Clutch apparatus and control method for clutch apparatus

A clutch apparatus comprising:

• a friction clutch that is subjected to a pressing force to generate a friction force between friction members;
• a piston that is subjected to a hydraulic pressure to press the friction clutch;
• a hydraulic chamber in which the hydraulic pressure is allowed to act on the piston;
• a hydraulic pump that feeds hydraulic oil to the hydraulic chamber;
• an electric motor that drives the hydraulic pump;
• and
• a control apparatus that controls the electric motor to adjust a discharge pressure of the hydraulic pump, wherein,
• the control apparatus includes:
• a feedback control apparatus that feedback-controls the electric motor using a correction value based on a deviation between a target value and an actual value of the discharge pressure of the hydraulic pump such that the discharge pressure of the hydraulic pump is equal to a target pressure;
• a hydraulic-oil temperature estimating apparatus that estimates a temperature of the hydraulic oil based on a ratio between a current value of a motor current supplied to the electric motor and a rotation speed of the electric motor;
• and
• a correction amount adjusting apparatus that changes a correction amount provided by the feedback control in accordance with the estimated temperature of the hydraulic oil,
• wherein the clutch apparatus is free of a temperature sensor which detects the temperature of the hydraulic oil.