An intake system of an engine supplies gas at least containing fresh air to each cylinder. The system includes an EGR passage that communicates with an internal space of a downstream intake passage and introduces some EGR gas into the downstream intake passage. The EGR passage includes a projected section in a substantially polygonal or cylindrical shape that is projected to the internal space of the downstream intake passage. The projected section is formed in such a shape that a projection length H1 in an outer circumferential surface on an upstream side is longer than a projection length H2 in an outer circumferential surface on a downstream side.

An electrically controlled pneumatic surge prevention device includes a controller, an air filter, a turbocharger, an intercooler, a throttle valve, air pipes, an electromagnetic valve connected using signals to the controller, and a surge prevention valve connected to the electromagnetic valve. The surge prevention valve is connected to a sixth air pipe connecting the intercooler and the throttle valve via a fourth air pipe. The electromagnetic valve is arranged at a third air pipe, and the surge prevention valve is connected to a second air pipe connecting the air filter and the turbocharger via the third air pipe. Also provided is a control method of an electrically controlled pneumatic surge prevention device.

A high altitude air start equipment for an aircraft reciprocating engine includes: a compressor configured to suck and compress air, and supply the compressed air to the aircraft reciprocating engine; and a motor configured to supply the compressed air to the reciprocating engine to restart the reciprocating engine or to restore output by outputting rotational power to the compressor when the reciprocating engine stops or malfunctions during flight of the aircraft.

The intake manifold includes an intake air introduction port, a surge tank and a plurality of intake pipes. The intake air introduction port is connected to one end side of the surge tank in a direction in which the intake pipes are arranged. The surge tank is provided with a stepped portion over the direction in which the intake pipes are arranged. The stepped portion has an erected wall erected from a surface of the surge tank and connected to the plurality of intake pipes, and a curved wall connecting a tip side of the erected wall and the surface of the surge tank. Further, the surge tank is provided with a concave portion recessed toward the stepped portion at an intermediate portion in the direction in which the intake pipes are arranged.

Techniques for controlling a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system comprise determining a desired differential pressure (dP) at an inlet of a boost device based on an engine mass air flow (MAF) and a speed of the engine, wherein the engine further comprises a dP valve disposed upstream from an EGR port and a throttle valve disposed downstream from the boost device, determining a desired EGR mass fraction based on at least the engine MAF and the engine speed, determining a maximum throttle inlet pressure (TIP) based on the engine speed, the desired EGR mass fraction, and a barometric pressure, and performing coordinated control of the dP valve and the throttle valve based on the desired dP and the maximum TIP, respectively, thereby extending EGR operability to additional engine speed/load regions and increasing engine efficiency.

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).

Techniques for controlling a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system comprise determining a desired differential pressure (dP) at an inlet of a boost device based on an engine mass air flow (MAF) and a speed of the engine, wherein the engine further comprises a dP valve disposed upstream from an EGR port and a throttle valve disposed downstream from the boost device, determining a desired EGR mass fraction based on at least the engine MAF and the engine speed, determining a maximum throttle inlet pressure (TIP) based on the engine speed, the desired EGR mass fraction, and a barometric pressure, and performing coordinated control of the dP valve and the throttle valve based on the desired dP and the maximum TIP, respectively, thereby extending EGR operability to additional engine speed/load regions and increasing engine efficiency.

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.

An electrically controlled pneumatic surge prevention device includes a controller, an air filter, a turbocharger, an intercooler, a throttle valve, air pipes, an electromagnetic valve connected using signals to the controller, and a surge prevention valve connected to the electromagnetic valve. The surge prevention valve is connected to a sixth air pipe connecting the intercooler and the throttle valve via a fourth air pipe. The electromagnetic valve is arranged at a third air pipe, and the surge prevention valve is connected to a second air pipe connecting the air filter and the turbocharger via the third air pipe. Also provided is a control method of an electrically controlled pneumatic surge prevention device.

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).