JP3092454B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the ignition timing of an internal combustion engine, and more particularly to an ignition timing control device for controlling the ignition timing of the engine during idle operation.

[0002]

2. Description of the Related Art It has been known that the ignition timing of an internal combustion engine has a great effect on the exhaust gas, fuel efficiency, drivability and the like of the engine. Therefore, the ignition timing is controlled to be an optimal timing according to the operating state of the engine. Therefore, in a basic ignition timing control device that performs this type of control, an optimum ignition timing according to the operating state of the engine is calculated by a computer, and the ignition plug is operated based on the calculated timing. In this type of control device, the computer calculates and determines the optimal ignition timing stored in advance based on the engine speed and load during normal operation other than idle operation.

On the other hand, in this type of control device, in order to secure idling stability during idling operation in which the load on the engine is small, the computer uses a fixed ignition timing that is predetermined in advance, or the computer uses the engine. The ignition timing according to the rotation speed of the engine is calculated.

[0004] However, when the internal combustion engine is mounted on an automobile, accessory devices such as an air conditioner and a power steering operate during idling operation.
The load on the engine increases. In this case, if the computer simply uses the fixed ignition timing or the ignition timing according to the rotational speed for the control, the ignition timing obtained by the control is in an over-advanced state with respect to the ignition timing required according to the load state. Becomes Therefore, in the internal combustion engine, there is a possibility that so-called knocking may occur or idle stability may deteriorate.

Therefore, an ignition timing control device aiming at coping with the above-mentioned problem has been disclosed by the present applicant in Japanese Unexamined Patent Publication No.
No. 3-309774. In the control device of this publication, when the engine is in a high load state due to the operation of the air conditioner or the like during the idle operation of the engine, the electronic control unit (ECU) determines that. And EC
U limits the ignition timing calculated based on the rotation speed of the engine or the predetermined fixed ignition timing based on the ignition timing calculated based on the load and the rotation speed of the engine during normal operation. That is, when the ignition timing calculated during the idling operation is a more advanced timing than the ignition timing calculated during the normal operation, the ignition timing calculated during the normal operation is used as the ignition timing during the idling operation. This prevents the ignition timing from being advanced more than necessary. As a result of this control, the idle stability of the engine is further improved.

[0006]

However, fuels generally used in gasoline engines are classified into premium gasoline having a high octane number and regular gasoline having a low octane number. The difference in fuel type causes a difference in the limit timing of knocking in a gasoline engine, so that the optimal ignition timing in the engine differs according to the fuel type. For this reason, in an engine of a premium specification premised on the use of premium gasoline, various settings relating to ignition timing control are performed in order to obtain an optimal ignition timing according to the type of fuel. Similarly, in an engine of a regular specification on the assumption that regular gasoline is used, various settings relating to ignition timing control are performed in order to obtain an optimum ignition timing according to the type of fuel.

Here, when the control device of the above publication is applied to a gasoline engine, if the engine is of a premium type, the ECU determines the idle time based on the knocking limit time according to the type of fuel. The ignition timing calculated during operation is restricted. That is, the ECU sets the ignition timing during the idling operation to a relatively retarded timing. Therefore, for example, when a general user uses regular gasoline for a premium engine, the set knocking limit time is a relatively retarded time for the type of fuel. Would. for that reason,
Despite the restriction that the ignition timing during idling operation is not set to the advanced state, the fuel may self-ignite relatively early, and knocking may not be prevented.

Further, the easiness of occurrence of knocking in the engine slightly varies depending on the individual difference of the engine and aging. Therefore, in order to prevent the occurrence of knocking, it is also effective to consider factors other than the type of fuel, such as individual differences in the engine and changes over time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and a first object of the present invention is to provide an engine having an idling stability in a range where the engine is not unnecessarily advanced even if the engine load increases during idling operation. It is an object of the present invention to provide an ignition timing control device for an internal combustion engine, which can ensure knocking and prevent occurrence of knocking, and can perform the same in response to a change in the type of fuel used.

It is a second object of the present invention to secure idling stability and prevent knocking from occurring even if the engine load increases during idling, without causing unnecessary advancement. Use of fuel type change,
It is an object of the present invention to provide an ignition timing control device for an internal combustion engine, which is capable of coping with the individual difference of the engine and the aging.

[0011]

[0012]

To achieve the above Symbol purpose SUMMARY OF THE INVENTION In the present invention, as shown in FIG. 1, an internal combustion engine M
1. An ignition timing control device for an internal combustion engine, which controls an ignition timing for activating an ignition device M2 for igniting an air-fuel mixture drawn into the internal combustion engine 1 according to an operation state of the internal combustion engine M1. A rotational speed detecting means M3 for detecting a rotational speed of M1, a load detecting means M4 for detecting a load of the internal combustion engine M1, an idle detecting means M5 for detecting an idling operation state of the internal combustion engine M1, The first ignition timing calculating means M6 for calculating the first ignition timing based on the detection results of the rotation speed detecting means M3 and the load detecting means M4, and the idle operation based on the detection results of the idle detecting means M5. Idle determination means M7 for determining, and when the idle determination means M7 determines that the engine is in idling operation, a predetermined fixed ignition timing,
Alternatively, based on the detection result of the rotation speed detecting means M3, when the second ignition timing calculating means M8 for calculating the second ignition timing at the time of the idling operation and the idling determining means M7 determine that it is not during the idling operation. A first ignition timing for setting a target ignition timing based on the first ignition timing;
When it is determined by the ignition timing setting means M9 and the idle determination means M7 that the engine is in the idling operation, the first ignition timing is set as the upper limit timing on the advance side and based on the first and second ignition timings. Second ignition timing setting means M10 for setting a target ignition timing, knock detection means M13 for detecting knocking of internal combustion engine M1, and knocking occurrence timing based on the detection result of knock detection means M13. Knock learning means M14 for learning, and ignition timing correction means M15 for correcting the first ignition timing used in second ignition timing setting means M10 based on the learning result of knock learning means M14. It is intended to be prepared.

