JP6453664B2 - Pedestrian collision detection device - Google Patents

Description

  The present invention relates to a pedestrian collision detection device, and more particularly to a pedestrian collision detection device incorporating a sensor unit that detects a pedestrian collision.

  It is known that a secondary collision occurs when a traffic accident occurs between a pedestrian and a vehicle. This secondary collision means that when a vehicle traveling at a predetermined speed or more collides with a pedestrian, the pedestrian collides with a vehicle bumper, and then is lifted onto the front hood and collides with a windshield or the like. is there.

  Patent Document 1 discloses a pedestrian protection device that inflates and deploys an airbag on a front hood in order to protect a pedestrian from a secondary collision. Referring to FIG. 1 of Patent Document 1, an airbag module 10 provided in the pedestrian protection device is installed on a front hood 4 of a vehicle. The airbag module 10 is configured to inflate and deploy the airbag 15 on the front hood 4.

  Patent Document 2 discloses a vehicle collision detection device that can appropriately perform pressure detection by a pressure sensor. Specifically, referring to FIG. 2 of Patent Document 2, a chamber member 7 is formed on the upper side of the front surface of the bumper reinforcement 4, and an absorber 6 is formed on the lower side thereof. Also, a breathing hole 7b is formed in the lower surface of the chamber member 7, and the pressure introducing port 8c of the pressure sensor 8 is sealed in the through hole on the upper surface of the chamber member 7 so that the pressure introducing port 8c and the chamber space are in communication with each other. It is fixed. This prevents rainwater or the like from entering the chamber member 7.

  Patent Document 3 discloses a vehicle front structure provided with a bumper absorber having a hollow structure. Specifically, referring to FIG. 2 of this Patent Document 3 and the description thereof, a resin bumper absorber 20 is disposed along the vehicle width direction, and the bumper absorber 20 is viewed from the side of the vehicle. The cross section has a substantially hat shape opened to the vehicle rear side. The front bumper reinforcement 18 and the bumper absorber 20 form a hollow structure.

Japanese Patent No. 2920284 JP 2011-73570 A JP 2012-171405 A

  However, the above pedestrian protection device has a problem that the sensitivity of the sensor fluctuates due to temperature fluctuation.

  This problem will be described in detail with reference to FIG. FIG. 9A is a graph showing the temperature characteristics of the stress of the foam material, and FIG. 9B and FIG. 9C are cross-sectional views showing the pedestrian collision detection device 100.

  FIG. 9B shows a pedestrian collision detection device 100 provided in a vehicle according to the background art described above. The pedestrian collision detection device 100 includes a bumper support member 102, a foam material 104 disposed on the front surface of the bumper support member 102, a bumper skin 108 constituting a design portion of the vehicle, and the foam material 104 and the bumper skin 108. And a detection tube 106 disposed therebetween. The pedestrian collision detection device 100 is of a so-called pressure fluctuation type, detects a change in the internal pressure of the detection tube 106 compressed at the time of the collision with a pressure sensor, and based on the output of the pressure sensor, the above-described airbag is used. Actuate safety devices.

  Since the foam material 104 and the bumper skin 108 constituting the pedestrian collision detection device 100 are made of synthetic resin, their hardness is temperature-dependent. That is, the synthetic resins constituting them become hard at low temperatures and soft at high temperatures.

  FIG. 9A shows the temperature characteristics of the stress of the foam material 104, the vertical axis shows the stress of the foam material, and the horizontal axis shows the temperature. As is apparent from this figure, the stress of the foam material increases when the temperature is lower than the normal temperature, and the stress of the foam material decreases when the temperature is higher than the normal temperature. That is, the foam material is easily deformed at a high temperature.

  Therefore, as shown in FIG. 9B, when the vehicle collides with the collision target 110 when the foam material 104 and the bumper skin 108 are at a low temperature, the amount of the collision target 110 entering the vehicle becomes small. This is because the bumper skin 108 and the foam material 104 are hard at a low temperature, and these stresses are large. Thus, when the amount of the collision object 110 entering the vehicle decreases, the pressure fluctuation of the detection tube 106 decreases, and the detection amount of the pressure sensor also decreases. Therefore, even if the vehicle collides with a pedestrian, there is a possibility that an unexploded state in which a safety device such as an airbag does not operate may occur.

