Pedestrian airbag system

Abstract

To provide a pedestrian airbag system that can stably release inflation gas from the airbag when a pedestrian is caught. [Solution] The airbag 30 is formed by joining the outer edges of the vehicle body side panel 65 and the pedestrian side panel 66 to form a bag shape, and includes a protective main body 40 that covers the area near the hood panel when inflation is complete, and a gas discharge part 56 that can exhaust the inflation gas that has flowed into the protective main body. The gas discharge part is formed to be continuous with the protective main body and is positioned to protrude outward from the outer edge joining part that constitutes the outer edge of the protective main body when inflation is complete, and includes a temporary joining part 48 in the area outside the outer edge joining part that joins the vehicle body side panel and the pedestrian side panel and closes the end side. The temporary joining part is configured to release the joined state between the vehicle body side panel and the pedestrian side panel when the internal pressure of the protective main body rises when a pedestrian is caught.

Description

Technical Field

[0001] The present invention relates to a pedestrian airbag device disposed near a hood panel of a vehicle.

Background Art

[0002] Conventionally, as an airbag used in an airbag device, in order to suppress a rapid increase in internal pressure when receiving a protected person (such as an occupant or a pedestrian), there is a configuration having an exhaust hole capable of exhausting the inflation gas flowing into the inside to the outside (for example, see Patent Document 1). Specifically, in a conventional airbag device, an exhaust hole is disposed at a position near the outer peripheral edge of the airbag when inflation is completed, and this exhaust hole is folded to the inner peripheral side of the airbag together with the peripheral region, and the peripheral region is sewn so as to maintain the folded state. And, the stitching part that maintains the folded state of the arrangement area of this exhaust hole is released from the stitching state by cutting a part of the stitching thread between immediately before and immediately after the completion of inflation of the airbag, and the peripheral region of the exhaust hole is released from the folded state, and the exhaust hole is opened.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional airbag, the stitching part that maintains the folded state is disposed near the outer peripheral edge of the airbag that is inflated in a substantially disc shape (specifically, at a position slightly inside the outer peripheral edge). Therefore, for example, when wrinkles or the like occur near the outer peripheral edge of the airbag at the time of inflation completion, stress concentration that breaks the stitching thread constituting this stitching part may not easily occur in the stitching part, and the exhaust hole may not be opened quickly.

[0005] Pedestrian airbag systems are designed to protect pedestrians (including cyclists) who collide with a vehicle by using an inflated airbag to catch them. However, because the time between collision detection and the start of pedestrian capture is relatively long, it is desirable to maintain a relatively high internal pressure in the airbag for a considerable period of time. To maintain this internal pressure, airbags are typically formed from coated fabric, which has a gas leak-preventing coating applied to the surface of the woven fabric. However, in order to smoothly protect pedestrians with the inflated airbag, it is desirable that the internal pressure of the airbag at the time of pedestrian capture is not too high, and that any excess inflation gas that has entered the interior be smoothly released at the time of pedestrian capture.

[0006] The present invention aims to solve the above-mentioned problems and to provide a pedestrian airbag device that can stably release inflation gas from the airbag when a pedestrian is caught. [Means for solving the problem]

[0007] The pedestrian airbag device according to the present invention comprises an airbag that is folded and stored in a storage area located near the hood panel of a vehicle, and an inflator that supplies inflation gas to the airbag, The airbag is configured to form a bag by joining the outer edges of a vehicle-side panel positioned on the vehicle body side and a pedestrian-side panel positioned on the pedestrian side when inflation is complete, and includes a protective main body positioned to cover the hood panel or the area near the hood panel when inflation is complete, capable of catching pedestrians, and a gas discharge section that opens when a pedestrian is caught, allowing the inflation gas that has flowed into the protective main body to be exhausted. The gas discharge section is formed to extend from the protective main body and, when the airbag has finished inflating, is positioned to protrude outward from the outer edge connecting section that constitutes the outer edge of the protective main body. Furthermore, in the area outside the outer edge connecting section, there is a temporary connecting section that connects the vehicle-side panel and the pedestrian-side panel, thereby closing the terminal end. The temporary coupling portion is characterized by being configured to release the coupling between the vehicle-side panel and the pedestrian-side panel when the internal pressure of the protective body increases during pedestrian detection.

