楔形减阻旋耕刀设计与试验

为解决旋耕整地作业阻力大、能耗高等问题,该文基于旋耕刀理论受力模型设计了一种楔形减阻旋耕刀。采用Inventor和HyperMesh软件分别创建国标旋耕刀及楔形减阻旋耕刀的三维模型和切削土壤模型,分析了楔形减阻旋耕刀的应力强度,对比了国标旋耕刀与楔形减阻旋耕刀的切削阻力。通过田间试验对比了国标旋耕刀与楔形减阻旋耕刀的扭矩、功耗与碎土率。结果表明:楔形减阻旋耕刀所受最大应力为29.49 MPa,远小于材料的屈服强度430 MPa,在保证刀身强度的前提下,与国标旋耕刀相比,楔形减阻旋耕刀质量减轻8.3%;平均切削阻力较国标旋耕刀下降10.65%。在相同工况条件下,楔形减阻旋耕刀的平均扭矩为648.916 N·m,较国标旋耕刀下降11.35%;楔形减阻旋耕刀的平均功耗为67.3kW,较国标旋耕刀下降9.29%,碎土率提高4%,耐磨性能与国标旋耕刀持平,能够达到在降低作业功耗的同时,提高耕作质量并保证刀具使用寿命。

Design and test of wedge drag reduction rotary blade

Abstract: In order to solve the problems of high resistance and high power consumption of rotary tillage and land preparation, the rotary blade is studied based on theoretical analysis, simulation and field experiment in this paper. First, a wedge drag reduction rotary blade is designed based on the theoretical force model of cutting tools in mechanical soil dynamics. Second , the three-dimensional model of the national rotary blade and the wedge drag reduction rotary blade is established by using the Inventor software and the simulation experiment is carried on. The cutting soil model of 2 kinds of rotary blades is established by using HyperMesh software, and the material parameters, boundary constraints and working parameters are defined. On this basis, the soil cutting process, stress and cutting resistance are analyzed. It is proved that the wedge drag reduction rotary blade design is reasonable. In order to verify whether the wedge drag reduction rotary blade meets the strength requirement, the stress of the rotary blades is analyzed, and the cutting resistance of the national rotary blade and the wedge drag reduction rotary blade are compared. Third, field comparative experiments are carried out on national rotary blade and wedge drag reducing rotating blade with the evaluation indexes of torque, power consumption and soil breakage. The results show that the cutting resistance of the wedge drag reduction rotary blade is smaller than that of the national rotary blade; the maximum stress of the national rotary blade is 35.68 MPa and the maximum stress of the wedge drag reduction rotary blade is 29.49 MPa, which is less than that of the national rotary blade and far less than the yield strength of the material 430 MPa. On the premise of ensuring the strength of the blade body, the weight of the wedge drag reduction rotary blade is reduced by about 50 g, which is about 8.3% lower than that of the national rotary blade. The maximum cutting resistance of the national rotary blade is 530 N, the average cutting resistance is 375.5 N, and the maximum cutting resistance of the wedge drag reduction rotary blade is 510 N, the average cutting resistance is 335.5 N, the average cutting resistance of the wedge drag reduction rotary blade is 10.65% lower than that of the national rotary blade, which proves the feasibility of the wedge drag reduction rotary blade designed; The average torque of the wedge drag reduction rotary blade is 11.35% lower than that of the national rotary blade. In the working process of rotary blades, the average power consumption of the national rotary blade is 74.2 kW, the average power consumption of the wedge drag reduction rotary blade is 67.3 kW, and the average power consumption of the wedge drag reduction rotary blade is 9.29% lower than that of the national rotary blade. The average breaking rate of soil of the national rotary blade is 75%, and the average breaking rate of wedge drag reduction rotary blade is 79%, which is 4% higher than that of the national rotary blade; After continuous 33 hm2 tillage, rotary blades did not break, and the average wear of the national rotary blade is 98.5 g, the average wear of the wedge shaped drag reduction rotary blade is 97.3 g, the wear difference is 1.3%, and the wear degree is the same. The wedge drag reduction rotary blade can effectively solve the problems of high resistance and high power consumption of rotary blade, which is helpful to accelerate the development of arable land machinery, improve the mechanization level of cultivated land, and reduce the production cost of crops.