Design And Optimization Of Rice Seedling Transplanter Mechanism Based On Pascal Spiral Gear

Rice is the favorite staple food for my country, accounting for about 60% of the country’s people live on rice, so rice yield is the key of ensuring food security in China.In recent years, China’s urbanization process is constantly advancing.Therefore the development of the rice planting machine is the only way which must be passed to the increase of grain yield.At present, China’s rice harvest mechanization capability can basically meet the conditions,But the lower rice planting mechanization level has affected the production capacity and the yield of rice,Therefore, whether we can develop the rice planting mechanization rapidly in China is a major problem in ensuring food security which we are facing.Rice seedling transplanting technology is an innovation way of planting rice,Transplanting seedling of rice can be bred roots with a full bowl type nutritional clod seedlings, transplanting with pot soil, no hurting to the roots, no planting injury,compared with the blanket shaped seedling transplanting mode can be increased by 10% ~ 20%,Obvious yield increasing effect.Pot seedling transplanting technology makes the rice planting expanded from high accumulated temperature zone to low temperate zone, increase the fine grain planting area and is the only way to adapt to the cultivation of super rice.At present, the prior rice seedling transplanting mechanism in domestic and foreign is with complex structure,low efficiency, high cost, poor stability, difficult to guarantee the quality of work,These became the main reasons in limiting rice seedling transplanting technology developing in China’s large area.Therefore the development of a simple and stable structure, low price, high efficiency and good operation quality of rice seedling transplanting mechanism is the effective method to solve the mechanization of rice seedling transplanting application and promotion and it will be able to promote to improve the level of the rice planting mechanization in our country.This paper studies on the domestic and international current situation of rice seedling transplanting mechanism,analysis of the pros and cons of various types of rice seedling transplanting machine,In the modernization of transplanting machine innovation design research platform, developed a high-speed rice seedling transplanting mechanism based on Pascal spiral gear nonuniform transmission operational principle.The main research contents are as follows:(1) Through the research and analysis of the working principle of the transplanting mechanism at home and abroad,we found the problem of rice pot seedling transplanting mechanism which we should solve.That is how to through a simple mechanism completes taking seedling, transporting and planting seeding action efficiently in a work cycle.(2) This paper analyzes Pascal spiral gear pitch curve characteristics and studys on the transmission law of conjugate gear,then in view of the existing shortcomings of rice seedling transplanter,the first time put Pascal spiral gear used into transplanting mechanism which forming planetary gear train with variable ratio transmission,And then put forward the planetary gear train rice seedling transplanter based on Pascal spiral gear.(3) Through the analysis of Pascal spiral gear planetary gear rotary transplanting mechanism, established kinematics and dynamics model of the mechanism,got kinematic equations of each gear of the transplanting mechanism, understood the dynamic performance of the mechanism, providing the data for improving the design reasonably and effectively, and provide a theoretical basis for the subsequent development of the transplanting mechanism computer aided analysis and optimization software.(4) Using Visual Basic 6 software development platform, using CAA technology,according to the agronomic requirements of rice pot seedling transplanting andtransplanting mechanism work requirements, to determine the optimal target of the mechanism.Based on the kinematics model of the transplanting mechanism, developed a analysis and optimization computer aided software system of rice transplanting mechanism, optimized a set of design parameters to meet the requirements of the transplanting mechanism.(5) According to the design parameters which optimized by software in the fourth chapter,designed in the AutoCAD2008 platform, completed the structural design and drew the mechanical drawings for the transplanting mechanism, lay a solid foundation for the prototype development.(6) According to drawings of the two-dimensional structure,using the UG software, completed the three-dimensional modeling of parts and virtual prototype assembly of the transplanting mechanism,And the virtual model is put into the Adamsto run a prototype simulation.By contrast the velocity 、 acceleration and kinematics trajectory curve of the transplanting mechanism optimized by software developed independently,verified the feasibility and calculation of the mechanism, which provides theoretical support for transplanting machine prototyping.