Abstract: A head-side jacket through which coolant flows is formed in a cylinder head. A main circulation path and a sub circulation path through which coolant fed from a coolant pump respectively circulates are formed. The head-side jacket is separated into an exhaust-port side jacket formed around an exhaust port, and a combustion-chamber-side jacket closer to a combustion chamber than the exhaust-port-side jacket. A heat exchanger is not formed in the main circulation path including the combustion-chamber-side jacket, but is formed in the sub circulation path excluding the combustion-chamber-side jacket and including the exhaust-port-side jacket.

Abstract: An accessory mounting structure for an engine includes an engine body, and a transmission disposed on an end of the engine body in the cylinder array direction and to which output of the engine is transmitted via a crankshaft of the engine body. When the output side of the crankshaft with respect to the transmission in the cylinder array direction is defined as a rear side, and the side of the crankshaft opposite to the rear side is defined as a front side, a fuel pump configured to feed fuel to an injector, and a starter configured to rotate the crankshaft at an engine start time are disposed on a rear end portion of an intake manifold mounting surface of the engine body. When the engine is viewed from the cylinder array direction, the starter projects outwardly with respect to the fuel pump in the engine width direction.

Abstract: An engine cooling device includes a heater circulation passage including an exhaust-side channel and a heater channel, the exhaust-side channel extending through an exhaust port-side portion of a cylinder head, the heater channel extending through a heater core; an auxiliary device circulation passage including a main channel and an auxiliary device channel, the main channel extending through a portion of the cylinder head other than the exhaust port-side portion, the auxiliary device channel extending through an auxiliary device; a temperature detecting portion configured to detect a temperature of an engine; and a channel switching valve configured to perform connection between the main channel and the auxiliary device channel and connection between the heater circulation passage and the auxiliary device circulation passage depending on the detected temperature falling within one of three temperature ranges.

Abstract: A supercharged engine is provided, which includes an engine body having cylinders, an intake passage disposed outside the engine body and connected to the cylinders via intake ports, a supercharger provided in the intake passage and spaced apart from an intake-side side surface of the engine body, the intake-side side surface being connected to the intake passage, and a fuel pump disposed on the intake-side side surface. A portion of the intake passage constitutes an intervening part located between the supercharger and the engine body. The intervening part overlaps with the fuel pump in one of vertical and lateral directions of the engine body.

Abstract: A cooling device of a multi-cylinder engine circulates a coolant from a water pump through water jackets of a cylinder head and a cylinder block. The cooling device includes a main jacket of the water jacket of the cylinder head, formed around combustion chambers, an exhaust jacket of the water jacket of the cylinder head, communicating to the main jacket and formed on an opposite side of exhaust ports to the combustion chambers, a circulation system for suppressing that the coolant flows through the main jacket in an engine cold start, by circulating the coolant through the water pump and the exhaust jacket, and a convection suppressor for suppressing that the coolant flows into the main jacket from the water jacket of the cylinder block in the engine cold start, by suppressing a convection of the coolant inside the water jacket of the cylinder block.

Abstract: A pump attaching portion is formed at a specified outside portion of an engine body beside a boss portion of a cylinder-head fastening bolt in such a manner that the pump attaching portion is continuous from the boss portion. The pump attaching portion has an attachment face, which contains a cooling-water introducing port, which is located on the outside of the flange wall and faces toward an engine front side in such a manner that the position of the attachment face is retreated from the flange wall. Accordingly, the sufficient pump-support rigidity can be ensured, restraining the pump attaching portion from projecting greatly toward the side of the engine body.

Abstract: A pump attaching portion is formed at a specified outside portion of an engine body beside a boss portion of a cylinder-head fastening bolt in such a manner that the pump attaching portion is continuous from the boss portion. The pump attaching portion has an attachment face, which contains a cooling-water introducing port, which is located on the outside of the flange wall and faces toward an engine front side in such a manner that the position of the attachment face is retreated from the flange wall. Accordingly, the sufficient pump-support rigidity can be ensured, restraining the pump attaching portion from projecting greatly toward the side of the engine body.

Abstract: An EGR plate member configured of an EGR plate inner and outer is interposed between a cylinder head and an intake manifold, including an exhaust gas recirculation passage formed therein. The EGR plate member has a lower protruding portion to protrude outward beyond respective connecting faces thereof with the cylinder head and the intake manifold. A common passage portion of the exhaust gas recirculation passage is substantially formed at the protruding portion. Part of the common passage portion has its laterally-long cross section which is offset toward the cylinder head. The offset portion of the EGR plate member has its greater thickness than other part thereof, extending below an intake port flange portion. Accordingly, the exhaust gas can be cooled by an outside air, thereby reducing an improper heat influence on the intake manifold.

Abstract: An EGR plate member configured of an EGR plate inner and outer is interposed between a cylinder head and an intake manifold, including an exhaust gas recirculation passage formed therein. The EGR plate member has a lower protruding portion to protrude outward beyond respective connecting faces thereof with the cylinder head and the intake manifold. A common passage portion of the exhaust gas recirculation passage is substantially formed at the protruding portion. Part of the common passage portion has its laterally-long cross section which is offset toward the cylinder head. The offset portion of the EGR plate member has its greater thickness than other part thereof, extending below an intake port flange portion. Accordingly, the exhaust gas can be cooled by an outside air, thereby reducing an improper heat influence on the intake manifold.

Abstract: An exhaust system having an exhaust manifold that comprises a plurality of single-shell discrete exhaust pipes connected to an engine, a double-shell collective chambered pipe joined to the discrete exhaust pipes and comprising an internal pipe shell into which exhaust gas streams passing through the discrete exhaust pipes are introduced and merge together and an external pipe shell surrounding the internal pipe shell, and a spherical joint connecting the collective chambered pipe to the exhaust pipe. The discrete exhaust pipe has a bent portion and a straight portion continuously extending from the bent portion to the collective chambered pipe. The bent portions of the respective discrete exhaust pipes are oriented toward a center of a straight row of cylinders so as to lay the straight portions of the discrete exhaust pipes nearly parallel to one another.

Abstract: An exhaust system having an exhaust manifold that comprises a plurality of single-shell discrete exhaust pipes connected to an engine, a double-shell collective chambered pipe joined to the discrete exhaust pipes and comprising an internal pipe shell into which exhaust gas streams passing through the discrete exhaust pipes are introduced and merge together and an external pipe shell surrounding the internal pipe shell, and a spherical joint connecting the collective chambered pipe to the exhaust pipe. The discrete exhaust pipe has a bent portion and a straight portion continuously extending from the bent portion to the collective chambered pipe. The bent portions of the respective discrete exhaust pipes are oriented toward a center of a straight row of cylinders so as to lay the straight portions of the discrete exhaust pipes nearly parallel to one another.