JP2009220783A - Collision detection device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collision detection device for a vehicle capable of accurately determining a collision between a road side article and a pedestrian by suitably arranging a pressure detection chamber member arranged in a vehicle bumper. <P>SOLUTION: The collision detection device for the vehicle is provided with: an upper absorber 3 arranged at a front side of the vehicle of a bumper reinforcement 2 in the vehicle bumper and absorbing shock by being deformed accompanying with the collision; a lower absorber 4 arranged on a lower end in the vehicle bumper below the upper absorber 3 and absorbing the shock by being deformed accompanying with the collision; the chamber member 1 arranged in the vehicle bumper and formed with a chamber space at the inside; and a pressure sensor 7 for detecting the pressure in the chamber space, and is constituted so as to detect the collision to the vehicle bumper based on the detection result of the pressure sensor 7. The chamber member 1 is arranged above the lower absorber 4 and below the upper absorber 3 so as to be adjacent to it. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle collision detection device that detects that a collision object has collided with a bumper mounted on the vehicle, and is particularly applied to a device that determines whether or not the collision object is a pedestrian.

  In recent years, safety has been improved in vehicles in the event of an accident. Regarding vehicle safety, not only is it necessary to ensure the safety of the vehicle occupant in the event of an accident, but it has also been required that the pedestrian not be fatally damaged when the pedestrian collides with the vehicle.

  As a protection means for protecting a pedestrian that has collided with a vehicle, there is a method of reducing an injury value (impact received by a pedestrian) received by a pedestrian who collides with the vehicle and falls into the bonnet, such as an airbag deployed on a bonnet. is there. By reducing the impact of pedestrians on airbags, pedestrians can be prevented from receiving fatal damage. In the protective device provided with such means, it is desired to identify a collision between a pedestrian and a roadside object (a pole, a post cone, etc.) that displays a roadside belt boundary line erected along the roadside.

As a conventional vehicle collision detection device, for example, there is one described in Japanese Patent Application Laid-Open No. 2007-290682 (Patent Document 1). In this vehicle collision detection device, a chamber member that defines a chamber space is disposed in front of a bumper reinforcement that constitutes a bumper of the vehicle, and a change in pressure in the chamber space causes a collision between the collision object and the vehicle bumper. A collision is detected.
JP 2007-290682 A

  However, in such a vehicle collision detection device, although a plurality of chamber members are arranged in the vehicle width direction, the pressure fluctuation due to the deformation of the chamber members can be adjusted, and there is an advantage that the detection accuracy is improved. There is room for improvement in the mounting position of the members.

  The present invention has been made in view of such circumstances, and roadside objects (for example, resin poles, post cones, etc.) by appropriately arranging chamber members for pressure detection disposed in a vehicle bumper. An object of the present invention is to provide a vehicle collision detection device that can accurately determine a collision between a vehicle and a pedestrian.

  An upper absorber that is disposed on the vehicle front side of the bumper reinforcement in the vehicle bumper and absorbs an impact by being deformed in accordance with the collision, and a collision that is disposed at the lower end in the vehicle bumper below the upper absorber. A lower absorber that absorbs an impact by being deformed along with the chamber member, a chamber member that is disposed in the vehicle bumper and in which a chamber space is formed, and a pressure sensor that detects a pressure in the chamber space. A collision detection apparatus for a vehicle configured to detect a collision with the vehicle bumper based on a detection result of the pressure sensor, wherein the chamber member is above the lower absorber, and the upper absorber It is characterized by being arranged adjacent to the lower part of.

  Thus, by providing a chamber member adjacent to the lower side of the upper absorber disposed on the vehicle front side of the bumper reinforcement and above the lower absorber disposed on the lower end in the vehicle bumper, the road side A collision between an object and a pedestrian can be accurately determined.

  In other words, roadside objects (poles, post cones, etc.) that display the roadside belt boundary line erected along the road shoulder are made of resin material, so if a collision with the vehicle occurs, the roadside objects themselves have Due to the elastic characteristics (elastic coefficient), the point that is erected is the end point, the contact point with the vehicle is a fulcrum, and then it is bent to the side of the collision vehicle and then flipped to the opposite side of the collision vehicle.

  On the other hand, in the case of a pedestrian, the lower absorber disposed at the lower end of the vehicle bumper absorbs the impact while damaging the pedestrian's feet and impacting the upper side of the leg (near the knee). The upper absorber disposed on the front side of the bumper reinforcement in order to cushion the pedestrian jumps up the pedestrian on the vehicle hood while absorbing the impact while deforming in the same manner.

