JPS5977045A - Fuel supply control method of internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance the rate of fuel consumption and the performance of exhaust gas purification of an internal-combustion engine of variable suction type in swirling system, in which each cylinder is equipped with two suction passages, by changing the fuel injection timing between the period while the combustion is made in layers and the period otherwise. CONSTITUTION:Cylinder head 1 is equipped with two suction 3, 4 and two exhaust 5, 6 valve per combustion chamber 2, i.e. per cylinder, and No.1 and No.2 suction passages 7, 8 are provided in communication with said suction valves 3, 4. The two suction passages 7, 8 shall converge in the neighborhood of the terminal with a suction manifold 9 and be put in connection with this suction manifield 9. Also the suction passages 7, 8 are formed as a helical suction passage and a straight suction passage, respectively, and No.2 suction passage 8 thereof is equipped with a suction gas control valve 10. While the number of revolutions of the engine is below a certain level and the suction gas control valve 10 is being closed, the fuel is injected in No.1 suction passage from fuel injection valve 11 in the middle or later stage of the suction stoke.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply control method for an internal combustion engine used in a vehicle such as an automatic 71i, and particularly to a method for controlling the fuel supply of an internal combustion engine that has an intake control valve and selectively controls a relatively strong intake stool. The present invention relates to a fuel supply control method for an internal combustion engine having a so-called variable intake swirl type intake boat structure.

Various types of variable intake swirl type intake ports have been proposed in the past, each having an intake control valve and configured to selectively generate a relatively strong intake swirl. The intake passage and the second intake passage are arranged so that a relatively strong intake swirl is generated only when the second intake passage is selectively closed by an intake control valve. The variable intake swirl type intake port structure of this scale is, for example, published in JP-A-IN! 53-12'7
No. 914 and Japanese Unexamined Patent Publication No. 57-105534 Niifi, and was also proposed in Japanese Patent Application No. 51149-1982 and Japanese Patent Application No. 120634-1981.

In an internal combustion engine that has an intake port structure configured to generate a relatively strong intake swirl.

When a relatively strong intake swirl is occurring, fuel is supplied into the combustion chamber in the latter half of the intake stroke, resulting in stratified intake along the direction of piston movement in the combustion chamber, and stratified combustion causes the mixture to reach the lean limit. It also increases the mechanical octane rating of internal combustion engines.

Stratified combustion is carried out by supplying fuel into the combustion chamber in the latter half of the intake stroke only when a relatively strong intake swirl is generated in the combustion chamber. In an internal combustion engine with an intake port structure, stratified combustion occurs if fuel is supplied into the combustion chamber in the latter half of the intake stroke only when the intake control valve is closed; When fuel is supplied into the combustion chamber in the latter half of the intake culm, stratified combustion does not occur.

In the injection supply of fuel r1, if the fuel used is a liquid fuel such as gasoline or gasohol, the fuel is supplied to the internal combustion engine 1 [J,
Or, in order to be heated by the heating means built into the intake boat, the -th intake stroke is completed (after the intake valve opens and the next intake stroke is started (as soon as possible). It is preferable that the injection is supplied to the intake passage at the same time.For this reason, in an internal combustion engine equipped with the variable intake swirl type intake port structure as described above, the intake control valve is injected into the intake passage at the same time as when it is open and when it is closed. Similarly, if fuel is injected in the latter half of the intake stroke, stratified combustion will not occur and fuel vaporization will be poor.
DI of deterioration of fuel efficiency and increase of unburned components in exhaust gas
It produces a better effect.

In an internal combustion engine that uses the intake port structure of the variable intake swirl 6 type as described above, there are two cases in which stratified combustion occurs due to the generation of a relatively strong intake swirl and two cases in which stratified combustion occurs without a relatively strong intake swirl. The fuel injection timing is switched and set according to the optimal fuel injection timing, which differs depending on when no combustion occurs.
When stratified combustion occurs, good stratified combustion occurs, and when stratified combustion does not occur, the fuel vaporizes well, reducing fuel consumption and reducing unburned components in IJI gas. The purpose is to provide a fuel supply control method.

According to the present invention, one cylinder has a first intake passage and a second intake passage, and the second intake passage is selectively closed by an intake control valve. (In a fuel supply control method for an internal combustion engine having an intake port structure configured to generate a relatively strong intake stool only when the intake stool is The fuel is injected and supplied to the first intake passage in the first to later stages, and when the intake control valve is open, the fuel is supplied to the first intake passage at a time other than the latter half of the intake culm. This is achieved by a fuel supply control mjj method in which fuel is injected and supplied toward at least one of the first intake passages -h.

