As an important part of the automobile safety structure, the front anti-collision beam plays a vital role in the driver's life safety and property safety. But we must be clear that the "anti-collision steel beam" is really not for anti-collision, but for conducting force, that is, absorbing energy, because once it hits, the beam will inevitably deform. The significance of the front anti-collision beam is the device that the vehicle bears the impact force for the first time. There is an important knowledge in passive safety of car body, that is, a little force will force the whole car body out. That is to say, a certain position of the car body has been hit. If only this part is allowed to bear the load, the protection effect will be poor. If the whole skeleton structure bears the stress at a certain point, the stress intensity at a certain point can be minimized, and the front anti-collision steel beam plays an obvious role here.
In high-speed collision, anti-collision steel beams play the role of transmitting force, and in low-speed collision, anti-collision steel beams can play the role of reducing maintenance costs. So why do some cars have foam on their anti-collision steel beams? Of course, this is not that the anti-collision steel beam "transforms" into foam, but that a layer of foam is added to the anti-collision steel beam as an energy-absorbing block. It can play a better role in protecting pedestrians at low speed and protect the safety of people inside and outside the car to the greatest extent.
There are many structures of anti-collision beams, which can be seen clearly from the side. The "Ω" shape can effectively guide the deformation direction and has a good energy absorption effect, which can alleviate the discomfort of passengers in the car to some extent.
The shape of the "mouth" has a hollow cross section and a large deformation range, which can reduce the damage probability of the rear part and reduce the maintenance cost. The picture below shows the "day" shape.
The word "eye" is similar to the word "mouth" and has stronger protection ability.
Bow, classic energy-absorbing protection design, ensures a certain strength and has better energy-absorbing effect. Its shape is similar to ω, but thicker.
Double-layer design, with secondary buffer, will better protect pedestrians, light collision will not directly contact the main pole body, which can reduce maintenance costs.
In addition to different shapes, there are also differences in materials, such as steel and aluminum alloy. Ultra-high-strength steel with tensile strength above 1000MPa is widely used in most automobile collision beams, and its thickness is mostly about 2 ~ 3 mm. In recent years, many automobile brands have begun to use aluminum alloy materials to make collision beams. The density of aluminum alloy is one third of that of steel, and the weight of aluminum alloy with the same volume is only one third of that of steel.
The steel bumper anti-collision beam improves the tensile strength of the steel plate, and the energy absorption performance of the material is improved by reducing the thickness. On the contrary, the aluminum alloy bumper anti-collision beam can improve the energy absorption performance by optimizing the structural design and setting different thicknesses. Properly designed aluminum alloy bumper beam is not only lighter than steel bumper beam, but also can absorb more energy. Although aluminum alloy bumper beam is lighter and more effective, its manufacturing cost is higher than that of steel bumper beam.
The energy-absorbing box is a metal box between the anti-collision beam and two body longitudinal beams, which is simply understood as an energy-absorbing box. Energy is impact. When vehicles collide, the anti-collision beam has a certain degree of energy absorption. However, if the energy is too large and exceeds the bearing capacity of the anti-collision beam, it will transfer the energy to the energy-absorbing box, which will absorb all the impact force and deform itself to ensure the longitudinal beam from being hurt to the maximum extent. Generally, a guide groove is designed on the energy-absorbing box to guide the deformation trajectory. So most energy-absorbing boxes are irregular rectangular cylinders. Low-cost cheap cars may cancel the energy-absorbing box structure, and the effect of collision energy absorption is very poor.
The front anti-collision beam and energy-absorbing box are the most basic and important components in vehicle front safety protection, which can effectively protect the vehicle, reduce collision damage and reduce maintenance costs. According to the different design shapes and materials, the protective effect is high or low. With the reduction of cost and the development of technology, aluminum alloy front anti-collision beams and energy-absorbing boxes will be gradually popularized.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.