Patent ID: 7320434

Claim:
A method for controlling an electronically controlled thermostat which controls a temperature of a cooling water of an engine, the method comprising: providing an actuator which is configured to vary a degree of a valve opening without depending only on an actual temperature of a cooling water and comprises a WAX type thermo-element, a heat generating device attached to the WAX type thermo-element, a control controller which performs electrical powering for actuating the actuator and corrects a heat radiation amount of the WAX type thermo-element and hysteresis in parts that drive the actuator, and a controller which detects or calculates a difference between an actual flow rate and a target flow rate of the cooling water; calculating an elapsed time from the electrical powering to resulting actuation of the actuator, variation of the temperature of the cooling water and an amount of water temperature variation per unit time for predicting the temperature of the cooling water following the elapsed time; generating a predicted temperature of the cooling water; and controlling the actuator in accordance with the predicted temperature of the cooling water.