关键词: 寒地黑土区, 秸秆还田机, 静力学仿真, 精量喷药, 最优设计

Abstract: Aiming at the problems of high‑power consumption and slow straw decomposition speed of rice straw returner in the cold black soil area, a straw returner with the function of fine spraying of decomposers was designed, and the combination of ploughing parameters with the minimum torque of the knife shaft  was explored. The automatic lifting‑and‑levelling device, the fungicide spraying device, the straw quantity identification system and the curved cutter of the field returning machine were designed. The fungicide spraying device adopted the PLC-driven solenoid valve to control the spraying quantity. The straw quantity identification system could evaluate the quantities of crushed‑and‑piled‑up straw and stubble straw respectively and transfer the data information to the fungicide spraying device. Workbench 2022 R1 software was used to simulate and analyze the design of field return cutter, and the optimum parameters of the cutter were 240 mm blade length, 80 mm blade width and 115° bending angle. A three‑factor‑three‑level rotary orthogonal test was used to establish the relationship between the cutter torque and the test factors. Design-Expert software was used for ANOVA processing, and the results showed that the relationships of the factors on the indexes were as follows: [A>B>C>A2>AB>BC] ([A] is the ploughing depth, [B] is the rotational speed, [C] is the amount of straw per unit area).  The response surface plot of the interaction was obtained and the optimal parameter combinations  was the ploughing depth of 20 cm, the rotational speed of 240 r/min, and the amount of straw per unit area of 3.5 kg/m2. A validation test was carried out, and the test results showed that the average torque was 24.32 N ⋅ m, the relative error with the predicted value of the model was 0.7%, the prediction model was reliable and the straw burying rate reached 96.8%.

Key words: cold black soil area, straw returning machine, hydrostatic simulation, precision spraying, optimal design