[0008] In the pedestrian airbag device of the present invention, a gas discharge section capable of exhausting the inflation gas that flows into the protective body when a pedestrian is caught is positioned to protrude outward from the outer edge coupling section that constitutes the outer edge of the protective body when the airbag inflation is complete. Furthermore, the terminal end of this gas discharge section is closed by a temporary coupling section formed by coupling the vehicle body side panel and the pedestrian side panel in a region outside the outer edge coupling section. As a result, the gas discharge section (temporary coupling section) is less affected by the vicinity of the outer edge of the protective body (the outer edge coupling section located on the outer edge side), and when the internal pressure inside the protective body rises when a pedestrian is caught, a force can be stably applied to the temporary coupling section to release the coupling between the pedestrian side panel and the vehicle body side panel, allowing the coupling state of the temporary coupling section to be released stably and quickly. As a result, by releasing the coupling state of the temporary coupling section, the terminal end of the gas discharge section can be stably opened to separate the pedestrian side panel and the vehicle body side panel, allowing the inflation gas inside the protective body to be stably exhausted to the outside.

[0009] Therefore, the pedestrian airbag device of the present invention can stably release inflation gas from the airbag when a pedestrian is caught.

[0010] Furthermore, in the pedestrian airbag device of the present invention, the temporary connection portion is composed of a sutured portion in which the vehicle body side panel and the pedestrian side panel are sewn together using suture thread. It is preferable that the suture site be positioned in the intermediate area, protruding toward the protective main body, and having a starting point that becomes the starting point for rupture when the internal pressure increases.

[0011] If a pedestrian airbag system is configured in this way, when the airbag has finished inflating, stress concentration can be generated near the starting point of the suture that constitutes the temporary joint. This allows the suture to be quickly broken (cut) near the starting point, and the temporary joint (sewn state) can be quickly resolved by the occurrence of thread detachment, etc. [Brief explanation of the drawing]

[0012] [Figure 1] This is a plan view of a vehicle equipped with a pedestrian airbag system, which is one embodiment of the present invention. [Figure 2] This is a schematic longitudinal cross-sectional view showing a pedestrian airbag device according to an embodiment. [Figure 3] This is a plan view of the airbag used in the pedestrian airbag device of the embodiment, in a flat, unfolded state. [Figure 4] Figure 3 is a bottom view of the airbag. [Figure 5] Figure 3 is a partially enlarged plan view showing the area near the gas discharge port of the airbag. [Figure 6] Figure 3 is a plan view showing the arrangement of the base materials that make up the airbag. [Figure 7] This is a plan view of a vehicle showing the state in which the pedestrian airbag device of the embodiment has completed inflation. [Figure 8] This is a schematic longitudinal cross-sectional view showing the left airbag in the pedestrian airbag device of the embodiment after it has completed inflation. [Figure 9] This is a partially enlarged schematic cross-sectional view showing the state before and after the opening of the gas discharge section, which is arranged to be continuous with the protective main body, in the pedestrian airbag device of the embodiment. [Figure 10]In the pedestrian airbag device according to the embodiment, it is a schematic partial enlarged perspective view showing a state where the left airbag has completed inflation, and shows the states before and after receiving a pedestrian.

Mode for Carrying Out the Invention

[0013] Hereinafter, an embodiment of the present invention will be described based on the drawings. In the embodiment, as airbag devices for pedestrians, as shown in FIGS. 1, 2, 7, and 8, two airbag devices for pedestrians ML and MR mounted below both left and right ends near the rear end 8a of the hood panel 8 of the vehicle V will be taken as an example for explanation. In this specification, unless otherwise specified, the front-rear, up-down, and left-right directions will be described in accordance with the front-rear, up-down, and left-right directions in the vehicle V, respectively.

