JPS5847159A - Method of controlling ignition time of multicylinder internal combustion engine - Google Patents

Abstract

PURPOSE:To always secure the maximum output efficiency of an engine, by prescribing a plurality of combinations of ignition time for the cylinders of the engine to modify the combination of ignition time to increase the rotational frequency of the engine. CONSTITUTION:Ignition time is calculated by a control circuit 26 which receives the output signals of an intake air quantity sensor 16 and a rotational frequency sensor 18. An ignition device 20 is controlled depending on the result of the calculation. The control circuit 26 selects a plurality of combinations of ignition time for cylinders near desired ignition time. An engine is run at the combinations for a predetermined period during which running condition signals are detected. The detected signals corresponding to the combinations of ignition time are compared with one another to determine the combination corresponding to the running condition farthest from the optimal running condition. The combination corresponding to the farthest condition is changed into a new combination of ignition time. The combination of ignition time is thus modified to attain the optimal running condition.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for optimally arranging the fence during a *IImK disaster in order to improve the fuel consumption rate in an internal combustion engine.゛Internal combustion 41IN ignition timing, generally speaking, the average value that maximizes the output and minimizes the fuel consumption rate is the engine sF.
:/Determined by E rotation number and @atmospheric pressure (or 9! airflow position). In the case of a multi-cylinder engine, it is a common practice to use the average common ignition timing for each cylinder. However, due to variations in waiting time and changes over time, the ignition timing that provides the maximum output varies from cylinder to cylinder, and as mentioned above, the average ignition timing is always suitable for that cylinder. This will cause output loss.
In view of the shortcomings of the conventional technology, each I
By giving the optimum ignition timing to IC11, the maximum output efficiency is always ensured, and the ignition timing can be controlled to the optimum ignition timing without being affected by factors other than ignition timing, such as the actuator operation. The first goal is to make it happen.

The following will be explained with reference to the drawings: 1st round ignition timing, engine speed (torque), and 1. This shows the general relationship between
It is normal for there to be variations in max and optimum ignition timing #opt. Therefore, for the sake of simplicity, if we consider a two-cylinder engine, which is the minimum number of engines with a single engine, as shown in Figure 2, when the ignition timing of each cylinder #142 is changed, the engine speed will be contoured as shown by the broken line. rl・r′m,
Convert to i like rs... Therefore, the combination of ignition timing of each cylinder that forms the peak of engine speed is 0.0.
1) t, #・opt), and reverse I/cM, the maximum rotational speed can be obtained by driving each cylinder with this optimum ignition timing combination.

The present invention uses the method described below to search for a combination of ignition timings for each cylinder that provides the maximum engine speed. First, to explain the principle of this method, in Figure 2, the ignition timing of the *19 IC cylinder is set to 01K and the ignition timing of the #2 cylinder is set to 01, and the engine is operated with this ignition timing combination (point L). NI is obtained as the rotational speed of , and is assumed to be 9. (Note that #1@#ll in ζζ should be considered as a correction amount for the basic advance angle 0, which is determined by the intake air amount (or intake pressure) and engine rotational speed, for convenience of later explanation. In other words, the origin in Figure 11112 is not 0 but 0 in terms of ignition timing advance, and #1 is added to this for #yield, and the circle is the actual advance value.)Next, the above point and is a combination of ignition timings (#1+Δ01) at point H where the ignition timing is slightly changed (for example, the ignition timing of cylinder 1111 is slightly increased by Δ01, while the ignition timing of #2 cylinder is set to t).
・Operate at #l) and set the rotation speed at that time to N1.

Furthermore, operation is performed at a combination (a jj ffi + Δ#1) at another point S (for example, the ignition timing of the #2 cylinder is increased by Δ-maru, while the ignition timing of the #l cylinder is set to #1). The number of rotations that can be achieved is N1. Then, the rotation speed obtained by operating again with the first combination of points B is set as In'. The ignition timing combinations for a 62g IC cylinder are shown in the table below.

