Cutter head, tool changing device and method for coping with upward floating of shield tunneling machine in upper-soft and lower-hard stratum

The invention provides a cutterhead, a tool changing device and a method for coping with upward floating of a shield tunneling machine in an upper-soft and lower-hard stratum, and belongs to the field of rail transit tunnel excavation and tunneling construction. The cutterhead comprises a cutterhead body, a main cutter beam assembly, auxiliary cutter beam assemblies and center plate assemblies, the main cutter beam assembly comprises a cross beam assembly and a vertical beam assembly which are distributed in a cross mode, the auxiliary cutter beam assemblies are arranged on the two sides of the end, close to the edge of the cutterhead, of the main cutter beam assembly, and the center plate assemblies are arranged on the edge of the cutterhead and located between every two adjacent auxiliary cutter beam assemblies. Compared with a traditional cutter head, six heavy tearing cutters and two wedge tooth hobs are replaced, and four heavy tearing cutters are additionally arranged. Through the special design and mut