A Research On Optimization Design Method For Two Cylinders Engine Mounting System

Based on the law of motion of the piston-crank mechanism, the imbalanced characteristics of the 2-cylinders engine is analyzed. The balance theories of different balance methods as well as their effect are presented. The imbalance force and moments of a 2-cylinders engine in different balance conditions are numerically simulated. With the model of 2-cylinders engine mounting system built, the motion of the engine and the mount reaction force in different balance conditions are calculated and analyzed.A multi-objective optimization model of 2-cylinders engine mounting system is established. The natural frequency, decoupling rate and the mount reaction force of the 2-cylinders engine mounting system are optimized. Based on the GUI module of Matlab, a software to design and optimize the 2-cylinders engine mounting system is programmed. With the software, user can calculate the unbalance excitation of the 2-cylinders engine, study the motion law of the mount system and get the optimization results of the stiffness, locations and local angles of the mounts.The generation mechanism of gyro effect for the engine crankshaft is described. A model of powertrain mounting system containing a gyro moment item is established. Taking a 2-cylinders engine mounting system as studying example, the natural frequencies of the powertrain and frequency response characteristics are calculated with and without consideration of the gyro effect. The calculated result is used to analyze the influences of gyro effect to the mounting system.