| The sweet-potato-stalk separator is a key component of the sweet potato combine harvester,which affects the work efficiency and work quality of the whole machine.In this paper,a grooved roller pressing type the sweet-potato-stalk separator suitable for single-row,stalk-killed sweet potato field is designed,and the optimization research on the operation work parameters of the sweet-potato-stalk separator is carried out.The research content is as follows:1.Study the planting mode and physical characteristics of sweet potato,and calculate the relevant ridge size,sweet potato tuber depth size,and stalk diameter size,and determine the reference basis for the design of subsequent key components.Carrying out a sweet-potatostalk separation test study during the sweet potato harvest period,and prove the relationship between the moisture content of the sweet potato stalk and the separation force of the sweetpotato-stalk presents a quadratic function,and from a new perspective that the optimal sweet potato is determined to be 4-8 days later than the empirical harvest period.The analysis of the mechanized harvesting process of sweet potato clarifies the excavation and sweet-potatostalk separation is one of the key processes,and the quality of the work requires separation.The overall design of the sweet-potato-stalk separator and the basic components is the digging and conveying assembly,picking roll assembly,and elastic curved bar assembly.2.The key components of the whole machine are studied,the operation principle of the whole machine and the sweet-potato-stalk separator is analyzed.The mechanical analysis of the two states of the sweet potato mixture in the excavation and conveying assembly,and the length of the sweet-potato-stalk separator is determined to be 1856 mm,measured by the width of the ridge bottom determines the width of the separator to be 566 mm.According to the speed of the main drive shaft and the transmission ratio with the picking roll shaft,the gear radius of the picking roll shaft is determined to be 41.8mm.The distance between the picking roll shaft and the lower layer of the conveyor bar is determined through field tests the parameter is 2mm,and the folding angle parameter of the lower guard plate component is 155°.The kinematic analysis of the sweet potato mixture is carried out to determine the main parameters that affect the working quality of the sweet-potato-stalk separator are the main drive shaft speed and the horizontal inclination of the conveyor,and the key moving parts the modal analysis and static analysis were carried out on the picking roll shaft to determine the natural frequency and stress concentration position of each mode of the picking roll shaft.3.Through theoretical analysis and experimental research to determine the main quality parameters that affect the working quality of the sweet-potato-stalk separator: the main machine has the moving speed,the horizontal inclination of the conveyor,and the main drive shaft speed.The evaluation indicators are sweet potato extraction rate and sweet potato damage rate.The factor test determined the functional relationship between the three main influencing factors of the moving speed of machine,the speed of the main drive shaft and the horizontal inclination of the conveyor and the quality parameters of the operation,and determined that the three factors have a significant impact on the two test indicators.Using BOX-BENHNKEN the central combination test method carried out a multi-factor orthogonal test,established a response surface model and optimized it.The test results showed that the moving speed of machine was 0.7m/s,the angle of between delivery device and horizontal was 24°,and the rotation speed of driving shaft was 127r/min.The sweet potato extraction rate was 98.14% and the damage rate was 2.76%.The test results met the quality requirements of sweet potato harvesting operations. |
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