JPH0654110B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

The present invention relates to an ignition timing control device for an internal combustion engine.

It is well known that the octane number of gasoline has a strong correlation with knock resistance in an internal combustion engine. That is, the higher the octane number of gasoline, the less likely it is to knock. FIG. 1 shows an ignition timing-output shaft torque characteristic in an internal combustion engine in which commercially available regular gasoline and premium gasoline (having an octane number higher than that of regular gasoline) are used. Point A is the knock limit point when using regular gasoline, and point B is the knock limit point when using premium gasoline. Knock occurs when the ignition timing is advanced beyond the knock limit point. According to Fig. 1, the ignition timing can be advanced to point B when using premium gasoline.
It is possible to improve the output shaft torque. FIG. 2 is an ignition timing characteristic diagram showing the ignition timing at points A and B in FIG. 1 with respect to the rotational speed of the internal combustion engine.

In the internal combustion engine having such characteristics, when the regular gasoline and the premium gasoline are mixedly used or converted and used, the output of the engine is improved by advancing the ignition timing according to the mixture ratio of the regular gasoline and the premium gasoline. It will be possible.

[Conventional technology]

By the way, in the conventional ignition timing control device, since the reference ignition timing characteristic is set only for a predetermined gasoline, for example, regular gasoline, in the case of mixed use or conversion use of premium gasoline, the reference ignition timing as it is. In terms of characteristics, the engine output could not be expected to be improved, and the reference ignition timing had to be reset to the advance side by some method. In particular, when using regular gasoline and premium gasoline as a mixture, depending on the mixture ratio, there is a knock limit point between (A) and (B) as shown by the broken line in Fig. 2 (c), and the advanceable limit changes. Therefore, it is not easy to reset the reference ignition timing. Even if the reference ignition timing could be reset to the knock limit point, the knock limit point fluctuates due to environmental conditions during engine operation, such as temperature and humidity, and during excessive operation such as engine acceleration. Since knocks are likely to occur, it was impossible to avoid knocking the engine.

[Outline of Invention]

The present invention has been made with respect to the above point, and stores the first ignition timing data and the second ignition timing data corresponding to regular gasoline and premium gasoline, respectively, and detects a knock occurrence using a knock sensor. Then
The reference ignition timing displacement amount indicating the mixing ratio of regular gasoline and premium gasoline of the gasoline in use is determined from the detected value, and it is between the first ignition timing data and the second ignition timing data accordingly. As described above, by setting the reference ignition timing to the advance side or the retard side, the mixture ratio of regular gasoline and premium gasoline is automatically determined, and the reference ignition timing is adjusted to the optimum position.
The ignition timing is retarded so as to immediately suppress the occurrence of knocking when knocking occurs during sudden changes in environmental conditions during engine operation or during transient operation.

