Liquid material discharge device for discharging a fixed amount of liquid material

A liquid material discharge device comprising:

• a storage container in which a liquid material is stored;
• a discharge port through which the liquid material is discharged;
• a pressure control valve that adjusts a pressure of a compressed gas supplied from an external compressed gas source to a setting value by raising and lowering the pressure of the compressed gas supplied from the external compressed gas source;
• a discharge valve that establishes or cuts off communication between the pressure control valve and the storage container, the discharge valve comprising an inlet port, an outlet port and an exhaust port;
• a controller that controls operation of the discharge valve such that during a discharge operation, the inlet port and the outlet port are communicated with each other, and at the end of the discharge operation, the communication between the inlet port and the outlet port is cut off, and the outlet port is communicated with the exhaust port to vent the compressed gas inside the storage container through the exhaust port;
• a first flow line connecting the pressure control valve and the inlet port of the discharge valve, the pressure control valve supplies the compressed gas and the pressure of the compressed gas is adjusted in the first flow line between the pressure control valve and the discharge valve;
• and
• a second flow line connecting the outlet port of the discharge valve and the storage container,
• wherein the liquid material discharge device further comprises a third flow line branched from the first flow line upstream of the inlet port of the discharge valve and downstream of the pressure control valve, and a leak valve or a leak orifice provided on the third flow line,
• the leak valve or the leak orifice is configured to leak a part of the compressed gas the pressure of which is adjusted by the pressure control valve so as to suppress pressure fluctuations in the second flow line and the storage container, and
• during the discharge operation, the leak valve or leak orifice is configured to continuously leak an amount of the compressed gas which is supplied through the first flow line and the third flow line from the pressure control valve and which is necessary to keep the pressure of the compressed gas in the first flow line lower than the setting value such that the pressure control valve continues to perform a supply operation of the compressed gas during the discharge operation.