JPH02241973A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To provide stable fuel injection characteristics by positioning the edge on the valve axial center side of a turning groove, on the axial center side closer than the central position between the axial center and the inner wall surface of a fuel turning element, and keeping the distance between one valve axial side edge of the turning groove and the valve axial center and that between the other edge of the groove and the inner wall surface at a given relationship. CONSTITUTION:An edge 13a on the valve axial center side of a diametrical groove 13 provided in a fuel turning element 7 is positioned on the axial center side closer than the central position between the axial center and the inner wall surface 7a of the fuel turning element 7, and the positions of respective groove edge positions are constructed so that the distance l1 between one valve axial side edge 13a of the diametrical groove 13 and the valve axial center and the distance l2 between the other edge 13b of the diametrical groove 13 and the inner wall surface 7a may become l1 > l2. Moreover, the central position is the center between the valve axial center and the inner wall surface 7a of the fuel turning element 7, which is 1/2 time as large as the corresponding diameter (d) of the inner wall surface 7a. Furthermore, the width W of the groove is 1/2d - l1 - l2, and the fuel passing through the diametrical groove 13 is led to the first fuel turning chamber 14 and is jetted from a fuel jetting hole 5 through the second fuel turning chamber 15.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electromagnetic fuel injection valve for an internal combustion engine, and in particular,
In the type that swirls the fuel on the upstream side of the valve seat,
The present invention relates to the packaging of the swirling element, which allows the atomized fuel to be injected at a small injection angle while maintaining high flow rate accuracy.

[Conventional technology]

Examples of electromagnetic fuel injection valves that swirl fuel on the upstream side of the valve seat include JP-A-55-104564 and JP-A-56-
There is No. 75955. The former -4=== has a plurality of inlet orifices and one outlet orifice, the inlet orifices being spaced apart from the swirling chamber by the maximum diameter. Moreover, the latter U is provided with a plurality of swirl passages that introduce fuel from the tangential direction. These M add a strong swirl and have a large injection angle.

Therefore, application to fuel injection systems is preferred over single-point systems, where a single-point system is one where a single injection point, unlike a multi-point system, where a one-to-one correspondence occurs. It has one fuel injection valve that sends fuel to multiple cylinders. The injection point is inside the intake manifold assembly, or above or below the airflow MAW device (throttle valve) leading to the intake manifold. Since the fuel is injected into a relatively wide space within the intake manifold collecting pipe, a large spread is sufficient.

Fuel intake air is distributed to each cylinder in accordance with intake air. On the other hand, in a multi-point system, a fuel injection valve is arranged in a branch pipe of an intake manifold corresponding to each cylinder of the engine, and atomized fuel is injected into the branch pipe near the related intake valve. Since the fuel is injected into a narrow space within the branch pipe, its spread must be limited and small.

Adhesion of fuel to the inner wall surface of the intake manifold causes a delay in fuel transportation to the cylinders, which is undesirable because it deteriorates the engine's transient characteristics, idle stability, and the like.

The object of the present invention is to have stable fuel spray characteristics.

An object of the present invention is to provide an electromagnetic fuel injection valve that is compatible with a multi-point system.

[Means for Solving the Problems] In order to achieve the above object, the electromagnetic fuel injection valve of the present invention has an end face on the valve axis side of a swirl groove provided in a fuel swirling element, which is in contact with the axis and the fuel swirling element. a distance Ql between the valve axis side end face of the pivot groove and the valve axis, and a distance Ql between the other end face of the groove and the inner wall face;
The positions of the groove end faces are configured such that Ql>Qz.

[Effect]

The fuel that has passed through the swirl groove flows into the opposing annular passage, that is, the first fuel swirl chamber, but the fuel flows into the second fuel swirl chamber at the bottom of the ball valve without causing unstable flow such as swirling.
The fuel flows through the fuel swirling chamber to the downstream fuel injection hole. At this time, the fuel flow rate passing between the cores is relatively slow, and the swirling force is weak.

Therefore, the spread angle of the atomized fuel injected from the fuel injection hole is small, and adhesion of fuel to the inner wall of the intake manifold of the internal combustion engine is suppressed, thereby increasing the operating efficiency of the engine. Moreover, the passage loss of the fuel flowing through the swirl groove is extremely small.
The supplied pressurized fuel can be efficiently converted into turning energy. The most advantageous injection structure can be obtained as a fuel injection valve.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. The structure and operation of an electromagnetic fuel injection valve (hereinafter referred to as ``injection valve'') 1 according to the present invention will be explained using FIG. 1.

