Research On Cutting Performance And Optimization Design Of Creeping Bamboo Twister

In this paper,a crawling bamboo twister is designed,the factors affecting the cutting performance of the twister blade are studied,and the key parts are simulated and lightweight optimized.The main research contents and conclusions are as follows:In order to study the factors affecting the cutting performance of the blade,a mechanical model was established for cutting bamboo branches with the blade.The relationship between the cutting performance of the blade and the sliding cutting angle and wedge angle of the blade was analyzed theoretically,and the cutting resistance coefficient K was introduced;A blade cutting performance test platform is designed and built for single factor test.Taking the cutting resistance as the index,the relationship between blade cutting performance and blade sliding angle,blade wedge angle and blade sliding speed is verified.It is obtained that the smaller the blade sliding angle and blade wedge angle,the better the blade cutting performance is;The higher the sliding cutting speed of the blade,the better the cutting performance of the blade.BP neural network and box Behnken central composite test method are used to carry out multi factor composite test,and the mathematical model of the combination relationship between blade cutting performance and blade sliding cutting angle,blade wedge angle and blade sliding cutting speed is established.By comparing the determination coefficient r^2 of the model with the prediction effect,BP neural network model can accurately predict the data set,and box Behnken central composite test method can have a high fitting effect on the original data set;It is found that the sliding cutting speed of the blade has the greatest influence on the cutting performance,followed by the wedge angle of the blade and the sliding cutting angle of the blade.Using SolidWorks software,the virtual prototype model of the crawling bamboo branching machine is established.The whole machine is composed of a clamping climbing mechanism,a branching mechanism and a frame.The layout of the pruning blade is designed,and the sliding cutting angle of the blade is determined δ=54.4°,according to the requirements of bamboo diameter(30mm-70mm),a knife rest mobile platform which can automatically adapt to different bamboo diameter is designed.The clamping form of the clamping mechanism is determined;According to the climbing demand of the whole machine,the output power required by a single drive motor is calculated to be 20W.The finite element method and the finite element analysis software ANSYS are used to conduct sliding cutting simulation tests for different blade wedge angles.Through the comparative analysis of the test results,the best blade wedge angle is selected α=18°;Through the topology optimization method,the cutting stock of the tool rest is optimized.After optimization,the quality is reduced by 32.8%and the deformation is reduced by 6%;The modal analysis and critical speed calculation of the clamping axle are carried out,and the first six modal shapes,corresponding frequencies and critical speed of the clamping axle are obtained;Comparing the stress simulation results of racks with different thicknesses,the thickness of 1.5mm is selected as the optimal rack thickness,and lightweight optimization is carried out.After optimization,the weight of the rack is reduced by 31.4%.After lightweight optimization,the weight of the movable edge of the rack is reduced by 35%.The crawler type bamboo twister studied in this paper has a height of 380mm and an overall dimension of 155mm after optimization × 210mm,the weight of the whole machine is 4.96kg,which provides a reference for realizing the mechanization and automation of bamboo pruning,and provides technical reserves for the development of bamboo mechanization.