大型HAGC缸试验方法与技术研究

发布时间：2018-01-28 18:33

  本文关键词： 伺服液压缸 HAGC缸 液压CAT 试验方法　出处：《武汉科技大学》2014年博士论文　论文类型：学位论文

【摘要】：HAGC（HydraulicAutomaticGaugeControl）缸广泛应用于板带轧机，对其静、动态性能进行检测与判定十分必要。本文针对大型HAGC缸性能测试方法和测试系统进行研究，开展了以下几个方面的工作： 综合了国内外HAGC缸使用、制造与测试技术资料，分析了市场需求与技术特点，探讨了HAGC缸静、动态指标科学测试的理论价值和工程意义。通过对现有HAGC缸测试方法定性及定量分析，针对轧机机架弹性变形、板带弹塑性变形的复杂工况特点，创新性地提出了能模拟现场工况的加载方法和负载试验技术，实测表明有较高的测试精度、系统可靠，通用性好。 通过对测试系统关键部件--加载机架建立有限元模型，从静力学和动力学两方面进行定量仿真分析，并对部分仿真结果进行了测试验证。仿真分析与实验结果表明：加载机架上下横梁中间加工成月牙形，能改善应力分布，使相同载荷下机架总重量较小；4500t载荷作用下，机架强度能满足HAGC缸测试系统静态加载要求，机架高度（Y）方向刚度适中，拉伸量可达5.33mm，在HAGC缸测试过程中能产生较大变形位移量，有利于位移传感器的测量；机架变形所产生的内摩擦阻尼远小于HAGC缸的动摩擦力，机架高度方向变形为第4阶振型，其固有频率远大于HAGC缸测试频率范围，机架承受动态载荷时，位移变形响应速度快，远大于HAGC缸的动态测试响应范围，因此机架的瞬态过程性能不会对HAGC缸动态测试结果造成实质性影响。分析了测试系统中电液伺服阀、HAGC缸、连接管道、位移传感器、伺服控制器 等主要组成元器件，分别建立了数学仿真模型，并在此基础上形成了测试控制系统的仿真数字模型。按实际选定了仿真参数，运用软件对液压位置闭环控制测试系统进行了仿真分析与PID校正比较，利用开环Bode图对稳定性进行了分析，通过单位阶跃响应及闭环Bode图对系统快速性、准确性进行了计算分析。讨论了伺服阀与被试液压缸之间连接管道的刚度、长度、通径，液压油的弹性模量、粘度，机架刚度等可变因素对试验系统测试结果的影响程度，结果表明管道的刚度、长度、通径对动态测试结果影响较大，可达基本响应时间的10%以上，机架刚度所致影响可达基本响应时间的4.9%，油液因弹性模量变化所致影响可达基本响应时间的1.7%，其他因素的影响很小，可不予考虑。 开发了针对大型HAGC缸静动态性能检测的测试系统，，包括液压系统、电气控制系统、监控程序和画面、传感系统、计算机测控及软件系统。测试系统动态加载能力达4500t，液压油源流量1000l/min，压力31.5MPa，耐压试验达70MPa，能方便快捷地完成直径2200mm以内的HAGC缸的空载起动摩擦力、带载动摩擦力、带载频率特性、带载阶跃响应、空载活塞偏摆等全套静动态指标自动检测任务。 在理论研究和测试验证基础上，制定了伺服液压缸技术条件与试验方法标准，已经批准为广东省地方标准:伺服液压缸第2部分:试验方法（DB44/T1169.2-2013）。
[Abstract]:HAGC (HydraulicAutomaticGaugeControl) cylinder is widely used in strip mill. It is very necessary to detect and determine its static and dynamic performance. Aiming at the performance test method and test system of large HAGC cylinder, the following aspects are studied.
Comprehensive domestic and international HAGC cylinder, manufacturing and testing technology, analyzes the market demand and technical characteristics, discusses the HAGC cylinder static, dynamic index of scientific testing theoretical value and engineering significance. Based on the existing HAGC cylinder test methods of qualitative and quantitative analysis for rolling mill frame plate with elastic deformation, elastic-plastic deformation the complex working condition, put forward the innovation of the loading method can simulate field conditions and load test technology, test results show that the accuracy, high system reliability, good versatility.
The key components of the test system, loading frame finite element model is established, the quantitative simulation analysis from two aspects of static and dynamic, and some simulation results have been validated. The simulation analysis and experimental results show that the loading rack under the middle of the cross beam processed into crescent, can improve the stress distribution, the total weight of the frame under the same load is small; the load of 4500t, the frame strength can meet the static loading test system of HAGC cylinder, the height of the frame (Y) direction of moderate rigidity and tensile capacity of up to 5.33mm, can produce larger deformation displacement in HAGC cylinder in the process of testing, measurement for displacement sensor; the dynamic internal friction the friction damping is much smaller than that of HAGC cylinder frame deformation, height direction of the frame deformation as fourth modes, the natural frequency is far greater than the HAGC cylinder test frequency range, the frame subjected to dynamic load, displacement The shape response speed is much faster than that of the HAGC cylinder, so the transient performance of the rack will not have a substantial impact on the dynamic test results of the HAGC cylinder. The electro-hydraulic servo valve, HAGC cylinder, connecting pipe, displacement sensor and servo controller are analyzed.
As the main components, the mathematical simulation model was established, and on the basis of the formation of digital simulation model test and control system. According to the actual selected simulation parameters, the use of software simulation analysis and correction of PID hydraulic position closed-loop control testing system, using the open-loop Bode diagram of stability analysis, through the unit step on fast response and closed-loop Bode diagram, the accuracy is calculated and analyzed. The servo valve and cylinder pipe connection between the solution of stiffness, length, diameter, elastic modulus, viscosity of hydraulic oil, the influence degree of frame stiffness variable factors on the test results, the pipeline the results show that the stiffness, length, diameter of the dynamic test results are affected, up to 10% above the basic response time, frame rigidity caused by up to 4.9% basic response time, because of the elastic oil The influence of modulus change can reach 1.7% of the basic response time, and the influence of other factors is very small, but it can not be considered.
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