Abstract: A fuel-injector-replacement device obtains a learning value of characteristic data of an injector while an engine is running. The learning value stored in an ECU is updated into the learning value. When the engine is stopped, the characteristic data stored in an INJ-EEPROM are updated into the characteristic data stored in the ECU. When the engine is started, it is determined whether the characteristic data stored in the ECU agrees with the characteristic data stored in the INJ-EEPROM. When these data do not agree with each other, it is determined that the fuel-injector is improperly replaced without updating the characteristic data stored in the ECU.

Abstract: A characteristics-detecting-portion analyzes a fuel injection condition based on a fuel pressure waveform which represents a variation in a detection value of the fuel pressure sensor and then detects the fuel-injection-characteristic value based on the analyzed fuel injection condition. The detected parameter is learned and stored in a memory in association with a fuel temperature detected by a fuel temperature sensor. A fuel-injection-rate model is established based on the learned detected parameters. A command-fuel-injection start time and a command-fuel-injection period are defined by use of the fuel-injection-rate model and the current fuel temperature.

Abstract: A fuel injection device includes a fuel injection valve for injecting fuel, which is distributed from a pressure-accumulation vessel. A pressure sensor is located in a fuel passage, which extends from the pressure-accumulation vessel to a nozzle hole. The pressure sensor is located closer to the nozzle hole than the pressure-accumulation vessel. A storage unit stores individual difference information obtained by an examination. The individual difference information indicates an injection characteristic of the fuel injection valve and indicates at least one of an injection response time delay between an injection start point and a time point, at which a fluctuation is caused by the start of fuel injection in detected pressure of the pressure sensor, and a parameter for calculating the injection response time delay.

Abstract: A fuel injection control device (ECU) for controlling injection supply of fuel to an engine is applied to an injector that has a valve body formed with a fuel injection hole, a needle accommodated in the valve body for opening and closing the injection hole, and a piezoelectric element for driving the needle such that the needle reciprocates and that can continuously adjust an injection rate in accordance with an injection command signal to the piezoelectric element. The fuel injection control device senses a fuel pressure waveform indicating a transition of fuel pressure fluctuation accompanying a predetermined injection of the injector based on an output of a fuel pressure sensor and calculates an injection command signal for approximating a predetermined injection parameter concerning the predetermined injection to a reference value of the parameter based on the sensed fuel pressure waveform.

Abstract: A fuel injection device includes a fuel injection valve for injecting fuel, which is distributed from a pressure-accumulation vessel. A pressure sensor is located in a fuel passage, which extends from the pressure-accumulation vessel to a nozzle hole of the fuel injection valve. The pressure sensor is located closer to the nozzle hole than the pressure-accumulation vessel and configured to detect pressure of fuel. The fuel injection device further includes a storage unit for storing individual difference information, which indicates an injection characteristic of the fuel injection valve. The injection characteristic is obtained by an examination. The individual difference information indicates a relationship between an injection state when the fuel injection valve performs fuel injection and a fluctuation in detected pressure of the pressure sensor. The fluctuation is attributed to the fuel injection.

Abstract: A fuel injection characteristic sensing device obtains an injection characteristic of a target injector (an injector of each cylinder of a multi-cylinder engine) at each time. The device has a program for sequentially sensing fuel pressure at a sensing point corresponding to a fuel pressure sensor, which is provided at a fuel inlet of each injector, based on an output of the fuel pressure sensor. The device has a program for detecting predetermined timings (injection timings such as an injection start timing and an injection end timing) in a series of operations concerning fuel injection of the injector of each cylinder based on the sequentially sensed fuel pressure. Thus, the injection characteristic at each time including a temporal characteristic change can be obtained.

