Design And Experiment Of Flexible Disk Planting Device

As an important planting method,vegetable seedling transplanting can increase the accumulated temperature of crops,reduce frozen seedlings,increase the seedling growth rate,and increase the yield of vegetables per mu.At present,most of the transplanting machines in my country are mainly semi-automatic models with low planting efficiency,which cannot cope with the increasingly shortage of labor.This paper refers to the research status of transplanting machines at home and abroad,combined with physical characteristics research,theoretical analysis,motion simulation and other methods,designed a set of flexible disk planting device that can be used for high-speed transplanting,and conducted experimental research.The details are as follows:1.After checking the domestic and foreign models,combined with the vegetable transplanting process,the overall plan for longitudinal clamping conveying and flexible disk clamping planting was determined.2.Select the broccoli,cauliflower and chili pot seedlings for leaf expansion,pot seedling height,stem diameter and other parameters to provide a reference for the design of the planting disk size.Using the texture analyzer,the flexible compression test of the bowl was performed to determine the distance between the hard rubber layers of the longitudinal clamping conveyor belt.When the distance between the splints was 20mm,the average loss rates of broccoli,cauliflower,and chili pot matrix were 6.13%,6.39%and 11.82%respectively,has little effect on the growth of pot seedlings after planting.When using the texture analyzer to conduct the stalk compression characteristic test,the yield strength of the U section of broccoli,cauliflower and chili pot seedlings was 0.933MPa,0.931 MPa,0.928MPa,which provided a basis for the design of the structural parameters of the planter.3.According to the working principle of the planting device,the motion analysis is carried out,and the static trajectory of the pot seedling is approximated as an arc,and the calculation formula of the polymerization angle is deduced.A flexible disk planting test stand with adjustable structure and motion parameters of the planter was built.Using high-speed photography technology,the static trajectory model of pot seedlings and the calculation formula of the aggregation angle were verified and tested.Under the combination,the actual trajectory points and the theoretical trajectory arc have a high degree of fit,and the fitting correlation coefficients R2 are 0.954,0.981,and 0.988;the theoretical polymerization angle is close to the actual average polymerization angle,and the errors are 2.28%,4.11%and 2.62%respectively.Through the mechanical analysis of the seedlings in the clamping process,the formula for calculating the clamping force is obtained.When a is selected to be 10?20°,combined with the stalk compression characteristic data,it is estimated that in order to avoid the stalk clamping damage,the value range of L is 34.8?59.7mm.4.Using Adams to simulate the movement of pot seedlings in the planter,the effect of motion parameters on the speed of pot seedlings is obtained,which provides a reference for the experimental analysis;the forward speed of the unit,the rotation angular velocity of the planting disk,and the polymerization angle are selected for planting.The single-factor test of the state shows that each factor has an effect on the upright qualification rate;the unit's forward speed 3 levels,the planting disk rotation angular speed 5 levels,and the polymerization angle 3 levels are selected for the orthogonal test of the planting state,and the effect is obtained.The primary and secondary factors of the planting uprightness qualification rate are as follow:unit forward speed>planting disk rotation angular speed>aggregation angle;while using defoliated pot seedling in the experiment of the effect of planting walking speed ratio ? on planting inclination,compared with virtual analysis,it is found that both when there are different forward speeds of the units,the smaller the ?,the more obvious the trend of the forward tilting of the seedlings,and conversely,the more obvious the trend of the backward tilting;?=1 in the results of the virtual analysis is the "watershed" of the forward and backward tilting of the seedlings.In the actual test results,this rule is not very obvious,but when the ?=1 is nearby,a high pass rate of planting uprightness is obtained.5.Through analysis of the performance test results,suggestions for the selection of motion parameters during field planting operations are given:the forward speed of the unit should be controlled below 1.5km/h as far as possible,and the system planting stability is higher within this speed range.When planting small and medium plant distances(?25cm),we can choose a higher planting frequency(100?120 plants/line)for operation.At this time,the corresponding unit forward speed is lower;When transplanting long plant distances(>30cm),we should reduce the planting frequency and slow down the advancing speed to ensure a higher rate of planting uprightness;,meanwhile the rotation angular speed of the planting disc should be adjusted to the state of ?=1 as much as possible.