JPH0543537B2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a rear-end collision prevention device for a vehicle.

``Prior art'' and ``Problems to be solved by the invention'' For example, when various types of work vehicles, trucks, and other vehicles are stopped on the road and construction work is being carried out, there is a possibility that a vehicle running on these vehicles may be stopped on the road. In the event of a rear-end collision due to a driving error or the like, there is a risk that not only the vehicles of both vehicles will be damaged, but also personal injury may occur, especially on expressways, which may lead to a catastrophe.

Possible measures to prevent such accidents include attaching a shock absorber to the bumper of the vehicle, or attaching a shock absorber such as a hydraulic damper to vehicles such as the above-mentioned work vehicles when necessary; however, the former For example, in order to obtain the shock absorbing capacity necessary to protect the driver in the event of a rear-end collision on a highway, a shock absorber as large as possible is required, and such shock absorbers are long and heavy. Therefore, attaching such a shock absorbing device to the bumper, which is unnecessary for normal driving, has various problems in terms of vehicle weight, appearance, drivability, cost, economic efficiency, etc., and has not been put into practical use. is the current situation. In addition, the latter requires a large stroke and is therefore large and heavy, which poses problems in transportation and handling.In addition, it is necessary to prepare dampers that are used very infrequently and to constantly inspect and maintain them. Furthermore, at present, it is hardly used because a large impact load is instantaneously generated when an impact occurs.

Therefore, in most cases, in the past, during construction, indicator lights, pylons, etc. were installed around the construction area to alert drivers, and this prevented a momentary driving error. There was a strong possibility that a major accident could occur due to such factors.

"Means for Solving the Problem" In view of the above-mentioned circumstances, the present invention has been made to solve the above-mentioned problems of the prior art. In addition to forming a hollow space that penetrates each cell, each cell has a common length in the cell axis direction, so that the impact load in the event of a rear-end collision is absorbed by permanent strain caused by buckling of the cell wall in the cell axis direction. Using a shock absorbing device constructed by covering the peripheral portion of the constructed honeycomb core shock absorbing material with a cover member formed of a material having a compressive strength lower than the compressive strength of the shock absorbing material. Become. The shock absorber has its lower side held in contact with the ground such as a road, independently of the vehicle, and is designed to support the shock absorber in the longitudinal direction of the vehicle in the vicinity of the front or rear bumper of the vehicle when the vehicle is stopped. The cushioning material is detachably and retractably fixed by an appropriate attachment means in a direction in which the cell axis directions of the cushioning material substantially coincide with each other.

``Function'' This device for preventing rear-end collisions for vehicles combines a honeycomb core cushioning material that forms a hollow space through which each cell passes linearly and has a common length, and a cover member with a predetermined compressive strength. It is equipped with a shock absorber whose lower surface side is held in contact with the ground independently of the vehicle, and this shock absorber is attached to the vehicle in a detachable and indexable manner.

In the honeycomb core shock absorbing material of this shock absorbing device, about 75% of the cell walls in the cell axis direction, which substantially coincides with the longitudinal direction of the vehicle, undergo permanent deformation due to buckling caused by compression during a rear-end collision. It has the property of absorbing a large amount of impact load. In addition, since the lower side of the shock absorber is held in contact with the ground, this type of shock absorption is performed stably and reliably, without the impact of a rear-end collision deviating from its direction of action. , vehicle damage and personal accidents can be prevented.

In addition, this shock absorber is installed in a removable and indexable manner to the vehicle, and the shock absorbing material of this shock absorber is made of an extremely lightweight honeycomb core, making it easy to transport and handle. It's very simple and easy. In addition, if the external appearance maintains the predetermined dimensions, it will function reliably and no inspection or maintenance is required. Furthermore, since it is separate and independent from the bumper on the vehicle side, it can be removed and stored separately when it is not needed, and there is no risk of impairing the weight, appearance, running performance, economy, etc. of the vehicle.

"Embodiments" The present invention will be described below based on embodiments shown in the drawings.

In FIGS. 1 to 3, 1 is a shock absorber, and this shock absorber 1 is constructed as follows.

