OIL RING FOR INTERNAL COMBUSTION ENGINE.

摘要

Disclosed is an oil ring for an internal combustion engine, which does not undergo the adhesion or deposition of an oil sludge and does not cause the adhesion between constituent members of an engine when the engine is driven for a long period and can exhibit an excellent oil control function for a prolonged period. At least a part of the surface of an oil ring for an internal combustion engine is covered with a metal coating film having a surface free energy of 40 mJ/m2 or less and a hydrogen bonding force of 1.0 mJ/m2 or less. As the metal coating film, a metal coating film containing Ni or Cu or an alloy coating film containing Ni or Cu is used.