The shock absorber of the Macpherson-style independent suspension is an important force transmission component, which not only transmits the driving force that propels the vehicle forward, but also plays a guiding role in ensuring that the vehicle travels in a straight line. Frequent starting and stopping of the vehicle will cause the vehicle's center of gravity to change repeatedly, which will cause the shock absorber piston rod to bend, deform or even fail. In severe cases, it will also cause the suspension support and the body to loosen. The failure and loosening of the shock absorber will directly destroy the relative position of the kingpin inclination.
The shock absorber doubles as the king pin, and its axis is the connection between the upper and lower hinge centers. When the wheel rolls, the up and down jump will inevitably cause the up and down swing of the lower swing arm, and the shock absorber will also swing with the lower swing arm. The swing of the shock absorber causes the angle change of the kingpin axis and the change of the wheel base. Due to the constraint of the swing arm support rod, the angle change of the kingpin axis and the change of the front wheel track size are very small under normal circumstances, and will not affect the normal matching of the front wheel camber and the front wheel toe. However, when the support rod bracket cushion is worn loose and the restraint on the lower swing arm is relatively reduced, the angle swing of the kingpin axis will increase, and the change of the front wheel track will also increase.
The steering knuckle is movably connected with the lower swing arm through the lower swing arm ball head, and most of the lateral force acting on the tire is transmitted to the lower swing arm by the steering knuckle through the swing arm ball head. Therefore, the swing arm ball head is very easy to wear, especially when the dust cover of the swing arm ball head is broken or the grease is aging, which will accelerate the early damage of the swing arm ball head. The looseness of the swing arm ball joint will accelerate the looseness and wear of a series of steering transmission rods such as the tie rod ball joint and the intermediate bushing.
The function of the swing arm support rod is to ensure the correct position of the kingpin axis, so as to ensure that the dimensions of each part of the front wheel steering trapezoid do not change, so that the matching of the parameters of the front wheel reaches the best value. If the front support rod is deformed, it will affect the correct position of the kingpin axis, destroy the steering trapezoid, and make the front wheel positioning ineffective.
