JP2583461B2 - Fuel injection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for injecting fuel pressurized by a fuel pump into an intake passage via a fuel injection valve, and particularly to a throttle valve. Fuel is injected from a single fuel injection valve toward the intake path on the downstream side, and the fuel is supplied to an intake pipe connected to each cylinder of the engine, so-called single point injection (hereinafter referred to as SPI) fuel injection. It concerns the device.

[Conventional technology]

JP-A-53-72923 as a fuel injection device in the SPI system
There is a number. This is because the fuel is discharged uniformly in the intake path,
The main purpose is to supply fine fuel evenly to each intake pipe connected to each cylinder. For this purpose, a throttle valve arranged upstream of a throttle valve that controls air passing through the throttle valve is provided. An internal air chamber for receiving air from a main air passage of
A circular fuel swirl chamber for receiving fuel injected by a fuel injector perpendicular to the inner surface to form a fuel ring therein; an orifice for restricting air flow through the atomizer; and vaporized mixing An outlet port for returning air to a main air passage downstream of the throttle valve.

Thus, fuel injected by the fuel injector in response to actuation by the electronic controller enters the groove at a relatively high rate and forms a fuel ring therein. Due to the circular motion of the fuel in the groove, the fuel spreads as a thin film on the inner surface of the groove. This film of fuel is gradually carried away by the flow of air exiting the orifice and broken into smaller particles than can be obtained with conventional atomizers.

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

[Problems to be solved by the invention]

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

~ 1.Ejecting fuel from the fuel injection valve eccentrically in the tangential direction of the groove, generating a vortex in the groove to form a thin film fuel ring on the inner surface of the groove, and gradually discharging this fuel ring by air According to this, when the spray angle of the fuel injected from the fuel injection valve into the groove changes, the spray angle of the fuel injection valve is generally 10 ° to 40 °. Even if the thin film vortex state of the fuel to be changed changes and the amount of air supplied from the orifice into the groove is constant, the amount of fuel carried out of the outlet port into the main air passage by the air may change, This is not preferable for supplying a uniform fuel (due to a change in the state of the thin film vortex).

When the discharge pressure of the fuel pump that supplies pressurized fuel to the fuel injection valve changes, the fuel pressure injected into the groove from the fuel injection valve changes, and according to this, the fuel formed on the inner surface of the groove Changes the state of the thin film vortex, and has the same problem as described above.

The injection energy of the fuel injected into the groove is used to generate a vortex on the inner peripheral surface of the groove, and does not positively act on mixing with the air supplied from the air passage. That is, the fuel film formed on the inner surface of the groove is gradually carried away by the flow of air coming out of the orifice. Therefore,
The fuel and air are not positively and finely mixed in the groove.

When the engine suddenly decelerates, 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 inside of the groove via the outlet.

The negative pressure of the intake air also acts on the fuel surface of the thin-film fuel ring formed on the inner peripheral surface of the groove, and may cause the fuel to separate inward of the groove. The fuel mixture in the vicinity is disturbed. In other words, the distribution of the fuel near the outlet of the groove becomes light and shade, thereby preventing a uniform supply of fuel.

The fuel injected from the fuel injection valve is injected into a groove having a relatively large chamber volume to form a fuel ring on the inner surface of the groove, and the flow rate of the fuel ring on the inner surface of the groove decreases as going downward. However, this fuel may be scattered (dripping) into the groove, and the mixing state of the fuel near the outlet of the groove deteriorates.

Injection shapes of the discharged fuel injected from the fuel injection valve include a flare type in which the fuel is diffused and a pencil beam type in which the fuel is converged. In order to form a vortex in the groove, it is desirable that the fuel makes a circular motion at a relatively high speed on the inner surface of the groove. For this purpose, a fuel injection valve having a pencil beam type injection shape is preferable. In the flare type, the fuel is unlikely to diffuse into the groove and generate a vortex on the inner surface of the groove.

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

2. As shown in FIGS. 3 and 4 of JP-A-53-72923, an orifice is provided between a groove and an outlet. Is mixed in a relatively large groove upstream of the orifice, and when the air-fuel mixture is supplied to the intake passage, the mixture is throttled again at the orifice. And it is not preferable in terms of fuel atomization.

