Mounting structure for acceleration sensor for detecting collision of vehicle

Abstract

Provided is a mounting structure for an acceleration sensor which is advantageous for reliably detecting a collision regardless of the height position at which a bumper fascia collides with an object.　According to the present invention: a support bracket 14 extends vertically across a first location A1 and a second location B1; an upper end in the extension direction of the support bracket 14 is arranged opposite and near a rear surface 10A of the bumper fascia 10 at the first location A1; a lower end in the extension direction of the support bracket 14 is arranged opposite and near the rear surface 10A of the bumper fascia 10 at the second location B1; either the upper end or the lower end of the support bracket 14 is fixed to the rear surface 10A of the bumper fascia 10; and an acceleration sensor 12 is attached to the other of the upper end or the lower end.

Description

Mounting structure for acceleration sensor for detecting collision of vehicle

[0001] The present invention relates to a mounting structure for an acceleration sensor for detecting a frontal collision of a vehicle.

[0002] Pedestrian protection devices are known that protect pedestrians, cyclists, and motorcycle occupants by using a pop-up mechanism installed on the vehicle to push up the rear end of the hood, creating a space below the hood when the front bumper of the vehicle collides with a pedestrian's thigh or the wheel of a bicycle or motorcycle. Other pedestrian protection devices are known that protect pedestrians, cyclists, and motorcycle occupants by inflating and deploying an airbag from the space created by the pop-up mechanism to cover the top surface of the hood. The above-mentioned pedestrian protection devices determine the occurrence of a collision based on the results of comparing detection signals from multiple acceleration sensors attached to the back surface of the bumper fascia that constitutes the bumper with threshold values, and activate the protection device. However, the point where the bumper fascia collides with the wheel of the bicycle or motorcycle is located lower than the point where the bumper fascia collides with the pedestrian's thigh. Therefore, for example, if an acceleration sensor is positioned vertically corresponding to the thigh, the collision load input to the acceleration sensor when the bumper fascia collides with the thigh will be of an appropriate magnitude. In contrast, when a bumper fascia collides with a bicycle or motorcycle wheel, the collision load input to the acceleration sensor is input at a location vertically distant from the acceleration sensor, resulting in a lower value compared to when the collision load is input to the thigh. In other words, there is a concern that the magnitude of the acceleration sensor's detection signal may not be sufficient depending on the height of the object that the bumper fascia collides with. Therefore, Patent Document 1 discloses a technology that, based on image information acquired by an on-board camera, identifies whether the object that the bumper collides with is a pedestrian or a bicycle or motorcycle wheel, and changes the threshold value used to determine the detection results obtained from the acceleration sensor depending on whether the object is a pedestrian or a wheel. Specifically, the threshold value for the wheel is changed to a lower value than the threshold value for the pedestrian.

[0003] Patent No. 6131925

[0004] However, the above-mentioned conventional technology requires an on-board camera, which increases costs, and also requires complex information processing to identify the object based on image information obtained from the on-board camera, which has the disadvantage of increasing the control load of the pedestrian protection device, and some kind of improvement is required. The present invention has been devised in consideration of the above-mentioned circumstances, and its object is to provide an acceleration sensor mounting structure that is advantageous in reliably detecting a collision regardless of the height position at which the bumper fascia hits the object, and is advantageous in reducing the cost and control load of the pedestrian protection device.

[0005] In order to achieve the above object, one embodiment of the present invention is a mounting structure for a vehicle collision detection acceleration sensor that detects a collision by mounting an acceleration sensor on the underside of a bumper fascia of a front bumper, wherein a portion of the bumper fascia at a predetermined height in the vertical direction is defined as a first portion, and a portion of the bumper fascia at a predetermined height below the first portion is defined as a second portion, a support bracket is provided that extends in the vertical direction between the first portion and the second portion, the upper end of the support bracket in the extending direction is positioned adjacent to and opposite the underside of the bumper fascia at the first portion, and the lower end of the support bracket in the extending direction is positioned adjacent to and opposite the underside of the bumper fascia at the second portion, either the upper end or the lower end of the support bracket is fixed to the underside of the bumper fascia, and the acceleration sensor is mounted to the other of the upper end or the lower end. In one embodiment of the present invention, the support bracket further includes a plurality of fixed brackets provided at intervals in the vehicle width direction and fixed to the back surface of the bumper fascia of either the first portion or the second portion and extending in the vehicle width direction, the plurality of support brackets being connected to each other via the fixed brackets and fixed to the back surface of the bumper fascia. In another embodiment of the present invention, the fixed bracket has a plurality of fixing portions attached to the back surface of the bumper fascia, and the attachment portions of the plurality of support brackets to the fixed bracket and the plurality of fixing portions are located in close proximity to each other. In addition, one embodiment of the present invention is characterized in that the cross section of the support bracket perpendicular to the extension direction has a rear plate portion extending in the vehicle width direction, a pair of side plate portions protruding forward of the vehicle from both ends of the rear plate portion in the vehicle width direction, and a flange portion extending in the vehicle width direction from the front end of the side plate portion, forming an approximately hat-shaped cross section that convex toward the rear of the vehicle, and the acceleration sensor is attached to the rear surface of the rear plate portion, and the flange portion is widened in the vehicle width direction to form an attachment portion that is attached to the back surface of the bumper fascia via the fixed bracket.In one embodiment of the present invention, the acceleration sensor is attached to the support bracket via a fastening member that penetrates the rear plate portion, and the front end edge of the side plate portion is formed to be located further forward of the vehicle than the fastening member. In another embodiment of the present invention, a portion of the fixing bracket where the fixing portion is not provided is displaced further forward of the vehicle than a portion of the fixing bracket where the fixing portion is provided. In another embodiment of the present invention, the first portion is set at a portion of the bumper fascia at a height suitable for detecting a collision with a pedestrian, and the second portion is set at a portion of the bumper fascia at a height suitable for detecting a collision with a motorcycle.

