Design And Performance Experiment Of Feeder House And Threshing Separation Device For Ratoon Rice Combine Harvester

Rice occupies a leading position in China’s grain production and consumption,and it ranks among the top in the world in terms of planting area and output.Ratooning rice is one of the many rice varieties in China,it is a kind of rice harvested through certain cultivation and management measures to make the dormant buds on the rice pile continue to germinate and grow into ears after harvesting the first season rice,it has the advantages of time saving,labor saving,environmental protection and production increase.With the development of ratooning rice,the mechanization of ratooning rice harvest is become more and more important,it is necessary to design and test the feeder house and threshing separation device of ratooning rice combine harvester.In order to provide a reference for the design of threshing and separating device for ratooning rice,this paper studies the effects of different grass valley ratios on the performance of the threshing and separating device.The threshing and separating device was tested with rice with different grass valley ratio rice,and the distribution rule of each extract,threshing loss rate and MOG under different grass valley ratios were analyzed.According to the existing research and the biological characteristics and harvesting characteristics of ratooning rice,the feeder house and threshing separation device for the combined harvester of ratooning rice were designed.The static analysis of the feeder house was carried out and the structure was optimized.Through the comparison of the experiment,the entrainment loss rate and the grain unthreshed rate of the two threshing elements with Short rasp-bar plate teeth rigid pole tooth and rigid pole tooth are analyzed.The threshing drum rotation speed,guide plate guide angle and concave plate screen grid axial spacing were selected to conduct single factor and multi-factor tests on the threshing and separating device.Through analyzing the test results,the influence of each factor on the performance index and the best working parameter combination were obtained.The main contents are as follows:(1)The effect of grass valley ratio on the performance of threshing and separating device.The main morphological parameters of the tested rice and the main parameters of the combined harvester were introduced.The rice with different grass valley ratios were cut manually,and the performance test was carried out on the longitudinal axial flow threshing and separating device.Through the experiment,the distribution rule of each extract,threshing loss rate and threshing impurity rate under different grass valley ratios were obtained.Among them,the entrainment loss rate and grain unthreshed rate increased gradually with the decrease of grass valley ratio,while the MOG increased with the gradual increase of the grass valley ratio.It provides a reference for the design of the threshing and separating device of the combine harvester.(2)Design and analysis of feeder house.The characteristics of ratooning rice materials were measured,and the moisture content,thousand-grain weight,etc.were determined.Based on the existing research and combined with the characteristics of ratooning rice materials,this paper designs a feeder house for a ratooning rice combine harvester.Combined with relevant research,determine the parameters of each component,use ANSYS software to perform static analysis on the casing of the feeder house.Through cloud chart to analyze its strength and optimize part of the structure to improve the life and working stability of the casing of the feeder house.Compared with the same type of feeder house,the designed feeder house reduces its overall quality by 16.7% and meets the strength requirements.(3)Overall design of threshing separation device.Analyzed The working principle of the threshing and separating device.The principle of threshing and the type of threshing and separating device are summarized.Based on the material characteristics of ratooning rice and the existing research,a threshing and separating device suitable for ratooning rice combine harvester was designed.The overall structure of the threshing and separating device is introduced.At the same time,the design of the core components such as the spiral feed head and threshing drum is completed.(4)Field experiment of ratooning rice combine harvester.Taking the grain unthreshed rate and the entrainment loss rate as the test performance evaluation indicators,the three influencing factors of threshing drum speed,guide plate guide angle and concave plate screen grid axial spacing are taken as the research objects.First,a single factor test is performed.By comparing the two types of threshing elements of the threshing roller,namely,short rasp-bar plate teeth rigid pole tooth and rigid pole tooth rod teeth,it is concluded that when the threshing element is rigid pole tooth rod teeth,the grain unthreshed rate and the entrainment loss rate are less.Based on the singlefactor test,the multi-factor test was performed using rigid pole tooth rod teeth as the threshing element.The test results show that the regression equation fits well within the constraints,and the influence of various factors on the grain unthreshed rate is as follows: threshing drum speed> guide plate guide angle> concave plate screen grid axial spacing;For the rate of entrainment loss,various factors affect the size: threshing drum speed> guide plate guide angle> concave plate screen grid axial spacing.The response surface analysis method is used to draw the response surface and analyze the influence of different factor levels on the test performance indicators,and finally get the best working parameter combination: the threshing drum speed is 760r/min,the guide plate guide angle is 19°,and the concave plate screen grid axial spacing is 19 mm.A new round of field tests was carried out on the improved ratoon rice feeder house and threshing separation device,and the grain unthreshed rate and entrainment loss rate obtained were in line with national requirements,indicating that the design of the ratoon rice feeder house and threshing separation device achieved the expected goals.