电液控制冲击试验机液压系统的研究

【作者】 吴嵩；

【导师】 丁凡；

【作者基本信息】 浙江大学 ， 机械电子工程， 2004， 硕士

【摘要】 抗冲击性能作为产品可靠性的重要组成部分，现在已备受产品生产者和使用者的关注。冲击试验则是测试产品抗冲击性能的一个重要手段。为了提高检测产品的抗冲击性能的试验水平，改进和完善冲击试验机性能则是一个重要的研究方向。本论文主要针对目前机械式冲击试验机存在的不足，应用电液控制技术提出了一种新型的电液控制冲击试验机的结构，进行了分析和研究。论文分为以下几个章节： 第一章首先在综合国内外文献的基础上介绍了冲击试验机的发展历史，研究与应用现状，并介绍了冲击试验与冲击波形的运用状况。然后介绍冲击试验机的核心部件力脉冲发生器的发展概况与研究动态。最后介绍了本文的相关技术电液比例／伺服领域的发展现状，在此基础上提出了本文的研究意义和研究内容。 第二章首先推导出三种力脉冲波形的加速度，速度和位移的时间函数关系，分析了力脉冲成形的要素和实现过程。提出了蓄能器-阀-液压缸系统构成的新型电液控制的冲击试验机结构及系统组成。分析和推导了蓄能器充气和排气工作过程的气体弹簧刚度计算公式，阀控缸系统活塞的位移、速度、加速度以及最高极限速度公式。最后了分析新结构的电液大流量控制阀的结构和工作原理。 第三章主要利用计算机仿真软件对由蓄能器-阀-液压缸组成的电液控制冲击试验机系统进行了理论分析，包括电液大流量控制阀工作过程的数学建模和电液控制冲击试验机系统控制过程的建模，液压执行元件蓄能器-阀控液压缸工作过程的数学建模，分析了结构参数和工作条件参数对系统性能的影响，以及系统动态响应的过程。 第四章主要阐述了电液大流量控制阀的液动力产生机理，计算及其对系统的干扰作用，在此基础上针对该阀的结构和工作特点提出阀芯所受液动力的补偿方法和结构，然后对阀口处的流场进行了有限元仿真计算，探索了液动力大小与补偿结构的各参数之间的关系，最后得出能实现液动力补偿的合理结构。 第五章首先介绍了蓄能器-阀-液压缸试验系统的组成，试验方法，然后对试验结果进行了分析。得出了有价值的结论，为进一步开发新型的电液控制冲击试验机打下基础。 第六章是论文总结和展望。更多还原

【Abstract】 Both manufacturers and users are giving their more attention to the shock resistance of products nowadays, which is a important constituent of its reliability, and shock testing is a indispensable means of checking resistance to impact. To. improve the level of shock test, improving and strengthening the performance of the shock machine is an important research objective. Against the disadvantages that existing in current mechanical shock testers, the thesis mainly presents a new-type structure of electro-hydraulic control shock tester and makes much study and analysis on it. It is consisting of six sections as follow.Chapter 1 first introduces the development-history, present state on the research and application of product shock testers, the current application situation of shock teasing and its force pulse on the base of having collected and analyzed plenty of documentation. Then it states the general development situation and research trends on the force pulse generator, and the present status of electro-hydraulic proportional/servo control technique. In the end this thesis points out the main content and significance of the research work.Chapter 2 derives the acceleration, velocity, and displacement functions of the three force pulse waveforms and states the generation course of corresponding wave profile in its first section. And then puts forward a new-type force pulse generator that is integrated from accumulator, hydraulic cylinder, valve and specifies the mechanical structure of electro-hydraulic proportional/servo system. Furthermore it analyzes and deduces the both the calculatior formula of stiffness coefficient on the pneumatic spring in the accumulator, and the formulas of the acceleration, velocity, displacement, and maximum speed on the piston in the hydraulic cylinder being controlled by a valve. The last part of the chapter illustrates and analyses the structural principle of large-capacity control valve.Chapter 3 analyses the design of shock tester system composed of accumulator, hydraulic cylinder, and valve through computer simulation software Matlab6.1, including firstly the modeling of system control structure, secondly the modeling and simulation on the dynamic process of accumulator and hydraulic cylinder controlled by valve, and the force characteristic and dynamic response of large-capacity proportional valve, then summarizes the relation between product characteristic and several main structural parameters. In the last part of the section it calculates and analyses the work process of whole integrated component.Chapter 4 firstly analyses the generation mechanics, calculating method and interference effect of flow force in the outflowing large-capacity proportional valve. Then it not only presents a structural design to compensate the flow force according to the performance characteristic of the cone valve, but also calculates and simulates the flow field at the valve port through CFD software Fluent6.0. At last it studies the influence of compensation structure parameters and obtains better projected dimensions.Chapter 5 firstly introduces the experiment platform design of accumulator-valve -hydraulic cylinder system and testing method. Then it summarizes and analyses the experiments result and obtains some valuable conclusions. It has laid the foundation for future research and development of electro-hydraulic control shock tester.Chapter 6 summarizes the whole thesis.更多还原