Pedestrian protection airbag system

Abstract

[Problem] To provide a pedestrian protection airbag apparatus that is capable of reliably and promptly deploying an airbag in a desired direction. [Solution] The protection airbag apparatus according to the present invention comprises: an airbag that deploys from the boundary section between the hood and the windshield of a vehicle to thereby protect a pedestrian or the like which has collided with the vehicle; and a flap that is provided on the outer periphery of the folded airbag and is capable of controlling the deployment direction of the airbag. The flap comprises a weak section that ruptures or is opened, due to the airbag deploying and inflating, such that the airbag can deploy in a desired deployment direction.

Description

[Technical Field]

[0001] The present invention relates to a pedestrian protection airbag device that protects pedestrians and cyclists in a collision with a vehicle. [Background technology]

[0002] It is well known that vehicles are equipped with one or more airbag devices to protect occupants in the event of a vehicle accident. Airbag devices include various types, such as driver airbag devices that deploy an airbag near the center of the steering wheel to protect the driver, curtain airbag devices that deploy an airbag downward inside the vehicle window to protect occupants in the event of a lateral impact, rollover, or rollover accident, and side airbag devices that deploy an airbag between the occupant and the side panel to protect the occupant in the event of a lateral impact. There are also pedestrian protection airbag devices that protect pedestrians and cyclists in the event of a vehicle collision.

[0003] Some pedestrian protection airbag devices have a rod-shaped compressed airbag that is positioned near the boundary between the hood and windshield of the vehicle so that it extends laterally (in the vehicle width direction). In such pedestrian protection airbag devices, it is difficult to control the deployment direction of the airbag, and there is a risk that it will not deploy quickly in the desired direction.

[0004] For example, even if it is desired to quickly deploy an airbag over the hood, the airbag may deploy upward in the initial stage of deployment, resulting in a momentary delay before it assumes the appropriate deployed shape along the hood. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-200800 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a pedestrian protection airbag device that can reliably and quickly deploy an airbag in a desired direction.

[0007] In particular, the object is to provide a pedestrian protection airbag device that can reliably protect pedestrians and cyclists by quickly deploying the airbag onto the hood. [Means for solving the problem]

[0008] In order to solve the above problems, the protective airbag device of the present invention includes an airbag that deploys from the boundary between the hood and windshield of a vehicle to protect a pedestrian or the like in a collision with the vehicle, and a flap that is provided on the outer periphery of the folded airbag and can control the deployment direction of the airbag. The flap has a weakened portion that breaks or opens as the airbag inflates and deploys, so that the airbag can deploy in a desired direction.

[0009] In the specification and claims of this application, the direction of travel of a vehicle traveling straight ahead is referred to as the "forward direction," the opposite direction is referred to as the "rearward direction," and when indicating a coordinate axis, it is referred to as the "front-rear direction." Furthermore, the terms "right side" and "left side" refer to the right and left sides of the vehicle when facing forward in the width direction of the vehicle, which is perpendicular to the direction of travel of the vehicle, and when indicating a coordinate axis, they are referred to as the "left-right direction" or "left-right width direction."

[0010] In the above invention, the object of protection by the airbag is defined as "pedestrians, etc.", and the object of protection includes not only pedestrians but also people riding bicycles (cyclists).

[0011] A "windshield" is sometimes called a "windscreen." A "bonnet" is sometimes called a "hood." The term "folded" is a concept that includes at least a state of being folded like an accordion and a state of being rolled.

[0012] According to the present invention configured as described above, the flap holds the compressed (rolled or folded) airbag, and the weak portion is provided in the deployment direction, so that the airbag can be deployed reliably in the desired direction. That is, by adjusting the position of the weak portion, the deployment direction of the airbag can be appropriately controlled. Furthermore, by adjusting the degree of weakness of the weak portion, the deployment timing of the airbag can be controlled. For example, by making the weak portion difficult to break, the timing of full deployment of the airbag can be delayed. Conversely, by making the weak portion easy to break, the timing of full deployment of the airbag can be advanced.

