Study On The Factors Affecting The Harvesting Rate Of Cotton Pickers

China is the country with the largest cotton yield in the world,with a total national cotton output of 6.096 million tons in 2018.Xinjiang is one of the main cotton producing areas in China,and its cotton quality is excellent.In recent years,Xinjiang has more and more cotton pickers.According to statistics,the total number in 2018 has exceeded 3600.There are still some deficiencies in the actual production of cotton picker,improving the harvesting rate of cotton picker has become an urgent technical problem,which is of great significance to the development of cotton industry.In this paper,the data of cotton plant traits was collected through field trials to establish a three-dimensional model of cotton plants.The COMSOL software was used to simulate the cotton plant compression process,the distribution of cotton peach before and after cotton plant compression was calculated,and the harvesting rate was calculated based on the distribution rule of cotton picker spindle,the effect of cotton plant traits on the cotton picker picking effect was studied.The basic parameters of the picking room structure were changed to simulate the experiment,and the influence of the picking room structure of the cotton picker on the picking rate was studied.The finite element analysis of the key parts of the cotton picker is carried out to study its mechanical properties,which provides a reference for the strengthening treatment of the key parts and guarantees the reliability of the cotton picker’s operation.(1)It is found that cotton maturity has a direct effect on the harvesting rate of cotton picker,semi-opened cotton and over-opened cotton are easy to form legacy cotton and cotton fell to the ground.It was found that the separating force between cotton bolls and cotton hulls after picking by cotton picker was greater than that before picking.(2)Through the simulation test of the compression process of cotton plant,it is found that the harvesting rate of cotton picker is different with different characters of cotton plant.When the height of cotton plant is in the range of 70~80 cm,the net harvesting rate is 92.78%,when the average length of cotton branches is in the range of 130~135 mm,the net harvesting rate is 93.88%,when the angle between cotton branches and main stem is in the range of 50~55,the net harvesting rate is 93.88%.Choosing cotton varieties suitable for mechanical picking is conducive to improving the harvesting rate of the cotton picker.(3)By changing the picking structure parameters of the cotton picker,it is found that the distance of the spindle distribution,the width and height of the picking room have a significant effect on the harvesting rate of the cotton picker.When the width of the picking room is 90 mm,the height of the picking room is 90 cm,and the spacing of the spindles is 45 mm,the picking effect of the cotton picker is best.(4)Through the finite element analysis of the key parts of the cotton picker,it is found that the stress concentration of the edge and the vertex of the spindle hook tooth tip is relatively high,which reveals the failure process of the spindle from the tooth edge to the whole surface of the hook tooth,the wear of the hook teeth causes the mechanical property of the spindle to decline.When the notch of elastic pin is installed in the horizontal direction,the surface stress is evenly distributed,which is beneficial to extending its fatigue life and improving the working stability of the cotton picker.