JPH0814139A - Fuel injection valve integrated with ignition plug - Google Patents

Abstract

PURPOSE:To prevent covering of an ignition plug so as to prevent misfire of an engine, engine stall, and defective starting. CONSTITUTION:Right and left center electrodes 22 on the inside and right and left earth electrodes 23 on the outside are arranged centering around a nozzle 25 with same width on one straight line. The center electrodes 22 are standingly provided in parallel with the axis from a valve body 30, and formed into curved plates so as to be cut off at both sides of the concentric circle. Meanwhile, the earth electrodes 23 are standingly provided from a housing 31 in parallel with the axis, and the extreme side is bent inside into a nearly L-shape. The shape of the center electrode 22 is set so that the central angle (beta) corresponding to the width of the inner circumferential face 22a of the center electrode 22, and the central angle (alpha) corresponding to the width of the outer circumferential face 22b are in the relation (alpha)<(beta). Namely, the section of the center electrode 22 perpendicular to the axial direction is formed into a shape being cut off from a ring by a prescribed width from a ring.

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 an internal combustion engine, and more particularly to an ignition plug integrated fuel injection valve in which the fuel injection valve is integrally formed with an ignition plug.

[0002]

2. Description of the Related Art In recent years, due to social demands such as low fuel consumption and low emissions, the fuel mixture supplied to the engine is made thin, and only the fuel mixture in the vicinity of the spark plug is made rich and ignited for combustion. Combustion is desired, and a method for realizing this stratified combustion uses an in-cylinder direct injection fuel injection valve that directly injects fuel into the cylinder from the viewpoint that the state of the fuel mixture can be adjusted appropriately. ing.

As an in-cylinder direct injection fuel injection valve of this type, for example, there is a technique of a fuel injection valve integrated with a spark plug described in Japanese Patent Laid-Open No. 1-104961. In this fuel injection valve integrated with a spark plug, the spark plug and the fuel injection valve are integrated, and as shown in FIG. 6, an injection port P2 is opened and closed at the tip side of the axial center of the fuel injection valve P1. Is provided with a valve body P3 for
The conductive member P4, the insulating member P4, the second conductive member P5, and the like are provided. A wire-shaped second electrode P7 is erected from the second conductive member P6 in the axial direction, and is arranged close to the second electrode P7 from the first conductive member P4. Likewise, the wire-shaped first electrode P8
Is bent slightly outward and is erected. In other words, the discharge portion of the spark plug is provided around the injection port P2 by the first electrode P7 and the second electrode P8 which are arranged in parallel through the gap P9.

[0004]

However, the fuel injection valve P1 having the above-mentioned structure is not always sufficient because of the following problems. That is, the first electrode P7 and the second electrode P
No. 8 is arranged outside the injection port P2 side by side in the circumferential direction with a gap P9 interposed. Therefore, when fuel is injected, both electrodes P7, P8 are hit by the fuel spray. I will end up. Therefore, the fuel spray hitting the electrodes P7, P8 enters the gap P9 between the electrodes P7, P8, causing a so-called spark plug fogging phenomenon, which leads to engine misfire and eventually engine stall, or starting failure. There is a fear.

The present invention has been made to solve the above problems, and provides a fuel injection valve integrated with a spark plug capable of preventing the ignition plug from being fogged and preventing engine misfire, engine stall, and starting failure. The purpose is to

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 is a fuel injection device with an integrated spark plug in which an inner electrode for igniting fuel and an outer electrode are arranged outside the fuel injection port. In the valve, the outer electrode is arranged outside the inner electrode with a gap, and the inner electrode is arranged so as to block the discharge surface on the interval side of the outer electrode. Is the gist.

According to a second aspect of the present invention, the central angle β corresponding to the width of the inner peripheral surface of the inner electrode and the central angle α corresponding to the width of the outer peripheral surface of the inner electrode are set so that α <β. A fuel injection valve integrated with a spark plug according to claim 1 is characterized by the above.

According to a third aspect of the present invention, there is provided an ignition plug according to the first or second aspect, wherein the inner electrode has a tip on the inner peripheral surface side projecting from a tip on the outer peripheral surface side. The body type fuel injection valve is the main point.