[0013]

[0014]

[0015]

[0016]

[0017]

According to the configuration of the present invention, as shown in FIG. 1, during operation of the internal combustion engine M1, the first ignition timing calculation means M6
As a result, the first ignition timing is calculated based on the rotation speed and the load. Further, the idle determining means M7 determines whether or not the engine is in the idling operation based on the detection result of the idle detecting means M5. Further, knock learning means M14
Thus, the timing of occurrence of knocking is learned based on the detection result of knock detection means M13. The learning value reflects the difference in the octane number of the fuel used in the internal combustion engine M1, as well as the individual difference and the aging of the internal combustion engine M1.

If it is determined that the engine is not idling, the target ignition timing to be used by the ignition device M2 is set by the first ignition timing setting means M9 based on the first ignition timing. .

On the other hand, when it is determined that the engine is in the idling operation, the second ignition timing in the idling operation is
It is calculated by the second ignition timing calculation means M8 based on a predetermined fixed ignition timing or a rotation speed. Further, the target ignition timing to be used in the ignition device M2 is determined by the second ignition timing setting means M10 based on the first and second ignition timings, with the first ignition timing as the upper limit timing on the advance side. Is set. That is, the internal combustion engine M1 during idling operation
When the load is low, the target ignition timing is set based on the second ignition timing. When the load is relatively high, the target ignition timing is set relatively on the retard side based on the first ignition timing. It is set at the time of. At this time, the first ignition timing used in the setting means M10 is the ignition timing correction means M
15 is corrected based on the learning result of knock learning means M14. For example, when the learning value related to the knocking occurrence timing is relatively retarded, the first ignition timing is relatively retarded compared to when the learned value is advanced. It is corrected at the time.

Therefore, even when the load on the internal combustion engine M1 increases during idling operation, the target ignition timing does not become unnecessarily advanced, and the combustion of the air-fuel mixture is stabilized.
In addition, when the octane number of the fuel used changes, or when the internal combustion engine M1 has individual differences or changes over time, the above-described effects can be obtained in accordance with those differences.

[0021]

EXAMPLES Hereinafter, an embodiment embodying the ignition timing control apparatus for an internal combustion engine in the present invention will be described in detail with reference to FIGS. 2-9.

FIG. 2 is a schematic configuration diagram showing a gasoline engine system including an ignition timing control device for an internal combustion engine mounted on an automobile in this embodiment. This automobile is equipped with a well-known automatic transmission, a power steering device, and an air conditioner. A plurality of cylinder bores 3 are formed in a cylinder block 2 constituting the engine 1 as an internal combustion engine. A cylinder head 4 is mounted on the upper side of the cylinder block 2 so as to close each cylinder bore 3. A piston 5 is attached to each cylinder bore 3 so as to be vertically movable, and the piston 5 is connected to a crankshaft 1 a via a connecting rod 6. Inside the cylinder bore 3, the piston 5 and the cylinder head 4
The space surrounded by is a combustion chamber 7.

The cylinder head 4 is provided with an ignition plug 8 corresponding to each of the combustion chambers 7. The head 4 is provided with an intake port 9 and an exhaust port 10 communicating with each combustion chamber 7. Each port 9, 1
0 is connected to an intake passage 11 and an exhaust passage 12 respectively. Each of the ports 9 and 10 is provided with an intake valve 13 and an exhaust valve 14 for opening and closing, respectively. Each of the valves 13 and 14 is driven by a valve train (not shown) including a camshaft in conjunction with the rotation of the crankshaft 1a. The timing for opening and closing the valves 13 and 14 is synchronized with the rotation of the crankshaft 1a. That is, the valves 13 and 14 are opened and closed at a predetermined timing in synchronization with a series of strokes of an intake stroke, a compression stroke, an explosion / expansion stroke, and an exhaust stroke of the engine 1.

An air cleaner 1 is provided on the inlet side of the intake passage 11.
5 are provided. A surge tank 16 for smoothing the pulsation of air passing through the intake passage 11 is provided in the middle of the intake passage 11. On the downstream side of the surge tank 16, fuel injectors 17 are provided in the vicinity of the intake ports 9 corresponding to the respective cylinder bores 3. These injectors 17 include:
Fuel in a fuel tank (not shown) is pumped by a fuel pump (not shown). And the injector 1
7 is controlled based on a predetermined command signal, so that the fuel injection amount and injection timing for the intake port 9 are controlled. That is, fuel injection amount control is performed. Exhaust passage 12
Is provided with a catalytic converter 18 having a built-in three-way catalyst for purifying exhaust gas.

The outside air taken in from the air cleaner 15 is introduced into the intake passage 11. Each injector 1
The fuel injected from 7 forms a mixture with the outside air.
This air-fuel mixture is taken into the combustion chamber 7 when the intake valve 13 is opened during the intake stroke of the engine 1. Thereafter, when the ignition plug 8 operates in the combustion chamber 7, the air-fuel mixture burns, the piston 5 operates, and the driving force is obtained in the engine 1. The exhaust gas after combustion is guided to the exhaust passage 12 when the exhaust valve 14 is opened in the exhaust stroke of the engine 1, is purified by the catalytic converter 18, and is discharged to the outside.

