交流式放電加工電源之分析與改良設計

Abstract

在以前的加工中，我們對加工物的精確度及硬度並不十分重視，但是隨著 時代的進步，一些需要高精密度和高硬度加工材料的東西越來越多，而放 電加工就提供了一個最經濟又有效的解決之道．對於像鈦合金的渦輪葉片 這種又硬又耐熱又需要高精確度的物質，也都能對其作精密加工而不破壞 其表面特性．影響放電加工的速度ˋ精度因素向當地多，舉凡所加電壓ˋ 電流ˋ切閉時間ˋ切開時間ˋ電容ˋ加工液導電度ˋ加工液流量等條件， 都會對加工造成影響．其中，關於放電加工原理，已有不少文章討論過， 然而，我們認為放電加工的電壓ˋ電流源的時序控制對於加工物的精確度 有直接的影響，因此，我們先對既有的放電加工電源電路分析其優缺點， 我們再提出改進的共振式電源電路，除了以電腦軟體作電路的分析與模擬 之外，並實際作出電源電路來量測驗證它．目前已有不錯的一些成果，相 信未來實際應用在放電加工上將有令人滿意的成果． In the past, we didn't mind the hardness and accuracy of machining material. But now, along with the progress of the industry, the demands of machining of very hard, stiffness materials with high accuracy are rising higher and higher. Electro-Discharge-Machining (EDM) provides an economic and effective method for machining processes under such more stringent demands. For example, EDM can do accurate machining to very hard, stiffness material like titanium alloy intocomplex shapes as turbine blades without further destroying its surface properties. There are many factors such as voltage, current, on/ off timing, capacitance, conductivity of machining liquid, machining liquid's flowing rate, and etc.,will affect the processing speed and accurate results of the EDM machining. Many papers have discussed the theorems of electro-discharge. However, we believe that the accurate timing control of the current and voltage source in EDM machining by proper circuit design has direct influences on the performance of EDM machining. At first, we discuss the previous power source circuit's advantages and disadvantages. Then we propose an improved resonant power source circuit for EDM machining. Besides thorough circuit analysis and modeling by computer programs, we further implement a realistic power source circuit and verify the improving results. Now we have some good experimental results and computer analysis models, we believe in its well implementation in future EDM machining applications by further optimization.