CONSTRAINED LAYER DAMPED STEEL BAFFLE

摘要

A damped steel baffle for an engine cam cover aids in separation of oil mi st entrained in a flow of crankcase air vented through the cam cover, and direc ts the air to a PCV valve atop the cover. The baffle forms a channel for the air, and effectively absorbs noise generated within the cover. Oil droplets condense on channel a nd baffle surfaces, and drain to an engine oil sump. The interface between baff le and cam cover is sealed with a foam gasket layer or RTV sealant. The baffle is constructed of two metal layers joined together by a thin layer of viscoelastic adhesive that converts vibrational energy into heat to dampen resonant vibrations. Amplitudes of vibration are significantly lower than for plain steel baffles, hence low er sound radiation is achieved. The individual steel layers are 0.2 to 0.6 mm thick; the viscoelastic layer has a thickness up to 0.15 mm.