Research Of Key Technolegy Of The High Performance Rice Transplante

Rice plant has a very important status in our country's grain production. Comparedwith other grain plants, rice has the biggest planting area and the highest per unityield. The yields of rice are the most than other grain plants, which is about 40 percentof all grain yields in our country. However, our country's mechanization level of riceplanting is lower than other countries for a long time. This has seriously affected thedevelopment of rice planting in our country.Recently, with the improving of the whole agricultural mechanical level, themechanization of rice planting has a great progress. By the end of 2003, the area ofrice-planting mechanization is nearly 13,500,000 square meters and the level ofmechanical planting reaches 6%. But compared with the advanced countries, themechanization level of rice planting is still lower. Therefore it is very important andsignificant to research the theory and technology of high speed rice transplant.The transplanting frequency of modern high speed transplanter is about twice asmuch as the traditional transplanter. Its working breadth and burthen has raised much.So there appears a series of problems about theory and technology. Based on a lot ofcorrelative lectures reading and theory research, this dissertation researches the keytechnology of high speed transplanter, namely the key theory and technology ofrotary-type transplanting mechanism and moving-box mechanism, and obtains someinnovative results and analysis methods which have use value. These contents have certainguiding significance for the design and producing of high speed transplanter. The mainresearch contents and the conclusions of this dissertation are arranged as follow.1) It studies the situation of mechanization of transplanting rice seedlings indomestics and abroad, analyses the problems of mechanization of transplanting riceseedlings, discusses the rice transplanting's request to the rice-transplanter,and proposes the key technologic problems which affect the development ofmechanization of modern high-speed transplanting rice seedlings.2) According to the basic request of agricultural transplanting rice seedlings, thearticle analyses seedling needle's kinetic path in the course of mechanicaltransplanting rice seedlings and brings forward the relationship between machine'sonward velocity and seedling needle's velocity during taking seedlings, delivering seedlings, transplanting seedlings, rotation, escaping, and backhaul when seedlingneedle does the mechanical transplanting work. Taking gear curve of differentvelocity transplanting mechanism as the object of study, in the research of seedlingneedle's kinetic path and the theory of gear driving curve, it analyses andresearches the turnover wheels' gear curve shape of rotary-type transplantingmechanism. Proved theoretically, if it completes the agronomy request to path oftransplanting seedlings, rotary-type transplanting mechanism must adoptnoncircular gears, because the ordinary circular gear can't fulfill the taskforwarded by agronomy. Also, it studies the driving ratio of noncircular gears inrotary-type transplanting mechanism of high-speed transplanter, proving thetheoretic base for the design and parameter-optimized of rotary-type transplantingmechanism.3) In the research of kinematic model of rotary-type transplanting mechanism, itbuilds the displacement model of the point of mechanical motive interference inthe mechanism of transplanting arms. Through the visual function in the VB system,the paper puts forward identifying motive interference of rotary-typetransplanting mechanism rapidly based on VB. On the VB platform, computers canautomatically identifying mechanical motive interference in time, providing animportant theory platforms for optimized design and parameter-optimized design ofthe rotary transplanting mechanism. Besides, by using the method of orthogonalexperiment, it analyses the factors of mechanical motive interference in therotary-type transplanting mechanism and fixes how important the factors are. Whatit have mentioned above provides the basis for optimizing the design of rotarytransplanting mechanism and checking the motive interference.4) At present, when the working rotating speed of high-speed transplanter advances,it appears the phenomenon that the function of transplanting rice seedlings ofrotary-type transplanting mechanism drops suddenly. So, it is very essential toresearch the dynamics characteristic of transplanting arms. After analyzingseedling needle's kinetic path and theory of kinetic path of the pole of pushingseedlings, it finds why the phenomenon happens and puts forward the design theory,maximum working rotating speed of high-speed transplanter, at the premise offilling transplanting rice seedlings well, which is finished by transplanting arms.5) Taking different velocity rotary-type transplanting mechanism as the studyingobject, the research that the article discusses the dynamics simulating of virtual prototype about the primary part of high-speed transplanter has been made. Andconsidering the characteristic of noncircular gears in rotary-type transplantingmechanism, it sets up the model of different velocity rotary-type transplantingmechanism. Besides, to the model that has been built, it analyses the experimentof virtual prototype about its kinematics and dynamics characteristic.6) On the platform of high-speed transplanter, it does kinematic characteristic trailof different velocity rotary-type transplanting mechanism, and makes the contrastbetween the result done by the experiment and the virtual prototyping trail's resultof its mechanical motion based on ADAMS. And it is proved that the analytical datais premise by kinematic analysis to complicated noncircular gears of transplantingmechanism, in virtue of mechanical virtual simulation of ADAMS.7) It studies the primary part of high-speed transplanter—sliding part of spired axisin moving-box mechanism. Based on the stress analysis to spired axis mechanism,in the aspect of sliding part which smoothes through alveolus intersection, theresearch of parameters optimization, about the middle alveolus of spired axis andthe dimension of sliding part, has been studied. To the problem that the reverseportion at the both sides of spired axis lashed fiercely and fraies quickly, thearticle finely analyses the best curve of alveolus when adding cushiony spring atthe both sides. To decrease lashing when sliding part moves in the reverse portionof alveolus, the article makes the conclusion, the sliding part's acceleration andits changing value when arc, parabola, trigonometric function as the curve of spiredaxis alveolus reverse portion and proposes the better reverse portion curve.