The Research Of Asynchronous Linear Hotwire Cutting System For Foam Pattern

Generally, CNC electric wire cutting devices are widely used to cut polystyrene sheet-based foam to make small-batch EPC molded foam patterns. But, many companies still cut it manually with electric wire, by which the surface quality and dimensional accuracy can not be guaranteed.Although electric wire cutting can promote the efficiency and precision of the process, only parts with simple structure can be cut by this method, while curved surface can not. Instead, four or multi-axis devices including robots are adopted by foreign companied to cut parts with curved surfaces. But at the same time the structures of the devices are much more complicated, the price is high and the flexibility is low. What's more, different standards of codes are adopted by different manufacturers, which also increase the difficulty to operate. As a result, it is hard to find a suitable way to cut EPD foam parts with curved surface. It is of great value for the lost foam casting process to develop a system which is compatible with multiple CNC codes to cut the foam.In electric wire cutting, the device cuts the foam by control the relative position of the two endpoints of the wire. When the relative position of the two points keeps constant, it is called synchronous cutting. Similarly, when the position is not fixed, it is called asynchronous cutting. In this paper, at first, the asynchronous cutting device is designed with the help of the software Pro/Engineering. The efficiency and stability of the device is guaranteed by using advanced motion control card and respective driver. And then, a device controlling software named SmartCutting is developed with the development platform Microsoft Visual Studio on the Microsoft Windows system. The software is developed based on the layered software design method, in which the software is divided into different modules based on the functions. There are 5 modules, including software analysis module, error testing module, parameter setting module, simulation module and device driving module. At the same time, in order to solve the compatibility between different coding standards and the interaction between different modules, a middle path suitable for the coding standards is proposed, which also increase the reproducible availability of different modules. The middle path is generated by combining two different paths. The simulation module is the core functional module in SmartCutting, in this module, model building, advanced and real-time manufacturing process simulation can be realized, thus reducing the uncertainty in the real cutting process and improving the design of the model.At last, the device is assembled and tested. Cutting paths for the dimensional wire cutting and asynchronous cutting process are generated and tested. The models manufactured by the device are compared to the simulation result to test the feasibility of the system. The result shows that the developed asynchronous electric wire cutting system is capable of the simulation and cutting of the EPS foam. In the system, different plans can be selected for different demands, and then the cutting path can be generated and simulated. Once the simulation is successful, it can be applied to the real situation, which highly boosted efficiency and quality of the products.