An upstream side of the surge tank 16 is provided with a throttle valve 19 which operates in conjunction with operation of an accelerator pedal (not shown). By adjusting the opening degree (throttle opening degree) TA of the valve 19, the amount of outside air taken into the intake passage 11, that is, the intake air amount Q is adjusted.

In the vicinity of the throttle valve 19, a throttle sensor 3 as idle detecting means in the present invention is provided.
1 is provided. The sensor 31 detects the throttle opening TA and outputs a signal corresponding to the detection result.
The sensor 31 includes a well-known idle switch (not shown). This idle switch is turned on when the throttle valve 19 is fully closed,
An idle signal IDL indicating this is output. An air flow meter 32 is provided downstream of the air cleaner 15. The meter 32 detects the amount of intake air Q taken into the intake passage 11 and outputs a signal corresponding to the detection result. An intake air temperature sensor 33 is provided near the air cleaner 15. The sensor 33 detects the temperature of the intake air (intake temperature) THA taken into the intake passage 11 and outputs a signal corresponding to the detection result.

In the middle of the exhaust passage 12, an oxygen sensor 34
Is provided. The sensor 34 detects the oxygen concentration OX in the exhaust gas and outputs a signal corresponding to the detection result.
The cylinder block 2 is provided with a water temperature sensor 35. The sensor 35 detects the temperature (cooling water temperature) THW of the cooling water of the engine 1 and outputs a signal corresponding to the detection result.

Spark plug 8 corresponding to each cylinder bore 3
, The ignition signal distributed by the distributor 20 is applied. The distributor 20 distributes the high voltage output from the igniter 21 to each spark plug 8 in synchronization with the rotation angle of the crankshaft 1a, that is, the crank angle (CA). The ignition timing of each ignition plug 8 is determined by the output timing of the high voltage output from the igniter 21. In this embodiment, each of the above-described ignition plugs 8, distributors 20, and igniters 2
1 constitutes the ignition device of the present invention. Then, by controlling the igniter 21 based on a predetermined command signal, the ignition timing of the ignition plug 8 is controlled. That is, ignition timing control is performed.

The distributor 20 has a built-in rotor (not shown) that rotates in conjunction with the rotation of the crankshaft 1a. Distributor 20
A rotation speed sensor 36 as a rotation speed detecting means in the present invention and a cylinder discrimination sensor 37 are provided. The rotation speed sensor 36 detects the rotation speed NE of the engine 1 (engine rotation speed) NE from the rotation of the rotor, and outputs a signal corresponding to the detection result. The cylinder discrimination sensor 37 similarly detects a reference position at a crank angle from the rotation of the rotor at a predetermined ratio, and outputs a reference signal GP indicating the detection result. In this embodiment, it is assumed that the crankshaft 1a makes two rotations during a series of strokes of the engine 1, and the rotation speed sensor 36 detects the crank angle at a rate of 30 ° per pulse. Also, the cylinder discrimination sensor 37 outputs 1
The crank angle is detected at a rate of 360 ° per pulse. In this embodiment, the air flow meter 32 and the rotational speed sensor 36 constitute a load detecting means in the present invention.

Further, in this embodiment, a knock sensor 38 constituting the knock detecting means of the present invention is attached to the cylinder block 2. This sensor 38
Detects a vibration generated due to knocking or the like in the engine 1 and outputs a knock signal KCS according to the detection result.

In addition, in this embodiment, a bypass passage 22 is provided in the intake passage 11. The passage 22 bypasses the throttle valve 19 and connects the upstream side and the downstream side of the throttle valve 19. The passage 22 is provided with a well-known linear solenoid type idle speed control valve (ISCV) 23. This ISCV23
Is operated to stabilize the operation during the idling operation when the throttle valve 19 is fully closed. By controlling the ISCV 23 based on a predetermined command signal during the idling operation, the opening degree of the bypass passage 22 is adjusted, the intake air amount Q taken into the combustion chamber 7 through the bypass passage 22 is adjusted, and the engine speed NE is adjusted. Is controlled. That is, idle speed control is performed.

In this embodiment, an electronic control unit (EC
U) 51 inputs the signals detected by the sensors 31 to 38 described above. Then, based on these detection signals, the ECU 51 executes each of the injectors 17, the igniters 21 and I to control the ignition timing of the engine 1, the fuel injection amount, the idle speed control, and the like.
Each of the SCVs 23 is controlled. In this embodiment, E
The CU 51 constitutes first and second ignition timing calculating means, first and second ignition timing setting means, octane number discriminating means, ignition timing changing means, knock learning means, and ignition timing correcting means in the present invention. .

As shown in the block diagram in FIG. 3, ECU 5
1 is a central processing unit (CPU) 52, a read-only memory (R
OM) 53, random access memory (RAM) 54,
A backup RAM 55 and a timer counter 56 are provided. In the ECU 51, these units 52 to 56, an external input circuit 57, an external output circuit 58, and the like are connected by a bus 59 to form a theoretical operation circuit.

The ROM 53 stores the above-described ignition timing control,
Predetermined programs related to fuel injection amount control, idle rotation speed control, and the like are stored in advance. The RAM 54 temporarily stores the calculation results of the CPU 52 and the like. The backup RAM 55 stores data stored in advance. In the timer counter 56, a plurality of counting operations are performed simultaneously.

The external input circuit 57 is connected to the sensors 31 to 38 described above. The external output circuit 58 includes each injector 17, the igniter 21 and the I
SCVs 23 are respectively connected. And CPU
Reference numeral 52 reads, as an input value, detection signals relating to the sensors 31 to 38, which are input via the external input circuit 57. C
PU5 2 each based on their input values member 17,2
1 and 23 are controlled.

