JPH04128559A - Fuel injector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a method for injecting fuel pressurized by a fuel pump through a fuel injection valve. Regarding the fuel injection device that injects fuel into the intake passage, especially toward the intake passage downstream of the throttle valve,
The so-called single-point injection method (hereinafter referred to as the SPI method) injects fuel from a single fuel injection valve and supplies this fuel to the intake pipes connected to each cylinder of the engine.
The present invention relates to a fuel injection device.

[Conventional technology]

As such an SPI type fuel injection device, Japanese Patent Application Laid-Open No. 51-7
There is No. 2923. The purpose of this technology is to uniformly discharge fuel into the intake passage and to evenly supply fuel to each of the two intake pipes connected to each cylinder.
An internal air chamber located downstream of the throttle valve that controls the airflow through the throttle valve and receives air from the throttle valve σ main air passage, and a fuel injected by the fuel injector perpendicular to the inner surface of the throttle valve. F-type fuel N that receives and forms a fuel ring inside.
It includes a vortex chamber, an orifice to limit the leakage of air through the atomizer, and an outlet boat to return 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 causes the fuel to spread in a thin film over 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.

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

(Problems to be Solved by the Invention) This conventional fuel injection device has the following problems to be solved.

~1. This is because the fuel is injected from the fuel injection valve eccentrically in the tangential direction of the groove, creating a vortex within the groove and forming a fuel ring within the groove; ■ Spray of fuel injected into the groove from the fuel injection valve As the angle changes (the spray angle of the fuel injector is generally 10° to 40c'), the thin film vortex of fuel formed on the inner surface of the groove changes, and the flow from the outlet boat to the main air passage changes. This impairs the uniformity of the atomized state of the fuel discharged into the intake pipes, thereby impairing the uniform supply of fuel to each intake pipe.

■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 also changes. According to this, a thin film vortex of fuel in the groove Conditions also change, making it difficult to obtain a uniform atomization state of the fuel.

■The injection shape of the discharged fuel injected from the fuel injection valve is a flare shape in which the fuel diffuses, and a pencil beam shape in which the fuel converges. In order to form an n flow in s, the fuel flows on the inner surface of the groove at a speed of 1't11f/, a circle Mw with a heavy velocity.
For this purpose, a fuel injection valve having a pencil beam injection shape is preferable.

In the flare type, the fuel diffuses into the groove, making it difficult to generate swirl on the inner surface of the groove.

Therefore, the injection shape of the fuel injection valve is increased by 1IJI, and there is little freedom in selecting the fuel injection valve.

~2. This is because the fuel injected from the fuel IP4 injection valve was injected into a compound with a relatively large chamber volume: (The flow velocity of the swirling fuel on the inner surface of the α groove decreased, and the
1 m may be scattered inward into the groove, which deteriorates the mixing condition near the outlet of the groove and makes it difficult to supply fuel uniformly.

(2) During rapid deceleration between 11 and 11, 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. Therefore, the vortex formed in the groove may be separated from the inner surface of the groove toward the inside of the groove due to this intake negative pressure, and this may affect the uniformity of the fuel near the outlet of the groove. Not desirable.

~3, Figure 143, No. 4 of JP-A-53-72923
As shown in the figure, in the case where an orifice is provided between the groove and the outlet, the fuel injected from the fuel-N injection valve is injected into droplets with a relatively large chamber volume, so the fuel flow rate is low. Since the fuel is lowered and then throttled by the orifice, it is focused by the orifice and is less favorable in terms of fuel atomization.

[Means to solve problems]

The fuel injection device of the present invention has been made to solve the above-mentioned problems, and has excellent fuel atomization characteristics and uniformity in the SP1 method, has a high degree of freedom in adapting to the engine, and is easy to maintain. In order to achieve the above-mentioned purpose, the present invention provides an excellent fuel injection device that supplies fuel injected from a fuel injection valve to the engine through an intake passage on the F flow side from a throttle valve. In the injection device.

It is located in the intake passage on the downstream side of the throttle valve, is approximately parallel to the longitudinal axis x-x of the intake passage, the downstream side is closed and the downstream side is open, and the opening on the downstream side is 1. A fuel injection path is provided with an enlarged slope portion whose inner diameter gradually expands toward the downstream side of the intake path; an injection 4F injection passage opening into the fuel injection passage; disposed at least within the enlarged slope part of the fuel injection passage and forming a continuous annular gap along the longitudinal axis Y-Y of the fuel injection passage together with the enlarged slope part; a cone member provided with an enlarged inclined protrusion; an air intake passage passes through the annular fuel quantity @ member comprising the fuel injection passage, the injection valve injection passage, and the cone member; A throttle valve body including a throttle valve for opening and closing control is removably sandwiched between an injection valve body through which an intake passage passes.

[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. The fuel that has collided with the cone member stagnates at a high injection speed through the annular gap formed between the enlarged inclined part of the fuel injection passage and the enlarged inclined protrusion of the cone member, and flows into the downstream side of the fuel injection passage. It is injected from the outlet into the intake passage.

