Frame function and layout requirements
Most modern cars have a frame as a skeleton of the entire car. Most parts and assemblies of the car are fixed by the frame, such as the engine, drive train, suspension, steering system, cab, cargo box and related operating mechanisms. The frame serves to support the connection of various parts of the car and to withstand various loads from inside and outside the car.
The structural form of the frame should first meet the requirements of the general layout of the car. During complex driving, there should be no interference between the assemblies and components that are fixed to the frame. When the car is driving on a rough road, the frame may undergo torsional deformation under load and bending deformation in the longitudinal plane; when one side of the wheel encounters an obstacle, the entire frame may be twisted into a diamond shape. These deformations will change the relative position between the components mounted on the frame, thereby affecting their normal operation. Therefore, the frame should also have sufficient strength and proper rigidity. In order to improve the light weight level of the entire vehicle, the quality of the frame is required to be as small as possible. In addition, the frame should be placed closer to the ground to lower the center of gravity of the car to improve the driving stability of the car. This is especially important for passenger cars and cars.