Pedestrian protection airbag system

Abstract

Provided is an airbag device for pedestrian protection that achieves both rapid expansion and deployment of an airbag cushion and suppression of damage to the airbag cushion, for example, and that can be readily adapted to a demand for enlarging a pedestrian protection area.　An airbag device for pedestrian protection 10 comprises an airbag cushion 12 that expands and deploys outside a vehicle compartment at the time of vehicle impact, and a first inflator 14a and a second inflator 14b that each activate at the time of vehicle impact to supply gas for expansion and deployment to the airbag cushion 12. The first inflator 14a and the second inflator 14b have different timings of activation at the time of vehicle impact.

Description

Technical Field

[0001] The present invention relates to a pedestrian protection airbag device for protecting pedestrians who have collided with a vehicle.

Background Art

[0002] For example, the pedestrian protection airbag device described in Patent Document 1 is mounted near the boundary between the bonnet and the windshield of a vehicle. When a collision between the vehicle and a pedestrian is detected, an inflater is activated, thereby supplying inflation gas to the airbag cushion and instantaneously inflating and deploying the airbag cushion. The inflated and deployed airbag cushion covers the rear side of the bonnet, the lower front end of the windshield, and the lower parts of the left and right A-pillars to protect the head of a pedestrian who has collided with the vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a pedestrian protection airbag device, the inflated and deployed airbag cushion is inflated and deployed over a relatively wide area, such as across the vehicle width direction. Considering that there may be a future requirement to expand the pedestrian protection area, with only one inflater, the inflation and deployment of the airbag cushion may be delayed, and there is a risk of a delay in the timing of pedestrian protection.

[0005] One possible solution to these problems is to use multiple inflators. However, using multiple inflators can cause an excessive increase in internal pressure during the initial stages of inflation and deployment of the airbag cushion. As a result, there is a risk that the seams of the airbag cushion may rupture. There is also a risk that the inflated and deployed airbag cushion may damage the windshield (causing the glass to break).

[0006] The present invention aims to provide a pedestrian protection airbag device that can achieve both rapid inflation and deployment of the airbag cushion and suppression of damage to the airbag cushion, and that can easily respond to the demand for expanding the area of ​​pedestrian protection. [Means for solving the problem]

[0007] A pedestrian protection airbag device according to one aspect of the present invention comprises an airbag cushion that inflates and deploys outside the vehicle compartment during a vehicle collision, and a plurality of inflators, including a first inflator and a second inflator, each of which operates during a vehicle collision to supply gas for inflation and deployment to the airbag cushion, wherein the timing of their operation during a vehicle collision differs.

[0008] According to this embodiment, since the operating timing of the first and second inflators is different, the rapid pressure increase in the initial stages of inflation and deployment of the airbag cushion can be suppressed. This reduces damage to the airbag cushion. Furthermore, for example, if the inflated and deployed airbag cushion forcefully strikes a part of the vehicle (e.g., the windshield), damage to that part (e.g., glass breakage) can be suppressed. In addition, since gas for inflation and deployment is supplied to a single airbag cushion from multiple inflators, the airbag cushion can be inflated and deployed quickly. Therefore, it is easier to respond to the requirement of expanding the pedestrian protection area. Incidentally, it is preferable that the performance of the multiple inflators is the same, but inflators with different performance may be used. [Brief explanation of the drawing]

[0009] [Figure 1] This is a top view showing the state of the pedestrian protection airbag device according to Embodiment 1 when it is activated (when inflation and deployment are complete), along with the vehicle. [Figure 2] This is a cross-sectional view showing the state of the pedestrian protection airbag device according to Embodiment 1 before activation (before deployment), when cut along the line II-II in Figure 1. [Figure 3] This is a cross-sectional view showing the state of the pedestrian protection airbag device according to Embodiment 1 when it is activated (when inflation and deployment are complete), as seen when cut along the line II-II in Figure 1. [Figure 4] (A) A plan view seen from the top side, and (B) A bottom view (viewed from the back side) of the airbag cushion according to Embodiment 1 in a flat position (before inflation and before folding). [Figure 5] This is a block diagram showing the control configuration of a pedestrian protection airbag device according to Embodiment 1. [Figure 6] This flowchart shows a control method for a pedestrian protection airbag device according to Embodiment 1. [Figure 7] This is a side view showing the state of the pedestrian protection airbag device according to Embodiment 2 when it is activated (when inflation and deployment are complete), along with the vehicle. [Figure 8] This is a top view showing the state of the pedestrian protection airbag device according to Embodiment 3 when it is activated (when inflation and deployment are complete), along with the vehicle. [Modes for carrying out the invention]

