| 摘要 |
PURPOSE:To ensure the safety by automatically disengaging a gear in a transmis sion while an air pressure is left necessary for disconneting a clutch when the air pressure of an air tank is dropped down. CONSTITUTION:The first solenoid valve 9 for interrupting air supply after controlling a transmission 2 switched and the second solenoid valve 10 for opening a rear chamber 7b of a clutch cylinder 3 to communicate with the atmosphere simultaneously with interrupting action of this first solenoid valve 9 are provided in an air pipe 8 of connecting an air tank 11 to the rear chamber 7b of the clutch cylinder 3. In a constitution, there are provided an air pressure sensor 18 for closing the second solenoid valve 10 by opening the first solenoid valve 9 by a computer 15 when a pressure of the air tank 11 is dropped down to a fixed value or less, shift emergency valves 13a, 13b for controlling the transmission to a neutral position in the case of engaging a gear by detecting a gear position of the transmission when the pressure of the air tank 11 is lowered down to the fixed value or less and a relay valve 17 switched by sensing the pressure of the air tank 11 to give a signal pressure to the shift emergency valves 13a, 13b. |
