Airbag system

Abstract

The present invention provides an airbag device that allows for the provision of gas vents in the airbag while suppressing an increase in the size of the folded airbag. [Solution] The airbag device 10 includes an airbag 30 that covers the left front pillar 55 of the vehicle 50 from above when inflation is complete. The airbag 30 has a gas outlet 30x which is an opening for discharging the inflation gas inside the airbag 30 to the outside, a first suture portion 30v1 which seals the gas outlet 30x and releases the suture when external pressure is applied to the airbag 30 after inflation is complete, thereby opening the gas outlet 30x, and a second suture portion 30v2 which is provided around the first suture portion 30v1 and releases the suture when the internal pressure of the airbag 30 rises due to the inflow of inflation gas from the time the supply of inflation gas by the inflator 12 is started until the airbag 30 is completed to inflate.

Description

Technical Field

[0001] The present invention relates to an airbag device mounted on a vehicle that receives and protects a human such as a pedestrian outside the vehicle by an airbag.

Background Art

[0002] Conventionally, as in the configuration described in Patent Document 1, an airbag is deployed from near the rear end of the hood panel at the time of a vehicle collision, and an airbag device that receives and protects a pedestrian or the like outside the vehicle that is about to collide with the pillar of the vehicle is known. This airbag is stored inside the vehicle in a folded state before the start of inflation, and when inflation gas is supplied at the time of a vehicle collision or the like, it expands and is deployed while being fed out to the outside of the vehicle, and is configured to cover the pillar of the vehicle when inflation is completed.

[0003] Also, Patent Document 1 discloses a configuration in which an airbag is provided with a gas discharge port that is an opening for discharging excess inflation gas inside the airbag to the outside. By providing such a gas discharge port, excess inflation gas is discharged and the reaction force of the airbag is reduced, and it is suppressed that pedestrians or the like are bounced up by this reaction force.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Patent Document 1 describes a configuration in which the base fabric that seals the gas outlet is cut by the external pressure applied to the airbag when the airbag catches a pedestrian, thereby opening the gas outlet. However, in this configuration, it is necessary to provide an extra base fabric on the airbag to seal the gas outlet, which may increase the size of the folded airbag and worsen its packaging.

[0006] Therefore, the present invention aims to provide an airbag device that can suppress the increase in size of the folded airbag while providing a gas outlet in the airbag. [Means for solving the problem]

[0007] A typical configuration of an airbag device according to the present invention for solving the above problems is an airbag device comprising: an airbag that is folded and stored inside a vehicle, inflates when inflation gas is supplied and is deployed to the outside of the vehicle, and is configured to cover at least a part of the front pillar of the vehicle from above when inflation is complete; and an inflator that releases the inflation gas supplied to the airbag, wherein the airbag has a gas outlet which is an opening for discharging the inflation gas inside the airbag to the outside; a first suture that seals the gas outlet, the suture of which is released when external pressure is applied to the airbag after inflation is complete, thereby opening the gas outlet; and a second suture provided around the first suture, the suture of which is released when the internal pressure of the airbag rises due to the inflow of the inflation gas from the time the supply of the inflation gas by the inflator is started until the airbag is completed to inflate.

[0008] According to the present invention, in an airbag system, it is possible to provide a gas outlet in the airbag while suppressing an increase in the size of the folded airbag. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic plan view of a vehicle equipped with an airbag system. [Figure 2] This is a schematic plan view of the vehicle, showing the airbag system in a fully inflated state. [Figure 3] This is a schematic cross-sectional view of the vehicle cut along the A1-A1 section shown in Figure 1. [Figure 4] Figure 2 is a schematic cross-sectional view of the vehicle cut along the A2-A2 section. [Figure 5] This is a perspective view of the area around the gas vent of a vehicle with the airbags inflated. [Figure 6] This is a perspective view of the area around the gas vent of a vehicle with the airbags inflated. [Figure 7] This is a diagram showing an airbag laid flat before inflation begins. [Figure 8] Figure 7 is a magnified view of the area around the gas outlet of the airbag. [Modes for carrying out the invention]

[0010] The following description will explain an airbag device 10 according to one embodiment of the present invention, with reference to the drawings. Note that the dimensions, materials, shapes, etc., of the components described below are not intended to limit the scope of this invention to those components unless otherwise specified.