The air chamber formed in the intake path, the vortex chamber and the inner wall of the intake path are connected at a single connection portion,
According to this, the airflow flowing in the intake passage becomes uneven, and it is difficult for the fuel and air to be mixed uniformly.

[Means for solving the problem]

The fuel injection device according to the present invention has been made in view of the above-mentioned problems, and aims at obtaining a fuel injection device excellent in atomization characteristics and uniformity of fuel in the SPI system. 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 the throttle valve. It is substantially parallel to the longitudinal axis XX, its upstream side is closed and its downstream side is open, and its inner diameter part temporarily expands toward the downstream side of the intake passage at the downstream side opening. A fuel injection path provided with an enlarged inclined portion; an injection valve injection path opening into the fuel injection path for injecting and supplying fuel injected from the fuel injection valve into the fuel injection path; Opened in the intake path on the more upstream side, the other end is an injection valve An air passage which opens into morphism path; disposed in the enlarged inclined portion of at least the fuel injection path,
The longitudinal axis YY of the fuel injection path together with the enlarged inclined portion
A cone member having an enlarged inclined protrusion that forms a continuous annular gap along the axis; a fuel in which the fuel injection passage is formed at the center in the intake passage downstream of the throttle valve. The injection path boss is orthogonal to the longitudinal axis XX of the intake path, and is connected to the inner wall of the intake path with a plurality of connecting portions for equally dividing the intake path.

[Action]

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. Air or air in the intake passage upstream of the throttle valve flows into the fuel flowing through the air through the air passage, and the fuel and air are mixed in the injection valve injection path, and the fuel containing this air is injected into the injection valve. The fuel is injected from the passage toward the cone member in the fuel injection passage.

The fuel that has collided with the cone member is dispersed at a high injection speed into an annular gap formed between the enlarged inclined portion of the fuel injection path and the enlarged inclined protrusion of the cone member. The fuel flows down toward the outlet of the fuel injection path, and is injected into the intake path from the downstream outlet of the fuel injection path.

In the fuel containing air flowing down the annular gap, the annular gap is formed with a relatively small volume (small gap), the flow rate of the air-containing fuel is not reduced, and further, the annular gap is downstream. By forming the fuel foam continuously toward the opening on the side, a reliable annular fuel foam can be formed, and the fuel containing the annularly formed air is supplied from the end of the fuel injection passage to the inner surface of the intake passage. It can inject while expanding toward.

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 portions that equally divide the intake passage, the airflow flowing through the intake passage flows symmetrically, and the annular air injected from the fuel injection passage is formed. The fuel contained and the air in the intake passage are uniformly mixed in the intake passage.

〔Example〕

Hereinafter, an embodiment of the fuel injection device according to the present invention will be described as a first embodiment.
This will be described with reference to FIG. FIG. 2 is a cross-sectional view of an essential part taken along line II-II of FIG.

Reference numeral 1 denotes a throttle valve body through which an intake passage B penetrates downward from above in FIG. 1, and is attached to a throttle valve shaft 2 rotatably supported by the throttle valve body 1 in the intake passage B. The intake valve B is controlled to be opened and closed by the throttle valve 3.

Reference numeral 4 denotes an injection valve main body disposed below the throttle valve main body 1. The intake passage B penetrates the injection valve main body 4 from above to below. 4, the intake path B penetrating the main bodies 1 and 4 in the vertical direction is formed.

5, when a current flows through the solenoid coil by a signal from an ECU (Electronic Control Unit) E, the core is sucked, and the needle valve, which is integral with the core, is sucked until it hits the spacer, and the valve is fully opened.
The fuel injection valve is a known fuel injection valve that injects fuel pressurized by a fuel pump from a tip portion thereof. (Description of the internal structure of the fuel injection valve is omitted.) Reference numeral 6 denotes a fuel injection path provided in the injection valve main body 4 and configured as follows. That is, the fuel injection passage 6 has a circular cross section, is located in the intake passage B downstream of the throttle valve 3 (downward in FIG. 1 and on the engine side), and has a longitudinal axis line of the fuel injection passage 6. YY is on the longitudinal axis XX of the intake passage B, and its upstream side is closed at the closed end 6A, and its downstream side is directed toward the inside of the intake passage B via the open end 6B. Open.

