Navel orange fruit diameter grading device

The utility model discloses a navel orange fruit diameter grading device. Conveying belt is arranged at the top of the rack, a feeding hopper is arranged at the top of the rack; a discharge hole is formed in the bottom of the feed hopper and is positioned above the conveyor belt; a portal frame is further fixedly connected to the rack. A rodless cylinder A and a rodless cylinder B are symmetrically fixed in the middle of the portal frame; the bottoms of the rodless cylinder A and the rodless cylinder B are respectively and fixedly connected with a rod cylinder; the end part of each rod cylinder is connected with a pressing plate; a photoelectric sensor is arranged between the rodless cylinder A and the rodless cylinder B in the middle of the portal frame; the rodless cylinder A and the rodless cylinder B drive the pressing plate to press the surfaces of navel oranges, an inclined plate A is arranged at the end of the rack, the lower end of the inclined plate A communicates with a box,the left side of the rack