JPS5844270A - Ignition timing control method of multi-cylinder internal-combustion engine - Google Patents

Abstract

PURPOSE:To constantly provide maximum output power efficiency by changing combination of ignition timings such that every cylinder is ignited at an optimum timing so as to offer the maximum engine r.p.m and coverge the ignition timing. CONSTITUTION:Cylinders no.1 and 2, for example, have contour lines (r1) through (r3) of engine speeds which are drawn with respect to the center of respective optimum ignition timings theta1opt and theta2opt. The find the ignition timing at which the engine's output power efficiency may be maximum, the engine is controlled by three ignition timings coded by N1, N2 and N3 to derive the relation that may increase the engine speed, and a code N4 (R1) is then found. Based on the increment DELTAtheta of the ignition timing, the codes R3 and R4 are found and the cylinders are operated at codes R1, R3 and R4 to find the relation that may increase the engine speed. By repeating said processes, the maximum engine efficiency points theta1opt and theta2opt at a point A may be obtained. The engine may be therefore operated at the maximum output efficiency without any influence of difference in performance of engine, aged deterioration of any other adverse factors.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applied to a method of optimally controlling ignition timing for each cylinder in order to improve the fuel consumption rate in the engine. Determined by rotation speed and intake pressure (or intake flow rate). And in 1 of Taki-, the average common ignition timing is each *! I
It is common to use IK. However, the ignition timing that gives the maximum output varies from cylinder to cylinder due to variations in manufacturing, changes over time, etc., and the average ignition timing described above may not necessarily be optimal for that cylinder, but may cause a loss in output. Become.

The present invention addresses the drawbacks of the prior art. Mi, each pneumothorax Kjl
The purpose is to ensure the maximum output efficiency by providing the lj04 ignition timing, and to smoothly move the vehicle to the ignition timing that provides the optimum operating condition.

The tfJI1 diagram below shows the general relationship between the ignition timing and the carrot rotation speed (F~ri), and shows the optimal ignition timing # to maximize the carrot rotation speed.
Has one opt. And this optimal ignition timing #op
Normally, t varies between cylinders. Therefore, for the sake of simplicity, if we consider the minimum number of 11-units, 2-units, as shown in FIG. 2, each cylinder 11! ! When the ignition timing is changed by $2, the engine rotational speed changes as shown by the contour line r1·r sur s- as shown by the broken line. Therefore, there are combinations of ignition timings #10pt and 1m0pt for each cylinder that form the mountain of engine rotational speed, and conversely, if you drive each 9 IC cylinders with this combination of optimal ignition timings, you will get the maximum The number of revolutions (torque) can be obtained.

In the present invention, a combination of ignition timings for each cylinder that provides a high engine speed is searched for by the method described below. First, let's explain the principle of this method.Second! i1
In this case, let the ignition timing of the -1 cylinder be the ignition timing of the 9th cylinder, and the ignition timing of the 2nd cylinder be the ignition timing of the engine. u′1 is obtained and is set as 9. (Gang, ζ here #s, #
For convenience of explanation later, g is the amount of intake air (or intake pressure).
and the basic progression M#s determined by the lJ1 rotation number of the engine
It can be thought of as a positive quantity for That is, the origin in Fig. 2 is the ignition timing difference, which is 0 and not θ, and adding #1 or #snow to this actually increases the ignition timing slightly, while the ignition timing of II & 2 cylinders - Kura does. I! Let lie be the rotational speed obtained by operating at another point S (for example, θ at the time of ignition of the #20 cylinder.If the combination of the ignition timings of the lifts of Rimasaki 2 Kisaki is shown in the table below, It becomes like 1.

Table 1 Next, find the average value In the example shown in the figure, L) with a rotational speed of 81 is searched. Then, on the straight line connecting this average value 1 and the ignition timing combination L at the minimum rotational speed N1, a new round point R1 is set on the opposite side of L with respect to 1 (in other words, in the direction in which the rotational speed increases). Then, the combination of ignition timing at this point R1 (#1+Δσ・−1
+Δ#), operate with this combination, replace the rotation speed N4 at that time with the minimum rotation speed N1, and calculate Ns・Na
Compare the three rotational speeds of N4 and N4 and compare the minimum rotational speed (UN
*) At the same time, find the average value 1' of the combination of three points ^ period, and find the minimum rotation speed on the straight line connecting this average value c' and the point S, which is the minimum rotation speed. Set a new point R on the opposite side of the ignition timing combination So (i.e. in the direction in which the rotational speed increases). From now on, repeat this d, IjsmR*-*Ra-
*R4-eRl -Rs -mRv By modifying the ignition timing combination one after another in the direction of increasing the rotational speed like mRs, you can reach the peak of the rotational speed.

