JPH1077934A - Assist air device of fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement a stable fuel spray condition by regulating an air inflow to an adapter of an air assist device of a fuel injection valve. SOLUTION: An air assist device of a fuel injection valve comprises an adapter 2 having mixing injection passages 19a, 19b provided to a tip of a fuel injection valve body for mixing fuel from a fuel injection hole with an air introduced from the outside to inject the mixture to the outside. The adapter 2 is provided with an air inflow hole 15 for regulating an air inflow, an air flow space 16 into which an inflow air from the air inflow hole 15 is introduced, and an air inflow groove 18 for introducing air from the air flow space 16 to the mixing injection passage 19a, 19b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air assist device for atomizing fuel from a fuel injection valve in an electronic control fuel injection device, and more particularly, to an adapter having a fuel injection valve and air flow injection in such an air assist device. Mounting structure.

[0002]

2. Description of the Related Art In recent years, especially in an electronically controlled fuel injection device, an adapter having an airflow injection hole is mounted around a fuel injection hole of a fuel injection valve in order to improve atomization of fuel injected from the fuel injection valve. Air assist devices are being considered. In this device, the adapter is connected to an intake pipe between an air flow meter and a throttle valve, or simply to an intake pipe upstream of a throttle valve by an assist air passage, and a part of intake air is divided from the intake pipe to assist the assist. The fuel is introduced into the above-mentioned adapter through an air passage, guided to the vicinity of the fuel injection hole of the fuel injection valve from this adapter, and made to act on the fuel flow from the fuel injection hole to atomize the injected fuel.

As this kind of known technology, Japanese Patent Publication No. 3-122 is disclosed.
No. 25 publication exists. In this known technique, as shown in FIG. 10, an adapter 36 having an airflow space 37 for introducing assist air near the front end liquid hole 31a of the fuel injection valve body 31 is attached. The adapter 36 forms a conical divergent air flow injection port 36b at the end, and after the assist air passes through the gap between the adapter 36 and the outer periphery of the fuel injection valve main body 31, the liquid hole at the end of the fuel injection valve is formed. The fuel is injected from 31a toward a fuel flow injected in a direction parallel to the valve axis of the fuel injection valve. The adapter 36 is fitted into the engine-side mounting hole 40a so as to be sealed at both upper and lower ends and has an annular gap 52 between the seal portions. The air intake hole 54 is formed between the annular gap 52 between the seal portions and the airflow nozzle 36.
b and the fuel injection valve 3 so as to be concentric with the airflow injection port 36b and protrude into the airflow injection port.
Two tips are arranged. The front end of the fuel injection valve 32 is entirely surrounded by an airflow nozzle 36b, and the liquid hole 3 of the fuel injection valve is provided.
An airflow in a direction parallel to the fuel flow injected from 1a is formed from the airflow nozzle 36b, and the outer periphery of the fuel injection valve body 31 near the airflow nozzle 36b gradually tapers toward the airflow nozzle 36b. . In addition, the assist air passage 3
0 is connected to a horizontal hole 40c in the mounting portion 40,
0c is open to the gap 52.

[0004] As a further known technique, Japanese Patent Application Laid-Open No. 4-505 is disclosed.
In the '494 publication, a predetermined air gap is formed between the tip of the fuel injection valve and an annular surface at the center of the adapter, and air is injected from the air gap to merge with fuel injected from the fuel injection opening. I am trying to make it.

[0005]

In the former prior art (Japanese Patent Publication No. 3-12225), the protrusion at the tip of the fuel injection valve is entirely surrounded by the airflow injection port 36b, so that the fuel injection spreads. However, the particle size of the fuel flow after mixing fuel and air is such that the outer particle size is smaller and the particle size becomes coarser toward the center of the fuel flow. Is expected, and furthermore, it is expected that there will be a difference in flow velocity between the outside and the inside of the fuel flow, and there is a concern that a fuel flow having a uniform density cannot be obtained. Further, there is a concern that it is difficult to configure the adapter structure for multidirectional injection.

