摩擦式鋸切之切斷模式研究

Abstract

摩擦式鋸切是利用鋸片高速旋轉使被加工物在與鋸齒接觸部份因摩擦熱溶解而切斷的一種鋸切方式，摩擦式鋸切雖然切斷速度很快，但其切斷面會殘留極大的毛邊，往往需要二次加工修整切斷面，對加工成本十分不利。如欲改善這些現象則必須先理解摩擦式鋸切之切斷模式。本研究擬以實驗的方式，探討摩擦式鋸切在鋸削過程當中，鋸片線速度與鋸切進給速度對工件受力之影響，進而闡明摩擦式鋸切的切斷模式。 理論部份，本研究以正交切削模式為基礎，配合弓鋸鋸削模式，以建立切削參數與切削率間之關係。另外，配合金相組織的觀察，分析摩擦式鋸切的切斷模式。 由實驗結果發現，摩擦式鋸切的切斷機構主要包含鋸斷與熔斷兩部份，兩者所佔的比例與鋸削進給速度、鋸片線速度等皆有關係。

Friction sawing is one of the sawing process that uses a very high speed round blade to cut the workpiece.During the sawing process, melting of the workpiece occurred because of the severe friction between cutting blade and the workpiece.This kind of sawing method though can cut the workpiece off very fast, however, very often a very large piece of burr will leave on the cut off face and need further machining to clear it.To solve the problem we need to understand the mechanism of friction sawing. In this study we investigate the effects of blade line speed and feeding speed on the cutting force, examine the photomicrograph of the cut off face. It is found that many grains on the cutting face show there are severe deformation and sometimes even melting during the sawing process.The percentage of the melting is related to the sawing blade line speed and feeding speed.