JP2811698B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device for electronically controlling the ignition timing of an internal combustion engine.

2. Description of the Related Art Conventionally, various types of electronic ignition timing control devices of this type have been provided.
There is one described in 3768 Publication and the like. This is such that the correction time of the ignition timing corresponding to the angular acceleration is set to zero at the boundary of the dead zone of acceleration / deceleration, and outside the dead zone, the correction time changes continuously according to the angular acceleration with the zero as a base point. In addition, variations in the ignition advance angle that occur when the rotation speed is unstable such as during idling operation are suppressed, and the ignition timing is corrected in accordance with the angular acceleration.

Problems to be Solved by the Invention Incidentally, as a control method for correcting an error in the ignition timing generated by the angular acceleration of the crankshaft as described above,
A correction coefficient is obtained by a linear interpolation extrapolation method having a period described below, and a predetermined advance control is performed based on the correction coefficient. That measures the time required to rotate between the reference position pulses crank angle sensor is generated and stored, and calculates the difference value T _d between the previous value T ₂ and the current value T _1, the difference value Therefore, it is difficult to accurately control the ignition timing during acceleration over a wide range from a low speed to a high speed. More specifically, a specific example will be described first with reference to FIGS. 13 to 15 showing the relationship between the target ignition timing at the time of idling and the actual ignition timing. That is, when there is no angular acceleration correction, the actual ignition timing (broken line) is greatly delayed from the target ignition timing (solid line) during a series of accelerations as shown in FIG. On the other hand, when the angular acceleration is corrected by the above-described method and the correction coefficient is selected so that the target ignition timing and the actual ignition timing match on the low rotation speed side, if the correction is not performed, Although the accuracy is improved, the actual ignition timing (dashed line) is retarded with respect to the target ignition timing (solid line) as the engine speed increases as shown in FIG. On the other hand, if the correction coefficient is selected so that the target ignition timing matches the actual ignition timing on the high rotation side, the actual ignition timing on the low rotation side differs from the target ignition timing (solid line) as shown in FIG. The timing (broken line) is advanced. When the correction coefficient has a constant value, it is difficult to perform a highly accurate ignition timing at the time of acceleration.

Means and Solution for Solving the Problems The present invention has been made in view of the above-mentioned conventional problems, and generates a reference position pulse according to the number of cylinders at a predetermined crank angle as shown in FIG. A crank angle detecting means 100 for measuring the ON / OFF pulse width of the reference position pulse, and a means 200 for calculating the engine speed,
A means 300 for calculating a difference value between a time measurement value between the present and previous predetermined angles by a pulse or an OFF pulse and a time measurement value between the previous time and the predetermined angle two times before and a calculation of an ignition advance value according to the engine operating state. Means 400 for determining the angular acceleration correction coefficient as a function of the engine speed, and means 600 for correcting the difference value of the time measurement values, the ignition advance value, and the ignition timing correction during acceleration. Means 700 for determining whether or not the throttle opening amount is equal to or less than the idle speed.
And a means 800 for stopping the ignition timing correction by the ignition timing correction means 600 when the throttle opening is equal to or less than the idle speed. As described above, since the ignition timing correction coefficient is obtained as a function of the engine speed in particular, it is possible to appropriately suppress the ignition timing error caused by the angular acceleration. Moreover,
According to the present invention, when the opening of the throttle is equal to or less than the idle rotation speed, the ignition timing correction stopping means 800 stops the ignition timing correction by the ignition timing correction means 600, so that the idle rotation can be stabilized.

That is, the basic technical purpose of correcting the ignition timing based on the angular acceleration correction coefficient and the like by the above-described ignition timing correction means 600 is to optimize the ignition timing when the engine speed is rapidly increased during acceleration of the vehicle. The point is to improve the output by controlling. Therefore, if the above-described ignition timing correction is performed during idling, for example, if the rotation fluctuates slightly, that is, if the rotation slightly increases, the ignition timing correction means 60
There is a possibility that the ignition timing control works in the direction to increase the rotation by the ignition timing correction control by 0, and the idle rotation is increased.

Thus, as in the present invention, if the ignition timing correction control is stopped by the ignition timing correction stop means 800 during idling, stable rotation can always be obtained even if slight rotation fluctuation occurs. Conversely, even when the engine speed slightly decreases, control in the direction of reducing the rotation can be prevented, so that idling rotation can be stabilized.

Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

FIG. 4 shows a mechanical structure of a four-cycle four-cylinder electronically controlled internal combustion engine 1 to which the present invention is applied.
Is a microcomputer provided with a CPU 3, a ROM 4, a RAM 5, and an I / O port 6. The microcomputer 2 is a microcomputer which is provided with an intake air amount signal from an air flow meter 8 provided in an intake pipe 7.
Qa and, and opening degree signal TVO from opening detection sensor 10 of the throttle valve 9, other coolant temperature signal T _w from the water temperature sensor 11, the reference voltage V _s of the O ₂ sensor 13 provided in the exhaust pipe 12
Also, the current engine operating state is detected by inputting an engine speed signal N from a photoelectric crank angle sensor 21 built in the distributor 14, the ignition timing is controlled, and the signal is output to the ignition plug 15. On the other hand, the amount of injected fuel is controlled and the signal is output to the fuel injection valve 16.

The crank angle sensor 21 is connected to a rotor plate 22 connected to the disc shaft 17 as shown in FIG.
A light-emitting diode and a light-receiving diode (not shown) set above and below the rotor plate 22, and a signal processing unit. The rotor plate 22 includes # 1, # 2, # 3, and #
Four signal slits corresponding to four gases 23, 24, 25, 26
And one cylinder determination reference signal slit 27 are provided on the same circumference. The above four signal slits 23,2
4, 25, 26 are set to the same length in the circumferential direction, and are arranged at symmetrical positions with respect to each other with respect to the disc shaft 17, that is, at equal intervals of 180 ° (90 ° in the figure) by the rotation angle of the crankshaft. Has been established. Each signal slit 23, 24, 25, 26 has a crank angle 180 which is a reference position pulse signal for each cylinder.
As shown in Fig. 3a, the ON signal (H level P _H ) of ゜ rises from about 75 ° before the top dead center (TDC) of the crank rotation angle and falls about 5 ° before TDC. The width from the H-level edge to the L-level edge is set. On the other hand, the length of the cylinder determination reference signal slit 27 in the circumferential direction is set shorter than the length of each of the signal slits 23, 24, 25, and 26, and is in the vicinity of the # 1 cylinder signal slit 23, that is, about 30 mm after the TDC. Within the H level edge (O
H) is set at about 5 ° after TDC.

Then, ON-OFF pulse to the third crank angle 180 ° H level signal as shown in FIG. A P _H and the cylinder discrimination reference signal P _S by the light passing through each slit 23,24,25,26,27 Signal is output. The microcomputer 2 having received each pulse signal measures the time between the crank angle 180 ° signals to detect the engine speed N, and detects the engine speed N and the intake air amount signal from the air flow meter 8.
And performing variable ignition timing control Te by the Qa and the cooling water temperature T _W and the ignition timing value data sought is stored in advance as a function of the water temperature sensor 11 with (see FIG. 3 c), idling or deceleration At times, fixed ignition timing control is performed according to the engine speed N without using the ignition timing value data (see FIG. 3B). The H level P _H (ON) width of the 180 ° crank angle pulse signal is set to 70 ° and the L level P _O (OFF) width is set to 110 °. The pulse width is the same as the H level pulse width of 180 °, and the ignition timing is at the same time as the L level edge. On the other hand, the energization time in the variable ignition timing control is based on the energization time stored in the microcomputer 2 as the energization angle. calculated sought, the ignition timing is set to advance the timing of a predetermined angle relative to the H level P _H of the crank angle 180 ° signal, in the variable ignition timing control, the angular acceleration during vehicle acceleration Control is also performed to control the resulting ignition timing error by predetermined means described later.

In addition, the microcomputer 2 performs the simultaneous injection of all cylinders based on the crank angle position detection signal at the time of starting, for example, at the initial stage of the fuel injection control according to the engine operating state. It is performed a so-called sequential injection for injecting sequentially based on the cylinder discrimination signal P _S to the compression top dead center of each cylinder and.