Next, find the average value i for each cylinder in the combination of the initial ignition timings of the first three (i.e., the combination of initial ignition timings with Kl added to the cylinder). Combination of timings (in the example in Figure 2, L is the rotation speed NM)
In this case, the same ignition timing combination L is operated twice for a specified period of time, and the difference in rotational speed N1°N' between the two times is due to a cause other than a change in the ignition timing. μlI
&Accessories A/
Depending on the operation, the rotational speed varies linearly in proportion to time, making the two rotational speeds O intuitive.

Then, atta 7 in combination H, 8 of firing timing.
, tvlkf'1, etc., by direct compensation], and find the deviation from the measured rotation speed N L II s,
From this deviation, the combination of ignition timings that minimizes the rotation speed due to the influence of ignition timing alone is determined.

Next, on the straight line connecting this average value 0 and the ignition timing combination L at the minimum rotational speed H1, a point R1 on the opposite side of L with respect to - (in other words, in the direction in which the rotational speed increases) is KM9.
Set. And this point R*QJ fire timing combination (
#*', #s').

Operate with this combination and obtain the rotation speed N4, I! Operate with the ignition timing combination of point H to obtain the rotation speed HC, replace the rotation speed N4 with the minimum rotating machine shaft, and set N
Point 8 from the difference between the proverb and li N. The number of rotations due to the access μ operation etc. in R51C is determined by linear interpolation i1, and this l1l
Based on the deviation between the iII value and the actual measurement value, calculate 3 of N1, Ns and N4.
Find the point H at which the minimum rotation speed (Nm in the figure) is due only to the influence of the ignition timing among the three rotation speeds. Next, find the average value -' of the three ignition timing combinations, and combine this average IIl'' with the minimum rotation speed. A new point R■ is set opposite the ignition timing combination H resulting in the minimum rotational speed (that is, in the direction in which the rotational speed increases) on the straight line connecting the point H.

If you repeat this, Rs-a-R snow→Rs −
By modifying the ignition timing combination one after another in the direction of increasing rotation speed, such as R4-IIRI→R・mRv-mRa, you can reach the peak of rotation speed. Figure 3 shows the basics. The method for determining a new ignition timing combination #new (ie, R) for pixels H, S, and LK is illustrated.

In this case, the average value is expressed in pect μ as −H+S+L a = −・・−−−・−−−−11)
Ignition timing alignment that minimizes the rotation speed 6
#new the new point that should be replaced with m1n (i.e. L)
given that.

#new = # -a (#min -#) --
-------=-cut a: Becomes a constant.

For convenience of explanation, the explanation was given as 2-ki IIK-)vh, but even if the engine has more cylinders than this, the same basic In
Therefore, the ignition timing of each cylinder can be corrected and controlled so as to maximize the rotational speed. ・This figure shows the changes in the combination of the fourth ignition period and the fluctuations in the rotational speed for a four-cylinder engine. be.

In @), operate the engine for a predetermined period of time using each of the ignition timing combinations from ■ to ■, and the same ignition timing combination ■゛ as ■, and connect the rotation speeds N * a N 鳳' of ■ and ■′. Find the distance of each ignition timing combination ■・■・■・■ (rotational speed difference ΔN) from the straight line, and select the combination of ignition timings where this ΔN is the smallest (in the figure, ΔNm ■) as the new round ignition timing. Combination ■'El Correct.

Next, in the 4th cut, operate the engine with each ignition timing combination of ■・■・■, ■′・■″O, and the same ignition timing combination as ■゛, and as above, select the combination that gives the smallest ΔN.
Correct the eel to ■″, then cut K > h, ■, ■″, ■
′・■′・■′ and the same ignition timing combination ■′ as ■, and select the combination ■′ that gives the smallest ΔN.
Correct it to By repeating this operation, the ignition timing combination can be accurately corrected to the optimum ignition timing combination. In addition, d) Show how to obtain ΔN by linear interpolation.
3) It is determined by to'-t.

Next, to explain the apparatus for realizing the method of the present invention, in FIG. There is. Intake air is introduced into each cylinder from the intake manifold 12, and the flow μ valve 14 controls the flow rate of this intake air.
It is installed upstream of the air intake system and measures the amount of intake air. In addition, instead of measuring the intake air flow rate with the nib flow meter 16, the pressure inside the intake pipe may also be measured. 18 is a rotational speed sensor, which generates a signal according to the engine rotational speed. As the rotational speed sensor, a well-known σ crank angle sensor that generates a pulse signal for each angle of rotation of the engine can be used.

