BASIC RESEARCH ON THE VIBRATION AND NOISE OF INTERNAL COMBUSTION ENGINES - (4TH REPORT, VIBRATION ANALYSIS BY THE MULTIPLE COMPONENT MODE SYNTHESIS METHOD).

The vibration of an internal combustion engine is analyzed by the multiple component mode synthesis method (MCMS) proposed by the authors. An engine is regarded as a combined system of a piston, a connecting rod, a crank shaft, a flywheel and a cylinder block. First, the vibration of the crank shaft is analyzed independently by the component mode synthesis method. The crank shaft is divided into 20 components, the natural modes of all components calculated by the finite element method are composed to make the equation of motion in the modal coordinates, and the vibration of the crank shaft is analyzed with this equation. Next, the vibration of the cylinder block is analyzed independently by MCMS. Finally the vibration of the total structure of the engine is analyzed by MCMS. All calculated results agree well with the experimental ones.