JPS63285266A - Ignition timing control device - Google Patents

Abstract

PURPOSE:To prevent the breakdown of an engine by distributing a driving signal to each ignition coil on a cylinder identifying signal, and estimating the ignition coil to which the driving signal is to be distributed this time from its preceding distribution, and then distributing the driving signal to the above-estimated ignition coil when the ignition coil to which the driving signal is distributed on the cylinder identifying signal differs from the above-estimated one. CONSTITUTION:A cylinder identifying signal (SGC) level is estimated so as to estimate an ignition coil to which 8 driving signal is to be distributed this time from its preceding distribution, and when an estimated SGC level coincides with an actual SGC level, the driving signal is distributed to the ignition coils 8, 9 on the actual SGC level respectively. When both the above-mentioned SGC level, are different, the driving signal is distributed on the estimated SGC level, and when both the above-mentioned SGC levels are continuously different, the driving signal is distributed on the actual SGC level. Thus, even when noise causes abnormality in SGC, the driving signal can be accurately distributed, and moreover even when estimated information becomes wrong, the driving signal can cope with the above wrong information. An engine 1 can be therefore prevented from badly running and breaking down.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition timing control device for a low voltage power distribution system of an engine.

[Conventional technology]

Conventional ignition timing control devices include a high-voltage power distribution system that applies high voltage to the spark plugs of each cylinder via one rotor, and an ignition coil for each cylinder, which distributes drive signals to each spark plug. There is a low voltage distribution system. Low-voltage power distribution systems are used to improve engine performance by increasing ignition energy, reduce noise sources by eliminating high-voltage power distribution, and improve product image.

FIG. 1 shows an ignition timing control device for a low-voltage power distribution system of an engine, in which 1 is an engine, 2 is a spark plug provided for each cylinder of the engine 1, and 3 is an intake pipe of the engine 1; 4 is a companion Karman vortex air sensor (abbreviated as AFS) provided at the inlet of the intake pipe 3; 5 is an air cleaner provided further to the inlet side of the AFS; 6 is the intake pipe 4;
The throttle valve 7 is a crank angle sensor that detects the 10 rotational speed of the engine, and generates a crank angle reference signal (abbreviated as SGT) and a cylinder identification signal (abbreviated as SGC). 8 is ≠ 1 and spark plug 2 of Na 4
9 is the ignition coil that applies high voltage to the spark plug 2 of ÷2 and ◆3, 10 is the AF
Output of S4, SGT.

5G (This is an ignition control unit that receives four inputs and distributes drive signals to the ignition coils 8 and 9. 11 to 13 are interfaces;
14 and 15 are first and second counters, 16 to 18 are first to third timers, 19 is a 4-channel converter that converts the power supply vB to A/1), and 20 is a ROM.

CPU with RAM, 21 is a knot circuit, 22゜23
is an AND circuit, 24, 25 is a driver, and 26° and 27 are transistors.

In the above configuration, the ignition control unit 10 outputs the output of the AFS 4,
SGT% SGC is input and a drive signal is alternately distributed to each ignition coil 8,9. The ignition coils 8 and 9 apply high voltage to two spark plugs 2 each, but if one cylinder is in the compression stroke, the other cylinder is in the exhaust stroke, and the spark plugs 2 are ignited one by one.

[Problem that the invention seeks to solve]

However, there are various types of noise in the engine 1, and when these noises are superimposed on the SGC, the flicker circuit may not be able to remove this noise depending on its magnitude, and the SGC'r may be misread. Moreover, an abnormality may occur in the SGC due to poor contact of the connector or a defect in the crank angle sensor 7. In these cases, the drive signals for the ignition coils 8 and 9 could not be distributed properly, resulting in problems such as inability to run and engine destruction due to erroneous ignition.

