JPH05549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ignition timing control device for an internal combustion engine,
More specifically, the present invention relates to an ignition timing control device for an internal combustion engine that corrects ignition timing and improves transient responsiveness by detecting fluctuations in internal combustion engine cylinder pressure and detecting transient states of engine operation. Note that in this specification, the term "transient state" is used to mean acceleration or deceleration of engine operation.

(Prior Art) In a conventional ignition timing control device for an internal combustion engine, the ignition timing main control value is determined based on the engine speed and load condition, and the ignition timing main control value is also determined based on the engine cooling water temperature, throttle valve opening, manifold negative pressure, The main control value is corrected by detecting the transient state of engine operation based on the amount of accelerator pedal depression and the like. As an example, the apparatuses described in Japanese Patent Publication No. 58-40027 to Japanese Patent Application Laid-Open No. 61-16272 can be mentioned.

Furthermore, a technology has recently been proposed, such as the technology described in Japanese Patent Publication No. 58-33394, which detects the internal cylinder pressure of an internal combustion engine and controls the ignition timing so that the maximum pressure angle is located at the target angle. Even in such a case, it has been proposed to detect the transient state from the engine cooling water temperature as usual.
One example is the technique described in Publication No. 21913.

(Problems to be Solved by the Invention) However, the first conventional device requires a large number of detection means and their processing circuits in order to detect a transient state, which has the disadvantage of complicating the device configuration. Ta. Furthermore, when detecting a transient state, the detection accuracy is not sufficient because it is detected indirectly through changes in engine cooling water temperature, etc., and since it is not feedback control, we cannot expect much from the correction effect. It was hot. Therefore, the main control values had to be precisely determined, and corrections were only used as a side effect, which inevitably led to an increase in the main control value map and the need for large-capacity memory to store it. The disadvantage was that it was necessary to prepare for Furthermore, since the detection of transient states was indirect, it was difficult to say that the transient response was sufficient.
It is difficult to say that sufficient consideration has been given to drivability. Further, the conventional example described in the second Japanese Patent Publication No. 56-21913 cannot avoid the same disadvantage in that a large number of detection means and their processing circuits are required to detect a transient state. In addition, feedback control is used to directly detect the combustion state of the engine, find the deviation between the target angle and the actual maximum pressure angle, and determine the control value in the direction of eliminating the deviation. There was no suggestion as to how to eliminate the deviation in a transient state without impairing drivability. Furthermore, no countermeasures were provided for knocking, which tends to occur frequently during transient conditions.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional device, detect the cylinder pressure of the engine, directly detect the combustion state of the engine, and provide feedback control of the ignition timing. By measuring and detecting the transient state of engine operation, the target value of the maximum pressure angle is retarded in stages, improving transient response and drivability, and preventing knocking. An object of the present invention is to provide an ignition timing control device for an internal combustion engine, which can more accurately grasp a transient state by detecting it from the combustion state, and can reduce the number of detection means and its processing circuit.

Furthermore, by providing a means to directly detect the combustion state and converging the maximum pressure angle θpmax to the target value, it is possible to achieve ignition closer to the so-called MBT, thereby improving output, and also preventing a decrease in output even in transient conditions. An object of the present invention is to provide an ignition timing control device for an internal combustion engine that minimizes the ignition timing and also avoids knocking that tends to occur frequently during transient conditions and when ignition near MBT.

(Means for Solving the Problems) In order to achieve the above object, the present invention, as shown in FIG. 10,
Pressure maximum value calculation means 12 is connected to the cylinder pressure detection means and inputs its output to calculate the maximum value of the cylinder pressure; Transient state determining means 14, which determines the fluctuation rate of the maximum cylinder pressure value between cylinders and compares the fluctuation rate with a predetermined value to determine that the engine operation is in a transient state; a crank angle signal generating means 16 for generating a signal, connected to the crank angle signal generating means and the cylinder pressure detecting means;
A pressure maximum angle calculation means 18 inputting the outputs thereof and calculating a cylinder pressure maximum angle, connected to the pressure maximum angle calculation means and the pressure maximum value calculation means, a transient state detection means, and a crank angle signal generation means,
An ignition timing setting means 20 which inputs these outputs and sets the ignition timing of the engine so that the maximum pressure angle is located at the target value, and an ignition timing setting means 20 connected to the ignition timing setting means and which inputs the outputs and sets the ignition timing of the engine so that the maximum pressure angle is located at the target value. ignition means 22 for igniting the air-fuel mixture; when a transient state is detected, the maximum pressure angle target value is retarded by a predetermined amount compared to the steady operating state, and the ignition timing of the cylinder to be ignited next time is set to the above-mentioned value. It is configured to correct a value smaller than the quantitative one.