On the other hand, the annular fuel control member can be changed when changing the passage diameter of the fuel injection passage, the enlargement angle of the enlarged inclined portion, the shape of the cone member, etc., and even during maintenance, the annular fuel control member can be changed from the throttle valve body to the annular fuel control member. This can be done by removing it from the injection valve body.

[Embodiment] Hereinafter, an embodiment of the fuel injection device according to the present invention will be described with reference to FIG.

11 years old In Fig. 1, there is a throttle valve body through which an intake passage B passes downward from the L direction, and the intake passage B is attached to a throttle valve shaft 2 rotatably supported by the throttle valve body 1. 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 1 and separated from the throttle valve body 1, and an intake passage B also passes through this injection jf body 4 downward from the −1, direction. By connecting the throttle valve body 1 and the injection valve body 4 with screws, an intake passage B passing through each body 1.4 is formed.

5 is ECU (Electronic Control)
l Unit) When a current flows through the solenoid coil due to the signal E, the fur is attracted, and the flange of the needle valve, which is integrated with the core, 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 will be omitted.

) 6 is a fuel injection path 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 (engine # at the bottom in FIG. 1), and is centered on the longitudinal axis of the fuel #4 injection j86. The line Y-Y is on the longitudinal axis xx of the intake passage B, and its -hi flow side is closed, and its downstream side opens into the intake passage B via the open end 6B.

Then, the inner diameter thereof gradually expands toward the open end 6B on the downstream side from the expansion starting point A of the fuel injection path 6 (between the closed end 6A and the open end 6B of the fuel N injection path 6). An enlarged inclined 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. The inner diameter may be expanded, but must not be reduced (funnel-shaped).

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-Z of the injection valve injection passage 7 opens toward the longitudinal axis Y-Y of the fuel injection passage 6, and also opens into the fuel injection passage 6 upstream from the expansion starting point A.

A cone member 8 is disposed within the fuel injection passage 6 and forms an annular gap together with the inner diameter of the fuel injection passage 6. This cone member 8 is disposed within an enlarged inclined portion 6C of the fuel injection passage 6, and includes an enlarged inclined protrusion 8A having a continuous enlarged portion toward the downstream side, and an enlarged inclined protrusion 8A in the fuel injection passage 6D upstream from an enlarged starting point A. The cylindrical portion 8B is arranged at A continuous annular gap is formed toward C.

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. The annular gap is preferably around 11, but it is not limited to this value and is set as appropriate.

According to one aspect of the present invention, the fuel injection path 6. The injection valve injection path 7 and the cone member 8 are annular #l! material control member 9
established in The annular fuel control member 9 has a lower flat part 9A that abuts the stepped parts 4A and 4B extending laterally from the intake passage B of the injection valve body 4, and an upper flat part that abuts the end IA of the throttle valve body 1. 9B, the lower flat portion 9A of the annular fuel control member 9 is connected to the step portions 4A, 4 of the injection valve body 4.
After placing the end IA of the throttle valve main body 1 on the upper flat part 9Bj7-, and then fastening the throttle valve main body 1 and the injection valve main body 4 with screws 10, the annular fuel control member is assembled. 9 can be held between the injection jf main body 4 and the throttle valve main body 1.

Next, its effect will be explained.

When the engine is operating, air controlled by the throttle valve 3 flows in the intake path B, and fuel controlled by the fuel injection valve 5 is injected from the actual fuel injection path 6 toward the intake path B. be done.

Here, the behavior of the injected fuel injected from the fuel injection valve 5 will be looked at. The fuel injected from the fuel injection valve 5 is injected into the fuel injection path 6D upstream of the expansion starting point A via the injection valve injection path 7. The fuel injected into the fuel injection path 6D collides with the cylindrical portion 8B of the cone member 8 at a high speed, and due to this collision, the fuel is finely scattered.
It is finely dispersed over the entire outer circumference of the cylindrical portion 8B. In the kneading process, a small annular gap is formed between the fuel injection passage 6D on the 1-stream side from the expansion starting point A and the cylindrical portion 8B of the cone member 8 (maintained at a small volume), and the injected fuel is This is achieved by not slowing down.

Here, the fuel injected from the fuel injection valve 5 into the injection valve injection path 7 is simply injected toward the fuel injection path 6 as high-velocity fuel tactilely pressurized by the fuel pump. In other words, the shape of the injected fuel injected from the fuel injection valve 5 may be either a flare shape or a pencil beam shape.

Next, the finely dispersed fuel held at a high velocity within the annular gap between the cylindrical portion 8B of the cone member 8 and the fuel injection path 6D upstream of the expansion starting point A flows into the expanded inclined protrusion of the cone member 8. The fuel is injected into the annular gap formed by the portion 8A and the enlarged inclined part 6C of the fuel injection passage 6, and flows down along the inclined annular gap while being uniformly distributed within this annular gap.

This is because the flow velocity of the dispersed fuel can be prevented from decreasing by making the annular gap so small, and because the inclined annular gap is continuous along the longitudinal axis Y-Y of the fuel injection path 6. This is because the direction of fuel flow is regulated by the formation of the fuel.