  On the other hand, as shown in FIG. 9C, when the vehicle 104 collides with the collision target 110 when the foam material 104 and the bumper skin 108 are at a high temperature, the approach amount of the collision target 110 is compared with that at the low temperature. Then it grows. The reason for this is that the bumper skin 108 and the foam material 104 are soft at high temperatures and their stress is small. As the amount of entry of the collision object 110 increases, the pressure fluctuation of the detection tube 106 also increases, and the detection amount of the pressure sensor increases. Therefore, there is a possibility that an accidental explosion may occur in which a safety device such as an airbag is activated even though the vehicle does not collide with a pedestrian.

  For the above reasons, there has been a problem that the sensitivity of the pressure sensor fluctuates depending on the outside air temperature or the temperature of the vehicle, leading to an erroneous explosion or no explosion.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a pedestrian collision detection device whose operation is stabilized by reducing temperature dependency.

Pedestrian collision detection apparatus of the present invention includes a bumper support member extending along the vehicle width direction, and the shock absorbing member extending along the arranged and the vehicle width direction in front of the bumper support member, the A bumper skin disposed in front of the shock absorbing member, a pipe-shaped detection tube disposed between the shock absorbing member and the bumper skin and extending along the vehicle width direction, and a pressure of the detection tube A pressure sensor for measuring variation; and an opening for taking in air introduced into the shock absorbing member from outside the vehicle, the shock absorbing member being continuous from one end side to the other end side in the vehicle width direction. and it has a hollow portion which is a hollow extending, the sense tube is disposed in front of the hollow portion, when the vehicle is traveling, the air taken from the outside of the vehicle, said opening Via the department It was introduced into the hollow portion of the hammer absorbing member, by flowing the air along the vehicle width direction inside of the hollow portion, characterized by cooling the shock absorbing member.

  According to the present invention, air taken from the outside of the vehicle when the vehicle travels is introduced into the hollow portion of the shock absorbing member. Therefore, even when the shock absorbing member is in a high temperature state, when the vehicle resumes running, the shock absorbing member can be immediately cooled by circulating outside air through the hollow portion of the shock absorbing member. Therefore, since the stress of the shock absorbing member is recovered at an early stage, erroneous explosion and non-explosion of a pedestrian protection device such as an air bag are suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a perspective view which shows the front-end part of the vehicle provided with the pedestrian collision detection apparatus, (B) decomposes | disassembles a pedestrian collision detection apparatus. It is a perspective view shown. It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) and (B) are sectional drawings. It is a figure which shows the pedestrian collision detection apparatus of this invention, and is a block diagram which shows the connection structure. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a perspective view which shows the front-end part of the vehicle provided with the pedestrian collision detection apparatus, (B) shows the built-in bumper support member etc. It is a perspective view. It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a perspective view which shows the front-end part of a vehicle, (B) is a perspective view which shows the bumper support member etc. which are incorporated, (C) FIG. 2 is a cross-sectional view showing a front end portion of a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a perspective view which shows the bumper support member etc. which are incorporated in the front-end part of a vehicle, (B) is sectional drawing which shows the front-end part of a vehicle. is there. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the pedestrian collision detection apparatus of this invention, (A) is a perspective view which shows the bumper support member etc. which are incorporated in the front-end part of a vehicle, (B) is sectional drawing which shows the front-end part of a vehicle. is there. It is a graph which shows the effect by the pedestrian collision detection device of the present invention. It is a figure which shows the pedestrian collision detection apparatus of background art, (A) is a graph which shows the temperature characteristic of foam material, (B) and (C) are sectional drawings which show a pedestrian collision detection apparatus.

  Hereinafter, the pedestrian collision detection device of the present embodiment will be described with reference to the drawings. In the following description, description will be made using the vertical and horizontal directions as appropriate, but the horizontal direction indicates the horizontal direction when facing the traveling direction (front) of the vehicle.

