A blowby gas return apparatus is provided that achieves inhibition of condensation of water vapor in blowby gas in branched return passages. A blowby gas return apparatus that returns blowby gas generated in an engine having a plurality of cylinders to an intake system of the engine includes a distribution portion inside a head cover of the engine, and distributes the blowby gas to intake paths of the cylinders. The distribution portion includes an introduction portion through which the blowby gas is introduced and a plurality of branch passages communicating with the introduction portion, plurality of branch passages branching from the introduction portion to communicate with the intake paths.

An apparatus and a method are provided for a crankcase breather vent assembly to direct blow-by gases out of an engine crankcase. A vent base comprising a generally cylindrical vessel communicates received blow-by gases into an interior cavity of a breather vent that comprises a filter medium. Baffles disposed within an interior cavity of the vent base capture oil carried along with the blow-by gases. The captured oil is directed to an oil sump of the engine by way of a suitable hose. A bonnet fastenably receives the breather vent and is configured to reduce a buildup of oil residue on nearby engine components. An outer profile of the breather vent is tapered along a longitudinal dimension of the filter medium to facilitate unrestricted air flow through the filter medium when the bonnet is installed onto the breather vent.

This blow-by gas discharge device is provided with: blow-by gas piping 23 which is extended from the height position of the upper end of an internal combustion engine 1 to the height position of the lower end, is exposed to the outside air, and has an outlet 33 open to the atmosphere; and a heating chamber 24 which is provided between the ends of the blow-by gas piping, is formed in the flywheel housing 10 of the internal combustion engine, and heats blow-by gas.

An internal combustion engine includes a crankcase with a plurality of piston-cylinder arrangements and a valve head positioned above the crankcase at least in part containing a valve train. The internal combustion engine further includes a head cover coupled to the valve head and having a blowby outlet and a baffle positioned between the head cover and the crankcase and defining an oil passage internal to the baffle. Engine oil circulates through the oil passage of the baffle to transfer heat to blowby gas flowing from one or more of the plurality of piston-cylinder arrangements before exiting the valve head through the blowby outlet in the head cover.

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 blow-by gas recirculation device that, while having a structure in which a passage for blow-by gas is in a head cover and an oil separator, an increase in size of an engine is suppressed and the risk of the freezing is mostly avoided by shortening the length of an external pipe for the blow-by gas. Therefore, the blow-by gas recirculation device guides blow-by gas from a crankcase to an intake passage through an in-cover gas passage formed inside a head cover. An oil separator that traps and removes oil from the blow-by gas is attached to the inside of the head cover. A pressure regulating valve is provided on the outlet side of the in-cover gas passage in the head cover. A separator outlet, which is an outlet for the blow-by gas in the oil separator, is overlapped on a blow-by gas inlet portion of the pressure regulating valve.

An oil mist separator for an internal combustion engine includes a cylinder head cover, a baffle plate, and a cam spray plate. The baffle plate is fixed to an inner surface of the cylinder head cover. A section between the cylinder head cover and the baffle plate defines an oil separation chamber. The cam spray plate is fixed to a surface of the baffle plate opposite to the cylinder head cover. The cam spray plate defines an oil passage. The baffle plate includes a discharge hole through which oil separated from blow-by gas by the oil separation chamber is discharged. The cam spray plate includes a passage defining portion and a baffle plate portion. The passage defining portion defines the oil passage. The baffle plate portion is integrated with the passage defining portion and overlapped with the discharge hole.

Engine includes: crankcase housing crankshaft extending in vertical direction; cylinder block mounted on side of crankcase and formed with cylinder; cylinder head mounted on side of cylinder block and provided with air inlet port and air outlet port communicating with cylinder; cylinder head cover mounted on side of cylinder head and covering air inlet port and air outlet port; mount case including: supporting portion provided below crankcase and cylinder block and supporting crankcase and cylinder block; and extending portion extending from supporting portion below cylinder head and cylinder head cover; oil pan provided below mount case and storing lubricating oil; and communication tube communicating first space formed between cylinder head and cylinder head cover and second space formed between mount case and oil pan. Communication tube is provided between cylinder head cover and extending portion.

A PCV system includes a PCV valve configured to be inserted into a port formed on a mating component of an engine and regulate a flow of blow-by gases from a crankcase to an intake manifold. A PCV line includes a first end, and a second end configured to fluidly couple to the air intake manifold. A PCV valve cap is coupled to the PCV line first end and configured to further couple to the mating component to secure the PCV valve in the port and establish a fluid coupling with the mating component. The PCV valve is separate and distinct from the PCV valve cap such that a disconnection of the fluid coupling between the PCV line first end and the mating component separates the PCV line from the PCV valve such that the PCV valve no longer regulates flow through the PCV line into the intake manifold.

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.