Experimental Investigation And System Optimization On Threshing And Separating System Of Rape Combine Harvester

This paper presents the present development of rape combine home and abroad and the running principle of typical threshing and separating system. And comparative experimental investigations are done between different threshing and separating systems, such as rasp-bar-plate-tooth drum with grid concave, axial-flow -short-rasp-bar drum with grid concave and spike-tooth drum with grid concave.In this paper, influencing factors on the performance of threshing and separating system are analyzed before determining the factors to be studied in the experimental investigations which are carried out according to the principle of orthogonal test. Then, based on the characteristic of rape and the developmental situation of combine in our country at the present time, we choose three kinds of threshing and separating system mentioned previously as subjects investigated and carry out experimental investigations on the DF-1.5 experimental bench. Through experiments we get the regularities of distribution of outlier along cylinder's axial direction, entrained loss, unthreshed loss and power consumption of respective system, and make a comparison with them between the different systems. Furthermore, by means of regression analysis, the mathematical models of threshing and separating system-- axial-flow-short-rasp-bar drum with grid concave, including threshing and separating rate and power consumption, are established with software named DPS used for data processing. Finally, we proceed a multi-objective optimization on the system based on genetic algorithm, so as to get the comprehensively optimistic running parameters for it.Through analytical studying on the experimental results of three different types of threshing and separating system, we make out the differences of working performance of them, which deepens our understanding on working regularity of different threshing and separating systems. At the same time, the best working parameters are determined through establishing mathematical models and proceeding multi-objective optimization for the threshing and separating system with axial-flow-short-rasp-bar drum and grid concave. Moreover, all these research results provide some theoretical basis for further study on the threshing and separating system of rape combine, and play an important and realistic role in accelerating mechanization of rape harvest in our country.