| 摘要 |
<p>This invention relates to a clutch switching circuit which can be utilized suitably for a multi-stage static hydraulic mechanical nonstage transmission. If pressure regulating valves having good override characteristics are used, slip or breakage of a clutch will occur. Therefore, this invention provides a clutch switching circuit which provides communicating throttle passages (311, 321, 331, 341) in the valve body of the pressure regulating valves (211, 221, 231, 241) so that a working fluid flows towards the clutch when the valves are closed. When the clutch is switched, the working fluid flows in a quantity equivalent at least to the oil leakage flow quantity so that the slip or breakage of the clutch can be prevented while pressure regulating valves having good override characteristics are used. The invention provides also a clutch switching circuit wherein common oil passages (301, 302) leading to a plurality of clutches corresponding to the gears which are not adjacent to one another are provided, and the pressure regulating valves (411, 421) and pressure reducing valves (412, 422) used commonly for a plurality of gears are installed in the common oil passages. Thus, the invention halves the number of valves of prior art apparatuses and simplifies the circuit construction.</p> |