The internal combustion engine used in the vehicle of own m fir W is often a so-called ρ cylinder internal combustion engine that has multiple cylinders, and in this case, when the intake control valve is closed, the Independent If; T fill kl fuel 0
・It is a so-called independent patrol that performs 1, and this fuel r3 + 11r
The t-river period is the middle to the latter half of the intake stroke of each cylinder. When the intake control valve is closed, [Noru Fuel II's Moeho for UEi is n7 depending on the fuel injection amount per stroke and the engine speed so that injection ends immediately after the end of the intake stroke.] It would be nice if it could be changed. This fuel injection start timing control is described in Japanese Patent Application No. 121182/1982 filed by the same applicant as the present applicant.
The liquid fuel supply method according to the present invention may be carried out in the same manner as the supply method disclosed in this patent application.

The fuel injection timing when the intake control valve is open is as early as possible for the next intake stroke after the - intake stroke is completed and the intake valve is closed to promote fuel vaporization. Therefore, the most preferable fuel injection timing at this time is immediately after the intake valve closes Iζ. In a multi-cylinder internal combustion engine, if independent injection is performed even when the intake control valve is open, the settings for each cylinder will be the same, but if fuel is injected and supplied to each cylinder all at once, the so-called , - In the case of simultaneous injection, and in so-called group injection, in which each cylinder is divided into groups and each cylinder is injected at the same time, the same engine operation is applied to each cylinder. It’s time to travel! ! Although it is not possible to inject fuel into the cylinder, for most of the cylinders, the timing is favorable for promoting fuel vaporization.
That is, it is possible to set the fuel injection timing so that at least the fuel is injected at a time other than the latter half of the intake stroke. J' is [r of fuel 1 when the intake control valve is open and C is
The timing of loJ Ili' may be set to the same timing as the ignition timing based on the ignition timing JIIJ fii No. 9 to facilitate control for determining the timing of the ignition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in accordance with embodiments with reference to the accompanying drawings.

1 to 3 are schematic diagrams showing the cylinder portion of a spark ignition internal combustion engine suitable for implementing the fuel supply control method according to the present invention. The internal combustion engine shown in FIGS. 1 and 2 has one combustion chamber (cylinder) 2 in a cylinder bed 1. It has one intake valve 3.4 and two exhaust valves 5.6 at fQ. Intake valve 3 in cylinder head 1
A first intake passage V87 and a second intake passage 8, which are connected to the intake manifold 9 and the intake manifold 9, are numbered. is connected to. In the embodiment shown in FIG. 1, the second intake passage 7 is configured as a helical intake passage, and in the embodiment shown in FIG. 2, it is configured as a biased intake passage. 8i′! , T- is constructed as a straight intake passage in both the embodiments shown in FIGS. 1 and 2.

The cylinder head 1 is provided with an intake control valve 10 that selectively opens and closes an opening 11 of the second intake passage 8. The intake control valve 10 is illustrated so as to close when the intake air amount and the engine speed are each above a predetermined value, and to open when the intake air amount is above a predetermined value or the engine speed is above a predetermined value. (See Chapter 6, Section 1).

When the intake control valve 10 is closed, the first intake passage 7
After that, air is taken only through the intake valve 3, and in this state, the intake air generates a relatively strong intake swirl in the combustion chamber 2. On the other hand, when the intake control valve 10 is open, air is taken in from both the intake valves 3 and 4 via the first and second intake passages 7 and 8, and in this state, a strong intake air flows into the combustion chamber 2. Although no swirl occurs, intake resistance is low and intake is performed with high filling efficiency.

Further, a fuel fl+ injection valve 11 is attached to the cylinder head 1, and this fuel injection valve 0/1 valve '11 injects gasoline toward the branching part of the first intake passage 7 and the second intake passage 8. J, sea urchin C, which sprays liquid fuel like this.

The internal combustion engine shown in FIG. 13 has a cylinder head 1, one combustion chamber 2fi3, one intake valve 12 and one exhaust valve'.
The cylinder head 1 is provided with an intake passage 14 that communicates with the intake valve 12, and the intake passage 14 is provided near the intake valve '12! The ζ guide vane 15 is divided into a straight intake passage 16 and a straight intake passage 17.
It is opened and closed by an intake control valve 10.

Also in the internal combustion engine shown in FIG. 3, the intake control valve 10 is connected to the intake control valve 10 shown in FIGS.
Since the opening and closing control is performed in the same manner as in 10, intake air is performed in the same manner as in the internal combustion engine shown in FIGS. 1 and 2.

In FIGS. 2 and 3, reference numeral 18 indicates a spark plug, and reference numerals 19 and 20 indicate exhaust passages.

