The invention relates to an unloading device of a railway freight transportation hopper car. The unloading device is a link mechanism arranged between a pneumatic unloading device and a hand-operated unloading device of the railway freight transportation hopper car, belonging to the
rail traffic field. The unloading device comprises a
clutch and a main air
pipe of a pneumatic
system, wherein the
clutch is arranged on a poking fork which has a poking pin; the poking fork is arranged on a main transmission shaft which is arranged on a support; and the main transmission shaft is provided with a
handle. The key technology of the unloading device comprises the following steps that: the
handle is connected with a connecting rod, and the other end of the connecting rod is connected with a
changeover cock which is arranged on the main air
pipe of the pneumatic
system. The unloading device adopts a linkage mechanism, that is, the
handle, the connecting rod, the
changeover cock and the car body are formed into a four-linkage mechanism; therefore, by means of the
transmission function of the four-linkage mechanism and the switching of the
changeover cock, hand-operated action is realized when pneumatic function is
shut down, thereby solving the problem of pneumatic misoperation during hand-operated unloading. In addition, the linkage mechanism can reach the goal of reliable operation through controlling the length and the position of the connecting rod so as to eliminate hidden danger.