稻麦油兼用高速气送集排器螺旋斜置式搅种装置研制

Development of the spiral-inclined seed stirring equipment in high-speed air-assisted centralized metering for rice,wheat,and rapeseed

针对稻麦油兼用气送式集排器高速作业时搅种装置易伤种、影响排种稳定性等问题,该研究设计了一种螺旋斜置式柔性搅种装置。基于Hertz接触理论分析确定了搅种装置影响种子破损的主要因素为搅种棒材质、顶端结构及搅种转速。通过EDEM仿真试验对比分析了梯形和圆弧形搅种棒与种群接触力随时间的变化趋势,明确了搅种棒安装方式对供种性能的影响,结果表明,圆弧形搅种棒与种群接触的切向力和法向力均小于梯形搅种棒,搅种棒倾斜角度为45°时供种稳定性较优。开展台架单因素试验确定了性能较优的搅种转速比范围,结果表明,水稻和小麦种子在搅种转速比范围1.0~2.0内性能较优,油菜种子在搅种转速比范围0.5~1.5内性能较优。开展三因素三水平二次旋转正交组合试验,构建了稻麦油种子破损率、供种速率及其稳定性变异系数的回归模型,明确了作业速度在10~14 km/h范围内搅种转速的较优匹配关系并进行田间验证试验。田间验证试验结果表明,当作业速度为12 km/h,在较优参数组合下,稻麦油总排量稳定性变异系数分别为1.92%、1.27%和1.14%,1 m^(2)内成苗总株数变异系数分别为15.47%、12.98%和17.93%,符合稻麦油兼用高速作业标准要求。研究结果可为稻麦油兼用型排种器实现高速低损播种作业的参数设置提供依据。

Air-assisted centralized metering can be operated at high speed for rice,wheat,and rapeseed.However,the seed stirring device is prone to damage the seeds,leading to the low stability of discharge quantity.In this study,a spiral-inclined flexible seed-stirring device was designed for high-speed,air-assisted,and centralized metering.The influencing factors on the seed damage were determined using Hertz contact theory,including the material properties of the seed stirring rod,the top structure,and the stirring speed.A comparison was made on the variation in the top structure of the seed stirring rod and the contact force of the population over time using EDEM simulation.A systematic investigation was also implemented to clarify the impact of the seed stirring rod on the seed supply.The test results show that the tangential and normal forces of the arcshaped seed stirring rod in contact with the population were smaller than the trapezoidal seed stirring rod.There was better stability of seed supply when the inclination angle of the seed stirring rod was 45°.A single-factor test was conducted on a bench to determine the optimal range of seed stirring speed ratio.The results showed that the rice and wheat seeds performed better within the range of 1-2 seed stirring speed ratios,while the rapeseed seeds were in the range of 0.5-1.5 seed stirring speed ratios.A three-factor,three-level,and quadratic rotation orthogonal experiment was carried out to optimize the influencing factors.A regression model was then established for the damage rate,seed supply rate,and stability coefficient of variation of rice,wheat,and rapeseed.There was an optimal matching relationship between the stirring speed and the operating speed within the range of 10-14 km/h.Field experiments were also conducted to verify the simulation.It was found that the stability coefficients of the variation in the total displacement of rice,wheat,and rapeseed were 1.92%,1.27%,and 1.14%,respectively,under the optimal combination of parameters,when the operating speed was 12 km/h.The coefficients of variation in the total number of seedlings within 1 m^(2) were 15.47%,12.98%,and 17.93%,respectively,which fully met the requirements of the standard for the high-speed seeding.The finding can provide a strong reference to achieve high-speed and low-loss seeding in the parameter selection of high-speed,air-assisted,and centralized metering devices for rice,wheat,and rapeseed.