JPH0643830B2 - Ignition timing control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition timing control device for an internal combustion engine, and more particularly to a technique for correcting ignition timing in an engine accelerating operation state to improve vehicle vibration.

<Prior Art> As a conventional ignition timing control device, for example, Japanese Patent Laid-Open No. 59-
There is one as disclosed in Japanese Patent No. 126071.

In this type of conventional type, generally, the ignition timing is set when the reference crank angle position signal is output from the crank angle sensor that detects the rotation angle of the crankshaft of the internal combustion engine, and the ignition timing is set when the set ignition timing is reached. We are in control.

<Problems to be Solved by the Invention> By the way, particularly in an internal combustion engine or the like equipped with an electronically controlled fuel injection device, fuel injection control is performed with good responsiveness in accordance with the engine operating state, and therefore the following problems occur. Was occurring.

That is, since the fuel injection amount is increased and corrected during the acceleration operation, the engine torque follows the change in the opening degree of the intake throttle valve with good responsiveness and rapidly increases.

However, since the vehicle is heavy and has a large inertia, the vehicle speed and the engine speed cannot follow the sudden output increase of the engine with good responsiveness, and the vehicle torsional vibration (the rattling vibration between the traveling direction and the retreating direction of the vehicle). , And hereinafter referred to as vehicle vibration), and changes in the engine speed also occur, which deteriorates drivability and riding comfort. Particularly in the case of a front-wheel drive vehicle in which the engine is mounted laterally (the cylinder row is lateral) with respect to the vehicle traveling direction, the vibration direction of the engine and the vibration direction of the vehicle coincide with each other, and vehicle vibration is likely to occur.

As a countermeasure against such vehicle vibration, conventionally, Japanese Patent Laid-Open No. 61-283
As disclosed in Japanese Laid-Open Patent Publication No. 748, there is a system in which the ignition timing is retarded immediately after acceleration to suppress the rise of the engine torque, but in this system, the acceleration response may be impaired.

For this reason, the present applicant first applied for a correction of the ignition timing in the direction of suppressing the rotational speed fluctuation based on the rotational speed change amount when acceleration is detected (patent application on March 25, 1987). However, in the conventional ignition timing control device, the ignition timing change amount for each ignition is limited to be within a predetermined crank angle for the purpose of, for example, operating stability in steady state and prevention of shock occurrence. Even when trying to correct the ignition timing so as to suppress the rotational speed fluctuation during acceleration, the ignition timing change amount is limited to be within the predetermined crank angle, so that the ignition speed can be sufficiently suppressed. I could not get the timing corrected.

That is, in the conventional ignition timing control device, the amount of change in the ignition timing for each ignition is limited so that the crank angle is within 3 °, for example, but in order to satisfactorily suppress the rotational speed fluctuation in the engine acceleration state. It has been experimentally determined that, for example, a retard / advance correction of about 10 ° is required. As shown in FIG. 5, the ignition timing change is actually within 3 ° which is less than the required amount. The actual situation is that the required amount of correction cannot be obtained because the amount is limited, and effective rotation speed fluctuation suppression cannot be performed.

The present invention has been made in view of the above circumstances, the ignition timing of the internal combustion engine that can effectively control the vehicle vibration and the like without impairing the acceleration responsiveness and without being hindered by the change amount limitation of the ignition timing. An object is to provide a control device.

<Means for Solving Problems> Therefore, according to the present invention, as shown in FIG. 1, a basic ignition timing setting means for setting a basic ignition timing corresponding to a steady operating state according to an engine operating state, and an engine. An engine speed detecting means for detecting the engine speed, an engine speed change amount calculating means for calculating the engine speed change amount for each predetermined period based on the engine speed detected by the engine speed detecting means, Acceleration operation state detection means for detecting an acceleration operation state, and the basic ignition timing based on the rotation speed change amount calculated by the rotation speed change amount calculation means for a predetermined period when the acceleration operation state of the engine is detected by the acceleration operation state detection means. Ignition timing correction means for correcting the basic ignition timing set by the setting means in the direction of suppressing a change in the engine speed, and the basic ignition timing corrected by the ignition timing correction means. The first ignition timing is set by comparing the previous ignition timing with the current ignition timing and limiting the ignition timing change amount within a predetermined range.
The ignition timing change means compares the previous ignition timing set by the basic ignition timing setting means with the present ignition timing except when the basic ignition timing is corrected by the ignition timing limiting means and the ignition timing correction means. No. 1 second ignition timing limiting means for setting the present ignition timing by limiting the ignition timing to a predetermined range narrower than the limited range by the ignition timing limiting means, and ignition for outputting an ignition signal to the ignition device at the set ignition timing. And a signal output means.