[0010] <Definitions of Terms and Overview of Embodiments> A pedestrian protection airbag device according to a preferred embodiment of the present invention will be described with reference to the attached drawings. In this document, up and down, left and right, and front and back are defined as follows. When a passenger is seated in a vehicle seat in a normal posture, the direction the passenger is facing is referred to as the front, and the opposite direction as the rear, and when indicating the axis of the coordinate system, it is referred to as the front-to-back direction or the vehicle front-to-back direction. Similarly, when a passenger is seated in a seat in a normal posture, the right side of the passenger is referred to as the right direction, and the left side of the passenger is referred to as the left direction, and when indicating the axis of the coordinate system, it is referred to as the left-to-right direction or the vehicle width direction. Likewise, when a passenger is seated in a normal posture, the direction of the passenger's head is referred to as the up direction, and the direction of the passenger's waist is referred to as the down direction, and when indicating the axis of the coordinate system, it is referred to as the up and down direction.

[0011] The pedestrian protection airbag system according to this embodiment primarily protects pedestrians, and the following explanation will use pedestrians as an example. However, it is not limited to pedestrians; for example, people riding bicycles or motorcycles (cyclists), as well as people riding skateboards or kick scooters, are also included as protected individuals.

[0012] The pedestrian protection airbag device according to this embodiment includes an airbag cushion that inflates and deploys outside the vehicle compartment in the event of a vehicle collision, and a plurality of inflators, including a first inflator and a second inflator, each of which operates in the event of a vehicle collision to supply gas for inflation and deployment to the airbag cushion.

[0013] "Vehicle collision" primarily refers to a situation where a vehicle collides with a pedestrian. Determining whether a collision has occurred, and whether that collision involved a pedestrian, can be done using known methods, such as detection by sensors (pressure sensors or acceleration sensors) installed on the vehicle's bumper.

[0014] "Outside the vehicle compartment" means the area outside the vehicle's interior. For example, a pedestrian protection airbag system is mounted near the boundary between the vehicle's hood and windshield, and the airbag cushion inflates and deploys from near this boundary outwards in the vehicle's width direction. The inflated airbag cushion then covers the rear of the hood, the lower front end of the windshield, and at least the lower parts of the left and right A-pillars, protecting the head of a pedestrian who collides with the vehicle. The area covering the A-pillar may extend upwards, including the intermediate region above the lower part of the A-pillar, or it may extend across the entire A-pillar.

[0015] However, in other embodiments, the pedestrian protection airbag system may be mounted in a location other than near the boundary between the hood and the windshield. For example, it may be mounted on the front end of the hood, and the airbag cushion may inflate and deploy from the gap at the front end of the hood upwards in the vehicle width direction. In this case, the inflated and deployed airbag cushion covers the front and / or rear portion of the hood, protecting pedestrians who collide with the vehicle.

[0016] The following describes an example of an airbag cushion inflating and deploying from near the boundary between the bonnet and the windshield. Note that "bonnet" is sometimes referred to as "hood," and "windshield" is sometimes referred to as "front glass."

[0017] The airbag cushion is normally folded and housed within the housing. The folded airbag cushion has, for example, a roll shape, an accordion shape, or a combination of these shapes. The airbag cushion inflates and deploys upon receiving gas supply from a plurality of inflators during a vehicle collision. In the pedestrian protection airbag device of the present embodiment, by shifting the operation timings of the plurality of inflators, while maintaining the prompt inflation and deployment of the airbag cushion, a rapid pressure increase at the initial stage of the inflation and deployment of the airbag cushion is suppressed. It is preferable that the performances of the plurality of inflators are the same, but those with different performances may also be used.

[0018] <Embodiment 1> As shown in FIG. 1, the pedestrian protection airbag device 10 includes an airbag cushion 12 that inflates and deploys outside the vehicle compartment during a vehicle collision. The airbag cushion 12 inflates and deploys upon receiving gas supply for inflation and deployment from the first inflator 14a and the second inflator 14b. At this time, the airbag cushion 12 inflates and deploys from the boundary portion 26 between the bonnet 22 and the windshield 24 of the vehicle 20, covers the rear side 22a of the bonnet 22 and the lower front end 24a of the windshield 24, and also covers the lower portions of the left and right A-pillars 28, 28. Although not particularly shown, the range covering the A-pillar may be provided to extend to the upper intermediate region including above the lower portion of the A-pillar or to cover the entire A-pillar.

