Electronically controlled regulator

An electronically controlled regulator, comprising, inside a body including an introduction port and a discharge port, a pressure regulating valve including:

• a valve shaft in which a valve body is coaxially arranged, the valve shaft moveable in a reciprocating manner in an axial direction;
• a valve seat having a seat face with which the valve body is adjustable into close contact on a high-pressure fluid chamber side following the introduction port;
• and
• a discharge pressure regulating unit that adjusts a pressure of a fluid by changing a distance between the valve body and the valve seat while driving an electronically controlled electric motor to reciprocate the valve shaft via a valve shaft moving structure including a feed screw disposed between an outer peripheral surface of the valve shaft and an inner peripheral surface of a rotor, in which the electronically controlled regulator discharges a high-pressure fluid introduced from the introduction port into a high-pressure fluid chamber from the discharge port as a pressure-reducing fluid having a set pressure on a discharge pressure chamber side while depressurizing and adjusting the high-pressure fluid via the pressure regulating valve;
• wherein the valve body is an annular valve body;
• wherein the valve shaft is formed of a cylindrical member in which the annular valve body is coaxially arranged and which has a passage through which a fluid is passable;
• wherein a discharge pressure of the fluid is adjusted via operating the valve body on a distal end side via the discharge pressure regulating unit to change the distance between the valve body and the seat face;
• wherein a cylindrical space is formed in a discharge pressure chamber and a piston that receives fluid pressure in the discharge pressure chamber is slidably disposed in the cylindrical space together with the valve shaft in a state where the piston is fixed to an outer peripheral side of the valve shaft;
• wherein a spring is disposed in the cylindrical space, the spring constantly biasing the valve shaft in a valve closing direction while bringing a distal end side into contact with the piston;
• wherein a fluid pressure received by the piston is converted into a pressure load in a direction of pressing the valve body against the seat face at a time of closing the valve when the electric motor is stopped;
• and
• wherein occurrence of a positional deviation of the valve shaft due to a backlash provided in a meshing portion of the feed screw is avoided via a biasing force of the spring at a time of pressure regulation.