〔Example〕

Next, examples of the present invention will be described. FIG. 3 shows the first of the present invention.
It is a block diagram showing an embodiment of the. In FIG. 3, reference numeral 1 denotes a knock sensor which is attached to the engine and detects knock of the engine. Reference numeral 2 denotes a knock determination unit that determines whether or not knock has occurred from the output signal of the knock sensor 1, and includes a bandpass filter BPF21 and a noise level detector 2
2. Comprised of a comparator 23. The input of the bandpass filter 21 is connected to the knock sensor 1, and the output is connected to one comparison input of the comparator 23 and the noise level detector 22. The output of the noise level detector 22 is connected to the other comparison input of the comparator 23. Reference numeral 3 is a delay angle control amount determination unit that calculates from the output of the knock determination unit 2 and determines a delay angle control amount for suppressing knock generation of the engine.
It is composed of an integrator 31 and an A / D converter 32. The integration input of the integrator 31 is connected to the output of the comparator 23, and the output is connected to the input of the A / D converter 32. Reference numeral 4 is a reference ignition timing displacement amount determination unit that determines the displacement amount of the reference ignition timing of the engine, and includes a pulse generator 41, a counter 42, and a timer 4.
3, up-down counter 44, timer 45, memory 4
It is composed of 6. The input of the pulse generator 41 is connected to the output of the comparator 23, and the output is connected to the count input of the counter 42. The timer 43 is connected to the reset input of the counter 42. The up count input of the up / down counter 44 is connected to the output of the counter 42, and the down count input is connected to the timer 45. The data input of the memory 46 is connected to the output of the up / down counter 44, and the data output is connected to the preset input of the up / down counter 44. Reference numeral 5 is a first ignition timing characteristic storage unit (hereinafter referred to as ROM5), and 6 is a second ignition timing characteristic storage unit (hereinafter referred to as ROM6), which is determined by the engine speed and load as shown in FIG. The ignition timing data is stored in each address. Reference numeral 7 denotes a first ignition timing calculator, which includes a proportional coefficient calculator 71, an interpolation calculator 72,
It is composed of a subtractor 73. The proportional coefficient calculator 71 has an input connected to the output of the up / down counter 44, and converts the count content of the up / down counter 44 into a proportional coefficient and outputs it. The interpolation calculator 72 inputs the data of the ROM 5 and the ROM 6 and the output value of the proportional coefficient calculator 71, and stores them in the ROM.
5 and the data of the ROM 6 are interpolated by the coefficient output from the proportional coefficient calculator 71, and the ignition timing data obtained by the calculation is output. The subtractor 73 has two inputs connected to the output of the interpolation calculator 72 and the output of the A / D converter 32, respectively, and subtracts the output value of the A / D converter 32 from the ignition timing data output from the interpolation calculator 72. And outputs ignition timing data shifted to the retard side. Reference numeral 8 is a crank angle sensor for detecting the crank rotation angle of the engine, and 9 is a pressure sensor for detecting the intake air pressure of the engine. A second ignition timing calculator 10 calculates the engine speed from the output signal of the crank angle sensor 8, detects the load state of the engine from the pressure sensor 9, and is determined by those engine speed and load. The value is converted into an address value, and the address value is output to the ROM 5 and the ROM 6. Then, the second ignition timing calculator 1
0 is the output of the first ignition timing calculator (output of the subtractor 73)
The ignition timing data is read, the ignition timing is calculated from the output data of the first ignition timing calculator 7 with the output signal of the crank angle sensor 8 as a reference, and the ignition signal is output. 1
Reference numeral 1 denotes a switching circuit that intermittently energizes the ignition coil 12 in synchronization with the ignition signal output from the second ignition timing calculator 10 to generate a high voltage necessary for ignition of the internal combustion engine.
The knock sensor 1 and the knock determination unit 2 constitute knock detection means for detecting knock of the internal combustion engine. The reference ignition timing displacement amount determination unit 4 and the proportional coefficient calculator 71 constitute parameter setting means for setting parameter information that gradually changes in correlation with the octane number of the fuel used, based on the outputs of the knock detection means 1 and 2. ing. ROM 5 and 6
Is set for each operating state of the internal combustion engine so as to provide a first basic ignition timing and a second basic ignition timing respectively corresponding to the first reference fuel and the second reference fuel having different octane numbers. The storage means is configured to store the ignition timing data and the second ignition timing data. The crank angle sensor 8 and the pressure sensor 9 constitute a driving state detecting means for detecting a driving state. The interpolation calculator 72 outputs the corresponding first ignition timing data and second ignition timing data from the storage means 5 and 6 on the basis of the outputs of the operating state detecting means 8 and 9, and outputs both of them. Basic ignition timing setting for setting basic ignition timing information between the first basic ignition timing and the second basic ignition timing corresponding to the parameter information based on the ignition timing data and the outputs of the parameter setting means 4 and 71. Constitutes a means. The second ignition timing calculator 10, the switching circuit 11, and the ignition coil 12 constitute ignition timing control means for controlling the ignition timing of the internal combustion engine based on the output of the basic ignition timing setting means 72.

Further, the calculator 73, the second ignition timing calculator 10, the switching circuit 11, and the ignition coil 12 ignite the internal combustion engine based on the output of the basic ignition timing setting means 72 and the output of the retard control amount determining means 3. Ignition timing control means for controlling the timing is configured.

Next, the operation of the first embodiment will be described.

