Cooling apparatus of vehicle driving system

A cooling apparatus of a vehicle driving system for driving a vehicle, comprising:

• an engine water circulation passage, in which cooling water flows as engine cooling water for cooling an internal combustion engine of the vehicle driving system;
• an engine radiator for cooling the engine cooling water by outside air;
• a hybrid system water circulation passage, in which the cooling water flows as hybrid system cooling water for cooling a hybrid system including at least one of a battery and a motor of the vehicle driving system;
• a hybrid system radiator for cooling the hybrid system cooling water by the outside air;
• and
• a heat pump for cooling the hybrid system by a cooling medium flowing in a cooling medium circulation passage of the heat pump, the heat pump including a condenser for exchanging heat between the cooling medium and the engine cooling water,
• wherein the cooling apparatus further comprises an electronic control unit configured to:
• flow the engine cooling water in the engine water circulation passage through the engine radiator to cool the internal combustion engine by the engine cooling water when an engine cooling condition is satisfied, the engine cooling condition being a condition that a process of cooling the internal combustion engine by the engine cooling water is requested,
• activate the heat pump to cool the hybrid system by the cooling medium when a heat pump activation condition is satisfied, the heat pump activation condition being a condition that a process of cooling the hybrid system by the cooling medium of the heat pump is requested, and
• activate the heat pump to cool the hybrid system by the cooling medium and flow the engine cooling water in the engine water circulation passage through the internal combustion engine and the condenser to cool the cooling medium by the engine cooling water at the condenser when an engine water circulation condition is satisfied, the engine water circulation condition being a condition that the heat pump activation condition is satisfied, and the engine cooling condition is not satisfied,
• wherein the engine water circulation passage and the cooling medium circulation passage are configured to exchange heat between the cooling medium and the engine cooling water only at the condenser,
• wherein the engine water circulation condition includes a condition relating to a temperature of the cooling medium flowing into the condenser, and
• wherein the electronic control unit is further configured to stop flowing the engine cooling water in the engine water circulation passage when a temperature of the engine cooling water flowing into the condenser is equal to or higher than the temperature of the cooling medium flowing into the condenser even while the engine water circulation condition is satisfied.

A cooling apparatus of a vehicle driving system for driving a vehicle, the cooling apparatus comprising:

• an engine water circulation passage, in which engine cooling water flows for cooling an internal combustion engine of the vehicle driving system;
• an engine radiator for cooling the engine cooling water by outside air;
• a hybrid system water circulation passage, in which hybrid system cooling water flows for cooling a hybrid system including at least one of a battery and a motor of the vehicle driving system;
• a hybrid system radiator for cooling the hybrid system cooling water by the outside air;
• a heat pump for cooling the hybrid system by a cooling medium flowing in a cooling medium circulation passage of the heat pump, the heat pump including a condenser for exchanging heat between the cooling medium and the engine cooling water;
• and
• an electronic control unit configured to:
• in response to an engine cooling condition being satisfied, the engine cooling condition being a condition that a process of cooling the internal combustion engine by the engine cooling water is requested,
• cause the engine cooling water to flow in the engine water circulation passage through the engine radiator to cool the internal combustion engine by the engine cooling water,
• in response to a heat pump activation condition being satisfied, the heat pump activation condition being a condition that a process of cooling the hybrid system by the cooling medium of the heat pump is requested,
• activate the heat pump to cool the hybrid system by the cooling medium in addition to cooling the hybrid system by the hybrid system radiator,
• in response to the heat pump activation condition being not satisfied,
• cause the hybrid system cooling water to flow in the hybrid system water circulation passage to cool the hybrid system by the hybrid system radiator, without the hybrid system being cooled by the heat pump, and
• in response to both (a) the engine cooling condition being not satisfied and (a) an engine water circulation condition being satisfied, the engine water circulation condition including (i) a condition that the heat pump activation condition is satisfied and (ii) a condition that a temperature of the cooling medium flowing into the condenser is higher than a predetermined cooling medium temperature,
• activate the heat pump to cool the hybrid system by the cooling medium in addition to cooling the hybrid system by the hybrid system radiator, and
• cause the engine cooling water to flow in the engine water circulation passage through the internal combustion engine and the condenser to cool the cooling medium by the engine cooling water at the condenser,
• wherein the engine water circulation passage and the cooling medium circulation passage are configured to exchange heat between the cooling medium and the engine cooling water only at the condenser, and
• wherein the electronic control unit is further configured to stop flowing the engine cooling water in the engine water circulation passage when a temperature of the engine cooling water flowing into the condenser is equal to or higher than the temperature of the cooling medium flowing into the condenser even while the engine water circulation condition is satisfied.