Automatic wire changing mechanism of 3D printer

The utility model discloses an automatic wire changing mechanism of a 3D printer. The automatic wire changing mechanism comprises a rotary wire changing mechanism, a clamping wire feeding mechanism, a detection mechanism and a mounting plate, according to the utility model, the main shaft is mounted on the mounting plate, the two star-shaped parts are mounted on the main shaft, and the consumable wire which is mounted in advance is driven by the arc-shaped small hooks at the tail ends of the star-shaped parts; when the sensor detects that the previous coiled wire is used up, the motor drives the main shaft to rotate; the star-shaped part brings new consumables to the second sensor and stops; a pinion is mounted on the steering engine, a rack is mounted on the fixing part, the pinion is meshed with the rack, and the steering engine rotates to drive the fixing part to press the consumable and the bull gear; the large gear is installed on the motor, the motor rotates, the large gear rotates, consumable wires are