Effects of viscoelastic properties of engine cover sealing system on noise and vibration attenuation外文电子书籍.pdf

Int J Mech Mater Des (2006) 3:277–284 DOI 10.1007/s10999-007-9030-6 Effects of viscoelastic properties of engine cover sealing system on noise and vibration attenuation Y. Charles Lu Received: 8 February 2007 / Accepted: 27 April 2007 / Published online: 25 May 2007 Springer Science+Business Media B.V. 2007 Abstract Automobile engine cam cover seals are function being sealing the oil inside the engine from made of elastomeric materials and used to seal the leaking, the cam cover also has the function of interfaces between cover and underlying structures. attenuating noise caused by engine vibration. Due to The design of engine cam cover seals has been its large surface area and relatively small thickness, traditionally focused on the sealability aspects. the cam cover has been identified as one of the major Recently, there has been additional demand that contributors to radiated engine noise (Challen 1982; these seals be designed as vibration isolators to Hong et al. 2001; Lu and Anderson 2002; Lu and attenuate the radiated noise from the engine. To D’Souza 2004; Nashif 1982). accomplish this goal, the frequency-dependent vis- The cam cover assembly includes primarily the coelastic properties of the sealing components will cover itself and elastomeric sealing system, e.g., the have to be considered during the design process. This gaskets and grommets. The gaskets are long rubber article examines the frequency-dependent viscoelas- strips sitting between cover flange and engine head or tic properties of some commonly used elastomeric spark-plug towers, while the grommets are typically seals at various mounting configurations. An analyt- rubber doughnuts pre-installed on metal fa