Dissertation > Agricultural Sciences > Agricultural Engineering > Agricultural machinery and implements > Planting machinery > Planting machine

The New Mechanism Analysis and Optimization for Throwing Rice Seeding Orderly by Vibrating Transportation Based on the Airflow

Author LiJianPing
Tutor ZhaoYun
School Zhejiang University
Course Agricultural Mechanization Engineering
Keywords ordered seedlings thrower finite element analysis vibration transport airflow high speed photograph
CLC S223.9
Type PhD thesis
Year 2006
Downloads 175
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Seedling throwing is a new type of seedling planting technology and Ordered seedling throwing which has the advantage of planting and traditional seedling throwing is one of seedling throwing methods with a certain row and column space. Ordered seedling thrower is a hot research topic. As an important part, dividing seedling organization is the key point and difficulty in the research of ordered seedling thrower. In this research a new mechanism of dividing seeding based on acting of airflow and vibration, which is total different with present ordered seedling throwing and dividing mechanism, is put forward. The purpose of this research is to build a model to choose and optimize parameters through the study of the effect of dividing mechanism factors on seedling dividing. The research content and results are as following:1) based on the study of ordered seedling thrower all over the world, pointed out the complexity of current seedling dividing mechanism, low efficiency and big operating space problems because of put seedling tray on the thrower, a new mechanism of dividing seedling based on airflow and vibration is put forward. This new mechanism combines vibration together with airflow. Vibration makes seedlings move forward on vibration board and air makes seedlings stand straight. Then seedlings will arrange their order automatically and rotor claws will throw seedlings one by one to soil. Seedlings fall on ground through direct tubes for seedlings.2) Study the kinetics of vibration transport parts by using method of finite element and got the machine parts natural frequency and vibration model. According to the mode test, the result of test indicated that the datum of the finite element analysis and the test datum were in good agreement. Thus it is possible to optimize the parameters of vibration transport mechanism.3) The kinematics and kinetics of seedlings are analyzed on vibration transport board. Through test, it is proved that the simulation seedlings movement value is similar to the test value. Seedling instantaneous velocity is changeable and fluctuant by the analysis of instantaneous velocity using high speed camera. Theoretic analysis and calculation method of seedlings on vibration board can be used in the vibration transport parts parameter analysis and optimization.4) The concept of seedlings automatic position correction is put forward ,and kinematics and kinetics of seedlings are analyzed when seedlings are blocked by nails on vibration board during the process of vibration transportation. Through test of single seedling, group seedlings and the observation and analysis of high speed camera, it can be proved that seedlings soil bowl will move forward under the force of inertia when they are blocked off by nails on vibration board. Seedlings automatic position correction which orders the disordered seedlings automatically can be realized by appropriate machine parameter choice.5) It is feasible that seedlings stand straight by the theoretic analysis of seedlings kinetics under the force of airflow. By the characteristic analysis and test on seedling, a suitable airflow speed during seedlings vibration can ensure seedlings move toward in the stand-up posture and arrange orderly. 6) The rotor force formula are built. By using high speed camera, the situation of taking seedlings is observed and analyzed nuder having block strip or no block strip at different the claw shape and rotor speed, such as arc shape, level shape and slope shape. It is easy for seedlings to fall down with the effect of soil bowl down and leaf above when there are block strips, while it is difficult to have the same effect without block strips, when the rotors speed is very high, stable work can’t be done. Usually good operation effect can be obtained under the low rotors speed.7) The movement formula of seedlings is built in the guide tube and test the depth of seedlings in the mud. Through the experiment, it can be found that the depth of seedlings in the mud is about 3~13 mm which meet the seedlings plant agriculture requirement when the drop height is 0.75~1.5m.8) In the end, there was a conclusion for the paper, and tentative plans for further research were put forward.

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