Collision detection device for a vehicle

Abstract

Collision detection device for a vehicle, comprising: a bumper damper (2) arranged on a front side of a bumper reinforcement (9) in a bumper (7) of the vehicle; a detection pipe component (3) mounted in a groove portion (2a) defined in the bumper damper (2) so as to extend in a width direction of the vehicle, a hollow part (3a) being defined in the detection pipe component (3); a pressure sensor (4) which detects a pressure in the hollow part (3a) of the detection tube component (3), wherein a collision of an object (H) against the bumper (7) is detected on the basis of a pressure detection result by the pressure sensor (4), and the detection tube component (3) is mounted in the gutter portion (2a) in a state in which the detection tube component (3) has at least one arched arc portion (31-34) curved in an up-down direction of the vehicle, characterized in that the detection pipe component (3) is mounted in the gutter portion (2a) in a state in which the detection pipe component (3) has a horizontal portion (30) extending in a horizontal direction of the vehicle and the bulge arc portion (31-34) curved to at least one of an upper side and a lower side relative to the horizontal portion (30); one end of the arched arc portion (31-34) in the width direction is connected to the horizontal portion (30) and the other end of the arched arc portion (31-34) in the width direction is connected to another horizontal portion extending in the horizontal direction adjacent to one end in the width direction; and the detection tube component (3) has the bulge arc portion (31-34) at a corner part (C) of the bumper (7) which is inclined in a front-rear direction of the vehicle around one end of the bumper (7) in the width direction of the vehicle.

Description

[0001] The invention relates to a collision detection device for a vehicle which detects a collision with a pedestrian and the like.

[0002] Conventionally, a vehicle is equipped with a pedestrian protection device for reducing the impact on a pedestrian when the pedestrian collides with the vehicle. The vehicle includes a collision detection device with a sensor arranged in a bumper of the vehicle. When the sensor detects that a pedestrian collides with the vehicle, the pedestrian protection device is activated to reduce the impact on the pedestrian. A rising hood is one of the pedestrian protection devices. When a collision is detected, the rising hood raises the rear end of a hood to increase the distance between the pedestrian and hard objects such as an engine. The collision energy acting on a pedestrian's head is absorbed using the space, so the impact on the pedestrian's head is reduced.

[0003] A collision detection device for a vehicle includes a chamber component defining a chamber space internally. The chamber component is disposed on the front surface of a bumper reinforcement in a bumper of the vehicle. Pressure in the chamber space is detected with a pressure sensor. When an object such as a pedestrian collides with the bumper (bumper cover), the chamber component is deformed by deformation of the bumper cover, and a pressure change is generated in the chamber space. The pressure change is detected by the pressure sensor, so that the collision of the object with the bumper can be detected.

[0004] The document DE 10 2013 016 239 A1 discloses a vehicle with a flexible cross member and a bumper fascia, wherein at least the bumper fascia is provided with a partially flexible support element, wherein a hose of a hose sensor system for detecting an impact on the bumper fascia is arranged between the at least one support element and the bumper fascia.

[0005] Furthermore, the document DE 10 2015 113 850 A1, which is prior art according to Section 3 (2) of the Patent Act, shows a vehicle bumper structure comprising a bumper reinforcement whose longitudinal direction runs along a vehicle width direction and which is arranged on an inner side in the vehicle longitudinal direction of a bumper cover arranged at an outer end in the vehicle longitudinal direction, an absorber which is adjacent to an outer side in the vehicle longitudinal direction of the bumper reinforcement and whose longitudinal direction runs along the vehicle width direction, and a pedestrian collision detection sensor which includes a pressure tube which is accommodated in the absorber in an overall state extending along the vehicle width direction, which outputs a signal according to a pressure change of the pressure tube and in which a total volume of the pressure tube which is accommodated in an outer end portion of the absorber in the vehicle width direction,is greater than the total volume of the pressure pipe accommodated in a central section of the absorber in the vehicle width direction.

[0006] The document DE 10 2005 005 881 B4 further describes a pedestrian protection device for a motor vehicle, comprising a damping device arranged between an outer wall and a rigid support part of a bumper, which comprises a shock-absorbing material for absorbing energy in the event of an impact, and an electrical sensor device comprising at least one sensor integrated into the damping device for detecting the impact. The sensor is arranged in a channel formed in the shock-absorbing material, has a plurality of curved sections, and is positioned behind the outer wall at a distance that varies across the width of the bumper, so that differently stiff regions of the bumper are compensated to achieve a largely homogeneous sensing profile.

[0007] Also recently, a tubular collision detection device for a vehicle has been proposed, for example, in JP 2014-505629 A, which detects a collision using a tubular component that is small and easy to handle compared to the chamber-type collision detection device. The collision detection device includes a bumper damper disposed in the bumper, a hollow tubular component mounted on a groove portion defined in the bumper damper to extend in the vehicle width direction, and a pressure sensor that detects a pressure change in the tubular component. When a pedestrian collides with the front of a vehicle, the bumper damper deforms and absorbs the impact, and simultaneously, the tubular component deforms.At this time, the pressure in the pipe component is increased, and the pressure change is detected by the pressure sensor so that a collision of the pedestrian with the vehicle can be detected.

[0008] However, in the collision detection device for a vehicle, for example, when the impact generated by the collision with the pedestrian at the front of the vehicle is released toward the side of the vehicle, the pipe component may not be completely deformed at a time of collision at a corner portion of the bumper cover adjacent to the end in the vehicle width direction that is inclined toward the front-rear direction of the vehicle. In addition, the pipe component may not be completely deformed at a high-rigidity part where the rigidity of the bumper cover or a component in the bumper is relatively high because a load applied to the pipe component becomes small at the time of collision. In such a case, the output may not be completely deformed.The output signal of the sensor may become small when a pedestrian collides, and it may be difficult to ensure the required output signal. Therefore, an object of the invention is to reduce fluctuation in the output signal of the pressure sensor depending on the collision position in the vehicle width direction in the bumper.

[0009] An object of the invention is to provide a collision detection device for a vehicle which is capable of detecting a collision with high accuracy regardless of the collision position in the vehicle width direction of the bumper.

