JP2017008901A - Ignition control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ignition control device which suppresses the displacement of ignition execution timing when an engine rotational speed is abruptly increased, and can enhance the control accuracy of the ignition execution timing more than a conventional control method.SOLUTION: An ignition control device of an internal combustion engine calculates an ignition execution crank angle CIGE by an ignition plug 7 according to an engine operation state, converts an angle period from electricity-carrying finish reference timing CIGRE up to the ignition execution crank angle CIGE to an ignition standby time TIGE, and performs ignition at a time point at which the ignition standby time TIGE elapses from the electricity-carrying finish reference timing CIGRE. When a CRK pulse of a crank angle six-degree interval is created, and also when it is determined that a crank angle which is detected on the basis of the CRK pulse is at a retardant side rather than the ignition execution crank angle CIGE, and a succeeding CRK pulse is created after the determination within a period from the electricity-carrying finish reference timing CIGRE up to the lapse of the ignition standby time TIGE, the ignition control device performs the ignition at that time point.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an ignition control device for an internal combustion engine, and more particularly to an ignition control device for controlling the execution timing of ignition by a spark plug provided in a combustion chamber.

  Patent Document 1 discloses ignition timing control for controlling the output timing (energization start timing) and energization angle (energization time) of an ignition primary current using a crank angle signal (REF signal and POS signal) synchronized with the rotation of an internal combustion engine. The device is shown. According to this device, control is performed to increase the maximum value of the ignition timing advance amount in a transient state including when the engine is started, compared to a non-transient state, and in the transient state, the energization start timing of the primary current is non-transient. By advancing from the state, sufficient energization time is ensured by the ignition execution timing.

  Patent Document 1 does not disclose a specific control method of the ignition execution timing, which is the timing when the energization time has elapsed from the energization start timing, but is generally performed as shown in FIG. Energization start timing CIGS and energization end timing CIGE (corresponding to ignition execution timing) of the ignition coil (primary coil) indicated by the crank angle at the predetermined calculation timing CCAL (for example, 120 degrees before the top dead center at the end of the compression stroke) Calculate according to the state. At this time, energization is performed from the energization start reference timing CIGRS (for example, 90 degrees before the top end of the compression stroke) to the energization start timing CIGS and the energization end reference timing CIGRE (for example, 30 degrees before the end of the compression stroke top dead center). The angle period until the end timing (ignition execution timing) CIGE is converted into the energization standby time TIGS and the ignition standby time TIGE, respectively, using the engine speed at that time. Thereafter, at the energization start reference timing CIGRS, the energization standby timer TMIGS is set to the energization standby time TIGS and started, and at the energization end reference timing CIGRE, the ignition standby timer TMIGE is set to the ignition standby time TIGE and started.

  Energization of the primary coil starts from time tIGS (CIGS) when the value of the energization standby timer TMIGS becomes "0", and energization of the primary coil occurs at time tIGE (CIGE) when the value of the ignition standby timer TMIGE becomes "0". Finish and execute ignition.

Japanese Patent No. 3791364

  According to the ignition execution timing control method described above, if the engine speed is constant after the calculation timing CCAL, the time tIGE at which the value of the ignition standby timer TMIGE becomes “0” is the energization end timing as shown in FIG. Although it coincides with CIGE, for example, when the engine speed rapidly increases, the time tIGE is delayed from the energization end timing CIGE, and the actual ignition execution timing is calculated as the predetermined calculation timing CCAL (= energization) There is a problem of delaying from the end timing CIGE).

  The control method in the transient state disclosed in Patent Document 1 simply advances the energization start timing CIGS in order to sufficiently secure the energization time of the ignition coil, and cannot solve the above problem.

  The present invention has been made paying attention to this point, and can suppress the deviation of the ignition execution timing when the engine speed rapidly increases, and can improve the control accuracy of the ignition execution timing over the conventional control method. An object is to provide an ignition control device.

