摘要 |
PURPOSE:To more reduce shift shock being generated on the contray of intention of a driver by making variable a shift time in order to engage a clutch. CONSTITUTION:The pressure of discharged oil from an oil pump 1 is adjusted into line pressure PL by a pressure relief valve 2, and impressed on the IN side of an electromagnetic pressure relief valve 6. A control signal SC is computed based on the signals of throttle opening, vehicle speed, turbine rotating speed of an automatic transmission, and the like which are physical quantities continuously changing according to the operating condition of an internal combustion engine. By inputting this control signal SC to the electromagnetic pressure relief valve 6, the line pressure PL impressed on the IN side of the electromagnetic pressure relief valve 6 is directly adjusted into clutch oil pressure PC impressed on a clutch 7 from the OUT side of the electromagnetic pressure relief valve 6. Hereby, a variation time of the clutch oil pressure becomes variable, so as to reduce shift shock. |