The Simulation Study For The Working Process Of Wide Type Paddy-Field Wheels In Micro-Tillage Machines

Micro-tillage machines have been widely used in the small area paddy field in the south of China. The wide type paddy-field wheel (referred to wide wheel) is one of the important working parts of the micro-tillage machine, whose head is used for tilling and tail is for driving. Besides working for driving, the wide wheel can also break and mix soil. Currently, scholars at home and abroad, have studied the general paddy-field wheel, using the method of physical tests and mechanical analysis. But the wide wheel’s operating mechanism, influencing factors and parameter optimization have not been thoroughly studied, resulting in unsitisfied working performance of the wide wheel. Therefore, it is significant to study the operation mechanism and optimize the structural parameters of the wide wheel, using the method of physics experiments and simulation experiments for improving the wide wheel’s working performance and working quality.In this paper, based on the method of Smoothed particle hydrodynamics(SPH), and the experimental designed method of quadratic regression orthogonal rotation, we build the dynamic simulation model of soil-wide wheel system and the multivariate coupling mathematical model to study the influencing law and mechanism between the influencing factors, i.e., the diameter, the lug width, the lug tilt angle, the lug break angle and the number of lug, and the performance indexes, i.e., the moving average, the mix degree and the slipping rate. Then we use the fmincon function of MATLAB toolbox to optimize the influencing factors and obtain the optimum structural parameters of wide wheel. The simulation results show that the soil-wide wheel system dynamic simulation model has a high accuracy, and the structural parameters of the wide wheel have great influence on the average moving speed, the mix degree and the slipping rate. The optimum combination of structural parameters is that the diameter is 451 mm, the lug width is 65 mm, the lug tilt angle is 65°, the lug break angle is 30°, and the number of lug is 9. With optimum combination of the structural parameters for simulation experiment, the performance indexes are as follows. The average moving speed is 542.200 mm/s, the mix degree is 42.692%, and the slipping rate is 26.017%.