JPS6035159A - Fuel control device of electronic fuel injection engine - Google Patents

Abstract

PURPOSE:To high accurately inject fuel to be increased when an engine is accelerated, by applying a fuel increase pulse to any one of the fuel injection valves when the engine is accelerated, in the case of a fuel control device which provides the fuel injection valve respectively in a plurality of intake passages independently opened to each combustion chamber. CONSTITUTION:In the case of a fuel control device which provides a plurality of intake passages B, B independently opened to each combustion chamber A and respectively has fuel injection valves C in each of the intake passages B, an injection amount increase pulse is applied from an increase pulse applying means E to either one of the fuel injection valves C or C when an acceleration detecting means D detects acceleration by a throttle valve opening speed or the like. The increase pulse applying means E is formed so as to output, when an engine is accelerated, an acceleration fuel increasing temporary pulse having a pulse width corresponding to an engine speed and intake negative pressure or the like and different from a basic pulse width. In such way, an injection amount accurately corresponding to a pulse width of the applied fuel increase pulse can be obtained by injecting a relatively large amount of fuel from one injection valve C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronic fuel injection engine, and more particularly to a fuel control device for an engine in which a plurality of intake passages are provided for each combustion chamber.

(Prior art) For example, according to Japanese Patent Application Laid-Open No. 57-93626, a first intake boat and a second intake boat are provided which open independently in the combustion chamber of each cylinder, and a second intake boat is provided. An engine is shown with a two-intake boat and a shutter valve. At low speeds or low loads, the shutter valve is closed and intake air is supplied to the combustion chamber only from the first intake boat, thereby increasing the flow velocity of the intake air and improving its miscibility with fuel and ignitability. Also, at high speeds or high loads, a large amount of intake air can be supplied by both the first and second intake boats. In such an engine, as shown in the above-mentioned publication, fuel is usually supplied by a fuel injection valve installed in the first intake boat. In some cases, fuel injection valves are installed on both of the second intake boats.

By the way, when fuel is supplied by a fuel injection valve like the above-mentioned engine, by applying a pulse signal to the fuel injection valve with a pulse width that corresponds to the rotational speed of the engine and the intake negative pressure, it is possible to Increase/decrease control of the fuel injection amount is performed. However, with this type of engine control, the fuel injection amount increases only by the amount corresponding to the increase in suction negative pressure during acceleration, resulting in a fuel shortage and the problem that the required acceleration performance cannot be obtained. arise. Regarding this problem, for example,
As disclosed in the 7931 Q publication, during acceleration, in addition to the basic pulse with a pulse width corresponding to the rotation speed and intake negative pressure, an extraordinary pulse is applied to the fuel injection valve to compensate for the increase in intake negative pressure. An attempt has been made to increase the acceleration performance by 1 by injecting more fuel than the corresponding amount.

However, in the case of an engine in which each combustion chamber is provided with a plurality of intake ports as described above, and in particular in the case of an engine in which each intake boat is provided with one fuel injection valve, the above-mentioned The problem of how to control the increase in the amount of fuel injection during such acceleration is most preferable in terms of combustibility and the like has not been resolved.

(Object of the Invention) The present invention solves the above-mentioned problems in a fuel injection engine with a fuel injection system having a plurality of intake passages each independently opening into a combustion chamber. In addition, in an engine in which each intake air passage is equipped with a fuel injection valve, the characteristics of the injection amount with respect to the applied pulse width of the fuel injection valve are unstable in the low injection range1. The fuel injection valve is configured to centrally inject and supply fuel, which is sometimes injected more often, by one injection valve. The purpose of this is to accurately control increased fuel injection during acceleration, prevent disturbances in the air-fuel ratio, and obtain good combustion conditions or acceleration performance.

(Structure of the Invention) A fuel control device for an electronic fuel injection engine according to the present invention is configured as follows in order to achieve the above object.

That is, as shown in FIG. 1, in an engine in which a plurality of intake passages B, B each opening independently in the combustion chamber A are provided, and each intake passage B, B is provided with a fuel injection valve C9C, respectively. Acceleration detection means for detecting the acceleration of the engine by, for example, the opening speed of a throttle valve, and when the detection means detects acceleration, one of the above fuel injection valves C1C An increasing pulse applying means E is provided for applying an increasing pulse for injection. During acceleration, this increase pulse applying means E outputs an extraordinary pulse for acceleration increase, in addition to the basic pulse having a pulse width corresponding to the engine speed, intake negative pressure, etc. As a result, the amount of fuel injection m is increased during acceleration, and the desired acceleration performance is obtained, but this increased amount of injection is applied to multiple fuel injection valves 0. Since this is carried out for one of the fuel injection valves C, that injection valve injects a relatively large amount of fuel when the suspension injection Q=1. Therefore, the injection amount accurately corresponds to the pulse width of the applied increase pulse.

