JP2018140764A - Collision detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collision detection device which enables reduction of the number of components to simplify the structure.SOLUTION: A collision detection device is mounted on a vehicle 1 including a bumper cover 2 fixed to a vehicle body 100 or a vehicle body component 101 connected to the vehicle body 100 by bolts 14. The collision detection device includes: deformation detection parts 20 capable of detecting deformation of the bumper cover 2; and a signal processing part 30 which determines that objects 50, 62 collide with the bumper cover 2 on the basis of signals input from the deformation detection parts 20. Each deformation detection part 20 is attached in a state where the bolt 14 for fixing the bumper cover 2 to the vehicle body 100 or the vehicle body component 101 connected to the vehicle body 100 is inserted into the deformation detection part 20.SELECTED DRAWING: Figure 31

Description

  The present invention relates to a collision detection device mounted on a vehicle.

  2. Description of the Related Art In recent years, a collision detection apparatus that detects that an object such as a person has collided with a bumper cover of a vehicle has been developed. The information detected by the collision detection device can be used, for example, in a device that lifts the vehicle hood instantaneously or a device that activates an air bag outside the vehicle in order to reduce the impact applied to the person who collided with the bumper cover. is there.

  In the collision detection device described in Patent Document 1, a plurality of piezoelectric sensors that detect deformation of the bumper cover are attached to the back surface of the bumper cover. The plurality of piezoelectric sensors are arranged side by side at a predetermined interval in the longitudinal direction of the bumper cover. The signals output from the plurality of piezoelectric sensors are respectively input to the signal processing unit. The signal processing unit detects the position where the object collides with the bumper cover based on the signal input from each piezoelectric sensor.

Japanese Patent No. 4482510

  However, in the collision detection device described in Patent Document 1, the number of piezoelectric sensors increases according to the length of the bumper cover, and further, the number of wirings that electrically connect the plurality of piezoelectric sensors and the signal processing unit is increased. To increase. For this reason, this collision detection device has a problem that the number of parts increases and the circuit configuration becomes complicated, resulting in an increase in manufacturing cost. In addition, the number of signals input to the signal processing unit increases, and the load of signal processing by the signal processing unit increases. In response to such a problem, the inventor detects the collision of an object with respect to the bumper cover by detecting a collision of a wide area with a piezoelectric sensor per sheet, reducing the number of parts such as the piezoelectric sensor, and the configuration. We found the problem of being effective for simplicity. The sensor used for detecting the collision of the object with the bumper cover is not limited to the piezoelectric sensor described above, and various deformation detection units that can detect the deformation of the bumper cover can be employed. As the deformation detection unit, for example, a strain gauge, an optical fiber, a pressure-sensitive rubber, a capacitance sensor, and the like can be employed in addition to the piezoelectric sensor.

  In view of the above points, the present invention provides a collision detection device capable of reducing the number of parts and simplifying the configuration by detecting a collision of a wide area with a deformation detection unit per sheet. Objective.

In order to achieve the above object, the invention described in claim 1 is a vehicle including a bumper cover (2) fixed to a vehicle body (100) or a vehicle body part (101) connected to the vehicle body by a bolt (14). A collision detection device mounted on (1),
A deformation detection unit (20) attached in a state of being inserted into the bolt and capable of detecting deformation of the bumper cover;
A signal processing unit (30) for determining that the object (50) has collided with the bumper cover based on a signal input from the deformation detection unit.

  The inventors have clarified the distribution of strain generated in the bumper cover when an object collides with the bumper cover by performing experiments and simulations. It was found that the number of deformation detectors attached to the bumper cover can be reduced by attaching the deformation detectors at locations where strain concentrates on the bumper cover at a plurality of collision positions with respect to the bumper cover. Specifically, when an object collides with an arbitrary place on the bumper cover, the bumper cover is fixed to the vehicle body part connected to the vehicle body or the vehicle body (hereinafter referred to as a vehicle body part or the like) and the vicinity thereof. The strain is concentrated. Therefore, when the deformation detection unit is attached in a state where it is inserted through the bolt that fixes the vehicle body part and the bumper cover, the deformation detection unit responds to the collision when an object collides with various places on the bumper cover. Can be output. As a result, this collision detection device can reduce the number of parts and simplify the configuration by reducing the number of deformation detection units and the number of wires connecting the deformation detection units and the signal processing unit. it can.

The invention according to claim 12 is a collision detection device mounted on a vehicle (1) having a bumper cover having a fixing portion (8) for fixing the bumper cover to a vehicle body part around the bumper cover (2). There,
A deformation detector (20) attached to a position including the vicinity (N) of the fixed portion of the back surface of the bumper cover;
A signal processing unit (30) for determining that the object (50) has collided with the bumper cover based on a signal input from the deformation detection unit.

  From experiments and simulations by the inventors, it has been found that when an object collides with the front surface, side surface, or bent portion of the bumper cover, an overall deformation occurs in which the entire bumper cover is displaced using the fixed portion as a fulcrum. Therefore, by attaching the deformation detection unit to a position including the vicinity of the fixed part, the deformation detection unit outputs a signal corresponding to the collision, regardless of whether the object collides with the front part, the side part, or the bending part. It turns out that it is possible. Therefore, this collision detection device can reduce the number of parts and simplify the configuration by reducing the number of deformation detection units and the number of wires connecting the deformation detection units and the signal processing unit. .

  In the present specification, “in the vicinity of the fixed portion” refers to a portion where deformation occurs around the fixed portion with the fixed portion serving as a fulcrum when the entire bumper cover is deformed. Specifically, when a flange portion is provided on the outer edge of the bumper cover main body and a fixed portion is set on the flange portion, “near the fixed portion” means from the connection position of the flange portion and the bumper cover main body. For example, the range is within 50 mm.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a mimetic diagram of vehicles in which a collision detection device of a 1st embodiment is carried. It is a perspective view of the bumper cover which attached the piezoelectric sensor with which a collision detection apparatus is provided. It is a top view of the III direction of FIG. FIG. 4 is an enlarged view of the back surface of the bumper cover as viewed from the IV direction in FIG. 3. It is explanatory drawing explaining a state when an object collides with the front part of a bumper cover. It is explanatory drawing explaining a state when an object collides with the side part of a bumper cover. It is a perspective view of the bumper cover which attached the piezoelectric sensor of 2nd Embodiment. It is a top view of the VIII direction of FIG. It is explanatory drawing explaining a state when an object collides with the front part of a bumper cover. It is explanatory drawing explaining a state when an object collides with the side part of a bumper cover. It is a perspective view of the bumper cover which attached the piezoelectric sensor of 3rd Embodiment. It is a top view of the XII direction of FIG. It is a perspective view of the bumper cover which attached the piezoelectric sensor of 4th Embodiment. It is a top view of the XIV direction of FIG. It is a perspective view of the bumper cover which attached the piezoelectric sensor of 5th Embodiment. It is a top view of the XVI direction of FIG. It is an enlarged view of the back surface of the bumper cover of the XVII part of FIG. It is explanatory drawing explaining a state when an object collides with the front part of a bumper cover. It is explanatory drawing explaining a state when an object collides with the side part of a bumper cover. It is the elements on larger scale of the bumper cover which attached the piezoelectric sensor of 6th Embodiment. It is a perspective view of the bumper cover which attached the piezoelectric sensor of 7th Embodiment. It is a top view of the XXII direction of FIG. It is explanatory drawing explaining a state when an object collides with the front part of the bumper cover which attached the piezoelectric sensor of the comparative example. It is explanatory drawing explaining a state when an object collides with the side part of the bumper cover which attached the piezoelectric sensor of the comparative example. It is a perspective view which shows the left front part of the vehicle which attached the piezoelectric sensor of 8th Embodiment. It is sectional drawing of the XXVI-XXVI line | wire of FIG. It is a perspective view which shows the left front part of the vehicle which attached the piezoelectric sensor of 9th Embodiment. It is a perspective view which shows the left front part of the vehicle which attached the piezoelectric sensor of 10th Embodiment. It is a perspective view which shows the left front part of the vehicle which attached the piezoelectric sensor of 11th Embodiment. It is a perspective view which shows the right front part of the vehicle which attached the piezoelectric sensor of 12th Embodiment. It is a schematic diagram of the vehicle by which the collision detection apparatus of 13th Embodiment is mounted. It is an exploded view of the front part of the vehicle by which the collision detection apparatus of 13th Embodiment is mounted. It is a top view which shows an example of a deformation | transformation detection part. It is sectional drawing of the XXXIV-XXXIV line | wire of FIG. It is a top view which shows another example of a deformation | transformation detection part. FIG. 36 is a sectional view taken along line XXXVI-XXXVI in FIG. 35. It is sectional drawing which shows the 1st example of attachment of a deformation | transformation detection part. It is sectional drawing which shows the 2nd example of attachment of a deformation | transformation detection part. It is sectional drawing which shows the 3rd example of attachment of a deformation | transformation detection part. It is sectional drawing which shows the 4th example of attachment of a deformation | transformation detection part. It is a schematic diagram of the vehicle by which the collision detection apparatus of 14th Embodiment is mounted. It is an exploded view of the front part of the vehicle by which the collision detection apparatus of 14th Embodiment is mounted. It is the schematic diagram which showed the test device of the collision detection apparatus. It is an analysis figure of the stress distribution which occurs in a bumper cover when an impactor is made to collide with the predetermined position of a bumper cover. FIG. 45 is an analysis diagram of stress distribution generated in the bumper cover in the XXXXV direction view of FIG. 44. It is an analysis figure of the stress distribution which occurs in a bumper cover when an impactor is made to collide with another position of a bumper cover. FIG. 47 is an analysis diagram of a stress distribution generated in the bumper cover when viewed in the XXXXVII direction in FIG. 46. It is a schematic diagram of the vehicle by which the collision detection apparatus of 15th Embodiment is mounted. It is the elements on larger scale of the back surface of the rear bumper of 15th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment will be described with reference to the drawings. The collision detection apparatus according to the first embodiment detects that an object such as a pedestrian collides with a bumper cover provided in a vehicle.

