High-speed Rotary Cutting Mechanism And Clearance Control Method For Double-length Cigarette

With the increasing variety and demand of cigarette,tobacco machinery has been continuously optimized in the direction of equipment flexibility,production automation,and electromechanical integration.In this paper,based on the cigarette cutting system of ultra-highspeed cigarette-making machine,through the working principle and motion analysis,the mechanism of high-speed rotary cutting of double-length cigarette is studied.In order to ensure the cutting quality of the cigarette end face,based on genetic algorithm,a cigarette cutting constant velocity model was established to obtain the structural parameters and cutting error analysis of cigarettes of different lengths.The interference avoidance method of the ledger and the cutter and the optimization of the ledger clearance value are proposed to further improve the cutting quality of cigarettes and the stability of the system operation.Dased on the dynamic model of the cigarette cutting system with clearances,the effect of the ledger mechanism and cutter mechanism with clearances on the system was studied.The main research contents include:(1)Cutting mechanism of cigarette cutting system is anaylzed.Based on the working principle and motion analysis of the ledger mechanism and cutter mechanism of the cigarette cutting system,the mathematical relationship between the structural parameters is determined.Through the dynamic model of cigarette cutting system,the interference between the ledger and the cutter was studied.(2)Constant speed model is established and error of cigarette cutting system is analyzed.Defining the angle of the cutter device and the rotating diameter of the ledger devices as the variaties,and the equal horizontal velocity of the cigarette bar,the ledger and the cutter along the axis of the cigarette bar is the optimization goal,and a genetic algorithm is used to establish a constant speed model of cigarette cutting.Based on the cigarette cutting constant velocity model,the optimal structural parameters are obtained,and the cigarette cutting errors at different cigarette speeds are analyzed.(3)The clearance value of the ledger is optimized.Taking the production of cigarettes with a length of 118 mm as the goal,a numerical calculation model of cigarette cutting devices is established based on MATLAB,and dynamic interference analysis is performed on the entire cutting process.Through three different ledger adjustment schemes and modification of the cutter shape,the clearance value of the ledger is optimized and the quality of cigarette cutting is improved.(4)Analysis of the dynamic characteristics of the cigarette cutting system with clearances.Based on the two-state model,the continuous contact force method is used to establish a dynamic model of the cigarette cutting system with clearances.Through simulation calculations,the influence of the clearance value and the number of clearances of different kinematic joints on the cigarette cutting system is studied,and a method to solve the unstable cutting motion caused by clearance of the rotating joint is proposed.The technical problem of interference between the ledger and the cutter is solved theoretically by optimizing the structural parameters and working parameters,which makes the cutting performance stable and provides theoretical guidance for improving the quality of cigarette cutting.Therefore,the research has certain reference value for the independent development of intelligent cigarette-making machines.