| 摘要 |
PURPOSE:To prevent lowering of the controllability to be caused by oil viscosity by inputting the signal such as oil temperature or the like into a dither appling means for appling dither to the electrical signal to an oil pressure control valve, and making frequency and amplitude of dither variable in response to the oil temperature. CONSTITUTION:In a control unit 70, the solenoid current is set by a setting unit 82 on the basis of the target secondary pressure to be computed by a computing unit 81, and the solenoid current is set by a setting unit 96 on the basis of the target primary pressure to be computed by a computing unit 95, and the dither current from a dither appling unit 100 is applied to the solenoid current by driving units 83, 97 to be output to a proportional solenoid 51 of a secondary pressure control valve and a proportional solenoid 61 of a primary pressure control valve. In this case, the signal from an oil pressure sensor 101 is input to the dither appling unit 100 to make the frequency and an amplitude of dither variable against the oil temperature, namely, viscosity of the oil. Namely, when the oil temperature is low, amplitude is increased, and when the oil temperature is high, frequency is increased. Hysteresis of a valve is thereby always reduced to improve the controllability. |
