A switching membrane for a pressure control valve has a plate-shaped flat body with a central area and a bending area surrounding the central area. The central area is provided with a closure area. For switching the switching membrane, the central area can be moved back and forth by a bending movement of the bending area in a direction transverse to an extension of the central area. At least the bending area is made of fluorocarbon rubber. A pressure control valve, especially for crankcase ventilation, is provided with a valve housing that has a housing cover and further is provided with a valve seat. A switching membrane as described above is disposed in the valve housing and switches at pressure differences of at most 500 mbar to release or shut off a flow of fluid at the valve seat.

A learned neural network learned in weights using an engine load, an engine speed, and an intake pressure inside the engine intake passage downstream of the throttle valve (19) as input parameters of the neural network and using leakage of blow-by gas from a blow-by gas feed path (20) as a truth label is stored. At the time of operation of the vehicle, the learned neural network is used to detect the abnormality of leakage of blow-by gas from the blow-by gas feed path (20) from the above input parameters.

A method of removing oil from blowby vapors in an engine having a crankcase and an intake manifold includes filtering the blowby vapor from the engine crankcase to form a vapor depleted of oil and a collected oil. The vapor depleted of oil is communicated to the engine manifold. At high engine loads the collected oil is held in a chamber, and at low engine loads while the engine is still running, the collected oil is forced from the chamber back the crankcase.

A separator device for a system for recirculation of the blow-by gases of an internal combustion engine includes a casing containing a separation chamber and having an inlet for communication with the engine crankcase and an outlet for communication with the engine intake manifold, and drainage outlets ending in the engine crankcase, for returning the liquid separated in the separation chamber into the engine crankcase. Actuator means sensitive to pressure in the engine crankcase are associated to the inlet and to the drainage outlets so that when the pressure in the engine crankcase is higher than the pressure in the separator device, the inlet is open and the drainage outlets are closed, while when the pressure in the engine crankcase is lower than the pressure in the separator device, the inlet is closed and the drainage outlets are open.

An internal combustion engine for an automotive vehicle has an intake manifold receiving fresh air via an inlet duct. The engine includes a crankcase. A turbocharger is provided having a compressor with an inlet coupled to the inlet duct and an outlet coupled to the intake manifold. A first vent line couples the crankcase with the compressor inlet. A second vent line couples the crankcase with the compressor outlet and intake manifold. The second vent line has a valve blocking air flow into the crankcase and allowing air flow out from the crankcase. The first vent line comprises a dual-acting valve having a first flow capacity into the crankcase and a second flow capacity out from the crankcase which is greater than the first flow capacity. Thus, crankcase ventilation is optimized for both engine idle and high engine load conditions.

An internal combustion engine for an automotive vehicle has an intake manifold receiving fresh air via an inlet duct. The engine includes a crankcase. A turbocharger is provided having a compressor with an inlet coupled to the inlet duct and an outlet coupled to the intake manifold. A first vent line couples the crankcase with the compressor inlet. A second vent line couples the crankcase with the compressor outlet and intake manifold. The second vent line has a valve blocking air flow into the crankcase and allowing air flow out from the crankcase. The first vent line comprises a dual-acting valve having a first flow capacity into the crankcase and a second flow capacity out from the crankcase which is greater than the first flow capacity. Thus, crankcase ventilation is optimized for both engine idle and high engine load conditions.

To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

A leakage detection device detects leakage in a PCV passage that at least includes a scavenging line that communicates between a crank chamber of an engine and a portion of an intake passage of the engine that is on a downstream side of a throttle valve and a fresh air line that communicates between the crank chamber and a portion of the intake passage that is on an upstream side of the throttle valve. The leakage detection device includes a pressure measurement, a first valve and a leakage determination unit. The pressure measurement unit measures pressure in the PCV passage. The first valve opens/closes the fresh air line. The leakage determination unit determines presence or absence of leakage in the PCV passage on a basis of the pressure in the PCV passage at a time when the first valve is closed.

Disclosed is a method for detecting disconnection of a closed breather 18 separating and recovering oil mist from blow-by gas 17 extracted from an engine 1 to return the blow-by gas through a gas return pipe 19 to an intake pipe 5. Under condition of no exhaust gas 9 recirculation being conducted, a mass flow rate of in-cylinder working gas is calculated based on a boost pressure, an intake temperature of an intake manifold 7 and a rotational frequency of the engine, and whether the calculated mass flow rate is divergent from a value detected by an air flow sensor 24 is determined. When determined to be divergent, the divergence in a last determination is compared with a current divergence; if difference between the divergences is beyond a predetermined range, the gas return pipe 19 is determined to be in disconnection from the intake pipe 5.

This blow-by gas system is provided with: a blow-by gas flow path through which a blow-by gas discharged from an internal combustion engine passes; and an oil separator disposed midway along the blow-by gas flow path. A downstream end of the blow-by gas flow path connects to at least one of a predetermined portion of an intake passageway and a midway portion of an air introduction passageway. The predetermined portion is a portion at which at least some of the blow-by gas that has flowed into the intake passageway flows into the air introduction passageway together with an intake air in the intake passageway.