JP2003148299A - Fuel injection valve and internal combustion engine loaded with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve improved in atomization by effectively increasing an injection flow speed and effectively forming a eddy current in the upstream of an injection hole and making fuels collide with each other outside the injection hole, and to provide an internal combustion engine loaded with the same. SOLUTION: The wall of an external peripheral fuel radiation chamber 201 opposite to a plate member 111 is formed into an inclined wall surface 202 to form a flow passage cross sectional area smaller, as a fuel flows in the peripheral direction. Or, the wall surface of the external peripheral fuel radiation chamber 201 opposite to the upstream of the plate member 111 is provided with a stage difference 601 to form a eddy current 701.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve for injecting fuel into an internal combustion engine, and to a technique for forming a fuel spray excellent in atomization.

[0002]

2. Description of the Related Art Generally, a fuel injection valve used in an automobile engine or the like surrounds a cylindrical nozzle portion provided with a fuel passage in an axial direction and an orifice provided on an inner peripheral side of a tip portion of the nozzle portion. A valve seat member having a valve seat on the inner peripheral side thereof, a valve body having a base end side provided by being inserted into the fuel passage of the nozzle part as an adsorption part and a tip end side as a valve part, and the nozzle part And an electromagnetic actuator that is provided on the base end side of the valve and that energizes to attract the adsorption portion of the valve element and open the valve element. Examples of such a fuel injection valve for an internal combustion engine include those described in, for example, JP 2001-27169 A or JP 2001-46919 A. Fuel injection valve reduces fuel consumption,
Atomization of fuel is one of the important factors from the viewpoint of reducing the emission of unburned gas components (HC, CO) of combustion and stable operation performance of the engine.

In such a conventional fuel injection valve, a plate member is provided at the tip of the nozzle to cover the valve seat member, and the fuel flowing out from the orifice of the valve seat member is provided at the center of the plate member. A plurality of injection holes for atomizing and injecting are formed. Then, when the valve element is opened, the fuel supplied into the nozzle portion is injected from each injection hole toward the intake port of the engine or the like. In this case, the flow velocity of the injected fuel is increased as much as possible by adjusting the number and size of the plurality of injection holes provided in the plate member and the angle of the injection holes penetrating in the plate thickness direction, and the spray particle size is increased. Is controlled.

[0004]

However, in the fuel injection valve of the prior art, by adjusting the number and size of a plurality of injection holes and the angle of the injection holes penetrating in the plate thickness direction, the spray particle size can be adjusted. Since it is controlled, the number, size and angle of the injection holes that can be processed are regulated by the size of the plate member, and there is a limit to reducing the spray particle size, and it is not always possible to obtain sufficient atomization performance. There was a problem that I could not do it.

As a result, in an internal combustion engine equipped with such a fuel injection valve, there is a limit to effective reduction of fuel consumption and reduction of combustion unburned gas components (HC, CO). .

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to adjust the number and size of a plurality of injection holes and the angle of the injection holes penetrating in the plate thickness direction. In addition to the means for improving atomization performance, the injection flow velocity can be effectively increased near the injection hole, the vortex flow can be effectively formed on the upstream side of the injection hole, and the fuel collides with the outside of the injection hole. It is to provide a fuel injection valve and an internal combustion engine equipped with the fuel injection valve capable of improving atomization performance.

[0007]

In order to solve the above problems, the present invention relates to a plate member having a plurality of injection holes penetrating in the plate thickness direction, a fuel outer peripheral radiation chamber on the upstream side of the plate member, A fuel contracting portion is provided upstream of the fuel outer peripheral radiation chamber, a valve seat is provided upstream of the fuel contracting portion, a valve body for opening and closing a fuel passage between the valve seat and the valve body is driven. In a fuel injection valve provided with a drive means, a distance between a wall surface of the plate member and a wall surface of the fuel outer peripheral radiation chamber facing the upstream side of the plate member becomes shorter as it goes in the outer peripheral direction of the plate member. A fuel injection valve characterized by the above.

In order to solve the above problems, the present invention provides
A plate member having a plurality of injection holes penetrating in the plate thickness direction, a fuel outer peripheral radiation chamber on the upstream side of the plate member, a fuel contracting portion on the upstream side of the fuel outer peripheral radiation chamber, and the fuel contracting portion. In a fuel injection valve provided with a valve seat on the upstream side, a valve body for opening and closing a fuel passage between the valve seat, and a drive means for driving the valve body, the fuel injection valve is opposed to the upstream side of the plate member. A fuel injection valve is characterized in that a step is provided on a wall surface of the fuel outer peripheral radiation chamber.

