Abstract:In order to solve the problem of poor uniformity and large trench resistance in the wide seedling strip wheat planter, a wheat precision planter based on cell wheel seed-metering device and seed conveying tube with inner-quartering part was designed. The planter could implement the following function at one time: seedling belt cleaning, fertilization, wide strip seeding, active covering soil and compacting and so on. The diameter of cell wheel seed-metering device was 60mm, the number of cell columns was 4, and the number of each cell columns was 20. The cells were arranged in a horizontal staggered condition. In order to ensure uniform distribution of seed in the seedling strip, the inner-quartering seed conveying tube was designed. The tube can convey seeds in interval space. The outlet of the seed conveying tube was 32°. The seed and fertilizer were ordered covering by soil, which was thrown by rotary tillage. The rotating speed was 260r/min. To ensure the capacity of soil covering, the position of seed and fertilizer conveying tube and fertilizer was devised by kinematic analysis of soil. The distance range rotary shaft from seed and fertilizer tube was 0.36m and 0.50m, respectively. The experiment of seed-metering device and the planter was conducted. The results of laboratory test showed that the coefficient of variation of inline uniformity, the coefficient of variation of row displacement, and the seed fragmentation rate were 9.31%, 2.30% and 0.38%, respectively, under condition that the rotation speed of cell wheel was 35r/min. Field test showed that the coefficient of variation of uniformity in the wide seedling strip was 11.55%, and the average width of wide seedling strip was 8.2cm. The results also showed that the rotary tillage could clean stubble well and avoid the problem of congestion by rank grass. At the same time, by using the principle of rotary tillage and throwing soil, and soil covered the seed and fertilizer with layered, the average depths of sowing and fertilization were 3.2cm and 9.4cm, respectively. And the average vertical spacing between seed and fertilizer was 6.2cm. The variation coefficients of sowing depth and fertilizing depth were 4.15% and 2.97%, respectively, and the variation coefficient of the distance between seed and fertilizer was 5.48%, which met the national standard and agronomic requirements.