Next, in the gasoline engine system, will be described with reference to FIGS. 4-9 for the processing content of the ignition timing control executed by the ECU 51. FIG. 4 shows an “ignition timing calculation routine” executed by the ECU 51.
And is executed periodically at predetermined intervals.

When the process proceeds to this routine, first, in step 100, based on the detection signals of the sensors 31, 32, and 36, the values of the idle signal IDL, the intake air amount Q, and the engine speed NE are read. At the same time, the value of knock retard amount AKB is read. The knock retard amount AKB is calculated by a separate “AKB calculation routine” described later. This knock retard amount AKB is for correcting the ignition timing control during the idling operation by reflecting the difference in the octane number of the fuel used in the engine 1.

Subsequently, at step 110, a first basic ignition timing ABF is calculated based on the intake air amount Q and the engine speed NE. The basic ignition timing ABF is set based on the crank angle as a timing earlier than the top dead center TDC. Here, the value of the load on the engine 1 (the amount of intake air per revolution of the engine 1 = Q / NE), which is obtained from the relationship between the intake air amount Q and the engine rotational speed NE, and the value of the engine rotational speed NE are reflected. The basic ignition timing ABF is calculated by a known method with reference to a predetermined two-dimensional map (not shown). This basic ignition timing ABF is used for ignition timing control during normal operation which is not originally during idle operation. However, as described later, this basic ignition timing ABF
Is used to limit the ignition timing in order to prevent the ignition timing from being over-advanced during idling operation. Therefore, the basic ignition timing ABF is calculated irrespective of whether it is during idling operation. In this embodiment, the ECU 51 that executes the process of step 110
Corresponds to the first ignition timing calculation means in the present invention.

Next, at step 120, it is determined whether or not the idle signal IDL is "ON". That is,
It is determined whether or not the engine is in an idling operation in which the throttle valve 19 is fully closed. Here, when the engine 1 is in the normal operation, the process proceeds to step 130, and when the engine 1 is in the idling operation, the process proceeds to step 121. In this embodiment, the ECU 51 that executes the processing of step 120 corresponds to an idle determination unit in the present invention.

In step 130, step 11
At 0, the first basic ignition timing ABF calculated this time is temporarily stored in the RAM 54 as the target ignition timing ABS, and the subsequent processing is temporarily terminated. In this embodiment, the ECU 51 that executes the processing of step 130 corresponds to the first ignition timing setting means in the present invention.

[0042] In step 121, mosquitoes down preparative value C0 in the timer counter 56 to determine whether or not "3 seconds" or more. The mosquitoes down DOO value C0 shows the elapsed time after the start of the engine 1. Engine 1
Until a predetermined time elapses after the start of the engine, the rotation fluctuation of the engine 1 is large, and the idle correction value AID based on the rotation fluctuation cannot be accurately calculated. Here, the magnitude of the count value C0 is determined to avoid that. When the count value C0 is less than “3 seconds”,
The process shifts to step 125, where the count value C0 becomes “3”.
If it is “seconds” or more, the process proceeds to step 122.

On the other hand, after shifting from step 121, in step 122, based on the currently read engine rotational speed NE, the smoothed value NE as a weighted average value is obtained.
Calculate M. Further, in step 123, the rotational speed deviation ΔN is calculated from the difference between the current smoothed value NEM and the current value of the engine rotational speed NE.

In step 124, the idling correction value AI is calculated based on the rotational speed deviation ΔN calculated this time.
D is calculated, and the calculation result is stored in the RAM 54. Here, the idle correction value AID is calculated with reference to the map as shown in FIG. This idle correction value AID is
When the ignition timing is advanced under the condition that the throttle opening TA and the air-fuel ratio are constant during the idling operation of the engine 1, the engine rotation speed NE increases, and when the ignition timing is retarded, the engine rotation speed NE decreases. It is required in view of such characteristics. Then, the engine speed NE during idling, that is, the idle speed is compared with a predetermined target speed (or an average value of the idle speed), and when the idle speed is lower than the target speed. Is a value for stabilizing the idle rotation speed by advancing the ignition timing, and delaying the ignition timing when the idle rotation speed exceeds the target rotation speed.

Step 12 shifts from step 121
At 5, the idle correction value AID is set to "0" and stored in the RAM 54. In this embodiment, the ECU 51 that executes the processing of steps 120 to 125 is performed.
Corresponds to an idle correction value calculating means for calculating an idle correction value AID for correcting a target ignition timing ABS, which will be described later, according to a change in the engine speed NE during idling operation.

Subsequently, at step 140, the second basic ignition timing ABN is calculated based on the engine speed NE read this time. This basic ignition timing ABN
Are set based on the crank angle as a timing earlier than the top dead center TDC. Here, the basic ignition timing ABN, calculated with reference to the map as shown in FIG. In this map, “engine stall area” and “deceleration area” related to engine speed NE
, The basic ignition timing ABN is equal to the engine speed N.
It changes continuously with the change of E, and in the range of the "idle region", the basic ignition timing ABN changes little with respect to the change of the engine speed NE. This basic ignition timing ABN is used to set the ignition timing during idling operation,
It is calculated only during idling operation. In this embodiment, the ECU 51 that executes the processing of step 140 corresponds to the second ignition timing calculation means in the present invention.

In step 150, the value of the second basic ignition timing ABN obtained this time is added to the idle correction value AI.
By adding D, a second
After the correction, the basic ignition timing α is calculated. Step 16
0, the first basic ignition timing AB obtained this time is
By subtracting the value of the currently read knock retard amount AKB from the value of F, the first corrected basic ignition timing β during idling operation is calculated.

