Engine cooling system

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• a bypass circuit connected to the cooling water circulation circuit to bypass the radiator,
• an electric-powered variable displacement water pump disposed in the cooling water circulation circuit adjacent an engine inlet,
• a flow rate control valve for controlling a flow rate of cooling water flowing through the radiator,
• an outlet water temperature detector for detecting an engine outlet water temperature in the cooling water circulation circuit,
• an inlet water temperature detector for detecting an engine inlet water temperature in the cooling water circulation circuit, and
• a control means having means operatively connected to said water pump, said flow rate control valve, said outlet water detector and said inlet water temperature detector for controlling the operation of the water pump in accordance with at least the engine outlet water temperature and controlling the operation of the flow rate control valve in accordance with at least the engine inlet water temperature, wherein said control means is capable of performing a feed-back control of the water pump using, as a target value, a target outlet water temperature determined from at least an engine speed and an engine intake pressure as parameters, and performing a feed-back control of the flow rate control valve using, as a target value, a target inlet water temperature determined from at least the engine speed and the engine intake pressure as parameters.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• an electric-powered variable displacement water pump disposed in the cooling water circulation circuit adjacent an engine inlet,
• a water temperature detector for detecting an engine water temperature, and
• a control means having means operatively connected to said water pump and said water temperature detector for controlling the operation of the water pump in such a manner to switch-over a feed-back control according to the engine water temperature and an open loop control from one to another in accordance with the operational condition of the engine.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• a variable flow rate control valve mounted in said cooling water circulation circuit,
• an engine inlet water temperature detector for detecting an engine inlet water temperature,
• an engine outlet water temperature detector for detecting an engine outlet water temperature, and
• a control means having means operatively connected to said control valve, said inlet water temperature detector and outlet water temperature detector, said control means being switched over between a first control state for controlling an opening degree of the variable flow rate control valve to bring the engine outlet water temperature into a target outlet temperature, when the engine inlet water temperature is in a low water temperature level, and a second control state for controlling the opening degree of the variable flow rate control valve to bring the engine inlet water temperature into a target inlet temperature, when the engine inlet water temperature is in a high water temperature level.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• a bypass circuit connected to the cooling water circulation circuit to bypass the radiator,
• an electric-powered variable displacement water pump disposed in the cooling water circulation circuit adjacent an engine inlet,
• a flow rate control valve for controlling a flow rate of cooling water flowing through the radiator,
• an outlet water temperature detector for detecting an engine outlet water temperature in the cooling water circulation circuit,
• an inlet water temperature detector for detecting an engine inlet water temperature in the cooling water circulation circuit, and
• a control means having means operatively connected to said water pump, said flow rate control valve, said outlet water detector and said inlet water temperature detector for controlling the operation of the water pump in accordance with at least the engine outlet water temperature and controlling the operation of the flow rate control valve in accordance with at least the engine inlet water temperature, wherein said control means controls the operation of the water pump in such a manner as to switch-over a feed-back control according to an engine water temperature and an open loop control from one to another in accordance with the operational condition of the engine.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• a bypass circuit connected to the cooling water circulation circuit to bypass the radiator,
• an electric-powered variable displacement water pump disposed in the cooling water circulation circuit adjacent an engine inlet,
• a flow rate control valve for controlling a flow rate of cooling water flowing through the radiator,
• an outlet water temperature detector for detecting an engine outlet water temperature in the cooling water circulation circuit,
• an inlet water temperature detector for detecting an engine inlet water temperature in the cooling water circulation circuit, and
• a control means having means operatively connected to said water pump, said flow rate control valve, said outlet water detector and said inlet water temperature detector for controlling the operation of the water pump in accordance with at least the engine outlet water temperature and controlling the operation of the flow rate control valve in accordance with at least the engine inlet water temperature, wherein said control means is switched over between a first control state for controlling the opening degree of the variable flow rate control valve to bring the engine outlet water temperature into a target outlet temperature, when the engine inlet water temperature is in a low water temperature level, and a second control state for controlling the opening degree of the variable flow rate control valve to bring the engine inlet water temperature into a target inlet temperature, when the engine inlet water temperature is in a high water temperature level.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• a bypass circuit connected to the cooling water circulation circuit to bypass the radiator,
• an electric-powered variable displacement water pump disposed in the cooling water circulation circuit adjacent an engine inlet,
• a flow rate control valve for controlling a flow rate of cooling water flowing through the radiator,
• an outlet water temperature detector for detecting an engine outlet water temperature in the cooling water circulation circuit,
• an inlet water temperature detector for detecting an engine inlet water temperature in the cooling water circulation circuit,
• a control means having means operatively connected to said water pump, said flow rate control valve, said outlet water detector and said inlet water temperature detector for controlling the operation of the water pump in accordance with at least the engine outlet water temperature and controlling the operation of the flow rate control valve in accordance with at least the engine inlet water temperature, and
• a knocking detector connected to said control means for detecting a knocking of the engine, and wherein said control means controls the opening degree of the variable flow rate control valve so as to reduce the target inlet temperature and reduce a difference between the engine outlet water temperature and the engine inlet water temperature in response to the detection of the knocking during the operation of the engine at a high load in the mean water temperature level.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• an electric-powered variable displacement water pump disposed in said cooling water circulation circuit adjacent an engine inlet,
• an engine outlet water temperature detector for detecting an engine outlet water temperature,
• a knocking detector for detecting a knocking of the engine, and
• a control means having means operatively connected to said water pump, said outlet water temperature detector and said knocking detector for performing a feed-back control of the water pump to vary a rate of cooling water circulation in accordance with the engine outlet water temperature and reducing a target value for the feed-back control when the knocking is detected, wherein said control means is capable of performing a feed-back control of the water pump using, as a target value, a target outlet water temperature determined from at least an engine speed and an engine intake pressure as parameters, and performing a feed-back control of the flow rate control valve using, as a target value, a target inlet water temperature determined from at least the engine speed and the engine intake pressure as parameters.

An engine cooling system comprising

• a cooling water circulation circuit interconnecting an engine body and a radiator,
• an electric-powered variable displacement water pump disposed in said cooling water circulation circuit adjacent an engine inlet,
• an engine outlet water temperature detector for detecting an engine outlet water temperature,
• a knocking detector for detecting a knocking of the engine, and
• a control means having means operatively connected to said water pump, said outlet water temperature detector and said knocking detector for performing a feed-back control of the water pump to vary a rate of cooling water circulation in accordance with the engine outlet water temperature and reducing a target value for the feed-back control when the knocking is detected, wherein said control means is switched over between a first control state for controlling the opening degree of the variable flow rate control valve to bring the engine outlet water temperature into a target outlet temperature, when the engine inlet water temperature is in a low water temperature level, and a second control state for controlling the opening degree of the variable flow rate control valve to bring the engine inlet water temperature into a target inlet temperature, when the engine inlet water temperature is in a high water temperature level.