Design And Experiment Of Key Components Of Rapeseed Direct Seeding Machine Touching Soil

Rapeseed is the largest oil crop in China,with 80%of the planting area distributed in the middle and lower reaches of the Yangtze River.In this area,it is humid and rainy,and the soil is heavy.When rapeseed is mechanizedly planted,the high and large amount of straw stubble is retained on the surface,which leads to the problems of blocking and adhesion,hanging grass and wrapping grass when the soil-touching parts of the rapeseed direct seeding machine are operated,resulting in the decline of the quality of the machine operation and the low efficiency of the operation.In this paper,combined with the agronomic requirements of rapeseed planting,through theoretical research,design analysis,simulation and field experiments,the design and test of the key components of the soil-touching parts of the rapeseed direct seeding machine are carried out,and the actual operation effect is verified.The main research contents are as follows:（1）Aiming at the problems of adhesion,blocking,and grass wrapping of the key soil-engaging parts of the soil-engaging parts of the rape direct seeding machine when working on the high-stubble sticky soil surface,combined with the agronomic requirements of the rape direct seeding seedbed finishing,a combination of combined furrowing parts,double-edged reverse rotary tillage parts,and active anti-blocking and deep fertilization parts was proposed.The combination of the operation scheme realizes the furrowing,straw burial,soil crushing and deep fertilization operations,and clarifies the working principle and working process of the furrowing,soil crushing and stubble burying,viscosity reduction and anti-blocking.（2）The design and parameter analysis of the furrowing parts of the rape direct seeding machine were carried out.A combined ditching component with continuous working surface is designed,which is composed of a plough before breaking soil,a side plate after sealing soil and a plough after shaping soil.It mainly includes:（1）Using the principle of ruled surface buckle,according to the characteristics of drag reduction and soil breaking of smooth arc wire,the plough wire before breaking soil is designed to be arc,and the height of arc wire H₁ is determined to be 335 mm,the corresponding central angleδ₁ is80°,the end tangent angleε₁ is 100°,the working width of soil breaking surface is 120mm,the angleθ₀ between any point on the wire and the forward direction is 35°,and the penetration angleθis 10°.（2）Based on the design of horizontal curve element line,combined with the quality requirements of furrowing operation,the height H₂ of the plow surface after shaping was determined to be 304 mm,and the opening range was 40 mm～214 mm,and the curve element line equation was fitted as a parabola.The minimum tangent angleγ_min is 7°,the maximum tangent angleγ_max is 35°,and the angle between the bottom edge of the surface and the horizontal plane is 4°.（3）Based on the requirements of the inner structure of the side plate of the rotary tiller and the relative position of the plow before the soil breaking and the plow after the shaping,the influence of the plow surface structure on the soil migration trajectory was analyzed,and the structural parameters of the soil sealing side plate were determined.The length is 660 mm and the width is 320 mm.（3）The structural parameters design of rotary tillage knife roller and deep fertilization shovel was carried out,mainly including:（1）Rotary tillage knife roller adopts a shaft barrel-shaped knife roller,the diameter of the knife barrel is 146 mm,the wall thickness is 5 mm,the outer diameter of the knife plate is 270 mm,the inner diameter is 146 mm,and the thickness is 8 mm;（2）According to the sliding cutting principle,the edge curve of the single-edge rotary blade is determined to be an equal-entry spiral,and the rotation radius of the single-edge rotary blade is 245 mm.The bending angleγ_a of the tangent section of the blade is 31°,the clearance angleξof the tangent section is 20°,and the bending angleγ_b of the tangent section is 27°.（3）The structural parameters of the curved blade are consistent with the single blade rotary blade.The straight blade edge curve is determined to be an eccentric circular curve,and the radius of rotation is 275 mm.（4）The rotary radius of the front arc surface is 255 mm,and the fertilization depth is 90 mm～130 mm.（4）The EDEM simulation of the key components of the rape direct seeding machine was carried out,including:（1）The simulation model of the machine-soil-straw based on the discrete element method was constructed.The optimization test was carried out with the working width,bending angle and bending line angle of the rotary blade as the test factors,and the straw burial rate and rotary tillage power consumption as the test indexes.The optimal combination of blade parameters was obtained.When the working width was75 mm,the bending angle was 125°,and the bending line angle was 25°,the straw burial rate of the machine was 88.13%.（2）The simulation test of the whole machine operation quality was carried out with the optimal blade structure parameters.It was concluded that the average furrow depth was 168.22 mm,the average furrow width was 242.93 mm,the surface flatness was 22.14 mm,and the straw burial rate was 88.63%after the single operation of the machine.After the operation,the topsoil soil straw was evenly mixed,81.60%of the straw was distributed in the topsoil 100 mm away from the surface,and the fertilization shovel body was smooth.The average fertilization depth was 121 mm,which met the requirements of deep fertilizer application.（5）Field experiments were carried out under six working conditions.The heights of surface straw in the field under six working conditions were 444 mm,204 mm,148 mm,627 mm,656 mm and 678 mm,respectively.The test results were as follows:（1）The working performance and quality of furrowing and rotary tillage components were verified in working condition 1,and the active anti-blocking function test and deep fertilization operation quality of rotary tillage components with deep fertilization shovel were verified in working condition 2 and working condition 3.The results showed that the working performance of each soil-engaging component was good.The combined furrowing component,double-edged reverse rotary tillage component and active anti-blocking deep fertilization component were proposed.The furrow ditching,straw burying,soil crushing and deep fertilization were realized.（2）In working condition 4,the performance test of high-stubble heavy surface machine was carried out.The tillage depth of the machine reached 170.10 mm,the average furrow depth was 180.90 mm,the average furrow width was 392.00 mm,and the straw burial rate after tillage reached 90.60%.The average fertilization depth is 122.10 mm.（3）The operation quality comparison test of the whole machine was carried out under condition 5 and condition 6.The test results of working condition 5 show that compared with the operation of ordinary rotary tillage parts,the straw burying rate of the developed machine reaches 90.34%,which is increased by28.47%,the flatness of the box surface is 19.19 mm,and the operation stability of the combined furrow opening parts reaches 90.24%.There is no adhesion of grass on the deep fertilization parts,and the trafficability is good.The test results of working condition 6show that compared with the 2BFQ-8 rape direct seeding machine,the straw burying rate of the developed machine reaches 91.79%,which is 27.19%higher,and the flatness of the box surface is 22.14 mm.After the operation of the combined ditching parts,the average ditch depth was 184.00 mm and the average ditch width was 386.80 mm.The deep fertilization parts did not appear the phenomenon of hanging grass blockage,and the passability was good.