A nozzle assembly of a fuel injector includes a nozzle body in which a needle member is adapted to translate. The nozzle assembly is further provided with an electrical circuit so that an electrical signal enabling contact detection is measurable between the needle member and the nozzle body. The nozzle assembly also includes a piezoresistive device which continuously varies the electrical signal during the final closing displacements, or the initial opening displacements, of the needle, the variations of the signal being a function of a differential pressure.

A method of detecting failures of an engine control computer including at least: a hardware layer, a software layer comprising at least one activation cycle of the load m phase(s) of activation of said load with: actuation of the load, first timeout, deactivation of the load, second timeout. The method of detecting failures includes a measurement time window during which the following are carried out: an initialization of the measurement variables, detection of an actuation of the load, an action of reinitializing the engine control computer if at least one of the following conditions is valid: T1>T1_ref, T2<T2_ref, T3>T3_ref, T4<T4_ref.

The present disclosure relates to an injection valve comprising an injector body, a needle body, a control space, a control valve, and a piezoelectric actuator. The injector body has a recess and a fluid inflow and a fluid outflow. The needle body is arranged axially movably in the recess of the injector body and suppresses a fluid flow through an injection opening of the injector body in a closed position of the needle body and otherwise releases it. The control space is disposed in the recess between the fluid inflow and the fluid outflow. The control valve may be arranged in the control space to suppress a fluid flow between the control space and the fluid outflow in a closed position of the valve body and to otherwise release it. The piezoelectric actuator may be coupled mechanically to the control valve via a first transmitter for opening the control valve.

The subject matter of this specification can be embodied in, among other things, a method for characterizing a fluid injector that includes receiving a collection of waveform data, identifying a pull locus, determining a detection threshold level value, identifying a first subset of the collection of data representative of a selected first electrical waveform of the collection of electrical waveforms, identifying an opening value, identifying a representative closing value, identifying an anchor value, identifying a second subset of the collection of data based on the collection of data, the pull locus, the first subset, and the opening value, identifying a maximum electrical value, identifying an opening locus based the collection of data, the anchor value, and the maximum electrical value, identifying a hold value, and providing characteristics associated with the fluid injector comprising the pull locus, the opening locus, the hold value, the anchor value, and the representative closing value.

A fuel injection control device is for a fuel injection system including a fuel injection valve for injecting a fuel in an internal combustion engine. The fuel injection system is configured to perform multiple-stage injection for injecting fuel multiple times in one combustion cycle. The fuel injection control device includes an information acquisition unit to acquire a parameter, which indicates an influence of a pre-stage injection on a post-stage injection, in the pre-stage injection and the post-stage injection subsequent to the pre-stage injection in the multi-stage injection. The fuel injection control device further includes a correction unit to correct a mode of the post-stage injection based on the parameter.

A fuel injector assembly in one embodiment includes a nozzle, at least one needle, and at least one actuator. The nozzle includes at least one cavity in fluid communication with nozzle openings. The at least one needle is movably disposed within the at least one cavity, and prevents flow through the nozzle openings in a closed position. The at least one actuator is configured to move the at least one needle within the cavity. The at least one actuator is configured to move the at least one needle to at least a first fuel delivery configuration and a second fuel delivery configuration. A first amount of fuel is delivered through the nozzle openings with the at least one needle in the first fuel delivery configuration, and a second amount of fuel is delivered through the nozzle openings with the at least one needle in the second fuel delivery configuration.

Methods and systems for operating a direct fuel injector of an internal combustion engine are described. In one example, a nozzle needle is moved in two directions to maintain fuel flow through the direct fuel injector and to reduce the possibility of the nozzle needle impacting a piezoelectric actuator. The method and system may permit long fuel injection times without causing undesirable impacts between components of a fuel injector.

A fuel injection valve (6) is configured such that the effective opening area of an injection port (61) increases as its lift amount increases. A fuel injection control unit (an engine control unit 100) injects fuel in a lift amount changing mode wherein, when fuel is injected into a combustion chamber (17) in the terminal period of the compression stroke, the lift amount of the fuel injection valve is set to a predetermined large lift amount in the earlier period of the injection period, and in the later period of the injection period following the earlier period of the injection period, the lift amount is set to a small lift amount smaller than the large lift amount and is in a range where the fuel injection speed increases.

A fuel injector assembly in one embodiment includes a nozzle, at least one needle, and at least one actuator. The nozzle includes at least one cavity in fluid communication with nozzle openings. The at least one needle is movably disposed within the at least one cavity, and prevents flow through the nozzle openings in a closed position. The at least one actuator is configured to move the at least one needle within the cavity. The at least one actuator is configured to move the at least one needle to at least a first fuel delivery configuration and a second fuel delivery configuration. A first amount of fuel is delivered through the nozzle openings with the at least one needle in the first fuel delivery configuration, and a second amount of fuel is delivered through the nozzle openings with the at least one needle in the second fuel delivery configuration.

Various embodiments includes a method for determining energization data for an actuator of an injection valve of a motor vehicle comprising: receiving input data at a control unit; and determining the energization data based on the received input data into account with the control unit. Determining the energization data includes using a polynomial regression model.