Self-expansion locking anchor pipe

The utility model belongs to the technical field of tunnel engineering, and particularly relates to a self-expansion locking anchor pipe. The device consists of an anchor pipe and arch frame fixed connection end, a universal joint, a double nipple threaded sleeve, a hollow anchor pipe with a protective sleeve and a small sheet, self-expansion concrete and an expansion exciting agent storage bag. The connecting structure is easy to install, the problem can be solved only through mechanical connection with the steel arch without welding, tunnel air pollution is effectively reduced, and the construction progress is accelerated. According to the utility model, through the self-tightening double nipple and the universal joint, the installation fault tolerance degree and the pre-tightening degree can be improved, the positioning is simple, and the force transmission effect is clear. Expansion concrete and excitation expansion materials are placed in advance in a factory, modularization of the device is completed, a