关键词: 取投苗装置, 穴盘苗, 轨迹优化, 运动学, 凸轮轮廓曲线

Abstract: In order to reduce the damage to the seedling substrate caused by the seedling picking and throwing device, a kinematic model was constructed and used to analyze the gripping trajectory of a single DOF seedling automatic picking and throwing device. Aiming at the problem of the unsatisfactory insertion posture and large swing of the picking finger, the length of the connecting rod was made equal to the axis distance in the planetary gear train so that the trajectory curves of the reciprocating seedling retrieval could overlap. Additionally, the cam groove parameters were changed to make the cam groove seedling insertion track and the camshaft center track have the same slope. This ensured the picking finger posture and the trajectory to insert tray coincided. Also, the parameters of the bracket and the finger were optimized to make the posture of the finger coincide with the cusp track thereby reducing the crosssectional area of the insertion direction. A stepped profile was adopted for the disc cam to improve the success rate of pushing seedlings. In order to avoid squeezing the seedling bowl with fingers, the axial cam contour line was optimized to be the combined regular cam profile curve, so that the angle between the seedling finger posture and the track of the end cusp of the finger was reduced to 0.117° during the insertion process.

Key words: fetching and throwing device, plug seedlings, trajectory optimization, kinematics, cam profile curve