| 摘要 |
PROBLEM TO BE SOLVED: To realize accurate control, without having to use a special circuit, even if an operation characteristic of a solenoid control valve fluctuates by changes in temperature conditions, when operating a hydraulic actuator by the use of the solenoid control valve. SOLUTION: This variable valve timing controller displaces a phase of a camshaft by the hydraulic actuator to control valve timing to a desired timing. In a phase angle control routine, a target phase angle is set, on the basis of a detected operation state (steps S1, S2), and a proportional-integral correction value and a control duty ratio to the solenoid control valve (OCV) are set, on the basis of a phase angle difference between the target phase angle and an actual phase angle (steps S5, S6). When fluctuations in the operation characteristic of the solenoid control valve are estimated from temperature condition parameters, a correction value according to the temperature conditions is set (steps S7, S8), and the temperature correction value is added to correct the control duty ratio.
|
