JP2599694B2 - Electromagnetic fuel injection valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection hole which can be opened and closed by a needle valve, provided in an injector body, and can supply assist air to a fuel flow injected from the fuel injection hole. The present invention relates to an electromagnetic fuel injection valve.

[0002]

2. Description of the Related Art Conventionally, such an electromagnetic fuel injection valve is already known from Japanese Utility Model Laid-Open No. 1-61461.

[0003]

SUMMARY OF THE INVENTION
In Japanese Patent No. 61, the air assist passages are respectively opened in a pair of fuel injection passages, and atomization of fuel is performed by supplying assist air to a fuel jet flowing through each fuel injection passage. However, mixing and atomization of fuel and assist air become non-uniform due to increase / decrease in fuel injection amount and increase / decrease in assist air supply amount, resulting in variation in fuel injection particle size. There is.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electromagnetic fuel injection valve in which atomization and uniformity of injected fuel and stabilization of a discharge form are achieved.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a fuel injection hole which can be opened and closed by a needle valve, provided in an injector body. In an electromagnetic fuel injection valve capable of supplying assist air toward the fuel injector, an outer fuel spray guide formed in a cylindrical shape for regulating the spray angle of the fuel is provided on the injector body downstream of the fuel injection hole, A pintle provided at the tip of the needle valve through the injection hole is inserted into the outer fuel spray guide means, and the inner fuel spray guide means is fixedly disposed coaxially and opposed to the pintle in the outer fuel spray guide means. A fuel injection passage is formed between the outer fuel spray guide and the inner fuel spray guide. Passage is provided in the outer fuel spray guide means at a position corresponding to the fuel injection passage, characterized in that a plurality of second air assist passageway that opens toward the inner fuel spray guide means is provided.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show a first embodiment of the present invention. FIG. 1 is a sectional view showing a state in which an electromagnetic fuel injection valve is mounted on an engine. FIG. FIG. 3 is an enlarged view of a main part of FIG. 2, and FIG.
FIG. 5 is a sectional view taken along line 4-5 in FIG.

First, in FIG. 1, a valve seat member 9 forming an intake valve port 8 opening to a ceiling portion of a combustion chamber 3 is fixed to a cylinder head 2 connected to an upper surface of a cylinder block 1 of an engine. In addition, an intake port 4 connected to the intake valve port 8 is provided, and an intake manifold 5 communicating with the intake port 4 is coupled to a side surface of the cylinder head 2. Intake valve ports 8 that open the intake valve 6, the rod portion 6 ₁ is slidably guided by a valve guide 7 provided in the cylinder head 2,
Umbrella portion 6 ₂ can be seated on the valve seat member 9 are those formed by integrally connected to driven to open and close by a valve operating mechanism (not shown).

At the end of the intake manifold 5 near the cylinder head 2, an electromagnetic fuel injection valve I for injecting fuel from the intake port 4 toward the intake valve port 8 is mounted.

Referring to FIGS. 2 and 3, the electromagnetic fuel injection valve I includes a substantially cylindrical main body housing 11, in which a coil 12 is wound around the outer periphery. Bobbin 13 to be mounted, ring-shaped yoke 14, stopper plate 15, injector body 1
6 and the cap 17 are on the tip side (the lower end side in FIG. 2).
And the leading edge of the main body housing 11 is caulked to the outer periphery of the cap 17.

A cylindrical fixed iron core 11 ₁ coaxially surrounded by a bobbin 13 is provided integrally with the main body housing 11.
Portion surrounding the bobbin 13 coaxially in the body housing 11 is coupled to the yoke 14 as the yoke 11 _2. A movable core 18 is accommodated in a space defined by the yoke 14 and a portion of the bobbin 13 near the yoke 14 so as to be movable in the axial direction. A cylindrical spring seat 19 is press-fit into the center of the main body housing 11 from the rear end side (upper end side in FIG. 2), and is contracted between the spring seat 19 and the movable iron core 18. the spring 20 returns to be movable iron core 18 is biased in a direction away from the fixed iron core 11 _1.

[0012] the rear end of the needle valve 21 to the movable iron core 18 are caulking, the needle valve 21 is inserted into the circular guide hole 16 ₁ provided in the injector body 16. Thus, the needle valve 21 has guide portions 21 ₁ , 21 having a substantially rectangular cross section at two locations spaced apart in the axial direction.
21 ₁ are provided, and their guide portions 21 ₁ , 2
1 ₁ is slidably fitted to the guide hole 16 _1. Moreover the valve portion 21 ₂ is provided on the distal end of the needle valve 21.
On the other hand, a tapered valve seat 16 _{2 is} formed at the distal end of the injector body 16 so as to be coaxial with the guide hole 16 _1.
Together are provided, the fuel injection hole 16 ₃ so as to be opened in the center of the valve seat 16 ₂ is provided, the valve portion 21 _2, the fuel injection hole 16 ₃ seated on the valve seat 16 ₂
Can be closed.