  First, the bumper cover 2 provided in the vehicle 1 on which the collision detection device is mounted will be described.

  As shown in FIGS. 1 to 3, the bumper cover 2 includes a front part 3 located in front of the vehicle, a side part 4 located on the side of the vehicle, and a bend having a smaller radius of curvature than the front part 3 and the side part 4. Part 5. In each figure, the boundary between the front portion 3 and the bent portion 5 is indicated by a broken line 6, and the boundary between the side portion 4 and the bent portion 5 is indicated by a broken line 7, but the front portion 3, the side portion 4 and the bent portion 5 are illustrated. Is formed continuously.

  The bumper cover 2 is fixed to body parts around the bumper cover 2. In FIG. 1, the fixing portion 8 that fixes the bumper cover 2 to the vehicle body parts around the bumper cover 2 is indicated by a broken line. The vehicle body parts around the bumper cover 2 and the fixing portion 8 of the bumper cover 2 are fixed by bolts or the like as fastening members.

  The vehicle 1 on which the bumper cover 2 is installed is provided with headlights 10 in front of the vehicle and in the left and right directions in the vehicle width direction. The headlight 10 is provided above the bumper cover 2. The bumper cover 2 is provided with a mounting hole 13 at a position below the headlight 10 to which at least one of the fog lamp 11 and the ventilation duct 12 is attached.

  Next, the collision detection device will be described. The collision detection device includes a piezoelectric sensor 20, a signal processing unit 30, and the like.

  As shown in FIGS. 1 to 4, a piezoelectric sensor 20 for detecting a collision of an object with the bumper cover 2 is attached to the back surface of the bumper cover 2. The piezoelectric sensor 20 is an example of a deformation detection unit that can detect deformation of the bumper cover 2. The piezoelectric sensor 20 is attached to a position including the bent portion 5 on the back surface of the bumper cover 2. Specifically, the piezoelectric sensor 20 is attached to a position including a portion between the fog lamp 11 and the ventilation duct 12 and the headlight 10 in the bent portion 5 of the bumper cover 2. The area of the part is smaller than the area of the front part 3 or the side part 4. That is, as shown in FIG. 2, the distance α in the height direction of the part is shorter than the distances β and γ in the height direction of the front part 3 or the side part 4.

  The piezoelectric sensor 20 is a film-like sensor having a piezoelectric element and a film portion that protects the piezoelectric element. When the piezoelectric sensor 20 is stretched in a predetermined direction, the piezoelectric sensor 20 outputs a voltage signal corresponding to the stretched length from the piezoelectric element. In the following description, the predetermined direction is referred to as a sensitivity direction D of the piezoelectric sensor 20. In FIG. 4 and the like, the sensitivity direction D of the piezoelectric sensor 20 is indicated by a double-headed arrow with a symbol D. The piezoelectric sensor 20 is attached so that the sensitivity direction D is along the longitudinal direction of the bumper cover 2.

  As shown in FIG. 1, the signal output from the piezoelectric sensor 20 is transmitted to the signal processing unit 30. The signal processing unit 30 determines whether an object has collided with the bumper cover 2 based on a signal input from the piezoelectric sensor 20. Specifically, the signal processing unit 30 stores a predetermined threshold corresponding to the vehicle speed of the vehicle 1. The signal processing unit 30 can determine that a person has collided with the bumper cover 2 when the output of the piezoelectric sensor 20 is larger than the predetermined threshold value. At that time, the electronic control device mounted on the vehicle 1 can execute a technique for instantly lifting the rear of the hood of the vehicle 1 and alleviating the impact on the person who rides on the hood. The electronic control device can also execute a technique for inflating an air bag installed outside the A-pillar and the cowl to mitigate a shock to a person.

  Then, the effect | action of the collision detection apparatus of 1st Embodiment is demonstrated.

  When an object collides with the bumper cover 2, the bumper cover 2 undergoes local deformation and overall deformation. The local deformation is a deformation of the bumper cover 2 around the collision location. The overall deformation is a deformation in the vicinity of the fixed portion 8 that occurs when the entire bumper cover 2 is displaced with the fixed portion 8 as a fulcrum. Of the local deformation and the entire deformation, the piezoelectric sensor 20 of the first embodiment can detect the local deformation of the bumper cover 2.

  FIG. 5 schematically shows a state when the object 50 collides with the front portion 3 of the bumper cover 2. When the object 50 collides with the front surface portion 3 of the bumper cover 2, as shown by arrows S1 and S2, elongation occurs around the collision location, and local deformation occurs. As described above, the curvature radius of the bent portion 5 of the bumper cover 2 is smaller than the curvature radius of the front surface portion 3 and the curvature radius of the side surface portion 4. Therefore, the rigidity of the bent part 5 is larger than the rigidity of the front part 3 and the rigidity of the side part 4. Therefore, local deformation that occurs when the object 50 collides with the front surface portion 3 of the bumper cover 2 is transmitted to the bent portion 5, and is difficult to be transmitted to the side surface portion 4 beyond the bent portion 5. Therefore, the piezoelectric sensor 20 attached to the bent portion 5 can output a signal corresponding to the collision force when the object 50 collides with the front surface portion 3 of the bumper cover 2.

  FIG. 6 schematically shows a state when the object 50 collides with the side surface portion 4 of the bumper cover 2. When the object 50 collides with the side surface portion 4 of the bumper cover 2, as shown by arrows S3 and S4, elongation occurs in the area around the collision area, and local deformation occurs. This local deformation is transmitted to the bent portion 5 and hardly transmitted to the front portion 3 beyond the bent portion 5. Therefore, the piezoelectric sensor 20 attached to the bent portion 5 can output a signal corresponding to the collision force when the object 50 collides with the side surface portion 4 of the bumper cover 2.

  As described above, the collision detection device according to the first embodiment can detect local deformation of the bumper cover 2 regardless of whether the object 50 collides with the front surface portion 3 or the side surface portion 4 of the bumper cover 2. Is possible.

  Here, for comparison with the collision detection device of the first embodiment, a collision detection device of a comparative example will be described with reference to FIGS. 23 and 24.

  The piezoelectric sensors 40 included in the collision detection device of the comparative example are attached to the front surface portion 3 and the side surface portion 4 of the back surface of the bumper cover 2, respectively.

  FIG. 23 schematically shows a state when the object 50 collides with the front portion 3 of the bumper cover 2. When the object 50 collides with the front surface portion 3 of the bumper cover 2, as shown by arrows S1 and S2, elongation occurs around the collision location, and local deformation occurs. As described above, this local deformation is transmitted to the bent portion 5 and hardly transmitted to the side surface portion 4 beyond the bent portion 5. Therefore, when the object 50 collides with the front part 3 of the bumper cover 2, the piezoelectric sensor 40 attached to the front part 3 outputs a signal corresponding to the collision force. On the other hand, the piezoelectric sensor 40 attached to the side surface portion 4 does not output a signal corresponding to the collision force.

  FIG. 24 schematically shows a state when the object 50 collides with the side surface portion 4 of the bumper cover 2. When the object 50 collides with the side surface portion 4 of the bumper cover 2, as shown by arrows S3 and S4, elongation occurs in the area around the collision area, and local deformation occurs. As described above, this local deformation is transmitted to the bent portion 5 and is not easily transmitted to the front portion 3 beyond the bent portion 5. Therefore, when the object 50 collides with the side surface portion 4 of the bumper cover 2, the piezoelectric sensor 40 attached to the side surface portion 4 outputs a signal corresponding to the collision force. On the other hand, the piezoelectric sensor 40 attached to the front portion 3 does not output a signal corresponding to the collision force.

  As described above, the collision detection device of the comparative example detects the local deformation of the bumper cover 2 by attaching the piezoelectric sensors 40 to the front surface portion 3 and the side surface portion 4 of the bumper cover 2.

  In contrast to the comparative example described above, the collision detection device of the first embodiment has the following operational effects.

  (1) In 1st Embodiment, the piezoelectric sensor 20 with which a collision detection apparatus is provided is attached to the position containing the bending part 5 among the back surfaces of the bumper cover 2. As shown in FIG.

