| 摘要 |
PURPOSE:To provide a variable flow control device adapted to variably control the flowrate of a fluid, which device is small in size and simple in structure and has high-speed responsive ness with a small amount of power consumption. CONSTITUTION:Within a valve body 38 having an inflow passage 39 and an outflow passage 40 there are provided a valve member 42 capable of varying the flowrate of a fluid, a valve seat 43 corresponding to a flowrate control portion 44 of the valve member 42 receiving the inflow pressure of the valve member 42, and a cylinder portion 41 for guiding a pressure balance portion 45 of the valve member 42 similarly receiving the inflow pressure. The variable flow device is further provided with an energizing means 52 for urging the flow control portion 44 of the valve member 42 in such a direction as to move this portion 44 away from the valve seat 43, an electromagnetic drive portion 28 for causing a force to act on the valve member 42 in such a direction as to move the valve member 42 toward the valve seat against the urging force of an energizing means 52, and a communication passage 55 for making communication between the cylinder portion 41 and the outflow passage 40. The fluid pressure from the inflow passage in particular acts on the flow control portion 44 and on the pressure balance portion 45 of the valve member 42, respectively, in opposite directions. This enables driving the valve member 42 with a small electromagnetic force, thus obtaining a small-sized, simple-structured and low-power driven variable flow device. |