In step 170, it is determined whether or not the second corrected basic ignition timing α is greater than the first corrected basic ignition timing β. That is, it is determined which is on the advance side based on the top dead center TDC. Here, if the second corrected basic ignition timing α is not greater than the first corrected basic ignition timing β, the process shifts to step 180; otherwise, the process shifts to step 190. Transition. Here, if the load on the engine 1 during the idling operation is small, the process proceeds to step 180 because the second corrected basic ignition timing α does not become larger than the first corrected basic ignition timing β. I do. In contrast,
If the load on the engine 1 during the idling operation is large, the second corrected basic ignition timing α becomes larger than the first corrected basic ignition timing β, and the process proceeds to step 19.
Move to 0.

[0049] In step 180, since the second corrected basic ignition timing α is Ru timing der the retard side of the β first corrected basic ignition timing, the corrected basic ignition timing α
Is temporarily stored in the RAM 54 as the target ignition timing ABS,
Thereafter, the processing is temporarily terminated.

On the other hand, in step 190, since the second corrected basic ignition timing α is Ru timing der the advance side than the β first corrected basic ignition timing, from the corrected basic ignition timing β The idle correction value AID is subtracted, the result of the subtraction is temporarily stored in the RAM 54 as the target ignition timing ABS, and the subsequent processing is temporarily terminated.

That is, in the processing of steps 170 to 190, when the load on the engine 1 is large, the second corrected basic ignition timing α is set to a value advanced from the first corrected basic ignition timing β. Therefore, the second corrected basic ignition timing α is limited with the first corrected basic ignition timing β as the upper limit timing on the advance side. In this embodiment, the processing of steps 170 to 190 described above is executed.
The CU 51 corresponds to a second ignition timing setting unit in the present invention.

After that, the ECU 51 determines the value of the target ignition timing ABS in accordance with a separate processing routine.
By driving the Lee Gunaita 21, the spark plug 8
Is operated to ignite the fuel. That is, the ignition timing is actually output based on the target ignition timing ABS. The details of the processing related to the ignition timing output are generally well-known techniques, and thus description thereof is omitted here.

Next, a description will be given of the calculation of the knock retard reflection amount AKN used for controlling knocking occurring in the engine 1. FIG. 6 is a flowchart showing an “AKN calculation routine” executed by the ECU 51, which is periodically executed at predetermined intervals.

When the processing shifts to this routine, first, in step 200, each of the sensors 31, 32, 35,
Based on the detection signals 36 and 38, the idle signal IDL,
The values of the intake air amount Q, the cooling water temperature THW, the engine speed NE, and the knock signal KCS are read.

Subsequently, at step 300, the above-mentioned knock retard amount AKB is calculated. This knock retard amount A
Calculation of KB is performed according to the "AKB calculating routine" separately, as shown in the flowchart of FIG.

That is, in step 301, the maximum retardation amount AKMX is calculated based on the read intake air amount Q and the engine rotation speed NE. This calculation is performed with reference to a predetermined two-dimensional map (not shown) reflecting the value of the load on the engine 1 obtained from the relationship between the intake air amount Q and the engine speed NE and the value of the engine speed NE. Will be

Subsequently, in step 302, it is determined whether or not the idle signal IDL is "ON". That is, it is determined whether or not the vehicle is idling. here,
If the engine 1 is in normal operation, the process proceeds to step 303. If the engine 1 is in idle operation, the process proceeds to step 304. In this embodiment, the ECU 51 that executes the processing of step 302 also corresponds to the idle determination unit in the present invention.

In step 303, knock control amount AKC is set to "0 ° CA" and stored in RAM 54. Thereafter, the process proceeds to step 317. On the other hand, in step 304, it is determined whether or not the operating state of the engine 1 is in a knock control region where knock control should be performed. This knock control region corresponds to a range set in advance with respect to the engine speed NE and the engine load.

If the operation state of the engine 1 is not in the knock control region, the process proceeds to step 317 after executing step 303. If the operating state of the engine 1 is in the knock control region, the process proceeds to step 3
Move to 05.

In step 305, it is determined whether or not the engine 1 has knocked. This knocking determination is made based on knock signal KCS. here,
If there is knocking, in step 306,
A new knock control amount AKC is set by adding “0.4 ° CA” to the value of the current knock control amount AKC. If knocking is not, in step 307, another mosquito-down bets value C1 in the timer counter 56 is "300m
Seconds ”or more. This count value C1
Is a value counted to advance the knock control amount AKC at predetermined time intervals when knocking does not occur.

Then, the count value C1 is "300 m
If it is less than “second”, the process is performed as it is in step 31
Move to 0. If the count value C1 is equal to or longer than "300 ms", a new knock control amount AKC is set in step 308 by subtracting "0.08 CA" from the current value of the knock control amount AKC. Step 3
After the count value C1 is reset to “0” in step 09, the process proceeds to step 310.

In step 310, it is determined whether or not the operating state of the engine 1 is in a learning region in which knock learning control is to be performed. This learning region corresponds to a range preset for the engine speed NE and the engine load.

If the operating state of the engine 1 is not in the knocking learning region, the routine proceeds to step 317.
Move to. If the operating state of the engine 1 is in the knocking learning region, the process proceeds to step 311.

[0064] In step 311, another mosquito-down bets value C2 further in the timer counter 56 is "500m
Seconds ”or more. The mosquito-down door value C2
Is a value that is counted for learning and updating a knock learning value AKG described later every predetermined time.

