Electromagnetic solenoid with a replaceable fixed iron core

Abstract

An electromagnetic solenoid for use with a fluid control valve is disclosed in which a fixed iron core and a casing for housing a solenoid coil can be fabricated separately from each other without difficulty, and in which the configuration and the clearance between the fixed iron core and a movable iron core or the length of the extension of the fixed iron core from an end wall of the casing can be readily changed in accordance with the desired magnetic attraction characteristics thereof as required. The cylindrical casing has an end wall formed at its one end and is open at its other end, the open end being closed by an end cap member to form a yoke for a magnetic circuit. The fixed iron core is adapted to be separably connected with the end wall of the casing. An output rod is disposed in the casing with its one end extending outwardly through the end wall of the casing, the output rod slidably extending through the fixed iron core and being supported at its opposite ends by the end wall of the casing and the end cap member through a pair of slide bearings for axial sliding movement. A movable iron core is received in the hollow of the solenoid coil and fixedly mounted on the output rod in a face-to-face relation with the fixed iron core. The end wall of the casing has an insertion bore formed therein, and the fixed iron core has its one end firmly fitted into the insertion bore.