Design And Research Of Spray Rod Suspension Device For Profiling Operation

In recent years,with the progress of science and technology and the change of spray mode in field operation,the manual portable sprayer has been unable to meet the needs of spray operation in Xinjiang due to the factors of small power,narrow spray width and low intelligent level.It has gradually been marginalized by the market and lost its mainstream position in the sprayer.Spray rod sprayer has become the most popular sprayer in the field of plant protection because of its high spraying efficiency,good spraying quality and strong controllability.The long spraying rod of this plant protection machine greatly improved the operation speed and spraying quality in the field application in Xinjiang.However,if the spray rod is too long,the spray rod will deflect and tilt due to the fluctuation of asymmetric working ground,resulting in the decrease of spray distribution uniformity and affecting the spraying effect.In severe cases,the end of the spray rod will touch the ground and damage the spray rod.Therefore,the attitude adjustment system must be designed for such spray rod sprayers to maintain the correct position of the spray rod relative to the ground.Therefore,in order to suppress the irregular movement of the spray rod and achieve the purpose of accurate control of the spray rod,it is necessary to carry out real-time,stable,accurate and dynamic profiling control of the spray rod.In view of the above phenomenon,this thesis takes the self-propelled spray rod suspension frame as the research object,and takes the automatic adjustment of the spray rod as the goal.A spray rod suspension frame device is designed,which can automatically simulate the height of the ground and crop canopy.The purpose is to improve the spraying quality of the spray rod sprayer and ensure the safety of the unit and crops.The main research contents are as follows :(1)On the basis of consulting a large number of references,this thesis summarizes the current research status of spray rod hangers at home and abroad,and compares and analyzes the problems existing in the current spray rod hangers,so as to determine the research objectives,research contents and technical routes of this thesis.(2)The mechanical structure parts of the profiling operation spray rod suspension device are designed and assembled by Solidworks software,including height profiling mechanism,active profiling mechanism,spray rod ranging profiling mechanism and other parts.The working principle analysis and design calculation of each mechanism are carried out,and the hydraulic cylinder model is selected.(3)According to the motion demand of the profiling mechanism of the boom suspension frame,the hydraulic control system based on PLC is designed.The working principle of the hydraulic system is analyzed,and the control hardware and execution hardware of the system are selected and calculated.Finally,the controller model is Mitsubishi FX2N-14 MR series PLC,and the main control valve model is STPSL3C1 D / 63-3-32J16 / ON / ER2 * 6-E1-G24 six-way valve;the software program and man-machine interface of profiling control system based on PLC are developed.(4)According to the principle of hydraulic control system,the simulation model is built by using AMEsim software.The simulation results show that the established simulation model of hydraulic control system has good response performance and rapid adjustment,which can completely simulate the displacement change of hydraulic cylinder piston rod when the spray rod is excited in the field.(5)In order to test whether the designed test bench meets the requirements of profiling control,the profiling range verification and response performance test of spray rod hanger are carried out in manual mode and automatic mode.The verification results show that the range of each profiling mechanism is consistent with the design in manual mode;In the automatic mode,the suspension height adjustment test shows that the suspension displacement rises and falls smoothly and the response time is short in the whole control process;The profiling test of active and passive suspension shows that the profiling performance of passive suspension is poor,but it can be quickly adjusted to the horizontal position under the active actuator regulation,but there is also an angle deviation of 0.12 o after leveling;The ranging profiling test of the spray rod shows that during the profiling process of the spray rod to the ground,the spray rod is always in a state of jitter,and the jitter error is within ±20 mm,with a small range.