! The diagram s3 shows how to obtain a new ignition timing combination *neW (ie, R) using the basic three points H, S, and LlfCJ11. In this case, the average value will be expressed as P). In addition, if the new point that should be replaced with the ignition timing combination axis in (i.e. L) that minimizes the rotation speed is -new, then ennew=#-a (#win-J)------ 0--
(2) a: Becomes a constant.

In addition, in the process of searching for the optimal ignition timing, add 1 to the number of cylinders obtained by replacing the value of the combination of ignition timings with the lowest rotational speed and the 041 combination of ignition timings, which is an advance ignition timing obtained by calculation formula-2). Among the added number of ignition timing combinations,
If the rotation speed is the lowest in the newly replaced combination of ignition timings, change the calculation formula 〇 so that the combination of ignition timings before the replacement is not found again, and the vibrations are converged. , to control the optimum ignition timing. By changing this calculation formula, it is possible to suppress meaningless fluctuations in the ignition timing around the optimum ignition timing (a combination of two types of ignition timing oscillates over a predetermined period, as in the R1 layer in Figure 112). It is possible to bring the ignition timing closer to the optimal ignition timing.

For convenience of explanation, the explanation has been given using 2 cylinders as %A, but even in engines with more cylinders than this, the ignition timing of each cylinder can be corrected and controlled to maximize the rotation speed using the same am. It can be carried out.

Next, I will explain the principle of the present invention by referring to a device that embodies the principle of the present invention. In FIG. #3. It has 4 cylinders of $4. Intake air is introduced into each cylinder from the air manifold 12, and the throat μ valve 14 controls the flow rate of this intake air. Measure the amount of intake air. Inhalation by air 70-meter 16! ! IJK for measuring air flow rate
II & pressure in the trachea may be measured, 18 is a rotation speed sensor, flftfI according to the engine O11 rotation speed.
A well-known crank angle sensor that generates a bus signal for each crank angle of the engine can be used as the 0 rotation speed sensor.

20 is the ignition device, which includes an igniter, a distributor, and an igniter! It is connected to each *11 spark plug electrode via a line 22.

The ignition net control signal 26 constitutes an activation signal for the ignition device 20, and is programmed to carry out the method described below and has the function of a computer. ＠Air intake meeting center! 16 and the rotary wrinkle sensor 18 are connected to the wires 30 and 3, respectively.
, 2 to the control circuit 26. Control circuit 2
6 calculates the ignition timing determined by the combination of intake air amount and rotational speed, and outputs an ignition timing signal according to the calculation result to the ignition device via the line 34.

Figure 5 shows a tick diagram of the ignition steel control circuit 26, in which the input port 42 is connected to an intake air amount sensor,
16 and rotation speed sensor +18. A/
The D converter 40 converts the analog signal from the intake air amount sensor 16 (or intake pressure sensor) into a digital signal U@. Output port 46 serves as a signal gate to ignition device W120.

The input port 42 and the output port 46 are connected via a path 54 to the 0PU4B and ROM 50° RAM 52, which are the constituent elements of the combination bomber. From the occurrence of the signal 11115&, the signal Ki4 is generated and the signal line 9 is performed.

The control circuit 26 is programmed to control the optimum ignition timing for each cylinder based on the principles of the present invention as described above. In step S1, the ignition timings are set by #js#lK stages, as in (a) and (b), respectively. By driving in this condition, the engine speed changes as shown in [1], and the ignition pass occurs as rumored.

At the predetermined ignition pulse intervals cro to Cfen4 near this first step 8sO311, clock pulses are taken like -0 and the number is counted, and this is taken as the engine rotational speed at step 81 of j11. At Step 8m of the 2nd E, set Han 1114x cylinder shape -1 + Δ-1 2nd air 11 Hiro -1 Hiro, and similarly operate the predetermined number of ignitions, Ofo ~ 0f
enl @ 0ri 1 bite! Measure the rotational speed Me as Kupa JIS/, X song. Similarly, measure the rotation speed lim at step 918s of gear 3. The new ignition timing #1'', 0 on the opposite side of the minimum rotating machine O is measured in this way.
■' with @SS diagram calculation method, perform the prescribed ignition operation in the same way, and measure the rotational speed N4 by making many cross cycles. This will be repeated below.

Having described the general outline and outline of the rounding program for executing ignition timing control in the present invention, it will be described in detail with reference to the flowchart of FIG.

