JPH0742653A - Fuel supply device for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide an air-fuel supply device simple in structure and low-priced with a fuel passage and an air passage, provided with an air flow fairing annular passage, partitioned by the insertion of a fuel injection valve, and make the air flow act effectively on the injected fuel so as to suppress the adhesion of fuel to the intake pipe inner wall surface of an. internal combustion engine and to heighten the combustibility of the engine, thereby reducing the HC discharge quantity and improving fuel consumption. CONSTITUTION:A fuel supply device for an internal combustion engine is constituted in such a way as to supply part of intake air upstream of a throttle valve to the injected fuel injected from a fuel injection valve. In such a fuel supply device, an air supply member is not fitted onto the fuel injection valve side but the fuel injection valve is integrated into an adaptor 1 fixedly inserted into the fitting hole of the internal combustion engine to form an air passage and a fuel passage. The adaptor 1 is formed of a large diameter cylindrical part 1a opened at one end thereof, and a small diameter cylindrical part 1b with an air lead-in hole at the path part and with a gas-liquid injection hole 6 at the end face part. At the time of integrating the fuel injection valve therein, air flow is faired and supplied to the injected fuel so as to prevent the atomization of fuel and the scattering of fuel spray.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for an electronically controlled internal combustion engine, and in particular, it has a simple and inexpensive structure and has suitable injection characteristics (spray shape) for remarkably enhancing the combustibility of the engine. A fuel supply device for an internal combustion engine that can be obtained.

[0002]

2. Description of the Related Art Recently, in automobile internal combustion engines, legal regulations such as exhaust emission regulations associated with environmental pollution problems and fuel consumption regulations associated with global warming have been strengthened year by year. In order to meet these requirements, as an electronically controlled fuel injection device, an air-assisted fuel injection device that supplies air to the injected fuel to promote atomization of the fuel is being studied as part of improving combustion in an internal combustion engine. Related to such an apparatus, there are JP-A-4-203262 and JP-A-4-234564.

Japanese Patent Application Laid-Open No. 4-203262 discloses a throttle valve arranged in an intake passage, a fuel injection valve arranged in an intake passage downstream of the throttle valve,
A bypass passage for bypassing the throttle valve, and a duty-controlled opening / closing means interposed in the bypass passage, wherein the opening / closing means is modulated at a predetermined cycle. The assist air passage for supplying the assist air is provided, and the upstream end of the assist air passage is opened to the intake passage on the upstream side of the upstream end opening of the bypass passage.

Further, the one described in JP-A-4-234564 is a fuel injection device for an internal combustion engine equipped with an air assist device for atomizing the fuel injected from the fuel injection valve with air. An air-fuel mixture passage located downstream of the injection hole in the injection direction, which serves to mix the injected fuel with the air supplied from the air assist device, and is formed shorter than the air-fuel mixture passage and connected to the end of the air-fuel mixture passage. In addition, a nozzle having a mixture injection hole for branching and directing the mixture in a plurality of desired directions is provided at the tip of the fuel injection valve.

[0005]

In the first prior art described above, the influence of the pulsation generated due to the fluctuation of the air amount in the bypass passage is avoided, and a constant flow rate of assist air is always secured to vaporize the fuel. The purpose is to promote atomization and atomization to obtain good combustibility, but sufficient consideration has not been given to the prevention of the spray spray, and there is concern that fuel may adhere to the inner wall surface of the intake pipe of the engine. To be done. Also, when viewed structurally, the member that supplies the assist air to the injected fuel is attached to the tip of the injection valve body, and this member has a plurality of air intake holes. The air supplied from is supplied via an adapter inserted and fixed in a mounting hole formed on the engine side. With such a configuration, there is a concern that it may be disadvantageous in terms of processing man-hours such as processing a plurality of holes in a member that supplies air to the injected fuel and mounting the member to the tip of the injection valve.
In the above-mentioned second conventional technology, the air-fuel mixture passage is elongated and disposed in the intake passage of the engine so that the spray to be injected is directed toward the intake valve. There is no need to worry about fuel adhesion. However, since the passage of the air-fuel mixture is long, a considerable amount of airflow energy is required to expect the effect of atomization. On the other hand, from a structural point of view, as in the case of the first conventional technique, the member that supplies the assist air to the injected fuel is attached to the tip of the injection valve body, and this member has an air intake hole. Has become. Further, the air supplied from the bypass passage is configured to be supplied via an adapter that is inserted and fixed in a mounting hole formed on the engine side. There is concern that it will be disadvantageous in terms of processing man-hours such as mounting.

