Patent ID: 8869827

Claim:
A pressure regulator comprising: a housing including a primary-side port, to which a pressure fluid is supplied, and a secondary-side port, which communicates with the primary-side port via a communication hole and from which the pressure fluid flows; a valve assembly having a valve element, which opens and closes a valve seat formed on an opening end portion side of the communication hole, and a valve spring, which applies a spring force to bias the valve element in a direction of closing the valve seat; a diaphragm assembly including a pressure-regulating diaphragm and a pressure-regulating spring, the pressure-regulating diaphragm being mounted in the housing opposite the valve element, and forming, by partition, a pressure-regulating chamber communicating with the secondary-side port and a spring chamber communicating with an outside, the pressure-regulating spring being mounted between a retainer provided on the pressure-regulating diaphragm and a spring receiving member disposed in the spring chamber opposite the retainer, and applying a spring force to bias the valve element in a direction of releasing the valve element from the valve seat, wherein the retainer is provided with a support rod portion protruding toward the spring receiving member; a stem having a tip face that opens and closes a relief hole, the relief hole being formed in the support rod portion of the retainer and causing the pressure-regulating chamber and the spring chamber to communicate with each other, the relief hole being open on an end face of the support rod portion of the retainer, the stem applying a spring force of the pressure-regulating spring to the valve element, and constituting the valve assembly; and a dynamic-vibration absorbing apparatus, which is provided around the support rod portion of the retainer and disposed in the spring chamber, suppresses a vibration of the diaphragm assembly when the pressure-regulating diaphragm is separate from the stem, and suppresses vibrations of the diaphragm assembly and the valve assembly when the valve assembly is moved with the diaphragm assembly, with the stem closing the relief hole, to open and close the valve seat and adjusts a pressure in the secondary-side port, wherein the dynamic-vibration absorbing apparatus includes a spring member surrounding the support rod, the spring member movably connecting an annular mass body to the diaphragm assembly.