FLUID DAMPING BLOCK

PURPOSE: To provide high damping behavior in a low frequency vibration range by arranging an working section and counter stop such that while the working section is stationary, there is space between them and even if vibration is transmitted at such a small oscillation as specified value or high, the working section and counter stop are not brought into contact with each other. CONSTITUTION: A fluid working chamber 4 and a pressure equalizing chamber 7 are charged with liquid and communicated with each other through a damping opening 5, which is designed so that high damping performance can be displayed in a low frequency vibration range up to 30 Hz. Two overflow openings 6 are provided between the chambers 4 and 7 in parallel with the opening 5, and a pressure relief valve 8 is provided in each overflow opening 6. The pressure relief valve 8 has an elastically flexible valve plate-shaped working section 10 which is arranged in spaced relation with a counter stop 11 while the working section 10 is stationary, and when a high frequency vibration is transmitted at a small oscillation of 30 Hz or higher, fluid flows around the valve plate, preventing harmful pressure change from causing to both chambers 4 and 7. When a low frequency of a large oscillation is transmitted, the working section 10 and the counter stop 11 are brought into contact with each other. This makes the liquid flow from a high pressure chamber to a low pressure chamber through the opening 5, providing a high damping effect.