【作者】 闵超庆；

【导师】 龚国芳；

【作者基本信息】 浙江大学 ， 机械电子工程， 2012， 硕士

【摘要】 面对我国疆域辽阔,铁路密集,新线施工与旧线维修工作量巨大,大型养路机械发展成其必然。捣固车作为一种大型养路机械设备高效出色地完成线路维护与施工的任务,其核心设备为捣固装置。捣固装置通过夹持与夯实激振机构产生高频振动作用于道床石碴,促使石碴成其“石流”均匀、密实排布于轨枕之下,保证轨枕铺设质量从而利于高速列车平稳运行。目前捣固车市场基本被奥地利、瑞士和美国三国公司垄断,产品均采用机械式强迫振动技术实现捣固镐与石碴碰撞,结果必然会降低捣固镐寿命,加之国内捣固车核心技术的自主创新仍旧处于起步阶段,因此,实现捣固装置的创新设计有着举足轻重的意义。本文基于国际现有的捣固装置技术和存在的问题,提出了一种液压激振与夹持运动独立的新型捣固装置,该装置采用新型电液激振器实现高频振动。论文首先分析了新型捣固装置的工作原理；建立了装置虚拟样机并进行仿真,同时对新装置进行了有限元分析；基于新型捣固装置激振原理设计了一种阀芯旋转式四通高速换向阀和微行程双作用液压缸；利用MATLAB/Simulink对电液激振器系统动态特性进行研究；利用计算流体动力学软件对激振液压缸工作腔内部进行流场可视化分析；最后设计了新型电液激振器试验台并拟定试验方案。论文主要研究内容如下：第一章论述了捣固装置的研究背景、结构、分类及现有三种主要的捣固装置激振特点,随后讲述了捣固装置的国内外发展现状。同时基于捣固装置采用的电液激振技术,对电液激振技术进行相关文献的跟踪学习,最后提出了本课题的研究内容及研究意义。第二章提出了一种新型捣固装置并阐述其工作原理；基于CAX技术创建装置虚拟样机并进行运动学分析,研究装置结构尺寸与性能参数之间的规律,从而确定基于新型捣固装置电液激振器的主要设计参数包括激振力、幅值、频率；同时对新装置从静力学、模态及接触非线性等三个方面进行有限元分析,保证装置应用强度。第三章基于新型捣固装置提出了一种新型电液激振器,阐述了其工作原理并对其中的关键元件一阀芯旋转式四通高速换向阀和微行程双作用液压缸进行原理分析与设计。换向阀采用步进电机驱动阀芯旋转,设计转阀峰值流量250L/min,液压缸采用自动限位方式避免液压缸活塞与端盖碰撞,最大幅值8mm,最大输出激振力25kN。第四章在MATLAB/Simulink环境下,通过简化建立电液激振器理论模型,分析研究换向阀频率、阀口周向导通宽度及液压缸限位孔数量对电液激振器系统动态特性的影响,为进一步优化元件设计提供依据。第五章利用Fluent软件对高频激振液压缸进行内部流场可视化研究。通过选取液压缸不同位置处的不同截面,对压力场、速度场及流场流线进行分析,分析高频振动工况下液压缸工作腔内部流场是否产生气蚀、气穴及漩涡带来的噪声与能量损失,从而为液压缸内部结构优化提供依据。第六章基于验证电液激振器性能及元件结构参数对其影响,本文在浙江大学流体传动与机电系统国家重点实验室原有“985”工程元件测试试验平台上,设计并加工电液激振器试验台。论文对试验台的机械结构、液压系统、负载模拟系统、参数测量与数据采集系统进行了设计与选型,并拟定电液激振器性能测试试验方案。第七章总结了论文主要研究工作与成果,并对今后进一步研究工作作了论述。更多还原

【Abstract】 There will be lots of work of maintenance and construction in the railway fields because of wide area and intense railroads. As a result, large machinery has become popular. Tamper, the core equipment of tamping vehicle, is good at completing the work. The stones, which are excited by the squeeze and compaction device, flow in compact sequence under the bed ballast. Finally, fast trains have a good performance. At present, there are three main kinds of tampers on market from USA, Switzerland, Austria. Forced mechanical vibration technology is applied on these products which will reduce the life of tamping ends. So innovative design of tamper has an significance along with the development of tamper in China.A new type of tamper is proposed in the paper based on present products in the world. When product works, vibration and squeeze motion are separate. The vibration is realized by exciter used in the tamper. The operation principle of new tamper is studied at first. The three-dimension model and kinetic simulation are finished along with finite element analysis. A new type of rotary valve with high speed and minute-displacement double-rod cylinder are proposed. The dynamic properties are studied with the use of MATLAB/Simulink. The analysis of flow field of cylinder is finished by computation fluid dynamic software. At last, test rig design and plan of experiment are carried out.The studies are included as follows,In chapter 1, the research background, structure and characteristics of three main kinds of tamping device are formulated, as well as the current development state of tamping device. Then here come researches on the excitation technology applied on tamper. Finally the significance and research content of this subject are discussed.In chapter 2, a new type of tamping device is proposed and operation principle is formulated. The three-dimension model and kinetic simulation are finished with the use of CAX, which helps to study the relation between structural and performance parameters. As a result, the design of electrohydraulic exciter is determined. The statics, modal and non-linearity analyses are carried out.In chapter 3, a new type of electrohydraulic exciter is proposed based on the tamper. Operation principle is formulated. The designs of rotary valve and cylinder are carried out. The rotation of valve is realized by stepper motor. The compact between piston and wall is removed by the application of the auto-limitation structure of cylinder.In Chapter 4, the simulation model of electrohydraulic exciter is established with use of MATLAB/Simulink after the simplification. The relations between frequency of valve, conducting width of valve port, the number of ports of cylinder and dynamic characteristics of exciter are studied respectively, which do help to improve the design of valve and cylinder.In chapter 5, the flow field of cylinder with high frequency is studied with the use of Fluent. The pressure and velocity fields of different working positions and cross sections are studied. The study of cavitation erosion, air cavity and spiral vortex in the flow field of cylinder which bring in the noise and energy-loss is finished.In chapter 6, in order to verify the performance of electrohydraulic exciter as well as the relation between structural parameter and property, the design and machine of test rig are being carried out. The test rig is laid on the test platform of hydraulic part in SKL of ZJU. The mechanic part, hydraulic system, load model system, measurement and data acquisition system are designed. The product choosing is finished. At last, the experiment plan is determined.In Chapter 7, conclusions are given and new views are put forward in the future.更多还原