In this case, the fuel injection valve that injects the increased amount will be hl 1.
Although it is possible to specify one injection valve, for example, the injector that injects the increased amount may be selected depending on the throttle opening, etc. In that case, the injector that injects the increased amount may be switched during acceleration. However, multiple injection valves do not perform increased injection at the same time.

(Example) Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

-5- As shown in Fig. 2, an engine 1 has a plurality of combustion chambers 2...
2, and each combustion chamber 2 has a 1st, 2nd intake boat 31, 32 and a 1st. Second exhaust boat 41. ．． 42, and each boat 31, 32, 41, and 42 has a first . 2nd intake valve 51.52
and 1st. Second exhaust valves 6+, 62 are provided. Further, an intake pipe 7 is provided on one side of the engine 1, and the intake pipe 7 has a surge tank section 8 and the same number of combustion chambers 2...2 branched from the surge tank section 8. Branch 9
... 9, and each branch part 9 has each combustion chamber 2.
The above-mentioned No. 1. The first intake boats 31 and 32 communicate with the second intake boats 31 and 32, respectively. A second branch 91.92 is provided. As a result, the first nozzle tank section 8 and each combustion chamber 2 are connected to each other. A second intake passage 101, 102 is formed.

Further, a shutter valve 11 is provided on each second intake passage 102 to close the second intake passage 102 when the load is low, and a shutter valve 11 is provided on each first intake passage 101 to shut off the second intake passage 102.
And each of the second intake passages 102-6- and 102-6 are located downstream of the upper h11 and ivy valves 11, respectively. 9, where the second fuel injection valves 121 and 122 are installed, and these fuel injection valves 121112
2, the control unit 13 applies first and second pulse signals 'J8 + and S2, respectively, and when the signals are applied, the injection valves 12t and 122 inject the fuel in the bales corresponding to the pulse width of the applied pulses into the intake passage. 10+ and 102, respectively. In that case, the -1- control unit 13 receives a signal S3 from the intake negative pressure 14 installed in the supply tank section 8 of the intake pipe 7.
and a throttle opening sensor 16 that detects the opening of the throttle valve 15 provided at the original position in the surge tank section 8.
No. 13 S4 from the 5L engine 1, a crank angle signal S5 from 17 that detects the crank angle of the 5L engine 1, and an idle switch 1 that detects the idle state of the engine 1.
These signals @83~S
6, the output timing and pulse width of the pulse signals S1 and S2 are determined.

Incidentally, on the side opposite to the side where the intake pipe 7 of the engine 1 is provided, there is a first.
An exhaust pipe 19 is provided that joins the exhaust gases discharged from the second exhaust boats 41, 42.

Next, the operation of the above embodiment will be explained.

The control unit 13 is constituted by a microcomputer and executes a background routine shown in FIG. 3 and an interrupt routine shown in FIG. 4.

The interrupt routine shown in FIG. 4 starts execution when the engine 1 reaches a predetermined crank angle (for example, 60 degrees before top dead center of a specific cylinder) based on the signal @S5 from the crank angle sensor 17, and first Based on the signal $5, step P1. P2 calculates the engine speed, and
At step P, 3, the signal S3 from the intake negative pressure hinger 14 is
Detects intake negative pressure. Next, in step P4, from two maps in which pulse widths corresponding to the engine speed and intake negative pressure are set in advance as shown in FIG. - 8 - 1. Read the pulse width of the basic pulse x 1 and the second basic pulse x 2, and have the injection timing in step P5. Then, step P6 is executed when a predetermined injection timing (for example, top dead center of a specific cylinder) comes, and the first . The second basic pulse x 1° x 2 is the pulse signal S t
, S 2 as the first. Second fuel injection valve 121.122
are applied respectively. As a result, each fuel injection valve 121, 1
22, fuel is injected into the intake passages 101 and 102 at a rate corresponding to the rotational speed of the engine 1, intake negative pressure, etc.

In that case, if the load is below a certain level and the ivy valve 11 in the second intake passage 102 is closed, as shown in FIGS. Since the region where the intake negative pressure is below a certain level in the map for the second basic pulse shown in FIG. is set so that it will not be sprayed.

Therefore, the above-described interrupt routine shown in FIG. 4 is executed with the background routine temporarily stopped when a predetermined time comes during the execution of the background routine shown in FIG. , the background routine is restarted again when execution is finished. Next, this background routine will be explained.

