JPS5820933A - Fuel injection controller - Google Patents

Abstract

PURPOSE:To accomplish a favorable combustion balance, by setting the fuel injection timing at the moment the crank angle of the third cylinder is in the range from an angle of 40 deg. before the bottom dead center to an angle of 60 deg. after the bottom dead center. CONSTITUTION:The frequency of an ignition signal 2 fed from an ignitor 1 which generates 3 ignition signals per two revolutions of the engine is divided by 3 by a frequency dividing circuit 3, and a frequency-divided signal 4 thus obtained causes the fuel to be injected from an injector 7 by an injection timing generating signal 6 obtained through a delaying circuit 5 by which the crank angle of the third cylinder being in the stroke at the time of ignition of the first cylinder is delayed to be in the range from an angle of 40 deg. before the bottom dead center to an angle of 60 deg. after the bottom dead center. Accordingly, since the intake action has been weakened even when the intake valve of the third cylinder is stil open, the intake condition of the third cylinder approaches to those of the two cylinders, the distribution of fuel to each of the cylinders is stabilized, a favorable combustion balance is attained between the cylinders, and exhaust gas characteristics are also enhanced.

Description

[Detailed description of the invention] The present invention is a companion fuel injection control device Km suitable for small cylinder engines.
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Fuel injection control system that injects fuel sound into the intake pipe, generally, the fuel injection amount is 0IIIllllIl, and in order to simplify the control pipe, it is simultaneous at every revolution, for example, in a 6-cylinder engine, one revolution of the engine is necessary to ensure the combustion of all cylinders! Half of the amount was injected, and in the next 11 turns, l! In the case of a 6-cylinder engine, a method is implemented in which the injection timing line is synchronized with the ignition value number O division wave, as shown in Figure 1 (4).
As shown in FIG. 2, a method is often adopted in which the frequency of the ignition signal, which has three pulses per engine rotation, is divided by t-X and used as an injection timing signal. In the case of a 4-cylinder engine, the engine's 1
Since the injection timing signal is obtained by dividing the frequency of the large signal by t% at a certain point in the rotation = pulse, injection can be easily performed at every turn.

If ζro is a 3-cylinder carrot, the company is all! As shown in Figure 1 (IK), the ignition signal is repeated alternately with 2 pulses and 1/(kJ'l) every 11 revolutions of the engine, so the ignition signal changes like a 4-cylinder carrot in a 4G cylinder engine. It is not possible to obtain the injection timing signal in synchronization with the branch wave and perform 1 lil rotation Klfi fuel injection t, so the ignition signal t-, which has 3 pulses in 2 rotations, is frequency divided and 11 fuel injections are performed in 2 rotations. In other words, in a 3-cylinder engine, all the fuel for 1113 cylinders is injected during the 21E rotation of the engine.For this reason, in a 3-cylinder engine, the amount of fuel injected per day is large, and the injection amount is increased. Intake conditions vary greatly depending on whether each cylinder is in the intake, compression, explosion, or exhaust stroke at any given time, and whether the intake valve is open or not, and fuel distribution among the three cylinders is unstable. As a result, the air-fuel ratio for overabsorption increases, leading to an increase in unburned hydrocarbons (He).

The purpose of this engine #0 is to stabilize the fuel distribution pipe between the three cylinders and improve the combustion balance.A fuel injection control device that can obtain a 9% smoother engine rotation state and improve the characteristics of exhaust gas (HC). I'm going to provide an Il meeting.

To achieve the above objective, the fuel injection control wheel th by the present inventor is basically synchronized with the rotation of the engine and generates a large signal at two points during the second rotation of the engine, producing an ignition sound. The fuel pipe is injected within the range of the crank angle of the @S cylinder which is in the intake stroke during the cylinder firing period from 1 degree before the bottom dead center to 0 degrees after the bottom dead center.

Still another configuration is to inject within the above range after detecting that the engine is in a state of idling and deceleration.

According to the above structure, the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings and in comparison with a conventional example.

FIG. 2 is a diagram showing the injection timing and the O-intake valve timing of each cylinder. In Figure 2, the vertical axes (1), (3), and (1, 3, and 2 cylinders, respectively) indicate the ignition order, and the horizontal axis indicates the crank angle. The ignition timing point is 10 degrees before the top dead center of each cylinder under the control of the ignition timing S, which is 10 degrees before the top dead center of each cylinder.
The frequency was divided into − and the injection was performed in synchronization with the point size of the first cylinder. When injecting during the busy firing period of Jllll cylinder 0 (Fig. 2■
(at the time of) Intake valve behavior of each cylinder, the first cylinder is closed during the combustion stroke, the third cylinder is open during the intake stroke, and the second cylinder is closed during the exhaust stroke. It can be seen that there is a large difference between the conditions. Among these, the intake valve is fighting during the fuel injection timing of the 3rd cylinder, so if the fuel is injected when the 3rd cylinder piston descends to near the bottom dead center, the intake operation light will disappear even if the intake valve is wide open. Since it is weakening, the other two cylinders O
It can be seen that the condition approaches the lk person condition (time point J in Figure 2).

