JPH01187367A - Ignition timing controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate any variation in combustion among respective cylinders by comparing a mean crank angle at each cylinder with that in all cylinders, calculating an ignition timing compensation value between cylinders, and on the basis of this compensation value, compensating the fundamental ignition timing. CONSTITUTION:A controller 20, controlling each ignition timing in two ignition means 9, 21, sets fundamental ignition timing with a means 22 on the basis of each detection signal out of respective sensors 16, 18. On the basis of each detection signal out of respective sensors 7, 18, it detects a crank angle at each cylinder with a means 23. In addition, it operates a mean crank angle at each cylinder with a means 25, while it calculates a mean crank angle in all cylinders with a means 26. On the other hand, it compares the mean crank angle at each cylinder with that of all cylinders, and calculates an ignition timing compensation value by cylinder with a means 27. Then, it compensates the fundamental ignition timing with the ignition timing compensation value, and calculates the actual ignition timing with a means 28.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention advances or retards the ignition timing so that the crank angle position δ that provides the maximum in-cylinder pressure of each cylinder becomes the average crank angle position of all cylinders. The present invention relates to an ignition timing control device for an internal combustion engine.

[Problems to be solved by the prior art and the invention 1 Generally, in internal combustion engines, ignition timing affects the output and fuel efficiency of the internal combustion engine! ! ! ! It is an important object to be controlled, and various control devices have been devised and adopted.

Conventionally, the control device for this scale has a basic system that detects the presence or absence of knocking based on the output of a knock sensor installed in the cylinder block, such as the knocking feedback system TI11, and determines the presence or absence of knocking according to the operating state of the engine. A device that retards the ignition timing when knocking occurs. Based on the output signal from the angle sensor ', the combustion mass ratio is determined, which indicates the ratio of the effective heat generation to the intake air-fuel mixture generated up to a predetermined crank angle, and the target combustion quality fa is set according to the current operating conditions; 'l'1
(3) A cylinder pressure sensor detected by a cylinder pressure sensor as shown in Japanese Patent Publication No. 011/1986-55461. so that the peak position of internal pressure is the optimum crank angle position.
There are some that correct the ignition timing and perform tIIllall.

By the way, in general, in multi-cylinder internal combustion engines, (1) the amount of air taken into each cylinder differs due to the complexity of the intake pipe shape or the interference between the cylinders of the air taken in, and (2) the amount of air taken into each cylinder differs. The combustion temperature differs slightly for each cylinder due to the cooling route of the cylinder, etc. (3) The combustion chamber volume of each cylinder, piston shape, etc.
(4) The air-fuel ratio differs slightly from cylinder to cylinder due to differences in the amount of fuel injected due to injector stickiness, etc. For these reasons, the optimal air-fuel ratio and ignition timing are It is thought that this varies from cylinder to cylinder, and in the current engine that employs the same ignition timing for all cylinders (11J), there is room to improve the combustion variation for each cylinder.

In particular, in high-performance engines, where there is a recent trend toward low fuel consumption in the Alpine H1, if there are fluctuations in t and τ in the combustion of each cylinder, it will have a large effect on output fluctuations, causing energy loss and making output unstable. This not only causes a decrease in the total output of the engine, but also causes problems in vibration countermeasures, J3 control, air-fuel ratio controllability, etc.

[Purpose of the Invention] The present invention has been made in view of the above circumstances, and it not only provides stable output characteristics, but also improves the total output of the engine, achieves low fuel consumption, and provides excellent quietness. Another object of the present invention is to provide an ignition timing 111 control device for an internal combustion engine that is suitable for high-performance engines.

[Means and effects for solving the problem] The ignition timing control device for an internal combustion engine according to the present invention sets the basic ignition timing based on the engine operating range determined by the intake air amount and the engine speed. 16 cylinder-specific crank angle detection means for detecting a crank angle indicating a maximum cylinder pressure for each cylinder based on an output signal of a crank angle sensor and an output signal of an in-cylinder pressure sensor disposed in each cylinder; Cylinder-by-cylinder average crank angle calculating means calculates the cylinder-by-cylinder average crank angle by averaging a predetermined cycle of crank angles determined by a separate crank angle detecting means, and the cylinder-by-cylinder average crank angle calculating means an average rank angle sifting means for calculating the average crank angle of all cylinders by averaging the average crank angle of each cylinder; and an average crank angle of each cylinder calculated by the average crank angle of each cylinder; a cylinder-by-cylinder ignition timing correction amount calculation means for calculating an ignition timing correction amount for each cylinder by comparing the average crank angle of all cylinders calculated by the all-cylinder crank angle calculation means; and a basic ignition timing correction amount calculation means set by the basic ignition timing setting means. and ignition timing q output means for calculating the actual ignition timing for each cylinder by correcting the ignition timing with the cylinder-specific ignition timing correction amount calculated by the cylinder-specific ignition timing correction amount calculation means.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic diagram of the main parts of the engine, FIG. 2 is a schematic plan view of the engine, FIG. 3 is a sectional view taken along the line ■-■ of FIG. 2, and FIG. FIG. 3 is a cross-sectional view taken along line IV-IV in FIG. FIG. 8 is a flowchart showing the control procedure of the control means.