[0019] A sensor 32 for detecting a vehicle collision is provided on the front bumper 30 of the vehicle 20. The sensor 32 can use various known methods such as, for example, an acceleration sensor or a pressure sensor. The sensor 32 is connected to the controller 34, and a signal from the sensor 32 is input to the controller 34. The controller 34 determines whether the vehicle 20 has collided with a pedestrian based on the detection result of the sensor 32. When it is determined that there has been a collision with a pedestrian, the controller 34 activates the inflators 14a, 14b to inflate and deploy the airbag cushion 12.

[0020] As shown in FIG. 2, the airbag cushion 12 is normally folded and housed within the housing 16. The housing 16 is, for example, a shallow-bottomed metal case with an open upper portion, and extends in the vehicle width direction. The opening of the housing 16 is covered by a cover 18, and a breaking portion 18a, which consists of, for example, perforations, slits, groove portions, etc., is formed on the cover 18. The breaking portion 18a is configured to be torn by the inflated and deployed airbag cushion 12, thereby facilitating the airbag cushion 12 to pop out upward from the cover 18.

[0021] Inflators 14a and 14b are fixed to the bottom wall portion 16a of the housing 16. Utilizing this fixation, the bottom portion of the airbag cushion 12 is also fastened to the bottom wall portion 16a of the housing 16. Specifically, after the inflators 14a and 14b are inserted into the airbag cushion 12, the stud bolts 41a and 41b of the inflators 14a and 14b protrude outward from the bottom portion of the airbag cushion 12 (see FIG. 4(B)). The stud bolts 41a and 41b protrude below the bottom wall portion 16a and are fastened and fixed to the lower surface of the bottom wall portion 16a with nuts. At this time, the bottom portion of the airbag cushion 12 is pressed by the inflators 14a and 14b against the upper surface of the bottom wall portion 16a. Thereby, the airbag cushion 12 is fixed to the housing 16 together with the inflators 14a and 14b.

[0022] Thus, in the pedestrian protection airbag device 10, at least the airbag cushion 12, the inflators 14a and 14b, the housing 16, and the cover 18 constitute a modularized airbag device. And by fixing the housing 16 to the body of the vehicle 20 or a bracket attached thereto, etc., the pedestrian protection airbag device 10 is mounted at the boundary portion 26 between the bonnet 22 and the windshield 24. Note that the reference numeral 29 shown in FIG. 2 is a wiper.

[0023] As shown in Figure 3, the airbag cushion 12 ruptures the cover 18 during inflation and deployment, and then inflates and deploys outside the cover 18. When inflation and deployment are complete, the airbag cushion 12 has a front inflation section 51 located on the hood 22 in a side view, and a rear inflation section 52 located near the lower end of the windshield 24. The airbag cushion 12 is composed of a single chamber, and the front inflation section 51 and the rear inflation section 52 are in communication. The rear inflation section 52 is located from the front end to the rear end of the lower end of the windshield 24, overriding the wiper 29.

[0024] Figure 4 shows the airbag cushion 12 in a flat position (i.e., before inflation and before folding). The airbag cushion 12 is formed into a bag shape by sewing or bonding one or more base fabrics at appropriate positions, or by weaving using OPW (One-Piece Woven). For example, the airbag cushion 12 is formed by sewing the outer base fabric 12a and the inner base fabric 12b at their respective edges. This defines an air chamber (bag) inside the space between the outer base fabric 12a and the inner base fabric 12b, inside the seam. When gas from inflators 14a and 14b is supplied to this air chamber, the air chamber-defining portions of the outer base fabric 12a and the inner base fabric 12b inflate and expand.

[0025] The state shown in Figure 4(A), as can be understood by comparing it with Figure 1, is also close to the top view of the airbag cushion 12 when inflation and deployment are complete. Therefore, the airbag cushion 12 can be considered to have a central inflation section 53 located in the center of the vehicle width direction when viewed from above, and a pair of lateral inflation sections 54 and 55 located at both ends in the vehicle width direction when inflation and deployment are complete. The central inflation section 53 and the pair of lateral inflation sections 54 and 55 are in communication. The central inflation section 53 covers the area near the rear end of the bonnet 22 and the front lower end of the windshield 24 in the center of the vehicle width direction, and the pair of lateral inflation sections 54 and 55 have a shape that protrudes upward so as to cover the lower part of the A pillars 28 and 28.