Then, when the count value C2 is "500 m
If it is less than “second”, the process is performed as it is in step 31
Move to 7. If the count value C2 is equal to or longer than “500 ms”, in step 312, the count value C
After resetting “2” to “0”, the process proceeds to step 313. In step 313, it is determined whether or not the value of knock control amount AKC determined as described above is equal to or greater than “2 ° CA”. Here, if the value of the knock control amount AKC is less than “2 ° CA”, in step 314, “0.1 ° CA” is added to the current knock learning value AGK, and the addition result is used as a new knock value. Set as learning value AGK. Thereafter, the process proceeds to step 317.

On the other hand, if the value of knock control amount AKC is equal to or larger than “2 ° CA” in step 313, the process proceeds to step 315. And step 31
5, the value of knock control amount AKC is also “4 ° C.
A ”is determined. Here, if the value of knock control amount AKC is equal to or more than “4 ° CA”, in step 316, “0.1 ° CA” is subtracted from the current knock learning value AGK, and the result of the subtraction is set as a new value. It is set as knock learning value AGK. Thereafter, the process proceeds to step 317. When the value of knock control amount AKC is “4 °
If it is less than "CA", the process is directly performed in step 3
Move to 17.

Here, the knock learning value AGK calculated as described above reflects not only the difference in the octane number of the fuel, but also the individual difference of the engine 1 and its aging. Then, steps 303, 310, 311 and 314-31
6 and in step 317, based on the parameters AKMX, AGK, and AKC determined this time,
The knock retard amount AKB is calculated according to the following formula, and the subsequent processing is temporarily terminated.

[0068] AKB = AKMX-AGK + AKC i.e., knocking retard amount AKB, as shown in FIG. 9, is calculated as a retard side of the value for the target ignition timing ABS.

The knock retard amount ABK is calculated as described above, and the knock control amount AKC and the knock learning value AGK are calculated accordingly. In this example,
ECU that executes the processing of steps 302 to 316
51 corresponds to knock learning means in the present invention. Then, in a series of processes of steps 302 to 316, the value of knock control amount AKC is set to “2” based on the presence or absence of knocking.
Knock learning value A so as to have a value in the range of
GK is updated.

Here, the fuel used for the engine 1 is
A general user may change between premium gasoline with high octane number and regular gasoline with low octane number. When the engine 1 has the premium specification, the ignition timing control is performed based on the second basic ignition timing ABN suitable for the premium specification. However, when the fuel is changed to regular gasoline, knocking occurs frequently because the knocking limit time related to the fuel is relatively retarded. Therefore, knock control amount AKC increases, and knock learning value AGK decreases to some extent. Therefore, by determining the magnitude of knock control amount AKC or knock learning value AGK, it is possible to determine the use of legal gasoline.

Conversely, when the ignition timing control is performed based on the second basic ignition timing ABN of the regular specification, and the fuel is changed to premium gasoline,
Since the limit time of knocking related to the fuel is relatively advanced, knocking is reduced. For this reason,
Knock control amount AKC decreases, and knock learning value AGK
Is somewhat larger. Therefore, the knock control amount AKC,
Alternatively, it is possible to determine the use of premium gasoline by determining the magnitude of knock learning value AGK.

In this embodiment, the above steps 313,
At 315, the magnitude of knock control amount AKC is determined, and based on the determination result, at steps 314, 316, the knock learning value is updated. Therefore, the ECU 51 that executes the processing of steps 313 to 316
Corresponds to the octane number discriminating means in the present invention.

Therefore, the value of the knock retard amount AKB reflects the magnitude of the knock control amount AKC and the knock learning value AGK, and further reflects the use of premium gasoline or regular gasoline. Is done.

In this embodiment, since the value of knock retard amount AKB is used to calculate the first corrected basic ignition timing β in the flowchart of FIG. 4 , the target used during idling operation is set. The ignition timing ABS reflects the use of premium gasoline or regular gasoline. Therefore, the ECU 51 executing step 160 in the flowchart of FIG. 4 corresponds to the ignition timing changing means and the ignition timing correcting means in the present invention.

Returning to the flowchart of FIG. 6 again, after the processing of step 300 is performed as described above, in step 210, the cooling water temperature THW read this time is read.
Is determined to be lower than a predetermined reference value TH1. This determination is made in order to know whether or not the engine 1 is in a cold state. Therefore, the reference value TH1 is set to an appropriate value (for example, “60 ° C.”). here,
If the cooling water temperature THW is not lower than the reference value TH1, the process directly proceeds to step 230. Cooling water temperature TH
If W is lower than the reference value TH1, step 220
, The knock retard amount AKB determined this time is set to “2 °
CA "is added to correct the knock retard amount AKB. This is because, when the engine 1 is cold, the knock feedback control based on the detection signal of the knock sensor 38 is not performed.
Since the knock learning value AGK itself has low reliability,
Knock learning value AG so that it is retarded by “2 ° CA”
K is being corrected.

Then, after shifting from steps 210 and 220, in step 230, it is determined whether or not the idle signal IDL is "ON", that is, whether or not the idle operation is being performed. Here, when the engine 1 is in the normal operation, in step 240, the value of the knock retard amount AKB calculated in step 220 is set as the knock retard reflection amount AKN, and the subsequent processing is temporarily ended. . If the engine 1 is in idling operation, step 2
At 50, "0" is set as the knock retard reflection amount AKN, and the subsequent processing is temporarily terminated.

The knock retard reflection amount AKN is calculated as described above. This knock retard reflection amount AKN is determined by the engine 1
During the normal operation of the vehicle, together with the above-mentioned target ignition timing ABS, the required ignition timing ACA to be finally used for performing the ignition timing control is used. That is, the required ignition timing ACA is calculated according to the following formula.

