Design of Five-aixs CNC System for Electric Discharge Grinding (EDQ) Polycrystalline Diamond (PCD) Tools

摘要

Polycrystalline Diamond (PCD) tools are widely used while machining wood-based composites because of its outstanding hardness, thermal conductivity and abrasive resistance. However, the above mentioned beneficial properties such as super hardness also cause problems in manufacturing PCD tools using traditional process methods. The main problem now in manufacturing PCD tools is the low efficiency and difficulties while manufacturing PCD tools with complex curved surface.To manufacture PCD tools with complex curved surface more efficiently, in this paper, the mechanical structure, hardware circuit and software system of five-axis EDG CNC system are introduced. To satisfy the unique requirements of EDG, a proper mechanical structure of 5 CNC controlled axis and 2 manual axis are given, as well as the design of hardware circuit of EDG based on PCI Bus. The software system which is designed based on RT-Linux is divided into four modules: real-time cyclical tasks module, real-time gusty tasks module, non real-time tasks module and EDG process database. , This paper gives out the solutions of the specific functions of this special CNC system, including automatic measurement, automatic programming, automatic electrode wear compensation, and detection and control of spark gap. The detailed structure and organization of the software system is also provided.At last, through actual cutting experiments of woodworking PCD tools, the correctness and practicality of this system is verified.