When the coil 12 wound on the bobbin 13 is demagnetized, the movable iron core 18 is at a position separated from the fixed iron core 11 ₁ by the spring force of the return spring 20, and the needle valve 21 has its valve portion 21 _2. I was seated on the valve seat 16 ₂ located in the closed position of the fuel injection hole 16 _3. When the coil 12 Thus is excited, it is attracted to the fixed iron core 11 ₁ side against the spring force of the movable iron core 18 is the return spring 20, the valve seat and the needle valve 21 is the valve portion 21 ₂ accordingly 16 ₂ is moved away from the moving to a position for opening the fuel injection hole 16 _3. At this time, by the flange 21 ₃ provided in the middle portion of the needle valve 21 abuts against the stopper plate 15, the moving end in the direction away from the valve seat 16 ₂ the needle valve 21 is restricted.

[0014] When the fuel injection hole 16 ₃ is opened as described above, the fuel supplied from a fuel supply source (not shown) at the rear end of the main body housing 11, filter 22, spring seat 1
9, a through hole 18 ₁ provided in the movable iron core 18, a yoke 1
4, a through hole 15 ₁ provided in the stopper plate 15, a gap between the guide hole 16 ₁ of the injector body 16 and the guide portions 21 ₁ , 21 ₁ of the needle valve 21, a valve portion 21 ₂ and a valve seat 16 _2. is the gap, and the fuel injection hole 16 ₃ sequentially passes injected between. The amount of fuel injected from the electromagnetic fuel injection valve I is measured by controlling the length of time during which the coil 12 is energized.

[0015] Referring also to FIGS. 4 and 5, the cap 17, the fitting hole 17 ₁ of the fuel injection hole 16 ₃ coaxially provided in the fitting hole 17 _1, the fuel injection Hole 1
6 cylindrical outer fuel to ₃ coaxially connected to the spray guide means 3
1 is fitted. Moreover the end opposite its front end portion or the injector body 16 in the outer fuel spray guide means 31, one notch 31 ₁ along a radial line is provided, the support arms 17 ₂ provided in the cap 17 There is fitted into the cutout 31 _1. Thus the outer fuel spray guide means 31 will be holding a fitting state of the fitting hole 17 _1. Pintle 34 Thus to penetrate the fuel injection hole 16 ₃ is inserted into the outer fuel spray guide means 31.

[0016] The support arms 17 _2, the inner fuel spray guide means 32 of the spindle facing the pintle 34 in the outer fuel spray guide means within 31 coaxially provided integrally, the inner fuel spray guide means 32 and the outer fuel Spray guide means 31
The fuel injection passage 33 is formed between the _two and excluding the portion where the support arm 172 is provided.

A pintle 34 integral with the needle valve 21
The tip portion of the tapered surface 34 as a tapered surface 34 ₁ which diameter increases toward the front (lower side in FIG. 3), smaller in diameter toward the front with coaxially connected to the large diameter end of the tapered surface 34 _{1 2} by the umbrella portion 34 ₃ is formed. Therefore the fuel injected from the fuel injection hole 16 ₃ is atomized by colliding with the valve head 34 ₃ of the pintle 34, the outer surface or sprayed outward defined by an inner surface of the outer fuel spray guide means 31 of the fuel injection passage 33 The angle θ ₁ and the inner surface of the fuel injection passage 33, that is, the inner fuel spray guide means 3
2, the fuel is sprayed from the fuel injection passage 33 in a cone shape having a spray inner angle θ ₂ defined by the outer surface of the fuel injection passage 33.

By the way, the fuel spray pattern from the fuel injection passage 33, which is formed to spray the lack portion occurs at the supporting arm 17 a _second portion for supporting the inner fuel spray guide means 32, an electromagnetic fuel injection the housing body 11 of the valve I, the spray lack portion so as to correspond to the rod portion 6 ₁ of the intake valve 6 is attached to the intake manifold 5, whereby the spray fuel air-fuel ratio adhering to the rod portion 6 ₁ Changes are avoided.

The housing body 11 of the electromagnetic fuel injection valve I
An annular air chamber 37 (see FIG. 1) is formed between the intake manifold 5 and an air supply source (not shown).
The air from the air chamber 37 is jetted from the inner fuel spray guide means 32 toward the pintle 34 as assist air, and is jetted from the outer fuel spray guide means 31 toward the fuel jet flowing through the fuel injection passage 33. .

That is, the inner fuel spray guide means 32 is provided with a first air assist passage 38 which is opened facing the tip of the pintle 34, and is provided with a first air assist passage 38.
It is communicated to the air chamber 37 via the air supply passage 39 provided in the support arms 17 ₂ and the cap 17. Further, on the outer periphery of the outer fuel spray guide means 31, there is provided a concave portion which forms an air flow passage 40 between the outer fuel spray guide means 31 and the fitting hole 17 _1. Are communicated with the air chamber 37 by a plurality of, for example, three passages 41. Moreover, the outer fuel spray guide means 31 is provided with a plurality of second air assist passages 42 ₁ ... Which open toward the inner fuel spray guide means 32 at positions corresponding to the fuel injection passages 33. The passages 42 ₁ are commonly connected to the air flow passage 40.