Figure 2 (a) shows the normal state of the SGC; in this case, the SG
C becomes as shown in Figure 81, and SGT becomes as shown in Figure Fb1. Also, the output of the third timer 18 becomes as shown in Figure (C). The output of the output port P6 of the CPU 20 becomes SGT If the SGC at the time of rising is H, it is H, and if it is L, it is L, so the result is as shown in Figure (d).For this reason, the drive signal for the ignition coil 8 generated by the driver 25 is (e) The drive signal for the +27+3 ignition coil 9 generated by the driver 24 becomes as shown in (f), and the output pulse of the timer 18 having the energization time width of the ignition coils 8 and 9 is distributed alternately.

However, for example, when noise is superimposed on the SGC as shown in FIG. 2 [Bl (a), the output of P6 becomes Ta
As shown in Figure 2, the drive signals are misdistributed as shown in Figures (e) and (g).

This invention was made to solve the above-mentioned problems, and its purpose is to prevent misdistribution of drive signals due to noise or SGC abnormality, and to prevent the engine from being unable to run or being destroyed. .

[Means for solving problems]

Ignition timing control according to this invention! The Il device distributes the drive signal to each ignition coil based on the cylinder identification signal, predicts the ignition coil to be distributed this time based on the previous distribution, and if the one based on the cylinder identification signal and the predicted one are different, A distribution means is provided for distributing the drive signal to the ignition coil according to the prediction.

[For production]

The distribution means according to the present invention predicts the ignition coil to be distributed this time, and if the ignition coil does not match the ignition coil according to the cylinder identification signal, distributes the drive signal to the predicted ignition coil.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. The schematic structure of the ignition timing control device according to this embodiment is the same as that shown in FIG.

Next, the entire operation of the above device will be explained with reference to the flowchart of FIGS. 5-C1. Figure 5 shows the entire main routine, initialization is performed in step 101, step 102
Now, convert the battery voltage VB f~. Step 10
3, the counters 14 and 15 calculate 7'c the output of AFS4 and the period of SGT TAFS.

From ThcT to engine intake air amount per intake A/N (
Abbreviated as AN. ) is calculated. Similarly step 104
Now, calculate the engine rotation eccentricity from TSGT. In step 105, ignition timing data θA' is obtained from the map shown in FIG. 6(5) stored in the ROM, and similarly, in step 106, energization time data TDWi is obtained from the map shown in FIG. 6fE).

FIG. 5 (Bl shows the interrupt processing routine of the pulse period TAFS of AFS4, and in step 201, TAFS 'fr
: Read and reset the counter 14 in step 202.

FIG. 5 1cI shows the interrupt processing after the rise of SGT, and in step 301, the SGT period TSGT f is read,
In step 302, the second counter 15 is counted as TD=TA.
- Calculate TD■L. TA is the time from the rise of SGT to the end of energization, as shown in Figure 4, and T
D is the output noise width of the second timer 17. That is,
The second timer 17 changes from L to H at the same time as SGT rises, and changes from H to L after time TD. At this point in time, the timer 18 becomes H, and energization to the ignition coils 8 and 9 starts. In step 304, the timer 17 is set to TDk.
In step 305, the timer 18 is set to TD■11.
set.

In step 306, the timer 17 is triggered to start the ignition operation, and in step 307, the data of the least significant bit of the friend distribution register for predicting the current distribution amount from the previous distribution in the distribution register in the CPU 20 is inverted.

Step 308 reads all SGC levels, Step 3
In step 09, it is determined whether the least significant bit of the distribution register and the SGC level are the same, and if they are the same, in step 310, the SGC level is set and updated in the least significant bit of the register.

In step 311, a determination counter in the CPU 20 (a counter that determines how many consecutive times the predicted SGC, that is, the least significant bit of the distribution register and the actual SGC do not match) is set to n. In step 312, it is determined whether the least significant bit of the distribution register is 1 or O. If it is 1, it is output to P6 at step 313, and if it is 0, all L is output to P6. If the judgments in step 309 are not the same, in step 315
1 and determine whether it is O or not, and if it is not 0, step 3
Proceeding to step 12 and subsequent steps, the output of P6 is determined by the least significant bit of the distribution register. If it is 0, that is, if the predetermined number of mismatches is 9, it is determined that the predicted distribution information is incorrect for some reason because noise does not occur continuously, and the actual S
The lowest pick lf is updated by GC, and distribution is performed by actual SGC.

