Self-locking telescopic structure

The utility model relates to a self-locking type telescopic structure which comprises a transport vehicle, a supporting frame is vertically installed on the transport vehicle, and two limiting plates are installed on the supporting frame in parallel in the width direction. The device further comprises a first telescopic joint and a second telescopic joint, the first telescopic joint and the second telescopic joint are installed between the two limiting plates in a limited mode through a sliding rail, one end of the first telescopic joint and one end of the second telescopic joint are limited by a transport vehicle, the first telescopic joint and the second telescopic joint are sequentially installed in parallel relative to the supporting frame, and gear belts are installed on the sides, facing the supporting frame, of the first telescopic joint and the second telescopic joint. A clamping groove is formed in the side, facing the second telescopic joint, of the bottom face of the first telescopic joint. A slidi