滑移装载机闭式行走系统研究

发布时间：2018-05-24 23:32

本文选题：滑移装载机 + 行走系统　；参考：《吉林大学》2012年硕士论文

【摘要】：近年来，伴随着许多工业部门和技术领域对高响应、高精度和高功率液压系统的需求不断扩大，促使液压驱动技术日趋成熟完善，在以滑移装载机为代表的小型工程机械领域中，已普遍采用静液压传动技术。闭式行走系统作为滑移装载机的核心液压系统之一，其动态品质对整机工作的操纵性、可靠性和安全性都有着重要影响，因此，如何实现滑移装载机响应迅速、控制精确、工作平稳是研究滑移装载机行走系统的关键所在。但目前国内滑移装载机生产企业对行走系统动态特性的研究依然处于起步阶段，多数仍采用传统的方法设计系统，即以完成执行机构动作循环和满足系统静态性能要求作为设计目标，这种以静态计算为主的设计方法，容易使系统出现不稳定的工作状态，导致发动机熄火等现象的发生。本文结合校企合作项目“装载机液压系统及传动系统动态仿真分析及对比测试研究”，对广泛应用于滑移装载机中的闭式行走系统动态特性开展研究，以传递函数法推导获得的数学模型为理论基础，依托AMESim(Advanced ModelingEnvironment for Simulation of engineering systems)仿真软件作为动态分析平台，结合实验验证的研究思路，使理论、仿真、实验三者形成相互验证指导关系，进而分析说明影响闭式行走系统动态特性的主要因素。综合全文研究工作，主要包括如下几个方面： (1)基于对泵控马达及闭式系统回路特点的分析，详细阐述了滑移装载机行走系统的工作原理。以整机因功率匹配不合理而导致的熄火问题作为切入点，从理论上论述了补油系统与DA控制策略等相关解决方法的技术原理。 (2)在建立变量泵伺服反馈机构及闭式系统回路数学模型基础上，基于闭式行走系统工作原理，推导获得系统的总体传递函数框图，通过对影响行走系统动态特性结构参数的定性分析可知：降低变量泵伺服控制滑阀阀芯流量增益、压力流量变化系数，增加其对中弹簧刚度有利于提高系统工作稳定性；增加油液体积弹性模量、降低变量泵排量梯度及DA阀节流孔直径有利于提高系统响应特性。 (3)依托AMESim仿真软件平台，建立了具有位置伺服反馈作用的变量泵、具有调速输出特性的发动机、具有转速传感器功能的DA控制阀以及滑移装载机行走系统的总体仿真模型。通过对元件参数的批处理仿真，明确了变量泵伺服控制机构、动态负载及主回路油液对系统动态特性的影响，验证了理论分析的正确性。并针对滑移装载机几种典型工况，将仿真曲线与实验曲线进行数据比对，验证了仿真模型的准确性，并为后续性能优化方案提供参考评估。 (4)制定了滑移装载机行走系统动态性能实验测试方案，，分别对变量泵伺服控制信号、变量泵排量以及整机载荷等因素进行测试，实验结果验证了相关理论分析的正确性。并针对滑移装载机存在的熄火问题，提出采用DA控制策略对系统进行改进。实验测试表明采用该优化方案后，行走系统可有效避免熄火现象的发生，保证系统工作的稳定可靠性。
[Abstract]:In recent years, with the high response of many industrial sectors and technical fields, the demand for high precision and high power hydraulic systems is expanding, and the hydraulic driving technology is becoming more and more mature. In the field of small engineering machinery represented by sliding loaders, the static hydraulic pressure transmission technology has been widely used. The closed walking system is used as sliding loading. One of the core hydraulic systems of the machine, its dynamic quality has an important influence on the maneuverability, reliability and safety of the whole machine. Therefore, how to realize the quick response, precise control and smooth work of the sliding loader is the key to the study of the walking system of the sliding loader.
However, at present, the research on the dynamic characteristics of the walking system is still in the beginning stage in the domestic skid loader production enterprises. Most still use the traditional method to design the system, that is to complete the execution cycle of the executive mechanism and meet the static performance requirements of the system as the design goal. This design method, based on static computing, is easy to make the system appear. The unstable working state causes the engine to stall.
This paper combines the dynamic simulation analysis and comparative test of the hydraulic system and transmission system of the school enterprise cooperation project, and studies the dynamic characteristics of the closed walking system widely used in the sliding loader. The mathematical model derived from the transfer function method is the basis for the study, and the AMESim (Advanced ModelingEnvironment fo) is supported by the transfer function method. R Simulation of Engineering Systems) simulation software, as a dynamic analysis platform, combined with the research ideas of experimental verification, makes the theory, simulation and experiment three to form mutual verification guidance relations, and then analyzes the main factors that affect the dynamic characteristics of the closed walking system. The comprehensive full text research work mainly includes the following aspects:
(1) based on the analysis of the characteristics of the pump control motor and the closed system circuit, the working principle of the sliding loader's walking system is elaborated in detail. The technical principle of the related solutions, such as the oil filling system and the DA control strategy, is discussed in theory, based on the problem of the flameout caused by the unreasonable power matching.
(2) on the basis of the mathematical model of the variable pump servo feedback mechanism and the closed system loop, based on the working principle of the closed walking system, the overall transfer function block diagram of the system is derived. Through the qualitative analysis of the structural parameters affecting the dynamic characteristics of the walking system, the flow gain and pressure of the lower variable pump servo control valve valve spool valve core are obtained. The coefficient of flow change, increasing the stiffness of the medium spring is beneficial to improving the stability of the system, increasing the elastic modulus of the fluid, reducing the displacement gradient of the variable pump and the diameter of the throttle hole of the DA valve, is beneficial to improving the response characteristic of the system.
(3) relying on the AMESim simulation software platform, a variable pump with position servo feedback is established, the engine with the characteristic of speed regulation output, the DA control valve with the function of the speed sensor and the overall simulation model of the walking system of the sliding loader. The servo control mechanism of the variable pump is clearly defined by the batch simulation of the parameters of the component. The effect of the state load and the oil liquid on the main circuit on the dynamic characteristics of the system verified the correctness of the theoretical analysis, and compared the simulation curves with the experimental curves to verify the accuracy of the simulation model and provide a reference evaluation for the follow-up performance optimization case.
(4) the dynamic performance test scheme of the sliding loader's walking system is set up, and the factors such as the variable pump servo control signal, the variable pump displacement and the whole machine load are tested respectively. The experimental results verify the correctness of the related theoretical analysis. The DA control strategy is proposed to the system for the existence of the sliding loader. The experimental results show that after adopting the optimization scheme, the walking system can effectively avoid the occurrence of flameout and ensure the stability and reliability of the system.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH243

【引证文献】