Abstract:Aiming at the problems of high resistance, high power consumption, low stubblebreaking rate, and poor ridge shape after the operation of subsoil stubble-breaking machine after straw return to the field in northeast ridging area, a stubble-breaking blade with interaction with subsoiler was designed. The mounting distance between the subsoiler and stubblebreaking blade was determined to be 60mm by discrete element simulation. Meanwhile, in order to satisfy the same relative acceleration between the cutting edge of stubble-breaking blade and soil particles at different depths (30mm,60mm,90mm,120mm) during operation, the sliding angle at different depths was obtained by combining the kinetic analysis of the stubble-breaking blade and subsoiler, and the cutting edge curve of the stubble-breaking blade was determined.Taking the blade disk diameter and stubblebreaking blade mounting angle as the test factors, and operating resistance and power consumption as the test indexes, a two-factor, five-level center combination test was carried out.The test results showed that the minimum operating resistance and power consumption were obtained at the blade disk diameter of 312mm and the mounting angle of 73.2° (the operating resistance was 1167N and the power consumption was 14.6kW). In the field test, the depth of stubble-breaking blade entering the soil and the forward speed of machine were taken as the test factors, the working resistance, ridge height/width ratio and stubble-breaking rate were taken as the test indexes. The optimized results showed that when the depth of blade entering the soil was 102mm and the forward speed was 0.65m/s, the working resistance was 1467N, ridge height/width ratio was 0.529, and stubble-breaking rate was 95.4%. Comparative field performance tests were conducted at this optimal operation parameter, and test results showed that compared with the traditional stubble-breaking blade, the serrated stubble-breaking blade operating resistance was reduced by 13%, the height/width ratio of the ridge was increased by 6%, and the stubble-breaking rate was increased by 1 percentage points, which was able to meet the quality of the machine operation and the agronomic requirements.