JP4973950B2 - Collision detection device - Google Patents

Description

  The present invention relates to a collision detection device that is attached to a vehicle and detects a collision with the vehicle, and more particularly to a collision detection device that detects a collision of a vehicle with a bumper.

  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 means for protecting a pedestrian that has collided with a vehicle, a method of reducing the injury value (impact received by the pedestrian) received by a pedestrian who collided with the vehicle and fell into the hood has been considered. In such a protective device, it is important to detect a collision with a vehicle such as a pedestrian.

  An apparatus for detecting a collision with a vehicle is disclosed in Patent Document 1, for example. A device for detecting this collision includes a reinforcement fixed to a side member of the vehicle, a fixing member that passes through at least the reinforcement and fixes the side member and the reinforcement, and is disposed in front of the reinforcement and sealed. A collision detection device that has a chamber member that partitions the chamber space and a pressure sensor that detects a pressure in the chamber space, and detects a collision between a vehicle and a collision object from a variation in pressure in the chamber space, The chamber member has a vertically curved shape that avoids the front of the fixing member.

When a lashing hook for attaching a rope for pulling the vehicle is attached to a vehicle provided with a device for detecting the collision at a position on the front side of the back plate of the vehicle, the chamber member has a curved shape to avoid the lashing hook. It will be a thing. In such a case, the shape of the chamber member becomes complicated and blow molding becomes difficult. In addition, when the optimum position of the chamber member provided on the front surface of the reinforcement and the securing hook overlaps, one of the optimum positions is sacrificed.
JP 2007-290689 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a collision detection device in which a lashing hook can be attached and detached, and both the lashing hook and the chamber member are provided at an optimum position on the front surface of the reinforcement. And It is another object of the present invention to provide a collision detection device having a chamber member shape that can be easily blow-molded.

  In order to solve the above-mentioned problems, the present inventor has studied the collision detection device that can be assembled to the bumper of the vehicle, and as a result, has reached the present invention.

The collision detection device according to the present invention includes a reinforcement that is horizontally fixed to a base portion of a vehicle, a chamber member that is disposed in front of the reinforcement and that forms a beam-like internal space, and a pressure in the internal space. A collision detection device that detects a collision by detecting a pressure variation in the chamber space based on a deformation of the chamber member due to the collision, and the reinforcement is disposed on a portion of the vehicle facing the chamber member. The chamber member has an attachment portion for attaching a lashing hook for securing the chamber member, and the chamber member is inserted in a portion facing the attachment portion of the reinforcement through the attached portion attached to the attachment portion of the lashing hook in the front-rear direction. A volume corresponding to the volume of the internal space reduced by the cylinder portion on at least one of the upper wall and the lower wall of the cylinder portion forming the through-hole penetrating through And having to the convex portion forming the shark space projecting only upward, a.

  In the collision detection device of the present invention, the chamber member is provided with a through hole for penetrating the securing hook. That is, the lashing hook is detachable at an optimum position on the front surface of the reinforcement, and a chamber member having a through hole through which the lashing hook is inserted is also provided at the optimum position on the front surface of the reinforcement. For this reason, the position of the lashing hook and the position of the chamber member are optimal for the collision detection device of the present invention, both when pulled by a rope through the lashing hook and when detecting a pedestrian collision.

Further, in the collision detection device of the present invention, the chamber member forms an additional space that has a volume corresponding to the volume of the internal space reduced by the cylindrical portion that forms the through hole through which the lashing hook is inserted and projects only upward. Have a convex part. That is, by compensating the volume reduced by providing the cylindrical portion with the additional space of the convex portion, the volume change amount of the chamber space, which is reduced by the deformation of the chamber member due to the collision, becomes equivalent to the portion without the cylindrical portion, and the chamber The amount of increase in pressure in the space is also equivalent to when it collides with a portion without a cylindrical portion. Thereby, the fall of the determination accuracy of a collision can be suppressed. The chamber member may be substantially straight.

  The collision detection device of the present invention is fixed to the base of a vehicle and includes a reinforcement, a chamber member, and a pressure sensor. A vehicle to which the collision detection device is fixed refers to a vehicle such as a passenger car, a truck, a bus, and a tram that normally travels on a road. More specifically, it refers to a road traveling vehicle equipped with a bumper or other collision buffer.

  The reinforcement constituting the collision detection device is a member that is fixed to a base portion of the vehicle, that is, a main part of the structural strength of the vehicle, for example, a side member, and comes into contact with a collision object that collides with the collision vehicle. Bumper or bumper reinforcement or crash box located on the vehicle side of the bumper. This reinforcement normally functions as a member that receives a collision force extending in the vehicle width direction at the front end and the rear end of the vehicle. Reinforce requires considerable strength to protect the vehicle against collisions and is manufactured from steel plates, aluminum alloy extrusions, reinforced resins, and the like. Reinforce requires a front portion and strength large enough to face the chamber member and receive a collision force acting on the chamber member.

