154QY40型液压汽车起重机_毕业设计.doc

154QY40型液压汽车起重机 摘 要 随着经济迅速发展，我国的基础建设力度正逐渐加大，道路交通，机场，港口等基础设施的建设规模也越来越大，起重机的需求增加With the rapid development of economic, Chinas infrastructure is gradually increasing intensity. Such as road transport, airports, ports and other infrastructure are becoming ever larger. At the same time the demand for cranes increased. Based on the type of XCMG QY40 Truck Crane Groups understanding, and combined with my own knowledge. Through the analysis and calculations of crane and working principle of the functional. Then analysis and calculations to determine the systems basic structure and main circuit components. And checking system performance and heat were checked to meet the requirements to be achieved by crane. In addition, from electro-hydraulic proportional valve described the characteristics of electro-hydraulic proportional variable pump control technology for the intelligent control; using electro-hydraulic proportional control of the amplitude circuit; synchronized telescopic electro-hydraulic proportional control; electro-hydraulic proportional control of the second lift decline; electro-hydraulic proportional control automatic leveling legs stretched out several problems, which obtained using electro-hydraulic proportional control technology on the impact of truck crane hydraulic system and effect. Showing the electro-hydraulic proportional control technology in hydraulic truck crane system and the hope of a new trend. key words: Crane truck Hydraulic pressure system Energy-efficient Performance parameter Proportion of the electric liquid 目录 摘 要 I Abstract II 1 概述 1 1.1起重机的特点以及其在国民生产中的作用 1 1.2 液压传动应用于汽车起重机上的规定或限制及其优越性 1 1.2.1 工作环境和工作条件 1 1.2.2 在汽车起重机上应用液压系统的优劣 1 1.3本课题来源、任务要求和整机性能参数 2 1.3.1 课题来源 2 1.3.2 设计任务要求 3 1.3.3 整机主要性能参数 3 1.4 本课题主要研究工作 4 2 分析系统工况，确定主要参数 5 2.1 典型工况分析及对液压系统要求 5 2.1.1 汽车起重机液压系统功能、组成和工作特点 5 2.1.2 工况分析 6 2.1.3 各液压系统要求 6 2.2 液压系统类型选择 8 2.2.1 该起重机液压系统分析 8 2.2.2 各机构动作组合、分配及控制 9 2.3 各种执行元件的选择 10 2.4 各主要参数的确定 11 2.4.1 工作机构主要参数 11 2.4.2 液