Wire Tension Control of Wire Electrical Discharge Machining Through System Dynamic Analysis

應用系統動態分析於放電加工之線張力控制

王丕文(Pi-Wen Wang) ； 陳冠彬(Guan-Bin Chen)

《中國機械工程學刊》 37卷4期 (2016/08) Pp. 325-333

摘要

本文發展了放電加工機繞線系統之動態模擬技術，根據此物理模型，發展出兩個穩定線張力之裝置。第一個裝置為主動供線系統，即是在供線輪裝設馬達主動將線往前送，進而隔絕供線輪質量附加於繞線系統之質量，使系統自然頻率大幅度上升，第二個裝置為多層三明治阻尼吸振器，由可撓曲之三明治阻尼板構成，當系統受到擾動時，可以藉由三明治板的變形吸收擾動能量，增加系統阻尼係數。本文首先建立了繞線系統之物理模型，模擬結果顯示主動供線裝置可以大幅度增加系統之自然頻率，而多層三明治阻尼吸振器可以進一步增加系統的阻尼係數。實際裝設主動供線系統於商用機台進行測試時，線張力變動量可以由130 gf降至70 gf，自然頻率可以由2 Hz增加至9 Hz，當同時裝設兩個裝置時，線張力變動量可以進一步降低至43 gf。

並列摘要

A dynamic modeling technique for the wire transport system of wire electrical discharge machining (wire-EDM) is proposed. Based on the technique, two devices are proposed to control the wire tension. The first device is the active wire feed apparatus, a motor mounted on the wire spool to actively feed the wire. It eliminates the inertial effect of the wire spool on the system, increasing the system fundamental frequency. The second device is a multilayer damped vibration absorber (MDVA). The high-damping MDVA is a flexible device that oscillates as wire tension variation occurs. The perturbation on the wire tension can be attenuated. A physical model of the wire transport system with both mechanisms is constructed, and the effects of both devices on the wire tension are investigated theoretically. Theoretical studies show that the system fundamental frequency can be effectively increased by the active wire feed apparatus, and the MDVA can increase the system damping coefficient. Both devices are mounted on a wire-EDM machine tool to test the wire tension variation. Results show that the wire tension variation can be reduced from 130 gf to 70 gf by mounting the active wire feed apparatus, and the fundamental frequency can be increased from 2.0 Hz to 9.0 Hz. Installing the MDVA on the system slightly reduces variation in the wire tension, but the high frequency perturbation is eliminated to a significant degree. If both devices are installed on the system, the wire tension variation can be further reduced to 43 gf.

並列關鍵字

wire tension ； wire-EDM ； damped vibration absorber ； wire transport system