The shock absorber 1 of the rear-end collision prevention device for this vehicle is as follows:
Each cell 2a forms a hollow space that penetrates linearly, and the length of each cell 2a in the cell axis direction is common, so that the impact load at the time of a rear collision is transferred to the cell wall in the cell axis direction. A cover member 3 made of a material having a compressive strength lower than the compressive strength of the cushioning material 2 covers the periphery of the honeycomb core cushioning material 2, which is configured to absorb permanent strain caused by buckling. It is made up of things. The shock absorber 1 has its lower side held in contact with the ground such as a road separately from the vehicle such as the work vehicle 5, and is attached to the front or rear of the vehicle such as the work vehicle 5 in a stopped state. The cushioning material 2 is removably and removably fixed by an appropriate attachment means in a direction in which the longitudinal direction of the vehicle and the cell axis direction of the cushioning material 2 substantially coincide with each other while being spaced apart from the vicinity of the bumper 6 of the vehicle. ing. These will be explained in detail below. In other words, in the case of a rear-end collision, the cell 2a can absorb the impact load acting in the axial direction of the cell 2a by the permanent strain caused by buckling caused by the cell 2a being compressed in the axial direction. This is a cushioning material formed of a honeycomb core configured with a honeycomb core, and the surrounding part of this cushioning material 2 is covered with a cover member 3 made of a material having a compressive strength lower than the compressive strength of the cushioning material 2. Covered. 4 is a frame member provided on the cover member 3 on the open end side of one cell 2a in the honeycomb core constituting the cushioning material 2; Magnetic metal plates 7, 7 are attached. Reference numeral 8 denotes a magnet provided at a position that is the same distance as the distance between the metal plates 7, 7 in the bumper 6.

Now, when the shock absorber 1 is fixedly attached to the work vehicle 5 which is in a stopped state with its longitudinal direction along the direction of road travel, the shock absorber 1 is installed on the bumper 6 on the rear side of the work vehicle 5 in the direction of travel of the road. By adhering the metal plate 7 to the magnet 8, the shock absorber 1 is placed so that its lower surface is in contact with the road and the axial direction of the cells 2a of the shock absorbing material 2 are positioned along the direction of travel of the working vehicle 5. fixed to the side.

In addition, when the bumper 6 of the working vehicle 5 is formed of a magnetic material such as steel, a magnet 8 is provided at a predetermined portion of the frame member 4 of the shock absorber 1, and the structure is such that the bumper 6 is attracted to the bumper 6 by the magnet 8. It's okay to be hot.

Next, an example of calculating a predetermined size necessary for absorbing the impact load of the honeycomb core constituting the cushioning material 2 will be explained.

(1) The required cross-sectional area A of the honeycomb core is calculated using the formula A=0.8GW/σcr. (2) The required thickness T of the honeycomb core in the cell axis direction is calculated using the formula T=WV ² /2gσcrA. be able to.

Here, σcr: crushing strength of the honeycomb core, g: gravitational acceleration, W: weight of the rear-end collision vehicle, V: speed of the rear-end collision vehicle, G: allowable G,
0.8: Safety factor.

In addition, if the speed of the vehicle is V, and the value of G when it rear-ends the honeycomb core and suddenly stops is set to the allowable G, the stopping distance S of the rear-end vehicle, that is, the buckling due to the compression of the honeycomb core. Therefore, the thickness that can absorb the impact load is calculated by the following formula.

The acceleration α is α=Gg, (3) and the time t from rear-end collision to stopping is t=V/α, (4) the stopping distance S is S=Vt−1/2αt ² It can be determined by the formula.

Therefore, the speed V of the rear-ending vehicle is 80 km,
When the weight W is 1 ton and the driver's permissible G is set to 40, the distance S that allows sudden stopping is: V = 80 x 1000/3600 ≒ 22.2 (m/sec) From equation (3), t = 22.2/40 x 9.8≒0.057 (sec) Acceleration α=40×9.8=392 (m/sec ² ) Therefore, from equation (4), S=22.2×0.057−1/2×392 ×0.057 ² ≒0.628(m), Honeycomb core is an abbreviation for the thickness in the cell axis direction.
Since 75% of honeycomb cores have the property of absorbing impact loads by buckling due to compression, in this case, the thickness of the honeycomb core in the cell axis direction, T, is as follows: T = S / 0.75 = 0.628 / 0.75 ≒ 0.837 (m ) or above.