[0006] According to one embodiment of the present invention, even if a portion of the bumper fascia that is far from the acceleration sensor in the vertical direction collides with an object, the collision load input from the object to the bumper fascia is transmitted to the support bracket via the mounting portion, causing the displaceable portion to displace toward the rear of the vehicle, thereby ensuring the magnitude of the detection signal from the acceleration sensor, similar to when a portion of the bumper fascia that is close to the acceleration sensor in the vertical direction collides with the object. Therefore, even if the portion of the bumper fascia that collides with the object in the vertical direction is far from the acceleration sensor, this is advantageous for reliably detecting the collision of the bumper fascia with the object, reducing the cost of the pedestrian protection device, and is advantageous for reducing the control load of the pedestrian protection device. Furthermore, the support brackets are provided in a plurality at intervals in the vehicle width direction, and further include a fixed bracket fixed to the back surface of either the first section or the second section of the bumper fascia and extending in the vehicle width direction, and when the plurality of support brackets are connected to each other via the fixed brackets and fixed to the back surface of the bumper fascia, even if the portion of the bumper fascia that collides with an object is distant from the support bracket in the vehicle width direction, the portion of the bumper fascia that has deformed due to the collision load reliably abuts against the fixed bracket, so that the collision load is reliably transmitted to the support bracket via the fixed bracket and the displaceable portion of the support bracket can be reliably displaced toward the rear of the vehicle, which is more advantageous in reliably detecting the collision of the bumper fascia with an object. Furthermore, if the fixed bracket has a plurality of fixing portions attached to the back surface of the bumper fascia, and the attachment portions of the plurality of support brackets to the fixed bracket are located in close proximity to each other, the rigidity of the attachment portions of the support bracket and the fixed bracket can be increased. This is more advantageous in ensuring that the load is transmitted to the support bracket via the fixed bracket, and the displaceable portion of the support bracket can be displaced more reliably toward the rear of the vehicle, which is more advantageous in ensuring that the collision of the bumper fascia with the wheel Y is detected.Furthermore, a cross section perpendicular to the extension direction of the support bracket has a rear plate portion extending in the vehicle width direction, a pair of side plate portions protruding forward of the vehicle from both ends of the rear plate portion in the vehicle width direction, and a flange portion extending in the vehicle width direction from the front end of the side plate portion, forming a generally hat-shaped cross section convex toward the rear of the vehicle. The acceleration sensor is attached to the rear surface of the rear plate portion, and the flange portion is widened in the vehicle width direction to form a mounting portion for mounting on the back surface of the bumper fascia. This increases the rigidity of the support bracket, allowing the collision load from the fixed bracket to be efficiently transmitted to the support bracket, more reliably displacing the displaceable portion of the support bracket toward the rear of the vehicle, which is more advantageous for reliably detecting a collision of the bumper fascia. Furthermore, because the flange portion can receive the bumper fascia that has receded due to a collision, the acceleration can be more reliably and accurately transmitted to the acceleration sensor even if the fixed portion of the support bracket collides with an object. Furthermore, if the acceleration sensor is attached to the support bracket via a fastening member that penetrates the rear plate portion and the front end edges of the side plate portions are formed to be located further forward of the vehicle than the fastening member, the fastening member for attaching the acceleration sensor does not protrude from the support bracket and is housed inside the hat cross section, thereby improving protection performance against an object in the event of a collision. Furthermore, if the portion of the fixed bracket that does not have a fixing portion is displaced further forward of the vehicle than the portion of the fixed bracket that does have a fixing portion, when the portion of the bumper fascia that is forward of the fixed bracket portion collides with an object and the bumper fascia is deformed toward the rear of the vehicle, a load is reliably input from the deformed bumper fascia to the portion of the fixed bracket, and the load is reliably transmitted to the support bracket, which more reliably displaces the displaceable portion of the support bracket toward the rear of the vehicle, which is more advantageous for reliably detecting a collision of the bumper fascia with an object.Furthermore, if the first portion is set at a height suitable for detecting a collision of the bumper fascia with a pedestrian and the second portion is set at a height suitable for detecting a collision of the bumper fascia with a motorcycle, the magnitude of the detection signal from the acceleration sensor can be ensured in either the case of a collision between the bumper fascia and a pedestrian or a collision between the bumper fascia and a motorcycle, which is advantageous in reliably detecting the collision of the bumper fascia with an object.

