JP2583458B2 - 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 breaks down 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.

Fuel was injected from the fuel injection valve eccentrically in the tangential direction of the groove to generate a vortex in the groove to form a thin fuel ring on the inner surface of the groove, and this fuel ring was gradually carried out 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 unfavorable for supplying a uniform fuel (which means that the state of the thin film vortex has changed).

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, but the flow velocity 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.

[Means for solving the problem]

The fuel injection device according to the present invention has been made in view of the above-mentioned disadvantages, and aims to obtain a fuel injection device having excellent fuel atomization characteristics and uniformity in the SPI method. 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 the inside of the downstream side opening gradually expands toward the downstream side of the intake passage. A fuel injection path provided with an inclined portion; an injection valve injection path which is opened in the fuel injection path to supply the fuel injected from the fuel injection valve into the fuel injection path; Opened in the intake path on the upstream side, the other end is an injection valve An air passage which opens into the upstream side of the fuel injection passage through the opening of the Colors of the fuel injection 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
And a cone member having an enlarged inclined projection that forms a continuous annular gap along the axis.

[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, while the air or the air is discharged from the air path. Air in the intake passage upstream of the throttle valve flows into 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 portion of the cone member. The fuel is mixed with air flowing down toward the outlet of the injection path, and is injected from the outlet on the downstream side of the fuel injection path into the intake path.

In the fuel flowing down the annular gap, the annular gap is formed with a relatively small volume (small gap), the flow velocity of the fuel does not decrease, and the air velocity flowing through the annular gap is high. Since the gap is formed continuously toward the downstream opening, a reliable annular fuel foam can be formed, and the annularly formed fuel is directed from the end of the fuel injection passage toward the inner surface of the intake passage. It can spray while expanding.

〔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. 2, FIG. 2, FIG. 3, and FIG. FIG. 2 is a cross-sectional view of an essential part taken along the line II-II of FIG. 1, and FIG.
FIG. 4 is a cross-sectional view of a main part taken along the line III-III of FIG.
FIG. 4 is a cross-sectional view of a main part taken along line IV-IV.

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, an intake path B penetrating the main bodies 1 and 4 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 the flange portion contacts 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, its upstream side is closed, and its downstream side opens into the intake passage B through the open end 6B.

Then, the inner diameter of the fuel injection passage 6 gradually 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 passage 6). 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 (funnel 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 opens into the fuel injection path 6 upstream of the enlarged starting point A. (Note that the fuel injection valve 5 may be disposed in the throttle valve body 1.) One end of the fuel injection valve 8 is opened in the intake passage B upstream of the throttle valve 3 and the other end is provided in the fuel injection passage 7 of the injection valve. It is an air passage that opens into the fuel injection passage 6 upstream of the opening to the injection passage 6, and one end of the air passage 8 may be open to the atmosphere. The longitudinal axis PP of the air passage 8 opens toward the longitudinal axis YY of the fuel injection path 6.

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 co-member 9 is disposed in the enlarged inclined portion 6C of the fuel injection path 6 and has an enlarged inclined projection 9A having an enlarged portion that is continuous toward the downstream side, and a fuel injection path 6D that is located upstream of the enlarged starting point A.
And a cylindrical portion 9B disposed inside the fuel injection passage 6D and the cylindrical portion 9 upstream of the enlarged starting point A.
B, the enlarged inclined portion 6C and the enlarged inclined protrusion 9A 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.

Reference numeral 10 denotes a fastening screw for mounting the cone member 9 in the fuel injection path 6. Reference numeral 11 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 11.

 Next, this 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 the fuel injection valve 6 The fuel controlled at 5 is injected toward the intake path B.

Here, the behavior of air and fuel flowing through the fuel injection path 6 will be seen. In the air passage 8, one end of the air passage 8 is open to the atmosphere or the intake passage B upstream of the throttle valve 3, and the other end is connected to the intake passage B downstream of the throttle valve 3. And the pressure at the other end 8A of the air passage 8 is
Since the pressure becomes lower than the pressure of 8B, the air flows from one end opening 8B of the air passage 8 into the fuel injection path 6 through the other end opening 8A, and the air flowing into the fuel injection path 6 The fuel flows down the annular gap formed by the injection path 6 and the cone member 9, and is sucked into the intake path B with an annular airflow from the open end 6 B of the fuel injection path 6.

