JPH07197870A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To provide a fuel injection valve which is constituted to feed misty fuel in the constantly stable shape of a horseshoe. CONSTITUTION:An adapter 10 is arranged at the end part of a valve seat 6. An injection chamber 10C fronting on the injection nozzle of the valve seat 6 is formed in the adapter 10 and an injection flow passage 11 is opened to the injection chamber 11C. The injection flow passage 11 is divided into a plurality of division flow passages 13 partitioned by a flow dividing partition 12 and the opening end of the division flow passage 13 is opened to the end part of the valve seat 6. Partition pieces 14 protruded from a part of the inner peripheral wall of the injection flow passage 11 toward a central direction in a state to be positioned facing each other are arranged at the opening end to the injection chamber 10C of the injection flow passage 11 with a gap A therebetween. Air slit grooves 15 each formed on the same vertical cross section as that of the partition piece 14 and on the base part side of the partition piece 14 and having one side opened to the outer periphery of the adapter 10 and the other side opened in the injection flow passage 11 and the division flow passage 13 and extending along the longitudinal direction of a flow passage are formed in the injection flow passage 11 and the division flow passage 13 along the partition piece 14.

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 used in an internal combustion engine, and in particular, an improvement in the spray shape of fuel injected from an electromagnetic fuel injection valve (hereinafter referred to as fuel injection valve). It is about.

[0002]

2. Description of the Related Art Conventionally, a fuel injection valve that has been injected with fuel injected from a fuel injection valve while avoiding the valve shaft of an intake valve of an engine to reduce HC emissions and improve fuel efficiency is actually used. It is disclosed in Japanese Patent Laid-Open No. 3-129772.

In such a fuel injection valve, an air injection hole for injecting air from one side is formed with respect to the fuel spray injected from the injection hole, and air is injected from the air injection hole to the fuel spray. Therefore, the fuel spray is formed into a substantially horseshoe shape by the air injection pressure from one side.

[0004]

According to such a conventional fuel injection valve, the horseshoe-shaped fuel spray is injected in the first direction (downstream direction) and the second direction (lateral to the downstream direction). Direction) with a pressurized air stream injected in a direction). Therefore, a change in the state of fuel spray injected from the injection hole, (this is a change in the shape of the fuel spray or a change in the fuel spray velocity, mainly a minute change in the shape of the fuel injection hole, a change in the fuel injection pressure, etc. However, the change in the injection air pressure injected from the air injection holes causes the horseshoe-shaped fuel spray state to change, and it has not been possible to uniformly achieve a reduction in HC emissions and an improvement in fuel consumption. Further, the fact that the fuel spray is biased by the pressurized air flow to form the horseshoe-shaped fuel spray necessarily requires the pressurized air flow and does not have the pressurized air flow. It could not be used in fuel injection valves.

The present invention has been made in view of the above problems, and by constantly obtaining a stable horseshoe-shaped fuel spray state, it is possible to effectively reduce the amount of HC discharged and improve fuel efficiency, and especially pressurize. It is to provide a fuel injection valve capable of obtaining a horseshoe-shaped fuel spray state without depending on the generated air flow (air injection).

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a needle in which a movable core is driven by energizing an electromagnetic coil disposed inside a housing, and is integrally driven with the movable core. An electromagnetic valve that controls the opening and closing of the valve seat formed on the valve seat arranged at the end of the housing by the valve portion of the valve, and injects fuel from the injection hole that is downstream of the valve seat and opens at the end of the valve seat. In a type fuel injection valve, an injection chamber into which fuel injected from an injection hole flows, an injection flow path opening to the injection chamber, and a flow dividing wall are provided to divide the injection flow path into a plurality of parts at the end of the valve seat. , A plurality of branch channels that open toward the ends, and an adapter that is disposed at the opening end of the injection channel of the adapter to the injection chamber and that extends from a part of the inner peripheral wall of the injection channel toward the center. And project opposite each other The partition piece having a gap provided, further,
The injection channel and the branch channel are on the base side of the partition on the same vertical section as the partition, one side is open to the outer circumference of the adapter, the other side is the injection channel and the branch channel is open. The first characteristic is that the air slit groove along the longitudinal direction of the flow path is formed along the partition.

A second feature of the present invention is that an air passage is opened in the injection chamber formed in the adapter.

