JPH04153567A - Fuel injector - Google Patents

Abstract

PURPOSE:To uniformly mix the fuel which is jetted from a fuel injection passage and contains air in an annular form, with the air in an intake passage by connecting a fuel injection passage boss with the inner wall of the intake passage, by a plurality of connection parts which cross at right angle with the axis center line X-X in the longitudinal direction of the intake passage and equally divide the intake passage. CONSTITUTION:A expanded inclined part 6C whose inside diameter gradually spreads toward an opened port edge part 6B on the downstream side from an expansion starting point A of a fuel injection passage 6 is formed, and the inside diameter is spread continuously along the axis center line Y-Y in the longitudinal direction of the fuel injection passage 6. In the fuel injection passage 6, a cone member 9 forming an annular gap together with the inside diameter of the fuel injection passage 6 is arranged. A connection part 11 which connects a fuel injection passage boss 10 on which the fuel injection passage 6 having the cone member 9 inside is drilled, with the inner wall of an intake passage B is allowed to cross at right angle with the axis center line X-X in the longitudinal direction of an intake passage B, and one edge of the connection part 11 is connected with the inner wall of the intake passage B and the other edge is connected with the outside diameter of the fuel injection passage boss 10, and a plurality of connection parts 11 are arranged so that the intake passage B is equally divided.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a fuel injection device that injects fuel pressurized by a fuel pump into an intake passage through a fuel injection valve, and particularly relates to a fuel injection device that injects fuel pressurized by a fuel pump into an intake passage through a fuel injection valve. Fuel injection in the so-called single point injection method (hereinafter referred to as the SPI method), in which fuel is injected from a single fuel injection valve toward the intake path on the downstream side, and this fuel is supplied to the intake pipes connected to each cylinder of the engine. It is related to the device.

[Conventional technology]

Japanese Unexamined Patent Publication No. 53-7 as a fuel injection device in the SPI system
There is No. 2923. The main purpose of this is to discharge fuel uniformly into the intake passage and to evenly supply fine fuel to each intake pipe connected to each cylinder.
An internal air chamber located upstream of the throttle valve that controls air passing through the throttle valve receives air from the throttle valve's main air passage and controls the fuel injected by the fuel injector at right angles to the inner surface. a circular fuel swirl chamber that receives and forms a fuel ring therein, an orifice that restricts the flow of air through the atomizer, and an outlet boat that returns the vaporized mixture to the main air passage downstream of the throttle valve. .

Thus, fuel injected by the fuel injection valve in response to actuation by the electronic controller enters the groove at a relatively high velocity and forms a fuel ring within the groove. The circular motion of the fuel within the groove spreads the fuel in a thin film on the inner surface of the groove. This film of fuel is gradually carried away by the air stream exiting the orifice, breaking it into smaller particles than can be obtained with conventional atomizers.

Also, the residence time of the fuel inside the groove significantly increases the fuel supply time.

[Problem to be solved by the invention]

This conventional fuel injection device has the following problems to be solved.

~1. This is because fuel is injected eccentrically from a fuel injection valve in the tangential direction of the groove, creating a vortex within the groove to form a thin film-like fuel ring on the inner surface of the groove, and this fuel ring is gradually carried away by air. , ■ When the spray angle of the fuel injected into the groove from the fuel injection valve changes (the spray angle of the fuel injection valve is generally 10' to 406°), the fuel formed on the inner surface of the groove Even if the amount of air supplied from the orifice into the groove is constant, the amount of fuel carried by the air from the outlet port into the main air passage may change (thin film vortex). (due to changes in conditions) is unfavorable for uniform fuel supply.

