Design and test of single row sweet potato vine recycling machine

Abstract: Sweet potato is an important raw material for food, feed, industrial, it also is a high quality anti-cancer health food and new energy material. It is widely cultivated in the world, and China is the largest producer of sweet potato in the world, the average perennial planting area of sweet potato is more than 3 million hm2, accounting for about 45% of the global planting area of sweet potato. The yield of sweet potato vine is generally more than 2×104 kg/hm2, and the sweet potato vines is rich in nutrients and is an ideal feed material. The sweet potato vines grow vigorously along the ground surface, and the vines are intertwined between the ridges, it is difficult to collect the vines mechanically. Sweet potato harvest mainly includes cleaning the vines and breaking the ridge to harvest, the treatment of vines before harvest has great influence on its harvest efficiency, labor intensity and yield. At present, the collecting mechanization of sweet potato vine in China is almost blank, which seriously restricts the development of sweet potato industry. Cleaning up the vines by hand is a labor intensive and low work efficiency work , which seriously restricts the enthusiasm of farmers in production. At present, the main problem of sweet potato vine treatment machinery at home and abroad is that the vines are crushed and scattered in the field, so the sweet potato vines cannot be collected and used as feed or energy, thus causing greater economic losses and easily aggravating the spread of diseases and insect pests. Aiming at the difficulty that the sweet potato vines can only be harvested by hand, a kind of single row sweet potato vine recycling machine matched with a small four-wheeled tractor was designed. Through theoretical analysis and experiment, the structure and working principle of the recycling machine were analyzed, and key components such as cutting device, vine picking device and feeding device were design. Using Box-Behnken experimental design method, quadratic regression models with the vine collected rate, the vine stubble height, the sweet potato injury rate as the response indexes were established. Through the analysis of model interaction and response surface, the change laws of the influence of cutter roller speed, the forward speed of machine and the ground clearance on the response indexes were obtained. The regression model was optimized by Design-Expert8.0 software, and the accuracy of the predicted results was verified by experiments. The relative error between the measured value and the predicted value was less than 5%, indicating that the model was high reliability. The order of significance of each factor on the vine collected rate was the forward speed of machine, cutter roller speed and ground clearance, the order of significance of each factor on the vine stubble height was the ground clearance, cutter roller speed and forward speed of machine, the order of significance of each factor on the sweet potato injury rate was the ground clearance, cutter roller speed and forward speed of machine. The optimal working parameters were that the cutter roller speed was 2 000 r/min, the forward speed of machine was 2.5 km/h and the ground clearance was 15 mm. Under the condition of optimum working parametersthe vine collected rate was 93.16%, the vine stubble height was 33.8 mm, and the sweet potato injury rate was 0.26%, the working effect was better. The research results are of great significance in promoting the development of light and simplified production of sweet potato industry.