  With reference to FIG. 1, the schematic structure of the pedestrian collision detection apparatus of this form is demonstrated. FIG. 1A is a perspective view showing a front end portion of the vehicle 10, and FIG. 1B is an exploded perspective view showing a pedestrian collision detection device 11 built in the front portion of the vehicle 10.

  With reference to FIG. 1 (A), the design part of the front part of the vehicle 10 is comprised from the upper part from the front hood 12, the grill 16, and the bumper skin 14. FIG. It is provided behind the member constituting the pedestrian collision detection device 11 of this embodiment, the grill 16 or the bumper skin 14. And if the pedestrian collision detection apparatus 11 detects that the vehicle 10 collided with the pedestrian, the airbag arrange | positioned in the vicinity of the front hood 12 will inflate and deploy, and will protect a pedestrian from a secondary collision. Alternatively, a hop-up hood device (not shown) operates and the rear portion of the front hood 12 is lifted upward to reduce the impact on the pedestrian's head.

  Referring to FIG. 1 (B), a pedestrian collision detection device 11 of this embodiment includes a bumper support member 18 attached to the vehicle body side from the rear, and a foam material 20 (impact disposed on the front surface of the bumper support member 18. An absorption part), a detection tube 22 (sensor part) incorporated in the front part of the foam material 20, and a bumper skin 14 are mainly provided. The pedestrian collision detection device 11 of this embodiment is of a so-called pressure fluctuation type.

  The bumper support member 18 is a cylindrical member made of a metal extending in the width direction of the vehicle, and has a role of supporting the foam material 20 and the like and absorbing energy at the time of a large collision. In a pedestrian collision or a light collision, the bumper support member 18 is not deformed in principle.

  The foam material 20 is made of a resin material, and is continuously formed from the vicinity of the left end of the bumper support member 18 to the vicinity of the right end. As the material of the foam material 20, a foamed resin made of PP foam material or polyethylene is adopted. The foam material 20 has an action of absorbing an impact by being deformed when a pedestrian collides.

  The detection tube 22 is a pipe-shaped resin member having a circular cross section, and the inside thereof is substantially sealed. The detection tube 22 is disposed from the vicinity of the right end of the bumper support member 18 to the vicinity of the left end. A pressure sensor or the like (not shown) is disposed on the detection tube 22, and a collision of a pedestrian is detected by detecting a pressure fluctuation when the detection tube 22 is compressed due to an impact at the time of collision. ing. In this embodiment, the detection tube 22 is housed in a portion where the front surface of the foam material 20 is partially recessed.

  With reference to FIG. 2, the structure of the pedestrian collision detection apparatus 11 of this form is explained in full detail. FIG. 2A is a cross-sectional view showing the structure of the pedestrian collision detection device 11 during normal running, and FIG. 2B is a cross-sectional view showing the pedestrian collision detection device 11 when a pedestrian collision occurs. FIG.

  Referring to FIG. 2A, a foam material 20 is fixed to the front surface of the bumper support member 18. The foam material 20 is a soft member made of foamed resin as described above, and the cross-sectional shape thereof has a substantially hat shape opened to the rear side. Specifically, the foam material 20 includes a front surface portion 20C having a main surface facing forward, an upper surface portion 20A extending rearward from the upper end portion of the front surface portion 20C, a lower surface portion 20B extending rearward from the lower end of the front surface portion 20C, It is composed of

  The hollow portion 21 is configured as a gap between the foam material 20 having a substantially hat shape and the bumper support member 18. In other words, the hollow portion 21 forms a closed cross section surrounded by the upper surface portion 20 </ b> A, the front surface portion 20 </ b> C, the lower surface portion 20 </ b> B of the foam material 20 and the front surface of the bumper support member 18. As with the bumper support member 18 and the like, the hollow portion 21 is continuous from the vicinity of the left end of the vehicle 10 shown in FIG. 1A to the vicinity of the right end, and has openings at both ends.

  The detection tube 22 is housed in a recess 24 in which the front surface of the foam material 20 is recessed backward.