[0013] The "flap" is a fabric-like member made of a flexible material, and can be made of the same or similar fabric as the airbag. The shape of the flap can be rectangular, trapezoidal, or other shapes depending on the part of the airbag to which the flap is connected and the shape of the airbag itself.

[0014] The weakened portion may be formed in the vicinity of a rear region of the folded or rolled airbag. The "rear region" may also be a region on the windshield side opposite to the front of the vehicle.

[0015] By forming the weak part of the flap that holds the airbag near the rear region of the folded or rolled airbag, the airbag can be reliably deployed outward from the gap between the hood and the windshield without interfering with the hood and hindering deployment when it deploys.

[0016] The airbag includes a main chamber that can be deployed forward on the hood from the boundary portion, and the flap can be configured to hold the main chamber without the fragile portion breaking or opening until the main chamber reaches the hood as the airbag deploys.

[0017] Here, "until it reaches the top of the hood" does not necessarily mean that the entire main chamber is completely mounted on the hood, but also means that the main chamber is raised to a position that does not interfere with the main chamber's forward deployment on the hood.

[0018] By configuring the flap so that the weak portion does not break or open until the main chamber reaches the hood, it is possible to quickly and reliably push the main chamber up onto the hood.

[0019] The weakened portion may be formed near a front region of the main chamber of the folded airbag.

[0020] Here, "near the front region of the airbag" means a location corresponding to the front end of the airbag facing forward of the hood, but does not necessarily have to be the strict tip.

[0021] The weakened portion may be formed on the upper surface of the main chamber of the folded airbag.

[0022] The weakened portion may be a slit or a breakable stitching line.

[0023] The flap may be configured to hold the airbag, including the vicinity of the center of the airbag in the vehicle width direction.

[0024] The airbag may further include a sub-chamber connected to a lower portion of the main chamber and deployed prior to the main chamber.

[0025] The sub-chamber and the main chamber may be configured to be in fluid communication with each other via an inner vent.

[0026] The sub-chamber may have a smaller volume than the main chamber and may be configured to deploy under the hood.

[0027] By minimizing the volume of the subchamber, the subchamber can be deployed quickly.

[0028] The main chamber may be rolled or folded in a front-to-back direction, and the front and back edges of the flap may be connected to the front and back edges of the sub-chamber by stitching.

[0029] The main chamber in a rolled or folded state can be surrounded from the front and rear by the flap and the sub-chamber.

[0030] The flap can be configured to surround the main chamber and the sub-chamber in a rolled or folded state over the entire periphery in the front-to-rear direction.

[0031] The area of ​​the main chamber's front region that extends over the hood is larger than the area of ​​the main chamber's upper region that extends over the windshield, and the front region and the upper region can be rolled or folded separately.

[0032] The main chamber and the sub-chamber are preferably folded or rolled separately.

[0033] By folding or rolling the main chamber and sub-chamber independently, the main chamber does not get in the way of the sub-chamber when it first expands and deploys, allowing the sub-chamber to deploy smoothly and quickly.