The above-mentioned matters of concern cause high manufacturing cost of the fuel injection valve and cause defective combustion when the engine is mounted.

An object of the present invention is to solve such a problem. In particular, the number of parts is reduced without attaching an assist air supply member to the tip of the injection valve. That is, the air passage and the fuel passage are formed by incorporating the fuel injection valve into the adapter that is inserted and fixed in the mounting hole formed on the engine side. Another object of the present invention is to rectify the air flow supplied through the bypass passage in the adapter so that it acts uniformly on the injected fuel from the entire circumferential direction to effectively promote atomization. Further, this air flow suppresses spray scattering, reduces fuel adhesion to the inner wall surface of the intake pipe, improves combustibility of the engine, reduces HC, and improves fuel efficiency. It responds to demands such as exhaust emission regulations associated with problems and fuel economy regulations associated with global warming.

[0008]

A first feature of the present invention for achieving the above object is to have an adapter and a fuel injection valve inserted in the adapter, and to inject the fuel depending on an operating state of the engine. In a fuel supply apparatus for an internal combustion engine, which controls injection of fuel from a valve and supplies a part of intake air upstream of a throttle valve to the injected fuel, the adapter has a large-diameter tubular portion whose one end is open. And a small-diameter cylindrical portion integrally provided at the other end of the large-diameter cylindrical portion, having an air introduction hole in the diameter portion and a gas-liquid injection hole in the end surface portion. Has a body portion and a nozzle portion having a diameter smaller than that of the body portion, and a guide portion is formed on the inner wall of the small diameter tubular portion or the nozzle portion, and the fuel injection valve is inserted and fixed in the adapter. The outer circumference of the nozzle and the diameter portion of the small diameter tubular portion Between the walls, and the air passage between the end face portion the inner wall of the small diameter portion cylindrical portion and the end portion of the nozzle,
The fuel passages are respectively defined between the outer circumference of the main body portion and the inner wall of the large-diameter tubular portion.

A second feature of the present invention is that in the fuel supply system for an internal combustion engine as described in the first feature of the present invention,
The air passage between the air introduction hole and the gas-liquid injection hole formed in the small-diameter tubular portion of the adapter has a minimum passage cross section in an annular gap formed near the gas-liquid injection hole. I have configured it.

Further, a third feature of the present invention is, in the fuel supply system for an internal combustion engine described in the first or second feature of the present invention, the air introducing hole formed in the small-diameter cylindrical portion of the adapter. Therefore, the air flow is rectified by the relatively long annular air passage between the gas-liquid injection holes.

Further, a fourth feature of the present invention is to perform fuel injection control from a fuel injection valve according to the operating state of the engine,
In a fuel supply device for an internal combustion engine that supplies a part of intake air on the upstream side of a throttle valve to the injected fuel, a large-diameter cylindrical portion whose one end is open, and the other end are integrally formed, According to the number of cylinders of the engine, a plurality of air-fuel supply devices, each of which has an air introduction hole in the diameter portion and a small-diameter cylindrical portion having a gas-liquid injection hole in the end surface portion, are connected, and The gas-liquid injection hole portion of the air-fuel supply device is provided so as to be located in the intake main passage of the engine, and the air reaching the gas-liquid injection hole acts effectively during fuel injection to the inner wall of the intake passage of the engine. It is configured to suppress the fuel adhesion of the above.

[0012]

The adapter (air-fuel supply device) which is inserted and fixed in the mounting hole formed on the intake pipe side of the engine has a large-diameter cylindrical portion whose one end is open, and the other end which is integrally formed. The small-diameter cylindrical portion is formed and has an air introduction hole in the diameter portion and a gas-liquid injection hole in the end surface portion. When the fuel injection valve is inserted and fixed in the adapter, a fuel flow passage is formed in the large-diameter cylindrical portion and an air flow passage is formed in the small-diameter cylindrical portion.

Here, the air flow passage is a relatively long annular passage extending from the air introduction hole to the gas-liquid injection hole, and the annular passage is the outer circumference of the nozzle of the fuel injection valve and the inner circumference of the small-diameter cylindrical portion. Although formed in between, it is constituted by another annular passage having a smaller diameter than the annular passage formed between the nozzle tip end surface portion of the fuel injection valve and the inner circumference of the tip of the small diameter tubular portion. Therefore, the air flowing through these annular passages is rectified during the flow and accelerated in another annular passage having a small diameter in the gas-liquid injection hole portion to collide with the fuel spray. The collision with the fuel spray is performed from the entire circumference of the fuel spray, and atomization is effectively promoted.