20 The ignition system/equipment consists of an igniter, a distributor, and an ignition valve, and is connected to each cylinder O spark plug via a line 22. connected to the electrode.

The ignition control circuit 26 forms the activation signal for the ignition system 20 and functions as a combeater programmed to carry out the method described below. Intake air volume sensor? 16 and rotation speed sensor 58 are lines 30 and 3 respectively.
The I#I control circuit 26, which is connected to the control circuit 26 through 2, calculates the ignition timing determined by the combination of the intake air amount and the rotation speed.

An ignition timing signal corresponding to the result of this calculation is output to the ignition device via line 34.

FIG. 6 shows a block diagram of the ignition control circuit 26, in which the input boat 42 receives signals from the intake air amount sensor 16 and the rotational speed sensor f18. A/
The D converter 40 converts the analog signal from the intake air amount sensor +16 (or intake pressure sensor) into a digital μ signal. Output port 46 serves as a signal gate to igniter 20.

Input port 42 and output II! -) 46 is a compi-It:) structure tl element Ib40PU48@ROM5G
.

Connect to RAM 52 via path 54 and generate cloak 1
Black from 15g! The signal changes in synchronization with the signal.

The control circuit 26 is programmed to obtain the optimum ignition timing for each cylinder based on the invention described above. In the calculation step S1, the ignition timing is set to #* and #嘗, respectively, as in octopus and H.If you drive in this state, the engine speed will change as in (c), and as in (e). An ignition pulse is emitted.The predetermined ignition pulse near the end of this III step S1 is taken in as shown in OfO~0 fend!The number of ignition pulses is counted, and the number of ignition pulses is counted. The engine speed is 11.

gIn the second step Sm, the first fi- is -1 + 80,
The second cylinder is left at 01, and similarly operated for a predetermined number of ignitions, clicks between 0fo and Ofend, J%/, rotation as X number @! Measure the i yuzume. Similarly, in step 183, the rotation speed Nm is measured. Further, in a fourth step S4, the engine is operated with the same ignition timing combination as in the first step, and the one-rotation speed N N is measured. The proverb says that the average number of revolutions measured as IN and N? Find the ignition timing 0h# which gives the minimum rotation speed based on the distance from the straight line connecting the Perform a predetermined ignition operation and calculate the rotation speed N4 as the number of cross pulses (fifth step S&). Then, as a sixth step (not shown), operate with the same ignition timing combination as in the second step S2, and calculate the rotation speed N4.
m' is measured, and step S ass sea is performed in the same manner as described above.
Among m combinations of ignition timings, the combination of ignition timings that minimizes the engine speed based only on the ignition timing factor is found, a new ignition timing combination is created on the opposite side, and this process is repeated.

The general outline of the rounding program for executing ignition timing control in the present invention has been explained above.
This will be explained in detail using a chart.

First, when the internal combustion engine starts, the program executes step 1.
00] This ignition timing calculation interrupt process 11 μm is executed.0 Next, in step 101, the intake air amount sensor 1 is
6 (or intake pressure sensor), the intake air amount (or intake pressure) detected at rotation speed cent t18 and the rotation speed, zero base ignition timing O
1. Specifically, Memo 9KFi intake air,
The basic ignition timing is mapped to the combination of the amount of intake air and the rotational speed, and then the basic ignition timing is calculated from the actually measured intake air amount and the rotational speed. In step 102, it is determined whether the engine is steady based on the change line of the rotation speed and intake negative pressure.If the engine is not steady, NO
Branch 9C and go to ST*flO3.

In 103, the step counter is l;0, the ignition number counter is 0f=O, and the clock/couple β counter is nT2=Q.
Then, in step 104, the flags to be described later are cleared to 1, 2, and 2, respectively.
3. --Set K for the M honorary Q cylinder. Here 01. ＃鵞-・-8M is the amount of correction of the ignition timing, which is stored according to the intake air amount (or intake pressure) and rotational speed, as explained with reference to Fig. 2), and is calculated using the step W7''101. The ignition timing is calculated by adding the basic ignition timing calculated.In step 105, the process returns to the main μm timing.