  In order to achieve the above object, an invention according to claim 1 is an ignition control device for an internal combustion engine for controlling an ignition execution timing by a spark plug (7) provided in a combustion chamber of the internal combustion engine (1). Crank angle pulse generating means (10) for generating a crank angle pulse (CRK pulse) at a predetermined rotation angle (6 deg) in synchronization with the rotation of the crankshaft (8), and the ignition according to the operating state of the engine Ignition execution crank angle calculation means for calculating an ignition execution crank angle by the plug, and an ignition standby time (using an engine rotation speed (NE)), an angle period from a reference crank angle to the ignition execution crank angle (CIGE). Ignition standby time calculation means for converting to TIGE), and when the ignition standby time (TIGE) has elapsed from the reference crank angle (CIGRE) ( Ignition execution control means for executing ignition by the spark plug at IGE), the ignition execution control means within a period until the ignition standby time (TIGE) elapses from the reference crank angle (CIGRE), The crank angle detected based on the crank angle pulse is determined to be the same as or more retarded than the ignition execution crank angle (CIGE), and the next crank angle pulse is generated after the determination time (CDET, tDET). In this case, ignition by the spark plug is executed at the crank angle pulse generation time (CIGEM, tIGEM).

  According to this configuration, the ignition execution crank angle by the ignition plug is calculated according to the engine operating state, the angle period from the reference crank angle to the ignition execution crank angle is converted into the ignition standby time using the engine rotation speed, When the ignition standby time has elapsed from the reference crank angle, ignition by the spark plug is executed. A crank angle pulse having a predetermined rotation angle interval is generated in synchronization with the rotation of the crankshaft of the engine, and a crank angle detected based on the crank angle pulse is determined within a period until the ignition standby time elapses from the reference crank angle. When it is determined that the crank angle pulse is equal to or more retarded than the ignition execution crank angle, and the next crank angle pulse is generated after the determination time, ignition by the spark plug is performed at the crank angle pulse generation time. Therefore, when the engine speed increases rapidly, ignition by the spark plug is executed at the time of occurrence of the crank angle pulse before the ignition standby time elapses from the reference crank angle. As a result, the delay of the actual ignition execution timing can be suppressed, and the control accuracy of the ignition execution timing can be improved over the conventional control method.

  The invention according to claim 2 is the ignition control device for an internal combustion engine according to claim 1, wherein the calculation processing by the ignition execution crank angle calculation means, the ignition standby time calculation means, and the ignition execution control means is It is characterized by being executed at an angular period (30 deg) longer than a predetermined rotation angle (6 deg).

  According to this configuration, the calculation process of the ignition execution crank angle and the ignition standby time and the ignition execution control process are executed at an angular cycle longer than the predetermined rotation angle, so that the calculation is performed at every predetermined rotation angle. Thus, the processing load on the arithmetic unit can be reduced.

It is a figure which shows the structure of the internal combustion engine and its control apparatus concerning one Embodiment of this invention. It is a time chart for demonstrating the specific method of ignition timing control. It is a flowchart of the process which performs ignition timing control. It is a time chart for demonstrating the conventional ignition timing control method.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of an internal combustion engine and a control device thereof according to an embodiment of the present invention. An internal combustion engine (hereinafter simply referred to as “engine”) 1 has, for example, six cylinders and includes an intake passage 2. A throttle valve 3 is provided in the intake passage 2.

  The fuel injection valve 6 is provided for each cylinder between the engine 1 and the throttle valve 3 and slightly upstream of the intake valve (not shown) in the intake passage 2, and each injection valve is connected to a fuel pump (not shown). At the same time, it is electrically connected to an electronic control unit (hereinafter referred to as “ECU”) 5, and the opening timing and opening time (fuel injection timing and fuel injection time) of the fuel injection valve 6 are controlled by a control signal from the ECU 5. .

