JP2007314159A - Vehicle collision detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle collision detector capable of suppressing expansion of an arrangement space and complication of an arrangement structure. <P>SOLUTION: The vehicle collision detector comprises a distortion detection means 15 for detecting the distortion generated in a side member 14 or a crash box 16, and a collision detection means 31 for detecting the collision of a vehicle with an object based on the distortion detected by the distortion detection means 15. When a portion relatively high in the strength in the longitudinal direction of the vehicle of the side member 14 or the crash box 16 and a portion relatively low therein are provided, the distortion detection means 15 detects the distortion of the portion relatively low in the strength. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle collision detection device that detects that a vehicle has collided with an object. In particular, the present invention is applied to an apparatus that detects that a vehicle has collided with a pedestrian.

  Various techniques are known for detecting that a vehicle has collided with an object. For example, Japanese Patent Application Laid-Open No. 2004-212281 (Patent Document 1) discloses a collision by measuring a change in tension at the time of collision of a wire that has a predetermined initial tension and is laid along the front surface of a bumper force. Is described.

  Japanese Patent Laying-Open No. 2004-156945 (Patent Document 2) describes that a collision is detected by a stress sensor embedded along a front bumper. This stress sensor includes an elastic conductive tube and a central electrode member inserted through the inner periphery thereof with a space therebetween. And it is supposed that a collision will be detected when an elastic conductive tube and a center electrode member contact and electrically conduct.

Japanese Patent Application Laid-Open No. 7-190732 (Patent Document 3) discloses a light leaking fiber provided at one end of a light leaking fiber provided in a front bumper, a light receiving unit provided at the other end, and a light leaking fiber by collision. Describes that a collision is detected when the light receiving unit decreases and the amount of light received by the light receiving unit decreases.
JP 2004-212281 A JP 2004-156945 A JP-A-7-190732

  However, in the conventional technique, it is necessary to arrange the wire, the stress sensor, and the light leaking fiber along the front bumper, respectively, and therefore it is necessary to provide these arrangement space and arrangement structure. Therefore, the arrangement space is enlarged and the arrangement structure is complicated.

  This invention is made | formed in view of such a situation, and it aims at providing the collision detection apparatus for vehicles which can suppress the expansion of an arrangement space and the complexity of an arrangement structure.

  A vehicle collision detection device according to the present invention is a vehicle collision detection device that detects that a vehicle has collided with an object, and includes a bumper force arranged to extend in the left-right direction of the vehicle, A side support member that is a side member or a crash box arranged so as to extend in the vehicle front-rear direction by being coupled to the end, a strain detection unit that detects strain generated in the side support member, and a strain detection unit And a collision detection means for detecting that the vehicle has collided with an object based on the detected distortion.

  According to the vehicle collision detection device of the present invention, the distortion used for collision detection is distortion generated in a side member or a crash box originally provided in the vehicle. That is, it is possible to detect that the vehicle has collided with an object without newly providing a collision detection member such as a wire, a stress sensor, or a light leaking fiber as in the conventional art. Thus, since it is not necessary to newly provide a member for collision detection, it is possible to suppress an increase in arrangement space and a complicated arrangement structure. A known strain gauge or the like can be used as the strain detection means.

  Here, as described above, the side support member is a side member or a crash box. That is, when a vehicle has a side member and a crash box, the side support member may be either a side member or a crash box. The crash box is a member that absorbs energy when the vehicle collides with an object.

  In the vehicle collision detection device of the present invention, the side support member includes a portion having a relatively high strength and a low strength in the vehicle front-rear direction, and the strain detection means includes the vehicle front-rear direction of the side support member. It is preferable to detect a strain at a part having a low intensity.

  A side member or a crash box generally has high rigidity, and its amount of distortion is small in a collision with a pedestrian or the like, and is not easy to detect. Therefore, by providing the side support member with a portion having a relatively high strength in the vehicle front-rear direction and a portion with a relatively low strength, when the vehicle collides with an object, Stress concentrates in a portion where the strength in the longitudinal direction of the vehicle is relatively low. As a result, the stress generated in the portion of the side support member where the strength in the vehicle longitudinal direction is relatively low is larger than the stress generated in the portion of the side support member where the strength in the vehicle longitudinal direction is relatively high. Become. And distortion becomes large, so that compressive stress is large.

  In other words, even when the collision load that the vehicle receives when the vehicle collides with an object is small, the distortion that occurs in the portion of the side support member that has a relatively low strength in the vehicle front-rear direction is sufficiently detected by the strain detection means. It can be made large enough to be detected. Therefore, even when the collision load received by the vehicle when the vehicle collides with the object is small by using the distortion generated in the portion where the strength in the longitudinal direction of the vehicle is relatively low among the side support members. It is possible to reliably detect that the vehicle has collided with the object.

  Here, in the vehicle collision detection device of the present invention, the side support member may have a notch. The notch includes a concave portion formed on the outer side of the side support member, a through hole, and the like. In this case, the portion of the side support member having a low strength in the vehicle front-rear direction is around the notch. Thus, when the side support member has a notch, when the vehicle collides with an object, stress concentrates around the notch. As the stress increases, the strain increases. That is, even when the collision load that the vehicle receives when the vehicle collides with an object is small by using the distortion that occurs around the notch that is a portion of the side support member that has low strength in the vehicle longitudinal direction. It is possible to reliably detect that the vehicle has collided with the object.

  In the vehicle collision detection device of the present invention, the side support member is configured to be bent in the vehicle left-right direction or the vehicle up-down direction with respect to the first portion and the first portion extending in parallel with the vehicle front-rear direction. You may make it provide the 2nd part integrally formed in the 1st part. In this case, a portion of the side support member having a high strength in the vehicle front-rear direction is the first part of the side support member, and a portion of the side support member having a low strength in the vehicle front-rear direction is the side support member. It becomes the boundary between the second part or the first part and the second part.

  For example, when the side support member is a plate-like member, and the first portion of the side support member is a parallel part in the vehicle front-rear direction and the vehicle vertical direction, the side support member first The two parts are bent in the vehicle left-right direction with respect to the first part. That is, when the vehicle collides with an object, compressive stress acts on the first part of the side support members, and bending stress acts on the second part of the side support members. Moreover, a bending stress acts also on the boundary part of 1st part and 2nd part among side support members. When the vehicle collides with an object, the bending stress generated in the second member or the bending stress generated at the boundary between the first member and the second member is larger than the compressive stress generated in the first member. As the stress increases, the strain increases. In other words, when the vehicle collides with an object by using distortion generated in the second part, which is a portion of the side support member having low strength in the longitudinal direction of the vehicle, or distortion generated at the boundary between the first part and the second part. Even when the collision load received by the vehicle is small, it is possible to reliably detect that the vehicle has collided with the object.

  Further, the side support member may be formed of a plate-like member and have a relatively thick part and a thin part. In this case, the portion of the side support member having a high strength in the vehicle front-rear direction is a portion having a large plate thickness, and the portion of the side support member having a low strength in the vehicle front-rear direction is a portion having a small plate thickness, or It becomes a boundary between a thick part and a thin part.

  In other words, a portion of the side support member where the plate thickness is thin has a smaller cross-sectional area perpendicular to the vehicle longitudinal direction than a portion where the plate thickness is thick. Therefore, when the vehicle collides with an object, the compressive stress generated in the portion where the plate thickness is thin among the side support members is larger than the compressive stress generated in the portion where the plate thickness is thick. Further, when the vehicle collides with an object, stress concentrates on the boundary between the thick part and the thin part. Therefore, the compressive stress generated at the boundary between the thick and thin portions is larger than the compressive stress generated at the thick portion. And distortion becomes large, so that compressive stress is large. In this way, by using the distortion that occurs in the portion where the plate thickness is thin, which is a portion where the strength in the longitudinal direction of the vehicle is low, or the distortion that occurs at the boundary between the portion where the plate thickness is thick and the thin portion, Even when the collision load received by the vehicle when the vehicle collides with the object is small, it can be reliably detected that the vehicle collided with the object.

  By the way, when a vehicle equipped with a vehicle collision detection device collides with another vehicle or a building, the vehicle receives a large collision load. In this case, the side support member may be bent and deformed. That is, the side support member is plastically deformed. For example, when the vehicle collides with a pedestrian or the like, the collision load received by the vehicle is small. In this case, the side support member is only elastically deformed and may not be plastically deformed.

  Therefore, the strain detection means in the vehicle collision detection device of the present invention may detect the strain in the elastic region of the side support member. That is, the distortion detection means can detect distortion that occurs when, for example, the vehicle collides with a pedestrian or the like. In other words, the vehicle collision detection device of the present invention can determine whether or not the vehicle has collided with a pedestrian.

