Design and Parameters Optimization of a Provoke-Suction Type Harvester for Ground Jujube Fruit

Abstract

Low working efficiency is an important reason for the limited application of the traditional aspirated-air type jujube fruit pickup machine. In this study, a provoke-suction type harvester for ground jujube fruit (PSH) was designed, based on the principle of negative pressure suction after shoveling the jujube fruit mechanically. The main working parameters were analyzed and the structures of the key devices were designed. Then, a three-factor and three-level Box–Behnken method was used to evaluate the performance of the PSH. The results showed that the pickup rate, impurity rate, and working efficiency were 99.36%, 5.63%, and 1672.3 kg∙h−1, respectively; as the forward speed, provoke teeth buried depth, and airflow velocity were 0.21 kg∙h−1, 74 mm, and 26.4 kg∙h−1, respectively. Furthermore, the verification results showed that the pickup rate, impurity rate, and working efficiency were 98.05%, 5.97%, and 1591.2 kg∙h−1, respectively, moreover, the relative errors were 1.32%, 6.04%, and 4.85%, respectively, indicating that the parameter optimization model can accurately predict the test results. The working efficiency of the PSH was significantly improved compared with the traditional aspirated-air type jujube fruit pickup machine. This research can provide a reference for the development of the jujube fruit pickup machine.

Design and Evaluation of a Mechanical Floor-Standing Jujube Picker

“…According to the test method of DG/T 188-2019 "Fruit Picker" [33], every 20 m of length between the rows of the jujube trees was taken as the test area. Before the test, the jujubes and impurities in the compartment should be removed, and the working prototype should be debugged according to the parameters required for the test before commencing the test.…”

“…Therefore, air blowing was used to separate jujubes from jujube branches and leaves. The jujubes cannot be blown off; thus, the air velocity of the fan should be larger than the impurities and less than the critical velocity of the jujubes to meet the required wind force for cleaning [20]. The critical velocity of impurities is 3.4-5.6 m•s −1 , and that of jujubes is 27.13-34.28 m•s −1 , according to the literature [20][21][22].…”

“…The jujubes cannot be blown off; thus, the air velocity of the fan should be larger than the impurities and less than the critical velocity of the jujubes to meet the required wind force for cleaning [20]. The critical velocity of impurities is 3.4-5.6 m•s −1 , and that of jujubes is 27.13-34.28 m•s −1 , according to the literature [20][21][22]. Therefore, the YWF2E-300 axial flow fan with an air volume of 3300 m 3• h −1 was selected on the basis of the critical velocity of the jujubes and impurities [23].…”

Design and Test of a Comb-Brush-Type Honeysuckle-Picking Device

“…To determine the optimal parameters of the device, we employed the Box-Behnken test design method [30,31]. This involved conducting a three-factor, three-level quadratic orthogonal rotary center combination test.…”

Parameter Optimization and Testing of a Self-Propelled Combine Cabbage Harvester

“…t ≥ t 1 : the advancing speed of the machine v is too slow, since the working distance is constant (the length of the pulling roller is constant), the acting time on the cabbage by the pulling roller per unit of time is increased, and the cabbages are rubbed and damaged; thus, the qualifying rate of harvesting is reduced. At the same time, if t is too long, the working efficiency of the machine is reduced; thus, the advancing speed should be set to a reasonable rate [17,18].…”