FIG. 5 shows the operation of each unit of the knock determination unit 2. The knock sensor 1 is a generally well-known vibration acceleration sensor, which is attached to a cylinder block of an engine or the like, converts mechanical vibration of the engine into an electric signal, and generates a vibration wave signal as shown in FIG. 5 (a). Is output. The bandpass filter 21 passes only the frequency component peculiar to the knock from the output signal of the knock sensor 1 to suppress the noise component other than the knock, and as shown in (a) of FIG. It outputs a good signal. The noise level detector 22 can be composed of, for example, a half-wave rectification circuit, an averaging circuit, an amplification circuit, etc., and outputs the output signal of the bandpass filter 21 ((a) in FIG. The signal is converted to a DC voltage level by averaging, further amplified by a predetermined amplification degree, and output from the bandpass filter 21 (see (b) in FIG. 5 (b) as shown in (b) in FIG. 5 (b). )) The DC voltage that is higher than the noise component and lower than the knock component is output. The comparator 23 is the hand pass filter 2
When the output signal of No. 1 ((a) in FIG. 5 (b)) and the output signal of the noise level detector 22 ((b) in FIG. 5 (b)) are compared and no knock occurs (fourth) Since the output signal of the bandpass filter 21 ((a) of FIG. 5 (b)) does not exceed the output signal of the noise level detector 22 ((b) of FIG. 5 (b)) in FIG. When nothing is output and a knock occurs (Fig. 5D)
The output signal of the hand-pass filter 21 is shown in FIG.
(a) of (b) is the output signal of the noise level detector 22 (fifth
Since it exceeds (b) in FIG. 2 (b), a pulse train is output as shown in FIG. 5 (c). Therefore, the occurrence of knock can be determined by the presence / absence of the output of the pulse train (FIG. 5 (c)) from the output of the comparator 23.

FIG. 6 shows the operation of each part of the retard control amount determining part 3 and the reference ignition timing displacement determining part 4. The integrator 31 integrates the pulse train (FIG. 6 (c)) output from the comparator 23, and outputs an integrated voltage as shown in FIG. 6 (d). When the pulse train of the comparator 23 is output, it operates to increase the output voltage of the integrator 31 according to the pulse train, and when the pulse train is not output, it operates to decrease the output voltage of the integrator 31. The output voltage of the integrator 31 is controlled by the first ignition timing calculator 7 and the second ignition timing calculator 10, which will be described later, through the A / D converter 32 to retard the ignition timing. It works as a voltage. That is, when a knock occurs, the output voltage of the integrator 31 rises due to the pulse train output of the comparator 23, retards the ignition timing, and suppresses the knock occurrence. When knocking stops, the output voltage of the integrator 31 drops and the ignition timing is advanced. Therefore, the retard control amount determining unit 3 forms a closed loop control system for retarding the ignition timing in real time due to knocking, as shown by the output voltage of the integrator 31 in FIG. 6 (d). The rising and falling speeds of the output voltage of the integrator 31 are determined by the retarding response due to knocking and the stability of the closed loop control. However, since immediate controllability is required, it is set to a value with relatively fast response. .

Further, the reference ignition timing displacement amount determining unit 4 is to determine the displacement amount of the reference ignition timing based on the degree of knock occurrence.
The pulse generator 41 outputs a pulse to the pulse train (FIG. 6 (c)) output from the comparator 23, as shown in FIG. 6 (e). That is, the pulse generator 41 outputs one pulse for each knock occurrence for one ignition. Pulse generator 41
Output pulses are counted by the counter 42, and the content of the count is shown in FIG. 6 (f). The timer 43 outputs a pulse at every predetermined time as shown in FIG. 6 (g),
The count value of the counter 42 is reset to zero from the pulse. Further, the output of the counter 42 becomes a high level when the count value of the counter 42 becomes a predetermined value (count value 3 in FIG. 6) or more as shown in FIG. 6 (h). That is, the counter 42 outputs a high level signal when a predetermined number of knocks occur within a predetermined time. This is to calculate the knock occurrence rate. The up / down counter 44 counts up by one step when the output of the counter 42 rises from the low level to the high level. Further, the timer 45 outputs a pulse at every predetermined time as shown in FIG. 6 (j), and the up / down counter 44 is set to 1 by the pulse.
Step down count. Up-down counter 44
The counting contents of is shown in FIG. 6 (i). In addition, the memory 46
Stores the count value output from the up / down counter 44 when the ignition switch is turned off or when the power supply voltage drops, and presets the count value stored when the ignition switch is turned on or the power supply voltage is restored as the count value of the up / down counter 44. That is, the memory 46
Thus, the displacement amount of the reference ignition timing can be stored and retained even when the engine is stopped. As described above, the reference ignition timing displacement amount determination unit 4 calculates the knock occurrence rate, and when the occurrence rate is equal to or higher than the predetermined value, the reference ignition timing displacement amount is delayed to delay the reference ignition timing (the count value output by the up / down counter 44. ), And if the displacement amount does not shift to the retard side within a predetermined time, the displacement amount shifts to the advance side. Therefore, the reference ignition timing displacement amount determining unit 4 is also similar to the retard control amount setting unit 3 in the first ignition timing calculator 7 and the second ignition timing calculator 10 described later.
A closed loop control system for retarding the ignition timing due to the occurrence of knock is formed via. However, the difference between the reference ignition timing displacement amount determining unit 4 and the retard angle control amount determining unit 3 is that the ignition timing control amount determining unit 3 retards the ignition timing in real time in order to suppress knock occurrence by knock detection. On the other hand, in the reference ignition timing displacement amount determining unit 4, the knock occurrence rate is calculated by knock detection, and the reference ignition timing is displaced to the retard side or the advance side based on the calculation result, so that the gasoline used. The reference ignition timing is adapted to the octane number of. Therefore, the responsiveness in the displacement of the reference ignition timing displacement amount determining unit 4 to the advance side and the retard side is set relatively slower than the responsiveness of the retard angle / advancing angle of the retard control amount determining unit 3.