  The reinforcement has an attachment portion that detachably fixes the lashing hook. As this attachment portion, a known one that detachably fixes a conventional lashing hook can be used. Specifically, a nut that can be attached and detached by a screw number welded to a reinforcement can be mentioned.

  The chamber member is a chamber member used in a conventional collision detection device provided with a cylindrical portion and a convex portion. Therefore, the conventional chamber member can be used as it is except for the cylindrical portion and the convex portion. This chamber member can be made of resin that forms a beam-like internal space extending in the horizontal direction. Here, the beam shape means a shape that extends in the horizontal direction and has a substantially constant cross section, and preferably has a rectangular cross section. For example, when the pedestrian collides with the vehicle, the chamber member collides with the front surface of the chamber member, and the collided portion of the chamber member is sandwiched between the leg portion and the back plate to be crushed. Assumed. That is, only a specific portion of the front wall that has collided with the leg portion of the chamber member is pressed toward the back plate and crushed. The portion of the front wall of the chamber member where the legs do not collide does not collapse and does not deform.

  The chamber member has a cylindrical portion that defines a through hole penetrating from the front wall to the rear surface. The through hole is inserted through the attached part of the lashing hook, and when the vehicle is pulled by a rope or the like, the attached part of the lashing hook is inserted through the through hole of the cylindrical part and fixed to the reinforcement. Fixed to the mounting part. The other end to which the rope of the lashing hook is hung is projected forward from the front wall of the chamber member. The cylindrical portion that defines the through-hole needs to be strong enough not to be damaged by the insertion of the lashing hook and the pulling of the vehicle by the lashing hook. However, when the pedestrian's leg collides with the front wall part with the cylinder part when the lashing hook is not fixed, it is crushed and pushed to the back plate side like the front wall part without the cylinder part. It must be crushed.

  The chamber member further has a convexity forming at least one of an upper wall and a lower wall of the cylindrical portion and having an additional space protruding upward and / or downward having a volume corresponding to the volume of the internal space reduced by the cylindrical portion. Have a part. The convex part which forms an additional space shall extend an upper wall and / or a lower wall in the front-back direction. The cross section of the additional space may be longer in the horizontal direction than in the vertical direction. The cross-sectional shape can be a square shape, a crescent shape, a trapezoidal shape, or the like. In addition, when the cross section of a chamber member is a square shape, it is preferable that the cross section of a convex part is made constant. However, when the cross section is circular, elliptical, or the like, the cross section of the convex portion need not be constant.

  The internal space of the chamber member does not need to have a completely sealed structure, and it is sufficient that pressure fluctuations occur reliably with respect to a decrease in the volume of the internal space due to crushing due to a collision. The chamber member can be made of resin. As the resin, a synthetic resin that can be easily deformed and blow-molded, such as polyethylene and polypropylene, can be used.

  The pressure sensor is a sensor that detects the pressure in the internal space of the chamber member, and a sensor that is used in a conventional collision detection device or an air pressure measurement sensor that measures air pressure can be used.

  The lashing hook is used to hang a rope for towing a vehicle. The lashing hook has a detachable attached part to the attachment part of the reinforcement at one end and a hook etc. to which the rope is hung at the other end. It is a rod-shaped member, and conventionally known members can be used.

  The collision detection device of the present invention can be provided with components provided in the bumper. For example, a shock absorber can be provided below the chamber member on the front side of the reinforcement. In addition, a decorative soft cover can be provided on the front surface of the chamber member.

  The collision detection device of the present invention is preferably arranged so that the chamber member comes into contact with the position of the leg portion of the pedestrian in a state where the pedestrian stands upright. The height of the leg here refers to the position of the knee from the calf for adults, and near the thigh for children. Thereby, a chamber member is pressed by the leg part of a pedestrian, is pinched | interposed with a reinforcement, and is crushed. As a result, the pressure in the chamber space rises, and the collision is detected when the sensor detects it.

  Hereinafter, the present invention will be described using examples.

  The collision detection apparatus of the Example of this invention is typically shown in FIGS. FIG. 1 is a schematic view seen from above a front portion of a vehicle assembled with a collision detection device, FIG. 2 is a cross-sectional view of a main part of the collision detection device, FIG. 3 is a front view of the collision detection device, and FIG. It is principal part sectional drawing of the state which attached the lashing hook to the collision detection apparatus.

