Methods and systems are provided for estimating exhaust gas recirculation (EGR) flow in an engine including an EGR system. In one example, a method may include operating the EGR system in an open loop feed forward mode based on an intake carbon di oxide sensor output above a threshold engine load and/or when a manifold absolute pressure (MAP) is above a threshold pressure, and operating the EGR system in a closed loop feedback mode based on a differential pressure sensor output when the engine load decreases below the threshold load and/or when the MAP decreases below the threshold pressure.

Methods and systems are provided for estimating exhaust gas recirculation (EGR) flow in an engine including an EGR system. In one example, a method may include operating the EGR system in an open loop feed forward mode based on an intake carbon di oxide sensor output above a threshold engine load and/or when a manifold absolute pressure (MAP) is above a threshold pressure, and operating the EGR system in a closed loop feedback mode based on a differential pressure sensor output when the engine load decreases below the threshold load and/or when the MAP decreases below the threshold pressure.

A method for cleaning an exhaust gas recirculation (EGR) valve includes scheduling a cleaning for the EGR valve, and receiving a signal indicative of a temperature of exhaust gas produced with an internal combustion engine. The method may also include generating a command to actuate an intake throttle valve to a restrictive position to increase the temperature of the exhaust gas for cleaning the EGR valve, and generating a signal to repeatedly actuate the EGR valve.

A method for cleaning an exhaust gas recirculation (EGR) valve includes scheduling a cleaning for the EGR valve, and receiving a signal indicative of a temperature of exhaust gas produced with an internal combustion engine. The method may also include generating a command to actuate an intake throttle valve to a restrictive position to increase the temperature of the exhaust gas for cleaning the EGR valve, and generating a signal to repeatedly actuate the EGR valve.

A method for cleaning an exhaust gas recirculation (EGR) valve includes scheduling a cleaning for the EGR valve, and receiving a signal indicative of a temperature of exhaust gas produced with an internal combustion engine. The method may also include generating a command to actuate an intake throttle valve to a restrictive position to increase the temperature of the exhaust gas for cleaning the EGR valve, and generating a signal to repeatedly actuate the EGR valve.

A method for cleaning an exhaust gas recirculation (EGR) valve includes scheduling a cleaning for the EGR valve, and receiving a signal indicative of a temperature of exhaust gas produced with an internal combustion engine. The method may also include generating a command to actuate an intake throttle valve to a restrictive position to increase the temperature of the exhaust gas for cleaning the EGR valve, and generating a signal to repeatedly actuate the EGR valve.

An electrically controlled valve for the circulation of hot fluids is made up of an electromagnetic actuator and a valve. The valve has an opening provided with a movable sealing member driven by a rotation shaft perpendicular to the axis of the opening, the electromagnetic actuator driving the rotation of the shaft, the output shaft of the actuator being substantially coaxial with the rotation shaft. The front end of the rotation shaft and the front end of the output shaft are not in direct contact. The coupling between the rotation shaft of the valve and the output shaft of the actuator is provided by a coupling member placed between the front end of the output shaft and the front end of the shaft. The coupling member transmitting rotation torque with a misalignment tolerance between the output shaft and the rotation shaft of the valve. The valve also having thermally insulation for mechanical connection between peripheral areas of the body of the actuator and the body of the valve.

An electrically controlled valve for the circulation of hot fluids is made up of an electromagnetic actuator and a valve. The valve has an opening provided with a movable sealing member driven by a rotation shaft perpendicular to the axis of the opening, the electromagnetic actuator driving the rotation of the shaft, the output shaft of the actuator being substantially coaxial with the rotation shaft. The front end of the rotation shaft and the front end of the output shaft are not in direct contact. The coupling between the rotation shaft of the valve and the output shaft of the actuator is provided by a coupling member placed between the front end of the output shaft and the front end of the shaft. The coupling member transmitting rotation torque with a misalignment tolerance between the output shaft and the rotation shaft of the valve. The valve also having thermally insulation for mechanical connection between peripheral areas of the body of the actuator and the body of the valve.

The invention reduces exhaust emission by quickly supplying CO2 into a cylinder, and restraining a delay in EGR, when an EGR request occurs. An engine 10 includes an upstream EGR passage 34, a middle EGR passage 36, a downstream EGR passage 38, a bypass passage 40, an EGR valve 42, a changeover valve 44, an EGR cooler 46, a CO2 adsorbent 48. When an EGR request does not occur, the ECU 70 keeps a temperature of the CO2 adsorbent 48 in a release temperature region by the heater 50, and opens the EGR valve 42 by a valve opening set time period t so that a gas in the middle EGR passage 36 is replaced with CO2 released from the CO2 adsorbent. When an EGR request occurs, CO2 accumulated in the middle EGR passage 36 can be quickly supplied into a cylinder, without releasing CO2 from the CO2 adsorbent 48.

The invention relates to a control device for an internal combustion engine using the center-of-gravity position of a heat generation rate for combustion control. This control device controls the center-of-gravity position of a heat generation rate to correspond to a reference position in a case where an engine cooling water temperature is equal to or higher than a reference cooling water temperature and controls the center-of-gravity position of a heat generation rate to correspond to a crank angle further on an advance side than the reference position in a case where the engine cooling water temperature is lower than the reference cooling water temperature.