Next, the operation of the first embodiment will be described.
Then, the coil 12 is excited and the needle valve 21 is opened.
The valve 21_TwoIs the valve seat 16_TwoAway from fuel
Injection hole 16_ThreeIs released, high-pressure fuel burns.
Injection hole 16_ThreeSquirted from. Fuel
Is the umbrella part 34 of the pintle 34_ThreeTapered surface 34 at ₁
It is atomized while radiating and diffusing radially. this
At this time, the first air assist passage of the inner fuel spray guide means 32 is performed.
Sprayed from the road 38 toward the tip of the pintle 34
Assist air is umbrella part 34_ThreeTapered surface 34_TwoCollide with
And diffused and uniformly mixed with the atomized fuel.
In addition, the first air assist passage is provided so as to face the fuel flow.
Since the assist air is supplied from the road 38, a large relative
At high speeds, the air flow collides with the fuel flow, further promoting atomization
And the particle size is stabilized.

The atomized fuel is ejected to the outside through the fuel injection passage 33. In the fuel injection passage 33, assist air is blown from the plurality of second air assist passages 42 ₁ . Therefore, atomization of the fuel is further promoted, and for example, atomization of 60 μm or less becomes possible. Moreover, it is generally difficult to stabilize the fuel discharge form when the fuel is atomized. However, the atomization is performed together with the assist air from the first air assist passage 38 and the plurality of second air assist passages 42 ₁ . By jetting the fuel, the fuel discharge foam can be stabilized. Therefore, the atomized fuel, which has been atomized, made uniform and the discharge foam stabilized, is supplied to the combustion chamber 3 of the engine.
And it can contribute to the improvement of the combustion efficiency in the combustion chamber 3.

FIGS. 6, 7 and 8 show a second embodiment of the present invention, in which the outer fuel spray guide means 31 is connected to the inner fuel spray guide means 32 at a position corresponding to the fuel injection passage 33. FIG. A plurality of, for example, three second openings
Provided the air assist passage 42 ₂ ... long slit shape in the circumferential direction at a position spaced a circumferential direction, their second air assist passages 42 ₂ ... it is communicated with the common airflow path 40.

According to the second embodiment, the same effects as in the first embodiment can be obtained.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, the outer fuel spray guide means 31
It may be integrated with the injector body 6 or the cap 17.

[0027]

As described above, according to the present invention, the cylindrical outer fuel spray guide means for regulating the fuel spray angle is provided on the injector body on the downstream side of the fuel injection hole. A pintle provided at the tip of the needle valve is inserted into the outer fuel spray guide means,
A fuel injection passage is formed between the inner fuel spray guide means and the outer fuel spray guide means which are fixedly disposed coaxially and opposed to the pintle in the outer fuel spray guide means,
The inner fuel spray guide means is provided with a first air assist passage which is open to face the front end of the pintle, and the outer fuel spray guide means has a first air assist passage at a position corresponding to the fuel injection passage. A plurality of second air assist passages are provided, which are opened at the same time. After the atomization and uniformization of the fuel are promoted by the assist air from the first air cyst passage, the assist air from the plurality of second air assist passages is further increased. Atomization and uniformity are promoted, and atomization and uniformity of the injected fuel and stabilization of the discharge foam can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which an electromagnetic fuel injection valve according to a first embodiment is mounted on an engine.

FIG. 2 is an overall longitudinal sectional view of an electromagnetic fuel injection valve.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is a view taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is a longitudinal sectional view corresponding to FIG. 3 of the second embodiment.

FIG. 7 is a view taken along line 7-7 of FIG. 5;

FIG. 8 is a sectional view taken along line 8-8 in FIG. 5;

[Explanation of symbols]

Reference Signs List 16 injector body 16 ₃ fuel injection hole 21 needle valve 31 outer fuel spray guide means 32 inner fuel spray guide means 33 fuel injection passage 34 pintle 38: first air assist passage 42 ₁ , 42 ₂ ... second air assist passage I: electromagnetic fuel injection valve

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location F02M 61/18 360 F02M 61/18 360G 69/00 310 69/00 310A

Claims (1)

(57) [Claims] A fuel injection hole (16 ₃ ) which can be opened and closed by a needle valve (21) is provided in an injector body (1).
Provided 6), the fuel injection hole (16 ₃₎ capable of supplying assist air towards the fuel stream injected from electromagnetic fuel injection valve, is formed in a cylindrical shape for regulating the spray angle of the fuel that the outer fuel spray guide means (31) is provided in the injector body (16) downstream of the fuel injection hole (16 _3), fuel injection holes (16 ₃₎ through provided on the tip of the needle valve (21) The pintle (34) to be inserted is inserted into the outer fuel spray guide means (31), and the inner fuel spray guide means () is fixedly disposed coaxially and opposed to the pintle (34) in the outer fuel spray guide means (31). 3
A fuel injection passage (33) is formed between the outer fuel spray guide means (2) and the outer fuel spray guide means (31), and a second fuel spray guide means (32) is formed so as to face the tip of the pintle (34). One air assist passage (38) is provided, and the inner fuel spray guide (3) is provided at the position corresponding to the fuel injection passage (33) to the outer fuel spray guide (31).
A plurality of second air assist passages (4
2 ₁ , 42 ₂ ) is provided.