| Because of its excellent corrosion resistance,wear resistance and high strength,stainless steel pipe is widely used in various fields of production and life at present.But since entering the new century,with the rapid development of sophisticated industries,medical and health,aerospace,nuclear energy and shipping and other fields of the stainless steel tube used in the quality of the surface of the continuous improvement,and long stainless steel tube due to the particularity of its structure,resulting in the inner surface is difficult to achieve finishing processing.Therefore,it is of great significance to explore efficient and clean finishing technology of stainless steel tube inner surface.Magnetic honing is a new surface finishing technology driven by magnetic force.Previous studies have shown that the magnetic honing system can finish the inner surface of stainless steel pipes with high efficiency and quality,and can effectively reduce the roughness of the inner surface and improve the quality of the inner surface.However,at the same time,the honing system has the problem of high temperature rise during long time processing,which greatly limits the promotion and application of this technology.In this paper,two methods of input optimization and magnetic circuit optimization to reduce internal heat generation are proposed to solve the problem that the temperature rise of magnetic honing system is large and continuous processing is difficult.The system loss analysis,three-dimensional global temperature field calculation,input optimization analysis,magnetic circuit optimization analysis are mainly studied.Finally,the accuracy of the method and the results are verified through the system temperature rise machining experiment.This paper aims to achieve sustainable processing of honing system by reducing internal heat generation.The specific content is as follows:(1)Firstly,the heating reason of electromagnetic magnetic honing system is analyzed.Based on the motor loss calculation theory and electromagnetic field finite element analysis theory,the winding copper loss,iron core loss and friction loss of the system are analyzed and calculated.This part provides data support for temperature field analysis.(2)the second according to the structure characteristics of honing system,external cooling characteristics,based on the analysis theory and fluid mechanics theory,the motor temperature field in the Fluent software to build the system 3 d whole field finite element model,on the basis of assumptions on line winding more shares simplified processing,for core uneven teeth and yoke of loss made targeted treatment.According to the calculation results of temperature field,the distribution trend of temperature rise in each part of the system and its causes are analyzed in detail.(3)Then,the finite element calculation software Ansoft Maxwell was used to analyze the electromagnetic field of the honing system.Starting from avoiding the reduction of input of "big horse and small car",torque adaptation was taken as the standard and programmable V/F control was taken as the implementation means to optimize the starting and steady input respectively.Through the parameterization function of Maxwell software,the starting excitation parameters were calculated and selected in the case of considering mechanical effects,and the steady-state excitation parameters were calculated and selected without considering mechanical effects.(4)Finally,the magnetic circuit was optimized.Compared with the mature permanent magnet synchronous motor,the magnetic circuit of the magnetic honing system is not perfect enough and the magnetic leakage is relatively serious.The overall power factor of the system is low,the dissipation is relatively large,and the heating is serious.To solve this problem,the radial position,width and shape of permanent magnet and the size of magnetic pole boots were taken as structural variables to optimize the magnetic circuit.Based on Maxwell's parameterization function,the influence of each structural variable on the system loss was studied.Based on this criterion,the magnetic circuit was optimized to improve the power factor of honing system,so as to guide the design of a new generation of rotor grinding tools.(5)The temperature field calculation results,the cooling effect of input optimization and the processing effect of the system after input optimization were tested respectively through the system temperature rise processing experiment.The results show that: 1)The temperature field calculation method is reasonable.After the initial temperature compensation,the maximum error is 5% and the average error is 3.8%.The calculated temperature data and temperature rise distribution trend are more accurate.2)The input optimization effect is obvious,which effectively improves the phenomenon of big horse and small car in the system.After input optimization,the maximum temperature rise of the system winding is reduced from 89.3? to 67.7?,with a reduction degree of 24%.Input optimization can greatly reduce the system heating and ensure the sustainability of processing.3)After the optimization excitation is added to the system,the finishing effect has little change,and the deviation of the finishing effect is less than 5% outside some points,indicating that the optimization of excitation can still guarantee the processing effect of the system. |
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