| 摘要 |
PURPOSE:To maintain the stabilized flow rate of fuel gas all the time by controlling the position of a valve body according to the difference between a set value given to a servo valve and the pressure of fluid to be controlled in a control valve for fuel gases. CONSTITUTION:When a certain drive signal is supplied to the coil 23 of an electromagnetic pump 22, a fluid inside a chamber 24 is sent under pressure to a chamber 25 and then returned through a servo valve 3 to the chamber 24. When a desired set signal is given to a coil 31, a plunger 32 moves downwards against a spring 39 to lessen the opening area of a port 36, whereby the pressure inside the chamber 25 is raised and the valve body 14 goes down through a folower 27 and a rod 26. As a result, a fluid inside an inlet pathway 11 flows into an outlet pathway 12 and the pressure inside the pathway 12 is transmitted from a port 16 to a feedback chamber 35. The pressure lifts the plunger 32 through a diaphragm 33 to enlarge the opening area of the pathway 36. |
