| Double Spiral Rotary Tillage and Stubble-Mulch Roller is the core components of Boat-rotary Tillage and Stubble-Mulch machine. Reducing its power consumption is the key to improve working performance of Boat-rotary Tillage and Stubble-Mulch machine. The research team has been ongoing theoretical and experimental study for the process that the double helix knife roll cut paddy soil. So far, the dynamics of transverse knife who is the key components of the double helix knife roll in the process of cutting paddy soil still need to be further articulated.Previous experimental study shows that the structural parameters and motion parameters of the Double Spiral Rotary Tillage and Stubble-Mulch Roller have a significant impact on power consumption and effect of the work. In this paper, taken linear transverse knife and transverse knife to the study object and cutting soil force and cutting soil torque to the evaluation indicators to explore its dynamics regular pattern. The main contents and results are as follows:(1) Cutting test has been done in paddy field.Cutting test in paddy field has been carried out use linear transverse knife. The single factor experiment results show that, the soil cutting resistance first increases then decreases and obtain the maximum value in the vicinity of24h with the increase of immersion time In the soaking time of12h～36h range, and soil cutting resistance increases with the increase of cutting speed, and the longer blade longitudinal length, the bigger the soil cutting resistance, and the amount of straw increases, soil cutting resistance increases. The orthogonal experiment results show that, the influence of various factors on the soil cutting resistance is soaking time> blade longitudinal length> straw amount> cutting speed.(2) Three coordinate inversion test of the knife roller model has been done in three-coordinate measuring machine. In order to optimize the mechanism of the cutting feature of horizontal knife in the soil-straw mixture, the similitude method was used to research the cutting process and a model rotary knife roller was designed which proportion was1:2as real roller. In order to ensure accuracy of experiment the shape distinction between the model roller and real roller was checked with reverse engineering techniques. The model spiral horizontal knife and bend knife were studied on the FD Y685type three-coordinate measuring machine, and theirs three-dimensional shapes were reconstructed by CATIA V5software. The knives were set on the workbench of the machine while the locating surface was the bottom plane of the bend knife, and the axis of the model spiral horizontal knife was vertically placed on the workbench, then both knives were scanned by the machine with laser. The point cloud was obtained and filtered by CATIAV5software which could use to confirm the shape or the position of the knives. Due to accurately studied the knives shape, two coordinate systems were set up, one was XgYgZg on the roller and the other was XYZ on the machine. Some feature points were chosen in the point cloud on bend knife and spiral horizontal knife and analyzed with Matlab software. According to those feature points both the bend knife shape and model spiral horizontal knife shape were reconstructed and the relative position of two coordinate systems was founded. The spiral horizontal shape between model knife and real knife was compared and the shape distinctions were found from ten feature points on the model knife. Results indicated that the maximum distance between those measurement points and theirs reverse points was6.016mm, and the minimum distance was0.624mm, the average distance was3.243mm.The maximum relative error rate between measurement points and theirs reverse points was5.2%, while the minimum relative error rate was0.6%and the average relative error rate was3.6%. Reverse reconstruction was an advanced and high-precision technology which was able to accurately measure and reconstruct agricultural equipment shape, especially complicated shape.(3) Model roller cutting force and torque has been test in indoor soil bin. A Virtual Instrument Test System based on Lab VIEW Software has been designed, who can measurement model roller working power, speed and torque real-time. Using the system and model roller some relevant tests in the indoor soil bin have been carried out. The orthogonal experiment results show that, the influence of various factors on the cutting knife roller torque is soil moisture content> tillage depth> speed> knife roller speed. Taken speed (χ1), knife roller speed(χ2), deep tillage (χ3) three factors on the model knife roller of soil cutting torque on a regression orthogonal experiment, variance analysis showed that only deep tillage (χ3) to test index had a significant effect, and the linear equation is y=-1.045+0.132x3(p<0.01). |
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