红花丝采摘装置的凸轮机构运动失真研究

针对红花丝采摘装置漏采的问题,对其采摘装置进行动力学分析。研究表明:凸轮机构的运动失真是导致采摘性能降低主要因素,表现为凸轮与推杆顶端出现局部脱离,造成冲击振动,带动安装在推杆上的动齿与主轴上的定齿振动,导致红花丝夹不紧,出现漏采现象。为此,建立了推杆在弹簧作用下的动力学模型,利用MatLab软件对推杆在弹簧作用下动力学模型进行了分析,调整该模型参数,使凸轮回程型线产生对推杆的支持力始终小于弹簧的弹力,保证凸轮与推杆始终接触,消除动齿与定齿的振动,降低红花丝采摘装置漏采率,改善红花丝采摘装置的运动性能。同时,对凸轮升程型线进行设计,通过Creo软件仿真,推杆运动平稳,通过高速摄像验证设计理论的正确性,提高了红花丝采摘装置的采净率。

Study of Movement Distortion for Cam Mechanism Based on Safflower-filament Harvesting Device

For the low picking efficiency of the safflower-filament harvesting device,the movement characteristics was analyzed.Through analyzing the cam driving mechanism of the safflower-filament harvesting device,the cam driving mechanism losing its trajectory results in the low picking efficiency of the safflower-filament harvesting device.The main reason of conducting cam driving mechanism losing its trajectory is that the pushing bar separated from the cam in the part of the cam return-stroke,which conduct that the moving finger and still finger that are used to picking safflower filaments vibrate,making the picking efficiency low.The mathematical model of the pushing bar displacement pushed by the spring was established.The mathematical model of the pushing bar free displacement and the cam return-stroke trajectory function were programmed by the MATLAB.The parameters of the cam return-stroke trajectory function can not be changed continually tillthe trajectory of the cam return-stroke is above the curve the pushing bar displacement pushed by the spring,which makes the pushing bar always and the cam touch.The pushing touching the cam can avoid the vibration and improve picking performance of the safflower-filament harvesting device.The cam return-stroketrajectory of the five times polynomial is optimal when the cam return-stroke is 4.9mm and cam return-stroke angel is 0.129π,improving picking efficiency of the safflower-filament harvesting device.