  Referring to FIG. 2B, when an impact due to a pedestrian collision or the like occurs in the vehicle, the bumper skin 14 is deformed rearward by the impact, and the foam material 20 is pressed rearward by the bumper skin 14. Is done. At this time, since the bumper support member 18 is not deformed or moved during a pedestrian collision, the bumper skin 14 and the foam material 20 are supported by the bumper support member 18 from the rear. As a result, the foam material 20 is deformed so as to be compressed in the front-rear direction, so that the impact energy is absorbed and the impact energy acting on the legs of the pedestrian is reduced.

  When the foam material 20 is compressed in the front-rear direction as described above, the detection tube 22 disposed at the front end of the foam material 20 is also compressed in the front-rear direction, and the internal pressure increases. This pressure fluctuation is measured by a pressure sensor (not shown), and the above-described pedestrian protection device such as an airbag is operated according to the output of the pressure sensor.

  With reference to FIG. 3, operation | movement of the pedestrian collision detection apparatus 11 is demonstrated. FIG. 3 is a block diagram showing each part constituting the pedestrian collision detection device 11.

  The pressure inside the detection tube 22 (FIG. 2B) is measured by the pressure sensor 26, and information indicating this pressure is output to an ECU 30 (Electronic Control Unit) (control means). In addition, information indicating the speed of the vehicle 10 is input from the speed sensor 28 to the ECU 30. Furthermore, information indicating the temperature outside the vehicle measured by the temperature sensor 29 is also input to the ECU 30.

  The ECU 30 determines whether or not to activate a pedestrian protection device such as an air bag based on information obtained from these sensors. Specifically, it is determined whether or not the vehicle 10 has collided with a pedestrian by performing arithmetic processing on information input from the pressure sensor 26. In addition, the information input from the speed sensor 28 is processed to determine whether or not the speed of the vehicle 10 at the time of the collision is within a speed range in which a pedestrian protection device such as an air bag should be operated.

  Furthermore, in this embodiment, the operation threshold value used for determining whether or not to operate the pedestrian protection device is varied by performing arithmetic processing on the information input from the temperature sensor 29. Specifically, if the outside air temperature measured by the temperature sensor 29 is high, the operation threshold value is raised, and even if the foam material 20 shown in FIG. To do. On the other hand, if the outside air temperature measured by the temperature sensor 29 is low, the operation threshold is lowered so that no explosion occurs even if the foam material 20 shown in FIG.

  When it is determined that the vehicle 10 has collided with a pedestrian under a predetermined condition, the airbag 32 is inflated and deployed on the upper surface of the front hood 12 (see FIG. 1A) based on the output of the ECU 30. When the pop-up hood 34 is provided, the rear portion of the front hood 12 shown in FIG. 1A is lifted upward based on the output from the ECU 30. These protect pedestrians.

  With reference to FIG. 4, the pedestrian collision detection apparatus 11 of this form is explained in full detail. 4A is a perspective view showing a front portion of the vehicle 10, and FIG. 4B is a perspective view partially showing the pedestrian collision detection device 11. As shown in FIG. In FIG. 4B, the air flow is indicated by arrows.

  Referring to FIG. 4A, an opening 36 is formed by opening the vicinity of the left end of bumper skin 14 in a rectangular shape. The opening 36 is for taking outside air for cooling the foam material 20 into the interior from the outside of the vehicle during traveling.

  Referring to FIG. 4B, a duct 38 is installed between the left end of the foam material 20 and the opening 36 described above. The duct 38 has a left end connected to the opening 36 shown in FIG. 4A and a right end connected to the hollow portion 21 of the foam material 20. In other words, the duct 38 makes the external atmosphere of the vehicle 10 communicate with the hollow portion 21 of the foam material 20. The duct 38 is assembled to the bumper skin 14 or the bumper support member 18.

  When the vehicle 10 travels, the air taken in from the opening 36 by dynamic pressure is introduced into the hollow part 21 of the foam material 20 via the duct 38. The air introduced into the hollow portion 21 flows through the hollow portion 21 from the left end portion to the right end portion, and is then discharged from the right end portion into the vehicle or outside the vehicle. Thus, when the vehicle 10 travels, the high temperature foam material 20 can be cooled by circulating the outside air through the hollow portion 21 of the foam material 20. Therefore, the stress of the foam material 20 is ensured above a certain level, the pressure acting on the detection tube (FIG. 2 (B)) at the time of a pedestrian collision is within a predetermined range, and an unexploded or erroneous explosion of a safety device such as an airbag. Is prevented. Further, since the air can be continuously fed from the opening 36 formed near the left end of the bumper skin 14 to the right end of the foam material 20, the foam material 20 is cooled as a whole. There are advantages.