[0007] 1 is a rear view of the acceleration sensor mounting structure of the embodiment, as seen from the rear side of the bumper fascia. It is a cross-sectional view taken along line A-A in FIG. 1. It is a cross-sectional view taken along line A-A in FIG. 1 in a modified example. It is a rear view of a state in which a plurality of support brackets are assembled to a fixing bracket, as seen from the rear side of the bumper fascia. It is a plan view of FIG. 4, as seen from above. (A) is a rear view of the support bracket as seen from the rear of the vehicle, (B) is a cross-sectional view taken along line B-B in (A), and (C) is a cross-sectional view taken along line C-C in (A).

[0008] An embodiment of the present invention will now be described. In the following drawings, the symbol FR indicates the front of the vehicle, the symbol UP indicates the upper side of the vehicle, and the symbol HL indicates the vehicle width direction. As shown in FIG. 1 , the acceleration sensor mounting structure according to this embodiment includes a bumper fascia 10, a plurality of acceleration sensors 12, a plurality of support brackets 14, and a fixing bracket 16. The bumper fascia 10, together with a bumper beam (not shown) provided inside it, constitutes a front bumper at the front of the vehicle. The bumper fascia 10 is attached to the bumper beam and a frame member (not shown) that constitutes the front of the vehicle. The bumper fascia 10 is made of a synthetic resin material strong enough to be deformed by a collision load applied in the event of a collision with an object, and extends over substantially the entire width of the front of the vehicle in the vehicle width direction. In one embodiment of the present invention, a pair of headlamp openings 1002 for arranging headlamp units are provided at the upper portions of both sides of the bumper fascia 10 in the vehicle width direction. An upper grille 1004 for taking in airflow is provided between the pair of openings 1002 and extends in the vehicle width direction. In addition, below the upper grille 1004, a plurality of lower grilles 1006 are arranged at intervals in the vehicle width direction and extend in an elongated shape in the vehicle width direction to take in wind generated by running the vehicle.

[0009] 1 , multiple acceleration sensors 12 are attached to a back surface 10A of the bumper fascia 10 facing rearward of the vehicle via support brackets 14 and fixing brackets 16. The acceleration sensors 12 detect the impact load input when the bumper fascia 10 collides with the thigh of a pedestrian or the wheel of a bicycle or motorcycle, generate a detection signal, and supply it to a control unit of a pedestrian protection device (not shown). If the control unit determines that the supplied detection signal exceeds a predetermined threshold, it protects the pedestrian or the rider of the bicycle or motorcycle by pushing up the rear end of the hood using a pop-up mechanism provided on the vehicle to form a space below the hood, or by inflating and deploying an airbag through the space formed below the hood to cover the top surface of the hood.

[0010] 1 , a portion of the bumper fascia 10 at a predetermined height in the vertical direction, i.e., an area suitable for pedestrian detection, is designated as a first portion A1, and a portion of the bumper fascia 10 at a predetermined height below the first portion A1, i.e., an area suitable for motorcycle detection, is designated as a second portion B1. The support bracket 14 extends in the vertical direction across the first portion A1 and the second portion B1. The upper end of the support bracket 14 in the extending direction is positioned adjacent to and facing the back surface 10A of the bumper fascia 10 at the first portion A1, and the lower end of the support bracket 14 in the extending direction is positioned adjacent to and facing the back surface 10A of the bumper fascia 10 at the second portion B1. Either the upper end or the lower end of the support bracket 14 is fixed to the back surface 10A of the bumper fascia 10, and the acceleration sensor 12 is attached to the other of the upper end or the lower end; in this embodiment, the lower end of the support bracket 14 is fixed to the back surface 10A of the bumper fascia 10, and the acceleration sensor 12 is attached to the upper end of the support bracket 14. A plurality of support brackets 14 are provided at intervals in the vehicle width direction, and each has a fixing bracket 16 that is fixed to the back surface 10A of the bumper fascia 10 at either the first portion A1 or the second portion B1 and extends in the vehicle width direction, and the plurality of support brackets 14 are connected to each other via the fixing bracket 16 and are fixed to the back surface 10A of the bumper fascia 10.

