Design Of The Spider-transfer Drum System And Stability Analysis Of Cigarette Transfer

PROTOS2-2 ultra-high speed cigarette-making machine is the focusing introducing models of China Tobacco Machinery Equipment Group.The machine is high-speed,high-reliable and high-qualified,which significantly improves the cigarette quality and efficiency,and reduces the consumption of raw and auxiliary materials.The research object of this thesis is spider-transfer drum system which is the core component of the machine by creating systematic geometric models and calculation modes,the indicators of stability evaluation are presented through kinematic simulation.Then,the thesis studies the design method and the clearance kinematic characteristics of Fourier cam mechanism.The main contents are as follows:(1)The working principle of spider-transfer drum was analyzed,and its geometric modeling was established.How to determine the main parameters of spider mechanism and transfer drum mechanism were analyzed on the basis of the operating principles of cigarette transfer system.By analyzing the cigarette transferring instantaneous velocity of spider mechanism and the experimental results of high speed photography,how the production rates affect the cut tobacco drop when the spider grabs cigarette could be concluded.The relatively accurate calculation modes are obtained based on the determination methods of the main parameters of transfer drum mechanism.(2)The kinematics analysis and transfer performance evaluation of spider-transfer drum system were carried out.After creating the kinematics calculation models of cigarette transfer system,analytic methods were applied respectively to the researches of spider mechanism and transfer drum mechanism to verify the accuracy of the numerical model and the reliability of the calculation results.The results of kinematics calculation presented the relative displacement and velocity between the insider/outside rod passage centers of the suction carriers on the spider and the rod passage centers of active/fixed hands on transfer drum.According to the above analyses,the stability evaluation indicators of cigarette transfer are the relative displacement and velocity of the rod passage centers in two pairs of cigarette transfer spider.(3)The design method of Fourier cams of transfer drum mechanism was studied.As the core component by which the transfer drums mechanism controls the stability of cigarette-transfer,Fourier cams are studied,together with its design methods.When taking limited Fourier series,the transfer function of Fourier cams approximates the motion rule of cam mechanism,which can avoid the driving link resonance of cam mechanism.Aiming at calculating the random error between the ideal motion and the Fourier series motion function in far/near rest area,the Fourier series motion function can be presented through minimizing gauss square difference.By altering the maximum acceleration of motion function,this thesis analyzes the changing relationship between the maximum deviation and maximum acceleration of Fourier series motion function in far/near rest area.On account of the design method of Fourier cams mentioned above,the designing of main cam contour curve in transfer drum is processed.(4)Considering the Fourier cam slot of transfer drum,the kinematics analysis of cigarette transfer system was carried out.Based on the continuous contact model with slot,the mechanism kinematic pair slot can be described by non-quality rod.Taking the spider-transfer drum system as research object,the kinematics calculation model considering cam pair slot of transfer drum is built and kinematics simulation is processed,which studies the effects which slot has on the stability of cigarette transfer system.