The fuel supply according to the present invention is of an injection type using a fuel tq injection valve 11, and the fuel injection timing is set to y (appropriate fuel such that This is a liquid fuel supply method that switches settings depending on the injection timing.

FIG. 4 is a block diagram illustrating one embodiment of a control system used to implement the fuel supply 911 method according to the present invention. Fuel injection control is performed using a micrometer beater 21. The microphone 1 computer 21 receives information regarding the internal combustion engine's crank angle, reference crank angle, and cylinder discrimination from the crank angle sensor 4J 22 and the air flow meter 23.
Information regarding the intake air m is inputted from the ignition system 24, and information regarding the arrival of the ignition timing is inputted from the ignition system 24, and the fuel injection length (fuel injection time) and the fuel I'l are inputted according to these information.
lOJ IIY III is calculated and determined, and an injection signal based on this is output to the fuel injection valve drive circuit 25, and an opening/closing control signal for the intake control valve 10 is output to the intake control valve control neck 26. ing.

Fig. 5 shows a method of controlling the supply of fuel 1'11 according to the present invention.
FIG. In the embodiment shown in FIG. 5, fuel 131 is injected independently for each cylinder whether the intake control valve 10 is closed or open, and When the intake control valve 10 is closed, fuel injection ends before the intake stroke ends; when the intake control valve 10 is open, fuel injection starts immediately after the ignition timing arrives. is set to be

The flowchart shown in FIG. 5 has an interrupt routine C depending on the ignition timing and a predetermined crank angle, and is repeatedly executed when the Nij ignition timing arrives and at every predetermined crank angle. This interrupt routine is initialized by setting each -flag to 0 when the power is turned on to the microphone combination 21, and then starts at step 1.

In step 1, the engine speed N detected by the crank angle sensor 22 and calculated based on the Ic crank angle and the intake air gap detected by the air flow meter 23 are read.

Next, in step 2, intake air IQ/engine speed N
From this, the fuel injection time τ per stroke is calculated.

Next, in step 3, it is determined whether the currently executed interrupt routine is an ignition timing interrupt.

If it is an ignition timing interrupt, the process proceeds to step 5 via step 4, whereas if it is a constant rank angle interrupt and not an ignition timing interrupt, the process directly proceeds to step 5.

In step 4, flag E:1 is set to 1. ,
This flag F+ is one time fuel 1. After the Q shooting, the Sadakasuke period arrived, and the flag showed how old it was.

Next, in step 5, it is determined whether the engine speed N is smaller than a predetermined value N1. , N-2N+, the process proceeds to step 6, and when it is not N.'NI, the process proceeds to step 19.

In step 6, the intake air ff1Q reaches a predetermined value Q+
A determination is made as to whether or not it is smaller than that. When Q-01, proceed to step 7, and when Q<Qt'<>, t
Proceed to J Sun' - Tubu 19.

In step 7, the flag [I! It is determined whether or not is 1. This flag 1:2 is intake control a1
This flag indicates the opening/closing of one valve 10, and the flag F2=
When the flag F2 is not 1, the process proceeds to step 8, and when the flag F2=1, the process proceeds to step 10.

In step 8, a valve-closing command signal for closing the intake control valve 10 is output to the microphone coater 21J, intake control valve controller 14A, and 26. The closing region of the intake control valve 10 is shown in FIG.

After step 8, the process proceeds to step 9, in which C sets the flag [2 to 1 and proceeds to the next (-step 10).

Ste. In the knob 10, it is determined whether the flag 1"-3 is 1 or not. The flag 13 is the intake control valve 1.
This is a flag indicating whether or not the ignition timing has arrived when the valve 0 is open, and whether or not fuel injection has been completed during the same engine working stroke. If the flag F+1 is not 1, the process proceeds to step 11, and for the poem in which the flag F3=1, the process proceeds to step 17.

In step 11, the engine speed N and the fuel injection time τ
Thus, the fuel injection start crank angle θ is determined. This fuel injection crank angle θ is set so that the fuel injection ends at a constant crank angle regardless of the length of the fuel injection time τ, that is, the crank angle immediately before the end of the intake stroke. θ becomes smaller as the fuel injection time τ becomes longer and as the engine speed N increases.

After step 11, the process advances to step 12, and in this step, the fuel injection start crank angle θ determined in step 11 is determined.

After step 12, the process proceeds to step 13, in which the crank angle OA detected by the crank angle calibrator 22 is read.

After step 13, the process proceeds to step 1/I, and in step 14, it is determined whether or not the crank angle CA is the fuel injection start crank angle θ. When it is CA-○, it advances to Stella 115, and when it is not CA-○, it is reset.

In step 15, an injection signal is output from the microphone monitor 21 to the fuel injection valve drive circuit 25.