[0026] Figure 4(B) also shows the areas of the forward inflatable portion 51 and the rear inflatable portion 52 in a side view of the airbag cushion 12. Here, the area of ​​the forward inflatable portion 51 is larger than the area of ​​the rear inflatable portion 52, but this ratio of areas can be appropriately changed depending on the type of vehicle, etc. For example, in the case of a small vehicle where the pedestrian's collision position extends to the rear side of the vehicle on the hood, the area of ​​the rear inflatable portion 52 can be made larger than that of the forward inflatable portion 51.

[0027] Next, we will explain inflators 14a and 14b with reference to Figures 2-4. Inflators 14a and 14b are each configured to supply gas for inflation and deployment to the airbag cushion 12. Various types of inflators 14a and 14b can be used, such as those filled with a gas generating agent, compressed gas, or both. In this case, inflators 14a and 14b with the same performance are used.

[0028] For example, the inflator 14a has a bottomed cylindrical body filled with a gas generating agent and an ignition device provided at the open end of the cylindrical body. The cylindrical body is provided with a number of (two in this case) stud bolts 41a spaced apart in the axial direction of the cylindrical body, and is fixed to the housing 16 via these stud bolts 41a. In addition, a number of ejection holes are formed on the circumferential or bottom surface of the cylindrical body. By igniting the gas generating agent inside the cylindrical body with the ignition device, gas is generated and the gas for inflation and deployment is instantaneously supplied into the airbag cushion 12 from the number of ejection holes.

[0029] The inflators 14a and 14b are housed inside the airbag cushion 12. As illustrated in Figure 4, they may be inserted into the airbag cushion 12 through an opening 12c. In this case, the opening 12c is formed, for example, in the backing fabric 12b of the airbag cushion 12. Connectors are provided at the end portions 42a and 42b of the inflators 14a and 14b to facilitate electrical connection with the controller 34, and the wire harness connected to the connector is provided to exit the airbag cushion 12 through the opening 12c. Additionally, the stud bolts 41a and 41b of the inflators 14a and 14b protrude to the outside of the airbag cushion 12 through through holes formed in the backing fabric 12b.

[0030] As shown in Figure 4, the inflators 14a and 14b are installed at different positions in the left-right direction (vehicle width direction). For example, the inflators 14a and 14b are arranged so that they do not overlap with each other in whole or in part in the vehicle width direction. Here, the inflators 14a and 14b are arranged on one side and the other side of the centerline in the vehicle width direction without overlapping with each other in whole. Specifically, inflator 14a is installed to the left of the vehicle 20 relative to the center in the vehicle width direction, and inflator 14b is installed to the right of the vehicle relative to the center in the vehicle width direction.

[0031] Furthermore, the inflators 14a and 14b are positioned along the vehicle width direction. This means that the center position of inflator 14a and the center position of inflator 14b are located on the same line parallel to the vehicle width direction. Here, the cylindrical inflators 14a and 14b have their cylindrical axes aligned with the vehicle width direction. In addition, the ignition devices (42a and 42b) of the cylindrical inflators 14a and 14b are facing each other, and the bottom surface of the cylinder (where the ejection holes are formed) is facing outward in the vehicle width direction.

[0032] In other embodiments, when the inflators 14a and 14b are installed along the vehicle width direction, the posture or orientation of the inflators 14a and 14b does not need to be parallel to the vehicle width direction. Also, if the inflators 14a and 14b are not installed along the vehicle width direction, the positions of the inflators 14a and 14b will be different in the vehicle's longitudinal direction.

[0033] Figure 5 shows the control configuration 60 of the pedestrian protection airbag system 10, including the inflators 14a and 14b. The controller 34 in the pedestrian protection airbag system 10 is an electronic control unit (ECU) equipped with a CPU 71, memory 72, and input / output interface 73, and is configured as, for example, a microcomputer. The CPU 71 performs desired calculations according to the control program and performs various processes and controls. The memory 72 includes, for example, ROM and RAM. The ROM stores the control program and control data processed by the CPU 71, and the RAM is mainly used as various work areas for control processing. The sensor 32 and the inflators 14a and 14b are electrically connected to the input / output interface 73. With this configuration, the controller 34 receives an input signal from the sensor 32 and, when it determines that the vehicle 20 has collided with a pedestrian, outputs an activation signal to the inflators 14a and 14b.

