| 摘要 |
PURPOSE:To reduce a transmission rate of vibration, by adjusting the damping force of a liquid sealed engine mounting device through the ratio of a vibrative frequency of periodical external force from a road surface to the natural vibrative frequency in the supporting system of an engine. CONSTITUTION:The level difference of a vibrative frequency (p) of periodical external force from the natural vibrative frequency omegan in the supporting system of an engine is decided by detecting the external force from a road surface through a road surface displacement detecting sensor 20, and if the frequencies are in a relation where p/omegan<sq. rt. 2, a feed air valve 12 closes while a discharge air valve 14 opens generating the atmospheric pressure in an air chamber 10, and liquid in a liquid chamber 3 and a bellows 4 is moved through an orifice 5 by the vertical movement of a frame 6 generating fixed damping force. Next, if in the relation where p/omegan>sq. rt. 2, a contact point (a) of the road surface displacement detecting sensor 20 is turned on, urging the discharge air valve 14 to be closed while deenergizing the feed air valve 12 to be opened. Accordingly, compressed air is fed to the air chamber 10 from a compressed air tank 11, further after a certain time, if the pressures in the air chamber 10 and the liquid chamber 3 are equalized, the feed air valve 12 is closed, causing a flow of liquid to be eliminated through the orifice 5 thus decreasing the damping force. |
