Development And Experimental Research Of Teeth Belt Buckwheat Pickup Test Platform

Buckwheat has high food value and medicinal value.It is recognized by the FAO as an excellent food and medicine.The biological characteristics of buckwheat is special,which is inconsistent with the mature period of the grain.Meanwhile,the mature buckwheat grain is easily drop.These have brought great difficulties to the mechanized harvesting of buckwheat.Its low loss rate of mechanized harvesting technology and equipment are urgent issues to be solved.The harvest period of the two-stage mechanized harvest is longer than the combined harvest.The post-harvest process can increase buckwheat production and grain quality,so that the cleanliness of the recycled grain is high,the harvesting operation can greatly reduce the loss rate.Therefore,the two-stage harvesting is more suitable for buckwheat Mechanized harvest.However,the high pickup rate of buckwheat is still a prominent issue in its two-stage mechanical harvest.In order to reduce the loss of picking up of the two-stage mechanical picker.In this paper,the self-developed pick-up harvesting test platform was used to study the effect of the toothed belt picker on buckwheat picking loss and analyze the experimental results by response surface analysis method.The main research contents and conclusions of this paper are as follows:(1)Test the tensile force and shear force of stems in different buckwheat varieties and different parts.The experience results showed that the connection force between the buckwheat twigs and the main stalks was the largest,the stalks and branches were the second,the connection force between the grains and the stalks was the smallest.There was no significant difference in the connection force between the heads of the two buckwheat cultivars,tensile force is 20 ~ 30 N and shear force is 40 ~ 55 N.When the growth is equivalent,at the same loading speed and position,the average connecting force of XiNong 9979 that is 30% greater than that of sweet buckwheat 92-1.It showed that the stalks had high degree of lignification and the ability of shear resistance was stronger than sweet buckwheat 92-1.(2)Designing model and simulation analysis the key components of the pick-up test stand.Based on SolidWorks,the three-dimensional design of pick-and-place test benches such as tooth-belt pickers,crucible conveyor belts and racks was performed.Pre-assembly and interference check of the test bench were performed to lay the foundation for the manufacture and assembly of the test bench.Simple simulation diagram of the tooth belt picker was established by using matlab software and the motion process of the tooth belt pick-up tooth was simulated and analyzed.The simulation results showed when the conveying speed for buckwheat windrow and the rotational speed of toothed belt are all 0.8m/s,the resulting leakage area is smaller and the impact on buckwheat is smaller.So the two-stage harvest fit the low loss of buckwheat picking up harvest.(3)Testing the basic performance of the pick-up test bench.According to the requirements of the harvesting machine design standards,when the feeding amount was 2.0kg/s,the conveying performance of the buckwheat was tested on the test bench.The test results showed when the conveyor belt conveyor speed is: 0.6m/s,0.8m/s and 1.0m/s,the maximum acceleration distance of the conveyor belt is 3.57 m,the total length of the conveyor belt is 20 m to meet the test requirements.(4)The paper analyzed the main influence factors of affecting the harvest loss rate in twostage pickup that is the conveying speed for buckwheat windrow,the rotational speed of toothed belt and the inclination of toothed belt pickup,obtained the regression equation of three factors impacted loss rate of pickup.Analysis of variance showed that the regression model was significant and the simulation was insignificant,that is,the error of the rig test was small.The response surface method was used to optimize the analysis of the regression equation,the rotational speed of toothed belt affected the picking loss rate of buckwheat very much,the conveying speed for buckwheat windrow less and the inclination of toothed belt pick-up the lest.Newton iteration method is used to optimize the design parameters of the regression equation,received a set of solving pick loss rate optimal parameter combinations is: the conveying speed for buckwheat windrow of 0.8m/s,the rotational speed of toothed belt 0.82m/s,he inclination of toothed belt pick-up of 11.56°,the theoretical loss rate of 2.99%.However,taking into account the problem of parameter adjustment during the bench test or actual mechanical operation,the optimal working parameters of toothed belt pickup during the process of picking work for buckwheat were determined,which is the conveying speed for buckwheat windrow of 0.8m/s,the rotational speed of toothed belt of 0.8m/s and the inclination of toothed belt pickup of 12 °,then the picking loss rate is 3.01%,the optimal loss rate of 2.99%.