<Operation> When the acceleration operation state of the engine is detected by the acceleration operation state detection means, the basic ignition timing set by the basic ignition timing setting means according to the engine operation state is calculated by the rotation speed change amount calculation means. Based on the rotation speed change amount, the correction is performed for a predetermined period in the direction of suppressing the change in the rotation speed. Then, the current ignition timing corrected based on the rotational speed change amount is compared with the previously corrected ignition timing, and the first ignition timing limiting means is used to keep the ignition timing change amount within a predetermined range. This ignition timing is limited and set.

That is, when the ignition timing obtained by correcting the basic ignition timing has a deviation of a predetermined value or more compared with the previous ignition timing,
The ignition timing of this time is limited to a value obtained by changing the corrected ignition timing of the previous time by an allowable maximum. Further, except when the basic ignition timing is corrected by the ignition timing correction means,
The previous ignition timing set by the basic ignition timing setting means is compared with the present ignition timing, and the second ignition timing limiting means sets the current ignition timing within a predetermined range from the previous ignition in the same manner as the first ignition timing limiting means. Limit to stay within.

However, the limit range of the ignition timing by the second ignition timing limiting means is set smaller than that of the first ignition timing limiting means. In other words, by making the limit range of the first ignition timing limiter larger than the limit range of the second ignition timing limiter, the first ignition timing limiter corrects the ignition timing to suppress the change in the rotational speed during acceleration. I try to avoid being hindered.

<Example> Below, one Example of this invention is described based on drawing.

In FIG. 2 showing the configuration of this embodiment, an air flow meter 3 for detecting an intake air flow rate is provided in an intake passage 2 of an engine 1.
And a throttle sensor 5 as an acceleration operation state detecting means for detecting the opening degree of the intake throttle valve 4, and these detection signals are inputted to a control device 6 having a microcomputer built therein. Further, the engine 1 is provided with an electromagnetic fuel injection valve 7 for each cylinder. These fuel injection valves 7 are opened by an injection pulse signal output from the control device 6 corresponding to the fuel injection amount, and fuel is injected and supplied to the engine 1.

An ignition plug 8 is provided in each cylinder of the engine 1.
The high voltage generated in the ignition coil 9 is sequentially applied to the spark plugs 8 through the distributor 10, whereby spark ignition is performed to ignite and burn the air-fuel mixture. Here, the ignition coil 9 controls the generation timing of the high voltage via the power transistor 11 attached thereto. The ignition timing is controlled by controlling the ignition signal from the control device 6 that controls the ON / OFF timing of the power transistor 11. The spark plug 8, the ignition coil 9, the distributor 10 and the power transistor 11 constitute an ignition device.

The distributor 10 has a built-in photoelectric crank angle sensor 12. The crank angle sensor 12 includes a signal disk plate 14 that rotates integrally with the distributor shaft 13, and a detection unit 15. The signal disc plate 14 is provided with 180 position signal (2 ° signal) slits 16 and four reference crank angle signal (180 ° signal) slits 17 for four cylinders. One of the angle signal slits 17 is #
It is also used to identify one cylinder. The detector 15 detects the slits 16 and 17, and outputs a position signal and a reference crank angle signal including a cylinder discrimination signal to the control device 6.

Reference numeral 18 denotes an idle control valve that is provided in an auxiliary air passage 19 that bypasses the intake throttle valve 4 and that controls an idle speed.
Is an air cleaner.

Next, the operation will be described with reference to the flowcharts of FIGS. 3 and 4.

FIG. 3 shows an engine speed change amount calculation routine for each reference crank angle signal input.

First, in step (denoted as S in the figure, the same applies hereinafter) 1,
The reference crank angle signal (REF
Pulse) is determined, and if so, the process proceeds to step 2.

In step 2, the time from the input of the previous reference crank angle signal to the input of the current reference crank angle signal, that is, the input cycle T of the reference crank angle signal
Calculate _REF .

In step 3, the engine speed N ₀ (= 6) is calculated based on the reference crank angle signal input period T _REF obtained in step 2.
0 / 2T _REF ) is calculated. This function corresponds to the engine speed detecting means.

In step 4, the engine speed N obtained at the previous input of the reference crank angle signal is set to Nθ, and the engine speed N ₀ obtained this time is set to N.

In step 5, the previous engine speed Nθ is subtracted from the current engine speed N set in step 4, and the change amount ΔN of the engine speed N for each reference crank angle signal input is calculated. This function corresponds to rotation speed change amount calculation means.

