發(fā)布時(shí)間：2018-09-10 11:22

【摘要】：齒輪軸是機(jī)械傳動(dòng)中不可或缺的部件之一,具有傳動(dòng)效率高、結(jié)構(gòu)緊湊和使用壽命長(zhǎng)等一系列優(yōu)點(diǎn)。傳統(tǒng)的齒輪軸的切削加工生產(chǎn)方式已逐步被精密鍛造成形工藝取代,并取得了良好的效果。根據(jù)齒輪軸的工況要求,在鍛造生產(chǎn)中提高齒輪軸鍛件的力學(xué)性能與尺寸精度是改進(jìn)產(chǎn)品質(zhì)量的重要手段。 鍛造過程中,在保證齒輪軸鍛件成形性的前提下,研究?jī)?nèi)部組織形態(tài)的變化,并改進(jìn)工藝方案以獲得更加均勻細(xì)小且分布合理的微觀組織,是提高鍛件性能的有效措施。同時(shí),減小鍛造過程中模具磨損,也是提高鍛件精度,節(jié)約模具成本的重要方法。本文應(yīng)用三維有限元數(shù)值模擬技術(shù)研究齒輪軸的精鍛成形,獲得了變形過程中的流動(dòng)規(guī)律,溫度變化,應(yīng)力應(yīng)變等參數(shù),并且通過結(jié)合不同的模型計(jì)算,得到了齒輪軸鍛件內(nèi)部微觀組織與成形模具磨損的分布,并提出工藝改進(jìn)方法。 對(duì)單工步及多工步成形方案進(jìn)行模擬,基于Yada動(dòng)態(tài)再結(jié)晶理論公式,分析坯料初始溫度、壓下速度及摩擦系數(shù)等因素對(duì)熱鍛過程中的鍛件內(nèi)部再結(jié)晶的影響規(guī)律,比較了不同成形方案的內(nèi)部組織演化過程。使用Deform軟件中Flownet功能,模擬不同工藝條件鍛造流線分布。為改善成形中材料流動(dòng)均勻性,提出局部控溫工藝,并分析了控溫后的材料流動(dòng)形態(tài)�；诟倪M(jìn)后的Archard模型磨損公式,對(duì)Defrom軟件二次開發(fā),分析不同工藝下齒輪軸熱鍛模具的影響,同時(shí)模擬了采用浮動(dòng)模結(jié)構(gòu)的工藝過程,得出浮動(dòng)模移動(dòng)速度對(duì)模具磨損的影響規(guī)律。綜合比較,齒輪軸熱鍛多工步成形在改善組織分布、流線形態(tài)及模具磨損方面比單工步成形取得了更理想的效果。 根據(jù)數(shù)值分析結(jié)果,進(jìn)行齒輪軸熱鍛成形實(shí)驗(yàn),選取內(nèi)部材料分析金相組織,并制作鍛造流線樣本,對(duì)比模擬結(jié)果,驗(yàn)證了數(shù)值模擬結(jié)果的可靠性。在數(shù)值模擬和實(shí)驗(yàn)研究的基礎(chǔ)上,對(duì)實(shí)用化工藝提出指導(dǎo)建議。
[Abstract]:Gear shaft is one of the indispensable parts in mechanical transmission. It has a series of advantages, such as high transmission efficiency, compact structure and long service life. The traditional production mode of gear shaft cutting has been replaced by precision forging technology, and good results have been obtained. According to the requirements of gear shaft working conditions, it is an important means to improve the product quality to improve the mechanical properties and dimensional accuracy of gear shaft forgings in forging production. In the process of forging, on the premise of ensuring the formability of gear shaft forgings, it is an effective measure to improve the properties of forgings by studying the change of internal microstructure and improving the technological scheme to obtain more uniform and well-distributed microstructures. At the same time, reducing die wear in forging process is also an important method to improve forging precision and save die cost. In this paper, the three-dimensional finite element numerical simulation technique is used to study the precision forging of gear shafts. The flow law, temperature change, stress strain and other parameters in the process of deformation are obtained. The microstructure of gear shaft forging and the distribution of wear of forming die were obtained, and the process improvement method was put forward. Based on the theoretical formula of Yada dynamic recrystallization, the effects of the initial temperature of the blank, the speed of pressing and the friction coefficient on the internal recrystallization of the forging are analyzed. The internal structure evolution process of different forming schemes was compared. The distribution of forging streamline under different technological conditions is simulated by using Flownet function in Deform software. In order to improve the uniformity of material flow, a local temperature control process was proposed, and the material flow pattern after temperature control was analyzed. Based on the improved Archard model wear formula, the influence of the hot forging die of gear shaft under different processes is analyzed by the second development of Defrom software. At the same time, the process of adopting floating die structure is simulated. The influence of moving speed of floating die on die wear is obtained. Compared with simplex forming, the multi-step forming of gear shaft is more effective than simplex forming in improving the structure distribution, streamline shape and die wear. According to the results of numerical analysis, the hot forging experiment of gear shaft was carried out, the metallographic structure was analyzed by selecting internal materials, and the forging streamline sample was made, and the simulation results were compared to verify the reliability of the numerical simulation results. On the basis of numerical simulation and experimental research, some suggestions for practical process are put forward.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2011
【分類號(hào)】：TH133.2;TG316

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 余志鵬;提高齒輪軸熱鍛成形充填性的工藝措施研究[D];山東大學(xué);2012年

2 付志強(qiáng);B1500HS硼鋼板再結(jié)晶過程數(shù)值模擬及實(shí)驗(yàn)研究[D];山東大學(xué);2012年

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本文編號(hào)：2234293