[0034] The controller 34 can be configured as an airbag ECU capable of communicating with the vehicle's ECU, and can control the operation of inflators not only in the pedestrian protection airbag system 10's inflators 14a and 14b, but also in other airbag systems (e.g., front airbag system, curtain airbag system, etc.).

[0035] In other embodiments, the vehicle-side ECU may determine whether or not the vehicle 20 has collided with a pedestrian, and the controller 34 may receive collision information from the vehicle-side ECU and output operating signals to the inflators 14a and 14b.

[0036] Figure 6 is a flowchart showing the control method for the pedestrian protection airbag device 10. This control method is executed by the controller 34 when it is determined that the vehicle 20 has collided with a pedestrian (vehicle collision: S10).

[0037] In this control method, the timing of the operation of inflators 14a and 14b is different. That is, inflator 14a operates at a first timing, and inflator 14b operates at a second timing that is different from the first timing. Here, the controller 34 changes the timing of the operation signal output so that the second inflator 14b operates later than the first inflator 14a. Specifically, first, the first inflator 14a outputs an operation signal to supply gas for inflation and deployment to the airbag cushion 12 (S11), and then the second inflator 14b outputs an operation signal to supply gas for inflation and deployment to the airbag cushion 12 (S12).

[0038] Here, the difference in the timing of the operation of inflators 14a and 14b (ignition delay time) should be, for example, 5 to 20 msec. If it is less than 5 msec, it will be almost the same as operating inflators 14a and 14b simultaneously, and the internal pressure of the airbag cushion 12 may rise excessively in the initial stages of inflation and deployment. If it exceeds 20 msec, the rise in internal pressure of the airbag cushion 12 in the initial stages of inflation and deployment may be insufficient. In particular, inflation and deployment may be delayed on one side of the airbag cushion 12 in the vehicle width direction. As a result, the timing of pedestrian protection may be delayed, and pedestrian protection may not be properly achieved.

[0039] By setting the inflation time to a range of 5-20 msec, the rapid pressure increase during the initial inflation and deployment of the airbag cushion 12 can be suppressed (i.e., the peak internal pressure can be reduced). In addition, this allows the airbag cushion 12 to inflate and deploy quickly. In particular, it suppresses variations in the amount of inflation and deployment in the vehicle width direction, allowing the airbag cushion 12 to inflate and deploy as a whole, which leads to appropriate pedestrian protection.

[0040] Within the range of 5 to 20 msec, 10 msec, or 1 msec above or below that, is preferable. However, please note that this delay time is greatly affected by the type and performance of the inflator used.

[0041] As described above, the pedestrian protection airbag device 10 of this embodiment comprises an airbag cushion 12 that inflates and deploys outside the vehicle compartment when a vehicle collision occurs, and a plurality of inflators, including a first inflator 14a and a second inflator 14b, each of which operates when a vehicle collision occurs to supply gas for inflation and deployment to the airbag cushion 12. The first inflator 14a and the second inflator 14b operate at different timings when a vehicle collision occurs.

[0042] With this configuration, the rapid pressure increase during the initial inflation and deployment of the airbag cushion 12 is suppressed, thereby reducing damage to the airbag cushion 12 (such as rupture of seams). This eliminates the need to separately reinforce the airbag cushion 12 to account for the high output from multiple inflators. Furthermore, it reduces damage to a part of the vehicle 20 (such as the windshield 24) if the inflated and deployed airbag cushion 12 forcefully strikes that part (such as glass breakage). Thus, it is possible to achieve both rapid inflation and deployment of the airbag cushion 12 and suppression of damage to the airbag cushion 12. In addition, it is possible to satisfy pedestrian head protection performance and easily respond to the demand for expanding the pedestrian protection area.

[0043] In this embodiment, the inflators 14a and 14b have identical performance. Therefore, for example, the configuration and control can be simplified.

[0044] In this embodiment, the inflators 14a and 14b are provided at different positions in the vehicle width direction. Therefore, variations in the amount of inflation and unfolding in the vehicle width direction can be suppressed.