■When the discharge pressure of the fuel pump that supplies pressurized fuel to the fuel injection valve changes, the pressure of the fuel injected from the fuel injection valve into the groove changes, and according to this, the fuel is formed on the inner surface of the groove. The thin film vortex state of the fuel changes, resulting in the same problem as in (2) above. ′ ■The injection energy of the fuel injected into the groove is used to create a vortex on the inner peripheral surface of the groove, and does not positively affect the mixing with the air supplied from the air passage. The film of fuel that forms on the inner surface of the groove is gradually carried away by the air flow exiting the orifice. Therefore,
The fuel and air are not actively mixed finely within the groove.

? / During rapid deceleration of the throttle valve, an extremely large intake negative pressure is generated in the intake passage downstream of the throttle valve, and this intake negative pressure acts on the entire interior of the groove via the outlet.

Therefore, this intake negative pressure also acts on the fuel surface of the thin-film fuel ring formed on the circumferential surface of the groove, and there is a possibility that the fuel may be peeled off toward the inside of the groove. This causes disturbances in the fuel mixture in the vicinity. In other words, the distribution of fuel near the outlet of the groove becomes uneven, which prevents uniform fuel supply.

i The fuel injected from the fuel injection valve is injected into a groove with a relatively large chamber volume and forms a fuel ring on the inner surface of the groove, but the flow velocity of the fuel ring on the inner surface of this groove decreases as it goes downward. However, there is a possibility that this fuel may scatter (sag) inward of the groove, resulting in a worsening of the fuel mixing condition near the outlet of the groove.

■The jet shape of the discharged fuel injected from the fuel injection valve is either a flare shape in which the fuel diffuses or a pencil beam shape in which the fuel converges. In order to form a vortex flow within the groove, it is desirable that the fuel moves circularly at a relatively high speed on the inner surface of the groove, and for this purpose, a fuel injection valve having a pencil beam injection shape is preferred.

In the flared shape, fuel diffuses into the groove and is less likely to generate swirl on the inner surface of the groove.

Therefore, the injection shape of the fuel injection valve is easily limited.

~2. As shown in Figures 3 and 4 of JP-A-53-72923, an orifice is provided between the groove and the outlet, and the air supplied from the air passage and the inner surface of the groove are Mixing with the thin film of fuel flowing through the air is carried out in a groove with a relatively large volume upstream of the orifice, and when supplied to the intake passage, this air-fuel mixture is throttled again at the orifice, so that the fuel is converged by the orifice. This is not preferable in terms of fuel atomization.

The air chamber formed in the intake passage, the vortex chamber, and the inner wall of the intake passage are connected by a single connection part, which causes the air flow flowing through the intake passage to be uneven, resulting in a separation of fuel and air. are difficult to mix uniformly.

[Means to solve problems]

The fuel injection device of the present invention was created in view of the above-mentioned problems, and aims to provide a fuel injection device with excellent fuel atomization characteristics and uniformity in the SPI method, and to achieve the above-mentioned purpose. In a fuel injection device for an internal combustion engine that supplies fuel injected from a fuel injection valve to the engine via an intake passage downstream of a throttle valve, a Approximately parallel to the longitudinal axis x-x, the upstream side is closed and the downstream side is open, and the downstream opening has an inner diameter portion that gradually expands toward the downstream side of the intake path. A fuel injection passage provided with an enlarged slope; An injection valve injection passage opening into the fuel injection passage for injecting and supplying fuel injected from the fuel injection valve into the fuel injection passage; Opens in the intake path on the more upstream side,
an air passage whose other end opens into the injection path of the injector; and an air passage disposed within at least the enlarged slope of the fuel injection path, and the longitudinal axis of the fuel injection path together with the enlarged slope! ! jY-
and a cone member having an enlarged inclined protrusion forming a continuous annular gap along Y, and the fuel injection passage is bored in the center of the intake passage on the downstream side of the throttle valve. The fuel injection passage boss is connected to the inner wall of the intake passage through a plurality of connecting portions that are perpendicular to the longitudinal axis x-x of the intake passage and equally divide the intake passage.

