Pilot type pressure regulator

A pilot type pressure regulator for regulating a pressure of compressed air in accordance with a pilot pressure, the pressure regulator comprising:

• a port block provided with:
• a primary port to which compressed air is supplied;
• and a secondary port communicating with the primary port via a main valve hole, wherein regulated compressed air is discharged from the secondary port, and a main valve shaft provided with a main valve body for opening and closing the main valve hole is mounted in the main valve hole and movable in an axial direction;
• and
• a main valve diaphragm which is disposed between a mounting end surface of the port block and a pressure regulating adaptor mounted to the mounting end surface, which partitions and forms a secondary pressure chamber communicating with the secondary port and a pilot pressure chamber on the side opposite to the secondary pressure chamber, and which contacts an abutting end surface of the main valve shaft,
• wherein the port block is provided with an exhaust flow path in which air is discharged from the secondary port when the pressure of the secondary port exceeds a set value,
• wherein an opening portion of the exhaust flow path is provided so as to open on an outer surface of the port block,
• wherein the main valve shaft is provided with:
• an axial exhaust hole formed so as to open on the abutting end surface;
• and a radial exhaust hole causing the exhaust flow path and the axial exhaust hole to communicate with each other.