JP2000009006A - Ignition timing control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably increase engine speed to a target idle rotational speed at the time of starting an engine in which a normal ignition timing after starting is on the retarding side compared to a fixed ignition timing at the time of starting. SOLUTION: It is determined whether an engine is in a shifting condition after a starting condition. When the answer is YES, a shifting ignition timing IGINT is compared to a normal ignition timing IGLOG. When the normal ignition timing IGLOG is on the retarding side compared to the shifting ignition timing IGINT, the normal ignition timing is replaced with the shifting ignition timing. Ignition is performed with the shifting ignition timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In the ignition timing control of an internal combustion engine, particularly in the ignition timing control at the time of starting, the ignition timing is fixed at a predetermined retard value at the time of engine start, and after the start is completed, the engine speed and the engine load are set. From this, the basic ignition timing is searched on a map, and the normal ignition timing is calculated by correcting the search value with the engine cooling water temperature or the like.

[0003] At the time of a low temperature start, after the start is completed, the normal ignition timing is corrected to a low temperature and advanced, and the difference between the normal ignition timing and the fixed retard value at the start is large. If it shifts immediately, the engine speed fluctuates and the engine output torque fluctuates. In view of this, the present applicant has previously proposed in Japanese Utility Model Publication No. 7-40689 a technique for gradually advancing the ignition timing from a fixed retard value to a normal ignition timing.

[0004]

The above-mentioned problems are mainly intended to solve the problems at the time of low-temperature starting. Apart from that, in recent years, high compression of the engine has been attempted. Is set relatively to the retard side.

The transition to the normal ignition timing is performed, for example, when the engine speed reaches a predetermined speed. However, since the basic ignition timing is set to a relatively retarded side, the normal ignition timing is set. May be retarded from the fixed value at the start.

As a result, as shown in FIG. 5, there has been a problem that the engine speed once increased has decreased and does not stably increase to the target idle speed.

In some cases, as shown in FIG.
When the engine speed falls below a predetermined speed, the ignition timing is returned to a fixed value (a value in the advance direction) again, and after the switching speed is again reached, the ignition timing returns to the normal ignition timing control value in the retard direction again. There was a disadvantage that the engine speed fluctuated due to the return.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned disadvantages, and to provide an ignition timing control device for an internal combustion engine in which the engine speed is stably increased to a target idle speed when the engine is started. Is to do.

More specifically, an object of the present invention is to reduce the engine speed during engine start even in an internal combustion engine in which the ignition timing after the start is completed is determined to be more retarded than the fixed value at the start. An object of the present invention is to provide an ignition timing control device for an internal combustion engine, which is configured to stably increase to a target idle speed.

[0010]

According to a first aspect of the present invention, there is provided an operating state detecting means for detecting an operating state of an internal combustion engine, the operating state detecting means detecting an operating state of the internal combustion engine based on the detected operating state. First ignition timing setting means for setting the ignition timing of the engine to a first value, and second ignition timing setting for setting the ignition timing of the internal combustion engine to a second value when the internal combustion engine is in a starting state. Means for determining whether or not the internal combustion engine is in a post-start transition state from a start state, and determining whether the internal combustion engine is in the post-start transition state when the internal combustion engine is in the post-start transition state. Comparing the first value with the second value, and determining that the ignition timing is determined to be the second value when the first value is determined to be more retarded than the second value; and To perform ignition based on the set ignition timing It was as configuration equipped with a stage.

Thus, even in an internal combustion engine in which the ignition timing after completion of the start is determined to be more retarded than the fixed value at the time of the start, the engine speed is stably maintained at the target engine speed at the start of the engine. Can be raised.

According to a second aspect of the present invention, when it is determined that the first value is on the advance side of the second value, the ignition timing determination means advances the second value by a predetermined amount. The ignition timing is determined based on the angle-corrected value.

Thus, in addition to the above-described effects, even in an internal combustion engine in which the ignition timing after the completion of the start is determined to be more advanced than the fixed value at the time of the start, the engine output torque fluctuates when the engine is started. Without causing the engine speed to stably rise to the target idle speed.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an entire ignition timing control device for an internal combustion engine according to the present invention.

In FIG. 1, reference numeral 10 denotes a four-cylinder, four-cycle internal combustion engine (hereinafter referred to as "engine"). A throttle valve 14 is arranged in the intake pipe 12 connected to the main body 10a of the engine 10. A throttle opening sensor 16 is connected to the throttle valve 14, outputs an electric signal corresponding to the opening θTH of the throttle valve 14, and sends it to an electronic control unit (hereinafter referred to as “ECU”) 20.