[Effect]

According to the fuel injection device configured as described above, the fuel injected from the fuel injection valve is injected toward the cone member in the fuel injection path via the injection valve injection path. Atmospheric air or air in the intake passage upstream of the throttle valve flows into the fuel flowing through the air passage, and the fuel and air mix in the injection passage of the injection valve, and the fuel containing this air is injected by the injection valve. The fuel is injected from the fuel injection path toward the cone member within the fuel injection path.

The fuel that collides with the cone member is dispersed at a high injection speed into the annular gap formed between the enlarged inclined part of the fuel injection path and the enlarged inclined protrusion of the cone member, and this finely divided fuel is The fuel flows down toward the outlet of the fuel injection path, and is injected into the intake path from the outlet on the downstream side of the fuel injection path.

The annular gap is formed with a relatively small volume (small gap), and the flow rate of the air-containing fuel does not decrease. The continuous formation toward the side opening allows a reliable annular fuel form to be formed, and the fuel containing air formed in this annular shape is transferred from the end of the fuel injection path to the inner surface of the intake path. It is possible to spray while expanding towards the target.

On the other hand, since the fuel injection passage boss is connected to the inner wall of the intake passage with a plurality of connecting parts that divide the intake passage into equal parts, the airflow flowing through the intake passage flows symmetrically, and the annular air injected from the fuel injection passage is The contained fuel and the air in the intake passage are uniformly mixed in the intake passage.

〔Example〕

Hereinafter, one embodiment of the fuel injection device according to the present invention is shown in FIG.
This will be explained with reference to FIG. FIG. 2 is a cross-sectional view of the main part taken along the line ■--■ in FIG. 1.

1 is a throttle valve main body through which an intake passage B passes from the top to the bottom in FIG. A throttle valve 3 is arranged, and the opening and closing of the intake passage B is controlled by this throttle valve 3.

Reference numeral 4 denotes an injection valve body disposed below the throttle valve body □, and an intake passage B passes through this injection valve body 4 from the top to the bottom, and the throttle valve body 1 and the injection valve By connecting the main bodies 4, an intake passage B is formed that vertically passes through each main body 1.4.

5 is ECU (Electronic Control)
When a current flows through the renoid coil in response to a signal from E, the core is attracted, and the flange of the needle valve, which is integrated with the fur, is sucked until it hits the spacer, and the valve is fully opened, and the fuel pump is applied. This is a known fuel injection valve that injects pressurized fuel from its tip. (Description of the internal structure of the fuel injection valve is omitted.) Reference numeral 6 denotes a fuel injection passage provided in the injection valve body 4, and is configured as follows. That is, the fuel injection passage 6 has a circular cross section, is located in the intake passage B on the downstream side of the throttle valve 3 (lower side on the engine side in FIG. 1), and is located along the longitudinal axis of the fuel injection passage 6. Y-Y is on the longitudinal axis x-x of the intake passage B, the upstream side thereof is closed at the closed end 6A, and the downstream side is directed into the intake passage B via the open end 6B. Open your mouth.

Then, the inner diameter of the fuel injection passage 6 expands toward the opening end 6B on the downstream side from the expansion starting point A (between the closed end 6A and the open end 6B of the fuel injection passage 6). A sloped portion 6C is provided. The enlarged inclined portion 6C has an inner diameter that continuously expands along the longitudinal axis Y-Y of the fuel injection passage 6, and whether the inclination is linear or curved, there is no step. However, the inner diameter must be expanded and not reduced (funnel-like).

In FIG. 1, a linear enlarged inclined portion 6C is shown.

Reference numeral 7 denotes an injection valve injection passage for injecting fuel injected from the fuel injection valve 5 into the fuel injection passage 6, one end of the injection valve injection passage 7 is connected to the nozzle portion of the fuel injection valve 5, and the other end is connected to the nozzle portion of the fuel injection valve 5. opens into the fuel injection passage 6. The longitudinal axis z-7 of the injector injection passage 7 opens toward the longitudinal axis Y-Y of the fuel injection passage 6, and in this example, the longitudinal axis z-7 of the fuel injection passage 7 opens toward the longitudinal axis Y-Y of the fuel injection passage 6. Open to. (Furthermore, the fuel injection valve 5 may be arranged in the throttle valve body 1.) One end of the fuel injection valve 8 opens into the intake passage B on the upstream side of the throttle valve 3, and the other end opens into the injection passage 7 of the injection valve. It is an open air passage,
One end of this air passage 8 may be opened to the atmosphere.