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

The annular fuel injected into the intake passage B is uniformly and well mixed with the air encased within the intake passage B.

This is because the fuel injected from the open end 6B of the fuel injection passage 6 forms a completely annular spray shape as described above, expands, and is injected toward the inner wall of the intake passage B.

In other words, the portion of the air flowing through the intake passage B that has the highest speed is a portion that is 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 flows through this air chamber where the wave velocity is high. This is because the fuel is uniformly injected in an annular shape toward the air, and the fuel is well mixed with the air.

By being able to inject uniform fuel into the intake passage B, uniform fuel can be supplied to each intake pipe connected to each cylinder of the engine, resulting in significant engine performance improvements such as improved engine output and stable rotation. We were able to achieve this goal.

On the other hand, from the enlarged origin fiA of the fuel injection passage 6, the inner diameter of the fuel injection passage 6B on the source side, the enlarged inclination angle of the enlarged inclined portion 6C, and the shape of the inclined surface (for example, straight or curved) or the open end 6B. The shuttle, and also the longitudinal axis Y of the fuel injection passage 6
- Eccentricity between Y and the longitudinal axis x-x of the intake path B, etc.
The specifications of the fuel injection passage 6 are set to suit each engine, but in this case, even if the specifications of each of the above elements are changed, it is only necessary to change the annular fuel control member 9, so the main body It is possible to achieve an extremely economical response compared to changing the

Furthermore, since the annular gap is a relatively small gap 1-5, when performing maintenance on that part during periodic inspection of the vehicle, the annular fuel control can be performed by separating the throttle valve body 1 and the injection valve body 4. Since the member 9 can be removed from the main body 1.4, maintenance efficiency can be significantly improved.

〔Effect of the invention〕

As described above, the fuel injection system 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 solvent injection valve to the engine via an intake passage downstream of a throttle valve, the intake passage is located in the intake passage on the side below the throttle valve. It is approximately perpendicular to the longitudinal axis x-x, and its flow side is closed and its downstream side is open. A fuel injection passage provided with an enlarged slope portion that gradually expands; An injection valve injection passage opened into the fuel injection passage for injecting and supplying fuel injected from the fuel injection valve into the fuel injection passage; a cone member having an enlarged slope protrusion disposed within at least the enlarged slope of the fuel injection passage and forming a continuous annular gap along the longitudinal axis Y-Y of the fuel injection passage with the enlarged slope; iii, an annular fuel control member comprising a fuel injection passage, an injection valve injection passage, and a cone member, an intake passage passing through the inside thereof, and a throttle valve for controlling opening and closing of the intake passage. Since the main body is removably sandwiched between the main body and the injection valve main body through which the intake passage passes, the main body is disposed at least within the enlarged inclined part of the fuel injection passage, and the main body is disposed in the enlarged inclined part along with the enlarged inclined part in the longitudinal direction of the fuel injection passage. Since the cone member has an enlarged inclined protrusion that forms a continuous annular gap along the axis Y-Y, the fuel injected into the intake passage from the open end of the fuel injection passage is Since the flow velocity of the fuel injected from the fuel injection valve is not reduced due to the gap between the fuel injection path and the cone member, and the cone member forces the fuel into an annular shape, uniform and completely annular fuel can be produced. Since the fuel could be injected into the intake passage, it had an extremely large effect on engine output and rotational stability, especially in SPI fuel injection systems.
The fuel injection path can be economically adapted to the engine, and the maintenance of the fuel injection path and cone member can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of essential parts showing one embodiment of a fuel injection device according to the present invention. 1. 5. Throttle valve body 3, Throttle valve 4
,,,,rql,injection valve body 5,,,,fuel injection valve 6,,,,,fuel injection path 6B,,-,
Opening end portion 6C,... Enlarged slope portion D..., Fuel injection path 111 upstream of the enlarged starting point A.
．． Fuel injection passage 8. ,,,Cone member A, ,,,
Enlarged inclined protrusion 8 B-, cylindrical portion 191. Enlargement starting point B,..., intake passage 621. annular fuel control member

Claims (1)

[Scope of Claims] 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, comprising: , is approximately parallel to the longitudinal axis X-X of the intake passage, its upstream side is closed and its downstream side is open, and the downstream opening has an inner diameter portion extending toward the downstream side of the intake passage. a fuel injection passage provided with an enlarged slope that gradually expands; 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; at least the fuel injection passage; a cone member having an enlarged inclined protrusion disposed within the enlarged inclined part of the injection passage and forming a continuous annular gap along the longitudinal axis Y-Y of the fuel injection passage with the enlarged inclined part; An intake passage passes through the annular fuel control member including the fuel injection passage, an injection valve injection passage, and a cone member, and a throttle valve body equipped with a throttle valve for controlling opening and closing of the intake passage is inserted inside the annular fuel control member. A fuel injection device that is detachably held between a fuel injection valve body and an injection valve body through which an air intake passage passes.