JPS5514920A - Diaprhagm type air pump unit - Google Patents

Abstract

PURPOSE:To drive diaphragm means to make pumping work by introducing fluid pressures alternately into two signal chambers from two fluid pressure sources by the use of valve means for reducing the load and the self-weight of an engine without the need of a large driving force. CONSTITUTION:When a valve part 45 linked with a motor 47 is brought to a position to connect a port 14 with a port 15 and a port 16 with a port 17, a negative pressure into the first signal chamber 19 and the air into the second signal chamber 20 are respectively introduced. Consequently, the first diaphragm means 18 is displaced upward by the pressure difference between fluids in both chambers 19 and 20, and the second diaphragm means 30 is displaced in the same direction by linking. Thus, the capacity of a pump chamber 37 is reduced and that of a pump chamber 38 is increased. In this construction, compressed air is discharged through a discharge port 32 from the pump chamber 37, and the air is sucked into the pump chamber 38 through a suction port 31 for making smooth pumping work only by giving fluid pressures without the need of a large driving force.