JPH03105065A - Ignition timing controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate knocking, securing the superior acceleration operation independently of the octane number of fuel by delayed-angle-controlling the ignition timing of an internal combustion engine when the operation state of the internal combustion engine in acceleration is a previously determined operation state. CONSTITUTION:An internal combustion engine is equipped with at least a spark plug 5 and a fuel injection valve 12. In this case, a means A judges if the octane number of the fuel jetted from the fuel injection valve 12 is high or low while, the acceleration operation of the internal combustion engine is detected by a means B. When the operation state of the internal combustion engine in acceleration operation is a previously determined operation state, a means C controls the delay-angle of the ignition timing of the internal combustion engine. In this case, the operation state in which knocking tends to generated, accompanied with the increase of the octane number of the fuel, is set at the operation state of the internal combustion engine. Independently of the octane number of the fuel, the generation of knocking or continuation is eliminated, securing the superior acceleration operation.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an ignition timing control device for an internal combustion engine.

[Conventional technology]

There is a known ignition timing control device that retards the ignition timing by a certain period of time when the engine starts accelerating operation in order to prevent knocking from occurring in the early stages of engine acceleration (Japanese Patent Laid-Open No. 57-99269). (Refer to Publication No.) a Also, based on the occurrence of knocking, it is determined whether regular gasoline with a low octane number, which is more likely to cause knocking, or premium gasoline with a higher octane number, which is less likely to cause knocking, is being used. There is a known ignition timing control device that uses different basic ignition timing characteristics depending on whether the gasoline being used is regular gasoline or premium gasoline (Japanese Patent Laid-Open No. 60-1906).
(See Publication No. 70).

[Problem to be solved by the invention]

By the way, in the ignition timing control device described in the above-mentioned Japanese Patent Application Laid-Open No. 57-99269, the same amount of retardation is applied during engine acceleration operation, regardless of whether the gasoline used is regular gasoline or premium gasoline. The ignition timing is retarded. However, in this case, if the retard amount is set to the optimal retard amount for regular gasoline, when premium gasoline is used, the ignition timing will be too retarded compared to the optimal ignition timing for premium gasoline. There is a problem in that good acceleration cannot be obtained even though premium gasoline is used. On the other hand, if the retardation amount is set to the optimal retardation amount for premium gasoline, when regular gasoline is used, the ignition timing will be too advanced compared to the optimal ignition timing for regular gasoline. There is a problem in that knocking occurs even though the ignition timing is retarded.

On the other hand, in the ignition timing control device described in the above-mentioned Japanese Patent Application Laid-Open No. 60-190670, the basic ignition timing characteristics are changed depending on whether the gasoline used is regular gasoline or premium gasoline. There is no suggestion of retard control.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, as shown in the configuration diagram of the invention shown in FIG. comprising means A, acceleration detection means B for detecting acceleration operation, and ignition timing control means C for retarding the ignition timing when the operating state of the engine during acceleration operation is a predetermined operating state, The above predetermined operating state is an operating state in which knocking is likely to occur as the octane number of the fuel increases.

In addition, in order to solve the above problems, according to the present invention, as shown in the configuration diagram of the invention in FIG. The apparatus comprises an octane number determining means A for determining the octane number, an acceleration detecting means B for detecting acceleration driving, and an ignition timing control means C for retarding the ignition timing during acceleration driving, and the amount of retardation of the ignition timing is determined based on the octane number of the fuel. decreases as the amount increases.

In addition, in order to solve the above problems, according to the present invention, as shown in the configuration diagram of the invention in FIG. octane number determining means A for determining the octane number; acceleration detecting means B for detecting accelerated driving; and ignition timing control means C for retarding the ignition timing when the knocking intensity occurring during accelerated driving is higher than a predetermined setting intensity. The above setting strength increases as the octane number of the fuel increases.

[For production]

The engine operating condition that retards the ignition timing, the amount of retardation of the ignition timing, or the setting intensity of knocking that retards the ignition timing is determined according to the octane number of the fuel used to ensure good acceleration while knocking occurs. The design is designed to completely prevent the occurrence of knocking, or to prevent severe knocking from continuing even if knocking occurs.

