| China is the largest cotton producer in the world at present.Xinjiang is China’s main national commodity cotton base and the most important high-quality cotton production area.In terms of cotton planting area and cotton output,Xinjiang ranks first in China.Cotton stalk is the main by-product of cotton planting and is an important biomass resource.If it can be recycled,it can create huge economic value.However,at present,the research on cotton stalk pulling device in China is in its initial stage,and the existing various cotton stalk pull-up harvesting devices have many shortcomings.The existing cotton stalk pulling device in foreign countries is mainly aimed at the local cotton planting mode with large single row and equal spacing,which is not suitable for such diversified planting mode in China.Based on the above research background,this paper carried out relevant research on cotton stalks under the dense planting mode of machine-picked cotton in Xinjiang.The main work and conclusions are as follows:(1)Various physical characteristics of cotton stalk at harvest time were obtained by field investigation.The maximum pull-out force of cotton stalk was 821 N,and there was a positive correlation between the pull-out force and the diameter of cotton stalk.The moisture content of cotton stalk was tested.The results showed that the moisture content of cotton stalk was 33.7% after machine picking,and 25.4% after natural drying for half a month.Based on cotton stalk moisture content test,the bending resistance test of cotton stalk was carried out.The test results showed that the bending resistance of cotton stalk broke at the minimum bending Angle of 64.88°.There was a positive correlation between the bending resistance of cotton stalk and the moisture content of cotton stalk,and the influence of cotton stalk diameter on the bending resistance of cotton stalk was obvious.(2)Based on the analysis of the present status of research on cotton harvest device at home and abroad,clarifies the research developed a new type of cotton pulling device design requirements,and on the basis of field investigation to obtain the test used cotton machine adopt planting cotton planting patterns and various physical parameters of cotton,determine the horizontal axis of roller cotton pulling device scheme and working principle of the machine.(3)The key working parts of the machine are mainly stalk feeding device and stalk pulling device.Through the analysis of its working process and dynamics,the structural parameters and working parameters of stalk feeding device and stalk pulling device are obtained.The design of stalk feeding device is triangular structure,the working width is 1200 mm,the vertical height is 700 mm,and the bottom height is 200 mm.The rotary radius of the pulley is 80 mm,the spacing of the rod is 200 mm,and the speed of the rod should be greater than 1.414 m/s.The device is composed of a pair of stalk pulling rollers with a rotation radius of100 mm and a working width of 1250 mm.The rotation speed of the stalk pulling rollers is required to be between 191 and 287 r/min.In order to enhance the adaptability of devices for cotton’s biggest pull force condition,the increase of roller spacing in stem pull roller on regulating mechanism,manufacture,installation of maneuverability into consideration,determine the structure parameters of roll gap adjusting mechanism,and selection of cylindrical spiral compression spring,to remain the state of pressure between the roller and cotton,and then realize the cotton was pulling smoothly.The machine adopts chain drive to meet the actual operation requirements of the machine.(4)The test results showed that the factors had great effects on the performance of horizontal-roller clamping cotton stalk pulling device.The significant effects of machine forward velocity,stalk conveying rod velocity and the speed of stalk pulling roller on leakage rate were in a decreasing order,the significant effects of the speed of stalk pulling roller,stalk conveying rod velocity and machine forward velocity on plucking rate were in a decreasing order.Verification test results indicated that when machine forward velocity was 0.78 m/s,deflector rod velocity was 1.75 m/s,the speed of stalk pulling roller was 239 r/min,cotton stalk leakage rate of the device was 10.52% and plucking rate was 7.39%,which was basically consistent with the prediction results of model optimization,and the structural design was reasonable.The research results can provide a reference for the structure improvement design and operation parameters optimization of the horizontal-roller clamping cotton stalk pulling device. |
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