Vibration Reduction Analysis And Balancing Mechanism Design For Inline Four Cylinder Diesel Engine

Engine vibration and noise level has become one of the important assessment indexesof engine performance integrated. Good vibration quality is main approach of improvingengine market competitiveness, but also the important ways to reduce vehicle vibration.Restraining internally main excitation force source that causes engine vibration is one ofmain engine vibration reduction technology. Assembling balancing mechanism is one ofthe main measures to solve engine vibration, which is already applied widely in enginevibration reduction.Due to periodical of work process and parts motion, the unbalance force and torquegenerated in reciprocating engine running are the main vibration excitation force source.But compared with six cylinder engine, in some field four-cylinder diesel engine hasobvious matching advantage, which their height and width are corresponding loose, butlength harshly, and power and torsion require higher. At the same time, the structurefeatures of four-cylinder engine determine that it can not eliminate the influence of two-order reciprocating inertial force by its own balance.Therefore it is necessary to design aparagraph of balancing mechanism to inhibit or offset the vibration caused by its excitationforce source make the engine implement dynamic balance of internal mechanism motion.This paper studies certain inline four cylinder diesel engine, on the basis of sixcylinder diesel engine introduced from abroad, which is designed and developed by certaindiesel engine company according to the need of the market, aiming at medium-size trucksand buses.This paper makes the certain inline four cylinder diesel engine for example to carryout diesel engine vibration reduction analysis and optimal design of balancing mechanismby multi-rigid-body dynamics software ADAMS, the research is mainly as follows:1) Based on the kinematics and dynamics of engine, analyzing main excitation forcesource of inline single cylinder internal-combustion engine, can get unbalanced two order reciprocating inertia force, and capsized moment such main internal excitation force sourceof inline four cylinder engine. Analysis of the change rule of capsized moment in workinglays a foundation for balancing mechanism decorated a form and optimized.2) ADAMS software builds multi-rigid-body dynamics entity model of inline fourcylinder engines, to get main parameters and characteristic curve of excitation sourcethrough dynamic simulation: the body vertical vibration curve and vibration accelerationcurves, capsized moment curve and angle acceleration curves around the crankshaftdirection.3) When four cylinder engines runs in single working condition, analyze theoreticallyform decorated for double-shaft balancing mechanism. According to characteristics of fourcylinder engine running in commonly working environment in different road, implementoptimization for form decorated of double-shaft balancing mechanism.4) Establishing four cylinder engine multi-rigid-body dynamics simulation solidmodel with double-shaft balancing mechanism, implement optimized experimental designof balancing mechanism, through the minimum of engine body vertical vibrationacceleration and angle acceleration around the crankshaft direction as optimization target,and the structural parameters of balancing mechanism as design variables, to get theconcrete structure size of balancing mechanism according to optimization resultscalculated. Based on power consumption and lubricant flow of balancing mechanism, withHolland algorithm, can find bearings axis path of the balancing mechanism and theminimum oil film trajectory to lay the foundation for overall design of balancingmechanism.