber 17 and inflates and deploys along the roof portion is provided separately from the main chamber 17. The main chamber 17 is inflated and deployed by gas that flows in from the horizontal chamber 228 through a vent hole 228a. The vent hole 228a corresponds to a second vent.

[0056] By making the horizontal chamber 228 a separate chamber from the main chamber 17, it is possible to adjust the flow direction and flow rate of the inflation gas flowing into the main chamber 17, as well as the deployment position and deployment direction (L1) of the main chamber 17, by adjusting the shape and length of the horizontal chamber 228 and the position of the vent hole 228a.

[0057] (Interpretation of the technical scope of the present invention) Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of the technical ideas expressed in the claims.

[0058] REFERENCE SIGNS LIST 10 Vehicle interior 14 Airbag device 17 Main chamber 18 Sub-chamber 22 Vent hole 24 Windshield 26 Bent portion 28 Horizontal chamber 30 Upper tether 30a Front end portion 30b Rear end portion 32 Lower tether 32a Front end portion 32b Rear end portion 118 Protrusion 228a Vent hole

Claims

1. An airbag device equipped with an airbag that protects an occupant by deploying in front of the occupant inside a vehicle cabin, the airbag device comprising: a main chamber that deploys downward from a roof portion of the vehicle; and a protrusion that deploys from a lower portion of the main chamber so as to protrude forward of the vehicle.

2. The airbag device according to claim 1, wherein the protrusion is a sub-chamber that is provided in fluid communication with the main chamber and is configured to be inflated and deployed by gas flowing from the main chamber via the first vent.

3. The airbag device according to claim 2, wherein the first vent is located below the center of the main chamber in the longitudinal direction when viewed from the side of the vehicle.

4. The airbag device according to claim 2, characterized in that, when viewed from the side of the vehicle, the sub-chamber is configured to deploy in a direction generally perpendicular to the longitudinal direction of the main chamber in the deployed state.

5. The airbag device according to claim 1, wherein said protrusion is formed integrally with said main chamber.

6. The airbag device according to claim 1, wherein the main chamber is configured to deploy with a lower portion inclined with respect to the vertical direction toward the occupant.

7. The airbag device according to claim 1, wherein the main chamber has a bent portion near an upper end thereof.

8. The airbag device according to claim 1, further comprising a horizontal chamber connected to an upper end of the main chamber and inflated along the roof portion, the main chamber being configured to inflate and deploy by gas flowing in from the horizontal chamber.

9. The airbag device according to claim 8, wherein the horizontal chamber is formed as a chamber separate from the main chamber, and wherein inflation gas flows from the horizontal chamber to the main chamber through a second vent.

10. An airbag device as claimed in any one of claims 1 to 8, further comprising at least two tethers connected to the inner surface of said main chamber for restricting the deployment of said main chamber in the front-rear direction.

11. The airbag device according to claim 10, wherein the at least two tethers include an upper tether and a lower tether, and when the airbag is deployed, rear ends of the upper tether and the lower tether are located above and below the head of an occupant (corresponding to a THOR AM50 dummy developed by the NHTSA: National Highway Traffic Safety Administration).

12. The airbag device according to claim 10, wherein the at least two tethers include an upper tether and a lower tether, and rear ends of the upper tether and the lower tether are positioned above and below the head of an occupant (corresponding to a THOR AF05 dummy in the standard developed by the NHTSA: National Highway Traffic Safety Administration) when the airbag is deployed.

13. The airbag device according to claim 11, wherein the length of the upper tether is set shorter than the length of the lower tether.

14. The airbag device according to claim 12, wherein the length of said upper tether is set shorter than the length of said lower tether.

15. An airbag device as described in claim 13, characterized in that, when viewed from the side of the vehicle, the upper tether is arranged to slope upward from the front to the rear, and the lower tether is arranged to slope downward from the front to the rear.

16. An airbag device as described in claim 14, characterized in that, when viewed from the side of the vehicle, the upper tether is arranged to slope upward from the front to the rear, and the lower tether is arranged to slope downward from the front to the rear.

17. The airbag device according to claim 7, characterized in that, when inflated and deployed, the upper surface of the bent portion receives a reaction force from the windshield of the vehicle, causing the main chamber to inflate and deploy in a direction intersecting the windshield.

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