[0011] The airbag system 10 is installed in the vehicle 50 and protects people such as pedestrians M outside the vehicle 50 by catching them with airbags 30 and 40. In the following description, unless otherwise specified, the left-right direction refers to the left and right directions relative to the vehicle 50, the front-rear direction refers to the front and rear directions relative to the vehicle 50, and the up-down direction refers to the vertical up and down directions. That is, the left-right direction refers to the width direction of the vehicle 50, and the front-rear direction refers to the forward or reverse direction when the vehicle 50 is moving straight.

[0012] Figure 1 is a schematic plan view of a vehicle 50 equipped with an airbag system 10. Figure 2 is a schematic plan view of the vehicle 50, showing the state in which the airbags 30 and 40 of the airbag system 10 have completed inflation. Figure 3 is a schematic cross-sectional view of the vehicle 50 cut along the A1-A1 section shown in Figure 1. Figure 4 is a schematic cross-sectional view of the vehicle 50 cut along the A2-A2 section shown in Figure 2.

[0013] As shown in Figures 1 to 4, the vehicle 50 is equipped with a front windshield 54, a hood panel 59 covering an engine compartment (not shown), and a cowl top panel 58 positioned between the front windshield 54 and the hood panel 59. The vehicle 50 is also equipped with a left front pillar 55 positioned to the left of the front windshield 54 and a right front pillar 56 positioned to the right of the front windshield 54.

[0014] The hood panel 59 is composed of two panels: an inner panel 59x1 positioned on the inside of the vehicle and an outer panel 59x2 positioned on the outside of the vehicle. In the normal state when the airbag system 10 is not deployed, the rear end 59a of the hood panel 59 is positioned slightly above the front end 58c of the cowl top panel 58, thereby creating a small gap 50h between the rear end 59a of the hood panel 59 and the front end 58c of the cowl top panel 58. The cowl top panel 58 is also provided with a protruding portion 58x that extends upward to prevent rainwater and other liquids from entering the interior of the vehicle 50 through this gap 50h. A wiper 57 is attached to the upper surface of the cowl top panel 58 to scrape off water droplets adhering to the front windshield 54.

[0015] The airbag system 10 includes an airbag 30 mounted on the left side of the vehicle 50, an inflator 12 that releases the inflation gas supplied to the airbag 30, and a case 13 that houses the folded airbag 30. The airbag system 10 also includes an airbag 40 mounted on the right side of the vehicle 50, an inflator (not shown) that releases the inflation gas supplied to the airbag 40, and a case (not shown) that houses the folded airbag 40.

[0016] Here, the airbag 40, the inflator that supplies inflation gas to the airbag 40, and the case that houses the airbag 40 have the same configuration and are arranged symmetrically with respect to the left and right of the airbag 30, the inflator 12, and the case 13. They are attached to the vehicle 50 by the same attachment configuration and operate symmetrically with respect to the left and right. Therefore, hereinafter, the airbag 30, the inflator 12, and the case 13 will be described in detail, and the description of the airbag 40, the inflator that supplies inflation gas to the airbag 40, and the case that houses the airbag 40 will be omitted as appropriate.

[0017] The airbag device 10 further includes an acceleration sensor 17 used for detecting a collision of the vehicle 50, an actuator (not shown) that lifts the rear end portion 59a of the hood panel 59 upward, and a control device (not shown) that controls the operations of the inflator 12, an inflator (not shown) that supplies inflation gas to the airbag 40, and the actuator according to the detection result of the acceleration sensor 17.

[0018] The acceleration sensor 17 is attached to the front bumper 53 of the vehicle 50 and detects the impact generated by a collision or the like of the vehicle 50 as acceleration. The control device (not shown) is configured with a CPU, a memory, etc., and is attached to a predetermined position inside the vehicle 50. This control device is electrically connected to the inflator 12, an inflator (not shown) that supplies inflation gas to the airbag 40, and an actuator (not shown), and transmits an operation signal to these members according to the detection result of the acceleration sensor 17.

