JP6406079B2 - Vehicle collision detection device - Google Patents

Description

  The present invention relates to a vehicle collision detection device for detecting a collision with a pedestrian or the like of a vehicle.

  Conventionally, there is a vehicle including a pedestrian protection device for reducing an impact on a pedestrian when the pedestrian collides with the vehicle. In this vehicle, a bumper unit is provided with a collision detection device, and when this sensor detects that a pedestrian or the like has collided with the vehicle, the pedestrian protection device is activated to reduce the impact on the pedestrian. It has a configuration. This pedestrian protection device includes what is called a pop-up hood, for example. This pop-up hood raises the rear end of the engine hood when a vehicle collision is detected, increases the clearance (clearance) between the pedestrian and hard parts such as the engine, and uses that space to the pedestrian's head. It absorbs collision energy and reduces the impact on the head.

  In the vehicle collision detection device described above, a chamber member having a chamber space is disposed in front of a bumper reinforcement in the vehicle bumper, and the pressure in the chamber space is detected by a pressure sensor. There is something. With this configuration, when an object such as a pedestrian collides with the bumper (bumper cover), the chamber member is deformed along with the deformation of the bumper cover, and a pressure change is generated in the chamber space. The pressure sensor detects this change in pressure to detect an object collision. Some of such vehicle collision detection devices are provided with two pressure sensors in order to improve the collision detection accuracy of the pressure sensor and ensure redundancy.

JP 2012-96562 A

However, in the vehicle collision detection device having the above-described configuration, it is necessary to provide two pressure sensors, and there is a problem that the configuration is complicated and the cost is increased.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicle collision detection apparatus with improved collision detection accuracy with a simple configuration.

The invention of the vehicle collision detection device (1), which has been made to solve the above problems , is disposed in the vehicle bumper (8) so as to extend in the vehicle width direction on the vehicle front side of the bumper reinforcement (11). A detection tube member (2, 21, 22) having a hollow portion (2a, 21a, 22a) formed therein, and a pressure sensor (3, 31) for detecting the pressure in the hollow portion of the detection tube member The detection tube member is formed separately from the detection tube member, and is arranged so as to be deformable in accordance with the deformation of the detection tube member. The power supply means (7, 311) supplies power, and the detection tube member A plurality of conductive members (41a, 41b, 41c, 41d, 421a, 421b, 422a, 422b) that extend in the vehicle width direction and face each other at a predetermined interval in a direction orthogonal to the vehicle width direction. Voltage between at least two of said conductive member in contact with the deformation of the detecting tube member, current, electric resistance value, based on at least one of the change of the electrostatic capacitance, the detecting tube member The deformation sensor ( 41, 43 ) that detects the collision position of the object in the vehicle width direction of the bumper by detecting the deformation of the bumper, and the pressure detection result by the pressure sensor and the detection result by the deformation sensor exceed the respective threshold values The determination means (6 , S21, S22 ) for determining whether or not an object has collided with the bumper based on whether or not the bumper has reached , and the threshold value according to the collision position detected by the deformation sensor. And a threshold value changing means (6, S18) .
Further, the invention of the vehicle collision detection device (1) is arranged in the vehicle bumper (8) so as to extend in the vehicle width direction on the vehicle front side of the bumper reinforcement (11), and inside the hollow portion (2a). , 21a, 22a), a detection tube member (2, 21, 22), a pressure sensor (3, 31) for detecting the pressure in the hollow portion of the detection tube member, and a pressure-sensitive conductive elastomer And a conductive member (2b) which is integrally formed with the detection tube member and is arranged so as to be deformable along with the deformation of the detection tube member, and which is supplied with power from a power supply means (7, 311), and the conductive material. Based on a change in at least one of the voltage value, current value, electric resistance value, and capacitance of the member, the deformation of the tube member for detection is detected, so that the bumper can be disposed in the vehicle width direction. An object collides with the bumper based on whether or not the deformation sensor (41, 43) for detecting the collision position of the object, and the pressure detection result by the pressure sensor and the detection result by the deformation sensor exceed the respective threshold values. Determining means (6, S21, S22) for determining whether or not a collision has occurred, and threshold changing means (6, S18) for changing the threshold according to the collision position detected by the deformation sensor. It is characterized by having.

  According to this configuration, the determination unit determines that the object (pedestrian) has collided with the bumper based on the pressure detection result of the pressure sensor and the detection result of the deformation sensor that detects a physical quantity different from the pressure. Thus, it is possible to improve the accuracy of collision detection and ensure redundancy. In addition, since it is not necessary to provide a plurality of pressure sensors to ensure the redundancy of collision detection, the cost can be reduced. Furthermore, because of the configuration using different types of sensors including pressure sensors and deformation sensors, the risk of simultaneous failures such as manufacturing defects is reduced compared to configurations using multiple sensors of the same type to ensure redundancy. can do. In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is a diagram illustrating an overall configuration of a vehicle collision detection device according to a first embodiment of the present invention. It is an enlarged view of the bumper part of FIG. It is a block diagram which shows the logic circuit of a collision determination. It is sectional drawing of the bumper part of FIG. It is a figure which shows the effect | action of a conductive sensor. It is a figure which shows the characteristic of a conductive sensor. It is sectional drawing which shows the internal structure of a pressure sensor. It is a flowchart which shows the flow of a collision determination process. It is a figure which shows the outline of the deformation | transformation sensor of the collision detection apparatus for vehicles in 2nd Embodiment. It is a figure which shows the effect | action of the deformation | transformation sensor of FIG. It is a figure which shows the relationship between a collision position and the threshold value of a collision determination. It is a block diagram which shows the logic circuit of a collision determination. It is a flowchart which shows the flow of a collision determination process. It is a figure which shows the outline of the collision detection apparatus for vehicles in 3rd Embodiment. It is a figure which shows the effect | action of the deformation | transformation sensor of FIG. It is a figure which shows the characteristic of the deformation | transformation sensor of FIG. It is a figure which shows the effect | action of the deformation | transformation sensor in the modification which provided the power supply part inside the pressure sensor. FIG. 18 is a view corresponding to FIG. 17 in another modification in which a power supply unit is provided inside the pressure sensor. It is a figure which shows the outline of the collision detection apparatus for vehicles in 4th Embodiment. It is sectional drawing of the bumper part of 4th Embodiment. It is sectional drawing of the electroconductivity sensor of 4th Embodiment. It is a schematic diagram which shows the electrical connection relationship of a conductive sensor. It is sectional drawing which shows the connection part of the pressure sensor of 4th Embodiment, and the tube member for a detection. It is a block diagram which shows the electric constitution of the collision detection apparatus for vehicles. It is a flowchart which shows the flow of an abnormality determination process. It is a schematic diagram which shows the mode of the collision generation | occurrence | production in the tube member for a detection. It is a schematic diagram which shows the mode of abnormality generation | occurrence | production in the tube member for a detection. It is a figure which shows the effect | action of the deformation | transformation sensor in the modification which provided the power supply part inside the pressure sensor. It is sectional drawing which shows the modification of the arrangement structure of the tube member for a detection. It is sectional drawing which shows the other modification of the arrangement structure of the tube member for a detection.

[First Embodiment]
Hereinafter, a vehicle collision detection apparatus according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 3, the vehicle collision detection apparatus 1 of the present embodiment includes a hollow detection tube member 2, a pressure sensor 3, a deformation sensor 4, a speed sensor 5, and a collision detection ECU 6 (corresponding to a determination unit). ), A power supply unit 7 (corresponding to power supply means), and the like. This vehicle collision detection device 1 detects a collision of an object (such as a pedestrian) with a bumper 8 provided in front of the vehicle. As shown in FIG. 4, the bumper 8 is mainly composed of a bumper cover 9, a bumper sorber 10, and a bumper reinforcement 11.

  The detection tube member 2 has a hollow portion 2a formed therein and extends in the vehicle width direction (vehicle left-right direction). The front surface 11a of the bumper reinforcement 11 in the vehicle bumper 8 (the vehicle front side) ) And on the vehicle rear side of the bumper sorber 10 (see FIG. 4). One end (left end) of the detection tube member 2 is connected to the pressure sensor 3 and the other end (right end) is closed.

  As shown in FIG. 5, the tube member for detection 2 is made of a pressure-sensitive conductive elastomer obtained by mixing a conductive material 2b (corresponding to a conductive member), which is a conductive particle, with an insulating synthetic rubber. For example, ethylene propylene rubber (EPDM) or the like is used as the synthetic rubber, and copper or the like is used as the conductive material 2b. This pressure-sensitive conductive elastomer has a characteristic that the electrical resistance value of the conductive material 2b changes with a change (strain) in pressure applied to the synthetic rubber. Specifically, when the pressure-sensitive conductive elastomer is deformed, the electric resistance value of the conductive material 2b is decreased, and when the deformation is eliminated, the electric resistance value of the conductive material 2b is increased (see FIG. 6). In the present embodiment, the detection tube member 2 itself is used as a part of the deformation sensor 4 by utilizing the change in the electric resistance value of the pressure-sensitive conductive elastomer.