Next, the first ignition timing calculator 7 will be described. The proportional coefficient calculator 71 converts the count value output from the up / down counter 44 into a proportional coefficient. Now, when the proportional coefficient calculator 71 inputs the count value N from the up / down counter 44, this N is divided by the preset maximum count value Nmax from the up / down counter 44, and the division result is proportional. Coefficient k And Therefore, when premium gasoline is used, the knock limit point is on the relatively advanced side, so the count value of the up / down counter 44 is approximately N = 0, and the proportional coefficient is k = 0. On the other hand, when regular gasoline is used, the knock limit point is on the relatively retarded side, so the count value of the up / down counter 44 is approximately N = Nmax,
The proportional coefficient is k = 1. Also, when using a mixture of premium and regular gasoline, the knock limit point exists between the use of premium gasoline and regular gasoline as shown in Fig. 2 (c), so the count value of the up-down counter 44 is 0 < N <Nmax and the proportional coefficient becomes 0 <k <1. Therefore, it can be seen that the proportional coefficient k is a coefficient indicating the mixing ratio of premium gasoline and regular gasoline.

On the other hand, ROM5 and ROM6 are the second ignition timing calculator 1
An address value corresponding to the engine speed and load is received from 0, and the ignition timing data stored at that address is output to the interpolation calculator 72. Now, the ignition timing characteristic of the ROM 5 is set for premium gasoline, the ignition timing data at the above address is set to θ _B , the ignition timing characteristic of the ROM 6 is set for regular gasoline, and the ignition timing data at the above address is set to θ _A Then, since the ignition timing characteristic of the ROM 5 is set to be the same as that of the ROM 6 or set to the advance side, θ _A ≦ θ _B. Therefore, the interpolation calculator 72 uses θ _A and θ
Proportional interpolation calculation is performed between _B with the proportional coefficient k. That is, when θ _B − (θ _B −θ _A ) −k is calculated and the result is θ _C , θ _C is k: (1−1−0) between θ _B and θ _A.
It becomes the value internally divided to k). Therefore, when premium gasoline is used, k = 0 and θ _C = θ _B , and when regular gasoline is used, k = 1 and θ _C = θ _A , and when premium gasoline and regular mixed gasoline are used, 0 <
Since k <1, θ _A <θ _C <θ _B. Therefore, θ
_{Since C} is a value that internally divides θ _A and θ _B based on the proportional coefficient k indicating the mixing ratio of premium gasoline and regular gasoline, the above interpolation calculation is performed even when mixing premium gasoline and regular gasoline. As a result, it is possible to obtain the optimum reference ignition timing according to the mixing ratio of premium and regular gasoline.

At this time, since it is not necessary to update the data in the ROMs 5 and 6 and the basic ignition timing can be simply calculated by the interpolation calculator 72, a long processing time is not required.