  With reference to FIG. 5, the other form of the above-mentioned pedestrian collision detection apparatus 11 is demonstrated. FIG. 5A is a perspective view showing the front structure of the vehicle 10, FIG. 5B is a perspective view showing a pedestrian collision detection device 11 built in the vehicle 10, and FIG. It is sectional drawing in the CC line of FIG. 5 (A).

  With reference to FIG. 5A, here, the opening 40 is formed by opening the vicinity of the center of the bumper skin 14 in a rectangular shape. The opening 40 is for taking in air for cooling the foam material 20 when the vehicle 10 travels.

  With reference to FIG. 5 (B), the opening part 42 is formed by partially opening the front face part 20 </ b> C constituting the foam material 20. The opening 42 has a rectangular shape and is formed in the vicinity of the central portion of the foam material 20 in the left-right direction. Moreover, since the opening part 42 only opened the front part 20C of the foam material 20 partially, there is almost no load fall of the foam material 20 by forming the opening part 42. FIG.

  As shown in FIG. 5C, the vicinity of the front end portion of the vehicle 10 includes a grill 16, a bumper skin 14 and a grill 17 from above. The opening 40 formed in the bumper skin 14 and the opening 42 formed in the foam material 20 are formed at overlapping positions when the vehicle 10 is viewed from the front. Further, the front end portion of the foam material 20 is close to the rear surface of the bumper skin 14. Therefore, outside air can be introduced into the hollow portion 21 of the foam material 20 without using an introduction means such as a duct.

  When the vehicle 10 travels, the air taken from the opening 40 of the bumper skin 14 is introduced into the hollow portion 21 of the foam material 20 via the opening 42 of the foam material 20. Referring to FIG. 5 (B), about half of the introduced air flows through the hollow portion 21 toward the left and is discharged from the left end portion of the foam material 20. Further, the remaining half of the introduced air circulates in the right direction in the hollow portion 21 and is discharged from the right end portion of the foam material 20. Thus, the foam material 20 is cooled by the air taken in from the outside at the time of running | circulating through the hollow part 21 of the foam material 20. As shown in FIG.

  With reference to FIG. 6, the further another form of the pedestrian collision detection apparatus 11 is demonstrated. 6A is a perspective view showing the pedestrian collision detection device 11, and FIG. 6B is a cross-sectional view showing the front portion of the vehicle.

  Referring to FIG. 6A, here, opening 44 is formed by opening upper surface portion 20A of foam material 20 in a rectangular shape. The opening 44 is provided near the center of the foam material 20 in the left-right direction.

  With reference to FIG. 6B, a duct 46 communicates with the opening 44 of the foam material 20 described above. The upper end of the duct 46 is disposed immediately after the grill 16, and the lower end of the duct 46 communicates with the opening 44 of the foam material 20. Further, the duct 46 has an upper end portion facing forward and a lower end portion facing downward. In other words, the shape of the duct 46 in a side view is a shape obtained by rotating the alphabet L by 180 degrees. Further, since the grill 16 is configured in a lattice shape, outside air is introduced into the vehicle via the grill 16 during traveling.

  When the vehicle including the pedestrian collision detection device 11 travels, a part of the air that has passed through the grill 16 passes through the duct 46 and the opening 44 as shown in FIG. 20 hollow portions 21 are introduced. As shown by an arrow in FIG. 6A, about half of the air introduced into the hollow portion 21 flows to the left end portion of the foam material 20 and is then discharged to the outside. Further, the remaining half of the air introduced into the hollow portion 21 is discharged to the outside after flowing to the right end portion of the foam material 20. During traveling, air flows through the hollow portion 21 of the foam material 20 in this way, so that the foam material 20 is cooled early and a safety device such as an airbag can be operated.

