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 improved blow-by gas return structure minimizes the occurrence of a drawback caused by freezing at a low temperature by bringing a state where freezing minimally occurs in a blow-bay gas passage such as a pipe disposed outside an engine. The blow-by gas return structure is configured such that a blow-by gas is introduced into an intake manifold through an inner passage formed in a head cover. The blow-by gas return structure includes an outer pipe which connects a blow-by gas outlet of the head cover and a blow-by gas inlet of a main pipe of the intake manifold in a communicable manner, and a temperature elevating mechanism configured to elevate a temperature of the blow-by gas inlet. The temperature elevating mechanism is configured such that a cooling water transfer passage is formed in a portion of the blow-by gas inlet of the main pipe.

An internal combustion engine includes a crankcase having first and second pluralities of openings. A oil separation module has at least one inlet housing that communicates with a oil separation filter and is connectable to at least one opening from the first plurality of openings or from the second plurality of openings to define a crankcase vent.

A fluid pipe device is provided, which includes a pipe member forming a flow channel for flowing a fluid; a heating member for generating heat to heat the pipe member; a metal heat transfer member abutting against the heating member and conducting the heat to the pipe member; and a terminal member electrically connecting the heating member and the heat transfer member. The heat transfer member includes a first heat transfer member and a second heat transfer member, and at least one of the first heat transfer member and the second heat transfer member forms the terminal member at one portion, and the first heat transfer member is provided in the pipe member in such a way as not to be exposed inside the flow channel of the pipe member.

This blow-by gas discharging device is provided with: a blow-by gas pipe 23 that extends from the upper end height position to the lower end height position of an internal combustion engine 1 and that has an outlet 33 exposed to outside air and opened to the atmosphere; a heating chamber 24 that is provided to the midway of the blow-by gas pipe, and formed in a flywheel housing 10 of the internal combustion engine so as to heat a blow-by gas; and a drain mechanism that is provided to the heating chamber so as to discharge oil accumulated in the heating chamber.

This blowby gas discharging device is provided with a heating chamber 24 which is interposed midway along a blowby gas pipeline, is formed in a flywheel housing 10 of an internal combustion engine, and heats blowby gas. The internal combustion engine is provided with a power transmission mechanism 13 for transmitting power from a crankshaft 6 to a camshaft 7, and a mechanism chamber 14 accommodating the power transmission mechanism. The heating chamber is adjacent to the mechanism chamber across a separating wall 41, and a retaining portion 60 for causing oil inside the mechanism chamber to be retained is provided in the separating wall.

This blowby gas discharging device is provided with a heating chamber 24 which is interposed midway along a blowby gas pipeline, is formed in a flywheel housing 10 of an internal combustion engine, and heats blowby gas. The internal combustion engine is provided with a power transmission mechanism 13 for transmitting power from a crankshaft 6 to a camshaft 7, and a mechanism chamber 14 accommodating the power transmission mechanism. The heating chamber is adjacent to the mechanism chamber across a separating wall 41, and a retaining portion 60 for causing oil inside the mechanism chamber to be retained is provided in the separating wall.

This blow-by gas discharging device is provided with: a blow-by gas pipe 23 that extends from the upper end height position to the lower end height position of an internal combustion engine 1 and that has an outlet 33 exposed to outside air and opened to the atmosphere; a heating chamber 24 that is provided to the midway of the blow-by gas pipe, and formed in a flywheel housing 10 of the internal combustion engine so as to heat a blow-by gas; and a drain mechanism that is provided to the heating chamber so as to discharge oil accumulated in the heating chamber.

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.

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.