Abstract: A switching device for double nozzles of a 3D printer, which includes two transmission blocks, a rotary part and two spring parts. The two transmission blocks are in mirror image structures with each other and are respectively mounted on two nozzle devices; each transmission block is provided with a pressure supporting and transmiting portion, and the pressure supporting and transmiting portion includes a pressing-down stopping portion, a pressure transmiting portion, and a restoring stopping portion which are connected in sequence; the rotary part is connected to the case and is provided with two pressing parts; the two spring parts respectively sleeve the two nozzle devices, and the spring part supports the corresponding transmission block; the rotary part can rotate in a reciprocating manner, the rotary part drives the pressing parts to move on the two pressure supporting and transmiting portions.

Abstract: Discharge heat preserving methods and devices for a 3D printer are disclosed. In some embodiments, a hot airflow is blown to a discharge outlet (111) of a nozzle device (110) mounted on the 3D printer to form a heat preserving area at the discharge outlet (111) of the nozzle device (110). A printing material discharged from the discharge outlet (111) of the nozzle device (110) stays in the heat preserving area for 2-10 s. The hot airflow is blown to the discharge outlet (111) of the nozzle device (110) from a lateral direction of the nozzle device (110). In other embodiments, the printing material discharged from the discharge outlet (111) of the nozzle device (110) stays in the heat preserving area for 3-6 s.

Abstract: A switching device for double nozzles of a 3D printer, which includes two transmission blocks, a rotary part and two spring parts. The two transmission blocks are in mirror image structures with each other and are respectively mounted on two nozzle devices; each transmission block is provided with a pressure supporting and transmiting portion, and the pressure supporting and transmiting portion includes a pressing-down stopping portion, a pressure transmiting portion, and a restoring stopping portion which are connected in sequence; the rotary part is connected to the case and is provided with two pressing parts; the two spring parts respectively sleeve the two nozzle devices, and the spring part supports the corresponding transmission block; the rotary part can rotate in a reciprocating manner, the rotary part drives the pressing parts to move on the two pressure supporting and transmiting portions.