  The ignition plug 7 of each cylinder of the engine 1 is connected to the ECU 5, and the ignition timing is controlled by an ignition signal from the ECU 5. An ignition coil (not shown) is connected to the spark plug 7, and when the primary current is supplied to the primary side of the ignition coil and the primary current is cut off, a high voltage is generated on the secondary side of the ignition coil. Thus, ignition is performed (discharge is performed in the spark plug 7).

An intake pressure sensor 9 for detecting the intake pressure PBA is provided downstream of the throttle valve 3 in the intake pipe 2, and the detection signal is supplied to the ECU 5.
A crank angle position sensor 10 for detecting the rotation angle of the crankshaft 8 of the engine 1 is connected to the ECU 5, and a signal corresponding to the rotation angle of the crankshaft 8 is supplied to the ECU 5. The crank angle position sensor 10 is a cylinder discrimination sensor that outputs a pulse (hereinafter referred to as a “CYL pulse”) at a predetermined crank angle position of a specific cylinder of the engine 1, and a start position of a specific stroke (for example, an intake stroke) of each cylinder. A TDC sensor that outputs a TDC pulse at a crank angle position before a predetermined crank angle with respect to the dead center (TDC) (every crank angle of 120 degrees in a 6-cylinder engine), and a constant crank angle cycle shorter than the TDC pulse (for example, a cycle of 6 °). It consists of a CRK sensor that generates one pulse (hereinafter referred to as “CRK pulse”), and a CYL pulse, a TDC pulse, and a CRK pulse are supplied to the ECU 5. These pulses are used for various timing controls such as fuel injection timing and ignition timing, and detection of engine speed (engine speed) NE.

  The ECU 5 shapes input signal waveforms from the crank angle position sensor 10, the intake pressure sensor 9, and various sensors (not shown), corrects the voltage level to a predetermined level, converts an analog signal into a digital signal, and converts the converted digital An input circuit that outputs signals, a CPU that executes various arithmetic processes, a memory that stores various arithmetic programs executed by the CPU and arithmetic results, a drive control signal output from the CPU, a fuel injection valve 6 and a spark plug 7 An output circuit is provided for supplying the output.

  The CPU of the ECU 5 calculates a fuel injection time and a fuel injection timing in accordance with detection signals from various sensors, and executes a process of calculating an ignition timing (an ignition coil energization start timing CIGS and an energization end timing CIGE). A fuel injection control signal and an ignition control signal for driving the fuel injection valve 6 and the spark plug 7 are generated and output according to the fuel injection timing and the ignition timing.

  FIG. 2 is a time chart for explaining a specific method of ignition timing control. FIGS. 2A and 2B correspond to the case where the engine speed NE is substantially constant, and FIG. ) (D) corresponds to the case where the engine speed NE increases rapidly after calculating the energization end timing (ignition timing) CIGE. In these drawings, “TDC” corresponds to the top dead center at the end of the compression stroke of the ignition target cylinder, and the downward arrow indicates the generation time of the CRK pulse. A number (93 to 107) that increases each time a CRK pulse is generated is an index CRKCNT for specifying a CRK pulse generation interval period (hereinafter referred to as “CRK angle period”), and takes a value from 0 to 119. In the compression stroke of the control target cylinder (# 6 cylinder) shown in the figure, it is defined to take values from 75 to 104. Note that the energization standby timer TMIGS is not shown.

  The method shown in FIGS. 2A and 2B is the same as the conventional method described with reference to FIG. 4, and the operating state of the engine 1 at a predetermined calculation time CCAL (120 degrees before the top dead center at the end of the compression stroke). Accordingly, the energization start timing CIGS and the energization end timing CIGE are calculated, and the angle period from the energization end reference timing CIGE (30 degrees before the compression stroke end top dead center) to the energization end timing CIGE is the engine speed NE at that time. Is converted into the ignition standby time TIGE. The ignition standby timer TMIGE is set to the ignition standby time TIGE at the energization end reference timing CIGRE and started, and the energization of the primary coil is ended at the time tIGE (matching CIGE) when the value of the ignition standby timer TMIGE becomes “0”. Thus, ignition is performed.

