This engine is provided with multiple injectors, and an excess fuel return pipe. The injectors inject fuel from a fuel tank into a combustion chamber. The excess fuel return pipe returns excess fuel from the injectors to the fuel tank. The excess fuel return pipe is provided with multiple injector connecting pipes and multiple linking pipes. The linking pipes are formed from an elastically deformable hose. Each of the multiple injector connecting pipes is connected to the corresponding injector. Each of the multiple linking pipes links together two mutually adjacent injector connecting pipes. Across the multiple linking pipes, pipe connecting units, to which an injector connecting pipe and a linking pipe are connected, are arranged along the same straight line.

A fuel injector body includes an at least partially annular configuration defining a longitudinal axis, a circumferential direction, and a radial direction. A first counterbore and a first cavity extend from the first end toward the second end, and an external interface portion includes a sealing surface disposed axially between the first end and a shoulder. The first cavity defines a bottom surface and a peripheral surface defining a first cavity diameter, and the sealing surface defines a sealing surface diameter. A ratio of the sealing surface diameter to the first cavity diameter ranges from 0.3 to 4.4.

A fuel injector capable of injecting a plurality of different fuels in a single fuel injection event includes a body including a primary fuel path and a pilot fuel path and a first plunger in fluid communication with the pilot fuel path. The fuel injector also includes a second plunger in fluid communication with the primary fuel path and with the pilot fuel path, a hydraulic control chamber within the pilot fuel path, and an injection valve at which the primary fuel path and the pilot fuel path connect to each other.

A piezoelectric injector includes: a first piezo actuator and a second piezo actuator; a control valve connected to the first piezo actuator and the second piezo actuator through a control piston; at least one drain chamber in which the control valve and the control piston are movably received; a control chamber connected to the drain chamber through a first drain throttle and a second drain throttle having different diameters; and a needle movable by a change in fuel pressure of the control chamber to open and close at least one nozzle orifice. As at least one of the first piezo actuator and the second piezo actuator expands, a fuel is drained from the control chamber to the drain chamber through at least one of the first drain throttle and the second drain throttle.

A fuel injector includes an injector housing, an outlet check, an injection control valve assembly, and a valve seat orifice plate integrating a valve seat and various orifices for outlet check control. In the valve seat orifice plate a drain orifice extends between a valve seat surface and a check control chamber formed between a closing hydraulic surface of the outlet check and the valve seat orifice plate. First and second re-pressurization orifices extend between an outer surface of the valve seat orifice plate and the check control chamber.

The invention relates to a method for operating a fuel injector (10) and to a fuel injector (10) which is configured to carry out the method. The method comprises the steps of introducing a fuel under high pressure into a feed passage (78) and branching off a substream of the fuel under high pressure into a control space (74) in which an axial end face (70) of the nozzle needle (50) is loaded with the pressure such that the nozzle needle (50) is hydraulically loaded in the closing direction, and of opening a control valve (90) such that an outflow path arranged downstream of the control valve (90) in an outflow direction is freed and fuel flows out of the control space (74) in order to relieve the nozzle needle (50), wherein the fuel flowing out via the outflow path is divided into at least two substreams.

A fuel injector assembly for a fuel-actuated fuel injector includes an injector body, and an injection control valve assembly. The injector body includes therein a low-pressure fuel passage extending from a clamping face to an armature cavity to convey spent actuating fuel to the armature cavity. The fuel injector assembly also includes a flushing drain formed by the injector body and fluidly connected to at least one of a valve pin bore in the injector body or the armature cavity. The flushing drain forms, together with the low-pressure fuel passage and the armature cavity, a cooling circuit for the spent actuating fuel. The flushing drain extends to a drain opening formed in an outer body surface of the injector body. Related methodology is also disclosed.

A coil assembly in a fuel injector includes a magnetic core and; a winding wound around the core, the winding being overmoulded and forming a cylindrical overmoulding. An axial blind hole extends towards the interior of the coil assembly from a first surface to a distal end, the blind hole being suitable for housing at least one spring for loading a magnetic armature. The coil assembly is provided with a degassing hole passing through the core and the overmoulding from the blind axial hole to an axial outer cylindrical surface, the degassing hole being provided in the magnetic core and having a restriction that is arranged in a first section that is proximal to the blind axial hole.

A pressurized fuel injection system for an engine includes a pressure sensor in a low pressure rail, an electronic pressure regulator valve in flow communication with and downstream from the low pressure rail and in flow communication with and upstream from a fuel supply, and a controller configured to receive a pressure signal from the pressure sensor and to control the electronic pressure regulator valve in response to the pressure signal to maintain a target pressure in the low pressure rail.

An evaporated fuel treatment device includes a fuel tank that stores fuel for an internal combustion engine, a canister that adsorbs evaporated fuel generated in the fuel tank, a pump that pressurizes and depressurizes a diagnostic target system including the fuel tank, a pressure detection unit that detects pressure in the diagnostic target system, a fuel state detection unit that detects a state of the fuel in the fuel tank, a leakage diagnosis unit that diagnoses leakages of evaporated fuel from the diagnostic target system, the diagnostic target system based on a change in a detection value detected by the pressure detection unit when the pump pressurizes or depressurizes the diagnostic target system, and a diagnosis determination unit that determines whether the leakage diagnosis unit performs the diagnosis based on a change in a state detection value detected by the fuel state detection unit.