The Finite Element Contact Complex Displacement Analyses To Piston Of Diesel Engine

Accompanying with the development of productive force in modern society and the improvement of science and technology, a trend of high power, high velocity and reliability appears in the field of Internal combustion engine, so the design of internal combustion engine is facing the new challenge. In recent years, with the strengthening of the people's concept in environment protection, the vibration, noise and the emission of exhausted gases are restricted more and more seriously. Piston-linkage mechanism ,as the mechanism to transfer the power of engine, bearing the heavy gas-explosive force, inertial force etc, is easy to arise vibration and noise. Besides, the joint clearance in mechanism could also irritate the vibration and worsen the dynamic properties of mechanism. So the kineto-elasto-dynamic analysis to the piston-linkage mechanism of internal combustion engine has obvious realistic significance.This thesis, on the basis of modern theories of vibration, KED analysis and finite element method, sets up a kinetic model of piston-linkage mechanism of diesel engine, by I-DEAS software of SDRC USA, which involves the effect of joint clearance in mechanism. By the presumption of "transient structure" in KED analysis, the mechanism' s dynamic responses in every transient structure conditions are calculated, and it provides a reliable theory basis for the optimization design of diesel engine.The form of piston skirt is the key structure for piston. It directly affects the engine's working reliability whether it's good or not. According to the past method , piston can only be decided whether it meets the need of engineering in test after it has been turn out .This paper simulates the real working condition of piston by combining the KED method and FE-contact analysis way .It reflects deforming rule of piston ,and makes it possible that the structure problem of piston skirt can only be found during the design period ,so the cost of developing new product is lowered and the time is shorted .This paper proves that the thought is practical and the result of simulation to piston LR4100 is in accord with practice. Above all , this method has practical value in engineering . and the following condition can be made from practicing.1. This paper realizes the evaluation of piston skirt form in condition of assembly by the way of finite element technology. IT combines the computer technic with contact mechanics and discovers a new way to evaluate the piston form .2. This paper sets up a solid model with multiple real piston skirt form. It sums up a evaluating way to piston form by testing result. For the piston developing cost and time is largely lowered, it has obvious efficiency both in economy and society.