  Here, when a strain gauge is used as the strain detection means, the detected strain changes depending on the position where the strain gauge is fixed. That is, the fixed position of the strain gauge affects the detection accuracy. However, it is not easy to fix the strain gauge at an accurate position on a side support member such as a very large side member. Further, for example, when directly fixing a strain gauge as a strain detecting means to a side-coated side support member, it is necessary to first remove the coating of the side support member where the strain gauge is fixed. . This is to sufficiently secure the adhesive strength of the strain gauge. Therefore, the man-hour for fixing a strain gauge to a side support member increases.

  Therefore, it is preferable that a strain gauge or the like as a strain detection means is not directly fixed to the side support member but an attachment member is interposed. That is, the vehicle collision detection device of the present invention further includes a mounting member fixed to the side support member so as to face a portion of the side support member having a low strength in the vehicle front-rear direction. Is fixed to the attachment member, and the distortion of the attachment member according to the distortion of the portion of the side support member having a low strength in the vehicle front-rear direction may be detected.

  That is, the strain gauge as the strain detecting means is fixed to the mounting member, and the mounting member is fixed to the side support member. In this case, since the strain gauge as the strain detection means can be fixed to a smaller mounting member than the side member or the like, the strain gauge can be fixed at an accurate position. Further, since the mounting member can have a larger shape than the strain detecting means such as a strain gauge, the mounting member is fixed to a large side support member such as a side member at an accurate position. It becomes easy. Therefore, through the attachment member, as a result, the strain detecting means can be fixed to the side support member at an accurate position. Furthermore, when fixing the mounting member to the side support member, it is not necessary to peel off the portion of the side support member that fixes the mounting member. Therefore, the work man-hour can be reduced.

  Further, the vehicle collision detection device of the present invention is disposed so as to extend in the vehicle front-rear direction by being coupled to a bumper force that is disposed so as to extend in the left-right direction of the vehicle, and an end portion of the bumper force. A side support member that is a side member or a crash box, a strain detection unit that detects strain generated in the side support member, and detects that the vehicle has collided with an object based on the strain detected by the strain detection unit The vehicle collision detection device may further include a separate fixing member formed separately from the side support member and fixed to the side support member. In this case, the strain detecting means is fixed to the separate fixing member and detects the strain of the separate fixing member according to the strain of the side support member.

  Thereby, even if the side support member has a very complicated shape and it is difficult to attach the strain detection means, the strain detection means can be easily attached by using the separate fixing member. And since the distortion which arises in a separate fixing member is a thing according to the distortion of a side support member, the distortion which arises in a side support member indirectly certainly can be detected by a distortion detection means.

  Here, the separate fixing member may be fastened to the side support member with a bolt so that the bolt axis direction coincides with the vehicle front-rear direction. Since the bolt axis direction coincides with the vehicle front-rear direction, the separate fixing member can be prevented from shifting in the vehicle front-rear direction with respect to the side support member when the side support member is compressed and deformed due to a vehicle collision. Therefore, the strain detection means can reliably detect the strain generated in the side support member.

  The separate fixing member includes a portion having a relatively high strength and a low strength in the vehicle front-rear direction, and the strain detecting means detects a strain in a portion of the separate fixing member having a low strength in the vehicle front-rear direction. It is good to do so. The part with low strength in the vehicle front-rear direction of the separate fixing member is, for example, a part whose width in the orthogonal direction is narrower than other parts. As described above, the separate fixing member has a portion having a high strength and a portion having a low strength, and the strain detecting means detects the strain of the portion having the low strength, whereby the strain can be detected more reliably. In particular, even when the collision load that the vehicle receives when the vehicle collides with an object is small, the distortion that occurs in the portion of the separate fixing member that has a relatively low strength in the vehicle front-rear direction is sufficiently detected by the strain detection means. It can be made large enough to be detected. Therefore, even when the collision load received by the vehicle when the vehicle collides with the object is small, it can be reliably detected that the vehicle collided with the object.

  The separate fixing member includes a first member that is sandwiched between the rear surface of the bumper reinforcement and the front surface of the side support member, and extends from the first member toward the front or rear of the vehicle. A plurality of second members that are integrally formed with the first member so as to be present and that are fixed to at least one of the vehicle side surface and the vehicle upper and lower surfaces of the side support member. And may be fixed to each second member to detect the strain of the second member.

  That is, the strain detection means is composed of a plurality fixed to a plurality of second members. There are a plurality of second members, which are formed integrally with the first member. That is, a plurality of second members for fixing the respective strain detection means are formed as one component together with the first member. Thereby, the attachment property of a some 2nd member becomes favorable, and it has the inhibitory effect of the increase in a number of parts.

  Further, the end of the second member that is far from the first member may be fastened to the side support member with a bolt so that the bolt axis direction coincides with the vehicle longitudinal direction. Since the bolt axis direction coincides with the vehicle front-rear direction, the second member of the separate fixing member does not shift in the vehicle front-rear direction with respect to the side support member when the side support member is compressed and deformed due to a vehicle collision. You can Therefore, the strain detection means can reliably detect the strain generated in the side support member.

  Further, the side support member is connected to the end of the bumper reinforcement and is arranged to extend to the rear of the vehicle, and the side support member is connected to the rear end of the crash box and extends from the crash box to the rear of the vehicle. A first member disposed between the crash box, the bumper reinforcement, and the side member, and a first member. A plurality of second members that are integrally formed with the first member so as to extend from the vehicle forward or rearward to the vehicle and that are fixed to the other one of the bumper reinforcement and the side member. The detection means may be fixed to each second member and detect the distortion of the second member.

  Here, the outer peripheral shape of the crash box is often more complicated than that of the side member or the bumper reinforcement. Therefore, it is not easy to attach the separate fixing member to the crash box. Therefore, the first member of the separate fixing members is disposed so as to be sandwiched between one of the bumper force and the side member, and the second member of the separate fixing members is the other of the bumper force and the side member. By fixing to, the separate fixing member can be easily fixed.

  Further, when the second member is fixed to the other one of the bumper force and the side member, the second member is attached to the other one of the bumper force and the side member so that the bolt axis direction coincides with the vehicle front-rear direction. It is good to be fastened with a bolt. Since the bolt axis direction coincides with the vehicle front-rear direction, the second member of the separate fixing member does not shift in the vehicle front-rear direction with respect to the side support member when the side support member is compressed and deformed due to a vehicle collision. You can Therefore, the strain detection means can reliably detect the strain generated in the side support member.

  In addition, when the separate fixing member includes the second member, the second member may be formed in a step shape in a direction intersecting the vehicle front-rear direction. By forming the second member into a stepped shape, when there is a variation in the mutual fixing position of the second member and the member to be fixed of the second member, the variation can be absorbed and both can be reliably fixed.

  The side support member includes a locking hole in at least one of the vehicle side surface and the vehicle upper and lower surface, and the separate fixing member is inserted into the locking hole at one end side so that the vehicle is fixed to the locking hole. The other end side may be fixed to the side support member by engaging in the front-rear direction. Thereby, the one end side of the separate fixing member is simply inserted into the locking hole and does not need to be fastened with, for example, a bolt. Therefore, the separate fixing member can be easily attached.

  Further, the side support member is connected to the end of the bumper reinforcement and is arranged to extend to the rear of the vehicle, and the side support member is connected to the rear end of the crash box and extends from the crash box to the rear of the vehicle. The vehicle front-rear direction fixing position to the separate fixing member of the strain detection means is preferably located on the vehicle rear side from the center portion in the vehicle front-rear direction of the crash box. More preferably, the vehicle front-rear direction fixing position of the strain detection means to the separate fixing member may be located in a range of one third from the rear side in the vehicle front-rear direction of the crash box.

  Here, the vehicle front side of the crash box is coupled to both ends of the bumper reinforcement. The bumper reinforcement is formed so as to bend from the center in the vehicle left-right direction toward both ends. Accordingly, both ends of the bumper reinforcement to which the crash box is coupled are curved portions. Therefore, when the crash box receives a compressive force from the bumper force due to a vehicle collision, a lot of force in a direction other than the vehicle front-rear direction is included on the vehicle front side of the crash box. On the other hand, on the vehicle rear side of the crash box, the force in the direction other than the vehicle front-rear direction is smaller than that on the vehicle front side. In particular, the force in the direction other than the vehicle front-rear direction becomes smaller toward the rear of the vehicle. Therefore, by fixing the strain detecting means at a position corresponding to the vehicle rear side of the crash box, it is possible to reliably detect the vehicle longitudinal force generated by the collision.

  The side support member may be formed in a hollow shape, and the separate fixing member may be disposed in the internal space of the side support member. That is, the separate fixing member is not disposed so as to protrude to the outside of the side support member. Thereby, space saving can be achieved.

