Moskalenko I. Improving methods of profiling lateral surface of the piston in internal combustion engines

Dynamic processes in the piston-cylinder internal combustion engine as a result of a group of mechanical, thermal and hydrodynamic factors. Scientific substantiation and improvement in the method of profiling the lateral surface of the piston internal combustion engine through the use of mathematical models of processes occurring in triboconjugation "piston-cylinder-lubricating layer." All theoretical and experimental studies are based on the fundamental provisions of the internal combustion engine, the theory of hydrodynamic lubrication theory of machines and mechanisms, modern mathematical tools. Evaluation of thermo mechanical stress state of the piston carried out by finite element method (CAD / CAE) with classical boundary conditions. A calculation-experimental method of determining the dynamics of the piston, which allows you to calculate the parameters of motion of the piston and the amount of mechanical losses in the pair "piston-cylinder". Using such data may: clarify the configuration of the contact areas and pressure distribution function at the side surface of the piston; Thermo-stressed state to determine piston assemblies; update configuration clearances between the piston and the cylinder; predict the current and averaged over a cycle of the coefficient of friction; to assess the carrying capacity of the lubricant layer and the friction mode. Using the proposed method of designing the profile of the side surface to reduce the clearances between the piston assembly and the cylinder; reduce the wall thickness and mass of the piston; reduce the inertial loads; to increase the carrying capacity of the lubricant layer in triboconjugation "piston - lubricating layer - cylinder"; narrow zone of mixed friction; reduce heat release and temperature piston assemblies, and, as a consequence, increase the viscosity of the lubricant; reduce mechanical friction costs in the cylinder-piston group. Improved method for profiling the side surface of the piston internal combustion engine through the use of multi-level mathematical models of the dynamics of the piston; It proposed a promising method of experimental study of the dynamics of the piston in the engine operating conditions, based on non-contact measurement of clearances between the piston and the cylinder; proposed a criterion for evaluating the bearing capacity of the lubricant layer and the friction regime in triboconjugation "piston-cylinder-lubricating layer" using the modified number Somerfield. Scientific provisions of the dissertation are used in the design of the profile of the side surface of the piston 11194-1004015MU engine VAZ 11194 at PJSC "AVTRAMAT" (Kharkov) and the execution of works on finishing the construction of small pistons reciprocating engines D-250 and MS-10P at JSC "Motor Sich" (Zaporozhye). Eengine building.