金屬引伸成型製程之參數設計

Investigation on the Effects of Process Parameters in Metal Drawing

蔡佳利(Jia-Li Tsai)

指導教授 ： 陳永樹

元智大學/工程學院/機械工程學系/碩士(1998年)

摘要

金屬引伸加工過程中，其主要製程參數概括挾持力大小、模具間隙、引伸速度及磨潤狀況等。本研究將針對這些參數對引伸成品表面品質之影響做一系統性探究。主要為利用力學分析，對加工所需之挾持力加以控制，且配合機台設備，設計一計時電路裝置來量測引伸速度；並於加工過程中變換不同尺寸的模具來改變模具間隙及交互採用不同黏度之潤滑劑來進行實驗。而由上述製程參數之影響結果，若以最終成品厚度分佈及其應變變化之來探討，可得知在成型杯底部之圓角處由於其應變變化相當劇烈，因此極易於該處產生破壞，且當施加較大之挾持力時，此破壞之效果更加顯著；另外，在衝壓力─衝程之關係比較中可清楚地觀察到於引伸初期，衝壓負荷隨著衝程而遞增，兩者成正比關係。有了這些參數影響之認知，本文最後以成品之表面粗糙度與成型厚度作為最佳化分析之判斷依據，配合田口式實驗計畫法，找出最佳之製程參數。
關鍵字: 引伸，挾持力，應變，衝壓力，田口式實驗法

關鍵字

引伸 ； 挾持力 ； 應變 ； 衝壓力 ； 田口式實驗法

並列摘要

For a metal drawing process, the process parameters including: blank-holder force, tool clearance, drawing speed, and lubrication are the key issues affecting the final product quality. The study uses a systematic method to investigate how these factors influence the surface quality of the drawn product. For controlling the blank-holder force, we apply the basic theory of mechanics to transfer the tightening torque into the blank-holder clamping force. Also, a circuit specially designed for measuring the drawing speed was used. By varying the punch sizes, we are able to change the tool clearance. During the process, different lubricants were also utilized in order to study its effect in the process.
By checking the final product thickness change and the corresponding strain variations after the process, it is found that there are severe variations at the bottom corner of the drawn product. The strain also increases rapidly with the increase of the blank-holder force. This interprets why fracture always originates that position. When taking the punch load versus punch stroke, it is observed that at the load increases almost linearly with the stroke and this also agrees with the theoretical results.
With all these knowledge of parameter influence, we then use Taguchi method to do a series of experiments to search for the best combination of these parameters by obtaining the best product surface roughness and thickness. A good agreement for the best process parameter sets was found when using these two checking criteria.
Keywords:drawing, blank-holder force, strain, punch load,
Taguchi Methods

並列關鍵字

drawing ； blanker-holder force ； strain ； punch force ； Taguchi Methods

參考文獻

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