[0010] According to one aspect of the invention, a collision detection device for a vehicle includes: a bumper damper disposed at a front side of a bumper reinforcement in a bumper of the vehicle; a detection tube component mounted in a groove portion defined in the bumper damper to extend in a width direction of the vehicle, a hollow part being defined in the detection tube component; a pressure sensor that detects a pressure in the hollow part of the detection tube component and detects a collision of an object against the bumper based on a pressure detection result by the pressure sensor. The detection tube component is mounted in the groove portion in a state where the detection tube component has at least one bulging arc portion curved in an up-down direction of the vehicle.The detection pipe component is further mounted in the gutter portion in a state where the detection pipe component has a horizontal portion extending in a horizontal direction of the vehicle and the cambered arc portion curved toward at least one of an upper side and a lower side relative to the horizontal portion. One end of the cambered arc portion is connected in the width direction to the horizontal portion, and the other end of the cambered arc portion is connected in the width direction to another horizontal portion extending in the horizontal direction adjacent to one end in the width direction. The detection pipe component has the cambered arc portion at a corner part of the bumper inclined in a front-rear direction of the vehicle around one end of the bumper in the width direction of the vehicle.

[0011] Accordingly, since the detection tube component is mounted in the gutter portion in a state where the detection tube component has at least one or more bulge arc portions bent in the up-down direction of the vehicle, the collision area (i.e., the cross-sectional area perpendicular to the collision direction) of the detection tube component becomes large at the time of collision with an object in front of the vehicle, and the deformation amount of the detection tube component (i.e., the volume compressed by the collision) can be increased. This can prevent the output of the pressure sensor from changing due to the collision position in the vehicle width direction of the bumper.That is, because the detection tube component is arranged in the groove portion in the state where the detection tube component has the bulge arc portion, the output signal of the pressure sensor can be improved at the position where the output signal of the pressure sensor may become small. Consequently, collision detection can be performed with high accuracy regardless of the collision position in the vehicle width direction of the bumper. Fig. 1 is a schematic view illustrating a collision detection apparatus for a vehicle according to a first embodiment. Fig. 2 is an enlarged view showing a shock absorber part of Fig. 1 represents. Fig. 3 is a sectional view of the bumper part along a line III-III of Fig. 2. Fig. 4 is a view illustrating a detection pipe component attached to a gutter portion of a bumper damper, as viewed from a rear of the vehicle. Fig. 5 is a schematic view illustrating a curvature state of a curvature arc portion of the detection tube component. Fig. 6 is a graph illustrating a relationship between an offset amount of the bulge arc portion and a rise rate in an output signal of a pressure sensor. Fig. Figure 7 is a schematic diagram illustrating a situation where the vehicle collides with a pedestrian. Fig. 8 is a view illustrating, from a rear side of the vehicle, a detection pipe component according to a second embodiment attached to a gutter portion of a bumper damper. Fig. 9 is a view illustrating, from a rear side of the vehicle, a detection pipe component according to a third embodiment attached to a gutter portion of a bumper damper. Fig. 10 is a view illustrating, from a rear side of the vehicle, a detection pipe component according to a fourth embodiment attached to a gutter portion of a bumper damper. Fig. 11 is a view illustrating, from a rear side of the vehicle, a detection pipe component according to a fifth embodiment attached to a gutter portion of a bumper damper. Fig. 12 is a view illustrating, from a rear side of the vehicle, a detection pipe component according to a sixth embodiment attached to a gutter portion of a bumper damper. [First embodiment]

[0012] A collision detection apparatus for a vehicle according to a first embodiment will be described with reference to Fig. 1 to Fig. 7. As explained in Fig. 1 and Fig. 2, the collision detection device 1 of this embodiment includes a bumper damper 2, a hollow detection tube component 3, a pressure sensor 4, a speed sensor 5, and a collision detection electronic control unit (ECU) 6. The collision detection device 1 detects a collision of an object (such as a pedestrian) with a bumper 7 disposed at the front of the vehicle. As shown in Fig. 3, the bumper 7 mainly includes a bumper cover 8 and a bumper reinforcement 9 in addition to the bumper damper 2.

[0013] The bumper damper 2 absorbs an impact force in the bumper 7 and is made of, for example, polypropylene foam. As shown in Fig. 3, the bumper damper 2 is disposed at a position opposite a front surface 9a of the bumper reinforcement 9, for example, at the front of the vehicle, and extends in the vehicle width direction. Although not shown, the bumper damper 2 and the bumper reinforcement 9 are fitted and fixed by fitting parts defined in the bumper damper 2 and the bumper reinforcement 9, respectively. Furthermore, the rear surface 2b of the bumper damper 2 and the front surface 9a of the bumper reinforcement 9 are in contact with each other.

[0014] The bumper damper 2 has a groove portion 2a in the upper side of the rear surface 2b of the bumper damper 2. The groove portion 2a is configured to extend along the vehicle width direction, that is, the vehicle left-right direction, and the detection tube component 3 is mounted in the groove portion 2a. The groove portion 2a has a rectangular cross-sectional shape and extends in the vehicle width direction. The length of the groove portion 2a in the vehicle up-down direction is longer than the length (that is, the outer diameter) of the detection tube component 3 in the vehicle up-down direction. Furthermore, the length of the groove portion 2a in the vehicle front-rear direction is approximately the same as the outer diameter of the detection tube component 3. The cross-sectional shape of the groove portion 2a is not limited to the rectangle and may be round or elliptical.

[0015] As in Fig. As shown in FIG. 4, the gutter portion 2a of this embodiment includes a horizontal gutter portion 20 extending in the horizontal direction of the vehicle and a curved gutter portion 21 curved toward the upper side relative to the horizontal gutter portion 20. The curved gutter portion 21 is defined for mounting the detection pipe component 3 in the gutter portion 2a in the state where the detection pipe component 3 is bent in the up-down direction.

[0016] In this embodiment, a load applied to the detection tube component at the time of a collision becomes small at a high-rigidity part G where the rigidity is relatively high due to the angled shape, such as a front grille (not shown), or at a corner part C of the bumper cover 7, whereby it is assumed that the output of the pressure sensor 4 may become small. That is, the deformation amount of the bumper damper 2 may become small at the high-rigidity part G where the rigidity of the front grille is high at the time of a collision. In addition, since the bumper cover 8 is round at the corner part C, when an impact generated by a collision is released toward the lateral side of the vehicle, the detection tube component 3 may not be completely deformed, and the output of the pressure sensor 4 may become small.

