一種複合式陣列微細線極張力控制機構設計與陣列微線切割放電加工技術研究

Abstract

在高精密製造業中，微線切割放電加工技術具有精密、高效的切割能力，能被應用於電子(Electronic)、光學(Optics)、醫療(Medical)等重點發展行業。在其中陣列式微線切割加工技術能夠以更高的加工效率加工具重複特徵的複雜造型，然而現今陣列式微線切割加工技術多會遇到放電能量分散問題。本研究提出一種以「複合式」之微細線陣列張力控制技術搭配直徑30μm的黃銅線完成用於高產量製造精微元件的陣列式微線切割放電加工技術。複合式陣列微細線極張力控制機構包括線極由旋轉中的雙等速同步馬達控制驅動，確保線極傳送穩定；此外本研究提出單線極配重機構，透過配重件設計，對每一條銅線分別進行線張力微調，以達到穩定各線極張力的效果；為對陣列線進行整體線張力調控，本研究提出一種彈簧壓桿吸收振動機構的裝置，透過彈簧伸縮變化來吸收不穩定的線極張力。實驗結果發現，在雙等速同步馬達及單線極配重機構雙重作用下，線極振幅可收斂至0.5~2.5 μm間；在雙等速同步馬達、單線極配重機構及彈簧壓桿吸收振動三重作用下，線極振幅可收斂至1.5 μm以下。以Ø30 μm線極切割碳化鎢溝槽，其槽寬可被精確控制在37~38 μm間。在另一方面，為避免陣列線切割過程的放電能量分散問題發生，本創作也提出單線極單電源設計，以三組各自獨立的放電電源分別接入三條線極，互相間不導通。實驗證實，陣列線極切割模式為單線線極切割模式的2倍效率；而陣列切割模式下，單線極單電源設計為單線極共用電源設計的1.5倍效率。本研究以單線極單電源加上複合式陣列微細線極張力控制機構設計，不僅能提供高穩定性的精微陣列切割加工機構，同時也大幅提高生產精微造型的效率，是值得被商業化的創作技術。This study proposes a"composite" microwire array tension control technology combined with a 30 μm diameter brass wire for high-yield manufacturing of fine micro components using array-type micro wire electro-discharge machining (w-EDM). The composite array microwire extreme tension control mechanism includes a wire electrode driven by a dual synchronous motor control to ensure stable transmission. In addition, this study proposes a single wire-electro counterweight mechanism, which adjusts the tension of each copperwire individually through a counterweight design to stabilize the tension of each wire electrode. To achieve overall tension control of the array wires, this study introduces a suspended elastic wire tension correction system designed to absorb vibrations, stabilizing unstable wire electrode tensions through the compression and extension of the spring. Experimental results show that, under the dual-action of the dual-speed synchronous motor and the single wire-electro counterweight mechanism, the wire electrode's amplitude can be reduced to between 0.5 and 2.5 μm. Under the triple action of the dual-speed synchronous motor, the single wire-electro counterweight mechanism, and the spring-loaded support vibration absorption mechanism, the wire electrode amplitude can be reduced to below 1.5 μm. Using a Ø30 μm wire electrode to cut a tungsten carbide groove, the groove width can be precisely controlled between 37 and 38 μm. On the other hand, this creation also introduces a single wire-electro single power supply design to avoid the issue of dispersed discharge energy during the array wire cutting process. The experiment confirms that the array wire electrode cutting mode has twice the efficiency of the single wire electrode cutting mode; in the array cutting mode, the single wire-electro single power supply design is 1.5 times more efficient than the shared power supply design for single wire electrodes. This study, using a single wire-electro single power supply combined with a composite array microwire tension control mechanism, not only provides a highly stable fine array cutting machining system but also significantly improves the efficiency of fine shape production, making it a promising technology for commercialization.