[0019] The inflator 12 is a substantially cylindrical member disposed inside the airbag 30 and has gas discharge ports (not shown) for discharging inflation gas at the front end portions in the left - right direction. The inflator 12 operates when an operation signal is input from a control device (not shown) to generate inflation gas, discharges the inflation gas from the gas discharge ports, and supplies it to the inside of the airbag 30.

[0020] In addition, the inflator 12 is attached to the inner panel 59x1 of the hood panel 59 together with the airbag 30 and the case 13 by a metal bolted clamp 18. Specifically, the bolted clamp 18 includes a reduced-diameter annular clamp portion 18a and a bolt portion 18b that protrudes upward from the outer peripheral surface of the clamp portion 18a. The clamp portion 18a is wound around the outer peripheral portion of the inflator 12. The bolt portion 18b is inserted into screw holes (not shown) formed in the airbag 30, the case 13, and the inner panel 59x1 in a state where the clamp portion 18a is wound around the inflator 12 and fastened with a nut 19. By fastening this nut 19, the clamp portion 18a is reduced in diameter to hold the inflator 12, and the inflator 12, the airbag 30, and the case 13 are integrally fixed to the inner panel 59x1.

[0021] The airbag 30 is a bag-shaped member, which is stored in the case 13 in a folded state before the inflation gas is supplied, and expands when the inflation gas is supplied therein, and is extended to the outside of the vehicle 50 while unfolding from the folded state. In the present embodiment, the airbag 30 is formed of an airbag panel 60 (see FIG. 7) which is a bag-shaped woven fabric made of polyester yarn.

[0022] When the inflation is completed, the airbag 30 is disposed outside the vehicle 50, and includes a wide cowl cover portion 30a in the left-right direction that covers the periphery of the left end portion 58a of the cowl top panel 58 and the periphery of the front end portion 55a of the left front pillar 55 from above, and a connection portion 30b that is disposed inside the vehicle 50 and connects the portion that houses the inflator 12 and the cowl cover portion 30a. Further, when the inflation is completed, the airbag 30 includes a wide pillar cover portion 30c in the front-rear direction that extends rearward from the cowl cover portion 30a and covers substantially the entire area other than the front end portion 55a of the left front pillar 55 from above, and a gas discharge portion 30d that extends leftward from the left end portion of the pillar cover portion 30c. The tip of the gas discharge portion 30d opens when a predetermined external pressure or more is applied to the airbag 30 after the inflation of the airbag 30 is completed, and serves as a gas discharge port 30x that discharges the excess inflation gas inside the airbag 30 to the outside.

[0023] Case 13 is a roughly rectangular box-shaped member made of sheet metal with an open rear end. As described above, Case 13 is fixed to the inner panel 59x1 of the hood panel 59 by a bolted clamp 18. In this embodiment, Case 13 is used with an open rear end, but in order to protect the airbag 30 from rainwater, etc., the rear end may be deformed or ruptured when the airbag 30 inflates, forming an opening, and the airbag 30 may be ejected to the outside of Case 13 through this opening.

[0024] Next, the protective operation of the airbag system 10 for pedestrian M will be described. First, when the vehicle 50 and pedestrian M collide, the acceleration sensor 17 detects this collision as acceleration. If the acceleration detected by the acceleration sensor 17 is above a predetermined level, the control device (not shown) determines that the vehicle 50 has collided and sends an activation signal to the inflator 12, an inflator (not shown) that supplies inflation gas to the airbag 40, and an actuator (not shown).

[0025] Next, the actuator, activated upon receiving the activation signal, lifts the rear end 59a of the hood panel 59. This widens the gap 50h between the hood panel 59 and the cowl top panel 58 of the vehicle 50. Also, the inflator 12, activated upon receiving the activation signal, supplies inflation gas into the airbag 30. Similarly, an inflator (not shown), activated upon receiving the activation signal, supplies inflation gas into the airbag 40.

[0026] Next, the airbag 30, which has been supplied with inflation gas and begun to inflate, deploys from its folded state and is ejected from the gap 50h to the outside of the vehicle 50. Subsequently, when more inflation gas is supplied to the airbag 30, it inflates to cover almost the entire area of ​​the left end 58a of the cowl top panel 58 of the vehicle 50 and the left front pillar 55 from above, completing its inflation.