First, when the internal combustion engine 411M is started, the program goes through step 100 and executes the interrupt processing routine for calculating the ignition timing.
16 (or intake pressure sensor) and the intake air amount (or intake pressure) detected by the rotation speed sensor 18 and the rotation speed), the basic ignition timing is calculated to be 0.0. Specifically, the memory has basic ignition timing mapping for combinations of intake air amount and rotational speed.

The intake air amount and engine speed are calculated based on the estimated intake air amount and rotational speed. In step 102, it is determined whether or not the engine is steady based on the changing state of the rotational speed and intake negative pressure.If the engine is not steady, the NOK branch is taken and the process goes to steady 103.

At 103, the step counter is set to 1;0, and the ignition number counter is set to Qf=9. The click pulse counter is set to zl p to Q, and the 7 toggles described later are cleared to E = 0. In the primary progressive 104, the start ignition timing is set to $1.2 each.
・3. ---Set for t14 of the Mth book. Here # 1 * # Torture...--θ
1 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 the figure Jg2, and the basic ignition timing calculated in step 101 is added to this. This is what is calculated as the ignition timing. 1
At 05, it returns to the main μm function.

If the steady state is determined by the static 102, the branch goes to YES and the ignition timing set as described above is performed.■1. ■Proverb.

The operation is carried out using the combination of . First, in step 106, the value of counter J, which is cleared for each cylinder, is incremented by one for each ignition, and in step 107, it is determined whether or not the value (JC) has reached the number of cylinders. The value of J is MKt! If so, in step 108, clear r=l and jl! If not, the process moves to step 109. In this step 109, the ignition timing ■ is determined for each light.

The basic advance angle is 0. and the ignition timing correction amount θ1. In the steady 110, the number of ignitions counter Of is incremented by one for each ignition. 1
．． In stay 1 of No. 11, it is determined whether or not the ignition times/number Of is 0fend in FIG. 6 (E).

At first, it naturally branches to tj OK, and at 117 the number of ignitions (3f
It is determined whether CtO is larger than CtO in FIG.

If NO, this indicates that the rotational speed measurement period has not yet entered, and the process returns to the main μm control at step 119. 117
Then, it is recognized that the number of ignitions Of has reached the number of ignitions 0fOK at which clock pulse lv measurement should start #fYES
The clock pulse count is started at 118, and then the main μm clock Kll! ) to return. If it is determined in step 1.11 that the number of ignitions Of has reached 0 fend ic, then in step 112, the power of the clock pulse at this time (run) negative np is stored in the memory. This count value represents the engine rotational speed N1 at step Sl.

And at 113, 1 ignition 1Mll1k counter is 0f=0
%Black! Clear the Kuba μ Ska Kunta np = OK, add 1 to the step counter and set the next ignition timing, 1
The operation is carried out at point H in FIG. 12, and the step S1 in FIG. 6 is entered.

First, in step 114, it is determined whether 1≦fine.

At this time, since 1=1, the BSK branches, and at step 115, the ignition timing correction amount for each cylinder is calculated as follows.

is set. (In Fig. 2.6, in the second step, the ignition timing of #1 cylinder is moved by Δ01 cumulative = 80,
2 cylinders are explained in terms of i, that is, Δeu=o, but Δ
#t1 does not have to be O. ) Step 116 returns to the main μm process. When the interrupt is entered again from the lOO step, 106.107.109 is returned as in the first step.
, 110, 111.117゜118-11.9 procedure is
is measured as the number of cross-buses, and the result is stored in memory in steps 112. Thereafter, in step 113, the ignition number counter Of and clock pulse counter np are cleared, and the stellar 1 counter 1 is incremented by 1, and the program enters step Jg3.

First, in 114, in the case of 2-*#, it is determined as YES, and the ignition timing correction amount is set in 1.115. After that, after returning to the main micrometer at 116, interrupting this groggle 5 again at 100, performing the heat treatment after 106 as before, and measuring the engine rotation speed Nm at this third step Ss at the clock pulse count value np. line b%1
12, it is stored in memory.

Next, in step 114C1, it is determined whether 1≦M. 2
In the case of a cylinder, the NOK branch is taken at this point, and in step 120, a search is performed for step 1=min, which minimizes the rotation speed in the previous rotation speed measurement step g1. (If the number of cylinders is more than this, add 1 to the ** number and divide into 115 steps until nine ignition timings are set.

Next, in step 121, it is determined whether a new ignition timing combination has been set (based on the state of the hook),
If set (KEY: l).

