Optimization Design For Hydraulic Lifting Mechanism Of Maize Harvester

In order to shorten the time of dumping,save labor force and improve discharge efficiency,now maize harvesters are equipped with hydraulic lifting mechanism,which can automatically make the carriage roll-over to achieve discharge.However,there are many types of hydraulic lifting mechanism,and they are not all fully suitable for the needs of the actual work environment when corn harvester is unloading,so we need to improve the hydraulic lifting mechanism.The study object of this paper is the hydraulic lifting mechanism of 4YZ-3A maize harvester which is provided by an agricultural machinery manufacturer.The hydraulic lifting mechanism is composed of carriage,tilting hydraulic cylinder and lifting bracket of carriage.Tilting hydraulic cylinder push carriage roll-over around the rotary shaft upper end of the lifting bracket when corn harvester is unloading.The maize is dumped into the carriage of the agricultural transport vehicles beside corn harvester.Due to the limitation of the height of the baffle on some agricultural transport vehicles,this type of hydraulic lifting mechanism can not be fully applicable to the harvesting environment in rural,so we must improve the hydraulic lifting mechanism.The hydraulic lifting mechanism of 4YZ-3A type corn harvester is improved to hydraulic lifting mechanism of high position,the height and horizontal overhang of the rotary shaft of carriage is increased,various types of hydraulic lifting mechanism are analyzed and their characteristics are compared,the form of hydraulic lifting mechanism and the maximum discharge angle is selected.The model of every component of the improved hydraulic lifting mechanism and the assembly model were established in SolidWorks software.The possible static interference of the improved hydraulic lifting mechanism is eliminated through interference inspection and modifying the interference parts.The solid model established in SolidWorks software is imported into ADAMS and constraints、load and driver is added to the model.Through kinematics simulation analysis,studying the curve of tilting hydraulic cylinder stroke of piston rod、carriage angular velocity、angular velocity of tilting hydrauliccylinder、angular acceleration of tilting hydrauliccylinder and thrust of the tilting hydraulic cylinder changing withtime,the performance of the improved hydraulic lifting mechanism of high positon is tested.The optimization design of the key pivot points of the lifting mechanism is carried out with the aim of minimizing the maximum thrust of the tilting hydraulic cylinder during discharging.The 3D solid model of sliding frame and the frame of carriage established in SolidWorks software is imported into ANSYS Workbench each other.The reliable of sliding frame and the frame of carriage are verified according to the stress and the displacement of it obtained through finite element analysis.And the lightweight design of the frame of carriage is made to reduce the quality from the original 188 kg to153kg,which is reduced by 18.62%.