Multistage connection, extension and contraction automatic rod locking and pressurizing device used for drilling rod of rotary drilling machine

The utility model relates to the technical field of drilling rods of rotary drilling machines, in particular to a multistage connection, extension and contraction automatic rod locking and pressurizing device used for a drilling rod of a rotary drilling machine. The device comprises a first motor, a second motor, a big arm, a tackle slidably connected with the big arm, an outer barrel connected with the tackle, and an inner barrel arranged in the outer barrel in a sleeved manner, and the inner barrel and the outer barrel are locked through the device after the inner barrel extends out; the outer barrel is connected with a rotary power head and can move up and down in the rotary power head, the tackle is connected with the second motor through a chain, an inner barrel limiting device is fixedly arranged in the inner barrel, the first motor is connected with the inner barrel limiting device through a steel wire rope, an inner buckle is arranged in the inner barrel, a first through hole corresponding to the inner buckle is formed in the inner barrel, a second through hole matched with the first through hole is formed in the outer barrel, at least one hook is arranged on the outer wall of the bottom of the outer barrel, at least one groove matched with hooking portions of the hooks is formed in the outer wall of the inner barrel, and the hooks are fixed on the wall of the outer barrel by adopting tension springs. The multistage connection, extension and contraction automatic rod locking and pressurizing device is simple in structure and convenient to operate, and working efficiency of the rotary drilling machine is improved.