Lock pin device

The invention discloses a lock pin device. The lock pin device comprises a sleeve pipe, a pin shaft arranged inside the sleeve pipe telescopically, and a lock block which is arranged on the pin shaft and can rotate in the longitudinal section of the pin shaft, wherein the rotary center of the lock block deviates from the middle axis of the pin shaft; a first extension arm and a second extension arm are arranged at a preset included angle, and the arm lengths of the two extension arms are both within the distance between the rotary center of the lock block and the inner walls of the two sides of the sleeve pipe; and a through groove extending in the axial direction is formed in the lateral wall of the sleeve pipe. According to the lock pin device disclosed by the invention, when the pin shaft needs to extend to the work station state, the pin shaft is moved to the lock position, the pin shaft is fixedly locked through clamping connection of the first extension arm, the second extension arm, the sleeve pipe and