| Seed potatoes tuber cutting planting is the main cultivation mode in China.The size,shape and uniformity of seed potatoes tuber directly affect the potatoes yield,seedling uniformity and seedling shape.At present,China’s seed potatoess are still mainly cut by hand.There are many problems,such as low operation efficiency,uneven size of potatoes blocks,high labor intensity,various processes and high cost,which affect the mechanized planting of potatoes,the quality and quality of seed potatoess and the overall development of potatoes industry.Therefore,studying potatoes mechanized seed production devices and solving the problems of the seed potatoes industry are the key to promoting the sustainable development of the potatoes industry.At present,the research on seed potatoes production mechanization technology and equipment in China is at the initial stage,and there is no seed potatoes cutting machine in the market.The basic research on seed potatoes production equipment needs to be strengthened,so as to promote the overall progress of seed potatoes industry mechanization technology and equipment research in China.According to the research status of seed potatoes cutting machine at home and abroad,according to the requirements of seed potatoes cutting agronomic technology,in order to break through the key core problems of seed potatoes cutting device,this study combined theoretical analysis,virtual simulation,bench performance test and other research methods to explore the influence of various factors on seed cutting efficiency and seed cutting qualified rate.The main research contents and results are as follows:(1)In this study,the basic physical characteristics,friction characteristics,and compression characteristics of seed potatoes,which are commonly used in the northeastern region,are tested.The test results show that the quality of seed potatoes is 70～140g,140～210g,and 210～300g.The major axis dimensions are mainly distributed in 55～75mm,75～95mm,90～110mm,the minor axis dimensions are mainly distributed in 45～65mm,45～65mm,70～90mm,and the height dimensions are mainly distributed in 40～56mm,45～65mm,70～90mm;the average density of single seeds of Zhongshu No.5 seed potatoes is 1.079 g/cm3,and the average density of single seeds of Dongnong 303 seed potatoes is 1.129 g/cm3;the sliding friction coefficient between cut potatoes and steel plate is 0.86;The rolling friction coefficients of Zhongshu No.5 whole potatoes and2Cr13 stainless steel plate and natural rubber plate are 0.236 and 0.258 respectively.The rolling friction coefficients of Dongnong 303 whole potatoes and 2Cr13 stainless steel plate and natural rubber plate are 0.254 and 0.294 respectively;Zhongshu 5 The elastic modulus of No.seed potatoes in the long axis,short axis,and height directions were 4.33,3.49,3.41,Poisson’s ratio was 0.41,0.42,0.45,and the shear modulus were 1.54,1.23,1.18,and Dongnong 303 seed potatoes The elastic moduli in the long axis,short axis,and height directions are 4.34,3.61,3.43,Poisson’s ratios are 0.39,0.41,and 0.43,respectively,and the shear moduli are 1.56,1.27,and 1.20,respectively.(2)Based on the research of material characteristics and the agronomic requirements of seed potatoes cutting,a new method of seed potatoes cutting based on the cooperation of vertical and horizontal knife groups was proposed.The operation principle of seed potatoes cutting device with the cooperation of vertical and horizontal knife groups was analyzed.The potatoes cutting components and cutting device with the main parts of vertical and horizontal knife groups,sieve plate groups and clamping roller groups were developed The key factors affecting seed cutting efficiency and seed cutting pass rate were determined as follows: radius of disc cutter,vertical center distance between conveying roller and disc cutter,rotation speed of disc cutter shaft,rotation speed of clamping roller shaft;bending angle of screen plate,installation angle of screen plate,distance between lower clamping roller and screen plate.(3)The accurate three-dimensional model of seed potatoes was established by scanning the seed potatoes with three-dimensional laser scanner.The finite element model of seed potatoes and disc cutter was established by using ANSYS software.The model was preprocessed by using LS pre post software,and the keyword command was added.The process of cutting seed potatoes with disc cutter was simulated and analyzed by LS DYNA software,and the cutting force curve was obtained and verified,The accuracy of the simulation results is verified by comparing the verification test results with the simulation results.Through the simulation analysis,taking the speed ratio of the transmission shaft of the conveying roller and the disc cutter shaft as the test factor,and taking the cutting force as the test index,the single factor test is carried out,and it is concluded that when the speed ratio of the transmission shaft of the conveying roller and the disc cutter shaft is 0.45 ～ 0.55,the cutting effect is the best.(4)Test bed for seed potatoes cutting Equipment with vertical and horizontal knife groups was designed.The radius of the disc cutter,the vertical center distance between the conveying roller and the disc cutter,the speed of the disc cutter shaft,and the rotation speed of the clamping roller were used as the test factors.Orthogonal experiment is carried out with the cutting efficiency as the test index,through the analysis of the test results and parameter optimization;the installation angle of the stripping guide,the bending angle of the stripping guide,the vertical center distance between the lower clamping roller and the disc knife are the test factors,and The qualified rate of cutting seeds is the test index,the Box-Behnken test is carried out,the test results are analyzed and the parameters are optimized;the verification test of the above test results shows that: when the radius of the disc cutter is 180 mm,the conveying roller and the disc cutter are perpendicular The distance is 190 mm,the speed of the disc cutter shaft is 115r/min,the speed of the clamping roller shaft is 56 r/min,the installation angle of the stripping guide is 17°,the bending angle of the stripping guide is 135°,the lower clamping roller and the disc knife When the vertical center distance is 220 mm,the maximum cutting efficiency of the vertical and horizontal knife group cooperative seed potatoes potatoes cutting device is 74.5kg/min,and the maximum cutting pass rate is 98.8%,the rationality of the structural design of the vertical and horizontal knife group cooperative potatoes cutting device,the rationality of the relevant theoretical analysis and the rationality of the optimization of the operating parameters were verified to meet the requirements of the potatoes cutting operation.The related research in this article provides a new idea for the research and design of the key device of the potatoes cutting machine,and puts forward an effective way for the problems of low cutting efficiency,low cutting qualification rate,high production cost,and long working hours in the process of potatoes cutting operations in my country.The solution provides technical reference and theoretical support for the related research and development of potatoes automatic seed cutter. |
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