The above-described intake pipe 12 forms an intake manifold (not shown) downstream of the throttle valve arrangement position, and a fuel injection valve (not shown) upstream of the intake valve (not shown) of each cylinder in the intake manifold. An injector 22 is provided for each cylinder.

The fuel injection valve 22 is a fuel pump (not shown)
Is mechanically connected to the fuel pump to
U20 is electrically connected to control the valve opening time,
While the valve is opened, the pumped fuel is injected (supplied) into the cylinder.

In the intake pipe 12, a throttle valve 14
A pressure sensor 26 is mounted downstream of the intake pipe 12 via a branch pipe 24.
An electric signal corresponding to the PBA is output.

An intake air temperature sensor 30 is mounted downstream of the engine, and outputs an electric signal corresponding to the intake air temperature TA. A water temperature sensor 32 is arranged near a cooling water passage of the engine body 10a. An electric signal corresponding to the water temperature TW is output.

In the internal combustion engine 10, a cylinder discrimination sensor 34 is attached near a camshaft or a crankshaft (both not shown), and outputs a cylinder discrimination signal CYL for each piston position of a predetermined cylinder.

Similarly, a TDC sensor 36 is mounted near the camshaft or crankshaft (both not shown), and for each crank angle (for example, BTDC10 degrees) related to the TDC position of a piston (not shown). A TDC signal pulse is output, and a crank angle sensor 38 is attached, and outputs a CRK signal pulse at a crank angle (for example, 30 degrees) cycle shorter than the cycle of the TDC signal pulse.

In the exhaust system of the internal combustion engine 10, an exhaust pipe 4 connected to an exhaust manifold (not shown) is provided.
An air-fuel ratio sensor (O ₂ sensor) 42 is provided at an appropriate position of 0, outputs a signal corresponding to the oxygen concentration O ₂ in the exhaust gas, and a three-way catalyst 44 is provided downstream thereof. It purifies the HC, CO, and NOx components therein.

A combustion chamber of the internal combustion engine 10 (not shown)
A spark plug 48 is arranged at the bottom. The ignition plug 48
It is electrically connected to the ECU 20 via the igniter 50.

Further, a knock sensor 52 is arranged on a cylinder head (not shown) of the engine body 10a, and outputs a signal corresponding to the vibration of the engine 10.

The outputs of these sensors are also sent to the ECU 20.

The ECU 20 comprises a microcomputer, an input circuit 20a for performing processing such as shaping input signal waveforms from the various sensors, converting voltage levels, or converting analog signal values into digital signals, and a CPU (for performing logical operations). A central processing unit) 20b, storage means 20c for storing various operation programs executed by the CPU, operation results, and the like, and an output circuit 20d.

In the ECU 20, the output of the knock sensor 52 is input to a detection circuit (not shown), where it is compared with a knock determination level obtained by amplifying a noise level.
The CPU 20b detects whether or not knock has occurred in the combustion chamber from the output of the detection circuit. Further, the CPU 20b counts the CRK signal pulse and detects the engine speed NE.

The CPU 20b searches a map which is set in advance and stored in the storage means 20c from the detected engine speed NE and the intake pipe absolute pressure PBA (engine load parameter), and calculates a basic ignition timing. The basic ignition timing calculated from the engine cooling water temperature TW and the like is corrected, and when knock is detected, the basic ignition timing is corrected for retard.

As will be described later, the CPU 20b determines the ignition timing when the engine is started, determines the fuel injection amount (valve opening time), and outputs the fuel through an output circuit 20d and a drive circuit (not shown). The injection valve 22 is driven.

Next, the operation of this apparatus will be described with reference to the flow chart of FIG. The program shown is
In synchronization with the TDC signal described above, more specifically, it is executed at 10 degrees ATDC in each cylinder.

In the following, the normal ignition timing (referred to as "IGLOG") is calculated in S10. This is performed by searching the map from the engine speed NE and the intake pipe absolute pressure PBA as described above to obtain the basic ignition timing (“IGL
OGBASE ”) and adding the coolant temperature TW, knock correction, and the like to the calculated basic ignition timing IGLOGBASE as necessary.

Then, the program proceeds to S12, in which the detected engine cooling water temperature TW is changed to a predetermined water temperature TWIGAST (for example, 50 °).
C) to determine if it exceeds.

When the result in S12 is NO, the program proceeds to S14,
It is determined whether hard ignition (HARD IG) has been selected. In this specification and drawings, the hard ignition (HAR
DIG) means the above-mentioned fixed value at the time of starting the engine.

At the time of cranking when the engine 10 is driven by a starter motor (not shown), or when the engine speed NE is changed to a hard ignition switching speed (for example, 600 rpm).
pm), hard ignition as shown in FIG. 3 is selected as the ignition timing.