  Further, the detection tube member 2 has a substantially square cross-sectional shape, and the length and width (corresponding to the outer diameter in the case of a circular tube) is, for example, about 10 mm. In this embodiment, the cross-sectional shape of the tube member for detection 2 is made into a substantially square shape, and the fall of the collision detection precision accompanying a temperature change is suppressed. That is, by making the cross-sectional shape of the detection tube member 2 substantially rectangular, for example, compared to the case where the detection tube member 2 having a circular cross-sectional shape is used, the collision portion of the detection tube member 2 (the bumper cover 9 at the time of collision). The portion other than the portion that is deformed along with the deformation is easily swelled by the pressure increase in the detection tube member 2. Since the expansion amount of the portion other than the collision portion in the detection tube member 2 increases at a high temperature and decreases at a low temperature, the detection tube member 2 has a low sensitivity at a high temperature with respect to the deformation amount of the same collision portion. High sensitivity at low temperatures. On the other hand, the amount of deformation of the collision portion of the tube member for detection 2 is determined by the characteristics of the bumper sorber 10, and the amount of deformation is large at high temperatures and the amount of deformation is small at low temperatures. Therefore, the deformation amount of the collision part that changes with temperature can be offset by the action of the parts other than the collision part swelling. Thereby, it is possible to suppress an increase in the output of the pressure sensor 3 as the temperature increases, and to suppress a decrease in collision detection accuracy accompanying a temperature change.

  As shown in FIGS. 1 and 2, the pressure sensor 3 is disposed on the vehicle rear side of the front surface 11 a of the bumper reinforcement 11. Specifically, one pressure sensor 3 is installed on the rear surface 11b of the left end portion of the bumper reinforcement 11, and is fixed and attached by fastening a bolt (not shown). The pressure sensor 3 is connected to one end (left end portion in FIG. 2) of the detection tube member 2 and configured to detect the pressure in the detection tube member 2. Specifically, the pressure sensor 3 is a sensor device that detects a change in pressure of gas, and detects a change in pressure of air in the detection tube member 2. As shown in FIG. 1, the pressure sensor 3 is electrically connected to the collision detection ECU 6 through a transmission line, and outputs a signal proportional to the pressure to the collision detection ECU 6.

  Further, as shown in FIG. 7, the pressure sensor 3 includes a main body portion 30, a sensor portion 31, a pressure introduction pipe 32, and a connector portion 33. The main body 30 is a box-shaped case for housing the sensor unit 31. The sensor unit 31 is made of a substrate or the like on which a sensor element for detecting pressure is provided. The pressure introduction tube 32 is a substantially cylindrical tube that introduces the pressure of the detection tube member 2 into the sensor unit 31, and is inserted into the detection tube member 2 from the main body unit 30. The sensor unit 31 detects a pressure change of the detection tube member 2 through the pressure introduction pipe 32. The sensor unit 31 is electrically connected to a connector 34 provided in the connector unit 33, and transmits a signal proportional to pressure to the collision detection ECU 6 via the connector 34 and a transmission line (see FIG. 1).

  The deformation sensor 4 is a conductive sensor including a conductive material 2b, a conduction path 4a (corresponding to a conductive member), a resistance measurement unit (not shown), a lead wire, and the like (see the right diagram in FIG. 5). The conductive material 2b and the conduction path 4a are arranged so as to be deformable in accordance with the deformation of the detection tube member 2, and are integrally formed with the detection tube member 2.

  The conduction path 4a is made of a pressure-sensitive conductive elastomer, and is formed by contact of the conductive material 2b when a load is applied to the tube member 2 for detection. The resistance measurement unit detects a change in the electrical resistance value accompanying the deformation of the detection tube member 2. That is, the detection tube member 2 is in a state in which the conductive material 2b is not in contact with each other in a state where the conductive material 2b is substantially evenly distributed and no conduction path 4a is formed when no pressure is applied (no deformation). (See the left figure in FIG. 5). When the load F is small, the electric resistance value is high as shown in FIG. On the other hand, when the load F is increased by pressurization, the conduction path 4a is formed, and the conduction path 4a increases three-dimensionally, so that the electrical resistance value becomes a small value. When the load F is eliminated, the conductive material 2b returns to the non-contact state again, and the electrical resistance value increases.

  The deformation sensor 4 (conductive sensor) is turned on when the electric resistance value detected by the resistance measuring unit is smaller than a predetermined threshold value, and is turned off when the electric resistance value is equal to or larger than the predetermined threshold value. It is configured. The deformation sensor 4 is electrically connected to the collision detection ECU 6 via a transmission line, and outputs an ON signal or an OFF signal to the collision detection ECU 6 (see FIG. 3).

  The speed sensor 5 is a sensor for detecting the speed of the vehicle. The speed sensor 5 outputs the detected vehicle speed as a vehicle speed signal to the collision detection ECU 6 via a transmission line.

  The collision detection ECU (Electronic Control Unit) 6 is mainly composed of a CPU, and controls the overall operation of the vehicle collision detection device 1. The pressure sensor 3, the deformation sensor 4, the speed sensor 5, and the pedestrian protection device Each of 12 is electrically connected (see FIG. 3). The collision detection ECU 6 receives a pressure signal from the pressure sensor 3, an electric resistance value signal from the deformation sensor 4, and the like. In the present embodiment, the collision detection ECU 6 performs the main determination based on the pressure detection result by the pressure sensor 3 and performs the safing determination based on the electric resistance value detection result by the deformation sensor 4. The collision detection ECU 6 performs the main determination and the safing determination using the AND circuit of the logic circuit, and then performs the vehicle speed determination based on the speed detection result by the speed sensor 5.

  The collision detection ECU 6 detects a collision of a pedestrian (object) to the bumper 8 by executing a collision determination process described later including each determination described above. When the collision detection ECU 6 determines that a pedestrian has collided with the bumper 8, the collision detection ECU 6 operates the pedestrian protection device 12.

  The power supply unit 7 supplies power to the deformation sensor 4 (the conductive material 2b of the detection tube member 2). Specifically, a predetermined DC power supply voltage is applied over the entire vehicle width direction from one end to the other end of the detection tube member 2.

  The bumper 8 is for reducing an impact at the time of a vehicle collision, and includes a bumper cover 9, a bumper sorber 10, a bumper reinforcement 11, and the like. The bumper cover 9 is a resin member such as polypropylene provided so as to cover the components of the bumper 8. The bumper cover 9 constitutes the appearance of the bumper 8 and at the same time constitutes a part of the appearance of the entire vehicle.

  As shown in FIG. 4, the bumper sorber 10 is provided on the front surface 11 a of the bumper reinforcement 11 and is disposed so as to surround the detection tube member 2. The bumper sorber 10 is a member having an impact absorbing function in the bumper 8 and is made of, for example, foamed polypropylene.

  The bumper reinforcement 11 is a rigid member made of metal, such as aluminum, disposed in the bumper cover 9 and extending in the vehicle width direction. As shown in FIG. A hollow member having a letter-shaped cross section. The bumper reinforcement 11 has a vehicle front side surface (front surface 11a) and a vehicle rear side surface (rear surface 11b). As shown in FIGS. 1 and 2, the bumper reinforcement 11 is attached to the front end of a side member 13 that is a pair of metal members extending in the vehicle front-rear direction.

  Usually, in a vehicle collision accident, there are many cases where the vehicle collides with a pedestrian or a vehicle existing in the traveling direction of the vehicle (front of the vehicle). For this reason, in this embodiment, the pressure sensor 3 is disposed on the rear surface 11b of the bumper reinforcement 11, and an impact (external force) due to a collision with a pedestrian or vehicle in front of the vehicle is provided in front of the vehicle. Direct transmission from the bumper cover 9 or the like to the pressure sensor 3 is protected by the presence of the bumper reinforcement 11.

  As the pedestrian protection device 12, for example, a pop-up hood is used. This pop-up hood instantly raises the rear end of the engine hood after a vehicle collision is detected, increases the clearance (clearance) between the pedestrian and hard parts such as the engine, and uses that space to make the pedestrian's head The impact energy on the pedestrian is absorbed and the impact on the pedestrian's head is reduced. Instead of the pop-up hood, a cowl airbag or the like that cushions a pedestrian's impact by deploying an airbag from above the engine hood outside the vehicle body to the lower part of the front window may be used.

  Here, the operation | movement at the time of the collision of the collision detection apparatus 1 for vehicles in this embodiment is demonstrated. When an object such as a pedestrian collides with the front of the vehicle, the bumper cover 9 of the bumper 8 is deformed by an impact caused by the collision with the pedestrian. Subsequently, the bumper sorber 10 is deformed while absorbing an impact, and at the same time, the detection tube member 2 is also deformed. At this time, the pressure in the detection tube member 2 rises rapidly, and this pressure change is transmitted to the pressure sensor 3.

