JPS61200379A - Ignition timing control equipment for internal-combustion engine - Google Patents

Abstract

PURPOSE:To put engine performance into full play by installing a control device for adjusting ignition time for respective cylinders individually in consideration of the state of knocking generation. CONSTITUTION:CPU 12 takes in signals from various kinds of sensors through an input/output interface circuit 20, calculates ignition time based on these signals in accordance with a program stored in ROM 14 and issues ignition signal IGN through the input/output interface circuit 20. The ignition signal IGN is added to the base 70 of a power transistor 74 through an amplifier 72, thereby driving the power transistor 74. A knocking detecting equipment 30 detects knocking. CPU 12 adjusts the basic ignition time for respective cylinders in accordance with the generation of knocking. Thus, performance of the engine can be put into full play.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background of the Invention] The present invention relates to an ignition timing control device for a gasoline engine, etc., and particularly to an ignition control device equipped with a knocking control function Y.

[Field of application of the invention]

As the performance of gasoline engines increases, the problem of knocking increases.

Therefore, in recent years, so-called knocking control devices, which are equipped with a sensor that detects knocking and immediately delay the ignition timing to suppress the knocking when knocking occurs, have been widely adopted.

By the way, conventional knocking (hereinafter simply referred to as knocking) control devices simply delay the ignition timing by a predetermined amount when knocking occurs, and then sequentially return the ignition timing to the basic ignition timing. The amount of ignition timing retardation is the same for each cylinder.

In gasoline engines, etc., there are large differences in the ignition timing at which knock occurs between each cylinder depending on the engine.
Is it possible to control knock control using a conventional knock control device for IJ?
Despite this, knocking is always occurring in cylinders where knocking is likely to occur.

So, what is the basic ignition timing now? If you set the basic ignition timing to the cylinder where knock is most likely to occur, this will not allow the engine to achieve its full performance.On the other hand, if you set the basic ignition timing to the cylinder where knock is most likely to occur, knock will occur. The easily-prone cylinder will always be in the knock zone, and when the ignition timing returns to the basic ignition timing after the ignition timing has been delayed, middle knock or heavy knock will always occur.

Note that "middle knock" and "heavy knock" are terms that indicate the degree of knock, with "middle knock" meaning a moderate knock, and "heavy knock" meaning a knock of a considerable degree. There is a lighter knocktalite knock, and a very light knock is called a trace knock.

In this way, conventional knock control devices are unable to absorb the differences in knock characteristics between each cylinder, resulting in poor engine performance. The drawback was that it could not be used to its full potential.

In addition, regarding such a knock control device, for example,
This is disclosed in Japanese Patent Application Laid-open No. 167880/1983.

[Purpose of the invention]

What is the purpose of the present invention σ9? What are the drawbacks of the above-mentioned prior art? Except,
Even if there are differences in knock characteristics between each cylinder in an engine, it is possible to always bring out sufficient engine performance. An object of the present invention is to provide an ignition timing control device for an internal combustion engine that can sufficiently suppress the ignition timing.

[Summary of the invention]

To achieve this objective, the present invention is characterized in that the basic ignition timing is controlled at a fixed point for each cylinder according to the occurrence of knock in each cylinder.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An ignition timing control device for an internal combustion engine according to the present invention will be described in detail below with reference to an embodiment shown in the drawings.

FIG. 1 shows an embodiment of the present invention, and in the figure, a central processing unit (hereinafter referred to as CPU) 1
2 performs digital calculation processing of various data such as ignition timing of the internal combustion engine. An ignition timing control program and fixed data are stored in R, 0M14. The RAM 16 is a readable and writable storage element. The backup RAM 17 maintains memory even when the internal combustion engine is stopped.
I (AM)

To CPU12'! Input/output interface circuit 20? Various sensors (in this example, the knocking detection device 3
0, a crank angle sensor 40.9, a load sensor 50, a water temperature sensor 60, and a load switch 80 are used. ) signal from? Based on this signal, ignition timing control is calculated according to a program stored in the ROM 14, and an ignition signal IGNv is outputted via the input/output interface circuit 20'M. The ignition signal IGNfX is added to the power transistor 74 via the amplifier 72 to drive the power transistor 74 . When the power transistor 74σ is disconnected, an ignition current is generated in the secondary coil of the ignition coil 760.

