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.

Evaluation of manufacturing tolerance using a statistical method and experimentation

“…In phase 20, the studied part is placed on the isostatic part-holder by a primary support (A 1 , A 2 and A 3 ) on the surface 2, a secondary support (A 4 and A 5 ) on the surface BB 4 and tertiary support (A 6 ) on the surface B 3 B . 5176E-05 9,816E-06 1,291E-05 1,2374E-05 1,35E-05 1,6327E-05 To obtain the variance, the same procedure used in phase 10 is applied.…”

“…A very broad review of the tolerancing method is presented in Wang et al [1]. In industry, the most common approaches are simply unidirectional and often based on the Δl method [2][3][4]. Such approaches are not able to handle small angular deviations from one machining phase to the next.…”