An engine system includes a throttle device, an EGR valve, and an ECU. The ECU diagnoses foreign-matter lodging abnormality of the EGR valve and the foreign-matter diameter based on intake pressure. When the existence of the abnormality and the foreign-matter diameter are determined, the ECU calculates a difference between a foreign-matter diameter and a predetermined learning determination value as a foreign-matter diameter difference. If this difference is larger than an abnormality determination value, the foreign-matter diameter is judged to be excessive and the throttle device is controlled to avoid engine stall. If the foreign-matter diameter difference is equal to or larger than a normality determination value and also equal to or less than the abnormality determination value, engine deceleration is continued. If the foreign-matter diameter difference is less than the normality determination value, the foreign-matter diameter is judged to be minute and the learning determination value is updated.

This engine system is provided with a throttle device, an EGR valve, and an ECU. The ECU diagnoses an abnormality of the EGR valve on the basis of an operating state during an engine deceleration, and diagnoses combustion deterioration of an engine on the basis of a crank angle speed change during the engine deceleration (not during a fuel cut-off). The ECU executes an engine stall avoidance control with the throttle device when it is determined there is an abnormality in the EGR valve, makes a final determination that the EGR valve has an abnormality and continues the engine stall avoidance control when it is determined thereafter that there is combustion deterioration, and makes a final determination that the EGR valve is normal and cancels the engine stall avoidance control when it is determined that there is no combustion deterioration.

This engine system is provided with a throttle device, an EGR valve, and an ECU. The ECU diagnoses an abnormality of the EGR valve on the basis of an operating state during an engine deceleration, and diagnoses combustion deterioration of an engine on the basis of a crank angle speed change during the engine deceleration (not during a fuel cut-off). The ECU executes an engine stall avoidance control with the throttle device when it is determined there is an abnormality in the EGR valve, makes a final determination that the EGR valve has an abnormality and continues the engine stall avoidance control when it is determined thereafter that there is combustion deterioration, and makes a final determination that the EGR valve is normal and cancels the engine stall avoidance control when it is determined that there is no combustion deterioration.

An engine system includes an injector, an EGR device (including an EGR valve having a step motor) to recirculate part of exhaust gas of an engine as EGR gas to the engine, and an electronic control unit (ECU) to control the injector, the EGR valve, and others based on an operating state of the engine. The ECU is configured to diagnose foreign-matter lodging abnormality of the EGR valve and a lodged foreign-matter diameter based on detected intake pressure during engine deceleration. When existence of the abnormality and the foreign-matter diameter are determined, the ECU controls the step motor to hold the EGR valve at a first opening degree smaller than a second opening degree needed to remove a foreign matter before fuel cut to the engine by the injector.

An exhaust flow control system comprises a housing defining first and second passages that are fluidly connected to first and second scrolls of a twin scroll turbocharger and to a high pressure exhaust gas recirculation (HPEGR) system, a poppet valve configured to (i) in an open position, fluidly connect the first and second scrolls to each other and to the HPEGR system via the first and second passages and (ii) in a closed position, fluidly disconnect the first and second scrolls from each other and from the HPEGR system, and a controller configured to command the poppet valve to one of the open and closed positions based on one or more engine operating parameters thereby allowing the twin scroll turbocharger to operate in both a twin scroll mode and a mono scroll mode while also allowing for HPEGR control with minimal additional system volume.

An exhaust flow control system comprises a housing defining first and second passages that are fluidly connected to first and second scrolls of a twin scroll turbocharger and to a high pressure exhaust gas recirculation (HPEGR) system, a poppet valve configured to (i) in an open position, fluidly connect the first and second scrolls to each other and to the HPEGR system via the first and second passages and (ii) in a closed position, fluidly disconnect the first and second scrolls from each other and from the HPEGR system, and a controller configured to command the poppet valve to one of the open and closed positions based on one or more engine operating parameters thereby allowing the twin scroll turbocharger to operate in both a twin scroll mode and a mono scroll mode while also allowing for HPEGR control with minimal additional system volume.

An exhaust flow control system comprises a housing defining first and second passages that are fluidly connected to first and second scrolls of a twin scroll turbocharger and to a high pressure exhaust gas recirculation (HPEGR) system, a poppet valve configured to (i) in an open position, fluidly connect the first and second scrolls to each other and to the HPEGR system via the first and second passages and (ii) in a closed position, fluidly disconnect the first and second scrolls from each other and from the HPEGR system, and a controller configured to command the poppet valve to one of the open and closed positions based on one or more engine operating parameters thereby allowing the twin scroll turbocharger to operate in both a twin scroll mode and a mono scroll mode while also allowing for HPEGR control with minimal additional system volume.

A valve assembly comprises: a valve housing comprising an interior cavity having upstream side and a downstream side; and a valve member movable within the valve housing between a closed position in which flow between the upstream side and the downstream side is prevented or substantially prevented and one or more open positions in which flow between the upstream side and the downstream side is enabled. The valve assembly further comprises: a sensor mounting flange on an exterior surface of the valve housing; a first bore in the valve housing linking the upstream side of the valve housing and the sensor mounting flange; and a second bore in the valve housing linking the downstream side of the valve housing and the sensor mounting flange; such that a sensor configured to measure a differential between the upstream side and the downstream side is mountable directly on the valve assembly.

A valve assembly comprises: a valve housing comprising an interior cavity having upstream side and a downstream side; and a valve member movable within the valve housing between a closed position in which flow between the upstream side and the downstream side is prevented or substantially prevented and one or more open positions in which flow between the upstream side and the downstream side is enabled. The valve assembly further comprises: a sensor mounting flange on an exterior surface of the valve housing; a first bore in the valve housing linking the upstream side of the valve housing and the sensor mounting flange; and a second bore in the valve housing linking the downstream side of the valve housing and the sensor mounting flange; such that a sensor configured to measure a differential between the upstream side and the downstream side is mountable directly on the valve assembly.

A valve form exhaust gas recirculation Mac in an engine includes a first barrel connectable to a first group of cylinders, a second barrel connectable to a second group of cylinders, and a center barrel between the first and second barrels and connectable to an intake oft he engine. A poppet valve with two valve heads mounted on a valve stem is provided to open and close openings between the first and second barrels, with one of the valve beads of the poppet valve opening into the center barrel Vanes are provided-in the center barrel to direct flow from the opening by the valve bead that opens into the center barrel toward the outlet opening.