〔Example〕

Referring to Figure 2, 1 is the engine body, 2 is the piston, and 3
4 indicates a cylinder head, 4 indicates a combustion chamber, 5 indicates a spark plug, 6 indicates an intake valve, 7 indicates an intake boat, 8 indicates an exhaust valve, and 9 indicates an exhaust port. It is connected to the tank 11.

A fuel injection valve 12 is attached to each branch pipe 10, and fuel is injected from these fuel injection valves 12 into the corresponding intake port 7. The surge tank 11 is connected to an air cleaner (not shown) via an intake duct 13 and an air flow meter 14, and a throttle valve 1 is installed in the intake duct 13.
5 is placed. On the other hand, the exhaust boat 9 is connected to an exhaust manifold 16, and an oxygen concentration detector 17 is disposed within the exhaust manifold 16.

The fuel injection valve 12 and the spark plug 5 are controlled by an electronic control unit 30
The injection timing from the fuel injection valve 12 and the ignition timing from the spark plug 5 are controlled based on the output signal of the electronic control unit 30.

The electronic control unit 30 consists of a digital computer with ROMs connected to each other by a bidirectional bus 31.
(Read-only memory> 32, RAM (random access memory) 33, CPU (microprocessor) 34
, a human-powered boat 35 and an output port 36. The air flow meter 14 generates an output voltage proportional to the amount of intake air, and this output voltage is input to the input port 35 via the AD converter 37.

The oxygen concentration detector 17 detects 0 when the air-fuel mixture supplied into the engine cylinder is lean. It generates an output voltage of about 1 volt, and when the air-fuel mixture supplied into the engine cylinder is rich, it generates an output voltage of about 0.9 volt. The output voltage of this oxygen concentration detector 17 is inputted to the human power port 35 via the AD converter 38. Further, a changeover switch 18 is provided which is manually switched by the driver depending on whether the gasoline used is regular gasoline or premium gasoline, and the output signal of this changeover switch 18 is inputted to the human-powered boat 35. Further, a water temperature sensor 19 that generates an output voltage proportional to the engine cooling water temperature is attached to the engine body 1, and the output voltage of this water temperature sensor 19 is manually inputted to the input boat 35 via an AD converter 39. The top dead center detection sensor 20 generates an output pulse every 180 crank angles, and the crank angle sensor 21 generates an output pulse every 30 crank angles. It is input to the input port 35. In the electronic control unit 30, the current crank angle is calculated from the output pulses of the top dead center detection sensor 20 and the crank angle sensor 21, and the engine rotation speed is calculated from the output pulses of the crank angle sensor 21.

On the other hand, the output port 36 is connected to the spark plug 5 and the fuel injection valve 12 via a corresponding drive circuit 40.41.

FIGS. 3 and 4 show an embodiment in which the ignition timing is retarded when the operating state of the engine during acceleration is a predetermined operating state.

FIG. 3 shows a routine for setting the initial retardation amount AACC of the ignition timing, and this routine is executed by interrupts at fixed time intervals.

Referring to FIG. 3, first, in step 100, it is determined from the output signal of the changeover switch 18 whether regular gasoline or premium gasoline is being used. If regular gasoline is being used, the process proceeds to step 101, and the engine cooling water temperature T is determined from the output signal of the water temperature sensor ■9 to a predetermined set temperature.
For example, it is determined whether the temperature is higher than 50°C. T〉50
℃, the process proceeds to step 102, and the engine load Q/N (intake air amount Q/engine speed N) is determined from the output signals of the air flow meter 14 and the crank angle sensor 21 to a predetermined setting value, for example, 0. It is determined whether or not it is larger than 5 1 /rev. Q/N>0. 5 f/rev
If so, the process proceeds to step 103, where the difference ΔQ/N between the engine load Q/N in the previous interrupt routine and the engine load Q/N in the current interrupt routine, that is, the rate of change in the engine load ΔQ/N is set to a predetermined setting value. , for example 0. 3
It is determined whether or not it is larger than 1l/rev. In addition,
The rate of change in engine load ΔQ/N represents the degree of acceleration, and therefore, instead of using ΔQ/N, the rate of change in intake pipe negative pressure or the rate of change in throttle opening may be used. Step 10 when ΔQ/N>0.317rev
Proceeding to step 4, the ignition timing retard amount AACC is set to 10°.