  This collision detection device includes a bumper reinforcement 1, a chamber member 2, a pressure sensor 3, an absorber 4, and a calculation means (not shown) corresponding to the reinforcement of the present invention.

  The bumper reinforcement 1 has a frame structure including a metal front wall 11, a rear wall 12, an upper wall 13, a lower wall 14, and a central wall 15, as shown in a cross section in FIG. 2. The bumper reinforcement 1 extends in the horizontal direction and is fixed to the front end portions of a pair of side members 9 of the vehicle. Between the upper wall 13 and the central wall 15 at both ends of the bumper reinforcement 1 in the horizontal direction, there are provided mounting portions 8 and 8 made of nuts welded to the front wall 11 and the rear wall 12 respectively. Yes. The mounting portions 8, 8 have shaft holes 80, 80 that are open at the front and closed at the rear, and a thread of an internal thread is formed on the inner peripheral surface that defines the shaft holes 80, 80. The attachment portions 8 and 8 are components that detachably fix the lashing hook 7 shown in FIG. The side member 9 is a strength member that constitutes the base of the vehicle, and its tip protrudes forward of the engine room.

  The chamber member 2 is a member having a beam-shaped internal space 20 extending in the horizontal direction and having a substantially square cross section, and is formed by blow molding a low density polyethylene resin. The chamber member 2 has cylindrical portions 21 and 21 at both ends in the horizontal direction, and sections the shaft holes 210 and 210 where both front and rear ends of the chamber member 2 are opened. These shaft holes 210, 210 are provided at positions that are coaxial with the shaft holes 80, 80 of the mounting portions 8, 8 fixed to the bumper reinforcement 1. The securing hook 7 is inserted through the shaft holes 80, 80.

  Further, the chamber member 2 has convex portions 22 and 22 having a trapezoidal cross section shown in FIG. These convex portions 22 and 22 are located above the cylindrical portions 21 and 21, and the volume of each convex portion 22 (corresponding to the additional space of the present invention) is formed to be the same as the volume of the cylindrical portion 21. In addition, these convex parts 22 and 22 protrude a part of upper wall which divides the upper part of the chamber member 2 upwards in the cross-sectional trapezoid shape.

  The chamber member 2 is fixed in contact with the upper portion of the front surface of the front wall 11 of the bumper reinforcement 1.

  The pressure sensor 3 is a sensor for measuring the pressure in the internal space 20 of the chamber member 2 and is conventionally known. The pressure sensor 3 detects a gas pressure and derives it as an electric signal to an arithmetic means. The pressure sensor 3 is fixed to the central portion of the front wall 11 of the bumper reinforcement 1. The pressure detection unit (not shown) of the pressure sensor 3 communicates with the internal space 20 of the chamber member 2 through a through hole (not shown) provided in the front wall 11 of the bumper reinforcement 1 and the rear wall of the chamber member. is doing.

  The absorber 4 is located below the chamber member 2 and is disposed in the lower part of the front surface of the front wall 11 of the bumper reinforcement 1. The absorber 4 is molded as a foamed resin, and its front surface is formed in a shape that matches the inner peripheral surface of the bumper cover 5.

  The computing means is connected to the pressure sensor 3 and calculates the pressure in the internal space 20 of the chamber member 2 from the detection signal of the pressure sensor 3 and determines a collision from the calculated pressure. The calculation means may be incorporated in the cpu previously installed in the vehicle, or may be incorporated in the pedestrian protection device.

  The bumper cover 5 is a plate-shaped resin molded body and is a decorative member that covers the chamber member 2 and the absorber 4. The bumper cover 5 is also formed with a through hole 51 coaxial with the shaft hole 210 of the chamber member 2.

  The lashing hook 7 is a component having one end portion serving as a male screw portion 71 and a loop portion 72 passing a rope to the other end. The lashing hook 7 is also referred to as a tow hook, and is used by being fixed to the mounting portion 8 when moving due to a vehicle accident or vehicle trouble. The lashing hook 7 is usually separated from the mounting portion 8 and stored in a vehicle tool box or the like.

  The collision detection by the collision detection apparatus of the present embodiment will be described below.

  As shown in FIG. 1, the bumper cover 5 of the vehicle in which the collision detection device of this embodiment is assembled has the bumper cover 5 covering the chamber member 2 and the absorber 4 to form the outer surface of the bumper of the vehicle.

  When a pedestrian collides with the bumper of the vehicle, the leg of the pedestrian presses the bumper of the vehicle. The leg portion of the pedestrian presses the chamber member 2 via the bumper cover 5, and the portion pressed by the chamber member 2 is deformed rearward and is crushed into a shape along the colliding leg portion. Due to the collapse of the chamber member 2, the volume of the internal space 20 decreases, and the air pressure in the internal space 20 increases. This increase in air pressure is detected by the sensor 3 and sent to the computing means to determine a collision.

