Study Of Circular Trenching And Fertilizing Device In Mountain Orchards

The ring furrow application operation can effectively improve the efficiency of fertilizer utilization,reduce environmental pollution,and effectively break the soil around the drip line of fruit trees and prune the root system.In this paper,after systematically analyzing the current situation of domestic and foreign research and combining the agronomic requirements of ring furrowing and fertilization of fruit trees,we propose a ring furrowing and fertilization device for orchards in hilly mountainous areas,which can complete the combined operation of ring furrowing,fertilization and mulching.The design of each component of the device was carried out and the calculation of the selection was completed;the structural design and theoretical analysis of the key component,the trenching and fertilizing component,were carried out,and the simulation analysis of the trenching and fertilizing component was carried out by the discrete element method to optimize its structure and operating parameters;the prototype was tested after the prototype was made and the operating performance of the prototype was determined to meet the design requirements.The main research contents and conclusions are as follows:(1)The overall scheme design of circular open trench fertilizer application device for orchards in hilly mountainous areas.According to the actual operating environment of orchards in hilly mountainous areas and the agronomic requirements of circular furrowing and fertilization of fruit trees,the design requirements of circular furrowing and fertilization devices for orchards in hilly mountainous areas are clarified.Three kinds of trenching and fertilizing schemes,namely offset disc type,vertical rotary tillage type and vertical spiral type,were proposed,and the trenching and fertilizing method of the device was determined to be vertical spiral type according to the design requirements and agronomic requirements.Determine the overall device design scheme and operation flow,the device mainly consists of furrowing and fertilizing components,anti-overload components,control module,power system,etc.(2)Structural design and simulation optimization of trenching and fertilizing components.The structural design of the trenching and fertilizer application component was carried out,and the design of segmented spiral was adopted to reduce the power consumption and the disturbance to the subsoil,and the theoretical analysis of its operation process was carried out to determine the pitch and rotation speed as the main factors affecting the operation power consumption.By combining physical and simulation tests,the best discrete element simulation model material parameters of organic fertilizer particles were obtained,i.e.,fertilizer-fertilizer dynamic friction coefficient of 0.056,fertilizer-fertilizer static friction coefficient of 0.355,and JKR surface energy of 0.011 J/m2.Single-factor simulation tests were conducted to investigate the influence of rotational speed and pitch on the operating resistance moment and soil disturbance effect.The results showed that the segmented spiral blade had lower operating resistance moment and less soil disturbance compared with the complete spiral blade.The quadratic regression models of rotational speed and pitch on the operating resistance moment and fertilizer mixing degree were constructed with the correction coefficients of Radj2=0.9925 and Radj2=0.9765,respectively,and the structural and operating parameters of the segmented spiral were optimized with the lowest operating resistance moment and fertilizer mixing degree close to 1 as the indexes.The optimal working speed of the spiral blade is 350r/min and the optimal pitch is 138 mm.(3)Study of other components of the device.According to the theoretical calculation and simulation test results,the power system of the device is designed,and the selection of each component is studied;the reliability analysis of the transmission spindle is carried out,and the maximum strain is 0.066 mm and the maximum stress is 11 Mpa,which meets the operational needs and design requirements;in order to prevent the machine from hitting the rocks and hard roots,which leads to the machine jamming or damage,the mechanical structure design of the anti-overload components is carried out,and the parameters of the key component compression spring are calculated.In order to prevent the machine from hitting the rocks and hard roots,the mechanical structure design of the anti-overload parts was carried out,and the parameters of the compression spring of the key parts were calculated.To investigate the inherent frequency and vibration pattern of the trenching components,to verify that the resonance will not occur under the working condition and to verify its reliability.(4)The design study of control module.According to the operation demand of the device and the operation order of each component,the overall scheme design of the control module is carried out,the human-machine interaction interface design is completed by APP Inventor software,and the software program is written and debugged based on ATmega2560 core board,then the hardware modules are selected and wired according to the software program,and installed into the machine after laboratory testing.(5)Trial production and performance test of the prototype of circular furrowing and fertilizing device for orchards in hilly mountainous areas.The prototype and idle commissioning of the device were carried out to ensure the stable operation of each component according to the operation process.The performance test of the device shows that the device can steadily carry out trenching and fertilizing operation,and the operating depth of the trench can reach more than 30 cm,the stability coefficient of trenching is93.5%,and the stability coefficient of fertilizing is 94.6%,and the device meets the design requirements.