| 摘要 |
PURPOSE:To improve the response performance of a throttle valve body and maintain correct flow-rate control for a long period by applying the operating force of a driving apparatus to the throttle valve body and position the throttle valve body by the equillibrium action of a fluid force and the operating force, thus controlling the flow rate. CONSTITUTION:When pressurized fluid flows into an inflow port 7 from the state in which the pressurized fluid does not flow into the inflow port 7 and a throttle valve body 10 is positioned at the left sliding end by the spring force of a spring 18 through a piston 17, the pressurized fluid flows into a passing valve chamber 14, passing through a flowing passage 6 and a pressure compensation valve 16. However, as an electric current does not flow in the coil 23 of dc electromagnetic device 22 as a driving means, the throttle part 15 is in closed state, and the fluid does not flow into an outflow port 9. The pressurized fluid acts onto the pressure receiving plane of a piston 17, passing through a passage 19, to yield the spring 18, then the piston 17 is shifted rightward, and the operation of the springy force 18 onto the throttle body 10 is released. |
