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標題: | 管件液壓成形局部脹形缺陷之研究 A Study of Localized Expansion Defect Occurred in the Tube-Hydroforming Process |
作者: | Zih-Wei Chen 陳梓維 |
指導教授: | 陳復國(Fuh-Kuo Chen) |
關鍵字: | 管件液壓成形,局部脹形,低壓成形,預成形,有限元素,前副車架, tube hydroforming,localized expansion,low-pressure hydroforming,preforming,finite element,front sub-frame, |
出版年 : | 2016 |
學位: | 碩士 |
摘要: | 管件液壓成形技術在汽車產業中有高強度及結構輕量化的優勢。本論文首先針對管件液壓成形製程中常見的局部脹形現象進行研究,接著針對汽車前副車架縱樑進行成形性探討與優化。
本論文首先建立局部脹形模型,針對管材幾何參數、製程參數以及材料參數進行探討,了解各參數對於局部脹形現象影響程度。同時也探討常見矩形截面設計對產生局部脹形之影響程度。在改善局部脹形研究方面,本論文探討如何以低壓成形製程及預成形設計改善局部脹形現象之可行性分析,未來可將研究結果應用在產生局部脹形缺陷的載具上,以快速排除局部脹形現象。 本論文另針對前副車架縱樑之管件液壓成形道次進行分析探討。首先對載具進行截面分析及依載具外型來進行初步的可成形性分析,接著在彎管成形道次中,使用現場芯棒進行彎管模擬,使模擬條件和現場一致;在預成形道次中,使用高擋牆設計使管材順利擠入模穴內,並在後續道次中有更好的成形性;而在液壓成形道次中,則透過蒐集之文獻資料,針對現場之液壓成形負載路徑進行修改,得到可滿足載具成形需求之負載路徑。另外也透過彎管飽滿度改善以及預成形模面設計來改變管材在液壓模具內部的分布情形,藉以減少局部脹形發生,確實提高載具成形之穩定性。最後,本論文也提供一成形性較佳的材料使本研究載具有更好的成形性。本研究成果可供開發管件液壓成形前副車架縱樑之人員參考。 The tube-hydroforming technology has advantages in producing high strength and lightweight structural components used in the automotive industry. In the tube-hydroforming process, fracture defect caused by localized expansion of tube cross section is commonly encountered. This study begins with the research on the effects of localized expansion on the formability of tube-hydroformed parts. Then, it focuses on the analysis of applying the tube-hydroforming technology to manufacture a defect-free front sub-frame trailing arm. In order to understand the influence of localized expansion on the part formability, the localized expansion models were developed in this study to analyze the deformation mechanisms resulted by various tube geometry parameters, process parameters and material parameters. Besides, this thesis also discusses the influence of different rectangular cross-section designs on the occurrence of localized expansion. As for improving the localized expansion phenomenon, the low-pressure hydroforming technology and preforming design were employed in this thesis to examine the feasibility for avoiding the occurrence of localized expansion. In the future, the research results achieved in this thesis can be applied to the tube-hydroforming process design for manufacturing automotive components without the occurrence of localized expansion phenomenon. In addition, this thesis investigates into the tube-hydroforming technology applied to manufacture a front sub-frame trailing arm. First, the feasibility study was conducted by analyzing the cross-sectional properties and the geometry of the component shape. Then, in order to conform the simulation to the real production condition, the same mandrel rod as that used in the tube bending process was adopted in the finite element simulations. As for preforming process, a V-shaped high retaining wall that makes the pre-bent tube fitted into the die cavity is designed and results in an optimal preformed shape for the following hydroforming process. In the hydroforming process, this thesis modifies the initial loading path referring to the published literature to generate a new loading path that provides a better formability for the tube-hydroformed part. This thesis not only controls the plumpness of the bent tube but also designs new preforming dies to improve the localized expansion phenomenon occurred in the tube-hydroforming process for manufacturing a front sub-frame trailing arm by changing the deformed shape of the tubular part inside the hydroforming die cavity. Lastly, this thesis proposes an alternative tubular material that would result in a better formability in the tube-hydroforming process of the front sub-frame trailing arm. The research results of this thesis could be valuable references in developing the tube-hydroforming process for manufacturing the front sub-frame trailing arm. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/50293 |
DOI: | 10.6342/NTU201601593 |
全文授權: | 有償授權 |
顯示於系所單位: | 機械工程學系 |
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