Hereinafter, the control operation of the microcomputer 2 will be described as a fifth operation.
The description will be made based on the flowchart in FIG. This basic routine interrupts at the rise or fall of the reference position pulse (H level P _H ...) Output from the crank angle sensor 21. First, between each pulse in section 1 (FIG. 3 ADT ₁ ~
DT _n ) and read the time ratio (DDT) in section 2
Is calculated by the formula of DT _n-1 / DT _n . Next, after turning on the start switch in section 3, it is determined whether or not the number of input pulses is equal to or more than a predetermined number. If it is ON, that is, if the number of pulses is five or less for two rotations or less of the crankshaft as in the initial stage of starting, the process proceeds to section 4 because no cylinder discrimination is performed. Here, the fuel injection is performed once every two H-level signals, the ignition is energized by the H-level signal, and the discharge control flag (FL
G) is set and the process proceeds to a routine (FLGA = 0) described later. On the other hand, if YES in section 3 above, 180 in section 5
判別 It is determined whether the pulse signal is at the H level or not. If the pulse signal is not at the H level, the process proceeds to the next routine by interruption due to a rising edge. If it is determined in section 5 that the signal is at the H level, the process proceeds to section 6, where it is determined whether the time ratio calculated in selection 2 is equal to or greater than a predetermined value. That is, here, the ratio θ _ON / θ between the current L level angle θ _OFF of the 180 ° pulse signal and the previous H level angle θ _ON.
It is determined whether _OFF (see FIG. 3) is larger than 3, for example. Here, "3 or more" is set to a value in which the resolution of the pulse width can be exhibited and a fixed advance angle range (5 ° to 10 °) of the ignition timing can be obtained. Here, when it is determined that the number is three or more (one out of five cylinder discrimination reference signals OH
Is set to 1 in the cylinder recognition signal FLGB in section 7 to simply recognize the cylinder. Next, section 8
From the measurement time T ₁₈₀ between the 180 ° angles described later The normal engine speed N is calculated by the following equation. Next, it is determined in section 9 whether or not the start switch is OFF, and if it is OFF, the engine speed N in section 10 is, for example, 400 rpm.
It is determined whether or not FLGC is equal to or more than 400 rpm, and if it is 400 r · p · m or more, it is determined whether or not FLGC is 1 in section 11.
In other words, here, it is determined whether or not all the conditions, such as the start switch and the engine speed, satisfy the condition for enabling the sequential control. If YES, the flag for performing the sequential injection and the ignition advance in the section 12 is set. Then, the process proceeds to a routine (FLGA = 2) described later.

On the other hand, if any one of the sections 9, 10, and 11 is NO, the process proceeds to the section 13, in which a flag for executing the simultaneous fuel injection twice a crankshaft rotation and the fixed energization angle and the ignition timing is set. Then, the process proceeds to a routine (FLGA = 1) described later.

On the other hand, if NO is determined in section 6 (other than the case of OH of the cylinder determination reference signal), it is determined in section 14 whether FLGB is 1 or not, that is, whether the cylinder recognition signal is on. And if YES, section 1
At 5 the M cylinder (CYL) is set to 0 and the reference is set. Where MC
YL is a variable using 0, 1, 2, and 3. When 0, the first cylinder is 1 and when 1 is the second cylinder, FLGB = 1
Sets MCYL to 0. Then section 16
To set the FLGC to 1 and set the time between 180 ° to T ₁₈₀ as an element to determine the engine speed N in section 17 as described above. Measured by So here, in section 15, MC
Since YL = 0, four times of DT ₂ + DT ₃ + DT ₄ + DT ₅ are added and measured. Then, in Section 18, there is to measure the time DTB This is a reference of the ignition timing and the angle of the previous H level P _H between clogging L level (110 °) between theta _1, in this case the cylinder discrimination because there is a reference signal P _S, including the signal P _S Measured by That is, measurement is performed by adding three times of DT ₃ + DT ₄ + DT ₅ .

Subsequently, in section 19, as shown in FIG.
The time DTB between 110 ゜ θ ₁ is sequentially updated, and a new reference value is measured and stored. This is used to calculate an angular acceleration component described later, and is a control element of each acceleration correction ignition timing control added to the variable ignition timing control (FIG. 3c). Next, FLGB is set to 0 in section 20. That FLGB is in a state where not standing cylinder discrimination reference signal P _S is 0, in Section 5 this time MCYL
= 0, the next is 0 + 1, the first cylinder, and the second is the second cylinder.
Recognized as a cylinder, the process proceeds to the section 8, and the above-described determination and processing are performed thereafter.