Next, an explanation will be given according to the ignition timing correction routine of FIG. This routine is executed every unit time (for example, 10 ms to 30 ms).

First, in step 11, it is determined whether or not the acceleration determination flag F is 0. If F = 1, steps 12 and 13 are omitted and the process proceeds to step 14 described later.
Go to 12.

In step 12, it is determined whether or not the acceleration operation is performed based on whether or not the rate of change ΔTVO of the intake throttle valve 4 is equal to or greater than a predetermined value. If it is not accelerating operation (NO), the process proceeds to step 20 described later, and if it is accelerating operation (YES), the process proceeds to step 13.

In step 13, the acceleration determination flag F is set to F = 1 and a timer for measuring time is started.

In step 14, it is judged whether or not the measured value t of the timer reaches a predetermined value t ₁ , and when t ≧ t ₁ , the process proceeds to step 15, t
If <t ₁ , proceed to step 20 described later.

If step 15 in the measurement of t is determined whether t ₁ + t ₂ is less than t <t ₁ + t ₂ proceeds to step _{16, t ≧ t 1 + t} 2
If so, the routine proceeds to step 17, the ignition timing correction at the time of acceleration operation is completed, and the acceleration determination flag F is set to zero. That is, the ignition timing correction is performed only for a predetermined time t ₂ after the predetermined time t _{1 has} elapsed from the acceleration detection.

In step 16, the engine speed change amount ΔN calculated in FIG.
Is determined to be positive or negative. When ΔN ≧ 0, the process proceeds to step 18, and when ΔN <0, the process proceeds to step 19.

In step 18, it calculates the ignition timing correction amount -ADV ₁ over constant k ₁ in .DELTA.N. In this case, ΔN is positive, that is, the number of revolutions tends to increase, so the ignition timing is controlled to be retarded (−) as ΔN increases.

On the other hand, in step 19, ΔN is also multiplied by a constant k ₂ to calculate the ignition timing correction amount ADV ₁ , but in this case, since the rotational speed tends to decrease (ΔN <0), ΔN increases (the absolute value increases). ), The ignition timing is set to advance (+).

This function corresponds to the ignition timing correction means.

Ignition timing correction amount ± ADV _{1 in} step 18 or step 19
Is calculated, in the next step 21, the limiter ΔADV _TRAN for acceleration is set as the ignition timing limiter ΔADV that limits the amount of change in the ignition timing ADV. This function corresponds to the first ignition timing limiting means.

On the other hand, in a state in which the ignition timing correction amount ± ADV ₁ based on ΔN is not set (the state in which the processing in step 18 or step 19 is not performed), the steady-state limiter ΔADV is set as the ignition timing limiter ΔADV in step 20. Set _CONS . This function corresponds to the second ignition timing limiting means.

The acceleration limiter ΔADV _TRAN is set to be larger than the steady-state limiter ΔADV _CONS .

Ignition timing limiter ΔAD in step 20 or step 21
After setting V, go to step 22.

In step 22, the basic fuel injection amount T calculated by the intake air flow rate Q detected by the air flow meter 3 and the engine speed N calculated based on the reference crank angle signal.
_{Based on p} (= K × Q / N; K is a constant) and the calculated engine speed N, a basic ignition timing ADV corresponding to a steady operation state is obtained by searching a map stored in the ROM of the microcomputer. Set to ₀ . This function corresponds to the basic ignition timing setting means.

In step 23, the basic ignition timing AD set in step 22
By adding the correction amount ± ADV ₁ set in step 18 or step 19 to V ₀ , the corrected ignition timing ADV _n (= A
Calculate DV ₀ ± ADV ₁ ).

When the correction amount ± ADV ₁ is not set in step 18 or step 19, the basic ignition timing ADV ₀ set in step 22 is directly used as the corrected ignition timing ADV _n .

In step 24, the absolute value of the value obtained by subtracting the last final ignition timing ADV _n-1 from the corrected ignition timing ADV _n set in step 23 and the ignition timing limiter ΔADV set in step 20 or 21 are calculated. Compare.

