Internal-positioning type float collar

An internal-positioning type float collar relates to the technical field of casing float collars used in the petroleum drilling and production industry and comprises a main body, a rubber sleeve, an upper cone, an upper slip, an upper check ring, a lower check ring, a lower slip, a lower cone, a pressing sleeve, a lock sleeve and a ball float type check valve, wherein the main body is a tubular structure; the rubber sleeve is an annular structure; both the upper cone and the lower cone are annular frustum structures; both the upper slip and the lower slip are internal conical structures with gaps; both the upper check ring and the lower check ring are annular structures; both the pressing sleeve and the lock sleeve are tubular structures; the part positioned at the upper part of a flange, of the main body is connected with the ball float type check valve; the part positioned at the lower part of the flange, of the main body is sequentially sleeved with the rubber sleeve, the upper cone, the upper slip, the up