Abstract: A fuel temperature sensing device has fuel temperature sensors provided to respective cylinders for sensing fuel temperature. Each fuel temperature sensor is arranged in a position closer to an injection hole than to a pressure accumulator in a fuel passage extending from the pressure accumulator to the injection hole. The device has an average value calculating section for calculating an average value of fuel temperature sensing values sensed with the fuel temperature sensors of the respective cylinders. The device has a deviation calculating section for calculating deviations between the average value and the fuel temperature sensing values of the respective fuel temperature sensors. The device has a correcting section for correcting the fuel temperature sensing value of each fuel temperature sensor to approximate the deviation to zero for each fuel temperature sensor.

Abstract: A fuel injection control device (ECU) for controlling injection supply of fuel to an engine is applied to an injector that has a valve body formed with a fuel injection hole, a needle accommodated in the valve body for opening and closing the injection hole, and a piezoelectric element for driving the needle such that the needle reciprocates and that can continuously adjust an injection rate in accordance with an injection command signal to the piezoelectric element. The fuel injection control device senses a fuel pressure waveform indicating a transition of fuel pressure fluctuation accompanying a predetermined injection of the injector based on an output of a fuel pressure sensor and calculates an injection command signal for approximating a predetermined injection parameter concerning the predetermined injection to a reference value of the parameter based on the sensed fuel pressure waveform.

Abstract: A characteristics-detecting-portion analyzes a fuel injection condition based on a fuel pressure waveform which represents a variation in a detection value of the fuel pressure sensor and then detects the fuel-injection-characteristic value based on the analyzed fuel injection condition. The detected parameter is learned and stored in a memory in association with a fuel temperature detected by a fuel temperature sensor. A fuel-injection-rate model is established based on the learned detected parameters. A command-fuel-injection start time and a command-fuel-injection period are defined by use of the fuel-injection-rate model and the current fuel temperature.

Abstract: A fuel injection device includes a fuel injection valve for injecting fuel. A pressure sensor is configured to output detection signal correspondingly to pressure of the fuel. The fuel injection device further includes a storage unit for storing individual difference information, which indicates an output characteristic of the detection signal. The output characteristic is obtained by an examination. The individual difference information indicates a relationship between change in test pressure and change in detection signal. The test pressure is actually applied to the pressure sensor in the examination. The change in detection signal is attributed to the change in test pressure.

Abstract: An internal combustion engine control device has a cylinder pressure sensor for sensing pressure in a combustion chamber and a fuel pressure sensor for sensing fuel pressure fluctuating in connection with fuel injection from an injector. The control device calculates a combustion characteristic of a cylinder (for example, an ignition delay or a combustion rate) based on both of a cylinder pressure sensing value and a fuel pressure sensing value. The control device corrects an EGR quantity, supercharging pressure, and injection start timing in accordance with the calculated combustion characteristic. Thus, the control device performs cooperative control of the injection start timing (an injection mode), the supercharging pressure and the EGR quantity (intake air conditions) in accordance with the combustion characteristic of the cylinder.

Abstract: A variation waveform of fuel pressure is obtained by use of a fuel pressure sensor which detects pressure of fuel supplied to an injector. A quantity of fuel supplied to the injector is estimated based on a waveform of the detected pressure that is greater than a reference value due to a fuel pumping, in the obtained variation waveform. Especially, in a case that the fuel pressure sensor is provided to each of a plurality of injectors, it is desirable to obtain the variation waveform based on the output of the fuel pressure sensor provided to a cylinder in which no fuel injection is currently performed.

Abstract: A fuel-injector-replacement device obtains a learning value of characteristic data of an injector while an engine is running. The learning value stored in an ECU is updated into the learning value. When the engine is stopped, the characteristic data stored in an INJ-EEPROM are updated into the characteristic data stored in the ECU. When the engine is started, it is determined whether the characteristic data stored in the ECU agrees with the characteristic data stored in the INJ-EEPROM. When these data do not agree with each other, it is determined that the fuel-injector is improperly replaced without updating the characteristic data stored in the ECU.