On the other hand, when premium gasoline is being used, the routine proceeds to step 105, where it is determined whether the engine cooling water temperature T is higher than a predetermined setting value, for example, 70°C.

When T>70°C, the process proceeds to step 106 where the engine load Q/N is set to a predetermined value, for example 0. 6 12
It is determined whether the value is larger than /rev. Q/
N > 0. 6 j2 / rev, the process proceeds to step 103, and ΔQ/N > 0. 3 R/r
If it is ev, the process proceeds to step 104, where the ignition timing retard amount AACC is set to 10 degrees.

FIG. 4 shows an ignition timing calculation routine, and this routine is executed by interruption at every fixed crank angle.

Referring to FIG. 4, first, in step 200, a predetermined setting value, for example 1°, is subtracted from the retard amount AACC. Next, in step 201, it is determined whether AACC has become negative, and AACC! When it reaches 1 and Q, the process proceeds to step 202 and AACC is set to zero.

In step 203, ignition timing AOP expressed in ignition advance amount is calculated based on the following equation.

AOP = ABSB + ACOLD - AACC Here, ABSε indicates the basic ignition timing determined by the engine load Q/N and the engine speed N, and ACOLD indicates the correction coefficient of the ignition timing that changes depending on the engine cooling water temperature and the like.

Therefore, it can be seen from FIG. 4 that when the retard amount AACC is set, the ignition timing AOP is immediately retarded by AACC, and then the ignition timing AOP is gradually advanced.

As shown in FIG. 3, when regular gasoline is used, T>50°C, Q/N>0.5j2/rev and ΔQ/N>0. 3 1 /rev, and when premium gasoline is used, T>70°C, Q/N > 0.6 1 /rev and ΔQ/N > 0. The retardation effect is performed at 3 1 /rev.

That is, the lower limit value of the cooling water temperature T and the lower limit value of the engine load Q/N at which the retardation effect is performed are smaller for regular gasoline than for premium gasoline. At the same cooling water temperature T and the same engine load Q/N, regular gasoline is more likely to cause knocking than premium gasoline. Therefore, regardless of the type of gasoline, T〉50℃
Big Q/N > 0. If the engine is retarded at 5 1 /rev, the engine will be retarded even though knocking will not occur when premium gasoline I1 is used, making it impossible to obtain good acceleration operation. On the other hand, regardless of the type of gasoline, T>70℃ and Q
/ N > 0. If the retardation effect is performed at 6 1 /rev, knocking will occur when regular gasoline is used. However, the lower limit of the cooling water temperature T and the engine load Q at which the retardation effect is performed
By making the lower limit value of /N smaller when regular gasoline is used than when premium gasoline is used, it is possible to prevent knocking and ensure good acceleration operation regardless of the type of gasoline. .

FIGS. 5 and 6 show another embodiment in which the ignition timing is retarded when the operating state of the engine during acceleration is a predetermined operating state.

FIG. 5 shows a routine for setting the ignition timing retard amount AACC, and this routine is executed by interrupts at regular intervals.

Referring to FIG. 5, first, in step 300, it is determined based on the output signal of the changeover switch 18 whether regular gasoline or premium gasoline is being used. If regular gasoline is being used, proceed to step 301 and check the engine load change rate Δ.
Q/N is a predetermined setting value, for example 0. 3 1
It is determined whether or not it is larger than /rev, and ΔQ/N
>0. When 3 R /rev, step 302
Then, the ignition timing retard amount AACC is set to 10 degrees.

On the other hand, when premium gasoline is being used, the process proceeds to step 303, where it is determined whether the rate of change in engine load ΔQ/N is larger than a predetermined setting value, for example, 0.4j2/rev, and ΔQ/N ＞Q, 4 1 /
When rev is reached, the process proceeds to step 302, where the ignition timing retard amount AACC is set to 10 degrees.

FIG. 6 shows the ignition timing calculation routine.

Each step 400, 401, in this routine
402.403 are each step 200.403 of the ignition timing calculation routine shown in FIG. 201, 202, and 203, and therefore the explanation of FIG. 6 will be omitted.

