According to the characteristics of micro EDM, to form a complete process control system, the following basic functions must be available. (1) The spindle rotation function is mainly speed control, and the system uses a DC servo motor as the actuator. (2) The spindle feed drive function includes speed control and position control. The stepper motor is used as the actuator, and the control system is required to work in two ways: jog and continuous rotation. (3) Micro-energy pulse power control function: Since the micro-energy pulse power supply has a great influence on various indexes of EDM, in the process of micro-EDM, the numerical control system needs to be able to control the pulse power parameters in real time, such as peak current, Open circuit voltage, pulse width, pulse, etc. It is required to be able to control each item individually. (4) The detection function of the machining discharge state can detect the voltage between the electrode pairs for the system to make a decision. (5) The knife lifting function is used to eliminate the erosion product in the discharge gap. Due to the harsh working environment of the micro-EDM digital control system, various external interferences are distributed on the processing site, and the electromagnetic wave interference generated by itself is a non-negligible interference source. Therefore, in addition to the above basic functions, the system must also be Reliability, anti-jamming, usability and other aspects are considered comprehensively. Take the following plan in the design: (1) Provide 16 digital outputs, complete current/voltage selection, pulse width and pulse interval selection, and various switching control functions; (2) Provide A/D conversion channel to monitor the processing status of the system in real time; (3) providing a pulse signal for controlling the speed and position of the stepping motor and the DC servo motor; (4) All levels and pulse signals are optically isolated to improve the anti-interference ability of the system. The analog signal uses an opto-isolated amplifier to separate the field signal from the control signal. (5) Many optimizations have been made to the power supply and wiring to reduce unreliable factors; (6) The connection between the system and the ISA bus, mainly the chip select signal, is realized by a programmable logic device GAL22V10, which simplifies the compilation circuit, enhances the reliability, and has certain confidentiality. (Finish) XPS extruded board foaming screw Xps Foaming Board Extrusion Line,Extrusion Line Xps Foaming Board,Xps Foaming Screw Foaming Board Extrusion Line ZHEJIANG JINJIA PLASTICS MACHINERY CO., LTD , https://www.jinjiascrew.com
Introduction to the design of EDM control system