  The side support member may include a flange having an inclined surface that is inclined with respect to the vehicle front-rear direction and the vehicle left-right direction, and the separate fixing member may be fixed to the inclined surface. If the separate fixing member is fastened and fixed with bolts or the like to the surface of the side support member that extends in the vehicle front-rear direction, the mounting property of the separate fixing member is very good. The separate fixing member may be displaced in the vehicle front-rear direction with respect to the side support member. If the separate fixing member is displaced in the vehicle front-rear direction with respect to the side support member, there is a possibility that the strain generated in the side support member cannot be reliably detected by the strain detection means. On the other hand, when the separate fixing member is fastened and fixed by bolts or the like to the surface of the side support member that extends in the direction orthogonal to the vehicle front-rear direction, the separate fixing member is attached to the vehicle with respect to the side support member. Although it can prevent shifting in the front-rear direction, it cannot be said that the mounting property is good. Therefore, by fixing the separate fixing member to the inclined surface of the flange, it is possible to reduce the shift in the vehicle front-rear direction while improving the mounting property.

  The vehicle collision detection device of the present invention determines whether or not the object is a pedestrian based on the distortion detected by the distortion detection means when the collision detection means detects that the vehicle has collided with the object. It is preferable to further include an object discriminating means for performing the operation. The strain detected by the strain detection means corresponds to the collision load that the vehicle receives due to the collision with the object. Therefore, by using this distortion, the type of the collided object can be determined. Specifically, after the collision load is calculated, the mass of the collided object can be calculated using the collision load by a method disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-156528. . When the mass of the colliding object can be calculated in this way, it can be easily determined whether the colliding object is a pedestrian or a building. In particular, as described above, when the strain detection means detects a strain in the elastic region of the side support member, it is determined that the object on which the vehicle collided is a pedestrian or an object equivalent to a pedestrian. be able to.

  According to the vehicle collision detection device of the present invention, it is possible to suppress the expansion of the arrangement space and the complexity of the arrangement structure.

  Next, the present invention will be described in more detail with reference to embodiments.

(1) 1st Embodiment The vehicle collision detection apparatus of 1st Embodiment is demonstrated. The outline | summary of the collision detection apparatus for vehicles of this 1st Embodiment is as follows. A circular hole 14a (shown in FIG. 1) is formed in the side member 14 arranged so as to extend in the vehicle front-rear direction. A strain gauge 15 is attached around the circular hole 14a. Based on the strain detected by the strain gauge 15 (shown in FIG. 2), the ECU 30 (shown in FIG. 3) determines whether or not the colliding object is a pedestrian. If it is, the pedestrian protection device 50 is activated. Hereinafter, the vehicle collision detection device will be described in detail.

  The vehicle collision detection device includes a configuration of a front portion of the vehicle, which will be described below, an ECU 30, and a vehicle speed sensor 40.

  First, the configuration of the front portion of the vehicle in the vehicle collision detection apparatus of the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view in the vehicle front-rear direction of a vehicle front portion in the vehicle collision detection device of the first embodiment. FIG. 2 shows an enlarged view of part A of FIG. As shown in FIGS. 1 and 2, a bumper cover 11, a bumper absorber 12, a bumper reinforcement 13, a side member 14, and a strain gauge 15 are arranged in the front portion of the vehicle.

  The bumper cover 11 is disposed on the foremost surface of the vehicle and covers the front surface of the bumper absorber 12. Therefore, when the vehicle collides with an object located in front of the vehicle, the bumper cover 11 normally collides with the object. The bumper absorber 12 is disposed on the front end side of the vehicle so as to extend in the left-right direction of the vehicle. The bumper absorber 12 is a member that absorbs an impact caused by an object collision from the front of the vehicle.

  The bumper force 13 is a structural member that extends in the left-right direction of the vehicle and constitutes a part of the vehicle frame. The width of the bumper reinforcement 13 in the vehicle left-right direction is substantially equal to the width of the bumper absorber 12 in the vehicle left-right direction. Further, the bumper reinforcement 13 is formed of a hollow member having a square cross section with a two-stage beam provided in the center of the interior as shown in FIG. 1, for example. The bumper reinforcement 13 is fixed to the vehicle rear end surface of the bumper absorber 12. That is, the bumper reinforcement 13 is disposed so as to extend in the vehicle left-right direction along the bumper absorber 12.

  The side members 14 (side support members in the present invention) are respectively arranged so as to extend from both ends of the bumper reinforcement 13 in the vehicle left-right direction to the rear of the vehicle. These side members 14 are structural members that constitute a part of the vehicle frame, like the bumper force 13. These side members 14 are, for example, hollow members having a rectangular cross section perpendicular to the vehicle longitudinal direction. The side member 14 is connected to the vehicle rear end surface of the bumper force 13 by a bolt or the like.

  Further, circular holes 14a (notches in the present invention) are formed one by one on the left and right sides of each side member 14 in the vehicle. These circular holes 14a are formed at substantially the center in the vehicle vertical direction of the vehicle left and right surfaces of the side member 14. That is, the strength in the vehicle front-rear direction differs between the side member 14 around the circular hole 14a and at a position far from the circular hole 14a. That is, the strength in the vehicle longitudinal direction is relatively low around the circular hole 14a in the side member 14, and the strength in the vehicle longitudinal direction is relatively high in a position far from the circular hole 14a in the side member 14. .

  Here, when the side member 14 receives a collision load due to the front of the vehicle colliding with an object, that is, when a compressive load is applied to the side member 14 in the vehicle front-rear direction, the circular hole 14a of the side member 14 is The distribution of stress generated in the portion positioned in the vehicle vertical direction is as shown by the thick solid line in FIG. That is, the stress generated around the circular hole 14a (portion surrounded by the broken line in FIG. 2) is significantly larger than the stress generated in other portions. In this way, stress is concentrated around the circular hole 14a, which is a portion having a low strength in the vehicle longitudinal direction. And the stress which arises in the side member 14 respond | corresponds to the collision load which the side member 14 receives when the vehicle front collides with an object. That is, even when the collision load received by the side member 14 due to the collision of the front of the vehicle with the object is small, the stress generated around the circular hole 14a in the side member 14 has a sufficiently large value.

  As shown in FIG. 2, the strain gauge 15 (strain detection means in the present invention) is disposed on the vehicle lower side of the periphery of the circular hole 14 a of the side member 14. And the strain gauge 15 detects the distortion which arises in the site | part arrange | positioned. That is, the strain gauge 15 detects a strain that occurs in a portion of the side member 14 that has a relatively low strength in the vehicle longitudinal direction. Here, the stress generated around the circular hole 14a in the side member 14 is very large as compared with other portions as shown by the thick solid line in FIG. Further, stress and strain have a linear relationship. Accordingly, the greater the stress generated at the site where the strain gauge 15 is disposed, the greater the strain detected by the strain gauge 15. Further, as described above, the stress generated in the side member 14 corresponds to the collision load received by the side member 14 when the front of the vehicle collides with an object. This corresponds to the collision load that the member 14 receives.

  Here, when the vehicle collides with, for example, a building or another vehicle, the collision load received by the side member 14 becomes very large. In such a case, the side member 14 may be bent and deformed. On the other hand, when the vehicle collides with a pedestrian or the like, for example, the collision load received by the side member 14 is smaller than when the vehicle collides with a building or the like. In such a case, the side member 14 may only be elastically deformed without being bent and crushed. The strain range that can be detected by the strain gauge 15 includes strain generated around the circular hole 14a in the side member 14 particularly when the side member 14 is only elastically deformed. That is, the strain gauge 15 is configured to reliably detect strain generated around the circular hole 14a in the side member 14 when the side member 14 is only elastically deformed.

  Further, when the vehicle collides with, for example, a pedestrian or the like and the side member 14 is only elastically deformed, the distortion generated in the side member 14 is reduced. However, since the strain gauge 15 is disposed around the circular hole 14a of the side member 14, the strain generated in the portion where the strain gauge 15 is disposed is large enough that the strain gauge 15 can be sufficiently detected. . Therefore, the strain gauge 15 can reliably detect the strain generated in the side member 14 when the vehicle collides with a pedestrian or the like.

  Next, the ECU 30 of the vehicle collision detection device will be described with reference to FIG. FIG. 3 shows a block configuration of the ECU 30 of the vehicle collision detection device. As shown in FIG. 3, the ECU 30 includes a collision detection unit 31, a collision load calculation unit 32, an object mass calculation unit 33, and an object determination unit 34.

  The collision detection unit 31 (collision detection means in the present invention) detects whether or not the front of the vehicle has collided with an object based on the strain detected by the strain gauge 15. Specifically, the collision detection unit 31 determines that the vehicle has collided with an object when the strain detected by the strain gauge 15 is greater than a predetermined threshold.

  Here, the strain detected by the strain gauge 15 is strain generated around the circular hole 14 a in the side member 14. Further, the strain range that can be detected by the strain gauge 15 includes strain generated around the circular hole 14a in the side member 14 when the side member 14 only undergoes elastic deformation. That is, the strain gauge 15 reliably detects the strain generated around the circular hole 14a in the side member 14 when the front of the vehicle collides with an object such as a pedestrian. Furthermore, when a vehicle front collides with a pedestrian or the like, a distortion generated around the circular hole 14a of the side member 14 is measured in advance by an experiment or the like, and a predetermined threshold value in the collision detection unit 31 is determined. Thereby, the collision detection part 31 can detect reliably whether the vehicle front collided with objects, such as a pedestrian.

