Simulation Research On Design Of Vvt System Of The Lj377mv Engine

The valve gear is an important component of the engine, and the performance of the engine depend on the design of the valve. Traditional valve timing engine is usually only based on the relatively narrow scope of the working condition of the engine, and the working process of the engine is fixed, it is difficult to take the different conditions of the gas distribution performance requirements into account, usually it is a compromise in accordance with the working environment. In order to obtain better engine performance, valve Timing should be made with the speed and load changing. In this paper, based on the Luoyang North Industries Group LJ377MV engine proto type, a cam switch to the VVT system is designed. The agency contains the double-intake cam, double-intake rocker arm, double-exhaust cam, double-exhaust and switching mechanism, in low speed and low-load low-speed cam drive low-speed rocker arm to control intake and exhaust doors; in high speed and high -load high -speed cam drive high -speed rocker arm to control intake and exhaust doorsIn this paper, the cylinder combustion, heat transfer and gas exchange model were select to establish the simulation of engine performance analysis model of BOOST. In the model, the VVT control strategy, based on engine working in different conditions, was discussed in detail.It is also analyzed the influence of the different conditions of the exhaust valve timing, valve lift, intake system on the performance of the engine. Analysis focused on the valve timing of exhaust valve opening time, intake valve close time, valve overlap angle, valve lift and intake system parameters on the performance of the engine. Through the simulation results, the best valve timing of the high-speed and low-speed can be found.Related parts were also designed to switch the VVT system, such as the rocker arm, spring, valve and so on. The strength and stiffness were calculated and checked by the finite element. The valve dynamics model of the cam was established by AVL-TYCON, and made kinetic analysis for it.