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] In the pedestrian airbag device ML, the airbag 30 has a vehicle body side wall portion 31 that is positioned on the vehicle body side when inflation is complete, and a pedestrian side wall portion 32 that is positioned on the pedestrian side, and the outer edges of the vehicle body side wall portion and the pedestrian side wall portion are joined together to form a bag shape, and is positioned to cover the area near the hood panel 8 when inflation is complete, and a gas discharge portion 45 is provided in the area of ​​the pedestrian side wall portion that opens when a pedestrian P is received and can exhaust the inflation gas that has flowed inside. The gas discharge portion includes an opening 46 formed by cutting out the pedestrian side wall portion, and a patch portion 48 that is configured to close the opening and be divided at a predetermined point when the internal pressure of the airbag rises when a pedestrian is received, thereby releasing the closed state of the opening.

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 through which the inflation gas flowing into the interior can be exhausted 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 at the completion of inflation, 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 configured such that a part of the stitching thread is severed between immediately before and immediately after the completion of inflation of the airbag to release the stitched state, 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] In conventional airbags, the sutured area that maintains the folded state is released by applying tensile force generated on the surface of the base material constituting the airbag to the surrounding area, thereby severing a portion of the suture thread. However, since this sutured area is located near the outer edge of the airbag, which is inflated in a roughly disc shape (more specifically, slightly inside the outer edge), if wrinkles or other issues occur near the outer edge of the airbag after inflation is complete, it may be difficult to rupture, potentially preventing the exhaust vent from opening 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 has a vehicle body side wall portion positioned on the vehicle body side when inflation is complete, and a pedestrian side wall portion positioned on the pedestrian side, with the outer edges of the vehicle body side wall portion and the pedestrian side wall portion joined together to form a bag shape, and is positioned to cover the hood panel or the area near the hood panel when inflation is complete, and is configured to catch pedestrians, and a gas discharge port is provided within the area of ​​the pedestrian side wall portion or vehicle body side wall portion that opens when a pedestrian is caught, allowing the inflation gas that has flowed inside to be exhausted. The gas exhaust section is An opening formed by cutting out the pedestrian side wall or the vehicle side wall, A patch portion is positioned to close the opening, and is configured to release the closed state of the opening by being separated at a predetermined location when the internal pressure of the airbag rises during pedestrian detection. It is characterized by having the following features:

[0008] In the pedestrian airbag device of the present invention, a gas discharge section provided in the airbag is located within the area of ​​the pedestrian side wall or vehicle side wall of the airbag. Specifically, the gas discharge section comprises an opening formed by cutting out the pedestrian side wall or vehicle side wall, and a patch section that closes this opening. A predetermined portion of this patch section is separated when the internal pressure of the airbag rises upon receiving a pedestrian, thereby releasing the blockage by the patch section (forming the opening by opening the patch section) and allowing the inflation gas to be exhausted. In other words, in the pedestrian airbag device of the present invention, the inflation gas that flows into the inside of the airbag passes through the opening formed in the pedestrian side wall or vehicle side wall and directly presses against the patch section. As a result, the internal pressure of the airbag rises upon receiving a pedestrian, and the pressing force from the inflation gas can quickly separate a predetermined portion of the patch section, allowing the blockage of the opening by the patch section to be released stably and quickly. As a result, the inflation gas inside the airbag can be stably exhausted to the outside through the opening.

[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, if the gas discharge section is located within the area of ​​the pedestrian side wall, the pedestrian side wall is positioned away from the vehicle body components (such as the hood panel and front windshield) when the airbag inflation is complete. Therefore, when a pedestrian is caught, the inflation gas can be stably discharged from the gas discharge section without being affected by such vehicle body components, which is preferable.

[0011] Furthermore, in the pedestrian airbag device with the above configuration, if at least three intermittently formed slits are arranged radially in the patch portion, when the internal pressure of the airbag rises when a pedestrian is caught, the area around the slits will rupture, making it possible to open the region between the slits in the patch portion radially, thus allowing the opening to be opened quickly, which is preferable. [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 gas discharge section of the airbag. [Figure 6] This is a cross-sectional view of the VI-VI region in Figure 5. [Figure 7] Figure 3 is a plan view showing the arrangement of the base materials that make up the airbag. [Figure 8]This is a plan view of a vehicle showing the state in which the pedestrian airbag device of the embodiment has completed inflation. [Figure 9] 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 10] This is a schematic, partially enlarged perspective view showing the state in which the left airbag has completed inflation in the pedestrian airbag device of the embodiment, illustrating the state before and after receiving a pedestrian. [Modes for carrying out the invention]

[0013] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In this embodiment, as a pedestrian airbag device, two pedestrian airbag devices ML and MR, which are located on the lower left and right ends near the rear end 8a of the hood panel 8 of the vehicle V, will be used as an example for the description. 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 of the vehicle V, respectively.

[0014] Since the two pedestrian airbag devices ML and MR have the same configuration and are arranged symmetrically, in this embodiment, the pedestrian airbag device ML, which is located on the left side, will be used as an example for explanation, and a detailed explanation of the pedestrian airbag device MR on the right side will be omitted. In this embodiment, when the pedestrian airbag devices ML and MR are activated, the rear end 8a of the hood panel 8 is lifted upward by an actuator (not shown) (see Figures 2, 9, and 10).