[0011] 1, 4, and 5, the fixing bracket 16 is made of sheet metal and includes a fixing bracket main body 18 that is elongated and extends in the vehicle width direction, and a plurality of fixing portions 20 that protrude downward from the lower edge of the fixing bracket main body 18 and are attached to the back surface 10A of the bumper fascia 10. Note that the acceleration sensor 12 is not shown in FIGS. 4 and 5. The position of the fixing bracket main body 18 in the vertical direction is a second portion B1 that corresponds to the position of the bumper fascia 10 that will collide with the wheel of the bicycle or motorcycle. Pairs of fixing portions 20 are provided at intervals in the vehicle width direction at multiple locations 1802 on the fixing bracket main body 18 to which the support bracket 14 is attached. 5, at both ends of the fixing bracket main body 18 in the extension direction excluding the center, a portion 1804 of the fixing bracket main body 18 where the fixing portion 20 is not provided is displaced toward the front of the vehicle compared to a portion 1802 of the fixing bracket main body 18 where the fixing portion 20 is provided, in other words, is located in a position closer to the rear surface 10A of the bumper fascia 10. The fixing portion 20 and the rear surface 10A of the bumper fascia 10 are attached via rivets, for example.

[0012] As shown in FIG. 1, the fixing bracket 16 is attached to the rear surface 10A of the bumper fascia 10 so that the fixing bracket main body 18 is located directly below the lower grille 1006 when viewed from the rear of the vehicle.

[0013] As shown in FIG. 1 , the multiple support brackets 14 extend in the vertical direction and are provided on a fixed bracket main body 18 at intervals in the vehicle width direction. The support brackets 14 are made of sheet metal and include an attachment portion 22 provided at one end in the extension direction and a displaceable portion 24 provided at the other end in the extension direction. In the present embodiment, the upper end of the support bracket 14 is provided as the displaceable portion 24, and the lower end is provided as the attachment portion 22. The attachment portion 22 is a portion that is attached to the rear surface 10A of the bumper fascia 10. As shown in FIG. 1 , in the present embodiment, the attachment portions 22 of the multiple support brackets 14 are connected to the fixed bracket main body 18 of the fixed bracket 16 attached to the rear surface 10A of the bumper fascia 10. Therefore, in the present embodiment, the attachment portions 22 are attached to the rear surface 10A of the bumper fascia 10 via the fixed bracket 16. A pair of fixing portions 20 are located at intervals in the vehicle width direction at the portion of the fixed bracket main body 18 to which the attachment portions 22 are connected. Therefore, the multiple mounting portions 22 and the multiple fixing portions 20 are located close to each other.

[0014] 6(A) to 6(C), a cross section perpendicular to the extending direction of the portion of the support bracket 14 excluding the mounting portion 22 has a rear plate portion 26 extending in the vehicle width direction, a pair of side plate portions 28 protruding forward of the vehicle from both ends of the rear plate portion 26 in the vehicle width direction, and a flange portion 29 extending in the vehicle width direction from the front end of the side plate portion 28, forming a generally hat-shaped cross section that convex toward the rear of the vehicle. The mounting portion 22 has the rear plate portion 26, the pair of side plate portions 28, and a pair of mounting plate portions 30 that protrude from the front ends of the pair of side plate portions 28 in directions separating from each other in the vehicle width direction and are attached to the fixed bracket main body 18. The pair of mounting plate portions 30 are attached to the fixed bracket main body 18 by welding, for example. In other words, the portion where the flange portion 29 is widened in the vehicle width direction constitutes the mounting plate portion 30; in other words, the portion where the flange portion 29 is widened in the vehicle width direction constitutes the mounting portion 22 that is attached to the back surface 10A of the bumper fascia 10 via the fixed bracket 16.

