Study On Anti-blocking Technology And Device Of Rotary Cutting With Slide Plate Pressing Straw For No-till Planter

Due to large amount of straw cover and straw of bulk and strong toughness, the planter has a bad performance in anti-blocking when wheat is planted in the field with maize straw cover. Exsiting power-driven anti-blocking technology has great improvement in anti-blocking, but still has problems. Based on the research of no-till anti-blocking technology at home and abroad, a technology of rotary cutting with slide plate pressing straw was put forward, and relevant device was developed and anti-blocking opening device matched to anti-blocking device was configurated. Key parameters for each component were determined by experimental research and theoretical analysis. On this basis, prototype was trial-produced and tested. The main results are as follows:(1) According to the problems that power-drived no-till anti-blocking device has high rotary speed, large power consumption, serious vibration and poor safety, large amount of soil disturbance and damage, and stubble cut by blade is thrown into seed bed and affects wheat emergence, based on support cutting, a technology of rotary cutting with slide plate pressing straw was put forward, and relevant device was designed. When straw was cut, slide plate pressed the straw and straw was support cut, at the same time, the straw was avoided flying back and affecting emergence. The device had low rotary speed, less soil degradation and good seeding quality.(2) According to the idea of support cutting on anti-blocking device of rotary cutting with slide plate pressing straw, laboratory experiment was designed. The results showed that:①When straw with certain diameter and moisture was cut, cutting speed was declined with blade weight increasing, and the same straw needs the same cutting kinetic energy;②when straw with certain diameter was cut, the cutting kinetic energy was first increased then decreased with straw moisture increasing. The cutting kinetic energy reached to highest when the straw moisture was50%or60%.(3) To avoid straw was accumulated in front of and at the bottom of slide plate and blocked, laboratory experiment was developed to test river diversion of anti-blocking device on straw. River diversion of the slide plate that straw passed slide plate successfully was tested. The related parameters include friction coefficient between straw and slide plate, and friction coefficient between straw and soil. Comparison river diversion of Q235, stainless steel, wood and plastic showed that Q235was the best material of support plate.(4) Geometric modeling and kinematics model of anti-blocking device of rotary cutting with slide plate pressing straw were analysed. Statics analysis by Ansys got stress in each direction and equivalent stress of blade and slide plate.On the basis, deep analysis of cutting progress of the device was got, and the cutting progress was devided into three parts, including cutting with support underneath the blade, cutting with support both underneath and above the blade, and cutting with support above the blade. Cutting lenghth L, force analysis model and variation of slip cutting τn for each part were derived.(5) Matched to anti-blocking device of rotary cutting with slide plate pressing straw, anti-blocking opening device was designed, included double-disc fertilizing opener and hoe seeding opener. Multiple anti-blocking methods such as double-disc opener cut or bypassed straw, and the tine of hoe opener was between two discs, which ensured good anti-blocking ability. The models of groove width d1, opening width df and furrow shape for double-disc opener, and the characteristics of seeding and soil covering for hoe opener were determined. Base on above, the configuration of double-disc opener and hoe opener was confirmed:the distance between double-disc opener and hoe opener in moving, vertical and horizontal direction was R/2<L<R, H=h1-h2and W=d1/2separately. The distance between seeds and fertilizers was30mm(6) Based on the theoretical and experimental analysis, key parameters and configuration parameters for each component on anti-blocking device of rotary cutting with slide plate pressing straw and anti-blocking opening device were determined. After produced, prototype was tested in the field. The result showed that:the average depth of seeds and fertilizers were2.59cm and6.68cm respectively, and the distance between seeds and fertilizers was4.53cm; average soil distanbance was20%, and actual opening width was higher than theoretical opening width, however, the width was much lower than the opening width made by strip rotary anti-blocking device; ground wheel slid was4.6%and3%, respectively; there was a good performance of stubble cutting on crop bed and good emergency performance. Compared with zonal rotary and strip chopping no-till planter respectively, no-till planter of rotary cutting with slide plate pressing straw has less disturbed soil, even emergence and lower rotary speed of blade.