A negative pressure control valve (44) is disposed in a part of an intake passage (12) upstream of a confluence (30) of an EGR passage (27) and the intake passage (12). When in an EGR region (Regr) where an EGR gas is recirculated to the intake passage (12) through the EGR passage (27), the negative pressure control valve (44) is controlled in a manner to ensure a differential pressure between an exhaust passage (13) and the intake passage (12). When in an operation region (R2) lower in load than the EGR region (Regr), the negative pressure control valve (44) is controlled in a closing direction so as to suppress occurrence of noise.

Various embodiments include a method for adjusting a mass flow through an exhaust-gas recirculation valve mechanically coupled to a throttle flap of an internal combustion engine which has a turbocharger comprising: determining a first setpoint value corresponding to a setpoint opening position of the exhaust-gas recirculation valve; determining a second setpoint value corresponding to a setpoint opening position of the throttle flap; comparing the first setpoint value to the second setpoint value; adjusting the mass flow of the exhaust-gas recirculation valve by varying an opening position of the exhaust-gas recirculation valve if the first setpoint value is higher than the second setpoint value; and adjusting the mass flow of the exhaust-gas recirculation valve by varying an opening position of the throttle flap if the second setpoint value is higher than the first setpoint value.

Various embodiments include a method for adjusting a mass flow through an exhaust-gas recirculation valve mechanically coupled to a throttle flap of an internal combustion engine which has a turbocharger comprising: determining a first setpoint value corresponding to a setpoint opening position of the exhaust-gas recirculation valve; determining a second setpoint value corresponding to a setpoint opening position of the throttle flap; comparing the first setpoint value to the second setpoint value; adjusting the mass flow of the exhaust-gas recirculation valve by varying an opening position of the exhaust-gas recirculation valve if the first setpoint value is higher than the second setpoint value; and adjusting the mass flow of the exhaust-gas recirculation valve by varying an opening position of the throttle flap if the second setpoint value is higher than the first setpoint value.

An EGR control device includes: a tumble generation valve, a recirculation passage, an EGR valve, an EGR valve opening degree deriving unit, and an EGR valve control unit. The tumble generation valve is configured to adjust a passage area of an intake passage of an engine. The recirculation passage is configured to recirculate an exhaust gas from an exhaust passage of the engine to the intake passage. The EGR valve is disposed on the recirculation passage and configured to open and close the recirculation passage. The EGR valve opening degree deriving unit is configured to derive an opening degree of the EGR valve on a basis of an engine speed, an engine load, and a tumble generation valve opening and closing rate. The EGR valve control unit is configured to drive and control the EGR valve to achieve the opening degree derived by the EGR valve opening degree deriving unit.

An EGR control device includes: a tumble generation valve, a recirculation passage, an EGR valve, an EGR valve opening degree deriving unit, and an EGR valve control unit. The tumble generation valve is configured to adjust a passage area of an intake passage of an engine. The recirculation passage is configured to recirculate an exhaust gas from an exhaust passage of the engine to the intake passage. The EGR valve is disposed on the recirculation passage and configured to open and close the recirculation passage. The EGR valve opening degree deriving unit is configured to derive an opening degree of the EGR valve on a basis of an engine speed, an engine load, and a tumble generation valve opening and closing rate. The EGR valve control unit is configured to drive and control the EGR valve to achieve the opening degree derived by the EGR valve opening degree deriving unit.

A valve device includes a shaft, a valve body, and a housing including a valve opening. An outwardly facing surface of the valve body is out of contact with the housing and a valve-facing surface is in contact with the housing in a fully closed state in which the valve body closes the valve opening. A valve seal surface includes a first valve seal surface protruding in a valve closing direction and a second valve seal surface recessed in a valve opening direction. A first seal distance in a radial direction from an outer diameter end of the first valve seal surface to a rotation axis is shorter than a second seal distance in the radial direction from an outer diameter end of the second valve seal surface to the rotation axis. The first valve seal surface and the second valve seal surface each have at least a curved surface.

A valve device includes a shaft, a valve body, and a housing including a valve opening. An outwardly facing surface of the valve body is out of contact with the housing and a valve-facing surface is in contact with the housing in a fully closed state in which the valve body closes the valve opening. A valve seal surface includes a first valve seal surface protruding in a valve closing direction and a second valve seal surface recessed in a valve opening direction. A first seal distance in a radial direction from an outer diameter end of the first valve seal surface to a rotation axis is shorter than a second seal distance in the radial direction from an outer diameter end of the second valve seal surface to the rotation axis. The first valve seal surface and the second valve seal surface each have at least a curved surface.

A system for deactivating at least one predetermined cylinder (1, 2, 3, 4) of an operational multicylinder engine, wherein each cylinder (1, 2, 3, 4) of said multicylinder engine comprises an intake duct with an inlet connected to the intake manifold (5) and an outlet connected to the cylinder (1, 2, 3, 4) in order to allow the intake of combustion gases from the intake manifold (5) to the cylinder (1, 2, 3, 4), the system comprising a first movable sealing means suitable for sealing the inlet of said intake duct of the predetermined cylinder (1, 2, 3, 4), a recirculation duct suitable for connecting said intake duct of said predetermined cylinder (1, 2, 3, 4) to an exhaust gas supply, and a second movable sealing means (10, 30) suitable for sealing said recirculation duct.

A system for deactivating at least one predetermined cylinder (1, 2, 3, 4) of an operational multicylinder engine, wherein each cylinder (1, 2, 3, 4) of said multicylinder engine comprises an intake duct with an inlet connected to the intake manifold (5) and an outlet connected to the cylinder (1, 2, 3, 4) in order to allow the intake of combustion gases from the intake manifold (5) to the cylinder (1, 2, 3, 4), the system comprising a first movable sealing means suitable for sealing the inlet of said intake duct of the predetermined cylinder (1, 2, 3, 4), a recirculation duct suitable for connecting said intake duct of said predetermined cylinder (1, 2, 3, 4) to an exhaust gas supply, and a second movable sealing means (10, 30) suitable for sealing said recirculation duct.

A regulating device for an internal combustion engine includes a housing in which is formed an exhaust gas recirculation pipe which opens into an intake pipe, and a regulating element eccentrically mounted on a shaft. The regulating element includes a first surface, a second surface, and guide ribs arranged on the second surface so that an exhaust gas flow flows into the intake pipe when the exhaust gas recirculation pipe is opened. In a first end position of the regulating element, where the intake pipe is at throttled upstream of an opening of the exhaust gas recirculation pipe, a normal vector of the first surface points to an upstream side of the intake pipe. In a second end position of the regulating element, where the exhaust gas recirculation pipe is closed, a normal vector of the second surface points to the exhaust gas recirculation pipe.