Jacek Michalski

Description of honed cylinders surface topography

Abstract A review of the existing methods describing the cylinder bore surface roughness was presented. An analysis of the surfaces of a large number of honed cylinders was performed. The relationship between conventional and proposed roughness parameters was studied using the principal components method as well as correlation and regression analysis. It follows from the analysis that one can fairly precisely describe a cylinder surface roughness profile using the following parameters: the emptiness coefficient R p / R t , the normalized rough core depth R k / R t , one of the height parameters ( R tm or R 3y are proposed) and the mean distance among deep valleys. A wider description includes also the real oil capacity and one of the horizontal parameters.

Effects of metallurgical structure and cylinder surface topography on the wear of piston ring-cylinder assemblies under artificially increased dustiness conditions

Abstract The aim of this work is to determine the effects of metallurgical structure and cylinder surface topography on the abrasive wear of piston-piston ring assemblies. The cylinders tested were made of grey cast irons of different structures. They had also various surface topographies as a result of honing by abrasive tools. These cylinders were tested during automotive gasoline engine operation under artificially increased dusty conditions. Similar investigations were carried out using a tribotest machine. After the engine tests, it is evident that cylinders of pearlitic-ferritic structure show the best abrasive wear resistance. This result can be explained by the possibility that quartz particles can be embedded in the comparatively big graphite flakes located within a soft ferrite matrix. The effect of the presence of phosphorus eutectic on the wear of piston ring-cylinder assemblies in comparison to the pearlitic structure is negligible. However, the influence of the surface topography of grey cast iron cylinders on abrasive wear during engine operation under increased dusty conditions is substantial.

Characterization of the shape of the roughness profile ordinate distribution of honed cylinder surfaces

Abstract A review of the existing methods of describing the shape of a cylinder bore surface profile amplitude distribution was presented. The relationship between conventional and proposed parameters was studied using the principal components method and correlation and regression analyses. As the result of the analyses, combinations of uncorrelated parameters containing a great deal of information about the profile were selected. It was found that they were the most useful for a machined surface profile roughness description in comparison with currently applied parameters, with respect to differentiating between manufacturing processes. The attempt at a classification of the engineering honing processes of cylinders was made. It was found that the proposed division ensured the cylinder surface topography differentiation.