Knocking becomes more likely to occur as the rate of change ΔQ/N of the engine load increases, that is, as the degree of acceleration increases.

Therefore, in this embodiment, the lower limit value of the rate of change ΔQ/N of the engine load that causes the retardation effect is made smaller when regular gasoline is used than when premium gasoline is used.

FIGS. 7 and 8 show an embodiment in which the amount of retardation of the ignition timing is changed depending on the type of gasoline.

FIG. 7 shows a routine for setting the ignition timing retard amount AA ('C), and this routine is executed by interrupts at regular intervals.

Referring to FIG. 7, first, in step 500, the rate of change ΔQ/N of the engine load is set to a predetermined setting value, for example 0. It is determined whether or not the value is greater than 3 12 /rev. ΔQ/N > 0. 3 1 /rev, the process proceeds to step 501, and it is determined whether regular gasoline or premium gasoline is being used based on the output signal of the changeover switch 18.
be done. If regular gasoline is being used, the process proceeds to step 502, where the ignition timing retardation percentage lAACC is set to 151. On the other hand, if premium gasoline is being used, the process proceeds to step 503, where the ignition timing retard amount ACC is set to 10''.

FIG. 8 shows an ignition timing calculation routine, and this routine is executed by interruption at every fixed crank angle.

Referring to FIG. 8, first, in step 600, it is determined based on the output signal of the changeover switch 18 whether regular gasoline or premium gasoline is being used. If regular gasoline is being used, proceed to step 601 and set the retardation amount AA.
A predetermined set value, for example 0.5°, is subtracted from CC, and then the process proceeds to step 603. On the other hand, if premium gasoline is being used, the process proceeds to step 602 where a predetermined set value, for example 1 degree, is subtracted from the retard amount AACC, and then the process proceeds to step 603.

In step 603, it is determined whether or not the retard amount AACC has become negative, and when ^ACCi O, step 604 is performed.
AACC is set to zero. Then step 605
Then, the ignition timing AOP is calculated.

The more retarded the ignition timing is during accelerated driving, the less likely knocking will occur. Therefore, in this embodiment, the amount of retardation A of the ignition timing immediately after the start of acceleration operation is greater when regular gasoline, which is more likely to cause knocking, is used than when premium gasoline is used, which is less likely to cause knocking.
I am trying to increase the ACC. Furthermore, as can be seen from FIG. 8, when regular gasoline is used, the ignition timing is advanced more slowly after being retarded than when premium gasoline is used.

FIGS. 9 to 12 show an embodiment in which the ignition timing is retarded when the knocking intensity that occurs during accelerated operation is higher than a predetermined setting intensity.

Referring to FIG. 9, in this embodiment, a changeover switch 8 is not provided, and a knocking sensor 22 is attached to the cylinder head 3. This knocking sensor 2
2 generates an output voltage proportional to the vibration intensity generated in the cylinder head 1, and this output voltage is inputted to the input port 35 via the AD converter 42. In this embodiment, in addition to the retard control when knocking occurs, a separate retard action is performed in accordance with the knocking intensity.

FIG. 10 shows a retard control routine due to the occurrence of knocking, and this routine is executed by interrupts at fixed time intervals.

Referring to FIG. 10, first, in step 700, it is determined from the output signal of the knocking sensor 22 whether the vibration intensity of the cylinder head 3 is greater than a predetermined set intensity X, that is, whether a large knock is occurring. It is determined whether or not. Step 70 if no major knock occurs
Proceed to step 3. On the other hand, if a large knock is occurring, the process proceeds to step 701, where a predetermined value, for example 2 degrees, is added to the ignition timing retard amount KCS. Next, in step 702, a large knock flag L indicating that a large knock has occurred is set, and the process proceeds to step 703.

In step 703, based on the output signal of the knocking sensor 22, it is determined whether the vibration intensity of the cylinder head 3 is greater than a predetermined setting intensity XZ (<X+) and smaller than X, that is, whether a small knock is occurring. It is determined whether or not.

