An engine head assembly includes a double-walled fuel connector assembly in an engine head and forming a high-pressure fuel supply passage and a low-pressure fuel return passage. The engine head assembly also includes a fuel injector. A high-pressure fuel inlet path extends between a fuel inlet and spray orifices through an injector body in the fuel injector. A low-pressure cooling fuel outlet path extends between an injection control valve seat in the fuel injector and a cooling fuel outlet in a nozzle case of the fuel injector. Expelled cooling fuel is passed through the low-pressure fuel return passage in the double-walled fuel connector.

An injector seal assembly including a nozzle combustion shield is disclosed, the thermally conductive component of the injector seal assembly defining at least one groove to allow fluid communication between the main combustion chamber and a gap defined by a fuel injector and the injector seal assembly to facilitate the prevention of corrosion of the components.

An injector seal assembly including a nozzle combustion shield is disclosed, the thermally conductive component of the injector seal assembly defining at least one groove to allow fluid communication between the main combustion chamber and a gap defined by a fuel injector and the injector seal assembly to facilitate the prevention of corrosion of the components.

The invention relates to an injector arrangement (1) having an injector nozzle (2) for injecting medium into a combustion chamber (3), particularly for injecting fuel into a combustion chamber (3) of an internal combustion engine, and having a sealing ring (20), which is pre-loaded in order to seal against a sealing surface (6) of a cylinder head (4), which comprises a through-hole (5), through which the injection nozzle (2) protrudes into the combustion chamber (3) and in which, in the radial direction between the injection nozzle (2) and the cylinder head (4), a heat protection sleeve (10) is arranged, one end (11) of which, facing the combustion chamber (3), is frictionally connected to the injection nozzle (2) by a radial pressing (12). In order to functionally improve the injector arrangement (1), an end (13) of the heat protection sleeve (10) furthest from the combustion chamber (3) is frictionally connected to the sealing ring (20) by an axial pressing (14).

The invention relates to an injector arrangement (1) having an injector nozzle (2) for injecting medium into a combustion chamber (3), particularly for injecting fuel into a combustion chamber (3) of an internal combustion engine, and having a sealing ring (20), which is pre-loaded in order to seal against a sealing surface (6) of a cylinder head (4), which comprises a through-hole (5), through which the injection nozzle (2) protrudes into the combustion chamber (3) and in which, in the radial direction between the injection nozzle (2) and the cylinder head (4), a heat protection sleeve (10) is arranged, one end (11) of which, facing the combustion chamber (3), is frictionally connected to the injection nozzle (2) by a radial pressing (12). In order to functionally improve the injector arrangement (1), an end (13) of the heat protection sleeve (10) furthest from the combustion chamber (3) is frictionally connected to the sealing ring (20) by an axial pressing (14).

An improved injector cup may be used in diesel engines that fits more securely into the engine's cylinder heads to better prevent engine coolant from leaking into the fuel and/or fuel leaking into the coolant. An improved injector cup may be designed to accommodate specific engine types and sizes in order to prevent engine coolant from leaking into the fuel and/or fuel leaking into the coolant.

In a combustion cycle in which fuel for forming a homogenized air-fuel mixture in the combustion chamber is injected from the first fuel injector, ignition-use fuel for forming an ignition-use air-fuel mixture in the vicinity of the electrode part is injected from the second fuel injector, and lean combustion is performed by an excess air rate of 2.0 or more, the ignition-use fuel is injected by at least an injection rate of 1.0 mm.sup.3/ms or more for a duration of 250 μs or more in an interval from a crank angle advanced by exactly 20 degrees from an ignition timing of the spark plug to the ignition timing, and the quantity of the ignition-use fuel is 2.0 mm.sup.3/st or less.

A partitioning wall is provided in a fluid space formed between a cover member and a body member, which surrounds a forward end of a fluid injection valve. The partitioning wall divides the fluid space into an inlet-side fluid space and an outlet-side fluid space in a circumferential direction of the fluid injection valve. A forward-end space, which is formed at a bottom of the fluid space, is communicated to the inlet-side and the outlet-side fluid spaces, so that cooling water flows from the inlet-side fluid space to the outlet-side fluid space through the forward-end space. The cooling water circulates in the forward-end space surrounding the forward end of the fluid injection valve to effectively cool down the fluid injection valve.

A partitioning wall is provided in a fluid space formed between a cover member and a body member, which surrounds a forward end of a fluid injection valve. The partitioning wall divides the fluid space into an inlet-side fluid space and an outlet-side fluid space in a circumferential direction of the fluid injection valve. A forward-end space, which is formed at a bottom of the fluid space, is communicated to the inlet-side and the outlet-side fluid spaces, so that cooling water flows from the inlet-side fluid space to the outlet-side fluid space through the forward-end space. The cooling water circulates in the forward-end space surrounding the forward end of the fluid injection valve to effectively cool down the fluid injection valve.

A fuel injector has a seat and at least one seat passage. The seat includes an outer tip surface through which the seat passage extends. A non-thermally conducting coating is provided on at least a portion of the outer tip surface and not on surfaces defining the seat passage. The coating is constructed and arranged to be heated by combustion gases so that the outer tip surface reaches a temperature greater than a temperature that the outer tip surface would reach if the coating was not provided so as to cause evaporation of fuel that contacts the outer tip surface, The seat passage is constructed and arranged to not be substantially heated by conduction from the outer tip surface and to be cooled by fuel passing there-through so as to prevent deposits of combustion from accumulating on surfaces defining the seat passage.