1摘 要汽車起重機式工程機械產(chǎn)品中重要組成部分，它由于機動性好而被廣泛應(yīng)用于礦山、建筑、港口、油田等領(lǐng)域。主要由變幅機構(gòu)、伸縮機構(gòu)、起升機構(gòu)、回轉(zhuǎn)機構(gòu)、支腿機構(gòu)組成。本文講述了 QY-20 汽車起重機液壓系統(tǒng)的設(shè)計。首先，通過對汽車起重機總體構(gòu)成及工作原理進行分析，在此分析基礎(chǔ)上提出了提液壓系統(tǒng)各功能回路的設(shè)計方案，并把各回路組合后得出了液壓系統(tǒng)原理圖；接著，設(shè)計并選擇了液壓系統(tǒng)各液壓元件并進行了相應(yīng)計算；然后，對主要執(zhí)行機構(gòu)-液壓缸進行了設(shè)計與強度校核；最后，通過 AutoCAD 制圖軟件繪制了本 QY-20 汽車起重機液壓系統(tǒng)原理圖的非標零件裝配圖及主要零件圖。通過本次設(shè)計，鞏固了大學(xué)所學(xué)專業(yè)知識，如：液壓與氣動傳動、機械原理、機械設(shè)計、材料力學(xué)、公差與互換性理論、機械制圖等；掌握了起重機械產(chǎn)品的設(shè)計方法并能夠熟練使用 AutoCAD 制圖軟件，對今后的工作于生活具有極大意義。關(guān)鍵字：起重機，起升，支腿，變幅，回轉(zhuǎn)2AbstractAs an important part of automobile crane engineering machinery products, it is widely used in mining, construction, port, oil field and other fields because of its good maneuverability. Mainly consists of variable amplitude mechanism, telescopic mechanism, lifting mechanism, rotating mechanism and supporting leg mechanism.This paper describes the design of hydraulic system of QY-20 truck crane. First of all, based on truck crane overall composition and working principle analysis, this analysis based on the proposed design scheme of hydraulic system and the function of the loop and to each circuit combination obtains the principle diagram of hydraulic system; then, design and selection of hydraulic system and the hydraulic pressure component and the corresponding calculation; then, on the main actuator hydraulic cylinders were design and strength check. Finally, through the AutoCAD drawing software drawn the QY-20 truck crane hydraulic system principle diagram of non-standard parts assembly drawing and main parts figure.Through the design, the consolidation of the University of the professional knowledge, such as: hydraulic and gas dynamic transmission, mechanical principles, mechanical design, mechanics of materials, tolerance and interchangeability theories, mechanical drawing; master the design method of hoisting machinery products and be able to skillfully use AutoCAD drawing software, for future work in life is of great significance.Key words: Crane, Lifting, Supporting legs, Amplitude, Rotation3目 錄摘 要 .IAbstract.II第 1 章 緒論.11.1 研究背景及意義.11.2 國內(nèi)外汽車起重機發(fā)展現(xiàn)狀.11.2.1 國內(nèi)發(fā)展現(xiàn)狀11.2.2 國外發(fā)展現(xiàn)狀21.3 汽車起重機的類型21.4 汽車起重機對液壓系統(tǒng)的要求31.5 主要內(nèi)容3第 2 章 總體分析.52.1 設(shè)計要求52.1.1 功能要求52.1.2 主要技術(shù)參數(shù)要求52.2 結(jié)構(gòu)及功能分析52.3 工況分析72.3.1 運動分析72.3.2 動力分析82.3.3 負載分析9第 3 章 液壓系統(tǒng)設(shè)計.103.1 額定壓力的確定103.2 基本回路設(shè)計103.2.1 支腿機構(gòu)回路的設(shè)計103.2.2 起升機構(gòu)回路的設(shè)計113.2.3 變幅機構(gòu)回路的設(shè)計113.2.4 伸縮機構(gòu)回路的設(shè)計123.2.5 回轉(zhuǎn)機構(gòu)回路的設(shè)計123.3 液壓系統(tǒng)原理圖13第 4 章 液壓元件的設(shè)計與選擇.144.1 液壓馬達和液壓泵的選擇.1444.1.1 卷揚馬達的選擇144.1.2 回轉(zhuǎn)馬達的選擇144.1.3 泵的選擇154.2 液壓閥的選擇164.3 液壓輔助元件選擇174.3.1 液壓油的選擇174.3.2 濾油器的選擇174.3.3 壓力表的選擇174.3.4 閥類元件的選擇174.4 液壓油箱的設(shè)計184.5 液壓油管設(shè)計194.5.1 油管通徑的計算194.5.2 壁厚的計算204.6 液壓系統(tǒng)的驗算214.6.1 壓力損失的驗算.214.6.2 發(fā)熱溫升的驗算22第 5 章 液壓缸的設(shè)計.245.1 支腿液壓缸的設(shè)計245.1.1 支腿垂直液壓缸245.1.2 支腿水平液壓缸275.2 變幅液壓缸的計算285.3 伸縮液壓缸的計算29總 結(jié).31參考文獻.32致 謝.33