[0015] As shown in FIG. 2 , the acceleration sensor 12 is attached to the rear surface 10A of the displaceable portion 24. In other words, the acceleration sensor 12 is attached to the rear surface of the rear plate portion 26 as shown in FIG. 6A . The acceleration sensor 12 is attached to the displaceable portion 24, for example, by inserting a screw through the acceleration sensor 12 from the rear of the vehicle and fastening it to a screw hole provided in the displaceable portion 24. More specifically, the acceleration sensor 12 is attached to the support bracket 14 via a fastening member 27 that penetrates the rear plate portion 26. The front edge 2802 of the side plate portion 28 shown in FIG. 6D is formed to be located further forward of the vehicle than the fastening member 27. In this embodiment, the position of the displaceable portion 24 in the up-down direction, in other words, the position of the acceleration sensor 12, corresponds to the position of the bumper fascia 10 that will collide with the thigh of a pedestrian. In other words, the position of the acceleration sensor 12 is located above and away from the point where the bumper fascia 10 will collide with the wheel of a bicycle or motorcycle. Furthermore, in this embodiment, the displaceable portion 24 is located at a position slightly rearwardly away from the rear surface 10A of the bumper fascia 10 (at a position near the rear surface 10A), and when the bumper fascia 10 collides with an object (thigh), the bumper fascia 10 deforms rearwardly of the vehicle and a collision load is input to the displaceable portion 24 from the bumper fascia 10, causing the support bracket 14 to bend, and the displaceable portion 24 to be displaceable rearwardly from the rear surface 10A of the bumper fascia 10. In other words, the displaceable portion 24 is located on the rear surface 10A of the bumper fascia 10 so that it can be displaced rearwardly from the rear surface 10A of the bumper fascia 10 as the bumper fascia 10 displaces rearwardly of the vehicle. Note that if the displaceable portion 24 is displaced in the fore-and-aft direction of the vehicle due to acceleration caused by acceleration / deceleration or braking while the vehicle is traveling and hits the rear surface 10A of the bumper fascia 10, an erroneous detection signal may be generated from the acceleration sensor 12, raising concerns about malfunction of the pedestrian protection device. Therefore, the support bracket 14 has enough rigidity to prevent the displaceable portion 24 from displacing rearward even when such acceleration is applied, thereby avoiding the generation of an erroneous detection signal from the acceleration sensor 12 and preventing malfunction of the pedestrian protection device.

[0016] 3 , the displaceable portion 24 may be attached to a mounting seat 32 provided on the bumper fascia 10 at a location near the back surface 10A by a clip 34. When the clip 34 is used, the clip 34 easily comes off the mounting seat 32 due to the collision load applied when the bumper fascia 10 collides with an object, and the displaceable portion 24 is displaced toward the rear of the vehicle. In other words, the displaceable portion 24 is disposed on the back surface 10A of the bumper fascia 10 so as to be displaced toward the rear of the vehicle from the back surface 10A of the bumper fascia 10 as the bumper fascia 10 is displaced toward the rear of the vehicle. By using the clip 34 in this manner, unnecessary displacement of the displaceable portion 24 toward the rear of the vehicle due to acceleration caused by acceleration / deceleration or braking while the vehicle is traveling is suppressed, thereby preventing the generation of erroneous detection signals from the acceleration sensor 12 and preventing malfunction of the pedestrian protection device.

[0017] Next, the effects will be described. As shown in Figure 2, when bumper fascia 10 collides with a pedestrian's thigh X, the collision load input from thigh X deforms portion α of bumper fascia 10 toward the rear of the vehicle, and back surface 10A of bumper fascia 10 hits displaceable portion 24, displacing displaceable portion 24 toward the rear of the vehicle, causing a detection signal generated by acceleration sensor 12 to be supplied to the control unit. In this case, because displaceable portion 24 is reliably displaced toward the rear of the vehicle by the collision load input from thigh X, acceleration sensor 12 can generate a sufficiently large detection signal. When the control unit determines that a collision with a pedestrian (object) has occurred, the control unit activates the pop-up mechanism to protect the pedestrian.

[0018] As shown in FIG. 2 , when the bumper fascia 10 collides with the wheel Y of a bicycle or motorcycle, the collision load input from the wheel Y deforms portion β of the bumper fascia 10 toward the rear of the vehicle, and the collision load is input to the mounting portion 22 of the support bracket 14 via the fixed bracket main body 18. As a result, the displaceable portion 24 displaces toward the rear of the vehicle with the mounting portion 22 as a fulcrum, causing the acceleration sensor 12 to supply a detection signal to the control unit. In this case, because the mounting portion 22 at the lower end of the support bracket 14 extending vertically is attached to the back surface 10A of the bumper fascia 10 via the fixed bracket 16, the displaceable portion 24 at the upper end of the support bracket 14, which is significantly spaced above the mounting portion 22, is reliably displaced toward the rear of the vehicle, allowing the acceleration sensor 12 to generate a sufficiently large detection signal. When the control unit determines that a collision with the wheel Y (object) has occurred, the control unit activates the pop-up mechanism to protect the rider of the bicycle or motorcycle.