  According to this, even when the object 50 collides with any position of the front part 3, the side part 4, or the bent part 5 in the bumper cover 2, the piezoelectric sensor 20 can output a signal corresponding to the collision. It is. Therefore, in this collision detection device, the piezoelectric sensor 20 is not attached to the front surface portion 3 and the side surface portion 4 by attaching the piezoelectric sensor 20 to the bent portion 5 or is attached to the front surface portion 3 and the side surface portion 4. It is possible to reduce the number of Therefore, this collision detection device can reduce the number of parts and simplify the configuration by reducing the number of piezoelectric sensors 20 and the number of wires connecting the piezoelectric sensors 20 and the signal processing unit 30. it can.

  (2) In the first embodiment, the piezoelectric sensor 20 is attached to the bent portion 5 at a position including a portion between the fog lamp 11 and the ventilation duct 12 and the headlight 10.

  According to this, the area of the part to which the piezoelectric sensor 20 is attached is smaller than the area of the front part 3 or the side part 4. Therefore, when the object 50 collides with the front part 3 or the side part 4 of the bumper cover 2, the stress of local deformation around the collision part is concentrated and transmitted to the bent part 5. Thereby, the elongation of the bent part 5 becomes large. Therefore, it is possible to increase the output of the piezoelectric sensor 20 by attaching the piezoelectric sensor 20 to the bent portion 5.

  (3) In the first embodiment, the piezoelectric sensor 20 is attached so that the sensitivity direction D is along the longitudinal direction of the bumper cover 2.

  According to this, generally, the bumper cover has a rigidity in the longitudinal direction smaller than that in the short direction. Therefore, when the object 50 collides with the bumper cover, the deformation amount in the longitudinal direction of the bumper cover becomes larger than the deformation amount in the short direction. Therefore, the output of the piezoelectric sensor 20 can be increased by setting the sensitivity direction D of the piezoelectric sensor 20 along the longitudinal direction of the bumper cover 2.

(Second Embodiment)
A collision detection apparatus according to a second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in that the mounting position and shape of the piezoelectric sensor 20 are changed with respect to the first embodiment, and the others are substantially the same as the first embodiment. Only the part will be described.

  As shown in FIGS. 7 and 8, in the second embodiment, the piezoelectric sensor 20 included in the collision detection device is attached across the front surface portion 3, the bent portion 5, and the side surface portion 4. Therefore, the piezoelectric sensor 20 of the second embodiment also reliably outputs a signal corresponding to the collision, even when the object 50 collides with any position of the front surface portion 3, the side surface portion 4, or the bent portion 5 of the bumper cover 2. Is possible.

  FIG. 9 schematically shows a state when the object 50 collides with the front portion 3 of the bumper cover 2. In this case, as indicated by arrows S1 and S2, elongation occurs in the area around the collision location, and local deformation occurs. Here, as described above, since the rigidity of the front portion 3 is smaller than the rigidity of the bent portion 5, when the object 50 collides with the front portion 3 of the bumper cover 2, the amount of deformation of the front portion 3 is that of the bent portion 5. It becomes larger than the amount of deformation. Therefore, the elongation of the piezoelectric sensor 20 increases due to the difference in deformation amount between the front portion 3 and the bent portion 5. Therefore, in the second embodiment, the output of the piezoelectric sensor 20 can be increased.

  FIG. 10 schematically shows a state when the object 50 collides with the side surface portion 4 of the bumper cover 2. In this case, as indicated by arrows S3 and S4, elongation occurs around the collision location, and deformation occurs. Here, as described above, since the rigidity of the side surface portion 4 is smaller than the rigidity of the bent portion 5, when the object 50 collides with the side surface portion 4 of the bumper cover 2, the deformation amount of the side surface portion 4 is It becomes larger than the amount of deformation. Therefore, the elongation of the piezoelectric sensor 20 increases due to the difference in deformation amount between the side surface portion 4 and the bent portion 5. Therefore, in the second embodiment, the output of the piezoelectric sensor 20 can be increased.

(Third embodiment)
A collision detection apparatus according to a third embodiment of the present invention will be described. The third embodiment is obtained by changing the mounting position and shape of the piezoelectric sensor 20 with respect to the first and second embodiments, and the other is substantially the same as the first and second embodiments. Only the parts different from the first and second embodiments will be described.

  As shown in FIGS. 11 and 12, the collision detection device according to the third embodiment includes the piezoelectric sensor 20 attached over the front portion 3 and the bent portion 5, and the side portion 4 and the bent portion 5. And an attached piezoelectric sensor 20. Therefore, in the piezoelectric sensor 20 of the third embodiment, even when the object 50 collides with any position of the front surface portion 3, the side surface portion 4, or the bent portion 5 of the bumper cover 2, as in the first and second embodiments. It is possible to reliably output a signal corresponding to the collision.

  Also in the third embodiment, similarly to the second embodiment, when the object 50 collides with the front portion 3 of the bumper cover 2, the front portion 3 is caused by the difference in deformation amount between the front portion 3 and the bent portion 5. The piezoelectric sensor 20 attached over the bent portion 5 is greatly deformed. Further, when the object 50 collides with the side surface portion 4 of the bumper cover 2, the piezoelectric sensor 20 attached across the side surface portion 4 and the bent portion 5 is caused by the difference in deformation amount between the side surface portion 4 and the bent portion 5. Deforms greatly. Therefore, also in the third embodiment, the output of the piezoelectric sensor 20 can be increased.

  Furthermore, in the third embodiment, since the piezoelectric sensor 20 having a smaller area than that in the second embodiment can be used, the output of the piezoelectric sensor 20 can be increased.

(Fourth embodiment)
A collision detection apparatus according to a fourth embodiment of the present invention will be described. In the fourth embodiment, the shape of the bumper cover 2 is changed with respect to the first to third embodiments, and the other parts are substantially the same as those of the first to third embodiments. Only parts different from the third embodiment will be described.

  As shown in FIGS. 13 and 14, the bumper cover 2 of the fourth embodiment has a smaller radius of curvature of the bent portion 5 than the bumper cover 2 described in the first to third embodiments, and the bent portion. 5 has a small area.

  Even if the bent portion 5 of the bumper cover 2 has such a shape, the piezoelectric sensor 20 provided in the collision detection device is attached to a position including the bent portion 5 on the back surface of the bumper cover 2. In addition, the piezoelectric sensor 20 is attached across the front part 3, the bent part 5, and the side part 4. For this reason, the piezoelectric sensor 20 of the fourth embodiment also has the same structure as the first to third embodiments, even when the object 50 collides with any position of the front surface portion 3, the side surface portion 4 or the bent portion 5 of the bumper cover 2. It is possible to reliably output a signal corresponding to the collision.

  Also in the fourth embodiment, as in the second and third embodiments, when the object 50 collides with the front portion 3 of the bumper cover 2, the piezoelectricity is caused by the difference in deformation amount between the front portion 3 and the bent portion 5. The sensor 20 is greatly deformed. Further, when the object 50 collides with the side surface portion 4 of the bumper cover 2, the piezoelectric sensor 20 is greatly deformed due to the difference in deformation amount between the side surface portion 4 and the bent portion 5. Therefore, also in the fourth embodiment, the output of the piezoelectric sensor 20 can be increased.

(Fifth embodiment)
A collision detection apparatus according to a fifth embodiment of the present invention will be described. In the fifth embodiment, the mounting position of the piezoelectric sensor 20 is changed with respect to the first to fourth embodiments, and the others are substantially the same as the first to fourth embodiments. Only parts different from the first to fourth embodiments will be described.

  As shown in FIGS. 15 to 17, a fixing portion 8 for fixing the bumper cover 2 to the vehicle body parts around the bumper cover 2 is provided on the outer edge portion of the bumper cover 2. As shown in FIG. 17, the fixing portion 8 is a place where a hole for inserting the bolt 14 is formed in a part of a flange provided on the outer edge of the bumper cover main body. The vehicle body parts around the bumper cover 2 and the fixing portion 8 of the bumper cover 2 are fixed by a bolt 14 or the like as a fastening member.

  The piezoelectric sensor 20 included in the collision detection device of the fifth embodiment is attached to a position including the vicinity of the fixed portion 8 on the back surface of the bumper cover 2. Specifically, the piezoelectric sensor 20 is attached to a position including the vicinity of the fixing portions 8 arranged at both ends in the longitudinal direction among the plurality of fixing portions 8 provided on the bumper cover 2. Here, the vicinity of the fixing portion 8 refers to a portion where the fixing portion 8 is deformed around the fixing portion 8 when the entire deformation of the bumper cover 2 occurs. Specifically, “in the vicinity of the fixing portion 8” refers to a range within 50 mm, for example, from the connection position between the flange and the bumper cover main body. In FIG. 17, a range “in the vicinity of the fixed portion 8” is indicated by a broken line N.

  The piezoelectric sensor 20 is attached so that the sensitivity direction D is directed from the fixed portion 8 toward the central region side of the side surface portion 4. By attaching the piezoelectric sensor 20 in this way, the output of the piezoelectric sensor 20 can be increased.