[0045] Furthermore, the inflators 14a and 14b are provided along the vehicle width direction. This also helps to suppress variations in the amount of inflation and deployment in the longitudinal direction of the vehicle. In particular, when the ignition devices of the cylindrical inflators 14a and 14b are placed facing each other, and the bottom surface of the cylinder with the ejection hole is oriented outward in the vehicle width direction, the inflation and deployment gas can be directed towards the pair of lateral inflation sections 54 and 55 in the airbag cushion 12.

[0046] Next, other embodiments will be described. Note that for the other embodiments, the differences from Embodiment 1 will be the main focus of the description, and components common to Embodiment 1 will be denoted by the same or similar reference numerals, and their descriptions will be omitted.

[0047] <Embodiment 2> The pedestrian protection airbag device 10 according to Embodiment 2 will be explained with reference to Figure 7. As shown in Figure 7, the airbag cushion 112 according to Embodiment 2 may have a sub-chamber 200 that inflates and deploys under the bonnet 22. That is, the airbag cushion 112 may have the configuration of the airbag cushion 12 according to Embodiment 1 as the main chamber 201, and may have a sub-chamber 200 connected to the underside of the main chamber 201.

[0048] In this case, the inflators 14a and 14b (omitted in Figure 7) can be inserted into the sub-chamber 200, for example, and fixed to the housing at the boundary portion 26. The expansion gas from the inflators 14a and 14b is first supplied to the sub-chamber 200, and then supplied to the main chamber 201 from the communication portion between the sub-chamber 200 and the main chamber 201. The positional relationship of the inflators 14a and 14b within the sub-chamber 200 can be the same as the positional relationship of the inflators 14a and 14b in Embodiment 1.

[0049] <Embodiment 3> Referring to Figure 8, the timing of the operation of the inflators 140a and 140b in the vehicle 20 when there is a vulnerable part 300 in the pedestrian protection airbag device 10 according to Embodiment 3 will be explained. The vulnerable part 300 refers to, for example, a part of the vehicle structure that is more easily deformed or moved by the influence of the inflated and deployed airbag cushion 12 compared to other parts of the vehicle 20.

[0050] In some cases, the vulnerable portion 300 moves to the front end or near the front end of the windshield 24, either retaining its original shape or deforming, upon contact with the inflated and deployed airbag cushion 12 and / or a portion of the cover 18 that has been ruptured by the inflation and deployment. Examples of such vulnerable portions 300 are parts other than the windshield 24, such as the wiper or related parts (e.g., wiper panel, wiper guard, wiper link, etc.) when the wiper link is located on one side of the vehicle.

[0051] If such a weak point 300 exists, the inflators 140a and 140b that are further away from the weak point 300 may activate first. For example, if the weak point 300 is near the front end of the windshield 24 and is on a first side (e.g., the right side) of the vehicle 20 rather than the center in the width direction, the inflator 140b located on the second side (e.g., the left side) opposite to the first side will activate before the inflator 140a. This makes it easier to suppress damage to the weak point 300 when the inflated and deployed airbag cushion 12 itself and / or a part of the ruptured cover 18 come into contact with the weak point 300. Therefore, it is possible to suppress the impact of this damage on the windshield 24 (e.g., glass breakage due to a broken part of the wiper link colliding with the windshield 24).

[0052] In some other cases, the vulnerable area 300 may be part of the windshield 24. The windshield 24 is generally asymmetrical, and either the left or right portion of the front end of the windshield 24 may protrude (extend) forward of the vehicle. This portion is more susceptible to contact by the inflated and deployed airbag cushion 12 and / or a portion of the cover 18 that has ruptured due to inflation and deployment, and thus can be a part where glass breakage is likely to occur.

[0053] Even when such a weak point 300 is present, the inflators 140a and 140b that are further away from the weak point 300 may activate first. This also helps to suppress damage to the weak point 300 (in this case, the protruding left or right portion of the front end of the windshield 24) when the inflated and deployed airbag cushion 12 itself and / or a part of the ruptured cover 18 come into contact with the weak point 300.

[0054] Please note that the location and impact of the vulnerable area 300 will vary significantly depending on the vehicle layout.

[0055] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The configurations of each embodiment can be combined with one another. Furthermore, the elements, their arrangement, materials, conditions, shapes, and sizes of each embodiment are not limited to those exemplified and can be modified as appropriate.

