Design And Experimental Study Of Orderly Rice Seedling Throwing Devic

At present,the main planting methods of rice in China are direct seeding and mechanical transplanting.There are many problems,such as high rate of seedling damage,high rate of missed seeding,low degree of automation,and long delay period.In addition,manual resurfacing is required,which greatly increases the cost input.As an advanced rice planting technology,orderly seedling throwing technology has changed the traditional operation mode of direct seeding and transplanting,overcome the defect of fixed row spacing of rice transplanter,and made the basic seedling quantity and density more reasonable than that of direct seeding and direct seeding.However,due to the impact of weather on the seedling throwing operation,the existing rice seedling throwing machines are prone to problems such as uneven rows,floating seedlings,and insufficient depth into the soil.In this paper,based on the agronomic requirements of orderly rice seedling throwing,consulting and sorting out relevant data,using advanced seedling throwing technology for reference,and according to the test results of the characteristics of rice bowl seedlings,an air blown orderly rice seedling throwing device was designed,theoretical analysis and mechanism design were carried out,a test bench for pneumatic orderly rice seedling throwing device was built,and performance tests and optimization tests were carried out.The main research contents include:(1)The material properties of rice pot seedlings were tested.Taking the rice varieties Longjing 31,Kongyu 131 and Kendao 23,which are widely planted in Heilongjiang Province,as the research objects,the material properties of three kinds of rice pot seedlings,such as quality,width,height,center of gravity,and soil pot moisture content,were obtained,providing a reference for the design of air blown orderly seedling throwing device.(2)An air blown rice seedling throwing device was designed.The key components of the seedling feeding belt,driving roller,fan,seedling receiving pipe,ventilation pipe,seedling guiding pipe,and air chamber were designed and calculated.The relevant parameter structures were determined.The working process was analyzed.The mechanical model of the seedling throwing mechanism under the dual effects of gravity field and air field was established.The movement and force of the potted seedlings were analyzed,The factors influencing the working performance of air blown rice seedling throwing device were obtained.(3)The performance test of the air blown rice seedling throwing device was conducted.The locomotive forward speed,the speed of the seedling feeding belt,and the fan speed were taken as the test factors,and the qualification rate of planting depth,the damage rate of potted seedlings,and the qualification rate of planting uniformity were taken as the evaluation indexes.Through the single factor test,the horizontal variation range of each influencing factor was determined,and the performance test of the seedling throwing device was carried out in the roast laboratory.The three factor five level quadratic orthogonal rotation combination test was used,and the design expert 12.0 software was used to optimize the analysis of the test results.The corresponding response surface and regression equation were obtained,and the best parameter combination affecting the seedling throwing performance was determined,And the verification test was carried out: the locomotive forward speed was 3.9 km/h,the fan speed was 2206 r/min,and the speed of the rice seedling belt was 0.45 km/h.At this time,the qualified rate of planting depth was 95.46%,the damaged seedling rate was 1.92%,and the qualified rate of planting uniformity was 91.45%.The error was within the allowable range,meeting the requirements of orderly seedling throwing.