Design And Experiment Of Cleaning And Conveying Device Of Sugar Beet Combined Harvester

The current domestic sugar beet harvest method generally adopts artificial or segmenting harvest,labor intensity,occupation of agricultural time,low production efficiency and poor quality of sugar beet harvest are increasingly prominent,seriously hindering the development of China’s sugar beet industry.On the basis of adapting to the harvesting mode of planting area and meeting the requirements of agronomy,this thesis designed a cleaning and conveying device of sugar beet combined harvester.It can complete the operation requirements of beet soil cleaning,impurity removal,ridge collection and transportation,and realize the purpose of reducing the impurity rate and damage rate of beet.Its main contents include:(1)The growth and physical characteristics of beet root tuber in the planting area were studied.The beet triaxial size distribution range was determined by measuring the beet size characteristics.The single factor test analysis of beet collision recovery coefficient was carried out by using the measurement method of recovery coefficient.The recovery coefficient of beet collision with different contact materials was obtained through the test,and the regression analysis of the test data was carried out to clarify the variation law of beet collision recovery coefficient under different collision conditions.The beet root friction coefficient was measured and analyzed by beet sliding method,and the influence law of different contact materials on the friction characteristics of beet was clarified,which provided important reference for the design of beet harvesting machinery and the analysis of beet motion characteristics.(2)The design scheme of the cleaning and conveying device of the sugar beet harvester was proposed.It was composed of three-stage cleaning and conveying devices:transfer wheel-auger roller device,rod-type chain screen device,and rubber tail screen device.The working principle of the whole machine and the technical characteristics of separation and cleaning were described;the hydraulic system was controlled for this device.Carry out functional design and analysis and calculation to determine the selection of the main hydraulic components of the device.(3)The structural parameters and operation parameters of the key components of the separation conveyor were determined.Through theoretical analysis and calculation,the structural dimensions of key components were determined.Firstly,the kinematic analysis of the soil block in the process of moving was carried out,and the main factors affecting the fragmentation and separation of the soil block were clarified.Secondly,kinematics and collision mechanics analysis of sugar beet in the falling process were carried out to obtain the main factors affecting the harvest quality of sugar beet.(4)A field test was carried out on the prototype of the sugar beet harvester.The single factor test was carried out with the rotation speed of the transfer wheel,the linear speed of the rod-type chain screen,and the inclination angle of the rubber tail screen as the test factors,and the beet impurity rate and the sugar beet damage rate were used as the test indicators.The influence law of each factor on the test index was clarified,and the value range of each factor was determined.On the basis of single factor,the quadratic regression orthogonal rotation combination test method is used to carry out multi-factor test.The Design-Expert8.0.6 software was used to analyze the variance of the test results,and the primary and secondary order of the factors affecting each test index was clarified.Through the response surface,the influence rule of each test factor interaction on the test index can be analyzed intuitively.(5)Using the optimization module of Design-Expert8.0.6 software,the optimal parameter combination of each factor is obtained: the rotation speed of the transfer wheel is 100.95r/min,the linear speed of the rod-type chain screen is 1.36m/s,and the inclination angle of the rubber tail screen is 39.31°.Under the optimal combination conditions,the impurity content of sugar beet was 3.50%,and the damage rate of sugar beet was 2.57%.The verification test was carried out on the optimal parameter combination.The test results showed that the impurity rate of sugar beet was 3.40%,and the damage rate of sugar beet was 2.60%,which could meet the requirements of cleaning and conveying operation of sugar beet harvester and meet relevant national standards.