Key Points and Notices In the Design of Some Ribbons in Automobile Sheet Metal Parts

2019-07-05 10:52:38

The body is mounted on the frame of the chassis and is carried or loaded by the driver and passengers. The bus body is generally an integral structure, and the truck body is generally composed of cab and container.

Body structure mainly includes: body shell (white body), doors, windows, front sheet metal parts, body interior and exterior accessories and body accessories, seats and ventilation, heating, air conditioning, air conditioning equipment, etc. It also includes cars and other equipment in trucks and special vehicles.

In automobile sheet metal parts, it is not necessary to make tendons everywhere, nor is it better to have tendons than to have no tendons. There are many performance requirements for automobiles. Sometimes, reinforcing ribs can improve some performance while causing damage to others. If the wrong reinforcement is designed in the wrong position, the performance of the vehicle will be greatly damaged. Therefore, in the design, attention should be paid to strengthening the positive and negative effects of ribs, so as to avoid wrong design. The following are the main points and points for attention in the design of some ribs.

When designing reinforcing bars to strengthen parts, the direction of reinforcing bars should be the same as that of forces; if local weakening is to be done, the direction of reinforcing bars should be perpendicular to that of forces, such as crushing bars. According to the direction of force transmission, the same reinforcing tendons play different roles.

In the design of load-bearing beams such as threshold beams, the following methods can be used to improve the load-bearing capacity: reducing large bending moment, or adopting reasonable section shape to improve the modulus of bending section. Therefore, the reinforcing bars in the cavity of the beam can not make the main reinforcing section change dramatically, otherwise it will affect the performance; the reinforcing bars should not make the section smaller, which will affect the moment of inertia of the section.

It is not suitable to make large and long reinforcing bars in high stress area under vehicle bending condition, single side jump condition and load condition, which will cause sheet metal cracking when the stress is concentrated on the surrounding part of reinforcing bars.

The reinforcing bars can not be used in the stamping thinning area, such as the corner of spare tire pit, which has a higher thinning rate. Additionally, reinforcing bars will increase the cracking risk of the sheet metal which is too thin.

In addition, there are triangular reinforcement, reinforcing reinforcement on the reinforcement, continuous reinforcement and so on. In fact, in the stamping process of different shapes of reinforcement, there will be local weak parts, wrinkling or local thinning may occur. Therefore, if it is not necessary, the reinforcing bars should not be interconnected or too complex. Otherwise, under different structural conditions and different manufacturing processes, the complex reinforcing bars are more likely to crack than simple reinforcing bars, which has a negative effect on vehicle performance. In practical design, the parts whose thinning rate reaches 20% or more by stamping CAE analysis should not be reinforced.

When cross reinforcement is needed, it should be considered that stress concentration is easy to occur at the intersection point and the rigidity of the intersection point is weak. Therefore, attention should be paid to the design of corner transition at the intersection point, and the radius of the corner should be twice the width of the reinforcement. In addition, when the axis of reinforcing bar is arc, it is easy to cause torsion in vibration. If it is not necessary, the axis of reinforcing bar should be straight line.

When the design of reinforcing tendon pays attention to its function, we should not only understand its negative effect, but also try our best to make up for it.

Stamping parts are mainly metal or non-metal sheet metal, with the help of press pressure, through the stamping die stamping forming, it has the following characteristics:

Stamping parts are manufactured by stamping on the premise of little material consumption. The parts are light in weight and good in stiffness. After plastic deformation, the internal structure of metal is improved, and the strength of stamping parts is improved.

The stamping parts have high dimensional accuracy, uniform size with the die, and good interchangeability. General assembly and use requirements can be met without further mechanical processing.

In the stamping process, because the surface of the material is not destroyed, the stamping parts have better surface quality, smooth and beautiful appearance, which provides convenient conditions for surface painting, electroplating, phosphating and other surface treatment.