Patent ID: 9551313
Date: 2017-01-24
CPC Classifications: F01P,F02N

Claim:
1. A method for warming an engine at cold startup wherein a water pump controllable in flow rate is employed for a cooling water system of the engine, a rotational frequency of said water pump being controlled to circulate cooling water at a flow rate depending on an operational state of the engine, the method comprising detecting a water temperature of the cooling water at the startup of the engine; and, when the detected water temperature falls below a set water temperature, stopping the water pump independently of a normal control of controlling the rotational frequency of the water pump depending on the operational state of the engine and calculating a total heat amount required for raising a current water temperature to said set water temperature, integrating a heat amount lost by the cooling water from the engine since the startup of the engine, operating the water pump for a required time to uniformize temperature distribution of the cooling water upon attainment of an integrated value to said total heat amount, and then detecting the water temperature of the cooling water again, repeating the method when the detected water temperature is still below the set water temperature and restoring the normal control when the detected water temperature is the same or above the set water temperature.