Structural Design And Parameter Optimization Of The Ejection Rice Pot Seedling Transplanting Mechanism

As a country with a large population,China has a great demand for grain production.Rice is one of the most important grain crops in China,which has large planting area and high yield,so it is of great significance to improve the yield and quality of rice mechanized planting.Compared with direct seeding and transplanting,rice transplanting has many advantages,such as short seedling stage,early tillering,etc.At present,although the transplanting mechanism on the market can basically meet the functional requirements of rice transplanting mechanism,but it often has some defects,such as floating seedlings and low erect rate,which affect the grain yield.Based on the background,a co-axial double-bar ejection transplanting mechanism for rice seedlings with rotating non-circular gear planetary gear train is presented in this paper,so that the needle track is "kidney-shaped",which can effectively improve the rate of seedling establishment;At the same time,the planting arm of the mechanism is designed as double-sleeve-pole mode.The seedling can be ejected into the soil by spring,which can effectively solve the problem of seedling floating.This machine can complete the work of taking seedlings,transporting seedlings and planting,and can transplant twice in one cycle,which has the advantages of high efficiency,good safety,high reliability and so on.As a complex multi-body mechanism,the working mechanism of the transplanting mechanism is very complex,and it has many performance requires,so the optimal design of the mechanism is always difficult and important.In this paper,a parameter optimization software is designed based on MATLAB,which can be used for human-computer interaction.The parameter-guided optimization method is used to automatically find non-inferior solutions that satisfy the kinematic constraints.At the same time,the influence of clearance on the characteristics of the mechanism are considered,the contact force model is established on the basis of the division of the contact mode of the clearance revolute joint,and the contact force calculation subroutine is correlated with the secondary development function of ADAMS.The effect of clearance on the dynamic characteristics of the mechanism is studied.The mean square deviation of the change of contact force is used as the standard to obtain the optimum value of the clearance.