  Further, as the detection tube member 2 is deformed, the contacted conductive material 2b is increased, whereby a conduction path 4a is formed in the deformation sensor 4 and the electric resistance value is reduced. This change in the electrical resistance value is measured by a resistance measuring unit electrically connected to the detection tube member 2.

  Next, the flow of the collision determination process by the vehicle collision detection apparatus 1 having the above configuration will be described with reference to the flowchart of FIG. However, this flowchart is an example, and the present invention is not limited to this. In the collision determination process of the present embodiment, it is determined whether or not a collision with a pedestrian that requires the operation of the pedestrian protection device 12 has occurred based on the detection results of the pressure sensor 3 and the deformation sensor 4.

  First, in the flowchart of FIG. 8, the collision detection ECU 6 of the vehicle collision detection device 1 acquires the vehicle speed based on the output from the speed sensor 5 (step S <b> 1, the following steps are omitted), and the vehicle speed is within a predetermined operating range. Is determined (S2). The operating range of the vehicle speed is, for example, a range of 25 km to 55 km / h. This operating range is due to the fact that the speed at which the pedestrian protection function of the pedestrian protection device 12 acts effectively is determined by conditions such as the vehicle shape.

When the vehicle speed is not within the operating range (S2: No), the process returns to S1, and when the vehicle speed is within the operating range (S2: Yes), the collision detection ECU 6 acquires the detection value of the pressure sensor 3 (S3 ), The effective mass is calculated (S4). Here, the “effective mass” refers to a mass that is calculated from the detected value of the pressure sensor 3 at the time of collision using the relationship between momentum and impulse. When a collision between a vehicle and an object occurs, the value of the detected pressure sensor 3 is different for a collision object having a mass different from that of a pedestrian. For this reason, by setting a threshold value between the effective mass of the human body and the mass of another assumed collision object, it is possible to classify the types of the collision object. This effective mass is calculated by dividing the interval integral value at a predetermined time of the pressure value detected by the pressure sensor 3 by the vehicle speed, as shown in the following equation.
M = (∫P (t) dt) / V (Expression 1)

Here, M is an effective mass, P is a value detected by the pressure sensor 3 at a predetermined time, t is a predetermined time (for example, several ms to several tens of ms), and V is a vehicle speed at the time of collision. As another method for calculating the effective mass, it is possible to calculate using an equation E = 1/2 · MV ² representing the kinetic energy E of the collided object. In this case, the effective mass is calculated by M = 2 · E / V ² .

  Next, the collision detection ECU 6 determines whether the calculated effective mass is equal to or greater than a predetermined threshold (S5). When the effective mass is less than the threshold value (S5: No), the process returns to S1, and when the effective mass is equal to or greater than the threshold value (S5: Yes), the collision detection ECU 6 acquires the detection value of the deformation sensor 4 (S6) The sensor 4 determines whether or not the ON operation has been performed (S7).

  When the deformation sensor 4 is turned on (S7: Yes), the collision detection ECU 6 determines that a collision between the vehicle and the pedestrian has occurred (S8), and generates a control signal for operating the pedestrian protection device 12. Then, the pedestrian protection device 12 is operated (S9). Thereby, the impact to the pedestrian due to the collision between the vehicle and the pedestrian is reduced. When the deformation sensor 4 is in the OFF operation (S7: No), the process returns to S1.

  As described above, the vehicle collision detection device 1 according to the first embodiment is disposed in the vehicle bumper 8 so as to extend in the vehicle width direction on the front surface 11a (vehicle front side) of the bumper reinforcement 11; A detection tube member 2 having a hollow portion 2a formed therein, a pressure sensor 3 for detecting the pressure in the hollow portion 2a of the detection tube member 2, and a deformation sensor 4 for detecting deformation of the detection tube member 2; And a collision detection ECU 6 which is a determination means 6 for determining that an object (pedestrian) has collided with the bumper 8 based on the pressure detection result by the pressure sensor 3 and the detection result by the deformation sensor 4. To do.

  According to this configuration, an object (pedestrian) has collided with the bumper 8 by the collision detection ECU 6 based on the pressure detection result of the pressure sensor 3 and the detection result of the deformation sensor 4 that detects a physical quantity different from the pressure. Therefore, it is possible to improve the accuracy of collision detection and ensure redundancy. In addition, since it is not necessary to provide a plurality of pressure sensors 3 to ensure the redundancy of collision detection, the cost can be reduced. Furthermore, because of the configuration using a plurality of different types of sensors including the pressure sensor 3 and the deformation sensor 4, there is a risk of simultaneous failure such as a manufacturing failure compared to a configuration using a plurality of sensors of the same type for ensuring redundancy. Can be reduced.

  Further, since the bumper reinforcement 11 that is a rigid member is provided on the vehicle rear side of the detection tube member 2, it is possible to prevent the detection tube member 2 from being bent toward the vehicle rear side in the event of a collision. The collision detection performance of the vehicle collision detection apparatus 1 can be ensured over the entire width direction.

  The pressure sensor 3 is a main sensor for collision detection, and the deformation sensor 4 is a redundant safing sensor for the main sensor. According to this configuration, for example, even when the pressure sensor 3 that is a main sensor for collision detection outputs an abnormal output due to a failure, the output of the deformation sensor 4 that is a safing sensor is used as a safing signal. It is possible to prevent the collision determination. In addition, instead of providing another pressure sensor 3 of the same type as the main sensor as a redundant safing sensor, a deformation sensor 4 that detects a physical quantity different from the pressure sensor 3 is used as a safing sensor. When the sensor 3 has a manufacturing defect or the like, it is possible to reliably prevent a problem that the main sensor and the safing sensor fail at the same time.

  In addition, it includes a conductive material 2b disposed so as to be deformable in accordance with the deformation of the detection tube member 2, and a power supply unit 7 that supplies power to the conductive material 2b. The deformation sensor 4 includes an electric power of the conductive material 2b. The deformation of the tube member for detection 2 is detected based on detecting a change in resistance value.

  According to this configuration, the deformation sensor 4 can detect the deformation of the detection tube member 2 by using the conductive material 2b disposed so as to be deformable along with the deformation of the detection tube member 2, and with a simple configuration. The collision detection accuracy of the vehicle collision detection apparatus 1 can be improved.

  Further, the conductive material 2b and the conduction path 4a, which are conductive members, are formed integrally with the detection tube member 2. According to this configuration, the conductive material 2b and the conduction path 4a which are a part of the configuration of the deformation sensor 4 are integrally formed and integrated with the detection tube member 2, so that it is not necessary to provide a separate sensor. The collision detection accuracy of the vehicle collision detection apparatus 1 can be improved with a simpler configuration.

  Specifically, the detection tube member 2 and the conductive material 2b are integrally formed of a pressure-sensitive conductive material, and the pressure-sensitive conductive material is a pressure-sensitive conductive elastomer. According to this configuration, by using the pressure-sensitive conductive elastomer in which the conduction path 4a is formed by applying a load to the detection tube member 2 and the conductive material 2b, the safing determination by the deformation sensor 4 over the entire vehicle width direction. Can be performed.

  The pressure sensor 3 is fixed to the rear surface 11b of the bumper reinforcement 11. According to this configuration, since the pressure sensor 3 is fixed to the rear surface 11b (rear side of the vehicle) of the bumper reinforcement 11, even if an object such as a pedestrian collides with the vicinity of the left end of the bumper 8, the bumper The impact 11 is reduced by the reinforcement 11, and the impact from the bumper cover 9 is not directly transmitted to the pressure sensor 3. For this reason, it is possible to prevent an external force from being applied to the pressure sensor 3 due to the deformation of the bumper cover 9 and the pressure sensor 3 to be damaged by the external force. Thereby, while being able to improve the tolerance of the collision detection apparatus 1 for vehicles, the reliability of the collision detection by the collision detection apparatus 1 for vehicles can be improved.

  Furthermore, since the pressure sensor 3 is fixed to the rear surface 11b of the bumper reinforcement 11 by fastening bolts, the pressure sensor 3 can be securely fixed to the bumper reinforcement 11 and the pressure sensor 3 is externally applied at the time of a collision. Can be prevented from coming off or being damaged.

