MX2008008018A - Energy absorption system for a motor vehicle - Google Patents

Abstract

The invention concerns an energy absorption system (1) suitable for a motor vehicle provided with side members (2). The system (1) comprises an upper absorption beam (3), designed to be arranged in front of the side members (2) of the motor vehicle, a lower absorption beam (4), designed to be arranged below the upper absorption beam (3), and at least two pillars (5) providing a rigid connection between the upper (3) and lower (4) beams. It further comprises a rigid cross member (6) extending between the side members (2) and directly attached on said side members (2), the upper beam (3) being pressed against said cross member (6).

Description

SYSTEM OF ABSORPTION OF ENERGY FOR AN AUTOMOBILE DESCRIPTION OF THE INVENTION The invention relates to the absorption of energy during a car crash. An energy absorption system must be able to effectively absorb the energy of a crash to protect the occupants of the car, and this without being too bulky. In the present application, "bar" is understood as a longitudinal structure which is in support on at least one, in general two, fixed points. Such a structure can integrate energy absorption means such as bee nests, capable of consuming the energy to deform, reducing the amount of residual energy transmitted to the fixed support points. In this case, a "bar of absorption" is called a bar. Therefore, "crossbar" is understood as a rigid structure that extends between two points by which it is fixed. It will be noted that a crossbar ensures less than 3% of energy absorption in the event of a crash. It is already known in the state of the art, mainly after FR 2 829 733, an energy absorption system for a car provided with spars, the system comprises an upper absorption bar, intended to be arranged in front of the stringers of the REF . : 194181 automobile, a lower absorption bar, intended to be arranged below the upper absorption bar, and at least two uprights that ensure a rigid link between the upper and lower absorption bars. The assembly constituted by the two bars and the two uprights form a frame of energy absorption which is fixed on the end of the stringers with interposition of absorbers that work in compression. In the state of the art, the stringers are not connected to each other except by the intermediary of the absorbers and the upper energy absorption bar. Now, the absorbers are generally "crash boxes" of which each one is known to absorb the energy of shocks directed exactly on the axis of the beam which carries it. In the event of an oblique impact or frontal collision whose impact on the frame is not exactly on the axis of the spar, the force exerted on the absorber necessarily comprises an oblique component that the absorber can not deal with resting on the spar. The energy of the shock is therefore risked to be integrally carried on the absorber and the spar who is more on the impact axis. In other words, the stringers are not effectively coupled together, so that in case of collision, the effort is not distributed over the two stringers. On the other hand, in the case of a collision on the upper absorption bar in a central area between the spars, this bar tends to work in flexion rather than compression, and does not absorb energy optimally. Thus, in order to compensate for the above-mentioned faults and effectively absorb the energy due to a collision, the overhang in the front of the vehicle is relatively high. The invention proposes to reduce the cantilever of the vehicle, and this without reducing the efficiency of the energy absorption system. For this purpose, the invention relates to an energy absorption system for a car provided with stringers, the system comprises an upper absorption bar, intended to be placed in front of the stringers of the automobile, a lower absorption bar, intended for to be placed below the upper absorption bar, and at least two uprights that ensure a rigid link between the upper and lower absorption bars, characterized in that it also comprises a rigid crosspiece that extends between the side rails and is directly fixed on these beams , the upper absorption bar is fixed in support against this crossbar. In the present description, the absorption function is considered to be fulfilled in that the absorber or absorption rod absorbs at least 7% of the shock energy. Thus, a simple hardening that XX consists for example in procuring urf support for the lower leg of a pedestrian does not constitute an absorption of energy. Due to the rigid crossbar, the stringers are effectively coupled and any effort carried on the bar is better distributed between the stringers. In addition, the upper absorption bar is in abutment against the rigid bar, it can only work in compression against this rigid bar during a collision, and consequently, can better absorb the shock energy. Thus, energy absorption is best ensured by the energy absorption system, it is possible to reduce the inclination. In addition, because the stringers and the crossbar are deformed little or nothing, the elements arranged in the back of this crossbar, such as a radiator, are better protected during a crash than in a classical system.

Particular advantageous embodiments - The upper and lower absorption bars are substantially horizontal and the uprights are substantially vertical when the system is mounted on the motor vehicle. - The motor vehicle is provided with an engine suspension, the lower absorption bar is in support on the extensions of the engine suspension. - At least one element chosen between the upper absorption bar, the lower absorption bar and one of the uprights is made of thermoplastic material. - The upper absorption bar, the lower absorption bar and the uprights form a monobloc piece made in one piece - The absorption system comprises at least one block member before the car, for example a grid of calender and / or a air baffle to favor the air outlet or the heat exchange, a horn device or a water tank. - At least one element chosen between the upper absorption bar, the lower absorption bar and one of the uprights comprise a network of ribs forming an energy absorption zone. - The energy absorption system is intended to be arranged in the front of the car. The invention also relates to a block ahead or behind the automobile, characterized in that it comprises an absorption system as defined above. The invention relates finally to a process for assembling an energy absorption system on a motor vehicle, characterized in that it comprises: a step of molding a single piece of an upper absorption rod, a lower absorption and at least two uprights that ensure a rigid link between the upper and lower bars, - a fixing step in support of the upper bar on a rigid crossbar, - a step of fixing the rigid crossbar on the side rails of the car.