  As described above, the air that has passed through the grill 16 is introduced into the hollow portion 21 of the foam material 20 via the duct 46, so that the air is formed without forming a dedicated opening in the bumper skin 14. It can be taken inside the material 20.

  The duct 46 is disposed at a position where it does not overlap the bumper support member 18 when viewed in the front-rear direction. Therefore, the pedestrian protection performance is not deteriorated by the fact that the duct 46 remains crushed when a collision occurs.

  With reference to FIG. 7, the further another form of the pedestrian collision detection apparatus 11 is demonstrated. FIG. 7A is a perspective view showing the pedestrian collision detection device 11, and FIG. 7B is a cross-sectional view showing the front portion of the vehicle.

  As shown in FIGS. 7A and 7B, here, the opening 48 is formed by opening the bottom surface 20B of the foam material 20 in a rectangular shape. The opening 48 is provided at a central portion in the left-right direction of the foam material 20.

  A duct 50 is disposed below the foam material 20, a lower end portion of the duct 50 is disposed immediately after the grill 17, and an upper end portion of the duct 50 communicates with the opening 48 of the foam material 20. The shape of the duct 50 in a side view is a shape obtained by inverting the alphabet L in the left-right direction.

  When the vehicle equipped with the above-described pedestrian collision detection device 11 travels, as shown in FIG. 7B, a part of the air that has passed through the grille 17 passes through the duct 50 and the opening 48 and is foam material. 20 hollow portions 21 are introduced. As shown by an arrow in FIG. 7A, about half of the air introduced into the hollow portion 21 flows to the left end of the foam material 20 and then is discharged to the outside. Further, the remaining half of the air introduced into the hollow portion 21 is discharged to the outside after flowing to the right end portion of the foam material 20. During running, the foam material 20 can be cooled at an early stage by circulating air through the hollow portion 21 of the foam material 20 in this way.

  According to the pedestrian collision detection device 11 shown in this figure, since air is taken into the hollow portion 21 of the foam material 20 via the duct 50 from the rear of the grill 17 through which outside air passes, an opening is formed in the bumper skin 14. There is an advantage that outside air can be introduced into the hollow portion 21 without forming.

  Based on FIG. 8, the effect by the above-mentioned pedestrian collision detection apparatus 11 is demonstrated, referring also to each above-mentioned figure. FIG. 8 is a graph showing this effect. The vertical axis mainly indicates the temperature, and the horizontal axis indicates the time.

  In this graph, the thin solid line A indicates the outside air temperature, the thick dotted line B indicates the vehicle speed, the thin dotted line C indicates the temperature inside the bumper skin 14, and the thin alternate long and short dash line D indicates the temperature of the outer surface of the bumper skin 14. A thin two-dot chain line E indicates the temperature of the foam material in the background art, and a thick solid line F indicates the temperature of the foam material 20 of the present embodiment. It is assumed that the outside air temperature A is constant. Here, the bumper inner temperature indicates the inner surface temperature of the bumper skin 14, and the bumper outer temperature indicates the outer surface temperature of the bumper skin 14.

  When the traveling period D1 in which the vehicle 10 is traveling shifts to the stopping period D2 in which the vehicle 10 is stopped, the bumper internal temperature C and the bumper external temperature D rise rapidly. Similarly, the temperature E of the foam material of the background art and the temperature F of the foam material of the present embodiment also increase. Here, in the stop period D2, the temperature E and the temperature F rise in the same manner, but in the graph, both are shifted to clearly show both temperatures. Thus, the reason why the temperature of each element constituting the vehicle front portion rises is that heat is conducted to each element from a radiator or the like that is in a high temperature state.

  When the vehicle travels again from the stop period D2 to a travel period D3 in which the vehicle 10 travels, the temperature of the bumper internal temperature C and the bumper external temperature D decreases. This is because the front part of the vehicle is cooled by the outside air. Further, the temperature E of the foam material of the background art and the temperature F of the foam material of the present embodiment both decrease relatively slowly. The reason why both the temperatures decrease is that, referring to FIG. 5C, the foam material 20 is cooled from the outer surface by the outside air that has passed through the grills 16 and 17 and is introduced into the vehicle.

