International Journal of Automotive Technology

  • 제8권1호
  • /
  • Pages.59-66
  • /
  • 2007
  • /
  • 1229-9138(pISSN)
  • /
  • 1976-3832(eISSN)
한국자동차공학회 (The Korean Society of Automotive Engineers)
권호 표지

REDUCTION OF HIGH FREQUENCY EXCITATIONS IN A CAM PROFILE BY USING MODIFIED SMOOTHING SPLINE CURVES

  • Kim, D.J. (Department of Mechanical and Automotive Engineering, University of Ulsan) ;
  • Nguyen, V.T. (Department of Mechanical and Automotive Engineering, University of Ulsan)
  • 발행 : 2007.02.28
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

High frequency excitation terms in a cam profile can excite vibration of a cam follower system. In this paper, modified smoothing spline curves are used to reduce the high frequency terms. The essential difference between the proposed method and other existing approaches is its ability to make the principal cam motions smooth while still exactly satisfying boundary conditions of follower displacement, velocity and acceleration. The boundary values usually depend on the ramp properties of a cam. Our method, thus, allows designers to smooth the existing cam motion without any damages on its ramp areas. Because the ramp height, velocity and acceleration are maintained exactly, more radical smoothing is possible. An example shows that the proposed method can be a powerful tool of cam profile smoothing, which removes high frequency components in the cam profile excitations without any changes in ramp properties.

키워드

참고문헌

  1. An, K.-Y. and Kim, D.-J. (2006). Cam profile design for impulsive noise reduction of automotive engine valve train. Trans. Korean Society of Automotive Engineers 14, 4, 139-148
  2. Boyd and Vandenberghe, L. (2004). Convex Optimization. Cambridge University Press, U.K
  3. Boyd, J. P. (2000). Chebyshev and Fourier Spectral Methods. Dover Pub., Inc. New York. USA
  4. Craven, P. and Wahba, G. (1979). Smoothing noisy data with spline functions. Numerische Mathematik, 31, 377-403 https://doi.org/10.1007/BF01404567
  5. Eilers, P. H. C. and Marx, B. D. (1996). Flexible smoothing with B-splines and penalties. Statistical Science 11, 2, 89-121 https://doi.org/10.1214/ss/1038425655
  6. Hardle, W. (1994). Applied Nonparametric Regression. Berlin. Germany
  7. Kano, H., Nakata, H. and Martin, C. F. (2005). Optimal curve fitting and smoothing using normalized uniform B-splines: a tool for studying complex system. Applied Math. and Comp. 169, 1, 96-128 https://doi.org/10.1016/j.amc.2004.10.034
  8. Norton, R. L. (2002). Cam Design and Manufacturing Handbook. Industrial Press, Inc. New York
  9. Norton, R. L., Eovaldi, D., Westbrook III, J. and Stene, R. L. (1999). Effect of valve-cam ramps on valve-train dynamics. SAE Paper No. 1999-01-0801
  10. Reinsch, C. H. (1967). Smoothing by spline functions. Numerische Mathematik, 10, 177-183 https://doi.org/10.1007/BF02162161
  11. Rothbart, H. A. (2004). Cam Design Handbook. McGraw-Hill. New York
  12. Sandgren, E. and West, R. L. (1989). Shape optimization of cam profile using a B-spline representation. ASME J. Mech., Trans. and Automation in Design, 111, 195-201 https://doi.org/10.1115/1.3258983
  13. Seidlitz, S. (1989). Valve-train dynamics - A computer study. SAE Paper No. 890620
  14. Stoddart, D. A. (1953). Polydyne cam design. Machine Design 25, 2, 146-154; 25, 3, 149-164
  15. Stone, M. (2002). Method of Mathematical Physics I. Primader-Casaubon. A. Florence. London
  16. Tsay, D. M. and Huey, Jr. C. O. (1989). Application of rational B-spline to the synthesis of cam-Follower motion program. ASME J. Mech., Trans. and Automation in Design, 115, 621-626