Research on Factors Affecting Cutting Resistance of Cutting Blade Based on Sand Trough Test

Abstract

The use of sand fixing equipment to lay straw checkerboard barrier has become the main means of desert control, while the design of laying system for sand fixing equipment lacks relevant theoretical guidance. The factors that influence the cutting resistance are complex in the process of laying straw checkerboard barrier. A sand trough test-bed was designed to study the factors affecting the cutting resistance in the blade cutting process. The structure of the test platform was composed of disc knife, sand tank, bracket, lifting slide rail device, force measuring device, driving device, etc. By establishing the mathematical model of the working force of the cutter, the diameter of the cutter was determined as 720 mm and the thickness of the cutter was 6 mm. The water content of the tested sand was 6.3%, the wet density was 1.141%, and the dry density was 1.140%. The sand barrier material was selected from the natural dry rice straw, the diameter of the single straw was about 4 ∼ 5mm, the length of the straw was about 700 mm, and the quality of the single rice straw evenly laid 1000 mm was 160 g. The driving device chose the stepping motor as power source, which can drive the lifting slide rail device moving in horizontal direction. The tension pressure sensor of the force measuring device was installed by articulated form, which can obtain test data. The parameters of the speed control system were calculated and the schematic diagram of the drive was designed, and the laying speed could be adjusted by adjusting the frequency of the stepping motor. The influence of the change of inserting depth, laying speed and laying thickness on the insertion resistance of the cutter disc were tested. Inserting depth and laying thickness had significant influence on insertion resistance and traction force. When the thickness of the thickness was 160 g/m and the insertion depth was 150 ∼ 210mm, the insertion resistance was around 1700 ∼ 2450 N, and the traction value was between the 550 ∼ 1200 N. When laying thickness reached 480 g/m, the insertion resistance reached about 3200 N, traction was up to 1600 N. According to the orthogonal test results, the best combination was insertion depth of 210 mm, laying speed of 0.056 ∼ 0.112m/s, and laying thickness of 480 g/m. The order of the main and secondary factors affecting the test results was the maximum insertion depth, the laying thickness and the minimum laying speed. A regression model between insertion resistance, traction force and insertion depth and thickness was established, and relevant experiments are carried out to verify the rationality of the model. It was found that the laying speed had little effect on the test results. The laying thickness had a more significant impact on insertion resistance, while insertion depth had a more significant impact on traction force according to the surface of double parameters. The experimental results provided a theoretical basis for the design of the laying and the traction power system of sand fixing equipment.