  Here, as compared with the temperature E of the foam material of the background art, the temperature F of the foam material of the present embodiment is lowered at an early stage and becomes the same level as the outside air temperature A. The reason for this is that, as described with reference to FIG. 4 and the like, the outside air is introduced into the hollow portion 21 of the foam material 20 to cool it when the vehicle travels. Therefore, the stress of the foam material 20 is ensured at a predetermined level or more at an early stage, and erroneous explosion or non-explosion of a pedestrian protection device such as an airbag is prevented. Therefore, even when the vehicle and the pedestrian collide after the vehicle resumes running, the pedestrian collision detection device 11 appropriately detects the collision, and the pedestrian protection device such as an airbag. Can protect pedestrians.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, For example, the following changes are possible in the range which does not deviate from the summary of this invention.

  Referring to FIG. 2A, the detection tube 22 is employed as a sensor unit for measuring the magnitude of impact caused by a collision. However, the sensor unit may be a sensor for measuring electrical characteristic values such as impedance.

  Further, referring to FIG. 2A, a pedestrian collision was detected based on a change in the internal pressure of the detection tube 22, but based on a change in the amount of air released to the outside from the end of the detection tube 22. A pedestrian collision may be detected.

  Further, in FIG. 2A, the foam material 20 is employed as the shock absorbing member, but a plate-shaped synthetic resin that is bent may be used as the shock absorbing member.

  Furthermore, although the form for introducing external air into the foam material 20 is shown in FIG. 4 to FIG. 7, these forms can be combined with each other.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Pedestrian collision detection apparatus 12 Front hood 14 Bumper skin 16 Grill 17 Grill 18 Bumper support member 20 Foam material 20A Upper surface part 20B Lower surface part 20C Front surface part 21 Hollow part 22 Detection tube 24 Recessed part 26 Pressure sensor 28 Speed sensor 29 Temperature Sensor 30 ECU
32 Airbag 34 Pop-up Hood 36 Opening 38 Duct 40 Opening 42 Opening 44 Opening 46 Duct 48 Opening 50 Duct

Claims (6)

A bumper support member extending along the vehicle width direction;
An impact absorbing member disposed in front of the bumper support member and extending along the vehicle width direction ;
A bumper skin disposed in front of the impact absorbing member;
A pipe-shaped detection tube disposed between the shock absorbing member and the bumper skin and extending along the vehicle width direction;
A pressure sensor for measuring the pressure fluctuation of the detection tube;
An opening for taking in air introduced into the shock absorbing member from the outside of the vehicle,
The impact absorbing member has a hollow portion that is a cavity continuously extending from one end side to the other end side along the vehicle width direction,
The detection tube is disposed in front of the hollow portion,
When the vehicle is traveling, the air taken from outside the vehicle, via said opening is introduced into the hollow portion of the shock absorbing member, along the vehicle width direction inside of the hollow portion A pedestrian collision detection device , wherein the shock absorbing member is cooled by flowing the air . A duct communicating the hollow portion of the shock absorbing member with the outside of the vehicle, and
2. The pedestrian according to claim 1, wherein when the vehicle travels, the air taken from the outside of the vehicle is introduced into the hollow portion of the shock absorbing member via the duct. Collision detection device. The impact absorbing member has an upper surface portion, a lower surface portion, and a front surface portion,
3. The pedestrian collision detection device according to claim 1, wherein the air taken in from the outside of the vehicle is introduced into the hollow portion via an opening provided in the upper surface portion. . The impact absorbing member has an upper surface portion, a lower surface portion, and a front surface portion,
3. The pedestrian collision detection device according to claim 1, wherein the air taken in from the outside of the vehicle is introduced into the hollow portion via an opening provided in the lower surface portion. . The impact absorbing member has an upper surface portion, a lower surface portion, and a front surface portion,
3. The pedestrian collision detection device according to claim 1, wherein the air taken in from the outside of the vehicle is introduced into the hollow portion through an opening provided in the front portion. . A temperature sensor for measuring the temperature of the outside air;
The control means for controlling the pedestrian protection device varies a threshold value used for determining whether or not to operate the pedestrian protection device based on information input from the temperature sensor. The pedestrian collision detection device according to any one of claims 1 to 5.

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