When the result in S14 is affirmative, the program proceeds to S16,
The ignition timing at the start (hereinafter, referred to as “IGINT”) is set to a fixed retard value IGINT1, for example, 5 degrees ATDC. Then, the program proceeds to S18, in which the starting ignition timing IGINT is set to the transition ignition timing IGAST.
Reset the IGAST bit to 0.

The ignition timing IGAST at the transition point is, specifically,
This means the ignition timing during the transition period from cranking until the engine speed NE reaches the target idle speed NOBJ. In S20, the flag F. Set IGAST bit to 0
Resetting to that means during the transition period.

Then, the program proceeds to S22, in which the normal ignition timing IG
LOG is replaced with the ignition timing IGAST at the transition (advance,
The ignition timing is determined as the transition ignition timing IGAST), and the program ends. The ignition timing IGL thus determined
Based on the OG, the CPU 20b executes ignition according to another subroutine flowchart not shown.

In the next and subsequent program loops, as shown in FIG. 3, when the engine speed NE increases and becomes equal to or higher than the hard ignition switching speed, the determination in S14 is denied and the routine proceeds to S24, where the flag F. It is determined whether the bit of IGAST is 1 or 0.

Since the bit of this flag has been reset to 0 in S20, it is normally determined to be 0 in S24, and the process proceeds to S26, where it is determined whether or not the detected engine speed NE exceeds the above-mentioned idle target engine speed NOBJ. to decide.

This idle target rotational speed NOBJ is calculated so as to be different from the engine coolant temperature TW in another subroutine flow chart not shown. Therefore, in S26, the detected engine cooling water temperature TW
The target idle speed NOBJ calculated from the above is searched for and obtained.

When the result in S26 is NO, the program proceeds to S28,
The normal ignition timing IGLOG is the starting ignition timing IGINT
It is determined whether or not this is the case, more specifically, whether or not the basic ignition timing IGLOG exceeds the starting ignition timing IGINT in the advance direction.

When the answer in S28 is affirmative, as shown in FIG. 3, there is a difference in the advance angle between the two, so that the program proceeds to S30, where a predetermined amount DIGAST (for example, 1 degree crank angle) is added to the value IGAST. Correct the lead angle.

Thus, as shown in FIG. 3, when the basic ignition timing IGLOGBASE is on the advance side of the hard ignition timing or the forcible soft ignition timing, the ignition timing is gradually returned to the advance direction and the normal ignition timing IGLOG is obtained. Can be reduced, and fluctuations in engine speed and engine output torque can be avoided.

Then, the program proceeds to S32, in which it is determined whether or not the advanced ignition timing IGAST is equal to or greater than the normal ignition timing IGLOG. Judge,
If not, the process proceeds to S22, where the normal ignition timing IGL
The OG is replaced by the ignition timing IGAST at the transition.

If it is determined in S26 that the detected engine speed NE exceeds the idle target engine speed NOBJ, it can be determined that the engine speed has increased to a stable range. Set the IGAST bit to 1.

In this case, the ignition may be performed at the normal ignition timing, and since the replacement work is unnecessary, S22 is skipped and the program is terminated. This is affirmed in S32, and the transition ignition timing IGAST and the normal ignition timing IGL
The same applies when it is determined that the difference in the advance angle from the OG has disappeared.

On the other hand, when the result in S28 is negative, that is, when it is determined that the normal ignition timing IGLOG is in the retarded direction with respect to the ignition timing IGINT at the starting time, the process proceeds to S36, and the ignition timing IGAST at the transition time and the ignition timing are started. Ignition timing IGI
It is determined whether or not NT is equal, and if affirmative, S3
0, skip the processing of S32 and proceed to S22,
If the result is no, the process proceeds to S34. When proceeding to S22, the ignition timing is determined to be the transition ignition timing IGAST, and when proceeding to S34, the normal ignition timing IGLOG is determined.

This will be described with reference to FIGS.

As shown in FIG. 3, the normal ignition timing IGLOG
When it is determined that the ignition timing is advanced with respect to the ignition timing IGINT at the time of starting, the ignition timing is gradually advanced through steps S30 and S32 to make advance correction. As in the case of (1), fluctuations in the engine speed and the engine output torque can be prevented.

On the other hand, as shown in FIGS. 4 and 5, in a high compression ratio engine proposed recently, the basic ignition timing (I
GLOGBASE) is set to a relatively retarded side,
The normal ignition timing IGLOG is also a value on the retard side compared to the hard ignition timing.

As a result, as shown in FIG. 5, the ignition timing is retarded at the time point when the normal basic ignition timing is switched, and the engine speed NE decreases. Therefore, as shown in the figure, a stable engine speed cannot be obtained when switching from the hard ignition timing to the normal ignition timing IGLOG.

