气送式油菜播种机集排器供种装置设计与试验

Aiming at the problems such as insufficient stability of the seed supply amount of the existing centralized seed metering device of the pneumatic seeder when the surface slope variation range in the rape planting area is large, a seed supply device is designed. This device uses an adjusting spring to adjust the distance between the seed cleaning brush and the externally tangent circular arc hole wheel, thereby controlling the seed filling and cleaning amount, realizing sowing on sloping land and stable seed supply. The working principle of the seed supply device is expounded, the curve equation of the externally tangent circular arc hole, the deflection angle of the main circular arc and the structural parameters of the seed amount adjusting mechanism are determined, and the mechanical relationship between the seed amount adjusting mechanism and the hole wheel is analyzed. The performance optimization test of the seed supply device is carried out by using the intelligent planting machinery test platform. Taking the thickness of the seed cleaning brush, the effective number of turns of the adjusting spring, the thickness of the adjusting plate and the deflection angle of the main circular arc as test factors, the quadratic rotation orthogonal combination test is used to analyze the influence of each factor on the stability of the seed supply amount on the sloping surface. The optimal parameter combination is determined by the main objective method as follows: the thickness of the seed cleaning brush is 13 mm, the effective number of turns of the adjusting spring is 82.5, the thickness of the adjusting plate is 7.8 mm, and the deflection angle of the main circular arc is 7.7°. The change rate of the seed supply rate under a fixed inclination of -5° to 5° relative to no inclination does not exceed 4.29%, and the coefficient of variation of the stability of the seed supply rate does not exceed 0.52%, and the seed supply stability is relatively good. The bench verification test under the optimal parameter combination shows that the change rate of the seed supply rate in a swinging state of -5° to 5° relative to no inclination does not exceed 1.6%, and the coefficient of variation of the stability of the seed supply rate does not exceed 0.86%, meeting the requirement for the stability of the seed supply amount for sowing rape on sloping land.

针对现有气送式播种机集排器供种装置在油菜种植区域地表坡度变化范围大时供种量稳定性不足等问题,设计了一种采用调节弹簧调节清种毛刷与外切圆弧型孔轮距离,从而控制充种及清种量、实现坡地播种、稳定供种的供种装置。阐述了供种装置的工作原理,确定了外切圆弧型孔曲线方程、主圆弧偏转角及种量调节机构结构参数,分析了种量调节机构与型孔轮间的力学关系。利用智能种植机械测试平台进行了供种装置性能优化试验,以清种毛刷厚度、调节弹簧有效圈数、调节板厚度、主圆弧偏转角为试验因素,采用二次旋转正交组合试验分析各因素对坡度地表供种量稳定性的影响。采用主要目标法确定最佳参数组合为:清种毛刷厚度为13 mm、调节弹簧有效圈数为82.5、调节板厚度为7.8 mm、主圆弧偏转角为7.7°,固定倾斜-5°~5°相对无倾斜下的供种速率变化率不超过4.29%、供种速率稳定性变异系数不超过0.52%,供种稳定性较优。最优参数组合下的台架验证试验表明,供种速率在摆动-5°~5°相对无倾斜状态的变化率不超过1.6%,供种速率稳定性变异系数不超过0.86%,满足油菜坡地播种供种量稳定性要求。