ESTIMATION OF VALVE SPRING SURGE AMPLITUDE USING THE VARIABLE NATURAL FREQUENCY AND THE DAMPING RATIO

다국어 초록 (Multilingual Abstract)

Internal vibration of the valve spring is a critical factor in determining the dynamic characteristics of highspeed valve train systems. Because precise prediction of the spring surge amplitude is a difficult problem, especially for nonlinear variable-pitch springs, the development stage requires a process of trial and error. In the present study, a new method that considers the variable natural frequency and variable damping ratio is proposed to predict the spring surge amplitude. First, the change in the natural frequency and damping ratio caused by compression is predicted from the initially given pitch curve at the free height. Second, the spring surge amplitude is estimated by solving the wave equation with nonlinear variable coefficients. The surge amplitudes of typical valve springs are also measured using a motoring test rig and are compared with theoretical results predicted by the spring drawing and cam profile data.

참고문헌 (Reference)

1 Seidlitz, S, "Valve train dynamics – A computer study" SAE 1989

2 Ortmann, C, "Powertrain analysis applications using Adams/Engine powered by FEV Part I: Valve Spring" 2000

3 Lee, J, "Nonlinear valve train dynamics simulation with a distributed parameter model of valve springs" 119 : 692-698, 1997

4 Schamel, A. R., "Modeling and measurement techniques for valve spring dynamics in high revving internal combustion engines" SAE 1993

5 Blair, B. G., "Measurement and computation of the characteristics of progressive valve springs" SAE 2010

6 Tolstov, G. P, "Fourier Series" Dover Publications, Inc 1962

7 H. LIU, "EFFECTS OF END COILS ON THE NATURAL FREQUENCY OF AUTOMOTIVE ENGINE VALVE SPRINGS" 한국자동차공학회 10 (10): 413-420, 2009

8 Pisano, A. P, "An experimental and analytical investigation of the dynamic response of a high-speed cam-follower system. Part 2: A combined, lumped/distributed parameter dynamic model" 105 : 699-704, 1983

9 Huber, R., "An efficient spring model based on a curved beam with non-smooth contact mechanics for valve train simulations" SAE 2010

10 Phlips, P. J, "An efficient model for valvetrain and spring dynamics" SAE 1989

11 Kim, D, "A combined model for high speed valve train dynamics (partly linear and partly nonlinear)" SAE 1990