Patent ID: 8886429

Claim:
An oil pressure control device of an automatic transmission, which includes: the automatic transmission including a drive force transmission mechanism that transmits drive force in a predetermined gear ratio by selectively engaging a plurality of frictional engagement elements with one another; and the oil pressure control device that controls an oil pressure for engaging the frictional engagement elements with one another, the oil pressure control device comprising: line pressure adjusting means for adjusting a line pressure serving as a basic pressure, the basic pressure being for engaging the frictional engagement elements with one another, from an oil pressure of hydraulic oil supplied from an oil pressure supply source; line pressure varying means capable of changing the line pressure adjusted by the line pressure adjusting means; a linear solenoid valve that adjusts a required oil pressure for engaging the frictional engagement elements with one another by engagement force, the engagement force being required by the frictional engagement elements, by adjusting a pressure of the hydraulic oil adjusted to the line pressure by the line pressure adjusting means; and control means for controlling the oil pressure, the oil pressure being adjusted by the linear solenoid valve, by controlling a value of a current supplied to the linear solenoid valve, wherein the control means sets a plurality of current values as the value of the current supplied to the linear solenoid valve in order to adjust (obtain) the same required oil pressure, and selects one current value from the plurality of current values in response to the line pressure changed by the line pressure varying means, and thereby performs control to switch the value of the current supplied to the linear solenoid valve in order to adjust the same required oil pressure.