Rigid-flexible Coupling Characteristic Analysis And Optimization Design Of Sand Fruit Picking Machine-sand Fruit Tree

As a unique fruit in northern China,in recent years,with the support of the local government,the planting area of sand fruit has gradually expanded.However,at present,in the northern part of China,picking is mainly carried out by manual picking.This picking method has a large workload,low efficiency and high cost,which has a great impact on the picking of sand fruit and sand fruit products,and seriously restricts the development of the industrial chain.This paper takes the sand fruit trees in Xing ’an League of Inner Mongolia as the research object,aiming to design a trunk vibration picking machine for picking sand fruit,so as to improve the efficiency of sand fruit picking operation of local fruit farmers,so as to solve the problems of long time and low efficiency of manual picking.Firstly,the physical characteristics of sand fruit trees are studied and analyzed,and the natural frequency and optimal excitation frequency of sand fruit trees are obtained,which provides a theoretical basis for the design of sand fruit picking machine.Combined with field investigation,the physical parameters of sand fruit trees were measured and the three-dimensional model was drawn.The Ansys Workbench simulation software was used to analyze the modal analysis and harmonic response on the three-dimensional model to obtain the 1-10-order natural frequency and the optimal excitation frequency of12.7 Hz.Secondly,this paper designs a trunk vibration sand fruit picking machine.The picking machine includes excitation device,clamping device and driving device.Through calculation,the size of eccentric block and eccentric block support shaft is determined,and the modal analysis and stress analysis of eccentric block and eccentric block support shaft in excitation device are carried out,so as to further optimize,verify that its natural frequency is much larger than the normal working frequency,and ensure the normal operation of the picking machine.Finally,the rigid-flexible coupling analysis of the rigid-flexible coupling model of ’ vibrating sand fruit picking machine-sand fruit tree ’was carried out by using Adams simulation software,and the acceleration response curves of the branch points of sand fruit tree under different excitation frequencies were obtained,which proved the effectiveness of the vibrating sand fruit picking machine.Further field tests were carried out on the vibrating sand fruit picking machine.The acceleration sensor was bundled at the side branch point of the sand fruit tree.The picking test recorded the acceleration of the side branch point at the excitation frequency of 9.7 Hz,12.7 Hz,15.7 Hz,and 18.7 Hz.The results show that the lateral acceleration increases with the increase of the excitation frequency.When the optimal excitation frequency is 12.7 Hz,the lateral acceleration decreases with the increase of the excitation frequency.Therefore,picking at a vibration frequency of 12.7 Hz can effectively improve the picking efficiency of local fruit farmers.