[0006] Further, the latter conventional technique (Japanese Unexamined Patent Publication No. Hei 4-505)
No. 494), since the annular portion concentrically located at the center of the adapter has a ring-shaped uniform thickness, a swirl flow cannot be generated in the fuel flow ejected from the adapter. Further, a fuel flow having a fine particle size cannot be formed, and furthermore, this publication does not describe a multidirectional injection.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. In an air assist device for a fuel injection valve, which introduces air by an adapter, mixes it with fuel, and injects the same, the shape and size of the adapter Improves the air inflow direction and processing, regulates the inflow amount of air into the adapter, realizes a stable fuel spray form, enables the adapter shape to be set freely, and sprays by generating a spray swirl flow The purpose is to achieve atomization of.

[0008]

According to the first aspect of the present invention, a valve element such as a needle valve is separated from or connected to a valve seat surface to open and close the valve, and fuel is injected from a fuel injection hole downstream of the valve seat surface. A fuel injection valve body, and an adapter mounted on the fuel injection hole side of the fuel injection valve body and having a mixing injection passage for mixing fuel from the fuel injection hole with air introduced from outside and injecting the mixture to the outside. A fuel injection valve, wherein the adapter has an air inflow hole on the outer peripheral side thereof for regulating an inflow amount of air, an airflow space into which inflow air is introduced from the air inflow hole, and an airflow space from the airflow space. An air inflow groove for introducing air into the mixing injection passage is provided.

More specifically, the structure of the invention according to claim 1 is an apparatus for injecting a mixture of fuel and air, wherein the valve body cooperates with a valve seat surface in a valve casing of a fuel injection valve. (Needle valve) and at least one downstream of the valve seat
The adapter has two fuel injection holes, and the adapter is fitted into, for example, a mounting port on the engine side so as to be sealed at both upper and lower ends, has an annular gap between the seal portions, and further has a tip end of the fuel injection valve. A device for press-fitting and inserting an assist air near a fuel injection hole at a tip of a fuel injection valve, wherein the adapter is formed so that at least one air inflow hole communicates with the annular gap at an outermost peripheral side. The air inflow hole has a function of regulating the amount of inflow of air. Further, the air that has flowed into the adapter from the air inflow hole flows into an airflow space that forms a substantially annular space area, and the fuel flows into the adapter projection inside the airflow space and toward the fuel injection opening. At least one injection hole for injecting a mixture of air and air. The air inflow groove communicates with the air inflow hole from the airflow space, and the air inflow area of the air inflow groove is set to be at least larger than the air inflow hole area.

According to a third aspect of the present invention, a fuel metering hole is formed between the fuel injection valve and the adapter so as to face the inlet of the mixing jet passage. The fuel metering plate is formed of, for example, a thin plate and has a function of measuring a fuel flow rate. The fuel metering plate is arranged neatly around the axis of the fuel injection valve, and in the case of two or more fuel injection valves.

According to a fourth aspect of the present invention, the adapter is formed by integral resin molding. Thereby, the shape of the air inflow hole can be freely set, and the adjustment of the flow rate of the air flowing into the adapter can be freely set. In addition, since the direction of air inflow into the mixing jet passage of the air inflow groove of the adapter can be freely set, the form of fuel injection according to various engines and intake characteristics can be freely set. Since the fuel flow can be discharged, a fuel flow having a stable particle diameter can be obtained with respect to atomization of the fuel flow, and a fuel flow having a small particle diameter can be stably obtained. Furthermore, since the air inflow area and the air inflow shape of the air inflow groove can be freely set in the resin molding processing range, a stable spray form and a stable small fuel flow particle size can be obtained as described above. That is, a stable velocity is obtained for the air flow velocity when colliding with the fuel flow.

According to a fifth aspect of the present invention, the air inflow area of the air inflow groove is set to be at least larger than the area of the air inflow hole.

According to a sixth aspect of the present invention, the air inflow groove is disposed directly or extremely close to the fuel injection hole side of the fuel injection valve body.

According to a seventh aspect of the present invention, the air inflow groove is formed to be long in the axial direction and short in the circumferential width direction.

The invention according to claim 8 is such that the air inflow groove is provided in a direction eccentric by a predetermined distance from the axis of the mixing jet passage.

According to a ninth aspect of the present invention, the air inflow groove is provided toward the axis of the mixing jet passage.

According to a tenth aspect of the present invention, the adapter has one or a plurality of mixed injection passages, which can be applied to a one-way fuel injection valve or a multi-way fuel injection valve.

