JP3353311B2 - Idle ignition timing control device - Google Patents

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 idling, and more particularly to an ignition timing control device for stabilizing the engine speed of an internal combustion engine at idling.

[0002]

2. Description of the Related Art Conventionally, at the time of idling of an internal combustion engine, the engine speed increases when the ignition timing is advanced under the condition that the throttle opening and the air-fuel ratio are kept constant, and the engine speed decreases when the ignition timing is delayed. In consideration of such characteristics, the engine speed at idle (idle speed) is compared with the target speed, and when the idle speed falls below the target speed, the ignition timing is advanced, while the idle speed becomes the target speed. There is known an ignition timing control method in which the idle timing is stabilized by delaying the ignition timing when the temperature rises further (Japanese Patent Application Laid-Open No. 58-176470).

[0003] In an internal combustion engine provided with an automatic transmission,
When the shift position of the automatic transmission is selected to be in the neutral range or the parking range at the time of idling, the ignition timing is controlled with the advance value determined according to the engine speed, and at idle the drive range such as the drive range An ignition timing control device in which the ignition timing is controlled at a constant angle advance from the advance value when the range is selected is also conventionally known (Japanese Patent Laid-Open No. 58-47775). . Further, an ignition timing control method in which the correction amount of the ignition timing is determined in accordance with the degree of increase or decrease of the engine speed at the time of idling of the internal combustion engine has been conventionally known (Japanese Patent Laid-Open Publication No. Sho 57/1972).
No. 83665).

[0004]

Therefore, by combining the above-mentioned prior arts, the ignition timing is corrected according to the degree of fluctuation of the engine speed when the internal combustion engine having the automatic transmission is idling. In this case, the ignition timing at the time of the neutral range or the parking range (hereinafter, referred to as N range) is set to the position shown by a in FIG. 9 and the shift position other than the above is set at the shift position (hereinafter, referred to as D range). The ignition timing at this time is set on the more advanced side than that of the N range, as shown by b in FIG. This is because, when the ignition timing at the time of idling is advanced, fuel efficiency can be improved when the engine speed is constant, but if the advance is too advanced, it is easy to misfire,
Also, since the vibration increases, the ignition timing is relatively set to a on the retard side in consideration of the misfire and the vibration in the N range where a remarkable load is not applied.
In the range, a load is applied, and the combustion becomes stable.
Even if the ignition timing is set to be more advanced than the ignition timing of the range, the risk of misfiring and vibration is small. Therefore, the ignition timing is set to b which is more advanced than a in the D range in consideration of improvement in fuel efficiency. is there.

However, this means that, as shown in FIG. 9, in the N range, the ignition timing set point a is located on a substantially linear slope of the ignition timing versus torque characteristic curve I, while
In the range, the set point b of the ignition timing is located on a non-linear curve close to the MBT (close to the torque peak) of the ignition timing versus torque characteristic curve II.

Therefore, in the N range, the torque increase TR when the ignition timing is corrected by a predetermined value from the set point a to the advanced side.
_1, whereas the absolute value of each of the torque decrease amount TR ₂ in the case where the same predetermined value correction and the retarded than the set points a is substantially the same, proceeds the set point b the ignition timing is in the D range a torque increase amount TR ₃ in the case of a predetermined value correction on the corner side, is relatively large in absolute value of each of the torque decrease amount TR ₄ in the case of the same predetermined value correction and the retarded than the set point b the difference Will occur.

Therefore, when the engine speed fluctuates during idling as shown by III in FIG. 10 in the D range, conventionally, when the ignition timing is controlled, the imbalance in the torque fluctuation due to the above-described ignition timing correction causes Although the fluctuation amount of the engine speed can be suppressed as shown by the one-dot chain line IV, the undulation of the engine speed cannot be uniformly corrected, resulting in poor drivability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been made to solve the above-mentioned problem by making the ignition timing correction amount during idling different between the advance side and the retard side. It is an object to provide a control device.

