【摘要】：裝載機是目前世界上應用范圍較廣的工程機械，在公路、礦山、港口等建設工程中都發(fā)揮著重要作用。變速箱是裝載機傳動系統(tǒng)重要的組成部分之一，其換擋性能的優(yōu)劣對整機的安全性和可靠性都有很大影響，因此改善變速箱的換擋性能尤為重要。評價一臺裝載機換擋性能的客觀標準是換擋平穩(wěn)性，由于動力換擋變速箱在換擋時，液壓系統(tǒng)剛度較大，一旦結合元件接觸過猛便會產(chǎn)生嚴重的換擋沖擊現(xiàn)象，這會嚴重影響駕駛的安全性和舒適性。因此提高換擋平順性、降低換擋沖擊是提高變速箱換擋性能的關鍵所在，也是本文研究的目的所在。 本文來自于校企合作項目“裝載機液壓系統(tǒng)及傳動系統(tǒng)動態(tài)仿真分析及對比測試研究”，基于目前裝載機工作時普遍存在的換擋沖擊現(xiàn)象，以輪式裝載機的變速系統(tǒng)為研究對象，利用AMESim軟件建立其系統(tǒng)模型并進行仿真分析，最后結合實驗加以驗證，從而對裝載機變速箱換擋性能進行了深入研究。 本文首先介紹了裝載機變速箱的分類、常用的換擋操縱方式，然后分別對變速系統(tǒng)的傳動部分和控制部分的結構、工作原理進行了分析；闡述了裝載機變速系統(tǒng)現(xiàn)存的換擋沖擊現(xiàn)象，并以此為出發(fā)點對裝載機變速箱的換擋性能展開研究。以定軸式電液控制的輪式裝載機變速箱為研究對象，對其換擋過程進行了動力學與運動學分析，并基于傳遞函數(shù)法對變速箱的液壓控制系統(tǒng)進行了數(shù)學模型的建立和分析。之后利用AMESim仿真分析軟件建立了變速箱的傳動系統(tǒng)和控制系統(tǒng)模型，尤其是電液控制部分先后采用系統(tǒng)模型和HCD庫模型兩種建立方式，以求更深入地分析變速箱的換擋性能。模型建立之后從多個角度對模型的仿真結果進行分析，特別是換擋離合器的壓力變化，因為它是影響變速箱換擋性能的關鍵所在，明確了該裝載機變速箱目前存在的換擋沖擊問題。另外為了確定離合器和控制系統(tǒng)各相關參數(shù)大小對變速箱換擋性能的影響程度，分別對各因素進行系列化仿真分析，，最終得出離合器的結構參數(shù)中以活塞直徑和活塞最大行程距離兩因素對換擋影響最大；電液控制系統(tǒng)調(diào)壓閥的結構參數(shù)中以緩沖彈簧剛度和節(jié)流孔大小兩因素對換擋性能影響最大的結論。最后通過實驗與仿真的對比，驗證了仿真模型的準確性，并提出了相應的改進措施以提高裝載機的換擋平順性。
[Abstract]:Loader is a widely used construction machinery in the world, which plays an important role in highway, mine, port and other construction projects. Gearbox is one of the important components of loader transmission system, its shift performance has a great impact on the safety and reliability of the whole machine, so it is particularly important to improve the gearbox shift performance. The objective criterion for evaluating the shift performance of a loader is shift stability. Because the hydraulic system stiffness is large when the power shift gearbox is in shift, once the combined components are in contact with too hard, there will be a serious shift impact phenomenon. This will seriously affect the safety and comfort of driving. Therefore, improving shift comfort and reducing shift impact is the key to improve gearbox shift performance, and it is also the purpose of this paper. This paper comes from the cooperation project between school and enterprise, "dynamic simulation analysis and comparative test research of hydraulic system and transmission system of loader", based on the phenomenon of shift impact commonly existing in the work of loaders at present. Taking the variable speed system of wheel loader as the research object, the system model is established by AMESim software and the simulation analysis is carried out. finally, the gearbox shift performance of wheel loader is verified by experiments, and the gearbox shift performance of wheel loader is deeply studied. This paper first introduces the classification of the gearbox of the loader and the commonly used shift control mode, and then analyzes the structure and working principle of the transmission part and the control part of the variable speed system respectively. This paper expounds the existing shift impact phenomenon of loader transmission system, and studies the shift performance of loader gearbox from this point of view. Taking the gearbox of wheel loader controlled by fixed axis electro-hydraulic as the research object, the dynamic and kinematic analysis of the shift process is carried out, and the mathematical model of the hydraulic control system of the gearbox is established and analyzed based on the transfer function method. Then the transmission system and control system model of gearbox are established by using AMESim simulation and analysis software, especially the electro-hydraulic control part adopts two methods: system model and HCD library model, in order to analyze the shift performance of gearbox more deeply. After the establishment of the model, the simulation results of the model are analyzed from many angles, especially the pressure change of the shift clutch, because it is the key to affect the gearbox shift performance. The problem of shift impact in the gearbox of the loader is clarified. In addition, in order to determine the influence of the relevant parameters of clutch and control system on the gearbox shift performance, the serial simulation analysis of each factor is carried out. Finally, it is concluded that the piston diameter and the maximum stroke distance of the piston have the greatest influence on the shift in the structural parameters of the clutch. Among the structural parameters of the pressure regulating valve of the electro-hydraulic control system, the stiffness of the buffer spring and the size of the throttle hole have the greatest influence on the shift performance. Finally, the accuracy of the simulation model is verified by comparing the experiment with the simulation, and the corresponding improvement measures are put forward to improve the shift comfort of the loader.
【學位授予單位】：吉林大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH243

【引證文獻】

相關碩士學位論文 前1條

1 張建;工程機械變速箱控制系統(tǒng)的研究與開發(fā)[D];吉林大學;2012年

本文編號：2486829