As described above, no member that forms an air passage is attached to the fuel injection valve, and the air and fuel flow passage is formed by the gap formed when the fuel injection valve is attached to the adapter. Due to the simple structure that it is formed, it becomes an inexpensive fuel supply device. In addition, the air that collides with the fuel spray atomizes the fuel and prevents the spray from scattering, so fuel adhesion to the inner wall of the intake passage of the engine is suppressed and the response of the fuel supplied to the engine is further enhanced. As a result, the air-fuel mixture necessary for combustion of the engine is formed early.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an external structure and a sectional structure of the adapter 1 of the present invention, which is partially sectioned. In this embodiment, an example in which the number of cylinders of the engine is 3 is shown. The adapter 1 has a large-diameter cylindrical portion 1a whose one end is open.
And a small-diameter cylindrical portion 1b integrally formed at the other end. A fuel inlet hole 2a and a fuel outlet hole 2b are provided in the diameter portion or the cylindrical portion of the large-diameter tubular portion 1a. In the figure, the fuel pipe 3 is attached to the holes 2a and 2b. An air introduction hole 4a and an air outflow hole 4b are provided in the diameter portion or the cylindrical portion 1c of the small diameter tubular portion 1b. Similarly, in the figure, this hole 4
The air pipes 5 are shown attached to parts a and 4b. Further, a gas-liquid injection hole 6 is provided in the axial center portion of the end surface portion 1d of the small-diameter cylindrical portion 1b. A relatively long distance is maintained between the gas-liquid injection hole 6 and the air introduction hole 4a and the air outflow hole 4b. For this configuration, see FIG.
4 will be described in detail when explaining FIG.

FIG. 2 shows an enlarged cross-section of a mounting hole 12a portion of an intake pipe 12 in an internal combustion engine to which the adapter 1 (air-fuel supply device) is mounted. The adapter 1 according to the present invention is inserted and fixed in the mounting hole 12a through the elastic member 12b and the mounting seat 12c. Further, the gas-liquid injection hole 6 of the adapter 1 is attached so as to be able to inject toward the valve body 14a of the intake valve 14 that opens and closes the intake hole 13.

Reference numeral 7 denotes a fuel injection valve. In this embodiment, a fuel injection valve of a type that supplies fuel into the inside in a lateral direction is adopted and has a nozzle portion 7a, a guide portion 7b, and a main body portion 7c. , And is coaxially inserted into the adapter 1 via the seal members 8a and 8b. In the present invention, the injection valve 7 is an injection valve that forms a thin film immediately after fuel injection, that is,
It is preferable to use a swirl method or a pintle method in which fuel is swirled and injected. Further, fuel injection from the injection valve 7 is performed by opening and closing the seat portion based on an on / off signal of a duty calculated by a control unit (not shown).

FIGS. 3 and 4 are explanatory views showing the insertion state of the fuel injection valve 7 into the adapter 1, and FIG. 4 is an enlarged sectional view of the portion A of FIG.

In these figures, when the injection valve 7 is inserted into the adapter 1, the outer periphery of the nozzle portion 7a and the small diameter tubular portion 1 are inserted.
The annular gap 1 is formed between the inner wall 1e of the diameter portion 1c in FIG.
f, that is, an annular air passage is formed, and an annular gap, that is, an air passage is formed between the end of the nozzle portion and the end surface portion 1d of the small diameter tubular portion 1b in the vicinity of the gas-liquid injection hole 6. , The air passage is the smallest, and the velocity of the air injected into the gas-liquid injection hole 6 is maximized. Further, an annular fuel passage is formed between the main body portion 7c of the fuel injection valve 7 and the inner wall of the large-diameter cylindrical portion 1a. The guide portion 7b having a diameter slightly larger than that of the nozzle 7a of the fuel injection valve 7 is coaxially in close contact with the inner wall 1e of the adapter 1 and contributes to the formation of the annular gap 1f, and the axial center of the injection valve 7 is It is aligned with the axis of the gas-liquid injection hole 6. The sealing material 8b provided near the upstream is
Leakage of fuel to the downstream side or air to the upstream side
It is preventing each. The annular gap 1f includes a guide portion 7b having a diameter larger than that of the nozzle portion 7a and a tubular portion 1b having a small diameter.
An example is shown in which the inner wall 1e is fitted to the nozzle wall 7e.
Instead of providing b, the nozzle portion 7 has the same diameter in the axial direction, and a guide portion protruding inward of the inner wall 1e of the adapter 1 is provided, and the guide portion and the nozzle having the same diameter in the axial direction are engaged to form an annular shape. It goes without saying that it can be obtained by other configurations such as forming a gap.