  Here, when viewed from the viewpoint of a collision object, the human body has a larger moment of inertia than a roadside object. In other words, the pedestrian who collided falls to the vehicle side while stroking his feet with the lower absorber disposed at the lower end of the vehicle bumper while trying to stop in the same space, and also hits the leg (near the knee). The upper absorber disposed in the vehicle bumper is deformed by the load.

  Accordingly, a chamber member having a function of transmitting collision detection to the pressure sensor as pressure fluctuations in the chamber space provided therein is adjacent to the lower part of the upper absorber and is disposed on the lower end in the vehicle bumper. Collision detection accuracy that can be reliably actuated when a collision occurs with a pedestrian with deformation of the upper absorber, because it does not work on roadside objects that have the property of bending due to a collision impact (or falling in the vehicle traveling direction). It is possible to realize a vehicular collision detection device with improved performance.

  As a preferred aspect of the present invention, the chamber member may have a front end surface located on the vehicle rear side with respect to a front end surface of the upper absorber. By providing such an arrangement relationship between the upper absorber disposed on the vehicle front side of the bumper reinforcement and the chamber member disposed adjacently below the absorber, for example, the internal The chamber member with the chamber space is made of a material softer than the upper absorber, and the chamber space can be distorted by deformation accompanying the shock absorption of the upper absorber (deformation of the chamber space with pressure fluctuation). Can be detected with higher accuracy. Further, the limited arrangement area of the vehicle bumper space can be used effectively, and the chamber member is made of a softer material than the upper absorber, so that an increase in the weight of the vehicle can be suppressed.

  As a preferred aspect of the present invention, the chamber member may be fixed via an attachment member protruding downward from the bumper reinforcement. By providing such a configuration, the mounting position of the chamber member can be mounted at an optimum position of the absorber and the bumper reinforcement in consideration of collision safety and pedestrian protection. Furthermore, since the chamber member is supported from the bumper reinforcement direction side against the pressing force accompanying the impact from the front side of the vehicle at the time of the collision, the distortion of the chamber space due to the collision can be surely generated. At the same time, it is possible to prevent the chamber member from dropping off due to a collision impact.

  As a preferred aspect of the present invention, the pressure sensor may be disposed below the bumper reinforcement and on the vehicle rear side of the chamber member. By providing such a configuration, a pressure sensor for detecting pressure fluctuations in the chamber space can be locked to the back surface side (bumper reinforcement side) of the mounting member facing the surface where the mounting member and the chamber member are in contact with each other. As a result, the space inside the vehicle bumper can be efficiently used and, for example, workability such as sensor attachment / detachment during overhaul is improved. In addition, exchangeability as a unit constituting a vehicle collision detection device in which the chamber member and the pressure sensor are integrated via the mounting member can be ensured.

  Next, the present invention will be described in more detail with reference to embodiments.

  The vehicle collision detection device of this embodiment will be described with reference to the drawings. In this embodiment, an upper absorber 3 that absorbs a collision impact by deformation of the bumper reinforcement 2 on the front side of the vehicle, and a lower portion that is lower than the upper absorber 3 and absorbs an impact on the lower end portion in the vehicle bumper. The absorber 4 is provided, and the chamber member 1 is disposed above the vehicle lower than the lower absorber 4 and adjacent to the lower part of the upper absorber 3.

  Inside the chamber member 1 is formed a chamber space 11a in which a pressure fluctuation is generated by being deformed in response to an impact of a vehicle collision. By detecting this pressure change with the pressure sensor 7, an object that collides with a vehicle bumper is detected. Detect collisions.

  FIG. 1 is a cross-sectional view of a vehicle collision detection device arranged in a vehicle bumper as seen from the vehicle width direction.

  As shown in FIG. 1, a bumper reinforcement 2, an upper absorber 3, a chamber member 1, and a lower absorber 4 at the lower end of the vehicle are provided in the vehicle bumper (the vehicle rear side of the bumper skin 5). The upper absorber 3 and the chamber member 1 are disposed on the vehicle front side of the bumper reinforcement 2, and the chamber member is disposed adjacent to the lower portion of the upper absorber 3 that absorbs a collision impact. A vehicle front side member (not shown) is adjacent to the bumper reinforcement 2 on the vehicle rear side.

  The chamber member 1 is disposed in the vehicle bumper on the vehicle front side of the bumper reinforcement 2, has a shape substantially along the bumper reinforcement 2, and a chamber space 11a is formed inside the chamber member 1. ing. The chamber member 1 is entirely formed using a resin material (for example, low density polyethylene).

