臺灣博碩士論文加值系統

一般管件以沖壓法進行縮口，由於沖壓加工法需將縮口量分配為多道次，以避免工件因變形過大而造成挫曲，因此模具的調校複雜，且模具數量較多而成本較高，並且在縮口前，胚料需經中間退火處理，以避免加工硬化而產生破裂。旋轉式型鍛屬於漸增成形法，其工件加工硬化少，模具設計簡易，僅需單道次成形便可達到與沖壓製程相近的縮口尺寸。本研究將利用實驗以及有限元素模擬軟體DEFORM-2D，比較在不同的旋鍛進給速率下，縮口部位的厚度與硬度變化，並與沖壓縮口法進行製程比較分析，以評估旋鍛縮口製程的可行性。
經由沖壓與旋鍛試驗後發現其瓶口端管厚相近，且旋鍛進給速率對於厚度的影響不明顯；在硬度分析方面，沖壓與旋鍛製程之內部硬度皆高於外部硬度，而且旋鍛的硬化程度小於沖壓縮口製程，另外改變旋鍛進給速率對硬度的影響不顯著，對照退火與未退火之沖壓與旋鍛製程發現，未退火之旋鍛縮口製程其硬度較均勻；在模擬方面亦驗證旋鍛件內部應變程度較外部高，並且旋鍛縮口製程軸向應力較小。

Stamping process is usually applied in sinking the open end of high pressure vessels. The amount of sinking has to be divided to several stamping operations to avoid buckling on the vessel body. Therefore, the adjustment of the stamping dies becomes complex, die parts are increased, and die cost becomes expensive. Moreover, process annealing is required to avoid fracture on the workpiece from excessive strain hardening in the transfer-stamping. Rotary swaging is a genre of incremental deformation. Strain hardening is minimal and its die design methodology is simple. It requires only one stage of rotary swaging to achieve the same geometry by transfer-stamping. This work applies experiments and FE software DEFORM-2D to investigate the effects of feeding speed on the distribution of thickness, hardness and strain for the rotary swaging process. The comparison is made with the transfer-stamping to evaluate the feasibility of sinking high pressure vessels with rotary swaging process.
The forming tests showed that thickness was similar from the stamping and rotary swaging processes. The influence of feeding rate on thickness was insignificant. Hardness tests indicated the hardness on the inner tube was greater than that of outer tube. Moreover, hardness level of rotary swaging was less than that of stamping. The influence of feeding rate on hardness was insignificant as well. Tube sinking with rotary swaging with preforms without annealing had better distributed hardness. The simulations also showed the effective strain on the inner tube was greater than that of outer tube. Axial stress was smaller in sinking with rotary swaging.

摘要………………………………………………………………………i
ABSTRACT…………….……………………..…………………………ii
誌謝…………………………………………………………………..iii
目錄……………………….………………………..……….……...iv
表目錄……………………….……………….……………...……..vi
圖目錄…………………………….………………………..……...vii
第一章 緒論…………………………………………………..…..1
1.1 前言……………………………………………………………..…1
1.2 文獻探討……………………………..……..…………………..2
1.3 研究目的……………………………………………..……………5
第二章 製程介紹與研究方法………………………………………….6
2.1 小鋼瓶深引伸-縮口沖壓製程介紹……………….……………..6
2.2 旋鍛成形之基本原理……………………………………………..8
2.3 實驗規劃……………………………….……………..…………12
2.3.1 模具設計與製作…………………………………...…………12
2.3.2 夾具設計與製作……………………………………..……….16
2.3.3 旋鍛試驗步驟………………………………………...………17
2.4 硬度試驗……………………………………………….………..18
2.5 模擬規劃………………………………………………………...20
2.5.1 DEFORM軟體介紹………………………………………….……20
2.5.2 沖壓模擬規劃……………………………………………….…20
2.5.3 旋鍛模擬規劃…………………………………………...……22
第三章 結果與討論……………………………………………………24
3.1 厚度分析…………………………………………….……………24
3.1.1 實驗部分…………………………………..….………………24
3.1.2 模擬部分…………………………………..…………….……25
3.2 硬度分析……………………………………………………...…25
3.2.1 縮口預成形管胚之硬度分析……………………………...…25
3.2.2 旋鍛縮口製程之硬度分析………………………………...…26
3.2.2.1 未退火管胚…………………..……………….……………26
3.2.2.2 退火管胚…………………………….…………….…….…30
3.2.3 沖壓縮口製程之硬度分析…………………..….……….….31
3.2.4 沖壓與旋鍛縮口之硬度比較……………………………..….32
3.3 應變分析………………………………………….………………34
3.4 應力分析…………………………………………….……………36
第四章 結論與建議…………………………….………..……….…38
4.1 結論…………………………………….……………………..…38
4.2 建議………………………………….………………………..…39
參考文獻…………………………………………………………….…40
英文論文大綱………………………………………………………...41

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