JPS58192957A - Fuel injection device of dual intake type internal- combustion engine - Google Patents

Abstract

PURPOSE:To reduce the quantity of exhaust HC in a cold time, by promoting the atomization of fuel in a dual intake type internal-combustion engine provided with an electron control fuel injection device. CONSTITUTION:The main intake passage 28 of siamese type and a subordinate intake passage 30 are provided, and a fuel injector 36 is provided on the main intake passage 28. An assist air pipeline 42 supplying assist air for promoting the atomization of fuel is provided near the injection port 36a of the injector 36. The fuel is atomized by the assist air introduced from the assist air pipeline 42 into an adapter 56 via an assist air intake port 56a. Thereby the particle size of the fuel injected from the injector 36 is minimized, and thus the supply of the fuel to each cylinder becomes smooth.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection device for a two-intake internal combustion engine, and particularly to a two-intake internal combustion engine equipped with an electronically controlled fuel injection device and suitable for use in a ±22-intake automobile engine. Concerning improvements to engine fuel injection devices.

A so-called two-intake internal combustion engine is known, in which a main intake passage supplies air-fuel mixture to the engine combustion chamber and a sub-intake passage supplies air to the engine combustion chamber.

Further, one of the devices for controlling the air-fuel ratio of the air-fuel mixture in an internal combustion engine such as an automobile engine uses an electronically controlled fuel injection device. In an internal combustion engine equipped with this electronically controlled fuel injection device t, for example, the fuel injection time is determined according to the intake air amount of the engine, the engine rotation speed, etc. In addition, the air-fuel ratio of the engine is controlled by opening an injector that injects fuel toward the engine's intake port, and is an exhaust gas purification measure that requires precise control of the air-fuel ratio. It has become widely used in automobile engines.

It is conceivable to use this electronically controlled fuel injection device in a two-intake type internal combustion engine as described above, but when the injector is installed in the main intake passage, generally speaking, the main intake passage is replaced with a one-intake type internal combustion engine. Ninth narrower than the engine intake passage,
Since the amount of injected fuel that adheres to the pipe wall increases and the amount of air that should be mixed with the injected fuel decreases, the fuel is not sufficiently transported. Therefore, (1) the amount of HC discharged, which is a harmful component in the exhaust gas, increases especially when the engine is cold. Also, (2
) Same (Especially when the engine is cold, the transient response of the fuel deteriorates, and the air-fuel ratio becomes lean at the beginning of acceleration, and the fuel ratio becomes rich at the straight wall of deceleration, resulting in a decrease in engine operating performance and ignition. This will cause the plug to smolder.Furthermore, (3) if the amount of fuel is increased during acceleration to compensate for the deterioration in engine operating performance, not only HC emissions (and CO emissions will also increase), but However, it had disadvantages such as deterioration in fuel efficiency.

On the other hand, it is also possible to arrange the injector between the main intake passage and the auxiliary intake passage and inject the fuel towards the middle wall of the intake passage, but in this case, the amount of fuel adhering to the pipe wall will be less than the above-mentioned amount. Not only does this increase the amount of fuel used in the combustion process, but it also has the problem that the distribution is not stable and it is difficult to obtain a stable combustion state.

-On the other hand, in recent years, attempts have been made to promote atomization of the fuel injected from the injector by the air flow velocity by sending -S of the intake air into the vicinity of the injection area of the injector. However, conventionally,
This air assist) has not been tested for application to a two-intake internal combustion engine.

The present invention has been made to solve the above-mentioned drawbacks of the conventional art, and by promoting atomization of the injected fuel, it is possible to supply fuel to the combustion chamber of the engine in spite of a small amount of air. Therefore, it is an object of the present invention to provide a fuel injection device for a two-intake internal combustion engine that can improve engine operating performance, exhaust gas permeation performance, and fuel efficiency, especially when the engine is cold.

The present invention provides a fuel injection device for a two-intake internal combustion engine, comprising:
A main intake passage that supplies air-fuel mixture to the engine combustion chamber, a sub-intake passage that also supplies air to the engine combustion chamber, an injector that injects fuel into the main intake passage, and a fuel injector near the nozzle of the injector. By being equipped with an air assist mechanism that delivers assist air that promotes atomization of
The above objective has been achieved.

Further, the main intake passage has a helical boat to further promote atomization.

Furthermore, at least a wall surface of the main intake passage to which the injected fuel adheres is coated Yrm L, and a lower side Krm thereof is coated.
By providing two or more longitudinal grooves or convex portions, the amount of injected fuel adhering to the wall surface is reduced.

Alternatively, the fuel injection by the injector is performed during the intake stroke of each cylinder to prevent the injected fuel from adhering to the pipe wall.

In addition, the lower the mK, the larger the assist air flow rate when the air assist mechanism is used to supply assist air via the pulp, which improves the atomization performance of Kl and C2, especially when the engine is cold. That's what I did.

Embodiments of the present invention will be described in detail with reference to Figure rMt- below.