In the next step 122, it is determined whether the operation (new step) with the ignition timing 0 combination replaced with the new nine corresponds to step 1 = win, which minimizes the desired rotation speed in 120, and YES. In any case, in the step d123, the constant tlta·yfiaa−Δalc of the arithmetic expression (2) is subtracted. Also, -KBY÷0 or new stage f
If i = win, then a = a in step t7''124
Change and attack as e, this step! 23 *titt
By adding , the ignition timing O near the optimum ignition timing
There is no S dynamic, no backlash, and it is possible to accurately converge on the optimal ignition timing.

Table 2 shows the contents of each ignition timing combination and the transition of new ignition timing combinations.

Table 2 (Note 1) shows that if the one with the lowest rotation speed among each combination, a, remains constant, from combination 412 onwards, the calculated new ignition timing combination will be 9 repetitions of Rz and Ru. - According to this method, at the time of A14, R x l is obtained from the new nine, and thereafter, the vicinity of the points Rtt and Rts is searched.

Next 11C125O station! Calculate the average ignition timing using the first equation 1). Since this equation is expressed in pect μ, @1
:1. t<), calculated for each Kizaki formula in each equation (5). Then, in step 126, a new ignition timing #ne' is determined based on this average ignition timing to increase the rotation speed using the second formula (%).
Since this formula for calculating ii is also in pect μ representation,
No. # (To) * (4)s '6th step to calculate new ignition timing for each component of formula 5)! 27, this new ignition timing θnew is set to the minimum rotation speed (1121!Ns in the 10th example)
) in the combination of ignition timings (i.e., equation 6) where Then, in 128 steps, the amount of ignition timing correction for each component is 07! and obtain 01.0 Liao* ++H1θ1, step 12
At 9, press the 7') key to IK-kv) and return to the main 4/-chin at 130.

Once the union name for the new ignition timing is set in this way, the Jl! 1g4 step in Figure 6 is 106. in Figure 7.
107,109. JlG, 111.117.118
For 1+μm, one revolution is performed at N40 times. Then, enter the routine from 120Fl to 129, calculate the average point and fire timing at three points of H and R*, determine one point Rm in the direction of increase in rotation speed, and calculate the R
Calculation of each cylinder component of the ignition timing at A of m is performed, the ignition timing correction amount is determined, and the same process is repeated thereafter to remove the peak of rotation i.

As described above, according to the present invention, each of the ignition timings 911,
Set multiple combinations for each cylinder, perform predetermined calculations so that the engine speed increases from the best combination, and make the ignition timing combination 911 positive, and set each operating condition KTh%/%.
The combination of ignition timings for each cylinder that maximizes the engine speed can be determined], and the combination of ignition timings that can be corrected can also be modified. Since the calculation formula for finding a new ignition timing combination has been changed, it is possible to operate at the ignition timing that maximizes the output efficiency without being affected by engine differences or changes over time. It is possible to smoothly converge on the timing.

[Brief explanation of drawings]

jB1 Zusha Characteristic diagram showing the relationship between ignition timing and engine speed, Figure 2 is a contour diagram showing changes in engine speed with respect to ignition timing combinations in the case of two cylinders, and Figure 38! il is a diagram showing a method of determining a new ignition timing in which the engine speed is increased from nine ignition timing combinations by adding the number of cylinders Kl. FIG. 4 is a block diagram of the internal combustion engine according to the present invention, and FIG.
The configuration diagram of the control circuit in the figure, FIG.
FIG. 7 is a diagram showing the concept of calculation gI & logic, and is a flowchart of ignition timing calculation in the present invention. 10-・Enrin main body, 16-・Intake air amount sensor 1
8--Engine speed sensor, 20--Ignition device. 26-fi control circuit. Substitute voice Rushi Manabe Takashi 2 Leap 3M No. 4■゛1 Fig. 6 51 'S! ---

Claims (1)

[Claims] Select a plurality of combinations of nine ignition timings having a predetermined value for each 111I in the vicinity of the target ignition timing, and select the selected ignition timing,
These,
During each drive, the driving condition signal of carrot rotation speed - is detected,
By comparing the detection signals for each of the above combinations of ignition timings, find the combination of ignition timings that is farthest from the optimum operating state and form the 9th driving line, and combine this combination of ignition timings with each combination of ignition timings. An ignition timing control method in which the ignition timing combination is changed to a new ignition timing combination calculated by a predetermined calculation formula from 1. If the operating state for the ignition timing combination is the operating state line that is farthest from the optimal operating state among the operating states for each ignition timing combination described above.1. An ignition timing control method for a multi-cylinder internal combustion engine, characterized in that the arithmetic expression for determining the new and good ignition timing combination is changed.