Design And Test Of Corn Straw Cutting Parts With Straw Piecewise Utilization

As one of the three major grain crops in China,corn has a large planting area and has abundant straw resources.However,there are problems in the utilization of straw resources.There are too much straw returning to the field,and the straw feed has low intake rate,etc.Therefore,it is necessary to use straw in piecewise,that is,the upper part of the corn straw be crushed and collected,and the lower part of the corn straw be crushed and returned to the field.The main parts of straw comprehensive utilization model is straw cutting.Therefore,begin to study on corn straw cutting parts with straw piecewise.The main research is as follows:(1)Research on mechanized utilization of straw.Straw returned amount too much will cause burning of the next crop seedlings,straw crushing effect unqualified makes the next crop seeds cannot grow properly.According to the mechanization of maize straw crushing way at China and other countries,researching on corn straw cutting parts with straw piecewise,to design a straw cutting and harvesting device and a saw-plate straw returning machine.(2)Design of straw cutting and harvesting device.The straw cutting and harvesting device installed under the snapping roll of the corn harvester header,is used to cutting the upper part of the corn straw after cutting off the corn straw at the height of 60 cm,and send the crushed straw to the fan for blowing and collecting.Selecting hob-cut to cut off the straw at 60 cm.According to the sawtooth kneading effect,a three-blade kneading blade is designed,and the design scheme of the blade is determined.Through analysis and calculation,determined parameters of the blade diameter,the cutting angle of the blade,the slant angle of the adjacent blade and the diameter of the cutter shaft.By dynamic balance check,the structure of the cutter shaft is optimized,and introducedcthe overall structure of the cutter shaft.Select the long bond and calculate its strength.Though the stress simulation analysis with the blade,determined the blade strength was reached the working strength.(3)Test and data analysis.In order to verify the crushing effect of the device,designed and processed a test bench.Through the data analysis of single factor test and orthogonal test,it is determined that the best effect is achieved when therotating speed of the cutter shaft is500 r/min,and the blades are mixed and arranged with jagged-blades and triangular-blades,and the qualified rate of straw crushing is up to 97.22 %,power consumption is 2.831 k W,reaching the expected requirements.(4)Development and test of saw-plate straw returning machine.According to the problems such as the working parts of the straw returning machine hit the soil at working,or the low qualified rate of straw crushing.Designed a saw-plate straw returning machine,that the swing-blade shaft is reverse rotation to cutting the straw and transporting to the saw-plate cutter.And next the saw-plate cutter pulverizing the straw for the second times.The design of shell clearance is narrow in and wide out,could better crushing straw and avoid clogging.Designed the driving system of saw-plate straw returning machine.Determined the shaft speed and transmission ratio.Designed a swing-blade and a saw-plate cutter.Determined the structure parameters of the swing-blade shaft and saw-plate cutter by force analysis.Finish the optimum design of the swing-blade shaft.Through ANSYS software simulation analysis,the designed structure is confirmed to reach the use requirements;Drawn 3d model with Solid Works,drawn 2d drawings with Auto CAD,completed the prototype trial-produce and completed field test.The result of field experiment shows that the qualified rate of straw pulverizing length is 95.71 %,that reach the design requirements.