FIG. 2 shows a specific configuration of a portion of the input/output interface circuit 20 that contributes to ignition timing control.

Position pulse signal (P
Placed with OS. ) are added to AND circuits 216 and 220. Further, a reference crank angle signal (referred to as R, EF) from the crank angle sensor 40 is applied to the reset terminal of the first counter register 210 and the set terminal of the R, S flip-flop 218. The first counter register 210 uses the AND circuit 216 and the R8 flip-flop 218 to control the PO
It starts counting S and outputs the counted value to the Y comparator 206. The comparator 206 compares the count value of the first σ] counter register with the fixed ignition timing data θ calculated by the CPU 1'2 and stored in the advance register 202, and when the two match, a set pulse "2" is sent to the R81g flip-flop 214. At the same time, the VC and RS flip-flops 218 are reset.

When a set pulse is input to the R, S flip-flop 214, the output of the Q output is cut off, the power transistor 74 of the point system is cut off, and a discharge current is output to the secondary coil of the ignition coil 760.

Next, the timing of starting energization of the ignition coil will be explained. ΦO 20th-) Counter register 212 &! , RS flip-flop 7'2 not determined by comparator 2()6
Based on the set pulse for 22YON46, counting of position pulses PO8 is started via the AND circuit 220, and output to the count value comparator 208. The comparator 208 compares this counted value with the values calculated by the CPU 2 and stored in the dwell register 204, and when they match, the reset pulses 4R, S
The RS flip-flop 222 is reset along with the output 16 to the flip-flop 214. The RS flip-flop 214 outputs ? to the Q terminal based on the reset pulse. The power transistor 744 is turned on, and energization to the primary coil of the ignition coil 760 is started.

Next, the knocking signal K N CK P cv CPU
12, Xσ,] will be explained.

Output pulse K N CK P & of the knock detection device 30
'! , are input to the counter register 234, and the number of KNCKP is counted in proportion to the intensity of the knock that has occurred. Process CPU12, counter register 2340
) The count value is taken in via the V bus 18.

The number of pulses NP that has not been taken into the CPU 12 is data corresponding to the knock intensity, and is used to calculate the ignition timing correction amount σ.

FIG. 3 is a timing chart showing the operation of the circuit shown in FIG. 2 described above. In the figure, A is a reference crank angle signal and B is a position pulse signal. C indicates the counting status of the first counter register 210, C1)
This is the setting value of the X advance register 202. IJ&
The output signal of the S comparator 206 indicates the count value of the tenth counter register 210, and the count value of the tenth counter register 210 is
Does the output occur when the set value of 2 is reached? It shows.

E indicates the counting status of the second counter register 212,
El is the set value of the dwell register 204. The output of the FGX comparator 208 is similar to the operation of the combiner 1206. G is a comparator 206. RS flip-flop 21 responsive to the outputs of 208, namely D and F.
Iroh showing the Q out of 4. H indicates the current flowing through the ignition coil 66 in response to the Q output, and I indicates the ignition timing.

Next, in Fig. 4, in response to the occurrence of knock, knock Q,...)
A block diagram of a knock detection device 30 configured to generate a number of pulses KNCKPQ depending on the intensity is not shown. In the figure, a knock sensor 401 is constituted by a piezoelectric element and converts the knock vibration of the cylinder σ of the engine into an electrical signal. The output signal VIN of this knock sensor 401
is input to the band pass filter 403 through the input processing circuit 402"1iff. This band pass filter 403 removes the parasitic vibration of the engine and detects the knock signal?
It is provided for efficient extraction, and is selected so that the band width (f') matches the frequency of the Enock signal.

The knock signal Y that has passed through the bandpass filter 403 is half-wave rectified by the half-wave rectifier circuit 404, and then divided into two systems.
1 system? The signal is amplified by a DC amplifier 405 as a representative signal of the knock, and after being smoothed by a smoothing circuit 406 as a judgment level for knock detection, it is amplified by a DC amplification circuit 407.

Comparator 409 generates a knock detection signal by comparing the signals of this system and outputs it to l10410.

FIG. 5 shows signal waveforms of each part of the block diagram shown in FIG. (1) is the output of the knock sensor 401, (2) is the output of the input processing circuit 402, and (3) is the output waveform of the band pass filter 403, which is half-wave rectified. Shitco signal (5) and smoothing (
(6) ) After comparison with the amplified signal (force), a knock detection signal K N CK P (8) is obtained.

