| 摘要 |
PROBLEM TO BE SOLVED: To simplify a constitution and facilitate negative pressure control in obtaining the following large deceleration ratio, in the case that when decelerating a vehicle, the deceleration ratio of a transmission is enlarged and an effective engine brake is obtained. SOLUTION: In a speed changer 22, a backup plate 61 serves as the reference, a partitioning plate 72 fixed to a drive shaft 49 in an opposite side to a movable disk 59 is provided. Each outer edge part of the movable disk 59 and the partitioning plate 72 is mutually connected, a space surrounded thereby is formed as a negative pressure introducing chamber 73. By sliding the movable disk 59, the negative pressure introducing chamber 73 can be extended/contracted. A negative pressure introducing passage 80 is provided, which makes the negative pressure introducing chamber 73 communicate with an intake passage in the downstream from a throttle valve, also an atmosphere introducing passage 81 is provided, which makes the negative pressure introducing chamber 73 communicate with an atmospheric side. A switching valve respectively opening/ closing both the passages is provided. |