A cone member 9 is disposed within the fuel injection passage 6 and forms an annular gap with the inner diameter of the fuel injection passage 6.

This cone member 9 is disposed within the enlarged inclined part 6C of the fuel injection path 6, and includes an enlarged inclined protrusion 9A having a continuous enlarged part toward the downstream side, and a fuel having a circular cross section upstream from the enlarged starting point A. It is composed of the fuel injection path 6D on the upstream side of the enlarged starting point A, the cylindrical portion 9B of the cone member 9, and the enlarged inclined portion 6C and the cone member 9. A continuous annular gap is formed from the top to the bottom by the enlarged inclined protrusion 9°A.

Thus, at the open end 6B of the fuel injection passage 6, an annular gap opens toward the intake passage B on the downstream side. It is preferable that the annular gap be approximately 1 mm, but it is not limited to this value and may be set as appropriate.

A fuel injection path 6 having the cone member 9 therein is provided.
is bored in the fuel injection path post 10, and this fuel injection path post 10 is located in the intake passage B on the downstream side of the throttle valve 3, and is integrally formed with the inner wall of the intake passage B and the connecting portion 11. connected to.

In particular, this connecting portion 11 has the following structure.

That is, this connecting part 11 is perpendicular to the longitudinal axis x-x of the intake passage B, and one end is connected to the inner wall of the intake passage B, and the other end is connected to the outer diameter of the fuel injection passage post 10, and the In the example in which a plurality of air passages are arranged so as to equally divide the passage B, since the intake passage B is divided into two, the connecting portions 11 are arranged in a straight line. When dividing into three parts, the connecting parts 11 are arranged at intervals of 120 degrees.

Reference numeral 12 denotes a screw for tightening the cone member 9 in the fuel injection passage 6. Numeral 13 is a fuel passage connected to a fuel pump (not shown), and the fuel injection valve 5 receives fuel from this fuel passage 13.

Next, its effect will be explained.

When the engine is operating, the intake path B downstream of the throttle valve 3
Air controlled by the throttle valve 3 and air passing through the air passage 8 flow inside, while fuel controlled by the fuel injection valve 5 flows from the fuel injection passage 6 toward the intake passage B. Injected.

Here, we will look at the behavior of the air and fuel flowing through the fuel injection path 6. Fuel injected from the fuel injection valve 5 in response to an output signal from the ECUE is injected into the fuel injection path 6D upstream of the expansion starting point A via the injection valve injection path 7. In the air passage 8, an opening 8B at one end opens into the atmosphere or into the intake passage B upstream from the throttle valve 3, and an opening 8A at the other end.
is opened in the injection valve injection path 7, and on the other hand, fuel pressurized to a high pressure (for example, 2.55 kg/crn') by a fuel pump (not shown) as described above is in the injection valve injection path 7. is discharged and flows through the fuel injection valve 5, so the air passage 8
Negative pressure is generated at the opening 8A at the other end of the injector opening into the injection path 7 due to the high-pressure fuel flow. 8B, the air flows down from the opening 8B at one end of the air passage 8 toward the opening 8A at the other end, and this air is drawn into the fuel flowing inside the injection valve injection passage 7. and mix.

Thus, fuel mixed with air (fuel containing air) is injected into the fuel injection path 6D upstream of the expansion starting point A via the injection valve injection path 7. The air-containing fuel injected into the fuel injection path 6D is transferred to the cylindrical portion 9B of the cone member 9.
The fuel containing air is finely scattered by this collision and is finely dispersed over the entire outer circumference of the cylindrical portion 9B. This is because a small annular gap is formed between the fuel injection path 6D upstream of the expansion starting point A and the cylindrical portion 9B of the cone member 9 (maintained at a small volume), and the injection contains air. This is achieved by not reducing the velocity of the fuel.