Description of an example An example of an energy absorption system according to the invention is illustrated by figure 1, which does not have any limiting character. This figure 1 is an exploded perspective view of a car energy absorption system according to an exemplary embodiment of the invention. This energy absorption system is designated by the general reference 1. The absorption system 1 is intended to equip a car equipped with beams 2, preferably made of metal material, and provided with extensions 7 of low structure, for example suspension extensions. the motor. The absorption system 1 is arranged preferably at the front of this car, forming part of the block before the automobile. Preferably, the energy absorbing system 1 comprises at least one block member in front of the automobile that can easily be replaced if it is destroyed during a crash. For example, the absorption system comprises a grid of calender and / or an air baffle to promote the exit of air or the exchange of heat, a horn device or a water tank.

The absorption system 1 comprises a rigid crosspiece 6, fixed to these beams 2, which thus form a rigid link between these beams 2.

Preferably, the cross member 6 is made of steel, aluminum or composite material. The absorption system 1 also comprises a first bar 3, named upper absorption bar. The upper bar 3, substantially horizontal, is preferably made of thermoplastic material or metal-plastic hybrid. It is provided with a network of ribs 8 that form a zone of energy absorption. It will be observed that this network of ribs can be densified to favor the absorption of energy. The upper bar 3 is fixed in support against the rigid cross member 6, in order to work only in compression during a collision. The absorption system 1 further comprises a second bar 4, named lower absorption bar. The lower bar 4, substantially horizontal, is preferably of thermoplastic material or of a metal-plastic hybrid. It is also provided with a network of ribs forming an energy absorption zone. The lower bar 4 is fixed in abutment on the engine shock absorber extensions 7. The posts 5, substantially vertical, which ensure a rigid link between the upper bars 3 and lower 4. Preferably, these uprights 5 are made of thermoplastic material. They are provided with a network of ribs forming an energy absorption zone. Preferably, the upper 3 and lower absorption bars 4 and the uprights 5 together form a monobloc frame made in one piece.

General explanations In the event of a collision, the frame constituted by the upper 3 and lower absorption bars 4 and the uprights 5 allow to offer a larger impact surface, so that two vehicles which are clashing are necessarily at the level of the system. absorption.

Thus, due to this frame, the rigid structures of each vehicle do not constitute more intrusive pieces of destruction for the other vehicle. In addition, the frame offers a larger absorption surface, so that an effort due to a shock is better distributed, which facilitates absorption and reduces aggressiveness. In other words, the framework improves compatibility between vehicles of different types and brands and reduces the intrusiveness and aggressiveness. During a collision with the frame, the effort is transmitted mainly to the crossbar. The crossbar is rigid, the effort is distributed between the stringers. Thus, the structural interactions between vehicles are improved and the risks of deformation of the non-structural parts of the vehicles are limited. It will be noted that the energy absorption system 1 is preferably mounted in the car during a mounting process such as: - a top absorption bar 3, a lower absorption bar 4 and at least two uprights are molded in one piece. 5 that ensure a rigid link between the upper 3 and lower bars 4, - the upper bar 3 is fixed on the rigid crossbar 6, - the rigid crossbar 6 is fixed on the side members 2 of the car.

Generalizations or alternatives contemplated An energy absorption system according to the invention may be adapted to be arranged to the rear of a car, then forming part of the rear block of the automobile. In this case, the low structure is for example an automobile floor. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (10)

CLAIMS Having described the invention as above, the contents of the following claims are claimed as property:

1. Energy absorption system for a vehicle equipped with stringers, the system comprises a top absorption bar, intended to be arranged in front of the stringers of the automobile, a lower absorption bar, designed to be arranged below the upper bar of the vehicle. absorption, and at least two uprights that ensure a rigid link between the upper and lower bars, characterized in that it also comprises a rigid crossbar that extends between the stringers and is fixed directly on these stringers, the upper bar is fixed in support against this crossbar .

2. Energy absorption system according to claim 1, characterized in that the upper and lower absorption bars are substantially horizontal and the uprights are substantially vertical when the system is mounted on the car.

3. Energy absorption system according to claim 1 or 2, characterized in that it comprises at least one block member in front of the car, for example a grid of calender and / or an air deflector to favor the exit of air or the Heat exchange, a horn device or a water tank.

4. Energy absorption system according to any of the preceding claims, characterized in that the car is provided with a low structure, for example a motor suspension or a floor of the car, the lower absorption bar is in support on the extensions of the low structure.

5. Energy absorption system according to any of the preceding claims, characterized in that at least one element chosen between the upper absorption bar, the lower absorption bar and one of the uprights is made of thermoplastic material.

6. Energy absorption system according to any of the preceding claims, characterized in that the upper absorption bar, the lower absorption bar and the uprights form a monobloc piece made in one piece.

7. Energy absorption system according to any of the preceding claims, characterized in that at least one element chosen between the upper absorption bar, the lower absorption bar and one of the uprights comprises a network of ribs forming an area of absorption of energy.

8. Energy absorption system according to any of the preceding claims, characterized in that it is intended to be arranged by the front of the car. Block in front or behind the car, characterized in that it comprises an absorption system according to any of the preceding claims. 10. Assembly process of an energy absorption system on a car, characterized in that it comprises: a step of molding a single piece of an upper absorption bar, a lower absorption bar and at least two uprights that ensure a rigid link between the upper and lower bars, a fixing step in support of the upper bar on a rigid crossbar, a stage of fixing the rigid crossbar on the side rails of the car.