Airbag device

Abstract

[Problem] To provide an airbag device that comprises an airbag that deploys from a roof portion of a cabin and that can appropriately protect an occupant. [Solution] The present invention is an airbag device that protects an occupant in a cabin of a vehicle, and comprises: a front airbag which inflates and deploys forward of the occupant seated in a seat; and an inflator which supplies an inflation gas to the front airbag. The front airbag is configured to include: a first chamber that deploys downward from the roof portion of the vehicle; and a second chamber that deploys forward of the first chamber.

Description

[Technical Field]

[0001] The present invention relates to an airbag device for protecting occupants in a vehicle, and more particularly to an improvement in an airbag device having an airbag that deploys from the roof portion of the vehicle compartment. [Background technology]

[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 from 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, as autonomous driving technology (level) for vehicles has advanced, the degree of freedom in vehicle interior design has increased. Under these circumstances, there is a risk that airbags that deploy from the steering wheel or instrument panel may not be able to adequately protect occupants. Therefore, as disclosed in Patent Documents 1 and 2, methods have been proposed in which airbags are deployed from the roof of the vehicle interior.

[0004] However, in the inventions disclosed in Patent Documents 1 and 2, the airbag is deployed toward the windshield, which may not adequately restrain the occupant depending on the occupant's physique and seating position. For example, if the seat is set to the forward-most position, there is a risk that the occupant's head will collide with the instrument panel before the airbag reaches the occupant. Also, in vehicles equipped with a large display monitor on the instrument panel, there is a risk that the deployed airbag will interfere with the monitor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent No. 2686206 [Patent Document 2] U.S. Patent No. 6,460,878 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides an airbag device for protecting an occupant in a vehicle cabin, comprising: a front airbag that inflates and deploys in front of the occupant seated in a seat; and an inflator that supplies inflation gas to the front airbag. The front airbag is configured to include a first chamber that deploys downward from the roof of the vehicle, and a second chamber that deploys in front of the first chamber.

[0008] Here, "in front of the occupant seated in the seat" can be thought of as, for example, the area between the occupant's head and the instrument panel. Also, "below" does not necessarily mean a completely vertical direction, but also includes a slight incline or curve.

[0009] Furthermore, the phrase "the front airbag deploys from the roof portion" includes, for example, a configuration in which the folded airbag is housed inside the roof lining and deploys into the vehicle cabin by rupturing a portion of the roof lining when the airbag device is activated, but does not exclude a configuration in which the folded airbag is installed outside the roof lining (on the vehicle cabin side).

[0010] As described above, the first chamber deploys downward from the roof of the vehicle, allowing the front airbag to deploy quickly in front of the occupant. In addition, because the second chamber deploys in front of the first chamber, it is possible to control the deployment behavior and shape of the entire front airbag by adjusting the arrangement, connection method, volume ratio, etc. of the first and second chambers.

[0011] The second chamber can be connected to the front of the first chamber. A communication port through which gas flows can be provided at the connection between the first chamber and the second chamber, and the inflation gas can be configured to flow from the first chamber to the second chamber through the communication port.

[0012] As described above, by configuring the inflation gas to flow from the first chamber to the second chamber, the first chamber can be deployed quickly first, making it possible to quickly restrain the forward movement of the occupant.

[0013] The communication port may be provided with a check valve to prevent inflation gas that has flowed into the second chamber from flowing back into the first chamber.

[0014] The check valve may be configured to close when the internal pressure of the second chamber reaches or exceeds a predetermined pressure.

[0015] For example, if a large occupant enters the first chamber, the internal pressure of the first chamber increases, the check valve opens, and inflation gas flows from the first chamber to the second chamber. This increases the longitudinal stroke (impact absorption range) of the entire front airbag, thereby providing adequate protection for the occupant.

