An intake passage structure for a turbocharger-equipped engine (1) includes a supercharging passage (71) and an air relief passage (72) provided in a compressor case (21a). The air relief passage (72) has an air outflow port (72a) formed through an inner wall surface of an upstream portion (71a) of the supercharging passage (71) upstream of the compressor (21). A projecting member (91) projecting radially inward of a specific portion (90) is provided on a portion of an inner wall surface of the specific portion (90) in a circumferential direction of the inner wall surface. The specific portion (90) ranges from a downstream portion of an upstream intake passage (32) to a portion of the supercharging passage (71) upstream of the air outflow port (72a).

An intake passage structure for a turbocharger-equipped engine (1) includes a supercharging passage (71) and an air relief passage (72) that are provided in a compressor case (72a). The air relief passage (72) has a first passage (73) and a second passage (74), each of which is in a non-linear shape. The first and second passages (73) and (74) each have an air outflow port (73a, 74a) formed through an inner wall surface of an upstream portion (71a) of the supercharging passage (71) upstream of a compressor (21). The air outflow ports (73a, 74a) are formed through different portions of the inner wall surface in a circumferential direction of the inner wall surface so as to overlap with each other in a direction along a central axis of the upstream portion (71a).

A method for operating an internal combustion engine is provided, wherein the internal combustion engine has at least one combustion engine and a fresh gas line and wherein a compressor, to which a trim adjuster is assigned, is integrated into the fresh gas line, said trim adjuster by which an edge section of the inlet cross section of a compressor wheel can be covered to a variable extent. In this case, the edge section of the inlet cross section is covered relatively little in a release position of the trim adjuster and covered relatively greatly in a covering position of the trim adjuster. It is provided that the trim adjuster is adjusted between the release position and the covering position, when substantially the same compressor pressure ratio and substantially the same fresh gas mass flow and substantially the same compressor efficiency are achieved in both operating positions.

A method of operating a motor vehicle having an internal combustion engine, wherein the internal combustion engine has at least one combustion engine which is connected by a rotary drive via a transmission and optionally a clutch with powered wheels of the motor vehicle, and further comprises a fresh gas line, and wherein in the fresh gas line, a compressor is integrated, which is associated with a trim controller, by means of which an edge-side portion of the inlet cross section of a compressor impeller of the compressor is coverable to a variable extent. In this case, in a release position of the trim controller, the edge-side portion of the inlet cross section is covered relatively little, preferably the least possible, and in a covering position of the trim controller, is mostly covered, preferably as much as possible.

A method of operating an internal combustion engine, wherein the internal combustion engine has at least one combustion engine, a fresh gas line, and a compressor integrated in the gas line, which is associated with a trim controller, via which an edge-side portion of the inlet cross section of a compressor impeller of the compressor is coverable to a variable extent. In this case, in a release position of the trim controller, the edge-side portion of the inlet cross section is covered relatively little, and in a covering position of the trim controller, is mostly covered. It is provided that in a transition from a traction mode of the combustion engine, in which the trim controller is in the release position, the trim controller is adjusted to an overrun mode of the combustion engine into the covering position. As a result, a so-called discharge hissing can be prevented or minimized.

When the forced induction mode is a single forced induction mode, and when it is determined that there is a request for switching to a twin forced induction mode, the control device executes a process including the step of executing an approach-run operation, the step of executing a control for equalizing the VN opening degree, and the step of switching to the twin forced induction mode when it is determined that a second boost pressure has reached a first boost pressure.

A control system and method for an engine including a turbocharger without a surge valve involve utilizing one or more pressure sensors configured to measure air pressure in an intake system of the engine, the intake system comprising a compressor of the turbocharger and a throttle valve downstream from the compressor, and a controller configured to control the engine to avoid surge at the compressor and eliminate a need for the surge valve by determining a desired position for the throttle valve based on a driver requested engine torque, determining a minimum mass flow through the compressor that avoids surge based on the measured air pressure in the intake system and a predetermined compressor map, and commanding the throttle valve to a target position to maintain at least the minimum compressor mass flow, wherein the target position is greater than the desired position, thereby avoiding surge at the compressor.

Methods and systems are provided for adjusting an active casing treatment of a compressor responsive to a predicted engine condition. In one arrangement, a controller may actuate a sleeve of a variable geometry compressor casing to a position selected based on each of a compressor pressure ratio and a mass flow through the compressor, as well as driver behavior and predicted road conditions; and adjust each of an EGR actuator and a boost actuator based on the selected position to maintain the compressor pressure ratio during the actuating.

Methods and systems are provided for controlling a turbocharged engine. In one arrangement, a method may include concurrently adjusting an exhaust recirculation gas flow and a turbine flow while adjusting geometry of a compressor to compensate for disturbance caused by the compressor adjustment.

A method of preventing surge for a vehicle may include detecting, by a controller, whether tip-out of an accelerator pedal is detected, comparing, by the controller, a difference value, obtained by subtracting an exhaust pressure from an intake pressure in a combustion chamber of an engine, with a predetermined reference value when the tip-out of the accelerator pedal is detected, driving, by the controller, a supercharger disposed at the rear end portion of a turbocharger at a predetermined number of revolutions per minute, which is lower than a normal number of revolutions per minute, when the difference value is greater than the reference value, and opening a bypass valve, which performs opening or closing operation and is disposed in a bypass line that diverges from an upstream point of the supercharger and is connected to a downstream point of the supercharger.