Patent Document ID: 8265844
Application ID: 12450228
Patent Flag: 1

Claim One:
1. A clutch control device in a power transmission device for vehicle having a clutch installed between an engine and a transmission, wherein: said clutch control device includes a clutch actuator driven by a working fluid, a stroke sensor for detecting the movement of said clutch actuator, a flow rate control valve for controlling the amount of the working fluid in said clutch actuator, and a flow rate control valve control device for controlling the position of a valve body of said flow rate control valve responsive to a detection signal from said stroke sensor; said flow rate control valve is connected to a communication passage communicated with said clutch actuator, to a pressure source passage communicated with a working fluid pressure source, and to a discharge passage for discharging the working fluid from said clutch actuator, and, at the neutral position of said valve body, said communication flow passage is cut off from said pressure source passage and said discharge passage; and said flow rate control valve control device is provided with a neutral position learning device for learning the neutral position of said valve body, and said neutral position learning device decides that the neutral position is attained when a rate of change of the detection signal from said stroke sensor becomes smaller than a predetermined value.