Also, if not 1 the FLGB above section 14 stands has not been issued cylinder identification signal P _S, thus performs the processing for one cylinder at a time adding MCYL section 21,
Then in section 22 Use the formula to measure the time of 180 ゜. Followed by 1 in section 23
10 ° theta ₁ time DTB measured from DT _n, the above-mentioned section
The process proceeds to 19 to perform the subsequent processing.

Hereinafter, the above-described routine of FLGA = 0, FLGA = 1, and FLGA = 2 will be described. First, routine FLGA = 0 from the section 4 which is not able to cylinder identification is again 180 ° pulse signal section 30 as shown in FIG. 6, it is determined whether or not including H level cylinder discrimination reference signal P _S , if YES energizes the ignition primary coil in the vicinity of the compression top dead center close as 75 ° in section 31, section 32 determines whether or not subjected to fuel injection in the last pulse H level P _H signal, YES If so, the process returns without performing any processing. If NO is determined in section 32, the section
At 33, all cylinders are simultaneously injected. That is, in this section 33, simultaneous injection of all cylinders is performed at a rate of once every two times of the H level signal, and therefore, three simultaneous injections are performed with two rotations of the crankshaft. Accordingly, the startability is improved and the engine rotation can be stabilized. If the section 30 determines that the 180 ° pulse signal is at the L level P _L , the section 34 cuts off the current of the ignition primary coil. That is, the ignition is performed at about 5 ° before the compression top dead center, and the routine returns. In the state where the cylinder discrimination is not performed, the ignition is also performed at the time of the cylinder discrimination reference signal in addition to the crank angle position signal. However, the cylinder discrimination reference signal is generated at 5 ° after the compression top dead center, and the compression process is performed. Since the ignition is performed immediately after, there is no adverse effect on the engine combustion operation, and a favorable combustion operation can be obtained.

Next, in the routine of FLGA = 1 following the section 13, since the cylinder identification has already been performed and the operating condition is such as at the time of starting, the control as shown in FIG. 7 is performed. First, 180 degree pulse signal section 40 determines whether or not the H level P _H, when an H level P _H above time ratio in section 41 determines whether or or "3" or greater than a predetermined value . If it is determined that the number is 3 or more, a cylinder identification flag is set in section 42 and the routine returns. If NO in section 40, that is, L level is determined, the process proceeds to section 43, where it is determined whether or not the cylinder identification flag is set. If the cylinder is set, the process returns as it is. In section 44, the ignition primary coil current is cut off and ignition is started based on the fixed ignition timing control. On the other hand, when the time ratio in the above section 41 is determined to be equal to or lower than "3", that is, when the came to H level P _H of the cylinder discrimination reference signal P _S than 180 ° pulse signal, energizing the primary coil section 45 and subsequently determines whether the injection in the previous H level P _H in section 46. If YES here, the process proceeds to the section 48, and if NO, the all-cylinder simultaneous injection is performed twice in one rotation of the crankshaft in the section 47 and the process proceeds to the section 48. This section 48
Then, the process of lowering the cylinder identification flag is performed, and the process returns.

Next, the FLGA = 2 routine following from section 12 is:
As shown in FIG. 8, it is determined in section 50 whether or not the 180 ° pulse signal is at the H level P _H. If NO, the process returns as it is, but if YES, the time ratio is “3” in section 51.
It is determined whether or not this is the case. Here, if YES, the signal is cleared, but if NO, ignition and energization are performed by variable ignition timing control in each cylinder corresponding to MCYL based on sequential control in section 52, and fuel injection is performed for each cylinder. Return as it is.

Next, the ignition timing correction control of the angular acceleration will be described based on the flowchart of FIG. That is, first, in the section 60, the engine speed N, the basic injection amount T _P , the engine cooling water temperature T _W ,
Load the throttle opening TVO, then follow section 61
Then, a predetermined ignition advance value (θ _ADV ) is determined from TDC based on the above-mentioned ignition timing value data obtained from the functions of N, T _P and T _W. In section 62, as shown in FIG.
It reads the pulse time DTB _n between 110 ° theta _1, followed by opening degree TVO of the throttle valve 9 in the section 62 determines whether or not a predetermined or higher. Here if it is determined as YES, i.e. the idle rotation or the opening degree, reads the pulse time DTB _n-1 between the last 110 ° theta ₁ in section 64, the process proceeds to section 65. In this section 65, the angular acceleration correction coefficient K is read from a table map previously obtained from the function of the engine speed N shown in FIG. Then the section
Ignition energization time t _IGN at 66 It is calculated by the following equation. Here theta ₂ is, for example, from 3H-level edge of the ON pulse signal after theta ₁ to TDC of # 2CYL 75
゜ angle. Then, a timer is set so that the ignition plug 15 ignites after the energization time (t _IGN ) corrected as described above in section 67.