[0056] For example, there may be three or more inflators, as long as there are at least two. Preferably, the inflators should all have the same performance and operate at different times during a vehicle collision. For example, three inflators of the same performance may be installed along the width of the vehicle, and one or both of the inflators on either side in the width direction may operate before the inflator in the center in the width direction. Alternatively, the performance of the inflators may be set to be different. In this case, setting the gas generation capacity of the inflators that operate first to be smaller than that of the inflators that operate later can more effectively reduce damage to the vehicle body.

[0057] <Additional considerations regarding various embodiments> [Embodiment 1] In a pedestrian protection airbag system equipped with an airbag cushion that inflates and deploys outside the vehicle compartment during a vehicle collision, The system comprises a plurality of inflators, including a first inflator and a second inflator, each of which operates during a vehicle collision to supply gas for inflation and deployment to the airbag cushion. A pedestrian protection airbag system in which the first inflator and the second inflator have the same performance but differ in their timing of activation during a vehicle collision. [Embodiment 2] The pedestrian protection airbag device of Embodiment 1, wherein the first inflator and the second inflator have the same performance.

[0058] [Embodiment 3] A pedestrian protection airbag device according to Embodiment 1 or 2, wherein the first inflator and the second inflator are provided at different positions in the vehicle width direction.

[0059] [Embodiment 4] When viewed from the front of the vehicle, The first inflator is located to the right of the vehicle, relative to the center in the vehicle width direction. The pedestrian protection airbag device of Embodiment 3, wherein the second inflator is located to the left of the vehicle, relative to the center in the vehicle width direction.

[0060] [Embodiment 5] The first inflator and the second inflator are one of the pedestrian protection airbag devices of embodiments 1 to 4, which are provided along the width direction of the vehicle.

[0061] [Embodiment 6] The aforementioned airbag cushion is configured to inflate and deploy at least in the vehicle width direction from the boundary between the vehicle's hood and windshield. A pedestrian protection airbag device according to any one of embodiments 1 to 5, wherein, if there is a vulnerable area near the lower end of the windshield that is on the first side of the vehicle, when viewed from the front of the vehicle, is on the first side of the vehicle than the center in the vehicle width direction, the second inflator, which is on the side opposite to the first inflator, activates first.

[0062] [Embodiment 7] The aforementioned vulnerable portion is a part of the vehicle structure that is easily deformed or moved due to the influence of the inflated and deployed airbag cushion, in the pedestrian protection airbag device of Embodiment 6.

[0063] [Embodiment 8] A pedestrian protection airbag device according to any one of embodiments 1 to 5, wherein the airbag cushion is configured to inflate and deploy from the boundary between the vehicle's hood and windshield.

[0064] [Embodiment 9] A pedestrian protection airbag device according to any one of embodiments 1 to 8, wherein the difference in the timing of activation of the first inflator and the second inflator during a vehicle collision is 5 to 20 msec.

[0065] [Embodiment 10] The system further comprises controllers connected to the first and second inflators, The controller, in the event of a vehicle collision, An operating signal is output to the first inflator so that the first inflator operates at a first timing, A pedestrian protection airbag device according to any one of embodiments 1 to 9, wherein an activation signal is output to the second inflator so that the second inflator operates at a second timing different from the first timing.

[0066] [Embodiment 11] A control method for a pedestrian protection airbag system comprising an airbag cushion that inflates and deploys outside the vehicle compartment in the event of a vehicle collision, a first inflator and a second inflator having the same performance, and a controller connected to the first inflator and the second inflator, In the event of a vehicle collision, The first inflator outputs an operating signal to supply gas for inflation and deployment to the airbag cushion, A control method for a pedestrian protection airbag device, comprising: causing the controller to output an operating signal from the second inflator to supply gas for inflation and deployment to the airbag cushion, such that the second inflator operates later than the first inflator.

[0067] [Embodiment 12] A control method for a pedestrian protection airbag device according to Embodiment 11, wherein the second inflator operates 5 to 20 msec later than the first inflator.

