Research On The Design Of Press Devices And Control Of Compaction Pressure For Small And Medium-sized Corn No-till Planter

Pressing was a crucial process in the sowing process.The quality of pressing operation was related to the effect of sowing and had an important impact on the growth of crops.The weather was dry when corn is sown,and there were problems such as hard surfaces,many soil blocks in furrows,and large vibration of sowing operations.As a result,the compaction pressure changed greatly and the compaction intensity was difficult to guarantee the agronomic requirements,which affected the growth of maize.The traditional small and medium-sized no-tillage planters lacked a control system for the pressure,resulting in a poor suppression effect.Based on the above problems,this paper designed a pressure control system based on the torsion-type rubber spring used based on the design of the press device.To ensure the uniformity of soil compaction after sowing.The main research contents were as followed :(1)The optimal compaction intensity range for maize growth was obtained by pot experiment.The experimental study on the effect of compaction intensity on corn seedling emergence and early corn growth traits was conducted using compaction intensity as the test factor and seedling emergence rate,seedling emergence speed,and plant height as the test index.The results showed that corn emergence reached more than 85% when the compaction intensity was in the range of 35 to 62 k Pa.(2)Design and testing of press device based on torsion-type rubber spring.The design and analysis of the torsion-type rubber spring led to the determination of the dimensions of the torsion-type rubber spring.By fitting and comparing the finite element simulation test with the bench test,the fitting equation of the torsion angle versus the torque of the torsiontype rubber spring was obtained.A mechanical analysis of the operating process was performed to determine the equation of the relationship between the torque of the torsiontype rubber spring and the compaction pressure.The parameters of the pressure wheel were designed to determine the diameter of the pressure wheel to be 400 mm and the width to be80 mm.Based on the dimensional parameters of the pressure wheel and based on the appropriate ballast compaction intensity from the pot experiment,the loads were found to range from 98 to 285 N,corresponding to a soil subsidence of 2.31 to 6.69 mm.Soil bin test using a torsion-type rubber spring based press device,measured soil compactness of 56.8k Pa and working resistance of 109.6 N.The operational performance could meet the agronomic requirements.(3)Apply EDEM discrete element analysis software to establish a simulation model of the contact between pressure wheels and soil,and analyze the relationship between pressure and soil compactness.The simulation results show that the compaction pressure shows a power function relationship with the soil compactness.At the same time,the soil compactness of the pressure wheel was 34-52 k Pa when it was simulated to operate under the load obtained from the theoretical design,which was in line with the range of compaction intensity obtained from the pot experiment and could meet the requirements of the seeding operation.(4)Design of the compaction pressure control system.A posture sensor was used to monitor the torsion angle of the torsion-type rubber spring,and a pressure sensor measured the force at the electric push rod.Hardware design of the compaction pressure control system,completing the design of the microprocessor,attitude sensor,pressure sensor,electric push rod,touch screen,and power and storage modules;Software design for the compaction pressure control system,completing the design of the main control system program,compaction pressure measurement and control subroutine and the design of the touch screen display subroutine.The compaction pressure control system was calibrated and response time tested with a correlation coefficient of 0.9317 for the calibration equation and a response time of 0.62 s.(5)Soil bin test of compaction pressure control system performance with conventional tension spring type compaction pressure regulation and torsion-type rubber spring type compaction pressure control system regulation.The results show that with the increase of forward speed,the fluctuation frequency of the compaction pressure will increase accordingly,but under the action of the compaction pressure control system,the compaction pressure was kept near the set value.Also,comparative tests showed that the compaction pressure control system improved the uniformity of compaction.The vibration-damping advantages of torsion-type rubber spring were evaluated and analyzed by using conventional tension spring compaction pressure regulation,torsion-type rubber spring compaction pressure regulation,and torsion-type rubber spring type compaction pressure control system regulation.The results showed that at a speed of 4 Km/h,the vibration frequency regulated by the torsion-type rubber spring type compaction pressure control system was 24.1% lower than that of the torsion-type rubber spring compaction pressure regulation,and 38% lower than that of the conventional tension spring compaction pressure regulation.