[0016] On the other hand, when a small occupant enters the first chamber, the internal pressure of the first chamber does not increase so much that the check valve does not open or opens slightly, resulting in no or only a small amount of inflation gas flowing from the first chamber to the second chamber. This results in a small overall inflation of the front airbag, providing gentle protection for the occupant.

[0017] The second chamber can be connected to the first chamber below the center in the up-down direction.

[0018] The first chamber may be configured to deploy behind an instrument panel.

[0019] Here, the "instrument panel" refers to the part of the vehicle located in front of the front seats and below the windscreen (windshield), which is generally made of resin and is sometimes called the dashboard.

[0020] The second chamber may be configured to inflate and deploy between the first chamber and the instrument panel.

[0021] The first chamber preferably has a larger volume than the second chamber.

[0022] The airbag device may further include a knee airbag that deploys from the lower part of the instrument panel toward the occupant's lower legs, and may be configured so that the lower end of one of the first chamber and the second chamber contacts the upper end of the knee airbag.

[0023] As described above, the lower end of at least one of the inflated first chamber and second chamber comes into contact with the upper end of the knee airbag, which has the advantage of supporting the lower side of the front airbag by the knee airbag and stabilizing the deployment behavior of the front airbag.

[0024] The first chamber may be formed with a first vent port for venting the inflation gas.

[0025] The second chamber may be configured without an exhaust port for exhausting the inflation gas.

[0026] The first chamber may be formed with a slit- or slot-shaped vent opening extending in the vertical direction, and may be configured to open wide when the lower end of the first chamber is subjected to pressure by some kind of obstacle.

[0027] For example, in situations where there is fragile luggage (obstacle) on the seat, or where a small child is lying down on the seat, or where a pet such as a dog or cat is sitting on the seat, it is possible to avoid situations where excessive pressure is applied to these obstacles and damage them.

[0028] The term "vertical direction" does not necessarily mean a completely vertical direction, but also includes a situation where the vent opening is tilted to some extent. In short, it is sufficient that the vent opening is configured so that it opens wide when an obstacle is placed on the seat.

[0029] The first chamber may be configured to deploy downward from near the boundary between the roof and the windscreen of the vehicle.

[0030] For example, in a typical vehicle, the first chamber can be deployed from a portion corresponding to the back side of the sun visor.

[0031] The second chamber can be configured to inflate and deploy between the first chamber and the windscreen, allowing the second chamber to utilize the reaction force from the windscreen during deployment, stabilizing the deployment behavior of the front airbag.

[0032] 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 in the direction of travel, "left" means the left side in the direction of travel, and "vehicle width direction" means the left-right direction. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 1 is a side view showing the interior of a vehicle equipped with an airbag device according to the present invention. [Figure 2] 2(A) and 2(B) are side views showing the deployed state of the front airbag according to the first embodiment of the present invention. [Figure 3] Fig. 3(A) is a front view showing the structure of a front airbag according to a first embodiment of the present invention, and Fig. 3(B) is a cross-sectional view taken along the line BB in Fig. 3(A). [Figure 4] 4(A) and 4(B) are cross-sectional views showing a first deployed state (A) and a second deployed state (B) of a front airbag according to a first embodiment of the present invention. [Figure 5] 5(A) and 5(B) are side views showing the deployed state of the airbag device according to the first embodiment of the present invention. [Figure 6] 6(A) and 6(B) are side views showing the deployed state of the airbag device according to the first embodiment of the present invention. [Figure 7] 7(A) and (B) are side views showing the deployed state of an airbag device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] 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, the occupants P0 and P1 are based on experimental dummies, but it goes without saying that the device functions in the same way when an actual occupant (human) is used. In the present invention, the term "occupant" refers to a dummy used in a frontal collision test (Hybrid III AM50 / NHTSA [National Highway Traffic Safety Administration (49 CFR The test is based on the frontal impact test dummy (human body dummy for frontal impact tests specified in Part 572 Subparts E and O). Occupant P0 is AM50 equivalent, with a physique equivalent to that of an average male in the United States, with approximate dimensions of 175 cm in height, 88 cm in seated height, and approximately 78 kg in weight. Occupant P1 is AF05 equivalent of the same standard, with the physique of a petite female in the United States (145 cm in height, 79 cm in seated height, and approximately 49 kg in weight).