Then, the inner diameter of the fuel injection path 6 temporarily increases toward the opening end 6B downstream from the expansion start point A (between the closed end 6A and the opening end 6B of the fuel injection path 6). Inclined part 6C
Is provided. The enlarged inclined portion 6C has an inner diameter continuously enlarged along the longitudinal axis Y-Y of the fuel injection path 6, and the inclined portion may be linear or curved. It may be in a shape. However, the inner diameter is enlarged and must not be reduced (rotate shape).

 FIG. 1 shows a linear enlarged inclined portion 6C.

Reference numeral 7 denotes a fuel injection passage 6
This is an injection valve injection path for injecting fuel into the fuel injection valve. One end of the injection valve injection path 7 is connected to the injection port of the fuel injection valve 5, and the other end is open to the fuel injection path 6. The longitudinal axis Z-Z of the injection valve injection path 7 opens toward the longitudinal axis Y-Y of the fuel injection path 6 and, in the present example, the fuel injection path 6 upstream of the enlarged starting point A. Open to (Note that the fuel injection valve 5 may be disposed in the throttle valve main body 1.) One end of the fuel injection valve 5 is opened in the intake passage B upstream of the throttle valve 3 and the other end thereof is in the injection valve injection passage 7. It is an air passage that opens, and one end of this air passage 8 may be open to the atmosphere.

A cone member 9 that forms an annular gap with the inner diameter of the fuel injection path 6 is disposed in the fuel injection path 6.

The cone member 9 is disposed within the enlarged inclined portion 6C of the fuel injection path 6 and has an enlarged inclined protrusion 9A having an enlarged portion that is continuous toward the downstream side, and a fuel having a circular cross section upstream of the enlarged origin A. And a cylindrical portion 9B disposed in the injection path 6D.
, The cylindrical portion 9B of the cone member 9, and the enlarged inclined path 6C and the enlarged inclined protrusion 9A of the cone member 9 form a continuous annular gap from above to below.

Thus, at the opening end 6B of the fuel injection path 6, an annular gap opens toward the intake path B on the downstream side. The annular gap is preferably about 1 mm, but is not limited to this value and may be set as appropriate.

The fuel injection path 6 having the cone member 9 therein is bored in the fuel injection path boss 10, and the fuel injection path boss 10 is disposed in the intake path B downstream of the throttle valve 3. Thus, it is integrally connected to the inner wall of the intake passage B with the connecting portion 11.

The connecting portion 11 has the following structure in particular. That is, the connecting portion 11 is orthogonal to the longitudinal axis XX of the intake passage B, one end is connected to the inner wall of the intake passage B, the other end is connected to the outer diameter of the fuel injection passage boss 10, and A plurality of roads are arranged so as to divide the road B equally. In this example, since the intake path B is divided into two, the connecting portions 11 are arranged on a straight line. When dividing into three, the connecting portions 11 are arranged at intervals of 120 degrees.

Reference numeral 12 denotes a fastening screw for mounting the cone member 9 in the fuel injection path 6. Reference numeral 13 denotes a fuel passage connected to a fuel pump (not shown), and the fuel injection valve 5 receives supply of fuel from the fuel passage 13.

 Next, the operation will be described.

During operation of the engine, air controlled by the throttle valve 3 and air passing through the air passage 8 flow into the intake passage B downstream of the throttle valve 3, while fuel is injected from the fuel injection passage 6. The fuel controlled by the valve 5 is injected toward the intake passage B.

Here, the behavior of air and fuel flowing through the fuel injection path 6 will be seen. The fuel injected from the fuel injection valve 5 by the output signal from the ECU E is injected via the injection valve injection path 7 into the fuel injection path 6D upstream of the enlarged starting point A. In the air passage 8, an opening 8B at one end opens into the atmosphere or the intake passage B upstream of the throttle valve 3, and an opening 8A at the other end opens into the injection path 7 of the injection valve. In the injection valve injection path 7,
As described above, the fuel pressurized to a high pressure (for example, 2.55 kg / cm ² ) by the fuel pump (not shown) is discharged through the fuel injection valve 5 and flows therethrough. A negative pressure due to the high-pressure fuel flow is generated in the opening 8A at the other end that opens into the inside, whereby the opening 8A at the other end of the air passage 8 is generated.
Is lower than the pressure of the opening 8B at one end, the opening 8B at one end of the air passage 8 extends from the opening 8B at the other end.
Air flows down to 8A, and this air is drawn into the fuel flowing in the injection path 7 and mixed.

