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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/72351


    Title: 精密熱鍛模擬及模具合理化分析;Precision Hot Forging Simulation and Tooling Analysis of Rationalization
    Authors: 徐智鈞;Hsu,chih-chun
    Contributors: 機械工程學系在職專班
    Keywords: 滾珠軸承;熱/溫鍛;有限元素分析;實驗;整體架構;Ball bearing;Hot/Warm forging;Finite element method;Experiment;Structural integrity
    Date: 2016-06-13
    Issue Date: 2016-10-13 14:49:17 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 摘 要
      在這項研究中,用於製造軸承環的多級溫鍛工藝數值模擬和實驗分析。該研究的目的是確定精加工鍛造過程,使得模具磨損延長和模具斷裂應該最小化的關鍵站。此外,為了確保所建議的修改是否適當時,執行在每個序列的三維有限元模擬,並謹慎進行實驗研究比較。
    軸承內外環精密熱間鍛造製程,以第二道次完成鍛最為重要,並直接影響最終鍛品精度,一般內外環精密熱間鍛造製程常見缺陷有偏料、皺摺、外觀成形不良等問題。透過模擬分析發現鍛造缺陷在製程中發生原因探討,利用有限元素分析預測材料偏移情形、材料流動皺摺原因與材料體積不足引響外觀成形未完全充填等問題。
      數值模擬結果表明,該重新設計的上沖頭的幾何形狀,精密鍛造過程的半徑(R2),顯示完全不同的變形率(有效應變/有效應力分佈)和材料流動形態,與倒角(C2)對應比較。所述數值模型的準確性已經通過與實驗測量比較驗證。此外,數值模擬和實驗驗證過程包括詳細模具設計和尺寸的變化,這是非常重要的在維持鍛模/沖頭的整體結構的完整性,因此,整個過程的穩定性。關於在廢料比率相比,該方法使用的不銹鋼為原料產出內環 /外環,環形式由熱/溫鍛和順序冷軋過程和廢料比率給出減小到〜9%。最後,它表明,在這項研究中的多級溫鍛過程可成功地應用到高批量生產(10,000個/小時)的內環/外環深溝軸承且具有穩定性和結構完整性軸承。
    關鍵字:滾珠軸承、熱/溫鍛、有限元素分析、實驗 、整體架構
    ;Abstract
    In this study, a multi-stage warm forging process for making bearing rings is numerically and experimentally investigated. The aim of the study is to determine the crucial station of the finishing forging process such that the tool wear is prolonged and tool fracture should be minimized. In addition, in order to ensure the appropriateness of the suggested modification, a 3-dimensional finite element simulation on each sequence is performed, and carefully compared with experimental investigations.
    Numerical simulations results indicate that the redesigned upper punch geometry, radius(R2) of the finishing forging process, demonstrates drastically different deformation rate (the effective strain/effective stress distribution) and material flow pattern, as compared with chamfer (C2) counterpart. Accuracy of the numerical models has been verified by comparing with experimental measurements . In addition, the numerically and experimentally validated process includes the detailed tooling design and dimension variation, which is of great importance in maintaining the overall structural integrity of the forging die/punch and thus, the stability of the whole process. Concerning on the waste ratio comparison, the method used steel rods are as raw material and the IR/OR rings form is given by hot/warm forging and sequential cold rolling processes and the waste ratio decreases to ~9%. Finally, it is shown that the multi-stage warm forging process in this study could be successfully applied to the high-quantity production (10,000 pieces/hr) of the IR/OR of the deep groove ball bearing with the stability and structural integratity of the whole process
    Keywords: Ball bearing; Hot/Warm forging; Finite element method; Experiment; Structural integrity
    Appears in Collections:[機械工程學系碩士在職專班 ] 博碩士論文

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