Furthermore, the authors of this case conducted experiments to determine the relationship between the delay in injection timing and the exhaust E concentration, and obtained the results shown in #31i&. In Figure #I3, the horizontal axis shows the crank angle, and the vertical axis shows the discharged HC concentration.

Here, it shows the exhaust concentration in the 3rd cylinder, which is the most problematic, but it is % from ignition synchronized injection to bottom dead center.
It can be seen that in trench A, the concavity concentration was high and the combustion state was unstable at ToJP, and after that it stabilized until about 0 degrees after bottom dead center and was burning well.

In the case of a 93-cylinder engine, adjust the fuel injection timing to 'h'.
So cylinder, here #i 3rd cylinder, O If the crank angle is in the range from the beginning before the queen point to the lead after bottom dead center, the intake distribution in the valley cylinder will be stable and the combustion nozzle (lance) will be good. As a result, the exhaust gas characteristics will be revised to 4I.

A detailed explanation of the present invention will be given below with reference to Figure KII4.
FIG. II4 is a 1μ footer showing an embodiment of the fuel injection control device according to the present invention. Point where ignition signal is generated 3 times in 2 revolutions of engine *Init 1 ignition signal 2' is frequency divided (b)
The frequency is divided by % at road 3, and the frequency division signal 4 changes the crank angle of the wi3 cylinder, which is at absorption level 111 at the time of the first cylinder's high point, to within the range of ω degrees after the bottom dead center from bottom dead center 1!140ftP. The structure is such that fuel is injected from the injector 7 based on the injection timing generation signal @IK obtained through the delayed retarding command 5. Here, the line delay circuit 5 is inserted after the frequency divider circuit 3, but since it is attached to the first frequency divider circuit 30111, it is worn out.

Diagram S: In addition to the fuel injection control device according to the present invention, o*xas
t is a diagram of a friend program. O between the three cylinders as mentioned above
Focusing on the fact that the error in air-fuel mixture distribution is large when the load is low, such as when idling or when decelerating, we have developed a system using the Sushi Doshinanana Hatake No. 091 installed on the accelerator pedal or throttle shaft. , it is determined whether the load is light or not. Route 9 is frequency-divided to l111!13 and delay route 5 is provided. When the load is light, the injection timing signal IAK via the delay circuit 5 is used to send fuel from the tine injector 7. is injected, and when the load is not light, the frequency divided signal 4 is used as an injection timing signal without passing through the delay circuit 5, and fuel is injected from the injector 7. In addition, 0 from the 9 negative pressure sensor installed in the light load type 111 ON brush suction pipe.
It is also possible to determine ↓p to No. 11.

As explained in detail above, according to the present invention, 4II!
At the time of A class injection, the ATGS cylinder O crank angle is within the range of 60 degrees from the initial point before the point Wk & is constant, and the intake valve of the 3rd cylinder is open and the suction action is still active. It is weakening and approaching the intake conditions of the other two cylinders,
The intake distribution of each cylinder is stable, and the combustion pattern is Arashiyoshi and TJL.
As a result, exhaust gas characteristics are also improved.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the ignition signal and fuel injection timing, and the figure is the same for the 6-cylinder carrot case (B).
Figure 7 shows the case of a 3-cylinder engine; Figure 3 shows the relationship between injection timing and exhaust HC concentration for the 2nd #A 3-cylinder engine; Figure I4 is a plotter diagram showing an embodiment of the fuel injection control device IO according to the present invention, and Figure jIIls is a plotter diagram showing another embodiment. 1 Ignition device 2 Ignition signal 3 Frequency dividing circuit 4 Frequency dividing signal 5 Delay circuit 藝 Injection timing signal 7 Injector 8 Opening sensor 541a separate i-way top dead center 1 Bottom dead center Patent applicant Suzuki Jidotan Kogyo Co., Ltd. Patent Attorney Hisashi Inoro

Claims (1)

[Claims] (1) After the first rotation KPI period of the engine, 3 rotations after that 2 rotations
In an engine that generates a revolution and ignites,
Fuel injection control is configured to inject fuel within the range of ω degrees O degrees after bottom dead center from the beginning before the queen point to the ignition timing of the I11 cylinder when the crank angle of the 3rd cylinder is in the suction property @. am. Shin) In an engine that synchronizes with the rotation of the engine and ignites 31 ignition 4M4# in its 2nd rotation, it is detected that the engine is idling or in a state of destruction, and the J[1 cylinder Inhalation li & KTo at O ignition timing
9. A fuel injection control device characterized in that the fuel injection control device is configured to inject fuel noisily within a range from a lead angle before bottom dead center to a lead angle of 0iui after bottom dead center.