Structural part welding preheating device

The invention discloses a structural part welding preheating device. A first sliding block and a second sliding block are both connected to a guide rail in a sliding manner, a mounting frame is fixedly connected to the first sliding block, an induction electric heating ring is fixedly connected to the mounting frame, a guide rod and an air cylinder are both fixedly connected to the second slidingblock, and a mounting base is connected to the guide rod in an inserted manner. An air cylinder shaft of the air cylinder is fixedly connected with the mounting base, two clamping plates are elastically supported on the mounting base, and a push rod is fixedly connected with the second sliding block. According to the device, the preheating temperature error of a workpiece is within +/-10 DEG C, the temperature of the preheated workpiece is uniform and reliable, the first-pass yield of the welding quality is improved by 15%-20%, the most important productivity is improved by more than ten times, the device can be used