JPH051647A - Electromagnetic fuel injection valve - Google Patents

Abstract

(57) [Abstract] [Purpose] The spray from the dividing means is a two-way spray without central spray to suppress fuel adhesion to the central partition wall of the intake port of the engine and improve transient response. In an electromagnetic fuel injection valve for a four-valve engine having a means 16 for dividing a fuel flow from a single injection hole, a plurality of fuel passages of the dividing means 16 are provided at positions symmetrical with respect to a valve axis. A cross-sectional area of the fuel passage 17 having an axis formed by connecting 18 at least by an arc 19 is gradually reduced from the upstream side to the downstream side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic fuel injection valve capable of distributing and supplying fine droplet fuel to a multi-valve engine having a plurality of intake valves for each cylinder.

[0002]

2. Description of the Related Art In a four-valve engine aiming at high output and low fuel consumption, it is necessary to prevent fuel from adhering to the center wall of the intake port and evenly supply the fuel to the two intake ports. Further, in order to form a homogeneous air-fuel mixture, the atomization degree must be sufficiently atomized in a short period of time. That is, the fuel injection valve for a four-valve engine must be a two-way spray that is excellent in atomization and fuel distribution.

Therefore, the authors have advanced the study focusing on the acceleration of atomization and are optimizing the shape of the spray dividing means. Japanese Patent Application Laid-Open No. 2-125956, which was previously filed, is representative of this, and includes a fuel swirl element provided on the upstream side of the valve seat to give swirling force to the supplied fuel, and a fuel swirl element provided on the downstream side of the valve seat. A plurality of circles having a cross section orthogonal to the valve axis and provided symmetrically with respect to the valve axis and having a diameter larger than the diameter of the fuel injection hole. And a fuel dividing means having a fuel passage formed by a circular arc in contact with the circle is provided on the downstream side of the fuel injection hole.

[0004]

In the above-mentioned prior art, since the spray from the fuel injection hole is guided and separated into the plurality of fuel passages in the downstream, coalescence of spray droplets is suppressed and atomization is improved.

However, the jet has a swirling flow component and an axial flow component, and this latter axial flow component is not the reason why it completely disappears in the dividing means, so that the spray of the axial flow component remains from the central portion. This central spray collides with the central partition wall of the intake port of the engine and becomes a wall flow.

An object of the present invention is to remove this central spray and obtain an electromagnetic fuel injection valve having excellent distribution performance. Also, the fuel is prevented from adhering to the central partition of the intake port of the engine to improve combustion efficiency.

[0007]

The first feature of the present invention for achieving the above object is to provide a fuel swirl element which is provided on the upstream side of a valve seat and which gives a swirl force to the supplied fuel, and a valve seat. A fuel injection hole provided on the downstream side of the fuel injection hole, and a cross section orthogonal to the valve shaft center on the downstream side of the fuel injection hole is provided at a position symmetrical with respect to the valve shaft center. In an electromagnetic fuel injection valve having a dividing means formed by a plurality of large circles and at least an arc that is in contact with the circles, the plurality of circles of the dividing means communicate with each other by at least the arc. The cross-sectional area of the fuel passage is gradually reduced from the upstream side to the downstream side of the dividing means.

[0008]

The spray from the fuel injection hole collides with the passage wall of the dividing means and is restricted. That is, at least the fuel passage, which is communicated by the circular holes, has a smaller cross-sectional area from the upstream side to the downstream side, and therefore the flow resistance increases.
Therefore, the axial flow component of the spray disappears in the passage portion and is not ejected.

Since the spray is guided to the plurality of fuel passages communicating with the passage, it is a good two-way spray without a central spray.

[0010]

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

FIG. 1 is an enlarged sectional view of an essential part for explaining a dividing means 16 which is a first embodiment according to the present invention.
2 is a sectional view taken along the line II-II of FIG. 1, and FIG.
FIG. 3 is a sectional view taken along the line I-III.

The dividing means 16 has two large-diameter fuel passages 18 arranged at equal intervals with respect to the valve axis, and a fuel passage 17 in which the passages 18 communicate with each other by a communicating wall 19 having an arc. , Passage 17 from upstream side to downstream side 1
The cross-sectional area is gradually reduced toward 7a. That is, the length from the passage wall 19 to the passage wall 19a decreases.

