JP2010047113A - Collision detection device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collision detection device for a vehicle in which a chamber member is certainly fixed to a vehicle body, damage to a mounting part caused by a large temperature variation in a hood of the vehicle is prevented, and the determination of a collision can be performed by detecting a pressure variation in the chamber member at the collision of the vehicle. <P>SOLUTION: In the vehicle bumper 10, the chamber member 20 is provided with: a chamber member body 21 in which a chamber space 21a is formed therein; and a plurality of mounting parts 22, 24 for fixing the chamber member body 21 to the vehicle body having linear expansion coefficients different from linear expansion coefficients of the chamber member body 21. Furthermore, the chamber member body 21 is provided with a first expansion/contraction part 23 formed between the predetermined adjacent mounting parts 22, 24 of the plurality of mounting parts 22, 24, and expandable and contractible in a direction for connecting the predetermined mounting parts 22, 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle collision detection device that detects a pedestrian collision with a vehicle bumper.

  In recent years, for the purpose of protecting pedestrians, in order to protect pedestrians, if an obstacle discriminating device is attached to the vehicle bumper part, it is determined whether or not the collision target is a pedestrian at the time of a vehicle collision. Techniques for operating these devices (for example, active hoods and cowl airbags) have been proposed, and their practical application has been studied.

  For example, Japanese Patent Laid-Open No. 2001-80545 (Patent Document 1) absorbs and reduces the impact of a secondary collision received by a pedestrian that collides with a vehicle by lifting the hood when the pedestrian collides with a bumper of the vehicle. A pedestrian protection system is disclosed. Specifically, when a traveling vehicle collides with a pedestrian, a pedestrian who has boarded the vehicle as a secondary collision may collide with the upper surface of the hood. At this time, when the hood is lifted up, the impact of the secondary collision is absorbed and reduced by deformation of the hood. Thereby, the damage of the secondary collision which a pedestrian receives can be reduced. As a result, damage to pedestrians due to accidents is reduced.

  Here, in the vehicle hood operating device described in Patent Document 1, an acceleration sensor is provided in the vehicle bumper, and the collision of the vehicle is determined based on the acceleration information detected by the acceleration sensor at the time of the collision. However, the acceleration sensor also detects vehicle vibration and acceleration / deceleration unrelated to the collision, and there is a possibility that the acceleration information at the time of the collision includes noise.

Therefore, in addition to detection by an acceleration sensor, for example, Japanese Patent Laying-Open No. 2006-117157 (Patent Document 2) discloses a vehicle obstacle determination device in which a chamber member and a pressure sensor are provided inside a vehicle bumper unit. Yes. In this vehicle obstacle discriminating apparatus, the pressure sensor detects a pressure change in the chamber member that is deformed at the time of a collision, and determines a vehicle collision based on the detected pressure change information. Thereby, the collision with the vehicle bumper part can be determined irrespective of the vibration of the vehicle or the state of acceleration / deceleration.
JP 2001-80545 A JP 2006-117157 A

  By the way, the chamber member is formed integrally with the absorber and fixed to the bumper reinforcement in the obstacle determination device for a vehicle described in Patent Document 2. Further, when the absorber and the chamber member are formed separately, the chamber member is generally fixed to a member adjacent to the chamber member such as a bumper reinforcement or an absorber.

  Here, the member which forms a vehicle body like a bumper reinforcement is requested | required of high intensity | strength. On the other hand, the chamber member is required to be deformed by being pressed by a bumper cover or the like at the time of a vehicle collision as described above. Therefore, the chamber member is formed of a resin such as polyethylene, for example, and naturally has a linear expansion coefficient different from that of a bumper reinforcement formed of a metal such as iron or aluminum.

