OPTIMUM DESIGN OF SEED HOLDING RING OF VERTICAL DISC SEED-METERING DEVICE

In this paper, the vertical disk mechanical seed-metering device is taken as the object to optimize the design of seed holding ring. The laboratory test is carried out with seed-metering test bench and high-speed camera system; and the influence law of starting and ending angle, front inclination angle and flexible buffer of seed holding ring on the seed filling performance is studied. The ending angle of seed holding ring shall be consistent with seed throwing angle of seed-metering device, and the starting angle of seed holding ring has a significant effect on seed filling performance. The quality of fill index will first increase and then decrease, reaching the maximum at 35.7 degrees; while miss fill index will first decrease and then increase, and the multiple fill index will be 0% when the starting angle is greater than 50 degrees; and seed damage index will first decrease and then increase. In order to improve seed filling performance, the front end of seed holding ring is treated with inner chamfering. The larger the angle is, the lower the quality of fill index, the higher the multiple fill index and the lower the miss fill index, but the seed damage index will also increase. By setting a flexible buffer in the front end of seed holding ring, the seed damage index can be effectively reduced. When the buffer is 60 mm, the seed can be cleaned smoothingly, and the seed damage index will be 0%.