Simulation Analysis And Optimization Of The Frame Structure Of The Riding Type Full Automatic Transplanting Machine

In China, the vegetable transplanting operation is mainly based on the semi-automatic small transplanting machine, with low efficiency, poor quality and reliability of the whole machine. Research on vegetable transplanter in China primarily focuses on seedling fetching mechanism, planting and other aspects, for the study of transplanting machine chassis frame is relatively less, and frame structure is the key link to restrict the research and development of the riding type automatic transplanting machine. As the main carrier, frame is not only used for the layout and installation of the assembly parts, but also to bear all kinds of external static and dynamic loads. Therefore, the frame structure directly determines the planting performance of the whole machine, requiring reasonable strength, stiffness and dynamic characteristics. On the basis of functional actions required by full automatic vegetable transplanting machine, design the frame structure reasonably, and implement finite element analysis and lightweight design of the virtual prototype. The accuracy of the numerical model of the frame has validated by experimental results, which provides reference for further research on the frame performance of the transplanting machine.The main research contents and conclusions of this paper are as follows:(1) According to the operation parameters, agronomic requirements and the operation performance of each functional unit, figure out the planning of machine transplanting action and relevant requirements, and then design the whole frame structure reasonably based on the relative position of each units. The finite element model of the frame structure is carried out, rationally simplified the model by many methods while guaranteeing and evaluating the mesh quality. The external load is applied to the upper frame, and a better upper frame finite element model is obtained.(2) The static and free modal analysis of the whole frame structure is carried out under the condition of full load bending and ultimate torsion, the static and dynamic characteristic parameters of the upper frame are obtained, and the results are evaluated.(3)According to the finite element analysis results to identify several regions of high stress on the upper frame; stress test is conducted on the key parts of the upper frame under the above two conditions, and the accuracy of the finite element model can be ensured by comparing and analyzing the results of experimental test and finite element analysis.(4) Through finite element analysis of the lifting bracket at the rear of the frame, the feasibility of light weight is explained. In the parametric modeling of the lifting support structure, select some parameters of high sensitivity as optimization design variables through the sensitivity analysis of structural parameters, and based on the DOE test design method, the response surface optimization method was used to optimize the structural parameters of the lifting support. After the light weight, the mass of the bracket falls by 37.38%, the maximum equivalent stress falls by 42.2%, thus improving stress distribution and achieving the lightweight design goal.