| Cotton stalk as the by-product of cotton industry is an important sustainable biomass material. However, the various thickness of the cotton stalk main stem and lots of branches make it difficult to be harvested manually. The common method to deal with the stalk are burning and burying, which pollutes environment and wastes resources. Thus, carrying out research on mechanical harvesting of cotton stalk technology has become one of the research emphasizes on full mechanization of cotton production technology.1) In this paper, virtual instrument technology based on Lab VIEW was utilized to study pulling resistance of cotton stalk and to find how dry basis moisture content of soil, cotton root diameter, pulling angle and pulling linear velocity affecting the pulling resistance. The field experiment results showed that the soil moisture had effect on drawing resistance; and there was a positive correlation linear regression relation between cotton root diameter and cotton stalk drawing resistance in the same soil condition. The drawing angle had significant influence on the stalk drawing resistance, and the optimal drawing angle was30°under the test conditions. The influence of the drawing resistance by the drawing speed was related to the soil condition, which was no significant impact on the drawing resistance with high soil moisture and low soil firmness, but the effect was opposite with the low soil moisture and high soil compactness, while the optimal drawing speed was6.28mm/s under the test conditions.2) Through the morphological study of cotton stalk, combined with resistance test results of pulling cotton stalk, a three-dimensional model of cotton stalk had been established, which provided a reference for pulling machine design.3) A chain type cotton pulling mechanism was developed based on the present structure characteristics of cotton harvesting machinery, and the two-dimensional and three-dimensional diagram of the machine had been drawn through the software of AutoCAD and UG. In order to meet the demand of pulling power of cotton, simulation software ADAMS was chosen to find out the needed power of the mechanism power-giving approach. Simulation result also helped to determine the parameters of main power units.4) John Deere28hp tractor was taken as a test chassis to reduce the instability of cotton stalk field pulling experiment. The pulling mechanism was hitched in the front of the track. The cotton stalk pulling function verification test was done after debugging the pulling machine, and the pulled-net rate, pulled-missing rate, pulled-break rate as evaluation index for univariate and multivariate test of the soil crushing device and different soil moisture.According to the research, this mechanism could finish the function of cotton pulling resistance; the disc type Broken soil device could have a good influence in orientation, soil breaking and decreasing pulling resistance. As the moisture content increased, the cotton completed pulling rate would increase, the leakage pulling rate and the breaking pulling rate would decrease, In the design of cotton pulling mechanism, we should consider the condition of soil and straw material and choose suitable time to harvest. It would be helpful for reducing power dissipation and improving the efficiency of harvesting.5) Because of the mechanism wasn’t laying well cotton stalk in the field, an indoor test was done with the improved cotton stalk pulling mechanism which selecting the pulling height, plant spacing, forward speed as influence factors. The test results show that: the forward speed was smaller, the laying form was better with the same pulling height, plant spacing and different forward speed; and the pulling height was lower, the laying form was better with the same forward speed, plant spacing and different pulling height. Under the text condition, the cotton stalk laying best when the forward speed was0.1m/s, pulling height was5cm and the planting spacing was60cm. The cotton stalk to "â†'" in the form of laying is the best. |
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