Analysis And Study On The Precision Of Spray Code System Of The Jet Code And Quality Inspection Machine

With the diversification of the packaging of medicine,foodstuffs,tobacco,alcohol and so on,more and more counterfeit and shoddy products appeared,and the quality of the two-dimension code is getting higher and higher required by some manufacturers such as medicines and cigarette products.Although the discrimination of codes has been met requirements,but the accuracy of the code location is still difficult to control.In order to make naked eyes can't distinguish the deviation of the position of Jetting code,many manufacturers require the error of the jet code to be within 0.1mm.However,due to the influence of belt vibration of existing coding platform,side positioning precision and die cutting error ect,the accuracy of the existing coding platform can only reach about 0.3 mm,which can't meet the requirements of such high precision.Harbin Kirin and other companies in domestic on the Jet code and quality inspection machine has been quite mature,the domestic inspection machine almost needn't to import,but there is still a gap with some foreign companies,HP and Bobst ect.Therefore,it is imperative to further improve the coding precision of the current Jet code and quality inspection machines.In order to improve the coding accuracy of the Jet code and quality inspection machine,some equipment manufacturers proposed using the printing machine cylinder feeding mode to replace the existing conveyor belt,this program was not implemented because of high costs and various reasons.In this paper,based on the analysis of offset and skew of substrate in the process of coding and the research of the existing high-precision positioning devices,it put forward a method that through precise positioning of the nozzle and real-time adjustment to improve the existing coding and inspection machine,and made a prototype.In this paper,firstly,puts forward the eccentric sleeve type high precision positioning device and direct-drive high-precision positioning device based on the analysis of offset and skew of substrate in the process of coding;Then the principles of the two schemes are analyzed,three-dimensional modeling and compare two schemes to determine the latter as the final solution;Finite element analysis software is used to analyze the stress and modal analysis of the key components of the device and to optimize the individual components;using hertzian contact theory to establish the stiffness model of the linear guide pair of the device.The whole dynamic model is established by Newton-Euler method and the natural frequency of the device was calculated,which provides the theoretical basis for the simulation analysis.On the basis of 3D models,the parts were processed and assembled,the models of electrical components were selected,and the experimental prototype of direct drive high-precision positioning device was made,and the motion simulation of the device was carried out.Finally,the prototype is preliminarily debugged,and the results show that the prototype meets the requirements.The innovations in this paper: 1.The application of adjusting the nozzle to improve the coding precision of the code inspection machine;2.Adopt the close-loop system consisting of the linear motor,the torque motor and the magnetic scale to carry on the high-precision positioning of the nozzle.