If a small knock is occurring, the process proceeds to step 704, where a predetermined value, for example 1°, is added to the ignition timing retard amount KCS. Next, in step 705, a small knock flag S indicating that a small knock has occurred is set, and the process proceeds to step 706. On the other hand, if a small knock has not occurred, the process proceeds to step 707, where it is determined whether or not a knock has not occurred for 0.5 seconds after a large knock or a small knock occurs. If no knock occurs for 0.5 seconds, the process proceeds to step 708, where a predetermined value, for example 0.5°, is subtracted from the ignition timing retard amount. Next, in step 709, the large knock flag L and the small knock flag S are reset, and then the process proceeds to step 706.

Therefore, when a large knock occurs, the retard amount KCS is rapidly increased and a large knock flag L is set, and then, if no knock occurs for 0.5 seconds, the retard amount KCS is gradually decreased. . On the other hand, when a small knock occurs, the retard amount KCS is increased relatively slowly and a small knock flag S is set, and then if the knock continues for 0.5 seconds and does not occur, the retard amount KCS is gradually increased. be reduced.

In step 706, it is determined whether the retard amount KCS exceeds a predetermined set value K0, and if KCS>K. If so, the process advances to step 710 and flag P is set. When regular gasoline is used, knocking is more likely to occur than when premium gasoline is used, and when premium gasoline is used, knocking stops when the retardation amount KCS is slightly increased. On the other hand, when regular gasoline is used, knocking does not stop occurring until the retardation amount KCS becomes considerably large. Therefore, it can be determined from the magnitude of the retardation amount KCS whether regular gasoline or premium gasoline is being used. That is, the retard amount KCS is K. This means that regular gasoline is being used, and in this case, flag P is set in step 710. Therefore, when flag P is set, it means that regular gasoline is being used, and once flag P is set, it remains set until the ignition switch is turned off.

Figure 11 shows the initial retardation amount A of the ignition timing during acceleration operation.
This shows an ACC set routine, which is executed by interrupts at regular intervals.

Referring to FIG. 11, first, in step 800, the rate of change ΔQ/N of the engine load is set to a predetermined setting value,
For example 0. It is determined whether or not the value is greater than 3 12 /rev. ΔQ/N > 0. 3R/rev
If so, the process advances to step 801 and the ignition timing retard amount A is determined.
ACC is assumed to be 10°.

FIG. 12 shows an ignition timing calculation routine, and this routine is executed by interruption at every fixed crank angle.

Referring to FIG. 12, first, in step 900, ignition timing AOP is calculated based on the following equation.

AOP=ABSB+ACOLD-KCS As can be seen from the above, if knocking occurs and the retardation amount KCS increases, the ignition timing AOP is retarded.

Next, in step 901, a predetermined setting value, for example l°, is subtracted from the retard amount AACC. Next, in step 902, it is determined whether or not the retard amount AACC has become negative, and when it becomes AACCKO, the process proceeds to step 903, where the retard amount AACC is set to zero. Next, in step 904, it is determined from the flag P whether regular gasoline or premium gasoline is being used. When the flag P is set, that is, when regular gasoline is being used, the process advances to step 905, where it is determined whether the small knock flag S is set.

If the small knock flag S is set, the process proceeds to step 906, where the ignition timing AOP is rapidly retarded by the retard angle IAAcc. On the other hand, when flag P has been reset, that is, when premium gasoline is being used, the process advances to step 907, where it is determined whether or not the large knock flag L has been set. If the large knock flag L is set, the process proceeds to step 906, where the ignition timing AOP is rapidly retarded by the retardation amount AACC.

In the embodiments shown in FIGS. 9 to 12, a small knock does not cause much discomfort to the driver, while a large knock does. Therefore, it is necessary to actively prevent the occurrence of large knocks. By the way, the way knocking occurs is quite different when using regular gasoline and when using premium gasoline. For example, when driving under sudden acceleration when regular gasoline is used. A small knock occurs, followed by a large knock. That is, if a small knock occurs, the ignition timing A increases because the retard amount KCS increases.
OP is retarded, but during sudden acceleration, the retardation effect by KCS is not in time, and as a result, the ignition timing AOP is delayed at the beginning of acceleration.
A small knock occurs because there is not a large difference between the ignition timing AOP and the ignition timing limit for knocking, but after a while, the difference between the ignition timing AOP and the ignition timing limit for knocking increases and a large knock occurs. Become. In other words, the occurrence of a small knock is a preview of the occurrence of a large knock.

