Abstract: An engine cooling system includes a coolant circuit, a multi-way valve, a relief route and a relief valve. The coolant circuit includes a first route and a second route into which the coolant circuit is branched off at a branched position. The first route passes through a radiator. The multi-way valve is provided at the branched position. The relief route sets a relief source to a portion downstream of a pump and upstream of the multi-way valve in the coolant circuit, sets a relief destination to a portion downstream of the radiator in the first route, and causes coolant to flow from the relief source to the relief destination so as to bypass the multi-way valve. The relief valve interrupts circulation of coolant through the relief route when the relief valve is closed, and permits circulation of coolant through the relief route when the relief valve is open.

Abstract: A drive system for fuel injection valves includes a battery, a capacitor, a drive control unit and an electronic control unit. The electronic control unit is configured to, when an energization start interval between a start of energization of a last one of the fuel injection valves and a start of energization of a current one of the fuel injection valves is longer than or equal to a peak reaching time of a last one of the fuel injection valves, extend an energization time of the current one of the fuel injection valves as the energization start interval reduces. The electronic control unit is configured to, when the energization start interval is shorter than the peak reaching time, reduce the energization time of the current one of the fuel injection valves is energized as the energization start interval reduces.

Abstract: A control device for a fuel injection valve includes a drive circuit that controls open/close operation of the fuel injection valve by passing an exciting current through a solenoid of the fuel injection valve and an ECU that reduces a peak current value as a fuel pressure in a delivery pipe at timing of a start of energization of the fuel injection valve decreases. The ECU reduces the peak current value as an amount of fuel discharged from a high-pressure fuel pump to the delivery pipe reduces.

Abstract: An electronic control unit that calculates an injection standby period, which is a period from an energization start point of the solenoid to a point at which the fuel injection valve opens, and adjusts an energization period of the solenoid in accordance with the calculated injection standby period. The electronic control unit of the control apparatus for a fuel injection valve then measures a reference fall detection period, which is a period from the energization start point to a reference fall detection point, and sets the injection standby period to be longer as the reference fall detection period is longer. Here, the reference fall detection point is a point at which the excitation current detected by the current detection circuit falls below a reference current value, which is smaller than a peak current value, while the excitation current decreases after reaching the peak current value.

Abstract: A fuel injection system for an engine, the fuel injection system includes injectors and an electronic control unit. The injectors include needle valves; and the ECU is configured to: (i) execute partial lift injection and full lift injection with the injectors, the partial lift injection being injection during which the needle valve does not reach a fully-open state and the full lift injection being injection during which the needle valve reaches the fully-open state; (ii) operate the engine in a partial lift injection region where the injection of a required injection amount of a fuel is shared by the partial lift injection and the full lift injection; and (iii) perform the amount of correction of the required injection amount with respect to the injection amount shared by the full lift injection when the required injection amount is corrected while the engine is operated in the partial lift injection region.

Abstract: A temperature reduction control for reducing the temperature of an injector is performed through first to third fuel supply control routines executed by an electronic control device. When the temperature of the injector is reduced by the execution of the temperature reduction control, heat transfer to the vicinity of the nozzle of the injector is reduced. Since the vicinity of the nozzle of the injector is less likely to be placed in a high-temperature environment by in accordance with reduction in heat transfer to the vicinity of the nozzle of the injector, the formation of deposit around the nozzle of the injector is suppressed.

Abstract: The apparatus of the present invention corrects a control target value of ignition timing using a multipoint learned value AGdp(n) for compensating for a change amount of the ignition timing caused by time-dependent change of the engine and a basic learned value AG(i) for compensating for a change amount of the ignition timing caused by a factor other than the aforementioned time-dependent change of the engine. In a multipoint learning range n in which the time-dependent change of the engine influences the ignition timing to a great extent, the control target is corrected using the multipoint learned value AGdp(n) and the basic learned value AG(i). In ranges other than the multipoint learning range n, the control target is corrected using only the basic learned value AG(i).

Abstract: An engine ECU executes operations including: extracting vibration intensities of a plurality of frequency bands from vibration detected by a knock sensor, multiplying the extracted vibration intensity of each frequency band by a weight coefficient and adding the results in correspondence with crank angles to calculate integrated values of every five degrees; calculating a coefficient of correlation based on a result of comparison between a vibration waveform of a frequency band and a knock waveform model prepared in advance; calculating a knock intensity; determining occurrence of knocking in accordance with the calculated coefficient of correlation and the knock intensity; and determining no occurrence of knocking in accordance with the calculated coefficient of correlation and the knock intensity.

Abstract: An output signal of a knock sensor is filtered with a plurality of band-pass filters to extract vibration waveform components of a plurality of frequency bands (f1-f4). Weighting coefficients (G1-G4) which multiply the vibration waveform component of each frequency band are established in such a manner as to be a small value as a noise intensity of each frequency band becomes larger. Thereby, the vibration waveform component of a plurality of frequency bands is synthesized by weighting according to an influence of a noise intensity of each frequency band. Even when the noise is superimposed on the vibration waveform component of any of the frequency bands, it becomes possible to reduce the influence of the noise and to synthesize the vibration waveform component of each frequency band, and an accurate knock determination can be performed based on the composite vibration waveform.

Abstract: An engine ECU executes a program including: detecting a magnitude of vibration of an engine; detecting a vibration waveform of the engine based on the magnitude; calculating a correlation coefficient, in the case where the engine speed is smaller than a threshold value, using the sum of values each determined by subtracting a positive reference value from a magnitude of a knock waveform model, as an area of the knock waveform model and, calculating the correlation coefficient, in the case where the engine speed is not smaller than the threshold value, using the area of the whole knock waveform model; and determining whether or not knocking has occurred using the correlation coefficient. The correlation coefficient is calculated by dividing by the area the sum of differences that are each the difference between the magnitude on the vibration waveform and the magnitude on the knock waveform model.

