超越负载工况下平衡阀稳定性研究

发布时间：2018-01-14 16:11

本文关键词：超越负载工况下平衡阀稳定性研究　出处：《吉林大学》2015年硕士论文　论文类型：学位论文

【摘要】：液压平衡阀是液压平衡回路上，能够产生一定的背压，用于平衡超越负载工况下执行元件的重量，防止执行元件的运动部件因重力的影响而产生自由下落，造成严重事故，以达到控制执行元件下降速度和提高液压系统刚度的一种液压元件。液压平衡阀是液压平衡回路实现平衡功能的关键性元件，，在平衡回路中能实现系统的平衡稳定作用，它的性能直接影响着整个机器的工作平稳性、可靠性和系统效率。卷扬液压系统是汽车起重机液压系统中一个重要的子系统，其职能是实现重物的起升和下降。在重物下降的过程中，负载力和负载的运动方向相同，即超越负载工况，系统容易产生压力冲击，动态性能不稳定。在关闭马达变量，保持吊重不变的情况下，卷扬液压系统的稳定性的影响因素主要集中在卷扬系统中的平衡阀。因此，研究平衡阀的结构参数和卷扬液压系统稳定性之间的关系具有理论和实际应用的意义。本文结合校企合作项目“国产平衡阀的改造”对平衡阀的结构参数和汽车起重机卷扬系统稳定性之间的关系展开研究。以超越负载工况下，卷扬系统重物下降抖动性为研究对象，基于AMESim（Advanced Modeling Environment for Simulations ofengineering systems）软件仿真平台分别建立了平衡阀和变量马达以及由它们所构成卷扬液压系统的HCD(Hydraulic Component Design)模型，采用传递函数法，动态仿真分析以及实验验证的研究方法对卷扬液压系统和平衡阀的结构参数之间的关系进行了研究。本文的主要内容有：（1）分别对几种常见的平衡回路的工作原理、缺陷进行了分析；比较了国内外平衡阀的发展现状。 (2)介绍了oil control平衡阀的工作原理；基于传递函数法建立了单级式平衡阀的数学模型。 (3)采用元件级建模方式，分别建立了平衡阀和变量马达的HCD模型。根据元件本身固有的特性，设置参数，验证HCD模型的正确性。在模型正确的基础上，搭建了卷扬液压系统模型。 (4)设计了卷扬液压系统动态性能测试方案，并进行了样机实验。主要对负载下降的过程，分别为零负载和10t负载，马达负载口的压力，卷扬起压力、卷扬落压力进行时仿真和实验的验证，实验结果与仿真结果吻合，验证了仿真模型及相关理论的正确性。 (5)基于卷扬液压系统HCD模型，分别对阀芯弹簧、控制活塞面积、阀芯节流口面积增益以及阀芯弹簧的预压缩力和卷扬液压系统稳定性之间的关系进行了研究。
[Abstract]:Hydraulic balancing valve is a hydraulic balancing circuit, which can produce a certain back pressure, which is used to balance the weight of the actuator under the condition of exceeding the load, and to prevent the moving parts of the actuator from falling freely because of the influence of gravity. In order to control the descending speed of the actuator and improve the stiffness of hydraulic system, a hydraulic element is a kind of hydraulic component. The hydraulic balance valve is the key element to realize the balance function of the hydraulic balancing circuit. The balance and stability of the system can be realized in the balance loop, and its performance directly affects the stability, reliability and system efficiency of the whole machine. The hoisting hydraulic system is an important subsystem in the hydraulic system of truck crane. Its function is to realize the lifting and lowering of heavy objects. In the process of lowering heavy objects, the load force and the movement direction of load are the same. That is, beyond the load conditions, the system is prone to pressure impact, dynamic performance instability. When the motor variables are closed to keep the lifting weight unchanged. The influence factors of the stability of the winch hydraulic system are mainly concentrated in the balance valve in the winch system. It is of theoretical and practical significance to study the relationship between the structural parameters of the balance valve and the stability of the hoisting hydraulic system. In this paper, the relationship between the structural parameters of the balance valve and the stability of the hoisting system of the truck crane is studied in combination with the school-enterprise cooperation project, "the Transformation of the domestic balance Valve", in order to exceed the load condition. The drop jitter of heavy objects in winch system is studied. Based on AMESim1 (. Advanced Modeling Environment for Simulations ofengineering systems. The software simulation platform establishes the HCD(Hydraulic Component design model of the balancing valve and variable motor, and the hydraulic system which is composed of them. The relationship between the structural parameters of the hoisting hydraulic system and the balance valve is studied by means of transfer function method, dynamic simulation analysis and experimental verification. The main contents of this paper are as follows: The working principle and defects of several common balancing circuits are analyzed respectively, and the development status of balancing valves at home and abroad is compared. The working principle of oil control balancing valve is introduced, and the mathematical model of single stage balance valve is established based on transfer function method. The HCD models of balance valve and variable motor are established by using the method of component level modeling. The parameters are set up according to the inherent characteristics of the component itself. The correctness of HCD model is verified. On the basis of correct model, the hoisting hydraulic system model is built. The test scheme of dynamic performance of winch hydraulic system is designed, and the prototype experiment is carried out. The main process of load drop is zero load and 10 t load, the pressure of motor load port, and the roll up pressure. The simulation results are in good agreement with the simulation results, which verify the correctness of the simulation model and related theories. Based on the HCD model of the winch hydraulic system, the piston area is controlled for the spool spring. The relationship between the area gain of valve core throttle, the precompression force of spool spring and the stability of winch hydraulic system is studied.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH137.5

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