Research On New Tamping Device And Operating Characteristic Analysis Of Tamping Device

Tamping device, the core equipment of tamping vehicle, is used to complete the tamping work of the railroad track bed ballast. High frequency vibration produced by vibration exciter and clamping movement by clamping hydraulic cylinder make ballast in motion and re-arranged to become dense. Currently with the rapid development of the domestic railway industry, large maintenance machinery has become the mainstream of the railway fields. Therefore we must import large maintenance machinery, digest its core technology and innovate independently. As independent innovation of domestic maintenance machinery is still in the initial stage, tamping device plays an important role in the large maintenance machinery. Over the years China has spent many large amount of money in importing different types of tamping machine for railway maintenance business overseas, therefore, innovative design of the core equipment of tamping vehicle-tamping device is very exigent.This paper, based on the three main existing international tamping devices, summarizes the kinematical characteristics of tamping device, creates a vibration model of tamping device and calculates equivalent combination and damping coefficient of ballast, then analyses the operating process of tamping device according to the vibration model. Subsequently the author puts forward a new exciting theory of tamping unit and designs the structure. At last, operating conditions and the strength of key components of tamping device is analyzed in Pro/MECHANICA.This article mainly includes the following:In chapter 1, the research background of tamping device is firstly described, and then the structure, classification and excitation characteristics of the three major tamping devices are briefly introduced. Moreover the current development state of tamping device is described. Finally the significance and research content of this subject is discussed.In chapter 2, the author creates the kinematical models of tamping device made in Matisa company and Plasser company separately, analyses the kinematical characteristics of the two kinds of tamping devices in analytics and makes a simulation in SimMchanics of MATLAB to protract the moving tracks of clamping cylinder, tamping arm and trace-ho. In the end the article summarizes operating characteristics of tamping device by comparing the moving tracks. In chapter 3, the author creates the vibration model of tamping device, calculates equivalent combination and damping coefficient of ballast and other interrelated parameters considering the impact of ballast factor on the vibration model. Then based on the vibration model the operation process of tamping device is analyzed, including the impact of clamping movement on the natural vibration frequency and amplitude of vibration system. At last the real-time measurement method of tamping density and relationship between vibration frequency and amplitude are discussed.In Chapter 4, the author establishes the three-dimensional solid model of Matisa tamping unit is in ADAMS, analyses the force of vibration to clamping hydraulic cylinder, then built the hydraulic model of tamping unit, by the co-simulation of mechanical model and hydraulic model, the characteristics of clamping hydraulic system are analysed.In chapter 5, the author designs a new type of tamping device with hydraulic excitation, introduces the operating principle of new device and electro-hydraulic vibration exciter, creates the kinematical model and dynamic model of vibration part of tamping arm, then calculates the main dynamics dimension of exciting cylinder, the dynamics dimension of clamping hydraulic cylinder according to sleeper spacing, clamping force and existing tamping unit, the ratio between the upper and lower tamping arms, the general layout of internal and external tamping arms and clamping cylinders. Finally, three-dimensional model of the new device is established in Pro/E, operating curves of tamping device in Pro/MECHANICA consists with the ones of theoretical analysis, proving the correctness of the model and the feasibility of new devices.In chapter 6, the author establishes the virtual prototype of tamping device with hydraulic excitation in ADAMS, analyses the working conditions of the impacting and clamping with vibration in operation process, makes a dynamics simulation with the working conditions simulated by the built-in function in ADAMS. Finally, the finite element analysis of key components of tamping device is finished in Pro/MECHANICA, the results show that the design strength of the new tamping device satisfies operational requirements.In Chapter 7, some conclusions are given and some new views are put forward in the future.