The cylinder head 3 includes: a lower deck; a wall portion including an upper deck and a lower deck; an upper deck that is provided above the lower deck so as to face the lower deck and that defines a cooling water flow space between the lower deck and the upper deck; and a wall portion that is formed between the lower deck and the upper deck and includes a valve-hole forming wall 40 forming an intake valve hole and an exhaust valve hole which are opened into a lower surface of the lower deck. The lower deck includes: a cooling water introduction hole that passes through the lower deck in a vertical direction so as to extend in a circumferential direction of a virtual circle VC surrounding a valve-hole forming wall in a plan view; and a rib that projects from an upper surface of the lower deck.

The cylinder head 3 includes: a lower deck; a wall portion including an upper deck and a lower deck; an upper deck that is provided above the lower deck so as to face the lower deck and that defines a cooling water flow space between the lower deck and the upper deck; and a wall portion that is formed between the lower deck and the upper deck and includes a valve-hole forming wall 40 forming an intake valve hole and an exhaust valve hole which are opened into a lower surface of the lower deck. The lower deck includes: a cooling water introduction hole that passes through the lower deck in a vertical direction so as to extend in a circumferential direction of a virtual circle VC surrounding a valve-hole forming wall in a plan view; and a rib that projects from an upper surface of the lower deck.

The disclosure relates to a cylinder head for covering a combustion chamber of an internal combustion engine. The cylinder head comprises at least one material recess for heat isolation, which is formed in a main body of the cylinder head and is arranged between a fluid-guide channel and a cooling channel. The material recess can be produced e.g. directly during the shaping (e.g. casting or pressing) of the cylinder head and/or thereafter. For example, in the event that exhaust gas is guided through the fluid-guide channel, a significantly lower heat input occurs from the hot exhaust gas into the cooling fluid. In addition, the thermal decoupling via the material recess leads to the hot exhaust gas cooling to a lesser degree in the fluid-guide channel.

The disclosure relates to a cylinder head for covering a combustion chamber of an internal combustion engine. The cylinder head comprises at least one material recess for heat isolation, which is formed in a main body of the cylinder head and is arranged between a fluid-guide channel and a cooling channel. The material recess can be produced e.g. directly during the shaping (e.g. casting or pressing) of the cylinder head and/or thereafter. For example, in the event that exhaust gas is guided through the fluid-guide channel, a significantly lower heat input occurs from the hot exhaust gas into the cooling fluid. In addition, the thermal decoupling via the material recess leads to the hot exhaust gas cooling to a lesser degree in the fluid-guide channel.

An engine EGR system is provided, which includes an engine body, an intake passage, an exhaust passage and an EGR passage configured to recirculate exhaust gas as EGR gas to the intake passage. The EGR passage includes an EGR cooler and an EGR internal passage constituting the EGR passage upstream of the EGR cooler, and including a passage passing through a cylinder head. The EGR internal passage has a bent pipe part including a first bent portion at which an upstream portion of the EGR internal passage is bent away from a gas inflow port of the EGR cooler, a second bent portion located downstream of the first bent portion and bending the EGR internal passage toward the gas inflow port, and an intermediate portion connecting the first and the second bent portions by being disposed therebetween. The water-cooling passage is disposed around the bent pipe part.

The invention relates to a cylinder head (1) for an internal combustion engine, with a prechamber (2) which is arranged in the cylinder head (1) and is defined by an inner wall surface (11) of a prechamber wall (5), wherein the prechamber (5) comprises a first chamber portion (3) and a second chamber portion (4), wherein the first chamber portion (3) has a greater maximum diameter (D) than the second chamber portion (4), wherein at least one ignition device (16) opens into the first chamber portion (3), and the second chamber portion (3) comprises at least one overflow channel (7) for the passage of flow into a combustion chamber (8) which adjoins a fire deck (6). Am improved dissipation of heat can be achieved if at least one inner wall surface (11) of the first chamber portion (3) comprises at least one first flattened portion (13).

The invention relates to a cylinder head (1) for an internal combustion engine, with a prechamber (2) which is arranged in the cylinder head (1) and is defined by an inner wall surface (11) of a prechamber wall (5), wherein the prechamber (5) comprises a first chamber portion (3) and a second chamber portion (4), wherein the first chamber portion (3) has a greater maximum diameter (D) than the second chamber portion (4), wherein at least one ignition device (16) opens into the first chamber portion (3), and the second chamber portion (3) comprises at least one overflow channel (7) for the passage of flow into a combustion chamber (8) which adjoins a fire deck (6). Am improved dissipation of heat can be achieved if at least one inner wall surface (11) of the first chamber portion (3) comprises at least one first flattened portion (13).

In a cooling apparatus including a high-temperature-side radiator in a high-temperature-side cooling circuit supplying a high-temperature coolant to a cylinder head, a low-temperature-side radiator in a low-temperature-side cooling circuit supplying a low-temperature coolant to an intercooler, and an electronic control unit, the high-temperature-side cooling circuit includes a first coolant passage where the high-temperature coolant flows around an exhaust port, a second coolant passage where the high-temperature coolant flows through the cylinder head without flowing around the exhaust port, and a flow rate adjustment valve adjusting a flow rate of the high-temperature coolant flowing through the first coolant passage. The electronic control unit executes a response improvement process for controlling the flow rate adjustment valve to reduce the flow rate of the high-temperature coolant flowing through the first coolant passage, and for controlling the low-temperature-side pump to increase a flow rate of the low-temperature coolant circulating through the low-temperature-side cooling circuit.

In a cooling apparatus including a high-temperature-side radiator in a high-temperature-side cooling circuit supplying a high-temperature coolant to a cylinder head, a low-temperature-side radiator in a low-temperature-side cooling circuit supplying a low-temperature coolant to an intercooler, and an electronic control unit, the high-temperature-side cooling circuit includes a first coolant passage where the high-temperature coolant flows around an exhaust port, a second coolant passage where the high-temperature coolant flows through the cylinder head without flowing around the exhaust port, and a flow rate adjustment valve adjusting a flow rate of the high-temperature coolant flowing through the first coolant passage. The electronic control unit executes a response improvement process for controlling the flow rate adjustment valve to reduce the flow rate of the high-temperature coolant flowing through the first coolant passage, and for controlling the low-temperature-side pump to increase a flow rate of the low-temperature coolant circulating through the low-temperature-side cooling circuit.

An internal combustion engine and a head gasket are provided. The internal combustion engine includes a block having at least one cylinder, a head joined to the block at a head interface, a cooling fluid circulation passage extending at least partially through the head and the block and having a first portion disposed in the head and a second portion disposed in the block, a head gasket having a plate extending across the head interface and separating the first portion of the cooling fluid circulation passage from the second portion of the cooling fluid circulation passage, and a plurality of orifices extending through the plate. The plurality of orifices is aligned with the cooling fluid circulation passage and is configured to control a flow of cooling fluid circulating between the first portion of the cooling fluid circulation passage and the second portion of the cooling fluid circulation passage.