| 摘要 |
PURPOSE:To prevent the mistaken use of a car at the time of two-wheel driving by making it possible to use an emergency low (EL) speed change stage only at the time of four-wheel driving in a speed change gear wherein the gear mechanism of the EL speed change stage having a further larger gear ratio than the first speed has been assembled into the speed change gear. CONSTITUTION:When a knob 38 is shifted to a two-wheel driving position, the atmospheric pressure is supplied into the control chamber 29 of a selector valve 27 by a selector valve 40, and a shifter rail 25 is moved to the left by a spring 30. Accordingly, an intake negative pressure is introduced into the chamber 37b of an actuator 35 via negative pressure passage 44, 45, and a shift rail 33 is moved to the left via a diaphragm 36. Consequently, a selector device 23 becomes a two-wheel driving state while separating a transfer gear 22 from a transfer shaft 21. When the shifter rail 25 is moved, keeping this state, to the right, and an EL speed change stage (not illustrated) is shifted via a shift fork 26, intake negative pressure is then supplied to the chamber 37a side by a selector valve 27, allowing a car to be automatically changed to a four-wheel driving state. |
