Abstract: An internal combustion engine includes: a cylinder having a combustion chamber formed at an upper side thereof and accommodating a piston to be reciprocally movable; a crankcase provided below the cylinder and accommodates a crankshaft; and a blow-by gas passageway recirculating blow-by gas, which leaks into the crankcase from the combustion chamber, to the combustion chamber through an intake system, in which an inner surface portion of the crankcase is provided with a blow-by gas intake part, and the blow-by gas intake part includes a protruding portion protruding in a direction in which the crankshaft extends, and the intake port opened in the protruding direction is formed at a tip end portion of the protruding portion.

Abstract: An intake system of an internal combustion engine with a supercharger includes: a negative pressure control valve which is disposed in the upstream side than an intake side supercharger in an intake passage; a first external gas introduction passage which introduces a single external gas made of blow-by gas, at a part of the intake passage which is on the upstream side of the intake side supercharger and on the downstream side of the negative pressure control valve; and a fresh air introduction passage which introduces fresh air to an internal combustion engine main body from the upstream side of the negative pressure control valve.

Abstract: An internal combustion engine includes: a cylinder having a combustion chamber formed at an upper side thereof and accommodating a piston to be reciprocally movable; a crankcase provided below the cylinder and accommodates a crankshaft; and a blow-by gas passageway recirculating blow-by gas, which leaks into the crankcase from the combustion chamber, to the combustion chamber through an intake system, in which an inner surface portion of the crankcase is provided with a blow-by gas intake part, and the blow-by gas intake part includes a protruding portion protruding in a direction in which the crankshaft extends, and the intake port opened in the protruding direction is formed at a tip end portion of the protruding portion.

Abstract: An intake system of an internal combustion engine with a supercharger includes: a negative pressure control valve which is disposed in the upstream side than an intake side supercharger in an intake passage; a first external gas introduction passage which introduces a single external gas made of blow-by gas, at a part of the intake passage which is on the upstream side of the intake side supercharger and on the downstream side of the negative pressure control valve; and a fresh air introduction passage which introduces fresh air to an internal combustion engine main body from the upstream side of the negative pressure control valve.

Abstract: A seal structure for an engine includes a cylinder block, a cylinder head assembled via a first seal member on the cylinder block, a chain cover assembled via a second seal member on the cylinder block and the cylinder head that are assembled on each other, and a holding recess portion formed at an outer surface of a joint portion among the cylinder block, the cylinder head, and the chain cover, the holding recess portion retaining a liquid gasket and being filled therewith.

Abstract: A seal structure for an engine includes a cylinder block, a cylinder head assembled via a first seal member on the cylinder block, a chain cover assembled via a second seal member on the cylinder block and the cylinder head that are assembled on each other, and a holding recess portion formed at an outer surface of a joint portion among the cylinder block, the cylinder head, and the chain cover, the holding recess portion retaining a liquid gasket and being filled therewith.