[0034] In the present invention, the airbag is configured to deploy from the boundary between the hood and windshield of the vehicle, and the gap at the boundary can be enlarged by the deployment of the airbag itself. Alternatively, a lifter that pushes up the rear part of the hood may be provided to enlarge the gap at the boundary between the hood and windshield. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a top view showing a pedestrian protection airbag device according to the present invention in an activated (deployed) state. [Figure 2] 2A and 2B are plan views showing the structure of the airbag of the pedestrian protection airbag device according to the first embodiment of the present invention, where (A) is a top view and (B) is a bottom view. [Figure 3] FIG. 3 is a plan view showing the panel configuration of the airbag according to the first embodiment of the present invention. [Figure 4] 4(A) and 4(B) are plan views showing a method for manufacturing the pedestrian protection airbag device (a method for compressing the airbag) according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a plan view and a cross-sectional view showing a method for manufacturing the pedestrian protection airbag device according to the first embodiment of the present invention (a method for compressing the airbag continued from FIG. 4). [Figure 6] 6(A) and 6(B) are a plan view and a cross-sectional view showing a method for manufacturing a pedestrian protection airbag device according to the first embodiment of the present invention (a method for compressing an airbag continued from FIG. 5). [Figure 7] 7(A) and 7(B) are cross-sectional views showing the deployment behavior of the pedestrian protection airbag according to the first embodiment of the present invention. [Figure 8] 8(A) and 8(B) are cross-sectional views showing the deployment behavior of the pedestrian protection airbag according to the first embodiment of the present invention. [Figure 9] 9(A) and 9(B) are perspective views showing the deployed state of the pedestrian protection airbag according to the first embodiment of the present invention. [Figure 10]FIG. 10 is a cross-sectional view showing a pedestrian protection airbag according to a second embodiment of the present invention in a housed state. [Figure 11] 11A and 11B are plan views showing the structure of an airbag of a pedestrian protection airbag device according to a third embodiment of the present invention, where (A) is a top view and (B) is a bottom view. [Figure 12] FIG. 12 is a plan view showing the panel configuration of an airbag according to a third embodiment of the present invention. [Figure 13] 13(A) and 13(B) are plan views showing a method for manufacturing a pedestrian protection airbag device (a method for compressing an airbag) according to a third embodiment of the present invention. [Figure 14] FIG. 14 is a plan view and a cross-sectional view showing a method for manufacturing a pedestrian protection airbag device according to a third embodiment of the present invention (a method for compressing an airbag continued from FIG. 13). [Figure 15] 15(A) and 15(B) are a plan view and a cross-sectional view showing a method for manufacturing a pedestrian protection airbag device according to a third embodiment of the present invention (a method for compressing an airbag continued from FIG. 14). DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0037] (First Example) Fig. 1 is a top view showing the state of a pedestrian protection airbag device according to the present invention when activated (deployed). Fig. 2 is a plan view showing the structure of an airbag of a pedestrian protection airbag device according to a first embodiment of the present invention, (A) being a top view and (B) being a bottom view. Fig. 3 is a plan view showing the panel configuration of the airbag according to the first embodiment of the present invention.

[0038] The protective airbag device according to this embodiment includes an airbag 18 that deploys from a boundary 16 between the hood 12 and windshield 14 of the vehicle 10 to protect a pedestrian or the like that collides with the vehicle 10, and a flap 24 that is provided on the outer periphery of the folded airbag 18 and is capable of controlling the deployment direction of the airbag 18. The airbag 18 includes a main chamber 20 that can deploy forward on the hood 12 from the boundary 16. The flap 24 is configured to restrict the upward deployment of the main chamber 20.

[0039] As shown in FIGS. 2 and 3, the airbag 18 includes a main chamber 20 and a sub-chamber 22 that is connected to the lower part of the main chamber 20 and deploys prior to the main chamber 20 .

[0040] As shown in FIG. 2, when the airbag 18 is laid flat, the sub-chamber 22 is connected to the main chamber 20 in a state where it is offset rearward with respect to the center line L1 in the front-rear direction of the main chamber 20.

[0041] As shown in FIG. 3, the main chamber 20 includes a front region 20a that extends forward on the hood 12 and an upper region 20b that extends upward along the windshield 14. In the main chamber 20, the area of ​​the front region 20a is larger than the area of ​​the upper region 20b. Furthermore, the left and right ends of the upper region 20b protrude upward so as to cover a portion of the A-pillar 19 (see FIG. 1). The area ratio between the front region 20a and the upper region 20b can be changed as appropriate depending on the type of vehicle in which the airbag device is installed. For example, in the case of a truck, SUV, or the like in which the windshield 14 is positioned at an angle close to vertical, the area of ​​the upper region 20b can be made larger than that of the front region 20a.