  As shown in FIGS. 2C and 2D, when the engine speed NE suddenly increases during the countdown of the ignition standby timer TMIGE, the energization end time tIGE at which the value of the ignition standby timer TMIGE becomes “0”. Is greatly delayed from the energization end timing CIGE. Thus, in the present embodiment, when it is detected that the value of the ignition standby timer TMIGE is not “0” at the CRK pulse generation timing CDET (generation time tDET) immediately after the energization end timing CIGE, At the CRK pulse generation time CIGEM (generation time tIGEM), the primary coil is turned off and ignition is performed.

  Unlike the examples shown in FIGS. 2C and 2D, when the value of the ignition standby timer TMIGE becomes “0” during the CRK angle period in which the index CRKCNT is “104”, the ignition is performed at that time. Execute.

  As a result, when the engine speed NE increases rapidly, it is possible to suppress the delay of the ignition execution timing CIGE and prevent the engine output from decreasing.

FIG. 3 is a flowchart of the process for executing the ignition timing control described above, and this process is executed every 30 degrees of the crank angle.
In step S11, it is determined whether or not the timing is 120 degrees before the top dead center of the compression stroke of the ignition target cylinder. If the answer is affirmative (YES), the energization start timing CIGS, the energization end timing CIGE ( Ignition execution timing), energization standby time TIGS, and ignition standby time TIGE are calculated, and the index CRKCNT of the CRK angle period including the energization end timing CIGE is calculated as an ignition execution index value CRKCNTIG (step S12). When the energization end timing CIGE coincides with the end of the CRK angle period (CDET) in which the index CRKCNT is “103” shown in FIG. 2C, for example, the ignition execution index value CRKCNTIG is calculated as “103”. The

  When the answer to step S11 is negative (NO), it is determined whether or not the timing is 90 degrees before the compression stroke end top dead center (energization start reference timing CIGRS) (step S13). If the answer is affirmative (YES), the energization standby timer TMIGS is set to the energization standby time TIGS and started (step S14), and the process waits until the value of the energization standby timer TMIGS becomes “0” (step S15). ). When the value of the energization standby timer TMIGS becomes “0”, energization of the ignition coil is started (step S16).

  If the answer to step S13 is negative (NO), it is determined whether or not the timing is 30 degrees before the compression stroke end top dead center (energization end reference timing CIGRE) (step S17). If the answer is affirmative (YES), the ignition standby timer TMIGE is set to the ignition standby time TIGE and started (step S18). In step S19, it is determined whether or not the value of the ignition standby timer TMIGE is "0". If the answer is negative (NO), the process proceeds to step S20, and the ignition execution index value CRKCNTIG (example shown in FIG. 2). Is determined whether the CRK angle period corresponding to the ignition execution index value CRKCNTIG has occurred (determining whether a CRK pulse indicating the end time of the CRK angle period corresponding to the ignition execution index value CRKCNTIG has occurred).

  If the answer to step S20 is negative (NO), the process returns to step S19, and if affirmative (YES), the process proceeds to step S21 to determine whether or not the next CRK pulse has occurred (step S21). If the answer to step S19 is negative (NO), the process returns to step S19. If the answer to step S21 becomes affirmative (YES) before the value of the ignition standby timer TMIGE becomes "0", ignition is executed at that time. (Step S22). If the value of the ignition standby timer TMIGE becomes “0” before the answer to step S21 becomes affirmative (YES), the process proceeds from step S19 to step S22, and ignition is performed.

