What are the four beams and six pillars in the used car industry? What does it do?

When buying and selling used cars, I often hear such as, "four beams and six columns", three large pieces, two sides of paint... What does it mean?

Let's talk about these four beams and six pillars today

In fact, the four beams and six columns refer to the front and rear side members and ABC columns of the vehicle. Although not as high as the engine and gearbox on the car, the important role of these parts can be unambiguous, whether the vehicle is an accident car they can play a decisive role.

First, the front and rear side members of the vehicle

The position of the front and rear rails: After opening the engine compartment, under the engine, the two cuboid pillars consistent with the direction of the body are the front side members, and the rear side members are under the trunk of the vehicle, and the shape is the same as the front beam.

• And what about the role of stringers?

We often hear people say the word anti-collision beam, as if whether the car is crash-resistant and high safety is this thing at work.

Here, to popularize a knowledge, the front and rear anti-collision beams are only a supporting role for passive safety, and in the event of a frontal collision, the bumper strengthens the cross member far less than the front sidebar to play a greater role. In fact, it is the front and rear rails that really play the main role in energy absorption in collisions (frontal impact or rear rear-end collision).

The longitudinal beam absorbs the collision energy through crushing deformation, of which the front sorghum bears 60% of the collision energy, and the energy absorption pressure that the rear stringer needs to bear is smaller than that of the front beam, but it is still the main force to absorb energy in the rear-end collision accident.

Therefore, if the front and rear side members are injured in an accident, the protective effect of these two beams on the driver will be greatly reduced during future driving.

The front and rear side members of the vehicle also carry the driving parameters of many vehicles, if injured, many parameters will change, this change is impossible to recover by means such as straightening repair in the later stage, and will also bring some hidden dangers. If the longitudinal beam injury is more serious, there may be misalignment and gnawing tires, even if the four-wheel alignment and dynamic balance cannot be restored. Therefore, when we consider buying a second-hand car, we must focus on the longitudinal beam, if you find deformed welding sheet metal traces, please give up directly!

Second, the ABC column of the vehicle

Location of ABC Column:

• The diagonal column between the front windshield and the front door is called the A-pillar (also known as the front pillar)
• The column between the front door and the rear door is called the B-pillar (also known as the middle column)
• The diagonal column between the rear door and the rear windshield is called the C-pillar (also known as the rear pillar)

The A-pillar plays a crucial role in car safety, especially in the event of a frontal collision, the A-pillar with high enough strength can effectively avoid deformation, so as to ensure that the occupants can open the door smoothly after the accident. In addition, the A-pillar with high shear strength can effectively avoid the A-pillar being cut off by the rear of the truck when the car rear-ends a large truck, so as to protect the safety of the occupants to the greatest extent.

The role of the B-pillar is particularly important during side impacts. The B-pillar itself is the carrier of multiple parts, the front door latch, the rear door hinge, the rear door limiter, and the front seat belt must be fixed on the B-pillar.

Unlike the AB pillar, the C-pillar has a weaker impact on frontal or side impacts, and it is strengthened more for the rigidity of the roof and the entire body.

Therefore, the role of the ABC column is like a cover, to protect the safety of the occupants in the car, if these three places are encountered due to an accident, only simple sheet metal putty and other methods can be used to restore the original appearance, but the internal rigidity after repair is much lower than the original factory.

• Dear car friends, it's almost the end of the year, have you considered changing the car, do you have a second-hand car to consider?
• If you have something to consider, please pay attention to the four beams and six pillars, if you have touched it, don't buy it no matter how cheap, because safety is greater than the sky!