JPS6035115A - Laminar charging engine - Google Patents

Abstract

PURPOSE:To accelerate atomization and evaporation and improve ignition performance by jetting-out fuel into a spark plug at a prescribed time in the course ranging from the latter half of intake cycle to compression cycle and mixing the air into the jetted-out fuel in the latter half of fuel injection. CONSTITUTION:In an engine in which the primary and the secondary intake ports 13 and 14 and an exhaust port 15 which are opened to the combustion chamber 7 of each cylinder are opened and closed by the primary and the secondary side intake valves 16 and 17 and an exhaust valve 18, a spark plug 20 is installed nearly at the center in the combustion chamber 7, and a fuel injection valve 21 is installed so that the jetted-out fuel is directed towards the spark plug 20. An air injection valve 22 is installed closely to the fuel injection valve 21 so that air is jetted-out in the direction in which interference with jetted-out fuel is generated. In low loaded state, the fuel injection valve 21 is controlled so that fuel is jetted-out at a prescribed time in the course ranging from the latter half of intake cycle to compression cycle, and the air injection valve 22 is controlled so that air is jetted-out in the latter half of the fuel injection period.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a stratified air charge engine that directs fuel towards a spark plug of the engine.

-1- Ten.

(Prior art) Conventional σ) In a general (7-spark JjJ large H5-engine (gasoline engine)), the intake air f1 is adjusted by a throat valve, and the amount of fuel corresponding to the intake air ω is supplied. The air is evenly distributed! The spark plug is ignited in the combustion chamber.

As a first stage for improving output and fuel efficiency in this J: Eel engine, as shown in Utility Model Application Publication No. 54-56006, for example, compressed air is supplied into the combustion chamber during the compression stroke to promote swirling flow. Some are known that increase the combustion rate.

By the way, if there is an air-fuel mixture with an ignitable air-fuel ratio near the spark plug, sufficient combustion is possible even if the fuel is lean in other parts of the combustion chamber. The engine can be operated. Focusing on this point, as a means to significantly improve fuel efficiency, J:
A so-called rib air supply engine is known that injects fuel toward a spark plug at a predetermined timing corresponding to the ignition timing. According to this engine, there is a limit E) in which fuel is supplied near the spark plug to provide the required air-fuel ratio.
1) If lean combustion is possible, even if excessive air is supplied, there will be no difference, so at low loads, it is recommended to use a large comb to polish the 1-throttle valve. This makes it possible to reduce the pumping loss during low angle loads.As a result, it is possible to significantly improve fuel efficiency.

In a stratified air charge engine in which fuel 111 is injected toward the spark plug in this way, at low load, the direction of ignition is 1-
Therefore, it is required to efficiently promote atomization and vaporization of the fuel. In particular, in this case, fuel injected late in the injection period is difficult to atomize by the ignition timing, while fuel injected early is likely to diffuse by the ignition timing. Taking this into consideration, it is desirable to satisfy the above requirements without unnecessary fuel diffusion.

(Object of the Invention) In view of these circumstances, the present invention provides a stratified air supply engine that directs fuel to the spark plug at a predetermined timing at least when the load is low. By actively atomizing and vaporizing the fuel described in "Odor - C1", it is also possible to avoid the situation where the fuel R1, which flows into the mouth before the injection period, is unnecessarily diffused and becomes lean (J1 16b with the purpose of improving the ignition of bamboo.

(Structure of the Invention) The stratified air supply Y engine of the present invention includes a fuel injection valve disposed in the direction t-1 to the spark plug of the engine, and the fuel 1111'l
An air injection valve that injects air in a direction that interferes with the nozzle port 1 fuel r1 from the injection valve, load detection means that detects the load state of the engine, and crank angle detection means that detects the crank angle of the -L engine. , a fuel P1 control means, and an air control means. The fuel F1 injector is controlled so that fuel is injected at a predetermined time in the compression culm from the latter half of the stroke, and the air control means controls the air so that the air is injected in the latter half of the fuel injection period. The configuration is one in which the injection valve is controlled.

As long as the above requirements are satisfied, the fuel injection valve and air injection valve may be provided in the combustion chamber () or may be provided in an intake boat near the combustion chamber.

