A blow-by gas treating device has an oil separator. A tubular attachment portion is disposed at a discharge port of the oil separator. A PCV valve is inserted in the attachment portion. The PCV valve includes an inflow hole, a discharge hole, a flow rate regulating portion, and a stopping portion. The stopping portion is located closer to the inflow hole than to the flow rate regulating portion. The stopping portion has a dimension greater than the inner diameter of the attachment portion in a direction perpendicular to the central axis of the attachment portion. The flow rate regulating portion is surrounded by the attachment portion. The stopping portion is arranged in the space defined by the oil separator.

The invention relates to a method for controlling the oil pressure of an oil pump (40, 140) in a combustion engine (100). The combustion engine (100) comprises a crankcase (11) and a separator (14, 114) for separating oil present in a blow-by gas from the crankcase (11). The method comprises the step (201) of providing oil pressure demand for a set of different engine operation conditions, the oil pressure demand defining the theoretical required oil pressure of the oil pump (40, 140); the step (203) of controlling the oil pressure of the oil pump (40, 140) based on the oil pressure demand for at least one engine operation condition in the set of different engine operation conditions; the step (205) of driving the separator (14, 114) using oil from the oil pump (40, 140), the oil being pressurized based on the oil pressure demand.

An internal combustion engine may be used to compress natural gas for vehicle fuel. The engine may contain a plurality of gas compression cylinders, at least one standard combustion cylinder to drive the compression cylinders, and a common crankshaft in a crankcase coupling the compression cylinders and the at least one standard combustion cylinder. Some combustible gas being compressed may leak past the piston rings of the compression cylinders into the engine crankcase posing a safety concern. This invention eliminates this concern by actively flushing the crankcase at a higher rate than normal.

Provided is a bi-directional PCV valve assembly, system and method. The bi-directional PCV valve may include a fluidic geometry that allows for a flow of fluid a high flow rate in one direction, forward flow, and a low flow rate in the opposite direction, reverse flow. The reverse flow includes a swirling flow that increases the pressure drop and reduces the flow rate to a third of the flow rate of the forward flow. The disclosed assembly produces a strong swirling flow (vortex) in the reverse direction and an efficient (low pressure drop) flow in the forward direction.

A positive crankcase ventilation gas diversion and reclamation system comprises a positive crankcase ventilation gas diversion line to divert oil laden positive crankcase ventilation gases from the air intake manifold of an internal combustion engine. A positive crankcase ventilation gas diversion line directs oil laden positive crankcase ventilation gases into a vapor headspace of a fuel tank. A pressure sensor measures a vapor pressure in a vapor headspace of a fuel tank, and a fuel tank vent valve is operative with a fuel tank vent line. A controller actuates the fuel tank vent valve into an open position and discharges fuel enriched vapor to the air intake manifold of the internal combustion engine. A method permits diverting positive crankcase ventilation gasses from the air intake manifold of an engine, and reclaiming oil laden fuel components and/or particulates from positive crankcase ventilation gasses.

Restrictors are disclosed that include a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof, and with the converging inlet cone and the diverging outlet cone each defining an inner passageway that transitions as a hyperbolic or parabolic function toward the throat.

The invention relates to an internal combustion engine, comprising an intake path, a crankcase, an exhaust gas path and a crankcase ventilation means, wherein the crankcase ventilation means is open, closed or separate. The internal combustion engine according to the invention comprises an intake path, a crankcase, an exhaust gas path and an open crankcase ventilation means, wherein the open crankcase ventilation means comprises a first line and a second line, wherein the first line is designed to connect the exhaust gas path to the crankcase in order to guide exhaust gas out of the exhaust gas path to the crankcase, and wherein the second line is designed to connect the crankcase to the exhaust gas path in order to discharge exhaust gas and leakage gases located in the crankcase from the crankcase and to feed them to the exhaust gas path.

A diagnosis device is intended for an internal combustion engine including a supercharger, a blow-by gas passage that communicates between a portion of an intake passage and a crankcase, a PCV pressure sensor that detects a PCV pressure in the blow-by gas passage, and a crankshaft. The device executes specifying a specific period for which the amount of fluctuations in the intake air amount per unit time is a prescribed value or more on condition that the intake air amount is a determination air amount or more, calculating the amount of fluctuations in the PCV pressure during the specific period, and determining, based on the amount of fluctuations in the PCV pressure, the presence of an abnormality in the blow-by gas passage. The device sets the determination air amount to a smaller value when the rotational speed of the crankshaft is high than when the rotational speed is low.

Disclosed is a new air intake system of an engine including a blow-by gas flow line configured to allow blow-by gas to flow into an intake manifold by recirculating the blow-by gas using a pressure difference according to load of the engine, an intake gas supply line configured to allow intake gas to flow therethrough, the intake gas supply line including a throttle valve configured to control an amount of the intake gas and a turbocharger configured to compress the intake gas, a new air supply line branched from the intake gas supply line and connected to the crankcase, the new air supply line allowing new air to selectively flow into the crankcase, and a new air bypass line configured to allow, when a part of the intake gas is selectively bypassed by the pressure difference, the part of the intake gas to flow into the crankcase.

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.