According to an eleventh aspect of the present invention, the adjustment of the lift amount of the fuel injection valve is performed by moving the valve seat in the axial direction of the fuel injection valve, and the fuel adjustment having a fuel adjustment hole in the valve seat. The adapter was applied to a fuel injection valve to which a plate was joined.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. (Structure of Embodiment) FIG. 1 is a sectional view showing the overall structure of an air assist device for a fuel injection valve according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In the figure, an air assist device for a fuel injection valve includes a fuel injection valve main body 1 for injecting fuel, and an adapter 2 attached to a tip of the fuel injection valve main body 1. This adapter 2
As described later, at least one mixed injection passage 19 (one in the unidirectional injection type, plural in the multidirectional injection type) into which fuel injected from the injection hole of the fuel injection valve body 1 is introduced, and The air flow space 16 is opened to the mixing jet passage 19.
And an air inflow groove 18 for supplying air through the fuel injection passage 19.
The air from the nozzle 8 impinges on the fuel to atomize the fuel.

The fuel injection valve body 1 generally has a housing 6 accommodating an electromagnetic actuation system (described later) and a valve casing 7 held at the front end of the housing 6 by caulking or the like. A needle valve 8 (valve element) is provided in a casing 7. This needle valve 8 is a valve casing 7
The valve seat 7a at the tip of the valve casing 7 is opened and closed, and a fuel metering plate 9 is joined to the valve casing 7 at the tip of the valve casing 7. The fuel metering plate 9 has at least one fuel metering hole 10 as an orifice hole for one mixing jet passage 19, and the needle valve 8 has a valve seat 7a.
It regulates the fuel injection amount when the valve is opened further upward. As described above, since the fuel metering hole 10 is arranged in the axial center portion of the fuel injection valve, the fuel flow determined from the fuel metering hole 10 is injected downstream of the fuel injection valve.

As shown in FIG. 1, the electromagnetic actuation system of the fuel injection valve main body 1 is arranged in series with an armature 50 holding the upper end of the needle valve 8 via the armature 50 and a spring 51. A core 52, a sleeve 53 provided inside the core 52, and an electromagnetic coil 54 surrounding the core 52;
And a bobbin 55 wound with a bobbin. Each component constituting this electromagnetic operation system is housed in the upper part of the housing 6. The winding of the electromagnetic coil 54 is connected to the terminal 5
6, the socket 57 protects the terminal 56 and is used for fitting and joining with an external terminal.

(Features of Embodiment) Embodiment 1
, An adapter 2 which is, for example, a resin molded product is attached to the tip of the fuel injection valve body 1. That is, the outer peripheral cylindrical portion 2 of the adapter 2 is attached to the outer peripheral portion of the cylinder near the valve portion of the valve casing 7.
A is press-fitted. Further, the resin of the adapter 2 is inserted into the adapter fitting groove 20 provided in the outer peripheral cylindrical portion of the valve casing 7, and is fixed by press-fitting the valve casing 7 and the adapter 2. The insulator 11 is installed between the rear end side (upper side in the figure) of the adapter 2 and the mounting side.
Is located on the front end side (lower side in the figure) of the
A ring 12 is provided. As a result, between the insulator 11 and the O-ring 12 and
An airflow annular space 14 is formed between the mounting side and the outer peripheral surface of the adapter 2. Furthermore, the airflow annular space 14 is attached so as to communicate with the assist air passage 3 provided in the engine-side body 13.

Here, the air flowing into the assist air passage 3 enters the air flow annular space 14 and is further guided to an air inflow hole 15 provided in the outer peripheral cylindrical portion 2A of the adapter 2. Since the air inflow amount is regulated by the air inflow hole 15, a fixed flow rate of air enters the adapter 2. The air inflow hole 15 may be composed of at least one hole and have a function of regulating the amount of air inflow, and the shape of the hole is a circle, a rectangle, a square, a triangle, and so on. The shape of the hole can be freely set in the range of resin molding, and the hole shape does not need to be set to a specific shape because it does not directly collide with the fuel flow.

The air having a predetermined flow rate flowing into the adapter 2 through the air inlet hole 15 is disposed in the adapter outer peripheral cylindrical portion 2A and located in an annular space area located downstream of the fuel metering plate 9. Flows into the airflow space 16 that forms The air that has flowed into the airflow space 16 is located at the axis of the fuel injection valve body 1 and has an adapter protrusion formed in a shape protruding from the bottom of the airflow space 16 toward the fuel injection valve body 1. The air is introduced into the air inflow groove 18 provided in the portion 17. The air inflow area of the air inflow groove 18 is set to be at least larger than the air inflow hole area.

