The invention relates to the production field of shock absorbers, in particular to a piston used for shock absorbers.

background art ：

With the rapid development of the automobile, McFlurson suspension system is more and more preferred by the automobile, but the suspension shock absorber is affected by the lateral force of the automobile, which increases the internal friction of the shock absorber, affects the performance of the suspension, and greatly reduces the comfort of riding.In order to guarantee the stability of the suspension performance play, bring better bus passengers feel, by optimizing the piston and workshop to cooperate, to a large extent satisfy this requirement: work for piston and cylinder with tight can increase the shock absorber of inner friction, fit clearance is too large, cannot achieve good sealing effect, can't provide the normal effective damping force;The piston and the working cylinder, the moving pair, are coaxial. The working cylinder is a straight-barrel part of fine rolling pipe, which has good straightness. Therefore, the linear motion in the working cylinder can be achieved by optimizing the piston structure to reduce the friction force in the shock absorber.

Disadvantages of the existing structure :(a) the original structure is assembled by two independent parts together, the two parts have machining error in the process of processing, assembly process will appear a large cumulative error;(b) the piston ring has a role in reducing friction in the working cylinder, if the two cooperate too tightly, it increases the internal friction with the working cylinder, and loses its role of reducing friction, if the two cooperate with a large gap, it loses the sealing effect, thus affecting the establishment of effective damping force.(c) of the original piston ring surface area is lesser, under the condition of the lateral force increase, the movement process of piston cylinder body and work creates friction, eccentric wear of the oil film is blocked, and then forms direct friction between the two metals, according to friction theory instruction, the friction coefficient ratio of friction coefficient with the time of the oil film placement several times or even more than ten times bigger.Powder treatment of gold and steel parts of the friction is large, easy to produce sound, hard phenomenon.