  Since the colliding pedestrian's leg is long in the vertical direction, the collapse due to the collision of the chamber member 2 extends the chamber member 2 in the vertical direction with the width of the leg.

  When the colliding pedestrian's leg portion includes the shaft portion 21 of the chamber member 2, the shaft portion 21 and the convex portion 22 located above the shaft portion 21 are also crushed. The volume of the crushed chamber member 2 is a volume obtained by subtracting the volume of the crushed shaft portion 21 and adding the additional space 220 of the crushed convex portion 22. Since the volume of the shaft portion 21 and the volume of the additional space 220 are equal, they cancel each other, and the volume of the chamber member 2 to be crushed is the same as that without the shaft portion 21 and the convex portion 22. That is, the same volume is crushed regardless of whether the pedestrian's leg collides with the portion that includes or does not include the cylindrical portion 22 of the chamber member 2. For this reason, even if it collides with the part including the shaft part of the bumper extending in the horizontal direction of the chamber member 2 or when it collides with the part not including the shaft part 22, the same volume will be crushed. The increase in air pressure in the space is also equal. For this reason, there is no possibility that the accuracy of the collision determined by the calculation means is lowered depending on the presence or absence of the shaft portion 22.

  The calculation means can also determine whether the collision object is a human body such as a pedestrian or the like or a hard structure such as another vehicle from the degree of change (change ratio) of the pressure. At this time, it is preferable that vehicle speed data is also input to the calculation means.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention. For example, in the embodiment, the absorber 4 is disposed below the chamber member, but the present invention is not limited to this. The absorber 4 may be disposed on the front surface of the chamber member 2.

  Further, as shown in FIG. 5, the convex portion 22 formed on the chamber member 2 can be provided below the shaft portion 21. Moreover, as shown in FIG. 6, the convex part 22 formed in the chamber member 2 can also be provided both above and below the shaft part 21. The total volume of the additional space formed by the upper and lower convex portions is the same as the volume of the additional space of one convex portion in the embodiment. Furthermore, as shown in FIG. 7, the cross-sectional shape of the convex portion can be a crescent shape. Furthermore, as shown in FIG. 8, the positions of the cylindrical portion 21 and the convex portion 22 may be the central portion in the horizontal direction of the chamber member 2.

It is the schematic diagram seen from the front side part of the vehicle which assembled | attached the collision detection apparatus of the Example. It is principal part sectional drawing of the collision detection apparatus of an Example. It is a front view of the collision detection apparatus of an Example. It is principal part sectional drawing of the state which attached the lashing hook to the collision detection apparatus of an Example. It is a front view of the collision detection apparatus which shows the modification of FIG. It is a front view of the collision detection apparatus which shows the other modification of FIG. It is a front view of the collision detection apparatus which shows the other modification of FIG. It is a front view of the collision detection apparatus which shows the other modification of FIG.

Explanation of symbols

1: Bumper reinforcement 2: Chamber member 20: Internal space 21: Tube portion 22: Convex portion 210: Shaft hole 220: Additional space
3: Pressure sensor 4: Absorber 5: Bumper cover 7: Locking hook 8: Mounting part

Claims (6)

Reinforce fixed horizontally at the base of the vehicle,
A chamber member disposed in front of the reinforcement and forming a beam-like internal space extending in the horizontal direction;
A pressure sensor for detecting the pressure in the internal space;
A collision detection device for detecting a collision by detecting a pressure variation in the chamber space based on deformation of the chamber member due to a collision,
The reinforcement has a mounting portion for attaching a lashing hook for tying the vehicle to a portion facing the chamber member,
The chamber member has a cylindrical portion that forms a through-hole penetrating the chamber member in the front-rear direction by inserting a portion to be attached to the attachment portion of the lashing hook into a portion of the reinforcement facing the attachment portion. And at least one of the upper wall and the lower wall of the cylindrical portion, a convex portion that forms an additional space that has a volume corresponding to the volume of the internal space reduced by the cylindrical portion and protrudes only upward ,
A collision detection apparatus comprising:   The collision detection device according to claim 1, wherein the additional space has a horizontal width whose cross section is longer than a vertical height.   The collision detection device according to claim 1, wherein the chamber member is formed of a soft resin that is easily deformable.   The collision detection device according to claim 1, further comprising an absorber disposed on a front surface of the reinforcement below the chamber member. The collision detection device according to claim 1, wherein the chamber member has a substantially straight shape.   The collision detection apparatus according to claim 1, wherein the reinforcement is a bumper reinforcement.