| 摘要 |
PURPOSE:To eliminate the need for increasing a traction input even if an operation resistance becomes large due to wear and rust by providing an elastic body for preventing the switchover of a valve device until a traction input becomes a defined magnitude in between an input member and a movable body. CONSTITUTION:As a clutch pedal is stepped in, a leftward traction input is applied to an input member 37. However, the leftward movement of the input member 37 is prevented until the traction input becomes a defined level due to the existence of a negative pre-load spring 30 for rightwardly energizing a valve plunger 29. And, when an operation resistance is increased and the traction input becomes above this level, the input member 37 is moved leftward against the negative pre-load 30 causing the valve member 40 to be seated on a valve seat 3 via the valve plunger 29. Thereby, the connection between a low pressure chamber 23 and a high pressure chamber 24 is cut off and, then, as air pressure is introduced into the high pressure chamber 24, pressure difference is generated between both chambers 23, 24 and a movable body 16 is operated due to the resultant pressure difference to disengage the clutch via an output member 51. |
