Welding and positioning device for assembling and welding air duct heater

The invention relates to the technical field of air duct heater manufacturing, in particular to a welding and positioning device for assembling and welding an air duct heater. The device comprises a bottom frame, a first bearing and overturning mechanism, a second bearing and overturning mechanism and an adjusting mechanism; the first bearing and overturning mechanism is arranged on one side of the bottom frame and used for bearing an air duct shell and driving the air duct shell to be overturned by 90 degrees in a suspended manner; the second bearing and overturning mechanism is arranged on the other side of the bottom frame and used for bearing a wire box or electric heating element tube plate and driving the wire box or electric heating element tube plate to be overturned by 90 degrees, the first bearing and overturning mechanism and the second bearing and overturning mechanism share one driving source to achieve synchronous driving, and the upper end face of the overturned air duct shell and the overturne