[0027] Similarly, the airbag 40, supplied with inflation gas and beginning to inflate, deploys from its folded state and is ejected from the gap 50h to the outside of the vehicle 50. Next, when more inflation gas is supplied to the airbag 40, it inflates to cover almost the entire area of ​​the right end 58b of the cowl top panel 58 of the vehicle 50 and the right front pillar 56 from above, completing its inflation. Subsequently, a pedestrian M that collides with the vehicle 50 and is thrown upward, about to strike the cowl top panel 58, the left front pillar 55, or the right front pillar 56, is caught and protected by the airbag 30 or airbag 40.

[0028] Furthermore, as shown in Figure 5, the gas outlet 30x of the airbag 30 is sealed by the airbag 30 being sutured at the first suture portion 30v1 until an external pressure exceeding a predetermined level is applied to the airbag 30 after the airbag 30 has finished inflating. As shown in Figure 6, after the airbag 30 has finished inflating, when an external pressure exceeding a predetermined level is applied to the airbag 30, such as when the airbag 30 catches a pedestrian M, the suture at the first suture portion 30v1 is released and the gas outlet 30x is opened.

[0029] Similarly, the gas outlet 40x of the airbag 40 is sealed by the airbag 40 being sutured at the first suture portion 40v1 from the time the airbag 40 is fully inflated until an external pressure exceeding a predetermined level is applied to the airbag 40. After the airbag 40 is fully inflated, if an external pressure exceeding a predetermined level is applied to the airbag 40, such as when the airbag 40 catches a pedestrian M, the suture at the first suture portion 40v1 is released and the gas outlet 40x is opened.

[0030] In this manner, airbags 30 and 40 maintain their internal pressure without releasing the inflation gas from the gas outlets 30x and 40x until they catch the pedestrian M. After catching the pedestrian M, the gas outlets 30x and 40x are opened to release the inflation gas and reduce the internal pressure. As a result, the pedestrian M is caught by airbags 30 and 40 while maintaining a high reaction force, and is prevented from being bounced up by the reaction force of airbags 30 and 40 and hitting the ground or other surface.

[0031] Next, the detailed configuration of the gas outlet 30x of the airbag 30 will be described. Figure 7 is an unfolded view of the airbag 30 laid flat before inflation begins. Figure 8 is a magnified view of the area around the gas outlet 30x of the airbag 30 shown in Figure 7.

[0032] As shown in Figures 7 and 8, the airbag 30 is formed by an airbag panel 60 in which the outer edge of the inner panel 60a, which constitutes the lower surface of the airbag 30 when inflation is complete, and the outer edge of the outer panel 60b, which constitutes the upper surface of the airbag 30 when inflation is complete, are sewn together at a seam 60x to form a bag-like structure. The inner panel 60a can be said to be the panel that forms the surface of the airbag 30 facing the cowl top panel 58 and the left front pillar 55 when inflation is complete. The outer panel 60b can be said to be the panel that forms the surface of the airbag 30 that catches a pedestrian M when inflation is complete.

[0033] The airbag panel 60 has a cowl cover forming portion 61 that forms the cowl cover portion 30a when the airbag 30 is inflated, a connection forming portion 62 that forms the connection portion 30b, a pillar cover forming portion 63 that forms the pillar cover portion 30c, and a gas discharge forming portion 64 that forms the gas discharge portion 30d. Inside the airbag panel 60, there are four tethers 65, 66, 67, and 68, one end of which is sewn to the inner panel 60a and the other end of which are sewn to the outer panel 60b, respectively, to regulate the thickness of the airbag 30 when inflation is complete.

[0034] Furthermore, in the airbag panel 60, the outer edges of the inner panel 60a and the outer edges of the outer panel 60b are not partially sutured at the suture portion 60x, and this unsewn portion becomes the gas outlet 30x of the airbag 30. As described above, the gas outlet 30x is sealed at the first suture portion 30v1 (first suture portion) from the time the airbag 30 is fully inflated until an external pressure exceeding a predetermined level is applied to the airbag 30. The first suture portion 30v1 is the portion where the inner panel 60a and the outer panel 60b are sutured together around the gas outlet 30x to seal the gas outlet 30x. After the airbag 30 is fully inflated, if an external pressure exceeding a predetermined level is applied to the airbag 30, such as when catching a pedestrian M, the airbag 30 deforms and the internal pressure increases. Consequently, the suture thread 81 of the first suture portion 30v1 breaks, the thread comes loose, and the suture of the first suture portion 30v1 is released. This opens the gas outlet 30x.

