Development of 3D Digital Proto-Typing Machine Based on Multi-Axes Controlled Hot-Wire Cutting for Polystyrene Foam

采用新研制的多关节机器人与工作台单元相结合的双旋转机床，对聚苯乙烯泡沫塑料进行了三维数字成型。结果，我们得到了以下有用的和有价值的评论。(1)生成适合于三维数字样机的三维形状数据，提出了一种多关节机器人路径传递的新方法。对于自由曲面，没有明确的数据，然后我们开发了一个使用三维形状数据的自动路径生成过程。(2)对所研制的三维数字样机的性能进行了评价，提出了一种高速控制系统，研究了机器运动精度与聚苯乙烯泡沫塑料加工表面精度的关系。在热线切割过程中，与金属切割过程相比，力可以忽略不计。因此，允许机器人以更高的速度运动，并在复杂的路径上控制机器人系统是一个重要的课题。对聚苯乙烯的成型采取了适当的控制方法并进行了试验。(3)明确了聚苯乙烯泡沫塑料的加工机理，找出了合适的切削条件，并考虑自由曲面确定了合适的热线形状。对热丝切削现象进行了讨论，并基于组合模型对热丝切削的热分解和热熔过程进行了模拟。通过数值分析，确定了最佳切削条件。在此基础上，构建了自由曲面8轴控制加工系统，并对其性能进行了测试。提出了路径生成方法，并通过实例验证了该方法的可行性。

3D digital proto-typing for polystyrene foam was carried out by using newly developed machine which combined multi-joint robot and table unit with two rotary motions. As a result, we obtained useful and worth remarks as follows.(1)To generate three dimensional form data suitable for 3D digital proto-typing machine, and to propose a new method of transferring for the path of multi-joint robot.As for the free form surface, there are no explicit data and then we developed an automated path generation process using three dimensional form data.(2)To estimate the performance of developed 3D digital proto-typing machine, to propose a high speed control system and to investigate the relationship between accuracy of machine movement and precision of machined surface of polystyrene foam.In the case of hot-wire cutting process, force is negligible small compared with the metal cutting process. Therefore, it is allowed to move with higher speed and to control the robot system in complicated path is important subject. Appropriate control methods were adopted and examined for form shaping of polystyrene.(3)To make clear the machining mechanism of polystyrene foam, to find out suitable cutting condition and to decide a proper shape of hot-wire considering free form surface.The phenomena of hot-wire cutting were discussed and the thermal decomposition and thermal melting were simulated based on the combined model. Through the numerical analysis, optimum cutting condition was cralified.Summing up these results, the 8 axes controlled machining system for free form surface was constructed and its performance was examined. The path generation procedure was proposed and its feasibility was proved applying to practical usage.