採用液壓成形管件之機車車架設計

本研究的目的是採用液壓成形技術，重新設計機車車架，以達到提升結構剛性15 %，同時減重 10 %。首先透過實驗模態分析，量測原始車架的自然頻率及模態振型，並藉此驗證原始車架之有限元素模型。比較分析及實驗結果可知，裸車與整車車架前12模態的自然頻率，與實驗模態分析結果差異不到6 %，驗證有限元素模型等效於實體結構，並藉此了解補強結構件於整車車架上質量與剛性的分布。應用斷面幾何設計，在不增加截面積的條件下，搭配靜態剛性分析評估以液壓成形擴大截面慣性矩的可行性，逐步設計一全新車架。最終完成之新設計車架與原車相比，靜態彎曲剛性增加39.44 % 及扭轉剛性增加15.58 %，而整車重量減少13.13 %。透過液壓成形的模擬與分析，探討車架在液壓成形階段的成形性，並藉由薄化率及成形極限圖加以評估，使得管件的薄化程度皆控制在10 % 以內，且車架主管及次管的主要應變，皆小於相應成形極限曲線80 % 的失效安全範圍，顯示在液壓成形實驗中應具有較高的成形性。最後，將成形後的管件重新放入車架結構當中，探討液壓成形後的管件於車架結構剛性與質量分布的影響。分析結果得知，成形後的液壓成形管件放入車體後，車架重量並無明顯變化，且整體剛性因成形管件厚度分布更為均勻的因素，尚有小幅提升的效果，顯示本研究的設計方法中，液壓成形管件不會因製程因素，使得車架結構物理參數產生太大變化，因此可作為往後車架變更設計的參考。

關鍵字

機車車架；實驗模態分析；結構剛性；管件液壓成形；有限元素分析

並列摘要

This objective of this research is to develop a new scooter frame with high stiffness and lightweight by using tube hydroforming. The ultimate goal of new frame design is to increase stiffness up 15 % and to reduce the frame weight up to 10 % in comparison with the original frame design. The original naked and completed frame design is evaluated using experimental modal analysis in the first place, since the natural frequencies and mode shapes of frame represent the distribution of frame stiffness and mass. The difference between experiment and analysis of natured frequencies results are less than 6 %. This guarantees that the finite element model is equivalent to the real frame. New frame is designed by changing the cross-sectional geometry and dimension based on the geometric calculation. Static analysis and normal mode analysis are performed to evaluate the bending stiffness, torsion stiffness and natural frequencies of the new design. The new frame is designed by changing the cross-sectional geometry and dimension based on the feasibility of tube hydroforming processes. Consequently, the bending stiffness and torsion stiffness of new frame are increased up to 39.44 % and 15.58 %, respectively. The frame weight is reduced up to 13.13 %. Finite element analysis is used to simulate the forming processes. Feasibility of tube hydroforming is based on thinning ratio and forming limit diagram. The thinning ratio of new frame tube are limited to less than 10 % in hydroforming processes. And the major strain are limited to less than safety margin of forming limit curve. This new designed parameters will be used to fabricate the prototype.

並列關鍵字

Scooter frame ； Experimental modal analysis ； Structure stiffness ； Tube hydroforming ； Finite element alalysis

參考文獻

[13] 黃奕翔，2012，以有限元素法分析摩托車吊架形式對振動之影響，國立成功大學機械工程學系。

[16] 林瑞彰，2003，管材之成形極限研究，國立中山大學機電工程研究所。

[3] Ch. Hartl, 2005, “Research and advances in fundamentals and industrial applications of hydroforming,” Journal of Materials Processing Technology, Vol. 167, pp. 383–392.

[4] Rasquinha, I. and Daniel, R., 2014, "Light Weighting through Tube Hydroforming," SAE Technical Paper, 2014-28-0013.

[5] Cha, M. and Kim, C., 2013, "A Study on Development of Body Structure Using Hydroforming of a Thin-Walled UHSS Tube," SAE Technical Paper, 2013-01-0035.

國際替代計量

採用液壓成形管件之機車車架設計

全文下載

主題瀏覽