Design and experiment of cutting blade for cane straw

Abstract: Straw cutting and crushing is the first link of various comprehensive utilizations of straw, but cane straw belongs to the anisotropy compound material, and the type and parameters of cutting blades have a great effect on the cutting performance of blades. In order to solve the great change of the sliding-cutting angle, uneven stress, large fluctuation, and other problems of the traditional cutting blade, this paper used the principle that the direction of motion of point and pole diameter always maintain the same angle on the curve of logarithmic spiral equation, established a logarithmic spiral equation of blade line, designed a special equal sliding-cutting angle saw tooth blade for cane straw, used 3FC-500 small-type straw cutting crusher to finish cutting tests on mature tomato and eggplant vines in different moisture contents, recorded the digital electric energy meter reading at opening and closing moments to calculate the cutting power, and recorded the opening and closing times as the cutting time, to investigate the cutting efficiency by cutting time. In a single feeding quantity of 2 kg, we finished the single factor experiments on blade type, blade material, and blade sliding-cutting angle, and verified the adaptability of the designed cutting blade to cane straw by the test and analysis of cutting power and cutting efficiency. The results showed that: in the same cutting condition, compared with the ordinary blade and equal sliding-cutting angle flat blade, the cutting power of the special blade is minimum, cutting efficiency is the highest, cutting effect is the best and has obvious advantages. The cutting power and time are only about half that of ordinary blade and about two-thirds that of equal sliding-cutting angle flat blade. Compared with the 45°, the cutting power and cutting times of 40°equal sliding-cutting angle saw tooth type blade are all lower, only about one-third the times of 45°. Compared with the material 65Mn, the cutting effect of material Cr12MoV equal sliding-cutting angle saw tooth type blade is better. The moisture content has a larger effect on cutting power and time; with the drop in straw moisture content, blade cutting power and cutting time are reduced so that the cutting efficiency is improved. The cutting power of straw in moisture content at approximately 75% is about 6 times that of the straw in moisture content of 20%, cutting time for 2 times, in the process of cutting, the straw moisture content should not be too high, otherwise it can easily lead to clogging. In addition, though the tomato and eggplant vines belong to cane straw, they have similar fibrous structures, though the proportion of epidermis, cortex, vascular bundle, and pith in straw microstructure are different, and the average tensile strength and elastic modulus of eggplant vines are higher than those of tomato vines, so when cutting, the cutting power is relatively higher, the cutting time is longer, and the cutting efficiency is lower than that of tomato vine. The force is uniform of the design of equal sliding-cutting angle saw tooth type blade in the process of cutting. It reduces the cutting power, improves the cutting efficiency, has good cutting effect, and has important significance for improving the working performance of straw cutting machines and reducing the energy consumption in the cutting process.