FIG. 4 is a longitudinal sectional view of an electromagnetic fuel injection valve 1 (hereinafter referred to as "injection valve") having a dividing means 16 according to the first embodiment of the present invention. The injection valve 1 is for injecting and supplying fuel by opening and closing the seat portion in accordance with a duty on / off signal calculated by a control unit (not shown). The electric signal is given to the coil 2 as a pulse, and when a current is passed through the coil 2, a magnetic circuit is constituted by the core 3, the yoke 4, and the plunger 5, and the plunger 5 is attracted to the core 3 side. When the plunger 5 moves, the ball valve 6 integrated with it moves away from the seat portion 9 of the valve guide 7 to open the fuel injection hole 8 (hereinafter referred to as an orifice). The ball valve 6 is composed of a rod 10 joined to one end of a plunger 5 made of a magnetic material, a ball 11 welded to the other end of the rod 10, and a non-magnetic material fixed to the upper opening of the plunger 5. Guide ring 12 and valve guide 7
Each of them is guided by the inner wall surface of the cylindrical fuel swirl element 13 which is inserted and fixed in the inner wall of the hollow portion. In addition, the stroke amount during movement is determined by the size of the gap between the receiving surface 10a of the neck portion of the rod 10 and the stopper 14.

On the other hand, the valve guide 7 is formed with a cylindrical portion 15 extending in the direction opposite to the seat surface 9, and the fuel dividing means 16 is inserted and fixed therein.

The fuel injection and supply of the injection valve 1 thus configured will be described.

The fuel is pressure-adjusted by a fuel pump or a fuel pressure regulator (not shown), flows into the solenoid valve assembly through the inflow passage 21 through the filter 20, and the outer periphery of the plunger 5, the clearance between the stopper 14 and the rod 10. , Is swirlingly supplied to the seat portion through the fuel swirling element 13, and is injected from the orifice 8 when the valve is opened.

Here, the fuel flow in the dividing means 16 will be described with reference to FIGS. 1 to 3 again. Orifice 8
The swirling flow component of swirling fuel ejected from the
After colliding with the wall surface of the fuel passage 17 having a slightly larger width, the communication wall 19 is guided toward the fuel passage 18 to form a separated flow downward. On the other hand, the axial flow component is directed toward the downstream near the axis, but the passage 1 near the outlet of the dividing means 16
The flow is suppressed by 7a, guided to the fuel passage 18 by the communication wall 19a, and combined with the swirling flow component. That is, the cross-sectional area is reduced due to the decrease of the communication wall 19 → 19a, the communication resistance is increased, and the fuel spray from the passage 17a is stopped. Therefore, there is a two-way spray without a central spray. When this is applied to an engine, fuel adhesion to the intake port central partition is suppressed, and transient response performance is improved.

FIG. 5 to FIG. 7 are enlarged views of essential parts for explaining the dividing means 30 showing the second embodiment according to the present invention, and FIG. 6 is a sectional view taken along line VI-VI of FIG. 7 is VI of FIG.
It is a sectional view taken along line I-VII.

In this embodiment, the center-to-center distances of the plurality of fuel passages 32 of the dividing means 30 are configured to decrease from the upstream side l _i toward the downstream side l ₀ . Reference numeral 31 denotes a fuel passage immediately below the orifice 8. Based on the above, the passage has a reduced cross-sectional area. A passage wall 33 connects the fuel passage 32 and the passage 31.

Now, when spray is generated from the orifice 8,
The flow from the passage 31 to 31a is separated into the left and right fuel passages 32 because the passage resistance gradually increases.

[0021]

According to the present invention, the fuel passage at the axial center of the dividing means is constructed such that the cross-sectional area thereof gradually decreases from the upstream side to the downstream side, so that the two-way distribution characteristic without central spray is provided. An excellent electromagnetic fuel injection valve can be provided, and when the engine is installed, fuel adhesion to the intake port central partition wall is avoided and transient response performance can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a dividing means according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a vertical sectional view showing an electromagnetic fuel injection valve having a dividing means according to the present invention.

FIG. 5 is a sectional view of an essential part showing a dividing means showing a second embodiment of the present invention.

6 is a sectional view taken along the line VI-VI of FIG.

7 is a sectional view taken along the line VII-VII in FIG.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naoyuki Tanaka 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Seisakusho Co., Ltd. Automotive Equipment Division (72) Inventor Masahiro Soma 2477 Kashima Yatsu, Katsuta-shi, Ibaraki Pref. 3 Hitachi Automotive Engineering Co., Ltd. (72) Inventor Tsunemitsu Kurobane 2520, Takata, Katsuta-shi, Ibaraki Co., Ltd. Hitachi, Ltd. Automotive Equipment Division

Claims (1)

Claim: What is claimed is: 1. A fuel swirl element provided upstream of a valve seat for imparting swirl force to supplied fuel; a fuel injection hole provided downstream of the valve seat; A plurality of circles, each having a cross section orthogonal to the valve axis on the downstream side of the injection hole, provided at a position symmetrical with respect to the valve axis, and having a diameter larger than the diameter of the fuel injection hole,
In an electromagnetic fuel injection valve having a dividing means formed by at least an arc that is in contact with the circle between the circles, a plurality of circles of the dividing means communicate at least the fuel passage formed by the arcs. An electromagnetic fuel injection valve, characterized in that the cross-sectional area is gradually reduced from the upstream side to the downstream side of the dividing means.