Therefore, as shown in FIG. 12, when a small knock occurs and the small knock flag S is set, the process proceeds from step 905 to step 906, where the ignition timing AOP is immediately retarded by a wide range, thereby preventing the occurrence of a large knock. I'm trying to prevent it.

On the other hand, when premium gasoline is used, knocking is inherently less likely to occur, and a small knock occurs during sudden acceleration, and if the ignition timing AOP is gradually retarded by the KCS, the small knock usually continues. Otherwise, the occurrence of small knocks often stops and large knocks do not occur.

Therefore, if the ignition timing AOP is significantly retarded at this time, the acceleration performance will only deteriorate and there will be no significant benefit. In this way, as shown in Figure 12, when premium gasoline is used, even if a small knock occurs, the ignition timing AOP
I'm trying not to let it lag too much. That is, only when a large knock occurs and the large knock flag L is set as a result, the process proceeds to step 906 and the ignition timing AOP is retarded by a large amount.

In the embodiments shown in FIGS. 2 to 8, the ignition timing AOP is retarded by AACC as soon as the acceleration operation is started so that knocking does not occur during the acceleration operation. In other words, anticipatory retard control is performed. On the other hand, in the embodiments shown in FIGS. 9 to 12, the ignition timing AOP is set to AACC so that a large knock does not occur when a small knock occurs.
It's just that it's slowing down Ohibin. Therefore, prospective retard control is performed in this case as well.

In the embodiments shown in FIGS. 2 to 8, the flag P shown in FIG. A changeover switch 18 shown in FIG. 2 may also be used.

〔Effect of the invention〕

Regardless of the octane number of the fuel used, it is possible to prevent knocking from occurring or to prevent severe knocking from continuing to occur while ensuring good acceleration operation.

[Brief explanation of drawings]

Fig. 1 is a diagram of the structure of the invention, Fig. 2 is an overall view of the internal combustion engine, Fig. 3 is a flowchart for setting the initial retard amount,
FIG. 4 is a flowchart for calculating ignition timing, FIG. 5 is a flowchart of another embodiment for setting the initial retard amount, and FIG. 6 is a flowchart of another embodiment for calculating ignition timing. , FIG. 7 is a flowchart of yet another embodiment for setting the initial retard amount, FIG. 8 is a flowchart of yet another embodiment for calculating ignition timing, and FIG. 9 is a flowchart for another embodiment of the internal combustion engine. Overall view of the embodiment, No. 10
The figure is a flowchart for executing retard angle control, No. 11.
The figure is a flowchart of yet another embodiment for setting the initial retard amount, and FIG. 12 is a flowchart of yet another embodiment for calculating the ignition timing. 5... Spark plug, 12... Fuel injection valve, 1
8... Selector switch, 22... Knocking sensor.

Claims (1)

[Claims] 1. Octane number determining means for determining whether fuel with a high octane number or fuel with a low octane number is used, acceleration detection means for detecting accelerated operation, and engine control during accelerated operation. and ignition timing control means for retarding the ignition timing when the operating state is a predetermined operating state, and the predetermined operating state is such that knocking is likely to occur as the octane number of the fuel increases. An ignition timing control device for an internal combustion engine that is in operation. 2. Octane number determining means for determining whether fuel with a high octane number or low octane number is being used, acceleration detection means for detecting accelerated driving, and ignition timing control that retards the ignition timing during accelerated driving. An ignition timing control device for an internal combustion engine, comprising: means for retarding the ignition timing in accordance with an increase in the octane number of the fuel. 3. An octane number determining means for determining whether fuel with a high octane number or a fuel with a low octane number is used, an acceleration detection means for detecting accelerated driving, and a knocking intensity that occurs during accelerated driving is predetermined. An ignition timing control device for an internal combustion engine, comprising ignition timing control means for retarding ignition timing when the intensity is higher than a set intensity, and wherein the set intensity increases as the octane number of the fuel increases.