Research On The Single-plant Thresher With Differential Speed And Flexible Belt For Soybean

In the work of breeding and scientific research what the work is cumbersome and the operation intensity is high,it is necessary to carry out threshing work on soybeans.Mechanized operation is necessary for improving breeding efficiency and reducing artificial labor.Due to the large number of varieties of soybean seeds for breeding,small sample size,and precious varieties,it is required to avoid the mixing of different seeds in the process of harvesting and threshing in residential plots.At present,most of the existing soybean threshers are drum-type threshing methods.The key threshing components are rigid materials such as threshing rollers and concave plates,which are liable to cause crushing and mechanical damage to soybean seeds.Due to the rare and rare varieties of soybean seeds for breeding,mechanical damage will affect the germination and emergence of soybean seeds.At present,the domestic soybean single plant threshing mainly includes artificial threshing and ordinary thresher.Artificial threshing methods are inefficient,occupying a large amount of labor,delaying agricultural time,and determining the impact of breeding indicators.Ordinary threshing machines generally use rigid threshing rollers,which cause mechanical damage to soybean seeds,high grain breakage,large entrainment losses,and difficulty in cleaning the inside of the machine,which can easily cause mixed seeds of different varieties.At present,the development of domestic soybean single-plant threshing machinery is relatively backward,so it is of practical significance and development prospects to satisfy the soybean detachment machinery that is convenient for cleaning and avoiding the mechanical damage of seeds.This article first systematically introduced the research status and characteristics of breeding and harvesting machinery at home and abroad,and analyzed the advantages and disadvantages of existing domestic and international threshing machinery.In view of the current research status,main problems and development direction of single-plant threshing machinery in China,taking into account the agronomic requirements for the threshing of soybean single-plant,a differential flexible belt type soybean threshing device was designed.Avoiding the dark injury caused by the traditional rigid contact method on the grain,and designing a cleaning device accordingly to carry out the wind selection on the threshed soybean grain after threshing.Eventually,seeds with high cleanliness,low degree of dark wounds,and soybean breeding conditions would be obtained.The main research contents and results are as follows:(1)Traditional threshing device types were classified and summarized.According to the characteristics of the breeding experiment and the technical requirements of the threshing machinery,the single-plant thresher with differential speed and flexible belt for soybean was designed that was proposed based on its design principles and indicators.Expound the principle of work,selecting the auxiliary power by calculation.In order to determine the structure and relative dimensions of the whole machine,the basic parameters and mechanical properties of the test material were studied.(2)In order to search for the best working parameters of the threshing prototype,a parameter optimization experiment of a differential flexible belt type soybean threshing device was designed was conducted.The key components such as drums,tensioned belt device,threshing fixed side panels were designed.The process of single-plant soybean threshing was divided into two stages: initial feeding and stable extraction.Theoretical analysis was conducted to determine the operating parameters of the influencing device threshing effect by formula derivation.The quadratic regression orthogonal rotation center combination test method was used to study the effects of the threshing gap,the speed difference between the upper and lower belt,the speed of the lower belt and the threshing stroke.The unsplit rate,entrainment loss rate,and average productivity as evaluation index,the structure and working parameters affecting the threshing performance of the device were optimized and studied.The orders of influence of each indicator were analyzed.Optimization results indicate: in the case of soybean grain moisture content 16%-18%,the most optimum combination region of the cylinder clearance was 7.55-13 mm,the top and low section velocity difference was 0.59-0.7 m/s,the low section velocity difference was 0.84 m/s,the threshing trip was 660 mm;under this condition,loss of unthreshed grain were less than 1.2%,loss of entrap grain were less than 0.9%,cracked grains were less than 0.8%,average productivity were more than 35 kg/h.This research provided the basis for the research and development of complete machine of single plant threshing machine with differential speed and flexible belt.(3)The proportions of soybean grain and pod were analyzed.Simulation modeling was used to investigate the effects of wind speed and airflow angle on the rate of grain loss and cleanliness in the cleaning device by using the CFD-DEM coupling method.The influence of wind speed and wind angle on the cleanliness and loss rate of kernels was obtained through simulation and simulation,which provided a reference for the optimization of subsequent cleaning devices.(4)The design adopts the technology of virtual prototyping with the Solidworks software,created the model the single-plant thresher wlth differential speed and flexible belt for soybean.It includes threshing device,cleaning device,feeding inlet,impurity removal port,transmission system,rack and so on.The force analysis and strength check of the main force parts of the prototype frame are carried out by ANSYS software.The deformation,stress and strain nephogram of the frame is obtained,and the stability of the frame is determined.