  Also, the outside air temperature naturally varies depending on the place where the vehicle travels and the time zone. The temperature in the hood of the vehicle is affected by the outside air temperature. In addition, in the hood of the vehicle, the amount of change in temperature is remarkably large due to vibration caused by running and heat dissipation from the engine. The linear expansion coefficient of the chamber member and the linear expansion coefficient of the bumper reinforcement to which the chamber member is fixed are different. Therefore, if a large temperature change occurs in the hood of the vehicle, stress is applied to the mounting part of the chamber member due to the difference between the expansion amount (which means the contraction amount) of the chamber member and the bumper reinforcement, and the chamber member is damaged. There was a risk. Further, in order to allow a difference in the amount of expansion between the members, a configuration in which a long hole is set in the mounting portion is conceivable. However, in this configuration, a slight gap is provided so that a member such as a bolt and the attachment portion can be freely moved in the expanding direction. As a result, the chamber member is not sufficiently fixed, and vibration and noise may occur in the mounting portion.

  The present invention has been made in view of the above problems, and the chamber member is securely fixed to the vehicle body and prevents the mounting portion from being damaged due to a large temperature change in the vehicle hood. An object of the present invention is to provide a vehicle collision detection device capable of determining a collision by detecting a pressure change in a member.

In order to solve the above problems, the structural features of the invention described in claim 1 are:
A chamber member disposed in the vehicle bumper on the vehicle front side of the bumper reinforcement and having a chamber space formed therein;
A pressure sensor for detecting a pressure change in the chamber space;
A collision detection means for detecting a collision with the vehicle bumper based on a detection result by the pressure sensor;
With
The chamber member includes a chamber member body in which the chamber space is formed, and a plurality of mounting portions for fixing the chamber member body to a vehicle body having a linear expansion coefficient different from a linear expansion coefficient of the chamber member body; With
The chamber member main body includes a first expansion / contraction portion that is formed between predetermined attachment portions adjacent to each other among the plurality of attachment portions, and that can extend and contract in a direction connecting the predetermined attachment portions.

The structural feature of the invention described in claim 2 is that in claim 1,
Three or more mounting portions of the chamber member are formed in the vehicle width direction,
The first telescopic portion of the chamber member is provided between the mounting portions.

The structural feature of the invention described in claim 3 is that in claim 1 or 2,
The mounting portion of the chamber member is formed on the vehicle rear side of the chamber member main body,
The first telescopic portion of the chamber member is provided at least on the vehicle rear side of the chamber member main body.

The constitutional feature of the invention according to claim 4 is the structure according to any one of claims 1 to 3,
The first elastic part of the chamber member is provided over the entire circumference of the chamber member main body.

The structural feature of the invention according to claim 5 is the structure according to any one of claims 1 to 4,
The pressure sensor includes a fixing portion fixed to the vehicle body,
The mounting portion includes a first mounting portion that is directly fixed to the vehicle body, and a second mounting portion that is indirectly fixed to the vehicle body via the fixing portion of the pressure sensor.
The second attachment portion includes a second expansion / contraction portion that can expand and contract in a connecting direction between the fixing portion of the pressure sensor and the chamber member main body.

The constitutional feature of the invention according to claim 6 is the structure according to any one of claims 1 to 5,
Said 1st expansion-contraction part is a bellows shape.

The structural feature of the invention described in claim 7 is that in claim 5,
Said 2nd expansion-contraction part is a bellows shape.

  According to the invention which concerns on Claim 1, the 1st expansion-contraction part between the adjacent predetermined attachment parts is provided among the some attachment parts which fix a chamber member to a vehicle body. As a result, the expansion difference between the vehicle body and the chamber member caused by a large temperature change in the vehicle hood can be absorbed. Therefore, the stress to the attachment part of the chamber member fixed to the member with a different linear expansion coefficient can be reduced, and damage to the attachment part can be prevented. Further, since the first telescopic portion absorbs the difference in expansion amount between the vehicle body and the chamber member, a configuration such as setting a long hole in the mounting portion is unnecessary, and the vehicle body can be reliably fixed. Therefore, it is possible to prevent vibration and noise from occurring in the mounting portion.

