A control device is provided capable of reliably preventing occurrence of a surging state by judging a possibility of the surging state in a relatively easy manner and promptly executing a surging state avoidance control. When a supercharging pressure decreasing state in which a target supercharging pressure decreases is detected, an operating speed of a wastegate valve is determined based on a detected engine rotational speed. That is, by lowering the operating speed as the engine rotational speed lowers, reduction in flow rate of the air passing through a compressor is prevented, and the occurrence of the surging state is reliably prevented. By lowering the operating speed instead of changing a target opening degree of the wastegate valve, a maximum opening degree of the wastegate valve can be suppressed, and responsiveness in the case where an acceleration request is made immediately after deceleration of an engine can be improved.

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).

Methods and systems are provided for a boosted internal combustion engine. In one example, a system may include an intake system for supplying charge air, a compressor arranged in the intake system, a first shut-off element arranged in the intake system upstream of an impeller of the compressor, a bypass line that branches off from the intake system upstream of the first shut-off element and that rejoins the intake system upstream of the impeller, a second shut-off element arranged in the bypass line, a compressed air line that opens into the bypass line downstream of the second shut-off element, and a third shut-off element arranged in the compressed air line. A map width of the compressor may be increased by providing airflow to the impeller via the bypass line during low mass flow conditions, and impeller acceleration may be expedited by providing compressed air via the compressed air line.

A control apparatus of a supercharging system for supplying an engine with compressed intake air, includes: a supercharger including a compressor configured to compress the intake air to be supplied to the engine; and a controller for controlling a control device affecting operation of the compressor. The controller includes: a compressor map storage part configured to store a compressor map which indicates a relationship of an intake volume flow rate, a pressure ratio, and a compressor rotation speed in the compressor; a current position calculation part configured to calculate a current position of an operational point of the compressor on the compressor map every predetermined period; a moving direction calculation part configured to calculate a moving direction of the operational point on the compressor map on the basis of the current position of the operational point calculated by the current position calculation part; and a control part configured to control the control device on the basis of the current position of the operational point calculated by the current position calculation part and the moving direction of the operational point calculated by the moving direction calculation part.

An engine system incorporating an intake manifold, a compressor, and a controller. The compressor may provide air to the intake manifold and the controller may be connected to the intake manifold and the compressor. The controller may receive a control signal and control air flow from the compressor to the intake manifold based on the received control signal. The controller may control the air flow from the compressor to the intake manifold based on a first equation when a value related to the control signal is on a first side of a threshold and according to a second equation when the value is on a second side of the threshold. The controller may control the air flow between the compressor and intake manifold according to the second equation to prevent the compressor from operating at a surge condition when controlling the air flow according to the first equation.

A surge avoidance control method that includes a surge detection step of determining whether the operation point of the compressor is positioned in a surge operation region at each predetermined timing; a surge avoidance opening-degree calculation step calculating a surge avoidance opening degree of the operation device necessary for moving the operation point of the compressor determined to be positioned in the surge operation region in the surge detection step out of the surge operation region; a correction opening-degree calculation step calculating a correction opening degree of the operation device on the basis of a moving velocity of the operation point of the compressor which is determined to be positioned in the surge operation region in the surge detection step; and an opening-degree command value calculation step calculating an opening-degree command value of the operation device on the basis of the surge avoidance opening degree and the correction opening degree.

The invention relates to a method of controlling engine derating of an internal combustion engine (10) being provided with a turbocharger (110) and a variable inlet guide vanes assembly (130) arranged upstream a compressor (120) of the turbocharger (110). The method comprises determining a current operational condition requiring engine derating, detecting a current operational condition of the compressor (120), and controlling the position of the variable inlet guide vanes assembly (130) based on the detected operational condition of the compressor (120).

In an internal combustion engine with exhaust gas turbochargers which operate in parallel and of which at least one can be switched on and off by a charge air duct blocking arrangement including a charge air duct blocking element, the charge air duct blocking arrangement is adapted to provide for a certain movement characteristic of the charge air duct blocking element resulting in a slower movement of the charge air duct blocking element resulting in a longer duration for the air duct blocking element to reach its open position and a faster movement during closing resulting in a rapid closing of the charge air duct blocking element.

Various methods and systems are provided for detecting surge of a turbocharger during engine operation. As one example, a system includes an engine coupled to a low pressure turbocharger and a high pressure turbocharger; and a controller with non-transitory instructions stored in memory that when executed during operation of the engine cause the controller to: indicate an occurrence of surge of the high pressure turbocharger in response to a deviation of a modeled speed of the high pressure turbocharger from a measured speed of the high pressure turbocharger by a threshold amount, where the modeled speed tracks the measured speed during non-surge conditions, as engine operating conditions change.

A pressure relief valve is provided. The pressure relief valve includes a hollow body having an inlet and an outlet, with the hollow body including at least one aperture extending through a surface of the hollow body. An actuator assembly is attached to the hollow body and a sleeve is slideably positioned about the hollow body, with the sleeve moveably attached to the actuator assembly. During operation, the actuator assembly moves the sleeve from a first position that covers the aperture to a second position that un-covers at least a portion of the aperture.