[0014] Since the two pedestrian airbag devices ML and MR have the same configuration and are arranged symmetrically left and right, in the embodiment, the pedestrian airbag device ML arranged on the left side will be taken as an example for explanation, and the detailed explanation of the pedestrian airbag device MR on the right side will be omitted. In the embodiment, when the pedestrian airbag devices ML and MR are operated, the rear end 8a of the hood panel 8 will be lifted upward by an actuator (not shown) (see FIGS. 2, 8, and 10).

[0015] As shown in FIGS. 1 and 2, the pedestrian airbag device ML is arranged adjacent to a cowl 6 which is a region behind the engine room (reference numeral omitted). The pedestrian airbag device ML includes an airbag 30, an inflater 22 that supplies inflation gas to the airbag 30, a case 15 as a storage part for storing the folded airbag 30 and the inflater 22, and an airbag cover 20 that covers the folded airbag 30. The cowl 6 is composed of a highly rigid cowl panel 6a on the body 1 side and a cowl louver 6b made of synthetic resin above the cowl panel 6a. Specifically, the pedestrian airbag device ML is arranged adjacent to a position on the front side of the cowl louver 6b (see FIG. 2).

[0016] The case 15 as a storage part is made of metal (sheet metal) and is fixed to the mounting part 2 composed of a flange or the like extending from the cowl panel 6a on the body 1 side of the vehicle V by using the bolt 26 of the mounting bracket 25 of the inflator 22 and the nut 27 (see FIG. 2). The case 15 has a substantially rectangular parallelepiped box shape with a protruding opening 15a at the upper end for protruding the airbag 30 during inflation. It includes a substantially rectangular plate-shaped bottom wall portion 16 extending substantially along the left-right direction (vehicle width direction) of the vehicle V, and a substantially square tube-shaped peripheral wall portion 17 extending upward from the outer peripheral edge of the bottom wall portion 16. The case 15 is disposed near the rear end 8a of the hood panel 8, specifically, on the front end side of the cowl 6 below the rear end 8a of the hood panel 8.

[0017] The airbag cover 20 is arranged to extend forward from the cowl louver 6b so as to be flush with the cowl louver 6b to cover the protruding opening 15a of the case 15. In the case of the embodiment, it is attached to the front part of the peripheral wall portion 17 in the case 15. This airbag cover 20 will be pushed open by the airbag 30 when the airbag 30 stored in the case 15 inflates (see the two-dot chain line in FIG. 2 and FIG. 8).

[0018] As shown in Figures 2 and 4, the inflator 22 is a roughly cylindrical shape positioned so as to be roughly aligned axially with the left-right direction (vehicle width direction) of the vehicle V, and is configured with a gas discharge section 23 for discharging expansion gas at its tip (left end in this embodiment). In this embodiment, the inflator 22 is held on its outer circumference by a plurality of mounting brackets 25 (three in this embodiment), and is encased in an inner tube 60, and inserted into the airbag 30 (more specifically, into the case-side portion 34 described later), and is fixed to the bottom wall portion 16 of the case 15 using bolts 26 of the mounting brackets 25 (see Figure 8). As described above, the bolts 26 of the mounting brackets 25 pass through the bottom wall portion 16 and are fastened with nuts 27 to the mounting portion 2 on the body 1 side of the vehicle V, fixing the case 15 to the mounting portion 2 together with the inflator 22 (see Figure 2). Furthermore, since the inflator 22 is inserted into the airbag 30, when the mounting bracket 25 is attached to the mounting portion 2, the airbag 30 is also attached and fixed to the bottom wall portion 16 of the case 15. The inflator 22 is configured to activate when a collision between the vehicle V and a pedestrian P is detected by a sensor (not shown) provided on the front bumper 3 of the vehicle V.

