| 摘要 |
PURPOSE:To enable the structure to be a small-size, simple and inexpensive one by introducing output air pressure into a feedback pressure chamber which is formed by installing diaphragms with different effective areas between a movable part and a stationary part. CONSTITUTION:Downward displacement of a movable part 3a caused by direct current flowing in a coil 3 gives a change tending to raise the back pressure of a nozzle 5, and further this is amplified by a pilot valve 6 to raise the output air pressure. The output air pressure is introduced to a feedback pressure chamber 14, where a upward force is given to a part 13 by the difference in effective areas of diaphragms 11 and 12 installed between the movable part 13 which moves solidly with the movable part 3 and a stationary part 17, and this force displaces the movable part 3a upward through a connecting rod 15 until this comes to a balanced state with the displacement force due to the electromagnetic action exerted on the movable part 3a, so that equilibrium of forces can be attained at such a place that the clearance between the movable part 3a and the nozzle 5 returns nearly to the initial state. |