In order to solve the above-mentioned problems, the present invention is directed to the above-mentioned fuel injection valve, wherein the plate members are arranged so that the fuel injected outside through the injection holes of the plate members collides with each other. A fuel injection valve is characterized in that a plurality of injection holes having a constant inclination angle are installed in the fuel injection valve.

With the above structure, the atomized particle size of the injected fuel can be reduced, and the fuel injection valve can be easily adapted to various internal combustion engines. By facilitating adaptation to various internal combustion engines, the efficiency of the internal combustion engine can be improved, and the effect of suppressing unburned fuel components in exhaust gas from the internal combustion engine can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The best embodiment of the present invention will be described below with reference to FIGS. In the following description, a plane including the axis of the valve body and parallel to the axis will be referred to as a vertical section.

FIG. 1 shows a normally closed electromagnetic fuel injection valve as an example of a vertical sectional view showing the structure of the fuel injection valve of the present invention. (However, the effect of the present invention is not limited to the electromagnetic fuel injection valve.) In the fuel injection valve of the present embodiment shown in FIG. 1, the magnetic yoke 105 surrounding the electromagnetic coil 109 and the electromagnetic A core 106 located at the center of the coil 109 and having one end in contact with the yoke 105; a valve body 102 that lifts a predetermined amount when the electromagnetic coil 109 is excited;
The seat surface 110 facing the valve body 102 and the valve body 10
2 and the seat surface 110, the fuel contracting portion 101 for condensing the fuel flowing through the gap, the fuel outer peripheral radiation chamber for flowing the fuel in the outer peripheral direction below the fuel contracting portion 101, and a plurality of fuel outer peripheral radiation chambers The plate member 111 having the injection holes 107 is provided. Further, at the center of the core 106, the valve body 102
A spring 108 is provided as an elastic member that presses against the seat surface 110 of the orifice 101. Coil 10
In the state in which 9 is not energized, the valve body 102 and the seat surface 110 are in close contact with each other. The fuel is supplied from the fuel supply port while being pressurized by a fuel pump (not shown), and the fuel passage 104 of the fuel injection valve is filled with the fuel up to the position where the valve body 102 and the seat surface 110 are in close contact with each other.
When the coil 109 is energized and the valve body 102 is displaced by the magnetic force to move away from the seat surface 110, the fuel is concentrated near the axial center at the fuel contraction portion 101, and then the plate member 1
The structure is such that it flows radially in the outer peripheral direction along 11 and is injected from a plurality of injection holes 107 toward an intake port of the engine or the like.

FIG. 2 is a vertical sectional view of the nozzle portion of the first embodiment of the fuel injection valve of the present invention. A feature of the present invention is that the fuel outer circumference radiating chamber 201 serving to flow the fuel in the outer circumference direction.
The wall facing the plate member 111 of the
Is what you are doing. By doing so, as the fuel flows from the center of the plate member 111 to the outer peripheral direction, the distance between the plate member 111 and the inclined wall surface 202 becomes shorter, and the flow passage cross-sectional area becomes smaller accordingly. go. In addition, FIG. 3 shows a plan view of the plate member 111 according to the first embodiment of the fuel injection valve of the present invention viewed from the injection hole outlet side. The plate member 111 has a plurality of injection holes 1
07 is provided, atomizes the fuel flowing out when the valve body 102 opens, and changes the fuel injection direction to the injection direction 30.
It plays the role of controlling in two directions, 1 and 302. In the first embodiment, ten injection holes are provided.

Hereinafter, the operation and effect of the fuel injection valve according to the present invention will be described in comparison with the case where the injection valve according to the conventional example is used. FIG. 4 shows a vertical cross-sectional view and a flow state of the nozzle portion of the first embodiment in the fuel injection valve of the present invention in comparison with the conventional example. (A) is a fuel injection valve of the present invention,
(B) is a conventional fuel injection valve. In the case of the fuel injection valve of the present invention of (A), by making the wall facing the plate member 111 of the fuel outer peripheral radiation chamber 201 into the inclined wall surface 202, the fuel flows from the center of the plate member 111 to the outer peripheral direction. As it goes, the distance between the plate member 111 and the inclined wall surface 202 becomes shorter, and the flow passage cross-sectional area becomes smaller. As a result, the fuel that has flowed radially in the outer circumferential direction along the plate member 111 in the fuel outer circumferential radiation chamber 201 is gradually accelerated between the plate member 111 and the inclined wall surface 202. Therefore, the flow velocity vector 402 of the fuel injected from each injection hole 107 becomes large, and atomization is further promoted, and the atomized particle size becomes small,
It is injected toward the intake port of the engine. On the other hand, in the case of the fuel injection valve according to the conventional example of (B), since the wall of the fuel outer peripheral radiation chamber 201 facing the plate member 111 is the horizontal wall surface 403, the fuel injected from each injection hole 107. Is smaller than the fuel flow velocity vector 402 in (A). This point is different from the flow of fuel in the fuel injection valve of the present invention in (A).

