Design Of Paddy Field Pedrail Wheeled Sprayer And Chassis Test

Rice is the main grain crop in China,and its planting area is about 30 million hm~2.However,the application of rice in China has always been dominated by manual operations,with high labor intensity,low efficiency,and poisoning incidents have occurred from time to time during the application of pesticides.The existing paddy field sprayers are mostly based on wheeled sprayers in the dry field or water and dry field.The modified sprayers are prone to slip and sag in the paddy field environment.Repeated operation of the sprayers over the years will deepen the muddy feet of the paddy fields and destroy the bottom layer of the soil.In response to the above problems,based on the previous research,the paper combined the steering mechanism of the wheeled vehicle with the running device of the tracked vehicle,and designed a paddy field pedrail wheeled sprayer to make it have smaller turning radius and lower grounding pressure.The specific work content is as follows:(1)According to the design requirements and technical indicators to determine the whole machine program.The key components of the sprayer are designed and selected,mainly including:running device,steering mechanism and boom truss.The hydraulic system of the sprayer is designed and selected,mainly including:hydraulic drive,hydraulic steering and hydraulic application.The sprayer can realize four-wheel drive and four-wheel steering functions.The 3D model and virtual assembly of the sprayer parts were drawn by Solidworks software.(2)The ANSYS software was used to perform static analysis of the frame model under horizontal bending and ultimate torsion conditions,and the stress and displacement distribution maps under two operating conditions were obtained.The simulation results show that the frame structure is reasonable and meets the requirements of strength and stiffness.The ANSYS software was used to analyze the frame model,and the first six natural frequencies of the frame model was compared with the external excitation frequency to ensure that the sprayer does not resonate with the engine and other components during driving.(3)The soil mechanical properties were studied based on the Bekker's pressure-sink model and the Janosi's shear stress-shear displacement model,mainly including:pressure characteristics and shear characteristics.The oven method was used to determine the moisture content of the soil sample at the test site to verify the reliability of data collected in the field test.The soil sample at the test site was used for the flat sag test and the direct shear test to obtain the pressure characteristics and shear characteristics of the soil at the test site.(4)Based on the study of the steering mode of wheeled vehicles and tracked vehicles,the kinematics and dynamics analysis of the pedrail wheeled sprayer was carried out,and the steady state steering model considering the slip and soil subsidence conditions was established.The steering radius and steering resistance of the sprayer under different deflection angles of the pedrail wheel are calculated according to the model.(5)In the field test,the bias rate of the sprayer when driving straight and the relationship between driving times and soil subsidence were obtained.The steering radius and steering resistance of the sprayer under different deflection angles of the pedrail wheel were measured.The rationality of the design of the sprayer and the correctness of the steady state steering model are verified by comparing with theoretical calculations.