[0019] As shown by the dashed lines in Figures 1 and 2 and in Figure 7, the airbag 30 includes a case-side portion 34 positioned from the case 15 side to the lower surface of the rear end 8a of the hood panel 8 when inflation is complete, a protective main body portion 40 positioned to extend rearward from the case 15 when inflation is complete and capable of receiving a pedestrian P, and a gas discharge portion 45 formed to extend from the protective main body portion 40. Furthermore, as shown in Figures 3, 4, and 6, the airbag 30 has substantially the same external shape and comprises a vehicle body side wall portion 31 (vehicle body side panel 65) positioned on the lower side which faces the body 1 when inflation is complete, and a pedestrian side wall portion 32 (pedestrian side panel 66) positioned on the upper side which faces the pedestrian and faces the vehicle body side wall portion 31. The outer edges of the vehicle body side wall portion 31 and the pedestrian side wall portion 32 (the outer edges 65a, 66a of the vehicle body side panel 65 and the pedestrian side panel 66) are joined (sewn) together over substantially the entire circumference (over the entire circumference except for the area of ​​the opening 46 in the gas discharge portion 45, which will be described later).

[0020] The case-side portion 34 is formed to extend forward from the cowl cover portion 41 of the protective body portion 40, which will be described later. It is the rear end portion (protective body portion 40 side) when inflation is complete, and is attached to the case 15. When inflation is complete, it is configured to cover the area above the front region directly above the case 15, that is, below the area near the rear end 8a of the hood panel 8 (see Figure 8). In this embodiment, the case-side portion 34 is slightly narrower than the cowl cover portion 41 of the protective body portion 40 (smaller width dimension in the left-right direction), and its inner edge (right edge in this embodiment) on the vehicle width side is configured to roughly coincide with the inner edge (right edge) of the cowl cover portion 41. In the vehicle body side wall portion 31, an insertion opening 35 for inserting the inflator 22 into the rear end portion 34 is formed in the region constituting the rear end portion of the case-side portion 34 (see Figure 4). The insertion opening 35 includes an insertion slit 36 ​​for inserting the inflator 22, which is enclosed on its outer circumference by the inner tube 60, into the airbag 30, an insertion hole 37 for inserting the bolt 26 of the mounting bracket 25, and a cover panel 38 that closes the insertion slit 36 ​​from the outer circumference. The insertion slit 36 ​​is formed in a substantially straight line substantially along the left-right direction, and the insertion hole 37 is formed in the area in front of the insertion slit 36 ​​(see Figures 4 and 6). The cover panel 38 covers the outer surface of the insertion slit 36, and its rear edge is joined (sewn) to the vehicle body side wall 31 behind the insertion slit 36, and a mounting hole 38a for the bolt 26 of the mounting bracket 25 to protrude is provided at the front end, corresponding to the insertion hole 37 (see Figures 4 and 6).

[0021] The protective body portion 40 is positioned to cover the area near the hood panel 8 when the airbag 30 has finished inflating, specifically, as shown in Figures 7 and 10, from the upper surface of the cowl 6 near the rear end 8a of the hood panel 8 to the front surface 5a (upper surface) of the front pillar 5L, and is a portion that can catch a pedestrian P. Specifically, as shown in Figures 3 and 4, the protective body portion 40 is formed to extend to the rear left from the case side portion 34 when the airbag 30 is deployed flat, and comprises a cowl cover portion 41 positioned substantially along the left-right direction behind the case side portion 34, and a pillar cover portion 42 extending rearward from the outer end (left end) of the cowl cover portion 41 in the vehicle width direction. In this embodiment, the cowl cover portion 41 is formed to extend only to the left (outward in the vehicle width direction) from the rear of the case-side portion 34, and when the airbag 30 has finished inflating, it is configured to cover the upper surface near the edge (left end) in the vehicle width direction of the portion that is on the rear end 8a side of the hood panel 8, mainly from the cowl 6 to the lower part 4a side of the front windshield 4 (see Figures 7 and 8). The pillar cover portion 42 is configured to cover the upper surface (front 5a) side of the left front pillar 5L over almost the entire front and rear area when the airbag 30 has finished inflating (see Figures 7 and 10, A). In this embodiment, when the airbag 30 is laid flat, the pillar cover portion 42 is configured to be wider at the front end, which is on the case-side portion 34 side, and to gradually narrow towards the rear end (see Figures 3 and 4).