  The piezoelectric sensor 20 attached in the vicinity of the fixed portion 8 is preferably more sensitive than the piezoelectric sensor 20 attached to the bent portion 5 described in the first to fourth embodiments. Thereby, even when the extension of the bumper cover 2 due to the overall deformation is smaller than the extension of the bumper cover 2 due to the local deformation, the signal processing unit 30 can reliably detect the output of the piezoelectric sensor 20.

  Then, the effect | action of the collision detection apparatus of 5th Embodiment is demonstrated.

  As described in the first embodiment, when the object 50 collides with the bumper cover 2, the bumper cover 2 undergoes local deformation and overall deformation. Among them, the whole deformation is a deformation in the vicinity of the fixed portion 8 caused by the displacement of the entire bumper cover 2 with the fixed portion 8 as a fulcrum. The piezoelectric sensor 20 of the fifth embodiment can detect the entire deformation of the bumper cover 2.

  FIG. 18 schematically shows a state when the object 50 collides with the front portion 3 of the bumper cover 2. When the object 50 collides with the front portion 3 of the bumper cover 2, the entire bumper cover 2 is displaced with the fixed portions 8 disposed at both ends in the longitudinal direction of the bumper cover 2 as fulcrums as indicated by arrows S5. To do. At that time, the position of the fixing portion 8 is hardly displaced. Therefore, as shown by an arrow S6, stress concentrates on a portion of the bumper cover 2 in the vicinity of the fixed portion 8, and elongation occurs, resulting in overall deformation. Therefore, when the object 50 collides with the front part 3 of the bumper cover 2, the piezoelectric sensor 20 attached at a position including the vicinity of the fixed part 8 outputs a signal corresponding to the collision force.

  FIG. 19 schematically shows a state when the object 50 collides with the side surface portion 4 of the bumper cover 2. Even when the object 50 collides with the side surface portion 4 of the bumper cover 2, as shown by the arrow S <b> 7, the entire bumper cover 2 has the fixed portions 8 arranged at both ends in the longitudinal direction of the bumper cover 2 as fulcrums. Displace. At that time, the position of the fixing portion 8 is hardly displaced. For this reason, as indicated by the arrow S8, the bumper cover 2 is stretched in the vicinity of the fixed portion 8, and the entire deformation occurs. Therefore, when the object 50 collides with the side surface portion 4 of the bumper cover 2, the piezoelectric sensor 20 attached at a position including the vicinity of the fixed portion 8 outputs a signal corresponding to the collision force.

  As described above, the collision detection device according to the fifth embodiment can detect the entire deformation of the bumper cover 2 regardless of whether the object 50 collides with the front surface portion 3 or the side surface portion 4 of the bumper cover 2. Is possible.

  The collision detection device according to the fifth embodiment has the following effects.

  (1) In the fifth embodiment, the piezoelectric sensor 20 included in the collision detection device is attached to a position including the vicinity of the fixed portion 8 on the back surface of the bumper cover 2.

  According to this, even when the object 50 collides with any position of the front surface portion 3, the side surface portion 4, or the bent portion 5 of the bumper cover 2, the piezoelectric sensor 20 can output a signal corresponding to the collision. is there. Therefore, in this collision detection device, the piezoelectric sensor 20 is attached to a position including the vicinity of the fixed portion 8, so that the piezoelectric sensor 20 is not attached to the front face portion 3 and the bent portion 5 or the number of piezoelectric sensors 20 is reduced. It is possible. Therefore, this collision detection device can reduce the number of parts and simplify the configuration by reducing the number of piezoelectric sensors 20 and the number of wires connecting the piezoelectric sensors 20 and the signal processing unit 30. it can.

  (2) In the fifth embodiment, the piezoelectric sensor 20 is attached in the vicinity of the fixed portion 8 disposed at the end portion in the longitudinal direction of the bumper cover 2.

  According to this, generally, the fixing portion 8 disposed at the end portion in the longitudinal direction of the bumper cover 2 is fixed to the tire house of the vehicle 1 or a vehicle body part in the vicinity thereof, and has high rigidity. For this reason, when the object 50 collides with the bumper cover 2, the fixed portion 8 is hardly displaced, so stress concentrates in the vicinity of the fixed portion 8 and the deformation near the fixed portion 8 is large. Become. Therefore, it is possible to increase the output of the piezoelectric sensor 20 by attaching the piezoelectric sensor 20 to a position including the vicinity of the fixed portion 8.

  (3) In the fifth embodiment, the piezoelectric sensor 20 is attached such that the sensitivity direction D is directed from the fixed portion 8 toward the central region side of the side surface portion 4. When the object 50 collides with the bumper cover 2 and the entire deformation occurs, the deformation amount of the portion from the fixed portion 8 toward the central region side of the side surface portion 4 becomes large. Therefore, it is possible to increase the output of the piezoelectric sensor 20 by attaching the piezoelectric sensor 20 according to the part.

(Sixth embodiment)
A collision detection apparatus according to a sixth embodiment of the present invention will be described. The sixth embodiment is obtained by changing the shape and mounting position of the piezoelectric sensor 20 with respect to the fifth embodiment, and is otherwise substantially the same as the fifth embodiment. Only the different parts will be described.

  As shown in FIG. 20, in the piezoelectric sensor 20 included in the collision detection device of the sixth embodiment, the film portion 21 that protects the piezoelectric element is formed larger than the piezoelectric element 22. A hole 23 is provided at a position away from the piezoelectric element 22 in the film portion 21. Bolts 14 as fastening members are inserted through holes 23 provided in the film part 21. Accordingly, the piezoelectric sensor 20 is fastened together with the vehicle body parts around the bumper cover 2 and the fixing portion 8 of the bumper cover 2. The piezoelectric sensor 20 is attached from the fixed portion 8 to the vicinity of the fixed portion 8.

  In the sixth embodiment, when the object 50 collides with the bumper cover 2, the piezoelectric sensor 20 is greatly deformed due to the difference between the deformation amount of the fixed portion 8 and the deformation amount near the fixed portion 8. Therefore, the output of the piezoelectric sensor 20 can be increased.

(Seventh embodiment)
A collision detection apparatus according to a seventh embodiment of the present invention will be described. In the seventh embodiment, the mounting position of the piezoelectric sensor 20 is changed with respect to the first to sixth embodiments, and the rest is substantially the same as the first to sixth embodiments. Only the differences from the sixth embodiment will be described.

  As shown in FIGS. 21 and 22, the piezoelectric sensor 20 included in the collision detection device of the seventh embodiment is attached to the fixed portion 8 provided near the front portion 3 of the bumper cover 2 or in the vicinity of the fixed portion 8. ing. The piezoelectric sensor 20 is also attached to a position including the bent portion 5 as the first piezoelectric sensor. The piezoelectric sensor 20 is also attached to a position including the fixed portion 8 or the vicinity of the fixed portion 8 disposed at both ends in the longitudinal direction as the second piezoelectric sensor.

  Similar to the first to sixth embodiments, the collision detection device according to the seventh embodiment can be applied to the bumper cover 2 regardless of whether the object 50 collides with the front portion 3 or the side portion 4 of the bumper cover 2. It is possible to detect the overall deformation.

(Eighth embodiment)
A collision detection apparatus according to an eighth embodiment of the present invention will be described. In the eighth embodiment, the mounting position of the piezoelectric sensor 20 is changed with respect to the first to fourth embodiments, and the other parts are substantially the same as those of the first to fourth embodiments. Only the parts different from the fourth embodiment will be described.

  As shown in FIGS. 25 and 26, generally, a ridge line 9 bent so as to protrude toward the front side of the vehicle around the mounting hole 13 to which at least one of the fog lamp 11 and the ventilation duct 12 is attached to the bumper cover 2 is provided. Is formed. In the present specification and the like, a line obtained by extending a part of the ridge line 9 located on the outer side in the vehicle width direction along the back surface of the bumper cover 2 among the ridge lines 9 is defined as the extension line EL.

  From experiments and simulations by the inventor, it has been found that when an object collides with various parts of the front portion 3 of the bumper cover 2, strain concentrates on the extension line EL. The strain generated in that case is generated so as to extend from the extension line EL toward the collision position of the front portion 3 with the extension line EL as a starting point. On the other hand, even when an object collides with various parts of the side surface part 4 of the bumper cover 2, strain concentrates on the extension line EL. The distortion generated in that case is generated so as to extend from the extension line EL toward the collision position of the side surface portion 4 from the extension line EL. Therefore, it is possible to increase the output of the piezoelectric sensor 20 by attaching the piezoelectric sensor 20 so as to include the extension line EL on the back surface of the bumper cover 2. In particular, since the bumper cover 2 is well deformed in a direction orthogonal to the extension line EL, the bumper cover 2 includes the extension line EL, and the extension line EL and the sensitivity direction D of the piezoelectric sensor 20 are substantially orthogonal to each other. It is preferable to attach the piezoelectric sensor 20. In addition, in FIG. 25 etc., the sensitivity direction D of the piezoelectric sensor 20 is shown with the dashed-dotted line.