Thus, fuel mixed with air (fuel including air) is injected into the fuel injection passage 6D upstream of the enlarged starting point A via the injection valve injection passage 7. The fuel containing air injected into the fuel injection path 6D collides with the cylindrical portion 9B of the cone member 9 at a high speed. The fuel containing air scatters finer due to the collision, and the cylindrical portion 9B scatters. Finely dispersed throughout the outer periphery of 9B. This is because the annular gap formed by the fuel injection path 6D upstream of the expansion starting point A and the cylindrical portion 9B of the cone member 9 is minutely formed, and the injection including air is maintained. Achieved by not slowing down the fuel.

The fuel containing finely dispersed air having a high speed in 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 enlarged starting point A is used for the cone member 9. The enlarged inclined protrusion 9A and the enlarged inclined portion 6C of the fuel injection path 6
Are injected into the annular gap formed by the above, and flow down along the inclined annular gap while being uniformly dispersed in the annular gap.

This is because the flow rate of the fuel containing the dispersed air can be suppressed from being reduced by the small annular gap, and the inclined annular gap is formed by the longitudinal axis YY of the fuel injection path 6.
And the flow direction of the fuel containing air is regulated at a certain distance.

The fuel mixed with the air is supplied to the fuel injection path 6
Is injected into the intake passage B from the annular gap formed at the opening end 6B of the nozzle with a complete annular spray shape evenly distributed.

Here, in the present invention, the following points must be particularly noted. In order to supply uniform fuel to each cylinder constituting the engine, it is necessary to supply symmetric, fine and uniform fuel at least in the intake passage of the fuel injection device. Here, regarding the high-speed operation of the engine in which the throttle valve 3 is opened at a high opening, the fuel flow rate of the fuel injected from the fuel injection valve 5 toward the fuel injection path 6 is large because the fuel consumption of the engine is large. There are many. When the fuel containing a large amount of air is injected at a high pressure into a small annular gap formed by the fuel injection passage 6 and the cone member 9, the speed of the fuel containing the air flowing through the gap is increased. The fuel containing air, which is finely and uniformly dispersed in the annular gap without being weakened, is injected into the intake passage B with a complete annular injection shape having symmetry following the annular gap. You.

On the other hand, when the engine in which the throttle valve 3 is opened to a low-medium opening degree is operated at low and medium speeds, the fuel consumption of the engine is smaller than that at the time of high-speed operation. The amount of fuel injected into the inside becomes small.

However, air flows into the injection valve injection path 7 from the air passage 8 due to a negative pressure or the like generated by the fuel flowing through the injection valve injection path 7, and mixes with the fuel flowing through the injection valve injection path 7. The fuel mixed with the fuel is injected into the fuel injection path 6, and the capacity of the fuel mixed with air in the annular gap of the fuel injection path 6 is not greatly reduced. Accordingly, although the amount of fuel supplied to the fuel injection path 6 is small, the volume of the fuel mixed with the air is small and the flow rate of the fuel containing air flowing through the annular gap of the fuel injection path 6 is increased. A fuel that can be held and does not adhere to the wall surface of the annular gap, the fuel and the air are mixed well, and the fuel is finely and uniformly dispersed in the annular gap. Is injected into the intake passage B with a perfect annular injection shape having symmetry following the annular gap.

As described above, the fuel containing the annular air injected into the intake passage B is uniformly and well mixed with the air flowing through the intake passage B. This is the open end 6B of the fuel injection path 6.
The fuel to be injected is injected into the intake passage B in a fine and complete annular spray shape as described above.

And a plurality of connecting portions 10 in the air passage B,
Are equally divided so that the airflow flowing in the intake passage B is symmetrically distributed. Further, the annular injected fuel is injected toward the vicinity of the inner wall of the intake passage B having the highest air flow velocity.

