毕业论文设计《154QY40型液压汽车起重机》.doc

PAGE 45 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，汽车起重机的需求也随之增加。本文通过对徐工集团的QY40型汽车起重机液压系统的了解，结合自己所学知识，通过对汽车起重机各功能和工作原理进行分析与计算，确定了系统各回路的基本结构及主要元件，并对系统性能的验算和发热进行校核，以满足该起重机所要达到的要求。本文还从电液比例电磁阀的特点阐述了电液比例控制技术对变量泵的智能控制；采用电液比例控制的变幅油路；电液比例控制同步伸缩；电液比例控制二次起升下滑；电液比例控制支腿的伸出自动调平几个问题，由此得出了采用电液比例控制技术对汽车起重机液压系统的影响和效果，展示了电液比例控制技术在汽车起重机液压系统中新发展趋势的希望。 关键字: 汽车起重机 液压系统 高效节能 性能参数 电液比例 Abstract 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 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc295287142 摘 要 PAGEREF _Toc295287142 \h I HYPERLINK \l _Toc295287143