[0008]

The fuel pressurized and supplied into the fuel injection valve is injected from the valve seat into the injection chamber through the injection hole. The fuel in the injection chamber flows down through the injection flow path, but when the fuel flows from the injection chamber into the injection flow path, the fuel is deformed by the partition into a circular cross section. The truncated circular fuel flowing down in the injection flow passage is divided by the flow dividing wall, and the divided fuel is injected from the end portion of the adapter through each division flow passage.
Then, since the air is continuously introduced from the air slit groove to the truncated circular portion of the fuel spray having the truncated circular shape that flows down the injection flow channel and each branch channel, the horseshoe-shaped fuel spray is surely provided in the branch channel. The horseshoe-shaped fuel spray can be injected from the opening end of each branch passage while maintaining the horseshoe shape.

Further, the introduction of air into the injection chamber is more effective in improving atomization of fuel in the injection chamber and improving atomization of horseshoe-shaped fuel spray injected from each branch passage. Yes, this is achieved by the second feature.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fuel injection valve according to the present invention will be described below with reference to FIGS. 1, 2, 3 and 4. Reference numeral 1 denotes a cylindrical housing having an opening in the vertical direction, and an electromagnetic coil 3 wound around a coil bobbin 2 from the upper end of the housing.
And the fixed core 4 is inserted, and the enlarged flange portion 4A of the fixed core 4 is inserted.
The upper end of the housing 1 is swaged inward toward the upper end of the enlarged flange portion 4A in a state where is disposed on the locking step portion 1A of the housing 1. The electromagnetic coil 3 is drawn out through the terminal 5, a flow path 4B is bored from the upper end to the lower end in the center of the fixed core 4, and an opening above the flow path 4B is provided in a fuel pump (not shown). An electric signal is input to the electromagnetic coil 3 connected to the discharge hole via the terminal 5.

A valve seat 6 is inserted from the lower end opening of the housing 1, and the valve seat 6 has a valve seat 6A and
Needle valve guide hole 6B opening upward from valve seat 6A and injection hole 6C opening downward from valve seat 6A
And are formed. In this needle valve guide hole 6B,
The needle valve 7 is movably arranged, and below the needle valve 7 is a pintle portion 7 inserted into the injection hole 6C.
A and a valve portion 7B that opens and closes the valve seat 6A are formed in a continuous manner, a movable core 8 facing the lower end of the fixed core 4 is integrally disposed above the needle valve 7, and the movable core 8 and A spring 9 is contracted between the fixed core 4 and the fixed core 4. That is, when the electromagnetic coil 3 is not energized, the needle valve 7
Is pressed downward, and the valve portion 7B of the needle valve 7 closes the valve seat 6A of the valve seat 6. The above is a conventionally known fuel injection valve.

In order to achieve the above object, the fuel injection valve according to the present invention has the following configuration. 10 is an adapter having an inner cylinder 10A, and a bottom portion 10B of the inner cylinder 10A has
An injection chamber 10C facing the injection hole 6C opening at the lower end of the valve seat 6 is provided as a recess. An injection passage 11 is opened at the bottom of the injection chamber 10C, and the injection passage 11 is divided into a plurality of division passages 13 by a flow dividing wall 12 provided on the downstream side. In this embodiment, two branch channels 13 are prepared, and the downstream side of each branch channel 13 opens at the lower end of the adapter 10. That is, the fuel injected from the injection hole 6C is branched by each branch passage 13 after passing through the injection chamber 10C and the injection passage 11, and then injected from the lower end of the adapter 10.

The following structure is further added to the adapter 10. Reference numeral 14 is a partition formed at or near the opening end of the injection passage 11 into the injection chamber 10C, and has the following structure. That is, the partition piece 14 projects from a part of the inner peripheral wall 11 </ b> A on the upstream side of the injection channel 11 so as to face each other toward the center, and has a gap A at its tip. This partition 14 should not close the cross section of the injection flow channel 11 and makes the cross section into an oval state, and the partition 14 of the inner peripheral wall 11A of the injection flow channel 11 14A toward the center from the base portion 14A. In this embodiment, a pair of plate-shaped partitions 14 facing each other are provided. The partition 14 faces each branching channel 13. The injection passage 11 in which the partition 14 is arranged has a horseshoe-shaped (C-shaped) cross section. The structure of the partition 14 is well understood by FIGS.

Further, the adapter 10 is provided with an air slit groove 15. This air slit groove 15 has the following requirements. (1) One end opens to the outer circumference 10D of the adapter 10, and the other end opens to the injection flow passage 11 and the branch flow passage 13. (2) On the longitudinal section including the partition 14, the base 14A side of the partition 14 extends in the longitudinal direction of the injection channel 11 and the branch channel 13. Therefore, in this embodiment, since there are two partitions 14, there are also two air slit grooves 15, and these air slit grooves 15 are provided facing each other.