  In an experiment conducted by the inventors, when the angle formed by the sensitivity direction D of the piezoelectric sensor 20 and the extension line EL is 90 °, the sensitivity direction D of the piezoelectric sensor 20 and the longitudinal direction of the bumper cover 2 are parallel to each other. The output of the piezoelectric sensor 20 was increased by about 10%. When the angle formed between the sensitivity direction D of the piezoelectric sensor 20 and the extension line EL is deviated from 90 °, the output of the piezoelectric sensor 20 is reduced accordingly. In other words, even if the angle formed between the sensitivity direction D of the piezoelectric sensor 20 and the extension line EL is slightly deviated from 90 °, it can be said that the output of the piezoelectric sensor 20 is in a large state. Therefore, in this specification and the like, “the sensitivity direction D of the piezoelectric sensor 20 and the extension line EL are substantially orthogonal” means that the angle formed by the extension line EL and the sensitivity direction D of the piezoelectric sensor 20 is 90 °. In addition to the error, it shall include an error of ± 15 °. That is, in this specification and the like, that the extension line EL and the sensitivity direction D of the piezoelectric sensor 20 are orthogonal to each other includes an angle between the extension line EL and the sensitivity direction D of the piezoelectric sensor 20 in a range of 75 ° to 105 °. It is a waste.

  In the eighth embodiment described above, one sheet is obtained by attaching the piezoelectric sensor 20 on the extension line EL where strain concentrates on the bumper cover 2 at a plurality of collision positions among the front surface portion 3 and the side surface portion 4 of the bumper cover 2. The hit piezoelectric sensor 20 can detect a wide area collision. Furthermore, by attaching the piezoelectric sensor 20 to the bumper cover 2 so that the sensitivity direction D of the piezoelectric sensor 20 and the extension line EL are substantially orthogonal to each other, the output of the piezoelectric sensor 20 is increased and a collision of a wider area is detected. Is possible. For this reason, this collision detection apparatus can reduce the number of piezoelectric sensors 20 that are not attached to the positions deviating from the extension line EL or that are attached to positions deviating from the extension line EL. Therefore, this collision detection device can reduce the number of parts and simplify the configuration by reducing the number of piezoelectric sensors 20 and the number of wires connecting the piezoelectric sensors 20 and the signal processing unit 30. it can.

(Ninth embodiment)
A collision detection apparatus according to a ninth embodiment of the present invention will be described. The ninth embodiment is obtained by changing the mounting position of the piezoelectric sensor 20 with respect to the first to fourth embodiments. The other aspects are substantially the same as those of the first to fourth embodiments. Only the parts different from the fourth embodiment will be described.

  As shown in FIG. 27, in the ninth embodiment, the piezoelectric sensor 20 is attached so that the central portion of the piezoelectric sensor 20 is positioned on the extension line EL. Thereby, when an object collides with one of the front part 3 or the side part 4 of the bumper cover 2, the one part of the sensitivity direction D of the piezoelectric sensor 20 differs from the other part across the extension EL. Become. Therefore, the output of the piezoelectric sensor 20 can be increased. The central portion of the piezoelectric sensor 20 includes a range portion of 10% of the total length of the piezoelectric sensor 20 in the sensitivity direction D in addition to the center position DS of the piezoelectric sensor 20 in the sensitivity direction D.

  In the ninth embodiment, it is possible to increase the output of the piezoelectric sensor 20 by attaching the piezoelectric sensor 20 to the bumper cover 2 so that the center of the piezoelectric sensor 20 is positioned on the extension line EL. Therefore, collision of a wider area can be detected by the piezoelectric sensor 20 per sheet.

(10th Embodiment)
A collision detection apparatus according to a tenth embodiment of the present invention will be described. The tenth embodiment is a combination of the eighth embodiment and the ninth embodiment described above.

  As shown in FIG. 28, in the tenth embodiment, the piezoelectric sensor 20 has a sensitivity direction D of the piezoelectric sensor 20 and an extension line EL substantially orthogonal to each other on the back surface of the bumper cover 2 and the piezoelectric sensor 20. It is attached so that the center part of may be located on the extension line EL. In the tenth embodiment, as compared with the eighth and ninth embodiments, the output of the piezoelectric sensor 20 can be further increased, and a collision of a wider area can be detected by the piezoelectric sensor 20 per sheet.

(Eleventh embodiment)
A collision detection apparatus according to an eleventh embodiment of the present invention will be described. 10th Embodiment changes the attachment position of the piezoelectric sensor 20 with respect to 8th-10th Embodiment mentioned above, About others, since it is substantially the same as that of 8th-10th Embodiment, Only portions different from the eighth to tenth embodiments will be described.

  As shown in FIG. 29, in the eleventh embodiment, the piezoelectric sensor 20 is attached to the back surface of the bumper cover 2 at a position including the center position between the upper portion of the mounting hole 13 of the bumper cover 2 and the lower portion of the headlight 10. It has been. Specifically, in FIG. 29, the distance L1 between the upper part of the mounting hole 13 of the bumper cover 2 and the center of the piezoelectric sensor 20 and the distance L2 between the lower part of the headlight 10 and the center of the piezoelectric sensor 20 are the same. .

  In general, a portion of the bumper cover 2 positioned below the headlight 10 is formed with a ridgeline 91 that is bent so as to protrude toward the front or side of the vehicle and extends along the headlight 10. In the bumper cover 2, the portion of the ridge line 91 formed under the headlight 10 has higher rigidity than other portions. In addition, as described above, the ridgeline 9 that is bent so as to protrude toward the front side of the vehicle is also formed around the mounting hole 13 of the bumper cover 2. In the bumper cover 2, the portion of the ridge line 9 around the mounting hole 13 has higher rigidity than other portions. Accordingly, the bumper cover 2 has a lower rigidity of the portion between the ridge lines 91 and 9 than the rigidity of the ridge line 91 below the headlight 10 and the ridge line 9 around the mounting hole 13 of the bumper cover 2. It has become. Among these, it can be said that the center position between the upper portion of the mounting hole 13 of the bumper cover 2 and the lower portion of the headlight 10 is a portion that is well deformed in accordance with the collision of an object.

  Therefore, in the eleventh embodiment, the piezoelectric sensor 20 is attached to the back surface of the bumper cover 2 at a position including the center position between the upper portion of the mounting hole 13 of the bumper cover 2 and the lower portion of the headlight 10. Thereby, it is possible to increase the output of the piezoelectric sensor 20 and detect a collision of a wider area. Furthermore, it is preferable that the piezoelectric sensor 20 is attached so that the sensitivity direction D and the extension line EL are substantially orthogonal to each other and the center portion of the piezoelectric sensor 20 is positioned on the extension line EL. Also in the eleventh embodiment, it is possible to achieve the same operational effects as in the eighth to tenth embodiments.

(Twelfth embodiment)
A collision detection apparatus according to a twelfth embodiment of the present invention will be described. The twelfth embodiment is a modification of the eighth to eleventh embodiments described above.

  As shown in FIG. 30, in the twelfth embodiment, among the ridge lines 9 formed around the mounting holes 13 of the bumper cover 2, a part of the ridge lines 9 located on the outer side in the vehicle width direction is along the back surface of the bumper cover 2. The extended line EL extended in this manner is inclined forward in the vehicle traveling direction from the bottom to the top. Even in the bumper cover 2 having this shape, the piezoelectric sensor 20 has the sensitivity direction D of the piezoelectric sensor 20 and the extension line EL substantially orthogonal to each other on the back surface of the bumper cover 2 and the center of the piezoelectric sensor 20. It is preferable to attach so that a part may be located on extension line EL. In addition, the piezoelectric sensor 20 is preferably attached to a position on the back surface of the bumper cover 2 including a central position between the upper portion of the mounting hole 13 of the bumper cover 2 and the lower portion of the headlight 10. Thereby, also in 12th Embodiment, there exists an effect similar to 8th-11th Embodiment.

(13th Embodiment)
A thirteenth embodiment will be described. In the thirteenth embodiment, the mounting position of the piezoelectric sensor 20 is changed with respect to the first to twelfth embodiments described above.

  As shown in FIGS. 31 and 32, the bumper cover 2 is fixed to the vehicle body 100 or a vehicle body part 101 connected to the vehicle body 100 by bolts 14 and 14a as fastening members. In the thirteenth embodiment, the vehicle body part 101 connected to the vehicle body 100 and the bumper cover 2 are fixed by a plurality of bolts 14 and 14a. In addition, when the vehicle body 100 and the vehicle body part 101 are integrally configured, the bumper cover 2 may be attached to the vehicle body 100.

  A bumper reinforcement 102 provided inside the bumper cover 2 is installed in front of the vehicle body 100. An absorber (not shown) is installed between the bumper reinforcement 102 and the bumper cover 2.

