| Because of its unique mobility and convenience,notebook computer is more and more favored by consumers.As the display part of notebook computer,the quality of screen will directly determine the quality of notebook computer.At present,the assembly of laptop screen still relies on manual way,which leads to low production efficiency and uneven product quality in mass production.In this paper,through the analysis of the screen assembly process,the overall design scheme of automatic assembly is determined.The screen automatic assembly line is divided into six stations:loading station,pre-cleaning station,dust detection station,assembly station and blanking station,and the key problems such as dust control,accurate alignment and accurate leveling in the assembly process are studied.The main research work is as follows:In order to solve the problem of bad product caused by poor effect of the existing blowing dust removal device,a clean dust control technology for assembly process based on computational fluid dynamics(CFD)analysis is proposed.The flow field inside the machine is analyzed by ANSYS FLUENT software,and the air blowing type dust removal and the air extraction type dust removal are compared.Based on this analysis,the dust removal effect of single air outlet,2 air outlets,3 air outlets and 4 air outlets are analyzed.In addition,based on the 4 air-outlets extraction dust removal,the flow rate is simulated from 250m~3/h to350m~3/h and 450m~3/h respectively.Aiming at the problems of resonance and alignment accuracy of alignment structure,a alignment method based on structural modal optimization and random sample consensus(RANSAC)is proposed.In order to solve the problem that the screen deviates and affects the quality of alignment assembly due to the mechanical vibration in the alignment process,the modal analysis method is proposed to analyze the structure and optimize it according to the analysis results.Aiming at the problem that alignment accuracy affects assembly quality,a line fitting algorithm of edge image based on RANSAC algorithm is proposed.In order to solve the problem of low assembly accuracy caused by various errors in the assembly process,a moving average correction method with function fitting correction is proposed based on the difference between the final assembly accuracy and alignment accuracy.In view of the problem of uneven pressure and long time of pressure stability,a method based on the optimization of the compression structure and the closed-loop control of pressure is proposed.Aiming at the problem of uneven pressing and long pressure stabilization time,a method based on pressing structure optimization and pressure closed-loop control is proposed.Aiming at the problems of uneven pressing and faults in the pressing system,the finite element analysis method of the pressing head of the pressing system based on ANSYS is proposed,and its structure is optimized and improved.In order to solve the problems of long pressure stabilization time and low pressure control accuracy,a closed-loop input shaping control method based on Smith predictor is proposed and compared with the traditional three loop pressure control method.Finally,the screen assembly automation production line is trial produced and debugged,and the working performance of the equipment is tested through the operation effect of the equipment.The results show that the dust removal rate,assembly accuracy and pressing effect of the equipment meet the technical requirements. |
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