JP2007203808A - Collision energy absorbing structure of automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an absorbing effect of collision energy in collision against another vehicle. <P>SOLUTION: A sub bumper beam 30 is moved to a working position below an approach angle line L of a front wheel from a retreating position above it by providing the sub bumper beam 30 on a front end of an elevation arm 61 to elevate by a ball screw mechanism 51 provided on a undersurface of a front side frame 12 and lowering the elevation arm 61 by the ball screw mechanism 51 when the collision against the other vehicle is predicted. Consequently, it is possible to improve the absorbing effect of the collision energy by holding the sub bumper beam 30 at the working position and colliding the sub bumper beam 30 against a bumper beam 41 and a side sill of the other vehicle in emergency when the collision is predicted while avoiding contact with a road surface by holding the sub bumper beam 30 in normal time when the collision is not predicted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a collision energy absorbing structure for an automobile provided with a sub-bumper beam that can be moved up and down by a ball screw mechanism below the bumper beam.

  As shown in FIG. 6, in a vehicle such as an SUV in which the position of the bumper beam 01 of the front bumper is increased, an under protector 02 is provided below and below the bumper beam 01.

In addition, a bumper that can be moved up and down by a vertical movement mechanism is provided at the rear of the large truck, and the bumper contacts the inclined road surface by adjusting the bumper height according to the ground height detected by the ground height sensor. Patent Document 1 below discloses that a bumper vehicle is kept as low as possible to prevent a rear-end collision vehicle from entering under its own vehicle.
JP-B-2-36420

  By the way, in the conventional vehicle shown in FIG. 6, in order to avoid the under protector 02 from coming into contact with the inclined road surface, it is necessary to raise the vertical position to some extent and to arrange it to a certain degree behind the bumper beam 01. there were. Therefore, the height of the bumper beam 03 of the other vehicle and the height of the under protector 02 of the own vehicle become substantially the same, and the bumper beam 03 of the other vehicle sinks under the under protector 02 of the own vehicle when a frontal collision occurs. There was a problem that the collision energy could not be absorbed sufficiently. Further, as shown in FIG. 7, when the own vehicle collides with the side surface of the other vehicle, the under protector 02 of the own vehicle is retracted behind the bumper beam 01, so that the under protector 02 is moved to the side sill 04 of the other vehicle. Before the collision and absorbing the collision energy, the bumper beam 01 may collide with the door 05 or the center pillar 06 of another vehicle and enter the vehicle interior.

  Therefore, if the bumper is moved to a lower position using the mechanism described in Patent Document 1, it is possible to prevent the other vehicle from entering under the own vehicle and the own vehicle from entering the vehicle interior of the other vehicle. . However, if the bumper height is changed according to the distance from the road surface, not only does the bumper come into contact with the road surface when the road surface slope changes during high-speed driving, but the bumper always moves up and down. The actuator noise and power consumption may increase repeatedly.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to enhance the effect of absorbing collision energy at the time of collision with another vehicle.

  In order to achieve the above object, according to the first aspect of the present invention, the left and right ball screw mechanisms respectively actuated by the actuators are provided on the lower surfaces of the left and right front side frames with the bumper beams fixed to the front ends, A sub-bumper beam is provided at the front ends of the left and right lifting arms that are lifted and lowered by the ball screw mechanism, and when the collision with another vehicle is predicted, the ball screw mechanism is operated to lower the lifting arm. A collision energy absorbing structure for an automobile is proposed in which the bumper beam is moved from the retracted position above the approach angle line of the front wheel to the operating position below.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the front end of the sub-bumper beam and the front end of the bumper beam in the operating position are aligned in the longitudinal direction of the vehicle body. A collision energy absorption structure for automobiles is proposed.