  According to the second aspect of the present invention, since the first expansion / contraction part is provided between all the attachment parts that cause the difference in expansion amount between the vehicle body and the chamber member, it is possible to more reliably prevent the attachment part from being damaged. Can do.

  According to the invention of claim 3, when the chamber member is fixed to the vehicle body on the vehicle rear side, stress due to the difference in expansion amount is applied to the vehicle rear side portion of the chamber member body. Therefore, the above-described effect can be achieved by providing the first stretchable portion at this site.

  According to the invention which concerns on Claim 4, compared with the structure which provided the 1st expansion-contraction part only in the vehicle rear side of the chamber member main body, the deformation | transformation shape of the expansion state from the contraction state of a chamber member main body can be stabilized. . Thereby, the stress to an attachment part can further be reduced and damage to an attachment part can be prevented more reliably.

  Here, for example, when the pressure sensor is fixed to the vehicle body using a fixing jig such as a bracket, the second attachment portion may be damaged due to the difference in expansion amount between the chamber member and the bracket. is there. Therefore, according to the invention according to claim 5, in the second mounting portion, the second expansion / contraction portion that can expand and contract in the connecting direction between the fixing portion of the pressure sensor and the chamber member main body absorbs this expansion amount difference. Can do. Therefore, it can prevent that a 2nd attachment part is damaged.

  According to the invention which concerns on Claim 6, 7, the expansion-contraction part can be easily formed in a chamber member main body. That is, it is excellent in productivity and has the above effects.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a vehicle collision detection device according to the present invention will be described with reference to the drawings.

<Embodiment>
A vehicle collision detection apparatus 1 according to an embodiment will be described with reference to FIGS. FIG. 1 is a plan view illustrating the interior of a vehicle bumper 10 on which the vehicle collision detection apparatus 1 is mounted. FIG. 2 is a cross-sectional view of the vehicle bumper 10 taken along the line AA in FIG. 3 is a cross-sectional view of the vehicle bumper 10 taken along the line BB in FIG.

  As shown in FIGS. 1 and 2, the vehicle collision detection apparatus 1 includes a vehicle bumper 10, a chamber member 20 disposed in the vehicle bumper 10, a pressure sensor 30, and pedestrian protection that is a collision detection means. An electronic control unit (hereinafter referred to as “pedestrian protection device ECU”) 40 of the device is mainly configured.

  The vehicle bumper 10 is mainly composed of a bumper cover 11, a bumper reinforcement 12, an absorber 13, a side member 14, and an under cover 15. Further, when the bonnet (not shown) or the like extends to the position of the bumper cover 11 shown in FIG. 2 due to the design of the vehicle performance or design, in the following embodiment, the vehicle bumper 10 includes a bonnet or the like. Shall be. Further, the vehicle body in the present invention includes a bumper reinforcement 12 and a side member 14 in the present embodiment.

  The bumper cover 11 extends in the vehicle width direction at the front end of the vehicle, and is attached to the vehicle body so as to cover a bumper reinforcement 12, an absorber 13, and a chamber member 20, which will be described later. The bumper cover 11 is a cover member made of resin (for example, polypropylene) and constitutes the appearance of the front end of the vehicle. The bumper reinforcement 12 is a metal beam-like member that is disposed in the bumper cover 11 and extends in the vehicle width direction.

  The absorber 13 is a foamed resin member that extends in the vehicle width direction and is attached to the front lower side of the bumper reinforcement 12 in the bumper cover 11. The absorber 13 compresses and deforms at the time of a vehicle collision, and thereby has an impact absorbing function in the vehicle bumper 10. Demonstrate. Moreover, although the length in the vehicle front-back direction of the absorber 13 changes with vehicle types, it is about 40-100 mm, for example. In addition, as the absorber 13, you may use what bent the iron plate and made it the substantially cylindrical body.

