Abstract: A two-port solenoid valve of the pilot-assisted type that is designed to function even when there is no pressure difference between the primary and secondary control passages. A pilot valve actuated by the armature of a solenoid opens and closes a pilot discharge passage, with the armature being also adapted to open the main valve that is connected thereto by means of a lifting spring. The pilot discharge passage immovably provided in the valve housing is intended for suppressing the vibration of the main valve in closing. The pilot valve thart comes in and out of contact with the pilot valve seat at one end of the pilot discharge passage is spring-thrusted in the closing direction and attached to the armature.

Abstract: A solenoid actuator of high performance comprising a coil surrounded externally with a magnetic frame and having a stationary core disposed therein, with a movable core attracted to the stationary core upon energizing the coil being disposed axially slidably, wherein the magnetic frame comprises a pair of magnetic frame parts each fabricated from a sheet material by bending the sheet so as to define a top plate and a bottom plate integrally joined with a side plate for covering the top, bottom and side of the coil, and the pair of magnetic frame parts are assembled to each other with their top plates and bottom plates being overlapped to each other, to thereby provide simplified structure and easy assembling.

Abstract: A solenoid actuator for use with an electromagnetic valve which includes a magnetic frame for establishing a magnetic circuit around an energizing coil, which is formed by bending a sheet-like magnetic frame constituent plate with an eddy current eliminating slit being defined therein, thereby enabling simplification in structure of the magnetic frame, effective utilization of electric power and reduction in the magnetic resistance, and attaining inexpensive fabrication, great electromagnetic force with electrical power-saving and small magnetic loss.

Abstract: A pilot-controlled electromagnetic valve having a pilot valve mounted on a member which is supported movably relative to a solenoid plunger and a main valve and connected to the plunger through a spring such that a pilot orifice is opened when the plunger approaches a fixed core of the solenoid undergoing a stronger magnetic pull.