Flow path switching valve and discharge control apparatus for fluid material using the same

A method of guiding fluid material to dispenser by using a discharge control apparatus for discharging the fluid material to the dispenser, the discharge control apparatus comprising:

• a cylindrical injection side portion having an injection chamber to which the fluid material pressurized by a compressed air is supplied, and having a cylindrical inner surface forming an outer valve seating surface which is continuous from the injection chamber;
• a storage container which communicates with the injection chamber, the fluid material being accommodated in the storage container;
• a partition member which is cylindrical and arranged on the inside of the outer valve seating surface in a radial direction so as to face with the outer valve seating surface, and partitions an internal space into a discharge chamber formed on the inside of the partition member and an annular feed chamber formed on the outside of the partition member;
• an inner valve seating surface provided to the tip end of the partition member, wherein a valve chamber is formed between the inner valve seating surface and the outer valve seating surface;
• a discharge control block formed with a control flow path which is connected to the feed chamber, wherein the volume of the control flow path is changed by a discharge rod;
• discharging means provided to the discharge control block to reciprocate the discharge rod;
• and
• a valve element having a base portion which is arranged in the valve chamber, and opens and closes an inner flow path formed between the inner valve seating surface and the base portion of the valve element, and an annular flange portion which is integrally formed with the base portion, and opens and closes an outer flow path formed between the annular flange portion and the outer valve seating surface with elastic deformation,
• wherein the flow path switching valve has:
• a first state in which the valve element contacts with the inner valve seating surface, and the annular flange portion abuts on the outer valve seating surface;
• a second state in which the valve element abuts on the inner valve seating surface, and the annular flange portion is separated from the outer valve seating surface;
• and
• a third state in which the valve element is separated from the inner valve seating surface, and the annular flange portion abuts on the outer valve seating surface,
• when the discharge rod is moved back, the valve element is put into the second state, and the flow path switching valve performs a filling operation to allow the fluid material to flow into the control flow path from the injection chamber,
• when the discharge rod is moved in a forward direction so as to increase the pressure in the feed chamber, the valve element is put into the third state, and the flow path switching valve performs a discharge operation to allow the fluid material to flow into the discharge chamber from the control flow path, thereby discharging the fluid material via a discharge port;
• and
• after the discharge operation, the fluid material is filled in the control flow path by moving the discharge rod to a backward position, and the valve element shifts into the first state with the fluid material filled in the control flow path,
• the compressed air is continuously applied to the storage container when the flow path switching valve performs the discharge operation and the filling operation, and used to supply the pressurized fluid material to the injection chamber from the storage container,
• the method comprising:
• a supply step of putting the valve element into the third state by moving the discharge rod in the forward direction, and supplying the fluid material to the discharge nozzle chamber, and
• a filling step of putting the valve element into the second state by moving the discharge rod to the backward position by a pressure force of the fluid material;
• and
• a balance step of putting the valve element into the first state by an elastic force of the flange portion after moving the discharge rod to the backward position.