JP2000272444A - Under-run preventing device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance shock absorbability while ensuring rigidity of an under-run protector, in an under-run preventing device for a vehicle provided with the under-run protector extended in the car width direction on the front or rear lower side of a frame. SOLUTION: An under-run protector 2 is formed in a manner wherein a section orthogonal to its car width direction has multiple holes 10. In the many holes 10, sectional density of the under-run protector 2 is set so as to decrease on the receiving surface side of a collision load thereof and increase toward the inside of a vehicle. The multiple holes 10 are integrally formed by extrusion molding of the under-run protector 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undercarriage prevention device for a vehicle.

[0002]

2. Description of the Related Art In a high-floor vehicle such as a truck, an underrun protector extending in a vehicle width direction is provided at a lower front portion or a lower rear portion of a frame in order to prevent a passenger car from getting under a frame in a collision. (For example, Japanese Patent Application No. 7-136882).

[0003]

2. Description of the Related Art In many cases, an underrun protector is formed in a square hollow section as shown in FIG. 5, and a frame (not shown) is provided at both ends thereof through brackets 21 respectively.
Supported by In this case, the input load (collision energy) at the time of collision only acts along each wall forming the hollow hollow cross section. When the hollow cross section of the underrun protector 20 is a solid cross section, the rigidity is increased, but a problem that the weight is large and bulky is considered.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an underrun protector capable of obtaining high rigidity and good shock absorption.

[0005]

According to a first aspect of the present invention, an underrun protector for a vehicle having an underrun protector extending in a vehicle width direction at a lower front portion or a lower rear portion of a frame is provided. The cross section orthogonal to the width direction is formed so as to have many holes.

According to a second aspect, in the first aspect, the large number of holes are set so as to change the cross-sectional density of the underrun protector in the longitudinal direction of the vehicle.

According to a third aspect of the present invention, in the second aspect, the large number of holes set the cross-sectional density of the underrun protector such that the cross-sectional density is smaller on the side of receiving the collision load and increases toward the inside of the vehicle.

According to a fourth aspect, in any one of the first to third aspects, the large number of holes are integrally formed by extrusion molding of an underrun protector.

[0009]

According to the first aspect of the present invention, partition walls are left between many holes in the underrun protector, and an input load at the time of collision acts on these partition walls. The rigidity of the protector can be increased. Further, in the process of crushing a large number of holes due to the input load at the time of the collision, the collision energy is gradually absorbed, and the effect of reducing the shock to the vehicle body at the time of the collision can be expected.

In the second invention, since the cross-sectional density of the underrun protector changes in the front-rear direction due to the large number of holes, the holes are crushed from a region having a low cross-sectional density to a region having a large cross-sectional density. Even if an excessive input load is applied, it is possible to prevent many holes from being crushed at once.

According to the third aspect of the present invention, a large number of holes of the underrun protector are always crushed in a predetermined order from the pressure receiving surface side to the inside of the vehicle due to an input load at the time of a collision. It can be effectively alleviated.

According to the fourth aspect of the invention, many holes are easily formed integrally by extrusion of the underrun protector. For this reason, the rigidity and shock absorption of the underrun protector can be improved at low cost.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 3, reference numeral 1 denotes a truck frame, 2 denotes a front underrun protector extending in a vehicle width direction below a front portion thereof, and brackets 3 are provided on both sides of a front portion of the frame 1. Each is joined at the base end,
The front underrun protector 2 is fixed to the front surface of the tip extending downward. Reference numeral 4 denotes a front bumper, and 5 denotes a front wheel suspension spring.

The front underrun protector 2 is formed to have a large number of square holes 10 as shown in FIG. 3 in a cross section orthogonal to the vehicle width direction. Many square holes 10
In this example, the cross-sectional density of the front underrun protector 2 is small on the front side of the vehicle (the side receiving the collision load) so as to change the cross-sectional density of the front underrun protector 2 toward the front and rear of the vehicle. The number of holes in each row and the cross-sectional shape thereof are set so as to increase the size. In this case, the front underrun protector 2 has a large number of square holes 10 formed integrally with the front underrun protector 2 by extruding aluminum.

With such a configuration, the partition walls 11 connecting between the many square holes 10 are left inside the front underrun protector 2, and these partition walls 11 are also subjected to collision (FIG. 1).
), The rigidity of the front underrun protector 2 can be efficiently increased while suppressing an increase in weight. Further, in the process of crushing many holes 10 due to the input load P at the time of the collision, the collision energy is gradually absorbed, and the effect of reducing the shock to the vehicle body at the time of the collision can be obtained.

Since the cross-sectional density of the front underrun protector 2 changes in the front-rear direction of the vehicle, the crushing of the square hole 10 progresses from a region having a small cross-sectional density to a region having a large cross-sectional density. Even if it works, it is possible to prevent many square holes 10 from being crushed at a stretch. In this case, since the cross-sectional density is small on the front side of the vehicle (the receiving surface side of the collision load P) and increases toward the inside (rearward) of the vehicle, the front underrun protector 2 responds to the input load P at the time of the collision. The rectangular holes 10 are always crushed from the pressure receiving surface side to the vehicle inside in a fixed order, so that the shock to the vehicle body side can be effectively reduced.

Since a large number of square holes 10 are easily formed integrally by extrusion of the front underrun protector 2, the rigidity and shock absorption of the front underrun protector 2 can be improved at low cost.

FIG. 4 shows another embodiment showing the cross-sectional shape of the front underrun protector 2. A large number of holes 10a are formed by extrusion of the front underrun protector 2. As shown in FIG.
Is formed. The front underrun protector 2
The number of circular holes 10a and the cross-sectional area may be laid out such that the cross-sectional density of the holes increases toward the front side of the vehicle, and the center portion is large and decreases toward the front and rear of the vehicle. Good. Of course, the present invention is also applicable to a rear underrun protector.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view illustrating an attached state of a front underrun protector.

FIG. 3 is a sectional view of a front underrun protector.

FIG. 4 is a cross-sectional view of a front underrun protector.

FIG. 5 is a sectional view of an underrun protector illustrating a conventional example.

[Explanation of symbols]

 Reference Signs List 1 frame 2 front underrun protector 3 bracket 4 front bumper 10, 10a hole 11 partition

Claims (4)

[Claims] An underrun protector for a vehicle having an underrun protector extending in a vehicle width direction at a lower front portion or a lower rear portion of a frame, wherein the underrun protector has a large number of holes perpendicular to the vehicle width direction. An undercut prevention device for a vehicle, wherein the device is formed to have 2. The undercut prevention device according to claim 1, wherein the plurality of holes are set so as to change the cross-sectional density of the underrun protector in the longitudinal direction of the vehicle. 3. The vehicle according to claim 2, wherein the number of holes is set such that the cross-sectional density of the underrun protector is smaller on the side of receiving the collision load and increases toward the inside of the vehicle. Undercut prevention device. 4. The undercut prevention device according to claim 1, wherein the plurality of holes are integrally formed by extrusion molding of an underrun protector.