Furthermore, when a honeycomb core with crush strength σcr=8.0Kg/cm ² is used, the cross-sectional area A of the honeycomb core is calculated from equation (1) as follows: A=0.8×40×1000/8.0=4000 (cm ² ). Therefore, if the length of one side is set to 50 cm, it is sufficient to use a honeycomb core having a cross-sectional area where the length of the other side is at least 80 cm.

An example of calculating the size of the cushioning material 2 has been explained above, but when carrying out the calculation, it is important to consider the weight and speed of the rear-end vehicle and set the size to be larger, so that the cushioning material with excellent safety can be calculated. 2 is obtained.

This vehicle's rear-end collision prevention device, that is, shock absorber 1
is configured as described above. Therefore, it becomes as follows. This rear-end collision prevention device for vehicles such as the work vehicle 5 includes a honeycomb core cushioning material 2 that forms a hollow space through which each cell 2a penetrates linearly and has a common length, and a cover member having a predetermined compressive strength. 3 is used in combination with the work vehicle 5, etc., and is equipped with a shock absorber 1 whose lower surface side is held in contact with the ground separately from the vehicle such as the work vehicle 5. It is attached to the vehicle in a removable and indexable manner.

In the honeycomb core shock absorbing material 2 of this shock absorbing device 1, about 75% of the cell walls in the cell axis direction of each cell 2a, which substantially coincides with the front-rear direction of the vehicle such as the work vehicle 5, are compressed during a rear-end collision. It has the property of absorbing a large impact load due to the permanent hole strain caused by buckling. Moreover, this type of shock absorption
Since the cover member 3 on the lower side of the shock absorber 1 is held in contact with the ground such as the road, the direction of its action will not be changed due to the impact of a rear-end collision, and the shock absorber 1 will operate stably and reliably. , damage to vehicles such as the work vehicle 5 and personal accidents can be prevented.

The shock absorber 1 is detachably and removably installed on a vehicle such as a working vehicle 5, and the shock absorber 2 of the shock absorber 1 is made of an extremely lightweight honeycomb core. Therefore, transportation and handling are extremely easy. Moreover, this shock absorber 1 functions reliably as long as the external appearance maintains the predetermined dimensions, and no inspection or maintenance is required. Furthermore, this shock absorber 1 is separate and independent from the bumper 6, etc. on the vehicle side of the work vehicle 5, etc., and can be removed and stored separately when not needed. There is no risk of harming economic efficiency, etc.

FIG. 4 shows another embodiment. In this embodiment, casters 10, 10 are provided at the lower corners of the shock absorber 1, and the shock absorber 2 is provided with casters 10, 10.
A towed bar 11 is provided in a protruding manner on one cell open end side of the honeycomb core constituting the honeycomb core, and the shock absorber 1 is connected and fixed to the working vehicle 5 via this towed bar 11. ing.

Therefore, in this embodiment, for example,
When carrying out construction while the work vehicle 5 is moving little by little, the shock absorber 1 is removed as the work vehicle 5 moves.
Since the shock absorber 1 can be moved without being damaged by contact with the ground, etc., there is no need to remove or attach the shock absorber 1 each time the work vehicle 5 is moved. In the case of construction, work efficiency can be improved.

