Patent ID: 6558136
Filing Date: 2003-05-06
Classification: F04B

Abstract:
A micropump underpressure control device, working in conjunction with a micropump having an inlet drawing in working liquid and an outlet ejecting working liquid, said micropump underpressure control device comprising:a control valve, installed at a supply pipe supplying working liquid to said micropump and further comprising a case, having an interior that is divided by a membrane into a working liquid chamber and a pressure chamber, with working liquid entering said working liquid chamber through a valve inlet and leaving said working liquid chamber through a valve outlet which is connected with said inlet of said micropump, a valve assembly at said valve inlet, opening and closing said valve inlet, and a connecting rod, connecting said membrane with said valve assembly, so that, when said membrane is deformed by pressure in said pressure chamber, said valve assembly is driven to open said valve inlet, allowing working liquid to enter said working liquid chamber and to proceed to said inlet of said micropump; and a transmission tube, transmitting outlet pressure at said outlet of said micropump to said pressure chamber of said control valve; wherein said membrane is from opposite sides pressed on by pressure in said working liquid chamber and by pressure in said pressure chamber, controlling entering of working liquid into said inlet of said micropump, with pressure at said inlet of said micropump being kept smaller than or equal to pressure at said outlet of said micropump by a fixed difference.