What are the three kinds of car frame structures?

According to the different stress and structure of the car body, it can be divided into bearing type and non-bearing type. The load-bearing body has no rigid frame, which strengthens the front, side wall, rear and floor. The engine, front and rear suspensions, part of the transmission system and other assembly parts are assembled on the car body, and the load of the car body is transferred to the wheels through the suspension device. Most cars use load-bearing bodies, which are low in noise, light in weight and relatively fuel-efficient, but relatively low in strength. Non-load-bearing car body, the frame is rigid, also called chassis longitudinal beam frame. Engine, transmission system, car body and other assembly parts are fixed on the frame, and the frame is connected with wheels through front and rear suspension devices. It has the advantages of high chassis strength, good anti-bumping performance and difficult deformation of the car body. Non-load-bearing body is large in size and weight, and is generally used for trucks, buses and off-road vehicles. The following car body bearing modes can include: loading and unloading the car body; The rear structure according to the shape of the car body can include folding rear car body, straight rear car body, cockpit rear car body and short rear car body; The box structure following the shape of the car body can be: three-chamber car body, two-chamber car body and single-chamber car body. There are three kinds of frame structures: 1. For cars with non-load-bearing body, the frame is rigid, also called chassis girder frame. The connection between the vehicle frame and the vehicle body is flexible through springs or rubber pads. Engine, partial transmission system, car body and other assembly parts are fixed on the frame through suspension devices, and the frame is connected with wheels through front and rear suspension devices. This non-load-bearing car body is large in size, heavy in weight and high in height. Generally used in trucks, buses and off-road jeeps, but there are also a few luxury cars because of their good stability and safety. 2. A car with a load-bearing body does not have a rigid frame, but only strengthens the front, side wall, rear end and floor. Assemble the engine, front and rear suspensions, part of the transmission system and other assembly parts at the positions required by the design on the car body, and transmit the automobile load to the wheels through the suspension device. In addition to its inherent load-bearing function, this load-bearing car body directly bears various load forces. After decades of development and improvement, the safety and stability of the load-bearing car body have been greatly improved, with the advantages of light weight, low height, no suspension device and easy assembly. So most cars adopt this body structure; 3. The car body and the frame are rigidly connected by threaded connection, riveting or welding. In this case, the automobile body not only bears the above load, but also helps to strengthen the frame and share part of the load of the frame to some extent.