Next, the air flow in the adapter 1 will be described with reference to FIG. The air flowing in from the air introduction hole 4a reaches the gas-liquid injection hole 6 through the annular gap 1f formed between the nozzle 7b of the fuel injection valve 7 and the inner wall 1e of the small diameter tubular portion 1b. At this time, the annular gap 1f, which is maintained at a relatively long distance, rectifies the flow. The air ejected from the gas-liquid injection hole 6 collides with the injected fuel uniformly in the circumferential direction and promotes atomization of the fuel.

FIG. 5 shows an electronically controlled fuel injection device for an internal combustion engine in which the adapter according to the first embodiment of the present invention is incorporated. Reference numeral 10 is a partial cross-sectional view of an engine that uses gasoline as a fuel. An intake manifold 12 having a throttle valve 11 built therein, an intake hole 13 and an intake valve 14 for opening and closing the intake hole 13, a combustion chamber 15, an intake manifold. 1 shows an air-fuel supply device 1 according to the present invention, which is attached to a wall portion of a valve 12 and is arranged so as to be capable of injecting toward a valve body 14a of an intake valve 14.

The air begins to flow in when the throttle valve 11 opens, and is filtered by an air cleaner (not shown). After that, the air reaches the throttle body 18, and the pressure difference between the upstream side and the downstream side of the throttle valve 11 is caused. Then, the air is divided into the air intake pipe 5 and the intake manifold 12. This air amount is measured by the air flow sensor 17. On the other hand, the fuel is pumped up from the fuel tank 20 by the fuel pump 19, passes through the fuel filter 21, and is adjusted by the pressure regulator 22 to a pressure higher than the pressure in the intake pipe by about 250 kPa. Will be distributed and supplied to.

The control system of the engine 10 determines an appropriate fuel injection amount according to the operating state of the engine.

The operation of the engine 10 is performed by the control unit 30 processing the intake air amount, the air temperature, the engine speed, etc., which are information on the operating condition. The fuel injection of the fuel injection valve 7 is based on the signal of the control unit 30, but the basic injection amount is detected by the intake air amount signal detected by the air flow sensor 17 and the crank angle sensor incorporated in the distributor 29. Calculated from the engine speed signal. This basic injection amount is corrected by various corrections according to the operating state at that time and sent to the fuel injection valve 7 as an injection signal. The throttle position sensor 25 and the O ₂ sensor 26 are used to detect the correction signal of the operating state of the engine 10.
and so on. Other control system parts include battery-2
7, the ignition switch 28 and the like are shown.

The air-fuel mixture of fuel and air is introduced from the intake hole 13 of the engine 10 into the combustion chamber 15 and is compressed in the compression process, after which it is ignited and burned by a spark plug (not shown).

The air introduced from the air intake pipe 5 is accelerated near the tip of the nozzle of the fuel injection valve 7, and then uniformly rectified in the circumferential direction and directed toward the injected fuel. As a result, atomization of the fuel is promoted, and the air colliding with the fuel spray prevents the spray from scattering. Therefore, fuel adhesion to the inner wall of the intake passage of the engine is suppressed, and the fuel is effectively directed toward the valve body 14a of the intake valve 14, the responsiveness of the fuel supplied to the engine is further enhanced, and the mixing required for combustion of the engine is promptly performed. Qi is formed, increasing the flammability and H
It is possible to reduce the emission amount of C and improve fuel efficiency.

FIG. 6 shows a second embodiment of the present invention.
An example using another fuel injection valve 40 is shown. The fuel injection valve 40 is of a type in which fuel is introduced from the axial direction, that is, a so-called top feed type, and the adapter 1 does not require the fuel pipe 3 and the seal members 8a and 8b as in the first embodiment. Becomes

FIGS. 7 to 8 show a third embodiment of the present invention, and FIG. 7 shows an enlarged cross section of a mounting hole 12a portion of another adapter 100 of the intake pipe 12 of the internal combustion engine. In the example, the air pipe 50 is provided in the mounting seat 12c provided in the mounting hole 12a. Figure 8
3A and 3B show an external structure and a sectional structure of the adapter 100, which are partially sectioned.

The adapter 100 does not need the air outflow hole 4b and the air pipe 5, and the structure is simplified. Needless to say, the same effects as those of the first embodiment can be obtained in the second and third embodiments.