[0035] The first suture section 30v1 includes a first straight section 30v1a (first straight section) in which the inner panel 60a and the outer panel 60b are sewn together in a straight line, and a second straight section 30v1b (second straight section) that branches off from the first straight section 30v1a and extends in a direction intersecting the direction in which the inner panel 60a and the outer panel 60b are sewn together in a straight line. Note that the first straight section 30v1a and the second straight section 30v1b include configurations in which the stitches are zigzag in shape, but the overall stitching is linear.

[0036] The first straight section 30v1a extends from approximately the center of the width direction W of the gas discharge forming section 64, that is, from approximately the center of the width direction W of the gas discharge section 30d of the airbag 30 when inflation is complete, to the rear end 30x1 of the gas outlet 30x. The second straight section 30v1b extends from approximately the center of the width direction W of the gas discharge forming section 64, that is, from approximately the center of the width direction W of the gas discharge section 30d of the airbag 30 when inflation is complete, to the front end 30x2 of the gas outlet 30x. In other words, the branching point 30v1z between the first straight section 30v1a and the second straight section 30v1b of the first suture section 30v1 is located approximately in the center of the width direction W of the gas discharge section 30d. The second straight section 30v1b, together with the first straight section 30v1a, forms a roughly V-shaped suture section. This roughly V-shaped opening faces the gas outlet 30x side.

[0037] Furthermore, the first suture portion 30v1 branches off from the first straight portion 30v1a and the second straight portion 30v1b at its branching portion 30v1z, and includes a third straight portion 30v1c in which the inner panel 60a and the outer panel 60b are sewn together in a straight line, extending in a direction intersecting the direction in which the first straight portion 30v1a and the second straight portion 30v1b extend. Note that the third straight portion 30v1c includes a configuration in which the stitching is zigzag, but the overall stitching is straight. The third straight portion 30v1c extends from the branching portion 30v1z toward the pillar cover forming portion 63 in a direction perpendicular to the width direction W of the gas exhaust portion 30d and the thickness direction of the airbag panel 60, and together with the first straight portion 30v1a and the second straight portion 30v1b, forms a roughly Y-shaped suture portion. This roughly Y-shaped opening faces toward the gas exhaust port 30x.

[0038] Furthermore, in the airbag panel 60, a second suture 30v2 (second suture) is formed around the first suture 30v1, where the inner panel 60a and the outer panel 60b are sewn together. In other words, in the airbag 30 before inflation begins, a second suture 30v2 is provided around the first suture 30v1, where the inner panel 60a and the outer panel 60b are sewn together. The area around the first suture 30v1 referred to here is within 120 mm of the first suture 30v1. In other words, if the first suture portion 30v1 is composed of a first straight section 30v1a, a second straight section 30v1b, and a third straight section 30v1c, as in this embodiment, then at least a portion of the second suture portion 30v2 should be positioned within 120 mm of any point on the first straight section 30v1a, within 120 mm of any point on the second straight section 30v1b, or within 120 mm of any point on the third straight section 30v1c. In this embodiment, since the third straight section 30v1c is located on the inflator 12 side, the second suture portion 30v2 is positioned around the third straight section 30v1c in order to reduce the stress on the first suture portion 30v1 as much as possible when expansion gas flows in.

[0039] The suture thread 82 of the second suture section 30v2 ruptures as the internal pressure of the airbag 30 increases due to the inflow of inflation gas from the time the inflator 12 starts supplying inflation gas to the airbag 30 until the airbag 30 completes its inflation. This causes the thread to come loose, and the suture of the airbag 30 by the second suture section 30v2 is released. In other words, the suture of the second suture section 30v2 is released as the internal pressure of the airbag 30 increases due to the inflow of inflation gas from the time the inflator 12 starts supplying inflation gas until the airbag 30 completes its inflation. Here, "completion of inflation of the airbag 30" refers to the point when the shape of the airbag 30 stabilizes after inflation begins and no significant deformation is observed.

