垄上灭茬刀优化设计与试验

Optimum Design and Test of Stubble Cutter on Ridge

针对灭茬刀耕作阻力大、磨损严重等问题,优化设计了灭茬刀及刀辊。通过理论分析,得到影响灭茬刀耕作阻力和损伤情况的因素为灭茬刀正切刃滑切角、侧切刃滑切角和弯折角,并确定灭茬刀作业状态稳定时正切刃滑切角的取值范围为0°~16°,侧切刃滑切角的取值范围为47°~68°,弯折角的取值范围为90°~130°。在有限元软件ABAQUS中对土壤建立Drucker-Prager本构模型,并进行了灭茬刀切割土壤的运动学仿真试验,设计为三因素三水平正交试验。结果表明:影响灭茬刀作业过程中应力和应变变化的主次因素为侧切刃滑切角、弯折角、正切刃滑切角,当正切刃滑切角16°、侧切刃滑切角68°、弯折角110°时,灭茬刀的应力和应变较优,且方差分析得到各因素对应力和应变的影响均显著。田间试验结果表明:优化设计的灭茬刀较行业标准灭茬率提高9.57%,碎土率提高6.6%,灭茬深度稳定性系数提高4.2%,灭茬刀作业效果优良。

Stubble cutter has large resistance during the process of tillage and it is easy to get worn badly.Aimed at these problems,this paper optimizes the design of stubble cutter and roller.Through the theoretical analysis,it is found that the factors affecting the tillage resistance and damage of the stubble cutter are the sliding angle of the cutting edge,the sliding angle and the bending angle of the cutting edge of the stubble cutter.It is found out that when the stubble cutter has a stable operation,the sliding-cutting angle of the tangential edge ranges from 0°to 16°,the sliding-cutting angle of the lateral edge ranges from 47°to 68°,the bending angle ranges from 90°to 130°.Druck-Prager structure is built on the soil in ABAQUS.Then the kinematics simulation experiment is used when the stubble cutter is cutting the soil.The experiment is three factors and three levels orthogonal experiment.The result indicates that during the process of stubble-cutting operation,the primary and secondary factors which influence the strain and strain variation are the sliding-cutting angle of the lateral edge,the bending angle and the sliding-cutting angle of the tangential edge.When the sliding-cutting angle of the tangential edge is 16°,the sliding-cutting angle of the lateral edge is 68°and the bending angle is 110°,the stubble cutter has the best strain and strain variation.The analysis of variance shows that every factor has a prominent influence on strain and strain variation.The results of field experiment show that the optimized design of stubble cutter increases 9.57%,6.6%,4.2%and 4.2%,respectively,compared with industry standard.The result of stubble cutter operation is excellent.