[0017] Then, the bulge groove portion 21, which is curved toward the upper side relative to the horizontal groove portion 20, is formed at a total of four locations, for example, two of the right and left high-rigidity parts G where the rigidity of the front grille is high, and two of the right and left corner parts C of the bumper cover 8. Thus, at these locations, the detection tube component 3 is fitted into the bulge groove portion 21 of the groove portion 2a in the state where the detection tube component 3 has the bulge arc portion 31. At the bulge groove portion 21 and the bulge arc portion 31, as viewed from the front-rear direction of the vehicle, the cross-sectional area per unit length in the vehicle width direction is larger than that of the horizontal portion 20 and the horizontal portion 30 by only a predetermined amount.Thereby, the output signal of the pressure sensor 4 at the time of collision at the bulge arc portion 31 of the detection tube component 3 can be improved. Furthermore, the curvature radius of the bulge groove portion 21 and the bulge arc portion 31 is set to not less than 15 mm.

[0018] As in Fig. 1 and Fig. As shown in FIG. 2, the hollow part 3 is formed inside the detection tube component 3 and extends in the vehicle width direction, that is, in the vehicle left-right direction. The detection tube component 3 is arranged at the position opposite to the front surface 9a of the bumper reinforcement 9 in the bumper 7 of the vehicle, that is, at the front side of the vehicle. The two ends of the detection tube component 3 are bent and connected to the respective pressure sensors 4, which will be mentioned later, outside the bumper reinforcement 9 on the left and right in the vehicle width direction.

[0019] The sensing tube component 3 has a circular cross-sectional shape and is made of a synthetic molded material, such as silicone rubber. The sensing tube component 3 has external dimensions such as an outer diameter of approximately 8 mm and a thickness of approximately 2 mm. Furthermore, the sensing tube component 3 may be made of another material, such as ethylene propylene rubber (EPDM).

[0020] In this embodiment, the detection pipe component 3 is mounted in the gutter portion 2a in the state where the detection pipe component 3 has the bulge arc portion 31 bent in the up-down direction of the vehicle (refer to FIG. Fig. 4 squares surrounded by a broken line) at the total of four locations, for example, two of the high-rigidity parts G on the right and left where the rigidity of the front grille is high, and two of the corner parts C on the right and left of the bumper cover 8. In addition, the detection tube component 3 has the horizontal portion 30 extending in the horizontal direction of the vehicle. The camber arc portion 31 is bent toward the upper side relative to the horizontal portion 30. The cross-sectional area per unit length in the vehicle width direction is larger in the camber arc portion 31 than in the horizontal portion by only a predetermined amount when viewed from the front-rear direction of the vehicle.That is, a distance from the horizontal portion 30 to a tip of the camber arc portion 31 (i.e., a position farthest from the horizontal portion 30) in the vehicle up-down direction is set to have a predetermined length. Furthermore, the length of the camber arc portion 31 in the vehicle width direction, i.e., the vehicle left-right direction, is set to about 200 mm.

[0021] The pressure sensor 4 is arranged on a rear side of the front surface 9a of the bumper reinforcement 9. More specifically, the pressure sensor 4 is installed at two right-and-left positions adjacent to the respective left and right ends of the bumper reinforcement 9, and is fixed to the rear surface 9b by fastening with an unillustrated bolt. In this embodiment, redundancy and detection accuracy are ensured by installing the two pressure sensors 4 in this manner.

[0022] As in Fig. 2, the pressure sensor 4 is connected to the right and left ends of the detection tube component 3, respectively, and is configured to detect the pressure in the hollow part 3a of the detection tube component 3. More specifically, the pressure sensor 4 is a sensor device that detects a change in the pressure of a gas and detects a pressure change of air in the hollow part 3a of the detection tube component 3. As shown in Fig. 1, the pressure sensor 4 is electrically connected to the collision detection ECU (electronic control unit) 6 via a transmission line and outputs a signal proportional to the pressure to the collision detection ECU 6. The collision detection ECU 6 detects a collision of a pedestrian with the bumper 7 based on the pressure detection result by the pressure sensor 4. In addition, the collision detection ECU 6 is electrically connected to the pedestrian protection device 10.

[0023] The speed sensor 5 is a sensor device that detects the speed of the vehicle and is electrically connected to the collision detection ECU 6 via the signal wire. The speed sensor 5 transmits a signal proportional to the speed of the vehicle to the collision detection ECU 6.

[0024] The collision detection ECU 6 includes a central processing unit (CPU) and controls general operations of the collision detection device 1. The collision detection ECU 6 is electrically connected to each of the pressure sensor 4, the speed sensor 5, and the pedestrian protection device 10 (see FIG. Fig. 1). A pressure signal is input from the pressure sensor 4 to the collision detection ECU 6, and a speed signal is input from the speed sensor 5 to the collision detection ECU 6. The collision detection ECU 6 performs a predetermined collision determination process based on the pressure signal from the pressure sensor 4 and the speed signal from the speed sensor 5. When a collision of an object such as a pedestrian against the bumper 7 is detected, the pedestrian protection device 10 is activated by the collision detection ECU 6.

[0025] The bumper 7 absorbs the impact when the vehicle encounters a collision and includes the bumper cover 8, the bumper damper 2, and the bumper reinforcement 9. The bumper cover 8 is arranged to cover components of the bumper 7 and is made of a plastic material such as polypropylene. The bumper cover 8 defines the appearance of the bumper 7 and defines part of the vehicle's appearance.

[0026] The bumper reinforcement 9 is a rigid component made of metal such as aluminum, and the bumper reinforcement 9 is arranged in the bumper cover 8 so as to extend in the vehicle width direction. As shown in Fig. 3, the bumper reinforcement 9 is a hollow member with a beam or support centrally located inside. The bumper reinforcement 9 has the front surface 9a on the front side and the rear surface 9a on the back side. As shown in Fig. 1 and Fig. 2, the bumper reinforcement 9 is attached to the front ends of side members 11, which is made of a pair of metal components extending in the front-rear direction of the vehicle.