FIG. 5 shows the flow velocity distribution at the outlet of the injection hole 107 of the first embodiment in the fuel injection valve of the present invention. Vz represents the flow velocity in the vertical direction when the vertical downward direction is positive. In the case of the fuel injection valve according to the conventional example of (B), the injection hole 107 penetrates obliquely as the flow velocity distribution at the outlet of the injection hole 107 is shown by the broken line. Therefore, the flow velocity distribution has a bias rather than a parabolic shape. On the other hand, in the case of the fuel injection valve of the present invention of (A) shown by the solid line, the flow velocity distribution has a bias as in (B), but the magnitude of the flow velocity vector is (B )
The feature is that it is larger than. Since the flow velocity vector at the injection hole outlet is increased in this way, atomization of the injected fuel is further increased, and the atomized particle size can be reduced.

In the fuel injection valve of the first embodiment described so far, the valve body 102 is a ball valve, but the valve body 10
Other than the ball valve, 2 may have another shape such as a conical shape.

From the above, the fuel injection valve of the first embodiment is
By making the wall facing the plate member 111 of the fuel outer peripheral radiation chamber 201 into the inclined wall surface 202, the distance between the plate member 111 and the inclined wall surface 202 becomes shorter as the fuel flows from the center of the plate member 111 to the outer peripheral direction. As it goes, the cross-sectional area of the flow path also becomes smaller. Therefore, the fuel is accelerated in the vicinity of the injection hole, the atomized particle size of the injected fuel becomes smaller, and atomization can be promoted.

FIG. 6 is a vertical sectional view of the nozzle portion of the second embodiment of the fuel injection valve of the present invention. Since the electromagnetic fuel injection valve similar to that of the first embodiment is used except for the nozzle portion, the description of its constituent elements is omitted. As shown in FIG. 6, the second embodiment is characterized in that a step 601 is provided on the wall surface of the outer peripheral fuel chamber 201 facing the upstream side of the plate member 111.

The operation and effect of the second embodiment of the fuel injection valve of the present invention will be described below with reference to FIGS. 7 and 8.
FIG. 7 shows a longitudinal sectional view and a flow state of the nozzle portion of the second embodiment of the fuel injection valve of the present invention. Perimeter fuel chamber 2
At 01, a part of the fuel flowing radially from the center to the outer periphery along the plate member 111 collides with the step 601 to form a vortex 701.

FIG. 8 shows how the vortex 701 promotes atomization. The vortex 701 generated in the fuel outer peripheral radiation chamber 201 rides on the fuel flow 801 and is injected from each injection hole 107. The presence of the vortex 701 has the effect of promoting the turbulence of the gas-liquid interface 802 between the fuel and the air, as compared with the case where there is no vortex.
The particle size of the spray particles 803 can be reduced.

In the fuel injection valve of the second embodiment described so far, the plate member 111 of the fuel outer peripheral radiation chamber 201 is used.
The wall opposite to was the horizontal wall surface 403. However, FIG.
As shown in FIG.
The wall facing 1 may be the inclined wall surface 202.

From the above, the fuel injection valve of the second embodiment is
Since the step 601 is provided on the wall surface of the fuel outer peripheral radiation chamber 201 facing the upstream side of the plate member 111, the vortex 701 is generated in the fuel outer peripheral radiation chamber 201. Then, this vortex 701 promotes the turbulence of the gas-liquid interface 802 between the fuel and air, the particle size of the spray particles 803 becomes smaller, and atomization can be promoted.

FIG. 10 is a plan view seen from the injection hole outlet side of the plate member 1017 of the third embodiment of the fuel injection valve of the present invention. Except for the plate member 1017, the same electromagnetic fuel injection valve as that of the first or second embodiment is used, and thus the description of its constituent elements is omitted.

