| 摘要 |
A valve (10) for controlling flow of hydraulic fluid. The valve (10) includes first and second valve members (80, 82), each having a plurality of lands and grooves. The valve members (80, 82) are relatively movable from a neutral position to a displaced position in which surface segments (202, 226, 208, 218) of respective pairs of lands overlap to form flow gaps (232, 234) for restricting flow of fluid between respective pairs of grooves. At least one (234) of the flow gaps is divergent by having a cross-sectional flow area which increases along a direction of fluid flow therethrough and at least one (232) of the flow gaps is convergent by having a cross-sectional flow area which decreases along a direction of fluid flow therethrough. The flow gaps (232, 234) have minimum cross-sectional flow areas (A, B) defined by the surface segments. The flow gaps (232, 234) are sized such that the minimum cross-sectional area (A) of the convergent flow gap (232) is larger than the minimum cross-sectional area (B) of the divergent flow gap (234) at a first rotational position, and are sized such that the minimum cross-sectional area (A) of the convergent flow gap (232) is smaller than the minimum cross-sectional area (B) of the divergent flow gap (234) at a second rotational position for suppressing valve noise.
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