Back opening mechanism for self-discharging disk tractor

The utility model relates to a back opening mechanism for a self-discharging disk tractor. The back pullout mechanism comprises side carriage railing panels and a rear carriage railing panel; sleeves are respectively fixed at the upper part outside the rear carriage railing panel and the upper parts of the rear ends of the side carriage railing panels, the side carriage railing panels are symmetrically distributed on the two sides of the rear carriage railing panel, pins are inserted into the holes of the sleeves, cotter pins are inserted into the holes on the pins and then separated; blocking spacers are arranged between the sleeves on the side carriage railing panels and the cotter pins, a locking shaft penetrates into a handle lock sleeve to be fixed on the symmetric central line below the rear carriage railing panel, the two ends of a locking shaft guiding sleeve covered on the locking shaft are respectively fixed on the symmetric central lines of the rear carriage railing panel and the carriage bottom pl