| Lifting of seedlings is an important part of out-planting. The quality of the lifting of seedlings has a directly impact on the survival rates of the afforestation after the seedlings are picked up. In recent years, the combine plant lifter is used widely in North America and Europe. The combine plant lifter can achieve multifunction simultaneously--digging, conveying, collecting, counting, baling or packaging and so on. It can reduce the laborers’ working strength and improve working efficiency. However, the lever of the plant lifter is so low at home, its structure is simple, and it can achieve a single process of digging seedlings, but the seedling dug out of need workers to pick it up. Its working efficiency is low and it is labor intensive. In order to develop the lever of the plant lifter at home, improve the efficiency of lifting of seedlings, and reduce working strength, developing a combine plant lifter that has a high working efficiency and achieving multiple working procedures makes a big difference.On the basis of plant lifters from home and with reference of foreign advanced technology, this article firstly determines the whole structure of the combine plant lifter and its basic technical parameters. In order to making the combine plant lifter worth effort of using it, the article detail analyzes and studies these factors that can influence its working performance, including seedling types, seedling growing status, soil types and climate conditions. In order to reduce working resistance, the performance parameters of the seedling lifter are analyzed and studied in detail, and their calculating formulas are presented in this article. Considering soil types and the physical and mechanical properties of the soil, this article analyzes the dynamics of the seedling lifter, establishes its traction resistance dynamics model, and makes the response surface figures of the main performance parameters to the traction resistance based on the MATLAB software, and then analyzes the response surface figures, finally, the optimal combination of the main performance parameters of the seedling lifter is got. In order to be convenient for the optimization of the seedling lifter, this article builds the3D parametric modeling of the seedling lifter by using the Pro/E software, and then makes the multi-objective optimization design of the seeding lifter by using ANSYS software, and has got the optimal structure parameters of the seedling lifter finally. By building mechanical models of the separating soil from roots, this article describes the fundamentals of the thing that vibration leads to the separation from roots and soil. In order to describe the theory of the separation from roots and soil further, this article makes a finite element analysis to it from its micromechanical analysis, with the help of considering the roots-soil complex as a fiber composite and introducing the concept of the roots-soil complex cell, and then simulates the process of the separation from roots and soil. This will provide the theoretical basis for the design of the roots and soil separation device. Through analyzing the force condition of the mixture of roots and soil on the pole-type conveying chains, the relative position between the seedling lifter and it is determined. Trough analyzing the matching relationship between the speed of the pole-type conveying chains and the running speed of the machine, their relationship has been got. By making modal analysis on the backbone of the rack, its first six orders of the mode of vibration and the natural frequency are been obtained in the article, and then the article proves that the resonance phenomenon in the backbone of the rack that is caused by the excitation frequency that hydraulic vibrator-separation device has created does not happen.Finally, the3D model of the combine plant lifter is obtained through assembling the entire machine based on the Pro/E software in the article. |
PDF Full Text Request