External circle honing head with centered feeding function

Disclosed is an external circle honing head with a centered feeding function. A main body of the external circle honing head is a hollow cylinder with a piston rod, two rings are fixed into a center cylindrical hole of the piston rod, an end surface of each ring is a conical surface, guiding discs are fixed onto guiding sleeves at two ends of the cylinder, a plurality of rectangular grooves are arranged on each guiding disc along the radial direction of a central circular hole of the guiding disc, a honing stick frame is mounted in each pair of rectangular grooves on each of the guiding discs on two sides of the cylinder in a sliding fit manner, a honing stick is fixed onto each honing stick frame, two through grooves are arranged on each honing stick frame, and a surface of each through groove is an oblique surface and slidably contacts with the conical surface of the corresponding ring. The rings move along with the piston rod, the oblique surfaces of the through grooves of the honing stick frames are squee