Research On Dynamic Leveling Technology Of Grain Harvester

With the increasing emphasis on agriculture in the country since the 19 th National Congress,the improvement of the level of agricultural mechanization is a problem that must be solved.The area of grain cultivation in China is vast,distributed in various regions of the country,and planted in mountainous areas,hills and other areas.The large area,resulting in a relatively harsh working environment of the harvester,once the center of mass of the car body is offset,it is easy to cause the phenomenon of roll,which seriously threatens the driver's personal safety and the efficiency of harvesting the grain.Therefore,the research on dynamic leveling of harvester has important theoretical value and practical significance.The working process of the harvester is studied,and the hydro-pneumatic suspension cylinder is chosen as the main actuator for leveling.According to the overall layout of the harvester,the connection mode of the cylinder block is designed.Under the working condition of 14 tons full load of the harvester,the structure design of the car body chassis is carried out.The stress and deformation of the chassis are analyzed by using ANSYS Workbench software,and the stress concentration position is carried out.Strengthen treatment.The independent and connected hydro-pneumatic suspension leveling systems are studied,and the synchronous leveling system is designed according to the actual situation.The synchronous leveling system is built in AMESim software.The main factors affecting leveling time,such as oil release coefficient and cylinder load,are analyzed.It is determined that cylinder load is the main factor affecting leveling time.According to the actual load distribution of cylinder body,the synchronous leveling system is balanced and balanced.The relationship between cylinder load and throttle valve opening is deduced by simulation verification under unbalanced conditions.According to the characteristics of harvester with variable mass,variable centroid and variable operating parameters,the angular acceleration of threshing drum and engine rotor and the pitch angle of cutting table are introduced to study the coupling relationship between variable mass,variable centroid and dynamic load of hydro-pneumatic suspension cylinder.The dynamic load balance equations of vehicle body are established by motion decoupling calculation,and the leveling system of 1/4 vehicle body is carried out.The model analysis establishes the dynamic model of the three-degree-of-freedom two-spring-damper-mass 1/4 car body leveling system,and establishes the dynamic system model to determine the leveling control algorithm.Software design for leveling system flow,mainly including digital and analog sensor acquisition of key parameters of I/O terminal allocation,development of touch screen,design of suspension position calibration,leveling parameter acquisition and display,tilting zero and hydraulic actuator Control and other human-computer interaction interface.Finally,the fabrication of each component of the sensor and the construction of the experimental platform are completed.According to the control strategy and leveling method,the control platform is designed.The feasibility of synchronous leveling of hydraulic system is verified by using angle sensor and double inclination sensor as the feedback device of the whole system.