In FIG. 1, reference numeral 2 denotes a substantially cylindrical housing that houses the main operating parts of the injection valve 1, and a nozzle assembly [3, which will be described next, is mechanically fixedly held in the lower part of the housing 2.

A valve seat 4 is formed on the inner surface of the lower part of this nozzle device 3, and a fuel injection hole 5 is bored in the lower axis thereof. Further, a cylindrical fuel swirling element 7 is mechanically fixed in a rapidly expanding hole 6 provided close to the valve seat 4. Reference numeral 9 denotes a rod related to a valve member that constitutes the main part of the valve device 8. A ball 10 is fixed to the lower tip of the rod 9, and a cup-shaped plunger 11 made of a magnetic material is fixed to the other end. .

The ball 10 slides within the inner wall surface 7a of the fuel swirling element 7 in the axial direction. When this ball 10 is seated on the valve seat 4, the fuel injection hole 5 is closed, but when it leaves the valve seat 4, the fuel injection hole 5 is opened. The fuel that reaches the fuel injection hole 5 flows through grooves 12 and 13 provided in the fuel swirl element 7, but these grooves are connected to an axial groove 12 having a sufficient gap to allow the passage of the fuel. Radial direction with small loss @1
3, and the fuel flows into the first swirling chamber 14 at the outlet of this radial groove 13. A second fuel swirling chamber 15 is formed between the lower part of the ball 10 and the conical valve seat 4, and promotes the swirling flow of the fuel flowing from the first fuel swirling chamber 14. 16 is a support surface 2a of the housing 2;
A horseshoe-shaped spacer member inserted between the support surfaces 3a of the nozzle device 3, this spacer member 16 regulates the gap with the protruding surface 8a of the valve device 8, and prevents the upward movement of the valve device 8. , that is, to secure the lift view.

A tubular iron core 17 is provided in the housing 2 at its center.

It is mechanically coupled to the upper part of the housing 2.

An adjustment pipe 18 is provided within the iron core 17, and a spring 19 is in contact with the lower end of the adjustment pipe 18. The other lower end surface of the spring 19 is connected to the valve device 8
The plunger 11 is in contact with the inner surface of the recess. That is, the biasing force of the spring 19 acts in a direction to seat the ball 10 of the valve device 8 on the valve seat 4.

An electromagnetic coil 21 wound around a bobbin 20 is housed in an annular space formed between the inner periphery of the housing 2 and the outer periphery of the iron core 17 . The electromagnetic coil 21 is connected to a terminal 23 attached to a synthetic resin connector 22 formed integrally with the badge 2. This terminal 23
is connected to an electronic control device (not shown) such as a computer, and receives pulse signals from the electronic control device.

The operation of the injection valve 1 having such a configuration will be explained next. The fuel pressurized to a predetermined pressure reaches the fuel swirl element 7 through the electromagnetic coil 21 and the vicinity of the valve device 8 . Thereafter, the axial groove 12 of the fuel swirl element 7 is removed. The fuel flows from the radial groove 13 to the valve seat 4 via the first fuel swirling chamber 14 .

1. When a pulse signal is not supplied to the electromagnetic coil 21 from an electronic control device (not shown), the iron core 17 is not magnetized and the valve device 8 is moved to the valve seat 4 by the biasing force of the spring 19.
is pressed to close the fuel injection hole 5.

When a pulse signal is applied from the electronic control device to the electromagnetic coil 21, the iron core 17 is magnetized, and the plunger 11 is thereby attracted to the iron core 17 against the biasing force of the spring 19. Therefore, the valve assembly fM, 8 is lifted upward and separated from the valve seat 5, thereby opening the fuel injection hole 5 and injecting the fuel that had been stopped.

Here, fuel atomization of the injection valve 1 will be briefly explained. Fuel swirling element 7 provided in rapidly expanding hole 6 of nozzle device 3
axial groove 12. The pressurized fuel passing through the radial groove 13 is
Since the loss is negligible, the first injection can be performed with sufficient injection pressure.
The fuel whose injection pressure is maintained here is efficiently replaced by swirling fuel, and reaches the second fuel swirling chamber 15. In the second fuel swirling chamber 15, swirling is further promoted. Here, in the fuel flow in the first fuel swirling chamber 14 and the second fuel swirling chamber 15, an unstable flow such as a vortex may occur, but a swirling flow is efficiently generated. Therefore, excellent atomized fuel can be obtained since it is injected with sufficient injection pressure and swirling force.

