| Ridge planting improves the temperature,light,water,gas and other environmental conditions of farmland soil,and has the effect of increasing crop yield,it is of great significance to develop furrowing and ridging machines for increasing grain yield in China.The objective of this study is to solve the instability of furrow and the great traction resistance,which commonly exist in furrowing machines.Based on the planting requirements of ridge of rape in the middle and lower reaches of Yangtze River,designed a double-wing moldboard-style furrow opener.The structural parameters of the double-wing moldboard-style furrow opener were optimized by using discrete element simulation test with area difference and traction resistance as evaluation indexes.According to the optimized structure parameters,the double-wing moldboard-style furrow opener was manufactured and the soil bin verification test was carried out.Finally,the performance of the optimized the double-wing moldboard-style furrow opener and the widely used plow-rotary combined opener in the market are compared in the soil bin.The research conclusions are as follows:1)The structure and parameters of double-wing moldboard-style furrow opener are designed.Based on agronomic requirement of rape planting in southern China,soil accumulation angle after tillage,geometric dimensions of furrow section,a double-wing moldboard-style furrow opener is designed,which is welded by guide soil surface,upper wing plate,middle wing plate,lower wing plate,bottom plate,plow-pole and hanging plate.In order to realize the goal of the furrow opener to export the soil in the furrow and push it to the ridge surface,the horizontal straight element method was used to design the soil guide surface of the double-wing moldboard-style furrow opener.The value range of key structural parameters of double-wing moldboard-style furrow opener was determined by theoretical calculation.2)A method for calibrating the contact parameters of soil discrete elements was proposed.Soil bin test was carried out with existing furrow opener,and cross sectional outline mapping device was used to map the outline of furrow.At the same time,the simulationg furrow test was carried out with EDEM simulation software,and the same test condition and parameters were adopted as the soil bin test.The main contact parameters of the simulated soil with were calibrated by rotating orthogonal simulation test with area of difference of cross section of furrow,between soil bin test and simulation test,as the response value.3.The optimized structure parameter combination of double-wing moldboard-style furrow opener was obtained by means of rotating orthogonal regression simulation test.Taking the area difference and traction resistance as the response value and the four key structural parameters of the double-wing moldboard-style furrow opener as the test factors,the optimal combination of structural parameters of the double-wing moldboard-style furrow opener was obtained by response surface optimization method,and the soil bin verification test was carried out.The test results are as follows: the optimal combination of the initial element Angle,the bottom plate Angle,the opening of the guide curve and the width of the middle wing is 60.59°,0.03°,221.06° and 90.56 mm.The results of soil bin verification test show that the error between the optimized double-wing moldboard-style furrow openers’ cross section area and the simulation test is 5.24%,and the error of traction resistance between the soil bin test and the simulation test is 5.83%,indicating that the soil bin verification test and the simulation test are basically consistent.4)A comparative test between the double-wing moldboard-style furrow opener and the installation of ditching and ridging was carried out.The results show that the resistance characteristics of the double-wing moldboard-style furrow opener and the installation of ditching and ridging are basically the same,and the forward speed of furrow opener has a significant influence on the stability error of the furrow section of the installation of ditching and ridging.When working in the same water content soil,the stability error of the furrow cross section of the double-wing moldboard furrow opener is obviously lower than that of the installation of ditching and ridging. |
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