鍛造直傘齒輪機加工品質改善方法之研究

The Study of Quality Improvement of Forging Straight Bevel Gear Machining.

呂冠賢(Kuan-Hsien Lu)

指導教授 ： 王培郁

國立虎尾科技大學/工程學院/機械設計工程研究所/碩士(2014年)

摘要

為獲取高強度及提高生產效率，直傘齒輪採鍛造製程儼然已成為趨勢。然而，鍛造齒輪在其表面粗糙度及齒溝偏擺精度一直為人詬病。齒溝偏擺精度取決於鍛造模仁製造程序及鍛胚之機加工。目前鍛造模仁之製程在本研究中是採直接硬雕刻，忽略其雕刻精度對齒溝偏擺精度之誤差影響。因此，本論文將只針對鍛胚在機加工製程中如何提升齒溝偏擺精度進行一研究分析。首先，應用Mathematica軟件建立直傘齒輪齒型數學模式進行齒面點資料計算，並匯入Pro/E建構直傘齒輪鍛造模仁三維模型及節圓治具三維模型，最後利用CAD/CAM技術將鍛造模仁及節圓治具直接硬雕刻。直傘齒輪齒面幾何區域是齒輪鍛胚幾何在經所有機加工到成品製程中，唯一不需加工的地方。因此，節圓治具的設計是藉以不需機加工之齒面當機加工承靠基準，最終定義出齒輪旋轉軸線、安裝距及齒厚，確保齒溝偏擺精度。然而，加工者為求加工效率的提昇，往往使用高進給率進行齒胚切削，因節圓治具 
與鍛胚齒面接觸承靠面積小，大的切削力造成鍛胚齒面損傷。為解決機加工效率問題、齒面損傷及同時又得確保齒溝偏擺精度，本文透過齒胚模仁的機加工承靠設計並進行批量實作，證實齒胚模仁的新設計能有效提升加工效率、不傷齒面且維持與使用節圓治具進行機加工之齒溝偏擺精度。

關鍵字

鍛造齒輪 ； 齒溝偏擺 ； 節圓治具

並列摘要

In order　to gain high　strength and improve the productionefficiency,making straight bevel gears by forging procedure　is already become a trend. However it has been criticizing for the　tooth surface finishing and pitch run out accuracy on forging gears.The pitch run out accuracy depends on forging die core manufacturing procedure and machined forging blanks. The process of forgingdie core in this research is using hard engraving which ignores thedeviation effect of pitch run out accuracy caused by the engravingaccuracy.Therefore, this thesis only focus on how to improve thepitch run out accuracy for machined forging blanks procedurestoanalysis.First,using Mathematica software to set up straightbevelgear tooth shape to process tooth face data to calculate and import Pro/E straight bevel gear forging die core 3D model andpitch diameter fixture 3D model.After that, using CAD/CAM toengrave forging die core and pitch diameter fixture directly. Straightbevel gear geometric area is the only part which do not need toprocess of gear blank　　　　geometric from mechanical to finishedproducts.Therefore, the design of pitch diameter fixture is that wedo not need the machined tooth face to be the bearing surface todefine the gear axis of rotation, mounting distance, tooth thickness to ensure the pitch run out accuracy. However, the processer inorder to increase the efficiency, often use high feed rate to cut gearblanks,since the contact bearing surface of pitch diameter fixtureand forging blanks is small,the large cutting power will cause the tooth face damaged.To solve the efficiency of process, tooth facedamaged and ensure run out accuracy at the same time, this thesis process in batch by the mechanical bearing design of gear blank core which prove the new design of gear blank core could increasethe processing efficiency,not to damage the tooth face andmaintain the run out accuracy of mechanical by pitch diameter fixture.

並列關鍵字

Forging Gear ； Pitch Run Out ； Pitch Diameter Fixture

參考文獻

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