The basic ignition timing information corresponding to the parameter information is R
Since the ignition timing data is set between the ignition timing data from the OMs 5 and 6, even if the knock detection means 1 and 2 generate an erroneous output, the value deviates from the value between the first and second ignition timing data. There is no such thing.

Further, in the first ignition timing calculator 7, the calculator 7
3 subtracts the output value θ _D of the A / D converter 32 of each delay control amount determination unit 3 from the output value θ _c of the interpolation calculator 72, and θ _E (=
The ignition timing data of θ _C −θ _D ) is output to the second ignition timing calculator 10. That is, with respect to the optimum reference ignition timing obtained by the interpolation calculator 72, the retard control amount is subtracted in order to suppress knock that occurs during transient operation of the engine or during sudden changes in environmental conditions. Slowly, each correction is performed.

The second ignition timing calculator 10 calculates the ignition timing based on the signal of the crank angle sensor 8 based on the ignition timing data (output value θ _E of the subtractor 73) and outputs the ignition signal. Since this is a well-known technique in the ignition timing control device, its explanation is omitted here.

Next, a second embodiment of the present invention will be described. This embodiment differs from the first embodiment in the configuration and connection of the reference ignition timing displacement amount determining unit 4, and the configuration of the first ignition timing calculator 7. FIG. 7 shows the configuration of this embodiment. In FIG. 7, 401 is a retard / advance angle determiner, 402 is a timer I, 40
3 is timer II, 404 is up / down counter, 405
Is a memory, 701 is an adder, 702 is a proportional coefficient calculator,
Reference numeral 703 denotes an interpolation calculator, and the same reference numerals as those in FIG. 3 denote the same parts. The up / down counter 404, the memory 405, the proportional coefficient calculator 702, and the interpolation calculator 703 are the same as the up / down counter 44, the memory 46, the proportional coefficient calculator 71, and the interpolation calculator 72 of the first embodiment. It is a thing. The input of the retard / advance determining unit 401 is the output of the retard control amount determining unit 3 (the output of the A / D converter 32).
The output value of the A / D converter 32 is compared with a predetermined value, and the advance angle judgment output or the delay angle judgment output is output depending on the comparison result. A signal is output from the angle determination output. The input of the timer I402 is connected to the delay angle determination / output of the delay angle / advance angle determination unit 401, and the output is connected to the up count input of the up / down counter 404. The input of the timer II 403 is connected to the advance angle determination output of the retard / advance angle determiner 401, and the output is connected to the down count input of the up / down counter 404. The input of the memory 405 is the up / down counter 40.
4 is connected to the output of the up / down counter 40
4 preset inputs. The adder 701 has two inputs, one of which is connected to the output of the reference ignition timing displacement amount determination unit 4 (the output of the up / down counter 404),
The other is connected to the output of the retard angle control amount determination unit 3 (output of the A / D converter 32). Then, the output of the adder 701 is connected to the input of the proportional coefficient calculator 702. Interpolation calculator 7
03 inputs the data of the ROM 5 and the ROM 6 and the output value of the proportional coefficient calculator 702, and inputs the calculation result to the second ignition timing calculator 10. The configuration of the other parts is similar to that of the first embodiment. In this case, the reference ignition timing displacement amount determining unit 4, the adder 701, and the proportional coefficient computing unit 702 correlate with the octane number of the fuel used, based on the output of the knock detecting units 1 and 2 or the retard angle control amount determining unit 3. Parameter setting means for setting parameter information that gradually changes. Further, the interpolation calculator 703 has a basic ignition timing setting means for setting basic ignition timing information based on both ignition timing data output from the storage means 5 and 6 and the outputs of the parameter setting means 4, 701 and 702. I am configuring.