(Embodiment) Fig. 1 schematically shows an embodiment in which the present invention is applied to a 4-cylinder 4-cycle engine. It shows the structure of In these figures, 1 is the engine body, 21 is an intake passage consisting of an intake pipe 3 and an intake manifold 4, 5 is an air cleaner installed in the 1st flow part of the intake passage 2, and 6 is an exhaust manifold. In the embodiment shown in the figure, a primary intake passage 8 and a secondary intake passage 9 are provided in the intake manifold 4 for each combustion chamber 7 of each cylinder of the engine body 1, and the secondary intake passage 9 is provided with a primary intake passage 8 and a secondary intake passage 9, respectively. A swirl control valve 10 is provided to adjust the opening degree of the passage 9. The operation of this swirl control valve 10 is controlled by control units 1 to /I, which will be described later.
-0, it is controlled via the actuator 11.

The combustion chamber 7 of each cylinder includes a primary intake port 13 communicating with the secondary intake passage 8, a secondary intake port I/14 communicating with the secondary intake passage 9, and an exhaust port 1-15. The openings of these bows +-13, 14, and 15 are provided with a primary intake valve 1G and a secondary intake valve 17, which are respectively opened and closed at predetermined timings by a valve mechanism (not shown). It is equipped with an exhaust valve 18. Further, a spark plug 20 is provided in the combustion chamber 7, and a spark plug 20 is provided inside the combustion chamber 7.
An I@man valve 21 and an air injection valve 22 are arranged.

The fuel injector 21 is directed toward the spark plug 20.
It is being Further, the air injection valve 22 is connected to the fuel injection valve 21.
The fuel injector 21 is disposed close to the fuel injector 21, and is arranged so as to inject air in a direction that interferes with the fuel injected from the fuel r1 injection valve 21. In addition, in FIG. 1, for convenience of drawing, only the fuel injection valve 21 and the air injection valve 2 are shown for the rightmost cylinder.
Although the arrangement of No. 2 has been made clear, fuel injection valves 21 and air injection valves 22 are similarly arranged in the other cylinders, respectively.

The fuel injection valve 21 is connected to a fuel injection pump 23. This fuel injection pump 23 is driven by the crankshaft 27 of the engine via a timing belt 24 and pulleys 25, 26, and supplies fuel to the fuel injection 111) 1 valve 21 of each cylinder. Then jet 1! RuJ: Sea urchin and its injection start n,'I! ! 1
11 and the injection end timing can be adjusted according to an electrical control signal. The air injection valve 22 is also connected to an air pump 30 via two air reservoirs, and the air pump 30 is driven by an open crank 27 via a belt 31 and pulleys 32, 33. I have to. In the figure, to promote pressure build-up in the two air reservoirs when starting the engine,
An air return passage 34 is provided between the air reservoir 29 and the air pump 30 (jl) In this air return passage 3/1, there is a recycle valve 3 that is opened and closed when the engine is started.
5 is provided. 36 is a check valve provided in the air passage 37 for air to the air pump 30, and 38 is a relief valve installed in the air relief passage 39.

Further, 40 is a control unit for various controls, for example, as shown in FIG. :Control unit 41 and various converters/12
Contains ~46. An accelerator opening signal is inputted to the control section 41 from the Ij1 axle angle sensor 51 via the Δ/l) converter 42, and the crank angle sensor) J
52 to F/V (Fixed Frequency-Voltage) converter 43 and Δ
The engine rotational speed foreshadowing is inputted via the /D converter 44, and the load condition is detected based on this accelerator opening degree and the engine rotational speed. It has been entered. (I) In the embodiment, the detection signal from the smoke sensor 53 is also adjusted to
The signal is input to the control unit/11 via the D converter 45.

In addition, for control at the time of starting which will be described later, the air release is
The pressure sensor 54 detects the pressure inside the bar 29.
The pressure signal given through the converter 46 and the star 1 signal given from the star drain 4J-55 as an interrupt signal are also input to the control section 41. burns 1 injector 21
It has a function as a fuel r1 control means to control fuel injection from the air injection valve 22, and an air control means to control air injection from the air injection valve 22, and has a function as an air control means to control air injection from the air injection valve 22. It controls the construction of the pump 23 and the opening/closing operation of the air injection valve 22. Also, 11
Actuator 11 of 11 Swirl control valve 10:
The recycle valve 35 is also controlled by the control section 11.

