| 摘要 |
PURPOSE:To alternatively obtain a vibro-isolating effect in accordance with an input frequency by providing a closed air chamber in an opposite side to a flexible film for the second balance chamber, in which fluctuation of an inter nal pressure is absorbed being based on the elastic deformation of the flexible film, and select-controlling supply and suction of air for this air chamber. CONSTITUTION:The first air chamber 60 is formed in an opposite side by inter posing the first diaphragm 46 to the first balance chamber 52, and the second air chamber. 62 is formed in an opposite side by interposing the second dia phragm 47. An internal part of the second air chamber 62 is connected by an air pressure pipe line 66 to a negative pressure source 70 through a selector valve 68 with the atmospheric pressure and negative pressure alternatively applied At the time of a vibration input in a low frequency region, the negative pressure is applied into the second air chamber 62 to impede the deformation of the second diaphragm 47, and circulation of fluid through the second orifice passage 58 is impeded. At the time of a vibration input in a high frequency region, the negative pressure in the second air chamber 62 is removed to deform the second diaphragm 47, and fluidization of the fluid through the second orifice passage 58 is generated. |