Here, if the difference between the last final ignition timing ADV _n-1 and the ignition timing ADV _n corrected this time is large and the absolute value is equal to or greater than the ignition timing limiter ΔADV, the routine proceeds to step 26. Then, in step 26, the ignition timing limiter ΔADV is added / subtracted to / from the last final ignition timing ADV _n-1 (subtracted when advanced is set and added when retarded compared to the previous time) to obtain the final ignition timing of this time. Set ADV. That is, when the ignition timing having a deviation exceeding the ignition timing limiter ΔADV with respect to the last final ignition timing ADV _n-1 is set in step 23, the ignition timing falls within the maximum allowable range ADV _n-1 ± ΔADV. It limits changes in ADV. Here, when the ignition timing ADV is being corrected so as to suppress the change in the rotational speed (when the processing is executed in step 18 or step 19), the ignition timing limiter ΔADV (for acceleration is larger than that in the normal time). Limiter ΔADV _TRAN ＞ Steady-time limiter ΔADV
_{Since (CONS} ) is set, a larger ignition timing change than normal is allowed, and it is possible to prevent the ignition timing correction for suppressing the change in the rotational speed from being hindered by the change amount limitation.

On the other hand, when it is determined in step 24 that the difference between the last final ignition timing ADV _n-1 and the ignition timing ADV _n corrected this time is small and the absolute value is less than the ignition timing limiter ΔADV, the routine proceeds to step 25. the correction ignition timing ADV _n corrected set is set as the current final ignition timing ADV in step 23.

In step 27 which functions as an ignition signal output means, according to the ignition timing ADV calculated in step 25 or step 26, the ignition signal is output, and when the ignition timing is reached, the power transistor 11 is de-energized and ignition is performed. Ignition is performed by discharging the plug 8 at a high voltage.

As described above, the ignition control is performed according to the request of the engine from the time when acceleration is detected to the predetermined time t ₁ , and thereafter, during the predetermined time t ₂ , the change of the engine speed is suppressed, that is, the engine speed N.
However, when the ignition timing is increasing, the ignition timing is retarded, and when the ignition timing is decreasing, the ignition timing is advanced.
In addition to making the rise of engine torque in the initial stage of acceleration good, increase / decrease engine torque in the direction opposite to the vehicle vibration to damp vehicle vibration and improve ride comfort during vehicle acceleration without impairing acceleration response. Become.

In addition, the ignition timing is advanced to suppress changes in engine speed.
When retarding the ignition timing, the ignition timing limiter ΔADV that limits the amount of change in the ignition timing ADV is set to a value larger than usual, so the number of revolutions is limited compared to when the amount of change in the ignition timing ADV is matched and limited to a small value during steady state. The change can be effectively suppressed.

<Advantages of the Invention> As described above, according to the present invention, the ignition timing is advanced / retarded in the direction of suppressing the change in the engine speed during the acceleration operation, and the advance / retard correction is performed. By limiting the amount of change in the ignition timing within a wider range than usual, the rotational speed change is effectively suppressed during acceleration without being hindered by the limit of the amount of change in the ignition timing. Is effectively damped to improve the ride comfort of the vehicle.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a configuration diagram showing an embodiment of the present invention, FIGS. 3 and 4 are flow charts showing various control routines of the same embodiment, and FIG. [Fig. 4] is a time chart for explaining the operation of the conventional example and the example. 1 ... Engine, 5 ... Throttle sensor, 6 ... Control device, 8 ... Spark plug, 9 ... Ignition coil, 10 ... Distributor, 11 ... Power transistor, 12 ... Crank angle sensor.

Claims (1)

[Claims] 1. Basic ignition timing setting means for setting a basic ignition timing corresponding to a steady operating state according to an engine operating state,
An engine speed detecting means for detecting an engine speed; a speed change amount calculating means for calculating a change amount of the engine speed every predetermined period based on the engine speed detected by the engine speed detecting means; Acceleration operation state detecting means for detecting the acceleration operation state of the engine, and the basic ignition timing setting based on the rotation speed change amount calculated by the rotation speed change amount calculating means for a predetermined period when the acceleration operation state of the engine is detected. Ignition timing correction means for correcting the basic ignition timing set by the means in a direction to suppress a change in the engine speed, and the previous ignition timing and the current ignition corrected at the time of correcting the basic ignition timing by the ignition timing correction means. A first ignition timing limiting means for setting the ignition timing of this time by limiting the ignition timing variation amount within a predetermined range by comparing the timing with a basic ignition timing correction means. Except when the correction is performed, the previous ignition timing set by the basic ignition timing setting means and the present ignition timing are compared to determine that the ignition timing change amount is within a predetermined range narrower than the limited range by the first ignition timing limiting means. Ignition timing of an internal combustion engine comprising: a second ignition timing limiting means for limiting the ignition timing for this time to set the present ignition timing; and an ignition signal output means for outputting an ignition signal to the ignition device at the set ignition timing. Control device.