The valve seat 6 and the adapter 10 are attached to the housing 1 as follows. That is, the stopper 16, the valve seat 6 provided with the needle valve 7, and the adapter 10 are sequentially arranged on the locking step portion 1B formed below the housing 1, and then the lower opening end of the housing 1 is connected to the adapter 10. Crim inward toward the collar portion 10E. According to the above, the adapter 1
0 is attached to the valve seat 6, the injection chamber 10C of the adapter 10 faces the injection hole 6C of the valve seat 6, and the plurality of branch channels 13 of the adapter 10 open from the lower end of the adapter 10.

Next, the operation will be described. The fuel pressurized by a fuel pump (not shown) is supplied into the fuel injection valve via the flow path 4B and reaches the valve seat 6A of the valve seat 6. When the electromagnetic coil 3 is not energized, the needle valve 7 is pressed by the spring 9 and the valve portion 7B closes the valve seat 6A, so that fuel is not injected from the injection hole 6C.

When a current having a predetermined duty ratio is supplied to the electromagnetic coil 3, a magnetic force is generated around the electromagnetic coil 3, and the needle valve 7 moves upward against the spring force of the spring 9 to cause the valve to move. The portion 7B opens the valve seat 6A. According to the above, the pressurized fuel stored in the fuel injection valve is the valve seat 6A.
Through the injection hole 6C into the injection chamber 6C, and the amount is measured by the injection hole 6C and the pintle portion 7A and injected into the injection chamber 10C.

The fuel in the injection chamber 10C is divided into each partition 1
4 flows down into the injection flow path 11 while passing through 4, but at the time of this passage, the fuel is blocked by each partition 14, so that the fuel in the portion corresponding to this partition 14 is blocked. . If the partition 14 is not provided in the shape of the ejection flow channel 11 of the present embodiment, the ejection flow channel 11
Although the cross-sectional shape of the fuel flowing through the fuel cell has an elliptical shape, since the partition pieces 14 are arranged so as to face each other as described above, the injection flow path 1
The cross-sectional shape of the fuel flowing through 1 is an oval with opposed elliptical tops. Then, when the fuel having the cross-sectional shape in which the opposite tops of the ellipses are in the shape of an oval is flowed down in the injection flow passage 11, the fuel is injected through the air slit groove 15 formed at the same position as the partition 14. The air is sucked into the flow passage 11 (the air is drawn in by the flow of the fuel having the flow velocity), and the air flows into the lacked circle portion of the fuel. The cross-sectional shape of (1) can still maintain a good state of no circle without fuel in the portion corresponding to the partition 14. (The air slit groove 15 is formed in the injection passage 11.
Is not drilled, the cross-sectional shape of the fuel flowing down in the injection flow passage 11 returns from a circular state to a circular state, or it is difficult to obtain an accurate circular state because the fuel enters the circular portion. is there. )

When the fuel flowing down through the injection flow passage 11 reaches the flow dividing wall 12, the fuel is divided by the flow dividing wall 12 and flows into each flow dividing passage 13. At the time of such branch flow, the fuel having a cross-sectional shape in which the opposite tops of the ellipses are in the shape of a truncated circle has a cross-section circular shape along the shape of the branch channel 12, but the fuel flowing in each branch channel 13 The horseshoe-shaped (C-shaped) atomized fuel having a circular cross-sectional shape is formed. This is an air slit groove 1 in which the fuel flowing in the branch channel 13 is bored along the longitudinal direction of the branch channel 13.
This is because the air can be continuously sucked in from No. 5 and the cross-sectional shape of the fuel can be made into an oval state by this air. (Shunt channel 1
3, when the air slit groove 15 is not formed, the cross-sectional shape of the fuel flowing down the shunt channel 13 returns from an oval state to a circular state, or the fuel enters the oval portion to form an accurate oval state. Hard to get. ) Then, the horseshoe-shaped mist-like fuel is injected from the opening of the branch passage 13 opening at the end of the adapter 10.

Thus, the horseshoe-shaped notch prevents the atomized fuel from colliding with the valve shaft of the intake valve, thereby significantly reducing the HC emission and improving the fuel consumption. is there.

