Mechanism Analysis And Optimal Design Of High-speed Rice Pot Seedling Transplanting Mechanism With Bezier Gears

There are two main ways of rice planting agronomic: direct seeding and transplanting.Transplanting is divided into blanket-like seedling transplanting and pot seedling transplanting.In the United States and some " big agriculture" countries of Europe, mainly adopt directseeding. Direct seeding is to throw rice seeds directly in paddy, is a disorderly cultivatemethods. Direct seeding can greatly reduce the labor intensity of rice cultivation, but notsuitable for China’s national conditions of planting in small plots; blanket-like seedlingtransplanting is to take cultivated blanket-like seedlings on the transplanter, through seedlingtransplanting mechanism torn into pieces, then plant into the field. Blanket-like seedlingtransplanting easily hurt rice, seedlings have a long period of remission after planting, notconducive to improving rice production; pot seedling transplanting is to transplant theseedlings with nutrition soil bowl into the paddy. Rice seedling transplanting seedlings plantedinto surface of ground with higher soil temperature, no remission period, with early tillering,root development, increase production advantages.Japan is the first country developed pot seedling transplanter and enter the market. Its potseedling transplanting machine adopts three sets of mechanism or device to complete seedlingpick-up, transport and plant: Seedling pick-up adopts the crank rocker mechanism; Transportingadopts belt delivery system; Planting adopts rotary planting device. Its institutional complexity,high cost and inefficient. In order to improve pot seedling transplanting system device withthree mechanism or device to complete seedling pick-up, transport and plant, thispaper developed a rotary rice pot seedling transplanting mechanism which completed the abovethree action with one mechanism.The main contents are as follows:1）Through institutional innovation, applied the Bezier gears non-constant transmission torice pot seedling transplanting mechanism design, invented a simple structure and low cost oftransplanting mechanism-rice pot seedling transplanting mechanism with planetary Beziergears, an mechanism to complete seedlings pick-up, transport and plant three actions, highproduction efficiency.2）Designed a new non-circular gear pitch curve forming method，using the Bezier curvefitting control points to get the non-circular gear pitch curve, and named the non-circular geardesigned by this method as Bezier gear.3）Based on pitch curve points deduced a non-circular gear slotting processing numericalmodel. Using this method for UG software secondary development, designed non-circular gear three-dimensional modeling software and get the software works registration right (registration number:2013SR000009).4) Introduced body composition and working principle of rice pot seedling transplanting mechanism with planetary Bezier gears, established the kinematics model of transplanting mechanism and analyzed the corners and displacement of the Bezier gears and transplanting arm cusps.5) According kinematics model of transplanting mechanism, based on the VB visual programming platform designed rice pot seedling transplanting mechanism with planetary Bezier gears aided analysis and optimization software, and access to software works registration right (registration number:2013SR066147). Using this software to optimize a set of optimum parameters to meet the requirements of rice pot transplanting:r1=12.5mm,φ1=18.5°, r2=27.7mm,φ2=45°, r3=49.6mm,φ3=75.5°, r4=48.8mm,φ4=104.5°, r5=58.4mm,φ5=131.5°, r6=47mm,φ6=165°, r7=18.2mm, φ7=195°, r8=11.9mm, φ8=224.5°, r9=27.7mm, φ9=255.5°, r10=60.5mm,φ10=285°, r11=47.8mm,φ11=316°,r12=23.7mm,φ12=345°,fai0=86°, det0=-29°, S=150mm, H1=65mm,afai0=-53°,H=180mm.6) In AutoCAD software completed structure design of rice pot seedling transplanting mechanism with planetary Bezier gears; in UG software completed dimensional model of the various components of transplanting mechanism, and assembled into a virtual prototype; in ADAMS software finished transplanting virtual prototype simulation.7) Developed transplanting mechanism’s physical prototype, using high-speed photography equipment complete transplanting mechanism circumstances of the shooting at high speed. Analyzed the key positions of transplanting mechanism’s body posture and relative trajectory.8) In our group independently developed mechanical transplanting test bench, completed the seedling transplanting mechanism seedlings pick-up test.