[0019] 3, when the bumper fascia 10 collides with the thigh X of a pedestrian, the clip 34 easily falls out of the mounting seat 32 due to the collision load input from the bumper fascia 10, which has deformed toward the rear of the vehicle, to the displaceable portion 24 via the mounting seat 32, and the displaceable portion 24 is displaced toward the rear of the vehicle from the back surface 10A of the bumper fascia 10, thereby achieving the same effect as above. Also, when the bumper fascia 10 collides with the wheel Y, the collision load is input from the bumper fascia 10, which has deformed toward the rear of the vehicle, to the mounting portion 22 of the support bracket 14 via the fixed bracket 16, and the support bracket 14 uses the mounting portion 22 as a fulcrum to displace the displaceable portion 24 toward the rear of the vehicle, causing the clip 34 to easily fall out of the mounting seat 32, and the displaceable portion 24 is further displaced toward the rear of the vehicle, thereby achieving the same effect as above.

[0020] According to this embodiment, a support bracket 14 is provided that extends in the vertical direction across the first portion A1 and the second portion B1, and the upper end of the extension direction of the support bracket 14 is positioned close to and opposite the back surface 10A of the bumper fascia 10 at the first portion A1, while the lower end of the extension direction of the support bracket 14 is positioned close to and opposite the back surface 10A of the bumper fascia 10 at the second portion B1, and either the upper end or the lower end of the support bracket 14 is fixed to the back surface 10A of the bumper fascia 10, and an acceleration sensor 12 is attached to the other of the upper end or the lower end. Therefore, even if a portion of the bumper fascia 10 that is distant from the acceleration sensor 12 in the vertical direction (in this embodiment, a portion of the bumper fascia 10 that is distant below the acceleration sensor 12) collides with an object, the collision load input from the object to the bumper fascia 10 is transmitted to the support bracket 14 via the mounting portion 22, displacing the displaceable portion 24 toward the rear of the vehicle. This ensures that the magnitude of the detection signal from the acceleration sensor 12 is the same as when a portion of the bumper fascia 10 that is close to the acceleration sensor 12 in the vertical direction collides with the object. This is advantageous for reliably detecting the collision of the bumper fascia 10 with the object, even if the portion of the bumper fascia 10 that collides with the object in the vertical direction is distant from the acceleration sensor 12. This eliminates the need for an on-board camera or complex information processing that identifies the object based on image information acquired by the on-board camera, as in the prior art, which is advantageous for reducing the cost of the pedestrian protection device and for reducing the control load of the pedestrian protection device.

[0021] Furthermore, in the present embodiment, a plurality of support brackets 14 are provided at intervals in the vehicle width direction, each having a fixed bracket 16 fixed to the rear surface 10A of the bumper fascia 10 at either the first portion A1 or the second portion B1 and extending in the vehicle width direction, and the plurality of support brackets 14 are connected to one another via the fixed bracket 16 and fixed to the rear surface 10A of the bumper fascia 10. However, the fixed bracket 16 may be omitted, and the lower end of the mounting portion 22 of the support bracket 14 may be attached to the rear surface 10A of the bumper fascia 10. In this case, when a collision load is input to the bumper fascia 10 from the wheel Y of a motorcycle or motorbike located below the thigh X in the vertical direction, the displaceable portion 24 of the support bracket 14 is displaced toward the rear of the vehicle, thereby ensuring the magnitude of the detection signal from the acceleration sensor 12, which is advantageous for reliably detecting a collision of the bumper fascia 10 with the wheel Y. Meanwhile, in addition to the above-mentioned effects, the present embodiment provides the following effects. That is, if a portion of the bumper fascia 10 that is far from the support brackets 14 in the vehicle width direction collides with the wheel Y, the wheel Y is generally smaller in shape than the thigh X, and therefore the contact area between the wheel Y and the bumper fascia 10 is small, so the collision load is applied locally to that portion of the bumper fascia 10, causing local deformation of the bumper fascia 10. Therefore, if a portion of the bumper fascia 10 located between the support brackets 14 collides with the wheel Y and is locally deformed, there is a concern that the collision load will be less easily transmitted to the support brackets 14. However, if multiple support brackets 14 are connected by the fixed brackets 16 as in the present embodiment, even if the portion of the bumper fascia 10 that collides with the wheel Y is far from the support brackets 14 in the vehicle width direction, the portion of the bumper fascia 10 that has deformed due to the collision load will reliably abut against the fixed brackets 16, and the collision load will be reliably transmitted to the support brackets 14 via the fixed brackets 16. Therefore, the displaceable portion 24 of the support bracket 14 can be reliably displaced toward the rear of the vehicle, which is more advantageous in reliably detecting the collision of the bumper fascia 10 with the wheel Y.