This is because a negative pressure acts on the annular gap formed at the open end 6B of the fuel injection path 6 in the intake path B downstream of the throttle valve 3. (Note that, as will be described later, it is not actually the case that only air is sucked out from the opening end 6B of the fuel injection passage 6, and this air is mixed with fuel and sucked out into the intake passage B. In the meantime, the behavior of only the air flow was observed.) On the other hand, the output signal from the ECU E
The more injected fuel is injected into the fuel injection passage 6D upstream of the enlarged starting point A via the injection valve injection passage 7. The fuel injected into the fuel injection path 6D collides with the cylindrical portion 9B of the cone member 9 at a high speed, and the fuel is finely scattered by the collision, and is finely distributed over the entire outer periphery of the cylindrical portion 9B. Disperse in. This is because the annular gap formed by the fuel injection passage 6D upstream of the enlarged starting point A and the cylindrical portion 9B of the cone member 9 is minutely formed (maintained in a small volume) to reduce the speed of the injected fuel. Achieved by not lowering.

The finely dispersed fuel having a high speed in the annular gap between the cylindrical portion 8B of the cone member 8 and the fuel injection path 6D upstream of the enlarged starting point A flows through the annular gap as described above. It is mixed with air and further refined, and is injected into an annular gap formed by the enlarged inclined projection 8A of the cone member 8 and the enlarged inclined section 6C of the fuel injection path 6, and is uniformly distributed in the annular gap. It flows down along the inclined annular gap while being dispersed.

This is because the decrease in the flow velocity of the dispersed fuel due to the small annular gap was suppressed, and the fuel was positively mixed with the air flow flowing through the annular gap toward the opening end 6B, This is achieved by forming the inclined annular gap continuously along the longitudinal axis YY of the fuel injection path 6 to regulate the flow direction of the fuel with 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 this large amount of fuel is injected into the small annular gap formed by the fuel injection path 6 and the cone member 9, the speed of the fuel mixed with the air flowing through this gap is sufficiently increased, and The fuel finely and uniformly dispersed in the gap is injected into the intake passage B with a perfect annular injection shape having symmetry following the annular gap.

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,
When the throttle valve 3 is at a low or medium opening degree, the pressure difference between the intake path B on the upstream side of the throttle valve 3 and the intake path B on the downstream side is large because the throttle valve 3 is in a relatively closed state. It becomes
According to this, the flow velocity of the air flowing down the fuel injection passage 6 through the air passage 8 can be sufficiently increased.

Thus, although the flow rate of the fuel flowing through the fuel injection path 6 (annular gap) is small, the flow rate of the air flowing through the fuel injection path (annular gap) is high, so that the fuel adheres to the wall surface of the annular gap. The fuel and the air are mixed well, and the fuel finely and uniformly dispersed in the annular gap has a perfect annular injection shape having symmetry following the annular gap. It is injected into B.

As described above, the annular fuel injected into the intake passage B is:
It is uniform and well mixed with the air flowing in the intake passage B. This is because the fuel injected from the open end 6B of the fuel injection path 6 forms a complete annular spray shape as described above and is expanded from the open end 6B and injected toward the inner wall of the intake path B. It depends. That is, the fastest part of the air flow velocity flowing in the intake passage B is a part relatively close to the inner wall of the intake passage B, and the fuel injected from the open end 6B of the fuel injection passage 6 becomes This is because the annular fuel is uniformly injected toward the inlet, and the fuel is well mixed with the air flowing through the intake passage B.

Thus, since uniform fuel having symmetry can be injected into the intake passage B, uniform fuel can be supplied to each intake pipe connected to each cylinder of the engine, thereby improving the output of the engine and stabilizing the rotation. And other remarkable improvements in engine performance.

Further, the effective area S ₂ of the injection valve injection path 7 must be one that allows the maximum injection amount of fuel injected from the fuel injection valve 5, the effective area S ₁ of the air passage 8, injector injection path than that fuel injected from 7 shall be sufficiently atomized mixture, must be greater than the effective area S ₂ of the injection valve injection path 7, more effective area S ₃ of the annular gap ,
And larger than the effective area S ₁ of the air passage as otherwise of inhibiting fuel flow is mixed with air.

FIG. 5 shows another embodiment, and only parts different from the structure of FIG. 1 will be described. (The same structure uses the same reference numerals as in FIG. 1.) The longitudinal axis YY of the fuel injection path 6 is substantially parallel to the longitudinal axis XX of the intake path B, and the inner wall of the intake path B It is eccentric by h toward the side. (In this example, it is eccentric to the left in FIG. 4.) According to this, as shown by the dashed line in FIG.
When the throttle valve 3 is opened, a large amount of air tends to flow to the left side of the intake passage B due to the downward slope of the throttle valve 3. Is drawn to the left side of the intake passage B, and the fuel distribution in the intake passage B can be intentionally changed. This is particularly the case in a SPI system in which fuel is supplied to each intake pipe from a single fuel injection valve 5 when a specific cylinder requires a rich air-fuel mixture as compared with other cylinders (in other words, a specific This is effective as a means for correcting the fuel supply characteristics to the cylinder when the cylinder requires a mixture mixture thinner than the other cylinders).