Reference numeral 1 in the figure indicates a four-cylinder horizontally opposed engine body, which is an example of an internal combustion engine, and the cylinder block 2 is located on both sides (LH) centering on the crank shirts 1 to 3.

It is divided into two banks (RH).

Each piston 4 fitted into each cylinder 2a, 2b, 2c, 2d installed in the LH bank and RH bank of the cylinder block 2 is connected to the crankshaft 3 via a connecting rod 4a. In addition, the piston 4 and cylinder head 5a of each of the cylinders 2a to 2d,
Combustion chambers 6a, 6b, 6c, 6 are located in the area surrounded by 5b.
d are formed respectively.

Further, each cylinder 2 of each cylinder head 5a, 5b
A cylinder pressure sensor 7 is mounted and fixed via an adapter 8 at positions corresponding to a to 2d, and a tip detection portion of this cylinder pressure sensor 7 faces each of the combustion chambers 6a to 6d. Note that this cylinder pressure sensor 7 is connected to the cylinder head 5a.
, 5b.

Further, each of the cylinder heads 5a and 5b5 is equipped with a spark plug 9 corresponding to each of the cylinders 2a to 2d.

In addition, an engine engine 510 faces each of the intake boats 1a communicating with the combustion chambers 68 to 6d, and furthermore, the upstream side of each intake boat 1a is connected to the intake manifold 1.
1 to a throttle chamber 14 in which a throttle valve 13 is interposed.
The upstream side of 4 is the intake pipe 15 and the hot wire air flow meter 16.
The main passage 16a communicates with the air cleaner 17.

The air flow meter 16 also includes the main passage 16.
There are 91 sub-passages 16b that bypass the sub-passages 16b, and a hot wire 16d and a temperature compensation plug 16e, which constitute a part of the bridge circuit provided in the controller 16c, are exposed in the sub-passages 16b. This air flow meter 1
6, the quality M flow of the intake air flowing through the sub passage 16b;
That is, the intake air mo is measured and a measurement signal is output from the controller 16C.

The crankshaft 3 also has an engine speed N
and a crank angle sensor 1 that detects the crank angle Crθ
8 are arranged in a row. Note that reference numeral 19 is a throttle sensor that detects the throttle opening degree θ.

On the other hand, the symbol @20 is a control means, and the above-mentioned sensors 7, 16, 18 (and the above-mentioned throttle sensor 19) are connected to the input side of this control means 20, and the above-mentioned injectors 10 are connected to the output side. At the same time, the spark plugs 9 are connected via ignition coils 21 that are individually installed.

Further, the control means 20 includes a basic ignition timing setting means 22.
, Cylinder-specific crank angle detection means 2 that indicates the cylinder-specific maximum combustion pressure
3. τ counter 24, cylinder-specific average crank angle sensor stage 2
5. All-cylinder average crank angle calculation means 26, cylinder-specific ignition timing correction adjustment means 27, ignition time tlj n peak means 28,
A driving means 29 and the like are provided.

The basic ignition timing setting means 22 determines from the intake air fif (Q detected by the air flow meter 16 and the engine rotation speed N detected by the crank angle sensor 18),
Search the ignition timing map MPIG for each cylinder stored in storage means such as backup RAM, read the ignition timing IGT written in the current operating range 1111 (grid point of the map), and use this as the basic ignition. Set as the time.

The above ignition timing map M P IG is provided for each cylinder, and as shown in FIG.
At each grid point composed of the l (Q) grid and the engine rotation speed (N) grid, the above-mentioned ignition time I! The latest ignition timing data IG■ output from the Iln output means 28 is sequentially written.

In addition, the cylinder-specific crank angle detection means 23 detects the output signal -3 of the cylinder pressure sensor 7 installed in each of the cylinders 2a to 2d, and the crank angle change of the crank angle sensor 18. From CrO, the maximum value P of cylinder pressure for each cycle
The crank angle θPI (AX) indicating H8× is detected for each cylinder, and the crank angle OPHAX is stored at the lattice point ( It is stored in the operating area (1 tL).