  Further, the detection tube member 2 has a substantially rectangular cross-sectional shape. According to this structure, the fall of the collision detection precision accompanying a temperature change can be suppressed by making the cross-sectional shape of the tube member 2 for detection into a substantially square shape. That is, when the cross-sectional shape of the detection tube member 2 is a square, for example, the detection tube member 2 other than the collision portion of the detection tube member 2 is used as compared with the case where the detection tube member 2 having a circular cross-sectional shape is used. It can be easily swelled by the pressure increase in 2. Since the expansion amount of the portion other than the collision portion becomes large at high temperature and becomes small at low temperature, the detection tube member 2 has low sensitivity at high temperature and high sensitivity at low temperature with respect to the deformation amount of the same collision portion. . On the other hand, the deformation amount of the collision portion is determined by the characteristics of the bumper sorber 10, and the deformation amount is large at a high temperature, and the deformation amount is small at a low temperature. Therefore, the deformation amount of the collision part that changes with temperature can be offset by the action of the parts other than the collision part swelling. Thereby, it is possible to suppress an increase in the output of the pressure sensor 3 as the temperature increases, and to suppress a decrease in collision detection accuracy accompanying a temperature change.

  In the first embodiment described above, the deformation sensor 4 detects the electrical resistance value by the resistance measuring unit and performs the ON / OFF operation. However, the present invention is not limited to this, and the current value is detected and the ON / OFF operation is performed. An OFF operation may be performed. In this case, the deformation sensor 4 may be configured such that a current measuring unit is provided, and the OFF sensor is operated when the current value is less than the predetermined threshold, and the ON sensor is operated when the current value is larger than the predetermined threshold.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. 9 to 13, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described. In the second embodiment, instead of the detection tube member 2 made of a pressure-sensitive conductive elastomer, the detection tube member 21 made of only synthetic rubber (ethylene propylene rubber or the like) and having a hollow portion 21a formed therein. Is used. Further, a line sensor 41 is used instead of the deformation sensor 4 as the deformation sensor. The line sensor 41 is provided on the inner peripheral surface of the detection tube member 21 so as to extend in the vehicle width direction (the vehicle left-right direction), and is opposed to each other with a predetermined distance therebetween, and two conductive lines 41a and 41b (conductive plates). It is comprised.

  A plurality of pairs of contactors 41c and 41d are arranged on the two conductive lines 41a and 41b side by side at a predetermined interval in the vehicle width direction. Specifically, a plurality of contactors 41c provided on the conductive line 41a on the bumper sorber 10 side and a contactor 41d provided on the conductive line 41b on the bumper reinforcement 11 side are arranged to face each other. The line sensor 41 detects a collision of an object by detecting that the pair of contactors 41c and 41d are in contact with the deformation of the detection tube member 21. In the second embodiment, the conductive lines 41a and 41b and the contactors 41c and 41d correspond to conductive members.

  In FIG. 9, the conductive line 41a is a resistance line having a specific resistance Ra, and the conductive line 41b is a resistance line having a specific resistance Rb. The specific resistance means an electric resistance value per unit distance. A power supply unit 7 is connected to the conductive line 41 a via a lead wire, and a DC power supply voltage V is supplied from the power supply unit 7. One end of the conductive line 41b is connected to a lead wire and grounded via a resistance element 41e having a resistance value Rc. The other end of the conductive line 41b is connected to a lead wire and grounded via a resistance element 41f having a resistance value Rc.

  And the voltage detection part 411 which detects the voltage value V1 of the resistance element 41e is connected to the both ends of the resistance element 41e. Further, a voltage detector 412 that detects a voltage drop V2 of the resistor element 41f is connected to both ends of the resistor element 41f.

  The line sensor 41 detects an object in the vehicle width direction of the bumper 8 by detecting a voltage value change (voltage drop) between the two conductive lines 41a and 41b that are in contact with each other by the voltage detection units 411 and 412. The collision position of (pedestrian) is detected. The line sensor 41 is connected to the collision detection ECU 6 via a transmission line, and outputs a collision detection signal to the collision detection ECU 6. The contactors 41c and 41d are separated from each other when the load is lost due to the elastic force of the detection tube member 21.

  As shown in FIG. 12, the collision detection ECU 6 performs main determination based on the pressure detection result by the pressure sensor 3 and performs safing determination based on the voltage value detection result by the line sensor 41. Further, the collision detection ECU 6 performs vehicle speed determination based on the speed detection result by the speed sensor 5.

  In the second embodiment, the collision detection ECU 6 specifies the pedestrian collision position based on the detection result of the line sensor 41, sets (changes) the threshold for main determination and safing determination, and then sets the main Perform judgment and safing judgment. That is, the threshold used for the main determination and the safing determination is set according to the pedestrian collision position detected by the line sensor 41. The collision detection ECU 6 determines that a pedestrian has collided with the bumper 8 based on the detection results of the pressure sensor 3 and the line sensor 41 being equal to or greater than the respective threshold values.

  Next, the flow of the collision determination process by the vehicle collision detection apparatus 1 of the second embodiment will be described with reference to the flowchart of FIG. However, this flowchart is an example, and the present invention is not limited to this. In the collision determination process of the second embodiment, it is determined whether or not a collision with a pedestrian that requires the operation of the pedestrian protection device 12 has occurred based on the detection results of the pressure sensor 3 and the deformation sensor 41. At the same time, the collision position is specified.

  First, in the flowchart of FIG. 13, the collision detection ECU 6 of the vehicle collision detection device 1 acquires the vehicle speed based on the output from the speed sensor 5 as in the first embodiment (step S11), and the vehicle speed is predetermined. It is determined whether it is within the operating range (S12).

  When the vehicle speed is not within the operating range (S12: No), the process returns to S11. When the vehicle speed is within the operating range (S12: Yes), the collision detection ECU 6 acquires the detection value of the pressure sensor 3 (S13), The effective mass is calculated (S14). The effective mass is calculated from (Equation 1), as in the first embodiment. Subsequently, the detection value of the line sensor is acquired (S15), and the collision position of the pedestrian is calculated (S16). Hereinafter, a method for calculating the collision position will be described.

  When the bumper cover 9 of the bumper 8 is deformed due to the collision between the vehicle and the pedestrian, the bumper sorber 10 is deformed while absorbing the impact, and the detection tube member 21 is also deformed. At this time, of the two conductive lines 41a and 41b disposed in the detection tube member 21, the collision part of the conductive line 41a on the bumper sorber 10 side is deformed, and the contactor 41c of the conductive line 41a and the contactor 41c The contactor 41d of the opposing conductive line 41b comes into contact (see the lower diagram of FIG. 10). When the contactors 41c and 41d (conductive lines 41a and 41b) are in contact with each other, the electric resistance value between the conductive lines 41a and 41b is close to 0, and the conductive lines 41a and 41b are short-circuited.

Here, as shown in FIG. 9, let X be the distance from the right end of the conductive line 41a to the pedestrian's collision position (part deformed by the collision). Further, the distance from the left end of the conductive line 41a to the pedestrian collision position is 1-X. In this case, the resistance value from the right end of the conductive line 41a to the collision position is X · Ra, and the resistance value from the left end of the conductive line 41a to the collision position is (1−X) · Ra. Further, the resistance value from the right end portion of the conductive line 41b to the collision position is X · Rb, and the resistance value from the left end portion of the conductive line 41b to the collision position is (1-X) · Rb. From these relationships, the distance X can be calculated by the following equation using the voltage value V1 at the resistance element 41e, the voltage value V2 at the resistance element 41f, and the resistance values Rb and Rc.
X = {(Rb + Rc) · V2−Rc · V1} / {(V1 + V2) · Rb} (Formula 2)
Thus, after calculating the collision position of the pedestrian, the collision detection ECU 6 sets the threshold of the effective mass (S17) and sets the threshold of the line sensor 41 (S18).

  As shown in FIG. 11, the ON requirement and the OFF requirement for collision determination differ depending on the position in the vehicle width direction of the bumper 8 on which the object (pedestrian) has collided. In the example shown in FIG. 11, the value of the effective mass is larger in the ON requirement on the vehicle center side than the ON requirement on the vehicle end side, that is, the threshold value on the vehicle end side is It is smaller than the threshold value on the center side. This is because the vehicle end side (corner portion) has a structure that is inclined with respect to the vehicle width direction, so the pressure is higher than the portion that is flat with respect to the vehicle width direction on the vehicle center side. This is based on the fact that the output from the sensor 3 is reduced. Also in the line sensor 41, the threshold value on the vehicle end side is set smaller than the threshold value on the vehicle center side. This is because the contact state of the contactors 41c and 41d (conductive lines 41a and 41b) at the time of the collision is weaker on the vehicle end side than on the vehicle center side, so that the output of the line sensor 41 is reduced. doing. Therefore, in S17 and S18, the effective mass and the threshold value of the line sensor 41 are changed according to the collision position of the pedestrian.

  The ON requirement assumes a case where a child weighing about 7 kg collides with a vehicle traveling at a speed of 25 km / h. The OFF requirement assumes a case where the vehicle collides with a roadside marker installed on the road. Since the mass (weight) is different between the human body (pedestrian) and the roadside marker, the detected value of the pressure sensor 3 and the detected value of the line sensor 41 are different between the human body and the other objects, and this difference is determined as a collision object. It is used for judgment.

  Next, the collision detection ECU 6 determines whether or not the effective mass calculated in S14 is greater than or equal to the threshold set in S17 (S19). When the effective mass is less than the threshold value (S19: No), the process returns to S11. When the effective mass is equal to or greater than the threshold value (S19: Yes), the collision detection ECU 6 acquires the detection value of the line sensor 41 (S20). It is determined whether or not the detected value 41 is equal to or greater than the threshold set in S18 (S21). Here, the detection value of the line sensor 41 is a voltage value detected by the voltage detection units 411 and 412.

  When the detection value of the line sensor 41 is equal to or greater than the threshold value (S21: Yes), the collision detection ECU 6 determines that a collision between the vehicle and the pedestrian has occurred (S22), and activates the pedestrian protection device 12. A control signal is output and the pedestrian protection apparatus 12 is operated (S23). Thereby, the impact to the pedestrian due to the collision between the vehicle and the pedestrian is reduced. In addition, when the detection value of the line sensor 41 is less than a threshold value (S21: No), it returns to S11.

  In the vehicle collision detection apparatus 1 of the second embodiment described above, a plurality of conductive members (conductive lines 41a and 41b and contactors 41c and 41d) are arranged in the vehicle width direction along the detection tube member 2, and the vehicle The line sensor 41 as a deformation sensor has a plurality of conductive lines 41a and 41b that extend in the width direction and face each other with a predetermined interval. The two line lines 41a and 41b are deformed as the detection tube member 2 is deformed. It is characterized by detecting contact.

  According to this configuration, the same effect as that of the first embodiment can be obtained. That is, by determining that the pedestrian has collided with the bumper 8 by the collision detection ECU 6 based on the pressure detection result of the pressure sensor 3 and the detection result of the line sensor 41 that detects a physical quantity different from the pressure, the vehicle And collision detection accuracy with a pedestrian can be improved. Further, since a plurality of conductive members (conductive lines 41a and 41b and contactors 41c and 41d) are arranged in the vehicle width direction along the detection tube member 2, a collision in the vehicle width direction of the line sensor 41 which is a safing sensor. A sufficient detection range can be secured.

  The conductive members (conductive lines 41 a and 41 b and contactors 41 c and 41 d) are formed separately from the detection tube member 21. According to this configuration, the line sensor 41 can be easily configured by adding the conductive lines 41a and 41b and the contactors 41c and 41d to the detection tube member 21, so that the vehicle collision detection can be performed by a simple manufacturing process. The collision detection accuracy of the device 1 can be improved.

  Further, the line sensor 41 detects an object in the vehicle width direction of the bumper 8 by detecting a change in voltage value and electric resistance value between the two conductive lines 41a and 41b that are in contact with the deformation of the detection tube member 21. The collision position of (pedestrian) is detected.

  According to this configuration, walking is performed with a simple configuration by detecting changes in the voltage value and electrical resistance value between the conductive lines 41a and 41b due to a collision using the line sensor 41 having the two conductive lines 41a and 41b. A person's collision position can be accurately detected.

  Further, the collision detection ECU 6 as the determination means determines that an object (pedestrian) has collided with the bumper 8 based on the detection results of the pressure sensor 3 and the line sensor 41 being equal to or greater than the respective threshold values. The threshold value is set according to the collision position of the pedestrian detected by the line sensor 41.

  According to this configuration, the threshold values of the pressure sensor 3 and the line sensor 41 are set according to the collision position of the pedestrian detected by the line sensor 41. For example, the output values of the pressure sensor 3 and the line sensor 41 By changing the threshold values between the vehicle center side and the vehicle end side, the collision detection accuracy can be effectively improved, and the bumper 8 can more accurately detect the collision of the pedestrian in the entire vehicle width direction. It can be carried out.

  In the second embodiment described above, the threshold value is changed between the vehicle center side and the vehicle end side, but the present invention is not limited to this. For example, you may set the threshold value in the design part of a vehicle center part small. This is based on the assumption that the output of the pressure sensor 3 and the deformation sensor 41 is smaller because the structure of the design at the center of the vehicle front end is harder than the other parts.

  A capacitor may be connected to the lead wire on the conductive line 41b side instead of the resistance elements 41e and 41f. In this case, the capacitance of the capacitor changes in accordance with the contact between the first conductive member 421b and the second conductive member 422b due to the deformation of the detection tube member 21 at the time of collision. A capacitance sensor that detects the change in capacitance may be used as a deformation sensor. Also by this capacitance sensor, it is possible to specify the collision position by providing a discrimination circuit for discriminating the positions of the contactors 41c and 41d in contact with each other.

  In the second embodiment, the case where two conductive lines are provided has been described. However, the present invention is not limited to this, and the present invention can be applied to a case where three or more conductive lines are provided.

  Moreover, although the line sensor 41 is configured to include the two conductive lines 41a and 41b, the present invention is not limited to this. In addition, it is possible to detect the collision position of an object (pedestrian) by using, for example, an optical fiber instead of the conductive line.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. 14 to 16, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts will be described. In the third embodiment, as in the second embodiment, a detection tube member 21 made of only synthetic rubber is used. Further, as a deformation sensor, a load sensor 42 shown in FIG. 14 is used instead of the deformation sensor 4 of the first embodiment.

  As shown in FIG. 14, the load sensor 42 includes a first conductor 421a and a first conductive member 421b disposed on the front side of the vehicle, and a second conductor 422a and a second conductive member 422b disposed on the vehicle rear side. , An output detection resistor 42c, a voltage detection unit 42d, and the like. The first conductive wire 421a, the first conductive member 421b, the second conductive wire 422a, and the second conductive member 422b are made of a conductive member and correspond to the conductive member of the present invention. The conductive members (the first conducting wire 421a, the first conducting member 421b, the second conducting wire 422a, and the second conducting member 422b) extend in the vehicle width direction (the vehicle left-right direction) along the inner peripheral surface of the detection tube member 21. Is provided.

  The first conducting wire 421a and the first conductive member 421b are arranged side by side in the vehicle up-down direction by five on the vehicle front side in the detection tube member 21. Further, five second conductive wires 422a and second conductive members 422b are arranged side by side in the vehicle vertical direction on the vehicle rear side in the detection tube member 21.

  The first conducting wire 421a is made of a copper wire, and the outer periphery is covered with a first conductive member 421b. Moreover, the 2nd conducting wire 422a consists of copper wires, and the outer periphery is coat | covered with the 2nd electrically-conductive member 422b. The first conducting wire 421a and the second conducting wire 422a are arranged in parallel to each other, and are arranged so as to extend in the vehicle width direction (vehicle left-right direction) of the detection tube member 21. The first conductive member 421b and the second conductive member 422b are made of conductive rubber and have a substantially square cross section.

  The five first conductive wires 421a are grounded via the output detection resistor 42c. Further, DC power is supplied from the power supply unit 7 to the five second conductive wires 422a through lead wires. A voltage detector 42d is connected between the first conductor 421a and the output detection resistor 42c.

  Next, the operation | movement at the time of the collision of the vehicle collision detection apparatus 1 in 3rd Embodiment is demonstrated. When an object such as a pedestrian collides with the front of the vehicle, the bumper cover 9 of the bumper 8 is deformed by an impact caused by the collision with the pedestrian. Subsequently, the bumper sorber 10 is deformed while absorbing an impact, and at the same time, the detection tube member 21 is also deformed. At this time, the pressure in the detection tube member 21 rises rapidly, and this pressure change is transmitted to the pressure sensor 3.

  Furthermore, the collision load is transmitted to the load sensor 42 as the detection tube member 21 is deformed. Thereby, in the deformation | transformation site | part of the tube member 21 for a detection, as shown in the right figure of FIG. 15, the contact area between the 1st conductive member 421b and the 2nd conductive member 422b has a positive correlation with a collision load. To increase. Further, the electrical resistance value between the first conducting wire 421a and the second conducting wire 422a decreases with a positive correlation with the collision load (see FIG. 16). Therefore, the output voltage detected by the voltage detector 42d increases with a positive correlation with the collision load. As a result, the load sensor 42 promptly detects a good collision load waveform regardless of where the bumper 8 has a collision.

  The load sensor 42 is electrically connected to the collision detection ECU 6 and outputs a collision load signal to the collision detection ECU 6. The collision detection ECU 6 determines whether or not a collision between the vehicle and the pedestrian has occurred based on the waveform of the collision load signal.

  The load sensor 42 is a redundant safing sensor for the pressure sensor 3 that is a main sensor, and has a switch function of turning on at the time of collision and turning off at the time of non-collision, and an electric resistance value corresponding to the collision load at the time of collision. It has a configuration having a variable resistance function to change the.

  The flow of the collision determination process by the vehicle collision detection apparatus 1 of the third embodiment is the same as that of the first embodiment except for S6 and S7 (see FIG. 8). In the third embodiment, in S6, the collision detection ECU 6 acquires the detection value of the load sensor 42 (S6 ′), and determines whether or not the load sensor 42 has been turned ON (S7 ′). When the load sensor 42 is turned on (S7 ′: Yes), the collision detection ECU 6 determines that a collision between the vehicle and the pedestrian has occurred based on the waveform of the collision load signal from the load sensor 42 (S8). ), The pedestrian protection device 12 is activated (S9).