The end face 17a of the adapter projection located at the tip of the adapter projection 17 may be in contact with or close to the surface of the fuel metering plate 9. A fuel metering hole 10 is formed in the adapter projection 17 on the side of the fuel injection valve body 1 on the axis.
A mixture ejection passage 19 for ejecting a mixture of fuel injected from the air and air guided from the air inflow groove 18 is formed. The mixed ejection passage 19 is formed of at least one, and forms the number of ejection ports and the ejection port shape corresponding to each of the unidirectional injection and the multidirectional injection. FIGS. 1 and 2 show the case of multi-directional injection, in which the number of the mixed ejection passages 19 of the adapter 2 is two, and the fuel metering holes 1 of the fuel metering plate 9 are provided.
Two 0s are also provided.

Further, the air flowing from the air inflow groove 18 goes to the mixing jet passage 19. In the present embodiment, since the adapter 2 is formed of, for example, resin, the cross section of the adapter 2 in various directions. The direction of the air inflow can be set at the time. For example, as shown in FIG. 2, a method is devised such that the air introduced from the air inflow groove 18 collides with the fuel flow as a swirling air flow in the mixing jet passage 19. In this way, under the fixed air flow rate, the ejection of the fuel having the extremely fine spray particle diameter is achieved, and the stable spray can be realized even in the spray form.

The state of the air introduction will be described in more detail with reference to FIG. Numeral 21 indicates the air inflow direction when the air enters the air inflow groove 18 from the airflow space 16 and further flows into the mixing jet passage 19. The mixing jet passage 19 in FIG. 2 is composed of two, and each mixing jet passage 19a, 19b has 3
One air inflow groove 18 is provided. The air inflow groove 18 is formed in the mixing jet passage 1 when viewed from a cross section perpendicular to the axial direction.
It is provided in an oblique direction so as to be directed to a direction decentered by a predetermined distance from the axis of No. 9. In addition, reference numeral 17a denotes an end surface of the adapter projecting portion which is a distal end surface of the adapter projecting portion 17.

As described above, in the present embodiment, at least one air-inflow groove is provided in at least one mixing-injection passage, and since the air-inflow groove is free to be formed, the airflow that collides with the fuel flow is formed. The setting is versatile, and setting with a wide degree of freedom for achieving the atomization of the ejected fuel becomes possible.

Embodiment 2 FIG. 3 is a perspective view showing the adapter protrusion of the fuel injection valve according to Embodiment 2, and is a three-dimensional view when the adapter protrusion 17 is viewed from obliquely above the adapter protrusion end face 17a. In the figure, an air inflow groove 18 is formed at the tip of an adapter
Has a slit shape that is long in the axial direction of the fuel injection valve (length H) and narrow in width (width W) in the circular arc direction of the cross section of the adapter 2. One is formed.

According to the present embodiment, the air flow from the vertically elongated slit-shaped air inflow groove 18 collides with the fuel flow in the mixing jet passage 19, whereby the atomization of the jet fuel is stabilized, and It is possible to achieve the injection of a fine fuel flow and to prevent deposits from adhering to the downstream end face of the fuel metering plate 9.

Embodiment 3 FIG. 4 is a plan view showing an adapter protrusion of the fuel injection valve according to Embodiment 3, and FIG.
5 corresponds to a view taken along line AA of FIG. In the figure, two (19a, b) mixing ejection passages 19 are provided,
This is an example in which two air inflow grooves 18 are provided for each of the mixed ejection passages 19a and 19b. And this air inflow groove 18
When viewed from a cross section perpendicular to the axial direction of the mixing ejection passage 19, the mixing ejection passage 19 is provided so as to be eccentric by a predetermined distance from the axis of the mixing ejection passage 19.

In the third embodiment, the air inflow groove 18
Is introduced from a direction eccentric from the axis of the mixing ejection passages 19a, b by a predetermined distance, so that the air flow swirls in the mixing ejection passages 19a, 19b and mixes with the fuel flow. is there.