[0042] A plurality of vent holes 26a are formed in the lower surface of the main chamber 20 to provide fluid communication with the sub-chamber 22. These holes are aligned with vent holes 26b formed in the upper surface of the sub-chamber 22 to form the inner vent 26. The periphery of the vent holes 26a in the main chamber 20 and the periphery of the vent holes 26b in the sub-chamber 22 are connected by sewing.

[0043] 3, in the main chamber 20 placed flat, the row of vent holes 26a is located rearward (upward in the figure) with respect to the center L1 in the front-to-back direction. Similarly, in the sub-chamber 22 placed flat, the row of vent holes 26b is located rearward (upward in the figure) with respect to the center L2 in the front-to-back direction.

[0044] The sub-chamber 22 is formed to have a smaller capacity than the main chamber 20. By minimizing the capacity of the sub-chamber 22, the sub-chamber 22 can be expanded quickly.

[0045] As shown in FIGS. 2 and 3, the sub-chamber 22 is provided with diffusers 30L and 30R for efficiently guiding gases emitted from the inflators 29L and 29R into the sub-chamber 22.

[0046] As shown in Fig. 3, the flap 24 is formed in a trapezoid shape with one side (the rear side in the figure) being wider, and has a slit 32 extending in the left-right direction formed near the center. In the present invention, a tearable stitching line can be used instead of the slit 32. What is important is that the slit 32 (weak portion) tears or opens as the airbag 18 deploys.

[0047] 2, one edge portion of the flap 24 in the front-to-rear direction (the wider edge portion in the figure) is connected by sewing to the vicinity of the rear edge of the sub-chamber 22 at a connecting point 33a. When the airbag 18 is folded, the other edge portion of the flap 24 in the front-to-rear direction (the narrower edge portion in the figure) is sewn to the front edge of the sub-chamber 22 at a connecting point 33b.

[0048] The flap 24 is a fabric-like member made of a flexible material, and can be made of, for example, the same or similar fabric as the airbag 18. The shape of the flap 24 can be a shape other than a trapezoid (for example, a rectangle, a square, a triangle, an oval, etc.) depending on the part of the airbag to which the flap is connected and the shape of the airbag itself.

[0049] The slit 32 of the flap 24 is configured to maintain the compressed state of the main chamber 20 without breaking or opening the flap until the main chamber 20 reaches above the hood 12 as the airbag 18 deploys. Here, in order to prevent the flap 24 from interfering with the main chamber 20 deploying forward above the hood 12, the flap may be formed with a length that is longer in the front-to-rear direction than the length of the airbag when folded, so that the flap is not broken only by the inflation and deployment of the sub-chamber 22, but only when the main chamber begins to inflate and deploy, for example by folding back a portion of the flap.

[0050] The slits 32 in the flap 24 are configured to maintain the compressed state of the main chamber 20 without breaking or opening until the main chamber 20 reaches the hood 12 as the airbag 18 deploys. Here, it is important that the flap 24 does not interfere with the main chamber 20 deploying forward onto the hood 12.

[0051] (Airbag folding process) Next, the folding process of the airbag 18 according to this embodiment will be described. Figures 4(A), (B), 5, 6(A), and 6(B) are plan views and cross-sectional views showing a method for manufacturing a pedestrian protection airbag device (a method for compressing an airbag) according to the first embodiment of the present invention.

[0052] 4(A), the outer periphery of the sub-chamber 22 is sewn to the main chamber 20, and the periphery of the vent holes 26 (26a, 26b) of the sub-chamber 22 and the main chamber 20 is sewn, thereby connecting the sub-chamber 22 and the main chamber 20. In addition, one edge of the flap 24 is sewn to the rear edge of the sub-chamber 22.

[0053] 4(B), the left and right sides of the airbag 18 (mainly the main chamber 20) are folded inward along the folding lines B1 so that the folding lines B1 are positioned outside the vent holes 26.

[0054] Next, as shown in Figure 5, the main chamber 20 is rolled from the front and rear to compress it. Here, since the main chamber 20 is wider at the front than the sub-chamber 22, the diameter of the roll on the front side is larger than the diameter of the roll on the rear side.

