Scissor-shaped pulley supporting frame type visual bore speculum

A shear-type pulley support frame type visual bore speculum adopts a framework of a detection head, a variable-diameter support frame, a controller and a display terminal, and a glass fiber reinforced plastic cable 7 is operated to drive the shear-type variable-diameter support frame 2 to keep the detection head 1 at the axis position all the time and stably move along the central axis of a bore tube. The camera 9.2 installed on the shear-type variable-diameter supporting frame 2 is used for carrying out endoscopic observation on the bore tube, video recording and photographing are carried out on defects of the bore tube, and clear detection images and data of the inner wall of the detected bore tube are obtained. The shear-type variable-diameter supporting mechanism is composed of a supporting column 16, three sets of shear-type supports 18 and an elastic adjusting device installed on the supporting column 16, is suitable for bores or pipelines with different calibers, keeps the detection head to be located