| 摘要 |
PROBLEM TO BE SOLVED: To increase a regulation range of a damping force and to generate a proper damping force throughout a whole area ranging from the low speed area of a piston speed to the high speed area thereof. SOLUTION: A piston 3 is fitted in a cylinder 2 and connected to a reservoir 6. A main damping valve 14 to intercommunicate a cylinder upper chamber 2a and the reservoir 6 through a main passage 11 is provided. Cylinder upper and lower chambers 2a and 2b are intercommunicated through an auxiliary passage 12 on the elongation side and a damping valve 15 on the elongation side and a variable orifice 16 on the elongation side are arranged. A cylinder lower chamber 2b and the reservoir 6 are intercommunicated through an auxiliary passage 13 on the contraction side are inter communicated through an auxiliary passage 13 on the contraction side, and a damping valve 18 on the contraction side and an orifice 17 on the contraction side are provided. By varying the flow passage areas of the varying orifices 16 and 17, orifice characteristics on the elongation side and on the contraction side are regulated and a pilot pressure is changed, the opening pressure of the main damping valve 14 is regulated. By providing valve characteristics before the main damping valve 14 is opened, a proper damping force is generated throughout the whole area of a piston speed by the auxiliary damping valves 15 and 18 on the elongation side and the contraction side. |
