| 摘要 |
<p>PURPOSE: To provide a hydraulic master cylinder for a vehicle hydraulic brake device allowing reduction in its length compared to a conventional cylinder. CONSTITUTION: This hydraulic master cylinder has a cylinder body 1 housing a valve 18 whose valve element 30 cooperates with a valve seat 30A supported by a piston 3, while the piston 3 performs a working movement, in use, to compress fluid in a pressure chamber 8 of the cylinder body 1. The valve element 30 and the valve seat 30A are relatively movable to permit opening and closing of the valve 18. A first abutment part 38 is arranged to set a retracted position of the piston 3, while a second abutment part, spaced from the first abutment part 38 in a direction opposite to the working piston movement, serves to hold the valve element 30 in a desired open position when the piston 3 is in the retracted position. The first abutment part 38 and the second abutment part are both formed on a sleeve 37 surrounding the piston 3.</p> |