[0009]

In order to achieve the above object, the present invention is configured as shown in a principle block diagram of FIG. In FIG. 1, a detecting means 11 detects an idle state of the internal combustion engine 10. The rotation speed detecting means 12 detects the engine rotation speed of the internal combustion engine 10. Further, the first calculating means 13 calculates the basic ignition timing according to the engine state at the time of idling. The second calculator 14 calculates a deviation between the engine speed detected by the speed detector 12 during idling and the target speed.

In addition, the correction amount calculating means 15 determines whether the basic ignition timing calculated by the first calculating means 13 is in a non-linear part near the torque peak of the ignition timing versus torque characteristic, and Engine speed is better than target speed
Calculated when the ignition timing is retarded
If the engine speed drops below the target speed,
A correction amount with the period on the advance side is calculated. Further, the ignition timing calculating means 16 corrects the basic ignition timing based on the correction amount calculated by the correction amount calculating means 15 and outputs a value for determining the ignition timing.

[0011]

According to the present invention, when the deviation between the engine speed calculated by the correction amount calculating means 15 and the target speed is the same when the internal combustion engine 10 is idling, the torque increase based on the advance angle correction is performed.
Torque reduction amount based on absolute value of addition and correction on the retard side
In order to make the absolute value of the ignition timing substantially the same as the absolute value of the ignition timing, the advance and the retard of the ignition timing are set so that the absolute value of the correction amount with the ignition timing on the advance side is larger than the absolute value of the correction amount with the ignition timing on the retard side A correction amount that is asymmetrical with respect to the side is calculated.

Therefore, in the present invention, the torque increase amount based on the correction amount for advancing the ignition timing by a predetermined value to the advance side of the basic ignition timing and the torque increase amount based on the correction amount for retarding the ignition timing to the retard side from the basic ignition timing by the same predetermined value as described above. The absolute value of each of the reduction amounts can be made substantially the same.

[0013]

FIG. 2 shows a system configuration diagram of an embodiment of the present invention. This embodiment is an example in which the present invention is applied to a spark ignition type internal combustion engine (engine) as the internal combustion engine 10. FIG. 2 shows a structural sectional view of an arbitrary cylinder, and an engine control computer (hereinafter referred to as an EFI computer) described later. )
21 controls each part of the system.

In FIG. 2, a piston 23 which reciprocates vertically in the figure is housed in an engine block 22. A combustion chamber 24 is connected to an intake manifold 25 via an intake valve 26, while an exhaust valve 27 is provided. Through the exhaust manifold 28.

The upstream side of the intake manifold 25 is connected through a surge tank 30 to an intake pipe 31 common to all cylinders. A throttle valve 3 is provided in the intake pipe 31.
3. Each of the air flow meters 32 is provided. The throttle valve 33 has a configuration in which the opening is adjusted in conjunction with the accelerator pedal, and the opening is detected by a throttle position sensor 34. The throttle position sensor 34 can detect whether or not the throttle valve 33 is fully closed, and constitutes the detection means 11.

A bypass passage 35 is provided which bypasses the throttle valve 33 and communicates between the upstream side and the downstream side of the throttle valve 33.
The idle speed control valve (ISC) whose valve opening is controlled by a solenoid
V) 36 is attached.

Numeral 37 denotes a fuel injection valve, which is supplied to an EFI computer 2 described later in the air flow passing through the intake manifold 25.
Inject fuel according to the instructions in 1. The oxygen concentration detection sensor (O ₂ sensor) 38 is connected to the exhaust manifold 2.
8 is provided so as to partially protrude therethrough, and detects the oxygen concentration in the exhaust gas before entering the catalyst device 39. Reference numeral 40 denotes a water temperature sensor, which is provided so as to penetrate the engine block 22 and partially project into the water jacket, and detects the temperature of the engine cooling water. Reference numeral 41 denotes an ignition coil built-in igniter for opening and closing a primary current.