The fuel containing finely dispersed air having a high velocity within the annular gap between the cylindrical portion 9B of the cone member 9 and the fuel injection path 6D on the upstream side of the expansion starting point A flows through the cone member 9. Injected into the annular gap formed by the enlarged inclined protrusion 9A and the enlarged inclined part 6C of the fuel injection path 6,
The liquid flows down along the inclined annular gap while being evenly distributed within the annular gap.

This is because the annular gap is so small that it is possible to prevent a decrease in the flow velocity of the fuel containing dispersed air, and the inclined annular gap can be made along the longitudinal axis Y-Y of the fuel injection path 6. This is achieved by regulating the flow direction of fuel that is formed continuously and contains air at a certain distance.

Then, the fuel mixed with the air is injected into the intake passage B through an annular gap formed at the open end 6B of the fuel injection passage 6 in a completely annular spray shape that is evenly distributed.

Here, in the present invention, the following points should be particularly noted: In order to supply equal fuel to each cylinder that constitutes the engine, symmetry must be established at least in the intake path of the fuel injection device. It is necessary to supply fine and uniform fuel. Here, when the engine is operated at high speed when the throttle valve 3 is opened to a high opening degree, since the fuel consumption of the engine is large, the fuel flow rate injected from the fuel injection valve 5 toward the fuel injection path 6 is There are many. When this fuel containing a large amount of air is injected at high pressure into the minute annular gap formed by the fuel injection passage 6 and the cone member 9, the speed of the fuel containing air flowing through this gap The air is not weakened, and the fuel containing air that is finely and uniformly dispersed within the annular gap is injected into the intake passage B with a completely symmetrical injection shape that follows the annular gap. Ru.

On the other hand, when the engine is operated at low and medium speeds when the throttle valve 3 is opened to a low and medium opening degree, the fuel consumption of the engine is small compared to that of a high-speed operation trout, and the fuel injection valve 5 is injected into the fuel injection path. 6
The amount of fuel injected into the tank will be small.

However, in the injection valve injection path 7, the injection valve injection path 7
Air flows into the air passage 8 due to the negative pressure generated by the fuel flowing through the injector, mixes with the fuel flowing through the injection valve injection passage 7, and the fuel mixed with this air is injected into the fuel injection passage 6. Therefore, although the amount of fuel supplied into the fuel injection path 6 is small, the volume of fuel mixed with air within the annular gap of the fuel injection path 6 is not significantly reduced. It is possible to maintain a high flow rate of the fuel containing air flowing through the annular gap of the fuel injection passage 6 with a small reduction in the volume of the fuel, and prevent the fuel from adhering to the wall of the annular gap. Therefore, the fuel and air are well mixed, and the fuel that is finely and uniformly dispersed within the annular gap is injected into the intake passage B with a perfect annular injection shape that is symmetrical, following the annular gap. is injected into.

In this way, the annular air-containing fuel injected into the intake passage B is uniformly and well mixed with the air flowing through the four intake passages B. This is the open end 6B of the fuel injection path 6.
As mentioned above, the fuel injected into the air intake passage B is finely divided into a completely annular spray shape and is injected into the intake passage B.

and a plurality of connection parts 10 in the intake passage B, and the intake passage B
This is due to the fact that the air flow flowing through the intake passage B is equally divided and distributed symmetrically, and furthermore, the annular injected fuel is injected toward the vicinity of the inner wall of the intake passage B where the air flow velocity is fastest.

As a result, uniform fuel can be supplied to each intake pipe connected to each cylinder of the engine, and significant improvements in engine performance such as increased engine output and stable rotation can be achieved.

