Abstract: Provided is a device for treating the inner surface of a cylinder barrel. A cover member (32) is provided, at the lower surface (59) thereof, with seal rings (54, 55, 56). The seal rings (54, 55, 56) are disposed concentrically about the center axis (63) of a cylinder barrel (43, 67). The lower ends of the seal rings (54, 55, 56) are disposed at different levels of height in such a manner that the farther away from the center axis (63), the higher the positions of the lower ends relative to the seal ring (54) closest to the center axis (63).

Abstract: A cylinder barrel inside surface treatment apparatus for providing a uniform treatment finish is disclosed. The treatment apparatus includes a pallet on which a cylinder block is placed with a gasket surface faced upward. A top opening of a cylinder barrel of the cylinder block is covered by a cover member having a concave portion communicating with the top opening. A nozzle having treatment solution spray holes is attached to the cover member. The treatment solution is sprayed toward a wall of the concave portion from the treatment solution spray holes and flows along the wall from a top end to a bottom end of the cylinder barrel inside surface.