As described above, in the above embodiment, the SGC level is predicted in order to predict the current distribution from the previous distribution, and when the predicted SGC level and the actual SGC level match, the actual SG
The ignition coil drive signal is distributed according to the C level, and when they do not match, distribution is performed according to the predicted SGC level, and when they do not match a predetermined number of times in succession, the entire distribution is performed according to the actual SGC level. Therefore, even if an abnormality occurs in the SGC due to noise, it is possible to correctly distribute the drive signal, and it is also possible to deal with the case where a deviation occurs in prediction information.

Further, the operating waveforms of each part when the SGC is normal are the same as those shown in FIG. 2, and FIG. 3 shows the case where noise is superimposed on the SGC. In this way, even if noise is superimposed on the SGC, the output of P6 becomes normal, and normal distribution can be achieved.

Incidentally, in the above embodiment, if no action is taken against the error in the prediction information, steps 311 and 315 are unnecessary. Further, the present invention can also be applied when an abnormality occurs in the SGC due to a cause other than noise.

Further, the present invention can be implemented even when four ignition coils are provided by coding the distribution register. For example, set O every time SGC of a cylinder with ≠1 occurs, and then increase +1 every time SGT occurs,
Each time the register contents become 4, it is set to 0, and the cylinders divided by 1 to 4 are coded as O to 3, respectively. Further, in the above embodiment, one timer 18 is provided to generate the coil drive signal, and its output is distributed. However, an independent timer is provided for each coil drive signal, and the trigger that activates all of the timers distributes the signal. It may be distributed according to the contents of the register. In this case, a coil drive signal with a closing rate of 100% or more can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, even if an abnormality occurs in the cylinder identification signal due to noise generated from various parts of the engine,
The current distribution is predicted from the previous distribution, and if the predicted ignition coil is different from the ignition coil based on the cylinder identification signal, the drive signal is distributed to the predicted ignition coil, which prevents the engine from making one rotation. It is possible to prevent damage caused by accidental ignition and to improve the ignition function.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the ignition timing control device according to the conventional device and the present invention, and FIG. 2 (5) and (B) show the SG of the conventional device, respectively.
C: Operation waveform diagram of each part in normal state and when noise is superimposed; FIG.
Figure 4 is an enlarged view of the operation waveform diagram of each part, Figure 5 (5) to tC
+ is a flowchart of this invention device, FIG. 6(A),
03) is an engine characteristic diagram. 1... Engine, 2... Spark plug, 4... Air flow sensor, 7... Crank angle sensor, 8, 9...
- Ignition coil, 10... Ignition control section.

Claims (2)

[Claims] (1) From the outputs of the load detection means for detecting the load on the engine, the rotation speed detection means for detecting the engine rotation speed, the cylinder identification signal generation means for generating the cylinder identification signal, the load detection means, and the rotation speed detection means, calculation means for calculating the optimum ignition timing; drive signal generation means for generating a drive signal corresponding to the ignition timing for each ignition coil provided corresponding to the cylinder; In an ignition timing control device equipped with a distribution means for distributing ignition coils in an orderly manner, the distribution means predicts the ignition coil to be distributed this time from the previously distributed ignition coil, and the predicted ignition coil is different from the ignition coil based on the cylinder identification signal. An ignition timing control device characterized in that a drive signal is distributed to a predicted ignition coil when (2) The distributing means is characterized in that if the predicted ignition coil and the ignition coil based on the cylinder identification signal are different for a predetermined number of consecutive times, the drive signal is distributed to the ignition coil based on the cylinder identification signal. An ignition timing control device according to claim 1.