An internal combustion engine includes a blow-by gas treating device. The blow-by gas treating device includes a separator having a line connection portion. The line connection portion includes an intake connection union, to which an intake connection line is attached, a sensor connection union, to which a pressure sensor is connected, a partition plate, which divides the space in the separator into a first space and a second space, and a constriction, which is provided in the partition plate and allows the first space and the second space to communicate with each other. The line connection portion is constituted by combining a first unit, which includes the partition plate and defines the first space, and a second unit, which defines the second space with the partition plate of the first unit. The intake connection union and the sensor connection union are provided in the second unit.

An abnormality assessment device includes an on-off valve that shuts an intake path on an upstream side of a connection portion of a breather line with respect to the intake path and an abnormality assessment element that assesses abnormality of the breather line. The abnormality assessment element assesses abnormality of the breather line based on a difference between an intake flow rate that is detected by an intake flow rate sensor and a target intake flow rate in a case where the on-off valve is closed.

A utility vehicle includes: an engine which is a drive source; a catch tank configured to perform a gas-liquid separation of a blow-by gas generated in the engine; a first breather passage configured to deliver the blow-by gas, which is discharged from the engine, to the catch tank; a second breather passage configured to supply a gas component, which has been separated in the catch tank, to an air intake system of the engine; and a return passage configured to return a liquid component, which has been separated in the catch tank, to the engine. The catch tank is disposed above a cylinder head covering. A breather outlet port, with which the first breather passage is fluid connected, and an oil return port, with which the return passage is fluid connected, are formed in an upper surface of the cylinder head covering.

An intake manifold may include a manifold inlet connected with an intake line into which fresh air flows and a recirculation line into which exhaust gas recirculation (EGR) gas flows; a manifold pressure sensor for measuring pressure of fluid flowing through the manifold inlet; and a sensor housing fluidly communicating with the manifold inlet and including a mounting space in which the manifold pressure sensor is mounted.

An active fuel vapor purge system includes: a turbocharger having a turbine and a compressor; a canister collecting fuel vapor; a purge pump pumping the collected fuel vapor; a main purge line connecting the canister and the purge pump; a first purge line branched from the main purge line and joined to an intake manifold at downstream of the compressor; a second purge line branched from the main purge line and jointed to an intake line at upstream of the compressor; purge control solenoid valves respectively disposed in the first purge line and the second purge line; a hydrocarbon sensor measuring an amount of hydrocarbon; a pressure sensor measuring an upstream pressure and a downstream pressure of the purge pump; and a controller controlling operation of the purge pump based on the amount of hydrocarbon and pressures at a front end and at a rear end of the purge pump.

A vehicle gas processing device is configured to supply gas generated by a vehicle to an intake pipe of a combustion engine. The device may includes: a gas pipe configured to communicate a gas generation source to the intake pipe, the gas pipe having a flexible end at least at an intake pipe side of the gas pipe; a check valve disposed between the intake pipe and the gas pipe, and configured to allow the gas to flow from the gas pipe toward the intake pipe and prohibit the gas to flow from the intake pipe toward the gas pipe; and a determining unit configured to determine that the gas pipe is detached from the check valve. The check valve is fixed to the intake pipe, and the gas pipe is detachably attached to the check valve.

A method for manufacturing a waterproof felt duct may include (a) laminating a waterproof film on one side of a first nonwoven fabric and laminating a second nonwoven fabric on the waterproof film laminated on the first nonwoven fabric to form a laminated body; (b) forming a waterproof felt base material by thermally adhering the laminated body; (c) cutting the waterproof felt base material into a desired shape; (d) molding a duct while surrounding the waterproof felt base material cut into the desired shape around the external surface of a molding jig having a worm gear shape; (e) heat-treating the molded duct; (f) cooling the heat-treated duct; and (g) ejecting the cooled duct from the molding jig.

A secondary air injection system may include an engine that includes a plurality of cylinders that generate a driving torque of a vehicle by combustion of a fuel; a main line connected to an exhaust manifold or an exhaust line which is connected to the plurality of cylinders; a recirculation line which is branched from the main line and then connected to an intake manifold; an air injection line which is branched from the main line and then connected to an intake line; and an electric supercharger which is provided in the intake line.

An engine assembly includes an engine, an intake assembly, and an air-oil separator. The engine defines a combustion chamber and a crankcase. The intake assembly includes an intake manifold wherein the intake manifold is in fluid communication with the combustion chamber. The air-oil separator defines an internal passageway having a separator volume and further defining an inlet and outlet in fluid communication with the separator volume. The inlet of the air-oil separator may be in fluid communication with the crankcase while the outlet of the air-oil separator may be in fluid communication with the intake manifold. The air-oil separator further includes a fine separator disposed across the internal passageway proximate to the inlet wherein the fine separator includes a curved backplate and a front plate.

An internal combustion engine includes a blow-by gas treating device. The blow-by gas treating device includes a separator having a line connection portion. The line connection portion includes an intake connection union, to which an intake connection line is attached, a sensor connection union, to which a pressure sensor is connected, a partition plate, which divides the space in the separator into a first space and a second space, and a constriction, which is provided in the partition plate and allows the first space and the second space to communicate with each other. The line connection portion is constituted by combining a first unit, which includes the partition plate and defines the first space, and a second unit, which defines the second space with the partition plate of the first unit. The intake connection union and the sensor connection union are provided in the second unit.