The disclosure relates to a method and a device for checking the functionality of a crankcase ventilation system of an internal combustion engine. The crankcase ventilation system includes two crankcase ventilation lines arranged between a crankcase outlet of a crankcase and an associated introduction point into an air path of the internal combustion engine, via which crankcase ventilation lines gas can be introduced from the crankcase into the air path. The method includes measuring a pressure in the crankcase, supplying the measured pressure values to a control unit, and calculating the gradient of the measured pressure. The method also includes performing a gradient check, checking whether the gradient satisfies a specified criterion, and returning to the measurement of the pressure if the gradient satisfies the specified criterion. The method also includes recording an entry in a fault memory if the gradient does not satisfy the specified criterion.

An oil decantation system for an internal combustion engine includes at least one main wall provided with a through-opening for a flow of blow-by gas and a separator device arranged downstream of said through-opening in the direction of travel of said flow of blow-by gas. The separator device includes a valve provided with a decantation component capable of retaining the oil contained in the blow-by gas and of allowing a flow of purified blow-by gas to pass through, wherein the valve is pivotably mounted on the main wall so that its inclination with respect to the main wall varies as a function of the flow of blow-by gas.

A blow-by gas leak diagnostic device includes a first PCV flow path, a second PCV flow path, a fresh air inlet, a pressure measurement unit, a first valve that opens and closes the first PCV flow path, a second valve that opens and closes the second PCV flow path, a third valve that opens and closes the fresh air inlet, a valve control unit, and a leak diagnosis unit. The valve control unit controls an opening degree of the third valve when a downstream side of an intake manifold with respect to a throttle valve has a negative pressure, and the second valve is in a closed state. The leak diagnosis unit diagnoses presence or absence of a leak in the first PCV flow path on the basis of an inner pressure of the first PCV flow path measured by the pressure measurement unit.

A blowby gas treatment device includes a pressure control valve, a fresh air induction pipe, a first blowby gas pipe, a second blowby gas pipe, a shutoff valve, a one-way valve, and a PCV valve. A leak diagnosis includes a first-stage diagnosis to determine whether or not falling of a pressure in a crank case after closing of the shutoff valve under a non-supercharging condition is normal. A second-stage diagnosis is implemented by moving the pressure control valve from a fully opened state into a fully closed state, and determining whether an intake air quantity in each state is equal to each other. When the intake air quantity in each state is equal to each other, presence of an in-system leak is determined. When a fully closed state intake air quantity is different from a fully opened state intake air quantity, presence of an out-of-system leak is determined.

A blowby gas treatment device includes a pressure control valve, a fresh air induction pipe, a first blowby gas pipe, a second blowby gas pipe, a shutoff valve, a one-way valve, and a PCV valve. A leak diagnosis includes a first-stage diagnosis to determine whether or not falling of a pressure in a crank case after closing of the shutoff valve under a non-supercharging condition is normal. A second-stage diagnosis is implemented by using an air fuel ratio feedback control, and determining whether or not a sensed intake air quantity obtained by an air flow meter is equal to an actual intake air quantity flowing into a cylinder set. When the sensed intake air quantity is equal to the actual intake air quantity, presence of an in-system leak is determined, and when the actual intake air quantity is larger, presence of an out-of-system leak is determined.

In a combustion engine, an exit stream of blow-by gases follows a fluid pathway through an oil and air separator and a breather filter, the oil and air separator including a first housing including a central chamber therein, the central chamber divided into a first outer portion and a second inner portion by a barrier; a filter material disposed between the first outer portion and the second inner portion; a cap directly coupled to the first housing, the cap including a first lumen therethrough, the first lumen including a first end disposed at the second inner portion; and a coupler removably coupling the cap and an extension portion including a second lumen therethrough.

The ventilator-equipped engine is configured to: guide a blow-by gas generated in a crankcase to an intake passage through an inside of a cylinder head, an inside of a head cover, and a pressure regulating valve; and to directly introduce fresh air into an internal space of the cylinder head by providing a fresh air introduction passage that extends across the intake passage and the cylinder head.

An electromagnetic valve includes a solenoid with a bobbin, a plunger, a yoke, and a coil, a flow path assembly including a first flow path, a second flow path, and a valve housing portion, and a valve that switches between an open state and a closed state between the first flow path and the second flow path. The plunger includes a passage that extends along an axial direction, and that opens toward another axial side to communicate with a gap between the plunger and the yoke, and an opening that opens radially outward from the passage to allow the passage communicating with the gap to communicate with the valve housing portion through the passage. The electromagnetic valve further includes a regulator to regulate a radially outward flow of a fluid flowing out from the passage into the gap at least in the open state.

An internal combustion engine having a crankcase with a base and an oil tank, wherein a first connection between the crankcase and the oil tank is formed with a first valve, which is open in the direction from the crankcase to the oil tank and closed in the opposite direction, and a second connection between the crankcase and the oil tank is formed with a second valve, which is open in the direction from the oil tank to the crankcase and is closed in the opposite direction. The first valve is arranged on the base of the crankcase and the second valve is arranged above the first valve.

In a recirculation valve, a first support target portion receives a biasing force of a biasing member on a first stepped surface and moves to one side in an axial direction, such that a first opening is blocked. The first support target portion moves to the other side in the axial direction against a biasing force of the biasing member due to a negative pressure on a downstream side with respect to an upstream side, such that the first opening opens.