FEM分析搓牙製程及改善螺絲強度之研究

Abstract

螺絲雖然只是一個不起眼的小零件，但是在機械工業中卻是扮演一個不可或缺的角色，要生產出品質優良的螺絲，首要的關鍵技術便是搓牙製程。搓牙製程裡的參數繁多，諸如牙板模尺寸、牙山幾何形狀、胚料的材料性質及牙板模間距等皆是影響滾製後之螺絲品質優劣的因素。 本研究由有限元素法建構螺絲滾壓製程分析模式，並深入分析搓牙製程面對不同的參數改變時會有何種影響，並探討改進之道。除此之外，利用此分析模型探討牙板模對螺絲強度的提升有何助益，首先針對現有不同的牙板模帶入此模型分析，然後了解讓其強度增大的機制，接著比對實際量測後的結果。本研究最後也證明了此種分析模式的可行性，模擬和實測的數據皆十分相近，此研究方法可提供給螺絲業者做為一個學術上的參考，利用此方法可以有效率、有系統的加快螺絲研發速度。

Although the screw is just a minor mechanical part that attracts less attention by engineers and researchers, it plays an important role in the machine industry. To produce high quality of screws, the initial key technique resides in Thread-Rolling manufacturing process. There are many parameters involved, such as the size and shape of Thread-Rolling die, the material of screws, and the distance between the Thread-Rolling dies. All these factors bear great influences on the output quality. The research contains the analytical approach by Finite Element Method（FEM）, and attempts are made to find out the way of improvement in quality. In addition, it is discussed the improvement of the screw strength by using the analysis model. In the beginning phase, different Thread-Rolling dies were introduced in the analysis model. Mechanism understanding and its strength enhancement were studied, and then measuring results were compared. Finally, it is shown the success of the analytical model which gives close agreement with experimental data. The method developed in this research provides an efficient and systematic process to enhance high quality of screws production.