  When the collision detection unit 31 detects that the vehicle has collided with an object, the collision load calculation unit 32 calculates a collision load that the vehicle receives when the vehicle collides with the object. Specifically, the collision load calculation unit 32 first determines whether or not the collision detection unit 31 has detected that the vehicle has collided with an object. When the collision detection unit 31 detects that the vehicle has collided with an object, the strain detected by the strain gauge 15 is input. And the collision load calculation part 32 calculates a collision load using this distortion. Here, the collision load has linearity with respect to the strain detected by the strain gauge 15.

  The object mass calculation unit 33 calculates the mass of the object that the vehicle has collided with based on the collision load calculated by the collision load calculation unit 32 and the vehicle speed detected by the vehicle speed sensor 40. Here, the calculation of the mass of the object with which the vehicle collides is performed by, for example, a method disclosed in Japanese Patent Application Laid-Open No. 2005-156528. The outline of the calculation method is to calculate the mass of an object on which the vehicle collides, using the one-time integral value of the collision load and the vehicle speed at the time of the collision.

  The object discriminating unit 34 (object discriminating means in the present invention) discriminates the type of the object based on the mass of the object with which the vehicle collides calculated by the object mass calculating unit 33. For example, when the mass of the object is within a predetermined range, it is determined as a pedestrian, and when it is larger than the predetermined range, it is determined as a building or a vehicle.

  If it is determined that the vehicle has collided with a pedestrian, the object determination unit 34 activates the pedestrian protection device 50. The pedestrian protection device 50 is a device that is mounted on a hood of a vehicle and protects the pedestrian when the vehicle collides with a pedestrian. The pedestrian protection device 50 is, for example, a device that raises the hood or an airbag device that is deployed on the hood.

  With the configuration described above, the strain detected by the strain gauge 15 is generated in a portion of the side member 14 where the strength in the vehicle front-rear direction is low, that is, around the circular hole 14a in the side member 14. By setting the strain, the strain detected by the strain gauge 15 can be sufficiently increased even when the vehicle collides with a pedestrian or the like having a relatively small collision load. That is, it is possible to reliably detect the distortion corresponding to the collision load generated in the side member 14 when the vehicle collides with the object. And it can detect that the vehicle collided with the object by using the distortion. Furthermore, by using the distortion, it is possible to determine the type of the object with which the vehicle has collided, in particular, whether or not it is a pedestrian.

  Moreover, the distortion used for collision detection is distortion generated in the side member 14 originally provided in the vehicle. That is, the side member 14 itself has a function as a sensor. Therefore, it is possible to detect that the vehicle has collided with an object without newly providing a member for collision detection such as a wire, a stress sensor, or a light leaking fiber as in the prior art. Thus, since it is not necessary to newly provide a member for collision detection, it is possible to suppress an increase in arrangement space and a complicated arrangement structure.

(2) 2nd Embodiment Next, the collision detection apparatus for vehicles of 2nd Embodiment is demonstrated with reference to FIG. FIG. 4 is a cross-sectional view in the vehicle front-rear direction of the front portion of the vehicle in the vehicle collision detection apparatus according to the second embodiment. Here, in the vehicle collision detection device of the second embodiment, the same components as those of the vehicle collision detection device of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the front portion of the vehicle in the vehicle collision detection device of the second embodiment includes a bumper cover 11, a bumper absorber 12, a bumper reinforcement 13, a side member 14, a strain gauge 15, A crash box 16 is arranged. That is, the crash box 16 is added to the front portion of the vehicle in the vehicle collision detection device of the second embodiment relative to the front portion of the vehicle in the vehicle collision detection device of the first embodiment. Here, in the side member 14 in 2nd Embodiment, what is corresponded to the circular hole 14a of the side member 14 in 1st Embodiment is not formed.

  Further, the crash box 16 (the side support member in the present invention) is disposed so as to be interposed between the bumper force 13 and each side member 14. Like the side member 14, the crash box 16 is a hollow member having a rectangular cross section perpendicular to the vehicle longitudinal direction, for example. The crash box 16 is a member that absorbs energy when the front of the vehicle collides with an object.

  And the circular hole 16a (notch part in this invention) is formed in the vehicle right-and-left surface of these crash boxes 16 one place at a time. These circular holes 16a are formed at substantially the center in the vehicle vertical direction of the vehicle left and right surfaces of the crash box 16. These circular holes 16a have the same function as the circular holes 14a of the side member 14 of the first embodiment. Therefore, the strength in the vehicle front-rear direction differs between the periphery of the circular hole 16a and the position far from the circular hole 16a in the crash box 16. That is, the strength in the vehicle longitudinal direction is relatively low around the circular hole 16a in the crash box 16, and the strength in the vehicle longitudinal direction is relatively high in a position far from the circular hole 16a in the crash box 16. .

  The strain gauge 15 is disposed on the vehicle lower side in the periphery of the circular hole 16 a of the crash box 16. That is, the strain gauge 15 detects a strain that occurs in a portion of the crash box 16 that has a relatively low strength in the vehicle longitudinal direction.

  Even if it is a case where it consists of such a structure, the effect similar to 1st Embodiment is exhibited.

(3) Third Embodiment Next, a vehicle collision detection apparatus according to a third embodiment will be described with reference to FIG. The vehicle collision detection device of the third embodiment is obtained by replacing the side member 14 in the vehicle collision detection device of the first embodiment with a side member 17 shown below. Therefore, only the side member 17 will be described in detail below. Here, FIG. 5 shows a horizontal sectional view in the vehicle front-rear direction of the side member 17 in the third embodiment.

  As shown in FIG. 5, the side member 17 is a hollow member having a rectangular cross section perpendicular to the vehicle longitudinal direction as a whole. More specifically, the side member 17 includes a front parallel part 17a, a rear parallel part 17b, and an intermediate inclined part 17c.

  The front parallel portion 17a (the first portion in the present invention) has a rectangular cross section and is disposed so as to extend in parallel with the vehicle longitudinal direction. The vehicle front end side of the front parallel portion 17a is in contact with the bumper reinforcement 13 (shown in FIG. 1). The rear parallel part 17b (the first part in the present invention) has a rectangular cross section with a larger vehicle left-right direction spacing than the front parallel part 17a. The rear parallel portion 17b is spaced apart from the front parallel portion 17a on the vehicle rear side, and is disposed coaxially with the front parallel portion 17a and extends parallel to the vehicle front-rear direction.

  The intermediate inclined portion 17c (second portion in the present invention) is integrally formed with the front parallel portion 17a and the rear parallel portion 17b so as to connect the vehicle rear end of the front parallel portion 17a and the vehicle front end of the rear parallel portion 17b. ing. The intermediate inclined portion 17c has a rectangular cross section. Further, the left and right vehicle surfaces of the intermediate inclined portion 17c are shaped to expand toward the rear of the vehicle. That is, the intermediate inclined portion 17c is connected to the front parallel portion 17a and the rear parallel portion 17b while being bent in the vehicle left-right direction.

  Here, when the front of the vehicle collides with an object, compressive stress acts on the front parallel portion 17a and the rear parallel portion 17b. On the other hand, bending stress acts on the intermediate inclined portion 17c, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and the boundary between the rear parallel portion 17a and the intermediate inclined portion 17c. And the said bending stress becomes large compared with the compressive stress which arises in the front parallel part 17a and the back parallel part 17b. This is because bending deformation is more easily deformed by a small stress than compression deformation.

  That is, the front parallel portion 17a and the rear parallel portion 17b have relatively high strength in the vehicle front-rear direction, the intermediate inclined portion 17c, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and the rear parallel portion 17a and the middle. At the boundary with the inclined portion 17c, the strength in the vehicle longitudinal direction is relatively low.

  Accordingly, when the side member 17 receives a collision load due to the collision of the front of the vehicle with an object, the intermediate inclined portion 17c of the side member 17, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and the rear parallel portion. The stress generated at the boundary between the portion 17 a and the intermediate inclined portion 17 c is larger than the stress generated at the front parallel portion 17 a and the rear parallel portion 17 b of the side member 17. As described above, among the side members 17 that are low strength in the longitudinal direction of the vehicle, the intermediate inclined portion 17c, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and the rear parallel portion 17a and the intermediate inclined portion 17c. Stress is concentrated on the boundary. Therefore, even when the collision load received by the side member 17 due to the collision of the front of the vehicle with the object is small, the intermediate inclined portion 17c of the side member 17, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and The stress generated at the boundary between the rear parallel portion 17a and the intermediate inclined portion 17c has a sufficiently large value.