ACA = ABS + ACL + AEGR−AKN Here, ACL is a correction value obtained according to the warm-up state of the engine 1. AEGR is the amount of exhaust gas recirculation (E
(GR amount).

According to the above configuration, during normal operation of the engine 1, the final required ignition timing ACA to be used in the ignition timing control is set based on the first basic ignition timing ABF. On the other hand, when the engine 1 is idling, the second basic ignition timing ABN to be used during the idling operation is calculated based on the engine speed NE. In this embodiment, the ECU 51 performs the idling operation.
Controls the ISCV 23 to perform idle speed control, so that the idle speed is controlled to a predetermined value and is controlled in accordance with a change in engine load. Further, the final target ignition timing ABS which should be finally used in the ignition timing control is determined by setting the first and second basic ignition timings ABF and ABN with the first basic ignition timing ABF as the upper limit timing on the advance side. Is set based on

That is, when the engine load during idling is low, the target ignition timing ABS is set based on the second basic ignition timing ABN. When the engine load is relatively high, the target ignition timing ABS is It is set to a relatively retarded timing based on the first basic ignition timing ABF. At this time, the first basic ignition timing ABF used in the above setting is changed based on the difference in the octane number of the fuel used in the engine 1, that is, the difference between the premium gasoline and the regular gasoline.

For example, when the engine 1 uses regular gasoline having a low octane number, the value of the first basic ignition timing ABF is relatively smaller than when premium gasoline having a high octane number is used. The timing is changed to the retard side.

Therefore, even when the engine load becomes high during idling operation, the target ignition timing ABS does not advance more than necessary, and the combustion of the air-fuel mixture in each combustion chamber 7 is stabilized. In addition, when the octane number of the fuel to be used changes, the above operation can be obtained according to the difference in the octane number.

As a result, during idling of the engine 1, even if the engine load increases due to the operation of the automatic transmission, the power steering device, the air conditioner, etc., the actual ignition timing is advanced more than necessary. The idle stability of the engine 1 can be ensured in a range where the engine 1 does not fall, knocking can be prevented, and the engine stall resistance can be enhanced. Furthermore, ensuring the idle stability and preventing the occurrence of knocking are performed by the engine 1
This can be done in response to changes in the type of fuel used. In other words, even if the user of the vehicle changes the fuel used between regular gasoline and premium gasoline arbitrarily, it is possible to ensure idle stability and prevent knocking.

Further, in this embodiment, the first basic ignition timing ABF is a knock learning value AGK obtained by the knock learning control.
Is corrected based on For example, when knock learning value AGK is relatively retarded, first basic ignition timing ABF is relatively retarded when compared with the case where learned value AGK is advanced. Is corrected to

Therefore, when the engine load increases during the idling operation, the above-described effects can be obtained in accordance with the difference between the individual components of the engine 1 and the change with time. As a result, the above-described idle stability can be ensured and knocking can be prevented with higher accuracy when the load increases during idling operation by an amount that is corrected for the individual difference and the aging change of the engine 1.

In addition, in this embodiment, in the flowchart of FIG. 4 , in step 150, the value of the second basic ignition timing ABN is corrected by an idle correction value AID corresponding to a minute change in the engine speed NE. , Step 19
If the target ignition timing ABS is 0, the idle correction value AID
Or to correct. Accordingly, the state of the engine speed NE during idling is stabilized by the amount of the correction, and the idling stability can be further improved.

The present invention can be embodied in another embodiment as follows. In another example below,
The same operation and effect as those of the above embodiment can be obtained. (1) In the above-described embodiment, the second basic ignition timing ABN during the idling operation is calculated based on the magnitude of the engine rotation speed NE, but may be calculated based on a predetermined fixed ignition timing.

[0088] (2) In the embodiment, in step 301 of the flowchart of FIG. 7, to calculate the maximum retardation amount AKMX based on the intake air amount Q and the engine rotational speed NE.

On the other hand, as shown in FIG. 10 , the minimum ignition timing AKGD and the first basic ignition timing ABF are set on a two-dimensional map from the relationship between the engine load and the ignition timing. Then, the maximum retardation amount AKMX may be calculated by subtracting the minimum ignition timing AKGD from the first basic ignition timing ABF with reference to the map.

(3) In the above-described embodiment, the ignition timing control device of the present invention is applied to the "El Jetronic" type engine 1 using the air flow meter 32, but the "Die Jetronic" using a vacuum sensor is used. "Type engine.

(4) In the above embodiment, the knock control amount AK
The octane number of the fuel is determined based on C or the knock learning value AGK, and the target ignition timing ABS is corrected and changed by reflecting the determination result.

On the other hand, the operating state of a switch or the like operated according to the difference in the octane number of the fuel by the user of the vehicle, the knock control amount AKC or the knock learning value AG
Based on K, the type of fuel currently in use is determined by an ECU (octane number determining means). In addition, a plurality of maps in which the relationship between the engine speed NE and the first basic ignition timing ABF for normal operation with respect to the engine load are set in advance are prepared in accordance with the type of fuel. And ECU
(Ignition timing changing means) selectively refers to a plurality of maps based on the determination result, and retards the second basic ignition timing ABN for idling operation based on the referenced first basic ignition timing ABF. It is also possible to add restrictions on the side.

(5) In the above embodiment, as shown in FIG. 9 , the ignition timing control is performed by correcting the target ignition timing ABS based on the knock retard amount AKB reflecting the parameters AKMX, AGK, and AKC. The knock learning value AGK is reflected in the required ignition timing ACA to be finally used to perform the operation.

