ELECTROMAGNETIC VALVE Russian patent published in 1999 - IPC

FIELD: engine manufacture; fuel injection systems of internal-combustion engines. SUBSTANCE: valve has at least one part, such as armature 27, whose surface is stepped to comply with optimal magnetic and hydraulic characteristics before wear-resistant coating is applied to it. Annular thrust section 69 formed by step has definite width of thrust or contact surface b which is maintained throughout entire service period because wear of step surface upon long-time operation does not cause increase in contact width. EFFECT: improved mechanical endurance and almost constant pull-in and drop-out time of moving part. 8 cl, 5 dwg