A method for studying the sealing performance of cylinder head matched surface

Abstract

The sealing performance of the matched surface between the cylinder body and the cylinder head directly affects the quality of the engine assembly. The surface morphology of the matched surfaces is a key factor affecting its sealing performance. In order to explore the sealing performance of cylinder head matched surface, this paper proposes a method based on the high-precision measurement. First, high-precision surface topography data of the cylinder head matched surface was obtained based on laser holographic interferometry. Second, based on the measurement data, the finite element contact model of the matched surface between cylinder head and gasket is established. Third, extract the leakage channel of the matched surface from the finite element contact model and perform CFD simulation analysis on it. Fourth, select the sample area where the leakage is most likely to occur on the matched surface of cylinder head and calculate its leakage rate. Combined with the relative contact area in the static seal contact theory to determine the threshold of the leakage rate, the seal performance of the two set of cylinder surfaces was evaluated. The results show that the method proposed in this paper can effectively evaluate the sealing performance of the matched surface of the cylinder head and find the cylinder head surface with poor sealing performance.