Abstract:
In response to the problem of high stubble damage rate during sugarcane harvesting, the interaction between sugarcane stalks and basecutter was analyzed, and a sugarcane stubble basecutting device was designed based on the combination of "sliding cutting and shearing cutting" to improve the cutting quality. The principle of unsupported cutting of traditional disc basecutters and supported cutting of sliding shear combination basecutters was analyzed. The result was shown that supported cutting could effectively reduce the bending resistance and inertia force of stems, thus preventing significant deformation of stems to a certain extent, effectively ensuring the cutting quality of stems, and sliding cutting can effectively reduce cutting resistance. The parameters of the key components of the basecutter were determined by establishing the force model of the stem. The sliding cutting operation is carried out using an equal sliding angle blade curve, and the sliding cutting angles and blade bevel angles were 40 ° and 45 °, respectively. The statics and modal analysis of the basecutter were conducted to prevent insufficient tool strength and resonance between the basecutter and the motor during shearing using ANSYS/Workbench. An optimal combination was achieved to fully meet the performance requirements, in terms of structural strength, where the yield strength of the basecutter was 450-650 MPa, while the maximum stress on the basecutter was 102 MPa, and the maximum displacement was 4.94×10
-5m. The excitation frequencies of the cutting and the feeding motors were 0-6.667 and 0-11.667 Hz, respectively. The modal analysis results show that the excitation frequencies of the two motors were much smaller than the first-order natural frequency of the basecutter (60.89 Hz). Therefore, the smooth operation of indoor experiments was obtained without any resonance. A basecutting test bench was built with adjustable cutting disc rotational speed, feeding speed, and cutting angle. The results of the single-factor test showed that when the cutting angle, cutting disc rotational speed, and feeding speed were 10 °-15 °, 140-220 r/min, and 1.1-1.7 m/s, respectively, the comprehensive evaluation value y was small and the cutting quality was better. The results of orthogonal experiment analysis of variance showed that each factor had a significant impact on the comprehensive evaluation value y. The range analysis of orthogonal experiments shows that the optimal experimental level is the cutting angle was 15 °, the cutting disc rotational speed was 180r/min, and the feeding speed is 1.4m/s. After experimental verification, the comprehensive evaluation values y were 0.256 and 0.298 at this time, indicated the cutting quality was better. Referring to the DG/T 117-2021 sugarcane harvesting machinery test method, the sugarcane stubble damage rate was inspected. The shear qualification rate was as high as 90.4%, and the stubble damage rate was reduced to below 10%. The operation quality of the sliding shear combined sugarcane basecutter met industry requirements.