- 學位論文
超音波輔助帶鋸機排屑之研究
The Research of Ultrasonic Assisted Band Saw Machine Chip Removal
摘要
鋸床普遍存在著加工效率低、刀具壽命低、精度低的問題，因在鋸切材料的過程中，鋸條會隨時承受張力、鋸條繞著鋸輪產生的扭轉力、切削力等眾多應力的影響之下，進而產生許多加工問題，而本論文以C-320GNC帶鋸機作為研究對象，利用超音波的高振幅特性來增加鋸條在加工時的切削力、排屑率與材料表面精度，進而增加刀具壽命以利降低製造成本。 本研究以廠商所提供的聲波焊頭外型進行設計與改良，利用田口法分別設計出一體成形式焊頭與組裝式焊頭求出符合頻率的聲波焊頭尺寸，並以ANSYS的有限元素分析法模擬出應力分布與振幅大小，進行分析對照。其結果顯示，組裝式焊頭無法有效發振，而一體成形式焊頭可順利發振，且實際振幅與模擬結果之誤差值不超過2%，證明頻率值符合實際要求。此外，為了將焊頭與帶鋸機做結合以達到輔助加工的效果，另外設計了可調式機構，以將聲波焊頭組裝至帶鋸機台上，找出最佳的加工參數。 此實驗主要以頻率20KHz的焊頭輔助切削中碳鋼(S45C)材料，經結果顯示，在超音波的輔助下，確實能增加鋸條的排屑率以降低材料切面受到鐵屑之刮傷。可得知影響結果的最大參數為焊頭發振間斷時間，佔了整體高達86.95%，且經由鐵屑型態可知，超音波可有效的增加切削力，使鋸切效果更為完整。
並列摘要
Low processing efficiency, tool life and accuracy are often found in saws, because in the process of cutting, the blade may suffer many problems under stress such as tension, twisting and cutting forces from the wheel. This paper sheds light on the possibility of increasing the blade cutting force, chip removal rate and material surface accuracy during machining by using the high-amplitude characteristics of ultrasound on C-320GNC bandsaw, thereby increasing tool life to reduce manufacturing cost. In this study, the appearance of horn which provided by manufacturers were designed and improved by Taguchi Method. Taguchi Method was used to calculate two kinds of sonic horn includes integrated and, separately. The ANSYS (Finite Element Analysis) was used to simulate the stress distribution and ultrasonic vibration. The results shows that comparing the actual results of integrated horn which could oscillate effectively with assembled horn, it's relatively error were less than 2%. Furthermore, the adjustably mechanism was devised to achieve the auxiliary processing by combining the horn and band saw machine. We installed the horn on band saw machine to find the best processing parameter. This experiment mainly involves the cutting of medium carbon steel (S45C) with the ultrasonic hornet frequency of 20KHz. The results show that ultrasound can really enhance the accuracy of section by increasing the blade chip removal and the parameter that affects the outcome the most would be the intermittent time of the horn (accounting for 86.95%). And through the iron filings patterns shows that ultrasound can effectively increase the force, so that the effect is more complete sawing.