Engine cooling device

Abstract

A cooling device circulates cooling water through an engine main body and a radiator using an electric pump and supplies cool air to the radiator using an electric fan, thereby cooling the engine main body. During a dead soak period after an engine is shut off, a control unit controls the operation states of the electric pump and the electric fan on the basis of cooling water temperature detected by a water temperature sensor, outside air temperature detected by an outside air temperature sensor, and battery voltage. Specifically, when the engine is shut off, if it is determined on the basis of the cooling water temperature and the outside air temperature that the engine is in a high temperature state, the control unit controls the electric pump and the electric fan.

1 . An engine cooling device to cool an engine by operating an electric pump to circulate cooling water in the engine and a radiator and operating an electric fan to supply cooling air to the radiator, the cooling device including:
 cooling water temperature detecting means to detect a temperature of the cooling water;   outside air temperature detecting means to detect a temperature of outside air;   battery voltage detecting means to detect a voltage of a battery for supplying electric power to the electric pump and the electric fan; and   control means to control start and stop, and operation time of each of the electric pump and the electric fan during dead soak following stop of the engine based on the temperature of the cooling water detected by the cooling water temperature detecting means, the outside air temperature of the outside air detected by the outside air temperature detecting means, and the voltage of the battery detected by the battery voltage detecting means.   
     
     
         2 . The engine cooling device according to  claim 1 , wherein the control means determines at the time when the engine is stopped whether or not the engine is in a high temperature state based on the detected cooling water temperature and the detected outside air temperature, and the control means operates the electric pump and the electric fan when the engine is determined to be in the high temperature state. 
     
     
         3 . The engine cooling device according to  claim 1 , wherein the control means operates the electric fan when the detected outside air temperature is equal to or higher than a predetermined value, the detected cooling water temperature is equal to or higher than a predetermined value, and the detected battery voltage is equal to or larger than a first predetermined value. 
     
     
         4 . The engine cooling device according to  claim 1 , wherein the control means operates the electric pump when the detected outside air temperature is equal to or higher than a predetermined value, the detected cooling water temperature is equal to or higher than a predetermined value, and the detected battery voltage is equal to or higher than a second predetermined value. 
     
     
         5 . The engine cooling device according to  claim 4 , wherein the control means operates the electric fan but does not operate the electric pump when the detected outside air temperature is equal to or higher than the predetermined value, the detected cooling water temperature is equal to or higher than the predetermined value, and the detected battery voltage is equal to or higher than a third predetermined value smaller than the first predetermined value, the detected battery voltage being less than the second predetermined value. 
     
     
         6 . The cooling device engine according to  claim 3 , wherein the control means does not operate the electric pump and the electric fan when at least one of conditions (a) to (c) is fulfilled; (a) the detected outside air temperature is less than the predetermined value, (b) the detected cooling water temperature is less than the predetermined value, and (c) the detected battery voltage is less than a third predetermined value. 
     
     
         7 . The engine cooling device according to  claim 5 , wherein the control means stops the electric pump when the detected battery voltage becomes less than a fourth predetermined value smaller than the second predetermined value while the electric pump and the electric fan are operating. 
     
     
         8 . The engine cooling device according to  claim 7 , wherein the third predetermined value is smaller than the fourth predetermined value. 
     
     
         9 . The engine cooling device according to  claim 1 , wherein the control means stops the electric pump and the electric fan after a lapse of a predetermined post-stop time following stop of the engine. 
     
     
         10 . The engine cooling device according to  claim 9 , wherein the control means calculates the post-stop time based on the detected outside air temperature and the detected cooling water temperature. 
     
     
         11 . The engine cooling device according to  claim 1 , wherein the control means determines a request flow rate of the cooling water based on the detected cooling water temperature and controls operation of the electric pump based on the determined request flow rate.