[0022] Furthermore, in this embodiment, the fixed bracket 16 has multiple fixing portions 20 attached to the rear surface 10A of the bumper fascia 10, and the attachment portions 22 of the multiple support brackets 14 to the fixed bracket 16 and the multiple fixing portions 20 are located in close proximity to each other, which increases the rigidity of the attachment points of the support bracket 14 and the fixed bracket 16. This is more advantageous in reliably transmitting a load to the support bracket 14 via the fixed bracket 16, and the displaceable portions 24 of the support bracket 14 can be more reliably displaced rearward of the vehicle, which is more advantageous in reliably detecting a collision of the bumper fascia 10 with the wheel Y.

[0023] In addition, in this embodiment, the cross section of the support bracket 14 perpendicular to the extension direction has a rear plate portion 26 extending in the vehicle width direction, a pair of side plate portions 28 protruding forward of the vehicle from both ends of the rear plate portion 26 in the vehicle width direction, and a flange portion 29 extending in the vehicle width direction from the front end of the side plate portion 28, forming a generally hat-shaped cross section that convex toward the rear of the vehicle, and the acceleration sensor 12 is attached to the rear surface of the rear plate portion 26, and the flange portion 29 is widened in the vehicle width direction to form a mounting portion 22 that is attached to the back surface 10A of the bumper fascia 10. Therefore, since the cross section of the support bracket 14 has a generally hat-shaped cross section that convex toward the rear of the vehicle, the rigidity of the support bracket 14 can be increased, and the collision load from the fixed bracket 16 is efficiently transmitted to the support bracket 14, which can more reliably displace the displaceable portion 24 of the support bracket 14 toward the rear of the vehicle, which is more advantageous in reliably detecting a collision of the bumper fascia 10 with the wheel Y. Furthermore, since the bumper fascia 10 that retreats due to a collision can be received by the surface of the flange portion 29, the acceleration can be transmitted more reliably and accurately to the acceleration sensor 12 even when the fixed portion 20 side of the support bracket 14 (the end opposite the acceleration sensor 12) collides with an object.

[0024] In this embodiment, the acceleration sensor 12 is attached to the support bracket 14 via fastening members 27 that penetrate the rear plate portion 26, and the front edges of the side plate portions 28 are formed to be located further forward of the vehicle than the fastening members 27. Therefore, the fastening members 27 for attaching the acceleration sensor 12 are housed inside the hat cross section without protruding from the support bracket 27, thereby improving protection performance against an object in the event of a collision.

[0025] Furthermore, in this embodiment, the portion of the fixed bracket 16 where the fixed portion 20 is not provided is displaced further forward on the vehicle than the portion of the fixed bracket 16 where the fixed portion 20 is provided. Therefore, if the portion of the bumper fascia 10 located forward of the vehicle, at portion 1804 of the fixed bracket 16 where the fixed portion 20 is not provided, collides with the wheel Y and the bumper fascia 10 is deformed toward the rear of the vehicle, the load is reliably input from the deformed bumper fascia 10 to the portion of the fixed bracket 16, the load is reliably transmitted to the support bracket 14, and the displaceable portion 24 of the support bracket 14 can be more reliably displaced toward the rear of the vehicle, which is more advantageous in reliably detecting the collision of the bumper fascia 10 with the wheel Y.

[0026] Furthermore, in this embodiment, first portion A1 is set at a height suitable for detecting a collision of bumper fascia 10 with a pedestrian, and second portion B1 is set at a height suitable for detecting a collision of bumper fascia with a motorcycle. Therefore, in either the case of a collision between bumper fascia 10 and a pedestrian or a collision between bumper fascia 10 and a motorcycle, the magnitude of the detection signal from acceleration sensor 12 can be ensured, which is advantageous for reliably detecting the collision of bumper fascia 10 with an object.

[0027] In the embodiment, the case where the displaceable portion 24 is provided at the upper end of the support bracket 14 and the mounting portion 22 is provided at the lower end has been described, but conversely, the displaceable portion 24 may be provided at the lower end of the support bracket 14 and the mounting portion 22 may be provided at the upper end. In this case, when the bumper fascia 10 collides with the wheel Y, the collision load input from the wheel Y deforms the portion β of the bumper fascia 10 toward the rear of the vehicle, and the back surface 10A of the bumper fascia 10 hits the displaceable portion 24, displacing the displaceable portion 24 toward the rear of the vehicle, causing the detection signal generated by the acceleration sensor 12 to be supplied to the control unit. In this case, the collision load input from the wheel Y reliably displaces the displaceable portion 24 toward the rear of the vehicle, allowing the acceleration sensor 12 to generate a sufficiently large detection signal. Furthermore, when the bumper fascia 10 collides with the thigh X of a pedestrian, the collision load input from the pedestrian's thigh X deforms the portion α of the bumper fascia 10 toward the rear of the vehicle, and the collision load is input to the mounting portion 22 of the support bracket 14 via the fixed bracket main body 18. As a result, the displaceable portion 24 displaces toward the rear of the vehicle with the mounting portion 22 as a fulcrum, causing the acceleration sensor 12 to supply a detection signal to the control unit. In this case, because the mounting portion 22 at the upper end of the support bracket 14 extending vertically is attached to the back surface 10A of the bumper fascia 10 via the fixed bracket 16, the displaceable portion 24 at the lower end of the support bracket 14, which is significantly spaced downward from the mounting portion 22, is reliably displaced toward the rear of the vehicle, allowing the acceleration sensor 12 to generate a sufficiently large detection signal. Therefore, even in such a case, the same effects as those of the embodiment can be achieved.

