Abstract: The character or nature of cooling water is correctly estimated. A cooling system for an internal combustion engine includes a radiator, a bypass passage which bypasses the radiator, a thermostat, and a control unit which changes a valve opening temperature of the thermostat. The cooling system for the internal combustion engine further includes an estimating unit which forbids valve opening of the thermostat and which estimates the character of the cooling water on the basis of temperature transition of the cooling water provided in this state.

Abstract: The character or nature of cooling water is correctly estimated. A cooling system for an internal combustion engine includes a radiator, a bypass passage which bypasses the radiator, a thermostat, and a control unit which changes a valve opening temperature of the thermostat. The cooling system for the internal combustion engine further includes an estimating unit which forbids valve opening of the thermostat and which estimates the character of the cooling water on the basis of temperature transition of the cooling water provided in this state.

Abstract: In a control method of an internal combustion engine exhaust gas control system which is applied to a hybrid vehicle that is powered by an internal combustion engine and an electric motor, an exhaust throttle valve, provided downstream of an exhaust gas control catalyst, is controlled to reduce its opening amount to a target opening amount when it is determined that warm-up control of the internal combustion engine needs to be executed. Next, a target injection quantity of fuel necessary to increase the temperature of exhaust gas flowing into the internal combustion engine to a target exhaust gas temperature is calculated. Then, assist torque from the electric motor is adjusted so that the sum of torque from the internal combustion engine when the fuel injection quantity has been set to the target injection quantity and the assist torque substantially equals a required torque.

Abstract: An opening and closing condition of a thermostat is optimized. In a cooling system for an internal combustion engine in which a cooling water, in which its specific heat becomes larger at a predetermined temperature than at other temperatures, is caused to circulates through a cooling water passage, there are provided a radiator, a bypass passage that bypasses the radiator, and a thermostat that interrupts the circulation of the cooling water to the radiator and circulates the cooling water to the bypass passage when it closes, and circulates the cooling water to at least the radiator when it opens, wherein the thermostat is set to open at the time when the temperature of the cooling water is higher than a predetermined temperature.

Abstract: A hybrid system control apparatus is provided in which an intercooler is disposed upstream of the motor cooling radiator in a flow path of the ambient air flowing in an engine compartment, and/or is disposed such that at least a portion of the intercooler and a portion of the motor cooling radiator contact each other. The hybrid system control apparatus includes a warm-up portion that increases temperature of the boost air by controlling a load of the engine in cold start of a hybrid system such that the boost pressure from the forced air induction device is equal to or higher than a target boost pressure.

Abstract: An internal combustion engine control device includes a NOx adsorber catalyst disposed in an exhaust passage, an EGR passage, a reducing agent adding device, a torque fluctuation reducing device, and a fuel injection device. The EGR passage draws a portion of exhaust gas from the exhaust passage downstream of the NOx adsorber catalyst and recirculates the exhaust gas into the intake passage. The reducing agent adding device adds a reducing agent to exhaust gas upstream of the NOx adsorber catalyst to reduce substances adsorbed by the NOx adsorber catalyst. When or after the reducing agent adding device adds the reducing agent, the torque fluctuation reducing device advances the timing of the fuel injection device or carries out a pilot injection to reduce a fluctuation in engine torque. The reducing agent adding device adds less reducing agent while the torque fluctuation reducing device is operating.

Abstract: A control apparatus for an internal combustion engine includes an exhaust gas recirculation unit; an intercooler that is provided in the intake passage, at a position downstream of a position to which the exhaust gas is recirculated back; a bypass passage through which an intake air flow bypasses the intercooler. When it is determined that the pH of the condensed water obtained from the exhaust gas is at the level at which the intercooler corrodes in the state where the exhaust gas is recirculated back by the exhaust gas recirculation unit, the control apparatus executes a control for cutting off an intake air flow toward the intercooler to direct the intake air flow only to the bypass passage. Thus, it is possible to ensure reliability of the intercooler.

Abstract: In a control method of an internal combustion engine exhaust gas control system which is applied to a hybrid vehicle that is powered by an internal combustion engine and an electric motor, an exhaust throttle valve, provided downstream of an exhaust gas control catalyst, is controlled to reduce its opening amount to a target opening amount when it is determined that warm-up control of the internal combustion engine needs to be executed. Next, a target injection quantity of fuel necessary to increase the temperature of exhaust gas flowing into the internal combustion engine to a target exhaust gas temperature is calculated. Then, assist torque from the electric motor is adjusted so that the sum of torque from the internal combustion engine when the fuel injection quantity has been set to the target injection quantity and the assist torque substantially equals a required torque.

Abstract: A hybrid system control apparatus is provided in which an intercooler (15) is disposed upstream of the motor cooling radiator (70) in a flow path of the ambient air flowing in an engine compartment, and/or is disposed such that at least a portion of the intercooler and a portion of the motor cooling radiator contact each other. The hybrid system control apparatus includes a warm-up portion (60) that increases temperature of the boost air by controlling a load of the engine in cold start of a hybrid system (1) such that the boost pressure from the forced air induction device is equal to or higher than a target boost pressure.

Abstract: An internal combustion engine control device includes a NOx adsorber catalyst disposed in an exhaust passage, an EGR passage, a reducing agent adding device, a torque fluctuation reducing device, and a fuel injection device. The EGR passage draws a portion of exhaust gas from the exhaust passage downstream of the NOx adsorber catalyst and recirculates the exhaust gas into the intake passage. The reducing agent adding device adds a reducing agent to exhaust gas upstream of the NOx adsorber catalyst to reduce substances adsorbed by the NOx adsorber catalyst. When or after the reducing agent adding device adds the reducing agent, the torque fluctuation reducing device advances the timing of the fuel injection device or carries out a pilot injection to reduce a fluctuation in engine torque. The reducing agent adding device adds less reducing agent while the torque fluctuation reducing device is operating.

Abstract: A control apparatus for an internal combustion engine includes an exhaust gas recirculation unit; an intercooler that is provided in the intake passage, at a position downstream of a position to which the exhaust gas is recirculated back; a bypass passage through which an intake air flow bypasses the intercooler. When it is determined that the pH of the condensed water obtained from the exhaust gas is at the level at which the intercooler corrodes in the state where the exhaust gas is recirculated back by the exhaust gas recirculation unit, the control apparatus executes a control for cutting off an intake air flow toward the intercooler to direct the intake air flow only to the bypass passage. Thus, it is possible to ensure reliability of the intercooler.