Design of soil-blocking plate guide mechanism of micro-cultivator based on Burmester theory

In order to solve the problem of the difficulty in cleaning up the grass wrapped around the rotary blade of the micro-cultivator, a design scheme for a movable soil-blocking plate for the micro-cultivator is proposed. The design method of its guiding mechanism is studied based on Burmester theory. Firstly, the four positions of the movable soil-blocking plate on the motion track are determined according to the size of the micro-cultivator. Secondly, the Burmester circle curve and the corresponding center curve are obtained though the motion analysis of mirror pole 4R linkage. Thirdly, the installation position of the driving rod is determined by geometric method, and its branch defects are identified. Finally, the 4R linkage and its driving rod are optimized based on the regional type map method. The results show that the design scheme of the movable soil-blocking plate of the micro-cultivator is feasible. The soil-blocking plate can be lifted according to the predetermined track when it is necessary to clean the entangled weeds without structural interference. The proposed regional type map method can effectively eliminate the driving defect solutions and kinematic defect solutions in the solution domain, thus greatly improving the search efficiency of feasible mechanism solutions. This study is also applicable to other rigid body guidance problems in agricultural machinery design.