Pressure regulating valve

A pressure regulating valve which regulates the pressure of fluid by opening and closing a passage leading to a low pressure side in response to the pressure of fluid, said valve comprising:

• a bellows formed in the shape of a bottomed cylinder and having a cylindrical wall which expands and contracts;
• a fixing member for fixing an opening end of said bellows;
• a valve seat disposed opposite to a bottom portion of said bellows;
• a valve body provided on an outside of the bottom portion of said bellows so as to come in and out of contact with said valve seat due to expansion and contraction of said bellows;
• a valve body retaining member provided on the outside of the bottom portion of said bellows and having an engaging portion used for the engagement with an outer peripheral wall portion of said bellows, said valve body retaining member serving to retain said valve body at the bottom portion of said bellows by being fixed to the outer periphery of the bottom portion of said bellows by means of said engaging portion;
• a spring disposed inside of said bellows and serving to bias said bellows in the direction of expansion;
• and
• a spring seat for receiving said spring provided inside of the bottom portion of said bellows and located so as to be opposite to said engaging portion through the peripheral wall portion of said bellows;
• wherein said spring seat comprises an annular disc portion serving to receive said spring and a cylindrical portion extending from said seat portion in the axial direction so as to be opposite to said engaging portion through the outer peripheral wall portion of said bellows.

A pressure regulating valve in which a valve body is driven by a bellows formed in the shape of a bottomed cylinder, said valve comprising:

• a plate having a reinforcing portion extending from an opening end of said bellows to the inside of the same so as to reinforce the opening end of said bellows and a fixing portion extending from the opening end of said bellows radially outwardly;
• and
• a cylindrical body to which the fixing portion of said plate is fixed so as to define the axial position of said bellows by said plate and which cooperates with the reinforcing portion of said plate to hold said bellows between them,
• wherein an O-ring and said bellows are held between said body and said plate.