Analysis And Research On Valve Cam Mechanism In CG Series Motorcycle Engine

Designing quality of valve mechanism of motorcycle engine is directly relate to power,external characteristic of torque,vibration and noise of motorcycle engine. China has been producing a lot of motorcycles, But research on principle of motorcycle is not enough. Now layout of camshaft of cam mechanism mainly includes OHC and OHV.CG type valve-train is made up of lower rockers, handspike, upper rockers, cam-shaft. Now CG type of motorcycle engine in market, from CG125 to CG200, are used same valve cam mechanism with the result that power of motorcycle engine is less than 60 kw. This paper's research object is valve train in CG series motorcycle engine, profile of cam, kinematics, the computing method of optimum synthesis of structure and dimension, dynamics are deeply researched and analyzed. CAD soft system for valve train in CG series motorcycle engine is developed. Major work are as follows:①On the basis of deep research on profile of cam of valve mechanism of internal combustion engine, creatively put forward and construct two new profile of cam, namely II type of low-order assembled with cosine and cycloid-cosine–cosine-cycloid type of profile of cam②The computing method of optimum synthesis of structure and dimension of valve train in CG series motorcycle engine is studied and the essence and principle of matching parameters of valve train are revealed.③Dynamic model of CG is valve train in CG series motorcycle engine is built. By analyzing and computing differential eguation, moving law and status of bearing force are gotten. Contrast and analyze single lumped mass and two lumped mass, conclude main factors which affect valve system.④Synthesizing above results of research, CAD soft system for valve train in CG series motorcycle engine is developed, accomplish dynamic analyze and object oriented design process.