| 摘要 |
PURPOSE:To adjust a damping force characteristic on both an expansion side and a contraction side according to vibration of a stroke of a piston rod in a hydraulic damper. CONSTITUTION:A piston 2 is fitted into a cylinder 1. Main oil liquid passages 3, 4 are formed in the piston 2. A bypass passage is constituted of an oil liquid passage 9 and a passage member 8. A guide 15 is disposed in the passage member 8. A shutter 22 is fitted to the guide 15. The shutter 22 is held in the neutral position by springs 29, 30, where the bypass passage can be opened. A chamber 15a inside the guide 15 is communicated with a cylinder chamber 1a by a passage member 17 via an orifice mechanism 24 and an orifice 25a while a chamber 15b is communicated with a cylinder chamber 1b via a communicating path 23a. In the case of large vibration of a stroke of the piston rod 7 flow resistance of the orifice becomes large. Accordingly, displacement of the shutter 22 due to an oil pressure is small, thus opening the bypass passage so as to decrease damping force. In the case of small vibration, resistance of the orifice becomes small. Consequently, displacement of the shutter 22 due to an oil pressure becomes large, thereby closing the bypass passage so as to increase damping force. |