[0022] The gas discharge section 45, which is formed to extend from the protective main body 40, is configured to open when a pedestrian P is received, allowing the expansion gas G that has flowed into the protective main body 40 to be discharged. In this embodiment, as shown in Figures 3, 4, and 7, it is formed to protrude to the left from the left edge 42a of the pillar cover section 42. More specifically, in this embodiment, the gas discharge section 45 is formed at a position slightly behind the center of the front-to-rear center of the pillar cover section 42. In this embodiment, the airbag 30 is made into a bag shape by sewing (joining) the outer edges 65a, 66a of the vehicle body side panel 65 and the pedestrian side panel 66, which have the same outer shape, together using sutures around the entire circumference except for the tip 45a of the gas discharge section 45. In other words, in the airbag 30 of the embodiment, the gas discharge section 45 is positioned to protrude outward (to the left) from the outer edge stitching section 52 (specifically, the left edge side section 52a that constitutes the left edge 42a of the pillar cover section 42) which is an outer edge connecting section that constitutes the outer edge of the protective body section 40 (located on the outer edge side) (see Figures 3-5). More specifically, the gas discharge section 45 does not include the outer edge stitching section 52, but is composed of a region that protrudes to the left (outward) from the outer edge stitching section 52, including the front edge component section 47F and the rear edge component section 47B, which will be described later. Specifically, when the airbag 30 is deployed flat, the gas discharge section 45 has an outer shape that is tapered and roughly trapezoidal. The front edge 45b and rear edge 45c of the gas discharge section 45 are closed by the front edge component 47F and the rear edge component 47B, respectively, which are arranged to extend from the outer edge stitching portion 52 that constitutes the outer edge of the protective body 40. The tip 45a side of the gas discharge section 45 is configured so that there are no stitching portions extending from the outer edge stitching portion 52 (i.e., the front edge component 47F and the rear edge component 47B) throughout its entire length. The tip 45a side of the gas discharge section 45 is closed by a stitching portion 48 which serves as a temporary joint, connecting (stitching) the vehicle body side panel 65 and the pedestrian side panel 66 (see Figure 5). This stitching portion 48, which serves as a temporary joint, can be released in response to the increase in internal pressure of the protective body 40 when a pedestrian is stopped.

[0023] The suture portion 48, which serves as a temporary joint, is positioned to close off the tip 45a of the gas discharge portion 45 along its entire length when the airbag 30 is viewed from above in a flattened state, and is roughly wedge-shaped with its intermediate portion protruding to the left (towards the cowl cover portion 41). As shown in Figure 5, the protruding end 48a of the intermediate portion of this suture portion 48 is positioned to the left and right of the left edge side portion 52a that constitutes the left edge 42a of the pillar cover portion 42 in the outer peripheral edge suture portion 52. This protruding end 48a of the suture portion 48 constitutes the starting point that becomes the starting point of rupture when the internal pressure rises. When the internal pressure of the protective body 40 rises after receiving a pedestrian P, the sutured portion 48, acting as a temporary joint, causes stress concentration at the protruding end 48a (starting point), which breaks the suture thread (low-strength thread T1 described later) near the protruding end 48a (starting point), causing the thread to come loose and releasing the connection between the vehicle body side panel 65 and the pedestrian side panel 66. This release of the sutured portion 48 creates an opening 46 on the tip 45a side of the gas discharge portion 45, allowing the expansion gas G to be exhausted from this opening 46 (see Figures 9B and 10B).

