An injector is designed to provide continuously variable injection rate shaping. With a hydro-mechanical internal feedback mechanism, injector needle position can be determined by controlling a feedback valve's on/off timing. According to the needle position, an injection needle valve opening can be controlled, and then the injection flow rate can be delivered proportionally. Also in accordance with the present invention a CRDI systems are provided including injectors of the present invention, wherein results demonstrate that injector designs of the present invention not only achieve rate shaping capability but also solve the above-noted problems of the current CRDI system. Finally, an iterative learning controller has also been developed to track the desired injection rate, and an injection rate estimator is designed to realize a cycle to cycle feedback control.

A two-position gate valve has a gate defining a full-flow passageway therethrough and defining a restricted-flow passageway therethrough, without defining a closed position. The full-flow passageway has an entrance with a first area and an exit with a second area, the second area being smaller than the first area, and the full-flow passageway continuously tapers from the entrance to the exit thereof. The restricted-flow passageway has an entrance with a third area and has an exit with a fourth area, the fourth area being smaller than the first area, the second area, and the third area, and the restricted-flow passageway continuously tapers from the entrance to the exit thereof. Flow through the full-flow passageway is in a first direction and flow through the restricted-flow passageway is also in the first direction and the ratio of the fourth area to the second area is in a range of 5 to 15.

A control device for a fuel injection valve including a variable lift mechanism of two or more stages is provided. The control device includes an inflection point detection unit for detecting an inflection point from at least one of a drive current when the fuel injection valve is opened or a drive voltage when the fuel injection valve is closed. The control device also includes a drive sensing unit for sensing a drive lift of the fuel injection valve from at least one of an inflection point of a drive current during valve opening operation or a drive voltage during valve closing operation. The control device is configured to limit the command drive lift when the sensed drive lift is different from a command drive lift.

In a fuel injection valve including a variable lift mechanism of two or more stages, when fuel is injected with a lift different from a command, exhaust emission deterioration and torque fluctuations may occur.

A control device for a fuel injection valve including a variable lift mechanism of two or more stages is provided, which senses a drive lift of the fuel injection valve from an inflection point of a drive current during valve opening operation or a drive voltage during valve closing operation, and limits the command drive lift when the sensed drive lift is different from a command drive lift.

A two-position gate valve has a gate defining a full-flow passageway therethrough and defining a restricted-flow passageway therethrough, without defining a closed position. The full-flow passageway has an entrance with a first area and an exit with a second area, the second area being smaller than the first area, and the full-flow passageway continuously tapers from the entrance to the exit thereof. The restricted-flow passageway has an entrance with a third area and has an exit with a fourth area, the fourth area being smaller than the first area, the second area, and the third area, and the restricted-flow passageway continuously tapers from the entrance to the exit thereof. Flow through the full-flow passageway is in a first direction and flow through the restricted-flow passageway is also in the first direction and the ratio of the fourth area to the second area is in a range of 5 to 15.

The present disclosure provides a method for operating an injector of an internal combustion engine, the nozzle needle of said injector being operated by a piezo actuator by means of a servo valve. The method may include eliminating the idle travel of the piezo actuator by maintaining a permanent direct force connection between the piezo actuator and the servo valve, so that a change in force on the servo valve due to a change in pressure in the valve chamber when the servo valve is opened and closed and when the nozzle needle of the injector is closed is always transmitted to the piezo actuator as a change in force, detecting the resulting change in voltage and/or capacitance of the piezo actuator, and ascertaining parameters with which the injection quantity which is output by the injector is regulated based on the result of the detection.