玉米原茬地侧向清茬刀设计与试验

针对玉米原茬地免耕播种作业过程中残留玉米根茬和须根导致施肥播种部件堵塞、播种质量降低等问题,该文设计了一种玉米原茬地免耕播种用侧向清茬刀,分析了侧向清茬刀工作与结构参数对根茬清除率、土壤扰动率和功耗的影响。对侧向清茬刀清茬、输送、抛扔等作业过程进行分析,并依此对侧向清茬刀结构及正切刃工作曲线进行设计,确定了影响其作业性能的关键参数。应用三因素三水平正交试验和模糊综合评价方法,选取正切刃折弯角α、正切刃宽度B、清茬刀角速度ω为影响因素,根茬清除率、土壤扰动率、当量功耗为性能指标,对影响作业性能的侧向清茬刀结构和工作参数进行优化。结果表明:在作业速度7.2 km/h条件下,正切刃折弯角0.86 rad、正切刃宽度50 mm、清茬刀角速度52 rad/s时,根茬清除率为94.3%,土壤扰动率为54.3%,当量功耗为3.4 kW,工作过程中未出现堵塞与秸秆缠绕现象。研究结果可为玉米原茬地免耕播种作业提供参考。

Design and test of lateral stubble cleaning blade for corn stubble field

Abstract: In Xinjiang region of China, the grape cultivation area needs to take soil buried cold-proof operation in winter to make the vines safely overwinter. However, the single soil buried cold-proof operation brings great difficulties to the subsequent soil clearing operations, such as incomplete soil mechanical clearing and low operation efficiency. The vineyards headed by Xinjiang change the cold-proof mode, and the cold-proof cloth is used to assist in soil buried cold-proof operation, which can play a better effect of heat preservation and moisture conservation and provide the possibility for complete soil clearing. But at the same time, there are some problems such as difficulty in recycling cold-proof cloth. In view of the problems in the above-mentioned soil clearing operation and the agricultural requirements of the trellis-type grape planting, combined with the operation requirements of the grape soil clearing under the cold-proof cloth assisted soil-buried mode, this paper designed the grape winter buried soil clearing and cold-proof cloth recycling machine, which is composed of a frame, a soil clearing component, a cloth recycling component and a hydraulic system, etc. This paper explained the structure and working principle of each part of the machine in detail, and analyzed the structure and parameters of key components. The tensile performance test of the cold-proof cloth used for one year was carried out to verify the feasibility of the cold-proof cloth recycling. The result showed that the tensile strength of the old cold-proof cloth was lower than that of the new cold-proof cloth, and the warp tensile strength was better than the across, but it was not enough to affect its recycling, based on this the correct direction of the cold-proof cloth using was determined, and the basis for the design of cloth recycling component was provided. Discrete element software EDEM was used to carry out simulation test of soil clearing operation. The simulation model consisted of soil ridge and soil clearing component modes in EDEM software. The soil clearing distance was used as the evaluation index of soil clearing effect, and the experimental factors were the curvature radius of the working face of the scraper, the blade numbers of the soil clearing impeller and its rotation rate. Under the condition of 2 km/h, the three-factor five-level simulation orthogonal test was carried out. The results showed that the order of influence of three factors on soil cleaning distance was that curvature radius, blade number and rotation rate. According to the variance analysis of test result, the curvature radius was the significant influencing factor, the blade number and rotation rate were the non-influencing factors, and the optimal parameter combination was that the curvature radius was 680 mm, the blade number was 4, the rotation rate was 500 r/min, and the clearing distance was 294.27 mm. The prototype was processed and the field verification test was carried out based on the optimal parameter combination. The test results showed that the soil clearing distance was 271 mm, and the relative error with the simulation test results was 8%. The buried soil was basically cleaned and the damage to the vines and the cold-proof cloth was small. The operation efficiency of the machine was more than 10 times of the manual soil clearing efficiency. This study can provide a new development idea for the operation of buried soil clearing in Xinjiang regions of China, and provide reference for the development of follow-up grape soil clearing machinery.