马铃薯播种机分体式滑刀开沟器参数优化与试验

针对马铃薯播种机的铧靴式和圆盘式开沟器存在的种薯株距分布不均、播种效果质量差、回土量小等问题,研制出分体式滑刀马铃薯开沟器,并进行关键参数优化,分析开沟和回土过程中土壤颗粒在开沟器上的运动规律,研究种薯落入垄沟后的运动过程,确定影响土壤覆盖种薯效果的因素。采用旋转正交的试验设计方法,以机具前进速度、开沟器侧面夹角、开沟器长度及开沟深度为试验因素,以种薯的横向偏移系数、株距变异系数和回土量为试验指标,分析实施田间试验结果,优化分体式滑刀开沟器的结构参数与最优运动参数:在前进速度为0.95 m/s、开沟器侧面夹角为60°、开沟器长度为500 mm、开沟深度为115 mm时,株距变异系数为10.8%、种薯的横向偏移系数为3.83 mm、回土量为24.1%,满足马铃薯播种作业的要求。该研究结果可为马铃薯开沟播种装置设计与应用提供参考。

Parameter optimization and experiment of splitter sliding-knife opener for potato planter

Abstract: The seed potato distribution is not uniform, and the seeding quality and quality of back fill is poor when potato seed casting into the furrow by using the ditching shoe and disc opener. In this study, the splitter sliding-knife potato opener was designed and optimized. It had a good embedded performance. The opener was towed by a tractor when the potato planter was operation. The installation site was under the seed-metering device and the longitudinal direction of opener can be adjusted to requirements. A V-shape furrow was got after the working process of opener. The soil particles were cutting and crashed by the edge of the shovel at the front side of the opener, and moved along the side surface of opener. Some of soil particles were fall into the furrow firstly to create a soft furrow thus providing a better furrow situation for potato to grow. In this paper, we also obtained the main factors that influenced soil covering for seed potato, by analysis of the soil particles in the process of motion on the side of the opener and the process of soil fall into furrow, and also kinematics analysis the seed potato falls into the furrow. The time at which the soil particles contact the bottom of the furrow was less than the time at which the soil particles fall into the furrow at the range of the resting angle. The planting effects were not only influenced by the parameters of opener, but also had a connection with the position of potato casted into furrow. The ideal seeding condition is that the potato fall into the bottom of the V-shape furrow, the lateral deviation coefficient of the seed potato is well, and the sowing quality is higher. To get good effects of planting, the time of potato fall into furrow should be less than that of soil particles fall back into furrow. The factors influencing the effect of the potato seed in the ditch were obtained through theoretical analysis after the movement parameters of planter were collected, and they were forward speed, depth of furrow, the length of opener and side angle of opener when initial conditions of the seeding were determined. A rotating orthogonal field experiment was designed. With forward speed, side angle of opener, length of opener and depth of furrow were taken as the experiment factors, coefficient of variation of row spacing, sowing width mean absolute deviation and quality of back fill as the test indices. The test was implemented in Heilongjiang Academy of Agricultural Sciences in June, 2015. The results showed the primary and secondary order of influencing factors for each test index. For the coefficient of variation of row spacing, the order was the depth of furrow, forward speed, the length of opener and side angle of opener. For the sowing width mean absolute deviation, the order was the depth of furrow, forward speed, side angle of opener and length of opener. For the quality of fill back, the order was the depth of furrow, forward speed, the length of opener and side angle of opener. The best structure parameter of splitter sliding-opener was obtained through field test. And results showed that the coefficient of variation of row spacing was 10.8%, sowing width mean absolute deviation was 3.83 mm, the quality of fill back was 24.1%, when the forward speed was 0.95 m/s, the opener of the side angle was 60 degree, the opener length was 500 mm, the depth of furrow was 115 mm. The comparison test showed that the V-furrow out of slide-knife opener was better than the ditch out of the traditional shoe-type opener. The reason was that the V-furrow can reduce seed movement and lateral displacement, to improve the consistency of the seed space. Besides, when the combination of the length of slide-knife opener was 500 mm and the side angle of the opener was 60°, the machine can provide enough time for potato seed into furrow, and the quality of fill back was also large so that potato seed can have enough soil cover and have a good ambient temperature and humidity for its growth. The sowing quality for the splitter sliding-opener was better than traditional opener. The opener designed was meeting the requirements of potato planting. The study of potato furrowing seeding device provided with reference to the design of a new theoretical support.