  According to the first aspect of the present invention, the sub bumper beam is provided at the front end of the lifting arm that is lifted and lowered by the actuator of the ball screw mechanism provided on the lower surface of the front side frame, and is lifted by the actuator when a collision with another vehicle is predicted. By lowering the arm, the sub-bumper beam can be moved from the retracted position above the approach angle line of the front wheel to the operating position below. As a result, the sub-bumper beam is kept below the approach angle line in an emergency when a collision is predicted, while maintaining the sub-bumper beam in the retracted position above the approach angle line and avoiding contact with the road surface in normal times when no collision is predicted. By holding the sub-bumper beam against the bumper or side sill of another vehicle, the collision energy absorption effect is enhanced, and the own vehicle rides on the other vehicle, or the own vehicle bumper beam moves to the other vehicle. It is possible to prevent the vehicle from entering the passenger compartment.

  According to the second aspect of the present invention, since the front end of the sub-bumper beam and the front end of the bumper beam in the operating position are aligned in the longitudinal direction of the vehicle body, when the host vehicle collides with the side surface of the other vehicle, By causing the sub bumper beam to collide with the side sill of the other vehicle substantially simultaneously with the collision with the door or center pillar of the other vehicle, it is possible to effectively prevent the bumper beam from penetrating into the vehicle interior of the other vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a side view of a front part of a vehicle body, FIG. 2 is an enlarged view of part 2 in FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view, FIG. 4 is an operation explanatory diagram at the time of a frontal collision, and FIG. 5 is an operation explanatory diagram at the time of a side collision.

  As shown in FIGS. 1 to 3, left and right front side frames 12, 12 extending in the longitudinal direction of the vehicle body are disposed along the left and right sides of the engine room 11 formed at the front of the vehicle body. Bumper beams 14 are coupled to the front ends of the side frames 12 and 12 by bolts 13. A bumper 18 is constituted by the bumper beam 14 and a bumper face 17 covering the front surface thereof.

  A ball screw mechanism 51 is provided on the front lower surface of each front side frame 12. The ball screw mechanism 51 includes a strong guide rail 52 that is fixed to the lower surface of the front side frame 12 and extends downward, and an upper bearing that is fixed to the lower surface of the front side frame 12 so as to be positioned in the upper surface opening of the guide rail 52. A member 53; a lower bearing member 54 that closes the lower surface opening of the guide rail 52; an upper bearing member 53; a screw shaft 55 supported at both upper and lower ends by the lower bearing member 54; and an electric motor provided on a side surface of the guide rail 52 An actuator 56, a worm 58 provided on the output shaft 57 of the actuator 56, and a worm wheel 59 provided on the screw shaft 55 and meshing with the worm 58.

  Nut members 60, 60 that are screwed into the screw shaft 55 are provided at the rear end, and left and right lifting arms 61, 61 projecting forward of the vehicle body from slits 52a, 52a formed in the vertical direction on the front surfaces of the guide rails 52, 52. A sub bumper beam 30 extending in the left-right direction of the vehicle body is fastened to the front end by bolts 62. Accordingly, when the actuators 56, 56 of the ball screw mechanism mechanisms 51, 51 are driven, the worms 58, 58, the worm wheels 59, 59, the screw shafts 55, 55 and the nut members 60, 60 provided on the output shafts 57, 57 are connected. The lifting arms 61 and 61 are moved up and down together with the sub-bumper beam 30.

  A line extending from the lower surface of the front wheel W to the front and forming an approach angle α with respect to the ground is defined as an approach angle line L. The approach angle α is set so that the lower end of the bumper 18 or the ball screw mechanism 51 is used when the vehicle moves from a flat road to an uphill road, when the vehicle moves from a downhill road to a flat road, or when the vehicle gets over a protrusion on the road surface. , 51 is set so that the lower ends of the roads do not contact the road surface.

  The bumper face 17 is provided with a radar device 34 for detecting an obstacle such as another vehicle, and an electronic control unit 35 to which the radar device 34 is connected controls the operation of the actuators 56, 56.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  In normal times when there is no risk of a vehicle colliding, the sub-bumper beam 30 is in the retracted position indicated by a chain line in FIG. 2, and at this time, the sub-bumper beam 30 is located above the approach angle line L. Therefore, when the vehicle moves from a flat road to an uphill road or when the vehicle moves from a downhill road to a flat road, the sub-bumper beam 30 is prevented from coming into contact with the road surface.