[0024] In the airbag 30 of this embodiment, the timing of rupture at the protruding end 48a (starting point) (i.e., the timing of the start of exhaust of the inflation gas G) can be appropriately set by varying the stitch pitch and the strength of the suture thread used in the suture portion 48, which serves as a temporary joint. Specifically, in this embodiment, the suture portion 48 is formed in a single-line shape and is formed using a suture thread (low-strength thread T1) that is weaker than the suture thread (high-strength general suture thread T0) that constitutes the outer edge suture portion 52 (outer edge joint portion) which is arranged in a double-line shape on the outer edge side of the airbag 30. In addition, in the airbag 30 of this embodiment, the amount of inflation gas G to be exhausted can be appropriately set by changing the shape of the tip 45a side of the gas discharge portion 45.

[0025] Inside the airbag 30, tethers 55, 56, 57, and 58 are provided to connect the pedestrian side wall portion 32 and the vehicle body side wall portion 31, thereby regulating the thickness when inflation is complete. Tether 55 is provided within the area of ​​the pillar cover portion 42, except near the rear end. More specifically, it is provided continuously along the length direction (front-rear direction) of the pillar cover portion 42 at a position approximately in the center of the width direction (approximately coinciding with the vehicle width direction) of the pillar cover portion 42. Multiple openings 55a (four in this embodiment) are provided in the front and rear of this tether 55, through which inflation gas can be inserted (see Figure 6). Tether 56 is provided partially at a position approximately in the center of the front-rear and left-right directions of the cowl cover portion 41. Tether 57 is provided extending to the left and right at a position near the front edge of the cowl cover portion 41. The tether 57 is positioned near the rear end 8a of the hood panel 8 when the airbag 30 has finished inflating. The tether 58 is positioned near the boundary between the case side portion 34 and the cowl cover portion 41 (protective main body portion 40), and is arranged roughly along the left-right direction so as to partially close this boundary. Multiple openings 58a through which inflation gas can be inserted are arranged side by side on the left-right side (two in this embodiment) (see Figure 6).

[0026] The inner tube 60, which covers the outer circumference of the inflator 22, is configured as a roughly three-pronged cylindrical shape, as shown by the dashed line in Figure 4. It has an insertion tube portion 60a into which the inflator 22 with the mounting bracket 25 attached is inserted, and outlets 60b and 60c are provided on both sides from the location of the gas discharge portion 23 in the insertion tube portion 60a, with outlets 60b and 60c at the tips for releasing expansion gas. Mounting holes (not shown in the figure) are formed in the insertion tube portion 60a for passing through the bolts 26 of each mounting bracket 25. The inner tube 60 is made of a tube base material 76 as shown in Figure 6.

[0027] As shown in Figure 6, the airbag 30 of this embodiment is composed of a vehicle side panel 65 that constitutes the vehicle side wall portion 31, a pedestrian side panel 66 that constitutes the pedestrian side wall portion 32, tether base materials 70, 71, 72, 73 that constitute the tethers 55, 56, 57, 58, and a tube base material 76 that constitutes the inner tube 60. These base materials are formed by cutting a coated fabric, which is made by weaving polyamide yarn or polyester yarn, with a gas leak prevention coating agent applied to its surface, into a predetermined shape.

[0028] To describe the installation of the pedestrian airbag device ML of this embodiment onto a vehicle V, first, the airbag 30 is folded so that it can be stored inside the case 15, and with the inflator 22, which has the mounting bracket 25 already assembled, inserted into the inner tube 60, the airbag 30 is inserted into the case-side portion 34 using the insertion slit 36. Then, the bolts 26 of each mounting bracket 25 that protrude from the mounting holes (not shown in the figure) of the inner tube 60 are made to protrude from the insertion holes 37 of the airbag 30, and then the cover panel 38 is closed so as to cover the insertion slit 36, and the bolts 26 are inserted into the mounting holes 38a. After that, the airbag 30 and inflator 22 are stored inside the case 15, the airbag cover 20 is attached to the case 15, the bolts 26 protruding from the case 15 are secured to the mounting portion 2 with nuts 27, and the inflator 22 is connected to an operating circuit (not shown), thereby enabling the pedestrian airbag device ML to be installed on the vehicle V. The pedestrian airbag system MR on the right side can also be mounted on vehicle V in the same manner.

