Authors

Abstract

Aiming at issues such as low instantaneous grasping ability, unsatisfactory cutting quality, and proneness to damage of the blades for existing harvesters, by observing the physiological structure and movement characteristics of the ant's mandible and by bionic design theory, a bionic blade was designed to optimize its performance. In this paper, Camponotus was selected as the research object to observe the movement of the right mandibular teeth. It was concluded that the movement of the ant's mandibular teeth was a cutting-sawing motion. A comparative analysis was carried out using the flat blade and the mandibular teeth blade, uncovering that the mandibular teeth movement formed a sliding cut with a variable sliding cutting angle. The mandibular teeth were beneficial for clamping the target and boosting the instantaneous grasping force. The fourth tooth of the mandible was selected as the bionic prototype. from which the contour curve was extracted and analyzed, followed by the design of the bionic blade. Through the finite element method, the influence laws of parameters such as the tooth pitch, structural angle, and blade inclination angle on the stress field and deformation of the bionic blade were analyzed under two force application circumstances: along the inclination direction of the tooth edge and the blade face direction. The results showed that when the applied force was along the tooth edge inclination, the total deformation of the bionic blade initially decreased and then increased with the tooth pitch increase. The maximum equivalent stress of the bionic blade rose gradually with the tooth pitch increase, and the total deformation decreased with the increase of the inclination angle of the tooth. The equivalent stress diminished with the rise in the inclination angle. With the increase of the structural edge angle, the total deformation of the bionic blade rose gradually. When the force was applied along the blade face direction, the deformation and stress values of the blade were significantly lower than those when the force was along the tooth edge inclination. The research findings can offer theoretical references for the design of bionic blades for harvesters.

Abstract in Chinese

针对现有收割机用刀具瞬时抓取能力低、切割质量不理想、刀具易损坏等问题，通过观察蚂蚁上颚生理结构和运动特征，依据仿生设计理论，设计仿生刀刃来优化其性能。本文选取弓背蚁为研究对象，观察右侧上颚齿运动，得出蚂蚁上颚齿的运动为一种切-锯运动。选择平刃与上颚齿刃进行对比研究，得出上颚齿运动过程形成滑切，且滑切角是变化的，上颚齿有助于钳住目标，提高瞬时抓取力。选取上颚第四齿为仿生原型，提取分析上颚齿的轮廓曲线，设计仿生刀刃。利用有限元方法，分析作用力沿着齿刃倾斜方向和刀面方向两种情形下，刀刃齿距、构造刃角和刀刃倾斜角等参数对仿生刀应力场和形变的影响规律。结果表明：当作用力沿齿刃倾斜方向时，仿生刀总变形量随着齿距的增加，呈现先变小后变大趋势，最大等效应力随着齿距增加而呈现逐渐增大趋势；总变形量随着齿刃倾斜角增加，呈现逐渐减小趋势；仿生刀等效应力随着齿刃倾斜角增加，呈现逐渐减小趋势；随着构造刃角增加，仿生刀总变形量呈现逐渐增大趋势。当作用力沿着刀面方向时，刀片形变和应力值都远远小于作用力沿齿刃倾斜方向的形变和应力值。研究结果可为收获机用仿生刀具设计提供理论参考。