In consideration of such a point, in this embodiment, the engine speed NE is set at the idling target speed N
Until OBJ is reached, the normal ignition timing IGLOG is fixed to the transition ignition timing IGINT. As a result, as shown in FIG. 4, the engine speed NE can be stably increased.

After the engine speed NE reaches the idle target speed NOBJ, the flag F.N. IG
Since the bit of the AST is set to 1, even if NE becomes NOBJ or less again for some reason, the ignition timing is shifted from the transition timing ignition timing IGINT in such a case by S24 to S32 (or S36). Will not be fixed.

If the result in S12 is affirmative, the flow skips to S34 because the temperature is not low and thus such control is unnecessary.

In this embodiment, as described above, the operating state detecting means (the crank angle sensor 38, the absolute pressure sensor 26, the water temperature sensor 32, the knock sensor 52, and its detection circuit) for detecting the operating state of the internal combustion engine (engine 10) , EC
U20), the ignition timing of the internal combustion engine is set to a first value (normal ignition timing IGLO) based on the detected operating state.
G) first ignition timing setting means (ECU 20,
S10) When the internal combustion engine is in a starting state, the ignition timing of the internal combustion engine is set to a second value (starting ignition timing IGIN
T or the transition timing ignition timing IGAST)
Ignition timing setting means (ECU 20, S14 to S2)
2) a post-start transition state determining means (i.e., whether the internal combustion engine is in a transition state from a start state to a post-start transition state, more specifically, by comparing the engine speed NE with an idle target rotation speed NOBJ); ECU20, S26), when it is determined that the internal combustion engine is in the transition state after the start, compares the first value IGLOG with a second value IGINT, and the first value is later than the second value. Ignition timing determining means (ECU20, S28, S36, S22) for determining an ignition timing to the second value when it is determined to be on the corner side, and ignition execution for executing ignition based on the determined ignition timing (ECU 20).

Further, the ignition timing determining means includes a first
Is determined to be on the advance side of the second value, the ignition timing is determined to be a value advanced by a predetermined amount from the second value (ECU 20, S28 to S32, S22). .

[0058]

According to the first aspect of the present invention, even in an internal combustion engine in which the ignition timing after the start is completed is determined to be more retarded than the fixed value at the time of the start, the engine speed is set to the target at the time of engine start. Can be stably increased up to the idling rotational speed.

According to the present invention, in addition to the above-described effects, even in an internal combustion engine in which the ignition timing after the completion of the start is determined to be more advanced than the fixed value at the time of the start, at the time of engine start, The engine speed can be stably increased to the target idle speed without changing the engine output torque.

[Brief description of the drawings]

FIG. 1 is a schematic diagram generally showing an ignition timing control device for an internal combustion engine according to the present invention.

FIG. 2 is a flowchart showing the operation of the apparatus in FIG. 1;

FIG. 3 is a time chart for explaining the operation of the flow chart of FIG. 2;

FIG. 4 is a time chart for similarly explaining the operation of the flow chart of FIG. 2;

FIG. 5 is a time chart similar to FIG. 4, showing the operation of the prior art.

[Explanation of symbols]

 Reference Signs List 10 internal combustion engine (engine) 20 ECU (electronic control unit) 20b CPU 22 fuel injection valve (injector) 26 absolute pressure sensor 32 water temperature sensor 38 crank angle sensor 50 ignition device 52 knock sensor

Continued on the front page F term (reference) 3G022 BA01 CA00 CA01 CA03 DA00 DA01 DA03 EA07 FA03 FA08 GA01 GA05 GA07 GA08 GA09 GA12 GA13

Claims (2)

[Claims] 1. A method comprising: a. Operating state detecting means for detecting an operating state of the internal combustion engine; b. First ignition timing setting means for setting the ignition timing of the internal combustion engine to a first value based on the detected operating state; c. Second ignition timing setting means for setting the ignition timing of the internal combustion engine to a second value when the internal combustion engine is in a starting state; d. A post-start transition state determining means for determining whether the internal combustion engine is in a post-start transition state from a start state, e. When it is determined that the internal combustion engine is in the transition state after the start, the first value is compared with a second value, and the first value is compared with the first value.
Is determined to be more retarded than the second value, ignition timing determining means for determining the ignition timing to the second value; and f. An ignition timing control device for an internal combustion engine, comprising: ignition execution means for executing ignition based on the determined ignition timing. 2. The ignition timing determining means, when it is determined that the first value is more advanced than the second value, sets the ignition timing to a value advanced by a predetermined amount from the second value. 2. The ignition timing control device for an internal combustion engine according to claim 1, wherein: