Abstract:In order to realize the directional seeding of pumpkin seeds, a combined direction method was proposed to standardize the movement attitude of pumpkin seeds and then orient them, and a combined directional seed metering device for pumpkin seeds was designed. The key components of the device to realize the direction of pumpkin seeds included two parts: limit clearing plate and deflector plate. Based on the geometric characteristics of pumpkin seeds, the structural parameters of the limit cleaning plate were determined. The kinematic equations of the direction process of pumpkin seeds were established, and the relationship between the attitude change and the structural parameters of the deflector plate during the direction process of pumpkin seeds was clarified, and the structural parameters of the deflector plate were determined. The coupling analysis method of CFD-DEM was used to verify the feasibility of directional seeding of the seed metering device. The value range of rotation speed of seed discs was determined. A test bench was built. With the flat adsorption rate as the test index, the diameter of the hole in the seed discs was determined by a single factor test. The single seed rate was the test indicators, and the value range of negative pressure and the number of holes in the seed discs were determined by the single factor test. The negative pressure, the number of holes in the seed discs and the rotation speed of the seed discs were selected as the test factors, and the single seed rate and directional success rate were the test indicators. A three-factor and three-level secondary center combination test was carried out, and the primary and secondary factors influencing the single seed rate of the seed arranger were the negative pressure, the number of holes in the seed discs and the rotation speed of the seed discs. The primary and secondary factors influencing the directional success rate was the rotation speed of the seed discs, the negative pressure, the number of holes in the seed discs. Field validation experiments were carried out on the optimized data, and the results showed that when the negative pressure was 10kPa, the number of holes in the seed discs was 16, and the rotation speed of the seed discs was 4r/min, the single seed rate was 94.7%, the directional success rate was 82.7%, and the positive and negative deflection angle of the seeds falling into the cave basin was 18.5°.
