廖運炫臺灣大學：機械工程學研究所楊昇佑Yang, Sheng-YuSheng-YuYang2007-11-282018-06-282007-11-282018-06-282005http://ntur.lib.ntu.edu.tw//handle/246246/61065在線切割放電加工中不可避免的時常會發生斷線情形，此時必須重新穿線才可繼續加工，不僅降低了加工效率、影響加工精度，更無法實現無人化的加工。因此自動穿線系統為線切割放電加工機極為重要的一模組。本文針對上述問題，開發出ㄧ新式的線切割放電加工機自動穿線系統設計，以提昇線切割放電加工機附加價值。 機械硬體設計部分，提出多種具有專利價值之單元模組設計，如:收線馬達單元、剪線及馬達定位單元等設計。其剪線機能方面，以交流放電方式修剪電極，此方法可有效改善加熱拉斷方式所造成線頭過細缺點，能有效控制斷點與銅線輪廓，硬體架構部分，採外掛式模組設計，相容性高可應用於不同機台架構，與國外同性能機型比較，單元零件少，因此成本較低，維修容易，市場發展潛力佳。 軟體控制部分，採用可程式控制器(PLC)與組合語言進行撰寫，穿線模擬部份則利用有限元素法，進行流場分析以獲得導引管合理加工尺寸及形狀。實驗結果顯示，利用所發展之機器能很成功地修剪出理想的線極外型，穿線成功率亦可達到理想結果，在工件高度50mm至100mm，切割起始孔徑1mm穿線成功率約可達84％~96％，斷線點穿線成功率約可達79％~91％，無工件狀態穿線成功率約可達76％~86％。此結果與國外現有機台穿線功能相比，成功率已達相同水準。開發出之系統預期將提升國產線切割放電加工機在國際市場之競爭力。The time consuming and tedious wire threading in Wire Electrical Discharge Machining (WEDM) before the start of the operation is always needed. In addition, wire breaking is inevitable during the machining process, and the chance to re-thread the wire is encountered from time to time. Hence the automatic wire feeder (AWF) is an essential unit closely related to machining efficiency and automation in WEDM. Despite various existing foreign and local patents, a new-type AWF based on modular design is developed in this thesis. Several units including wire receiving motor unit, wire cutting and shaping mechanism, motor positioning unit, etc. which have patent potential are proposed. The incorporation of special design cutter with electrical discharging for wire disconnecting while at the same time applying an appropriate tension on the wire during the wire disconnecting process results in very satisfactory profile wire. Besides, the disconnection point along the wire can be precisely controlled. The problem of too long and fine wire at the tip by using the heating and pulling strategy is prevented. The FEM is applied to simulate the fluid flow field and velocity within the pipe so that the proper shape of the wire guiding pipe can be determined. The developed system has less mechanical parts as compared to those of the existing systems. Hence, it is expected to be cost effective and easy for maintenance. In addition, the developed system is flexible, and it can be implemented on various wire-cut electrical discharge machine (Wire-cut EDM). The programmable logic controller (PLC) is taken for sequence control of the threading process. The associated software is written by the use of assembly language. Experiments are conducted to verify the threading performance of the developed system. It is found that the success rate is 84% ~ 96% for the 50~100 mm thickness workpiece having a 1mm in diameter initial hole. It is 79% ~ 91% when wire threading is carried out at the position of wire breaking. It is reduced to 76% ~ 86% when there is no workpiece in between the upper and lower wire guides. This performance is more or less comparable to the existing AWF. In conclusion, the AWF is successfully developed, and contribution to local EDM industry is expected.誌謝.......................................... Ⅰ 中文摘要...................................... Ⅲ 英文摘要...................................... Ⅳ 目錄.......................................... VI 圖目錄........................................ Ⅷ 表目錄........................................ ⅩI 符號說明...................................... ⅩII 第一章 緒論................................... 1 1-1 研究背景與動機................... 1 1-1-1 引言.................. 1 1-1-2 市場分析............. . 2 1-2 文獻回顧......................... 4 1-3 研究動機與方法................... 12 1-4 本文結構......................... 13 第二章 理論分析............................... 14 2-1 導引管噴嘴機構之概念設計......... 14 2-2 流體力學設計原理................. 16 2-3 噴嘴設計原理..................... 18 第三章 自動穿線系統開發....................... 23 3-1 自動穿線開發流程規劃............. 23 3-2 自動穿線系統單元設計............. 26 3-3 機械結構設計部分................. 27 3-3-1 供線滾輪單元設計...... 27 3-3-2 收線馬達單元設計...... 30 3-3-3 導引管穿線單元設計.... 31 3-3-4 剪線及馬達定位單元設計... 37 3-3-5 廢線收取單元設計...... 38 3-3-6 自動穿線系統完成圖.... 39 3-4 實驗設備統....................... 41 第四章 自動穿線控制系統....................... 43 4-1 加熱拉伸電路..................... 43 4-2 介面電路之規劃與撰寫............. 46 4-3 穿線系統主架構流程規劃........... 48 4-3-1 自動穿線選擇性分歧合流步驟規劃 49 4-4 自動穿線系統機械結構與可程式控制器之整合 50 第五章 實驗結果分析........................... 52 5-1 剪線機構設計與線頭斷面差異實驗... 52 5-1-1 實驗方法與結果........ 52 5-1-2 修剪線極實驗總結...... 59 5-2 自動穿線高度距離與穿線孔徑大小實驗 62 5-2-1 實驗方法與結果........ 62 5-2-2 穿線實驗總結.......... 66 第六章 結論與未來展望......................... 68 6-1 結論............................. 68 6-2 未來展望......................... 69 參考文獻...................................... 70 附錄A 自動穿線系統架構圖..................... 73 附錄B 自動穿線PLC控制回路與程式.............. 74 附錄C 震盪電路IC接腳圖....................... 87 附錄D 自動穿線系統單晶片程式碼............... 89 作者簡歷...................................... 947997907 bytesapplication/pdfen-US線切割放電加工機自動穿線系統剪線機能wire threadingWire-cut EDMautomatic wire feederwire cutting and shaping mechanismthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/61065/1/ntu-94-R92522709-1.pdf