Furthermore, the open end 6B of the fuel injection passage 6 is connected to the intake passage B on the engine 5 side.
If the positive pressure part of the pulsating pressure generated during engine operation acts on the annular gap from the open end 6B, the upper part of the fuel injection path 6 will open toward the closed end 6A. Since high-pressure fuel is injected into the fuel injection passage 6 into the injection valve injection passage 7 which is closed and opens into the fuel injection passage 6, even if such positive pressure is received, the fuel injection passage 6
The fuel injected into the injector does not flow back into the injection path 7 and the air passage 8, and all the fuel injected into the fuel injection path 6 flows into the intake path B from the open end 6B without any time delay. Since the fuel is injected and supplied at high pressure, it is possible to prevent variations in the air-fuel mixture in each cylinder and to suppress delays in fuel discharge, thereby making it possible to stabilize rotation and improve acceleration response.

Moreover, when the opening of the injector injection path 7 to the fuel injection path 6 is opened toward the enlarged inclined portion 6C of the fuel injection path 6, the fuel injection path 6D on the upstream side of the enlarged starting point A of the fuel injection path 6 and the cone There is no particular need to provide an annular gap formed by the cylindrical portion 9B of the member 9.

According to this structure, the fuel injected from the fuel injection valve 5 passes through the injection valve injection path 7 to the open end 6 of the fuel injection path 6.
I
It is possible to further speed up the supply of fuel during the rapid acceleration operation during period a, and it is possible to further stably improve acceleration performance.

Furthermore, when fuel containing air is injected from the injection valve injection path 7 toward the cylindrical portion 9B of the cone member 9 in the fuel injection path 6, the fuel injection path 6 with a circular cross section and the cylinder of the cone member 9 The fuel containing air can be uniformly distributed within the annular gap formed by the cylindrical portion 9B. A relatively dense fuel distribution may occur in the annular gap.

This is because the fuel injected from the injection valve injection path 7 branches into two branches on the outer surface of the cylindrical portion 9B, detours around each branch, flows to the back side, and is converged in the annular gap on the back side. Due to fear.

On the other hand, in this example, the fuel containing air injected from the injection valve injection path 7 collides with the enlarged inclined protrusion 9A of the cone member 9, and according to this, a part of the fuel is The flow is deflected upward at the portion 9A, and by this deflection of the fuel, the amount of fuel reaching the annular gap on the back side of the cone member 9 can be suppressed, thus preventing the cone member 9 from expanding. A more uniform distribution of fuel can be achieved within the annular gap formed by the inclined protrusion 9A and the enlarged inclined part 6C of the fuel injection passage 6, and a more uniform fuel supply can be achieved. In this way, the enlarged inclined portion 6C
Even if the fuel is injected later, the original effect of the present invention is still maintained because the annular fuel can be supplied into the intake passage B from the open end 6B of the fuel injection passage 6.

Furthermore, if the downstream end 11A of the connecting portion 11 is located upstream of the open end 6B of the fuel injection path 6, the airflow turbulence generated near the downstream end 11A of the connecting portion 11 will be directly affected. This reduces the influence on the annularly injected fuel injected from the open end 6B of the fuel injection path 6, and enables uniform fuel supply.

Furthermore, if the cross-sectional shape of the connecting portion 11 is gradually reduced from upstream to downstream of the longitudinal axis x-x of the intake passage B, the turbulence in the airflow caused by the connecting portion 11 can be recovered from the connecting portion 1.
Since the mixing is carried out immediately near the downstream end 11A of the fuel pump 1, uniform mixing of the injected fuel and air is not hindered.

〔Effect of the invention〕

As described above, the fuel injection device according to the present invention provides the following special effects.

In a fuel injection device for an internal combustion engine that supplies fuel injected from a fuel injection valve to the engine via an intake passage downstream from a throttle valve.