On the other hand, if it is determined in the above section 63 that the throttle opening amount (TVO) is equal to or less than the idle rotation, the energizing time is reduced in the section 68. It is calculated by the following equation. That is, when the engine is idling or lower,
The correction coefficient K is set to zero and the ignition timing is not corrected by the angular acceleration, but is set to the energization time based on the above-described fixed ignition timing control. As described above, especially when the throttle has an opening amount equal to or less than the idling speed, the ignition timing correction is stopped and the fixed ignition timing control is performed, so that the idling speed can be stabilized.

That is, the basic technical purpose of correcting the ignition timing based on the aforementioned angular acceleration correction coefficient and the like is to improve the output by controlling the optimum ignition timing when the engine speed suddenly increases during vehicle acceleration. It is in the point to let. Therefore, if the above-described ignition timing correction is performed during idling, for example, when the rotation is slightly changed, that is, when the rotation is slightly increased, the ignition timing control works in a direction to increase the rotation by the ignition timing correction control, and the idle rotation is reduced. There is a risk that it will rise.

Therefore, as in the present embodiment, if the ignition timing correction control is stopped during idling, stable rotation can always be obtained even if slight rotation fluctuation occurs.

Conversely, even when the engine speed slightly decreases, control in the direction of reducing the rotation can be prevented, so that idling rotation can be stabilized.

Here, the meaning of the angular acceleration correction coefficient K and the setting method thereof will be described with reference to FIGS. 11A to 11D and FIG. That is, when the rotation speed of the engine is constant, it is obvious that it is not necessary to perform the angular acceleration correction, and the more the rotation speed fluctuates, the more accurate the correction becomes. Considering now a case where the throttle valve 9 at which the fluctuation of the rotation speed is maximum is fully opened and rapid acceleration is performed is considered, first, when the throttle valve 9 is fully opened, the generated torque of the engine is reduced to the rotation speed. Because it is almost constant regardless of
11 As shown in FIG. C, the angular acceleration of the engine is substantially constant.
As a result, the engine rotational speed, which is the first-order integral of the angular acceleration, becomes a linear function as shown in FIG. 11B, and the engine rotational position θ, which is the second-order integral of the angular acceleration, becomes a quadratic function as shown in FIG. Becomes

Here, since θ was found to be a quadratic function of time t, it is represented by the general formula θ = 1 / 2at ² + bt + c.

Also, when considered in view of the theta = theta ₀ for subsequent state change based formula becomes ^{θ = 1 / 2at 2 + bt} ... '. A crank angle reference signal is generated at θ ₁ , θ ₂ , θ ₃ every predetermined crank angle θd (for example, 180 °),
t ₁ , t ₂ , t _n … Becomes

When t ₂ is obtained from the equation, t _n is obtained from the equation, and the difference t _n −t ₂ , that is, the time from the time t ₂ until the next crank angle reference signal is generated, is obtained. On the other hand, when the above correction equation χ is applied to the above equation, t _n −t ₂
= (T ₂ −t ₁ ) + K ｛(t ₂ −t ₁ ) − (t ₁ −t ₀ )｝... Substituting t ₁ , t ₂ obtained from the equation into the right side of the equation, When K is calculated with the right side = the right side of the equation, Here, considering the physical meaning of the expression, a is substantially constant as the angular acceleration, b is the engine rotation speed, and is changing every moment. θd is a predetermined value. Therefore, when K is obtained by substituting a, b, and θd, it is determined as shown by the solid line in FIG. When the engine rotation speed is low, the value becomes smaller than that at high speed, and the correction coefficient K is a function that depends on the rotation speed.

In this way, by preliminarily storing K in the table map shown in FIG. 12 during the operation of the engine, it is possible to quickly increase the value of K from the low speed to the high speed of the engine using the equation or the equation χ. Accurate ignition timing correction.

