Development Of Circulated Unidirectional Traveling Wire EDM Equipment

Wire Cut Electrical Discharge Machining(WEDM) is one of the most widely used technique of non-traditional machining. Its basic working principle is processing the workpiece into certain shapes with the moving electrode wire and modern numerical control and pulsed power supply technology. And now, it has been widely used in the fields of difficult-to-machine material, mold manufacturing, forming tool, precision parts machining, etc. However, the domestic wire cutting machine still uses the traditional wire traveling mode and CNC system in the development journey, which cannot meet the needs of customers about the high precision, high intelligence, low cost and open management of manufacturing in the internet era. So it is of great significance to develop new wire traveling mode and CNC system.The purpose of this thesis is to develop new wire-cutting processing equipment, including the research of circulated unidirectional traveling wire winding system, the WEDM CNC system based on HTML5 and relevant technical problems.Firstly, design and realize the circulated unidirectional traveling wire winding system, including the wire winding mechanism and wire guiding mechanism. Based on the analysis of advantages and disadvantages of the traditional reciprocating wire traveling mode for WEDM, a new wire traveling mode is devised, so called circulated unidirectional traveling device. On the basis of the formation principal of spatial helix, the circulated unidirectional traveling wire winding mechanism which consists of six guiding rods is designed. The guiding rods are aligned in a tilt angle which are implemented with specially designed shaft sleeves. The 3D model of the wire winding mechanism is created and its prototype is made. To realize wire biplane motion, the biplane wire guiding scheme is proposed. Design the bilateral constant tension control way. The possible wire slipping during running is modeled and analyzed. Furthermore, the measures of preventing the wire slipping is proposed as well. The slipping experiment is done and obtain the regression equation of the slip rate.Secondly, put forward the overall architecture of WEDM CNC system based on HTML5 and modern network technology. Design the client interface with HTML5, CSS3 and Java Script on the web browser and realize the functions of human-machine interaction and data processing. Design the CNC system server with Raspberry Pi and embedded Linux system and realize the functions of motion control and I/O control. Design the real-time communication module with Web Socket and realize the data interaction of client and server. Design the CNC code interpreter. Design the CNC interpolator with unit arc length increment method. Design the discharge condition detection module with average voltage detection method. Realize wire electrode automatic feed control and short circuit back with voltage to frequency conversion method. In order to enhance the system reliability and capacity of resisting disturbance, all the I/O circuits are designed with photoelectric isolating technology.Thirdly, design the assisting functional modules of circulated unidirectional traveling wire, including the pulsed power supply and wire laser welding scheme. Design and build the pulsed power supply of WEDM with the pulse signal control panel and discharge power board and realize the adjustability of electrical parameter. Design the wire laser welding scheme, including the laser and optical path system, argon gas protection device, welding mechanism and welding controller. At last, the experimental platform was set up to conduct the wire laser welding experiment.Finally, build the new circulated unidirectional traveling wire EDM equipment with circulated unidirectional traveling wire winding system, the WEDM CNC system based on HTML5 and the pulsed power supply. The machining experiment confirms the feasibility of the equipment.