Reference numeral 42 denotes a distributor, a cylinder discrimination sensor 43 for generating a reference position detection signal of the engine crankshaft, and an engine speed signal of, for example, 30.
And a rotation angle sensor 44 generated for each ° C. The rotation angle sensor 44 constitutes the rotation speed detecting means 12.
The output signal of the EFI computer 21 is input to the fuel injection valve 37 and the igniter 41, while necessary data is also transferred to the ECT computer 45.

The ECT computer 45 is a transmission control computer, which is constituted by a microcomputer, for example, a vehicle speed signal from a vehicle speed sensor 46 for detecting a vehicle speed by rotation of an output shaft, and a shift position (gear position) of an automatic transmission 47.
The gear position detection signal from the neutral start switch 48 for detecting the position of the gear is input through the EFI computer 21 to calculate the shift line, and based on the calculated shift line, the automatic transmission 47 controls the setting of the gear position (shift control). Perform The automatic transmission 47 is a device that automatically performs a clutch operation for starting and a shift operation for obtaining a necessary driving force, and has a fluid torque converter. 49 is an air conditioner switch, which is an air conditioner (not shown).
Detects the operating state of

In the above system configuration, the EFI computer 21 realizes the first calculating means 13, the second calculating means 14, the correction amount calculating means 15 and the ignition timing calculating means 16 by software processing. As is well known, the EFI computer 21 has a hardware configuration as shown in FIG. 2, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 3, an EFI computer 21 is a central processing unit (CPU).
50, a read-only memory (ROM) 51 storing a processing program, a random access memory (RAM) 52 used as a work area, a backup RAM 53 holding data even after the engine is stopped, an input interface circuit 54, a multiplexer A / D converter 5 with
6 and an input / output interface circuit 55 and the like, which are connected to each other via a bus 57.

The A / D converter 56 is an air flow meter 32
, An intake air amount detection signal, a detection signal from the throttle position sensor 34, a water temperature detection signal from the water temperature sensor 40, and an oxygen concentration detection signal from the O ₂ sensor 38, which are sequentially switched and input through the input interface circuit 54,
It is converted from analog to digital and transmitted to the bus 57 sequentially.

The input / output interface circuit 55 includes a detection signal from the throttle position sensor 34, a rotation speed signal corresponding to the engine rotation speed (NE) from the rotation angle sensor 44, a vehicle speed detection signal from the vehicle speed sensor 46, and a neutral start switch 48. , Each detection signal from the air conditioner switch 49 is input to the
Input to PU50.

The CPU 50 executes various arithmetic processes based on the data input from the input / output interface circuit 55 and the A / D converter 56 via the bus 57, and transfers the obtained data to the bus 57. Through the output interface circuit 55, the ISCV 36, the fuel injection valve 37,
The idle speed is controlled to the target speed by controlling the opening of the ISCV 36, and the fuel injection time by the fuel injection valve 37, that is, the fuel injection amount per unit time is controlled. The igniter 41 controls the ignition timing, and sends necessary data to the ECT computer 45. The ECT computer 45 has the same hardware configuration as the EFI computer 21.

Next, an embodiment of the idling ignition timing correction routine according to the present invention will be described with reference to FIGS. FIG. 4 is a flowchart showing an embodiment of the idle ignition timing correction routine. The EFI computer 21 implements the second calculation means 14 and the correction amount calculation means 15. In FIG. 4, the CPU in the EFI computer 21
In step 50, it is determined whether or not the throttle opening detection signal from the throttle position sensor 34 indicates that the throttle opening is fully closed (step 101). Is fully closed, it is determined that the engine is in an idle state, and the next step 102 is executed.
Then, it is determined whether a predetermined time has elapsed after the start.

Until a predetermined time elapses after the engine starts, fluctuations in the engine speed are so large that accurate ignition timing cannot be calculated.
Exit this routine. On the other hand, when a predetermined time has elapsed after the start, the routine proceeds to the next step 103, where a smoothed value (weighted average value) NES of the engine speed NE up to the previous start of this routine calculated based on the detection signal from the rotation angle sensor 44 is used.
The difference (deviation) ΔN between M and the current engine speed NE at the time of starting this routine is calculated. The above-mentioned average value NESM is, for example, a 1/32 average value. Therefore, the difference ΔN between the engine speeds is represented by the following equation.