First, this routine initializes the temporary pulse flag T and time counter value t in steps Q+ and Q2, and then sets the throttle opening value indicated by the signal S4 from the throttle opening sensor 16 to A- in step Q3. D-convert. Next, during normal running other than during Sanskrit, steps Q4 to Q6~Q7 are executed, and the time counter ll? J
1 is added to t, and the throttle opening value θ(1) which was A-D converted in step Q3 is stored using the added counter value t as a parameter. Then, by repeating this routine a predetermined number of times, when t>α (α: an integer of 1 or more) is reached, steps Q8 to Q9
Execute the throttle opening value θ(1) at that time and the throttle opening value θ(-α) α times before to calculate the throttle tl.
Calculate the average rate of change S-10--(θ(t)-1/(t-α))/α for n degrees, and when this is greater than the set value β, set the temporary pulse flag T to 1 in step Qto. Out. When this flag T is set to 1, steps Qt+ to Q+2 are executed, and fl11iltM pulse x 1' is sent from the J: sea urchin control unit 13 to the first fuel injection valve 121 as shown in FIG. 6(e). Output. As a result, as shown in FIG. 6(a), the throttle opening increases at a gradient of more than a certain level.1.5, that is, during acceleration, the first fuel injector
21 temporarily injects fuel, and the acceleration booster fuel is supplied into the first intake passage 101. Then, after the control unit 13 outputs the temporary pulse x1',
Step Q13° In Q10, the temporary pulse flag -1 is reset to 0, and the time counter 1iCit is cleared.

Here, the calculation or determination of the average rate of change of the throttle opening in step Q9 is performed only when the time counter value t>α in step Q8, because the cycle is extremely well known. This is because it is difficult to accurately read the rate of change in throttle opening. Furthermore, the reason why the time counter value t is cleared in step Q14 after outputting the temporary pulse x 1' is because even if the acceleration state continues, if the temporary pulse is output for each cycle, fuel will be oversupplied. This is because the temporary pulse x 1
' is output to Callan 1. When the value t exceeds α again from O, the average rate of change is calculated, and only if the acceleration state continues at that point, the next temporary pulse x 1 is output. ′ is output.

However, since the counter value 1 is not cleared when b is determined to be β in step Q9, the calculation and determination of the average rate of change in step Q9 is performed every time until b≧β.

Furthermore, when starting, the idle switch 18 is turned from ON to OFF.
A signal @S6 indicating this is input to the control unit 13. At this time, the control unit 1
Step 3 executes steps Q4 to Q5 for one cycle immediately after the switch 18 is switched, and sets the temporary pulse flag T to 1. Therefore, Fig. 6(e)
As shown in the figure, the average rate of change in throttle opening is the set value β.
Even in the case of -12- below, an extra pulse x1'' is applied to the first fuel injector 121 to perform increased injection.In that case, the idle switch 18
If the vehicle is to detect a steering operation from open to open, an extra pulse of 1" will be output not only when the vehicle starts, but also when the accelerator pedal is depressed during driving.

Incidentally, the characteristics of the injection amount with respect to the applied pulse of the fuel injection valve generally exhibit a tendency as shown in FIG. In other words, in a region where the applied pulse width is relatively large, an amount of fuel that accurately corresponds to the pulse width is stably injected, but in region B where the applied pulse width is small, it is difficult to control the injection. is difficult, and the characteristics become unstable.

However, as described above, since the increased injection amount during acceleration by the temporary pulse x 1' is performed only for the first fuel injection valve 121, the pulse (temporary pulse) x 1' is applied, and the injection amount corresponds precisely to the pulse width, resulting in darkness.

= 13 - Also, as in this embodiment, regarding the first fuel injection valve 121 installed in the first intake passage 101 for low angle loading when the shutter valve 11 does not leak the increased injection amount during acceleration. If this is done, since the first intake passage 101 has a narrow flow path area and therefore the flow rate of intake air is high, the increased amount of fuel during acceleration will be supplied to the intake air with a high flow rate. Fuel will be quickly supplied to the combustion chamber.

Therefore, good acceleration response can be obtained. In addition, since the first intake passage 101 is always open regardless of the magnitude of the load, as in the case where the fuel injection valve 122 on the second intake passage 102 injects an increased amount, the opening of the shutter valve 11 is delayed and the amount increases. There is no problem that the injected fuel is not supplied to the combustion chamber.

On the other hand, if there is no risk of delay in opening the shutter valve 11, the second fuel injection valve 122 on the second intake passage 102
It is also possible to increase the amount of fuel injection at the time of acceleration. In that case, the second intake passage 10 occupies most of the total intake air amount.
Since the increased amount of fuel is injected into the large amount of intake in the combustion chamber, a mixture close to the required air-fuel ratio is formed in advance before the nuclear fuel is introduced into the combustion chamber. The final air-fuel mixture formation in the room will be advanced by 11 steps.

Furthermore, it is also possible to switch the fuel injection valve that injects an increased diameter during acceleration, depending on the load, for example. Next, an example in this case will be described.