[0040] The second suture section 30v2 includes a first straight section 30v2a (first straight section) in which the inner panel 60a and the outer panel 60b are sewn together in a straight line, and a second straight section 30v2b (second straight section) that branches off from the first straight section 30v2a and extends in a direction intersecting the direction in which the inner panel 60a and the outer panel 60b are sewn together in a straight line. Note that the first straight section 30v2a and the second straight section 30v2b include configurations in which the stitches are zigzag, but the overall stitching is linear.

[0041] The first straight section 30v2a extends diagonally to the left and rear from approximately the center of the width direction W of the gas discharge forming section 64, that is, approximately the center of the width direction W of the gas discharge section 30d of the airbag 30 when inflation is complete. The second straight section 30v2b extends diagonally to the left and front from approximately the center of the width direction W of the gas discharge forming section 64, that is, approximately the center of the width direction W of the gas discharge section 30d of the airbag 30 when inflation is complete. In other words, the branching point 30v2z between the first straight section 30v2a and the second straight section 30v2b of the second suture section 30v2 is located approximately in the center of the width direction W of the gas discharge section 30d. The second straight section 30v2b, together with the first straight section 30v2a, forms a roughly V-shaped suture section. This roughly V-shaped opening faces the gas discharge port 30x side.

[0042] Furthermore, a portion of the third straight section 30v1c of the first suture 30v1 is located within the region 30v2e, which is demarcated by the first straight section 30v2a and the second straight section 30v2b of the second suture 30v2. The region 30v2e referred to here is the region enclosed by the first straight section 30v2a, the second straight section 30v2b, and the imaginary line S, when the branching section 30v2z is taken as the starting point of the first straight section 30v2a and the second straight section 30v2b, respectively, and the endpoints of both are connected by an imaginary line S.

[0043] Furthermore, the suture strength of the second suture section 30v2 is set to be weaker than that of the first suture section 30v1. These suture strength settings can be achieved, for example, by making the pitch of the first suture section 30v1 smaller than that of the second suture section 30v2, or by making the strength of the suture thread 81 of the first suture section 30v1 higher than that of the suture thread 82 of the second suture section 30v2.

[0044] Thus, the airbag 30 of this embodiment is equipped with a first suture portion 30v1 that seals the gas outlet 30x, and when external pressure is applied to the airbag 30 after inflation is complete, the suture is released, opening the gas outlet 30x. This provides the following effects.

[0045] In other words, if the airbag 30 is configured to have a separate base fabric to close the gas outlet 30x, and the base fabric is cut by the external pressure applied to the airbag 30, thereby opening the gas outlet 30x, then it is necessary to provide an extra base fabric on the airbag 30 to close the gas outlet 30x. As a result, the folded airbag 30 may become larger, potentially worsening its packaging capabilities.

[0046] In contrast, in this embodiment, the airbag 30 is provided with a first suture portion 30v1 that seals the gas outlet 30x, and when external pressure is applied to the airbag 30, the suture of the first suture portion 30v1 is released, opening the gas outlet 30x. This allows the gas outlet 30x to be opened at the moment a pedestrian M or the like is caught by the airbag 30, without the need to separately provide a base fabric to close the gas outlet 30x. Therefore, according to the airbag device 10 of this embodiment, it is possible to provide a gas outlet 30x in the airbag 30 while suppressing an increase in the size of the folded airbag 30.

[0047] Furthermore, the airbag 30 includes a second suture portion 30v2 provided around the first suture portion 30v1, which releases the suture as the internal pressure of the airbag 30 increases due to the inflow of inflation gas from the start of inflation gas supply until the airbag 30 completes inflation. This provides the following effects.

[0048] In other words, if the gas output of the inflator 12 is large, the internal pressure of the airbag 30 may rise from the time the supply of inflation gas is started until the airbag 30 completes inflation, and the force of deployment may cause the suture thread 81 of the first suture 30v1 to break, potentially unintentionally releasing the suture of the first suture 30v1. In that case, the gas outlet 30x will open before the pedestrian M is caught, resulting in the internal pressure of the airbag 30 being lower than expected when it catches the pedestrian M.

