Stalk cutting mechanism of no-tillage planter for wide/narrow row farming mode

A no-tillage planter of narrow row spacing was designed according to the agronomic requirements of wide/narrow row farming mode in the black soil region of Northeast China.Due to the narrow spacing of the seeder unit,a gear-tooth stalk cutting mechanism was designed in order to prevent residues from blocking the planter.The basic parameters,number and edge curve of the stalk cutting blade were designed and optimized.Three-factor and three-level combined orthogonal experiments were conducted using the factors of working speed(1.12 m/s,1.57 m/s and 2.02 m/s),tillage depth(75 mm,90 mm and 105 mm)and cutter spacing(15 mm,30 mm and 45 mm),which significantly affected stalk cutting rate and soil disturbance rate.The optimal combination is the working speed of 1.62 m/s,tillage depth of 92 mm and cutter spacing of 35 mm.Under this condition,the stalk cutting rate is more than 90%and soil disturbance rate is 7.5%-12.0%.The performance of the new no-tillage planter was tested by using the above parameters.The results showed that the no-tillage planter of narrow row spacing came up to the relevant national standards in China.

Adaptabilities of different harvesters to peanut plants after cutting stalks

At present,there are no harvesters specifically adapted to process peanuts after cutting stalks.In particular,methods for harvesting peanuts after cutting stalks have not been reported thus far.Therefore,to utilize peanut stalks as feed when harvesting plastic-film-grown peanuts,and to improve industry benefits,a three-stage harvesting method is proposed herein.In view of the three-stage harvesting method,the peanut stalks are cut before digging,with the remaining peanut plants being shorter,thereby increasing the peanut pod-stalk ratio.To investigate the adaptabilities of existing harvesters in harvesting peanuts after cutting stalks,three types of peanut harvesters-the self-propelled pick-up combine harvester,trailed pick-up combine harvester,and peanut picker were used to conduct a comparative test on harvesting intact peanut plants and plants after cutting stalks.The loss,breakage and impurity rates were used as evaluation indicators.The loss rates of these three harvesters were 14.64%,16.44%and 1.33%;the breakage rates were 21.28%,21.92%and 20.00%,and impurity rates were 4.60%,8.76%and 9.06%.Analysis of variance showed that cutting stalks had a significant impact on the work qualities of the three harvesters(p<0.05).With regard to the loss rate,results revealed that:the two peanut combine harvesters could not be adapted to harvest peanut plants after cutting stalks.The three harvesters had good adaptability to harvest peanut plants after cutting stalks,considering the breakage rate;however,based on the impurity rate,the three harvesters could not be adapted to harvest peanut plants after cutting stalks.The losses of the two combine harvesters consisted mainly of dropped and missed picking,with the sum of the losses accounting for 99.87%and 97.99%of the total losses of the two harvesters,respectively;this suggests that the drum pickup of the combine harvesters could not adapt to harvesting the peanut after cutting stalks.The breakage rates of the three harvesters were considerably reduced,suggesting that the pod picking devices of the three harvesters were suitable for harvesting the peanut after cutting stalks;the impurity rates of the three harvesters were considerably increased,indicating that the pod picking and cleaning devices of the three harvesters were not suitable for harvesting peanut after cutting stalks.To improve the adaptabilities of the harvesters,it is suggested that the speed of pickup elastic tooth,lateral spacing between adjacent elastic teeth,concave screen hole size of pod picking device,the structure and motion parameters of cleaning device should be optimized.The results of this study provide a reference for the development and improvement of peanut harvesters suitable for harvesting peanuts after the cutting of stalks.

Effects of maturity of citrus fruits on their stalks cutting force

When the citrus harvesting robot harvests citruses,the mechanical properties of citrus stalks have an important influence on the success rate of the citrus harvesting robot.During the harvesting,the maturity of citrus fruits not only determined the harvesting time of citrus fruits but also affected the mechanical properties of citrus fruit stalks.In this study,the changes in the cutting force of citrus fruit stalks were described during the maturity of citrus fruits,and the effect of the maturity on the cutting force of stalks was clarified,so as to determine the harvesting time with the minimum cutting force required for harvesting citrus fruits by the harvesting robot.During the maturity,the relevant parameters of fruit maturity,such as the hardness,pH,and solid solution content of citrus fruits,were monitored.The results showed that there is a significant correlation between the hardness,pH,the solid solution content of citrus fruits,and the cutting force of citrus fruit stalks during maturity.The single-factor mechanical model of hardness,pH,solid solution content of citrus fruits,and the cutting force of citrus fruit stalks were established based on the data of 2019,which were verified through tests in 2020.The test results are as follows:during the ripening period of citrus fruits,the fruit hardness varies in the range of 0.13-0.31 MPa,the hardness changes by 0.02 MPa,and the cutting force changes by about 2.0-6.0 N;the pH of the citrus fruits changes in the range of 2.8-4.0,and the cutting force changes by about 1.5-2.2 N for every 0.1 change in the pH;the variation range of fruit solid solution content is 6.5%-9.0%,and for every 0.2%change in solid solution,the cutting force of citrus fruit stalks changes by about 1.25-2.0 N.The mechanical models can predict the cutting force required to cut off citrus fruit stalks according to the relevant parameters of citrus fruit maturity and can provide a reference for effectively evaluating the required cutting force.