  For example, the strain gauge 15 is disposed at any one of the intermediate inclined portion 17c of the side member 17, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and the boundary between the rear parallel portion 17a and the intermediate inclined portion 17c. To do. Therefore, the strain gauge 15 has a strain generated at any of the intermediate inclined portion 17c of the side member 17, the boundary between the front parallel portion 17a and the intermediate inclined portion 17c, and the boundary between the rear parallel portion 17a and the intermediate inclined portion 17c. To detect. In FIG. 5, the strain gauge 15 is disposed at the boundary between the front parallel portion 17 a and the intermediate inclined portion 17 c of the side member 17 and detects strain generated in the portion.

  With the configuration described above, the strain detected by the strain gauge 15 is the strain generated in the portion of the side member 17 where the strength in the vehicle longitudinal direction is low, that is, the intermediate inclined portion 17c, the front parallel portion 17a, and the intermediate inclined portion. Even if the vehicle collides with a pedestrian or the like with a relatively small collision load by setting the distortion to occur at either the boundary with 17c and the boundary between the rear parallel part 17a and the intermediate inclined part 17c, The strain detected by the strain gauge 15 can be sufficiently increased. That is, it is possible to reliably detect the distortion corresponding to the collision load generated in the side member 17 when the vehicle collides with the object. And it can detect that the vehicle collided with the object by using the distortion. Furthermore, by using the distortion, it is possible to determine the type of the object with which the vehicle has collided, in particular, whether or not it is a pedestrian.

(4) Fourth Embodiment Next, a vehicle collision detection apparatus according to a fourth embodiment will be described with reference to FIGS. 6 and 7. The vehicle collision detection device of the fourth embodiment is obtained by replacing the side member 14 in the vehicle collision detection device of the first embodiment with a side member 18 shown below. Therefore, only the side member 18 will be described in detail below. Here, FIG. 6 shows a horizontal sectional view of the side member 18 in the vehicle front-rear direction in the fourth embodiment. FIG. 7 is a cross-sectional view taken along the line BB in FIG.

  As shown in FIGS. 6 and 7, the side member 18 is a hollow member having a rectangular cross section perpendicular to the vehicle longitudinal direction. Further, concave portions 18 a are formed on the outer surfaces of the left and right vehicle surfaces of the side members 18. That is, the plate thickness of the concave portion 18a of the side member 18 is relatively thinner than the plate thickness around the concave portion 18a. Therefore, the strength of the vehicle front-rear direction is relatively low at the portion where the side member 18 is thin, or at the boundary between the portion where the thickness is thick and the portion where the thickness is thin. Become.

  That is, when the side member 18 receives a collision load due to the collision of the front of the vehicle with an object, that is, when a compressive load is applied to the side member 18 in the vehicle front-rear direction, the portion of the side member 18 where the plate thickness is thin Alternatively, the stress generated at the boundary between the thick part and the thin part is larger than the stress generated at the thick part of the side member 18. As described above, the stress is concentrated at a portion where the plate thickness of the side member 18 which is a portion having a low strength in the longitudinal direction of the vehicle is thin, or a boundary between a portion where the plate thickness is thick and a thin portion. Therefore, even when the collision load received by the side member 18 due to the collision of the front of the vehicle with the object is small, the portion of the side member 18 where the plate thickness is thin, or the boundary between the portion where the plate thickness is thick and the portion where the plate thickness is thin The stress generated in is sufficiently large.

  The strain gauge 15 is disposed in the concave portion 18 a of the side member 18. Therefore, the strain gauge 15 detects a strain generated at a portion where the plate thickness of the side member 18 is thin, or a boundary between a portion where the plate thickness is thick and a thin portion.

  By configuring as described above, the strain detected by the strain gauge 15 is the strain generated in the portion of the side member 18 where the strength in the vehicle longitudinal direction is low, that is, the portion of the side member 18 where the plate thickness is thin, or The distortion generated at the boundary between the thick part and the thin part is sufficient to detect the distortion detected by the strain gauge 15 even when the vehicle collides with a pedestrian having a relatively small collision load. Can be bigger. That is, the distortion corresponding to the collision load generated in the side member 18 when the vehicle collides with the object can be reliably detected. And it can detect that the vehicle collided with the object by using the distortion. Furthermore, by using the distortion, it is possible to determine the type of the object with which the vehicle has collided, in particular, whether or not it is a pedestrian.

(5) Fifth Embodiment Next, a vehicle collision detection apparatus according to a fifth embodiment will be described with reference to FIGS. The vehicle collision detection device of the fifth embodiment replaces the side member 14 in the vehicle collision detection device of the first embodiment with a side member 19 shown below, and further includes a strain gauge mounting plate 20. Here, FIG. 8 shows a horizontal cross-sectional view of the side member 19 in the vehicle front-rear direction in the fifth embodiment. FIG. 9 shows an enlarged cross-sectional view taken along the line CC of FIG.

  As shown in FIGS. 8 and 9, the side member 19 is a hollow member having a rectangular cross section perpendicular to the vehicle longitudinal direction. A concave portion 19 a is formed on the inner side surface of the side member 19 on the left and right sides of the vehicle. That is, the plate thickness of the concave portion 19a of the side member 19 is relatively thinner than the plate thickness around the concave portion 19a. Therefore, the strength of the vehicle front-rear direction is relatively low at the boundary between the portion where the plate thickness of the side member 19 is thin or between the portion where the plate thickness is thick and the portion where the plate thickness is thin. Become. This is substantially the same as the side member 18 of the vehicle collision detection apparatus of the fourth embodiment described above.

  The strain gauge mounting plate 20 (the mounting member in the present invention) has a rectangular plate shape, and has an area larger than the area of the concave portion 19 a of the side member 19. Further, the strain gauge mounting plate 20 has an area larger than the area of the strain gauge 15. The strain gauge mounting plate 20 has a thickness approximately the same as the thickness of the concave portion 19 a of the side member 19. The strain gauge mounting plate 20 is arranged so as to cover the outer surface of the concave portion 19a of the side member 19, and a fastening member such as a rivet or a bolt is provided on a thick portion around the concave portion 19a of the side member 19 21 is fixed.

  When the front of the vehicle collides with an object, the strain gauge mounting plate 20 is distorted at the portion of the side member 19 where the plate thickness is thin, or at the boundary between the portion where the plate thickness is thick and the thin portion. Corresponding distortion occurs.

  In addition, the strain gauge 15 is disposed substantially at the center of the outer surface of the strain gauge mounting plate 20. That is, the strain gauge 15 is disposed so as to face the outside of the concave portion 19 a of the side member 19. Accordingly, the strain gauge 15 is a strain corresponding to the strain generated in the strain gauge mounting plate 20, that is, the strain generated at the boundary between the thin plate portion of the side member 19 or the thick plate portion and the thin portion. Can be detected.

  By configuring as described above, it is possible to detect that the vehicle has collided with the object, and to determine whether the object has collided with the vehicle, particularly a pedestrian, as in the fourth embodiment. can do.

  Here, the strain detected by the strain gauge 15 varies greatly depending on the position at which the strain gauge 15 is fixed. That is, the fixed position of the strain gauge 15 affects the detection accuracy. However, while the strain gauge 15 is very small, the side member 19 is very large. Therefore, it is not easy to fix the strain gauge to the side member 19 at an accurate position. For example, when the side member 19 is coated on the surface, when the strain gauge 15 is directly fixed, it is necessary to first remove the coating of the side member 19 where the strain gauge 15 is fixed. This is because the adhesive strength of the strain gauge 15 is sufficiently secured. Therefore, the man-hour for fixing the strain gauge 15 to the side member 19 increases.

  However, as described above, the above problem can be solved by fixing the strain gauge 15 to the side member 19 via the strain gauge mounting plate 20. That is, since the strain gauge 15 can be fixed to the strain gauge mounting plate 20 that is smaller than the side member 19, the strain gauge 15 can be fixed to an accurate position of the strain gauge mounting plate 20. Furthermore, since the strain gauge mounting plate 20 having a shape larger than that of the strain gauge 15 can be used, it becomes easy to fix such a strain gauge mounting plate 20 to the side member 19 at an accurate position. Therefore, as a result, the strain gauge 15 can be fixed to the side member 19 at an accurate position through the strain gauge mounting plate 20. Further, when the strain gauge mounting plate 20 is fixed to the side support member, it is not necessary to peel off the portion of the side member 19 where the strain gauge mounting plate 20 is fixed. Therefore, the work man-hour can be reduced.