[0027] Generally, when a vehicle has a collision, the vehicle tends to collide with a pedestrian or a vehicle, which in many cases is located at the front of the vehicle, that is, in the forward or traveling direction of the vehicle, that is, in front of the vehicle. In this embodiment, the pressure sensor 4 is arranged on the rear surface 9b of the bumper reinforcement 9 such that an impact caused by a collision with a pedestrian or a vehicle in front of the vehicle is prevented from being transmitted directly to the pressure sensor 4 from the bumper cover 8 located at the front of the vehicle due to the bumper reinforcement 9.

[0028] The pedestrian protection device 10 is, for example, a rising hood. The rising hood raises the rear end of a vehicle hood immediately after a collision is detected. The free space between a pedestrian and hard parts such as an engine is increased by the rising hood, and the collision energy to a pedestrian's head is absorbed using the space, thus reducing the impact to the pedestrian's head. Instead of the rising hood, a hood airbag may be used, which absorbs an impact to a pedestrian by inflating an airbag from the vehicle hood toward the lower part of a front windshield outside the vehicle.

[0029] Next, operations of the collision detection device 1 at a time when a collision occurs will be explained. When an object such as a pedestrian collides with the front of the vehicle, the bumper cover 8 of the bumper 7 is deformed by the impact caused by the collision with the pedestrian. Then, while the bumper damper 2 absorbs the impact, the bumper damper 2 is deformed, and at the same time, the detection tube component 3 is also deformed. At this time, a pressure in the hollow part 3a of the detection tube component 3 is rapidly increased, and a pressure change is transmitted to the pressure sensor 4.

[0030] In this embodiment, in view of a case where the output of the pressure sensor 4 becomes small, the detection tube component 3 is arranged in the gutter portion 2a in the state where the detection tube component 3 has the bulge arc portion 31 at the high-rigidity part G where the rigidity of the front grille is high and the corner part C of the bumper cover 8. Consequently, as viewed from the front-rear direction of the vehicle, the cross-sectional area per unit length in the vehicle width direction in the bulge arc portion 31 of the detection tube component 3 is made larger by only a predetermined amount than in the horizontal portion 30. Consequently, the output of the pressure sensor 4 at the time of collision at the high-rigidity part G of the front grille and the corner part C of the bumper cover 8 is increased.

[0031] A relationship between an offset amount Y of the bulge arc portion 31 and a rate of increase in the output signal of the pressure sensor 4 will be described with reference to Fig. 6. The "offset amount" means a length in the vehicle up-down direction from the horizontal portion 30 to the tip (the position farthest from the horizontal portion 30) of the cambered arc portion 31. The increase rate in the output signal of the pressure sensor 4 means a rate of increase in the output of the pressure sensor 4 when the offset amount Y of the cambered arc portion 31 is increased by bending the detection tube component 3. An output of the pressure sensor 4 is defined as standard (i.e., 100%) when a predetermined load per unit length in the vehicle width direction is applied to the horizontal portion 30, in other words, in the state where the detection tube component 3 is not bent. In addition, a length X of the camber arc portion 31 in the vehicle width direction, that is, in the vehicle left-right direction, is set to be about 200 mm.

[0032] As in Fig. As shown in FIG. 6, as the offset amount Y increases, the increase rate in the output signal of the pressure sensor 4 becomes large. That is, as the offset amount Y becomes large, the collision area (i.e., a cross-sectional area perpendicular to the collision direction) of the bulge arc portion 31 of the detection tube component 3 at the time of collision with the object (pedestrian H) in front of the vehicle becomes large. Since the deformation amount of the detection tube component 3 (i.e., a volume compressed by the collision) becomes large, the output signal of the pressure sensor 4 becomes large (see FIG. Fig. 7). In this embodiment, the output of the pressure sensor 4 may be increased at the time of collision due to the bulging arc portion 31 of the detection tube component 3.

[0033] Furthermore, when a vehicle has a comparatively low height, it is assumed that a pedestrian's leg is lifted by the bumper 7 at the time of collision, and that the pedestrian's upper body falls onto the hood. In this case, the impact generated at the upper part of the bumper 7 becomes large, and the bumper cover 8 may be greatly deformed from the upper side to the lower side. In this embodiment, the bulge arc portion 31 of the detection tube component 3 is bent toward the upper side relative to the horizontal portion 30 extending in the vehicle horizontal direction.For this reason, when the pedestrian collides with the vehicle, if the leg is lifted by the bumper 7 and if the upper body falls onto the hood, the external force added by the falling body from the upper side of the vehicle can be caused to be effectively transmitted to the detection tube component 3. Since the pressure change in the hollow part 3a of the detection tube component 3 is surely detected by the pressure sensor 4, the pedestrian's fall can be surely detected.

[0034] The collision detection ECU 6 of the collision detection device 1 executes a predetermined collision determination process based on the detection result of the pressure sensor 4. In the collision determination process, an effective mass of a collision object is calculated based on, for example, the detection result of the pressure sensor 4 and the speed sensor 5. If the effective mass is greater than a predetermined threshold, it is determined that a collision with a pedestrian is occurring. Furthermore, if the vehicle speed is within a predetermined range (for example, a range of 25 km / h to 55 km / h), it is determined that it is necessary to activate the pedestrian protection device 10 for the pedestrian.

[0035] The "effective mass" means a mass calculated using the relationship of a moment and an impulse from the signal detected by the pressure sensor 4 at the time of a collision. When a collision occurs between the vehicle and an object, if the object has a mass different from that of a pedestrian, the detected value of the pressure sensor 4 changes. For this reason, it becomes possible to distinguish the types of objects by setting a threshold value between the effective mass of a human body and the mass of another assumed object. More specifically, the pressure value detected by the pressure sensor 4 is integrated for a predetermined period of time, and the integrated value is divided by the vehicle speed detected by the speed sensor 5, so that the effective mass is calculated. M=(∫ P(t)dt) / V

[0036] M represents the effective mass, P represents the detection value from the pressure sensor 4 in a predetermined time period, t represents the predetermined time period (for example, from several milliseconds to several tens of milliseconds), and V represents the vehicle speed detected by the speed sensor 5 at the time of the collision. It is possible to calculate the effective mass using the formula E=1 / 2·MV 2 , which expresses a kinetic energy E of the collided object. In this case, the effective mass is given by M=2·E / V 2 calculated.