Thus, uniform fuel can be supplied to each intake pipe connected to each cylinder of the engine, and remarkable improvement in engine performance such as improvement in engine output and stability of rotation can be achieved.

The opening end 6B of the fuel injection passage 6 is connected to the intake passage B on the engine side.
When the positive pressure portion of the pulsating pressure generated during operation of the engine acts in the annular gap from the open end 6B, the upper part of the fuel injection path 6 is closed at the closed end 6A.
The high-pressure fuel is injected into the fuel injection path 6 into the fuel injection path 6 which is closed by the opening and opens to the fuel injection path 6. The injected fuel does not flow back into the injection valve injection path 7 and the air path 8, and all the fuel injected into the fuel injection path 6 is injected with high pressure from the open end 6B into the intake path B without time delay. Since the fuel is supplied, variation of the air-fuel mixture in each cylinder can be prevented, and a delay in fuel discharge can be suppressed, whereby rotation stability and acceleration responsiveness can be improved.

Further, when the opening of the injection valve 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 upstream of the expansion start point A of the fuel injection path 6 is connected to the cone. The annular gap formed by the cylindrical portion 9B of the member 9 does not have to be particularly provided.

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 of the fuel injection path 6.
Since the fuel is injected into the enlarged inclined portion 6C relatively close to 6B, the fuel supply can be further accelerated during the rapid acceleration operation of the engine, and the stability of the acceleration performance can be further improved.

Further, 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 having a circular cross section and the cylinder of the cone member 9 are formed. The fuel containing air can be evenly distributed in the annular gap formed by the cylindrical portion 9B, but is formed on the back side of the cylindrical portion 9B of the cone member 9 facing the opening of the injection valve injection path 7. A relatively dense fuel distribution may occur in the annular gap.

This is because the fuel injected from the injection valve injection path 7 bifurcates the outer surface of the cylindrical portion 9B and bypasses each to flow to the back side portion, where they converge in the annular gap of the back side portion. Due to fear. On the other hand, in the present example, the fuel containing air injected from the injection valve injection path 7 is:
The collision with the enlarged inclined projection 9A of the cone member 9 causes a part of the fuel to be deflected upward at the enlarged inclined projection 9A.
The amount of fuel reaching the annular gap portion on the back side of the fuel injection passage 6 can be suppressed. Therefore, the annular shape formed by the enlarged inclined protrusion 9A of the cone member 9 and the enlarged inclined portion 6C of the fuel injection path 6 can be suppressed. It is possible to achieve a more uniform fuel distribution in the gap and to supply a more uniform fuel. Even if fuel is injected into the enlarged inclined portion 6C, the annular fuel can be supplied into the intake passage B from the open end 6B of the fuel injection passage 6, so that the original effect of the present invention is still retained.

When the downstream end 11A of the connecting portion 11 is located at a position upstream of the open end 6B of the fuel injection path 6, the turbulence of the air flow generated near the downstream end 11A of the connecting portion 11 is directly increased. Therefore, the influence on the annular injected fuel injected from the opening end 6B of the fuel injection path 6 is reduced, and uniform fuel supply can be performed.

Furthermore, when the cross-sectional shape of the connecting portion 11 is temporarily reduced from upstream to downstream of the longitudinal axis XX of the intake path B, the turbulence of the air flow generated by the connecting portion 11 is recovered. Since it is performed immediately near the downstream end 11A, uniform mixing of the injected fuel and air is not hindered.

〔The invention's effect〕

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

In a fuel injection device for an internal combustion engine, which supplies fuel injected from a fuel injection valve to an engine via an intake passage downstream of a throttle valve, the fuel injection device is located in an intake passage downstream of the throttle valve and extends in a longitudinal direction of the intake passage. Substantially parallel to the axis XX,
A fuel injection passage having an upstream side closed and a downstream side opened, and a downstream side opening provided with an enlarged inclined portion whose inner diameter portion is temporarily enlarged toward the downstream side of the intake path; An injection valve injection path that opens into the fuel injection path to inject the injected fuel into the fuel injection path; one end opens into the atmosphere or an intake path upstream of the throttle valve, and the other end injects An air passage opening into the valve injection passage; disposed at least in an enlarged inclined portion of the fuel injection passage;
The longitudinal axis YY of the fuel injection path together with the enlarged inclined portion
A cone member having an enlarged inclined projection that forms a continuous annular gap along the axis; and a fuel injection passage formed at the center in the intake passage downstream of the throttle valve. Since the injection path boss is orthogonal to the longitudinal axis XX of the intake path and is connected to the inner wall of the intake path with a plurality of connecting portions for equally dividing the intake path, the intake port is opened from the open end of the fuel injection path. The fuel containing air injected into the passage is reduced in the flow rate of the fuel injected from the fuel injection valve by the gap formed by the fuel injection passage and the cone member from the low-speed operation of the engine in which the fuel flow rate is small to the fuel flow rate. In the entire operation range up to large high-speed operation, it can be directly collided with the cone member without lowering and can be finely dispersed in the annular gap, and the fuel is forced to annular by the continuously formed annular gap The throttle valve opening was low. Until a high opening degree, uniform and fine fuel containing complete annular air can be injected and supplied in a flared manner toward the inner wall of the intake passage, and only the injection valve injection passage is opened in the fuel injection passage. However, since the air passage is not open, even if a positive pressure portion of the pulsating pressure generated in the intake passage acts in the fuel injection, the fuel does not flow back into the air passage. By connecting the fuel injection passage boss to the inner wall of the intake passage with a plurality of connecting portions for equally dividing the intake passage, the air flow flowing in the intake passage can be made symmetrical in the intake passage without being offset. As a result, the mixing of fuel and air in the intake passage can be made uniform and symmetrical, and these are extremely effective in improving engine output and improving rotational stability especially in SPI type fuel injection systems. Playing That.

Further, according to the provisional reduction of the cross-sectional shape of the connecting portion from the upstream to the downstream, it is possible to suppress the turbulence of the air flow near the opening end of the fuel injection path, and further to reduce the downstream end of the connecting portion. According to the arrangement upstream of the open end of the fuel injection path, it is possible to suppress the turbulence of the air flow, particularly to the open end of the fuel injection path, and to achieve good engine operation without impeding uniform mixing of fuel and air. Performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a fuel injection device according to the present invention, and FIG. 2 is a longitudinal sectional view of an essential part along line II-II in FIG. DESCRIPTION OF SYMBOLS 1 ... Throttle valve body, 3 ... Throttle valve 4 ... Injection valve body, 5 ... Fuel injection valve 6 ... Fuel injection path, 6B ... Open end 6C ... Enlarged inclined section 7 ... Injection valve injection Road 8 Air passage 9 Cone member 9A Enlarged inclined projection 9B Cylindrical part 10 Fuel injection path boss 11 Connection part 11A Downstream end A A Enlarged Starting point, B ... Intake path

Claims (3)

(57) [Claims] 1. A fuel injection device for an internal combustion engine for supplying fuel injected from a fuel injection valve to an engine via an intake passage downstream of a throttle valve, wherein the fuel injection device is located in an intake passage downstream of the throttle valve. It is substantially parallel to the longitudinal axis XX of the intake passage, its upstream side is closed and its downstream side is open, and the downstream side opening has an inner diameter portion facing the downstream side of the intake passage for a while. A fuel injection path provided with an enlarged inclined portion that expands next; an injection valve injection path that opens into the fuel injection path to supply fuel injected from the fuel injection valve into the fuel injection path; Or, open in the intake path upstream of the throttle valve,
An air passage opening at the other end into the injection valve injection path; an annular passage disposed at least in the enlarged inclined section of the fuel injection path and continuous along the longitudinal axis Y-Y of the fuel injection path together with the enlarged inclined section. A cone member having an enlarged inclined projection that forms a gap; and a fuel injection passage boss in the intake passage downstream of the throttle valve, the fuel injection passage being formed at the center at the center. A fuel injection device connected to the inner wall of the intake passage with a plurality of connecting portions that are orthogonal to the longitudinal axis XX 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 temporarily reduced from upstream to downstream of the longitudinal axis XX of the intake passage. 3. The fuel injection device according to claim 1, wherein a downstream end of said connection portion is provided upstream of an open end of the fuel injection path.