دانلود رایگان مقاله ماشینکاری CNC کارآمد 5 محور سطوح free-form با دوران کامل

Abstract

We introduce a new method that approximates free-form surfaces by envelopes of one-parameter motions of surfaces of revolution. In the context of 5-axis computer numerically controlled (CNC) machining, we propose a flank machining methodology which is a preferable scallop-free scenario when the milling tool and the machined free-form surface meet tangentially along a smooth curve. We seek both an optimal shape of the milling tool as well as its optimal path in 3D space and propose an optimization based framework where these entities are the unknowns. We propose two initialization strategies where the first one requires a user’s intervention only by setting the initial position of the milling tool while the second one enables to prescribe a preferable tool-path. We present several examples showing that the proposed method recovers exact envelopes, including semi-envelopes and incomplete data, and for general free-form objects it detects envelope sub-patches.

6. Conclusion and future work

We have investigated a problem of approximating free-form surfaces by a set of envelopes of surfaces of revolution. The proposed algorithm is intended for the finishing stage of CNC flank machining where large scallop-free parts of the machined surface can be generated by a single sweep of the milling tool. The tangential movability analysis of a 3D line with respect to a free-form surface has been conducted to detect candidate lines with good movability from which initial ruled surfaces arise. Alternatively, we support also a surface-driven initialization to prescribe directly a preferable motion of the machining tool.