Estudo de viabilidade técnica e econômica para fabricação de pino de centro para feixe de molas

Abstract

The automotive sector has representativeness and influence in the current Brazilian economy and due to the poor quality of the highways in the country there is a decrease in the useful life of the components, especially the component parts of the suspension system of vehicles of the heavy line. In this context, the object of study of this work is the center bolt for leaf springs, a fastener responsible for joining and maintaining all the blades of the leaf spring of the mechanical suspension of heavy vehicles aligned along the axis. This work, developed in a metallurgical company, aims to elaborate a technical and economical feasibility study for the manufacture of these items, which are now bought and resold. For this, reverse engineering concepts were used to propose the designs of the product and the selected raw material. Also, tests were carried out on samples of the proposed material to obtain the yield curve and analytical calculations referring to the process in order to identify the maximum stresses and deformations. For the manufacturing process that demonstrated the need for investments, equipment was selected to be acquired and subsequently the costs of the product for internal manufacturing were defined. In the end, the economic viability was evaluated through net present value (NPV), internal rate of return (IRR) and payback time for three different scenarios, one normal, one pessimistic and one optimistic. The study presented negative NPV results for the pessimistic scenario, slightly negative NPV for the normal scenario and a positive NPV for the optimistic scenario. The paybak time reached for the normal scenario is 3.4 years (sic).