Fluid control system and valve to be used therein

A valve assembly comprising

• a fluid drive valve having a first body defining an inflow passage, an outflow passage, a first valve chamber, and a first valve seat;
• a stem running through the first valve chamber and supported to be movable in the vertical direction;
• a disk engaged with the stem for being brought into contact with and moved away from the first valve seat by motion of the stem;
• a valve closing spring thrusting the stem in the downward direction;
• a cylinder fixed to the upper portion of the body for forming a fluid pressure actuator;
• a piston provided in the cylinder, slidingly movable in the vertical direction and fixing the upper end of the stem;
• a first feed port opening in the upper face of the cylinder for introducing a working fluid fed from the side of the cylinder;
• a second feed port penetrating through the upper face of the cylinder;
• a piston cap which is fixed to the upper face of the piston and whose upper portion is slidably inserted in a penetration hole communicating with the second feed port;
• a penetration hole provided in the piston cap for introducing the working fluid from the second feed port into the lower space of the piston;
• and a communicating hole provided in the piston;
• and
• an electromagnetic valve composed of a second body having an inlet, an outlet, a second valve chamber, a second valve seat;
• wherein the outlet is integrally connected to the upper side of the cylinder of the fluid pressure actuator, with the inlet being connected to the first feed port provided in the upper face of the cylinder and the outlet being connected to the second feed port provided in the upper face of the cylinder;
• and wherein said electromagnetic valve has a plunger slidably supported by the second body, a disk on the plunger for contacting and separating from the second valve seat, a spring for thrusting the plunger in a valve closing direction in which the disk contacts the second valve seat, a magnetic core above the plunger, an excitation coil surrounding the core for causing the plunger to move, and a coil case enclosing the excitation coil.

A valve assembly comprising

• a fluid drive valve having a first body defining an inflow passage, an outflow passage, a first valve chamber, and a first valve seat;
• a stem running through the first valve chamber and supported to be movable in the vertical direction;
• a metal diaphragm engaged with the stem for being brought into contact with and moved away from the first valve seat by motion of the stem;
• a cylinder fixed to the upper portion of the body for forming a fluid pressure actuator;
• a piston provided in the cylinder, slidingly movable in the vertical direction and fixing the upper end of the stem;
• a first feed port opening in the upper face of the cylinder for introducing a working fluid fed from the side of the cylinder;
• a second feed port penetrating through the upper face of the cylinder;
• a piston cap which is fixed to the upper face of the piston and whose upper portion is slidably inserted in a penetration hole communicating with the second feed port;
• a penetration hole provided in the piston cap for introducing the working fluid from the second feed port into the lower space of the piston;
• and a communicating hole provided in the piston, and
• an electromagnetic valve composed of a second body having an inlet, an outlet, a second valve chamber, and a second valve seat;
• wherein the outlet is integrally connected to the upper side of the cylinder of the fluid pressure actuator, with the inlet being connected to the first feed port provided in the upper face of the cylinder and the outlet being connected to the second feed port provided in the upper face of the cylinder, and wherein said electromagnetic valve has a plunger slidably supported by the second body, a disk on the plunger for contacting and separating from the second valve seat, a spring for thrusting the plunger in a valve closing direction in which the disk contacts the second valve seat, a magnetic core above the plunger, an excitation coil surrounding the core, and a coil case enclosing the excitation coil.

A fluid control system comprising a principal control line and plural branch control lines for feeding plural types of fluids into the principal control line, with a processing device being attached to the principal control line, and plural valve assemblies in the branch control lines for switching the fluids supplied to the processing device, wherein each of the valve assemblies comprises:

• a fluid drive valve comprising a body defining an inflow passage, an outflow passage, a first valve chamber, and a first valve seat;
• a stem running through the first valve chamber and supported to be movable in the vertical direction;
• a metal diaphragm contacting and moving away from the valve seat of the body in accordance with the vertical movement of the stem;
• a cylinder fixed to the upper portion of the body for forming a fluid pressure actuator;
• a piston provided in the cylinder, slidingly movable in the vertical direction and fixing the upper end of the stem;
• a first feed port opening in the upper face of the cylinder for introducing a working fluid fed from the side of the cylinder;
• a second feed port penetrating through the upper face of the cylinder;
• a piston cap which is fixed to the upper face of the piston and whose upper portion is slidably inserted in a penetration hole communicating with the second feed port;
• a penetration hole provided in the piston cap for introducing the working fluid from the second feed port into the lower space of the piston and a communicating hole provided in the piston, and
• an electromagnetic valve comprising a body defining an inlet, an outlet, a second valve chamber, and a second valve seat and integrally attached to the upper side of the cylinder of the fluid pressure actuator, with the inlet being connected to the first feed port provided in the upper face of the cylinder and the outlet being connected to the second feed port provided in the upper face of the cylinder;
• a plunger slidably supported by the body;
• a disk on the plunger for contacting and moving away from the second valve seat;
• a spring for thrusting the plunder in the valve closing direction in which the disk contacts the second valve seat;
• a magnetic core above the plunger;
• an exciting coil surrounding the magnetic core;
• and a coil case enclosing the excitation coil.