Abstract:The regulation, monitoring and display mode of cleaning operation parameters of domestic grain combine harvester air and screen cleaning device is simple and low automation degree, resulting in low cleaning efficiency. Aiming to improve these problems, the theoretical basis of adjusting four cleaning operation parameters (the crank speed of vibrating screen, the opening of air door, the rotation speed of fan and the opening degree of fish scale screen) of the air and screen cleaning device of grain combine harvester were analyzed. The control and monitoring device of each cleaning operation parameter was designed independently. Based on the air and screen cleaning device of combine harvester, the multi parameter adjustable and measurable cleaning system was designed. The automatic control, monitoring and display of the cleaning operation parameters of the existing air and screen cleaning device, and the whole system was driven by electric power, realizing the green operation of the air and screen cleaning device of the harvester. Through the accuracy test, the adjustment accuracy of the four cleaning operation parameters of the multi parameter adjustable and measurable cleaning system was not less than 97.17%, which had good robustness, and can realize the accurate control and realtime display of the four cleaning operation parameters. The model 4LZ-4 full feeding crawler harvester equipped with multi parameter adjustable and measurable cleaning system was used in the field test of soybean harvester with total loss rate and impurity content as evaluation index of cleaning performance. The prototype ran well in the test. The results showed that the average loss rate and impurity content in the field experiment of soybean mechanical harvesting were 3.13% and 2.70%, respectively, which met the requirements of industry standard.