It should be noted that the table map may be configured such that different values can be selected according to the engine output according to the throttle valve opening or the fuel injection amount or the equivalent moment due to the engagement / disengagement of the clutch as shown in FIG. Needless to say.

As described above, in this embodiment, since the correction coefficient K is obtained from the function of the engine speed N, it is possible to appropriately suppress the ignition timing error caused by the angular acceleration. Also, a crank angle sensor
Since signal slits 23 to 26 corresponding to the number of cylinders and one cylinder discrimination reference signal slit 27 are arranged on the same circumference on the 21 rotor plate 22, the structure of the rotor plate 22 can be simplified. Further, since the cylinder discrimination reference signal slit 27 is formed within 30 ° after the compression top dead center, when the cylinder discrimination is impossible as in the early stage of starting, ignition is performed based on the cylinder discrimination signal in addition to the crank angle position signal. Even if it does, it will always be ignited before and after compression top dead center. Therefore, a situation in which ignition occurs during a suction stroke or the like is reliably avoided.

Note that the present invention is not limited to a four-cylinder engine.

Advantageous Effects of the Invention As apparent from the above description, according to the ignition timing control device for an internal combustion engine according to the present invention, in particular, the angular time between the reference position pulse generated this time from the crank angle detecting means and the previous time and the previous time and the last time before and after the previous time. The ignition timing at the time of acceleration is corrected by calculating the difference value of the measured value, the ignition advance value calculated according to the engine operating state, and the angular acceleration correction coefficient obtained as a function of the engine speed. As a result, an error in the ignition timing caused by the angular acceleration can be appropriately suppressed, and optimal ignition timing control during acceleration can be obtained. Moreover,
According to the present invention, when the throttle opening amount is equal to or less than the idle rotation speed, the ignition timing correction by the ignition timing correction means based on the angular acceleration correction coefficient or the like is stopped and the fixed ignition timing control is performed. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of an ignition timing control device according to the present invention, FIG. 2 is an enlarged view of a main part of a crank angle sensor used in an embodiment of the present invention, and FIG. 3 is a time chart of the crank angle sensor. FIG. 4, FIG. 4 is an overall configuration diagram showing control elements of the internal combustion engine to which the present embodiment is applied, FIG. 5 is a flowchart diagram showing basic control of the present embodiment, and FIG.
GA = 0 flowchart, Fig. 7 is FLGA shown in Fig. 5.
= 1, FIG. 8 shows FLGA shown in FIG.
2, FIG. 9 is a flowchart of the ignition timing correction control of this embodiment, FIG. 10 is a table map used for the ignition timing correction control, and FIGS. 11A to 11D show the meaning of the angular acceleration K. FIG. 12 is a characteristic map to be described, FIG. 12 is a map in which different values are stored in the table map shown in FIG. 10 according to a throttle valve opening and an equivalent moment of inertia due to clutch release, and FIG. 13 is a conventional ignition timing without angular acceleration correction. FIG. 14 and FIG. 15 are characteristic diagrams when angular acceleration is corrected by the linear interpolation extrapolation method. 100: crank angle detecting means, 200: engine speed calculating means, 300: difference value calculating means, 400: ignition advance value calculating means, 500: angular acceleration correction value determining means, 600: ignition timing Correction means, 700 ... Throttle opening amount detection means, 800 ...
Means for stopping ignition timing correction.

Claims (1)

(57) [Claims] 1. Crank angle detecting means for generating a reference position pulse for each cylinder at a predetermined crank angle, and means for calculating the engine speed by measuring the time of each ON / OFF pulse width of the reference position pulse. Means for calculating the difference between the time measurement between the current and previous predetermined angle and the time measurement between the previous and previous predetermined angle by the ON pulse or the OFF pulse, and the ignition advance according to the engine operating state Means for calculating a value, means for determining an angular acceleration correction coefficient as a function of the engine speed, and correction of ignition timing during acceleration from the difference between the time measurement values, the ignition advance value, and the angular acceleration correction coefficient. Means for judging whether or not the throttle opening amount is equal to or less than the idle speed, and means for stopping the ignition timing correction by the ignition timing correction means when the throttle opening amount is equal to or less than the idle speed. Ignition timing control apparatus for an internal combustion engine characterized by comprising a.