| The technology of hole deep-application of liquid fertilizer is to use fertilizer application tool to put fertilizer with precise and quantitative amount in the soil near the root of the crop,which can effectively increase the utilization rate of fertilizer,promote the absorption of crops,reduce the volatilization and loss of the effective components of fertilizer,and increase crop yields.According to the latest relevant policies,it is necessary to promote the reduction of agricultural inputs and improve the quality of agricultural development in order to improve the efficiency of use and reduce the total amount of the use of chemical fertilizers.The deep-application type liquid fertilizer hole application machine mainly consists of two key parts: the pricking hole mechanism and the distributor.At present,the developed pricking hole mechanism adopts the design idea of " pricking hole in orthostatic type ",and it is easy to collide with the crop stem and leaf during the operation of this kind of pricking hole mechanism.The trajectory of the pricking hole is not ideal;at the same time,the distributor can realize the single side spraying fertilizer and the fertilization efficiency is low.Based on the above problems,the technology of hole deep-application of liquid fertilizer is studied in this paper.According to the agronomic requirement of fertilizer application in crop cultivation period,a method of parameter reverse calculation is put forward to design the non-circular gears planetary pricking hole mechanism in oblique type,and the differential-type bidirectional distribution device for fertilizer supply is designed by using K-H differential gear train transmission principle.The mechanism analysis,structure design,mechanism performance research and exploration are carried out respectively.The main contents are as follows:(1)Constructing the inverse function relation of the parameters of the non-circular gears planetary pricking hole mechanism in oblique typeAccording to the idea of inverse design of the pricking hole mechanism parameters,the cubic Lagrange curve high precision interpolation technique is used to form the configuration of the spraying fertilizer needle.A theoretical model of different spraying fertilizer needle trajectories can be obtained by changing the coordinates of several types of points on the trajectory,and the kinematic model of the mechanism is obtained.Finally,the relation formula of the parameter reverse function of the pricking hole mechanism.(2)Development of kinematics simulation software and optimization analysis of the pricking hole mechanismBased on MATLAB GUI development platform,the kinematics simulation software of pricking hole mechanism is developed.With the aim of satisfying the vertical attitude of spraying fertilizer needle and the small width of the hole mouth,the effects of different value points and oblique angles on the hole mouth and attitude of spraying fertilizer needle are explored respectively.With the help of Man-machine interface,the data points of each irregular gear pitch curve,the length of the spraying fertilizer needle and the gears center distance are obtained.The paper compiles irregular gear tooth profile aided design software,and the data point file of irregular gear pitch curve is imported into this software,each irregular gear tooth profile is obtained.(3)Structure parameter design and mechanism analysis of differential-type bidirectional distribution device for fertilizer supplyBased on the transmission principle of K-H differential gear train,a differential-type bidirectional distribution device for fertilizer supply is designed using the combination mechanism of double planetary gears and annular gear.In order to ensure the synchronous operation with the hole picking mechanism,to determine the number of planetary gear and inner gear teeth,the ratio of planetary frame angular velocity to inner gear angular velocity,based on Visual Basic6.0 development platform,according to the precise and quantitative spraying characteristics of the spraying fertilizer needle in the soil,The contour curve of the spatial cam in the device is constructed.Through the simulation and analysis of the differential-type bidirectional distribution device for fertilizer supply,the velocity and acceleration curves of the driven member and the movement trajectory of planetary gear are obtained.Make clear the mechanism of hose non-interference in the movement of hole pricking mechanism connected with distribution device.(4)Performance analysis and bench test of hole pickingmechanismThrough high speed camera test,the trajectory of spraying fertilizer needle with different oblique angles were obtained,and the influence law between oblique angle and trajectory was analyzed.The experiment results show that with the increased of the oblique angle of the mechanism,the angle of spraying fertilizer needle in the soil gradually decreased,which verifies the correctness of the model based on the parameter reverse design method.By the pricking hole performance and crop damage test,take the work speed,the forward speed and oblique angle as the test factors,the hole mouth width,the hole distance and the rate of crop damage as the test optimization index,mathematical model and relation curve between indexes and factors were built,the hole mouth width,the hole distance and the rate of crop damage were optimized by using Design-Expert8.0.6 software,when the work speed,forward speed and oblique angle were 75 r/min,0.48 m/s and 23.3°,the performance of mechanism was optimal under above conditions,the hole mouth width,the hole distance and the rate of crop damage were 40.2 mm,220 mm and 0.33%.The rationality of the mechanism design are investigated.(5)Performance analysis and bench test of distributorTaking the liquid fertilizer pump pressure as the influencing factor,the fertilization quantity as the influence index,the function relation between the fertilization quantity and the liquid fertilizer pump pressure was obtained,predicting the liquid fertilizer pump pressure under the agronomic demand fertilization quantity;And the amount of fertilizer applied in a certain period of time is measured.According to Bernoulli equation,The energy losses of liquid fertilizer under different pressures were calculated to be 9.0,12.6 and 15.0 m,respectively,and the energy loss mechanism of liquid fertilizer was analyzed.It is verified that differential-type bidirectional distribution device for fertilizer supply has high efficiency of spraying fertilizer.(6)Field performance test of fertilizer deviceThe field performance test showed that the average value of hole mouth width,hole distance and crop damage rate were 42.7 mm,212.3 mm and 0.48% when the fertilizer device was used.In the field operation,the non-circular gears planetary pricking hole mechanism in oblique type reduced the mechanical contact and collision with the crop,and the damage rate of the crop was small;the vertical attitude of the spraying fertilizer needle was higher and the hole mouth was small;under a certain pressure of liquid fertilizer pump,the fluid fertilizer hose system had no leakage and blockage phenomenon,which verified the correctness of the optimization result. |
PDF Full Text Request