Avaliação do efeito do tratamento superficial no coeficiente de atrito de uma junta parafusada aplicada em ônibus rodoviários

Abstract

Bolted unions have a wide use in a bus. They are employed due to their versatility, promoting to the product a possibility of adjusting or disassembling this components for maintenance. It's necessary that the bolted joints applied in a bus resist the diferents applications were subjected, like the mechanical efforts caused by the quality of the pavement on roads or the weather in the environment that the vehicle used. The purpose of this work was evaluate the effects for the diferents surface treatment on the friction coefficient, to decrease the variation of the tensor force in a constant torque process applyed to a bolted joint on a support of the road bus door. By means in analytical calculations and practical tests the fasteners has been reevaluated to the new range torque in order to prevent failures in the bolted joints during the product's lifecycle. Through the experiments was possible find a variation of about 62% in the force obtained, from the different combinations used in this work. In the end of this work a methodology based in the VDI 2230 standard was developed for others bolted joints application in the company. [resumo fornecido pelo autor]