发动机伺服配气转阀设计及性能分析OA

Aiming at the problems of complex structure,large number of parts and easy to produce vibration and noise in the mechanical valve system of traditional four-stroke engine,a new type of rotary valve system directly driven by servo motor was designed.Through the coordinated rotation of the servo motor control valve core and the valve core sleeve,the on-off control and the flow area adjustment were realized.Based on the Kawasaki KLX230 engine,the mathematical model of the servo valve was established,and the performance difference between the servo rotary valve and the plunger valve was compared and analyzed.The results show that under the working condition of 3 000 r/min,the rotary valve can maintain a constant volumetric efficiency of 62.5%in the range of crankshaft angle of 40°～161°,and volumetric efficiency of the plunger valve only reaches the peak at the crankshaft angle of 107° and decreases with the deviation degree of the crankshaft angle from 107° when the crankshaft angle is below 107° or above 107°.The efficiencies of the two approache each other at 4 500 r/min.By deleting the camshaft transmission mechanism,the mechanical friction loss is reduced and the dynamic performance of the valve system is improved,which provides a new idea for the design of a wide range variable valve timing system and a high compression ratio engine.