  The vehicle collision detection apparatus 1 according to the third embodiment described above is a load sensor that detects a collision load of an object (pedestrian) on the bumper 8 as a deformation sensor instead of the deformation sensor 4 according to the first embodiment. 42 is provided. According to this configuration, in addition to being able to obtain the same effects as those of the first embodiment, the load sensor 42 can accurately measure the collision load between the vehicle and the pedestrian. Thereby, it is possible to reliably determine whether or not the colliding object is a pedestrian using the measured collision load, and it is possible to operate the pedestrian protection device 12 more appropriately.

  In addition, the conductive members (first conductive wire 421a, first conductive member 421b, second conductive wire 422a, second conductive member 422b) are formed separately from the detection tube member 21 and along the detection tube member 21. A plurality of them are arranged in the vehicle width direction.

  According to this configuration, a plurality of conductive members (first conductive wire 421a, first conductive member 421b, second conductive wire 422a, and second conductive member 422b) are arranged along the detection tube member 2 in the vehicle width direction. The collision detection range and the load detection range in the vehicle width direction of the load sensor 42, which is a safing sensor, can be sufficiently secured.

  In the third embodiment described above, the five first conductive members 421b are arranged adjacent to each other in the vertical direction and the five second conductive members 422b are arranged adjacent to each other in the vertical direction. I can't. For example, the first conductive members 421b and the second conductive members 422b may be arranged vertically with a predetermined interval. In addition, it is assumed that the shape, material, and number of installed first conductive member 421b and second conductive member 422b can be changed as appropriate.

  In the third embodiment described above, the power supply unit 7 is provided separately from the pressure sensor 3, but the power supply unit 7 may be provided inside the pressure sensor 3. Hereinafter, a case where a power supply unit is provided inside the pressure sensor will be described. In the example illustrated in FIG. 17, a power supply unit 311, an output detection resistor 312, and a voltage detection unit 313 are disposed inside the pressure sensor 31.

  The power supply unit 311 is connected to one end (the pressure sensor 31 side) of the five first conductive wires 421a and supplies DC power to the five first conductive wires 421a. The other end portions (the side opposite to the pressure sensor 31) of the five first conducting wires 421a are respectively connected to one end portion (the side opposite to the pressure sensor 31) of the second conducting wire 422a. The other end (the pressure sensor 31 side) of the five second conductive wires 422a is connected to an output detection resistor 312 disposed in the pressure sensor 31, and is grounded via the output detection resistor 312. A voltage detector 313 is connected between the second conductor 422a and the output detection resistor 312. The first conducting wire 421a has a specific resistance Ra, and the second conducting wire 422a has a specific resistance Rb. The output detection resistor 312 has a resistance value Rc.

  In the vehicle collision detection apparatus 1 having the pressure sensor 31 and the load sensor 42 configured as described above, when an object such as a pedestrian collides in front of the vehicle, as shown in FIG. The conductive member 421b and the second conductive member 422b are in contact with each other. At this time, the first conducting wire 421a and the second conducting wire 422a are electrically connected via the first conductive member 421b and the second conductive member 422b. The load sensor 42 can detect the collision position of the pedestrian in the vehicle width direction of the bumper 8 based on detection of the voltage value of the conduction path by the voltage detection unit 313 in the pressure sensor 31.

  In the example shown in FIG. 18, a power supply unit 311, an output detection resistor 312, and a voltage detection unit 313 are disposed inside the pressure sensor 31, and the power supply unit 311 is connected to the other end of the first conductor 421 a (the pressure sensor 31. Connected to the opposite side).

  One end of the second conducting wire 422a (on the pressure sensor 31 side) is connected to an output detection resistor 312 disposed in the pressure sensor 31, and is grounded via the output detection resistor 312. A voltage detector 313 is connected between the second conductor 422a and the output detection resistor 312. The first conducting wire 421a has a specific resistance Ra, and the second conducting wire 422a has a specific resistance Rb. The output detection resistor 312 has a resistance value Rc.

  In the vehicle collision detection apparatus 1 having the pressure sensor 31 and the load sensor 42 having the above-described configuration, when an object such as a pedestrian collides with the front of the vehicle, the first portion is detected at the deformed portion of the detection tube member 21 as shown in FIG. The conductive member 421b and the second conductive member 422b are in contact with each other, and the first conductive wire 421a and the second conductive wire 422a are electrically connected. The load sensor 42 can detect the collision position of the pedestrian in the vehicle width direction of the bumper 8 based on the voltage detection unit 313 detecting the voltage value of the conduction path.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. In FIG. 19 to FIG. 27, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The vehicle collision detection apparatus 1 according to the fourth embodiment includes a detection tube member 22, a pressure sensor 3, a conductivity sensor 43 (corresponding to a deformation sensor), a speed sensor 5, a collision detection ECU 6, a power supply unit 7, an abnormality detection. The ECU 14 (corresponding to the abnormality detection means), the abnormality notification lamp 15 (corresponding to the abnormality notification means), and the like are configured (see FIGS. 19 and 24).

  As shown in FIG. 21, the detection tube member 22 has a hollow portion 22a formed therein and has a circular cross-sectional shape. As shown in FIGS. 19 and 20, the detection tube member 22 is a member extending in the vehicle width direction (the vehicle left-right direction), and the front surface 11a of the bumper reinforcement 11 in the vehicle bumper 8 (vehicle It is disposed on the vehicle rear side of the bumper sorber 10 at a position facing the front side). The outer diameter of the detection tube member 22 is, for example, about 10 mm. The thickness of the peripheral wall of the detection tube member 22 is about 1 to 2 mm. As in the first embodiment, one end (left end) of the detection tube member 2 is connected to the pressure sensor 3, and the other end (right end) is closed (see FIG. 2). In FIG. 20, the resistor 43a and the conductor 43b are not shown.

  Moreover, the tube member 22 for a detection consists of a pressure sensitive conductive elastomer (pressure sensitive conductive rubber) similar to 1st Embodiment (refer FIG. 5). That is, the detection tube member 22 is made of an elastic member having conductivity, and has a characteristic that the electric resistance value R1 changes with a change (strain) in applied pressure. Specifically, when the detection tube member 22 is deformed, the electric resistance value R1 is decreased, and when the deformation is eliminated, the electric resistance value is increased (see FIG. 6).

  In the fourth embodiment, as shown in FIG. 23, a conductive wire 22c is arranged inside one end (left end) of the detection tube member 22. The conductive wire 22 c extends to the outside of the detection tube member 22 and is connected to the sensor unit 31 of the pressure sensor 3. The conductive wire 22c is used to detect the connection state between the detection tube member 22 and the pressure sensor 3 (pressure introduction pipe 32).

  Similar to the first embodiment, the pressure sensor 3 includes a main body 30, a sensor 31, a pressure introducing pipe 32, and a connector 33 (see FIG. 23). In the fourth embodiment, the sensor unit 31 is electrically connected to the conductive wire 22c of the detection tube member 22 described above. When the pressure sensor 3 is dropped or the like, the electrical resistance value of the conductive sensor 43 is changed as a result of a failure in the connection state of the conductive wire 22c between the detection tube member 22 and the sensor unit 31. To do. The abnormality detection ECU 14 detects that a dropout or the like has occurred in the pressure sensor 3 based on detecting a change in the electrical resistance value of the conductive sensor 43.

  As shown in FIG. 21, the conductive sensor 43 includes a resistor 43a, a detection tube member 22, and a conductor 43b. The conductive sensor 43 has a resistor 43a and a conductor 43b at a collision portion (a portion that deforms due to deformation of the bumper cover 8 at the time of collision) when an impact (external force) due to a collision with a pedestrian or the like of the vehicle is applied. It is comprised so that it may conduct | electrically_connect. Specifically, as shown in FIG. 24, at the time of a collision with a pedestrian or the like, a resistor 43a at a collision portion (see a white arrow in FIG. 26) on the outer peripheral surface of the detection tube member 22 on the vehicle front side. And the conductor 43b are conducted through the detection tube member 22.

  As shown in FIG. 21, the resistor 43 a has an annular cross-sectional shape, is fixed so as to cover the outer peripheral surface of the detection tube member 22, and is provided along the vehicle width direction. The resistor 43a has a specific resistance Ra. The conductor 43b has an annular cross-sectional shape, is fixed so as to cover the inner peripheral surface of the detection tube member 22, and is provided along the vehicle width direction. The conductor 43b has a specific resistance Rb.