[0068] [Embodiment 13] The aforementioned airbag cushion is configured to inflate and deploy at least in the vehicle width direction from the boundary between the vehicle's hood and windshield. A control method for a pedestrian protection airbag device according to embodiment 11 or 12, wherein the first inflator and the second inflator are provided along the width direction of the vehicle. [Explanation of Symbols]

[0069] 10...Pedestrian protection airbag device, 12...Airbag cushion, 12a...Outer base fabric, 12b...Inner base fabric, 12c...Opening, 14a...First inflator, 14b...Second inflator, 16...Housing, 16a...Bottom wall, 18...Cover, 18a...Break, 20...Vehicle, 22...Bonnet, 22a...Rear side, 24...Windshield, 24a...Front lower end, 26...Boundary, 28...A-pillar, 29...Wiper, 3 0…Front bumper, 32…Sensor, 34…Controller, 41a, 41b…Stud bolt, 51…Forward inflation section, 52…Rear inflation section, 53…Central inflation section, 54, 55…Lateral inflation sections, 60…Control configuration, 71…CPU, 72…Memory, 73…Input / output interface, 112…Airbag cushion, 140a, 140b…Inflator, 200…Sub-chamber, 201…Main chamber, 300…Vulnerable section

Claims

1. A pedestrian protection airbag device equipped with an airbag cushion that inflates and deploys outside the vehicle compartment in the event of a vehicle collision, The system comprises a plurality of inflators, including a first inflator and a second inflator, each of which operates during a vehicle collision to supply gas for inflation and deployment to the airbag cushion. The first inflator and the second inflator operate at different times during a vehicle collision. The aforementioned airbag cushion is configured to inflate and deploy at least in the vehicle width direction from the boundary between the vehicle's hood and windshield. A pedestrian protection airbag system in which, if there is a vulnerable area near the front end of the windshield that is on the first side of the vehicle, relative to the center in the vehicle width direction when viewed from the front of the vehicle, the second inflator, which is on the side opposite to the first inflator, activates first.

2. The pedestrian protection airbag device according to claim 1, wherein the vulnerable part is a part of the vehicle structure that is easily deformed or moved due to the influence of the inflated and deployed airbag cushion.

3. A pedestrian protection airbag device equipped with an airbag cushion that inflates and deploys outside the vehicle compartment in the event of a vehicle collision, The system comprises a plurality of inflators, including a first inflator and a second inflator, each of which operates during a vehicle collision to supply gas for inflation and deployment to the airbag cushion. The first inflator and the second inflator operate at different times during a vehicle collision. A pedestrian protection airbag system wherein the difference in the timing of activation of the first inflator and the second inflator during a vehicle collision is 5 to 20 msec.

4. The pedestrian protection airbag device according to claim 3, wherein the airbag cushion is configured to inflate and deploy from the boundary between the vehicle's hood and windshield.

5. The pedestrian protection airbag device according to any one of claims 1 to 4, wherein the first inflator and the second inflator have the same performance.

6. The pedestrian protection airbag device according to any one of claims 1 to 4, wherein the first inflator and the second inflator are provided at different positions in the vehicle width direction.

7. When viewed from the front of the vehicle, The first inflator is located to the right of the vehicle, relative to the center in the vehicle width direction. The pedestrian protection airbag device according to claim 6, wherein the second inflator is located to the left of the vehicle relative to the center in the vehicle width direction.

8. The pedestrian protection airbag device according to any one of claims 1 to 4, wherein the first inflator and the second inflator are provided along the width direction of the vehicle.

9. The system further comprises a controller connected to the first inflator and the second inflator, and the controller, in the event of a vehicle collision, An operating signal is output to the first inflator so that the first inflator operates at a first timing, A pedestrian protection airbag device according to any one of claims 1 to 4, wherein an operating signal is output to the second inflator so that the second inflator operates at a second timing different from the first timing.

10. A control method for a pedestrian protection airbag system comprising an airbag cushion that inflates and deploys outside the vehicle compartment in the event of a vehicle collision, a first inflator and a second inflator having the same performance, and a controller connected to the first inflator and the second inflator, In the event of a vehicle collision, The first inflator outputs an operating signal to supply gas for inflation and deployment to the airbag cushion, A control method for a pedestrian protection airbag device, comprising: causing the controller to output an operation signal from the second inflator to supply gas for inflation and deployment to the airbag cushion, such that the second inflator operates 5 to 20 msec later than the first inflator.

11. The aforementioned airbag cushion is configured to inflate and deploy at least in the vehicle width direction from the boundary between the vehicle's hood and windshield. The control method for a pedestrian protection airbag device according to claim 10, wherein the first inflator and the second inflator are provided along the width direction of the vehicle.

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