[0037] When it is determined that it is necessary to activate the pedestrian protection device 10 for the pedestrian, the collision detection ECU 6 outputs a control signal for actuating the pedestrian protection device 10, and the impact against a pedestrian is reduced by the pedestrian protection device 10.

[0038] As explained above, according to the first embodiment, the collision detection device 1 includes the bumper damper 2 arranged in the bumper 7 of the vehicle and located at the front of the bumper reinforcement 9, the detection pipe component 3 having the hollow part 3a inside and installed in the groove portion 2a formed in the bumper damper 2 so as to extend in the vehicle width direction, and the pressure sensor 4 which detects the pressure in the hollow part 3a of the detection pipe component 3 and detects the collision of the object (i.e., pedestrian) with the bumper 7 based on the pressure detection result from the pressure sensor 4.The detection pipe component 3 is mounted in the gutter portion 2a in the state where the detection pipe component 3 has at least one or more, for example, four, of the bulge arc portions 31 curved in the up-down direction of the vehicle.

[0039] Accordingly, since the detection pipe component 3 is mounted in the gutter portion 2a in the state where the detection pipe component 3 has at least one or more, for example, four, of the bulge arc portions 31 curved in the up-down direction of the vehicle, the collision area (i.e., the cross-sectional area perpendicular to the collision direction) of the detection pipe component 3 at the time of collision with the object (i.e., the pedestrian H) in front of the vehicle becomes large, so that the deformation amount of the detection pipe component 3 (i.e., the volume compressed by the collision) can be increased. Thereby, the output of the pressure sensor 4 can be prevented from changing depending on the collision position in the vehicle width direction of the bumper cover 8.That is, the output of the pressure sensor 4 can be improved by disposing the detection tube component 3 in the groove portion 2a in the state where the detection tube component 3 has the bulge arc portion 31 at the position where the output of the pressure sensor 4 can become small. Therefore, collision detection can be performed with high accuracy regardless of the collision position in the vehicle width direction of the bumper 7.

[0040] In addition, the detection pipe component 3 is mounted in the gutter portion 2a in the state where the detection pipe component 3 has the horizontal portion 30 extending in the vehicle horizontal direction and the bulge arc portion 31 curved toward the upper side relative to the horizontal portion 30.

[0041] Since the cambered arc portion 31 of the detection tube component 3 is curved toward the upper side relative to the horizontal portion 30 extending in the vehicle width direction, when a pedestrian collides with a vehicle, if the leg is lifted by the bumper 7 and if the upper body falls onto the hood, the external force added by the falling body from the upper side of the vehicle can be caused to be effectively transmitted to the detection tube component 3. Since the pressure change in the hollow part 3a of the detection tube component 3 is surely detected by the pressure sensor 4, the falling pedestrian can be surely detected, and the collision detection accuracy of the collision detection device 1 can be increased.

[0042] In addition, the cross-sectional area per unit length in the vehicle width direction when viewed from the front-rear direction of the vehicle is larger at the camber arc portion 31 than at the horizontal portion 30 by only a predetermined amount. Accordingly, at the time of collision with the pedestrian in front of the vehicle, since the area to which the external force is added becomes larger at the camber arc portion 31 than at the horizontal portion 30, the output of the pressure sensor 4 can be improved by disposing the camber arc portion 31 at a target position.

[0043] Furthermore, the gutter portion 2a includes at least one or more gutter portions 21 curved in the up-down direction of the vehicle. Since the gutter portion 2a includes at least one or more, for example, four, of the curved gutter portions 21 curved in the up-down direction of the vehicle, the detection pipe component 3 having the curved arc portion 31 can be easily fitted into the gutter portion 2a by attaching the detection pipe component 3 to the curved gutter portion 21.

[0044] Furthermore, the groove portion 2a includes the horizontal groove portion 20 extending in the vehicle horizontal direction and the bulge groove portion 21 curved toward the upper side relative to the horizontal groove portion 20. Since the horizontal groove portion 20 extending in the vehicle horizontal direction and the bulge groove portion 21 curved toward the upper side relative to the horizontal groove portion 20 are formed in the groove portion 2a, the detection pipe component 3 can be easily fitted into the groove portion 2a in the state where the detection pipe component 3 includes the horizontal portion 30 extending in the vehicle horizontal direction and the bulge arc portion 31 curved toward the upper side relative to the horizontal portion 30.

[0045] Furthermore, as viewed from the front-rear direction of the vehicle, the cross-sectional area per unit length in the vehicle width direction at the bulge trough portion 21 is larger by only a predetermined amount than that at the horizontal trough portion 20. Since, as viewed from the front-rear direction of the vehicle, the cross-sectional area per unit length in the vehicle width direction at the bulge trough portion 21 is larger by only a predetermined amount than that at the horizontal trough portion 20, the cross-sectional area of ​​the bulge arc portion 31 of the detection tube component 3 can be easily made larger than that of the horizontal portion 30 by only a predetermined amount.

[0046] In addition, the detection tube component 3 has the camber arc portion 31 at the position in the vehicle width direction where the load applied to the bumper 7 becomes small at the time of collision with an object (i.e., the pedestrian H). More specifically, the detection tube component 3 has the camber arc portion 31 at the highly rigid part G where the rigidity of the bumper cover 8 and the component (for example, the front grille) in the bumper 7 is relatively high, and has the camber arc portion 31 at the corner part C of the bumper 7 inclined toward the front-rear direction of the vehicle in the vicinity of the end in the vehicle width direction.

[0047] Accordingly, the output of the pressure sensor 4 can be increased by disposing the bulge arc portion 31 of the detection tube component 3 at the position in the vehicle width direction where the load applied to the bumper 7 becomes small at the time of collision with an object (i.e., the pedestrian H), for example, at the highly rigid part G where the rigidity of the bumper cover 8 or the front grille is relatively high and the corner part of the bumper cover 8.

[0048] In addition, the gutter portion 2a includes the bulge gutter portion 21 at the position in the vehicle width direction where the load applied to the bumper cover 8 of the bumper 7 becomes small at the time of collision with an object (i.e., the pedestrian H). More specifically, the gutter portion 2a includes the bulge gutter portion 21 at the highly rigid part G where the rigidity of the bumper cover 8 and the component (for example, the front grille) in the bumper 7 is relatively high, and includes the bulge gutter portion 21 at the corner part C of the bumper cover 8 of the bumper 7, which is inclined toward the front-rear direction of the vehicle in the vicinity of the end in the vehicle width direction.