Embodiment 4 FIG. FIG. 5 is a plan view showing an adapter protrusion of the fuel injection valve according to the fourth embodiment.
5 corresponds to a view taken along line AA of FIG. In the figure, two (19a, b) mixing ejection passages 19 are provided,
This is an example in which three air inflow grooves 18 are provided for each mixing ejection passage. Each air inflow groove 18 is provided in the mixing jet passage 1.
9 are provided toward the axis.

According to this embodiment, the air inflow direction 2
Numeral 1 is directed toward the center of the mixing jet passages 19a and 19b, that is, air is introduced toward the center of the fuel flow, and is jetted in a state where the air flow and the fuel flow are mixed.

Embodiment 5 FIG. FIG. 6 is a side sectional view of an air assist device for a fuel injection valve according to a fifth embodiment, and shows a structural example in which a unidirectional injection adapter is attached. In the figure, an adapter 22 is a one-way injection type adapter, and a fuel metering hole 10 of a fuel metering plate 9A.
A unidirectional injection mixing section for mixing air and fuel is formed downstream of A. The mixing section includes an upstream mixing jet passage 23 and a further downstream mixing jet passage 24. The upstream mixing jet passage 23 is mainly provided as a space for mixing the air and the fuel flow, and the downstream mixing jet passage 24 is mainly provided for the adapter 2.
The space shape of the downstream side mixed ejection passage 24 is determined in order to regulate the injection form of the mixed fuel ejected from the fuel mixture 2.

The other structure of the adapter 22 is the same as that shown in FIG. 1. The outer cylindrical portion 22A of the resin-molded adapter 22 is press-fitted to the outer cylindrical portion of the valve casing 7, and provided on the outer cylindrical portion of the valve casing 7. Adapter fitting groove 2
Then, the resin of the adapter 2 is inserted into the housing 2 and fixed by press-fitting the valve casing 7 and the adapter 2. The rear end side of the adapter 22 and its cylindrical outer peripheral surface 2
In 2A, an insulator is installed between the mounting side and the mounting side, and an O-ring is provided on the front end side of the adapter 22 and on the outer peripheral portion of the cylinder. As a result, an unillustrated airflow annular space is formed between the insulator and the O-ring, and between the mounting side and the outer peripheral surface of the adapter 22.

The outer cylindrical portion 22A of the adapter 22 is provided with an air inflow hole 15 for regulating the amount of inflow of air, and a constant flow of air enters the adapter 22. And
The air having this fixed flow rate flows into the airflow space 16 which is provided inside the adapter outer peripheral cylindrical portion 22A and forms an annular space region located downstream of the fuel metering plate 9A. The air that has flowed into the airflow space 16 is
And flows into an air inflow groove 18 provided in an adapter projection 17 formed in a shape protruding from the bottom of the airflow space 16 toward the fuel injection valve body 1.

The air flowing from the air inflow groove 18 is
Although the flow goes to the mixing jet passage 23, since the adapter 22 is a resin molded product, the air inflow direction can be set in various directions in the cross-sectional direction of the adapter 22.
For example, as described in the above-described embodiment, a method of colliding the fuel flow as a swirling air flow, or colliding the fuel flow straight in the axial direction of the fuel flow is devised. As described above, even in the fuel injection valve of the one-way injection system, the injection of the fuel having the extremely fine spray particle diameter is achieved under the fixed air flow rate, and the stable spray can be realized even in the spray form. .

Embodiment 6 FIG. FIGS. 7 and 8 are side sectional views showing a fuel injection valve body 42 having an adapter attached thereto, which is different from the above embodiment. FIG. 7 shows a fuel injection valve body 42 having a unidirectional injection adapter 2 attached thereto. Example
FIG. 8 shows a multi-directional injection adapter 22 attached to a fuel injection valve main body 42.
An example in which is attached.

The fuel injection valve body 42 of this embodiment is
The fuel metering plate 9 and the valve seat 25 located in the vicinity of the tip of the injection valve are of a type in which they enter the injection valve from the most distal end of the injection valve. In this type of fuel injection valve, first, the valve seat 25 is inserted through the opening at the tip of the valve casing 7, and adjustment of the lift amount of the fuel injection valve is performed by moving the valve seat 25 in the axial direction of the fuel injection valve and positioning the same. It can be done by doing. Thereafter, the fuel adjustment plate 9 having the valve seat 25 and the fuel injection opening 10 is joined. Therefore, valve seat 2
The fuel injection valve 5 and the fuel metering plate 9 are inserted into the fuel injection valve in the axial direction and inside the injection valve from the front end of the fuel injection hole on the fuel injection hole side.

