| Cotton is not only an important economic crop in China,but also a national strategic material,which has a significant impact on national economic and social development.Cotton production is a labor-intensive industry.In the cotton harvest period,due to the short time and heavy workload,there is a shortage of human resources.At the same time,with the social development,the labor cost is higher and higher,which increases the economic burden on cotton farmers.The traditional human resources harvest is more and more difficult to meet the demand of cotton production,which hinders the development of China's cotton industry.The development of mechanized cotton harvesting has become an urgent need to solve this problem.At present,China's mechanized cotton harvest rate is not high.In particular,in the Yangtze River and Yellow River cotton areas,because the cotton planting scale is scattered,it is not suitable for large-scale mechanized operation,and cotton harvest mainly depends on manpower.Therefore,the research and development of small and medium-sized cotton picker is conducive to improving the mechanized yield of cotton.On the basis of investigating the development history and current situation of cotton harvesting machinery at home and abroad,drawing lessons from the existing mature models,and according to the characteristics of cotton planting in China,this research designs and develops a telescopic tooth cotton picking device-gear picking drum,and carries out kinematic and dynamic simulation analysis,optimizes the structure,and obtains the structural parameters and movement of the picking device through the picking test The optimal combination of parameters.Main contents and conclusions:(1)The research situation of cotton picker at home and abroad is investigated,summarized,sorted and classified.The common brands and products of cotton picker at home and abroad are summarized,and the picking principle is introduced.(2)According to the research needs,the physical properties of cotton were studied.The binding force between cotton and boll shell,the connecting force between seed cotton fibers and boll characteristic parameters were tested.(3)This paper introduces the picking principle of the gear picking drum,analyzes its kinematics,calculates and derives the linear velocity equation of the gear end point,and determines its key parameters.The key components and structures are calculated and designed by SolidWorks,AutoCAD and other software.(4)In order to study the influence of the gear end speed,gear effective length,effective picking position,gear thickness and gear arrangement density on the picking rate and single seed cotton rate of the device,a test-bed was designed and manufactured,and five factors and three levels of orthogonal rotation combined test were carried out.The experimental results show that the optimal range is: linear speed 4.43-5.95m/s,effective length of gear 6.43-8.48 mm,effective picking position-31.37-44.79 °,gear thickness 0.8-1.12 mm,gear arrangement density 7.08-9.91.The results are as follows: the linear speed is 4.8m/s,the effective length of the gear is 8mm,the effective picking position is-31.37 ~-44.79 °,the thickness of the gear is 1mm,and the error of each evaluation index is within 10% when the density of the gear is 8,which shows that the optimization result is credible and the research model is reliable.(5)The field experiment of the self-propelled air suction cotton picker was carried out,and the picking effect before and after the optimization of the gear picking drum was compared.Some problems in the design of the whole machine were found in the experiment,and the further research direction was clarified. |
PDF Full Text Request