Positioning shaft machining system for shield tunneling machine

The invention belongs to the technical field of positioning shaft machining, and discloses a positioning shaft machining device for a shield tunneling machine, which comprises a machining bed body, a machining drill bit is mounted on one side of the upper surface of the machining bed body, and a control panel is mounted in the middle of the upper surface of the machining bed body. Through the arrangement of a machining drill bit, a movable lantern ring, a pull rod, a limiting ball and a positioning shaft body, when the device is used, a worker firstly places the positioning shaft body in the movable lantern ring, then the worker moves the movable lantern ring till the positioning shaft body is wrapped, and at the moment, the worker pulls the pull rod towards the bottom, so that the positioning shaft body is clamped in the movable lantern ring; at the moment, a pull rod jacks an internal limiting ball, so that the internal limiting ball forms a compact structure, then the pull rod is fixed, a machining drill b