  The side members 14 are a pair of metal members that are positioned in the vicinity of both left and right side surfaces of the vehicle and extend in the vehicle front-rear direction, and a bumper reinforcement 12 is attached to the front end thereof. Note that a crash box (not shown) may be provided at the tip of the side member 14 and the bumper reinforcement 12 may be attached via the crash box.

  The under cover 15 is engaged with the lower end of the bumper cover 11 and is attached for the purpose of preventing the engine room from being damaged by air rectification or stepping stones when the vehicle is running.

  The chamber member 20 is a resin-made box-like member that is attached to the upper side of the front surface of the bumper reinforcement 12 constituting the vehicle body in the bumper cover 11 and extends in the vehicle width direction as an overall shape. The linear expansion coefficient of the chamber member 20 is different from the linear expansion coefficients of the bumper reinforcement 12 and the side member 14 constituting the vehicle body. Specifically, the linear expansion coefficient of the chamber member 20 is larger than the linear expansion coefficients of the bumper reinforcement 12 and the side member 14. The chamber member 20 includes a chamber member main body 21, a first attachment portion 22, and a second attachment portion 24.

  The chamber member main body 21 has a chamber space 21a formed therein. As shown in FIG. 2, the chamber space 21 a is a space formed in a substantially hermetically sealed manner surrounded by a wall having a thickness of several millimeters inside the chamber member main body 21. Due to the temperature change in the hood of the vehicle, the chamber member 20 in the vehicle bumper 10 expands and contracts, and the volume in the chamber space 21a changes. This expansion / contraction amount is larger than the expansion / contraction amount of the bumper reinforcement 12 when the temperature change in the hood of the vehicle is the same. A vent hole (not shown) is provided on the wall surface of the chamber member 20. Even if the volume in the chamber space 21a varies, the balance between the atmospheric pressure in the chamber space 21a and the external air pressure is maintained.

  As shown in FIG. 2, the first attachment portion 22 is formed in a bowl shape protruding from the chamber member main body 21 in order to fix the chamber member main body 21 to the bumper reinforcement 12. In the present embodiment, the chamber member body 21 is fixed by bolting the first attachment portion 22 to the upper surface of the bumper reinforcement 12. Further, as shown in FIG. 1, the first attachment portions 22 are arranged at five locations at approximately equal intervals in the vehicle width direction, and are respectively bolted to the upper surface of the bumper reinforcement 12.

  Here, the chamber member main body 21 includes a first extendable portion 23. As shown in FIG. 1, the first expansion / contraction part 23 is provided between the first attachment parts 22 adjacent to each other among the five first attachment parts 22. That is, four first extending / contracting portions 23 are formed. Each first expansion / contraction part 23 is formed in a bellows shape that can expand and contract in a direction connecting adjacent first attachment parts 22 where the respective first expansion / contraction parts 23 are arranged. In this embodiment, each 1st expansion-contraction part 23 is formed so that it can expand-contract in the vehicle width direction. Thereby, the first attachment portion 22 can displace the separation distance between the first attachment portions 22 in a state where the chamber member body 21 is fixed to the bumper reinforcement 12.

  The second mounting portion 24 is formed in a hollow shape connected to the chamber space 21a in order to transmit a pressure change generated in the chamber space 21a to a pressure detection port of the pressure sensor 30 described later. The second mounting portion 24 indirectly fixes the chamber member 20 to the bumper reinforcement 12 via the bracket 31 of the pressure sensor 30. The second attachment portion 24 includes a second stretchable portion 25.

  As shown in FIG. 3, the second extendable portion 25 is provided between the chamber space 21 a and the bracket 31 of the pressure sensor 30 in the second attachment portion 24, and is formed in an expandable bellows shape. The bellows shape of the second extendable portion 25 is formed so as to be extendable in the direction connecting the chamber space 21a and the bracket 31 of the pressure sensor 30, that is, in the vehicle vertical direction in this embodiment. As a result, the second mounting portion 24 is adjacent to the second mounting portion 24 in a state where the chamber member 20 body is indirectly fixed to the bumper reinforcement 12 via the bracket 31 of the pressure sensor 30. The separation distance between the portion 22 and the second mounting portion 24 can be displaced.

