| 摘要 |
The shift valve operates in response to a governor pressure counteracting a throttle pressure and in response to a detent pressure used in a kickdown operation. The valve is capable of shifting up from a first speed range to a second speed range as well as shifting down from second speed to the first speed under control of the shift valve. The 1-2 shift valve comprises a spool having a pressure bearing surface adapted to receive either the throttle pressure or the detent pressure. In the first speed position, the spool closes off the detent line pressure and receives the throttle pressure on the pressure bearing surface. On the other hand, at the second speed position, the spool closes off the throttle pressure line and receives the detent pressure on the pressure bearing surface. In the down-shift position, the governor pressure corresponding to vehicle speed and the throttle pressure corresponding to a spring force and a throttle opening, are applied to the spool in opposition so that the spool is moved in accordance with a relationship between the governor pressure, spring force and throttle pressure.
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