  When the radar device 34 detects that the possibility of a collision with another vehicle has increased, the actuators 56 and 56 of the ball screw mechanisms 51 and 51 are actuated by a command from the electronic control unit 35, and the screw shafts 55 and 55 rotate. As a result, the sub-bumper beam 30 descends and stops at the operating position indicated by the solid line in FIG.

  In this state, when the host vehicle collides head-on with another vehicle as shown in FIG. 4, even if the bumper beam 14 of the host vehicle is at a higher position than the bumper beam 41 of the other vehicle, the lowered sub-bumper beam 30 is By catching on the bumper beam 41 of the other vehicle, it is possible to prevent the host vehicle from riding on the other vehicle and damaging the passenger compartment of the other vehicle.

  The collision energy input from the other vehicle to the bumper beam 14 is transmitted to and absorbed by the front side frames 12 and 12 as indicated by arrows in FIG. 2, and the collision energy input from the other vehicle to the sub-bumper beam 30. The energy is transmitted to and absorbed by the front side frames 12 and 12 via the lifting arms 61 and 61, the screw shafts 55 and 55, and the guide rails 52 and 52.

  Further, as shown in FIG. 5, when the host vehicle collides side-by-side with another vehicle with the sub-bumper beam 30 lowered to the operating position, the bumper beam 14 of the host vehicle collides with the door 42 and the center pillar 43 of the other vehicle. At substantially the same time, the sub-bumper beam 30 of the host vehicle collides with the side sill 44 of the other vehicle. At this time, since the side sill 44 and the floor frame 45 connected to the side sill 44 have higher rigidity than the door 42 and the center pillar 43, the collision energy is efficiently absorbed by the sub-bumper beam 30 of the own vehicle and the side sill 44 of the other vehicle. Thus, it is possible to prevent the bumper beam 14 of the own vehicle from penetrating into the passenger compartment of another vehicle.

  As described above, in an emergency in which a collision is predicted, the sub-bumper beam 30 is held at the retracted position above the approach angle line L (see FIG. 2) to avoid contact with the road surface in an emergency. Since the sub-bumper beam 30 is lowered to the operating position below the approach angle line L, when the host vehicle collides head-on with another vehicle, the host vehicle rides on the other vehicle (the other vehicle sinks under the host vehicle). The collision energy can be effectively absorbed and when the host vehicle collides with another vehicle, the collision energy can be effectively prevented by preventing the host vehicle from penetrating into the passenger compartment of the other vehicle. Can be absorbed into. Moreover, since the actuators 56 and 56 operate only when a collision with another vehicle is predicted, not only the power consumption of the actuators 56 and 56 is reduced, but also noise due to the operation of the actuators 56 and 56 becomes a problem. There is nothing.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, a CCD camera or a navigation system can be used instead of or in addition to the radar device 34 for predicting a collision.

Side view of the front of the car body 2 enlarged view of FIG. 3-3 enlarged sectional view of FIG. Action explanatory diagram at the time of frontal collision Action explanatory diagram at the time of side collision Action explanatory diagram at the time of frontal collision of the conventional example Action explanatory diagram at the time of side collision of the conventional example

Explanation of symbols

12 Front side frame 14 Bumper beam 30 Sub-bumper beam 51 Ball screw mechanism 56 Actuator 61 Lift arm L Front wheel approach angle line W Front wheel

Claims (2)

  Left and right ball screw mechanisms (51) operated by actuators (56) are provided on the lower surfaces of the left and right front side frames (12) to which the bumper beams (14) are fixed at the front ends, respectively. A sub-bumper beam (30) is provided at the front end of the left and right lifting arms (61) that move up and down, and when the collision with another vehicle is predicted, the ball screw mechanism (51) is operated to move the lifting arm (61). An automobile collision energy absorbing structure, wherein the sub-bumper beam (30) is moved downward from the retracted position above the approach angle line (L) of the front wheel (W) to the operating position below. The collision energy absorption structure for an automobile according to claim 1, wherein the front end of the sub-bumper beam (30) in the operating position and the front end of the bumper beam (14) are aligned in the longitudinal direction of the vehicle body.

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