[0049] Accordingly, the detection tube component 3 having the bulge arc portion 31 can be fitted into the gully portion 2a by forming the bulge arc portion 21 at the position in the vehicle width direction where the load applied to the bumper cover 8 of the bumper 7 at the time of collision with the object (i.e., the pedestrian H) is reduced, for example, at the highly rigid part G where the rigidity of the bumper cover 8 or the front grille is relatively high, and the corner part C of the bumper cover 8. This can improve the output of the pressure sensor 4 at the bulge arc portion 31 of the detection tube component 3.

[0050] Furthermore, the pressure sensor 4 is arranged at two positions, for example, at the right and left ends of the rear surface 9b of the bumper reinforcement 9, respectively, thus ensuring redundancy while detecting the pressure change in the detection tube component 3 with high accuracy. That is, incorrect detection can be prevented. In other words, accurate collision detection can be performed by performing collision determination using the output of the two pressure sensors 4. [Second embodiment]

[0051] A second embodiment will be described with reference to Fig. 8 described. In Fig. 8, the same reference numerals are given to the same portions as in the first embodiment to omit the explanation, so that only different portions will be explained. In the second embodiment, as in Fig. 8, the detection pipe component 3 is mounted in the gutter portion 2a in the state where a bulge arc portion 32 of the detection pipe component 3 is bent toward the lower side or downward relative to the horizontal portion 30. The gutter portion 2a includes the horizontal gutter portion 20 extending in the vehicle horizontal direction and the bulge gutter portion 22 bent toward the lower side or downward relative to the horizontal gutter portion 20.

[0052] Similar to the first embodiment, the bulge groove portion 22 is defined at a total of four locations, for example, two of the right and left high-rigidity parts G where the rigidity of the front grille is high, and two of the right and left corner parts C of the bumper cover 8, and is formed to be curved toward the lower side relative to the horizontal groove portion 20. Consequently, at the bulge arc portion 32 of the detection tube component 3, the output of the pressure sensor 4 at the time of a collision can be improved. Moreover, the curvature radius of the bulge groove portion 22 and the bulge arc portion 32 is set to not less than 15 mm.

[0053] According to the collision detection device 1 of the second embodiment, the detection pipe component 3 is mounted in the gutter portion 2a in the state where the detection pipe component 3 has the horizontal portion 30 extending in the vehicle horizontal direction and the bulge arc portion 32 curved toward the lower side relative to the horizontal portion 30. Furthermore, the gutter portion 2a has the horizontal gutter portion 20 extending in the vehicle horizontal direction and the bulge arc portion 22 curved toward the lower side relative to the horizontal gutter portion 20.

[0054] Also, in the second embodiment, the same effect as in the first embodiment can be obtained. Since the bulging arc portion 32 of the detection tube component 3 is curved toward the lower side relative to the horizontal portion 30, the offset amount of the bulging arc portion 32 can be set larger. That is, in this embodiment, since the horizontal groove portion 20 of the groove portion 2a is formed in the upper side of the rear surface 2b of the bumper damper 2 (see FIG. Fig. 3), a space for forming the bulge groove portion 22 can be made larger on the lower side of the horizontal groove portion 20 than on the upper side. Therefore, the cross-sectional area per unit length in the vehicle width direction, as viewed from the front-rear direction of the vehicle, can be set larger in the bulge groove portion 22. [Third embodiment]

[0055] A third embodiment will be described with reference to Fig. 9. In Fig. 9, the same reference numerals are given to the same portions as in the first embodiment to omit the explanation thereof, so that only different portions will be explained. In the third embodiment, as shown in Fig. 9, the gutter portion 2a includes the horizontal gutter portion 20 extending in the vehicle horizontal direction and a bulge gutter portion 23 curved toward the upper side and the lower side relative to the horizontal gutter portion 20 to have a wave shape. The detection pipe component 3 is mounted in the gutter portion 2a in a state where the detection pipe component 3 includes the horizontal portion 30 extending in the vehicle horizontal direction and the bulge arc portion 33 curved toward the upper side and the lower side relative to the horizontal portion 30.

[0056] More specifically, the groove bulge portion 23 is formed to be curved in the wave shape in the vehicle width direction from the corner part C adjacent to the end toward the highly rigid part G where the rigidity of the front grille is high. The detection pipe component 3 can be arranged in the groove portion 2a by fitting the detection pipe component 3 to the wave-shaped bulge groove portion 23 in the state (i.e., in the state of having the bulge arc portion 33) in which the detection pipe component 3 is curved in the wave shape from the corner part C adjacent to the end in the vehicle width direction toward the highly rigid part G where the rigidity of the front grille is high. In addition, Fig. 9 is a view of the gutter portion 2a of the bumper damper 2 on the left end side in the vehicle width direction, as viewed from the rear of the vehicle.

[0057] Therefore, the deformation amount of the detection tube component 3 (i.e., the volume compressed by the collision) can be effectively increased by disposing the bulge arc portion 33 bent in the wave shape. Consequently, the deformation amount of the detection tube component 3 deformed by the external force applied at the time of a collision can be increased at the highly rigid part G of the front grille and the corner part C of the bumper cover 8, so that the output signal of the pressure sensor 4 can be increased. Furthermore, the bending radius of the bulge groove portion 23 and that of the bulge arc portion are set to not less than 15 mm.

[0058] According to the collision detection device 1 of the third embodiment, the detection tube component 3 is fitted into the groove portion 2a in the state where the bulge arc portion 33 is bent toward the upper side and the lower side relative to the horizontal portion 30. Also in the third embodiment, the same effect as in the first embodiment can be obtained. That is, the collision area of ​​the detection tube component 3 at the time of collision with the object (i.e., the pedestrian H) in front of the vehicle can be effectively enlarged by disposing the bulge arc portion 33, which is bent in the waveform in the vehicle up-down direction, at the position where the output signal of the pressure sensor 4 can become small in the vehicle width direction. Accordingly, the output of the pressure sensor 4 can be further improved. [Fourth embodiment]

[0059] A fourth embodiment will be described with reference to Fig. 10. In Fig. 10, the same reference numerals are given to the same portions as in the first embodiment to omit explanation thereof, and only different portions will be explained. In the fourth embodiment, when viewed from the upper side of the vehicle, the detection tube component 3 has a plurality of bulge arc portions 34 that overlap each other.

