| 摘要 |
A brake fluid pressure control device for use in an automotive brake system including a master cylinder (1), a wheel brake (10), and a main fluid line (2) connecting the master cylinder (1) to the wheel brake (10). This device includes a power pump (3) provided in a fluid supply line for discharging fluid into the main fluid line (2). An on-off valve (4) is provided in the main fluid line (2) upstream of the point at which the outlet circuit of the pump (3) merges with the main fluid line (2). A fluid reservoir (5) is provided in the fluid supply line upstream of the pump (3). The reservoir (5) includes a housing and a piston (6) slidably mounted in the housing to partition the interior of the housing into a first chamber (8) and a second chamber (9) and biased by a spring (7) toward the first chamber (8). The spring (7) keeps the fluid pressure in the first chamber (8) above the atmospheric pressure. For automatic braking, a changeover valve (11) is changed over to supply fluid in the first chamber (8) into the inlet port of the pump (3). When the automatic braking is off, the inlet and outlet ports of the pump (3) are connected to the second and first chambers (8,9) of the reservoir (5), respectively, to supply fluid into the first chamber (8). <IMAGE> |
