Comparison of valve train dynamic models

To give reasonable evaluation of models,valve train dynamic models criteria were brought forward.A 170F diesel valve train was taken as example,one-mass,two-mass and four-mass models were built and the valve dynamic characteristics experiment was also carried out accordingly.Models computation stability was compared,and standard deviation,power spectrum and dispersed wavelet transform(DWT) methods were used to appraise the agreement between computed and experimental data.Comparison results show that DWT method can reflect the difference of computed and experimental data in time and frequency domain,and can be used as the criteria of dynamic model validity and applicability.Compared with one-mass and four-mass models,two-mass model is simpler and more rational, and its result accords well with experimental result.