[0026]

(Equation 1)

In the above equation, NESM _i-1 is an average value up to the previous time. Here, if the idle state enters a stable state after a certain period of time, the above-mentioned average value NESM
Becomes the idle target rotation speed by the idle rotation speed control.

After calculating the difference ΔN, the CPU 50 determines whether or not the shift position of the automatic transmission 47 is in the N range based on the detection signal of the neutral start switch 48 (step 104). ROM 51 for N range
5A is retrieved based on the difference ΔN, and an advance correction amount ΔS is calculated (step 105).

As can be seen from FIG. 5A, the map of the difference ΔN and the advance correction amount ΔS in the above-mentioned N range passes through the point ΔS = 0 when ΔN = 0 within a predetermined range. The characteristic shows that ΔS changes linearly in proportion to ΔN, and the characteristic is set to be point-symmetrical with respect to the points of ΔN = 0 and ΔS = 0. Therefore, in the case of the N range, ΔN becomes a positive value when the current engine speed NE becomes lower than the previous smoothed value (usually the idling target engine speed), so that the advance correction amount ΔS becomes positive. On the other hand, when the current engine speed NE increases from the previous smoothed value (usually the idling target engine speed), ΔN becomes a negative value, and thus the advance correction amount ΔS becomes a negative value. Becomes If the absolute value is the same regardless of whether ΔN is positive or negative, the absolute value of the advance correction amount ΔS is also equal.

On the other hand, if it is determined in step 104 that the range is not the N range, that is, the range is the D range, a map as shown in FIG. The angle correction amount ΔS is calculated (step 106).

The difference ΔN and the advance correction amount Δ in the D range
The two-dimensional map shown in FIG. 5B with S is ΔN = 0, ΔN = 0
It is represented by a polygonal line characteristic passing through the point of S = 0, and when ΔN is positive within a predetermined range, ΔS increases in proportion to ΔN,
When N is negative, the characteristic that ΔS decreases in proportion to the decrease of ΔN is shown. However, the slope when ΔN is positive is set to be steeper asymmetry than the gradient when ΔN is negative. . Therefore, even if the absolute value is the same when the difference ΔN is a positive value and when the difference ΔN is a negative value, the advance correction amount ΔS when the ΔN is positive
Is larger than the absolute value of the advance correction amount ΔS when ΔN is negative, and the advance side correction amount is larger than the retard side correction amount.

As a result, as shown in FIG.
Close to the torque peak of the torque characteristic curve II (same as II in FIG. 9)
The set point b of the basic ignition timing is located on the non-linear curve.
In the case of the D range, a counter value to the basic ignition advance value described later is set.
As a result, ΔN becomes a certain value + due to a decrease in the engine speed NE.
Advance angle correction amount when n is reached + S₁Ignition timing t _F
Torque increase TR at_FAnd ΔN is the above and the absolute value is
Same and opposite polarity-advance angle correction amount when n is reached-
S_TwoIgnition timing t_BTorque reduction amount TR_BWhen
Can have the same absolute value.

After calculating the advance correction amount ΔS in step 105 or 106 in FIG. 4, this ΔS is stored in the RAM 52 in FIG.
(Step 107), and this routine ends. Next, a description will be given of an embodiment of an ignition advance value calculation routine according to another embodiment of the present invention, by referring to the flowchart of FIG. This ignition advance value calculation routine is a routine for realizing the first calculation means 13 and the ignition timing calculation means 16.
For example, when started at every predetermined crank angle, first, the output of the intake air amount based on the detection signal of the air flow meter 32 becomes C
After being read by the PU 50 (step 201), the output of the engine speed NE is read by the CPU 50 (step 202). Subsequently, the basic ignition timing SBASE1 is calculated based on the map when the idle contact is off (IDL off) (step 203).