FIG. 6 shows the general flow Y of the ignition timing control device in this embodiment.

In FIG. 6, an interrupt request 600 occurs ("f/)" and the interrupt request analysis process in step 602 determines whether it is an interrupt request (I(, EF) or a timer interrupt (TIMER)). If so, according to the instructions of the task scheduler 604, A and D conversion of the input signal and input of the engine speed (606), calculation of basic ignition timing and energization time (608), digital input signal processing (
610) and correction processing (612).

FIG. 7 shows ignition timing 9 corresponding to step 608 in FIG.
This shows the energization time control routine. Here, the basic ignition timing θA ov (base)
A n v (base) = f (]'J+
L).

Here, N is the engine speed, and L is the load (for example, suction pipe negative pressure).

First, basic ignition timing processing is performed in steps 701 and 702. In step 703, is the counter data at the time of advance after retardation? Check pickpocket. If the content of the counter is 0, it is assumed that a certain period of time has elapsed (for example, 1 second), and the process proceeds to step 706. In step 706, data ΔθADV2' at the time of advance angle is
l:'Set. In step 707, since the predetermined time has elapsed and the angle is advanced, a data counter for confirming the elapse of a predetermined time is further set at 16°, and the process proceeds to step 708.

- 10,000, if the counter data is O in step 7 ()3, does that mean that the certain period of time has not passed yet? Therefore, at this time, the advance angle value ΔθADV2"" is set to 0. Kneading is performed in step 704. In step 705, the counter data value is decremented by 1 to measure the elapsed time Y. After this, the process advances to step 708.

FIG. 8 VC shows a rotation synchronization processing routine corresponding to step 616 in FIG.

In step 801, counter data (number of pulses NP) i
take in. Clear the counter Y after the import is complete. In step 802, the cylinder is determined, and the knock determination level (number of pulses) corresponding to the current cylinder is searched. This judgment level is a function of engine speed and load. In step 803, the counter data NP is compared with the knock judgment level Ns□Y. This determination level N8□ is for performing normal ignition timing control Y. If the counter data NP is equal to or higher than the determination level Ns□, it is determined that there is a knock, and the process proceeds to step 804, where the ignition timing is retarded. Δ
Is θADV1 the current correction amount? , ΔθAnv(t 1)
indicates the previous correction amount (-retard amount).

In step 805, the area shown in FIG. 10 is determined based on the current engine speed N and load (in this embodiment, it is divided into four areas depending on the engine speed N and load, but even if only the engine speed or load is It is also possible to divide it into smaller parts. ), and determine the maximum advance angle value. In step 806, the determination level N for controlling the counter value and the maximum advance angle value is determined.
A comparison of 8□ is made. In step 806, NP is Ns□
If it is not above, it is determined that the current knock is middle, and the maximum advance angle value (maximum value of advance angle after retardation) is corrected in step 807 α, (1) = α1 (ti) + α1
calculation is not possible. In step 806, the counter value NP
is less than N8□, it is assumed that there is no need to correct the maximum lead angle value.
-1) and previous σ) value? use. After this Q), step 8
Proceed to 09.

In step 809, the ignition timing is determined when knock occurs. Data for advance angle after retardation is set in a counter for advance angle (in this embodiment, data corresponding to 1 second is set). Note that this counter +zTIMER is counted by the interrupt to determine whether a certain period of time has elapsed. After this, the process advances to step 811.

On the other hand, if NP<Ns■ in step 803, it is determined that knocking has not occurred, and the process proceeds to step 810.

In step 810, the advance angle after the retardation is performed. However, if a certain period of time has not elapsed (1 second), step 70
4, ΔθADV□=0, so no advance angle is performed, and ΔθADV(t) is the previous value? Take.

In step 811, the basic ignition timing θADv(baSe)
Add the ignition timing correction amount to ignition timing θADV ('
) is determined.

θADv(t)20Anv(base)+ΔθADV(
').

In step 812, the current σ] area (FIG. 10) is searched based on the engine speed and load, and the correction amount α1(t) of the maximum advance angle value corresponding to the area is determined.

In step 813, the current basic ignition timing θA, T)
y (base) and the correction amount α1(t), the maximum advance angle value θrllax is θlT1. It is controlled by x-θADy(base)-α1(t).

