| 摘要 |
PURPOSE:To have comfortable shift operation at all times incl. with low oil temp. by setting the line pressure on the basis of information given by an oil temp. sensor of an automatic transmission so that engagement delay of a friction engaging element at the time of low oil temp. is compensated. CONSTITUTION:An electronic control device 10 sets the desired shift position on the basis of information given by a car speed sensor 2, throttle sensor 1, etc., and friction engaging elements are selectively engaged or disengaged through the action of shifting solenoids 4, 5 to perform speed changing. The line pressure as basis for engagement pressure of friction engaging element is set higher at the time of low oil temp. than normal temp. on the basis of information given by an oil temp. sensor 3 of an automatic transmission, and a linear solenoid valve 34 is driven through a driver circuit 23, and the line pressure is controlled by a primary valve 10. Thus the engaging time for friction engaging element is made identical to that at normal temp., and thus shifting operation at low temps. can be made comfortably. |
