| The cultivator-planting combine is able to complete a number of operations such as tillage and sowing,so the soybean till-planter is one of the most important machines to realize the full process of soybean production.Soybean till-planter that can complete the task of cultivated machinery,land preparation machinery and sowing machinery and other operating machinery,is required to continuously contact with the soil in the field.Therefore,it is of great significance to design the key soil-engaging components of soybean till-planter.In this paper,we mainly studied the coupling bionics surface texture for tillage component and the test of the tillage resistance parameter,and the pressure measurement of the press device of the soybean till-planter.There is a contradictionbetween the improved hardness of tillage component and weakened mechanical strength.In order to solvethis problem,the paper introduced a structure and material coupling bionics surface texture that wasacquired by structuring the bionics surface texture and controlling the processing of the cast.Using this method,ductile iron materials were used to prepare samples,and the relevant tests were carried out.The testresults of microstructure analysis showed that the single bionics surface texture or setting small chill did not produce the white ironstructure,and via combining the two methods,the white iron structure was appeared.The microhardness test results showed that coupling bionics surface texture has higher micro hardness and theaverage value was improved by 35.71% compared with the core matrix.The scratch test results showedthat when forming the same width of scratches,it needed 1.16 times load for the core matrix.The abrasive wear test results showed thatthe wear amount ofthesamples with bionic surface structure or setting cold iron were smaller thanthat of nothing,and both to build a bionic surface structure and set the cold iron sample was the smallest.The experimental results showed that the coupled bionic surface structure had the characteristics of good ductile cast iron toughness and high hardness of the external surface,so as to take into account the wear resistance and mechanical properties of the parts.Thewettability test results showed that the average contact angle of the coupling bionics surface texture washigh,and the values were increased by 14.91% compared with the core matrix.The larger contact angle was beneficial to reduce soil adhesion,and the gradient distribution of water contact angle on surface structure was favorable for desorption of soil.The stress analysis of abrasive wear test showed that the bionic surface structure had a great influence on the tangential force of the sample,andthe tangential force ofthe sample that possessed a bionic surface structurewas the smallest.The experimental results showed that the coupled bionic surface structure had a drag reduction effect.Based on the method of binary coupling bionic design,a coupling bionic subsoiler blade with bionic surface structure was designed and fabricated.Accurate measurement of tillage resistance for cultivate component is critical.The related resistance testing device has complex structure,high maintenance cost,lack of overload protection and difficulty in collection in farmland.Aiming at the problems of the related resistance testing device,the tillage resistance testing device(TRTD)for cultivate component(such as subsoiler,ridge shovel)was designed.The force analysis of double-wings subsoiler was carried out.The paper established a measurement method of tillage resistance that contained the relationship that correction factor k as a function of spring corner θ,tilling depth H,tilling speed V,soil bulk density ρ and subsoiler structure parameters.In order to evaluate the TRTD,a soil bin contrast test with traditional testing device(TTD)was conducted under six tillage condition treatments.The test results showed that the mean and variance of the measured sample from both testing device were not significant difference.The results of precision analysis showed that TRTD’s maximum relative error was 1.34% compared with TTD.The results of fluctuation analysis showed that TRTD’s fluctuation amplitude was similar with TTD and both relative deviations were not more than 5%.TRTD meets the requirement of accuracy and stability and possesses the function of overload protection,providing the condition to the acquisition of the tillage resistance.Based on the resistance test device designed in this paper,the horizontal tillage resistance of coupling bionic subsoiler blade and the traditionalsubsoiler blade were compared and analyzed.The results of the test showed that the bionic subsoiler blade reduced the tillage resistance to a certain extent.In this paper,a novel method was introduced based on a type of profiling elastic press roller to solve the problem that soil compaction pressure was difficult to monitor in real time.The pressure real-time values were acquired through the measurement of the profiling elastic press roller’s eccentricity.In order to evaluate the relationship between the profiling elastic press roller’s eccentricity and the pressure,the study was conducted in an indoor soil bin.The relationship between the profiling elastic press roller’s eccentricity and soil cone index,and the relationship between the static pressure and soil cone index,were investigated.With the equivalent relationship of the cone index,the data was curve fitted and the model equation was established between eccentricity and pressure,in the topsoil layer in which the depth is 0-0.1 m.In order to evaluate the pressure measurement method,the validation experiments were conducted.The relationship was compared between the cone index predicted from the press roller measurements and the cone index measured from the manual measurements.The results showed that the dots of scatter diagram were all concentrated around the 1:1 ratio line,with high R2 values,at three volumetric moisture contents.These experiments indicated that the predictions were very consistent with the manual measurements,indicating the pressure measurement method based on the profiling elastic press roller can be used into real-time pressure monitoring.Based on the theoretical analysis and the soil bin tests,the field experimentswere carried out.1)The tillage resistance field test was carried out on the subsoiler by using the tillageresistance test devicedesigned in this paper.The tillageresistance of the two types of subsoiler was compared andanalyzed.2)Thepressure field test examined the field work effect of the pressure measurement method based on profiling elastic press roller. |
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