[0015] As shown in FIGS. 1 and 2, the pedestrian airbag device ML is disposed adjacent to a cowl 6 in a region behind an engine room (reference numerals of the figure are 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 that stores 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 disposed 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 a mounting part 2 formed from a flange or the like extending from the cowl panel 6a on the body 1 side of the vehicle V by using bolts 26 and nuts 27 of a mounting bracket 25 of the inflater 22 (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, and includes a substantially rectangular plate-shaped bottom wall part 16 extending substantially along the left-right direction (vehicle width direction) of the vehicle V and a substantially rectangular tube-shaped peripheral wall part 17 extending upward from the outer peripheral edge of the bottom wall part 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 flush with the cowl louver 6b so as to cover the protruding opening 15a of the case 15. In the case of the embodiment, it is attached to a front part of the peripheral wall part 17 in the case 15. The 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. 9).

[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 9). 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 8, the airbag 30 comprises 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. Furthermore, as shown in Figures 3, 4, and 7, the airbag 30 has substantially the same external shape and is formed into a bag shape by joining (sewing) the outer edges 31a, 32a (outer edges 65a, 66a) of the vehicle body side wall portion 31 (vehicle side panel 65) positioned on the lower surface that becomes the body 1 side when inflation is complete and the pedestrian side wall portion 32 (pedestrian side panel 66) positioned on the upper surface that faces the vehicle body side wall portion 31 and becomes the pedestrian side, together over the entire circumference.

[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 side of the case 15, that is, below the area near the rear end 8a of the hood panel 8 (see Figure 9). 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 area 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 7). 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 7).

[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 8 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 at 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 8 and 9). 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 8 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 is configured to open when a pedestrian P is received, allowing the inflation gas G that has flowed into the airbag 30 (protective main body section 40) to be exhausted. In this embodiment, it is located within the area of ​​the pedestrian side wall section 32, which becomes the upper side when the airbag 30 has finished inflating. Specifically, in this embodiment, as shown in Figure 3, the gas discharge section 45 is located near the right edge (near the rear right end) of the pillar cover section 42, near the rear end 42a, on the pedestrian side wall section 32. As shown in Figures 3, 5, and 6, the gas discharge section 45 includes an opening 46 formed by cutting out the pedestrian side wall section 32, and a patch section 48 that closes the opening 46.

[0023] In this embodiment, the opening 46 is formed by cutting out a circular section of the pedestrian side wall 32. The patch portion 48 has a circular outer shape so as to be able to close the opening 46, and the opening 46 is closed by sewing (joining) its outer edge 48a to the outer edge 46a of the opening 46 all the way around. In this embodiment, the patch portion 48 is overlapped from the outer surface side of the pedestrian side wall 32. The patch portion 48 is formed from a coated fabric, similar to the airbag 30, as will be described later. In this embodiment, the patch portion 48 has four slits 49 arranged radially. Each slit 49 is formed by creating a series of straight cuts, with one end 49a close to the center of the patch portion 48 (opening 46) and extending radially, and the other end 49b positioned near the outer edge 48a (see Figure 5). When the internal pressure of the airbag 30 (protective main body 40) rises during pedestrian detection, the patch portion 48 ruptures (divides) the area between the ends 49a of each slit 49 (central portion 48b, intended to rupture), causing the area between each slit 49 to open radially into four door portions 48c (see dashed lines in Figures 5 and 6). When the four door portions 48c of the patch portion 48 open, the opening 46 opens over almost the entire surface, and the inflation gas G is exhausted from this opening 46 (see B in Figure 10).

[0024] In the airbag 30 of this embodiment, the timing of the rupture (separation) of the central portion 48b (i.e., the timing of the start of exhaust of the inflation gas G) can be appropriately set by varying the separation distance between the ends 49a of the slit 49 in the patch portion 48. 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 opening area of ​​the opening 46.

[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 7). 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 7).

[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 cylinder portion 60a into which the inflator 22 with the mounting bracket 25 already 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 cylinder 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 cylinder 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 7.

[0027] As shown in Figure 7, the airbag 30 of this embodiment is composed of a vehicle side panel 65 constituting the vehicle side wall portion 31, a pedestrian side panel 66 constituting the pedestrian side wall portion 32, a patch portion 48, tether base materials 70, 71, 72, 73 constituting each of the tethers 55, 56, 57, 58, and a tube base material 76 constituting 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 8, 9, and 10).