[0029] In the pedestrian airbag devices ML and MR of this embodiment, an operating circuit (not shown) detects a collision between the vehicle V and a pedestrian (specifically, a pedestrian or cyclist) based on an operating signal from a sensor (not shown) located on the front bumper 3. When this occurs, the inflators 22, 22 are activated, causing the airbags 30, 30 to inflate by introducing inflation gas into them, and each inflates to cover the area from near the left or right end of the rear end 8a of the hood panel 8 to the upper surface (front 5a) of the front pillars 5L and 5R (see the dashed lines in Figures 1 and 2, and A in Figures 7, 8, and 10).

[0030] In the pedestrian airbag device ML(MR) of this embodiment, a gas discharge section 45 capable of exhausting the inflation gas that flows into the protective body section 40 when a pedestrian P is received is positioned to protrude outward (to the left) from the outer edge joining section (specifically, the left edge side portion 52a of the outer edge suture section 52) that constitutes the outer edge of the protective body section 40 when the airbag 30 has finished inflating. Furthermore, the terminal end (tip 45a) of the gas discharge section 45 is closed off by a suture section 48, which serves as a temporary joining section formed by joining the vehicle body side panel 65 and the pedestrian side panel 66, in an area that is outward (to the left) from this joining section (left edge side portion 52a) (see Figures 3-5, 7). Therefore, the gas discharge section 45 (suture section 48) is less affected by the vicinity of the outer edge of the protective body section 40 (outer edge suture section 52 located on the outer edge side), and when the internal pressure inside the protective body section 40 rises due to pedestrian contact, a force can be stably applied to the suture section 48, which acts as a temporary joint, to release the connection between the pedestrian-side panel 66 and the vehicle-side panel 65, thereby stably and quickly releasing the connection by the suture section 48. As a result, when a pedestrian P comes into contact with the protective body section 40 (airbag 30) after inflation is complete (see Figure 9A), the internal pressure inside the protective body section 40 increases, and the connection of the suture section 48 is released, stably opening the terminal (tip 45a) side of the gas discharge section 45 so as to separate the pedestrian-side panel 66 and the vehicle-side panel 65 (see Figure 9B, 10B), and the inflation gas G inside the protective body section 40 can be stably exhausted to the outside through the formed opening 46.

[0031] Therefore, in the pedestrian airbag device ML(MR) of this embodiment, when a pedestrian is detected, the inflation gas G can be stably exhausted from the airbag 30.

[0032] Furthermore, in the pedestrian airbag device ML(MR) of this embodiment, the temporary joint consists of a suture portion 48 that sews the vehicle body side panel 65 and the pedestrian side panel 66 together using suture thread (low-strength thread T1). The suture portion 48 has a protruding end 48a in the middle portion that protrudes toward the protective main body portion 40 (pillar cover portion 42) and serves as a starting point for rupture when the internal pressure rises. Therefore, in the pedestrian airbag device ML(MR) of this embodiment, when the airbag 30 has finished inflating, stress concentration can be generated near the protruding end 48a (starting point) of the suture portion 48 that constitutes the temporary joint, and the suture thread (low-strength thread T1) can be quickly severed (cut) near this protruding end 48a (starting point), and the joint state (sewn state) of the temporary joint (suture portion 48) can be quickly resolved due to the occurrence of thread detachment, etc. Furthermore, the temporary joint is not limited to stitching with sutures; for example, the temporary joint may be formed by bonding (adhesion) with adhesive or welding the panels together. Even when the temporary joint is constructed by means other than stitching, it is desirable to provide a starting point that serves as the starting point for releasing the joint. In addition, in the airbag 30 of this embodiment, the gas discharge section 45 is located slightly behind the center of the pillar cover section 42 (near the rear end of the pillar cover section 42), but the location of the gas discharge section is not limited to this embodiment. Considering the impact of the expansion gas exhausted from the gas discharge section on pedestrians, it is preferable to position the gas discharge section away from the area that pedestrians will mainly come into contact with when the airbag is fully inflated (near the rear end of the pillar cover section in this embodiment).