(Function) Calculates the rate of pressure fluctuation between cylinders, determines whether the calculated value is within a predetermined range, determines that it is a transient state if it is outside the predetermined range, and gradually delays the maximum pressure angle target value. Since the structure is configured to correct the angle, responsiveness and drivability during transient times are improved, knocking can be prevented, and the number of detection means etc. can be reduced.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Incidentally, FIG. 2 is a block diagram of the apparatus according to the present invention, and FIG. 3 is a waveform diagram thereof.

In FIG. 2, reference numeral 24 indicates an internal combustion engine;
In the case of the embodiment, four cylinders are provided. A piezoelectric sensor 10 serving as the cylinder pressure detection means is disposed in each cylinder at a position facing the combustion chamber. The sensor output is input to a low pass filter 26 via a charge-to-voltage converter or high impedance circuit (both not shown). The cutoff frequency of the filter is set higher than the knocking frequency component, so that high frequencies during knocking can also be detected.

A multiplexer 28 is connected to the next stage of the low-pass filter 26. The multiplexer selectively inputs the filter output to the next stage in the order of cylinder explosion in response to a command from a control unit 42, which will be described later.

A peak hold circuit 30 is connected to the next stage of the multiplexer to peak hold the output and output it as shown in FIG. The circuit includes an operational amplifier 30a, the non-inverting input terminal of which is connected to the multiplexer output. The operational amplifier includes a second operational amplifier 30 connected as a voltage follower through diodes 30b and 30c.
d, and its output is negatively fed back to the inverting input terminal of the first operational amplifier 30a via a resistor 30e, and a diode 30f and a resistor 30g are inserted in the negative feedback circuit. The resistor 30
c and the second operational amplifier 30d, the connection line is grounded via the resistor 30h and the capacitor 30i, and the reset signal line 30j and the resistor 30i are connected to the ground.
01 to the collector terminal of the operating transistor 30k.

An A/D conversion circuit 32 is connected to the next stage of the peak hold circuit 30. The conversion circuit inputs the output from the peak hold circuit, converts it into digital data every predetermined unit time or angle, and the maximum value of the data indicates the maximum pressure value Pmax. Alternatively, at a predetermined crank angle before peak hold reset, convert the digital value to the maximum pressure value.
It may also be set as Pmax (Figure 3).

Further, the next stage of the peak hold circuit 30 includes an A/
A comparison circuit 34 is connected in parallel with the D conversion circuit 32, and a pulse down edge detection circuit 36 is further connected at the subsequent stage. Comparison circuit 34 is operational amplifier 3
4a, a voltage source 34b and a resistor 34c connected to its output side, and the peak hold circuit output is input to its inverting input terminal, and
The multiplexer output is directly input to the non-inverting input terminal side, and since there is a slight difference between the two input values, the configuration is such that a pulse signal is output at the position where the maximum pressure value occurs (FIG. 3). As shown in Figure 3, the pulse is, in principle, one pulse at the maximum value generation position when knocking does not occur (a in the same figure), and when knocking occurs and high frequency components are superimposed, is configured to output a pulse not only at this position but also every time the sensor (multiplexer) output exceeds the peak hold output, and as a result, a plurality of pulses are output (see figure b). Further, the pulse down edge detection circuit 36
It is composed of a resistor 36a, a capacitor 36b, a resistor 36c, an inverter 36d, and a NOR gate 36e, and it grasps the falling edge timing of the comparator output pulse and outputs a pulse with a predetermined time width so that it can be easily processed by the circuit described later. Figure 3).

Therefore, the time from the reference position, for example, the TDC position, to the pulse generation position is measured and the measured value is
By converting Tpmax into an angle, the maximum pressure angle θpmax can be calculated, and by counting the number of generated pulses, it is possible to detect whether or not knocking has occurred. Note that, as shown in c in the figure, if the sensor fails, no pulse is generated even after the time measurement is completed.

