A supercharged internal combustion engine has a supercharger operable to selectively supply a mass of air from below through above atmospheric air pressure according to the operating requirements of the engine. The supercharger has a shuttle combined with a throttle valve that controls the mass of air directed to an air mass bypass opening and supplied to the internal combustion engine. The shuttle has rollers that ride on rails that allow the shuttle to move to open and close the air mass bypass opening in communication with a casing that directs a mass of atmospheric air and a bypass mass of air interfused with the mass of atmospheric air to an air mass inlet of the supercharger.

A control apparatus for an internal combustion engine with a supercharger includes a boost-pressure detector. When first boost pressure control to control the supercharger such that a boost pressure reaches a target pressure starts, starts, the target pressure is set to an initial target pressure, gradually at a first rate, and then gradually increased to a steady-state target boost pressure at a second rate smaller than the first rate if the boost pressure is equal to or higher than a threshold pressure. Second boost pressure control is performed such that the boost pressure reaches a steady-state target boost pressure. Inhibiting/allowing circuitry is configured to inhibit execution of the first boost pressure control and allow execution of the second boost pressure control if the boost pressure is lower than the steady-state target boost pressure and if the steady-state target boost pressure is lower than the threshold pressure.

An electronic control unit is configured to select a first cam as a driving cam of an intake valve in a first operation range where a target value of an EGR rate is set to a specified EGR rate, and is configured to select a second cam as the driving cam in a second operation range smaller in valve duration and lift amount than the first cam. Accordingly, in most of the operation regions, the first cam is selected, and the second cam is selected only in a high-torque and high-speed region. When the second cam is selected in the high-torque and high-speed region, the state where an actual compression ratio is high can be eliminated, and suction efficiency can be decreased. Therefore, decrease in a knocking limit can be suppressed.

For example, during an acceleration transient period of time during which a demand load is raised, a supercharging pressure is raised before a mechanical compression ratio is lowered and an internal combustion engine falls in a high load state. At this time, there is a possibility that a generation of knocking and an excessive rise in a cylinder inner pressure occur. This possibility is a task to be solved. The internal combustion engine includes: a variable compression ratio mechanism which is capable of modifying the mechanical compression ratio; a turbo charger (2) which supercharges intake air utilizing an exhaust energy; and an exhaust bypass valve (7) which adjusts a supercharging pressure as a supercharging pressure adjustment mechanism. The mechanical compression ratio is detected by a control shaft sensor (34) and the supercharging pressure is limited on a basis of this mechanical compression ratio.

The present disclosure relates to dual compression engine boosting systems utilizing both a turbocharger and a supercharger and control systems relating to relative activation and deactivation of the boosting devices. Various Exhaust Gas Recirculation (EGR) configurations are also disclosed for the dual compression engine boosting systems.

A reciprocating compressor. A hollow cylinder tube contains a piston assembly having two pistons connected by a piston rod. At each end of the cylinder tube is an outer chamber between an end plate and an outer end of the proximate piston. These two outer chambers and the outer ends of the pistons define a power cylinder at each end of the cylinder tube. In the mid-portion of the cylinder tube, a center divider is situated between the pistons and has an aperture that allows the piston rod to reciprocate through it. The two inner chambers formed thereby and the inner ends of the pistons define two compression cylinders in the mid-portion of the cylinder tube. The two compression chambers share a suction manifold and a discharge manifold, but have independently operating suction and discharge valves.

A supercharged internal combustion engine has a supercharger operable to selectively supply a mass of air from below through above atmospheric air pressure according to the operating requirements of the engine. The supercharger has a shuttle combined with a throttle valve that controls the mass of air directed to an air mass bypass opening and supplied to the internal combustion engine. The shuttle has rollers that ride on rails that allow the shuttle to move to open and close the air mass bypass opening in communication with a casing that directs a mass of atmospheric air and a bypass mass of air interfused with the mass of atmospheric air to an air mass inlet of the supercharger.

A supercharged internal combustion engine has a supercharger operable to selectively supply a mass of air from below through above atmospheric air pressure according to the operating requirements of the engine. The supercharger has a shuttle combined with a throttle valve that controls the mass of air directed to an air mass bypass opening and supplied to the internal combustion engine. The shuttle has rollers that ride on rails that allow the shuttle to move to open and close the air mass bypass opening in communication with a casing that directs a mass of atmospheric air and a bypass mass of air interfused with the mass of atmospheric air to an air mass inlet of the supercharger.

A rotary unit is rotatably accommodated within a supercharger casing of a supercharger for pressurizing an intake air of an engine. The rotary unit includes a supercharger rotary shaft, an impeller fixed to a tip end portion of the supercharger rotary shaft, a rotating component rotatable together with the supercharger rotary shaft independently of the impeller, and a nut member for pressing the impeller and the rotating component in a direction axially of the supercharger rotary shaft to thereby fix them to the supercharger rotary shaft. The nut member is formed with an adjustment portion for the rotational balance adjustment.

Packaged boost systems and electrical assist assemblies presented. In one example, packaged boost system includes a supercharger, a brake assembly, and a transmission assembly that are packaged together in a generally axisymmetric configuration. In one example, a packaged electrical assist assembly includes a supercharger, a transmission assembly, and a brake assembly that are packaged together in a generally axisymmetric configuration.