| 摘要 |
In a fluid control valve apparatus, logic valve means (2) includes a valve housing (3, 4, 5), a first valve chamber (8) defined in the valve housing, a valve body (10) arranged in the first valve chamber for fluidtight movement therein in an axial direction and including opposite end portions and a conical surface portion (12), a valve seat (14) adapted to be brought into fluidtight sealing contact with the conical surface portion when the valve body moves in a valve closing direction, first and second hydraulic fluid chambers (16, 18) defined in the valve housing and adapted to be brought into communication with each other when the conical surface portion of the valve body is out of contact with the valve seat and brought out of communication with each other when the conical surface portion of the valve body is in contact with the valve seat, and a first pilot chamber (20) defined in the valve housing adjacent one end portion of the valve body for biasing the valve body in a valve closing direction by a first pilot pressure signal received therein. The logic valve means (2) further includes a second valve chamber (28) defined in the valve housing, an extension of the valve body formed by extending the other end portion of the valve body through the first hydraulic fluid chamber (16) and arranged in the second valve chamber for fluidtight movement in an acial direction, and a second pilot chamber (30) defined in the valve housing adjacent an end of the valve body extension for biasing the valve body in a valve opening direction through the valve body extension by a second pilot pressure signal received therein. The second pilot chamber is independent of the first pilot chamber with respect to hydraulic pressures. |