[0009]

According to the first aspect of the present invention, the outer electrode is arranged further outside the inner electrode arranged outside the fuel injection port with a gap for discharging, and the inner electrode is the outer electrode. It is arranged so as to block the discharge surface on the interval side.
Therefore, even when the fuel is injected from the fuel injection port, the injected fuel is blocked by the inner electrode and does not easily reach the gap or the outer electrode. Therefore, the fogging phenomenon of the spark plug is less likely to occur, and engine misfire, engine stall, and starting failure are prevented.

According to the second aspect of the present invention, the central angle β corresponding to the width of the inner peripheral surface of the inner electrode and the central angle α corresponding to the width of the outer peripheral surface thereof.
And α are set to satisfy α <β, it becomes more difficult for the spark plug to be fogged, and engine misfire, engine stall, and starting failure are preferably prevented.

According to the third aspect of the present invention, since the tip of the inner electrode on the inner peripheral surface side is formed so as to project from the tip of the outer peripheral surface side, the injected fuel is injected from the front end of the inner peripheral surface to the outer peripheral surface on the back side. To be reached. Therefore, the fogging of the spark plug is less likely to occur, and engine misfires, engine stalls, and starting failures are preferably prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings by using an example of a spark plug integrated electromagnetic fuel injection valve (hereinafter simply referred to as a fuel injection valve). (Embodiment 1) A) First, the configuration of the fuel injection valve will be described along the flow of fuel, using the main body cross-sectional view of the fuel injection valve of the present embodiment of FIG.

As shown in FIG. 1, reference numeral 1 denotes the whole body of the fuel injection valve. Fuel pressurized by a fuel pump (not shown) enters from a fuel inlet portion 2 and engages with the fuel inlet portion 2 with a screw. Flows into the fixed or integral housing 3. The insulator 5 made of ceramic or the like provided inside the housing 3 is pressed and fixed by a holder 27 screw-engaged with the housing 3 via a washer 28.
The insulator 6 made of ceramic or the like arranged on the tip side of the insulator 5 is fitted into the magnetic housing 17 via the washer 29 by the holder 4 screw-engaged with the magnetic housing 17 (stator). The pressing force is controlled by pressing and fixing to 16 and applying a predetermined tightening torque by screw rotation.

The fuel flowing into the fuel flow passage 7 formed by the so-called nested gap between the two insulators 5 and 6 flows through the inside of the insulator 5 and is arranged concentrically with the insulator 5. 6 and the guide 1 integrally formed by brazing or the like
0, and flows through the injection amount adjusting pipe 9 through the filter 8 fitted on the outer surface of the injection amount adjusting pipe 9 arranged concentrically with the guide 10.

Outside the valve body 12 including a part of the fuel flow passage 7, an armature 14 made of a soft magnetic material is concentrically arranged with an insulator 13 in between, for example, by brazing. They are joined by a method to form an integral structure. In addition, in order to secure a creeping distance in order to prevent high voltage discharge inside the main body 1, one end portion of each of the insulators 6 and 13 and the other insulators 5 and 6 close to each other is It has a nested structure that covers the ends of other insulators adjacent to each other.

The fuel introduced into the injection amount adjusting pipe 9 flows inside the valve body 30 through the inside of the spring 11, the flow passage 12a inside the valve body 12 and the communication hole 12b. And (fixed to the guide 10 by means such as caulking)
By pressing the valve body 12 in the fluid flow direction by the spring 11 that is biased by adjusting the amount of pushing of the injection amount adjusting pipe 9, the valve body 12 is seated on the valve body 30 in the normal state, and the injection hole ( The fluid flow passage leading to the fuel injection port) 25 is shut off.

Further, the electromagnetic coil 15 which is electrically connected to the winding terminal 26 is arranged concentrically with the magnetic connector 16 which is a soft magnetic material, the magnetic housing 17 and the armature 14 on the outer periphery of both the insulators 6 and 13. A magnetic circuit is formed by forming a movable gap in which the magnetic connector 16 and the armature 14 face each other. When a pulsed injector drive current is applied to the winding terminal 26, the electromagnetic coil 15 is excited to generate an electromagnetic force in the magnetic circuit, and the valve body integrally formed with the armature 14 is generated. 12 is moved in the direction opposite to the fluid flow direction until it engages with the spacer 32, the fluid flow passage communicating with the injection hole 25 is opened, and fuel spray is injected from the injection hole 25.

