| 摘要 |
PROBLEM TO BE SOLVED: To stabilize the function of a throttle valve mechanism, for improving reliability in a master cylinder so that a hydraulic fluid cuts off a backflow with excellent responsiveness, by providing the throttle valve mechanism in a communication passage of a pressure chamber of the master cylinder and a reservoir.SOLUTION: A master cylinder comprises a floating valve element 26 arranged in liquid passages 20 and 21 for linking a cylinder body 1 and a reservoir 8, formed so that a diameter becomes small toward the cylinder body 1 side and having a communication hole 29 for making a hydraulic fluid flow, and a seat part 27 formed in a holdable annular shape by loosely inserting the floating valve element 26 into the liquid passages 20 and 21. The master cylinder is provided with a throttle valve mechanism 24 for switching a valve opening state of making the hydraulic fluid flow between pressure chambers 3 and 6 and the reservoir 8 when the liquid passages 20 and 21 are not sealed by pistons 2 and 5, and a valve closing state of making a flow impossible by blocking up the liquid passages 20 and 21 by the floating valve element 26 by hydraulic fluid pressure when the hydraulic fluid flows to the reservoir 8 from the pressure chambers 3 and 6.SELECTED DRAWING: Figure 1 |
