DESIGN AND EXPERIMENT OF COMBINED CAVITY-TYPE PRECISION HOLE-DROP SEED-METERING DEVICE FOR RICE

Abstract

In order to solve the problems of unstable seeding quantity and poor applicability of traditional lightweight simplification mechanical seed-metering device, a combined cavity-type rice precision hole-drop seed-metering was developed. According to the material characteristics of rice seed and the requirements of seeding quantity, the innovative metering hole structure achieves the purpose of accurate filling of rice seed. In order to adapt to the demands of different rice seeds and improve the accuracy and convenience of the adjustment of the seeding quantity, the number of cavities involved in seeding operation was simply adjusted. Bench tests are carried out on the effects of the seed-inlet width, the metering hole slope angle, and the cavity outer angle on the precision seeding performance of the seed-metering device. The test results show that when the outer and middle seed-inlets width both are 3.8 mm, the innermost seed-inlet width is 5.4 mm, and the metering hole slope angle is 35 °, and the cavity outer angle is 85 °, the performance of the three kinds of rice was better. Opening outermost seed-inlet to seeding super hybrid rice, the qualified rate is 90.67%, the miss-seeding rate is 3.77%. Opening outer and middle seed-inlets to seeding hybrid rice, the qualified rate is 90.80%, the miss-seeding rate is 3.73%. Opening all three seed-inlets to seeding conventional rice, the qualified rate is 90.67%, the miss-seeding rate is 3.53%. The field test shows the seed-metering device can also meet the requires of these kinds of rice seeding.