In this embodiment, the control unit 13 executes the rebackground routine shown in FIG. 8. Steps R1 to R9 in this background routine are the same as the routine shown in FIG. 3. However, The first fuel injection valve 121 as a temporary pulse flag
The first temporary pulse flag T1 for the second fuel injector 122
A second temporary pulse flag 12 is provided, and a first temporary pulse flag T1 is set to 1 in step R5. Therefore, when the idle switch 18 is switched from ON to OFF, an extraordinary pulse y1'' is output to the first fuel injection valve 121 as shown in FIG.
From = 15 - an increased amount of fuel is injected into the first intake passage 101 . This is currently the second
This is because the shutter valve 11 of the intake passage 102 is closed.

However, during normal acceleration, if it is determined in step R9 that the average rate of change between the throttle angle and the throttle angle is greater than or equal to the set value β, then step R+ is performed.

Then, it is determined whether the throttle opening degree θ(1) at that time is greater than or equal to the set value 1. Then, if θ(t)<γ, the first m-hour pulse flag T1 is set to 1 in step R11, and if θ(1)≧γ, the second temporary pulse T2 is set to 1 in step Rt2. Ru.

If the first temporary pulse flag T1 is 1, further step R
13 to Rt6 are executed, and as shown in FIG. 9(b), the first temporary pulse y1' is output to the first fuel injection valve 121, and an increased amount of fuel is injected into the first intake passage 10t. On the other hand, if the second temporary pulse flag T2 is 1, steps 1<17 to R2o are executed, and as shown in FIG.
The second temporary pulse V2' is outputted to the second fuel injection valve 122 as shown in FIG.

-16- Therefore, as shown in Fig. 9(a), the throttle opening is set to 4? ) When accelerating to change from a state below γ to a state above 1, the first. The second fuel injection valves 121 and 122 sequentially perform increased injections, and while the throttle opening is small, increased amounts of fuel are injected into the high-speed intake of the first intake passage 101 at J:, and lζ fuel quickly enters the combustion chamber. When the shutter valve 11 is fully opened and the throttle opening is large, the increased amount of fuel is supplied to a large amount of intake air flowing through the second intake passage 102, promoting the formation of an air-fuel mixture. will be done.

In this case, b, 1st. Second fuel injection valve 12'l
, 122 do not inject at the same time to increase the amount, so the increase injection occurs in the region 14Aτ where the injection amount characteristics are stable as shown in FIG.
``It will be done.'' In addition, in the embodiment shown in FIG.
3, an intake pipe 7 having a surge tank portion 8 is used; in this case, the length and cross-sectional area of each intake passage 101, 102 can be set appropriately, and the intake inertia It is possible to improve the filling efficiency by effectively utilizing this.

-17- (Effects of the Invention) As described above, according to the present invention, there is provided an electronic engine which has a plurality of intake passages each independently opening into a combustion chamber, and each intake passage is equipped with a fuel injection valve. In fuel-injected engines,
Since an increasing pulse is applied to any one of the fuel injection valves during acceleration, that injection valve injects an amount of fuel that corresponds precisely to the pulse width of the applied pulse (1) J =l. This prevents disturbances in the air-fuel ratio when increasing the amount of fuel for acceleration, resulting in stable combustion and good acceleration performance.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of the present invention, Fig. 2 is a system diagram showing an embodiment of the present invention, Figs. 3 and 4 are flowcharts showing the operation of the embodiment, and Fig. 5 is used in the embodiment. FIG. 6 is a time chart showing the operation of the embodiment, FIG. 7 is an injection amount characteristic diagram of the fuel injection valve, and FIG.
The figures are a flow chart and a time chart showing the operation of another embodiment. -18- A (2)... Combustion chamber B (101, 102>... Intake passage C (12+, 122)... Fuel injection valve 1) (16)
... Acceleration detection means (throttle distance center) E (13) ... Increased pulse application means (roll unit i to controller 1) -19- 3rd circle or tart T=OQ1 t=0 02-tt, , Opening A-D ψ agent id Iless N. ON ◆ OFF EST ← 1 t4- t+1 Mata Rozukai open eyebrows-e(t)ki/horse. 7 11 Showa 6O-35159 (8) 4th Figure 1□ 8th JP-A Showa GO-35159 (10)

Claims (1)

[Claims] (1) A plurality of intake passages each independently opening into the combustion chamber, a fuel injection valve installed in each intake passage, an acceleration detection means for detecting acceleration of the engine, and the acceleration detection means detects acceleration. 1. A fuel control device for an electronic fuel injection engine, comprising: an increasing pulse applying means for applying an increasing pulse of injection amount to any one of the fuel injection valves when the injection amount increases.