استراتژی عملیات برش مارپیچی برای ماشینکاری سطوح مجسمه سازی به وسیله روش نقشه منسجم

Although compound surfaces and polyhedral models are widely used in manufacturing industry, the tool path planning strategies are very limited for such surfaces in five-axis machining and high speed machining. In this paper, a novel conformal map based and planar spiral guided spiral tool path generation method is described for NC machining of complex surfaces. The method uses conformal map to establish a relationship between 3D physical surface and planar circular region. This enables NC operation to be performed as if the surface is plat. Then through inversely mapping a planar spiral defined by a mathematical function into 3D physical space, the spiral cutter contact paths are derived without inheriting any corners on the boundary in the subsequent interior paths. The main advantage of the proposed method is that a smoother, longer and boundary conformed spiral topography tool path is developed. Therefore, the machined surface can be cut continuously with minimum tool retractions during the cutting operations. And it allows both compound surfaces and triangular surfaces can be machined at high speed. Finally, experimental results are given to testify the proposed approach

Rapid and efficient manufacturing of sculptured objects and dies is an important issue in modern industry. Over the years, surfaces of industrial products have become more complex because of the customers’ increasing requirements for function and aesthetic reasons. In this case, five-axis NC machining tools have gained wide applications. At the same time, due to the properties of high cutting speed and high feed rate, high-speed machining (HSM) centers have increasingly been utilized in industries. However, the conventional cutting conditions and tool path generation methods are usually employed in practice [1]. Currently, the available commercial CAD/CAM software for five-axis machining especially for HSM still lacks flexibility when specifying the tool orientation and tool path distribution for complex surface machining [2]. These systems mostly have limited functionality for the generation of multi-axis tool paths. When machining compound surfaces and triangular surfaces, the tool path generation methods are very limited, and the iso-planar method, which often needs many cutter lifts and the cutting force tends to fluctuate, is often used. As a result, the tool paths are very defective and also are no longer boundary conformed. Hence, gouge- and collision-free tool paths with smooth cutter movements are highly appreciated for their relatively higher surface quality, machining efficiency and superior dynamic property. Especially in high speed machining setting, such a path with smooth path dynamics rather than maximum machining strip width turns out to be very advantageous. For reducing lifts and achieving smooth path dynamics, in this paper a new spiral tool path generation method is presented based on conformal map for compound surfaces and triangular meshes machining.  

In this paper, we provide a novel tool path generation method and its detailed realization algorithms. Future work needs to address mapping of part surfaces with islands or holes. In addition, region-division based mapping and tool path planning strategy is also a challenge. If possible, we can simultaneously use several types of tool paths with boundary conformity according to the geometric property of the machined surface. Finally, planning spiral cutting operation with feed scheduling and developing some other types of paths in a mapping manner are also several possible extensions of the work presented in this paper.