As a result, the fuel injection valve 11 starts fuel injection when the crank angle CA is θ, and ends the fuel injection when the fuel injection time τ has passed M from this point. The end of this fuel injection is just before the intake valve closes. That is, the intake control valve 1 (
) is closed, fuel injections 0 and 1 are performed in the middle to late stages of the intake stroke.

After step 15, the process advances to step 16, and in step 16, flag 1:1 is set to O.

At step 10, the flag [3-1, proceeding to step 17 (■), Y indicates a time when fuel injection has already ended after the ignition timing has arrived in the same engine operating stroke, and at this time, there is no overlap. Avoid +1Q use (Step 1
In step 17, it is determined whether the flag [+ is 1 or not. .

When the flag is not F1-1, it is reset, and when the flag F is 1, the process proceeds to step 18, in which the flag [a is set to 0, and then it is reset.

When you advance to step 1 from step 5 or 6,
This is the time to open the intake 11i'J lit valve 10, and in step 19, it is determined whether the flag F2 is 0 or not. When the flag is not Fp-0, the process proceeds to step 20, and when the flag is Ft-0, the process proceeds to step 22.

Step 20k-In the microcomputer 21
A valve closing command signal is output to the intake control valve control unit RF26. This causes the intake control valve 10 to open. The opening region of the intake control valve 1() is shown in FIG.

After step 20, the process advances to step 21, and in this step, flag [2 is set to 0.

In step 22, it is determined whether the flag F'l is 1 or not. When the flag "1" is 1, the process proceeds to step 23, and when the flag is not E-1-1, it is reset.

In the slap 23, (flag) -3 is set to 1, and then the process proceeds to step 15. As a result, the fuel injection valve 21 performs fuel injection when the fuel injection time τ reaches the Uil valve, and injects fuel.In other words, when the control valve 10 is open, the fuel injection valve 21 performs fuel injection immediately after the ffi fuel injection timing arrives. will be held.

Here, I will refer to a specific example of Mikkomei.
Although the present invention has been described in detail, it will be obvious to those skilled in the art that the present invention is not limited thereto, and that various embodiments are possible within the scope of the present invention.

[Brief explanation of the drawing]

1 to 31 each show one cylinder section of an internal combustion engine suitable for implementing the fuel supply control method according to the present invention.
1 is a schematic configuration diagram, FIG. 4 is a block diagram showing one embodiment of a control device used to implement the fuel Fi1 supply control method by Mitsuaki Ki, and FIG. One of the fruits of the fuel supply control method! ! FIG. 6 is a graph showing the valve opening region and the valve closing region of the intake control valve. 1... Cylinder head, 2... Combustion chamber, 3.4...
- Intake valve, 5.6... Exhaust valve, 7... First intake passage, 8... Second intake passage, 9... Intake manifold, 10... Intake control valve, 11.・・Fuel injection valve, 1
2...Intake port, 13...Exhaust port, 14...
・Intake passage, 15... Guide vane, 16... Helical intake passage, 17... Straight intake passage, 18.
...Spark plug, 19.20...Exhaust passage, 21...
・Niku Me” Combikota. 22... Crank angle center, 23... Airf [l meter. 24... Ignition system, 25... Fuel injection valve drive circuit, 2
6...Intake control valve control device

Claims (1)

[Claims] (1) One cylinder has a first and second intake passage and a second intake passage, and the second intake passage is selectively closed by an intake control valve. Fuel supply control of internal combustion 1lrIA to right the intake boat m structure configured to generate a relatively strong intake swirl only when! In method h, when the intake control valve is closed, fuel is injected and supplied toward the first intake passage in the middle to late stages of the intake stroke, and when the intake control valve is open, fuel is injected and supplied toward the first intake passage. A fuel supply control method in which fuel is injected and supplied toward at least one of the first intake passage and the second intake passage at a time other than the latter half of the intake stroke. (2. In the fuel supply control method for an internal combustion engine as set forth in claim 1, the fuel injection supply start timing when the intake control valve is closed is set to immediately before the end of the intake stroke. (3) In the fuel supply control method for an internal combustion engine as set forth in claim 2, the fuel injection supply start timing is set at a constant time. A fuel supply control method characterized in that the fuel bay per stroke is determined according to "11 injection 111;l Hk" and the engine rotational speed. In the method for controlling the fuel supply of an internal combustion engine, which is characterized in that the fuel injection timing is the same as the ignition timing when the intake control valve is open, the fuel supply control method 1゜(5) Patent In the fuel supply control method for an internal combustion engine as described in any one of Claims 1 and 3, when the intake control valve is open, the injection start timing of the fuel v11 is set to the intake air. - A fuel supply control method characterized in that the fuel supply control method is performed immediately after the completion of a stroke.