Análise das forças atuantes em uma biela de um motor de combustão interna

Abstract

Internal combustion engines are continually improved and operate with increasingly greater combustion pressure criteria, mainly in the automobile segment, which indicates studies to improve their components. In this context, it is important to analyze the kinematics and dynamics of the connecting rod ? crank system of an engine that has had an increase in combustion pressure. The main objective of this work is to develop a mathematical model to determine the dynamic forces acting on the connecting rod-crank system with an emphasis on connecting rod analysis. Using a spreadsheet in Excel® software, graphs of forces acting on a connecting rod are generated and these results are validated with a dynamic simulation in Siemens NX® software. The Agrale M-95W engine is used to extract geometric and mass information, as well as the cylinder pressure curve. The virtual simulation in the Siemens NX® software demonstrated compliance with the calculations carried out via spreadsheet, thus enabling quick simulations just by changing the input values. It was noticed that by increasing the rotation by 33%, the inertia force became 78% greater, becoming the largest forces in a connecting rod. Another analysis was the variation in combustion pressure, which when increased by 20% generated a 25% greater force on the crankshaft piston. [resumo fornecido pelo autor]