Next, it is determined from the output detection signal of the throttle position sensor 34 whether or not the idle contact is ON (step 204). If it is determined that the idle contact is idle, the air conditioner switch 49 and the neutral start switch 48 are turned on / off. Off is determined (step 2
05). Subsequently, the map when the idle contact is on is displayed based on the intake air amount, the engine speed, the neutral start switch 48, and the like.
, And the basic ignition timing SBASEIDL according to the engine state at that time is calculated (step 20).
6).

Next, the basic ignition timing S calculated as described above
The basic ignition timing SBASEIDL at the time of idling is corrected by adding the advance correction amount ΔS calculated by the idle ignition timing correction routine shown in FIG. 4 to BASEIDL (step 207). Subsequently, the basic ignition timing S at the time of off-idling
BASE1 and basic ignition timing SBASEID at idle
L is compared with the size (step 208), and SBASE1 ≦
In the case of SBASEIDL, upper limit guard processing is performed to set the value of SBASEIDL to the basic ignition timing SBASE1 at the time of off idling calculated in step 203 (step 209), and the routine proceeds to step 210.

This is because the basic ignition timing SBASE1 is MB
Since it is set near T, SBASE1 ≦ SBASEI
When idle basic ignition timing as DL SBASEIDL
Is set to a more advanced value than SBASE1, the torque decreases. Therefore, the upper limit guard process is performed to prevent the torque from decreasing. On the other hand, step 208
If it is determined that SBASE1> SBASEIDL, the process proceeds to step 210 without performing the upper limit guard process of step 209 described above. If it is determined in step 204 that the idle contact is off,
209 is jumped and the process proceeds directly to step 210.

In step 210, when the idle contact is off, the basic ignition timing SBASE1 is set to an advanced value SBASE,
When the idle contact is on, the basic ignition timing SBASEI
The DL is stored in the RAM 52 as the advance value SBASE.
Thereafter, the ignition advance value θ is calculated and output based on the equation θ = SBASE + θα (step 211). Here, in the above equation, θα is an engine cooling water temperature, a gear shift and other various ignition timing correction terms, and is a value calculated by another known routine.

The CPU 50 supplies an ignition instruction signal to the igniter 41 before the top dead center (BTDC) based on the ignition advance value θ calculated in this way, and at the time of the calculated ignition advance value θ, the ignition coil is turned on. The primary current is cut off and the spark plug is ignited.

Thus, according to the present embodiment, at the time of idling when the D range is selected, the engine speed NE decreases (ΔN> 0) as shown in FIG. And NE rises (ΔN <0)
When trying to lower the engine speed by retarding,
When the same amount of torque fluctuation is required, the same amount of torque fluctuation can be obtained. Therefore, according to the present embodiment,
When the ignition timing is not controlled when the D range is selected, FIG.
When the engine speed fluctuates during idling as shown by the solid line III, the swell of the engine speed can be uniformly suppressed as shown by the solid line V in FIG. As compared with the IV, the rotation speed can be more sufficiently suppressed, and the idle rotation speed can be controlled to the target rotation speed.

The present invention is not limited to the above embodiment, and the advance correction amount can be calculated by a routine shown in FIG. That is, since the basic ignition timing at the time of idling and the air conditioner is turned on is advanced by a predetermined angle as compared with the basic ignition timing at the time of idling and the air conditioner is turned off, the above-described D range selection is performed at the time of turning on the air conditioner. The basic ignition timing is set to a non-linear portion near the torque peak of the ignition timing versus torque characteristic as in the case of the above.

Therefore, in another embodiment of the present invention, an idle ignition timing correction routine is executed as shown in FIG. In the figure, the same reference numerals are given to the same processing steps as in FIG. 4, and the description thereof will be omitted. As shown in FIG. 8, after calculating the difference ΔN, it is determined whether or not the air conditioner switch 49 is off (step 301). If the air conditioner switch 49 is off, the process proceeds to step 302, where the advance correction amount ΔS is calculated based on the map when the air conditioner switch 49 is off. The map when the air conditioner switch 49 is turned off is the same as the map shown in FIG. 5A, and shows a point-symmetric characteristic centering on the points of ΔN = 0 and ΔS = 0.

