Grinding Mechanism And Process Research On A New-type Milling-like Grinding Of Rail Material

Steel rail on the railroad are under long-term alternating load,which would produce severe rail wear and a variety of damages,seriously affecting the safety and stability of train operation and restricting the economic benefit of railway transportation.Therefore,it is necessary to repair the damaged rail regularly to improve the contact relation of the wheel and rail to the normal state.The rail milling vehicle is the main equipment of steel rail repairing,and its market demand is great.As one of its core working components,the milling cutter disc bears most of the material removal and prepares for the subsequent grinding.However,the wear of the milling cutter disc is faster,and during the machining process,the scrapped cutter blade must be changed in time,but the replacement is a relatively complex,time-consuming and high in cost process.Therefore this article from the point of view grinding instead of milling and based on the basic objective of rail material and its processing requirements,a new type of grinding process is proposed to replace the milling process in order to realize the high efficiency and low cost repair of the steel rail,and the basic research of the grinding wheel grinding rail is carried out.The main research contents in this paper are as follows:1)Aiming at the requirement of steel rail processing,a new type of single-layer brazed ordered CBN grinding wheel is designed,the structure of the grinding wheel base body is reasonably designed,a proper matrix material,an abrasive,a brazing material and an abrasive grain ordered arrangement mode are selected,and strictly controlling each manufacturing link,ensuring the consistency of the height of the abrasive grains outcrops,improving the abrasive grain bonding strength of the grinding wheel surface,reducing the grinding heat,reducing the grinding specific energy and the grinding temperature,improving the abrasion resistance of the grinding wheel,and realizing high-quality and high-efficiency processing of the steel rail material.2)Referring to the working parameters of the active steel rail milling and milling vehicle,The grinding rail material experiments are conducted to comprehensively evaluated grinding performance of the grinding wheel by grinding force,grinding temperature and specific grinding energy,and its grinding mechanism is analyzed.The characteristics and laws of grinding force,grinding force ratio,grinding temperature and specific grinding energy in different grinding parameters are studied by means of single variable method.3)Wear test of single-layer brazed CBN grinding wheel is carried out,and the wear of the grinding wheel is characterized by the change of the surface topography and the process signal of the grinding wheel,The effects of grinding wheel wear on grinding force,grinding force ratio,ratio of grinding energy,grinding temperature,surface roughness of workpiece and the morphology of Mo are analyzed.From the viewpoint of ensuring the surface integrity of the work piece,the durability index of the grinding wheel is comprehensively obtained.