FIG. 6 shows still another embodiment, and only parts different from the structure of FIG. 1 will be described. That is, in this embodiment, 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.

According to this structure, the fuel injected from the fuel injection valve 5 is injected into the enlarged inclined portion 6C relatively close to the open end 6B of the fuel injection path 6, so that the fuel is supplied during the rapid acceleration operation of the engine. The delay can be suppressed, and the stability of the acceleration performance can be improved. 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.

〔The invention's effect〕

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

A fuel injection device for an internal combustion engine that supplies 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 and extends in a longitudinal direction of the intake passage. An enlarged inclined portion which is substantially parallel to the axis XX, whose upstream side is closed and whose downstream side is open, and whose downstream side opening has an inner diameter portion gradually expanding toward the downstream side of the intake passage. A fuel injection path provided with: an injection valve injection path opened in the fuel injection path for injecting and supplying the fuel injected from the fuel injection valve into the fuel injection path; one end being upstream of the atmosphere or the throttle valve An air passage opening in the intake passage, and the other end opening in the fuel injection passage on the upstream side of the opening of the injection valve injection passage into the fuel injection passage; at least in the enlarged inclined portion of the fuel injection passage ,
The longitudinal axis YY of the fuel injection path together with the enlarged inclined portion
And a cone member having an enlarged inclined projection that forms a continuous annular gap along the fuel injection device, the fuel injected into the intake path from the open end of the fuel injection path is The flow rate of the fuel injected from the fuel injection valve does not decrease due to the gap formed by the passage and the cone member, and the fuel directly collides with the cone member and can be finely dispersed in the annular gap. And the fuel is forcibly made annular by a continuously formed annular gap, so that the throttle valve can be uniformly and finely divided from a low opening to a high opening. Thus, complete annular fuel can be injected and supplied toward the inner wall of the intake passage.

Thus, the present invention has an extremely large effect on improving the output of the engine and improving the stability of rotation, particularly in the SPI type fuel injection device.

Further, the fuel injected from the fuel injection valve into the fuel injection path via the injection valve injection path only needs to maintain a particular flow velocity, and is not affected by the spray shape and the spray angle of the fuel injected from the fuel injection valve. Spray-shaped fuel injectors can also be used.

The shape and angle of the fuel injected into the intake path via the fuel injection path can be changed by changing the shape (straight line, curve, compound line) of the enlarged inclined portion or the annular gap. The fuel supply characteristics to the pipe can be changed, and the degree of freedom of adaptation to the engine can be increased.

According to the arrangement of the longitudinal axis YY of the fuel injection path on the longitudinal axis XX of the intake path, the annular fuel formed by the fuel injection path and the cone member is Since the fuel is injected toward the center of the intake passage, uniform fuel can be supplied into the intake passage, and uniform fuel supply can be performed to the intake pipes connected to the cylinders.

Further, according to the fact that the longitudinal axis YY of the fuel injection path is substantially parallel to the longitudinal axis XX of the intake pipe and is eccentric to one side, the fuel distribution in the intake path is reduced. In particular, in the SPI system, when a specific cylinder requires a different fuel amount from other cylinders, it is possible to easily cope with the change.

Further, according to the fact that the injection valve injection path is opened to the fuel injection path on the upstream side of the enlarged starting point A of the enlarged inclined portion of the fuel injection path, the fuel is injected into the annular gap formed by the fuel injection path and the cone member. This allows a sufficient distance in the longitudinal direction with respect to the longitudinal axis of the injection path, whereby the fuel can be reliably formed in an annular shape and the directivity of the annular fuel along the enlarged inclined portion can be increased. it can. The increased directivity can improve the mixing with air in the intake passage.

Further, since the injection valve injection path is opened at the enlarged inclined portion of the fuel injection path, annular fuel supply can be performed from the fuel injection path, and the time required for fuel injected from the fuel injection valve to reach the intake path is increased. Therefore, the acceleration operability of the engine can be particularly improved.

