Processo de brunimento em camisas de cilindro de motores de combustão interna: uma análise da influência da velocidade de avanço no acabamento superficial

Abstract

An important part of the automotive productive chain is the engine’s remanufacturing, which is usually carried by service companies, more commonly know as the “engine rebuilding”. In this companies, the different engine components undergo procedures to recondition their operating characteristics. The cylinder liners are important components in internal combustion engines, once they delimit the combustion chamber along the pistons. The repair of these cylinder liners happen through a machining process called honing. A procedure capable of promoting good dimensional and geometric accuracy, as well as good surface quality. Determinant characteristics, since the good superficial finish of the cylinder liners contributes to the fuel comsumption reduction, mainly by the reduction of the losses by friction. Therefore, it is of importance to provide a research in this field whose mains goal is to make an investigation of the superficial finish generated by the honing process carried out by a company that provides services of engine’s rebuilt located in the city of Fortaleza, through superficial roughness evaluation and crossing angles formed by the honing process on the four cylinder liners of an internal combustion engine. In this study, each one of the cylinder liners was burnished with diferent feed rates The crossing angles and roughness parameters values found for the diferente feed rates studied were compared to standardized values of automakers. The roughness results have values within the recommended range only for the two lower studied speeds, whereas for the cylinder liners machined at the two top studied speeds, the roughness rates exceed the range. While the crossing angles were all below the recommended range for the evaluated speeds, suggesting that the feed rates were low for the process. It is concluded that the studied honing process has no conformities and therefore is necessary to make changes in some process qualities so the procedure reach better results. Suggesting that these changes can be less costly, such as the change of only the abrasive, or more costly, such as the change to a variable rotation honing machine to make the process even better and more flexible.