Cooling system for engine

Abstract

A cooling system includes a cooling portion for flowing a coolant therethrough, a coolant sensitive sensor portion detecting a temperature of the coolant, a heat exchanging device using a heat of the coolant, a circulation flow varying device for varying a circulation flow, a circulation path for flowing the coolant therethrough, and a controller for regulating the circulation flow by controlling the circulation flow varying device while referring to the temperature of the coolant upon a receipt of a request for a requested flow from the heat exchanging device. The controller determines a condition for warming-up when the warming-up of the engine is performed in accordance with the temperature of the coolant, controls the circulation flow varying device for warming-up the engine without circulating the coolant, and increases the circulation flow to the requested flow for a predetermined period of time when the requested flow is requested during the warming-up.

1 . A cooling system for an engine, comprising:
 a cooling portion formed at the engine for flowing a coolant therethrough;   a coolant sensitive sensor portion detecting a temperature of the coolant;   a heat exchanging device using a heat of the coolant;   a circulation flow varying device for varying a circulation flow of the coolant;   a circulation path for flowing the coolant therethrough via the cooling portion, the coolant sensitive sensor portion, the heat exchanging device, and the circulation flow varying device; and   a controller for regulating the circulation flow of the coolant by controlling the circulation flow varying device while referring to the temperature of the coolant upon a receipt of a request for a requested flow from the heat exchanging device; wherein   the controller determines a condition for warming-up the engine when the warming-up of the engine is performed in accordance with the temperature of the coolant, controls the circulation flow varying device for warming-up the engine without circulating the coolant, and increases the circulation flow to the requested flow for a predetermined period of time in a case where the requested flow is requested during the warming-up operation of the engine.   
     
     
         2 . The cooling system for the engine according to  claim 1 , wherein the controller increases the circulation flow stepwise. 
     
     
         3 . The cooling system for the engine according to  claim 1 , wherein the controller increases the circulation flow proportionally to an elapsed time. 
     
     
         4 . The cooling system for the engine according to  claim 1 , wherein the controller increases the circulation flow in accordance with a characteristic of a first order lag filter. 
     
     
         5 . The cooling system for the engine according to  claim 1 , wherein the controller regulates the circulation flow with a feedback control to limit a fluctuation of the temperature of the coolant. 
     
     
         6 . The cooling system for the engine according to  claim 1 , wherein the controller determines the condition for warming-up the engine in accordance with an amended temperature of the coolant which is obtained by filtering the temperature of the coolant after increasing the circulation flow to the requested flow. 
     
     
         7 . A cooling system for an engine, comprising:
 a cooling portion formed at the engine for flowing a coolant therethrough;   a coolant sensitive sensor portion detecting a temperature of the coolant;   a heat exchanging device using a heat of the coolant;   a circulation flow varying device for varying a circulation flow of the coolant;   a circulation path for flowing the coolant therethrough via the cooling portion, the coolant sensitive sensor portion, the heat exchanging device, and the circulation flow varying device; and   a controller for regulating the circulation flow of the coolant by controlling the circulation flow varying device while referring to the temperature of the coolant upon a receipt of a request for a requested flow from the heat exchanging device; wherein   the controller determines a condition for warming-up the engine when the warming-up of the engine is performed in accordance with the temperature of the coolant, controls the circulation flow varying device for warming-up the engine without circulating the coolant, and increases the circulation flow to the requested flow immediately in a case where the requested flow is requested during the warming-up operation of the engine, and determines the condition for the warming-up of the engine in accordance with an amended temperature of the coolant which is obtained by filtering the temperature of the coolant and changes gradually thereafter.   
     
     
         8 . A cooling system for an engine, comprising:
 a cooling portion formed at the engine for flowing a coolant therethrough;   a coolant sensitive sensor portion detecting a temperature of the coolant;   a heat exchanging device using a heat of the coolant;   a circulation flow varying device for varying a circulation flow of the coolant;   a circulation path for flowing the coolant therethrough via the cooling portion, the coolant sensitive sensor portion, the heat exchanging device, and the circulation flow varying device; and   a controller for regulating the circulation flow of the coolant by controlling the circulation flow varying device while referring to the temperature of the coolant upon a receipt of a request for a requested flow from the heat exchanging device; wherein   the controller determines a condition for warming-up the engine when the warming-up of the engine is performed in accordance with the temperature of the coolant, controls the circulation flow varying device for warming-up the engine without circulating the coolant, and increases the circulation flow to the requested flow in a case where the requested flow is requested during the warming-up operation of the engine, and determines the condition for the warming-up of the engine in accordance with an amended temperature of the coolant which is obtained by filtering the temperature of the coolant.   
     
     
         9 . The cooling system for the engine according to  claim 1 , wherein the circulation flow varying device corresponds to an electric water pump which varies a flow amount, a mechanical water pump actuated by the engine, or a flow regulating valve. 
     
     
         10 . The cooling system for the engine according to  claim 7 , wherein the circulation flow varying device corresponds to an electric water pump which varies a flow amount, a mechanical water pump actuated by the engine, or a flow regulating valve. 
     
     
         11 . The cooling system for the engine according to  claim 8 , wherein the circulation flow varying device corresponds to an electric water pump which varies a flow amount, a mechanical water pump actuated by the engine, or a flow regulating valve. 
     
     
         12 . The cooling system for the engine according to  claim 1  further comprising:
 a heat radiation path being branched from the circulation path between the coolant sensitive sensor portion and the heat exchanging device and joining the circulation path at a suction port of the electric water pump; 
 a radiator provided within the heat radiation path; and 
 a thermostat valve; wherein 
 the circulation flow varying device corresponds to an electric water pump which varies a flow amount, the coolant sensitive sensor portion is positioned at an outlet port of the cooling portion of the engine, and an outlet port of the electric water pump is positioned at an inlet port of the cooling portion. 
 
     
     
         13 . The cooling system for the engine according to  claim 7  further comprising:
 a heat radiation path being branched from the circulation path between the coolant sensitive sensor portion and the heat exchanging device and joining the circulation path at a suction port of the electric water pump; 
 a radiator provided within the heat radiation path; and 
 a thermostat valve; wherein 
 the circulation flow varying device corresponds to an electric water pump which varies a flow amount, the coolant sensitive sensor portion is positioned at an outlet port of the cooling portion of the engine, and an outlet port of the electric water pump is positioned at an inlet port of the cooling portion. 
 
     
     
         14 . The cooling system for the engine according to  claim 8  further comprising:
 a heat radiation path being branched from the circulation path between the coolant sensitive sensor portion and the heat exchanging device and joining the circulation path at a suction port of the electric water pump; 
 a radiator provided within the heat radiation path; and 
 a thermostat valve; wherein 
 the circulation flow varying device corresponds to an electric water pump which varies a flow amount, the coolant sensitive sensor portion is positioned at an outlet port of the cooling portion of the engine, and an outlet port of the electric water pump is positioned at an inlet port of the cooling portion. 
 
     
     
         15 . The cooling system for the engine according to  claim 1 , wherein the engine is mounted to a vehicle and the heat exchanging device corresponds to either a heater or a defroster. 
     
     
         16 . The cooling system for the engine according to  claim 7 , wherein the engine is mounted to a vehicle and the heat exchanging device corresponds to either a heater or a defroster. 
     
     
         17 . The cooling system for the engine according to  claim 8 , wherein the engine is mounted to a vehicle and the heat exchanging device corresponds to either a heater or a defroster.