A crank angle sensor 16 serving as the crank angle signal generating means is provided near the rotating part of the internal combustion engine 24, and the explosion at a predetermined crank angle, for example, in the four cylinders is detected in the order of the first, third, fourth, and second cylinders. go around
Cylinder discrimination signal every 720 degrees, and each cylinder every 180 degrees.
A TDC signal is output at the TDC position, and an angle measurement signal is output for each predetermined angle obtained by subdividing the TDC signal. Therefore, by counting the TDC signal after the cylinder discrimination signal is generated, the cylinder can be discriminated.
Incidentally, the engine speed can also be calculated from the angle measurement signal.

The cylinder discrimination signal may be configured to obtain a required detection signal based on a predetermined amplitude value obtained from a pressure sensor.

Further, the internal combustion engine 24 is provided with a negative pressure sensor 38 at an appropriate position between the throttle valve 40 of the internal combustion engine and an intake manifold (not shown) as a sensor for detecting the load state of the engine. This sensor is used together with the crank angle sensor to detect the operating state of the engine, and is used as a backup when the pressure sensor is abnormal, and can also be used for basic ignition timing calculation as described later.

A control unit 42 is connected to the next stage of the sensor groups 16 and 38, the A/D conversion circuit 32, and the pulse down edge detection circuit 36, and inputs their outputs. The control unit functions as the maximum pressure value calculation means 12, the transient state detection means 14, the maximum pressure angle calculation means 18, and the ignition timing setting means 20, and in the case of the embodiment, includes an input/output interface 42a and a CPU 42b. , memory 42c
and a clock 42d. The CPU includes a timer counter that counts the pulses of the pulse counter and the clock 42d to measure time, a cycle counter that counts ignition cycles for knocking control, and a cycle counter that counts the number of ignitions after the knocking ends. A lead angle counter is provided (not shown).

The ignition device 22, which is the ignition means, is connected to the next stage of the control unit, and upon receiving its output, the air-fuel mixture in the engine combustion chamber is ignited via a spark plug (not shown). Further, the peak hold circuit 30
The reset operation is also commanded from the unit through the reset line 30j.

Further, the unit receives input from a crank angle sensor 16, identifies cylinder status, and sends an input to a multiplexer 28.
to select the gate.

Next, the operation of the apparatus according to the present invention will be explained with reference to the waveform diagram in FIG. 3 and the flow charts in FIGS. 4 and 5.

First, in step 50, the cylinder is determined and a cylinder address C/A=n is assigned to specify the cylinder.
This is performed by the arrival of the cylinder discrimination signal and TDC signal of the above-mentioned crank angle sensor signal. This is because this control is characterized by being performed for each cylinder.

Simultaneously with the arrival of the TDC signal, the timer counter (TC) and pulse counter (PC) are started in step 52, and time measurement and pulse counting shown in FIG. 3 are started. In addition, before that, the multiplexer 28 at a predetermined angle of BTDC
It is assumed that the pressure sensor output of the relevant cylinder is being inputted at a predetermined crank angle via .

Next, in step 54, the ATDC predetermined angle is
For example, after 30 degrees have elapsed, refer to the counts of both counters. As shown in Figure 3, even though the timer counter has completed time measurement well beyond the maximum pressure value generation position, if the pulse counter value is "0" and no pulse is generated, the pressure It can be determined that the sensor is abnormal (Fig. 3c).

If not, it is determined in step 56 whether or not knocking has occurred by determining whether the pulse counter value exceeds a predetermined value. Note that the predetermined value is normally set to "1", but may be set to a value of "2" or more in consideration of the possibility that a plurality of pulses may be generated even during normal combustion due to noise or the like.

If the pulse count value is smaller than a predetermined value, it is determined that knocking does not occur, and the maximum pressure angle θpmax is determined in step 58. This is the conversion value k to the elapsed time Tpmax until the maximum pressure value generation position.
All you have to do is multiply it by Conversion value k = ((rotation speed rpm x 360
degree)/60 seconds).

Next, in step 60, the maximum pressure value Pmax is
Calculate. This is done by referring to the maximum value of the A/D conversion values.