[0033] In this embodiment, the pedestrian airbag device ML(MR) is described using as an example a pedestrian airbag device 30 that is folded and stored near the rear end 8a of the hood panel 8 and inflates to cover the upper surface from the lower part 4a of the cowl 6 and the front windshield 4 to the front pillar 5L, which is the area near the hood panel 8. However, the mounting position of the pedestrian airbag device is not limited to this embodiment. For example, the present invention may be applied to a pedestrian airbag device that includes an airbag configured to cover the upper surface of the rear end of the hood panel, a configuration that covers only the front side of the front pillar, or even a configuration that covers the upper surface of the front fender located to the side of the hood panel. Furthermore, in the embodiments, a pedestrian airbag system is exemplified in which two airbags each cover from the front (upper) side of the front pillar to the rear edge of the hood panel (near the lower edge of the cowl and front windshield). However, the present invention is also applicable to a pedestrian airbag system of the type that comprises one airbag having two pillar cover parts and a cowl cover part arranged to connect these pillar cover parts. In the pedestrian airbag system of the present invention, the airbag maintains a high internal pressure when inflation is complete, and when receiving a pedestrian, it appropriately releases the inflation gas, thereby being able to receive the pedestrian with an appropriate internal pressure. Therefore, it is particularly suitable for a pedestrian airbag system configured in which two airbags with relatively small volumes are arranged as separate units, as in the embodiments. [Explanation of Symbols]

[0034] 1...Body, 8...Hood panel, 15...Case (storage area), 22...Inflator, 30...Airbag, 31...Vehicle side wall, 32...Pedestrian side wall, 40...Protective main body, 42...Pillar cover, 42a...Left edge, 45...Gas discharge area, 45a...Tip, 46...Opening, 48...Suture area (temporary joint), 48a...Protruding end (starting point), 52...Peripheral edge suture (peripheral edge joint), 52a...Left edge side, 65...Vehicle side panel, 65a...Peripheral edge, 66...Pedestrian side panel, 66a...Peripheral edge, G...Inflation gas, T1...Low-strength thread (suture), V...Vehicle, ML,MR...Pedestrian airbag device.

Claims

1. A pedestrian airbag system comprising an airbag that folds and stores within a storage compartment located near the hood panel of a vehicle, and an inflator that supplies inflation gas to the airbag, The airbag is configured to be a bag-like structure formed by joining the outer edges of a vehicle-side panel positioned on the vehicle body side and a pedestrian-side panel positioned on the pedestrian side when inflation is complete, and includes a protective main body positioned to cover the hood panel or the area near the hood panel when inflation is complete, enabling it to catch the pedestrian, and a gas discharge section that opens when the pedestrian is caught, allowing the inflation gas that has flowed into the protective main body to be exhausted. The gas discharge section is formed to extend from the protective main body and is positioned to protrude outward from the outer edge connecting section that constitutes the outer edge of the protective main body when the airbag has finished inflating. It also has a temporary connecting section in an area outside the outer edge connecting section that connects the vehicle body side panel and the pedestrian side panel, thereby closing the end. A pedestrian airbag device characterized in that the temporary coupling portion is configured to release the coupling between the vehicle body side panel and the pedestrian side panel when the internal pressure of the protective main body rises when the pedestrian is received.

2. The temporary joint consists of a suture portion where the vehicle body side panel and the pedestrian side panel are sewn together using suture thread. The pedestrian airbag device according to claim 1, characterized in that the suture portion is positioned in the intermediate portion so as to protrude toward the protective body portion, and has a starting point portion that serves as the starting point for rupture when the internal pressure rises.

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