If it is determined to be steady in step 102, Yli:Sfc branches and the ignition timing is set as described above.■1. ■! ,−■,
An operation is performed using the combination of the following, and the zero rotation speed is measured at the first point L in FIG. 2 (that is, at the first step Ss in FIG. 7). First, in step 106, the value of the counter J, which is cleared for each number of cylinders, is incremented by one E for each ignition, and in step 107, it is determined whether the value of J has reached the number M of cylinders.

If the JO value has not reached the limit, J=I in step 108.
K is cleared, and if it has not been reached, the process moves to step 109. In this Stesive 109, the ignition timing ■1 is set to the basic advance angle 0 for each cylinder. and the ignition timing correction amount θ1). In step 110, the ignition number counter at
indicates that 1 ignition (HiK) is added.ll'
In step 1 and step 4, the number of ignitions Of is 0fen in Figure 7.
d. At first, the NOK branch is taken, and it is determined at 1-17 whether or not the number of ignitions Of is greater than Cfo in FIG. Even if it is NO, it indicates that the rotational speed measurement period has started and h'& is reached, so at 11G, the rotation speed is set to 11G. At 117, the number of ignitions Off increases Q
When it recognizes that the number of ignitions Ofo that should start the measurement of
I then started the clock pulse F and discussed the main points.
Returns to m chin with 119. At step f7'll, it is determined that the number of ignitions at has reached 0fend-, and at 112, the count value np of the number of ignitions at this time is stored in the memory. This count value represents the engine reflex rotation speed of the engine S1. Then, at 11B, the ignition number counter is set to 0f=0. Rinshikupaμsukatnta n
Clear p=OK, add one to the step counter, and set the next ignition timing.
In the figure, the second step 5nj (enters).

First, in 114, it is determined whether 1≦M.

At this time, since i=1, the process branches to ygs, and in step 115, the ignition timing correction amount for each cylinder is set as follows. (In Figure 2.7, in the second step - the ignition timing of the #1 cylinder is moved by Δ#1 = Δ-.
#2*ll is explained as it is, that is, Δ# reference mzQ, but Δ−■ does not have to be O.-6) In step 116, the main routine is returned. When I enter the interrupt from 10QOXfvp again, I11 step! Same as de 106.10
7・109.110 111-117・118.119
The enref rotation speed Hm in this 2nd step 1S Maro is measured as Ku9 Kupays number by the following procedure, and the result is 112
Stored during message exchange in step . After that, in the step 113, the ignition number counter (3f, a counter to counter np is cleared, and the step counter 1 is incremented by one), and the third step is entered.

First, in step 114, even in the case of two cylinders, it is still determined as τES, and in step 115, the ignition timing correction amount is set. then 11
After returning to the main routine at 6, interrupt this program again at loo, perform the processing from 106 onwards as before, and measure the engine rotation speed N1 at this third step 9 Ss in the form of the count value np of the p pass. and store it in memory at 112.

Next f) At sub-step 1140, a determination is made that 1st chapter ≦MO. In the case of two cylinders, the process starts at ζζ and branches to NO, and in step 12G it is determined whether or not 7 puffer key=0. In this case, since Km = O, proceed to XTE9”f129 and K
Set EY=IK and make the same correction jl as the first combination of the Makai period combinations to which the first-order Stellar Day 30''t' rotational speeds are compared (in this case, -1.-- in step 104). If the cylinder is 1, set M; 2) and return to the main routine.

Next, when step 120 is reached again, it branches to NO because KEY=1, and after setting fcRiY to 0 at step 121, at step 122, as explained in FIG. The rotational speed change ΔN is calculated according to equation 13). In step j23, the minimum value of the rotational speed change ΔN is determined.

Next, in step 124, calculate the average ignition timing 0 @ 1
1) Equation.

,,,,,H-! -, 19+, L,,,,.

