| 摘要 |
PURPOSE:To minimize the deflection of a movable body due to a pressure pulsation and to reduce the wear of the film of a potentiometer by a brush as a result by providing a pressure receiving surface which faces an upstream side between the upstream and downstream ends of the movable body. CONSTITUTION:The diameter of the head part 34 of the movable body 30 is phi1 and the diameter of the shaft part (external cylinder 32) is phi2; and those are the same as before, but a flange 32a which has a diameter phi3 and spreads outward radially is provided to the lower end side of the movable body 30, so the area of reception of the pressure DELTAP2 in an air damper chamber 500 is A3. Further, the pressure reception area of the pressure receiving surface 32a-1 facing the external surface of this flange, i.e. upstream side is A3-A2, and the pressure DELTAP1 operates on the area A3-A2 toward the downstream side. A force generated with the pressure DELTAP2 operating on the pressure reception surface 32a-1 given by the flange 32a, therefore, cancels part of a force operating on the movable body 30 in the upstream direction. Consequently, the quantity of deflection of the movable body 30 is reduced and the wear of the film of the potentiometer 40 by the brush 55 is reduced.
|