  The collision detection apparatus of the thirteenth embodiment also includes a piezoelectric sensor 20 as a deformation detection unit, a signal processing unit 30, and the like. The piezoelectric sensor 20 of the thirteenth embodiment is attached in a state of being inserted through a bolt 14 for fixing the vehicle body part 101 and the bumper cover 2. The piezoelectric sensor 20 is inserted in a bolt 14 provided at a position separated from the bolt 14a provided in the center in the vehicle width direction among the plurality of bolts 14 and 14a that fix the vehicle body part 101 and the bumper cover 2. It is attached. According to the experiments and simulations of the inventors, when an object collides with various locations of the bumper cover 2 by attaching the piezoelectric sensor 20 while being inserted through the bolts 14, the piezoelectric sensor 20 is It is possible to output a voltage signal corresponding to.

  A signal output from the piezoelectric sensor 20 is transmitted to the signal processing unit 30. The signal processing unit 30 determines whether an object has collided with the bumper cover 2 based on a signal input from the piezoelectric sensor 20. Specifically, the signal processing unit 30 stores a predetermined threshold corresponding to the vehicle speed of the vehicle 1. The signal processing unit 30 can determine that a person has collided with the bumper cover 2 when the output of the piezoelectric sensor 20 is larger than the predetermined threshold value.

  FIG. 33 and FIG. 34 show an example of the piezoelectric sensor 20 as a deformation detection unit. The piezoelectric sensor 20 includes a piezoelectric element 22 that uses a piezoelectric effect, a film portion 21 that protects the piezoelectric element 22, and a first protection member 24 and a second protection member 24 that are provided on one and the other in the thickness direction of the film portion 21, respectively. And a protective member 25. Two wirings 29 extend from the piezoelectric element 22 to the outside of the film portion 21.

  The piezoelectric element 22 is formed in an annular shape. The piezoelectric element 22 is formed such that the sensitivity direction D is the surface direction of the film part 21. The piezoelectric element 22 may be formed such that the sensitivity direction D is the thickness direction of the film part 21.

  The film part 21 is provided so as to cover the outside of the piezoelectric element 22. The first protective member 24 protects one side of the piezoelectric element 22 and the film portion 21 in the thickness direction. The second protective member 25 protects the other side in the thickness direction of the piezoelectric element 22 and the film portion 21. The piezoelectric element 22, the film part 21, the first protection member 24 and the second protection member 25 are provided with holes 26 through which the bolts 14 are inserted.

  The first protective member 24 and the second protective member 25 are formed of resin, metal, ceramic, or the like. If the first protective member 24 and the second protective member 25 are formed of resin, the strain of the bumper cover 2 can be efficiently transmitted to the piezoelectric element 22 and the output of the piezoelectric sensor 20 can be increased. The piezoelectric sensor 20 may be configured to eliminate the film portion 21 that protects the piezoelectric element 22 and directly protect the piezoelectric element 22 by the first protection member 24 and the second protection member 25.

  Note that the deformation detection unit is not limited to the piezoelectric sensor 20, and for example, a strain gauge may be employed. In that case, the deformation detection unit is configured such that a resistor included in the strain gauge is installed inside the film unit 21 instead of the piezoelectric element 22.

  34 and 35 show another example of the piezoelectric sensor 20 as a deformation detection unit. In this other example, the piezoelectric element 22 is provided in a part around the hole 26 through which the bolt 14 is inserted. Thus, the size, shape, and the like of the piezoelectric element 22 are not limited to those shown in FIGS. 33 to 35, and various configurations can be employed. Further, the overall shape of the deformation detection unit is not limited to that illustrated in FIGS. 33 to 35, and may be a shape in which a part in the circumferential direction is cut away, for example, a U shape in a plan view.

  Next, an example of an attachment method of the piezoelectric sensor 20 (hereinafter referred to as an attachment example) will be described. FIG. 37 shows a first attachment example of the piezoelectric sensor 20. In the first mounting example, the piezoelectric sensor 20 is provided between the bumper cover 2 and the vehicle body part 101 and inserted into the bolt 14. Specifically, in the first mounting example, each component is arranged in the order of the head 141 of the bolt 14, the bumper cover 2, the piezoelectric sensor 20, the vehicle body part 101, and the nut 103. The vehicle body part 101 and the nut 103 may be integrally formed by welding. Alternatively, the nut 103 may be eliminated by forming a female screw in the hole of the body part 101.

  When an object collides with an arbitrary place on the bumper cover 2, the bumper cover 2 is entirely pulled to the side on which the object collided starting from the bolt 14 fixed to the vehicle body part 101. On the other hand, the body part 101 and the bolt 14 are fixed to the body 100. Therefore, a relative displacement occurs between the vehicle body part 101 and the bolts 14 and the bumper cover 2. Therefore, the bumper cover 2 is distorted at a portion around the hole 2e through which the bolt 14 is inserted. This distortion may occur in various directions such as the surface direction of the bumper cover 2 or the thickness direction of the bumper cover 2. When the sensitivity direction D of the piezoelectric sensor 20 is configured to intersect the axis of the bolt 14, the piezoelectric sensor 20 detects the strain generated in the surface direction of the bumper cover 2 and determines the magnitude of the strain. It is possible to output a corresponding voltage signal. Further, when the sensitivity direction D of the piezoelectric sensor 20 is configured in a direction along the axis of the bolt 14, the piezoelectric sensor 20 detects strain generated in the axial direction of the bolt 14 due to deformation of the bumper cover 2, and the strain is detected. It is possible to output a voltage signal in accordance with the magnitude of.

  Subsequently, a second mounting example of the piezoelectric sensor 20 will be described with reference to FIG. In the second mounting example, the piezoelectric sensor 20 is provided between the head 141 of the bolt 14 and the bumper cover 2 and inserted through the bolt 14. Specifically, in the second mounting example, each component is arranged in the order of the head 141 of the bolt 14, the piezoelectric sensor 20, the bumper cover 2, the vehicle body part 101, and the nut 103. Also in this second mounting example, the piezoelectric sensor 20 detects the strain generated in the surface direction of the bumper cover 2 or the strain generated in the axial direction of the bolt 14 due to the deformation of the bumper cover 2, and determines the magnitude of the strain. It is possible to output a corresponding voltage signal.

  Next, a third attachment example of the piezoelectric sensor 20 will be described with reference to FIG. In the third mounting example, the piezoelectric sensor 20 is provided between the vehicle body part 101 and the nut 103 and inserted through the bolt 14. Specifically, in this third mounting example, each component is arranged in the order of the head 141 of the bolt 14, the bumper cover 2, the vehicle body part 101, the piezoelectric sensor 20, and the nut 103. In the third mounting example, the piezoelectric sensor 20 is configured such that its sensitivity direction D is along the axis of the bolt 14. Also according to the third mounting example, the piezoelectric sensor 20 can detect strain generated in the axial direction of the bolt 14 due to deformation of the bumper cover 2 and can output a voltage signal corresponding to the magnitude of the strain. .

  Then, the 4th example of attachment of the piezoelectric sensor 20 is demonstrated, referring FIG. In the fourth mounting example, the piezoelectric sensor 20 includes a first detection unit 27 and a second detection unit 28. The first detection unit 27 is configured in a direction in which the sensitivity direction D intersects the axis of the bolt 14. The second detection unit 28 is configured such that the sensitivity direction D is along the axis of the bolt 14. The first detector 27 and the second detector 28 are provided so as to overlap in the thickness direction. In addition, the 1st detection part 27 and the 2nd detection part 28 may arrange | position the several piezoelectric element 22 from which the sensitivity direction D differs in the piezoelectric sensor 20 of 1 sheet.

  In the fourth mounting example, the first detection unit 27 and the second detection unit 28 are sandwiched between the bumper cover 2 and the vehicle body part 101 and are inserted into the bolts 14. The position where the first detection unit 27 and the second detection unit 28 are arranged is not limited to the position shown in FIG. That is, you may arrange | position the 1st detection part 27 and the 2nd detection part 28 in the position demonstrated by the 2nd attachment example mentioned above or the 3rd attachment example. Further, the order in which the first detection unit 27 and the second detection unit 28 are vertically stacked may be switched.

  In the fourth mounting example, the first detection unit 27 can detect a strain generated in the surface direction of the bumper cover 2 and output a voltage signal corresponding to the magnitude of the strain. Further, the second detection unit 28 can detect strain generated in the axial direction of the bolt 14 due to deformation of the bumper cover 2 and can output a voltage signal corresponding to the magnitude of the strain. Therefore, the collision detection device can improve the accuracy of collision detection of an object with respect to the bumper cover 2.

(14th Embodiment)
A fourteenth embodiment will be described. 14th Embodiment changes the shape of the bumper cover 2 with respect to 13th Embodiment mentioned above.

  As shown in FIG. 41, the bumper cover 2 provided in the vehicle 1 on which the collision detection apparatus of the fourteenth embodiment is mounted includes a first bumper part 2a provided at a position including the vehicle side surface, and a second bumper cover 2 provided at the vehicle front side. And a bumper part 2b. The first bumper part 2a on the right side in the vehicle width direction and the first bumper part 2a on the left side in the vehicle width direction may be parts formed integrally through the lower side of the second bumper part 2b, or the like. It may be a separate part. The first bumper part 2a and the second bumper part 2b are joined by a joining member (not shown). Examples of the joining member include a locking hole, a locking claw, a screw, and a clip.

