Design And Research Of South Xinjiang Jujube Orchard Fertilizing Machine

Target fertilization technology can improve the utilization ratio of fertilizer, avoid the waste of fertilizer, and can reduce the pollution of redundant fertilizer on environment. This project based on target fertilization technology, designed a fertilizing machine that suited south Xinjiang jujube orchard, this machine used ultrasonic sensor detection technology, automatically detected if there had jujube or not,controlled outer sheave fertilizing apparatus running and fertilizing.This fertilizing machine matched with walking tractor, mainly consisted of ditching part, control system, fertilizing devices, depth limiting devices and soil cover devices. Used reverse ditching way,ditching part consisted of two rotary cutter. SCM was the core part of control system, used ultrasonic sensor to detect jujube, Stepper motor driver drove the stepper motor under the control of SCM, the power output shaft of stepper motor connected with the fertilizer shaft of outer sheave fertilizing apparatus through plum blossom coupling, stepper motor drove outer sheave fertilizing apparatus fertilizing. Soil cover palates pushed soil into the ditch, accomplished the fertilizing work.Analysed the ditching process of rotary cutter, concluded the motion trajectory equation and velocity equation of machete endpoint. Used large-scale finite element analysis software ANSYS/LS-DYNA to simulate the process of bent blade cutting the soil, the results showed that process of machetes cutting soil was relatively stable, the boundary of soil did not collapse, proved the simulation method was right. Von Mises stress of soil increased from zero to maximum, and gradually tended to be stable, maximum stress concentrated in the contact part of machetes and soil, because the soil suffered strong squeezing effect and shearing effect from machetes.Measured the physical characteristics of experimental fertilizer, bulk density of fertilizer was 0.941g/ml, real density was 1.503 g/ml, equivalent diameter was 2.764 mm, sphere ratio was 89.16%, angle of repose was 27.8°. Researched the relationship between fertilizing amount of outer sheave fertilizing apparatus and rotational speed of shaft, the experimental result showed that with the increase of rotational speed the fertilizing amount increased, and established the corresponding curve fitting model.Debugged the control system in the house, experiment result showed that the accuracy of stepper motor’s rotation time was relatively high, the system had certain reliability. Because of ultrasonic wave reflection during the experimental process, control system occurred false action phenomenon, we could raise the minimum of detection distance to increase the anti-interference ability, raise the position of ultrasonic sensor to avoid the interference of weeds. Experimented in jujube orchard of Tarim University,the result showed that ultrasonic sensor could detect jujube, could meet the design requirement, and the success ratio of target fertilization was 80%.