60MN水压机油控水系统控制特性研究

发布时间：2018-03-04 18:13

本文选题：水压机　切入点：水系统　出处：《燕山大学》2015年博士论文　论文类型：学位论文

【摘要】：大锻件的质量和生产能力是衡量一个国家工业发展水平的重要标志之一,大型水压机是大型锻件成形装备,提高大型水压机动力传输系统的控制性能至关重要。针对大型水压机动力传输系统进行元件级和系统级研究以提高其性能,具有重大理论和实践意义。目前大型水压机普遍采用油控水的控制方式,水系统主控制阀采用八阀分配器的传统形式,该动力传输系统主要存在两方面的问题:一是水系统的八阀分配器应用多年未作改进存在控制流量线性度不好的问题,影响整体控制性能;二是液压伺服系统和水系统没有做到深入融合整体控制,制约了整机性能的提高。针对上述问题,本文主要展开以下研究工作:(1)从阀杯孔口排布形式入手,对进水阀阀口通流面积进行计算分析并优化,得到阀杯孔口最佳重合度;建立进、排水阀流场分析有限元模型,通过流场分析得到其流场分布情况、流量及阀芯受力情况;以60MN自由锻造水压机为试验平台,验证优化后阀杯孔口排布形式下进水阀流量-位移特性的改进情况。(2)采用机理建模的方法对油控水系统的关键元件进行数学建模,包括水泵、蓄势器、进水阀、排水阀、主分配器、充液阀、管道、执行机构、负载、工作介质及电液伺服系统。推导油控水系统完整的数学模型,为后续的研究奠定理论基础。(3)在水压机电液位置伺服控制系统数学模型的基础上,为提高水压机伺服系统的静动态特性,对电液位置伺服控制系统的负载特性进行分析。为提高锻件的质量,保证控制系统受外部干扰情况下的可控性,提高电液位置伺服控制系统的鲁棒性,本文提出自抗扰的控制策略。借助MATLAB/Simulink软件,搭建自抗扰控制仿真模型,进行仿真分析,为实验研究奠定基础。(4)对60MN自由锻造水压机的控制特性进行了仿真和实验研究。介绍了60MN自由锻造水压机的实验测试系统、数据采集方法和数据分析工具。并建立了油控水系统和水系统的联合仿真模型,分别对系统在常锻和快锻两种工况下的控制特性进行仿真分析,通过实验验证了仿真模型的准确性。针对液压伺服系统鲁棒性差、抗干扰能力弱的问题,引入自抗扰控制方法,分析水压机空载和不同加载力下的控制性能。
[Abstract]:The quality and production capacity of large forgings is one of the important symbols to measure the level of industrial development in a country, and the large hydraulic press is the forming equipment of large forgings. It is very important to improve the control performance of power transmission system of large hydraulic press. It is of great theoretical and practical significance. At present, the control mode of oil and water is widely used in large hydraulic press, and the traditional form of eight valve distributor is adopted in the main control valve of water system. There are two main problems in this power transmission system: one is that the control flow linearity is not good when the eight valve distributor is used in water system for many years, which affects the overall control performance; Second, the hydraulic servo system and the water system have not been fully integrated with the overall control, which restricts the improvement of the performance of the whole machine. In view of the above problems, this paper mainly carries out the following research work: 1) starting with the arrangement form of the valve cup orifice. The flow area of inlet valve orifice is calculated and optimized, the optimum coincidence degree of valve cup orifice is obtained, the finite element model of flow field analysis of inlet and drain valve is established, and the distribution of flow field, flow rate and stress of valve core are obtained through flow field analysis. Taking the 60MN free forging hydraulic press as the test platform, the improvement of flow-displacement characteristics of the inlet valve under the optimized arrangement of the valve cup orifice is verified. The mechanism modeling method is used to model the key components of the oil-water control system, including the water pump. Accumulator, intake valve, drain valve, main distributor, filling valve, pipeline, actuator, load, working medium and electro-hydraulic servo system. In order to improve the static and dynamic characteristics of hydraulic press servo system, based on the mathematical model of hydraulic electro-hydraulic position servo control system, The load characteristics of electro-hydraulic position servo control system are analyzed. In order to improve the quality of forgings and ensure the controllability of the control system under external interference, the robustness of electro-hydraulic position servo control system is improved. In this paper, the control strategy of ADRC is put forward. With the help of MATLAB/Simulink software, the simulation model of ADRC is built, and the simulation analysis is carried out. The control characteristics of 60MN free forging hydraulic press are simulated and experimentally studied, and the experimental test system of 60MN free forging hydraulic press is introduced. Data acquisition method and data analysis tool. The simulation model of oil water control system and water system is established, and the control characteristics of the system under constant forging and fast forging conditions are simulated and analyzed, respectively. The accuracy of the simulation model is verified by experiments. Aiming at the problems of poor robustness and weak anti-interference ability of hydraulic servo system, the control performance of hydraulic press under no load and different loading forces is analyzed by introducing the method of automatic disturbance rejection control.
【学位授予单位】：燕山大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG315.4

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