Study On Key Components And Holistic Device Of Intro-row Mechanical Weeding Of The Ridge Cropping System In Northeast Of China

Intertillage is an important part of Chinese intensive cultivation, and it began with clearing farmland weeds. Weeds can grow either between the crop rows (inter-row) or within the crop rows (intra-row), and it compete with crop plants for moisture, nutrients and sunlight and can have a detrimental impact on crop yield and quality if uncontrolled. But weeding is an important and laborious task in field management, strong seasonal feature and short appropriate weeding time and a mass of labour power were used.Mechanical weeding has been considered as an essential component in organic farming, especially in recent years, there has been increasing interest in the use of mechanical intra-row weeders because of concern over environmental degradation and a growing demand for organically produced food. It is easy to eliminate weeds growing inter-rows by mechanical weeding and more economical.Intra-row weeds, however, are more difficult to eliminate than inter-rows weeds because of their close proximity to the crop plants with a consequent danger of damage. So it has significant important to Study on key parts and holistic device of intra-row mechanical weeding of the ridge cropping system in northeast of china.On the basis of analysis on the status quo about mechanical weeding technique research at home and abroad, aiming at the main technical difficulties and some key technical problems which exist in former designed weeding-cultivating machines on the course of intra-row mechanical weeding, paper had an theoretical analysis and experimental study to the weeding mechanism and key components and holistic device of the intra-row mechanical weeding of the ridge cropping system in northeast area of china. The study received funding from projects of the National Key Technology R&D Program for the 11th five-year plan (the project number:2006BAD11A05-06).The main research results include:1,Crop weeding has a strong seasonal feature and short appropriate weeding time, so in order to shorten the cycle of intra-row mechanical weeding experimental research, a multi-parameter adjustment mechanical weeding test bed had been developed. Through theoretical and lots of experimental analysis during three years, the paper makes exploration on weeding mechanism of the intra-row mechanical weed, improves and perfects the structure and configuration of critical working parts, and analyses the effect of relevant motion parameters and key components structure on weeding operating performance.2,To optimize the design and confirm the optimal combination of the key parameters of weeding unit which is part of weeding machine, the structure and working principles of the weeding unit were analyzed. A multi-index orthogonal experiment of four factors (the working speed, the rotation speed of weeding unit as well as the number and installation radius of weeding tines) were carried out, and each factor had four levels.For optimizing the best operational parameters combination, through variance and range analysis, the effect degree of the parameters of the weeding unit on its weeding performances were determined. The experiment result indicated that the number of weeding tines had significantly effect on the performances of the weeding unit. According to the analysis, the best scheme was:the number of weeding tines 12, and rotation speed 190 r/min, installation radius 170 mm, working speed 2.1 m/s. Under such working conditions, the wounded seedling rate, weeding rate, and seedling buried percentage were 4.41%,73.1%, less than 3%, respectively. The results can satisfied with the agronomic requirements of weeding between seedlings in dry farmland3,Based on mathematical model of mechanical weeding tine trajectory and parameters limitation and request at agronomy, a multi-objective optimization model is proposed for obtain ideal mechanical weeding effect. And by using Matlab7.0 Optimization Toolbox we obtain the optimal solution. The optimal combination of four main parameters includes the moving forward speed of the mechanism, tine numbers, distributing over radus of the tine and revolution of disc was design basis. Provide theoretical basis for designing intra-row mechanical weeder by Pro/E solid modeling and simulating.4,On the base of analyzing and study several intra-row weeding components, going deep into analysis the working principle and the injurious mechanism of the weeding component, analyzing the characteristics of motion about level disc spring-tine during the course of intra-row mechanical weed control, establishing three-dimension model for weeding component using PRO/E, and the quadric orthogonal revolve test was carried out and the effect of the factors on the weeding rate and injuring seedling rate was analyzed with Matlab and Excel software, the mathematic modle of weeding rate, injuring seedling rate relationship with influence factors were set up respectively, which provide means for intra-row mechanical weeding performance analysis and numerical simulation, as well as provide a reliable basis for the design of complete machine and its intra-row mechanical weeding components.5,A new intra-row weeding component and unit were designed and studied based on the analysis on weeders in china and abroad, the theoretical analysis, computerized simulation and experimental study were carried out on the key components of the machine. and the device was authorized a new and applicable patent in September,20106,Facing the long-standing problems existing in the development of the agricultural machine, such as the prolonged production period, the high production cost and the difficulty in the final assembly because of the interference between the interacted parts, a process of the virtual manufacturing and motion simulation of the weeding unit was introduced applying the Solidworks software, the proposed process improves the quality and efficiency of the weeding device design and deduces the developmental cost.7,In this paper, the finite element model of intra-row weeder frame was established by taking shell as a basic unit, it was calculated and analyzed by using ANSYS software. The results provide the theoretical support and technical application reference for design and use of the intra-row mechanical weeder.8,On the bases of above research,3ZCF-7700 multi-functional weeding-cultivating machine matching with high-power tractors (≥118.4Kw) was developed. The machine which was suitable for cultivating in the field of corn, soybean and beat could finish the processes of deep side fertilizing, scarification and weeding between seedlings, earth up, ridging and deep loosening. The experimental results of the machine in the corn field showed that the average weeding rate between seedlings was 76%, the injury seedling rate was less than 4.4%, the average weeding rate between rows was 95.7%, and the other various performances met the design requirements. The machine can satisfy with the agronomic requirements of intertillage management in dry farmland.9,Study shows that the penetrating depth of the spring-tine has an important on the performance of mechanical weeding during the process of working in the field. At present, numerous intra-row mechanical weeders make use of mechanical profiling device, and their profiling accuracy is relatively lower and less able to control the weeding depth very well, it is one of the important reason for mechanical weed control technology slow development. So an electro-hydraulic automation control profiling system has been researched and developed. The profiling system is used in each mechanical weed control unit can overcome the copying distortion on account of moving ahead or lag of time in the overall profiling, and can more sensitively in duce on the change of ground up and down, and greatly enhance the control accuracy of the penetrating depth of the spring-tine.