Research On Key Components Of Seeding Bowl Making Machine And Its Parameter Optimization Design Method

The problems existing in the operation process of the ZB-2500 type seeding bowl making machine which is mostly used by individual farmers in China is analyzed in this paper.There are several problems which include inaccurate positioning of intermittent mechanisms,frequent rigid collisions,tilting of the top surface of seeding bowl,cracks on the sides,tight upper part of the seeding bowl,and loose part of the lower part of the seeding bowl.The direction of the research is determined by analyzing the problem,that is,designing a intermittent mechanism with relatively high positioning accuracy-symmetrically offset slot geneva wheel mechanism and the pinwheel mechanism.Following is the main research content:1.By analyzing the working principle of the ZB-2500 type seeding bowl making machine,the design requirements of the intermittent mechanism are determined.The main limited conditions are that the maximum outer diameter of the intermittent mechanism follower cannot exceed 300mm and the internal needs to accommodate 6 uniform diameters of 67mm model cylinder.2.By analyzing the advantages and disadvantages of different intermittent mechanisms,combined with the types of intermittent mechanism which are selected according to the design requirements and an analysis of motion and kinetics is explored.Known parameters,design variables and constraints for intermittent mechanisms are determined by structural analysis,motion analysis,and kinetic analysis.3.The Solid Works software is used to establish a three-dimensional model for the intermittent mechanism.The motion function and simulation function are also used to perform motion simulation analysis and mechanical analysis on the intermittent mechanism,and the intermittent mechanism is optimized by the optimization function.The optimized intermittent mechanism is processed into solid parts.4.A positioning error test system is designed by the author,which aims to test the positioning accuracy of intermittent mechanisms.It is determined that the type of intcrmittent mechanism,the speed of the active part of the intermittent mechanism,the quality of the driven parts and the interaction among them are the factors,and the positioning error of the intermittent mechanism is used as the evaluation index for the orthogonal test.It is shown that the type of intermittent mechanism,the speed of the active part of the intermittent mechanism and the interaction between the two factors has the most significant impact on the positioning accuracy.The positioning accuracy of the pinwheel mechanism is better than that of the geneva wheel mechanism and superior to the original mechanism.Secondly,the positioning accuracy gradually increases with the decrease of the speed of the active part.When the positioning error of the intermittent mechanism exceeds 1.7°,the mechanical failure of the seeding bowl making machine will occur.The positioning error of the pinwheel mechanism and the symmetric offset geneva wheel mechanism is much smaller than the positioning error of 1.7°is shown in the orthogonal test.