Next, the configuration of the radial groove 13 of the fuel swirling element 7, which is the main object of the present invention, will be explained using FIGS. 2 to 7.

Figure 2 shows the nozzle device 3 and valve equipment! It is an enlarged sectional view of the main part of it8. Fuel flows in from the direction of the arrow in the figure, from the axial groove 12 of the fuel swirling element 7 to the first fuel swirling chamber 14 facing each other via the radial direction 13 according to the present invention.
The fuel flows to the downstream second fuel swirl chamber 15 and then to the fuel injection holes 5. d written in the figure is the inner wall surface 7a of the fuel swirling element 7.
represents the diameter of

FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, showing the end surface 13a (Ilt portion) of the radial groove 13 of the present invention on the valve axis side, the other end surface 13b (I2z portion) of the groove, and the center position of the radial groove 13 of the present invention. shown. The center position is the so-called center between the valve shaft center and the inner wall surface 78 of the fuel swirling element 7, and is 1/2 of the equivalent diameter d of the inner wall surface 7a.

Further, the width W of the groove is expressed as 1/2d Qx Qx.

The fuel that has passed through the radial groove 13 enters the facing first fuel swirling chamber 1.
4, and is injected from the fuel injection hole 5 through the second fuel swirling chamber 15 shown in FIG. In addition.

Cross-sectional area A of the radial groove 13 and cross-sectional area A of the fuel injection hole 5
The ratio A, /Ao to o is designed to be 7 or more, and the flow loss in the internuclear space 13 is very small.

FIG. 4 shows the width W and flow rate variation of i#13. The end surface 13a of the internuclear space 13 on the valve axis side in FIG.
This is an example of the result when the width W of the groove 13 is changed while fixing it at the position L. That is, the position of the other end surface 13b of the groove 13 changes. In Figure 4, the variation in flow rate is the groove width W
By gradually increasing , the variation changes from large variation → transition region → small variation. In areas with large variations,
A vortex as shown in FIG. 5 is generated in the first fuel swirling chamber 14 facing the u13. This vortex is gradually reduced by moving the other end surface 13b of the groove 13 away from the valve axis, and the flow is stabilized. Note that the flow rate variation is the fluctuation range ΔQ shown in the flow rate time change curve shown in Figure 5.
, the average flow rate Q. Returning to Figure 4, the permissible value for variation in static flow crucible (changes within 6% are allowed) exists even in the transition region, but it is a stable region with small variation. It is preferable to use from the viewpoint of production. The range described in the present invention corresponds to this stability region, and the flow of fuel passing between the cores is slow and the strength of swirl is weak. Therefore, the spread angle of the atomized fuel injected from the fuel injection hole becomes small. In the multi-point system, there is no fuel adhesion to the inner wall of the intake manifold, and the operating efficiency of the engine can be extremely high.

〔Effect of the invention〕

As explained above, according to the present invention, stable atomized fuel can be obtained at the injection angle of /J1, the injection f1M degree can be maintained at a high level, and fuel adhesion to the inner wall of the intake manifold of an internal combustion engine can be suppressed. The operating efficiency of the system can be increased.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view illustrating an electromagnetic fuel injection valve according to the present invention, FIG. 2 is an enlarged main sectional view of the nozzle device lt and the valve device, and FIG. FIG. 4 is a cross-sectional view for explaining the position of the groove end surface of the invention, FIG. 4 is a diagram showing the relationship between the groove width and performance according to the invention, and FIG. 5 is a diagram showing the vortex generated in the swirling chamber. DESCRIPTION OF SYMBOLS 1... Electromagnetic fuel injection valve, 4... Valve seat, 5... Fuel injection hole, 7... Fuel swirl element, 7a... Inner wall surface,
12... Axial groove, 13... Radial groove, 13a...
・Axis-side end surface of the groove, 13b...Other end surface of the groove, 14.
・・First fuel swirl 5/ f j Zumozu Fl-Taimura Tomi Z Zuozu 1st National Treasure Song W

Claims (1)

[Claims] 1. In an electromagnetic fuel injection valve equipped with a fuel swirling element disposed upstream of a valve seat and applying swirling force to supplied fuel, an end surface of a swirling groove provided in the fuel swirling element on the valve axis side Distance l_1 between the valve axis side end surface of the swirl groove and the valve axis, which is on the valve axis side from the center position between the valve axis center and the inner wall surface of the fuel swirling element, and the other end surface of the groove. An electromagnetic fuel injection valve characterized in that a distance l_2 between the inner wall surface and the inner wall surface is such that l_1>l_2.