Estudo de estratégias de medição para controle do dimensionamento geométrico e toleranciamento (Gd&T) em peças estampadas

Abstract

Geometric Dimensioning and Tolerance (GD&T) is a methodology used for dimensioning and its application has been extended in the automotive industry. One of the factors that explain its use is the cost savings generated by the increase in the tolerances range, making the non quality costs with parts non-conforming decrease. But what can be verified is that some companies are not prepared to apply correctly this methodology and this misinterpretation from the drawing leads to a wrong measurement strategy. The problem that is proposed to be solved is experienced by a company in one of its first process that is the parts incoming inspection. In this inspection some characteristics agreed between supplier and customer are verified, and the probability of differences between these measurements cannot be completely eliminated. These differences may be associated with several factors, including: the measuring process used, because generally suppliers uses gauges dedicated in the production line to measure its components while customer uses CMM or others universal instruments. The project studies the GD&T fundamentals and their correct application for the part conformity verification, the measurement process used, principally the coordinate measurement. Data from three different companies were collect: from the supplier, from the customer who uses the component and from the parent company in Europe that uses a similar piece. This study defined a measurement strategy that can eliminate possible differences between the supplier measurement and the customer one.