  The bumper reinforcement 2 is a substantially band-shaped metal frame having a surface facing the bumper skin 5, and is fixed to a front side member (not shown) of the vehicle in a state along the width direction of the vehicle. As shown in the figure, the bumper reinforcement 2 has an eye-shaped cross-sectional structure in which a beam is provided.

  The upper absorber 3 is disposed on the vehicle front side of the bumper reinforcement 2, and the surface facing the inner wall surface of the bumper skin 5 is formed in a curved shape that is curved along the inner peripheral surface of the bumper skin 5. (In the figure, it is abbreviated to a rectangular cross section). A lower absorber 4 is disposed below the upper absorber 3 and at the lower end of the vehicle bumper. Like the upper absorber 3, the surface facing the inner wall surface of the bumper skin 5 is the inner periphery of the bumper skin 5. It is formed in a curved shape that curves along the surface. Since the absorber function is intended to absorb and buffer the impact caused by the collision of the vehicle by its own deformation, both the upper / lower absorbers are generally formed of a foamed resin material.

  The upper absorber 3 and the lower absorber 4 are made of different foamed resin materials. Specifically, the lower absorber 4 is made of a material having relatively hard deformation characteristics. On the other hand, the upper absorber 3 is made of a material having relatively soft deformation characteristics. Therefore, the upper absorber 3 and the lower absorber 4 have a FS (force-displacement) characteristic that the collision stroke of the upper absorber 3 is relatively large and the collision stroke of the lower absorber 4 is relatively small during a pedestrian collision. Have.

  The pressure sensor 7 is a known sensor capable of detecting a change in gas pressure, and includes a pressure introduction pipe 7a for introducing pressure into the sensor element. The pressure sensor 7 is fixed to the mounting member 8 of the chamber member 1 whose main body having the sensor element protrudes downward from the bumper reinforcement 2, and the tip of the pressure introducing pipe 7 a is inserted into the chamber space 11 a of the chamber member 1. Has been.

  The chamber member 1 disposed on the vehicle front side of the bumper reinforcement 2 transmits its deformation due to the impact of the collision to the pressure sensor 7 as a pressure fluctuation accompanying distortion of the chamber space 11a provided therein. The pressure sensor 7 detects the pressure fluctuation of the air introduced from the chamber space 11a via the pressure introduction pipe 7a, and transmits it to, for example, a control circuit including a determination circuit. The control circuit detects the presence or absence of a collision of a pedestrian or the like with the vehicle bumper based on the pressure detection signal input from the pressure sensor 7.

  Next, the detection operation at the time of collision with the roadside object 6 in the present embodiment will be described in detail with reference to FIG. 2, and the detection operation at the time of collision with a pedestrian will be described in detail with reference to FIG.

  FIG. 2 shows an aspect at the time of a collision between the roadside object 6 and a vehicle equipped with a vehicle collision detection device. As shown in FIG. 2A, the vehicle collision detection device of the present embodiment is disposed in the vehicle bumper covered with the bumper skin 5. That is, an upper absorber 3 that absorbs and relaxes an impact is disposed in front of the bumper reinforcement 2 in the vehicle, and a chamber member 1 is disposed adjacent to the lower portion of the upper absorber 3. The chamber member 1 is fixed via an L-shaped attachment member 8 fixed to the lower surface of the bumper reinforcement 2, and a pressure sensor 7 that detects pressure fluctuations in the chamber space 11 a provided in the chamber member 1. However, it is attached to the back surface of the attachment member 8 (the surface side facing the side where the chamber member 1 is locked) via the pressure introducing pipe 7a. The lower absorber 4 is disposed below the upper absorber 3 and at the lower end in the vehicle bumper.

  As shown in the figure, the roadside object 6 is located in the vehicle forward direction. Here, the roadside object displays a roadside belt boundary line erected along the road shoulder, such as a pole or a post cone. In the illustrated example, the roadside object 6 is a case fixed to the road surface, and such a roadside object is generally made of a resin material and thus has flexibility.

  As shown in FIG. 2B, when a vehicle equipped with the vehicle collision detection device of the present embodiment collides with the roadside object 6, the roadside object 6 formed of the above-described flexible resin material is Since one end is fixed to the road surface, the upper end that is not fixed bends toward the traveling vehicle with the contact portion with the vehicle as a fulcrum. Then, once the roadside object 6 is bent, it is pushed down in the vehicle traveling direction (the direction of the white arrow in the figure) due to its resilience characteristics and the traveling vehicle load. That is, even if a collision between the roadside object 6 and the vehicle occurs, the impact absorbing upper absorber 3, the chamber member 1, and the lower absorber 4 disposed on the vehicle front side of the bumper reinforcement 2 in the vehicle bumper Will not be deformed by impact.

