| 摘要 |
PURPOSE:To eliminate generation of a shock during speed change by deenergizing an exhaust brake valve through a clutch switch relay with an clutch at an engaged condition when speed change control is judged to be necessary and disengaging the clutch. CONSTITUTION:The control device 38 judges if speed change control is necessary based on respective detecting signals from an accelerator pedal sensor 40, a gear position sensor 41 and an input shaft revolutions sensor 43. When speed change control is judged to be necessary, a clutch switch relay 46 and an exhaust brake valve 48 are deenergized with a clutch at an engaged condition. After a certain time has passed, the clutch is controlled so as to disengage. Namely, by opening the electromagnetic valve 33 of a clutch actuator 30 to feed pressure oil to a chamber 30c, a piston 30a is moved, finally pushing out a release bearing 26 and releasing the pressure of a driven plate 22 by a pressure plate 23. |
