Different Balance Of The Block Body Vibration Analysis

The Engine Block and the crankshaft is the main components of internal combustion engines,the gas pressure and other outbreaks of inertia force and torque are ultimately transmitted to the engineblock by crankshaft, these force and torque fluctuations and imbalances in the body can cause vibration and radiated noise. the performance of the machine's work has been impacted directly.As technology advances, the NVH performance of internal combustion engine has been set higher requirements, Reduce engine noise, vibration and control of radiation has become the focus of the engine industry. Study the dynamic response characteristics of the body, select a reasonable balance between matching the engine blocks and the crankshaft in order to achieve the optimum overall performance is very necessary, it will definitely become a important engine design direction for the study.In this paper, inline four-cylinder diesel engine and the different counterbalance crankshaft is the research object, established a crank and connecting rod model of multi-body dynamics, extracted a more accurate driving forces of the body, Driving forces through the programming transient loading, dynamic response characteristics of the body were analyzed, contrasted the different counterbalance crankshaft to the engine-block vibration and noise radiation effects, at the same time analyzed the pros and cons of various programs from the program from the effect of the different counterbalance on the balance and the crankshaft main bearing load, adopted finally the body surface vibration test to verify the correctness of simulation model, through the equivalent methods to evaluate the different vibration intensity from the counterbalance crankshaft vibration impact on the engine block.Based on the above study, with the balance rate to the unbalance quality of the connecting rod increases, the average bearing load of the main bearing decreases, the maximum bearing load increases, the maximum main bearing moment increases; In the main bearing, main bearing partitions and location of the crankcase, the maximum acceleration increases and the average acceleration decreases. Space permitting, we can increase the Counterbalance reasonably to reduce effectively the bearing average load and the vibration average acceleration to improve the vibration conditions.