Subsequently, in step 62, the pressure fluctuation rate ΔPmax is calculated, which is shown in FIG. 5 as a subroutine. Below, this subroutine will be explained with reference to FIG. 6. First, in step 62a, the maximum pressure value Pmax of the current cylinder calculated in step 60 is stored as Pmn, and then in step 62b, the maximum pressure value Pmax of the current cylinder calculated in step 60 is stored as Pmn. The maximum pressure value (hereinafter referred to as "Pmn-1") stored in the cylinder (cylinder address = n-1) (Fig. 6) and the same cylinder (cylinder address = n) stored in the same way
The pressure value in the previous cycle before the fourth ignition (hereinafter referred to as "Pmn-4") is read out. Incidentally, at the time of the first operation, these values are initialized as appropriate.

Next, in step 62c, the value of the current cylinder is
The fluctuation rates ΔPmax A and ΔPmax B are calculated by dividing Pmn by the values Pmn-1 and Pmn-4, and in step 62d, first, the fluctuation rate ΔPmax A is "1+".
It is determined whether or not the area exceeds a predetermined dead zone area.
The predetermined dead zone area is appropriately set, for example, to "0.1".

If it exceeds the predetermined value, that is, if the current pressure has increased by more than the predetermined value, then in step 62e, it is determined whether the other fluctuation rate ΔPmaxB exceeds "1+predetermined dead band area", and if the If so, it is determined that the fluctuation rate is relatively large and the engine operation is in a transient state, and in step 62f, the maximum pressure angle target value θpo is changed to the first predetermined angle correction, that is, to the retard side, to prevent knocking. This also prevents deterioration of the exhaust gas composition. Note that the first predetermined angle referred to herein means an angle sufficient to prevent knocking and the like.

If it is determined in step 62d that the variation rate ΔPmax A does not exceed "1 - a predetermined dead band region", it is determined in step 62g whether or not the fluctuation rate ΔPmax A falls below "1 - a predetermined dead band area".
At 62h, it is determined whether or not the other variation rate ΔPmax B falls below "1-predetermined dead band area". Similarly, if it is determined that it falls below, it is also set as a transient state and retarded angle correction is performed. That is, the present inventor has developed the present invention by focusing on the causal relationship between engine operation and the maximum cylinder pressure fluctuation rate, and when making a determination, the current cylinder pressure value is compared with the pressure value of another explosion cylinder immediately before and the previous cylinder pressure value. By double comparing the pressure value with the pressure value of the same cylinder in the cycle, it is ensured that there are no omissions, and it is configured to prevent erroneous judgments due to variations between cylinders.

After changing the target angle, in step 62i,
The ignition correction angle θt of the next ignition cylinder is set to the second predetermined angle retard side. Note that subtraction means retardation. The second predetermined angle herein means a value smaller than the first predetermined angle. Therefore, if the ignition correction angle θt is larger than the first predetermined angle in step 62l, it is set to the first predetermined angle (step 62m). That is, as will be described later, this control is performed for each cylinder in principle, but this ignition correction angle θt is given to the next ignition cylinder (cylinder address = n+1), and this correction amount is used as the target angle. By setting a value smaller than the correction amount, the ignition timing is gradually retarded for each cylinder, and the ignition timing is configured so that the target value is approximately reached in the same cylinder after the 4th ignition, thereby deteriorating drivability due to sudden changes in ignition timing. It is something to avoid. In other words, if a transient state occurs in the current cylinder, it is expected that the next cylinder will also be in a similar state, and the same correction angle will be given to the next ignition cylinder one after another, and the change will be made in the same cylinder after 4 ignitions. This is because it is expected that the angle will substantially match the target angle. Therefore, the second predetermined angle means a value such that the cumulative value after four ignitions is approximately equal to the first predetermined angle.

If the results of steps 62e, 62g, and 62h are negative, the pressure fluctuation rate is within the predetermined range and relatively small, so it is not determined that a transient state exists, and the maximum pressure angle target value θpo is set to the initial setting value. If the ignition correction angle θt is set and there is no retard correction value, no correction will be added, and if there is a predetermined angle retard correction value, the ignition angle will be gradually advanced by a second predetermined angle for each ignition cylinder,
Avoid deterioration of drivability due to sudden changes in ignition timing (steps 62j, 62n, 62o, 62k).
Furthermore, it is of course possible to select, as a comparison target, a cylinder that has undergone two ignitions or a cycle that is earlier than the previous cycle even if it is the same cylinder.