[0049] In contrast, by providing a second suture portion 30v2 around the first suture portion 30v1 as in this embodiment, the stress caused by the increase in internal pressure when the airbag 30 inflates and the momentum during deployment can be distributed between the first suture portion 30v1 and the second suture portion 30v2. Therefore, it is possible to suppress the unintentional release of the suture of the first suture portion 30v1 between the start of supplying inflation gas to the airbag 30 and the completion of the airbag 30's inflation.

[0050] Furthermore, the first suture portion 30v1 has a first straight section 30v1a that is sewn in a straight line, and a second straight section 30v1b that branches off from the first straight section 30v1a and is sewn in a straight line so as to extend in a direction intersecting the direction in which the first straight section 30v1a extends. This makes it easier to concentrate stress at the branching point 30v1z between the first straight section 30v1a and the second straight section 30v1b, and makes it easier to create a starting point for the breakage of the suture thread 81 compared to a configuration in which the first suture portion 30v1 is formed by a single straight suture portion. However, if this point is not taken into consideration, the first suture portion 30v1 may have any other arbitrary shape.

[0051] Furthermore, the branching point 30v1z between the first straight section 30v1a and the second straight section 30v1b is located approximately in the center of the width direction W of the gas discharge section 30d of the airbag 30. This shortens the time between the break of the suture thread 81 at the branching point 30v1z and the complete release of the sutures between the first straight section 30v1a and the second straight section 30v1b, allowing for rapid discharge of the inflation gas through the gas discharge port 30x.

[0052] Furthermore, the first straight section 30v1a, together with the second straight section 30v1b, forms a roughly V-shape or suture, and the opening of this roughly V-shape faces the gas outlet 30x side. As a result, the branching point 30v1z between the first straight section 30v1a and the second straight section 30v1b is more likely to be located closer to the inflator 12, making it easier to concentrate stress at the branching point 30v1z and creating an initiation point for the fracture of the suture thread 81.

[0053] In this embodiment, the second straight section 30v1b branches off from the end of the first straight section 30v1a, forming a roughly V-shaped suture. However, the same effect can be obtained by configuring the second straight section 30v1b to branch off from the middle of the first straight section 30v1a, forming a roughly Y-shaped suture. Furthermore, in this embodiment, since the first straight section 30v1a, the second straight section 30v1b, and the third straight section 30v1c form a Y-shaped suture, the starting point for the breakage of the suture thread 81 is the third straight section 30v1c.

[0054] Furthermore, the second suture portion 30v2 has a first straight portion 30v2a that is sewn in a straight line, and a second straight portion 30v2b that branches off from the first straight portion 30v2a and is sewn in a straight line so as to extend in a direction intersecting the direction in which the first straight portion 30v2a extends. This makes it easier to concentrate stress at the branching point 30v2z between the first straight portion 30v2a and the second straight portion 30v2b, and makes it easier to create a starting point for the breakage of the suture thread 82 compared to a configuration in which the second suture portion 30v2 is formed by a single straight suture portion. However, if this point is not taken into consideration, the second suture portion 30v2 may have any other arbitrary shape.

[0055] Furthermore, in the second suture portion 30v2, the second straight portion 30v2b, together with the first straight portion 30v2a, forms a roughly V-shaped suture portion, and this roughly V-shaped opening faces the gas outlet 30x side. As a result, the branching portion 30v2z between the first straight portion 30v2a and the second straight portion 30v2b is more likely to be located closer to the inflator 12, making it easier to concentrate stress at the branching portion 30v2z and creating an initiation point for the fracture of the suture thread 82. In this embodiment, the second straight portion 30v2b branches from the end of the first straight portion 30v2a, so that the two form a roughly V-shaped suture portion. However, the same effect can be obtained by configuring the second straight portion 30v2b to branch from the middle of the first straight portion 30v2a so that the two form a roughly Y-shaped suture portion.

[0056] Furthermore, a portion of the third straight section 30v1c of the first suture 30v1 is located within the region 30v2e, which is demarcated by the first straight section 30v2a and the second straight section 30v2b of the second suture 30v2. This allows the first suture 30v1 to be partially surrounded by the second suture 30v2 until the suture of the second suture 30v2 is released, thereby reducing the stress on the first suture 30v1 and effectively preventing the suture of the first suture 30v1 from being released unintentionally. In particular, in this embodiment, since the third straight section 30v1c, which is the starting point for the breakage of the suture thread 81 of the first suture 30v1, is partially surrounded by the second suture 30v2, the unintentional release of the suture of the first suture 30v1 can be more effectively prevented.

