A turbocharger system for simultaneously improving a fuel efficiency and obtaining a satisfactory hill start performance due to a downsized engine. The system includes an electric assist turbocharger which includes a turbine disposed in an exhaust passage of an engine and driven by exhaust gas, a compressor disposed in an intake passage and driven by a rotational torque of the turbine, and an electric motor assisting a driving force of the compressor and an electric motor control unit which drives the electric motor when detecting a start operation at a sloping road.

The present disclosure provides a boosting control method of an engine for cylinder de-activation (CDA). The method includes: a CDA operable area confirming step of determining, by a controller based on a driving state of the engine, whether the CDA is in an operable area after the engine starts; an actual boosting deriving step of deriving a total target boosting from the controller and calculating the desired actual boosting; a supercharger operable area confirming step of determining, by the controller, whether the supercharger is in the operable area; a supercharger target rotation speed deriving step of deriving, by the controller, a target rotation speed of the supercharger; and a supercharger passage opening step of closing a bypass valve to open a supercharger passage.

The present disclosure provides a boosting control method of an engine for cylinder de-activation (CDA). The method includes: a CDA operable area confirming step of determining, by a controller based on a driving state of the engine, whether the CDA is in an operable area after the engine starts; an actual boosting deriving step of deriving a total target boosting from the controller and calculating the desired actual boosting; a supercharger operable area confirming step of determining, by the controller, whether the supercharger is in the operable area; a supercharger target rotation speed deriving step of deriving, by the controller, a target rotation speed of the supercharger; and a supercharger passage opening step of closing a bypass valve to open a supercharger passage.

A controller calculates a specific humidity of an intake air based on a relative humidity of the intake air, an intake air temperature, and an intake air pressure. Then the controller calculates a water vapor amount in the intake air based on the specific humidity and a mass flow rate of the intake air obtained from an air intake rate. By calculating the water vapor amount in the intake air based on information that directly represents the status of the intake air, this water vapor amount may be calculated more accurately. As a result, a generation amount of condensed water may be estimated more accurately. Therefore, accumulation of condensed water may be suppressed while recirculating as much of a low pressure exhaust gas as possible, and thus fuel economy may be sufficiently improved.

A mechanically simplified electric and fluid (gas, vapor or liquid) control for a piston engine, including an engine valve actuator system that eliminates rotating cam shafts and heavy internal combustion engine valve closing springs by using an electromagnet and an armature which is attracted by the electromagnet to initiate movement of both a fluid control valve and the engine valve. When the control valve is moved only slightly off its seat by the armature, fluid pressure instantly drives the control valve a much greater distance closing the engine valve. Opening and closing time is regulated independently. Engine valves are opened by reversing the fluid pressure balance across the control valve at the time selected.

A divert-air valve for a compressor of an internal combustion engine includes a flow housing with an inlet, an outlet, and a duct arranged therein, an actuator housing, an electromagnetic actuator with an armature arranged in the actuator housing, a control body which is moved by the electromagnetic actuator so as to close off the duct, a housing interior in which the armature moves, openings arranged in the control body, a connector housing arranged to bear axially against the electromagnetic actuator and to at least partially delimit the housing interior, a first sealing ring arranged on the connector housing, and a second sealing ring which bears against the flow housing on an axially opposite side of the connector housing. The openings fluidically connect the housing interior to the duct. The first sealing ring bears against the electromagnetic actuator.

A divert-air valve for a compressor of an internal combustion engine includes a flow housing with an inlet, an outlet, and a duct arranged therein, an actuator housing, an electromagnetic actuator with an armature arranged in the actuator housing, a control body which is moved by the electromagnetic actuator so as to close off the duct, a housing interior in which the armature moves, openings arranged in the control body, a connector housing arranged to bear axially against the electromagnetic actuator and to at least partially delimit the housing interior, a first sealing ring arranged on the connector housing, and a second sealing ring which bears against the flow housing on an axially opposite side of the connector housing. The openings fluidically connect the housing interior to the duct. The first sealing ring bears against the electromagnetic actuator.

A system and method are provided for estimating an operating parameter of an exhaust manifold of an engine. In the system, a flow value is determined that corresponds to a flow rate of exhaust gas through an EGR conduit fluidly coupled between the exhaust manifold and the intake manifold. The EGR conduit includes an exhaust gas cooler disposed in-line with the EGR conduit and a property of the exhaust gas exiting an exhaust gas outlet of the cooler is measured. The operating parameter of the exhaust manifold is estimated as a function of at least the flow value and the property of the exhaust gas exiting the exhaust gas outlet of the cooler. Illustratively, the operating parameter of the exhaust manifold may be exhaust manifold pressure and/or temperature.

A straddle-type vehicle comprises a supercharging device which compresses intake-air to be sent to a combustion chamber of an engine; a catalyst provided in an exhaust passage through which an exhaust gas emitted from the engine flows; and a control section which controls the engine, wherein the control section performs an increase suppressing control for suppressing an increase in an exhaust gas temperature, in a case where the control section estimates that the exhaust gas temperature has exceeded an increase suppressing temperature set to be equal to or lower than a catalyst permissible temperature.

A straddle-type vehicle comprises a supercharging device which compresses intake-air to be sent to a combustion chamber of an engine; a catalyst provided in an exhaust passage through which an exhaust gas emitted from the engine flows; and a control section which controls the engine, wherein the control section performs an increase suppressing control for suppressing an increase in an exhaust gas temperature, in a case where the control section estimates that the exhaust gas temperature has exceeded an increase suppressing temperature set to be equal to or lower than a catalyst permissible temperature.