  On the other hand, FIG. 3 shows an aspect when the vehicle equipped with the vehicle collision detection device and the collision object are pedestrians. Since the configuration of the vehicle collision detection device arranged in the vehicle bumper covered with the bumper skin 5 is the same as that shown in FIG.

  As shown in FIG. 3 (a), a pedestrian is positioned in front of the vehicle, and the upper absorber 3 disposed on the vehicle front side of the bumper reinforcement 2 in the vehicle bumper is generally a leg of the pedestrian. It arrange | positions so that it may be located in the height facing the knee part of a part. When the collision occurs, the upper absorber 3 absorbs the impact and deforms, thereby reducing the degree of damage (injury value) to the leg of the pedestrian. In addition, the lower absorber 4 disposed at the lower end portion in the vehicle bumper is disposed so as to be positioned at a height that is generally opposed to the heel portion of the leg portion of the pedestrian. When a collision occurs, the lower absorber absorbs the impact and deforms, and similarly reduces the degree of damage (injury value) to the legs of the pedestrian.

  As shown in FIG. 3B, when a collision with a pedestrian occurs, the bumper skin 5 naturally contacts the pedestrian and deforms. The lower absorber 4 disposed at the lower end in the vehicle bumper reduces the degree of damage (injury value) to the pedestrian while being deformed in order to buffer the impact, and the pedestrian's feet (leg buttock) ).

  Here, from the viewpoint of the vehicle and the collision object, the human body (pedestrian) has a larger moment of inertia than the roadside object 6 described above. In other words, a pedestrian whose center of gravity has been destroyed due to his / her feet being crushed moves to fall into the vehicle while trying to stop in the same space in contact with the vehicle. Here, the upper absorber 3 in the vehicle bumper disposed at a position opposite to the knee portion of the leg portion of the pedestrian absorbs a collision impact while being deformed by a load applied to the leg portion (near the knee) to the pedestrian. The degree of damage (injury value) is reduced. When the upper absorber 3 and the lower absorber 4 are deformed, the bumper skin 5 is naturally deformed along the unevenness of the leg of the pedestrian that collided, and is particularly arranged adjacent to the lower part of the upper absorber 3. The bumper skin 5 facing the chamber member 1 is also deformed by receiving the load of the pedestrian who falls to the vehicle side.

  The chamber member 1 that has received a deformation force (pressing force) toward the vehicle rear side of the bumper skin 5 is distorted by the deformation of the chamber member 1 in the chamber space 11 a provided therein. And the pressure fluctuation accompanying the distortion of the chamber space 11a is transmitted to the pressure sensor 7 through the pressure introducing pipe 7a, so that the collision with the pedestrian can be detected.

  In this way, the pedestrian who has fallen to the vehicle side is spun up on the vehicle hood while deforming the bumper skin 5, the upper absorber 3, the chamber member 1, and the lower absorber 4, but for example, a collision is detected. The control circuit that has received the output of the pressure sensor 7 performs a predetermined collision determination and activates a protection device that reduces damage to the pedestrian who is jumped up on the vehicle hood, thereby protecting the pedestrian when a collision occurs. Can be realized.

  As is apparent from the above description, according to the present embodiment, the vehicle is disposed above the lower absorber 4 disposed at the lower end in the vehicle bumper and on the vehicle front side of the bumper reinforcement 2. By disposing the chamber member 1 so as to be adjacent to the lower part of the upper absorber 3, it is possible to reliably detect a collision with a pedestrian causing deformation of the upper and lower absorbers (3, 4). In addition, since it is possible to identify a collision with a roadside object (a pole, a post cone, etc.) that does not cause the upper and lower absorbers (3, 4) to be deformed even if a collision occurs, the vehicle has improved collision detection accuracy. A collision detection device can be realized.

  In particular, the front end surface (bumper skin 5 side) of the chamber member 1 is located on the vehicle rear side (bumper reinforcement 2 side) of the front end surface (bumper skin 5 side) of the upper absorber 3 disposed adjacent to the upper part. Thus, the chamber member 1 including the chamber space 11a is made of a material softer than the upper absorber 3, and the chamber space 11a is distorted by deformation accompanying the shock absorption of the upper absorber 3 (pressure fluctuations). Therefore, the collision detection with the pedestrian that causes the deformation of the upper absorber 3 can be detected with higher accuracy. Furthermore, since the depth of the arrangement space secured in the vehicle front direction in the vehicle bumper does not depend on the size of the chamber member 1, the limited arrangement area of the vehicle bumper space can be efficiently utilized. In addition to this advantage, since the chamber member 1 can use a soft resin material, it is possible to suppress an increase in the weight of the vehicle.

