Abstract
本文研究之目的，主要針對水平式鋸床來探討鋸削過程中，切削參數—鋸帶速度、進給力、工件寬度 (切削長度) 及鋸帶齒距 ( Blade Pitch) 對單位時間內之材料移除率 (Material Removal Ra te) ，即切削率(Cutting Rate) 的影響，並建立切削參數與切削率關係之理論模式。同時藉由實驗來瞭解鋸削過程中切屑堆積與鋸帶彎曲現象對切削率的影響，進而評估是否可藉由特定之帶鋸機構運動路徑，以獲得最佳之切削率。理論部份，則以正交切削(Orthogonal Cutting)模式及 Thom- pson 所發展之弓鋸鋸削模式為基礎，建立重負荷切削過程下的鋸削模式，同時，以單位體積切削能的觀念作進給力的預估，進而建立起切削參數與切削率之關係。並以實驗來驗證理論中之假設條件及切削率與切削參數之關係是否成立，以及瞭解鋸削模式中未建立之切屑堆積與鋸帶彎曲效應對切削率的影響。最後，以本文所建立之切削參數與切削率間之理論關係式為基礎，同時將實驗所得之切屑堆積與鋸帶彎曲效應對切削率的影響納入考慮，以決定最佳之切削長度 L# ，並希望修改帶鋸機構之作動方式，使得切削過程中任一瞬間之切削長度皆為 L# ，以達到最大之切削率。The principal purpose of this paper is to develop a sawingmodel which is designated to study the influential parameters,such as blade velocity, feed force, workpiece length and bladepitch, on the cutting rate. In order to realize the effects ofchip clogged and blade deflection on the cutting rate, an expe-riment was performed in this research. The feasibility of de-signing a special bandsaw mechanism to obtain the highestcutting rate was evaluated. Theoretically, without loss ofgenerality, a simplified sawing model based on orthogonalcutting and Thompson's hacksaw model for heavy-load cuttingprocess was developed to predict the feeding force by employingthe concept of cutting energy and to construct the relationsbetween cutting parameters and the cutting rate. Moreover, thecorrectness of assumptions and the sawing model was verified bythe experimental investigation. Finally, based on the modelestablished in this paper and by taking the effects of cloggingchip and blade deflection on the cutting rate intoconsideration, the optimum cutting length (L#) is determined.Consequently, a strategy for the modification of the motion ofthe bandsaw mechanism for obtaining the highest cutting ratewas proposed.