| Due to the late start of the development of vegetable planting mechanization in my country,the research on fully automatic transplanting machines is still in its infancy,with complicated structures,high functional requirements and high prices,which cannot be applied to most farmers.The semi-automatic transplanting machine is a transplanting machine with a high utilization rate,which greatly improves the planting efficiency and reduces the labor force.However,in the face of a wide range of vegetable varieties and agronomic requirements,the problems of low applicability,single function,and high cost of the existing semi-automatic transplanting machine have become unfavorable factors restricting the development of the vegetable industry.In response to these problems,a semi-automatic vegetable plug seedling transplanter with stable performance,low cost,convenient operation,meeting transplanting requirements and with the function of synchronous watering and irrigation was designed.The main research contents are as follows:Combined with the characteristics and deficiencies of the existing semi-automatic transplanting machines,the overall design requirements and performance indicators of the semi-automatic vegetable plug seedling transplanter were put forward,and the whole mechanical scheme was designed.In this paper,an eccentric disc duckbill planting mechanism is designed,which can complete seedling receiving,hole drilling and planting operations at one time,reducing the rate of seedling damage,improving planting quality and hole drilling stability.A new type of planting water spraying mechanism is designed to avoid the problem of single function of the transplanter.The device can adjust the single watering amount by adjusting the size of the water storage valve to realize timely and quantitative watering and irrigation of transplanted seedlings.Thus reducing the waste of agricultural water and saving labor.Analyzed the kinematics of eccentric disc duckbill planting mechanism and fixed planting water spraying mechanism.In order to avoid that the hole size is too large and the erection rate of plug seedlings is reduced,according to the movement trajectory and opening position of the planted duck’s bill,the size of the duck’s mouth hole is analyzed.The optimal trajectory characteristic parameters were analyzed and the longitudinal size of the duck mouth hole was minimized;the initial angle range of the L-shaped push rod installation that could make the plug seedlings fall smoothly and reach the specified planting depth was obtained;the process of drilling holes and seedlings was simulated for the planting mechanism under different trajectory characteristic parameters and initial installation angles,which verified the correctness of the theoretical analysis results.Established a mathematical model for the watering process of the planting water spraying mechanism,and analyzed the installation distance range of the water outlet when the watering effect is better.Analyzed and optimized the structure of the transplanter frame.The statics analysis of the frame structure of the transplanting machine under the actual full load condition has verified that the strength and rigidity of the frame meet the requirements.According to the analysis results,the size optimization design of the frame structure has been carried out,and the optimal wall thickness that satisfies the statics requirements was obtained.Modal analysis of the optimized frame structure shows that the frame will not resonate during the working process and can meet the requirements of dynamic characteristics.Experiments and analysis of the prototype of the semi-automatic transplanter for vegetable plug seedlings were conducted.The prototype has been tested under different planting frequencies.Combined with the evaluation index analysis,it is shown that the semi-automatic transplanter designed in this paper has good planting performance and planting accuracy,and its components run stably,and generally meet the design requirements and goals. |
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