A cylinder head cover includes a main body and a side projection portion. The main body is provided so as to cover a cylinder head, and collects a blowby gas. The side projection portion discharges the blowby gas toward an intake passage. The cylinder head cover includes a cover gas passage through which the blowby gas flows from a main body gas passage to an outlet of the side projection portion. A minimum passage cross-sectional area portion of the cover gas passage is provided not in the side projection portion but in the main body gas passage. The main body has a hole or a projection branch passage at a position of the main body gas passage that is downstream of the minimum passage cross-sectional area portion. The main body, the side projection portion, and the hole or the projection branch passage are integrally molded.

An internal combustion engine has a tank ventilation system and a crankcase ventilation system. The tank ventilation system is connectable to an intake system downstream of a throttle element via a first non-return valve in a first line and upstream of a compressor via a second non-return valve in a second line and a third non-return valve in a second sub-line. The crankcase ventilation system is connectable to the intake system downstream of the throttle element via a fourth non-return valve in a third line and upstream of the compressor via a fourth line and the third non-return valve. The intake system is connectable to the second line downstream of the throttle element at a transitional point between the second line and the second sub-line via a fifth nonreturn valve in a fifth line. A nozzle is formed at the transitional point from the fifth line to the second line and the second sub-line, and the second line opens into the nozzle downstream of the second non-return valve. A first pressure sensor for measuring the pressure in the second line is provided in the second line between the second non-return valve and the nozzle. Only a single pressure sensor is required to diagnose or detect a leak.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

A hybrid vehicle includes: a crankcase extending from a lower portion of a cylinder of an engine, the crankcase including a main body portion defining a crank chamber in which a crankshaft of the engine is accommodated, the crankcase further including a breather portion projecting upwardly from the main body portion and defining a breather chamber into which blowby gas is introduced from the crank chamber; a breather tube that introduces the blowby gas from the breather chamber into the intake passage; and a drive motor disposed rearwardly of the cylinder and mounted on a top surface of the crankcase. The breather portion has a facing surface facing an outer peripheral surface of the drive motor. The facing surface of the breather portion is shaped to conform to the outer peripheral surface of the drive motor.

The invention provides a system for ventilation of a crankcase (217) of an internal combustion engine, the system comprisingan air inlet guide (203, 212) adapted to guide air to at least one cylinder (220) of the engine,a closed circuit conduit (209) for guiding crankcase gas from the crankcase (217) to the air inlet guide (203, 212),wherein the system comprises gas detection means (2181, 2182, 2183) positioned in the air inlet guide (203, 212), for detecting crankcase gas in the air inlet guide.

A system for recirculating blow-by gases into an air intake duct of an internal combustion engine, includes a separating device to separate oil, in a flow of blow-by gases of the engine. The separator device has an inlet for receiving blow-by gases, at least one discharge for returning the oil separated to the engine, and an outlet for clean blow-by gases. A recirculation duct connects the outlet to an air intake duct of the engine. The recirculation duct has an end connected to the intake duct by a T-connector member, with a main duct portion arranged along the intake duct and a tubular element protruding inside the main duct portion. The tubular element protruding inside the main duct portion has an annular end surface that has an irregular profile, preferably in the form of a saw-like toothed profile.

Methods and systems are provided for a ducted plenum of a positive crankcase ventilation system for an engine. In one example, the ducted plenum may include a plurality of ducts coupled to a central chamber and an oil separator and valve arranged downstream of the central chamber. The ducted plenum may vent gases from an engine crankcase and deliver the vented gases to the engine intake system.

An intake system for an internal combustion engine includes a suction duct with a lateral bulge, an exhaust gas recirculation duct with a port into the suction duct, and a crankcase breather duct which extends into the lateral bulge in the suction duct.

Provided is a connection state determination device. The connection state determination device for the breather pipe determines the connection state of a breather pipe in an internal combustion engine having a supercharger, and the breather pipe is connected between an engine body including a crank case and an intake passage on the upstream side of a compressor of the supercharger, and communicates the crank case and the intake passage. The connection state determination device includes a pipe internal pressure sensor that detects the pressure inside the breather pipe, a pulsation waveform obtaining part for obtaining pulsation due to the variation of pressure inside the breather pipe as a pulsation waveform based on the detected pressure, and a connection state determination part that determines the connection state of the breather pipe based on the pulsation waveform.

An engine including: an exhaust manifold provided near one side surface of an engine; a turbocharger having an exhaust-side inlet connected to the exhaust manifold; and a rocker-arm-chamber-integrated intake manifold disposed on a cylinder head and integrally including a rocker arm chamber and an intake manifold. The intake manifold has a wall dividing the rocker arm chamber provided near one side surface of the engine and the intake manifold provided near another side surface thereof to isolate the rocker arm chamber and the intake manifold from each other. The rocker arm chamber has, in its upper portion, a positive crankcase ventilation device protruding therefrom and returning blowby gas to an intake system. The positive crankcase ventilation device has a blowby-gas discharge port connected with a gas conduit through which blowby gas is delivered to an intake-side inlet of the turbocharger.