A method for determining the opening for piezo servo-driven injectors may include measuring a voltage and a charge at an end of a charging process of the piezo actuator; determining a provisional scaling factor by calculating Q/U; determining the maximum of C.sub.VORL and using the instant at which the maximum occurs as an approximation value of the valve opening instant; measuring the charge and voltage at the approximation of the valve opening instant; solving the equation:
1.25F.sup.2/EC=(UCQ).sup.2 Where F=force acting on the piezo actuator, E=electrical parameter of the piezo actuator; determining a new scaling factor from the solution of the equation; calculating the difference (UCQ) and determining a maximum of said value; and using the instant at which said maximum occurs as valve opening instant.

A method for controlling at least one switchable valve, a brake impulse that slows down the valve movement being produced during the controlling of the at least one valve, the position and/or the length of the brake impulse being specified as a function of a switching time of the valve, it being checked whether a characteristic feature occurs that indicates the switching time, and, upon occurrence of the characteristic feature, the position and/or the length of the brake impulse being adapted based on the position of the characteristic feature.

The objective of the present invention is to provide an engine with improved startability and stable operation regardless of the driving environment and usage conditions. The engine is equipped with a control means, which calculates a standard injection timing on the basis of the target rotational frequency of the engine and a standard injection amount, that is, the amount of fuel injected, and which corrects the standard injection timing using at least one correction amount. A fuel injection control unit calculates a cooling water correction amount on the basis of the target rotational frequency of the engine, the standard injection amount, and the cooling water temperature, and when the cooling water temperature is less than a first prescribed temperature the control unit corrects the standard injection timing using only the cooling water correction amount.

Disclosed is an injector controlling method using an opening duration. The injector controlling method using an opening duration converts a target fuel quantity into an opening duration and sets relationship between the opening duration and an injector actuation signal in order to control the fuel quantity of injectors more accurately.

A method of predicting NOx generation amount of a compression ignition engine is provided. The method includes predicting a composition ratio of a gas in a mixture and a flame temperature using driving variables of an engine and calculating a nitrogen oxide generation rate using the composition ratio of the gas in the mixture and the flame temperature. Additionally, a nitrogen oxide generation concentration around flame is calculated using the nitrogen oxide generation rate and a total nitrogen oxide generation amount of a cylinder is predicted using the nitrogen oxide generation rate and the nitrogen oxide generation concentration.

The present invention is provided with: an injection timing detection unit; an engine rotation speed detection unit; an engine load detection unit; and a storing unit for storing control data of the variation in optimal ignition timing with respect to engine speed and engine load, and control data of correction coefficient pertaining to optimal ignition timing with respect to the engine load at a specific fuel injection timing. Referring to the control data, the variation in the optimal ignition timing is determined based on the detected fuel injection timing and the detected engine rotation speed; and, referring to the control data, the variation in the optimal ignition timing is determined based on the specific fuel injection timing and the detected engine speed, and the deviation between the respective variation in the optimal injection timing is determined.

An engine includes a control means that calculates a standard injection time based on the target number of revolutions of the engine and a standard injection amount being a fuel injection amount of the engine and corrects the standard injection time based on at least a correction amount, and a fuel injection control unit calculates a coolant correction amount based on the target number of revolutions, the standard injection amount, and a coolant temperature of the engine, and when the coolant temperature is less than a first predetermined temperature, the fuel injection control unit corrects the standard injection time only based on the coolant correction amount.

A compression ignition engine (10) operates to fuel an engine cylinder (12) to create an in-cylinder air-fuel charge and to cause that charge to autoignite. A fuel injector (20) operates to inject fuel into the engine cylinder for substantially the entire duration of a first phase (24) of fuel injection at substantially the maximum injection pressure that the fuel injector can deliver to create a premixed fraction of the in-cylinder air-fuel charge prior to autoignition. As the first phase ends, fuel injection transitions to a second phase (26) which commences in advance of autoignition. During the second phase, the fuel injector injects fuel into the engine cylinder at a rate of injection that is significantly less than the rate of injection used during the first phase.

A method of operating a gas or dual fuel engine having a plurality of cylinders, includes monitoring a characteristic of each of the plurality of cylinders during operation of the gas or dual fuel engine. The method also includes detecting a pre-ignition condition associated with one or more cylinders of the plurality of cylinders based on the monitored characteristic. The method further includes reducing fuel supply to the one or more cylinders having the pre-ignition condition. The fuel supply to remaining cylinders of the plurality of cylinders is increased, to maintain a constant power output of the gas or dual fuel engine. The method further includes adjusting an amount of air supplied to each of the plurality of cylinders based on the increased amount of fuel supplied to the remaining cylinders, to maintain an air-to-fuel ratio within a desired range.

A method for regulating a common rail injector, the method including acquiring a signal of a sensor, which signal is proportional to a pressure in a valve space of the common rail injector; evaluating a change in the signal over time in order to detect at least one operating event of the common rail injector; and modifying at least one operating variable of the common rail injector as a function of the at least one operating event, the at least one operating variable being selected from an opening duration, a closing duration, an opening point in time, and a closing point in time of a switching valve of the common rail injector, and from an opening duration, an opening point in time, and a closing point in time of a needle valve of the common rail injector.