- 學位論文
新型減振搪刀桿之可行性研究
Feasibility Study of a New Type Vibration-Reduction Boring Bar
摘要
精密切削為現今產業界佔有相當重要的地位，除了工具機本身之外，刀具之設計和選用也是極為重要，搪孔是精密加工不可缺少的一道程序，但由於搪刀桿本身具有較低之動態剛性，導致加工時易發生顫振，尤其是深孔加工更是相當不易，本研究計畫旨在建立能達到細長比為11，亦能減少顫振之搪刀桿。本文主要可分為兩部份，第一部份經由探討文獻，將過去研究搪桿參數分析結果為基礎，再加以改善其結構，並經由ANSYS WORKBENCH有限元素分析軟體進行模擬研究，目的是分析不同材質加以結合是否能提高剛性、減少顫振，經模擬分析後發現新設計的搪刀桿在外層為 之S45C，包覆內層 之SKD11的雙層結構新型搪桿時，靜態總位移量為0.192mm小於一般結構搪桿之總位移量0.19385mm，再經由振動模態的分析得知新型搪桿一到六模態的總位移量也都皆小於一般結構之搪桿，此數據為模擬結果後之最佳數據。 第二部份，經模擬分析結論，實際製作雙層結構新型搪桿，並進行切削實驗，再設定切削條件(包括轉速、切削深度、切削寬度)及細長比為參數，與一般結構之搪刀桿作比較，經由動態訊號分析器以及加速規分析實驗數據，經測試結果顯示新型搪刀桿在徑向總位移面積以及實驗切削過後工件表面粗糙度皆有明顯改善，由此結論可得知適當地選擇及組合材料，且因實際工作需求來限制搪刀桿之截面積，可以增加新設計搪桿之動態剛性，亦能減少位移和顫振，證明本研究所設計之搪刀桿可有效提升切削之減振效果。
並列摘要
As precision cutting takes a key position in modern manufacturing industry, in addition to the tooling machines applied, designing and selecting cutting tools are extremely important steps. An indispensable process when it comes to precision conversion, boring usually is carried out with vibration as the boring-bar itself is mostly made of lower dynamic rigidity and it is the defect that keeps depth boring a less successful task. This study aims to establish a length-diameter ratio at 11 for the sake of reducing chatter sensible vibration in boring-bar. This article consists mainly of 2 parts; Part 1 is based on, through literature research, the results of boring bar parameters involved in past works before adding improvements of its structure and eventually, the simulation study by analytical software carried out using limited elements on ANSYS WORKBENCH. The purpose is to assure whether, by using different materials at the same time, rigidity could be improved, shaking and vibration could go reduced. The simulation analysis indicates that the newly developed boring-bar has an outer layer of S45C of , while the inner wrapping layer SKD11 of forming a new type of boring tool of a dual-layer construction, the same creates a static displacement of 0.192mm, which is less than the total displacement of 0.19385mm produced by an average boring bar structure. A further analysis of vibration modulus results in minor total displacement than that of boring bars of regular construction of new type numbered 1 to 6. The figures are taken as the best ones delivered from the test. In Part 2, where the conclusions undergo a simulation analysis along with mean production of the new type of boring bar of two-layer construction. After a trial cutting, cutting conditions are set (which include rpm, cutting depth and cutting width)and the fineness-length ratio is used as a parameter in the comparison with boring-bar of regular construction. After analyzing the test figures using dynamic signal analyzer and acceleration gauge, it becomes clear that the new type boring-bar does improve remarkably in terms of radius total displacement area and workpiece surface roughness after cutting. The test itself makes a proper selection and combination of materials and, as the sectional area of the boring-bar is actually limited by mean working requirements, the newly designed boring bar does see its dynamic rigidity remarkably increase and, at the same time, displacement and chatter go down suggesting that the boring-bar referred in this study is successful when it comes to non-rattling effect in cutting.