  As shown in FIGS. 19 and 22, one end portion (right side end portion of the vehicle) of the conductive sensor 43 (resistor 43a, detection tube member 22, conductor 43b) is connected to the power supply portion 7 via a lead wire. Has been. The power supply unit 7 is for supplying power to the conductive sensor 43, and applies a predetermined DC power supply voltage Vin over the entire vehicle width direction from one end to the other end of the detection tube member 22. Apply.

  The other end portion (left end portion of the vehicle) of the conductive sensor 43 is connected to a lead wire and grounded via a resistance element 43c having a resistance value Rc. In addition, a voltage detector 431 that detects a voltage value Vout of the resistor element 43c is connected to both ends of the resistor element 43c. In the fourth embodiment, the resistor 43a and the conductor 43b correspond to conductive members.

  The abnormality detection ECU 14 is for detecting whether the detection tube member 22 is broken or the pressure sensor 3 is dropped. Specifically, the abnormality detection ECU 14 continuously obtains the electric resistance value of the conductive sensor 43 at predetermined time intervals, and when the electric resistance value becomes equal to or greater than a predetermined threshold value, the detection tube member It is detected that 22 is broken or the pressure sensor 3 is dropped.

  The abnormality notification lamp 15 is provided in the vehicle and is used to notify the vehicle occupant of the abnormality by turning on the lamp. The abnormality notification lamp 15 notifies the vehicle occupant of an abnormality when the abnormality detection ECU 14 detects that the detection tube member 22 is broken or the pressure sensor 3 is dropped (see FIG. 25).

  The collision detection ECU 6 continues to perform a collision determination with a pedestrian or the like of the vehicle even when the abnormality detection ECU 14 detects the breakage of the detection tube member 22 or the drop of the pressure sensor 3. To do. The collision determination process by the vehicle collision detection apparatus 1 in the fourth embodiment is also performed in the same manner as in the second embodiment. That is, the collision detection ECU 6 specifies the collision position of the pedestrian based on the detection result of the conductive sensor 43, sets (changes) the threshold value for the main determination and the safing determination, and then performs the main determination and the safing determination. Execute. The collision detection ECU 6 determines that a pedestrian has collided with the bumper 8 based on the detection results of the pressure sensor 3 and the conductivity sensor 43 being equal to or greater than the respective threshold values.

  Further, the collision detection ECU 6 of the fourth embodiment detects an object (in the vehicle width direction of the bumper 8) by detecting a change in voltage value (voltage drop) caused by the collision by the voltage detection unit 431 of the conductive sensor 43. Pedestrian) collision position is detected. Specifically, the collision position is calculated as described below.

  As described above, when a collision with a pedestrian or the like occurs, the resistor 43a and the conductor 43b are electrically connected via the detection tube member 22 at the collision portion of the detection tube member 22 on the vehicle front side. Here, the distance from the right end of the conductive sensor 43 to the pedestrian's collision position (part deformed by the collision) is X, and the resistance coefficient of the resistor 43a is ρ. In this case, the resistance value R from the right end portion of the resistor 43a to the collision position is R = ρX.

  When the voltage value V and the current value I in the conduction path of the conductive sensor 43 are set, the voltage value V of the conductive sensor 43 is V = ρX × I. Therefore, X = V / (ρ × I). Based on this relational expression, based on measuring the voltage value V and the current value I, the collision position of the pedestrian can be estimated also in the fourth embodiment, as in the second embodiment.

  Next, the flow of abnormality determination processing in the fourth embodiment will be described with reference to the flowchart shown in FIG. In this abnormality determination process, the abnormality detection ECU 14 continuously obtains the electric resistance value of the conductive sensor 43 at predetermined time intervals (S31), and whether or not the electric resistance value of the conductive sensor 43 is equal to or greater than a predetermined threshold value. Is determined (S32). When the electrical resistance value of the conductive sensor 43 is less than the predetermined threshold value (S32: No), the process returns to S31, and when the electrical resistance value of the conductive sensor 43 exceeds the predetermined threshold value (S32: Yes), detection is performed. It is determined that the tube member 22 is broken or the pressure sensor 3 is dropped (S33).

Here, the “breakage” of the detection tube member 22 includes a case where the detection tube member 22 is cracked, torn or the like due to aged deterioration or the like. As shown in FIG. 27, when a crack, tear or the like occurs in the detection tube member 22, the electrical resistance value of the conductive sensor 43 increases, and the detection tube member is detected based on detecting the change in the electrical resistance value. 22 breakage is detected. Specifically, the breakage is detected based on the voltage value Vout detected by the voltage detection unit 431. That is, in a state where the detection tube member 22 is not damaged, Vout is expressed by the following equation.
Vout = Rc / (R1 + Ra + Rb + Rc) × Vin (Formula 3)
When a crack, tear or the like occurs in the detection tube member 22, Vout is expressed by the following equation.
Vout = Rc / (R1 + Ra + Rb + Rc + R2) × Vin (Formula 4)

  R2 in the above (Equation 4) is the amount of increase in the electric resistance value due to cracking, tearing or the like in the detection tube member 22. In this way, it is possible to detect breakage in the detection tube member 22 based on detecting a change in the voltage value Vout of the voltage detector 431.

  In addition, the “dropping” of the pressure sensor 3 includes a connection failure between the detection tube member 22 and the pressure sensor 3, disconnection of the pressure sensor 3 from the detection tube member 22, and the like. Also in this case, it is possible to detect a dropout of the pressure sensor 3 based on detecting a change in the voltage value Vout of the voltage detection unit 431. For example, when the pressure sensor 3 is detached from the detection tube member 22, a short circuit occurs in the electrical path (conductive wire 22 c) of the conductive sensor 43. The abnormality detection ECU 14 detects the drop of the pressure sensor 3 by detecting the short circuit based on the voltage value Vout detected by the voltage detection unit 431.

  If the abnormality detection ECU 14 determines that the detection tube member 22 is broken or the pressure sensor 3 is dropped, the abnormality detection ECU 14 outputs a control signal to light the abnormality notification lamp 15 (S34). Thereby, the passenger | crew in a vehicle can visually recognize that abnormality, such as the failure | damage of the tube member 22 for a detection and the drop-off | omission of the pressure sensor 3, occurred in the vehicle collision detection apparatus 1. The abnormality notification means is not limited to the abnormality notification lamp 15 and may be a speaker, for example.

  The vehicle collision detection apparatus 1 according to the fourth embodiment described above includes the abnormality detection ECU 14 that detects breakage of the detection tube member 22 or dropout of the pressure sensor 3 based on the detection result by the conductive sensor 43. The abnormality detection ECU (14, S33) breaks the tube member for detection 22 or drops the pressure sensor 3 when the electrical resistance value of the conductive sensor 43 detected by the conductive sensor 43 exceeds a predetermined threshold value. It is detected that this occurs.

  According to this configuration, the abnormality detection ECU 14 determines whether or not the electrical resistance value of the conductive sensor 43 has become a predetermined threshold value or more, so that the detection tube member 22 is broken or the pressure sensor 3 is dropped. It can be detected accurately.

  In addition, the abnormality detection ECU (14, S32) is characterized by continuously detecting the detection tube member 22 or the pressure sensor 3 falling off at predetermined time intervals. According to this configuration, since the abnormality detection ECU 14 continuously detects the breakage of the detection tube member 22 or the drop-off of the pressure sensor 3 at predetermined time intervals, the breakage of the detection tube member 22 due to aged deterioration, It is possible to quickly find out that the pressure sensor 3 is dropped due to the vehicle traveling for a long time.

  The abnormality detection ECU 14 includes an abnormality notification lamp (15, S34) as abnormality notification means for notifying the vehicle occupant when the detection tube member 22 is broken or the pressure sensor 3 is dropped. It is characterized by that.

  According to this configuration, when the abnormality detection ECU 14 detects breakage of the detection tube member 22 or drop-off of the pressure sensor 3, the abnormality notification lamp 15 notifies the abnormality, so that the vehicle occupant can detect the detection tube member. It is possible to quickly recognize the breakage of 22 or the drop of the pressure sensor 3 and take appropriate measures such as sending the vehicle for repair.

  Further, the collision detection ECU 6 is characterized in that the collision detection is performed even when the abnormality detection ECU 14 detects that the detection tube member 22 is broken or the pressure sensor 3 is dropped.

  According to this configuration, even when the abnormality detection ECU 14 detects the breakage of the detection tube member 22 or the drop of the pressure sensor 3, the collision detection ECU 6 can continuously perform the collision determination. That is, when the collision detection by the collision detection ECU 6 is possible (pressure detection by the pressure sensor 3 is possible) in a state in which the degree of damage of the detection tube member 22 or the dropout of the pressure sensor 3 is low, Continue collision detection. Thereby, even if the abnormality detection ECU 14 is detecting an abnormality, the pedestrian protection device 12 can be appropriately operated when the collision detection ECU 6 detects a collision with a pedestrian or the like of the vehicle.