[0030] In the pedestrian airbag device ML(MR) of this embodiment, the gas discharge section 45 provided in the airbag 30 is located within the area of ​​the pedestrian side wall 32. Specifically, the gas discharge section 45 comprises an opening 46 formed by cutting out the pedestrian side wall 32 and a patch section 48 that closes this opening 46. A predetermined location of this patch section 48 (in this embodiment, the central portion 48b, which is the area between the ends 49a of the slit 49) is divided when the internal pressure of the airbag 30 rises upon receiving a pedestrian P, thereby releasing the blockage by the patch section 48 (forming the opening of the patch section 48) and allowing the inflation gas G to be exhausted from the opening 46 (see Figure 10B). In other words, in the pedestrian airbag device ML(MR) of this embodiment, the inflation gas G that flows into the airbag 30 passes through the opening 46 formed in the pedestrian side wall 32 and directly presses against the patch portion 48 (see Figure 6). As a result, when a pedestrian P is received, the internal pressure of the airbag 30 rises, and the pressing force of the inflation gas G causes a predetermined part of the patch portion 48 (the central part 48b) to be quickly separated, and the blockage of the opening 46 by the patch portion 48 can be stably and quickly released. As a result, the inflation gas G inside the airbag 30 can be stably exhausted to the outside through the opening 46 (see Figure 10B).

[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 gas discharge section 45 is located within the area of ​​the pedestrian side wall section 32. Since the pedestrian side wall section 32 is positioned away from vehicle body components (such as the hood panel 8, front windshield 4, and front pillar 5L) when the airbag 30 has finished inflating, the expansion gas G can be stably exhausted from the gas discharge section 45 without being affected by such vehicle body components when a pedestrian is caught.

[0033] If these points are not considered, the gas discharge section may be configured to be located on the vehicle body side wall side. In addition, in the airbag 30 of the embodiment, the gas discharge section 45 is located in the area on the rear end 42a side of the pillar cover section 42 on the pedestrian side wall section 32, but the location of the gas discharge section is not limited to the embodiment. Considering the smooth exhaust of the expansion gas from the gas discharge section 45, it is preferable to position the gas discharge section 45 in an area on the pedestrian side wall section 32 that is unlikely to be touched by pedestrians.

[0034] Furthermore, in the pedestrian airbag device ML(MR) of this embodiment, four intermittently formed slits 49 are arranged radially in the patch portion 48. Therefore, when the internal pressure of the airbag 30 rises when a pedestrian is stopped, the area around the slits 49 (specifically, the central portion 48b, which is the area between the ends 49a of the slits 49 in the patch portion 48) is ruptured, making it possible to open the area between the slits 49 in the patch portion 48 (door portion 48c) radially, as shown by the dashed lines in Figures 5 and 6, and to quickly open the opening 46. From the viewpoint of making the opening as wide as possible when ruptured, it is desirable to arrange at least three slits.

[0035] In this embodiment, each slit 49 is formed by creating a continuous, straight cut, but the slits may also be constructed by creating intermittent cuts in a perforated pattern. In the airbag 30 of this embodiment, the slits are not directly provided in the base fabric (pedestrian side wall portion 32 or vehicle side wall portion 31) that constitutes the airbag 30, but rather the slits 49 are provided in the patch portion 48 that closes the opening 46 formed in the base fabric (pedestrian side wall portion 32) that constitutes the airbag 30. This makes it possible to keep the opening area of ​​the opening 46 that opens when the peripheral portion of the slit 49 ruptures during an increase in internal pressure constant, and to keep the exhaust amount of inflation gas approximately constant. If the slits were to be directly provided in the base fabric that constitutes the airbag, the portion around the slit may rupture more than necessary when it ruptures, and there is a risk that the opening area at the time of opening cannot be kept constant. Furthermore, in the embodiment of the airbag 30, since the patch portion 48 is formed from coated fabric, it has higher strength than when it is formed from uncoated fabric, and the rupture of the peripheral portion of the slit when the airbag 30 has finished inflating but before it catches a pedestrian can be suppressed.

[0036] 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]

[0037] 1...Body, 8...Hood panel, 15...Case (storage area), 22...Inflator, 30...Airbag, 31...Vehicle side wall, 31a...Outer edge, 32...Pedestrian side wall, 32a...Outer edge, 45...Gas discharge section, 46...Opening, 48...Patch section, 48b...Connecting section, 49...Slit, G...Inflation gas, 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 comprises a vehicle body side wall portion positioned on the vehicle body side when inflation is complete, and a pedestrian side wall portion positioned on the pedestrian side, with the outer edges of the vehicle body side wall portion and the pedestrian side wall portion joined together to form a bag shape, and is positioned to cover the hood panel or the area near the hood panel when inflation is complete, and is configured to catch the pedestrian, and a gas discharge portion is provided within the area of ​​the pedestrian side wall portion or the vehicle body side wall portion that opens when the pedestrian is caught to exhaust the inflation gas that has flowed inside. The aforementioned gas discharge section An opening formed by cutting out the pedestrian side wall or the vehicle side wall, A patch portion is provided to close the opening, and is configured to release the closed state of the opening by being divided at a predetermined location when the internal pressure of the airbag rises when the pedestrian is caught, A pedestrian airbag system characterized by being equipped with [a specific feature].

2. The pedestrian airbag device according to claim 1, characterized in that the gas discharge section is disposed within the area of ​​the pedestrian side wall.

3. The pedestrian airbag device according to claim 1 or 2, characterized in that the patch portion has at least three intermittently formed slits arranged radially.

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