It is located in the intake passage on the downstream side of the throttle valve, and is approximately parallel to the longitudinal axis x-x of the intake passage, and its upstream side is closed and its downstream side is open. A fuel injection path is provided with an expanding inclined portion whose inner diameter portion gradually expands toward the downstream side of the passage; an injector injection path opening into the injector; one end opening into the atmosphere or into the intake path upstream of the throttle valve;
An air passage whose other end opens into the injection path of the injector; a cone member having an enlarged inclined protrusion forming a gap; perpendicular to the longitudinal axis x-x of
Since the intake passage is connected to the inner wall of the intake passage with a plurality of connecting parts that divide the intake passage into equal parts, the fuel containing air injected into the intake passage from the open end of the fuel injection passage is transferred between the fuel injection passage and the cone member. Due to the gap formed, the flow velocity of the fuel injected from the fuel injection valve directly collides with the cone member without decreasing in the entire operating range from low-speed operation of the engine with a small fuel flow rate to high-speed operation with a large fuel flow rate. The fuel can be finely divided into annular gaps, and the continuously formed annular gaps force the fuel into an annular shape. It is possible to inject and supply fuel containing fine, completely annular air toward the inner wall of the intake passage in a flare shape, and since only the injection valve injection passage is open in the fuel injection passage and the air passage is not open. Even if a positive pressure portion of the pulsating pressure generated in the intake passage acts on the fuel injection passage, the fuel will not flow back into the air passage. By connecting the inner wall of the intake passage with multiple connecting parts, the airflow flowing through the intake passage is not biased and can be made symmetrical within the intake passage. Mixing with air can be made uniform and symmetrical, which is extremely effective in improving engine output and rotational stability, especially in SPI type fuel injection devices.

In addition, by reducing the cross-sectional shape of the connection part from the upstream side to the downstream side, it is possible to suppress air flow turbulence near the opening end of the fuel injection path, and furthermore, the downstream end of the connection part can be reduced. By arranging the fuel injection path upstream of the opening end, it is possible to suppress airflow turbulence, especially toward the opening end of the fuel injection path, and to ensure good engine operation without interfering with uniform mixing of fuel and air. performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part showing an embodiment of a fuel injection device according to the present invention, and FIG. 1. Throttle valve body 3. Throttle valve 4
, Injection valve body 5 , Fuel injection valve 6 , Fuel injection path 6 B , Open end C, Enlarged inclined portion 911 . Injection valve injection path 911. Cone member A 92. Enlarged inclined protrusion 0, ..., fuel injection path post IA, ..., downstream end 911. Enlargement starting point 8 , Air passage 9 B , Cylindrical part 11 , Connection part B , Intake passage

Claims (3)

[Claims] (1) In a fuel injection device for an internal combustion engine that supplies fuel injected from a fuel injection valve to the engine via an intake passage downstream of a throttle valve, the intake passage is located in the intake passage downstream of the throttle valve. The upstream side is closed and the downstream side is open, and the inner diameter part of the downstream opening gradually expands toward the downstream side of the intake path. a fuel injection passage provided with an enlarged slope portion; an injection valve injection passage opening into the fuel injection passage for injecting and supplying fuel injected from the fuel injection valve into the fuel injection passage; one end of which is connected to the atmosphere or an aperture; Opens in the intake passage upstream from the valve,
an air passage whose other end opens into the injector injection path; an annular air passage disposed at least within the enlarged slope of the fuel injection path and continuous along the longitudinal axis Y-Y of the fuel injection path together with the expansion slope; a cone member having an enlarged inclined protrusion forming a gap; A fuel injection device connected to an inner wall of an intake passage with a plurality of connection parts that are perpendicular to the longitudinal axis X-X of the passage and equally divide the intake passage. (2) The fuel injection device according to claim 1, wherein the cross-sectional shape of the connecting portion is gradually reduced from upstream to downstream of the longitudinal axis XX of the intake passage. (3) The fuel injection device according to claim 1, wherein the downstream end of the connecting portion is provided upstream of the opening end of the fuel injection path.