汽车起重机回转液压系统动态特性仿真与实验研究
发布时间：2019-03-02 13:34
【摘要】：作为重物搬运重要设备的起重机在现代化生产过程中应用越来越广。由于电力、石油、化工,运输等行业的快速发展,起重机的种类越来越多、市场需求量也越来越大。 目前工程起重机广泛采用液压驱动,回转机构是起重机的重要机构,由于回转机构作业时具有转动惯量大的特性,所以作业时压力冲击较大,这种压力冲击会影响相关液压元件工作寿命,容易损坏相关的压力传感器和引起整机振动,造成动作微动性差,使得工作效率降低,从而制约回转系统的工作性能。合理的液压油路可以提高作业效率、改进整机性能、改善工作条件、减小发热量等。回转机构作业时应尽量平稳,制动时间应尽量短,起动、制动、换向时压力冲击要小,为满足这些要求,我们有必要对回转机构液压油路进行专门分析研究。只有了解系统的动态特性,才能对系统的各种参数进行合理的匹配。以往我国起重机制造企业在起重机液压系统的设计和评估分析上一般都是根据人们的经验和必要的产品借鉴,以静态考虑为主来设定设计方案,再通过实验在样机上发现问题。单纯地运用实验法,不仅仅要花费很大的精力和物力,而且有时变更参数或条件都比较困难,甚至可能无法实现。如果采用传统的传递函数理论分析法,不但很麻烦而且稍有失误其结果可能与实际相差甚远。而利用仿真分析的方法,可以使这一复杂的问题简单化。 本文是来源于学校和企业合作的“移动式起重机产品液压控制回路测试评估系统开发”实际项目,对汽车起重机回转液压系统展开研究,以目前同类系统普遍存在的问题为切入点,分析如何实现回转机构作业时压力平稳、缩短制动时间、减小起动、制动和换向时的压力冲击、改善系统的调速特性。 1.对50t汽车起重机的回转机构理论分析,建立回路的液压控制系统数学模型,应用传递函数法理论上分析了对液压控制系统有影响的一些参数。 2.建立回转机构液压系统仿真模型,在50t汽车起重机样车上进行实验,测出回转机构液压系统两种工况时压力动态曲线,通过仿真结果和实验结果对比,修正参数使模型更真实地反应实际情况,验证了仿真模型的正确性。 3.基于回转机构的AMESim仿真模型进行仿真分析,分别分析了转动惯量、负载阻力矩、缓冲阀的弹簧、缓冲阀的开口面积、泵的流量、换向阀的弹簧刚度、换向阀的开口面积、缓冲溢流阀的弹簧预紧力对系统的动态特性的影响。分析了如何减缓回转机构启动和制动时压力冲击、缩短制动时间、改善系统的调速特性,提高整机性能、作业效率和安全性。 根据起重机回转机构液压系统分析提出的建议对提高整机性能非常重要,希望本文的研究成果能对以后的同类产品的设计、评估提供一定的参考价值。
[Abstract]:Cranes, as important equipment for handling heavy objects, are used more and more widely in the modern production process. Due to the rapid development of electric power, petroleum, chemical and transportation industries, there are more and more kinds of cranes and more market demand. At present, hydraulic drive is widely used in engineering cranes. The rotary mechanism is an important mechanism of crane. Because the rotary mechanism has the characteristic of large moment of inertia when working, the pressure shock is bigger when working. This pressure shock will affect the working life of the relevant hydraulic components, damage the related pressure sensors and cause the vibration of the whole machine, and cause the poor action micro-motion, which will reduce the working efficiency, and thus restrict the working performance of the rotary system. Reasonable hydraulic oil circuit can improve the working efficiency, improve the performance of the whole machine, improve the working conditions, reduce the heat generation and so on. In order to meet these requirements, it is necessary to make a special analysis and study on the hydraulic oil circuit of the rotary mechanism in order to meet these requirements, the working time of the rotary mechanism should be as stable as possible, the braking time should be as short as possible, and the pressure shock should be small when starting, braking and reversing. Only by understanding the dynamic characteristics of the system, can the parameters of the system be properly matched. In the past, the design and evaluation analysis of crane hydraulic system in crane manufacturing enterprises in our country are generally based on the experience of people and the reference of necessary products, and the design scheme is set mainly by static consideration, and then the problems are found in the prototype through experiments. The simple application of the experimental method not only costs a lot of energy and material resources, but also sometimes it is difficult to change the parameters or conditions, and it may even be impossible to realize. If the traditional transfer function theory analysis method is adopted, it is not only troublesome but also slightly wrong, and the result may be very different from the actual one. The method of simulation analysis can simplify this complex problem. This paper is from the school and the enterprise cooperation "mobile crane product hydraulic control loop test and evaluation system development" actual project, the automobile crane rotary hydraulic system is carried out the research, Based on the common problems existing in the same system at present, this paper analyzes how to realize the stable pressure, shorten the braking time, reduce the pressure shock when starting, braking and reversing, and improve the speed regulation characteristics of the system. 1. Based on the theoretical analysis of the slewing mechanism of 50t truck crane, the mathematical model of the hydraulic control system of the loop is established, and some parameters which have influence on the hydraulic control system are analyzed theoretically by the transfer function method. 2. The simulation model of hydraulic system of rotary mechanism is established, and the pressure dynamic curve of hydraulic system of slewing mechanism is measured on a 50t truck crane sample car. The simulation results are compared with the experimental results. The modified parameters make the model reflect the actual situation more realistically, and verify the correctness of the simulation model. 3. Based on the AMESim simulation model of the rotary mechanism, the moment of inertia, the load resistance moment, the spring of the buffer valve, the opening area of the buffer valve, the flow rate of the pump, the spring stiffness of the reversing valve and the opening area of the reversing valve are analyzed. The effect of spring pre-tightening force of buffer relief valve on the dynamic characteristics of the system. This paper analyzes how to slow down the pressure shock during start-up and braking of rotary mechanism, shorten the braking time, improve the speed regulation characteristics of the system, and improve the performance, working efficiency and safety of the whole machine. According to the analysis of hydraulic system of crane slewing mechanism, it is very important to improve the performance of the whole machine. It is hoped that the research results of this paper can provide some reference value for the design and evaluation of similar products in the future.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH213.6
