Gate-type welding preheating device

The utility model discloses a gate-type welding preheating device, and belongs to the technical field of preheating. The gate-type welding preheating device comprises a fixed base and a fixed frame. A stretchable air cylinder is arranged in the fixed frame. A preheating mechanism is arranged at the front end of the stretchable air cylinder and comprises a lifting air cylinder. A guide rail is arranged at the front end of the fixed frame. A rotating mechanism is arranged on a sliding block on the guide rail and comprises a rotating air cylinder and an angle detector. A transducer is arranged at the front end of the rotating air cylinder, and a preheating head is arranged at the front end of the transducer. A temperature sensor is further arranged on the rotating mechanism. Compared with the prior art, when the gate-type welding preheating device carries out corner joint work, whether the temperature of a corner joint area is within a technological temperature range or not is detected through the temperature sensor, if the temperature of the corner joint area is within the technological temperature range, the temperature sensor feeds information back to a control device, the time difference between preheating completing and the corner joint starting process is avoided, the weld joint quality passing percent is improved, the working time is saved, and the working efficiency is improved.