| Potato is one of the four major staple food in the world,the most promising high yielding economic crop,the mode and scale of its cultivation is of great significance to the adjustment of agricultural structure and the development of grain production safety in China.China is a potato producing country,but not a powerful country,acreage and total output are occupied the first in the world,but the crop yield level is far below the world average,the main reason is the low level of mechanization of potato production in China.Potato mechanization as the most important part of the whole process of mechanization production,directly affect the yield and quality of potato.The seed metering device is the key part of potato seeder,there are still many technical problems of low working efficiency,serious multiples misses and poor adaptability.In order to meet the demand of potato mechanization planting,this paper adopts the idea of combining agricultural machinery and agronomy,this paper designed a kind of double row Criss-cross Spoon-belt potato precision seed metering device.The seed metering device adopts a kind of staggered arrangement and vibrating device in the seed belt to effectively reduce the problem of multiples and misses in the seeding process.In this paper,based on the agronomic requirement of precision sowing the characteristics of potato seed potato,using the method of theoretical analysis,EDEM simulation,high-speed camera and experimental study,this paper studied and explored the double row Criss-cross spoon-belt potato precision metering device,the main contents and conclusions of this study are as follows:(1)Determination and study of material properties of potato seedThree kinds of potato seed(Feiwuruita,Eugene 885,Dongnong 312),which were widely cultivated in the northeast of China,were selected to study the material properties,its basic physical properties(three axis dimension,geometric mean diameter,sphere ratio,quality,density,volume,moisture content,etc)were measured and setted up a variety of physical mechanics test bench,determination of the mechanical parameters(coefficient of static friction,internal friction angle,natural angle of slope,stiffness coefficient and elastic modulus)of seed potato,Which provided the theoretical basis for the structural design and simulation analysis of the potato seed metering device.(2)Optimization design and analysis of key components on Double row Criss-cross Spoon-belt potato precision seed metering deviceThe main structure and working principle of Double row Criss-cross Spoon-belt potato precision seed metering device were studied,optimized the key components of the two-spoon staggered seed assembly,active drive assembly,vibration and seed storage device and the lower side of the box,established a dynamic model for the process of filling,cleaning,guiding and investing,the structural parameters of the key components of the seeder were analyzed and optimized.(3)Based on the discrete element method of potato precision seed metering device seed-filling migration performance simulation analysisIn order to optimize the performance of the seed metering device,the virtual model of the seed metering device was established by the method of discrete element method,the single element virtual experiment was used to simulate the filling process of the seed metering device by using EDEM and analyzed the main causes of the multiples and misses of different size grades of potato in the process of filling,the optimal working parameters of the seed metering device were preliminarily screened,and the trial manufacture of the prototype was carried out to prepare for the subsequent bench test and field test.(4)Potato precision seed metering device Investment performance analysis and test based on the technology of high-speed cameraIn this paper,the Double row Criss-cross spoon-belt potato precision metering device was used as the research vector,focued on potato delivery migration mechanism,analysis of the impact of the main factors for delivery guide migration path.On this basis,we designed and set up a potato seed sowing test stand,combined with high-speed camera technology to analyze the trajectory of seed delivery,potato seed metering device and its matching opener optimization design.(5)Performance test of potato precision seed metering device test benchIn order to get the best working parameters of the seed metering device,the angle of inclination,the working speed and vibration amplitude were the main factors,the performance indexes of the seeding distance index,the multiples index and misses index were obtained,reference to the national standard GB/T 6242-2006 "mechanical planting potato planting machine test method" and NY/T 1415-2007 "potato planting machine quality evaluation of technical specifications",respectively using single factor and multi-factor orthogonal rotation combination test,establishing performance index and test parameters of mathematical model,using Design-Expert 8.0.10 software analysis of the test results,and the optimization results were tested and verified,and the rationality and rationality of the design were studied.The experimental results showed that the operating speed was 31.5r/min,the vibration amplitude was 11.7mm,the performance of the seed metering performance was optimal,the qualified index was 89.92%,the multiples index was 5.12%,the misses index was 4.96%.(6)Potato precision sowing device configuration and field testAccording to the requirements of potato planting in northeast China,the sowing device of potato precision was designed and integrated in the parts of opener,fertilizer apparatus,fertilizer box,soil-cover and press wheel.Dongnong 312,Eugene 885,Feiwuruita as tested varieties and then carried out field sowing test,the uniformity of sowing,the depth of seed fertilizer and follow-up yield were measured,tested equipment operation results.The results of the field experiment showed that the qualified index,the multiples index and the misses index were better than the national standard,average empty spoon rate was 3.44%,and a fertilizer depth of appropriate,the field emergence rate was higher than 90%,the average yield per mu is estimated to be 3230.9kg,which met the precision of potato agronomic requirements. |
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