本文编号：2433091
[Abstract]:Cranes, as important equipment for handling heavy objects, are used more and more widely in the modern production process. Due to the rapid development of electric power, petroleum, chemical and transportation industries, there are more and more kinds of cranes and more market demand. At present, hydraulic drive is widely used in engineering cranes. The rotary mechanism is an important mechanism of crane. Because the rotary mechanism has the characteristic of large moment of inertia when working, the pressure shock is bigger when working. This pressure shock will affect the working life of the relevant hydraulic components, damage the related pressure sensors and cause the vibration of the whole machine, and cause the poor action micro-motion, which will reduce the working efficiency, and thus restrict the working performance of the rotary system. Reasonable hydraulic oil circuit can improve the working efficiency, improve the performance of the whole machine, improve the working conditions, reduce the heat generation and so on. In order to meet these requirements, it is necessary to make a special analysis and study on the hydraulic oil circuit of the rotary mechanism in order to meet these requirements, the working time of the rotary mechanism should be as stable as possible, the braking time should be as short as possible, and the pressure shock should be small when starting, braking and reversing. Only by understanding the dynamic characteristics of the system, can the parameters of the system be properly matched. In the past, the design and evaluation analysis of crane hydraulic system in crane manufacturing enterprises in our country are generally based on the experience of people and the reference of necessary products, and the design scheme is set mainly by static consideration, and then the problems are found in the prototype through experiments. The simple application of the experimental method not only costs a lot of energy and material resources, but also sometimes it is difficult to change the parameters or conditions, and it may even be impossible to realize. If the traditional transfer function theory analysis method is adopted, it is not only troublesome but also slightly wrong, and the result may be very different from the actual one. The method of simulation analysis can simplify this complex problem. This paper is from the school and the enterprise cooperation "mobile crane product hydraulic control loop test and evaluation system development" actual project, the automobile crane rotary hydraulic system is carried out the research, Based on the common problems existing in the same system at present, this paper analyzes how to realize the stable pressure, shorten the braking time, reduce the pressure shock when starting, braking and reversing, and improve the speed regulation characteristics of the system. 1. Based on the theoretical analysis of the slewing mechanism of 50t truck crane, the mathematical model of the hydraulic control system of the loop is established, and some parameters which have influence on the hydraulic control system are analyzed theoretically by the transfer function method. 2. The simulation model of hydraulic system of rotary mechanism is established, and the pressure dynamic curve of hydraulic system of slewing mechanism is measured on a 50t truck crane sample car. The simulation results are compared with the experimental results. The modified parameters make the model reflect the actual situation more realistically, and verify the correctness of the simulation model. 3. Based on the AMESim simulation model of the rotary mechanism, the moment of inertia, the load resistance moment, the spring of the buffer valve, the opening area of the buffer valve, the flow rate of the pump, the spring stiffness of the reversing valve and the opening area of the reversing valve are analyzed. The effect of spring pre-tightening force of buffer relief valve on the dynamic characteristics of the system. This paper analyzes how to slow down the pressure shock during start-up and braking of rotary mechanism, shorten the braking time, improve the speed regulation characteristics of the system, and improve the performance, working efficiency and safety of the whole machine. According to the analysis of hydraulic system of crane slewing mechanism, it is very important to improve the performance of the whole machine. It is hoped that the research results of this paper can provide some reference value for the design and evaluation of similar products in the future.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH213.6
【引证文献】
相关硕士学位论文 前1条
1 夏树立;百米登高平台消防车回转液压系统仿真研究[D];大连理工大学;2012年
，本文编号：2433091
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