The honeycomb core constituting the cushioning material 2 in each of the above-mentioned embodiments may be integrally molded or may be divided into a plurality of pieces in the axial direction of the cell 2a or in other directions. Since they perform substantially the same function even if they are different, they may have any configuration. In the case of a split structure, if the impact load generated during a rear-end collision is small and only a part of the cushioning material 2 buckles, it is easy to replace the honeycomb core in that part, and the honeycomb core in that part can be easily replaced. It can be used again by replacing only the core. Furthermore, if a portion of the honeycomb core constituting the cushioning material 2 is configured to be slightly buckled in advance, the cushioning material 2 can withstand the impact load until the honeycomb core constituting it reaches its buckling strength. However, the impact force applied to the vehicle due to this impact load is greater than when the honeycomb core uniformly absorbs the impact load.
The drawback that a large load is applied to the vehicle at the initial stage of a collision is eliminated, and the cushioning material 2 immediately begins to buckle from the beginning of a rear-end collision, and the permanent strain caused by buckling absorbs all the impact load, resulting in greater safety. A cushioning material 2 having excellent properties can be obtained. Further, an outer plate member made of a material having a compressive strength higher than that of the honeycomb core constituting the cushioning material 2 is attached to substantially the entire rear end surface of the shock absorber 1 fixed to the work vehicle 5. For example, even if the bumper of the rear-impacting vehicle is in a position where it collides with the end of the shock absorber 1, or even if there is a protrusion such as a tow hook on the front of the bumper, in the case of a rear-end collision, The impact load applied to a part of the outer surface of the outer panel member is dispersed by the outer panel member and transmitted to the buffer material 2, and the buffer material 2 is compressed and buckled almost uniformly, so that the impact load of the outer panel member 2 is Functionality will not deteriorate.

Note that in the case of a configuration in which this outer panel member is provided, the outer panel member is not limited to a configuration in which the outer panel member is attached to the surface of the cover member 3. For example, the outer panel member is directly attached to the cushioning material 2 instead of the cover member. Of course, a configuration in which the rear end surface is covered may also be used.

In addition, if the cover member 3 is configured to be hermetically covered with a cushioning material 2 made of a material with excellent water resistance and corrosion resistance, such as plastic, it will last semi-permanently unless a rear-end collision occurs. can be used.

"Effects of the Invention" As explained above, the vehicle rear-end collision prevention device according to the present invention comprises a honeycomb core cushioning material in which each cell forms a linear hollow space and has a common length, and a honeycomb core cushioning material having a predetermined compressive strength. A shock absorber is used in combination with the cover member of the vehicle, and the lower surface side is held in contact with the ground separately from the vehicle, and the shock absorber is detachable from the vehicle and can be indexed. installed.

The shock absorbing material of this shock absorbing device has the characteristic that its cell walls absorb a large impact load due to permanent strain caused by buckling caused by compression during a rear-end collision. Moreover, this type of shock absorption is possible because the bottom side of the shock absorber is held in contact with the ground.
The direction of action is not disturbed by the impact of a rear-end collision, and the action is performed stably and reliably, thereby preventing vehicle damage and personal accidents.

In addition, this shock absorber is installed in a removable and indexable manner to the vehicle, and the shock absorbing material of this shock absorber is composed of an extremely lightweight honeycomb core, making transportation and handling extremely difficult. It's simple and easy. In addition, if the external appearance maintains the predetermined dimensions, it will function reliably and no inspection or maintenance is required. Furthermore, since it is separate and independent from the bumper on the vehicle side, it can be removed and stored separately when it is not needed, and there is no risk of impairing the weight, appearance, running performance, economy, etc. of the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of the shock absorber, and FIGS. 2 and 3 show an embodiment of the mounting means.
FIG. 2 is a perspective view of the shock absorber side attachment means, FIG. 3 is a side view showing the attached state, and FIG. 4 is a side view showing the state attached to the working vehicle by another attachment means. In the figure, 1 is a buffer device, 2 is a buffer material, 2a is a cell,
3 is a cover member, 4 is a frame member, 5 is a working vehicle, 6 is a bumper, 7 is a metal plate, 8 is a magnet, 10 is a caster, and 11 is a towed bar.

Claims (1)

[Claims] 1. Each cell forms a hollow space that penetrates linearly, and each cell has a common length in the cell axis direction, so that the impact load at the time of a rear-end collision is absorbed by the cell wall of the cell. The periphery of a honeycomb core cushioning material configured to absorb permanent strain due to buckling in the axial direction is covered with a cover member made of a material having a compressive strength lower than that of the cushioning material. The shock absorber is configured by using a shock absorber whose lower surface side is held in contact with the ground such as a road separately from the vehicle, and whose lower side is held in contact with the ground such as a road, and where the front of the vehicle is stopped. Alternatively, it should be removably and removably fixed to the vicinity of the rear bumper in a direction where the longitudinal direction of the vehicle and the cell axis direction of the cushioning material substantially coincide with each other, using appropriate mounting means. A vehicle rear-end collision prevention device characterized by: