| 摘要 |
<p>PURPOSE: To prevent a sealing cup from being injured even under severe service condition such as that of an ABS vehicle by opening a valve when the pressure and the flow speed at a relief port rise, so that the sealing cup does not bite in the relief port. CONSTITUTION: A poppet type valve 17 provided with a ball l7a opening by the dead weight is arranged on the passage communicating to the reservoir of a relief port 16. This valve 17 is opened when the pressure and the flow speed at the relief port 16 rise to fixed values, so that a sealing cup 3b provided on a piston 3 does not bite in the relief port 16 when the pressure of a pressure chamber rises. Consequently, even under severe service conditions such as that of an ABS vehicle, the sealing cup 3b does not bite in the relief port, and hence the sealing cup 3b can be prevented from being injured. Hence, durability of the sealing cup 3b can be improved.</p> |