[0031]

As described above, according to the present invention,
The number of parts can be reduced without attaching the assist air supply member to the tip of the injection valve. That is, the air passage and the fuel passage are formed by incorporating the fuel injection valve into the adapter that is inserted and fixed in the mounting hole formed on the engine side. Further, since the air flow is rectified in the adapter and uniformly acts on the injected fuel from the entire circumferential direction, atomization of the fuel can be effectively achieved. further,
Since the spray of spray is suppressed by this air flow, it is possible to reduce fuel adhesion to the inner wall surface of the intake pipe of the engine and improve combustibility, and to reduce HC emissions and improve fuel efficiency in practical use. The effect of can be obtained.

[Brief description of drawings]

FIG. 1 is a partially cutaway external view of an adapter in an embodiment of a fuel supply system for an internal combustion engine according to the present invention.

FIG. 2 is a partially enlarged sectional view of an intake pipe of an internal combustion engine equipped with an adapter according to the present invention.

FIG. 3 is an explanatory view showing a state of inserting a fuel injection valve into an adapter according to the present invention.

FIG. 4 is an enlarged sectional view of part A in FIG.

FIG. 5 is a diagram showing an electronically controlled fuel injection device for an internal combustion engine incorporating the adapter of the first embodiment according to the present invention.

FIG. 6 is a partially enlarged sectional view of an intake pipe of an internal combustion engine showing a second embodiment of the present invention.

FIG. 7 is a partially enlarged sectional view of an intake pipe of an internal combustion engine showing a third embodiment of the present invention.

FIG. 8 is an external structural diagram of an adapter showing a third embodiment of the present invention.

[Explanation of symbols]

1 ... Adapter, 1a ... Large diameter tubular portion, 1b ... Small diameter tubular portion,
1c ... Diameter part, 1d ... End face part, 1e ... Inner wall, 1f ... Gap, 3 ... Fuel pipe, 5 ... Air pipe, 6 ... Gas-liquid injection hole, 7 ... Fuel injection valve, 7a ... Nozzle part, 7b ... Guide part , 7c ... Main body

Claims (4)

[Claims] 1. An adapter and a fuel injection valve inserted into the adapter, the fuel injection control is performed by the fuel injection valve according to the operating state of the engine, and the injection fuel is sucked upstream of the throttle valve. In the fuel supply device for an internal combustion engine which supplies a part of air, the adapter is integrally provided at a large-diameter cylindrical portion whose one end is open, and at the other end of the large-diameter cylindrical portion. An air introduction hole in a portion, and a small-diameter tubular portion having a gas-liquid injection hole formed in an end face portion, the fuel injection valve has a main body portion, and a nozzle portion having a diameter smaller than the main body portion, A guide portion is formed on the inner wall of the small-diameter tubular portion or the nozzle portion, and by inserting and fixing the fuel injection valve into the adapter, the outer circumference of the nozzle and the inner wall of the small-diameter tubular portion of the diameter portion are formed. Between the end of the nozzle and the end surface of the small diameter tubular portion A fuel supply device for an internal combustion engine, wherein an air passage is defined between a wall and a fuel passage, and a fuel passage is defined between an outer circumference of the main body portion and an inner wall of the large-diameter cylindrical portion. 2. The fuel supply device for an internal combustion engine according to claim 1, wherein the air passage between the air introduction hole and the gas-liquid injection hole formed in the small-diameter cylindrical portion of the adapter,
A fuel supply device for an internal combustion engine, characterized in that the passage cross section is minimized in an annular gap formed near the gas-liquid injection hole. 3. The fuel supply device for an internal combustion engine according to claim 1, wherein a relatively long annular air between the air introduction hole and the gas-liquid injection hole formed in the small-diameter cylindrical portion of the adapter. A fuel supply device for an internal combustion engine, wherein an air flow is rectified by a passage. 4. A fuel supply device for an internal combustion engine, which controls fuel injection from a fuel injection valve according to an operating state of the engine, and supplies a part of intake air upstream of a throttle valve to the injected fuel. A large-diameter tubular part with one end open,
An air introduction hole is formed integrally with the other end portion,
A plurality of air-fuel supply devices configured by a small-diameter cylindrical portion having gas-liquid injection holes in the end face portion are connected according to the number of cylinders of the engine, and gas-liquid of the air-fuel supply device is connected. The injection hole portion is provided so as to be located in the intake main passage of the engine, and the air reaching the gas-liquid injection hole effectively acts at the time of fuel injection to suppress fuel adhesion to the inner wall of the intake passage of the engine. A fuel supply device for an internal combustion engine, which is configured.