(6) 6th Embodiment Next, the collision detection apparatus for vehicles of 6th Embodiment is demonstrated with reference to FIG.10 and FIG.11. FIG. 10 is a cross-sectional view in the vehicle front-rear direction of the vehicle front portion in the vehicle collision detection apparatus of the sixth embodiment. FIG. 11 is a side view of the crash box 16 and shows a detailed view of the separate fixing member 60. Specifically, FIG. 11A shows a view seen from the front of FIG. 10, and FIG. 11B shows a bottom view of FIG. Here, in the vehicle collision detection device of the sixth embodiment, the same components as those of the vehicle collision detection device of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 10, the front portion of the vehicle in the vehicle collision detection apparatus of the sixth embodiment includes a bumper cover 11, a bumper absorber 12, a bumper reinforcement 13, a side member 14, a strain gauge 15, A crash box 16 and a separate fixing member 60 are arranged. That is, the crash box 16 and the separate fixing member 60 are added to the front portion of the vehicle in the vehicle collision detection device of the sixth embodiment relative to the front portion of the vehicle in the vehicle collision detection device of the first embodiment. ing. Here, the side member 14 in the sixth embodiment is not formed to correspond to the circular hole 14a of the side member 14 in the first embodiment.

  Further, the crash box 16 (the side support member in the present invention) is disposed so as to be interposed between the bumper force 13 and each side member 14. Like the side member 14, the crash box 16 is a hollow member having a rectangular cross section perpendicular to the vehicle longitudinal direction, for example. The crash box 16 is a member that absorbs energy when the front of the vehicle collides with an object.

  As shown in FIGS. 11A and 11B, two L-shaped flanges 16b and 16b are fixed to the vehicle side surface of the crash box 16. The two L-shaped flanges 16b and 16b are arranged so as to face each other. In addition, a female screw is formed at a portion of the two L-shaped flanges 16b and 16b that is erected from the vehicle side surface of the crash box 16.

  The separate fixing member 60 has a U-shape, and a bolt insertion hole is formed on the facing surface. The distance between the opposing surfaces of the separate fixing member 60 is the same as the separation distance of the standing portions of the L-shaped flanges 16 b and 16 b fixed to the crash box 16. The opposing surface of the separate fixing member 60 is fastened to the L-shaped flanges 16b and 16b by fastening bolts. Here, the bolt axial direction of the fastening bolt is made to coincide with the vehicle longitudinal direction. Further, the separate fixing member 60 is formed such that the width of the central portion (the central portion in the left-right direction in FIG. 11B) is narrower than the widths of both end portions. This is because the strength in the vehicle front-rear direction at the center of the separate fixing member 60 is made lower than the strength in the vehicle front-rear direction at both ends. In other words, the central portion of the separate fixing member 60 is more easily distorted than both end portions. The strain gauge 15 is fixed to the central portion of the separate fixing member 60.

  Here, when the vehicle collides with an object, a collision load in the vehicle longitudinal direction is generated in the crash box 16. As a result, the crash box 16 is compressed and deformed in the vehicle longitudinal direction. Along with this deformation, the separate fixing member 60 is compressed and deformed in the vehicle front-rear direction. In this case, in particular, since the strength of the central portion of the separate fixing member 60 is relatively low, the strain generated in the central portion is sufficiently large. Then, the strain generated in the central portion of the separate fixing member 60 is detected by the strain gauge 15. Here, since the bolt axis direction coincides with the vehicle front-rear direction, even if the front of the vehicle collides with an object and a collision load in the vehicle front-rear direction occurs, the separate fixing member 60 is L-shaped. There is no deviation in the longitudinal direction of the vehicle with respect to the mold flanges 16b and 16b. Accordingly, the vehicle longitudinal load generated on the separate fixing member 60 substantially matches the load generated on the crash box 16. Thereby, the load generated in the crash box 16 can be reliably detected by the strain gauge 15.

(7) Seventh Embodiment Next, a vehicle collision detection apparatus according to a seventh embodiment will be described with reference to FIGS. 12 and 13. FIG. 12 is a side view of a portion including the crash box 16 in the vehicle collision detection device of the seventh embodiment, and shows a detailed view of the separate fixing member 70. FIG. 13 shows a detailed view of another separate fixing member 80. In addition, Fig.12 (a) shows the figure seen from the vehicle side, FIG.12 (b) shows the bottom view of Fig.12 (a). Fig.13 (a) shows the figure seen from the vehicle side, FIG.13 (b) shows the bottom view of Fig.13 (a). Here, in the vehicle collision detection device of the seventh embodiment, the same components as those of the vehicle collision detection device of the sixth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  Two female screw holes (not shown) are formed on the side surface of the crash box 16. The separate fixing member 70 has a U-shape. The separate fixing member 70 is formed with flanges 71 and 71 so as to spread outward from the U-shaped opening end. Bolt insertion holes are formed in the flanges 71 and 71. Here, the separation distance of the bolt insertion holes is La, and the U-shaped longitudinal length of the separate fixing member 70 is Lb. That is, the separation distance La of the bolt insertion hole is longer than the U-shaped longitudinal length Lb of the separate fixing member 70.

  Then, the fastening bolt is inserted into the bolt insertion hole of the separate fixing member 70 and screwed into the female screw hole of the crash box 16, thereby fixing the separate fixing member 70 to the crash box 16. At this time, the bolt shaft direction of the fastening bolt is made to coincide with the vehicle left-right direction, that is, the direction orthogonal to the vehicle front-rear direction. Further, the separate fixing member 70 is formed such that the width of the central portion (the central portion in the left-right direction in FIG. 12B) is narrower than the widths of both end portions. This is because the strength in the vehicle front-rear direction at the center of the separate fixing member 70 is made lower than the strength in the vehicle front-rear direction at both ends. In other words, the central portion of the separate fixing member 70 is more easily distorted than both end portions. The strain gauge 15 is fixed to the central portion of the separate fixing member 70.

  Here, as shown in FIGS. 13 (a) and 13 (b), the other separate fixing member 80 is different from the separate fixing member 70 shown in FIG. Just do it. In other words, the U-shaped longitudinal length of the separate fixing member 80 is Lc, which is shorter than the U-shaped longitudinal length Lb of the separate fixing member 70 shown in FIG. Yes.

  When the separate fixing member 70 shown in FIG. 12 and the separate fixing member 80 shown in FIG. 13 are compared, the separate fixing member 80 shown in FIG. However, the distortion which arises in the center part of the separate fixing member 80 becomes large. Therefore, it is possible to reliably detect the collision load generated in the crash box 16. Note that the shorter the U-shaped length in the vehicle front-rear direction, the more effective. For example, the U-shaped longitudinal length Lc of the vehicle may be 1/3 or less of the separation distance La of the bolt insertion hole.

(8) Eighth Embodiment Next, a vehicle collision detection apparatus according to an eighth embodiment will be described with reference to FIG. FIG. 14 is a side view of a portion including the crash box 16 in the vehicle collision detection device of the eighth embodiment. 14A shows a view from the side of the vehicle, and FIG. 14B shows a bottom view of FIG. 14A.

  As shown in FIG. 14, a female screw hole (not shown) is formed on the vehicle front side (left side of FIG. 14A) of the side surface of the crash box 16. Furthermore, a penetrating locking hole 16c is formed in the side of the crash box 16 on the vehicle rear side (the right side in FIG. 14B).

  The separate fixing member 90 has a U-shape. The length of the U-shaped opposing surface is slightly shorter on the left side in FIGS. 14A and 14B than on the right side. The separate fixing member 90 is formed with flanges 91 and 92 so as to spread outward from the U-shaped opening end. Here, a bolt insertion hole is formed in the flange 91 on one side (the left side of FIGS. 14A and 14B).

  14 is inserted into the locking hole 16c of the crash box 16 and engaged with the inner peripheral surface of the crash box 16. That is, the right flange 92 in FIG. 14 is engaged with the locking hole 16c of the crash box 16 in the vehicle front-rear direction and the vehicle left-right direction. Thereafter, the fastening bolt is inserted into the bolt insertion hole of the left flange 91 of FIG. 14 and screwed into the female screw hole of the crash box 16, thereby fixing the separate fixing member 90 to the crash box 16.

  Thus, since the one end side of the separate fixing member 90 is only inserted into the locking hole 16c of the crash box 16, the separate fixing member 90 can be fixed to the crash box 16 very easily.

(9) Ninth Embodiment Next, a vehicle collision detection apparatus according to a ninth embodiment will be described with reference to FIGS. 15 and 16. FIG. 15 is a top view of the vehicle front portion of the vehicle collision detection apparatus according to the ninth embodiment. FIG. 16 shows a separate fixing member 100 of the ninth embodiment. Specifically, FIG. 16 (a) shows a view of the separate fixing member 100 as seen from the front of the vehicle, and FIG. 16 (b) shows a right side view of FIG. 16 (b).

  As shown in FIG. 15, the front portion of the vehicle in the vehicle collision detection apparatus of the ninth embodiment includes a bumper cover, a bumper absorber, a bumper reinforcement 13, a side member 14, and strain gauges 15, 15, 15. And the crash box 16 and the separate fixing member 100 are arrange | positioned.