In the third embodiment, eight injection holes 1001-10
08 is provided on the plate member 1017. The plate member 1017 is provided with the injection holes 1001 to 1008 having a certain inclination angle so that the fuel injected to the outside through the injection holes of the plate member collides with each other.

Fuel injected in the injection direction 1009 from the injection hole 1001 and injection direction 1010 from the injection hole 1002.
The fuel injected into the vehicle collides with it. Similarly, the fuel injected from the injection hole 1007 in the injection direction 1015 and the fuel injected from the injection hole 1008 in the injection direction 1016 collide with each other. Each injection hole 1001
When the fuel injected to the outside through 1008 collides with each other, the effect of collision can further promote atomization.

From the above, the electromagnetic fuel injection valve according to the third embodiment makes the fuel collide with each other outside the injection hole,
Atomization can be further promoted.

Although the electromagnetic fuel injection valve has been described in the first to third embodiments, the present invention is not limited to this, and the electromagnetic fuel injection valve can be used within a range in which the same effect as that of the present embodiment can be obtained. It is also generally applied to fuel injection valves other than the formula.

FIG. 11 shows an example in which the fuel injection valve 1101 according to the present invention shown in FIG. 1 is mounted on an internal combustion engine. Since the same fuel injection valve as that shown in the first to third embodiments is used as the fuel injection valve, the description of its constituent elements is omitted. The internal combustion engine shown in FIG. 11 includes a cylinder head 1102, an intake valve 1103, a spark plug 1104 for igniting a mixture of fuel and air, a piston 110.
5, cylinder 1106, exhaust valve 1107, cylinder 11
Intake port 1108 for introducing air into the cylinder 06, and exhaust port 1109 for exhausting combustion gas from the inside of the cylinder 1106.
It consists of Further, the fuel injection valve 1101 has
A connector 1110 is provided for supplying a current for driving the injection valve.

Incidentally, in FIG. 11, the intake valve 1103 is shown in a closed state. However, in practice,
When fuel is sprayed from the fuel injection valve 1101 to the combustion chamber 1111, the intake valve 1103 is open. Here, the injection start timing of the fuel injection valve 1101 may be the timing at which the intake valve 1103 is actually opened, but even before the intake valve 1103 actually starts opening in consideration of the flight time of fuel. good. In this case, the fuel at the start of injection is the intake valve 1103 when the intake valve 1103 actually opens.
The flight time is set to reach 103. Furthermore, if it is within the allowable range, the fuel at the start of injection is the intake valve 1
The injection start timing can be set so that the intake valve 1103 is reached before the valve 103 actually starts opening the valve.

From the above, in the internal combustion engine of the fourth embodiment equipped with the fuel injection valve of the present invention, the atomization performance of the fuel spray injected from the fuel injection valve is excellent, so that the unburned gas component of combustion ( It is possible to reduce the emission amount of (HC, CO).

[0031]

According to the present invention, in the fuel injection valve, by making the wall facing the plate member an inclined wall surface, the flow passage cross-sectional area becomes smaller, so that the fuel is accelerated in the vicinity of the injection hole. Thus, atomization can be promoted. Further, by providing a step on the wall surface of the fuel outer peripheral radiation chamber facing the upstream side of the plate member, a vortex is generated in the fuel outer peripheral radiant chamber, and this vortex promotes turbulence at the gas-liquid interface between fuel and air. , Can promote atomization. Further, by disposing the injection holes in the plate member so that the fuels collide with each other outside the injection holes, atomization due to the collision effect can be promoted. Further, in the internal combustion engine equipped with the fuel injection valve of the present invention, since the atomization performance of the fuel spray injected from the fuel injection valve is excellent, the emission amount of unburned gas components (HC, CO) of combustion is reduced. It can be reduced.

[Explanation of symbols]