  As described above, in the present embodiment, the ignition execution timing (energization end timing CIGE) by the spark plug 7 is calculated according to the operating state of the engine 1, and the angle period from the energization end reference timing CIGRE to the energization end timing CIGE is It is converted into the ignition standby time TIGE using the engine speed NE, and ignition by the spark plug 7 is executed when the ignition standby time TIGE has elapsed from the energization end reference timing CIGRE. In synchronization with the rotation of the crankshaft of the engine 1, CRK pulses are generated at intervals of 6 degrees, and within a period from when the energization end reference timing CIGR elapses to the ignition standby time TIGE (FIG. 3, the answer to step S19 is affirmative) Is determined to be equal to or more retarded than the ignition execution timing CIGE (the answer to step S20 is affirmative), and the next CRK pulse is determined after the determination time. When it is generated (the answer to step S21 is affirmative), ignition by the spark plug 7 is executed at the time when the CRK pulse is generated. Therefore, when the engine speed NE rises rapidly, ignition by the spark plug 7 is executed at the time when the CRK pulse is generated before the ignition standby time TIGE elapses from the energization end reference timing CIGRE. As a result, the delay of the actual ignition execution timing can be suppressed, and the control accuracy of the ignition execution timing can be improved over the conventional control method.

  Further, the ignition timing control process shown in FIG. 3 is executed at a cycle of 30 degrees which is longer than the generation cycle (6 degrees) of the CRK pulse. By executing the ignition timing control process at the generation cycle of the CRK pulse, it is possible to improve the control accuracy of the ignition timing when the engine speed NE suddenly increases even if the conventional control method is applied as it is. In this embodiment, the ignition timing control process is executed at a cycle of 30 degrees, and the interrupt process (steps S20 and S21) is performed at the generation timing of the CRK pulse, so that the processing load on the arithmetic unit can be reduced.

  In the present embodiment, the crank angle position sensor 10 corresponds to crank angle pulse generation means, and the ECU 5 constitutes ignition execution crank angle calculation means, ignition standby time calculation means, and ignition execution control means.

  The present invention is not limited to the embodiment described above, and various modifications can be made. For example, in the embodiment described above, the execution period of the ignition timing control process is set to a crank angle of 30 degrees and the generation period of the CRK pulse is set to a crank angle of 6 degrees. However, the execution period of the ignition timing control process is set to a crank angle of 15 degrees. It is possible to modify the pulse generation cycle to a crank angle of 3 degrees.

1 Internal combustion engine 5 Electronic control unit (ignition execution crank angle calculation means, ignition standby time calculation means, ignition execution control means)
7 Spark plug 8 Crankshaft 9 Crank angle position sensor (Crank angle pulse generating means)
CIGE Energization end timing (ignition execution timing)
NE engine speed (engine speed)
TIGE ignition standby time TMIGE ignition standby timer

Claims (2)

In an ignition control device for an internal combustion engine that controls ignition execution timing by an ignition plug provided in a combustion chamber of the internal combustion engine,
Crank angle pulse generating means for generating crank angle pulses at predetermined rotation angle intervals in synchronization with rotation of the crankshaft of the engine;
Ignition execution crank angle calculation means for calculating an ignition execution crank angle by the ignition plug according to the operating state of the engine;
An ignition standby time calculating means for converting an angle period from a reference crank angle to the ignition execution crank angle into an ignition standby time using a rotation speed of the engine;
Ignition execution control means for executing ignition by the spark plug when the ignition standby time has elapsed from the reference crank angle;
The ignition execution control means is configured such that a crank angle detected based on the crank angle pulse is equal to or more retarded than the ignition execution crank angle within a period from the reference crank angle until the ignition standby time elapses. And when the next crank angle pulse is generated after the determination time, ignition by the spark plug is executed at the crank angle pulse generation time.   The calculation performed by the ignition execution crank angle calculation unit, the ignition standby time calculation unit, and the ignition execution control unit is executed by processing of an angular period longer than the predetermined rotation angle. An ignition control device for an internal combustion engine.

Images