Design Of Straw Chopper And Comparative Test Of Different Straw Returning Modes In Wheat And Corn Straw Whole-returning

China has huge amount of crop straw,the proportion of wheat and corn is large.Straw returning technology,can promoting soil fertility、crop yield and improving soil quality,has been widely used in various provinces and cities of China,but our modern farming tools related to the situation seriously restricted the application and development of the straw returning technology.Against the commonly used straw returning machinery in wheat and corn rotation area of China,in order to enhance the quality of straw returning,this article designed a kind of bending straight knife straw crusher(model 1JHSX-35)for whole-feeding rice-and-wheat combine harvester,studied the different modes of straw returning and determined the most appropriate mode.Carried out a series of studies:Put forward two kinds of the most appropriate straw returning machinery in wheat and corn rotation area of China,the straw crusher for whole-feeding rice-and-wheat combine harvesters(straw returning mode A)and the horizontal straw chopping and returning machine for tractor(straw returning mode B).Analyzed the research status of straw returning machinery at home and abroad and summarized the deficiencies of our study and some advanced technology overseas.Designed bending straight knife straw crusher,including: designed feeding chamber for connecting straw crusher and combine harvester;built knife roller shaft mechanical model,designed knife roller;analyzed knife cutting mechanism,determined the key parameters of knife;determined crushing chamber width and shape;designed the transmission system.Finally,determined the bending straight knife straw crusher.Basing on the finite element analysis software ABAQUS,checked mechanical strength of bending straight knife straw crusher: the maximum stress value was 87.36 MPa,the maximum deformation was 0.29 mm,verified the reliability of design.Analyzed the mechanical properties of wheat straw and established correlation parameters relational formula.By straw cutting simulation analysis,the minimum speed was more than 2000 r/min,the speed reasonable range of bending straight knife stalk crusher was 3000-3500r/min and the reasonable range of the knife angle was 20°-30°.Carried out crushing wheat straw dynamic simulation,analyzed the movement of wheat straw and straw crushing quality.Basing on LabVIEW and PXI,designed a testing device for the performance of straw crusher,which could detect the power consumption of the different kinds of straw crusher.Carried out field test.The comparative test of 1JHSX-35 and 4MQ-35 two models: the former loading power consumption was 6.26-9.37 kw,the latter was 6.68-10.1kw;the former straw crushing qualified rate was 92.39%,the latter was 88.97%;the former throwing scattered uneven degree was 13.39%,the latter was 15.15%;the former equipment operation average fuel consumption was 1249.3G/acre,the latter was 1275.825 G/acre.In summary,the performance of bending straight knife straw crusher was better.The comparative test of the straw returning mode A and mode B: straw crushing qualified rate: 90.68%、84.96%;throwing scattered uneven degree: 14.27%、10.31%;equipment operation average fuel consumption: 1262.5625 G/ acre、1531.775 G/ acre;corn emergence rate: 80.93%、83.70%;corn yield: 1430.697catty/acre、1387.71catty/acre;operation cost: 70-80yuan/acre、90yuan/acre.In summary,determined preliminary the mode A was better.