DESIGN AND EXPERIMENT OF AIR-SUCTION PRECISION SEED-METERING DEVICE FOR GARLIC

To address the challenges associated with garlic single-seed extraction, including seed damage, blockages, and the inefficiency of directional placement for irregularly shaped garlic seeds, an air-suction seed metering device, integrated with image recognition and orientation technology, was developed. The working principle of the product is expounded, and comprehensive analysis and design of key components—such as the seed dispenser, directional needle, and combined suction block—are presented. A test bench was constructed using Jinxiang hybrid garlic as the experimental material, with the negative pressure in the air chamber, the rotation speed of the seed dispenser, and seed quantity in the seed chamber as the primary experimental factors. The performance indicators included the single seed rate, cavitation rate, and double grain rate. A three-factor, five-level orthogonal design was employed to assess the effects of each factor and their interactions on the single seed rate. The optimal operating parameters for garlic species A, B, and C were identified as follows: the negative pressure in the air chamber was 11.85 kPa, 12.03 kPa, and 13.21 kPa, respectively; the rotation speed of the seed dispenser was 7.13 r/min, 6.85 r/min, and 7.25 r/min, respectively; and the seed quantity in the seed chamber was 138.97 mm, 140.90 mm, and 141.24 mm, respectively. The corresponding single seed rates were 95.98%, 96.50%, and 96.23%, respectively. Under these optimal operating conditions, the study further explored the effects of the positional parameters of garlic seeds of different grades, as well as the positional parameters of the directional needle, on the preliminary directional performance. The optimal positional parameters were subsequently determined. The results of this study offer critical insights and establish conditions for the intelligent orientation of garlic planting machines.