Returning to FIG. 4 again, after the subroutine of step 62, in step 64, the maximum pressure angle target value θpo is compared with the actual maximum pressure angle θpmax calculated in step 58 to determine the deviation Δθpmax. Note that if the target value is corrected in the subroutine, the corrected target value is set to θpo.

Next, in step 66, it is determined whether or not the knocking correction amount _KNR is not "0", that is, the remaining amount of the knocking correction amount is determined by referring to the memory 42c, and if the remaining amount is "0", the next knocking correction amount is determined. In step 68, it is determined whether the deviation Δθpmax is delayed or advanced. The deviation correction amount θpc is set as a value obtained by adding a third predetermined angle appropriately set to the previous θpc (initial setting "0") to advance the angle (step 70); The value is subtracted and retarded (step
72), if there is no deviation, stop at the previous value.
(Step 74). Incidentally, if this third predetermined angle is set to a relatively small value, the deviation is gradually resolved in a stepwise manner, so that drivability can be similarly improved. Note that, as mentioned above, subtraction means retard angle correction, and addition means advance angle correction.

If knocking is detected in step 56, the knocking correction angle KNR (initial setting "0") is immediately retarded by a fourth predetermined angle set appropriately (step 76). The angle is retarded until it reaches the fifth predetermined angle, which is appropriately set to be larger than the fourth predetermined angle (steps 78 and 80), and the deviation correction amount θpc is set to the value at the time of current ignition (step
82). If there is a knocking correction remaining in step 66, wait for a predetermined time or the number of ignitions after the knocking ends and return the advance angle by the fourth predetermined angle (steps 84 and 86), so that the deviation Δθpmax reaches the target value. On the other hand, in the case of advance, there is no need to return to the advance side, so θpc is retarded by a third predetermined angle (steps 88, 72), and in the case of delay, the correction amount θpc is left unchanged (step 82).
Note that a cycle counter and an advance angle counter in the control unit CPU are used to measure the predetermined time (number of ignitions) after the knocking ends.

Subsequently, in step 90, the sum of the correction amount θpc and the knocking correction amount _KNR is set as the feedback correction amount θf. If it is determined that the sensor is abnormal (step 54), the value obtained by retarding the sixth predetermined angle, which is appropriately set, is set as the feedback correction amount (step 92).

Next, in step 94, the feedback correction amount θf determined in this way is applied to the same cylinder (cylinder address =
Store it once (or rewrite it if it is already stored) so that it will be used as the correction value for the next cycle of n).
As mentioned above, since this control is for each cylinder, all the correction amounts including the knocking correction amount obtained in the above procedure will be reflected only in the relevant cylinder, so Control becomes possible.

Subsequently, in step 96, the stored feedback correction amount θf of the cylinder to be ignited next (cylinder address=n+1) is read out (initial setting is "0"), and ignition of the cylinder is commanded. At that time, the ignition timing is commanded as basic ignition timing + θf + θt.
Note that this “θt” and “K _NR ” at step 90
is itself a negative amount (retard amount), so “+”
Although expressed as follows, it actually means subtraction, that is, retardation. This θf is the feedback correction amount for the relevant cylinder read in the previous step, and θt is the sub-field in FIG.
This is the retard angle correction amount during a transient state, which is determined by a routine. Therefore, only the correction amount θt is used as a correction amount across cylinders, and by reflecting a correction amount smaller than the pressure target value correction amount to the next cylinder in this way, even during a transient period. Drivability is improved by retarding the angle in stages. Even with such a stepwise retardation, there is no problem because the transient state is detected relatively quickly by detecting the cylinder pressure and directly monitoring the combustion state. There is no
Furthermore, as a result of making knocking control possible, sufficient countermeasures against knocking, which is likely to occur during transient periods, have been taken.

This basic ignition timing calculation may be performed based only on the cylinder pressure to calculate the maximum pressure angle target angle θpo, or may be performed by detecting the operating state of the engine from the negative pressure sensor 38 and the crank angle sensor 16. It's good to wear. Even when calculating the basic ignition timing from the engine speed and negative pressure, the deviation between the actual maximum pressure angle and the target angle is detected after ignition, and the rotation speed-load map value is calculated using the corrected angle. Since this change is made in preparation for the next ignition and feedback control is performed to the target angle by sequentially repeating this process, the number of revolutions/load map values may be small, and therefore a small capacity memory is sufficient.