  The pressure sensor 30 is a sensor device capable of detecting a gas pressure, and is assembled so as to project a pressure detection port inside a second mounting portion 24 formed in a hollow shape. The pressure detection port of the pressure sensor 30 is configured to be able to detect a pressure change in the chamber space 21a transmitted by the second mounting portion 24. Then, the pressure sensor 30 outputs a signal of the detected pressure and transmits a signal to the guardian protection device ECU 40 via a signal line 40a described later.

  The bracket 31 (corresponding to the “fixing portion” of the present invention) is a metal fixing jig formed in a U shape, and is bolted to the upper surface of the bumper reinforcement 12 via a flange portion. Yes. As shown in FIG. 3, the bracket 31 holds the pressure sensor 30 so that the pressure detection port of the pressure sensor 30 protrudes into the second mounting portion 24.

  The pedestrian protection device ECU 40 (corresponding to the “collision detection means” of the present invention) is an electronic control device for performing deployment control of a pedestrian protection airbag and pop-up hood (not shown), and is output from the pressure sensor 30. Is input via the signal line 40a. The pedestrian protection device ECU 40 executes processing for determining whether or not a pedestrian has collided with the vehicle bumper 10 based on the detection result of the pressure sensor 30. In addition to the pressure detection result in the pressure sensor 30, a vehicle speed detection result from a vehicle speed sensor (not shown) is input to the pedestrian protection device ECU 40, and a pedestrian collision determination is made based on the pressure detection result and the vehicle speed detection result. It is preferable to be configured to perform.

  In the vehicle collision detection apparatus 1 described above, the operation of each part when a collision with the vehicle bumper 10 occurs will be described. The state of the vehicle bumper 10 before the occurrence of the collision is as shown in FIGS. When a pedestrian collision occurs in the vehicle bumper 10, the locally deformed bumper cover 11 presses the absorber 13 and the chamber member body 21 disposed on the front surface of the bumper reinforcement 12. And the absorber 13 pressed by the bumper cover 11 compresses and deform | transforms, and absorbs the impact to a vehicle. Further, the chamber member main body 21 is similarly compressed and deformed, thereby causing a pressure change in the chamber space 21a.

  This pressure change is transmitted through the chamber space 21 a from the collision portion and reaches the pressure sensor 30 via the hollow second mounting portion 24. And when the pressure detection port of the pressure sensor 30 protruded inside the second attachment portion 24 detects this pressure change, the pressure sensor 30 outputs the detected pressure to the signal line 40a. When pedestrian protection apparatus ECU40 performs the process which judges whether a pedestrian collides with vehicle bumper 10 based on the pressure detection result input via signal line 40a, and detects a pedestrian collision Then, a pedestrian protection device (not shown) is activated.

  Next, the operation of each part accompanying a temperature change in the hood of the vehicle in a state where no collision with the vehicle bumper 10 has occurred will be described. The chamber member main body 21 is fixed to the bumper reinforcement 12 by the plurality of first attachment portions 22 and the second attachment portions 24 as described above. Here, the bumper reinforcement 12 and the bracket 31 are made of metal, whereas the chamber member 20 is made of resin. That is, in general, the material of the chamber member main body 21 has a larger linear expansion coefficient than the bumper reinforcement 12 and the bracket 31.