[0035] Fig. 1 is a side view showing the interior of a vehicle equipped with an airbag device according to the present invention. Figs. 2(A) and (B) are side views showing the deployed state of a front airbag according to a first embodiment of the present invention. Fig. 3(A) is a front view showing the structure of a front airbag according to a first embodiment of the present invention. Fig. 3(B) is a cross-sectional view taken along the line BB in Fig. 3(A).

[0036] As shown in Figure 1, the airbag device according to the embodiment of the present invention protects an occupant P0 seated in a seat 11 in a vehicle interior 10, and includes a front airbag unit 14 housed in a roof portion 12 and a knee airbag unit 20 housed in an instrument panel 18. The front airbag unit 14 includes an inflator 16 that generates inflation gas. Similarly, the knee airbag unit 20 includes an inflator 22 that generates inflation gas.

[0037] The front airbag unit 14 is installed inside the roof portion 12, but can also be installed outside the roof portion 12. The front airbag unit 14 can also be located near the boundary between the windscreen (front glass) 24 and the roof lining 12, and can be installed, for example, behind a sun visor (not shown).

[0038] The front airbags 28, 30 are basically configured to deploy behind the monitor 26 mounted on the instrument panel 18.

[0039] 2(A), (B) and 3, the front airbag unit 14 includes front airbags 28, 30 that are inflated and deployed in front of the occupant P0 by inflation gas supplied from the inflator 16. The front airbags 28, 30 include a first chamber 28 that deploys downward from the roof portion 12 of the vehicle, and a second chamber 30 connected in front of the first chamber 28. Inflation gas flows from the first chamber 28 to the second chamber 30.

[0040] As shown in FIG. 2(A), the first chamber 28 and the second chamber 30 deploy behind the monitor 26 installed on the instrument panel 18. However, as shown in FIG. 2(B), the second chamber 30 can also be deployed between the first chamber 28 and the windscreen 24. In this case, when the second chamber 30 deploys, it can receive a reaction force from the windscreen 24. In order to achieve the deployment mode of the second chamber 30 shown in FIG. 2(B), it is possible to devise a method such as increasing the capacity of the second chamber 30. Furthermore, the second chamber 30 may deploy toward the windscreen 24 even when the monitor 26 is low or does not protrude above the instrument panel 18.

[0041] An exhaust port 34 is formed on the side of the first chamber 28, which has a larger capacity, so that gas inside the first chamber 28 can be discharged to the outside. On the other hand, the second chamber 30, which has a smaller capacity, does not have an exhaust port. However, an exhaust port of an appropriate size can be formed in the second chamber 30 if necessary.

[0042] Knee airbag unit 20 includes knee airbag 32 that is inflated and deployed toward the lower legs of the occupant by inflation gas supplied from inflator 22.

[0043] 2, when front airbags 28, 30 and knee airbag 32 are fully deployed, the lower end of second chamber 30 comes into contact with the upper end of knee airbag 32. In the figure, reference numeral 36 denotes the connection point between first chamber 28 and second chamber 30, and reference numeral 38 denotes the contact point between the lower end of second chamber 30 and the upper end of knee airbag 32.

[0044] 3, the capacity of the second chamber 30 is set to be smaller than the capacity of the first chamber 28. The second chamber 30 is connected to the first chamber 28 below the center C in the up-down direction.

[0045] Two circular communication ports 40a, 40b are formed at the connection point 36 between the first chamber 28 and the second chamber 30, and the outer peripheries of these communication ports 40a, 40b are connected by sewing. In addition, check valves 42a, 42b are provided in the communication ports 40a, 40b to prevent inflation gas that has flowed into the second chamber 30 from flowing back into the first chamber 28. The check valves 42a, 42b are configured to open when the internal pressure of the first chamber 28 reaches a predetermined pressure.

