Electronically controlled regulator

An electronically controlled regulator, comprising:

• a body formed with an introduction port and a discharge port;
• a pressure regulating valve disposed inside the body;
• an electric motor disposed inside the body;
• a pressure sensor detecting a value of a discharge pressure;
• a driver that drives and controls the electric motor based on the value of the discharge pressure;
• the pressure regulating valve including:
• a valve shaft that is coaxially disposed with a valve body and is able to reciprocate in an axial direction;
• a valve seat having a seat face capable of being in close contact with the valve body on a side of a high-pressure fluid chamber following the introduction port;
• and
• a discharge pressure regulating unit that regulates a pressure of a fluid by causing the valve shaft to reciprocate through driving of the electric motor electronically controlled to change a distance between the valve body and the valve seat, a high-pressure fluid introduced from the introduction port into the high-pressure fluid chamber being discharged from the discharge port as a depressurized fluid at a set pressure on a side of a discharge pressure chamber while being depressurized and regulated by the pressure regulating valve;
• a valve shaft moving structure configured as a feed screw mechanism including:
• a trapezoidal male screw formed on an outer peripheral face of a columnar motion shaft disposed on a distal end side of the valve shaft;
• and
• a trapezoidal female screw formed on an inner peripheral face of a rotor that is a cylindrical member constituting a part of the electric motor and meshing with the trapezoidal male screw, the trapezoidal female screw integrated with the inner peripheral face side of the rotor and rotatable around the trapezoidal male screw via the electric motor;
• wherein a cylindrical space is formed on the side of the discharge pressure chamber;
• wherein a piston receiving a fluid pressure in the discharge pressure chamber is slidably arranged 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;
• and
• wherein the fluid pressure received by the piston is converted into a pressure load in a direction where the valve body is pressed to the seat face during valve closing when the driving of the electric motor is stopped.