  In the fourth embodiment described above, the power supply unit 7 is provided separately from the pressure sensor 3, but the power supply unit 7 may be provided inside the pressure sensor 3. In the example shown in FIG. 28, a power supply unit 311, an output detection resistor 312, and a voltage detection unit 313 are disposed inside the pressure sensor 31.

  The power supply unit 311 is connected to one end of the resistor 43a (on the pressure sensor 31 side) and supplies DC power to the resistor 43a. One end of the conductor 43b (on the pressure sensor 31 side) is connected to an output detection resistor 312 disposed in the pressure sensor 31, and is grounded via the output detection resistor 312. A voltage detection unit 313 is connected between the conductor 43b and the output detection resistor 312. The resistor 43a has a specific resistance Ra, and the resistor 43a has a specific resistance Rb. The output detection resistor 312 has a resistance value Rc.

  In the vehicle collision detection device 1 having the pressure sensor 31 and the conductive sensor 43 having the above-described configuration, when a pedestrian or the like collides in front of the vehicle, as shown in FIG. 28, the collision portion (with the deformation of the bumper cover 8 at the time of the collision). In this case, the resistor 43a and the conductor 43b are electrically connected via the detection tube member 22. The conductive sensor 43 can detect the collision position of the pedestrian in the vehicle width direction of the bumper 8 based on detection of the voltage value of the conduction path by the voltage detection unit 313 in the pressure sensor 31.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and various modifications or expansions can be made without departing from the spirit of the present invention. For example, the arrangement positions of the detection tube members 2 and 21 may be changed. As shown in FIG. 29, the detection tube members 2 and 21 are arranged at the center of the bumper sorber 10 on the vehicle front side of the bumper reinforcement 11. It may be arranged at the top. Further, as shown in FIG. 30, the detection tube members 2, 21 may be disposed on the front upper portion of the bumper sorber 10 on the vehicle front side of the bumper reinforcement 11.
Furthermore, in the said embodiment, although the cross-sectional shape of the tube members 2 and 21 for a detection was made into substantially square shape, it is not restricted to this, A cross-sectional shape may use a polygon.

  In the above-described embodiment, the pressure sensor 3 is disposed on the rear surface 11b of the left end portion of the bumper reinforcement 11. However, the present invention is not limited to this, and the arrangement location of the pressure sensor 3 can be changed as appropriate. Suppose that Further, although the power supply unit 7 applies a predetermined DC power supply voltage, the present invention can be applied even if an AC power supply voltage is supplied.

  Further, a tube for connection may be provided in a portion of the detection tube members 2 and 21 that protrudes from the end of the bumper reinforcement 11 at the left end of the vehicle. This connection tube is a member having a hollow tube shape, one end is connected to the detection tube members 2 and 21 so that the hollow portion 2a communicates with each other, and the other end is connected to the pressure sensor 3 Is done. According to this configuration, since the pressure sensor 3 is connected to the detection tube members 2 and 21 via the connection tubes, the pressure sensor 3 is appropriately set while ensuring a pressure detection range by the detection tube members 2 and 21. It can be arranged at various positions.

  Further, if the connecting tube has higher rigidity than the detecting tube members 2 and 21, the strength of the connecting tube can be ensured, so that the bumper cover 9 is deformed at the time of collision. It is possible to prevent damage such as the connecting tube from being crushed or cut. Even if the connecting tube is bent from the end side of the detecting tube member 2 toward the rear surface 11b side of the bumper reinforcement 11, the bent portion of the connecting tube is buckled, which adversely affects collision detection. Can be prevented. Thereby, the tolerance of the collision detection apparatus 1 for vehicles can be improved more, and the reliability of collision detection can be improved more.

DESCRIPTION OF SYMBOLS 1 Vehicle collision detection apparatus 2, 21, 22 Detection tube member 2a, 21a, 22a Hollow part 2b Conductive material (conductive member)
3, 31 Pressure sensor 4 Deformation sensor 4a Conduction path (conductive member)
41 Line sensor (deformation sensor)
41a, 41b conductive line (conductive member)
41c, 41d Contactor (conductive member)
42 Load sensor (deformation sensor)
421a First conductor (conductive member)
421b First conductive member (conductive member)
422a Second conductor (conductive member)
422b Second conductive member (conductive member)
43 Conductivity sensor 43a Resistor (conductive member)
43b Conductor (conductive member)
6 Collision detection ECU (determination means)
7,311 power supply unit (power supply means)
8 Bumper 10 Bumper soba 11 Bumper reinforcement 11b Rear surface 14 Abnormality detection ECU (abnormality detection means)
15 Abnormality notification lamp (abnormality notification means)

Claims (12)

A detection tube member (in the vehicle bumper (8)) that extends in the vehicle width direction on the vehicle front side of the bumper reinforcement (11) and has hollow portions (2a, 21a, 22a) formed therein ( 2, 21, 22),
A pressure sensor (3, 31) for detecting the pressure in the hollow part of the tube member for detection;
The detection tube member is formed separately from the detection tube member, and is arranged to be deformable along with the deformation of the detection tube member. Power is supplied from the power supply means (7, 311), and along the detection tube member. A plurality of conductive members (41a, 41b, 41c, 41d, 421a, 421b, 422a, 422b) extending in the vehicle width direction and facing each other at a predetermined interval in a direction orthogonal to the vehicle width direction;
The tube member for detection based on a change in at least one of a voltage value, a current value, an electric resistance value, and a capacitance between the at least two conductive members that are in contact with the deformation of the tube member for detection. Deformation sensors ( 41, 43 ) for detecting the collision position of the object in the vehicle width direction of the bumper by detecting the deformation of
Based on whether the pressure detection result by the pressure sensor and the detection result by the deformation sensor are equal to or greater than the respective threshold values, determination means for determining whether or not an object has collided with the bumper (6 , S21, S22 ),
Threshold changing means (6, S18) for changing the threshold according to the collision position detected by the deformation sensor;
A vehicle collision detection device (1) comprising: A detection tube member (in the vehicle bumper (8)) that extends in the vehicle width direction on the vehicle front side of the bumper reinforcement (11) and has hollow portions (2a, 21a, 22a) formed therein ( 2, 21, 22),
A pressure sensor (3, 31) for detecting the pressure in the hollow part of the tube member for detection;
A conductive member (2b) that is integrally formed with the tube member for detection by pressure-sensitive conductive elastomer, is disposed so as to be deformable in accordance with the deformation of the tube member for detection, and is supplied with power from the power supply means (7, 311). )When,
Based on a change in at least one of a voltage value, a current value, an electric resistance value, and a capacitance of the conductive member, the deformation of the detection tube member is detected to detect the object in the vehicle width direction of the bumper. Deformation sensors ( 41, 43 ) for detecting a collision position ;
Based on whether the pressure detection result by the pressure sensor and the detection result by the deformation sensor are equal to or greater than the respective threshold values, determination means for determining whether or not an object has collided with the bumper (6 , S21, S22 ),
Threshold changing means (6, S18) for changing the threshold according to the collision position detected by the deformation sensor;
A vehicle collision detection device (1) comprising: The pressure sensor is a main sensor for collision detection,
The deformation sensor for a vehicle collision detection apparatus according to claim 1 or 2, characterized in that the safing sensor for redundancy of the main sensor. The deformation sensor for a vehicle collision detection apparatus according to any one of claims 1 to 3, characterized in that a load sensor for detecting a collision load of the object body to the bumper. The detecting tube member for a vehicle collision detection apparatus according to claim 1, any one of 4, characterized in that disposed on the vehicle front side of the bumper reinforcement. The vehicular collision detection device according to any one of claims 1 to 5 , wherein the pressure sensor is fixed to a rear surface (11b) of the bumper reinforcement. The detecting tube member for a vehicle collision detection apparatus according to any one of claims 1 6, characterized in that it has a cross-sectional shape of substantially square. Based on the detection result by the deformation sensors, any one of claims 1 to 7, characterized in that the breakage or detachment of the pressure sensor of the sensing tube member with an abnormality detection means (14) for detecting The vehicle collision detection device according to one item. The abnormality detection hand stage, as the electric resistance value of the conductive member that is detected by the deformation sensor if it becomes more than a predetermined threshold, falling damage or the pressure sensor of the sensing tube member occurs The vehicle collision detection device according to claim 8 , wherein the vehicle collision detection device is detected. The vehicle collision detection device according to claim 8 or 9 , wherein the abnormality detection means continuously detects breakage of the detection tube member or drop-off of the pressure sensor at predetermined time intervals. The abnormality notifying means (15) for notifying an occupant of the vehicle when the abnormality detecting means detects breakage of the detection tube member or dropping of the pressure sensor. The vehicle collision detection device according to any one of 8 to 10 . The determination unit according to any one of claims 8 to 11 , wherein the determination unit performs the collision determination even when the abnormality detection unit detects a breakage of the detection tube member or a drop of the pressure sensor. The vehicle collision detection device according to claim 1.

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