| 摘要 |
PURPOSE:To reduce the number of constituent parts as a whole and aim at simplification in constitution as well as to aim at the promotion of inexpensiveness in price, by constituting various driving states to make them settable to one pressure control valve capable of altering the setting hydraulic pressure electrically. CONSTITUTION:When H2, for example, is selected by a selecting switch 31, a microcomputer 14 sets a duty ratio to 0%, driving a duty controlling solenoid valve S4. that is to say, a port 19 is closed, whereby line hydraulic pressure is produced in a control port 7 of an L-H selector valve 1 and a first control part 24 of a driving force distributing control valve 20. Therefore, this line hydraulic pressure is fed to a clutch C3 and this is engaged, but it is released as exhaust pressure out of a brake B4 takes place. In addition, a clutch C4 is subjected to this exhaust pressure and released as well, coming into a high- speed 2WD state. On the other hand, when H4 is selected by the selecting switch 31, the duty ratio comes to, for example, 50% and the hydraulic pressure is set up between two types of hydraulic pressure, coming into a high-speed 4WD state the other way.
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