Automatic adjusting device for jacking of top arch frame in tunnel

The utility model belongs to the technical field of tunnel construction, and particularly relates to an automatic adjusting device for jacking a top arch frame in a tunnel, which comprises a protective square tube, symmetrically distributed bases are fixedly connected to two ends of the protective square tube, and symmetrically distributed supporting blocks are fixedly connected to opposite surfaces of the two bases. And the surface of one side of the supporting block is fixedly connected with the surface of one side of the protection square pipe, a lead screw is installed on the inner bottom wall of the base through a bearing, and one end of the lead screw penetrates through and extends to the upper surface of the base. According to the automatic adjusting device for jacking of the top arch frame in the tunnel, the automatic adjusting device is arranged on the outer surface of the screw rod, the automatic adjusting device comprises a chain wheel, and the inner wall of the chain wheel is fixedly connected wit