Further, the τ counter 24 counts the crank angle θPHAX stored at the same grid point (operating region) for a predetermined cycle (τ0).

Further, in the cylinder-by-cylinder average crank angle calculation means 25, if the number of crank angles θPHAXI...θPH^Xn detected and stored in the cylinder-by-cylinder crank angle detection means 23 exceeds a predetermined cycle (τ0), By averaging them, an average crank angle OPHAXAV is calculated for each cylinder.

Further, the all-cylinder average crank angle calculation means 26 calculates the all-cylinder average crank angle XAV by averaging the cylinder-specific average crank angle θP)IAX8V calculated by the cylinder-specific average crank angle sensor stage 25 over all cylinders. do.

Further, the cylinder-by-cylinder ignition timing correction opening means 27 calculates the difference 6o between the average crank angle θPHAX of each cylinder and the average crank angle XAV of all cylinders for each cylinder (Δ
0 = lXAV-0PHAXAVl).

Then, this difference ΔO is expressed as the engine rotational speed N and the intake air f.
Compare it with a reference value dD that is preset according to the engine operating range determined by f1Q, and find the deviation,
An ignition timing correction amount ΔIQ is calculated according to this deviation (see FIG. 7).

That is, when Zθ≦JD, the above ignition timing correction ωΔI
Let g remain as is (ΔI[l=Δ[(]).

Mata, 1θ>J[), and), θPHAXAV>X
In the case of 8V, extract the advance angle correction tIlα according to the deviation and apply it to the ignition timing correction value Δ1(l) stored in the map according to the operating region (1UIo=IJ
l(1÷α).

Furthermore, Δθ〉−〇 and θPHAXAV<
In the case of AV, calculate the retardation correction h1β according to the deviation, and update the ignition timing correction 5ΔI(l) (A Ia=z
Ig1β).

/! If UO is less than the reference value ΔD (Δθ<ΔD), the crank angle that indicates the maximum in-cylinder pressure of the relevant cylinder is closer to the crank angle that indicates the maximum in-cylinder pressure of all cylinders, so the ignition timing is corrected. do not have to. Also, 2θ〉
In the case of ΔDI, by appropriately setting the ignition timing map A19 according to the deviation, variations in combustion between each cylinder, that is, variations in crank angle without showing the maximum cylinder pressure of each cylinder, are reduced. .

Further, the ignition timing calculation means 28 advances the basic ignition timing IGT'' set by the basic ignition timing setting means 22 with the ignition timing correction i]431g calculated by the cylinder-by-cylinder ignition timing correction ffl extraction means 27. The ignition timing IGT for the relevant operating region is calculated by performing the correction α or the angle correction β.

Then, the ignition timing stored in the lattice points (operating region) determined by the N lattice and Q lattice of the ignition timing map M P IG provided corresponding to each cylinder,
The latest ignition timing I calculated by the ignition timing calculation means 28
It will be updated sequentially in GT.

On the other hand, for the ignition plug 9, the ignition timing setting means 28 sets the latest ignition timing IGT stored in the ignition timing map MPIQ to the engine speed N and the intake air f.
A signal based on this ignition timing IGT is output to the ignition coil 21 via the two driving means, and a large voltage is applied to the secondary side of the ignition coil 21. The generated voltages V, δ, etc. are ignited by applying this voltage to the spark plug 9 of each cylinder.

Next, the control f order of the control means 20 will be explained according to the flowchart of FIG.

First, in step 101, from the output signal of the cylinder pressure sensor 7 provided in each cylinder and the output signal of the crank angle sensor "18, the crank angle θPHAX indicating the maximum cylinder pressure PHAX for each cycle (see Fig. 7) is measured for each cylinder and stored at the corresponding grid point (operating region) of a map specified by the engine rotational speed N and intake air amount Q provided in a backup RAM or the like.

Then, in step IQ2, the crank angle θPHAX stored in the same operating region is counted by the τ counter 24, and the count value is set to b.Proceeding to step 103, the count value in the same operating region becomes equal to or greater than a predetermined count value τ0. Determine whether it has happened.

If τ is less than τ0, the process returns to step 101, and the crank angle θPHAX is detected and stored again.

If τ≧τ0, the process proceeds to step 104, and the τ01 stored in the relevant operating region (lattice point) of the map is
The average crank angle θPHAX is calculated for each cylinder by averaging the crank angles oPHAX for each cylinder.

