VIBRATION DAMPING DEVICE FOR A VEHICLE BODY

摘要

A damping force change mechanism includes an on-off valve located in a through hole of a piston rod. The on-off valve opens/closes a third hydraulic oil passage that allows a first oil chamber on a free piston side and a second oil chamber between a first piston and a second piston to communicate with each other. The on-off valve includes an expanded diameter portion in the first oil chamber extending outward in the radial direction. The expanded diameter portion faces the entire opening edge of the through hole and tightly contacts an end surface of the piston rod. The magnitude of a damping force is easily changed, and a damping force characteristic in a case in which the damping force is large is stabilized.