A method for manufacturing a turbine wheel comprising casting the turbine wheel from an austenitic nickel-chromium-based superalloy, subjecting the cast turbine wheel to hot isostatic pressing and then subjecting a surface of the hot isostatically pressed turbine wheel to plastic deformation, wherein said hot isostatic pressing is effected at a pressure of 98 to 200 MPa and a temperature of 1160 to 1220 C. for a time period of 225 to 300 minutes. There is further described a hot isostatically pressed cast turbine wheel manufactured from an austenitic nickel-chromium-based superalloy, the turbine wheel having a plastically deformed surface; and a turbocharger incorporating such a turbine wheel.

A method for manufacturing a turbine wheel comprising casting the turbine wheel from an austenitic nickel-chromium-based superalloy, subjecting the cast turbine wheel to hot isostatic pressing and then subjecting a surface of the hot isostatically pressed turbine wheel to plastic deformation, wherein said hot isostatic pressing is effected at a pressure of 98 to 200 MPa and a temperature of 1160 to 1220 C. for a time period of 225 to 300 minutes. There is further described a hot isostatically pressed cast turbine wheel manufactured from an austenitic nickel-chromium-based superalloy, the turbine wheel having a plastically deformed surface; and a turbocharger incorporating such a turbine wheel.

A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

A control apparatus is configured, after a torque increase request to increase an engine torque is made, to perform an air supply operation using an electric compressor where it is predicted that a pressure ratio of a turbo-compressor will become less than 1 after a throttle valve is opened accompanying the torque increase request, and, on the other hand, not to perform the air supply operation where it is predicted that the pressure ratio will not become less than 1 after the throttle valve is opened.

A control apparatus is configured, after a torque increase request to increase an engine torque is made, to perform an air supply operation using an electric compressor where it is predicted that a pressure ratio of a turbo-compressor will become less than 1 after a throttle valve is opened accompanying the torque increase request, and, on the other hand, not to perform the air supply operation where it is predicted that the pressure ratio will not become less than 1 after the throttle valve is opened.

A turbocharger includes a cooling passage. The cooling passage extends along a diffuser surface. Fluid for cooling the diffuser surface flows through the cooling passage. The turbocharger includes a water jacket, which is arranged at a connection portion between a blow-by gas recirculation passage and an intake passage. Coolant for warming blow-by gas flows through the water jacket. The cooling passage communicates with the water jacket. Coolant that has been drawn into the cooling passage flows through the water jacket after flowing through the cooling passage.

A turbocharger includes a cooling passage. The cooling passage extends along a diffuser surface. Fluid for cooling the diffuser surface flows through the cooling passage. The turbocharger includes a water jacket, which is arranged at a connection portion between a blow-by gas recirculation passage and an intake passage. Coolant for warming blow-by gas flows through the water jacket. The cooling passage communicates with the water jacket. Coolant that has been drawn into the cooling passage flows through the water jacket after flowing through the cooling passage.

A turbocharger for use with an internal combustion engine includes a compressor wheel having a central hub having a centerline, a root portion and an end portion. A plurality of blades is formed around the central hub. The plurality of blades includes a group of full-blades extending from the root portion of the central hub up to a maximum distance from the root portion along the centerline, the maximum distance being adjacent the end portion of the central hub. The plurality of blades further includes a group of partial-blades, the partial-blades extending from the root portion of the hub to an area along the centerline that is between 40% and 55% of the maximum distance along the centerline, and the plurality of blades is organized in repeating sets of blades arranged around the compressor wheel, each repeating set including at least one full-blade and at least one partial-blade.

A turbocharger for use with an internal combustion engine includes a compressor wheel having a central hub having a centerline, a root portion and an end portion. A plurality of blades is formed around the central hub. The plurality of blades includes a group of full-blades extending from the root portion of the central hub up to a maximum distance from the root portion along the centerline, the maximum distance being adjacent the end portion of the central hub. The plurality of blades further includes a group of partial-blades, the partial-blades extending from the root portion of the hub to an area along the centerline that is between 40% and 55% of the maximum distance along the centerline, and the plurality of blades is organized in repeating sets of blades arranged around the compressor wheel, each repeating set including at least one full-blade and at least one partial-blade.