Design And Test Of Three Wheeled High Clearance Operation Vehicle With Adjustable Track

Wheat-corn double cropping is the main planting pattern of grain crops in Henan region.The growth and development period of corn is short,and additional fertilizer has a very important effect on its yield.However,due to the height of corn stalk and the lack of special dressing machinery for corn,only artificially fertilizing,the intensity of labor is big,and the efficiency is low.Tobacco is an important economic crop in our country.The spraying,topping and other field management of tobacco in the middle and late stages are very important to ensure the quality.According to the operational requirements of tobacco and corn in the middle and late field management,a three wheeled high clearance field operation vehicle is designed.The main contents of study include the following 4 aspects:(1)According to the requirements of corn and tobacco,overall structure design of the operation vehicle is carried out.The vehicle includes frame,driving system,hydraulic system and matching machine,the frame mainly includes track adjustment mechanism and tool lifting mechanism.Track adjustment mechanism of the vehicle is designed based on five link mechanism,the track can be adjusted between 1.8 m and 2.4 m.Kinematic and dynamic analysis of track adjustment device is conducted.The kinematic relation of each component of the mechanism and the force of hydraulic cylinder is confirmed in the process of track adjustment.The track adjustment mechanism is simulated and analyzed using mechanical kinematics simulation software ADAMS,results show that the track can be adjusted between 1.8 m and 2.4 m and the displacement adjustment of unilateral track is 0.3 m.Optimization is conducted taking the minimum force of hydraulic cylinder as the target,The distance between hinge point and rear end face of the rear wheel frame is 199.2 mm,the hinge point is on the piston rod and the rear wheel frame.The lifting mechanism is designed adoptting the principle of moving pulley,and lifting height range from 0.6 to 1.8 m.(2)The driving system is designed in order to simplify the transmission system and reduce production cost.The driving system adopts the form of direct current drive and mechanical drive,DC motor is drived by the generator and the vehicle is drived by the DC motor through worm gear reducer.The main components of drive system are calculated and selected based on the design of vehicle structure and drive system.(3)The hydraulic system is mainly used to realize the track adjustment,machine lifting and machine operating,which is controlled by multi valve.According to the hydraulic system principle and the force of hydraulic cylinders,parameters of the hydraulic cylinders and hydraulic pump are calculated.A simulation analysis is applied to hydraulic track adjustment using dynamic simulation software AMESim,which insured that the track can be adjusted simultaneously.(4)The tobacco spraying device and the corn fertilizing device are designed based on the design of a three wheeled high clearance field operation vehicle.Track adjustment performance of the vehicle are tested according to GBT 3871-2006.The test results show that the minimum track of the vehicle is 1.82 m and the maximum track is 2.37 m.In conclusion,a three wheeled high clearance field operation vehicle is designed according to the characteristics of planting agronomic and the requirements of field management of corn and tobacco in Henan area.The performance of operation vehicle is tested preliminarily.