[0028] In addition, in the embodiment, the case where both the support bracket 14 and the fixed bracket 16 are made of sheet metal has been described, but one or both of the support bracket 14 and the fixed bracket 16 may be made of synthetic resin material, which would be advantageous in reducing the weight of the brackets.

[0029] 10 Bumper fascia 10A Rear surface 1002 Headlamp opening 1004 Upper grill 1006 Lower grill 12 Acceleration sensor 14 Support bracket 16 Fixed bracket 18 Fixed bracket body 1802 Location 1804 Location 20 Fixed portion 22 Mounting portion 24 Displaceable portion 26 Rear plate portion 27 Fastening member 28 Pair of side plate portions 2802 Front edge 29 Flange portion 30 Pair of mounting plate portions 32 Mounting seat 34 Clip X Thigh portion Y Wheel α portion β portion A1 First portion B1 Second portion

Claims

1. A mounting structure for a vehicle collision detection acceleration sensor that detects collisions by mounting an acceleration sensor on the underside of the bumper fascia of a front bumper, wherein a section of the bumper fascia at a predetermined height in the vertical direction is defined as a first section, and a section at a predetermined height below the first section is defined as a second section, and a support bracket is provided that extends in the vertical direction across the first section and the second section, the upper end of the extension direction of the support bracket is positioned adjacent to and facing the underside of the bumper fascia at the first section, and the lower end of the extension direction of the support bracket is positioned adjacent to and facing the underside of the bumper fascia at the second section, either the upper end or the lower end of the support bracket is fixed to the underside of the bumper fascia, and the acceleration sensor is mounted to the other of the upper end or the lower end.

2. The mounting structure for a vehicle collision detection acceleration sensor as described in claim 1, characterized in that the support brackets are provided in multiple locations spaced apart in the vehicle width direction, and further include a fixed bracket fixed to the back surface of the bumper fascia of either the first section or the second section and extending in the vehicle width direction, and the multiple support brackets are connected to each other via the fixed bracket and fixed to the back surface of the bumper fascia.

3. The mounting structure for a vehicle collision detection acceleration sensor according to claim 2, characterized in that the fixing bracket has a plurality of fixing portions attached to the rear surface of the bumper fascia, and the mounting portions of the plurality of support brackets to the fixing bracket and the plurality of fixing portions are located in close proximity to each other.

4. The mounting structure for an acceleration sensor for detecting a collision of a vehicle as set forth in claim 2, characterized in that the cross section of the support bracket perpendicular to the extending direction has a rear plate portion extending in the vehicle width direction, a pair of side plate portions protruding forward of the vehicle from both ends of the rear plate portion in the vehicle width direction, and a flange portion extending in the vehicle width direction from the front end of the side plate portion, forming a generally hat-shaped cross section that convex toward the rear of the vehicle, and the acceleration sensor is attached to the rear surface of the rear plate portion, and the flange portion is widened in the vehicle width direction to form a mounting portion that is attached to the back surface of the bumper fascia via the fixed bracket.

5. The mounting structure for a vehicle collision detection acceleration sensor according to claim 4, characterized in that the acceleration sensor is mounted to the support bracket via a fastening member that penetrates the rear plate portion, and the front end edge of the side plate portion is formed to be positioned further forward of the vehicle than the fastening member.

6. The mounting structure for an acceleration sensor for detecting a collision of a vehicle according to claim 2, characterized in that the portion of the fixing bracket where the fixing portion is not provided is displaced toward the front of the vehicle compared to the portion of the fixing bracket where the fixing portion is provided.

7. The acceleration sensor mounting structure described in claim 1, characterized in that the first portion is set at a portion of the bumper fascia at a height suitable for detecting a collision with a pedestrian, and the second portion is set at a portion of the bumper fascia at a height suitable for detecting a collision with a motorcycle.

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