Prediction And Experimental Verification Of Surface Roughness Of The Sidewall Surface Of The Variable Section Scroll In High Speed Milling

As the core component of the scroll compressor,the scroll disk has a surface roughness that has an important impact on the compressor's operating stability,wear resistance and life.The scroll plate has evolved from an equal section profile to a variable section profile.Its working efficiency is getting higher and higher,and the requirements on the machining accuracy of the scroll plate are getting higher and higher.As an important index for evaluating the machining quality of scroll,related research on the roughness of the side wall surface of the scroll and the machining accuracy has been the research hotspot of scroll fluid machinery in recent years.This topic focuses on the research of the surface roughness of the side wall of the variable cross-section scroll,and the specific content includes the following aspects:First,based on the working principle of the variable cross-section scroll and the principle of normal equidistance generation of the scroll profile,the design of the three-section base circle involute variable cross-section scroll profile is given.Using Matlab software to generate a three-section base circle involute variable-section scroll model based on the vortex disk profile equation,and then using Creo software to establish a three-section base circle involute variable-section scroll disk three-dimensional model.Secondly,according to the milling parameters related to the orthogonal test of the three-section base circle involute variable cross-section scroll,a multiple nonlinear regression prediction model of the surface roughness of the side wall surface is established,and the surface roughness BP of the side wall surface based on the improved genetic algorithm Neural network prediction model.The advantages and disadvantages of the two prediction models are compared and analyzed,and verified by using processing experiment data.Combining the advantages of the two models,the prediction average of the two models is used as the final prediction result,and a double prediction model of the wall surface roughness is established.The double-prediction model of the sidewall surface roughness is used to predict and analyze the single-factor response,and the mapping relationship between the milling parameters and the sidewall surface roughness is obtained.Then,based on the genetic algorithm,the milling parameters were optimized,and the maximum processing efficiency was established as the optimization target function,with the tool speed,cutting depth,side cutting amount and feed amount as variables,according to the actual processing conditions and processing quality The requirements determine the corresponding constraints,and use the genetic algorithm toolbox GAOT in Matlab to optimize the milling parameters.Based on the GUI platform in Matlab software,a milling parameter optimization system was developed,which provided a theoretical basis for the optimization of milling parameters in actual machining.Finally,based on the uniqueness of the three-section base circle involute variable cross-section scroll,an appropriate machining method was selected on the basis of the existing experimental conditions,a machining process was developed,and the optimized milling parameters(a_p=0.5mm,f_z=0.2mm,n=3000rmp,V=125m/min),the milling experiment of the three-section base circle involute variable cross-section scroll was carried out.At the same time,the three-dimensional surface microscopic morphology and roughness of the side wall of the scroll were measured,and the average surface roughness valueS_a was 0.575,and the average valueS_q was 0.578,which was basically consistent with the optimized surface roughness value of 0.575,and the optimized milling was verified.The correctness and applicability of the parameters.