During a predetermined operation state in which the opening degree of a throttle valve is fixed, an air flow meter positioned more on the upstream side than a pressure control valve detects a first intake air amount when the opening degree of the pressure control valve positioned on the upstream side of the throttle valve is set to a predetermined first valve opening degree and a second intake air amount when the opening degree of the pressure control valve is set to a predetermined second valve opening degree smaller than the first valve opening degree. On the basis of the first intake air amount and the second intake air amount, a diagnosis is made regarding whether there is an abnormality in a first pipe, a second pipe, a third pipe and the like which are included in a blow-by gas recirculation system for blow-by gas treatment.

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.

The present invention relates to an oil tank ventilation device for a hydraulic brake unit of a tramcar, comprising a vent plug, a sealing ring, a gas guide hole and a gas guide pipe; the gas guide hole is a through-hole structure arranged at an upper end inside an integrated valve block; the communications of electrical element protection case, integrated valve block and the oil tank are realized by the gas guide pipe stretched into an air chamber of the oil tank and by the vent plug configured in the electrical element protection case. When the surface of the oil tank is covered with ice or snow, the rain or snow can be effectively prevent from falling on the vent plug body and the driving safety of the train is ensured.

Methods and systems are provided for rationalizing a hydrocarbon sensor in a hybrid vehicle, the hydrocarbon sensor used for feed-forward air/fuel ratio control during fuel vapor canister purging events. In one example, a method comprises routing blow-by gasses from a crankcase of an engine of the vehicle to an intake manifold of the engine and then to a fuel vapor storage canister, and indicating whether the hydrocarbon sensor is functioning as desired based on a magnitude of a response of the hydrocarbon sensor during the routing. In this way, the hydrocarbon sensor may be diagnosed under conditions when the canister is substantially free from fuel vapors, and where engine run-time is limited.

Methods and systems are provided for rationalizing a hydrocarbon sensor in a hybrid vehicle, the hydrocarbon sensor used for feed-forward air/fuel ratio control during fuel vapor canister purging events. In one example, a method comprises routing blow-by gasses from a crankcase of an engine of the vehicle to an intake manifold of the engine and then to a fuel vapor storage canister, and indicating whether the hydrocarbon sensor is functioning as desired based on a magnitude of a response of the hydrocarbon sensor during the routing. In this way, the hydrocarbon sensor may be diagnosed under conditions when the canister is substantially free from fuel vapors, and where engine run-time is limited.

Disclosed is a blowby gas treatment device for an internal combustion engine with a supercharger, the blowby gas treatment device comprising: a fresh air introduction passage wherein one end of the fresh air introduction passage is connected to an upstream side of the supercharger and the other end is communicated with a crankcase of the internal combustion engine; a first blowby gas passage wherein one end of the first blowby gas passage is connected to a venturi part provided in an upstream side of the supercharger in the intake passage and the other end is communicated with the crankcase; a first check valve being interposed in the fresh air introduction passage and preventing a flow from the crankcase side to the intake passage side; and a second check valve being interposed in the blowby gas passage and preventing a flow from the intake passage side to the crankcase side.

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 blow-by gas processing device includes a blow-by gas pipe through which blow-by gas flows. A peripheral wall of the blow-by gas pipe is provided with a plurality of communication holes arranged in an extending direction of the blow-by gas pipe. A farthest communication hole, which is a communication hole located farthest from a base end of the blow-by gas pipe in the extending direction among the plurality of communication holes, is provided in a distal end portion of the blow-by gas pipe. A guide wall portion is provided in a part of the peripheral wall, which is located on the opposite side of a central axis of the blow-by gas pipe from a position of the farthest communication hole. The guide wall portion approaches the blow-by gas introduced portion as the guide wall portion extends toward a distal end of the blow-by gas pipe in the extending direction.

An oil dilution rate calculation system of an internal combustion engine acquires a blowby gas flow ratio showing the ratio of the flow of blowby gas to the flow of gas to the combustion chamber and an output current of the air-fuel ratio sensor during fuel cut control in which the internal combustion engine stops the feed of fuel to the combustion chamber and at a plurality of points of time of different flows of blowby gas passing through the blowby gas passage and flowing to the downstream side of the throttle valve in the intake passage, and calculate an oil dilution rate based on the acquired blowby gas flow ratio and output current.

An internal combustion engine having an engine block, a cylinder head, a crankcase and at least one cylinder includes a crankcase ventilation line connected to at least one intake line. The crankcase ventilation line is arranged at least predominantly within the internal combustion engine, in particular within the engine block and/or within the cylinder head, thereby greatly minimizing or eliminating the potential for release of crankcase gas to the environment.