Study On Design Of Valve-controlled Double-pump Crawler Corn Field Truck

The hydraulic running system has the characteristics of fast response,high control precision and good stability at low speed,and has been widely used in agricultural crawler working vehicles in recent years.Agricultural crawler working vehicle adopts hydraulic transmission instead of some complex mechanical transmission,which can make the drive system layout more flexible and compact,and the equipment more lightweight.At the same time,with the progress of technology,the hydraulic system takes into account the characteristics of high efficiency,low failure rate,easy operation and maintenance.After combining the electronic control technology with the hydraulic system,the hydraulic drive system plays a more and more important role in precision agriculture with the improvement of the control precision of hydraulic components.Maize in henan province,the author of this paper and its similar high stalk crops of tobacco growing agronomic requirements,design a kind of caterpillar work platform and supporting device,is used to meet the mountains and hills and small plots of land demand,caterpillar vehicle design mainly includes the frame design,cover design,design of hydraulic system,control system design.SolidWorks is used to complete the three-dimensional modeling of the working vehicle,the plug-in Simulation is used to complete the load verification of the frame,and the plug-in Flow Simulation is used to complete the verification of the suction tubing in the hydraulic system.Hydraulic system simulation under different working conditions is completed by AMESim.The main research contents are as follows:1.Design a set of full hydraulic drive system with speed feedback,which includes a track driven by an encoder,a double pump and double motor hydraulic transmission system,and a gantry frame with high passability.The feedback PID control algorithm is used to control the proportional servo valve in the double pump and double motor system,so that the speed of the track drive system can reach the desired speed.In this study,the state of straight line driving under cross-coupling control was studied.By detecting the speed information of the track driving system on both sides and comparing the expected speed information,the driving speed was adjusted at any time.Through this method,the ability of straight line driving to resist the impact of external load was studied.When steering,the research adopts the internal drop type differential steering under the independent PID control,the two sides of the track at constant speed to achieve the desired turning radius to bear the impact of external load.2.Using SolidWorks to complete the modeling of the crawler mechanism of the working vehicle;In wheel base adjustment scheme,put forward the frame structure of high through sexual composite beam structure framework scheme,through sexual connection frame welding molding solutions,high through sexual composite beam connection frame,double engine double pump control scheme,based on the above scheme comparison,determine high by composite beam structure scheme for the optimal execution;Completed the design of the cover for the crawler working vehicle;Through the mechanical analysis and modeling of the frame in the working state of full load,the climbing state of full load and the in-situ steering state of full load,the strength of the frame under the above working conditions is checked by SolidWorks mechanical Simulation plug-in Simulation.The results show that the deformation of the designed frame meets the design requirements under various working conditions.Completing plant protection and fertilization device design.3.Design the full hydraulic driving system for the crawler working vehicle;Proportional servo valve closed-loop control is used to design the control circuit and the strategy of short distance and remote control.According to the design principle and parameters,complete the selection of parts,complete the layout of the hydraulic system pipeline of the working car;The design parameters of AMESim software were used to verify the cross-coupling control of single-pump dual-motor system and dual-pump dual-motor system in straight line driving and single-channel control in steering state.The fluid Simulation verification of the suction tubing scheme was carried out through the fluid Simulation plug-in Flow Simulation in SolidWorks.It has been proved that it is reasonable to adopt double pump and double motor closed-loop control and the suction tubing in the pipeline layout scheme.4.The hydraulic control system test bed was built to collect the actual speed information under the load condition under the cross-coupling control of straight-line driving and the single channel control,and the test curve was obtained by comparing the expected speed.The analysis results showed that the speed test curve met the change requirements of the expected speed curve.The test results show that the steering deviation rate of straight line driving meets the national standard,the actual turning radius of steering driving is close to the expected radius,and the designed tracked working vehicle meets the design requirements.