[0055] Next, as shown in Figure 6(A), the flap 24 is placed over the rolled main chamber 20 and sewn to the front end of the sub-chamber 22. As a result, the rolled main chamber 20 is surrounded from the front and rear by the flap 24 and the sub-chamber 22.

[0056] Next, as shown in FIG. 6(B), the front portion of the sub-chamber 22 is folded in an accordion-like manner.

[0057] (Airbag deployment behavior) 7(A), (B), 8(A), and (B) are cross-sectional views showing the deployment behavior of the pedestrian protection airbag 18 according to the first embodiment of the present invention. Figures 9(A) and (B) are perspective views showing the deployed state of the pedestrian protection airbag according to the present invention.

[0058] Figure 7(A) shows the state before the airbag device is activated. When a collision occurs in the vehicle 10, inflation gas is supplied from the inflators 29L, 29R (see Figures 2 and 5) to the sub-chamber 22 via the diffusers 30L, 30R. Then, as shown in Figure 7(B), the sub-chamber 22 inflates and deploys so as to push the main chamber 20 upward. At this time, the front portion of the sub-chamber 22 receives a reaction force from members such as the housing and deploys rearward.

[0059] As the sub-chamber 22 expands, the portion corresponding to the main chamber 20 reaches above the hood 12, but the slit 32 in the flap 24 is not broken or opened. In this state, the slit 32 is located approximately at the front end of the main chamber 20.

[0060] When inflation gas flows from the sub-chamber 22 into the main chamber 20, the slit 32 in the flap 24 begins to open as shown in FIG. 8(A), but the flap 24 still restricts the main chamber 20 from expanding upward.

[0061] When inflation gas further flows into the main chamber 20, the flap 24 breaks at the slit 32, causing the main chamber 20 to deploy forward, as shown in Figure 8(B). Figures 9(A) and (B) show the airbag 18 (20, 22) fully deployed.

[0062] In this embodiment, the flap 24 restricts the upward deployment of the main chamber 20, and the main chamber 20 tends to deploy forward rather than upward, so that the main chamber 20 can be deployed quickly onto the hood 12.

[0063] In this embodiment, when the airbag 18 deploys from the boundary 16 between the hood 12 and windshield 14 of the vehicle, the deployment of the airbag 18 itself widens the gap at the boundary 16. However, the present invention is not limited to this configuration, and a lifter that pushes up the rear portion of the hood 12 may be provided to widen the gap at the boundary 16 between the hood 12 and windshield 14.

[0064] (Second Example) Fig. 10 is a cross-sectional view showing the stored state of a pedestrian protection airbag according to a second embodiment of the present invention. In Fig. 10, components that are the same as or correspond to those in the first embodiment described above are given the same reference numerals, and duplicated explanations will be omitted.

[0065] The airbag 120 according to this embodiment is a single airbag that is held in a rolled or folded state by a flap 124. A slit 132 is formed in the rear portion of the flap 124 as a weakened portion. By forming the slit 132 near the rear region of the folded or rolled airbag 120, interference with the hood 12 when the airbag 120 deploys is minimized, and the airbag 120 can be reliably deployed outward through the gap 16 between the hood 12 and the windshield 14.

[0066] The airbag 120 can also be folded or rolled up in two separate regions (20a, 20b) in the same manner as in the first embodiment described above.

[0067] (Third Example) FIG. 11 is a plan view showing the structure of an airbag of a pedestrian protection airbag device according to a third embodiment of the present invention, with (A) being a top view and (B) being a bottom view. FIG. 12 is a plan view showing the panel configuration of an airbag according to the third embodiment of the present invention. FIGS. 13(A) and 13(B) are plan views showing a manufacturing method (airbag compression method) of a pedestrian protection airbag device according to the third embodiment of the present invention. FIG. 14 is a plan view and a cross-sectional view showing a manufacturing method (airbag compression method continued from FIG. 13) of a pedestrian protection airbag device according to the third embodiment of the present invention. FIGS. 15(A) and 15(B) are plan views and a cross-sectional view showing a manufacturing method (airbag compression method continued from FIG. 5) of a pedestrian protection airbag device according to the third embodiment of the present invention.