” (d) In the control unit 41, d3 is set to various operating states in advance.
The injection start timing and injection end timing of G-J fuel and air are stored as a data map, and this map allows fuel to be injected in the latter half of the intake stroke or compression stroke at least when the load is low, and to inject fuel between the first and second injections. OA' blowing air in the second half! It is set so that For example, the above map is created so that the above timing is controlled by the J: Una characteristic shown in FIG. In Fig. 4, l"s and Fe respectively represent the injection start time and injection end time of fuel lp1, and As and Ae represent the injection start time and J: and injection end time of air, respectively. As shown in this figure, in the low load region, fuel N1 is injected in the second half of the compression stroke -9-, and the fuel is injected FO at the end of the secondary injection 04.

Ae is made to almost match the ignition timing (■).

Since the injection M depends on the injection period, the fuel end time "e8 and i1" and the fuel injection start time "S" are set so that an appropriate fuel injection amount can be obtained depending on the load. Also, at least at this low angle load, the air injection start time △S is 1± later than the fuel injection start time "S", and both injection end times "e" and "80" match!
ing. Control during high loads is not limited by the present invention, but stratified air supply is not necessary before high loads when the amount of fuel injection is increased, and rather, it is necessary to increase the air utilization rate and improve the output. It is preferable to ignite with r1 dispersed. For this reason, with the characteristics shown in the figure, even when the load is high to some extent, when fuel and air are injected, l! l'l is advanced so that fuel is injected in the first half of the intake stroke in the high load region. In this figure, the dashed-double line AS' indicates the timing of the start of air injection when smoke is generated. The correction coefficients are also stored in the map in advance! N-(There is.

Further, in the control section 41, the opening degree of the swirl control valve 10 under various load conditions is stored in advance as a disk map, and the swirl control valve 10 is closed when the load is low.
The above map is created so that the swirl control valve 10 is adjusted to an opening degree corresponding to a high load and an electric current.

The control executed by the control unit 1 by the flowchart 1 is shown in FIG. 5 and FIG. 6.

In the main routine shown in FIG. 5, first, detection signals of accelerator distance IA and T engine rotation speed R, which determine the load condition, are input (step X1), and based on these signals,
From the map set in J: which gives the characteristics shown in FIG. 4 in advance, each injection start timing As, Fs and each injection end time Δe,
Fe is calculated (steps X2, X3).

Furthermore, a correction coefficient Sa corresponding to the smoke signal S is set from the map, and the preset air jet! )j start time As
-11- is multiplied by the above correction coefficient Sa (steps X4°X5
). In this case, as shown in Figure 7, there is less smoke.
Correction body lI4! Sa is set to 1 and 1 so that as the smoke increases, the correction coefficient Sa decreases. Next, while repeatedly inputting the detection signal of the crank angle O, the ear rank angle θ is determined at the above-mentioned patrol start time As.

Reached Fs! After that, control is performed to start the injection of fuel r1 and air (steps x6 to Xa).
. Subsequently, the detection signal of the crank angle θ is repeatedly input, and after the crank angle θ reaches the injection end timings Ae and Fe, control is performed to end the fuel and air injection q4 (step 9-×11). Furthermore, the opening degree (S valve opening degree) So of the swirl control valve 10 is calculated according to the accelerator opening degree A and the engine rotation speed R,
The control signal that provides this opening degree So is the actuator 1
1 (Sfutub X+o, X1+). Thereafter, the process returns to step x1 and the above flow is repeated.

Through such control, when the load is low, the spark plug 2 is discharged from the fuel r1 injector 21 at a predetermined time in the latter half of the compression stroke.
Fuel is injected towards zero, the fuel is mainly supplied near the spark plug, and ignition is performed in other parts of the combustion chamber 7 with fuel being lean. Therefore, it is possible to ignite and burn the engine even with a small amount of fuel v1, and the engine can be operated.Also, since there is no problem even if excessive air is supplied from the secondary intake passage 8 to the combustion chamber 7, pumping loss is reduced. Ru.

In this case, the air is injected with the characteristics shown in FIG. 4, and the injected fuel is appropriately atomized and vaporized to the extent that it does not spread too much. In other words, at the time of ignition, the fuel r1 injected at the first period of the fuel injection period is diffused, and the fuel injected at the near timing is inherently difficult to atomize or vaporize. Therefore, to prevent the fuel from spreading too much and causing the area near the spark plug 20 to become lean, air injection is stopped during the first half of the fuel injection period.
In the second half of the fuel injection period, the injection air is used to perform binary atomization and vaporization of the fuel. However, when smoke occurs, the area near the spark plug 20 is too rich, so the air injection timing is advanced to adjust the degree of fuel diffusion.