Since this formula is in pectoμ representation, the *th
*), 15), and f+) for each cylinder component. After setting, at step 125, Hiroko uses the second formula (%) to increase the rotation speed based on the average ignition timing.
Since this formula is also in pect μ representation, the first
4), Step 0 to calculate the new ignition timing for each component of equation (6)! 1126 has this new ignition timing #ne
Combination of ignition timings that constitutes the minimum rotational speed change #m:
Ln (i.e. #1@#s* in equation (4)
=・"w). Then, in Step 9 of 127, set the ignition timing correction amount for each component and set it to 0!, θ Ca *
+-ea, tls, step 128 returns to fisiμm tin.

When the new ignition timing combination is set in this way, the fifth step in FIG. 87 is changed to 106/10 in FIG.
7.109.110.111, 117.11-5 μ-
The engine was taken to the dormitory and the rotational speed N4 was measured. After that, branching from step 111, 114120129
After 1 aoK, the same correction amount as in step 112 is set and the operation is carried out.The rotation speed 1' is measured, and as described above, the combination of the minimum ignition timing for the rotation speed change ΔN is determined. The rotation speed can be changed to a combination that increases the rotation speed. Thereafter, the same process is repeated and the peak of the rotational speed reaches a positive value of 1 [K].

As described above, the present invention sets a plurality of combinations of one ignition timing for each cylinder, and performs a predetermined calculation to correct the combination of ignition timings so that the engine speed increases from these combinations. 1 to obtain the combination of ignition timing for each cylinder that maximizes the engine rotation speed in each operating state),
In particular, the operation with at least one ignition timing combination K is performed 2E, and from the difference in the 6R rotation state signal such as the rotation speed, etc., of the two times of operation KJ)ff, the operating condition 611 is calculated by multiplying each ignition timing combination K. Since the ignition timing is corrected, it is possible to control the optimum ignition timing without being affected by external factors such as external factors such as external operation, and this ensures maximum output efficiency at all times. It has a great effect of being able to create compassion.

[Brief explanation of drawings]

! Figure Ii1 is a characteristic diagram showing the relationship between ignition timing and engine speed, and Figure 112 is the ignition timing combination K in the case of a 2g IC cylinder.
Contour diagram showing the change in engine reflex rotation speed, 11
In Figure 3, 1 is added to the number of cylinders. Determination of new ignition timing to increase engine speed from A ignition timing combination 1114 Figure t&
J, (b), b> is a diagram showing a change in one combination of ignition timing, and FIG. 4 d) is a diagram showing a method for calculating the rotation speed. Fig. 5 is a block diagram of the internal combustion engine according to the present invention, Fig. 61i1 is a block diagram of the control circuit in Fig. 4, and Fig. 7 is a timing diagram showing the public opinion of the calculation processing in the present invention. It is a flowchart which shows the ignition timing calculation processing procedure in this invention. 10- Engine body, * 5-91 people [1-Nin. 18-Engine speed cent o 2 G one ignition system. 26-・Control circuit・Representative Patent Attorney Sekibe Theory Figure 1 Figure 2 11 Place 1 Corner Figure 3 #Sacrificial Stomach and Maruko Sho Figure 5 = A! issue!

Claims (1)

[Claims] Q) Select a plurality of combinations of ignition timings having predetermined values for each cylinder in the vicinity of the target ignition timing, and - Operate for a predetermined period one after another with each of the selected combinations of ignition timings. By detecting operating status signals such as the engine speed during each of these operations and comparing the detection signals for each of the above four ignition timing combinations, the optimum operating condition can be reached by as much as 4' away from the optimum operating condition. An ignition timing control method that obtains a combination of 1M period ignition timings, changes this combination of ignition timings to a new combination of ignition timings, and corrects the combination of ignition timings in a direction that provides the most IIO operating condition. Then, the operation with at least one ignition timing combination among the plurality of ignition timing combinations is performed twice, the difference in the operating condition line signal between these two operations is determined, and from this difference, the other ignition timings are determined. An ignition timing control method for a multi-cylinder internal combustion engine, comprising correcting the operating condition aWI in a combination of ignition timings. (2) The ignition timing control method according to claim 1, wherein the -2B operation is performed at the beginning and end of the operations in the selected combination of ignition timings.