Next, FIG. 7 is an explanatory diagram showing the delay in detection. As described above, since the TDC detection delay angle to time (θ _TD or T _TD ) and the maximum pressure position detection delay angle to time (θ _SD or T _SD ) occur, the actual maximum pressure angle θpmax _ACT to (elapsed time Tpmax _ACT ) must be calculated as θpmax _ACT = θ _TD + (θpmax − θ _SD ).

FIG. 8 shows a second embodiment of the present device, in which a differentiating circuit 30' is used instead of the peak hold circuit.
This is what was used. Therefore, the multiplexer input is input to the A/D conversion circuit 32 on the one hand and A/D converted, and is also input to the differentiation circuit 3 in parallel.
0' is also input, and a zero cross output is sent to the comparator circuit 34 at the position where the maximum value occurs, and the next stage circuit 36 outputs a predetermined width pulse and inputs it to the control unit 42.

(Effects of the Invention) The present invention is configured to detect the cylinder pressure, detect the transient state of engine operation from the pressure change, and accordingly retard the maximum pressure angle target value in stages. It is possible to improve transient response and drivability, and to prevent knocking. Further, by detecting the combustion state, it is possible to grasp the transient state more accurately, and there is an advantage that the number of sensors and processing circuits for detecting the transient state can be reduced.
In addition, the basic ignition timing can be calculated only from the cylinder pressure or, as in the past, from the engine speed and load. Even when calculating from the engine speed and load, it is possible to calculate the basic ignition timing from the cylinder combustion state as well. As a result of feedback control to detect and focus on the target angle,
An extremely rough main control value map is sufficient, and the device has the advantage of being able to be configured with a small memory capacity.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a block diagram of the device according to the present invention, Fig. 3 is an output waveform diagram thereof, and Figs. 4 and 5 are flow charts showing the operation of the device. , FIG. 6 is an explanatory diagram explaining the contents of the flow chart in FIG. 5, FIG. 7 is an explanatory diagram showing countermeasures against detection delay, and FIG.
It is an explanatory view showing an example. 10... Cylinder pressure detection means (pressure sensor),
12... Maximum pressure value calculation means, 14... Transient state detection means, 16... Crank angle signal generation means (crank angle sensor), 18... Maximum pressure angle calculation means,
20... Ignition timing setting means, 22... Ignition means (ignition device) 42... Control unit (micro-
computer).

Claims (1)

[Scope of Claims] 1 a. Cylinder pressure detection means disposed in the cylinders of a multi-cylinder internal combustion engine to detect the cylinder pressure; b. Cylinder pressure detection means connected to the cylinder pressure detection means and inputting its output to detect the cylinder pressure a pressure maximum value calculation means for calculating the maximum value of the internal pressure; d) a crank angle signal generating means disposed near the rotating part of the internal combustion engine and generating a signal at a predetermined crank angle; e) the crank angle signal; pressure maximum angle calculation means connected to the generation means and the cylinder pressure detection means and inputting their outputs to calculate the cylinder pressure maximum angle; f the pressure maximum angle calculation means and the pressure maximum value calculation means; an ignition timing setting means connected to the state determining means and the crank angle signal generating means and inputting their outputs to set the ignition timing of the engine so that the maximum pressure angle is located at the target value; and g. ignition means connected to the engine and inputting its output to ignite the air-fuel mixture in the engine combustion chamber, and when a transient state is determined, the maximum pressure angle target value is retarded by a predetermined amount compared to the steady operating state. An ignition timing control device for an internal combustion engine, characterized in that the ignition timing of the cylinder to be ignited next is corrected to a value smaller than the predetermined amount. 2. The transient state determining means determines the fluctuation rate of the maximum pressure value among the plurality of explosion cylinders, determines whether the fluctuation rate is within a predetermined range, and determines that the transient state is present when it is determined that the fluctuation rate is not within the predetermined range. An ignition timing control device for an internal combustion engine according to claim 1, characterized in that the ignition timing control device for an internal combustion engine determines that. 3. The ignition timing control device for an internal combustion engine according to claim 1, wherein the plurality of explosion cylinders are different explosion cylinders or the same explosion cylinders between cycles.