Solenoid valve with 2-part fixed core

Abstract

A solenoid valve capable of handling a corrosive control fluid and developing an increased attraction force. The solenoid valveis adapted such that a fixed core is located in a wound coiland protruding through the lower surface of the coil, a plungerholding a valve sheetis supported by a plate springunder the fixed core, the valve sheetis normally retained in contact with a valve seatby spring force of the plate spring, and the valve sheetis separated from the valve seat against the spring force of the plate springwhen the coilis energized. The fixed core comprises two parts vertically coupled, an upper one of which is a first fixed corelocated in the coilin non-contact with the control fluid, the first fixed core being made of a material having high magnetic permeability, and a lower one of which is a second fixed corefitted, protruding downward, in the coil bobbin to cover the lower end of the coil bobbin, the second fixed core being made of a material having corrosion resistance to the high-corrosive control fluid.