It will worsen the stability of the vehicle. Controllability is reduced. Because the suspension is hung on the beam. Then there are the safety issues caused by deformation.

Whether the frame is skewed or not is generally judged by measuring the diagonal line of the frame. In order to ensure that the axes of the front and rear axles are parallel, the center of the pin hole of the steel plate seat fixed on the frame must be at the appropriate distance from front to back, left and right. .

The function of the frame is to support and connect the various assemblies of the car, so that each assembly maintains a relatively correct position and withstands various loads inside and outside the car.

The straightness and verticality of the longitudinal beams affect the strength of the frame and the installation of related assemblies. The straightness can be tested by pulling wires. The maximum bending of the plane on the frame should not exceed 5mm; the verticality The angle can be checked with a square ruler, and the maximum seam separation should not exceed 0.50 mm. The side bend of the longitudinal beam can be checked with a ruler. When the maximum bend exceeds 5 mm, it should be corrected.

Extended information

Causes of fracture or deformation

1) The vertical impact load on the frame caused by the car driving on uneven roads exceeds the limit of the frame. Use stress. In addition, when the car goes up or downhill, turns or is loaded unevenly, it will also cause local overload of the frame and cause the frame to break.

2) The frame design or attachments cause local torque and cause the frame to break. If the front cross-section of some frame longitudinal beams is small, and due to the influence of the engine and transmission, the cross beams are less distributed, which makes the stiffness of the frame worse. If under the action of dynamic load, the front longitudinal beams may be damaged. Broken, that is, the lower wing of the longitudinal beam is commonly broken.

In addition, the frame is also subject to local distortion caused by cantilever loads hanging from the longitudinal beams (such as fuel tanks, suspensions and spare tires, etc.), which is also the cause of frame fracture.

3) When the car is driving, one side of the front wheel is subject to great resistance, which makes the frame prone to diagonal plane deformation.

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