As described above, the adapters 2 and 22 of the present invention
In the type in which the fuel metering plate is located at the tip of the injector such as the fuel injection valve body 1, the type in which the fuel metering plate is inserted from the tip of the injector such as the fuel injector body 42 is used. Therefore, the application to various injection valves is expanded, and the application on the system is also expanded.

Mounting state of the embodiment. FIG. 9 is a system configuration diagram showing a state in which the fuel injection valve of the above embodiment is mounted. In the figure, 1 is a fuel injection valve main body, 2 is an adapter, 5 is an air flow meter, 4 is a throttle valve, and 13 is intake air. An engine-side body that partially forms a passage and includes an intake manifold and an engine head. The fuel injector main body 1 and the adapter 2 are fitted into the fuel injector mounting holes provided in the engine side body 13 by the number of engine cylinders in a press-fitted and integrated state. The fuel injection valve body 1 is connected to a fuel pipe and a fuel pump (not shown). When the throttle valve 4 is released, an amount of intake air flows in accordance with the opening of the throttle valve 4, and the air flow meter 5 measures the amount of intake air. Upon detection, fuel is injected from the fuel injection valve body 1 in an amount corresponding to the intake air amount. Since the fuel supply operation itself is well known, further description is omitted. Reference numeral 3 denotes an assist air passage, one end of which opens into the intake pipe between the air flow meter 5 and the throttle valve 4, and the other end opens near the fuel injection hole of the fuel injection valve. Then, a part of the intake air measured by the air flow meter 5 is diverted to the assist air passage 3 and re-introduced near the fuel injection hole of the fuel injection valve main body 1, and acts on the fuel flow to atomize the fuel. Done.

[0043]

According to the present invention, the flow rate of the air flowing into the adapter is regulated by the air inflow hole, guided to the air flow space formed inside the adapter, and further mixed and ejected in which the mixture of fuel and air is ejected. Since the air in the airflow space is introduced into the passage, it is possible to mix the fuel with a preset air flow rate, adjust the atomization of the fuel flow, and obtain a fuel flow having a stable particle diameter.

Further, by forming the adapter by integral resin molding, the shape of the air inlet hole can be freely set, and the flow rate of the air flowing into the adapter can be freely adjusted. In addition, since the shape of the air inflow groove of the adapter can be freely set and the direction of air inflow into the mixing and ejection passage can be freely set, the form of fuel ejection according to various engines and intake characteristics can be freely set. Since the swirl flow can flow out into the mixing jet passage, there is an effect that a fuel flow having a stable particle diameter can be obtained with respect to atomization of the fuel flow, and a fuel flow having a small particle diameter can be stably obtained. Furthermore, since the air inflow area and the air inflow shape of the air inflow groove can be freely set in the resin molding processing range, a stable spray form and a stable small fuel flow particle size can be obtained as described above. That is, there is an effect that a stable velocity can be obtained also for the air flow velocity when colliding with the fuel flow.

Further, by disposing the air inflow groove directly or very close to the fuel injection hole side of the fuel injection valve body, it is possible to improve the spray distribution of the inflow air and the fuel.

Further, by forming the air inflow groove to be longer in the axial direction and shorter in the circumferential width direction, it is possible to prevent deposits from adhering to the fuel injection holes or the end face on the downstream side of the fuel metering plate.

Further, by forming one or a plurality of mixed injection passages of the adapter, the adapter can be applied to a one-way injection fuel injection valve or a multi-way injection fuel injection valve.

According to the present invention, the adjustment of the lift amount of the fuel injection valve is performed by moving the valve seat in the axial direction of the fuel injection valve, and the fuel adjustment having a fuel metering hole in the valve seat. A fuel injection valve having a valve seat and a fuel metering plate inserted in the axial direction of the fuel injection valve from the front end of the fuel injection valve on the fuel injection hole side and inward of the injection valve. An adapter can be applied to the valve.

[Brief description of the drawings]

FIG. 1 is an overall structural diagram showing an air assist device for a fuel injection valve according to a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view illustrating an adapter protrusion according to a second embodiment.

FIG. 4 is a plan view showing an adapter protrusion according to a third embodiment.