  The first bumper component 2a has a part of the front part 3 located in front of the vehicle, a side part 4 located on the side of the vehicle, and a bent part 5 having a smaller radius of curvature than the front part 3 and the side part 4. doing. In the figure, the boundary between the front portion 3 and the bent portion 5 is indicated by a broken line 6, and the boundary between the side portion 4 and the bent portion 5 is indicated by a broken line 7, but the front portion 3, the side portion 4, and the bent portion 5 Are formed continuously. Further, the first bumper component 2a is provided with a mounting hole 13 at a position located below the headlight 10 to which at least one of a fog lamp and a ventilation duct is attached.

  On the other hand, the second bumper component 2b has a part of the front portion 3 located in front of the vehicle. That is, the first bumper component 2 a and the second bumper component 2 b are joined in the middle of the front portion 3. The second bumper part 2b includes a bumper grill 15 for taking air into the engine room. That is, in this specification, the bumper cover 2 includes the bumper grill 15.

  As shown in FIGS. 41 and 42, the piezoelectric sensor 20 of the fourteenth embodiment is also attached in a state of being inserted through the bolts 14 that fix the vehicle body part 101 and the bumper cover 2. The piezoelectric sensor 20 is inserted into a bolt 14 provided at a position separated from the bolt 14a provided at the center in the vehicle width direction among the plurality of bolts 14 and 14a for fixing the vehicle body part 101 and the bumper cover 2. It is attached in a state.

  A signal output from the piezoelectric sensor 20 is transmitted to the signal processing unit 30. The signal processing unit 30 determines whether an object has collided with the bumper cover 2 based on a signal input from the piezoelectric sensor 20. Specifically, the signal processing unit 30 stores a predetermined threshold corresponding to the vehicle speed of the vehicle 1. The signal processing unit 30 can determine that a person has collided with the bumper cover 2 when the output of the piezoelectric sensor 20 is larger than the predetermined threshold value.

  Then, the result of the effect confirmation test regarding the attachment position of the piezoelectric sensor 20 of 14th Embodiment is demonstrated.

  This effect confirmation test was performed using a test apparatus as shown in FIG. That is, in this test apparatus, a part of the vehicle 1 including the front bumper (hereinafter referred to as a cut body 61) is fixed on the test stand 60, and the impactor 62 is moved from the front of the cut body 61 to the front bumper at a predetermined speed. It is a thing to collide with. The front bumper includes a bumper cover 2 and a bumper reinforcement 102 provided inside the bumper cover 2. A plurality of piezoelectric sensors 20 are attached to the back surface of the bumper cover 2. In the effect confirmation test, the signal intensity output from the plurality of piezoelectric sensors 20 when the impactor 62 collides with the bumper cover 2, that is, the magnitude of the voltage was detected.

  44 and 45 are diagrams in which the stress distribution generated in the bumper cover 2 when the impactor 62 collides with a predetermined position on the boundary between the first bumper part 2a and the second bumper part 2b is analyzed. The analysis diagram of FIG. 44 shows the right half of the rear surface of the bumper cover 2 in the vehicle width direction. In FIG. 44, the collision position of the impactor 62 against the bumper cover 2 is indicated by reference numeral I1.

  On the other hand, the analysis diagram of FIG. 45 shows a part of the second bumper component 2b when FIG. 44 is viewed from the direction of the arrow XXXXV. As shown by the arrow S20 in FIG. 45, in this analysis diagram, stress concentration is present around the hole 2e through which the bolt 14 for fixing the vehicle body part 101 and the second bumper part 2b is inserted in the bumper cover 2. You can see what is happening. Therefore, by attaching the piezoelectric sensor 20 in a state of being inserted through the bolts 14, distortion generated around the holes 2 e through which the bolts 14 of the bumper cover 2 are inserted can be detected by the piezoelectric sensor 20.

  46 and 47 are diagrams in which a stress distribution generated in the bumper cover 2 when the impactor 62 collides with a predetermined position of the second bumper component 2b is analyzed. The analysis diagram of FIG. 46 shows the right half of the rear surface of the bumper cover 2 in the vehicle width direction. In FIG. 46, the collision position of the impactor 62 against the bumper cover 2 is indicated by reference numeral I2.

  On the other hand, the analysis diagram of FIG. 47 shows a part of the second bumper component 2b when FIG. 46 is viewed from the direction of the arrow XXXVII. As shown by the arrow S21 in FIG. 47, in this analysis view, stress concentration is also present around the hole 2e through which the bolt 14 for fixing the vehicle body part 101 and the second bumper part 2b of the bumper cover 2 is inserted. You can see what is happening. Therefore, by attaching the piezoelectric sensor 20 in a state of being inserted through the bolts 14, distortion generated around the holes 2 e through which the bolts 14 of the bumper cover 2 are inserted can be detected by the piezoelectric sensor 20.

  In the thirteenth and fourteenth embodiments described above, the piezoelectric sensor 20 is attached in a state of being inserted through the bolts 14 for fixing the vehicle body part 101 and the bumper cover 2. That is, the inventors of the bumper cover 2 in the bumper cover 2 when a portion of the bumper cover 2 around the hole 2e through which the bolt 14 is inserted collides with various places of the bumper cover 2 through experiments and simulations. It was found that this is a region where strain is concentrated. Therefore, by attaching the piezoelectric sensor 20 while being inserted into the bolt 14, when an object collides with various places on the bumper cover 2, the piezoelectric sensor 20 can output a signal corresponding to the collision. It is. Thereby, this collision detection apparatus can reduce the number of piezoelectric sensors 20 attached to the bumper cover 2. Therefore, this collision detection device can reduce the number of parts and simplify the configuration by reducing the number of piezoelectric sensors 20 and the number of wires connecting the piezoelectric sensors 20 and the signal processing unit 30. it can.

(Fifteenth embodiment)
The fifteenth embodiment will be described with reference to FIGS. 48 and 49. FIG. In the fifteenth embodiment, an attachment position of the piezoelectric sensor 20 is added to the fourteenth embodiment described above. In the fifteenth embodiment, the piezoelectric sensor 20 described in the thirteenth embodiment and the fourteenth embodiment is referred to as a piezoelectric sensor 20a serving as a first deformation detection unit. That is, the piezoelectric sensor 20a as the first deformation detection unit is attached in a state of being inserted through the bolt 14 that fixes the vehicle body part 101 and the bumper cover 2.

  As shown in FIG. 48, the collision detection apparatus of the fifteenth embodiment further includes a piezoelectric sensor 20b as a second deformation detection unit and a piezoelectric sensor 20c as a third deformation detection unit. The piezoelectric sensor 20 b as the second deformation detection unit is attached to a position including the bent portion 5 on the back surface of the bumper cover 2. The configuration of the piezoelectric sensor 20b is the same as that of the piezoelectric sensor 20 described in the first embodiment. The configuration of the piezoelectric sensor 20b as the second deformation detection unit may be the same as the configuration of the piezoelectric sensor 20 described in the second to fourth embodiments.

  FIG. 49 shows the right half of the rear surface of the bumper cover 2 in the vehicle width direction. As shown in FIG. 49, the piezoelectric sensor 20c as the third deformation detection unit is attached to a portion of the back surface of the bumper cover 2 in the vicinity of the boundary line 2d between the first bumper component 2a and the second bumper component 2b. ing. Specifically, the piezoelectric sensor 20c is attached to the back surface of the bumper cover 2 within a range of ± 100 mm in the normal direction from the boundary line 2d between the first bumper component 2a and the second bumper component 2b. In this specification, the range is referred to as “the boundary vicinity 18 between the first bumper component 2a and the second bumper component 2b”. In FIG. 49, the range of the boundary vicinity 18 is indicated by a one-dot chain line with reference numerals 18a and 18b. According to the experiments and simulations of the inventors, when an object collides with various places of the bumper cover 2 by attaching the piezoelectric sensor 20c to the boundary vicinity portion 18, the piezoelectric sensor 20c has a voltage corresponding to the collision. It is possible to output a signal.

  As shown in FIG. 49, the first bumper component 2 a and the second bumper component 2 b are overlapped with each other at a predetermined width, and are joined by a plurality of joining members 16 and 17. Examples of the joining members 16 and 17 include a locking hole and a locking claw 16, a screw 17, and a clip. In FIG. 49, an end portion of a portion where the first bumper component 2a and the second bumper component 2b overlap is indicated by a broken line 2c.

  Here, according to the experiments and simulations of the inventors, when an object collides with an arbitrary place of the bumper cover 2, the bumper cover 2 has a first bumper part 2a and a second bumper part 2b in the surface direction. The boundary line 2d is deformed in the normal direction. Therefore, the piezoelectric sensor 20c is preferably attached so that the direction of the sensitivity direction D intersects the boundary line 2d between the first bumper component 2a and the second bumper component 2b. Thereby, the output of the piezoelectric sensor 20c can be increased.