B) Next, the structure of the spark plug will be described. A high voltage for generating an ignition spark is introduced from an ignition coil (not shown) to an inner surface of an electrically insulating high voltage inlet portion 18 formed integrally with the insulator 5. Further, the high voltage passes through the rod 20 that is concentrically and integrally connected by, for example, brazing in the insulator 5, and adjusts the injection amount of metal through the metal spring 21 installed in the insulator 5. A valve body including a pipe 9, a metal spring 15 installed in both insulators 6 and 13, and a metal valve body 12 on the inner surfaces of the insulators 13 and 19 and being electrically integrated with a center electrode 22. Guided to body 30. Then, the center electrode 22 (which is the inner electrode) and the ground electrode 2 (which is the outer electrode)
In the gap (gap) 24 formed between the
Ignition sparks are generated by the discharge.

A valve body 30 having the center electrode 22 is provided.
An insulator 19 is disposed between the insulator 19 and the housing 31 integrally formed with the ground electrode 23. Further, a spacer 32 is pressed between the insulator 19 and the insulator 13. Insulator 33 is arranged.

In particular, in this embodiment, as shown in FIG. 2, the inner left and right center electrodes 22 (shown by diagonal lines) and the outer left and right ground electrodes 23 are the same with the injection hole 25 as the center. The width is arranged in a straight line. Of these, the center electrode 22 is erected from the valve body 30 parallel to the axis center (concentrically), and has a curved plate shape in which both sides of the concentric circle are cut. On the other hand, the ground electrode 2
Reference numeral 3 stands up from the housing 31 in parallel with the axis center (concentrically), and is bent inward in a substantially L shape at the tip end side thereof.

Further, in the present embodiment, the central angle β corresponding to the width of the inner peripheral surface 22a of the center electrode 22 and the central angle α corresponding to the width of the outer peripheral surface 22b thereof have a relationship of α <β. To
The shape of the center electrode 22 is set. That is, the cross section of the center electrode 22 perpendicular to the axial direction has a shape in which the ring is cut in parallel with a predetermined width.

As described above, in the fuel injection valve of this embodiment, the central electrode 22 constituting the discharge portion of the spark plug is
Since the ground electrode 23 is arranged so as to block the discharge surface (inner surface) 23a on the side of the gap 24, the fuel spray injected from the injection hole 25 is blocked by the center electrode 22 and discharged on the discharge surface 23a of the ground electrode 23. It is difficult to reach. Therefore, it is possible to prevent the fuel droplets from adhering to and staying in the gap 24, so that so-called spark plug fogging can be prevented. As a result, engine misfire and engine stall,
Further, there is a remarkable effect that it is possible to prevent problems such as starting failure.

Particularly in this embodiment, the central angle β of the inner peripheral surface 22a of the center electrode 22 and the central angle α of the outer peripheral surface 22b are such that α <
Since β is set, it is possible to reliably prevent the fuel from flowing into the gap. Further, since the cross-sectional shape of the center electrode 22 is a shape in which the rings are cut in parallel,
There is an advantage that the inner edge is sharp and the fuel is hard to wrap around at that point, and the processing is easy.

Further, when the fuel is injected, the fuel spray collides with the center electrode 22, so that the center electrode 22 is easily worn.
Can be cooled to improve its life. In addition, the fuel spray collides with the center electrode 22 that is heated to a high temperature due to combustion in the engine cylinder, so that the fuel can be atomized and the engine performance can be improved.

Next, another embodiment will be described. (Embodiment 2) The fuel injection valve of this embodiment is different from that of Embodiment 1 only in the structure of the discharge portion at the tip of the spark plug, and therefore only the differences will be described.

As shown in FIG. 3, in this embodiment, the upper and lower end surfaces (in the drawing) of the center electrode 42, which are hatched, are not arranged in parallel but widen inward. It is arranged. That is, the width of the inner peripheral surface 42a of the center electrode 42 is made wider than the width of the outer peripheral surface 42b.

