| No.13 coupler currently occupies a large proportion in the use of couplers for freight trains.As mechanical components,failures of couplers occur from time to time,which seriously affects the normal transportation of railways and causes large economic losses,so their maintenance work is particularly important.However,in order to ensure that the inspection and repair work of the coupler is carried out smoothly,the shot blasting cleaning work before the inspection is essential,it can effectively ensure the surface quality of the coupler,and is convenient for subsequent flaw detection and painting.Shot blasting has been widely used in engineering applications such as surface cleaning,surface strengthening,and material forming.Surface cleaning is an important application direction since the invention of the shot blasting process,occupies an indispensable important position in the surface cleaning method and is widely used in the derusting and decontamination of metal components such as pipes,bridges,ships,welds,etc,and ensure that the parts meet sufficient surface quality requirements such as cleanliness,roughness,etc,so this method is mostly used for surface cleaning before coupler overhaul.In the actual shot peening process,the shot peening parameters are generally selected according to factors such as the material of the workpiece,the degree of contamination,roughness requirements,etc,so that the workpiece can obtain a suitable surface quality.Moreover,factors such as shot peening efficiency and energy utilization rate should be considered to meet the actual production requirements.The process parameters of shot peening are generally: nozzle type,projectile material,projectile size,air source pressure,nozzle-target distance,nozzle-target relative moving speed,etc.The cleaning and strengthening of the surface mainly rely on the projectile impacting the target.Therefore,the impact position and distribution of particles on the target will directly affect the shot peening results,so ensuring excellent particle distribution quality is an important way to optimize the shot peening process.In the existing research on peening,the functional research on peening mainly revolves around the results and principles of particle impact,and the common research focuses on the selection of parameters such as nozzle type,nozzle size,particle velocity,etc.Find rules and make optimizations in their respective fields of analysis.Most of the studies also only analyze the state of the shot peening process at a certain stage,such as the acceleration of the particles by the nozzle,the impact of the particles on the target,and the mechanism of target strengthening.There are few studies on particle distribution and global analysis.Therefore,in order to study the particle distribution characteristics during shot peening,a method combining Fluent and Matlab is proposed to analyze the particle distribution results and laws of the nozzle during continuous motion,to optimize the problems in practical application to improve the shot peening efficiency and shot peening quality.The main research contents of this paper are as follows:1)The CFD simulation of the fixed-point spraying process was performed to obtain the particle distribution under different nozzles,and study the influence of the inlet pressure,target distance and spraying angle on the particle distribution.2)Superimposed calculation of fixed-point spraying results to obtain a simulation model of continuous translational spraying,comparing the particle distribution characteristics of nozzles at constant speed and variable speed translation.And using the mathematical model of continuous spraying to verify.Further analyze the effect of different path spacing on the distribution of particles between paths.3)On the basis of the simulation model of translational spraying,the API interface technology of Solidworks and the interpolation method of Matlab are added,which is applied to the simulation of the rotating spraying of any complex curved surface target.Taking a square cylinder as an example,and the effect of rotation speed on particle distribution are analyzed.A variable speed rotating shot peening method was proposed to improve the particle distribution quality.4)The full spraying process of coupler 13 was calculated using the rotary spraying model.The nozzle sprayed in a spiral downward manner relative to the coupler.The results of particle distribution during uniform rotation were calculated and analyzed.And using the laws of rotation speed and particle distribution,a variable speed rotating spraying method was proposed to optimize the cleaning process of the rotary spraying of No.13 coupler,to improve the efficiency and quality of coupler shot peening,and give a set of optimized shot speeds according to the actual shot peening process and coupler cleaning requirements. |
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