| 摘要 |
A brake master cylinder device includes a first and a second cylinder bore formed within a body. A piston member is formed with a first piston and a second piston, which are respectively engaged with the first and the second cylinder bores to define a first and a second cylinder chamber, the arrangement being such that when the piston member is moved in a certain direction the volumes of both the first and the second cylinder chambers are reduced together. The piston member is biased in the direction opposite to said certain direction. A fluid conduit opens from the second cylinder chamber for connection to a brake actuator. A means for transferring fluid allows brake fluid to pass substantially freely from the first cylinder chamber to the second cylinder chamber. A fluid accumulator is communicated with the first cylinder chamber, and commences to accumulate fluid from it when the pressure in it rises to a predetermined pressure value. At least when the piston member is in its extreme position in said opposite direction, a means for refilling the first cylinder chamber allows fluid to flow freely from a fluid reservoir to the first fluid chamber. Thus a two-stage performance of brake application is available.
|