The first embodiment of the present invention, as shown in FIGS. 1 and 2,
A ninth air cleaner 12 that takes in the atmosphere, an air 7I: l-meter 14 for detecting the flow rate of the intake air peered into by the air cleaner 12, and an air 7I meter 14 installed in the intake pipe 16 and installed in the driver's seat. A throttle valve 18 for controlling the flow rate of intake air, which is rotated in conjunction with an actuator pedal (not shown), and an opening f of the throttle valve 18 is detected. throttle sensor 20
, a surge tank 22 for preventing intake interference, and an intake manifold 24 having intake passages corresponding to each cylinder for distributing intake air to each cylinder of the engine 10.
The cylinder head 26 covers the upper part of the combustion chamber 10m of the engine 10, and the downstream side is separated from the cylinder head 26 for supplying air-fuel mixture or air to the combustion chamber 10a, respectively.
Siamese type main intake passage 28 and auxiliary intake passage 30, main intake valve 32 and auxiliary intake valve 34 for opening and closing the main intake passage 28 and auxiliary intake passage 30, respectively, in conjunction with engine rotation; An injector 36 that injects fuel into the intake passage 28, a spark plug 37 (FIG. 2),
Exhaust passage 3 for discharging exhaust gas from the combustion chamber 10m
8 and the exhaust vent M38t - a ninth exhaust valve 40 that opens and closes in conjunction with engine rotation, and a part of the intake air taken out from the upstream side of the throttle valve 18 of the intake pipe 16 to the injector 36. In the vicinity of the nozzle port 36m, there is an assist air pipe 42 that is fed as assist air to promote atomization of the fuel, and an idle adjustment screw 44 that adjusts the flow rate of the assist air flowing through the assist air pipe 42. and a meter air valve 46 that flows a large amount of idle air during fast idle, a distributor 48 having a distributor shaft 48a that rotates in conjunction with the rotation of the crankshaft of the engine 1o, and the distributor shaft that has been imploded by the distributor 48. A crank angle sensor 5o that outputs a crank angle signal according to the rotation of 48 m, and a crank angle sensor 5o installed in the engine block.
Cooling water temperature sensor 52 for detecting engine cooling water temperature
Then, the amount of intake air determined from the output of the air flow meter 14 and the crank angle signal of the output of the crank angle sensor 50 are determined, and the amount is corrected in accordance with the engine rotation speed of the basic sensor 52 output. Accordingly, the digital control circuit 54 outputs a valve opening time signal to the injector 36.

At the tip of the injector 36, as shown in detail in Figure 3, there is an adapter 56 in which a plurality of assist air inlets 56& are formed at the surface and a nozzle port 56b is formed at the bottom.
The assist air conduit 4 is fitted and inserted coaxially with the injector 36, and is connected to the assist air conduit 4 through an air gear rally 24m and an assist air passage 24b'i formed in the intake manifold 24 for distributing assist air to each injector 36.
Assist air introduced from No. 2 is injected together with the injected fuel to promote atomization of the injected fuel.

In FIG. 3, reference numerals 58 and 59 denote rubber seals and O-rings that also serve as heat insulation to isolate the area around the adapter 56 from the inside of the intake manifold 24 or the atmosphere.

The outlet side of the main intake passage 28 has a helical shape as shown in FIG. It is designed to further promote this.

Further, as shown in detail in FIGS. 4 and 5, the wall surface of the main intake passage 28 is coated with a Teflon coating 60, and two longitudinal grooves 62 are provided on the lower side thereof. This reduces the amount of fuel injected during the period when the main intake valve 32 is closed and adheres to the m-plane of the main intake passage 28, and also prevents liquid fuel from collecting in one place on the lower side of the main intake passage 28. No, it's set to 5. Therefore, when the main intake valve 32 is opened, the fuel in the main intake passage 28 is quickly transported to the combustion chamber 10m. Note that the structure for preventing concentration of liquid fuel in the main intake passage 28 is not limited to the longitudinal groove 62, and for example, as in the modification shown in FIG.
It is also possible to provide two longitudinal convexities @64 on the lower side.

The action will be explained below.

When the injector 36 is energized by the digital control circuit 54, the needle 36b moves upward in the figure and fuel is injected. Then, at this time, the assist air pipe 42
The fuel is then introduced into the a/mitter 56 through the assist air intake port 56a and is atomized by the assist air. Therefore, the shape of the fuel particles injected by the injector 36 is small, and the supply of fuel to each cylinder becomes a circle fT/4. Acceleration lean and deceleration rich are prevented.
Engine operating performance is improved. Also, the fuel supply 1111r during the warm-up process can be reduced, thereby reducing the amount of HC%CO, which is a harmful component in exhaust gas, and improving fuel efficiency.

Examples of the relationship between the engine cooling water temperature and the HC discharge amount, the state of change in the air-fuel ratio during acceleration, and the state of change in the air-fuel ratio during deceleration in this embodiment are shown by solid lines A in FIGS. 7 to 9, respectively. (Compared to the conventional example shown by the broken line B in Figures 7 to 9, the HC emissions are reduced, and both the lean deviation of the air-fuel ratio during acceleration and the rich deviation of the air-fuel ratio during deceleration are reduced. It is clear that

In the embodiment described above, the assist air was supplied by the differential pressure between the upstream and downstream sides of the throttle valve 18, but the method of supplying the assist air is not limited to this, and for example, the assist air, the air It is also possible to provide an air pump along with the air pulp 46 or the like in the middle of the conduit 42, and to operate the air pump when the opening degree of the throttle valve 18 becomes large, thereby preventing a decrease in the assist air flow rate.