[0060] More specifically, at the corner part C adjacent to the left end of the bumper cover 8 in the vehicle width direction, the bulge groove portion 24 bent in an inverted S shape is formed in the rear surface 2b of the bumper damper 2 (see FIG. Fig. 10). Further, at the corner part C adjacent to the right end of the bumper cover 8 in the vehicle width direction, the bulge groove portion 24 bent in an S shape is formed (not shown).

[0061] In addition, at the high-rigidity part G on the left side in the vehicle width direction where the rigidity of the front grille is high, the bulge groove portion 24 bent in the S-shape is formed in the rear surface 2b of the bumper damper (see FIG. Fig. 10). Further, at the high-rigidity part G on the right side in the vehicle width direction, the bulge groove portion 24 bent in the inverted S shape is formed (not shown). Furthermore, the horizontal groove portion 20 is formed in the rear surface 2b of the bumper damper 2 at portions other than the corner portion C and the high-rigidity part G. Moreover, the horizontal groove portion 20 defined between the corner portion C and the high-rigidity part G is opposite to the horizontal groove portion 20 at the other portions on the lower side.

[0062] The detection pipe component 3 is fitted to the bulge groove portion 24 such that, as viewed from the upper side of the vehicle, the detection pipe component 3 is arranged in the groove portion 2a in the state where the detection pipe component 3 is formed in the S-shape or the inverted S-shape at the total of four locations, for example, two of the corner parts C on the right and left of the bumper cover 8 and two of the high-rigidity parts G on the right and left where the rigidity of the front grille is high, that is, in the state where the bulge arc portions 24 overlap with each other. In addition, Fig. 10 is a view of the gutter portion 2a of the bumper damper 2 on the left end side in the vehicle width direction, as viewed from the rear of the vehicle.

[0063] According to the collision detection device 1 of the fourth embodiment, the bulge groove portion 34 is one of a plurality of bulge arc portions 34 that overlap each other as viewed from the upper side of the vehicle. Also in the fourth embodiment, the same effect as in the first embodiment can be obtained. That is, since the detection tube component 3 having the bulge arc portions 34 is mounted in the bulge groove portion 24 of the groove portion 2a at the position where the output signal of the pressure sensor 4 can become small, the output of the pressure sensor 4 can be improved by enlarging the collision range of the detection tube component 3 at the time of collision with the object (pedestrian H) in front of the vehicle. Therefore, collision detection can be performed with high accuracy regardless of the collision position in the vehicle width direction of the bumper 7. [Fifth embodiment]

[0064] A fifth embodiment will be described with reference to Fig. 11. In Fig. 11, the same reference numerals are given to the same portions as in the first embodiment to omit the explanation thereof, so that only different portions will be explained. In the fifth embodiment, as in Fig. 11, a holding part 25 for holding the detection pipe component 3 is formed on the front inner wall surface of the gutter portion 2a and protrudes toward the rear of the vehicle. Furthermore, the gutter portion 2a includes the horizontal gutter portion 20 extending in the vehicle horizontal direction and does not include the bulge gutter portion bent in the up-down direction.

[0065] The holding part 25 has a circular shape in cross section and protrudes rearward of the vehicle by a predetermined length, more specifically, only the length of the groove portion 2a in the front-rear direction. The detection pipe component 3 is mounted in the groove portion 2a on the upper side of the holding part 25. The detection pipe component 3 is held by the holding part 25 such that the detection pipe component 3 is disposed in the groove portion 2a in the state where the detection pipe component 3 is bent upward and downward, that is, in the state where the detection pipe component 3 has the bulging arc portion 31.

[0066] The length of the groove portion 2a in the up-down direction is set longer than the offset amount of the bulge arc portion 31, so that the detection pipe component 3 can be mounted in the state where the detection pipe component is curved upward and downward. Moreover, the offset amount is the length in the vehicle up-down direction from the horizontal portion 30 to the tip (i.e., the position farthest from the horizontal portion 30) of the bulge arc portion 31 (see FIG. Fig. 5).

[0067] According to the collision detection device 1 of the fifth embodiment, the gutter portion 2a has the holding part 25 projecting from the inner wall surface of the gutter portion 2a. The detection tube component 3 is mounted in the gutter portion 2a in the state of having at least one or more (four in this case) bulge arc portions 31 bent in the up-down direction of the vehicle and is held in the gutter portion 2a by the holding part 25.

[0068] In the fifth embodiment, the same effect as in the first embodiment can be obtained. Furthermore, the detection tube component 3 is held by the holding part 25 without forming the bulge groove portion 21 in the groove portion 2a. Consequently, the detection tube component 3 with the bulge arc portion 31 can be mounted in the groove portion 2a with a simple configuration. [Sixth embodiment]

[0069] A sixth embodiment will be described with reference to Fig. 12. In Fig. 12, the same reference numerals are given to the same portions as in the first embodiment to omit explanation thereof, so that only different portions will be explained. In the sixth embodiment, the detection pipe component 3 is held in the gutter portion 2a by a holding member 12 to be mounted in the gutter portion 2a in the state of having the bulge arc portion 31 bent up and down of the vehicle. In addition, the gutter portion 2a has the horizontal gutter portion 20 extending in the vehicle horizontal direction and does not have the bulge arc portion bent in the vehicle up-and-down direction.

[0070] The retaining member 12 may be, for example, a rubber band. The retaining member is one of a plurality of retaining members spaced apart from each other in the vehicle width direction and is adhesively bonded to the inner wall surface of the gutter portion 2a, while covering the outer surface of the detection tube component 3. This allows the detection tube component 3 to be located at a suitable position in the gutter portion 2a.

[0071] More specifically, the detection tube component 3 is arranged in the gutter portion 2a by being held by the holding member 12 in the state in which the detection tube component 3 is bent at several locations in the up-down direction of the vehicle. That is, similar to the first embodiment, the detection tube component 3 is mounted in the gutter portion 2a in the state in which it has the bulging arc portion 31 (refer to the squares surrounded by a broken line in Fig. 12) at a total of four locations, for example two of the highly rigid parts G on the right and left, where the rigidity of the front grille is high, and two of the corner parts C on the right and left of the bumper cover 8.

