马铃薯曲面式播种开沟器仿生设计与试验

针对马铃薯播种开沟器高速作业条件下作业阻力大、回土深度浅、干湿土易混合等问题，基于黄鳍金枪鱼下颚流线型曲线，采用水平直元线法将原有曲线重构为三维曲面，设计一种仿黄鳍金枪鱼下颚曲线的曲面式开沟器。根据马铃薯种植深度的农艺要求，当最大作业深度为150mm时，采用滑切原理确定了最大刃口角为132°，元线角为27°。为探究起土角对开沟器作业性能的影响，以作业阻力为评价指标，进行单因素试验，确定了分土板的起土角为45°。通过分析种薯下落到地表时的相对位移确定上挡土板的长度。干湿土分层仿真试验表明，开沟器作业不扰乱土层顺序。田间多工况对比试验表明，在开沟深度为100、125、150mm，作业速度为3.6、5.4、7.2km/h条件下，曲面式开沟器比芯铧式开沟器、靴式开沟器平均作业阻力减小18.3%、33.4%，平均回土深度增加70.4%、91.7%。田间性能对比试验表明，在开沟深度为150mm，作业速度为7.2km/h条件下，曲面式开沟器比芯铧式开沟器、靴式开沟器种沟中土壤含水率增加3.5%、4.7%，曲面式开沟器能减少干湿土混合，曲面式开沟器比芯铧式开沟器、靴式开沟器种薯横向偏移系数减小9.5%、10.1%，满足马铃薯种植开沟的农艺要求。

Bionic Design and Experiment of Potato Curved Surface Sowing Furrow Opener

In order to solve the problems of high resistance, shallow depth of soil return and easy mixing of wet and dry soil of potato sowing trencher under high speed operation conditions, the streamline curve of yellowfin tuna mandible was used. The horizontal linear element method was used, which can reconstruct the original curve into a three-dimensional surface. A curved grooving device imitating the curve of yellowfin tuna jaw was adopted, which could be adapted to the agronomic requirements of potato planting depth. When the maximum operating depth was 150mm, the sliding cutting principle was adopted, which can determine the maximum cutting edge angle of 132° and the element line angle of 27°. In order to explore the influence of soil lifting angle on the operating performance of the trencher, the operating resistance was taken as the evaluation index, and the single factor test was carried out, which determined that the soil lifting angle of the soil slat was 45°. The length of the upper retaining plate was determined by analyzing the relative displacement of the seed potato when it fell to the surface. The simulation test of dry and wet soil showed that the operation of trencher did not disturb the sequence of soil layers. Compared with the core type furrow opener and the boot type furrow opener, the average operating resistance of the curved type furrow opener was reduced by 18.3% and 33.4%, and the average returning depth was increased by 70.4% and 91.7% under the conditions of furrow depth of 100mm, 125mm and 150mm and operating speed of 3.6km/h, 5.4km/h and 7.2km/h. The field performance comparison experiment showed that the soil moisture content of the curved trench opener was increased by 3.5% and 4.7% compared with that of the core share trench opener and the boot trench opener, and the curved trench opener could reduce the mixing of wet and dry soil under the condition of the trench depth of 150mm and the operating speed of 7.2km/h. Compared with the core type furrow opener and the boot type furrow opener, the transverse migration coefficient of potato planting with curved surface furrow opener can be reduced by 9.5% and 10.1%, which can meet the agronomic requirements of potato planting furrow opener.