On the other hand, when the load is high, the fuel r1 injection amount is increased, fuel is injected in the first half of the intake stroke, and the swirl control valve 10 is opened to cause the intake air from the secondary intake passage 9 to flow into the combustion chamber 7. Since the swirl is increased, ignition is performed after the fuel is sufficiently diffused within the combustion chamber 7.

The interrupt routine shown in FIG. 6 is for controlling the start, and is started by a signal from the start sensor 54. First, a pressure signal from the pressure sensor 53 is input (step Y1), and the pressure It is determined whether P is greater than or equal to the set value α (step Y2). If the pressure P is less than the set value α, the recycle valve 35 is controlled to repeatedly open and close (step Y3), thereby promoting a rise in the pressure in the air reservoir 29. When the pressure P exceeds the set value α, the recycle pulse 135 is closed and starting fuel and air are injected (step-14-Y4). It is determined whether the startup has been completed or not (
Step Y5), when the starting is completed, the 1 shown in FIG.
J It seems like you are being returned to the main routine.

8 and 9 show another embodiment of the invention. In this embodiment, the fuel injection valve 21' and the air injection valve 22 are installed in the primary intake bow 1-13. The air injection valve 22 is arranged so as to inject air in a direction that interferes with the injected fuel. Further, in this embodiment, the opening and closing operation of the fuel injection valve 21' is directly controlled by the control unit/IO similarly to the air injection valve 22, and in this case, the fuel injection valve 21' is , is connected to a fuel injection pump (not shown) that is used in ordinary gasoline engines.

In this way, each of the injection valves 21' and 22 is connected to the intake boat 1.
3, it is necessary to inject fuel before the intake valve 16 closes, so as shown in Fig. 10, the fuel is injected at the end of the intake stroke in the low load region.
: and the injection start timing A S , F S il'3 and the end of the nozzle 1 III so that the air is injected θJ.
F e and Δe are set, but the other configuration of A is the same as in the first embodiment.

(Effects of the Invention) As shown in item 1 and 10, the present invention provides that when the engine is under low angle load, fuel is injected toward the large point plug from the latter half of the intake stroke to a predetermined period of the compression stroke. Since the air is mixed into the injected fuel through the nozzle 4 in the latter half of the fuel injection, the so-called stratified air supply improves fuel efficiency.
Atomization and vaporization of the fuel are promoted, and unnecessary excessive diffusion of the fuel is also prevented, thereby significantly improving ignitability and combustibility.

[Brief explanation of the drawing]

Fig. 1 is an overall schematic diagram showing an embodiment of the present invention, Fig. 2 is an enlarged view of the combustion chamber and its vicinity, Fig. 3 is a block diagram of the control system, and Fig. 4 is a diagram of the fuel and air flow. "Spout"
Characteristic diagrams of timing, Figures 5 and -16- Figure 6 shows 70 seconds, Figure 7 shows characteristics of air injection start timing correction coefficient according to smoke, and Figure 8 shows another example. Figure 9 is a diagram equivalent to Figure 2, Figure 10 is a schematic diagram of the whole.
The figure is a diagram corresponding to FIG. 4 in the case of this embodiment. 20... Spark plug, 21. 21'... Fuel injection valve, 22... Air l1llll injection valve, 40... Control] chive 1~ (control means), 51... Accelerator opening sensor,
52...Crank angle 1゜Patent applicant Toyo Kogyo Co., Ltd. -17- Figure 2 Figure 7 Figure 0 Figure 9 Figure 10

Claims (1)

[Claims] 1. A fuel injection valve disposed toward the spark plug of the engine, an air injection valve that injects air in a direction that interferes with the injected fuel from the fuel injection valve, and a load detection means that detects the load state of the engine. , a crank angle detecting means for detecting the crank angle of the engine, and receiving outputs from the load detecting means and the crank angle detecting means to inject fuel at a predetermined timing from the latter half of the intake stroke to the compression stroke when the engine is under low load. A stratified air supply engine comprising: a fuel control means for controlling the fuel injection valve; and an air control means for controlling the air injection valve so as to inject air in the latter half of a fuel injection period.