Further, in the above embodiment, the present invention can be applied to a two-intake internal combustion engine having a Siamese-type intake passage in which the main intake passage and the sub-intake passage are separated near the intake boat. The scope of application of the present invention is not limited to this, but the first
As shown in the second embodiment shown in FIG. 0 and FIG. It is clear that the same applies.

Furthermore, the above embodiments describe the present invention as a two-intake type internal combustion engine equipped with an electronically controlled fuel injection device that injects fuel simultaneously into all cylinders or into multiple cylinders simultaneously, regardless of the stroke of each cylinder. However, the scope of application of the present invention is not limited thereto, and can be similarly applied to a two-intake internal combustion engine equipped with an electronically controlled fuel injection device that sequentially injects fuel into each cylinder.

For example, if the present invention is
When applied to a cylinder engine, the fuel injection (arrow C) by each injector is performed during the intake stroke (shaded region D) of each cylinder, as in the third embodiment shown in 121d, Reduces the amount of fuel that adheres to the pipe wall of the main intake passage,
It is possible to further promote atomization. In the figure,
Arrow E is the ignition timing.

As explained above, according to the present invention, fuel atomization can be promoted and fuel can be supplied to the engine combustion chamber regardless of the small amount of air, and especially when the engine is cold,
C emissions can be reduced. Further, it is possible to reduce acceleration lean and deceleration rich phenomena caused by deterioration of transient response of fuel, and improve engine operating performance. Furthermore, it is no longer necessary to increase the amount of fuel to improve transient response, and the increase in HC emissions and CO emissions due to the
It has excellent effects such as being able to prevent increase in fuel efficiency and deterioration of fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of a first embodiment of a fuel injection device for a two-intake internal combustion engine according to the invention, and FIG.
FIG. 3 is a plan view showing the connection state of the intake passage and the arrangement position It of the injector in the first embodiment, FIG. 3 is an enlarged cross-sectional view showing details of the injector mounting part in the first embodiment, and FIG. , Similarly, an enlarged cross-sectional view showing the vicinity of the main intake boat in the @1 embodiment, FIG. 5 is an old cross-sectional view taken along the v-v line in FIG. 4, and #I6 is a modification of the first embodiment. FIG. 7 is a cross-sectional view showing the cross-sectional shape of the main intake passage in the example, and FIG. Figure 9 is a diagram that compares and shows examples of air-fuel ratio changes during acceleration; Figure 10 is
FIG. 11 is a sectional view showing the overall configuration of a second embodiment of the fuel injection device for a two-intake internal combustion engine according to the present invention, and FIG. 11 shows the valve arrangement, intake passage connection state, and injector arrangement in the second embodiment. FIG. 12, which is a plan view showing position a, is a diagram showing the fuel injection timing of each cylinder in a third embodiment of the fuel injection timing of a two-intake internal combustion engine according to the present invention. 10...engine, 10&...combustion phosphorus chamber, 14...
Air flow)-#, 16... Intake pipe, 18... Throttle valve, 22... Surge tank, 24... Intake manifold, 24m... Air gear rally, 24b... Assist air passage, 26... Cylinder head , 28... Main intake passage, 30... Sub-intake passage, 32... Main intake valve,
34... Sub-intake valve, 36... Injector, 36a
... Nozzle, 42... Assist air pipe, 44...
Idle adjustment screw, 46...Air valve, 50
...Cran l corner case, 54...Digital control circuit, 56...Adapter, 56m...Assist air intake port, 56b...Blowout port, 60...Teflon coating, 62... Longitudinal groove, 64... Longitudinal convex portion, 70... Main intake passage, 72... Sub-intake passage. Agent Takaya Ron (and 1 other person) 13 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) A main intake passage that supplies air-fuel mixture to the engine combustion chamber, a sub-intake passage that supplies air to the engine combustion chamber, and an injector that injects fuel into the main intake passage. A fuel injection device for a 2@air-type internal combustion engine, comprising: and an air assist mechanism that feeds assist air for promoting atomization of fuel near the nozzle of the injector. (2) The fuel injection device for a two-intake internal combustion engine according to claim 1, wherein the main intake passage has a helical port. 0) At least 11 m of the main intake passage to which the injected fuel adheres. is coated with a coating, and the lower part thereof has two
A fuel injection device for a two-intake internal combustion engine according to claim 1 or claim 2, wherein the fuel injection device is provided with at least three longitudinal grooves or convex portions. (4) The fuel injection device for a 211 internal combustion engine according to claim 1, wherein the fuel injection by the injector is performed during the intake stroke of each cylinder. (5) The two-intake internal combustion system according to claim 1, wherein the air assist mechanism supplies the assist air via air pulp so that the flow rate of the assist air increases as the temperature decreases. engine fuel injection am.