  When the temperature in the hood of the vehicle decreases due to a change in the outside air temperature or heat dissipation from the engine, the temperature of members such as the bumper reinforcement 12 and the chamber member 20 disposed in the vehicle bumper 10 also increases. descend. Then, the chamber member main body 21 having a large linear expansion coefficient contracts more in the vehicle width direction than the bumper reinforcement 12. At this time, the first expansion / contraction part 23 extends in the vehicle width direction and can absorb the difference in expansion between the bumper reinforcement 12 and the chamber member 20. Therefore, the stress to the first mounting portion 22 of the chamber member 20 fixed to a member having a linear expansion coefficient different from that of the chamber member main body 21 is reduced, and damage to the first mounting portion 22 can be prevented. Moreover, since the first expansion / contraction part 23 absorbs the difference in expansion amount, a configuration such as setting a long hole in the first attachment part 22 becomes unnecessary. Therefore, the chamber member 20 can be reliably fixed by fastening the first mounting portion 22 and the bumper reinforcement 12 with bolts. Therefore, it is possible to prevent generation of vibration and noise in the first attachment portion 22 due to vehicle vibration.

  Further, when the temperature in the hood of the vehicle is lowered, the temperature of the bracket 31 is also lowered in addition to the bumper reinforcement 12 and the chamber member 20. In this case as well, the chamber member 20 having a larger linear expansion coefficient than the bumper reinforcement 12 and the bracket 31 contracts more than the bumper reinforcement 12 and the bracket 31. At this time, the second expansion / contraction part 25 extends in the vehicle vertical direction, and can absorb the difference in expansion amount between the bracket 31 and the chamber member main body 21. Therefore, it is possible to prevent the second mounting portion 24 from being damaged.

  Here, in the present embodiment, the pressure sensor 30 is arranged at the right end of the chamber member 20. Therefore, the first mounting portion 22 located on the rightmost side of the vehicle is close to the second mounting portion 24. Therefore, since the influence of the expansion amount difference due to temperature change is also reduced, the first telescopic portion 23 between the first mounting portion 22 and the second mounting portion 24 is omitted as shown in FIG. Yes. However, when the separation distance between the first mounting portion 22 and the second mounting portion 24 increases due to the position change of the pressure sensor 30 or the like, a configuration in which the first telescopic portion 23 is also provided here is preferable. .

  Moreover, since the 1st expansion-contraction part 23 and the 2nd expansion-contraction part 25 are formed in the bellows shape, it can be set as the structure which provides an expansion-contraction part in the chamber member 20 easily. And by making it a bellows shape, a deformation | transformation of the chamber member main body 21 can be accept | permitted also in the direction different from the expansion-contraction direction set, respectively. For example, even when a deformation occurs such that the bumper reinforcement 12 and the chamber member body 21 are relatively curved, the stress on the first mounting portion 22 and the second mounting portion 24 can be reduced. . Further, in a state where such deformation is allowed, the cross-sectional areas of the first stretchable part 23 and the second stretchable part 25 do not decrease compared to before the deformation, so that the chamber member 20 is pressure generated in the chamber space 21a. The above effects can be achieved without reducing the change transmission performance.

<Modification of Embodiment>
In the embodiment described above, the first stretchable part 23 and the second stretchable part 25 are formed in a bellows shape. In addition, the 1st expansion-contraction part 23 and the 2nd expansion-contraction part 25 are good also as a structure formed of the elastic member which has a stretching property. With such a configuration, the cross-sectional shape can be kept constant with respect to the transmission direction of the pressure change in the first elastic part 23 and the second elastic part 25. Therefore, breakage of the first attachment portion 22 and the second attachment portion 24 can be prevented without reducing the transmission performance of the pressure change generated in the chamber space 21a.

  In the above-described embodiment, the first stretchable part 23 is formed in a bellows shape over the entire circumference. In addition, it is good also as a structure which forms a bellows shape only in the part to which expansion-contraction of the chamber member main body 21 is especially required. For example, in the present embodiment, since a plurality of the first attachment portions 22 are provided on the vehicle rear side of the chamber member main body 21, a bellows shape is formed on the vehicle rear side surface of the chamber member main body 21. Accordingly, the bellows-shaped irregularities are formed on the upper and lower surfaces of the chamber member main body 21 so as to gradually become smaller toward the front of the vehicle. By setting it as such a structure, the front surface of the chamber member main body 21 can be planarized over the whole vehicle width direction. Thereby, the vehicle bumper 10 is deformed when the vehicle collides, and the deformation can be stably caused in the chamber space 21a regardless of the portion of the chamber member main body 21. However, when the first extendable portion 22 is formed over the entire circumference, it can cope with thermal deformation of the chamber member main body 21 and can be easily manufactured.

