| Cerasus humilis is a kind of wild European lee cultivated by Chinese breeders in recent years,its contain rich nutrients,especially the content of calcium,so it has the high market economic value.Some domestic experts devote themselves to the cultivation and promotion of Cerasus humilis.As a growing numbering of people begin to pay attention to the cultivation and harvest of Cerasus humilis,the planting area of Cerasus humilis is increasing year by year in China.At present,the main method of harvesting Cerasus humilis is manual harvesting,which takes a long time and has low efficiency.However,it is not easy to preserve the fruit in mature stage,artificial harvesting is not suitable for large-scale cultivation of Cerasus humilis.Therefore,in order to improve the efficiency of fruit picking,ensure the economic benefits of fruit and promote the development of Cerasus humilis industry,it is necessary to realize the mechanization of fruit picking.Some domestic scholars have done a lot of research and made great progress in mechanized picking of Cerasus humilis.Based on Cerasus humilis branches interacted in mechanized harvest after winding comb tine comb phenomenon and fruit falls off with the direction of uncertain problems,by investigating Cerasus humilis grown in the field of the actual environment and plant parameters in combination with the experience and research results of predecessors,the methods of theoretical analysis of working principle,simulation and optimization of structural parameters as well as experimental verification of analysis results had been adopted successively,design a comb-type harvesting test bench in this paper.The main research contents and conclusions of this paper are as follows:(1)The length of the branches and plant row spacing of the Cerasus humilis were measured from the Cerasus humilis cultivate field located in Juxin Modern Agriculture Base,in Taigu County,Shanxi Province,and picking Nongda 4,Nongda 5,Nongda 6 and Nongda 7 Cerasus humilis to measure the dimensions of different varieties of Cerasus humilis,taking the minimum diameter of 12 mm as the dimension of comb tooth spacing,at the same time,the bonding force between fruit and stalk was measured by dynamometer and the maximum picking force of a single fruit was 8.19 N.(2)The collision between fruit and comb tooth during carding was analyzed,and the force of carding was also analyzed.(3)A comb-type harvesting test bench was designed.Based on the field parameters of Cerasus humilis and previous research experience,the main parameters of comb-type harvesting test bench were preliminarily designed.Its three-dimensional model was established with PROE three-dimensional design software,the static structural mechanics analysis the comb tooth was carried out with ANSYS and the final selection of the comb tooth diameter was 10 mm and the length of the comb tooth was 300 mm..(4)Pro E and ADAMS were used to carry out dynamic simulation test on the carding process of the test bench,and the motion trajectory of the comb tooth and the fall off track of the Cerasus humilis were simulated and analyzed.According to the software simulation and test results,the comb tooth and structural parameters of the test bench were re-optimized,and the different test indexes that affecting the collection rate were determined as the motor speed,the bending angle of comb tooth and the radian diameter of comb tooth arrangement.(5)Single factor simulation experiment and bench experiment were carried out,and fruit collection rate was used as the evaluation index.The motor speed,bending angle of comb tooth and radian diameter of comb tooth arrangement were selected as the experimental factors.Results showed that the collection rate decreased with the increase of motor speed;and increased with the increase of the bending angle of comb tooth or the radian diameter of comb tooth arrangement.The orthogonal experiment of three-factor and three-level quadratic rotation center combination was performed.The results showed that motor speed had the largest effect on collection rate,followed by radian diameter of comb tooth arrangement and bending angle of comb tooth.The optimal parameter combination was predicted by the response surface model as follows: motor speed of 25 r/min,bending angle of comb tooth of 120°,radian diameter of comb tooth arrangement of 868.45 mm and corresponding the collection rate reached 91.51%.In the actual bench test,the bench experiment was performed with the motor speed of 25 r/min,the bending angle of comb tooth of 120°,and the radian diameter of comb tooth arrangement of 900 mm,and the collection rate was 93.82%.The relative error with the predicted optimal result was 2.48%,It shows that the prediction accuracy of the model is high and the prediction data is reliable.The collection rate of the test bench was 93.82% compared with 81.26% for the current Cerasus humilis harvester,achieving the purpose of improving the collection rate. |
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