中型液压挖掘机多路阀操控性研究

发布时间：2018-06-02 06:54

本文选题：液压挖掘机 + 多路阀　；参考：《中南大学》2014年硕士论文

【摘要】：多路阀是将两个以上的阀块组合在一起,操纵多个执行元件运动的集成阀,液控先导阀是控制其阀芯换向的关键元件。作为液压挖掘机的核心元件,两者性能的好坏,直接决定整机的操控性能。本文以中型液压挖掘机动臂联和铲斗联为研究对象,深入分析多路阀和先导阀的结构原理,总结出评价多路阀操控性的指标：先导阀—多路阀综合特性曲线。研究多路阀操控性能,及改善操控性的方案,论文的主要工作如下： (1)建立多路阀阀芯位移特性和阀口流量特性的数学模型。深入分析先导阀特性曲线、多路阀阀芯位移特性曲线以及阀口流量曲线之间的联系,从而确定先导阀位移和多路阀阀口流量的关系,即先导阀—多路阀综合特性曲线,以此作为评价多路阀操控性的指标。 (2)基于AMESim和Fluent平台,对现有铲斗联和动臂联阀进行仿真分析,得到综合特性曲线。并从线性有效控制百分比、线性度和流量分辨率三个方面对综合曲线进行评价。结果表明现有多路阀具有调速区间窄,流量微调性能和流量分辨率差等缺点。针对这些问题,通过调整先导减压弹簧和多路阀复位弹簧的刚度和预紧力来增加调速区间,并通过提高多路阀过流面积曲线梯度来改善流量微调性能。 (3)以中型液压挖掘机为试验平台进行相关试验,包括先导压力测试、动臂和斗杆的单动作测试,将实验数据和仿真结果对比,验证仿真分析的正确性和优化方案的可行性。
[Abstract]:Multi-way valve is an integrated valve which combines two or more valve blocks and controls the movement of multiple actuator. The hydraulic pilot valve is the key element to control the valve core reversing. As the core component of hydraulic excavator, the performance of both directly determines the control performance of the whole machine. Taking the arm connection and bucket connection of medium hydraulic excavator as the research object, the structure principle of multi-way valve and pilot valve is analyzed in depth, and the index of evaluating the maneuverability of multi-way valve is summarized: the comprehensive characteristic curve of pilot valve and multi-way valve. The main work of this paper is as follows: A mathematical model of valve core displacement characteristics and valve flow characteristics is established. The relationship among pilot valve characteristic curve, multi-way valve core displacement characteristic curve and valve port flow curve is analyzed in order to determine the relationship between pilot valve displacement and multiway valve opening flow, that is, pilot valve-multiway valve comprehensive characteristic curve. This is used as an index to evaluate the maneuverability of multiway valves. 2) based on AMESim and Fluent platform, the existing bucket and arm coupling valves are simulated and analyzed, and the comprehensive characteristic curves are obtained. The synthetic curve is evaluated from three aspects: linear effective control percentage, linearity and flow resolution. The results show that the existing multi-way valves have the disadvantages of narrow speed range, poor flow fine-tuning performance and poor flow resolution. To solve these problems, the stiffness and preload of the pilot relief spring and the reset spring are adjusted to increase the speed regulation interval, and the flow fine-tuning performance is improved by increasing the gradient of the flow area curve of the multi-way valve. This paper takes medium hydraulic excavator as the test platform to carry out related tests, including pilot pressure test, single action test of moving arm and bucket rod, compares the experimental data with the simulation results, and verifies the correctness of the simulation analysis and the feasibility of the optimization scheme.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU621;TH137

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