  Furthermore, in the above-described embodiment, the second stretchable portion 25 is formed to be stretchable in the vehicle vertical direction. In addition, the second mounting portion 24 may be configured to be extendable in the vehicle front-rear direction in the vicinity of the position where the pressure sensor 30 is disposed. Moreover, in order to enable expansion and contraction in both directions, a configuration in which expansion / contraction portions are formed at both locations may be employed. With such a configuration, even when the relative deformation amount or displacement amount of the bumper reinforcement 12 and the chamber member main body 21 due to temperature change or vibration in the hood of the vehicle becomes large, deformation in the vehicle longitudinal direction is achieved. Can be tolerated. Therefore, damage to the second mounting portion 24 can be prevented and more stable vehicle collision detection can be performed.

FIG. 2 is a plan view showing the inside of a vehicle bumper 10 on which the vehicle collision detection device 1 is mounted. It is AA sectional drawing of the vehicle bumper 10 in FIG. FIG. 2 is a cross-sectional view of the vehicle bumper 10 taken along the line B-B in FIG. 1.

Explanation of symbols

1: Vehicle collision detection device 10: Vehicle bumper 11: Bumper cover 12: Bumper reinforcement 13: Absorber 14: Side member 15: Under cover 20: Chamber member 21: Chamber member main body 21a: Chamber space 22: 1st attachment part, 23: 1st expansion-contraction part 24: 2nd attachment part, 25: 2nd expansion-contraction part 30: Pressure sensor, 31: Bracket 40: Pedestrian protection apparatus ECU (collision detection means)
40a: signal line

Claims (7)

A chamber member disposed in the vehicle bumper on the vehicle front side of the bumper reinforcement and having a chamber space formed therein;
A pressure sensor for detecting a pressure change in the chamber space;
A collision detection means for detecting a collision with the vehicle bumper based on a detection result by the pressure sensor;
With
The chamber member includes a chamber member body in which the chamber space is formed, and a plurality of mounting portions for fixing the chamber member body to a vehicle body having a linear expansion coefficient different from a linear expansion coefficient of the chamber member body; With
The chamber member body includes a first expansion / contraction portion formed between predetermined attachment portions adjacent to each other among the plurality of attachment portions, and extendable / contractable in a direction connecting the predetermined attachment portions. Vehicle collision detection device. Three or more mounting portions of the chamber member are formed in the vehicle width direction,
The vehicle collision detection device according to claim 1, wherein the first telescopic portion of the chamber member is provided between the mounting portions. The mounting portion of the chamber member is formed on the vehicle rear side of the chamber member main body,
3. The vehicle collision detection device according to claim 1, wherein the first telescopic portion of the chamber member is provided at least on the vehicle rear side of the chamber member main body.   The vehicle collision detection device according to any one of claims 1 to 3, wherein the first expansion / contraction portion of the chamber member is provided over the entire circumference of the chamber member main body. The pressure sensor includes a fixing portion fixed to the vehicle body,
The mounting portion includes a first mounting portion that is directly fixed to the vehicle body, and a second mounting portion that is indirectly fixed to the vehicle body via the fixing portion of the pressure sensor.
5. The second mounting portion includes a second expansion / contraction portion that can expand and contract in a connecting direction between the fixing portion of the pressure sensor and the chamber member main body. The vehicle collision detection device according to claim 1.   The collision detection device for a vehicle according to any one of claims 1 to 5, wherein the first extension / contraction part has a bellows shape.   The vehicle collision detection device according to claim 5, wherein the second expansion and contraction portion has a bellows shape.

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