In an internal combustion engine, an oil return passage extending from a breather chamber can be formed without increasing the number of component parts and without increasing the size of the internal combustion engine. The internal combustion engine (1) comprises an engine block (30) defining a cylinder (2); a case member (19) fastened to a lower part of the engine block to define a crank chamber jointly with the engine block; a bearing member (50) fastened to the engine block in the crank chamber to rotatably support a crankshaft; a breather chamber (113) defined in the engine block; an inlet passage (112) formed in the engine block to communicate the crank chamber with the breather chamber; a connection pipe (114) communicating the breather chamber with an intake device; and an oil return passage (150) formed at least in the bearing member, and extending from a bottom part of the breather chamber to an oil return port (147) opening at an outer surface of the bearing member. The oil return port may be provided in a lower part of the bearing member.

An oil separator is designed for an internal combustion engine with a camshaft system, via which oil separator a medium containing oil-particle-enriched blow-by gases, is influenced to the effect that the oil particles and the blow-by gases are separated and supplied to an oil circuit or to an inlet system of the internal combustion engine. The oil particles are separated from the blow-by gases by rotation of the camshaft system. In order to optimize this oil separator, the camshaft system has at least one camshaft on which a centrifugal blade device acting as the oil separator is effective. The centrifugal blade device conveys the oil particles of the medium against housing walls which are adjacent relative to the camshaft and lead to the oil circuit, with the blow-by gases freed from oil particles being conducted into the inlet system by the pressure conditions prevailing in a crankcase of the internal combustion engine.

An oil separator is designed for an internal combustion engine with a camshaft system, via which oil separator a medium containing oil-particle-enriched blow-by gases, is influenced to the effect that the oil particles and the blow-by gases are separated and supplied to an oil circuit or to an inlet system of the internal combustion engine. The oil particles are separated from the blow-by gases by rotation of the camshaft system. In order to optimize this oil separator, the camshaft system has at least one camshaft on which a centrifugal blade device acting as the oil separator is effective. The centrifugal blade device conveys the oil particles of the medium against housing walls which are adjacent relative to the camshaft and lead to the oil circuit, with the blow-by gases freed from oil particles being conducted into the inlet system by the pressure conditions prevailing in a crankcase of the internal combustion engine.

Valves, internal combustion engines including such valves, and methods of on-board diagnostic leak detection for a crankcase ventilation system using such valves are disclosed. Each valve has a housing defining a first port and a second port in fluid communication with one another and defining a valve seat therebetween. A biasing member biases a poppet sealing member into a normally open position (defining unrestricted flow through the valve) and a commanded actuator is connected to the poppet sealing member. The poppet sealing member has an orifice therethrough defining a restricted flow path, and, upon command, the commanded actuator moves the poppet sealing member from the open position to a restricted flow position in which the poppet sealing member is seated against the valve seat for restricted flow thorough the orifice in the poppet sealing member.

Valves, internal combustion engines including such valves, and methods of on-board diagnostic leak detection for a crankcase ventilation system using such valves are disclosed. Each valve has a housing defining a first port and a second port in fluid communication with one another and defining a valve seat therebetween. A biasing member biases a poppet sealing member into a normally open position (defining unrestricted flow through the valve) and a commanded actuator is connected to the poppet sealing member. The poppet sealing member has an orifice therethrough defining a restricted flow path, and, upon command, the commanded actuator moves the poppet sealing member from the open position to a restricted flow position in which the poppet sealing member is seated against the valve seat for restricted flow thorough the orifice in the poppet sealing member.

An internal combustion engine includes a blow-by gas processing device. A cylinder head cover of the internal combustion engine is provided with a joint portion including a connection port to which a connection pipe is connected and a throttle portion having a passage sectional area smaller than a passage sectional area of the connection port. The joint portion is communicated with an inside of a cylinder head and a space in the joint portion serves as an oil separator. A pressure sensor is connected to the space in the oil separator via a connection passage. The connection passage includes a first pipe, a second pipe, and a chamber including a first connection port to which the first pipe is connected and a second connection port to which the second pipe is connected. The first connection port and the second connection port are open toward the same direction in the chamber.

An internal combustion engine includes a blow-by gas processing device. A cylinder head cover of the internal combustion engine is provided with a joint portion including a connection port to which a connection pipe is connected and a throttle portion having a passage sectional area smaller than a passage sectional area of the connection port. The joint portion is communicated with an inside of a cylinder head and a space in the joint portion serves as an oil separator. A pressure sensor is connected to the space in the oil separator via a connection passage. The connection passage includes a first pipe, a second pipe, and a chamber including a first connection port to which the first pipe is connected and a second connection port to which the second pipe is connected. The first connection port and the second connection port are open toward the same direction in the chamber.

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

A management device 100 comprises: a data acquisition unit 122 that acquires, from a plurality of vehicles 1, cumulative data for each parameter relating to stress acting on a compressor 33 for supercharging intake air delivered to an engine, and supercharging pressure exerted by the compressor 33; a damage degree specification unit 123 that specifies the degree of damage of a supercharging device 32 from the acquired cumulative data; a relationship specification unit 24 that specifies a relational expression indicating the relationship between the specified degree of damage and the supercharging pressure; a target information acquisition unit 125 that acquires the supercharging pressure exerted by the compressor 33 from a vehicle 1 to be diagnosed; and a diagnostic unit 126 that estimates the degree of damage of the compressor 33 to be diagnosed on the basis of the acquired supercharging pressure and the specified relational expression.