[0046] The check valves 42a, 42b are flexible fabric members arranged to cover the communication ports 40a, 40b, and may be made of, for example, the same fabric as the airbag. Ends of the check valves 42a, 42b are connected to the inner surface of the second chamber 30 by sewing.

[0047] The check valves 42a, 42b become convex toward the inside of the second chamber 30 due to the gas flowing from the first chamber 28 into the second chamber 30, opening the communication ports 40a, 40b and allowing gas to flow from the first chamber 28 into the second chamber 30. Thereafter, the check valves 42a, 42b are closed by the gas pressure inside the second chamber 30, preventing gas from flowing back into the first chamber 28. On the other hand, if the internal pressure of the first chamber 28 does not rise sufficiently, the communication ports 40a, 40b will remain closed by the check valves 42a, 42b.

[0048] Figures 4(A) and (B) are cross-sectional views showing the first deployed state (A) and the second deployed state (B) of the front airbags 28, 30 according to the first embodiment of the present invention, and correspond to the cross section in the direction BB in Figure 3(A). Figures 5(A) and (B) are side views showing the deployed state of the airbag when the occupant P1 has a small build.

[0049] As shown in FIG. 5(A), when a vehicle collision event occurs, the first chamber 28 of the front airbags 28, 30 begins to deploy downward in front of the occupant P1.

[0050] Thereafter, as shown in Fig. 5(B), when the occupant P1 enters the first chamber 28 while the first chamber 28 is nearly fully deployed, the internal pressure of the first chamber 28 does not increase significantly due to the small build of the occupant P1. Therefore, as shown in Fig. 4(A), the check valves 42a, 42b do not open, and inflation gas does not flow from the first chamber 28 to the second chamber 30, causing the front airbags 28, 30 to inflate to a small size overall. As a result, the occupant can be gently received and protected.

[0051] Furthermore, by the lower end of first chamber 28 coming into contact with the upper end of knee airbag 32, first chamber 28 does not drop more than necessary, and the deployed shape and deployed posture of first chamber 28 are stabilized.

[0052] 6(A) and 6(B) are side views showing the deployed state of the airbag when the occupant P0 is large in size.

[0053] As shown in FIG. 6(A), when a vehicle collision occurs, the first chamber 28 of the front airbags 28, 30 first begins to deploy downward in front of the occupant P1.

[0054] Thereafter, as shown in Fig. 6(B), when the occupant P1 enters the first chamber 28 with the first chamber 28 substantially fully deployed, the internal pressure of the first chamber 28 increases due to the large build of the occupant P1. As a result, as shown in Fig. 4(B), the check valves 42a, 42b open, and inflation gas flows from the first chamber 28 into the second chamber 30, causing the second chamber 30 to also fully deploy, as shown in Fig. 6(B). As a result, the longitudinal stroke (impact absorption range) of the entire front airbags 28, 30 increases, and the longitudinal movement of the occupant P0 can be reliably restrained.

[0055] Furthermore, the bottom of front airbags 28, 30 is supported by the lower end of second chamber 30 coming into contact with the upper end of knee airbag 32, and the deployed shape and deployed posture of front airbags 28, 30 are stabilized.

[0056] 7(A) and (B) are side views 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 duplicate explanations will be omitted. FIG. 7(A) shows a situation in which no occupant is seated in seat 11, and FIG. 7(B) shows a situation in which an obstacle 170 is placed on the seating surface of seat 11. The situation shown in FIG. 7(B) can be considered equivalent to a situation in which a small child is seated or lying down. For convenience of explanation, a knee airbag is not shown, but in reality, a knee airbag may be installed.

