蔬菜移栽机凸轮-连杆组合式取苗机构设计与试验

Design and Tests of Cam-link Combination Pick-up Device for Vegetable Transplanters

基于我国蔬菜生产实践,设计了一种凸轮-连杆组合式取苗机构。该取苗机构为Ⅰ型串联组合式创新机构,利用凸轮机构的任意运动规律特性,经双摇杆机构运动传递和放大,驱动滑块上的取苗末端执行器在限位滑道内垂直穴盘取苗、直立投苗。采用虚拟样机技术分析了取苗机构的运动特性,该机构能较好地代替人工完成自动取苗和投苗动作。试制了物理样机,进行自动取苗性能测试。结果表明:当取苗频率为40株/min时,取苗成功率平均值为92.03%,自动取苗效果较好。

Through a creative design of the I-type mechanism combination in series, a path manipulator to generate the appropriate working trajectory of seedling extraction was designed. It consists of three basic mechanisms. The postpositional offset slider-crank mechanism is to copy the required path of removing the seedlings from nursery trays. The preset cam mechanism creates a satisfactory follower motion law. Through the amplification of the middle four-bar mechanism, the postpositional mechanism under the control of the preset cam mechanism moves the end-effector to auto-extract seedlings from growing trays, transfer them, and discharge them into the planting unit where they are to be planted into the ground. The motion analysis of the designed seedling pick-up device was simulated with ADAMS software. The simulations indicated that this system is reasonable in overall design. Being the first prototype, the working efficacy of picking up seedlings from the cells was tested. The laboratory evaluation showed that the pick-up device can extract 40 seedlings / min with an average success ratio of 92.03%. The quality of extracting, transferring and discharging seedlings was satisfactory.