Next, in step 105, the average crank angle XAV for all cylinders is determined by summing and averaging the average crank angles OPHAXAV determined for each cylinder.

Thereafter, in step 106, the all-cylinder average crank angle XAV obtained in step 105 and the step 10
Find the difference Δθ for each cylinder from the cylinder-specific average crank angle oPHAXAV found in step 4 (2θ-IXAV-θPHAX
AVI).

Then, in step 107, the above difference -〇 is compared with a preset reference value ΔD, and Δθ</! In the case of U.D.
Step 1 without modifying the ignition timing IGT stored in the corresponding operating area of the ignition timing map M P IG.
13 to reset the τ count (τ-0) and end the program.

Further, if it is determined in step 107 that Δθ≧ΔD, the process proceeds to step 108, and the average crank angle θ for each cylinder is
Compare PHAXAV with the average crank angle XAV of all cylinders, and if θPHAXAV>
It is given to Δ■9 and updated (ΔI(1=zIO+α)).

In addition, in the case of θPHAXAV≦X8V, find the u-angle correction amount β according to the difference, and use that value as the ignition timing correction tItJ
io and updates it (ΔIg=ΔI(1+β).

Then, in step 111 and step 112,
The ignition timing IGT stored in the corresponding operation area of the ignition timing map M P IG is set in step 109゜11.
The ignition timing correction amount Δ10 found at 0 and the basic ignition timing! 6■
Update by the sum of 8 to find a new ignition timing IGT,
Thereafter, in step 113'r--the count value of the .tau. counter is reset (.tau.--), and the program ends.

[Effects of the Invention] As explained above, according to the present invention, the ignition timing is determined by comparing the average crank angle for each cylinder, which is obtained by averaging a predetermined cycle of crank angles indicating the maximum in-cylinder pressure, with the average crank angle for all cylinders. The correction amount is calculated for each cylinder, the basic ignition timing is corrected using this ignition timing correction group for each cylinder, and the actual ignition timing is calculated for each cylinder, so combustion variations between each cylinder,
In other words, the variation in the crank angle, which indicates the maximum cylinder pressure, is reduced, resulting in stable output characteristics, improved total engine output, lower fuel consumption, and a quieter engine by suppressing engine vibration. It has excellent effects such as the ability to control the optimum ignition timing for each cylinder, which is suitable for high-performance engines.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic diagram of the main parts of the engine, FIG. 2 is a schematic plan view of the engine, FIG. 3 is a sectional view taken along the line ■-■ of FIG. 2, and FIG. 3 is a cross-sectional view taken along line IV-IV in FIG. 5, FIG. 5 is a block diagram of the control means, FIG. 6 is a diagram without an ignition timing map, FIG. FIG. 8 is a flowchart showing the control procedure of the control means. 2a to 2d...Cylinder, 7...Cylinder pressure sensor, 18.
... Crank angle sensor, 22 ... Basic ignition timing setting means, IGT ... Ignition timing, 23 ... Crank angle detection means for each cylinder, 25 ... Average crank angle sensor stage for each cylinder, 26 ... Means for determining average crank angle for all cylinders, 27...
・Cylinder-specific ignition timing correction amount determination means, 28... Ignition timing calculation means, N... Engine rotation speed, P HAX...
Maximum cylinder pressure, Q...Intake air amount, XAV...Average crank angle for all cylinders, ΔI(+...Ignition timing correction amount, θP
HAX...Crank angle, θPHAXAV...Average crank angle by cylinder, τ...Predetermined cycle. Figure 3 5h Figure 4 Figure 6 Figure 7 Low angle

Claims (1)

[Claims] Basic ignition timing setting means for setting the basic ignition timing based on the engine operating range determined by the intake air amount and engine speed; cylinder-specific crank angle detection means for detecting the crank angle indicating the maximum cylinder pressure for each cylinder based on the output signal of the cylinder pressure sensor; Cylinder-by-cylinder average crank angle calculating means for calculating the cylinder-by-cylinder average crank angle, and all cylinders calculating the average crank angle for all cylinders by averaging the average crank angles of each cylinder calculated by the cylinder-by-cylinder average crank angle calculating means. The average crank angle calculation means compares the average crank angle for each cylinder calculated by the cylinder average crank angle calculation means with the average crank angle of all cylinders calculated by the all cylinder crank angle calculation means, and corrects the ignition timing. a cylinder-by-cylinder ignition timing correction amount calculating means for calculating the amount for each cylinder; and ignition timing calculation means for calculating actual ignition timing for each cylinder.