Tightening mechanism of sewing thread upper cylinder

The utility model relates to the technical field of sewing thread upper cylinders, in particular to a tightening mechanism of a sewing thread upper cylinder, which comprises a bottom plate, the top of the bottom plate is fixedly connected with a frame body, the top of the frame body is fixedly connected with the bottom of a shell, one end of the inner wall of the frame body is fixedly connected with a groove plate, and a transverse block is slidably clamped in a groove at one end of the groove plate. One end of the transverse block is fixedly connected with a vertical cylinder, and a tightening wheel is arranged on one side of the vertical cylinder. Through cooperation of a bottom plate, bolts, a frame body, groove plates, transverse blocks, rod bodies, vertical cylinders, springs, straight blocks, tightening wheels, a shell and an adjusting structure, a motor drives a grooved wheel on one side to rotate, a belt enables the two grooved wheels to rotate at the same time, the grooved wheels drive threaded rods