FIG. 5 is a plan view showing an adapter protrusion according to a fourth embodiment.

FIG. 6 is a side sectional view showing an air assist device for a fuel injection valve according to a fifth embodiment.

FIG. 7 is a side cross-sectional view of a fuel injection valve body according to Embodiment 6 with a unidirectional injection adapter attached.

FIG. 8 is a side sectional view in which a multidirectional injection adapter is attached to a fuel injection valve body according to a sixth embodiment.

FIG. 9 is a system configuration diagram showing a state where the fuel injection valve according to the embodiment is attached.

FIG. 10 is a side sectional view showing a conventional fuel injection valve.

[Explanation of symbols]

1,42 fuel injection valve, 2 adapters (multidirectional injection),
22 Adapter (unidirectional firing), 3 assist air passage, 6 housing, 7 valve casing, 7a valve seat, 8
Needle valve, 9 fuel metering plate, 10 fuel metering hole, 11 insulator, 12 O-ring, 13 engine side body, 14 air flow annular space, 15 air inlet hole, 16 air flow space, 17 adapter protrusion, 17a
Adapter protrusion end face, 18 air inflow groove, 19 (a,
b) Mixing jet passage, 21 air inflow direction.

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display F02M 69/00 310 F02M 69/00 310E 310L

Claims (11)

[Claims] 1. A fuel injection valve main body, which opens and closes a valve by a valve body coming and going to a valve seat surface to inject fuel from a fuel injection hole on a downstream side of the valve seat surface; An adapter mounted on the injection hole side and having an adapter having a mixing injection passage for mixing the fuel from the fuel injection hole and the introduced air from the outside and injecting the mixture to the outside, wherein the adapter includes: On its outer peripheral side, there are provided an air inflow hole for regulating the inflow amount of air, an airflow space into which the inflow air from the air inflow hole is introduced, and an air inflow groove for introducing air from the airflow space to the mixing injection passage. Air injection device for the selected fuel injection valve. 2. A device for injecting a mixture of fuel and air, wherein a valve body is separated from and brought into contact with a valve seat surface to open and close a valve, and fuel is injected from a fuel injection hole downstream of the valve seat surface. A fuel injection valve body to be injected; and a mixing injection passage mounted on the fuel injection hole side of the fuel injection valve body for mixing fuel from the fuel injection hole with air introduced from the outside and injecting the mixture to the outside. An adapter having at least one air inflow hole formed on an outer peripheral side thereof so as to communicate with the introduction of external air; the air inflow hole has a function of regulating an inflow amount of air; An airflow space into which the inflow air from the air inflow hole is introduced is formed, and a mixture of fuel and air is injected inside the airflow space and inside the adapter protrusion protruding toward the fuel injection hole. Mixed injection passage for And an air inlet groove for introducing air from the airflow space to the mixing injection passage is provided. 3. A fuel metering plate having a fuel metering hole formed between the fuel injection valve and the adapter, the fuel metering plate being formed so as to face an inlet of the mixing jet passage. Item 3. An air assist device for a fuel injection valve according to Item 2. 4. The air assist device for a fuel injection valve according to claim 1, wherein the adapter is formed by resin molding. 5. The air assist device for a fuel injection valve according to claim 1, wherein the air inflow area of the air inflow groove is set to be at least larger than the air inflow hole area. 6. The fuel injection according to claim 1, wherein the air inflow groove is disposed directly or in close proximity to the fuel injection hole side of the fuel injection valve body. Valve air assist device. 7. The air assist device for a fuel injection valve according to claim 1, wherein the air inflow groove is formed to be longer in the axial direction and shorter in the circumferential width direction. . 8. The fuel injection according to claim 1, wherein the air inflow groove is provided in a direction eccentric by a predetermined distance from an axis of the mixing jet passage. Valve air assist device. 9. The air assist device for a fuel injection valve according to claim 1, wherein the air inflow groove is provided toward an axis of the mixing jet passage. . 10. The air assist device for a fuel injection valve according to claim 1, wherein one or more mixing injection passages of the adapter are formed. 11. The fuel injection valve body according to claim 1, wherein the lift amount of the fuel injection valve is adjusted by moving the valve seat in the axial direction of the fuel injection valve, and the fuel valve has a fuel metering hole in the valve seat. 11. The air assist device for a fuel injection valve according to claim 1, wherein the metering plate is joined.