| 摘要 |
PURPOSE:To attain large setting even a switchable width of damping force though with a simple constitution by using a pressure difference, generated between upper/lower oil chambers themselves, to move a damping force switching valve. CONSTITUTION:A damping force switching valve 40 is arranged to be pressed by return springs 43, 45 from both upper and lower end faces UF, LF, in a housing 17. When a pressure of oil acting on both the end faces UF, LF is equal, the valve is held to a balance position. In the damping force switching valve 40, the second and third communication holes 17b, 17c are both not connected to a peripheral groove 40a in the balance position, to connect the second communication hole 17b to the peripheral groove 40, when displaced upward, and the third communication hole 17c to the peripheral groove 40a when displaced downward. On the other hand, an oil-tight chamber 50, only in the case of generating a clearance in a cone seal part by opening an opening/closing valve 33 driven by a laminated piezoelectric unit 27, communicates with an upper oil chamber 21. |
