Research On The Method Of KD186F/A-type Diesel Engine Noise Reduction

The environmental pollution has gained great concern from the public.As an important factor ofenvironment pollution,the noise of the internal combustion engine is getting more and more attentionthat they deserve.Noise has become an important indicator to evaluate the performance of the internalcombustion engine,so carrying out research of the internal combustion engine noise control is of greatsignificance.Here,Studing the KD186F/A-type of the Single-cylinder diesel engine’s noise source,provide the feasibility design options for the diesel engine overall noise reduction,which hasimportant implications for the practical engineering applications.Firstly,on the basis of analysing the structure and the working principle of the single cylinderdiesel engine,classify the various noises of the diesel engine,and study the generation mechanism andthe transmission path of the diesel engine’s noise.Focus on studying generation mechanism andfactors of the mechanical noise,aerodynamic noise and surface radiation noise.Secondly,analyse modal analysis of the crankshaft using ANSYS finite element method,andcalculate the first10order natural frequency and vibration mode of the crankshaft. From the modalmap can be seen,under the lower frequencies,most of the crankshaft is mainly bending deformation,the largest part of bending deformation appears in the junction of the main journal and rod journal andcrank arm,then put forward suggestions for improvement,to avoid resonance,provides the basis for thedevelopment of the new product;on the basis of analying the type of muffler,reintroduce improvementprogram of the structure of the original exhaust muffler;design the original exhaust mufflerstructure,considering both the efficiency of the diesel engine,ensuring aerodynamic performance ofthe silencer,and also guaranting the exhaust flow,resistance and sufficient strength afterimprovement,ensure the engine’s life period without damage,without losing the silencingeffect,achieve the purpose of reducing noise;For the diesel engine’s surface noise,mainly install localsound insulation cover,and then design the overall design of the diesel engine appearance, to achievethe purpose of noise reduction.Finally,By the method of the surface radiation noise measurement of the diesel engine tomeasure the improved diesel engine,the results indicate that the noise of the diesel engine reduces5~10dB, and has significant effect on noise reduction.