According to the opening of the longitudinal axis Z-Z of the injection valve injection path and the longitudinal axis P-P of the air passage toward the longitudinal axis Y-Y of the fuel injection path, The fuel injected from the fuel injection valve and the air flowing into the fuel injection path from the air passage collide with the center of the cone member, and the fuel atomized by the air is reduced over the entire outer circumference of the cone member. The fuel can be scattered, whereby the uniform and fine fuel can be dispersed in the annular gap formed by the fuel injection path and the cone member, so that the uniform annular fuel can be injected into the intake path. .

In addition, an intake passage penetrates the inside, a throttle valve body having a throttle valve that controls the opening and closing of the intake passage, and a fuel injection passage, an injection valve injection passage, an air passage, and a cone member that penetrate the inside of the intake passage. According to the fact that the injection valve body is formed of a synthetic material, the fuel injection path, the fuel injection valve, and the like are not arranged in the intake path of the throttle valve body, Perfect circular processing can be performed easily. The processing of the intake passage is important in limiting the fully closed air amount of the throttle valve.

Further, the throttle valve body and the injection valve body may be changed for adaptation to the engine. In such a case, only one of the main bodies needs to be changed, so that versatility can be improved.

In addition, according to the injection valve body formed of a synthetic resin material, the surface of the enlarged inclined portion of the fuel injection path can be formed smoothly without any processing, and this can form a reliable annular fuel, It is possible to promote uniformity of fuel in the intake passage.

Further, the effective area S _{3 of} the annular gap formed by the enlarged inclined portion of the fuel injection passage and the enlarged inclined protrusion of the cone member, the effective area S ₂ of the injection valve injection passage, and the effective area S ₁ of the air passage are represented by S. ₃ >
According to S ₁ > S ₂ , it is possible to surely supply the fuel into the intake passage without obstructing the flow of the fine fuel mixed with the air in the annular gap.

[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, FIG. 2 is a transverse sectional view of an essential part along a line II-II in FIG. 1, and FIG. FIG. 4 is a cross-sectional view of a main part taken along line IV-IV in FIG. 1, and FIGS. 5 and 6 are vertical cross-sectional views of main parts showing another embodiment. 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 ... Expansion inclined portion 6D ... Expansion start point A More upstream fuel injection path 7 ... injection valve injection path, 8 ... air path 9 ... cone member 9A ... enlarged inclined protrusion, 9B ... cylindrical part A ... expanded start point, B ... intake path

Claims (8)

(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 opened, and the inside diameter portion of the downstream side opening gradually decreases toward the downstream side of the intake passage. A fuel injection path provided with an enlarged inclined portion that expands; 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; Open in the intake passage upstream of the throttle valve,
An air passage having the other end opened in the fuel injection passage upstream of the opening of the injection valve injection passage into the fuel injection passage; and an air passage disposed at least in the enlarged inclined portion of the fuel injection passage and the fuel injection passage together with the enlarged inclined portion. A cone member having an enlarged inclined projection that forms a continuous annular gap along the longitudinal axis Y-Y of the fuel injection device. 2. A longitudinal axis YY of the fuel injection path.
2. The fuel injection device according to claim 1, wherein the fuel injection device is disposed on a longitudinal axis XX of the intake passage. 3. A longitudinal axis YY of the fuel injection path.
2. The fuel injection device according to claim 1, wherein the fuel injection device is substantially parallel to the longitudinal axis XX of the intake passage and is eccentric to one side of the intake passage. 4. The fuel injection device according to claim 1, wherein said injection valve injection path is opened to a fuel injection path upstream of an expansion starting point A of an expansion inclined portion of the fuel injection path. 5. The fuel injection device according to claim 1, wherein said injection valve injection path is opened at an enlarged inclined portion of the fuel injection path. 6. A longitudinal axis Z- of the injection valve injection path.
2. The fuel injection device according to claim 1, wherein Z, the longitudinal axis PP of the air passage is opened toward the longitudinal axis XX of the fuel injection path. 7. A throttle valve body having an intake passage penetrating therethrough and a throttle valve for controlling opening and closing of the intake passage, a fuel injection passage, an injection valve injection passage, an air passage, and an intake passage penetrating the inside.
And an injection valve body with a cone member,
2. The fuel injection device according to claim 1, wherein the injection valve body is formed of a synthetic resin material. 8. The effective area S _{3 of} the annular gap formed by the enlarged inclined portion of the fuel injection path and the enlarged inclined projection of the cone member, the effective area S ₂ of the injection valve injection path, and the effective area of the air passage.
The _{S 1, S 3> S 1} > fuel injector ranging first claim of claims made as S _2.