On the other hand, when it is determined in step 301 that the air conditioner switch 49 is turned on, the process proceeds to step 303, and the advance correction amount ΔS is calculated based on the map when the air conditioner switch 49 is turned on. This air conditioner switch 4
The map when 9 is on is the same as the map shown in FIG. 5 (B), and shows an asymmetric characteristic with respect to the points of ΔN = 0 and ΔS = 0. Thus, it is possible to prevent uneven correction of the undulation of the engine speed during idling, which is likely to occur when the air conditioner switch 49 is turned on.

[0043]

As described above, according to the present invention, when the basic ignition timing is set to a non-linear portion near the torque peak of the ignition timing versus torque characteristic, the ignition timing is advanced from the basic ignition timing. The absolute value of the torque increase amount based on the correction amount advanced by the predetermined value toward the corner side and the absolute value of the torque decrease amount based on the correction amount delayed by the same predetermined value toward the retard side from the basic ignition timing can be made substantially the same. As a result, the swell of the engine speed during idling can be suppressed as compared with the conventional case, the idle speed can be more stably controlled to the target speed, and the drivability can be improved. It has the feature of.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a system configuration diagram of an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a hardware configuration of an EFI computer in FIG. 2;

FIG. 4 is a flowchart showing one embodiment of an idle ignition timing correction routine of a main part of the present invention.

FIG. 5 is a diagram showing a map used in the routine of FIG. 4;

FIG. 6 is a diagram illustrating a relationship between ignition timing and torque at the time of idling when a D range is selected according to an embodiment of the present invention.

FIG. 7 is a flowchart showing one embodiment of an idle ignition advance value calculation correction routine of another main part of the present invention.

FIG. 8 is a flowchart showing another embodiment of the idle ignition timing correction routine of the main part of the present invention.

FIG. 9 is a diagram showing a conventional relationship between ignition timing and torque at the time of idling when a D range is selected and when an N range is selected.

FIG. 10 is a diagram showing a state of suppression of undulation of the number of revolutions of the conventional apparatus and the present embodiment in comparison.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Internal combustion engine 11 Detecting means 12 Revolution detecting means 13 First calculating means 14 Second calculating means 15 Correction amount calculating means 16 Ignition timing calculating means 21 EFI computer 41 Igniter 47 Automatic transmission 48 Neutral start switch 49 Air conditioner switch

Claims (1)

(57) [Claims] A detecting means for detecting an idle state of the internal combustion engine; a rotational speed detecting means for detecting an engine rotational speed of the internal combustion engine; and a first ignition timing calculating means for calculating a basic ignition timing according to an engine state during idling. Calculation means; second calculation means for calculating a deviation between the engine speed detected by the rotation speed detection means during idling and a target speed; and the basic ignition timing calculated by the first calculation means. When the engine speed is higher than the target speed during the engine operation state set to a non-linear portion near the torque peak of the ignition timing versus torque characteristic, the correction amount for retarding the ignition timing is set to one A correction amount calculating unit configured to calculate a correction amount for advancing the ignition timing when the engine rotation speed is lower than the target rotation speed, based on the correction amount calculated by the correction amount calculation unit; Ignition timing calculating means for correcting the basic ignition timing and outputting a value for determining the ignition timing, wherein the correction amount calculating means is configured to perform the second control when the engine speed exceeds the target speed. When the deviation of the engine rotation speed calculated by the calculation means is the same as the deviation of the engine rotation speed when the engine rotation speed falls below the target rotation speed, the advance angle side complement is calculated.
The absolute value of the torque increase based on the positive and the correction on the retard side
In order to make the absolute value of the amount of torque decrease based on the absolute value of the correction amount on the advance side larger than the absolute value of the correction amount on the retard side, the advance side and the retard side of the ignition timing are set to be substantially the same. An ignition timing control device at the time of idling, wherein an asymmetrical correction amount is calculated between the ignition timing control device and the ignition timing control device.