Abstract: An engine ECU executes a program including the steps of: calculating a knock magnitude N by dividing an integrated value lpkknk obtained by integrating the magnitude of vibration in the knock detection gate by BGL; controlling ignition timing according to a result of comparison between knock magnitude N and a determination value VJ; stopping updating of a standard deviation ? when it is determined that determination value VJ to be compared with knock magnitude N is to be changed; updating a median value VM by increasing an update amount of median value VM; and updating BGL according to median value VM and standard deviation ?.

Abstract: A knocking judgement method for an internal combustion engine, in which an engine ECU executes a program judging whether or not such ones of integrated values calculated by integrating the output of a knock sensor at every five degrees of a crank angle are larger than a tentative knock judgement value, in vibrations of a fourth frequency band containing the resonance frequency of the engine, tentatively judging that a knocking has occurred, in case the integrated value larger than the tentative knock judgement value is a predetermined number or more, and judging that no knocking has occurred, in case the integrated value larger than the tentative knock judgement value is not more than the predetermined number.

Abstract: An output signal of a knock sensor is filtered with a plurality of band-pass filters to extract vibration waveform components of a plurality of frequency bands (f1-f4). Weighting coefficients (G1-G4) which multiply the vibration waveform component of each frequency band are established in such a manner as to be a small value as a noise intensity of each frequency band becomes larger. Thereby, the vibration waveform component of a plurality of frequency bands is synthesized by weighting according to an influence of a noise intensity of each frequency band. Even when the noise is superimposed on the vibration waveform component of any of the frequency bands, it becomes possible to reduce the influence of the noise and to synthesize the vibration waveform component of each frequency band, and an accurate knock determination can be performed based on the composite vibration waveform.

Abstract: The apparatus of the present invention corrects a control target value of ignition timing using a multipoint learned value AGdp(n) for compensating for a change amount of the ignition timing caused by time-dependent change of the engine and a basic learned value AG(i) for compensating for a change amount of the ignition timing caused by a factor other than the aforementioned time-dependent change of the engine. In a multipoint learning range n in which the time-dependent change of the engine influences the ignition timing to a great extent, the control target is corrected using the multipoint learned value AGdp(n) and the basic learned value AG(i). In ranges other than the multipoint learning range n, the control target is corrected using only the basic learned value AG(i).

Abstract: An engine ECU executes a program including calculating a correlation coefficient by dividing the sum of respective absolute values, which are each a difference between a magnitude in an engine vibration waveform and a magnitude in a knock waveform model for every crank angle, by an area corresponding to magnitudes equal to or larger than a positive reference value in the knock waveform model, and determining whether or not knocking has occurred based on the correlation coefficient.

Abstract: An engine ECU executes a program that includes: calculating a median value and a standard deviation based on a calculated value based on the detected vibration of the engine; and subtracting a product of the standard deviation and a coefficient from the median value to calculate a magnitude of mechanical vibration specific to the engine. Knocking determination is carried out by comparing a knock magnitude calculated by dividing the magnitude value of the peak magnitude of the detected vibration of the engine by the magnitude of mechanical vibration specific to the engine with a predetermined determination value. Based on the knocking determination result, ignition timing of the engine is controlled.

Abstract: A device and associated method for controlling ignition timing of an internal combustion engine are provided. By comparing a determination value and knock magnitude, determination of knocking is made, and ignition timing is advanced or retarded. The device includes an operation unit that sets a correction amount of the determination value to a value corresponding to a degree of change of the determination value over time. The operation unit calculates, at a first timing, a first value related to an average value of the determination values; and calculates, at a second timing later than the first timing, a second value related to the average value of the determination values. The degree of change of the determination value is calculated as a difference between the first value and the second value.

Abstract: An engine ECU executes operations including: extracting vibration intensities of a plurality of frequency bands from vibration detected by a knock sensor, multiplying the extracted vibration intensity of each frequency band by a weight coefficient and adding the results in correspondence with crank angles to calculate integrated values of every five degrees; calculating a coefficient of correlation based on a result of comparison between a vibration waveform of a frequency band and a knock waveform model prepared in advance; calculating a knock intensity; determining occurrence of knocking in accordance with the calculated coefficient of correlation and the knock intensity; and determining no occurrence of knocking in accordance with the calculated coefficient of correlation and the knock intensity.

Abstract: A 90° integrated value calculating unit of an engine ECU calculates a 90° integrated value obtained by integrating a magnitude. A calculating unit calculates a knock magnitude by dividing 90° integrated value by a BGL. A value obtained by subtracting a standard deviation ? from a median value of 90° integrated value is determined as the BGL. An ignition timing control unit controls the ignition timing depending on whether knock magnitude is equal to or larger than a determination value. A median value calculating unit calculates median value of 90° integrated value. A standard deviation calculating unit calculates standard deviation of 90° integrated value. A first stop unit stops updating of median value and standard deviation when 90° integrated value is smaller than a first threshold value or is equal to or larger than a second threshold value.

Abstract: Out of synthesized waveforms of vibrations in a first frequency band A to a third frequency band C, a knock magnitude N is calculated by using a portion ? having an integrated value greater than a reference magnitude in a knock region but not using a portion having an integrated value greater than the reference magnitude out of the knock region (i.e., a region obtained by excluding the knock region from a knock detecting gate). In a case where knock magnitude N is greater than a determination value V(KX), it is determined that knocking occurs. In contrast, in a case where knock magnitude N is not greater than determination value V(KX), it is determined that no knocking occurs.