Upper die adjusting structure of punching machine

The invention belongs to the technical field of punching machines, and particularly relates to a punching machine upper die adjusting structure which comprises an upper die base, a connecting rod and an adjusting connecting device. The adjusting connecting device comprises a connecting seat, an adjusting nut sleeve, a locking nut sleeve and a limiting sleeve; the upper die base is provided with a downwards-sunken mounting cavity, the connecting base is arranged in the mounting cavity, and the connecting base is provided with a connecting cavity. The lower end of the connecting rod is provided with external threads and extends into the connecting cavity, and the adjusting nut sleeve and the locking nut are sequentially arranged at the lower end of the connecting rod in a sleeving mode and provided with internal threads meshed with the external threads. A sealed oil cavity is formed by the bottom of the locking nut sleeve and the bottom of the connecting cavity and connected with a hydraulic system. The adjusti