FIG. 8 shows the operation of the reference ignition timing displacement amount determining unit 4 in the second embodiment. FIG. 8 (d) shows the output voltage of the integrator 31. The output of the A / D converter 32 is obtained by converting it into a digital quantity. The retard / advance angle determiner 401 has two comparison reference values. One is the retardation judgment value. Another one
One is the advance angle judgment value. Then, the output value of the A / D converter 32 is compared with the retard angle determination value and the advance angle determination value. FIG. 9 shows an output mode of the retard / advance angle determiner 401. Now
When the output value V of the A / D converter 32 is equal to or greater than the retard angle determination value V ₁ , the retard angle mode is set, and the retard angle determination output is set to a high level as shown in FIG. When it is V ₂ or less, the advance angle mode is set, and the advance angle determination output is set to a high level as shown in FIG. 8 (1), and when it is between V ₁ and V ₂ , it is the stop mode and the retard angle determination output and Both the lead angle judgment output becomes low level. The timer I402 is shown in FIG. 8 at predetermined time intervals while the delay angle determination output of the delay angle / advance angle determination unit 401 is at a high level.
The timer II 403 outputs a pulse as shown in FIG. 8 (n) at predetermined time intervals while the advance angle determination output of the retard angle / advance angle determination unit 401 is at a high level. FIG. 8 (p) shows the count contents of the up / down counter. The up / down counter 404 counts up the output pulse of the timer I402 and counts down the output pulse of the timer II403. Therefore, the output value (A
(The output value of the D / D converter 32) is larger than the retard angle determination value V ₁ , the retard angle mode is set and the up / down counter 404
Is increased, and when it is smaller than the advance determination value V ₂ , the advance mode is entered, the count value of the up-down counter 404 is decreased, and the value of the up-down counter 404 is held between V ₁ and V _2. .

Next, the operation of the first ignition timing calculator 7 in the second embodiment will be described. The adder 701 adds the output value of the retard angle control amount determination unit 3 (output value of the A / D converter 32) and the output value of the reference ignition timing displacement amount determination unit 4 (output value of the up / down counter 404). . The output value of the retard control amount determining unit 3 indicates the retard control amount for suppressing knock in real time, and the output value of the reference ignition timing displacement determining unit 4 adjusts the reference ignition timing according to the octane number of gasoline used. Indicates the amount.
Therefore, the adder 701 outputs the sum of the retard control amount and the reference ignition timing adjustment amount. The proportional coefficient calculator 702 is the adder 7
The output value of 01 is converted into a proportional coefficient, and the interpolation calculator 703 interpolates the ignition timing data of the ROM 5 and the ROM 6 with the proportional coefficient output from the proportional coefficient calculator 702.
This is the same as the description of the embodiment.

As described above, in the second embodiment, the reference ignition timing displacement amount determining unit 4 determines the retard angle / advance angle based on the output value of the retard angle control amount determining unit 3, and determines the adjustment amount of the reference ignition timing. Then, the ignition timing calculation is performed based on the sum of the output value of the retard angle control amount determination unit 3 and the output value of the reference ignition timing displacement amount determination unit 4.

As described above, the transient operation of the internal combustion engine is performed by setting the parameter information that gradually changes in correlation with the octane number of the fuel used, based on the output of the retard angle control amount determination unit 3 or the retard angle control amount determination unit 3. The ignition timing can be retarded in real time even when the time or environmental conditions change suddenly, and knocking can be suppressed quickly.

In the above two embodiments, the reference ignition timing displacement amount determining unit 4 and the first ignition timing calculator 7 can be interchanged between the first and second embodiments. Further, in the above-mentioned embodiment, each arithmetic control unit, that is, the reference ignition timing displacement amount determining unit 4, the ROM 5, the ROM 6, the ignition timing calculator 7,
It is obvious that 10 and the like can be processed by software on a known computer.

〔The invention's effect〕

As described above, according to the present invention, when the regular gasoline and the premium gasoline are mixedly used, the first ignition timing data and the second ignition timing data respectively corresponding to the regular gasoline and the premium gasoline are stored, The knock sensor detects a knock, and based on that, parameter information having a correlation with the octane number of the fuel used is obtained, and a reference ignition timing is set based on this information and two ignition timing data stored in the storage means. By doing so, the reference ignition timing characteristic can be automatically adjusted to the optimum ignition timing in the regular and premium mixed gasoline. Further, according to the second aspect of the present invention, when the engine is in a transient operation or when the environmental condition changes suddenly. The ignition timing can be corrected by retarding the ignition timing in real time, and knocking can be immediately suppressed. There is an effect that becomes ability. or,
The octane number is determined not based on the presence / absence of knock, but based on the knock occurrence frequency, and the octane number, that is, the displacement amount of the ignition timing can be accurately determined. Further, since the basic ignition timing is set between the first and second ignition timing data, there will be no problem such that incorrect information greatly deviates from the appropriate value.