On the other hand, as shown in FIG. 11 , the target ignition timing A is determined based on the knock retardation reflection amount AKN determined based on knock learning value AGK and knock control amount AKC.
By correcting BS, the final required ignition timing AC
In A, the knock learning value AGK may be reflected. Here, the knock retard reflection amount AKN is smaller than the maximum retard amount AKMX. The knock learning value AGK is equal to the knock control amount A.
When KC is in the range of “2 to 4 ° CA”, “0.1
° CA ”as a unit.

(6) In the above embodiment, the ignition timing control device of the present invention is applied to a gasoline engine as an internal combustion engine. However, the ignition timing control device may be applied to an LPG engine.

While the embodiments of the present invention have been described above, it is to be noted that the above-mentioned embodiments include the following various embodiments according to the technical idea described in the claims. Are described together with the effects.

(A) In the invention according to claim 1 or 2, an idle correction value for calculating an idle correction value for correcting the target ignition timing in accordance with a change in the rotational speed of the internal combustion engine during idle operation. An ignition timing control device for an internal combustion engine provided with calculation means.

According to this configuration, the idle stability can be further improved by the idle correction value. still,
In this specification, means, members, and the like according to the configuration of the present invention are defined as follows.

(A) The learning means a method of deciding a better control method by making use of the experience of the past control. The control device itself evaluates and stores the control results so far, and based on the evaluation, This includes modifying parameter storage or control logic within the controller.

[0100]

[0101]

[0102]

According to the present invention, during operation of the internal combustion engine, it calculates a first ignition timing based on the rotational speed and load, during idle operation, a predetermined fixed ignition timing, or the rotational speed of the engine The second ignition timing is calculated based on the second ignition timing. Then, during the idling operation, the target ignition timing is set based on the first and second ignition timings, with the first ignition timing being the upper limit timing on the advance side. Further, at the time of idling, the first ignition timing is corrected based on the knocking learning result.

Therefore, even if the engine load becomes high during idling operation, the target ignition timing does not become more advanced than necessary, the combustion of the air-fuel mixture is stabilized, and their effects are caused by differences in the octane number of the fuel used. It can be obtained according to the individual difference of the internal combustion engine and the change with time. As a result, even if the engine load increases during idling operation, idle stability can be ensured in a range where the advance angle is not unnecessarily increased, and knocking can be prevented. Furthermore, there is an effect that these can be performed in response to a change in the type of fuel used, a difference between individual engines and a change with time.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a gasoline engine system including an internal combustion engine ignition timing control device according to the present invention.

FIG. 3 is a block diagram showing a configuration of an ECU and the like in one embodiment.

FIG. 4 is a flowchart showing an “ignition timing calculation routine” executed by an ECU in one embodiment.

FIG. 5 is a map showing a relationship between a rotational speed deviation (ΔN) and an idle correction value (AID) in one embodiment.

FIG. 6 is a flowchart illustrating an “AKN calculation routine” executed by an ECU in one embodiment.

FIG. 7 is a flowchart showing an “AKB calculation routine” executed by the ECU in one embodiment.

FIG. 8 illustrates an engine rotation speed (N
9 is a map showing a relationship between E) and a second basic ignition timing (ABN).

FIG. 9 shows the knock retard amount (AKB) in one embodiment .
It is an explanatory view showing a calculation method of.

FIG. 10 is a graph showing a maximum retardation amount (AKM ) in another embodiment .
6 is a map showing a calculation method of X).

FIG. 11 shows a target ignition timing (AB ) in another embodiment .
It is explanatory drawing which shows how to reflect a knock learning value (AGK) with respect to S).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine as internal combustion engine, 8 ... Spark plug, 20
... distributor, 21 ... igniter (8,20,
21 constitutes an ignition device, 31 ... throttle sensor (31 constitutes idle detection means), 32 ... air flow meter, 36 ... rotation speed sensor (36 constitutes rotation speed detection means, 32 and 36 denote loads) Knock sensor (38 constitutes knock detection means), 51 ... ECU (51 is idle determination means, first and second ignition timing calculation means, first and second ignitions) Timing setting means, octane number discriminating means, ignition timing changing means,
Knock learning means and ignition timing correction means are configured).

Claims (1)

(57) [Claims] The method according to claim 1 ignition timing to actuate the ignition device for igniting the air-fuel mixture sucked into the internal combustion engine, ignition timing control apparatus for an internal combustion engine so as to control in accordance with the operating state of the internal combustion engine A rotational speed detecting means for detecting a rotational speed of the internal combustion engine; a load detecting means for detecting a load on the internal combustion engine; and an idle detecting means for detecting an idle operation state of the internal combustion engine. First ignition timing calculation means for calculating a first ignition timing based on the detection results of the rotational speed detection means and the load detection means; and during idle operation based on the detection results of the idle detection means. Idle determination means for determining whether the engine is in idling operation when the idle determination means determines a predetermined fixed ignition timing or the rotation speed detection. A second ignition timing calculating means for calculating a second ignition timing at the time of idling operation based on a detection result of the stage; First ignition timing setting means for setting a target ignition timing based on the ignition timing; and when the idle determination means determines that the engine is in idling operation, the first ignition timing is set to an advanced side. Second ignition timing setting means for setting a target ignition timing based on the first and second ignition timings as an upper limit timing; knock detection means for detecting knocking of the internal combustion engine; Knock learning means for learning the timing of occurrence of knocking based on the detection result of the detection means; and the second ignition timing setting means based on the learning result of the knock learning means An ignition timing control device for an internal combustion engine, comprising: an ignition timing correction means for correcting the first ignition timing used in the above.