  Further, in the present embodiment, the chamber member 1 is fixed via the mounting member 8 projecting downward from the bumper reinforcement 2, so that the mounting position of the chamber member 1 is determined as collision safety or pedestrian protection. Can be mounted at the optimum positions of the absorber (3, 4) and the bumper reinforcement 2. In addition to the advantages of this arrangement relationship, the chamber member 1 is placed on the bumper reinforcement 2 side against the pressing force accompanying the impact from the front side of the vehicle at the time of a collision that causes deformation of the upper and lower absorbers (3, 4). Therefore, the chamber space 11a provided in the chamber member 1 can be reliably distorted and the chamber member 1 can be prevented from falling off due to a collision impact.

  Moreover, since the material which has a comparatively soft deformation characteristic is employ | adopted for the upper absorber 3, it can anticipate improving the pedestrian's leg protection effect (damage value reduction effect). Furthermore, since the lower absorber 4 is made of a material having relatively hard deformation characteristics, it can be expected to enhance the pushing-down effect on the roadside object.

  Since the pressure sensor 7 for detecting the pressure fluctuation caused by the distortion of the chamber space 11a can be disposed below the bumper reinforcement 2 and on the vehicle rear side of the chamber member 1, the transmission distance required for the pressure introduction pipe 7a. The transmission of the pressure fluctuation with the shortest distance (the distance between the chamber member 1 and the pressure sensor 7) can be realized. In addition, since the pressure sensor 7 can be locked on the back side (bumper reinforcement side) facing the locking surface of the mounting member 8 and the chamber member 1, efficient use of the space inside the vehicle bumper is possible. In addition, it is possible to improve workability such as attachment / detachment of the sensor at the time of overhaul, and since it can be integrated as an exchange unit including the chamber member 1, the pressure sensor 7, and the attachment member 8, Securement can be realized.

  Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  Hereinafter, each modification of the present invention will be described. For example, in the above embodiment, the fixing example of the chamber member 1 using the L-shaped attachment member 8 protruding below the bumper reinforcement 2 is shown. However, the flat attachment member 8 is attached to the front surface of the bumper reinforcement ( It may be fixed to the vehicle front side) and protrude below the bumper reinforcement 2. The latching effect which prevents drop-off with the simple structure which does not require shape processing is obtained similarly, and the exchange property at the time of overhaul can be improved. Even in such a form, it is desirable that the chamber member 1 be disposed adjacent to the lower part of the upper absorber 3 in order to ensure a collision detection effect accompanying the deformation of the upper absorber 3.

It is sectional drawing which looked at the collision detection apparatus for vehicles arrange | positioned in a vehicle bumper from the vehicle width direction. It is explanatory drawing which shows the aspect at the time of the collision with the vehicle and roadside thing which mount the vehicle detection apparatus of embodiment. It is explanatory drawing which shows the aspect at the time of the collision with the vehicle and pedestrian which mount the vehicle detection apparatus of embodiment.

Explanation of symbols

1: Chamber member 11a: Chamber space 2: Bumper reinforcement 3: Upper absorber 4: Lower absorber 5: Bumper skin 6: Roadside object 7: Pressure sensor 7a: Introduction pipe 8: Mounting member

Claims (4)

An upper absorber that is disposed on the vehicle front side of the bumper reinforcement in the vehicle bumper and absorbs an impact by being deformed in accordance with a collision;
A lower absorber that is disposed at the lower end in the vehicle bumper below the upper absorber and absorbs an impact by being deformed in accordance with a collision;
A chamber member disposed in the vehicle bumper and having a chamber space formed therein;
A pressure sensor for detecting the pressure in the chamber space,
In the vehicle collision detection device configured to detect a collision with the vehicle bumper based on a detection result of the pressure sensor,
The chamber member is disposed above the lower absorber and adjacent to the lower absorber.
A vehicle collision detection device. The front end surface of the chamber member is located on the vehicle rear side with respect to the front end surface of the upper absorber.
The vehicle collision detection device according to claim 1. The chamber member is fixed via an attachment member projecting downward from the bumper reinforcement.
The collision detection apparatus for vehicles according to claim 1 or 2 characterized by things. The pressure sensor is disposed below the bumper reinforcement and on the vehicle rear side of the chamber member.
The vehicle collision detection device according to any one of claims 1 to 3.

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