  And the separate fixing member 100 is comprised in detail from the 1st member 101 and the 4th 2nd member 102, as shown in FIG.15 and FIG.16 (a) (b). The first member 101 has a rectangular plate shape slightly larger than the vehicle front end surface of the crash box 16. The first member 101 has three bolt insertion holes. The first member 101 is sandwiched between the vehicle rear surface of the bumper force 13 and the vehicle front surface of the crash box 16. Further, the first member 101 is fixed to the bumper force 13 and the crash box 16 by inserting a fastening bolt for fastening the bumper force 13 and the crash box 16 into the bolt insertion hole.

  The second member 102 is a plate-like member that is integrally formed with the first member 101 so as to extend from each side of the first member 101 toward the rear of the vehicle. The second member 102 has a stepped central portion in the vehicle front-rear direction. Specifically, as shown in FIG. 16B, the vehicle front side portion of the second member 102 is located at a position farther from the central axis of the crash box 16 than the vehicle rear side portion of the second member 102. . That is, the second member 102 is formed in a step shape that extends in the vehicle left-right direction or the vehicle vertical direction. Further, strain gauges 15, 15, 15 are respectively fixed to the vehicle front side portions of the respective second members 102, and the strain generated in the second member 102 is detected.

  Further, a bolt insertion hole is formed in the vehicle rear side portion of each second member 102. Then, the fastening bolt is inserted into the bolt insertion hole and screwed into the female screw portion of the crash box 16, thereby fixing the separate fixing member 100 to the crash box 16. At this time, the bolt axial direction of the fastening bolt is made to coincide with the vehicle longitudinal direction. Therefore, even if the front of the vehicle collides with an object and a collision load in the vehicle front-rear direction occurs, the separate fixing member 100 does not shift in the vehicle front-rear direction with respect to the crash box 16. Therefore, the load in the vehicle front-rear direction generated on the separate fixing member 100 substantially matches the load generated on the crash box 16. Thereby, the load generated in the crash box 16 can be reliably detected by the strain gauge 15.

(10) Tenth Embodiment Next, a vehicle collision detection apparatus according to a tenth embodiment will be described with reference to FIGS. 17 and 18. FIG. 17 is a top view of the vehicle front portion of the vehicle collision detection apparatus according to the tenth embodiment. FIG. 18 shows a separate fixing member 110 according to the tenth embodiment. Specifically, FIG. 18A shows a state of the separate fixing member 110 as viewed from the front of the vehicle, and FIG. 18B shows a right side view of FIG. 18B.

  As shown in FIG. 17, the front portion of the vehicle in the vehicle collision detection device of the tenth embodiment includes a bumper cover, a bumper absorber, a bumper reinforcement 13, a side member 14, and strain gauges 15, 15, 15. And the crash box 16 and the separate fixing member 110 are arrange | positioned.

  The separate fixing member 110 includes a first member 111 and four second members 112 in detail as shown in FIGS. 17 and 18A and 18B. The first member 111 has a rectangular plate shape slightly larger than the vehicle front end surface of the crash box 16. The first member 111 has three bolt insertion holes. The first member 111 is sandwiched between the rear surface of the bumper force 13 and the front surface of the crash box 16. Further, the first member 111 is fixed to the bumper force 13 and the crash box 16 by inserting a fastening bolt for fastening the bumper force 13 and the crash box 16 into the bolt insertion hole.

  The second member 112 is a plate-like member that is integrally formed with the first member 111 so as to extend from each side of the first member 111 toward the rear of the vehicle. As for this 2nd member 112, the center part of the vehicle front-back direction is formed in the level | step difference shape. Specifically, as shown in FIG. 18B, the vehicle front side portion of the second member 112 is located at a position farther from the center axis of the crash box 16 than the vehicle rear side portion of the second member 112. . That is, this 2nd member 112 is formed in the level | step difference shape which goes to a vehicle left-right direction or a vehicle up-down direction. Further, strain gauges 15, 15, 15 are respectively fixed to the vehicle front side portions of the respective second members 112, and the strain generated in the second member 112 is detected.

  Further, a flange 112a is formed at the vehicle rear end of each second member 112 so as to spread outward. Bolt insertion holes are formed in the flange 112a. Then, a fastening bolt is inserted into the bolt insertion hole, and is screwed into a female screw portion (not shown) formed on the vehicle front end surface of the side member 14. Thereby, the separate fixing member 110 is fixed to the side member 14. At this time, the bolt axial direction of the fastening bolt is made to coincide with the vehicle longitudinal direction. Therefore, even when the front of the vehicle collides with an object and a collision load in the vehicle longitudinal direction occurs, the separate fixing member 110 may be displaced in the vehicle longitudinal direction with respect to the crash box 16 and the side member 14. Absent. Therefore, the load in the vehicle longitudinal direction generated on the separate fixing member 110 substantially matches the load generated on the crash box 16. Thereby, the load generated in the crash box 16 can be reliably detected by the strain gauge 15.

(11) Experiment Here, as shown in FIG. 19, when the strain gauge 15 is fixed at various positions of the crash box 16 on the left side of the vehicle, it is detected by the strain gauge 15 when the front of the vehicle collides with an object. The strain to be examined was examined. Here, the strain gauges 15 were fixed at five locations on the upper surface of the crash box 16 from the vehicle front side toward the vehicle rear side. Specifically, the strain gauge 15 includes a vehicle front end 15a of the crash box 16, an intermediate 15b between the vehicle longitudinal direction central portion and the front end of the crash box 16, a central portion 15c, an intermediate 15d between the central portion and the rear end, and It was fixed to the vehicle rear end 15e.

  Here, when the front of the vehicle collides with an object, the load actually generated in both the left and right crash boxes 16 was measured by a load cell. A value measured by this load cell is a target value. That is, the ideal state is a state in which the strain detected by the strain gauge 15 matches the measured value by the load cell.

  The experimental results are shown in FIG. That is, FIG. 20 shows the load detected by each load cell and the strain detected by each strain gauge 15a-15e after the vehicle collides with the object. Here, in FIG. 20, the measured value by the load cell is a load generated in the crash box 16, and a positive load is generated when the vehicle collides with an object. On the other hand, the strain detected by the strain gauge 15 takes a negative value when the vehicle collides with an object. That is, the closer the strain detected by the strain gauge 15 is to the state in which the waveform of the load detected by the load cell is inverted, the more accurate the strain corresponding to the load can be detected.

  Therefore, as shown in FIG. 20, the strain waveforms detected by the strain gauges 15a to 15e are compared with those obtained by inverting the load waveform detected by the load cell. The strain waveform detected by the strain gauge 15e is most approximate to the one obtained by inverting the load waveform detected by the load cell. On the other hand, the strain waveform detected by the strain gauge 15a is farthest from the one obtained by inverting the load waveform detected by the load cell. That is, the order in which the strain waveform detected by the strain gauge 15 is close to that obtained by inverting the load waveform detected by the load cell is the order of the strain gauges 15e, 15d, 15c, 15b, and 15a. Therefore, the position where the strain gauge 15 is fixed is preferably on the vehicle rear side of the crash box 16.

  Furthermore, the strain detected by the strain gauges 15a and 15b has a positive value between 100 and 150 seconds after the collision. On the other hand, the strain detected by the strain gauges 15c, 15d, and 15e does not become a positive value until around 160 seconds after the collision. By the way, the load waveform detected by the load cell has a positive value between 30 seconds and 150 seconds after the collision. That is, the strain gauges 15a and 15b cannot detect an accurate load generated in the crash box 16. Therefore, the strain gauge 15 may be fixed to the rear side of the vehicle in the vehicle longitudinal direction center of the crash box 16.

(12) Other Embodiments While the separate fixing member has been described above in various ways, it is not limited thereto. About another separate fixing member, it is good also as what is shown, for example in FIG.21, FIG.22, FIG.23 and FIG.

  As shown in FIG. 21, the crash box 16 is formed in a hollow shape, and the separate fixing member 120 may be disposed in the internal space of the crash box 16.

  Further, as shown in FIG. 22, an L-shaped flange 16 d (corresponding to the L-shaped flange 16 b of the sixth embodiment) is fixed to each surface of the crash box 16. The separate fixing member 130 includes a first member 111 and four second members 112 as in the separate fixing member 110 of the tenth embodiment. Then, the flange 112a of each second member 112 is fixed to the L-shaped flange 16d with a fastening bolt. At this time, the bolt axial direction of the fastening bolt is made to coincide with the vehicle longitudinal direction.

  As shown in FIG. 23A, the separate fixing member 130 has a U-shaped shape. Then, one side of the facing surface is fixed to the rear surface of the bumper force 13 with a fastening bolt, and the other side of the facing surface is fixed to the front surface of the side member 14 with a fastening bolt.

  Further, as shown in FIG. 23 (b), an L-shaped flange 16 e is fixed to the crash box 16. The separate fixing member 140 has a U-shape, and fixes one side of the opposing surface to the L-shaped flange 16e with a fastening bolt, and the other side of the opposing surface to the side member 14 with a fastening bolt. Fix it.