The horseshoe-shaped cutout position (the position of the C-shaped cutout portion) is not limited to this embodiment, and may be selected as appropriate. Further, the cross-sectional shape of the injection passage 11 is not limited to the elliptical shape, and may be set as appropriate. It may be circular. Further, in the inner cylinder 10A of the adapter 10, one end is opened to the outer periphery 10D of the adapter 10, and the other end is opened to the injection chamber 1
The air groove 20 opening at 0C is bored, and the adapter 10 having the air groove 20 bored therein is inserted into the outer periphery of the valve seat 6, so that one end has an outer periphery 10D of the adapter 10.
Air flow passage 21 that opens to the injection chamber 10C and the other end opens to the injection chamber 10C.
According to the above configuration, the atomization property of the atomized fuel flowing in the injection chamber 10C can be improved, and the well atomized horseshoe-shaped atomized fuel can be supplied from the branch flow passage 13.
It was possible to more effectively reduce the emission amount of C and improve the fuel consumption. This air is not used to obtain the horseshoe shape. Further, when the means for mixing the air is used, the adapter can be simply exchanged, so that the degree of freedom in selection can be remarkably easily achieved. An adapter 11 with an air flow path 13 is shown in FIG.

[0022]

As described above, according to the fuel injection valve of the present invention, the following effects can be achieved. The horseshoe-shaped fuel spray shape is such that the fuel injected into the injection chamber is forcibly formed into an oval state by the partition and injected into the injection flow passage, and that the fuel flowing in the injection flow passage is The air is continuously sucked from the air slit groove toward the cutout portion, and further, the air is drawn from the air slit groove toward the cutout portion of the fuel in the branch passage where the fuel branched from the injection flow passage flows. Since it is formed by continuously inhaling air, it is possible to obtain a stable horseshoe-shaped fuel spray shape, and it is possible to effectively reduce HC emission and improve fuel efficiency. The horseshoe type spray shape is determined by the arrangement of the intake valve of the engine, the arrangement of the fuel injection valve, etc., but when adapting to it, it is only necessary to replace the adapter, so it is optimal for various engines. The horseshoe-shaped atomized fuel can be obtained extremely economically and easily. Since the air flow path is opened in the injection chamber and air is supplied from the air flow path into the injection chamber, the fuel and air can be mixed in the portion where the fuel injection speed is the highest, and The atomization of the injected horseshoe-shaped sprayed fuel can be further improved, and when the air passage is provided, the adapter may be simply replaced with an adapter having the air passage.

[Brief description of drawings]

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

FIG. 2 is an enlarged vertical cross-sectional view of main parts of the valve seat and the adapter of FIG.

FIG. 3 is a plan view of the adapter of FIG. 2 seen from below.

4 is a vertical cross-sectional view of the fuel injection valve of FIG. 2 taken along the line BB.

FIG. 5 is an enlarged vertical sectional view of an essential part showing another embodiment of the adapter.

[Explanation of symbols]

 1 Housing 3 Electromagnetic Coil 6 Valve Seat 6A Valve Seat 6C Injection Hole 7 Needle Valve 7B Valve 10 Adapter 10C Injection Chamber 11 Injection Channel 11A Inner Wall 12 Dividing Wall 13 Dividing Channel 14 Partition 15 Air Slit Groove 21 Air Channel

Claims (2)

[Claims] 1. A movable core 8 is driven by energization of an electromagnetic coil 3 disposed inside the housing 1, and a valve portion 7B of a needle valve 7 driven integrally with the movable core 8 causes an end portion of the housing 1 to move. In an electromagnetic fuel injection valve that controls opening / closing of a valve seat 6A formed on a valve seat 6 that is arranged and injects fuel from an injection hole 6C that is located on the downstream side of the valve seat 6A and opens at the end of the valve seat 6 , Valve seat 6
An injection chamber 10C into which the fuel injected from the injection hole 6C flows, and an injection flow path 11 opening to the injection chamber 10C,
An injection passage 11 is divided into a plurality of flow passages 12 by a flow dividing wall 12, and an adapter 10 having a plurality of flow passages 13 opening toward an end is disposed, and the injection flow passage 11 of the adapter is connected to the injection chamber 10C. At the open end of the inner peripheral wall 11A of the injection flow passage 11
Partition pieces 14 are provided so as to face each other toward the center from a part thereof and have a gap A. Further, the injection passage 11 and the branch passage 13 are provided with partition pieces on the same longitudinal section as the partition piece 14. 14 is on the base 14A side, one side is open to the outer periphery 10D of the adapter 10, and the other side is the injection passage 1
1. An electromagnetic fuel injection valve having an air slit groove 15 opened in the branch passage 13 and extending in the longitudinal direction of the passage along the partition 14. 2. The injection chamber 1 formed in the adapter
The electromagnetic fuel injection valve according to claim 1, wherein the air passage 21 is opened at 0C.