[0072] In addition, similarly to the fifth embodiment, the length of the groove portion 2a in the up-down direction is set longer than the offset amount of the bulge arc portion 31, so that the detection pipe component 3 can be mounted in the state where the detection pipe component 3 is bent up and down.

[0073] According to the collision detection device 1 of the sixth embodiment, the detection pipe component 3 is mounted in the gutter portion 2a in the state of having at least one or more (four in this case) bulge arc portions 31 bent in the up-down direction of the vehicle and held in the gutter portion 2a by the holding member 12.

[0074] In the sixth embodiment, the same effect as in the first embodiment can be obtained. Furthermore, the detection tube component 3 is held by the holding member 12 without forming the bulge groove portion 21 in the groove portion 2a. Consequently, the detection tube component 3 having the bulge arc portion 31 can be mounted in the groove portion 2a with a simple configuration. [Further examples]

[0075] The invention can be variously modified to form variations within the scope of the claims. For example, instead of the horizontal portion 30, the detection tube component 4 may have an inclined portion not parallel to the vehicle horizontal direction. Furthermore, the number, arrangement position, and arc shape of the bulge arc portions 31-34 may be appropriately determined in accordance with the vehicle shape and the output characteristics of the pressure sensor 4.

[0076] Furthermore, in the above embodiments, in a collision determination process, it is determined that a collision with a pedestrian occurs when the effective mass becomes greater than or equal to a predetermined threshold to require the operation of the pedestrian protection device 10, but is not limited thereto. For example, the pressure value or the pressure change rate detected by the pressure sensor 4 can be used as a threshold for determining a collision.

[0077] Furthermore, the pressure sensor 4 is not limited to being mounted on the rear surface 9b of the bumper reinforcement 9, and the arrangement position of the pressure sensor 4 can be appropriately changed. For example, the pressure sensor may be mounted on the inner wall surface of the bumper reinforcement 9.

Claims

[1] A collision detection device for a vehicle, comprising: a bumper damper (2) arranged on a front side of a bumper reinforcement (9) in a bumper (7) of the vehicle; a detection pipe component (3) mounted in a groove portion (2a) defined in the bumper damper (2) so as to extend in a width direction of the vehicle, a hollow part (3a) being defined in the detection pipe component (3); a pressure sensor (4) which detects a pressure in the hollow part (3a) of the detection tube component (3), wherein a collision of an object (H) against the bumper (7) is detected on the basis of a pressure detection result by the pressure sensor (4), and the detection tube component (3) is mounted in the gutter portion (2a) in a state in which the detection tube component (3) has at least one arched arc portion (31-34) curved in an up-down direction of the vehicle, characterized by , that the detection pipe component (3) is mounted in the gutter portion (2a) in a state in which the detection pipe component (3) has a horizontal portion (30) extending in a horizontal direction of the vehicle and the bulge arc portion (31-34) curved to at least one of an upper side and a lower side relative to the horizontal portion (30); one end of the arched arc portion (31-34) in the width direction is connected to the horizontal portion (30) and the other end of the arched arc portion (31-34) in the width direction is connected to another horizontal portion extending in the horizontal direction adjacent to one end in the width direction; and the detection tube component (3) has the bulge arc portion (31-34) at a corner part (C) of the bumper (7) which is inclined in a front-rear direction of the vehicle around one end of the bumper (7) in the width direction of the vehicle. [2] A collision detection device according to claim 1, wherein the cambered arc portion (31-34) has a cross-sectional area per unit length in the width direction larger than that of the horizontal portion (30) by a predetermined amount, as viewed in a front-rear direction of the vehicle. [3] A collision detection device according to any one of claims 1-2, wherein the camber arc portion (34) is one of a plurality of camber arc portions (31-34) which overlap each other when viewed from an upper side of the vehicle. [4] The collision detection device according to any one of claims 1-3, wherein the groove portion (2a) has at least one arc groove portion (21-24) bent in the up-down direction. [5] A collision detection device according to claim 4, wherein the gutter portion (2a) has a horizontal gutter portion (20) extending in a horizontal direction of the vehicle, and the arc gutter portion (21-24) is bent toward at least one of an upper side and a lower side relative to the horizontal gutter portion (20). [6] A collision detection device according to claim 5, wherein the arcuate gutter portion (21-24) has a cross-sectional area per unit length in the width direction larger than that of the horizontal gutter portion (20) by a predetermined amount, as viewed in a front-rear direction of the vehicle. [7] The collision detection device according to any one of claims 1-6, wherein the detection tube component (3) has the bulge arc portion (31-34) at a position in the width direction of the vehicle where a load applied to the bumper (7) from the object (H) becomes smaller than at another position. [8] The collision detection device according to any one of claims 1-7, wherein the detection tube component (3) has the bulge arc portion (31-34) at a high-rigidity part (G) at which a rigidity of the bumper (7) and / or a component in the bumper (7) is high relative to another part. [9] The collision detection device according to any one of claims 4-6, wherein the gutter portion (2a) has the arc gutter portion (21-24) at a position where a load applied to the bumper (7) from the object (H) becomes smaller than at another position in the width direction of the vehicle. [10] The collision detection device according to any one of claims 4-6, wherein the groove portion (2a) has the arc groove portion (21-24) at a high-rigidity part (G) at which a rigidity of the bumper (7) and / or a component in the bumper (7) is high relative to another part. [11] The collision detection device according to any one of claims 4-6, wherein the gutter portion (2a) includes the arc gutter portion (21-24) at a corner part (C) of the bumper (7) which is inclined in a front-rear direction of the vehicle around an end of the bumper (7) in the width direction of the vehicle. [12] A collision detection device according to any one of claims 1-11, wherein the groove portion (2a) has a holding part (25) projecting from an inner wall surface of the groove portion (2a), and the detection tube component (3) is held in the groove portion (2a) by the holding part (25). [13] Collision detection device according to one of claims 1-11, wherein the detection tube component (3) is held in the groove portion (2a) by a holding element (12).

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