| 摘要 |
PROBLEM TO BE SOLVED: To provide a solenoid valve for accurately controlling back pressure of an accumulator provided on a control passage of a clutch of an automatic transmission regardless of the return flow from the accumulator. SOLUTION: This solenoid valve is provided with a plunger 16 to be reciprocated according to the applied current to an electromagnetic coil 13, a valve sleeve 20 on which a supplying port 25, a control port 26 and a drain port 27 are formed, a spool 30 having a supplying side land part 31 for controlling the communication between the supplying port and the control port and a discharging side land part 32 for controlling the communication between the control port and the drain port, and a spring 35 for bringing the spool 30 into contact with the plunger 16. The gradient of changing characteristics of suction force generated when the plunger presses the spool 30 in relation to the stroke and the gradient of changing characteristics of pressing force generated when the spring 35 presses the spool 30 in relation to the stroke are generally equalized to each other.
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