Hydraulic control device and driving force distribution device for four-wheel drive vehicle provided with the same

A hydraulic control device comprising:

• an electric motor;
• an oil pump driven by the electric motor;
• and
• a control means configured to control an operation of the electric motor,
• wherein the hydraulic control device controls an operation of an actuator using a hydraulic pressure of hydraulic fluid supplied from the oil pump,
• the hydraulic control device comprising a hydraulic fluid temperature estimation means configured to estimate a temperature of hydraulic fluid supplied to the actuator,
• wherein the hydraulic fluid temperature estimation means calculates an output of a logistic regression from an integrated value of driving currents of the electric motor and an average value of driving voltage of the electric motor, and estimates the temperature of the hydraulic fluid based on the calculated output of the logistic regression, and
• wherein the control means controls the operation of the actuator based on the temperature of the hydraulic fluid estimated using the hydraulic fluid temperature estimation means.