[0068] 11 to 15 correspond to Fig. 2 to Fig. 6 showing the first embodiment. Note that the third embodiment differs from the first embodiment in the structure of the flap 24 itself and the form of connection with the airbag 18, but other parts are the same, so only the differences will be described.

[0069] The flap 224 according to this embodiment has a longer length in the front-rear direction than the flap 24 of the first embodiment. In the state shown in Fig. 11, one edge of the flap 224 in the front-rear direction (the wider edge in the figure) is connected by sewing to the vicinity of the rear edge of the sub-chamber 22 at a connection point 233a.

[0070] 15, when the main chamber and the sub-chamber 22 are folded, the other edge of the flap 224 in the front-to-rear direction (the narrower edge in the figure) is free and not sewn to the sub-chamber 22. At this time, the flap 224 is configured to surround the entire periphery in the front-to-rear direction of the main chamber 20 and the sub-chamber 22 in the rolled or folded state.

[0071] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to these embodiments and can be modified as appropriate within the scope of the technical concept of the present invention.

Claims

1. an airbag that deploys from the junction of the vehicle's hood and windshield to protect a pedestrian or cyclist struck by the vehicle; a flap provided on the outer periphery of the folded airbag and capable of controlling the deployment direction of the airbag; The flap has a weakened portion that breaks or opens as the airbag inflates and deploys so that the airbag can deploy in a desired direction, and The pedestrian protection airbag device is characterized in that the weakened portion is formed in the vicinity of a rear region of the folded airbag.

2. The airbag includes a main chamber that can be deployed forward on the hood from the boundary portion, 2. The pedestrian protection airbag device according to claim 1, wherein the flap is configured to hold the main chamber without the fragile portion breaking or opening until the main chamber reaches above the hood as the airbag deploys.

3. A pedestrian protection airbag device as described in Claim 2, characterized in that the weak portion is formed near the front region of the main chamber of the folded airbag.

4. A pedestrian protection airbag device as described in Claim 3, characterized in that the weak portion is formed on the upper surface of the main chamber of the folded airbag.

5. A pedestrian protection airbag device as described in claim 1, characterized in that the weak part is a slit or a breakable sewing line.

6. A pedestrian protection airbag device as described in claim 1, characterized in that the flap holds the airbag, including near the center of the airbag in the vehicle width direction.

7. A pedestrian protection airbag device as described in any one of claims 2 to 4, characterized in that the airbag further includes a sub-chamber connected to the lower part of the main chamber and deploying prior to the main chamber.

8. A pedestrian protection airbag device as described in Claim 7, characterized in that the sub-chamber and the main chamber are fluidly connected by an inner vent.

9. A pedestrian protection airbag device as described in Claim 8, characterized in that the sub-chamber has a smaller capacity than the main chamber and is configured to deploy under the hood.

10. The main chamber is rolled or folded in the front-to-rear direction, 8. The pedestrian protection airbag device according to claim 7, wherein front and rear edge portions of the flap are connected to front and rear edge portions of the sub-chamber by sewing.

11. A pedestrian protection airbag device as described in Claim 10, characterized in that the flap and the sub-chamber are configured to surround the main chamber in a rolled or folded state from the front and rear directions.

12. A pedestrian protection airbag device as described in Claim 7, characterized in that the flap is configured to surround the main chamber and the sub-chamber in a rolled or folded state all around in the fore-and-aft direction.

13. The main chamber has a front region extending over the hood that is larger in area than an upper region extending over the windshield, 8. The pedestrian protection airbag device according to claim 7, wherein the front region and the upper region are rolled or folded separately.

14. A pedestrian protection airbag device as described in Claim 13, characterized in that the main chamber and the sub-chamber are folded or rolled separately.

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