Method of mounting piston ring

Abstract

The leading piston ring (R1) is positioned and disposed radially outward of a piston ring groove (11, 12, 13) in a state where being compressed in an axial direction by applying a feed force in the axial direction to plural piston rings (R) coaxially held at an outer periphery of a tubular holding portion (2) in a diameter-increased state to be pressed against a ring retainer (5) disposed axially outward of the holding portion (2). Then, the leading piston ring (R1) is mount into the piston ring groove (11, 12, 13) by moving the ring retainer (5) relative to the holding portion (2) so as to be separated from the holding portion (2) in the axial direction so that a compressive force in the axial direction is released and the diameter of the leading piston ring (R1) is decreased due to a self-contraction force. Figure 5A