Abstract: A common rail type fuel injection system of an engine includes: a common rail for accumulating and holding high-pressure fuel; a fuel pump for pressure-feeding fuel to the common rail; and an injector for injecting the high-pressure fuel accumulated and held in the common rail. A pressure sensor is disposed in a fuel suction port of the injector. An ECU sequentially detects a fuel pressure varied when the injector injects the fuel and sequentially detects a fuel pressure varied when the fuel pump pressure-feeds the fuel. When the injector injects the fuel, the ECU computes injection pressure by the detection values of these pressures and computes injection characteristics by the injector on the basis of the injection pressure.

Abstract: A pressure sensor is located in a fuel passage, which extends from a pressure-accumulation vessel to a nozzle hole of a fuel injection valve. The pressure sensor is located closer to a nozzle hole than the pressure-accumulation vessel for detecting pressure fluctuated by injection of fuel through the nozzle hole. An instruction signal output unit outputs an injection instruction signal so as to instruct an injection mode of fuel to the fuel injection valve. A defective injection determination unit determines whether a detected pressure of the fuel pressure sensor is fluctuated in a fluctuation mode in a range assumed from the injection instruction signal. The defective injection determination unit determines that a defective injection occurs when determining that the detected pressure is out of the fluctuation mode in the assumed range.

Abstract: An exhaust gas recirculation distribution variation sensing device has a torque sensing section that senses instantaneous torque caused with combustion of fuel injected from an injector for each cylinder, an injection quantity sensing section that senses an actual injection quantity of the injected fuel for each cylinder, and an exhaust gas recirculation distribution variation calculating section that calculates an exhaust gas recirculation distribution variation as a distribution variation of recirculated exhaust gas to respective cylinders based on a variation in the torque sensing value of the torque sensing section among the cylinders (i.e., a torque variation) and a variation in the injection quantity sensing value of the injection quantity sensing section among the cylinders (i.e., an injection quantity variation).

Abstract: A fuel pressure sensor is provided to each fuel injector respectively and is disposed in a fuel passage between the accumulator and a fuel injection port of the fuel injector in such a manner as to be close to a fuel injection port relative to the accumulator. Output values of a plurality of fuel pressure sensors are acquired, and an average of the output values is computed. The output values are corrected in such a manner as to agree with the average.

Abstract: A fuel injection control device (ECU) for controlling injection supply of fuel to a target engine includes a program for sequentially sensing fuel pressure fluctuating with injection of a predetermined injector of each cylinder of a multi-cylinder engine based on an output of a fuel pressure sensor, a program for detecting a diagram as a profile of a transition of a fuel quantity injected from the injector per unit time (i.e., an injection rate) at a present time based on the sequentially sensed fuel pressure transition, and a program for varying an injection command to the injector based on the diagram that is the profile of the injection rate transition and that is detected by the latter program and a predetermined basic diagram such that the diagram as the actual profile of the injection rate transition belongs to the basic diagram.

Abstract: A common-rail fuel injection system is equipped with a common-rail, a fuel pump 11, and an injector. The fuel pump has a plurality of fuel pumping systems. A pressure sensor is provided at a fuel inlet of the injector. When the fuel pump supplies fuel to each of the fuel pumping systems, an ECU detects a variation in fuel pressure in a fuel passage between the fuel pump and the injector. Based on the detected fuel pressure variation, the ECU computes a pumping characteristic with respect to each of the fuel pumping systems.

Abstract: A fuel temperature sensing device has fuel temperature sensors provided to respective cylinders for sensing fuel temperature. Each fuel temperature sensor is arranged in a position closer to an injection hole than to a pressure accumulator in a fuel passage extending from the pressure accumulator to the injection hole. The device has an average value calculating section for calculating an average value of fuel temperature sensing values sensed with the fuel temperature sensors of the respective cylinders. The device has a deviation calculating section for calculating deviations between the average value and the fuel temperature sensing values of the respective fuel temperature sensors. The device has a correcting section for correcting the fuel temperature sensing value of each fuel temperature sensor to approximate the deviation to zero for each fuel temperature sensor.