[0057] Furthermore, the suture strength of the second suture 30v2 is set to be weaker than that of the first suture 30v1. This prevents the suture of the first suture 30v1 from being released before the suture of the second suture 30v2 is released. Even if the suture strengths of the first suture 30v1 and the second suture 30v2 were the same, the distance between the inflator 12 and the second suture 30v2 is shorter than the distance between the inflator 12 and the first suture 30v1, so the stress on the second suture 30v2 would be relatively larger, causing the suture of the second suture 30v2 to be released before the suture of the first suture 30v1. However, by setting the suture strength as described above, it is possible to more reliably prevent the suture of the first suture 30v1 from being released before the suture of the second suture 30v2.

[0058] In this embodiment, an example is shown in which airbag 30 covers the area around the left end 58a of the cowl top panel 58 and almost the entire area of ​​the left front pillar 55 from above, and airbag 40 covers the area around the right end 58b of the cowl top panel 58 and almost the entire area of ​​the right front pillar 56 from above. However, the present invention is not limited to this, and the shapes of airbags 30 and 40 may be changed as appropriate, as long as either airbag 30 or 40 covers at least a part of the left front pillar 55 or the right front pillar 56 from above. Alternatively, a connecting part may be provided above the cowl top panel 58 to connect airbag 30 and airbag 40, so that airbag 30 and airbag 40 can be configured as a single airbag. [Explanation of symbols]

[0059] 10…Airbag device, 12…Inflator, 30…Airbag, 30v1…First suture, 30v1a…First straight section, 30v1b…Second straight section, 30v2…Second suture, 30v2a…First straight section, 30v2b…Second straight section, 30v2e…Area, 30x…Gas outlet, 40…Airbag, 40x…Gas outlet, 50…Vehicle, 55…Left front pillar, 56…Right front pillar

Claims

1. An airbag that is folded and stored inside the vehicle, inflates when an inflation gas is supplied and is deployed outside the vehicle, and is configured to cover at least a portion of the vehicle's front pillar from above when inflation is complete, An inflator that releases the inflation gas supplied to the airbag, In an airbag system equipped with, The aforementioned airbag, The airbag has a gas outlet which is an opening for discharging the inflation gas from inside the airbag to the outside, A first suture that seals the gas outlet, the suture is released when external pressure is applied to the airbag after inflation is complete, thereby opening the gas outlet. A second suture is provided around the first suture, and the suture is released in response to the increase in internal pressure of the airbag due to the inflow of the expansion gas from the time the supply of the expansion gas by the inflator is started until the airbag has completed inflation. An airbag device characterized by having the following features.

2. The first suture portion is, The first straight section is sutured in a straight line, A second straight section is sewn in a straight line, branching off from the first straight section and extending in a direction intersecting the direction in which the first straight section extends, The airbag device according to claim 1, characterized by including the following:

3. The airbag device according to claim 2, characterized in that the first straight portion together with the second straight portion forms a substantially V-shaped or substantially Y-shaped suture, and the first straight portion and the second straight portion are arranged such that the substantially V-shaped or substantially Y-shaped opening faces the gas outlet side.

4. The second suture portion is, The first straight section is sutured in a straight line, A second straight section is sewn in a straight line, branching off from the first straight section and extending in a direction intersecting the direction in which the first straight section extends, An airbag device according to any one of claims 1 to 3, characterized by including the following:

5. The airbag device according to claim 4, characterized in that at least a portion of the first suture is located within the region demarcated by the first straight portion and the second straight portion of the second suture.

6. The airbag device according to claim 4, characterized in that the first straight portion of the second suture portion together with the second straight portion of the second suture portion forms a substantially V-shaped or substantially Y-shaped suture portion, and the first straight portion and the second straight portion of the second suture portion are arranged such that the opening of the substantially V-shaped or substantially Y-shaped suture portion faces the gas outlet side.

7. The airbag device according to claim 1, characterized in that the suture strength of the first suture is higher than the suture strength of the second suture.

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