In step 814, the maximum advance angle value θfl11! and the current ignition timing θADv(t). Step 814
If θmax is less than θADV('), the process proceeds to step 815 and the maximum advance value is set to θrnax. If θm,x is equal to or greater than θADV(t) in step 814, the current ignition timing can still be advanced, so the current value is set in the ADV register in step 816. Through the above control, the advance angle value after retardation is controlled to a maximum of θmmK. If no knock occurs, the ignition timing for this cylinder is θ.
maw, and as a result, the basic ignition timing cannot be controlled as shown in the formula below.

θmaX=θADV(base)−α1(t) As described above, since the basic ignition timing is corrected for each cylinder, it is possible to prevent middle knock from occurring frequently.

FIG. 9 is an explanatory diagram of the operation of this embodiment, in which a certain cylinder is now at the basic ignition timing θAD y (base).
If a middle knock occurs at ■ during operation and exceeds NPfJ''-N8□ in step 801 in Fig. 8, ΔθA
DV 1 If the angle is retarded and there is no knock, the angle is advanced at a rate of ΔθADV□ to Δt (1 second). At this time, θmhx”
”The lead angle value is θ due to θAnv(base)-α1(t)
It is controlled by ADv(baSe)-α1.

If middle knock occurs in the same cylinder in the same operating range in ■, θm&'X-θAny (base
)2α1.

If middle knock occurs at O, θ. , X is θlT11x−θi, ny (b a S e )
3α.

controlled by. At this time, if trace knock occurs at 0, ΔθADV□ will be delayed and ΔθADV2 will reach Δt (1 second).
Finally, θn1llX = θADv (
b a se ) 3α1.In other words, in this case, the basic point Daisuke for this cylinder in this operating range has been changed to θADy(base)3α1, and the knock key is adjusted appropriately. It can be suppressed.

The same thing is done for the ignition timing of the remaining cylinders.In the end, according to this embodiment, the ignition timing is determined for each cylinder depending on the state of occurrence of knock in that cylinder. This means that the basic ignition timing can be retarded, and the adverse effects caused by knock can be sufficiently suppressed while maximizing engine performance.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to correct the basic ignition timing for each cylinder in accordance with the occurrence of knock in each cylinder. [Knock σ for each cylinder] Accurate ignition timing retard control can always be obtained depending on the occurrence situation, improving engine performance.
An ignition timing control device that can fully demonstrate Φ? It can be easily provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the ignition timing control device according to the present invention, FIG. 2 is a block diagram showing an embodiment of the input/output interface in the present invention, and FIG. 3 is a timing chart for explaining the operation. 4 is a block diagram showing one embodiment of the knocking detection device, FIG. 5 is a waveform diagram for explaining its operation, FIG. 6 is an explanatory diagram of a general flowchart in one embodiment of the present invention, and FIG. Fig. 7 is an explanatory diagram of the ignition timing control routine, Fig. 8 is an explanatory diagram of the rotation synchronization routine, and Fig. 9 is an explanatory diagram of the rotation synchronization routine.
The figure is a timing chart for explaining the operation of one embodiment of the present invention, and FIG. 10 is an explanatory diagram of the operating range in one embodiment of the present invention. 12... Central processing unit (
CPU), 14... Read-only memory (R
OM), 16...Random access memory (R
AM), 17... Backup RAM, 18.
... Data bus, 20 ... Input/output interface 7 ace (Ilo), 30 ... Knocking detection device, 40 ... Crank angle sensor, 50 ...
... Load sensor, 60 ... Water temperature sensor, 7
2...Amplifier, 74...Power transistor, 76...Ignition coil, 80...
・Load switch.

Claims (1)

[Claims] 1. A control function that delays the ignition timing by a predetermined amount in response to knocking detected during ignition operation at the basic ignition timing; In an ignition timing control device for an internal combustion engine, which is equipped with a control function that sequentially returns the ignition timing to the basic ignition timing in response to knocking, the basic ignition timing is corrected for each cylinder according to the occurrence of knocking. 1. An ignition timing control device comprising a control means and configured to delay and control basic ignition timing for each cylinder in response to knocking detection for each cylinder. 2. An ignition timing control device for an internal combustion engine according to claim 1, wherein the control means is configured to operate according to the intensity of knocking.