D. IVANOV1, G. KOSTADINOV1, T. MITOVA2 and I. DIMITROV2
1 Institute of Melioration and Mechanization, BG -1331 Sofia, Bulgaria
2 N. Poushkarov Institute of Soil Science, BG-1080 Sofia, Bulgaria
IVANOV, D., G. KOSTADINOV, T. MITOVA and I. DIMITROV, 2006. Herb stem cutter - design and research. Bulg. J. Agric. Sci., 12: 803-809
The article presents the results of investigations on a herb stem cutting machine. Investigations were performed as a series of controlled single-factor experiments. The basic target functions of the study were as follows: drives absorbed power of the machine (kW); specific energy consumption (kWh/t) and average cutting length (mm). The levels of controlled trial factors were as follows: machine load capacity with herb stem mass: Q = 0.5; 1 and 1.5 kg/s and feeding velocity of stem mass to the cutting drum: V = 2.0; 2.4 and 2.8 m/s. Here are the factors, maintained at stable levels: cutting drum peripheral velocity - 25 m/s at rotation frequency of 1176 min-1; cutting drum working width - B = 0.558 mm; cutting drum diameter D = 0.406 m; number of blades z = 6; blade thickness b = 10 mm; blade sharpening angle β = 34°; inclination of blades' edges to the counteredge α = 15°; front cutting angle φ = 50°; gap between blade and counterblade edges Δ = 0.5 mm; sharpening angle of the counterblade β1 = 90° and sharpness of counterblade cutting edge δ = 0.2 mm. The correlation between the variation of drive's absorbed power for start-up of the cutting drum, specific energy consumption and average cutting length, on the one hand, and the variation of controlled factors, on the other, was established. The respective adequate regression equations were simulated, describing the herb stem cutting processes with specific accuracy.