Automobile encyclopedia knowledge: collision and collision test have reference value.

Automobile Encyclopedia: Is the crash test valuable?

Two major motor vehicle collision detection agencies in China: C-NCAP &; C-IASI, the standard test of vehicles is the collision of bicycles from all angles, and the "collision" test that users are more interested in is rarely carried out. Why?

"Crash test" can be the most intuitive way to find out which car or model is safer, but this test is meaningless. Because cars with high curb weight are more dominant in collisions, taller cars will be safer than shorter cars, and cars with front rear drive will definitely be more "crash-resistant" than cars with middle rear drive, but each car has its own value.

Curb quality and structural strength

Assuming that both cars are made of high-strength and thermoformed steel in the same proportion, the result is basically that their frontal, offset, side and top strength collision tests are very good, because the structural strength is equivalent to the damage caused by inertial force. However, if two cars collide, the damage of the "light car" will be more serious, and the inertia force of the heavy car will be greater. It is conceivable to increase the impact on light vehicles based on "tons". (Force = mass × speed)

On the other hand, the loaded vehicle does not load the light vehicle, which is equivalent to the "energy-absorbing target vehicle/energy-absorbing obstacle avoidance" in CNCAP for collision test. At the moment of collision, the light vehicle should not only bear the damage caused by inertia force, but also strengthen the deformation of the frame during the collision. Therefore, the collision between light and heavy vehicles must be dominated by heavy vehicles, but not all users need SUVs or MPVs with huge volume, exaggerated weight and high power. Lightweight mini fuel-efficient car is also a good choice as a scooter. Just pay more attention to the road conditions when driving.

Body height and collision protection

Tall cars always give people a better sense of security, which is not a simple psychological suggestion.

The automobile anti-collision protection structure can be divided into two parts: the first part is the protection structure for large-area collision at the front or both sides of the automobile, and the order is cross beam, energy absorption box, longitudinal beam and frame. The second part is the wheels, A-pillar and frame on both sides, which will be impacted and transmitted by the impact force in turn. If the impact strength does not destroy the structural characteristics, the damage will not be great. If the strength is too high, the frame will eventually bear the impact force. However, the engine can also be used as a collision buffer, but it must have a "collision sinking design", and the concept is as follows.

Figure 1: transmission sequence of impact force

Figure 2: Concept of engine sinking protection

Key points: vehicles with high ground clearance must have an advantage in collision protection, because the front bumper will be higher than the low one. Then, in the collision, the water tank frame and the engine used as a low car directly bear the impact of the collision beam of a high car, and the former will inevitably be damaged to a greater extent, because the beam strength of the rear car will always be higher (the concept of rear-end collision is the same). So in theory, if you want higher safety standards, you need to choose SUV/MPV or pickup truck. However, based on the analysis of the protection system of engine sinking, the car with quite good driving experience is nothing more than the high cost of collision maintenance.

Engine position _ has a great influence

pioneer

Front and rear drive

Central rear drive

The above three driving platforms are the most commonly used types of small and micro passenger cars, of which the first two are the design with the engine arranged at the front of the car, commonly known as "long-headed cars". The safety factor of this kind of car is bound to be higher, because the reinforcement and length of the engine compartment can act as a collision subsidence area, and the engine sinking can naturally improve the safety factor, so these two cars have become the mainstream types of family cars.

"Central rear drive" is commonly known as "flat car", and the engine is arranged under the front seat. Because the engine is not at the front of the car, there is no need to deliberately strengthen the frame that fixes the engine in this area, and it does not need to be very long; Moreover, the inclination angle of the A-pillar can be very large, which can effectively reduce the manufacturing cost. But at the same time, the functions of collision buffer zone and "sinking protection" are lost, which leads to poor anti-collision ability of this kind of vehicles; This is the reason why the safety evaluation of vans and all kinds of trucks is not high, but besides vans can be replaced by pickup trucks, what can medium and heavy vans be replaced by?

Summary: Absolutely safe models can be found by referring to curb weight, structural strength, ground clearance and engine layout. However, it is difficult for C-end users to adjust, and the same model cannot be applied to everyone; Therefore, every car has its value, and there is no need to refer to the "collision result" when choosing a car. What you need to find is a car that can get a high CIASI score in the normal crash test.