电火花小孔加工脉冲电源的微观控制方法研究

Micro Control Method of Pulse Power Supply for Small Hole EDM

为解决电火花加工航空发动机涡轮叶片气膜孔等高温合金材料小孔的诸多难题,提出了一种基于CPLD硬件实现的微观控制方法,用于电火花小孔加工脉冲电源的研制。该方法应用CPLD设计了一种外部可触发型高速同步多回路脉冲控制电路,通过快速检测放电前的间隙状态和放电过程中单个脉冲的放电状态,可有序控制放电过程中每个脉冲的工作进程,优化放电脉冲能量输出,杜绝有害脉冲发生。最后,开展了脉冲电源加工试验。结果表明:可有效地减小重融层厚度,避免微裂纹产生,并提高加工效率和孔径的一致性。

In order to solve the problems of EDM machining small holes of superalloy materials such as gas film holes in turbine blades of aero-engine,a micro control method based on CPLD hardware was proposed for the development of pulse power supply for EDM small holes.This method uses CPLD to design an external triggered high-speed synchronous multi loop pulse control circuit.By quickly detecting the gap state before discharge and the discharge state of a single pulse in the discharge process,the working process of each pulse in the discharge process can be orderly controlled,the energy output of discharge pulse can be optimized,and the occurrence of harmful pulse can be eliminated.Finally,the processing experiment of pulse power supply is carried out,and the results show that the thickness of remelting layer can be effectively reduced,the generation of microcracks can be avoided,and the processing efficiency and aperture consistency can be improved.