[Brief description of drawings]

1 is an engine output shaft torque characteristic diagram, FIG. 2 is an engine ignition timing characteristic diagram, FIG. 3 is a block diagram showing a first embodiment of the present invention, and FIG. 4 is an ignition timing characteristic diagram. FIG. 5 is a diagram for explaining the operation of the knock discrimination unit 2, and FIG. 6 is a retard angle control amount determination unit 3
FIG. 7 is a block diagram showing the operation of the reference ignition timing displacement amount determination unit, FIG. 7 is a block diagram showing the second embodiment of the present invention, and FIG. 8 is a block diagram of the reference ignition timing displacement amount determination unit 4 in the second embodiment. FIG. 9 is a diagram for explaining the operation, and FIG. 9 is a diagram for explaining the output mode of the retard / advance angle determiner 401. 1 is a knock sensor, 2 is a knock determination unit, 3 is a retard angle control amount determination unit, 4 is a reference ignition timing displacement amount determination unit, 5 is a first ignition timing characteristic storage unit, and 6 is a second ignition timing characteristic storage unit. Division, 7
Is a first ignition timing calculator, 8 is a crank angle sensor, 9 is a pressure sensor, 10 is a second ignition timing calculator, 11 is a switching circuit, and 12 is an ignition coil. The same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Iwata 840 Chiyoda-cho, Himeji City, Hyogo Prefecture Mitsubishi Electric Co., Ltd. Himeji Works (72) Inventor Atsushi Ueda 840 Chiyoda-cho, Himeji City, Hyogo Mitsubishi Electric Corporation Himeji Works (56) Reference JP-A-58-143169 (JP, A) JP-A-58-138262 (JP, A)

Claims (2)

[Claims] 1. Knock detection means (1, 2; 1, 2) for detecting knock of an internal combustion engine, and parameter information which is gradually changed in correlation with the octane number of the fuel used based on the output of the knock detection means. Parameter setting means (4,71; 4,701,70)
2), set for each operating state of the internal combustion engine so as to provide a first basic ignition timing and a second basic ignition timing corresponding to the first reference fuel and the second reference fuel having different octane numbers, respectively. Storage means (5, 6; 5, 6) for storing the first ignition timing data and the second ignition timing data, and operating state detecting means (8, 9;) for detecting the operating state.
8 and 9), based on the output of the operating state detecting means, the corresponding first ignition timing data and second ignition timing data are output from the storage means, and both of the output ignition timing data and the above-mentioned ignition timing data are output. Basic ignition timing setting means (72;) for setting basic ignition timing information between the first basic ignition timing and the second basic ignition timing corresponding to the parameter information based on the output of the parameter setting means. 703), ignition timing control means (10, 11, 1) for controlling the ignition timing of the internal combustion engine based on the output of the basic ignition timing setting means.
2; 10,11,12), and an ignition timing control device for an internal combustion engine. 2. A knock detecting means (1, 2; 1, 2) for detecting knock of an internal combustion engine, and a retard angle for determining a retard control amount for suppressing knock occurrence based on an output of the knock detecting means. Control amount determining means (3; 3), parameter setting means (4) for setting parameter information that gradually changes in correlation with the octane number of the fuel used, based on the output of the knock detecting means or the retard control amount determining means. 71; 4, 701, 702), each operation of the internal combustion engine to provide a first basic ignition timing and a second basic ignition timing corresponding to a first reference fuel and a second reference fuel having different octane numbers, respectively. Storage means (5, 6; 5, 6) for storing first ignition timing data and second ignition timing data set for each state, and operating state detecting means (8, 9;) for detecting the operating state.
8 and 9), based on the output of the operating state detecting means, the corresponding first ignition timing data and second ignition timing data are output from the storage means, and both of the output ignition timing data and the above-mentioned ignition timing data are output. Basic ignition timing setting means (72;) for setting basic ignition timing information between the first basic ignition timing and the second basic ignition timing corresponding to the parameter information based on the output of the parameter setting means. 703), ignition timing control means (73, 10, 11, 12; 10, 1) for controlling the ignition timing of the internal combustion engine based on the output of the basic ignition timing setting means and the output of the retard control amount determining means.
An ignition timing control device for an internal combustion engine, comprising: