| Large ridge of double planting technology,which makes the crop can give full play to the marginal effect,increased ground temperature,significantly increased energy and fertilizer use efficiency.So,at present,this technology has been widely applied in Northeast China.And it can effective solution to the field canopy,poor air circulation and other issu es.However,chemical weeding techniques are commonly used to eliminate weeds in seedlings and rows,and the harm caused by environmental pollution and degradation of agricultural products is becoming more and more serious.Although the traditional mechanical weeding method is not as effective and adaptable as the widely used chemical weeding method,the mechanical weeding has the effects of breaking the ridge surface compaction,loosening the soil between the seedlings and the rows,and effectively increasing the surface temperature.As a consequence,mechanical weeding has always been favored by agricultural workers in the northeast grain production area with hig h mechanization level.The main problem is that it is easy to damage the seedlings when weeds n ear the seedlings are removed,and due to the stubble of the straw in the field,the mechanical weeding parts are also easy to entangle the grass and block it,resulting in dragging the soil and burying the seedlings,which causes the high injury rate and buried seedling.In addition,the field mechanical weeder of the big-row double-row planting mode of corn is rarely reported.Therefore,it is very necessary to carry out research on mechanical weeding and soil loosening machine for seedlings based on the large-ridge double-row planting technology model promoted in Northeast China.This article is based on a comprehensive analysis of domestic and international mec hanical weeding literature,combined with the problems existing in the weeding process of corn between seedlings in the double-row planting mode of northeast corn,based on the characteristics of the root development degree of crops and weeds and the mechanism of"grid"trajectories for loosening soil between seedlings,aiming at the agronomic requi rements of loosening soil weeding in the northeast corn large-ridge double-row planting mode,a corn loosening weeding machine was designed.The main contents completed are as follows:(1)According to the agronomic requirements of the loosening soil weedi ng in the northeast corn double-row planting mode,the overall structure of the corn soil loosening weeder was determined,and the overall structure and key components of the machine were designed and analyzed.(2)In this paper,the design of the corn seedling loosening weeding machine is completed,the structure of the loosening weeding operation unit,the design of the key parts of the loosening weeding operation between the seedlings and the rows and the analysis of the loosening weeding mechanism are completed.Each loosening weeding operation unit of the machine is designed to be independently profiled and independently driven,so as to ensure that it can be adjusted appropriately according to the ridge distance during the operation.The inter-row loose soil weeding assembly and the inter-row loose soil weeding assembly are the two key components in the operating unit.The profiling wheel used as a working un it,by profiling the ridge surface,more accurately and reliably controls the soil depth of the following two seedling loosening weeding assemblies.The combination of the two can achieve the weeding of loose soil between rows of maize seedlings and rows between large ridges and double rows.(3)In order to determine the key components of the loose soil weeding assembly in the seedlings,the structural parameters and motion parameters of the loose soil weeding components,the mathematical model and multi-objective optimization model of the locus of the loose soil weeding components were established.The main structural parameters and motion parameters of loose soil weeding components were determined,and Matlab was used to obtain a better solution.The measurement of the grid-like superimposed cogging obtained by Pro/e solid modeling and simulation verifies the correctness of the multi-objective optimal design,and provided a basis for the optimization test of the weeding device test bench in seedlings.(4)On the self-made test stand,the experimental design and parameter optimization of the artificially designed seedling weeding device were carried out.the method of quadratic orthogonal rotation combined test design is adopted,with the inclination angle of the tooth disc,the speed of the tooth disc,the uniform distribution radius of the hoe teet h and the number of hoe teeth as the influencing factors,Established mathematical models of the effects of multi-factors on weeding rate,injury rate and buried rate of seedlings respectively,analyzed the impact of each influencing factor on weeding rate and injury rate,and optimized the parameters to determine the optimal combination The operating speed is 1.86 m/s,the speed of the tooth disc is 190r/min,the number of hoe teeth is 12,the uniform distribution radius is 140 mm,the angle of the too th disc is 5~o,the weeding rate between seedlings higher than86%,and the seedling injury rate lower than 2.5%,buried seedling rate lower than 0.5%.(5)The result of the weeding test showed that optimized design of weeding device can adapt to the weeding operation of corn seedlings planted in double rows on the ridge.When adjusting the relevant parameters:the speed of the gear disc is 190 r/min,the number of hoe teeth is 12,the uniform distribution radius of the hoe teeth is 140 mm,and the incli nation angle of the gear disc is5~o.During the weeding operation at an operating speed of 1.86m/s,the average rate of weeding seedlings was 82.6%,the injured seedling rate was 2.8%,and the buried seedling rate was 0.42%among the five times. |
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