  Further, according to the experiments and simulations of the inventors, when an object collides with an arbitrary place of the bumper cover 2, the bumper cover 2 joins the first bumper part 2a and the second bumper part 2b. , 17 as a starting point. That is, stress concentration occurs in the bumper cover 2 where the shape changes rapidly. Therefore, it is preferable that the piezoelectric sensor 20c is attached so that the direction of the sensitivity direction D faces the bonding members 16 and 17. Thereby, the output of the piezoelectric sensor 20c can be increased.

  Further, according to the experiments and simulations of the inventors, when an object collides with an arbitrary place of the bumper cover 2, the bumper cover 2 is deformed by the deformation of the first bumper part 2a as compared with the deformation amount of the second bumper part 2b. The amount tends to increase. For this reason, the piezoelectric sensor 20c is preferably attached to the first bumper component 2a. Thereby, the output of the piezoelectric sensor 20c can be increased.

  In addition, the attachment method of the piezoelectric sensor 20c should just be attached to the boundary vicinity part 18 of the 1st bumper component 2a and the 2nd bumper component 2b, and is not limited to the attachment method mentioned above. For example, the piezoelectric sensor 20 c may be attached to the second bumper component 2 b in the boundary vicinity 18. Further, for example, the piezoelectric sensor 20c may be attached such that the direction of the sensitivity direction D is along the boundary line 2d between the first bumper component 2a and the second bumper component 2b.

  Subsequently, the result of the effect confirmation test regarding the attachment position of the piezoelectric sensor 20c as the third deformation detection unit in the fifteenth embodiment will be described with reference again to the analysis diagram of FIG. 44 referred to in the fourteenth embodiment. .

  As shown by the arrow S10 in FIG. 44, in this analysis view, it can be seen that stress concentration occurs in the boundary vicinity portion 18 between the first bumper component 2a and the second bumper component 2b. Therefore, by attaching the piezoelectric sensor 20c to the boundary vicinity portion 18, the output of the piezoelectric sensor 20c can be increased.

  Further, as shown by an arrow S10 in FIG. 44, in this analysis diagram, the bumper cover 2 has a larger stress generated in the first bumper component 2a than the stress generated in the second bumper component 2b. Can be seen. Therefore, by attaching the piezoelectric sensor 20c to the boundary portion 18 between the first bumper component 2a and the second bumper component 2b and the first bumper component 2a, the output of the piezoelectric sensor 20c can be increased.

  The collision detection apparatus according to the fifteenth embodiment described above includes the piezoelectric sensor 20a as the first deformation detection unit, the piezoelectric sensor 20b as the second deformation detection unit, and the piezoelectric sensor 20c as the third deformation detection unit. It has. Thereby, when an object collides with various places of the bumper cover 2, the collision detection device detects the collision of the object by the signal output to the signal processing unit 30 from each piezoelectric sensor 20a, 20b, 20c. be able to.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims. Further, the above embodiments are not irrelevant to each other, and can be combined as appropriate unless the combination is clearly impossible. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. Further, in each of the above embodiments, when referring to the shape, positional relationship, etc. of the component, etc., the shape, unless otherwise specified and in principle limited to a specific shape, positional relationship, etc. It is not limited to the positional relationship or the like.

  In the first to fourth embodiments described above, the piezoelectric sensor is attached to the bumper cover at a position including the bent portion. In the fifth to sixth embodiments, the piezoelectric sensor is attached to the bumper cover at a position including the vicinity of the fixed portion. In the eighth to twelfth embodiments, the piezoelectric sensor is attached to the bumper cover at a position including the extension line. In the thirteenth and fourteenth embodiments, the piezoelectric sensor is inserted through a bolt for attaching the bumper cover to the vehicle body part. In the fifteenth embodiment, in addition to the piezoelectric sensor mounting method described in the first to fourth, thirteenth, and fourteenth embodiments, a piezoelectric element is provided in the vicinity of the boundary 18 between the first bumper component 2a and the second bumper component 2b. A sensor was attached. On the other hand, in other embodiments, the piezoelectric sensor may be attached to other positions in addition to the positions described in the first to fifteenth embodiments. In that case, by increasing the detection area of the piezoelectric sensor attached to the position described in the above embodiment to be larger than the detection area of the piezoelectric sensor attached to any other position, the number of piezoelectric sensors and wirings can be reduced and the configuration can be simplified. Can be.

  The bumper cover is not limited to the shape exemplified in the above-described embodiment, and various shapes, materials, and thicknesses can be employed. For example, the bumper cover may not include one or both of a fog lamp and a ventilation duct.

  In each embodiment mentioned above, the piezoelectric sensor was illustrated as a deformation | transformation detection part. On the other hand, in other embodiments, various sensors that can detect the deformation of the bumper cover, such as a strain gauge, an optical fiber, a pressure-sensitive rubber, and a capacitance sensor, are employed as the deformation detection unit. Is possible.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Bumper cover 14 Bolt 20 Piezoelectric sensor 30 Signal processing part 50 Object 62 Impactor 100 Car body 101 Car body part

Claims (16)

A collision detection device mounted on a vehicle (1) having a bumper cover (2) fixed by a bolt (14) to a vehicle body (100) or a vehicle body part (101) connected to the vehicle body,
A deformation detector (20) attached in a state of being inserted through the bolt and capable of detecting deformation of the bumper cover;
A collision detection apparatus comprising: a signal processing unit (30) that determines that an object (50, 62) has collided with the bumper cover based on a signal input from the deformation detection unit.   The collision detection device according to claim 1, wherein the deformation detection unit is inserted into the bolt while being sandwiched between the bumper cover and the vehicle body or the vehicle body part.   The collision detection device according to claim 1, wherein the deformation detection unit is inserted through the bolt in a state of being sandwiched between the head (141) of the bolt and the bumper cover.   The collision detection device according to claim 1, wherein the deformation detection unit is inserted into the bolt while being sandwiched between a nut (103) screwed into the bolt and the vehicle body or the vehicle body part. .   The collision detection device according to claim 1, wherein the deformation detection unit is configured in a direction in which a sensitivity direction (D) intersects an axis of the bolt.   The collision detection device according to claim 1, wherein the deformation detection unit is configured such that a sensitivity direction (D) is in a direction along an axis of the bolt. The deformation detection unit
A first detector (27) configured in a direction in which a sensitivity direction intersects the axis of the bolt;
The collision detection device according to claim 1, further comprising: a second detection unit configured to have a sensitivity direction along a direction along the axis of the bolt. The deformation detection unit
A piezoelectric element (22) for outputting according to the applied force;
The collision detection apparatus according to any one of claims 1 to 7, further comprising a first protection member (24) and a second protection member (25) provided respectively on one side and the other side in the thickness direction of the piezoelectric element.   The collision detection apparatus according to claim 8, wherein the first protection member and the second protection member are made of resin.   The deformation detection unit includes the bolt (14a) provided at a central portion in the vehicle width direction among the plurality of bolts (14, 14a) for fixing the vehicle body or the vehicle body part connected to the vehicle body and the bumper cover. The collision detection device according to any one of claims 1 to 9, wherein the collision detection device is attached in a state of being inserted through the bolt (14) provided at a position spaced apart from the bolt. The bumper cover is configured by joining a first bumper part (2a) provided at a position including a vehicle side surface and a second bumper part (2b) provided at the front of the vehicle by a joining member (16, 17). Is,
The first bumper component includes a front part (3) located in front of the vehicle, a side part (4) located on the side of the vehicle, and a bent part (5) having a smaller radius of curvature than the front part and the side part. Have
When the deformation detection unit attached in a state of being inserted through the bolt is a first deformation detection unit (20a),
The collision detection device includes:
A second deformation detector (20b) attached to the bent portion of the back surface of the bumper cover;
The third deformation detection part (20c) attached to the boundary vicinity part (18) as a vicinity part of the boundary between the first bumper part and the second bumper part, further comprising: The collision detection apparatus according to one. A collision detection device mounted on a vehicle (1) having the bumper cover having a fixing portion (8) for fixing the bumper cover to a vehicle body part around the bumper cover (2),
A deformation detection part (20) attached to a position including the vicinity (N) of the fixed part on the back surface of the bumper cover;
A collision detection apparatus comprising: a signal processing unit (30) that determines that an object (50) has collided with the bumper cover based on a signal input from the deformation detection unit.   The collision detection device according to claim 12, wherein the deformation detection unit is attached in the vicinity of the fixing unit disposed at an end portion in a longitudinal direction of the bumper cover.   The collision detection device according to claim 12 or 13, wherein the deformation detection unit is attached from the fixed unit to the vicinity of the fixed unit. The bumper cover includes a fastening member (14) for fastening the vehicle body part and the fixing portion around the bumper cover,
The deformation detection unit is a piezoelectric sensor having a piezoelectric element (22) and a film part (21) protecting the piezoelectric element, and the fastening member is inserted into a hole (23) provided in the film part. The collision detection device according to any one of claims 12 to 14, wherein the vehicle body part around the bumper cover and the fixing portion are fastened together.   The collision detection device according to claim 1, wherein the deformation detection unit is a piezoelectric sensor or a strain gauge.

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