  Further, as shown in FIG. 23C, the separate fixing member 150 is substantially L-shaped, and one end side is fixed to the side surface of the crash box 16 with a fastening bolt, and the other end side is fixed to the side member 14. It is fixed to the front of the vehicle with fastening bolts.

  Further, as shown in FIG. 24, a substantially L-shaped inclined flange 16 f is fixed to the crash box 16. One end side of the L-shaped inclined flange 16 f is fixed so as to be inclined with respect to the side surface of the crash box 16. The separate fixing member 160 is substantially U-shaped, and one side of the opposing surface is fixed to the inclined surface of the L-shaped inclined flange 16f by a fastening bolt, and the other side of the opposing surface is The side member 14 is inserted into a locking hole (not shown) on the front surface of the vehicle and engaged in the vehicle front-rear direction.

The vehicle front-back direction sectional drawing of the vehicle front part in the vehicle collision detection apparatus of 1st Embodiment is shown. The A section enlarged view of FIG. 1 is shown. The block configuration of ECU30 of the collision detection apparatus for vehicles is shown. The vehicle front-back direction sectional drawing of the vehicle front part in the vehicle collision detection apparatus of 2nd Embodiment is shown. The horizontal sectional view of the vehicle front-back direction of the side member 17 in 3rd Embodiment is shown. The horizontal sectional view of the vehicle front-back direction of the side member 18 in 4th Embodiment is shown. FIG. 7 is a sectional view taken along line B-B in FIG. 6. The horizontal sectional view of the vehicle front-back direction of the side member 19 in 5th Embodiment is shown. The CC cross-sectional enlarged view of FIG. 8 is shown. The vehicle front-back direction sectional drawing of the vehicle front part in the vehicle collision detection apparatus of 6th Embodiment is shown. A detailed view of the separate fixing member 60 on the side surface of the crash box 16 is shown. FIG. 10 is a side view of a portion including a crash box 16 in a vehicle collision detection device according to a seventh embodiment, and shows a detailed view of a separate fixing member 70. A detailed view of another separate fixing member 80 is shown. The side view of the part containing the crash box 16 in the collision detection apparatus for vehicles of 8th Embodiment is shown. The top view of the vehicle front part in the collision detection apparatus for vehicles of 9th Embodiment is shown. The separate fixing member 100 of 9th Embodiment is shown. The top view of the vehicle front part in the collision detection apparatus for vehicles of 10th Embodiment is shown. The separate fixing member 110 of 10th Embodiment is shown. The figure explaining experimental conditions is shown. It is a figure which shows an experimental result. The separate fixing member 120 of other embodiment is shown. The separate fixing member 110 of other embodiment is shown. The separate fixing member 130,140,150 of other embodiment is shown. The separate fixing member 160 of other embodiment is shown.

Explanation of symbols

11: Bumper cover, 12: Bumper absorber, 13: Bumper force,
14, 17, 18, 19: side member, 14a: circular hole, 15: strain gauge,
16: Crash box, 16a: Circular hole, 17a Front parallel part,
17b: rear parallel part, 17c: intermediate inclined part, 18a, 19a: concave part,
20: Strain gauge mounting plate, 21: Fastening member,
30: ECU, 40: Vehicle speed sensor, 50: Pedestrian protection device,
60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160: Separate fixing member

Claims (20)

A vehicle collision detection device for detecting that a vehicle has collided with an object,
A bumper reinforcement arranged to extend in the left-right direction of the vehicle,
A side support member that is a side member or a crash box that is disposed so as to extend in the vehicle front-rear direction by coupling to an end portion of the bumper force,
Strain detecting means for detecting strain generated in the side support member;
Collision detection means for detecting that the vehicle has collided with an object based on the distortion detected by the distortion detection means;
A vehicle collision detection device comprising: The side support member includes a portion having a relatively high strength in the vehicle front-rear direction and a portion having a low strength,
2. The vehicle collision detection device according to claim 1, wherein the strain detection unit detects a strain of a portion of the side support member having a low strength in the vehicle front-rear direction. The side support member has a notch,
The vehicle collision detection device according to claim 2, wherein the portion of the side support member having a low strength in the vehicle front-rear direction is around the notch. The side support member is formed integrally with the first part so as to bend in the vehicle left-right direction or the vehicle up-down direction with respect to the first part, and a first part extending parallel to the vehicle front-rear direction. With two parts,
A portion of the side support member having a high strength in the vehicle front-rear direction is the first portion,
The vehicle collision detection device according to claim 2, wherein a portion of the side support member having a low strength in the vehicle front-rear direction is the second part or a boundary between the first part and the second part. . The side support member is formed of a plate-like member, and has a relatively thick part and a thin part,
Of the side support member, the portion with high strength in the vehicle front-rear direction is the portion where the plate thickness is thick,
The portion of the side support member having a low strength in the vehicle front-rear direction is a portion where the plate thickness is the thin portion or a boundary between the portion where the plate thickness is the thick portion and the thin portion. Vehicle collision detection device.   The vehicle collision detection device according to claim 2, wherein the strain detection unit detects the strain in an elastic region of the side support member. And a mounting member fixed to the side support member so as to face a portion of the side support member having a low strength in the vehicle longitudinal direction.
The strain detection means is fixed to the mounting member and detects strain of the mounting member according to strain of a portion of the side support member having low strength in the vehicle front-rear direction. The vehicle collision detection device according to claim 1. And a separate fixing member formed separately from the side support member and fixed to the side support member.
The vehicle collision detection device according to claim 1, wherein the strain detection unit is fixed to the separate fixing member and detects the strain of the separate fixing member according to the strain of the side support member.   The vehicle collision detection device according to claim 8, wherein the separate fixing member is fastened to the side support member with a bolt such that a bolt axial direction coincides with a vehicle front-rear direction. The separate fixing member includes a portion having a relatively high strength and a low strength in the vehicle longitudinal direction,
The vehicle collision detection device according to claim 8, wherein the strain detection means detects a strain of a portion of the separate fixing member having a low strength in the vehicle front-rear direction. The separate fixing member is
A first member disposed between a rear surface of the vehicle of the bumper force and a front surface of the vehicle of the side support member;
The first member is integrally formed with the first member so as to extend from the first member toward the front or rear of the vehicle, and is fixed to at least one of the vehicle side surface and the vehicle upper and lower surfaces of the side support member. A plurality of second members,
With
The vehicle collision detection device according to claim 8, wherein the strain detection unit includes a plurality of strain detectors, is fixed to each of the second members, and detects strain of the second member.   The vehicle collision according to claim 11, wherein an end portion of the second member that is farther from the first member is fastened to the side support member by a bolt such that a bolt axis direction coincides with a vehicle front-rear direction. Detection device. The side support member is coupled to an end portion of the bumper reinforcement and is arranged to extend rearward of the vehicle, and is coupled to a rear end of the crash box and is rearward of the vehicle from the crash box. A side member arranged to extend,
The separate fixing member is:
A first member disposed between the crash box and any one of the bumper force and the side member;
A plurality of second members integrally formed with the first member so as to extend from the first member toward the front or rear of the vehicle and fixed to the other one of the bumper force and the side member. Members,
With
The vehicle collision detection device according to claim 8, wherein the strain detection means is fixed to each of the second members and detects a strain of the second member.   14. The vehicle collision detection device according to claim 13, wherein the second member is fastened to the other of the bumper force and the side member by a bolt such that a bolt axial direction coincides with a vehicle longitudinal direction.   The vehicle collision detection device according to any one of claims 11 to 14, wherein the second member is formed in a step shape in a direction intersecting with a vehicle front-rear direction. The side support member includes a locking hole in at least one of the vehicle side surface and the vehicle upper and lower surface,
9. The separate fixing member according to claim 8, wherein one end side of the separate fixing member is engaged with the locking hole in the vehicle front-rear direction by being inserted into the locking hole, and the other end side is fixed to the side support member. The vehicle collision detection device as described. The side support member is coupled to an end portion of the bumper reinforcement and is arranged to extend rearward of the vehicle, and is coupled to a rear end of the crash box and is rearward of the vehicle from the crash box. A side member arranged to extend,
The vehicle collision detection device according to claim 8, wherein the vehicle front-rear direction fixing position of the strain detection unit to the separate fixing member is located on the vehicle rear side of the crash box in the vehicle front-rear direction center. The side support member is formed in a hollow shape,
The vehicle collision detection device according to claim 8, wherein the separate fixing member is disposed in an internal space of the side support member. The side support member includes a flange having an inclined surface that is inclined with respect to the vehicle longitudinal direction and the vehicle lateral direction,
The vehicle collision detection device according to claim 8, wherein the separate fixing member is fixed to the inclined surface.   Object detection means for determining whether the object is a pedestrian based on the distortion detected by the distortion detection means when the collision detection means detects that the vehicle has collided with the object. The vehicle collision detection device according to any one of claims 1 to 19.

Images