Patent ID: 6987437

Claim:
An electromagnetic actuator comprising: a movable core having at least one sliding face, that is subjected to gas soft nitriding, salt-bath soft nitriding, sulfo-nitriding, or nitriding treatment so that a surface roughness of the treated face is controlled to be within a prescribed range of 3.2 Rz and 2 Rz; a housing having at least one sliding face, Ni-P plating or Ni-P plating plus heat treatment being provided to said at least one sliding face, wherein the housing encompasses the movable core so that the core reciprocates with the housing; an attraction part, wherein the attraction part exerts a magnetic force on the moveable core to force the movable core in one of reciprocating directions; and a stator, wherein the stator forms a magnetic circuit along with the movable core, wherein at least one of said sliding faces of the housing and the movable core are in contact with each other.