Manufacturing simulation: Computer aided tolerancing for process planning

Abstract

The simulation of the process planning is a decisive stage in the manufacturing process of a set of parts. This simulation is generally carried out by the calculation of the working dimensions (WD) according to the blueprint dimensions (BPD), to the means of production and to the machining process. The calculation and the generating of the working dimensions can be done by using different methods such as the transfer method, the dispersion method and the tolerance chart method. This article presents a system of automatic generating of the working dimensions (WD) through the tolerance chart method. From the blueprint dimensions and from the process planning proposed, the system allows the automatic generating of three graphs: the blueprint dimensions graph, the blueprint dimensions and the stock removal graph, as well as the working dimensions graph. After the drawing of the two last graphs, the dimensional chains appear in the matrix from: Y=PX. At last, the calculation of the tolerance intervals for each dimension is done from the resolution of an equation system according to the minimum economic tolerances imposed by the manufacturing process and to the weight assigned to the tolerances.