101 ... Fuel constriction part, 102 ... Valve body, 103 ... Nozzle part, 104 ... Fuel passage, 105 ... Yoke, 106 ... Core, 107 ... Injection hole, 108 ... Spring, 109 ... Coil, 110 ... Seat surface, 111 ... Plate member, 20
DESCRIPTION OF SYMBOLS 1 ... Fuel outer peripheral radiation chamber, 202 ... Inclined wall surface, 301 ... Injection direction, 302 ... Injection direction, 401 ... Fuel flow velocity vector, 402 ... Fuel flow velocity vector, 403 ... Horizontal wall surface,
404 ... Fuel flow velocity vector, 601 ... Step portion, 701
... Vortex, 801 ... Fuel flow, 802 ... Gas-liquid interface, 803
... Spray particles, 1001 ... injection holes, 1002 ... injection holes, 1
003 ... Injection hole, 1004 ... Injection hole, 1005 ... Injection hole, 1006 ... Injection hole, 1007 ... Injection hole, 1008 ...
Injection hole, 1009 ... Injection direction, 1010 ... Injection direction, 1
011 ... Jet direction, 1012 ... Jet direction, 1013 ... Jet direction, 1014 ... Jet direction, 1015 ... Jet direction, 1
016 ... Jetting direction, 1017 ... Plate member, 1101
... Fuel injection valve 1102 ... Cylinder head 1103 ...
Intake valve, 1104 ... spark plug, 1105 ... piston,
1106 ... Cylinder, 1107 ... Exhaust valve, 1108 ... Intake port, 1109 ... Exhaust port, 1110 ... Connector, 1111 ... Combustion chamber.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a fuel injection valve showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the nozzle portion of the first embodiment of the fuel injection valve of the present invention.

FIG. 3 is a plan view of the plate member according to the first embodiment of the fuel injection valve of the present invention viewed from the injection hole outlet side.

FIG. 4 is a longitudinal sectional view of a nozzle portion of a fuel injection valve according to a first embodiment of the present invention and a view showing a flow state in comparison with a conventional example.

FIG. 5 is a diagram showing a flow velocity distribution at the injection hole outlet of the first embodiment of the fuel injection valve of the present invention.

FIG. 6 is a vertical cross-sectional view of a nozzle portion of a second embodiment of the fuel injection valve of the present invention.

7A and 7B are a vertical cross-sectional view of a nozzle portion of a second embodiment of a fuel injection valve of the present invention and a diagram showing a flow state.

FIG. 8 is a diagram showing how atomization is promoted by a vortex flow.

FIG. 9 is a vertical cross-sectional view of a nozzle portion of a second embodiment of the fuel injection valve of the present invention.

FIG. 10 is a plan view of the plate member of the third embodiment of the fuel injection valve of the present invention viewed from the injection hole outlet side.

FIG. 11 is a partial cross-sectional view of a fourth embodiment in which the fuel injection valve of the present invention is mounted on an internal combustion engine.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromasa Kubo             Hitachinaka City, Ibaraki Prefecture 2520 Takaba             Ceremony Company Hitachi Ltd. Automotive equipment group F-term (reference) 3G066 AB02 BA03 BA04 CC10 CC15                       CC24 CC26 CC48 CE22

Claims (4)

[Claims] 1. A plate member having a plurality of injection holes penetrating in the plate thickness direction, a fuel outer peripheral radiation chamber on the upstream side of the plate member, and a fuel contracting portion on the upstream side of the fuel outer peripheral radiation chamber. A fuel injection valve including a valve seat upstream of a fuel contracting portion, a valve body for opening and closing a fuel passage between the valve seat and a drive unit for driving the valve body, wherein The fuel injection valve, wherein the distance between the wall surface and the wall surface of the fuel outer peripheral radiation chamber that faces the upstream side thereof becomes shorter as it goes in the outer peripheral direction of the plate member. 2. A plate member having a plurality of injection holes penetrating in the plate thickness direction, a fuel outer peripheral radiation chamber on the upstream side of the plate member, and a fuel contracting portion on the upstream side of the fuel outer peripheral radiation chamber. A fuel injection valve including a valve seat upstream of a fuel contracting portion, a valve body for opening and closing a fuel passage between the valve seat and a drive unit for driving the valve body, wherein A fuel injection valve, wherein a step is provided on a wall surface of the fuel outer peripheral radiation chamber facing the upstream side. 3. The fuel injection valve according to claim 1, wherein the plate member is provided with a certain inclination angle so that the fuel injected to the outside through the injection holes of the plate member collides with each other. A fuel injection valve having a plurality of injection holes provided therein. 4. A cylinder, a piston which reciprocates in the cylinder, an intake means for introducing air into the cylinder, an exhaust means for exhausting combustion gas from the cylinder, and a fuel directly in the cylinder. Fuel injection valve for injecting fuel, fuel supply means for supplying fuel from the fuel tank to the fuel injection valve, air introduced into the cylinder by the intake means, and fuel injected into the cylinder by the fuel injection valve. An internal combustion engine comprising an ignition device for igniting an air-fuel mixture thereof, wherein the fuel injection valve according to any one of claims 1 to 3 is provided as the fuel injection valve.