| 摘要 |
PURPOSE: A control method for the solenoid valve of an automatic transmission is provided to enhance shift feel by calibrating hydraulic pressure according to the temperature change of fluid. CONSTITUTION: A control system for the solenoid valve in an automatic transmission consists of a traveling state sensor, a speed change controller and a driving device. The traveling state sensor contains a throttle valve opening degree sensor, a velocity sensor, a gear lever sensor and a fluid temperature sensor. The speed change sensor checks if the temperature of fluid is less than 0deg.C. If so, the speed change controller sets the operating cycle of the solenoid valve from a solenoid valve operating cycle map in a low temperature. The speed change controller sets a low temperature duty calibrating value according to the temperature of fluid from the duty calibrating map of a memory. A pressure adjusting solenoid valve is driven by the low temperature solenoid operating cycle. When the temperature of fluid is more than 0deg.C, the speed change controller sets the solenoid valve operating cycle in 28.6msec regardless of the temperature of fluid and stores the cycle in the comparing resistor of a timer. Then, the speed change controller sets a low temperature duty calibrating value from the duty calibrating map of the memory and stores the duty calibrating value in the resistor to drive the pressure adjusting solenoid valve until an engine starting is turned off.
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