航空座椅後椅腳之鍛壓製程設計與成形分析

Design and Analysis of Forging Process for the Rear Leg of Aircraft Seat

施亭妤(Ting-Yu Shih)

指導教授 ： 陳立緯

國立虎尾科技大學/工程學院/機械與電腦輔助工程系碩士班/碩士(2016年)

摘要

隨著航空座椅朝著安全性與輕量化的方向發展，為維持合理製造成本，其結構件之製程設計日趨重要，其中後椅腳為座椅結構中受力最大也最關鍵的零件之一，因應高強度且輕量化的結構設計，一般熱鍛技術，即使為多道次鍛壓也難以直接鍛打至所需尺寸，而須配合高成本的機械加工，以達到最終產品尺寸要求。為了節省製造工序與成本，本研究試圖以等溫鍛造的方式，直接鍛打出符合尺寸要求的座椅零件成品，並應用有限元分析軟體DEFORM-3D對市面上常見的椅腳進行成形分析，探討H型斷面之深槽型座椅後椅腳於鍛壓成形時的影響，與不同製程參數設計之研究，最後再以實驗模型進行等溫鍛造實驗，比對模擬分析與實驗之結果，以驗證後椅腳於此製程之成形可行性。
經研究結果顯示，利用DEFORM-3D有限元素軟體模擬鋁合金7075後椅腳之等溫鍛造成形，可有效呈現鍛造成形過程。其中鍛件等效應力主要分佈於腹板，等效應變主要分佈於腹板周圍圓角，所需最大成形負荷為1650噸。在非等溫鍛造成形分析上，提高模具與胚料溫度皆能降低鍛件成形負荷、應力與應變，其中胚料溫度的控制將是最影響成形負荷與應力的重要參數。經由模擬分析與實驗結果比對，鍛件外型輪廓與鍛流線分佈結果兩者相符合；在尺寸量測上，可得鍛件成形前後變形量最小的為端部厚度，其值為0.21%，變形量最大的為腹板厚度，其值達56.44%，亦與模擬分析結果相吻合。故由上述分析結果可驗證應用DEFORM-3D有限元素軟體模擬實驗鍛件於此製程上的可靠性，更能進一步證明航空座椅後椅腳在等溫鍛造成形上的可行性，且有助於了解鍛件在成形過程中材料流動現象、應力、應變、成形負荷及鍛流線分佈等情況與外型尺寸管控與預測。

關鍵字

有限元素分析 ； 等溫鍛造成形 ； 航空座椅零件 ； 鋁合金7075

並列摘要

As the aircraft passenger seat develops for safety and lightweight, in order to maintain reasonable production cost, its structure of process design is increasingly important. The rear leg, which sustains the maximum load-carrying capability, is one of the key components. In response to the high strength and light weight of structural design, it could hardly forged to the desired size and must to match the high cost of machining to achieve finally product size on the ordinary forging technique. To reduce the manufacturing process and cost, this study attempts to forge directly with seat parts production of meet the size by isothermal forging. The FEM analysis software DEFORM-3D was applied to discuss the formation of the H-type cross section of rear leg of aircraft passenger seat. Various manufacturing variables were designed for testing by using laboratory scale model. By comparing the result of simulation and experimentation, it proved the feasibility of applying such technique on rear leg of passenger seat.

Results showed the application of Deform-3D to simulate the forging of rear leg of passenger seat could effectively display the entire process. And, the effective stress for the forged piece of rear leg was primarily distributed the web plate, the effective strain was primarily distributed around the fillet corner of web plate, and the peak die load could reach 1650 tons. In the analysis on non-isothermal forming, increase die and blank temperature could reduce the forging forming load and stress and strain. The control of temperature for the blank molding was an important parameter for affecting the loading. From the experimentation and analysis comparison, the forged pieced of contour matched. In size comparison, the forged piece minimum deformation of end was 0.21%, the maximum deformation of web was 56.44%. By the results of the analysis can prove the reliability of using analysis software for this procedure, and further illustrate the application of the finite element software for feasibility of isothermal forging process of rear leg. And, it helped to understand the material dynamics, effective stress, effective strain, forming force and forging flow line in the process and its prediction and control of contour.

並列關鍵字

Finite element method ； Isothermal forging ； Aircraft seat parts ； Aluminum alloy 7075

參考文獻

[19]宣婷婷，2007，”超輕航空載具適航驗證程序之探討”，淡江大學碩士學位論文。

[26]吳玟真，2009，”輕型運動載具市場趨勢與適墜性分析”，淡江大學碩士學位論文。

[27]黃毓仁，2011，”輕型飛機航空座椅之適墜性分析”，淡江大學碩士學位論文。

[31]輕金屬先進技術發展與應用國際研討會，2003。

[34]許源泉，2005，塑性加工學，全華科技股份有限公司，台北。