Design And Research Of Hydraulic System Of Self-propelled Pepper Harvester With Mountain Tracks

Guizhou’s chili industry has outstanding advantages,and the production and sales scale is the first in the country,but Guizhou is a typical karst terrain province,the terrain is mostly hilly and mountainous,the chili ground monopoly is short and slope is large,resulting in no harvesting machinery applicable to chili mountain dense planting mode at home and abroad,while manual picking of chili exists in the shortage of high labor intensity,low efficiency and high harvesting cost.To address this problem,this paper researched the operating conditions of the mountain pepper harvester and the agronomic requirements of pepper,analyzed the working principle of the machine,and designed a compatible hydraulic power system;and selected and designed the key components of the hydraulic system;modeled and simulated the chassis circuit,working circuit and bin cleaning circuit of the mountain pepper harvester using AMESim software;finally,the hydraulic system test and field driving test were conducted on the prototype of the mountain pepper harvester.The article mainly obtained the following studies:(1)By analyzing the three-dimensional model of the mountain pepper harvester and the principle analysis of each operating unit of the harvester according to the working characteristics and requirements of the machine,the quantitative pump parallel variable pump system is adopted as the power source,and the load-sensitive hydraulic system of the chassis circuit and the working circuit based on the pressure compensation before the valve is designed for the working characteristics of different subsystems,and the overall design scheme of the hydraulic system of the mountain pepper harvester is determined by making full use of the engine power.(2)Kinematic and kinetic analysis of the main operating units of the mountain pepper harvester is carried out,and the parameters of the actuating elements in the subsystem are calculated and initially selected according to the analysis results and performance parameter requirements.Combined with the design requirements of the hydraulic system and the layout of the system,the selection of auxiliary components such as hydraulic pumps is carried out.(3)AMESim software is used to model the subsystems in the hydraulic system and verify the effectiveness of the load-sensitive circuit;analyze the system characteristics of the chassis circuit of the pepper harvester under climbing,straight-line driving and steering conditions;simulate the lifting cylinder and roller motor in the spiral comb picking mechanism circuit under variable flow and variable load conditions,and improve the cavitation and pressure shock of the lifting cylinder.Finally,the working performance of the material box and the cleaning circuit was verified.The simulation results show that the mountain pepper harvester has good chassis driving ability,and each actuator can work independently without interference and can meet the design requirements.(4)The test was conducted on the prototype of mountain pepper harvester,and the test program of hydraulic system performance and chassis driving performance was designed to test and verify the whole hydraulic system.The test results are: the maximum deviation rate of each motor speed in the system is 1.3%,the maximum deviation rates of displacement,rising speed and falling speed of each cylinder are 0.2%,7.1% and 3.9%,and the limit slope angle for climbing,the limit height for overturning the vertical wall and the limit width for crossing the trench are 27°,500 mm and 980 mm from the field driving test.the test results show that the mountain The test results show that the actuating elements of the mountain pepper harvester meet the design performance requirements and have good driving performance and safety.