[0057] 7(A), in addition to the exhaust port 134, a slit 160 is formed on the side surface of the first chamber 128. The other configurations are basically the same as those of the first embodiment described above. The slit 160 extends in the vertical direction and can be a simple cut with no width, or a slot shape with a certain horizontal width.

[0058] As shown in Figure 7(A), when a vehicle collision occurs with no occupant seated in the seat 11, the first chamber 128 of the front airbag begins to deploy downward from the roof portion 12 behind the monitor 26. Even when the first chamber 128 is almost fully deployed, the internal pressure of the first chamber 128 does not increase because there is no occupant, and as shown in Figure 4(A), the check valves 42a and 42b do not open, inflation gas does not flow from the first chamber 128 to the second chamber 130, and the second chamber 130 does not deploy.

[0059] On the other hand, as shown in FIG. 7(B), if a vehicle collision occurs while an obstacle 170 is placed on the seat surface of the seat 11, the first chamber 128 of the front airbag begins to deploy downward from the roof portion 12 behind the monitor 26. The lower end of the first chamber 128 comes into contact with the obstacle 170, preventing the first chamber 128 from deploying downward. The first chamber 128 widens horizontally, and the slit 160 widens in the front-to-rear direction (horizontally) to open widely. As a result, the internal pressure of the first chamber 128 does not increase, and as shown in FIG. 4(A), the check valves 42a and 42b do not open. As a result, inflation gas does not flow from the first chamber 128 to the second chamber 130, and the second chamber 130 does not deploy. Furthermore, excessive pressure on the obstacle 170 located on the seat 11 is prevented, reducing the possibility of damage to the obstacle 170.

[0060] (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 concept expressed in the claims.

Claims

1. An airbag device for protecting an occupant in a vehicle compartment, A front airbag that inflates and deploys in front of the occupant seated in the seat; an inflator that supplies inflation gas to the front airbag; The front airbag includes a first chamber that deploys downward from a roof portion of the vehicle and a second chamber that deploys in front of the first chamber, The first chamber is formed with a first exhaust port for exhausting the inflation gas and a slit-shaped or slot-shaped vent opening extending in the vertical direction, An airbag device, characterized in that the vent opening is configured to open widely when a lower end of the first chamber is subjected to pressure by some obstacle.

2. 2. The airbag device according to claim 1, wherein the second chamber is connected to a front side of the first chamber.

3. a communication port through which gas flows is provided at a connecting portion between the first chamber and the second chamber; 3. The airbag device according to claim 2, wherein the inflation gas flows from the first chamber to the second chamber through the communication port.

4. A check valve is provided in the communication port, 4. The airbag device according to claim 3, wherein the airbag device is configured so that inflation gas that has flowed into the second chamber does not flow back into the first chamber.

5. 5. The airbag device according to claim 4, wherein the check valve is configured to close when the internal pressure of the second chamber reaches or exceeds a predetermined pressure.

6. 6. The airbag device according to claim 2, wherein the second chamber is connected to the first chamber below a center thereof in the up-down direction.

7. 6. The airbag device according to claim 1, wherein the first chamber is configured to deploy behind an instrument panel.

8. 8. The airbag device according to claim 7, wherein the second chamber is configured to inflate and deploy between the first chamber and the instrument panel.

9. 6. The airbag device according to claim 1, wherein the first chamber has a larger capacity than the second chamber.

10. The front airbag includes a knee airbag that deploys from a lower portion of the instrument panel toward the lower legs of the occupant, 6. The airbag device according to claim 1, wherein a lower end of at least one of the first chamber and the second chamber is in contact with an upper end of the knee airbag.

11. An airbag device as described in claim 1, characterized in that the second chamber does not have an exhaust port for exhausting the inflation gas.

12. An airbag device as described in any one of claims 1 to 5, characterized in that the first chamber deploys downward from near the boundary between the roof and windscreen of the vehicle.

13. An airbag device as described in any one of claims 1 to 5, characterized in that the second chamber is configured to inflate and deploy between the first chamber and the windscreen.

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