In the structure of the second embodiment, the same effect as that of the first embodiment is obtained, and since the inner peripheral surface 42a has a wide width and its edges are sharp, the fuel spray is less likely to go into the gap 44. The advantage is that it is possible to further prevent problems such as engine misfire, engine stall, and starting failure. (Third Embodiment) The fuel injection valve of the present embodiment is different from that of the first embodiment only in the structure of the discharge portion at the tip of the spark plug, and therefore only the different points will be described.

As shown in FIG. 4, in this embodiment, the tip of the center electrode 52 on the inner peripheral surface 52a side is formed so as to protrude from the tip of the outer peripheral surface 52b side. In the configuration of the third embodiment, the same effects as those of the first embodiment are obtained, and it is difficult for the fuel spray to flow into the gap 54 from the tip end side of the center electrode 52, which causes further problems such as engine misfire, engine stall, and start failure. There is an advantage that it can be prevented. (Fourth Embodiment) The fuel injection valve of the present embodiment is different from that of the first embodiment only in the structure of the discharge portion at the tip of the ignition plug, and therefore only the different points will be described.

As shown in FIG. 5, in the present embodiment, the center electrode 62 is not a plate shape as in each of the above-mentioned embodiments but an annular shape surrounding the injection hole 65. The configuration of the fourth embodiment has the advantages that the same effects as those of the first embodiment can be obtained, and that the fuel spray is less likely to flow into the gap 64, and problems such as engine misfire, engine stall, and start failure can be further prevented. . Moreover, since the shape of the center electrode 62 is simplified, it is easy to manufacture and has an excellent ability to withstand damage.

It is needless to say that the present invention is not limited to the above-mentioned embodiments and can be carried out in various modes without departing from the gist of the present invention.

[0031]

As described in detail above, according to the first aspect of the invention, the outer electrode is arranged further outside the inner electrode arranged outside the fuel injection port with a gap for discharging. Moreover, the inner electrode is arranged so as to block the discharge surface on the interval side of the outer electrode. Therefore, even when the fuel is injected from the fuel injection port, the injected fuel is blocked by the inner electrode, and does not easily reach the gap or the outer electrode. Therefore, the fogging phenomenon of the spark plug can be prevented, so that engine misfire, engine stall, and starting failure can be prevented.

According to the second aspect of the present invention, the central angle β corresponding to the width of the inner peripheral surface of the inner electrode and the central angle α corresponding to the width of the outer peripheral surface of the inner electrode.
And α are set to satisfy α <β, it becomes more difficult for the spark plug to be fogged, and engine misfire, engine stall, and starting failure can be preferably prevented.

According to the third aspect of the present invention, since the tip of the inner electrode on the inner peripheral surface side is formed so as to project from the tip of the outer peripheral surface side, the injected fuel has the outer peripheral surface on the back side from the tip of the inner peripheral surface. Can be reached. Therefore, the fogging of the spark plug is less likely to occur, and engine misfire, engine stall, and starting failure can be preferably prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a spark plug integrated electromagnetic fuel injection valve according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a discharging portion of the spark plug of the first embodiment.

FIG. 3 is an explanatory diagram showing a discharging portion of an ignition plug according to a second embodiment.

FIG. 4 is an explanatory diagram showing a discharging portion of an ignition plug according to a third embodiment.

FIG. 5 is an explanatory diagram showing a discharging portion of an ignition plug according to a fourth embodiment.

FIG. 6 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

 22, 42, 52, 62 ... Center electrode, 23 ... Ground electrode, 24, 44, 54, 64 ... Gap, 25, 65 ... Injection hole (fuel injection port)

Claims (3)

[Claims] 1. An ignition plug integrated fuel injection valve, in which an inner electrode and an outer electrode for igniting a fuel are arranged outside a fuel injection port, wherein the outer electrode is arranged outside the inner electrode with a gap therebetween. At the same time, the fuel injection valve integrated with an ignition plug is characterized in that the inner electrode is arranged so as to block the discharge surface on the interval side of the outer electrode. 2. A central angle β corresponding to the width of the inner peripheral surface of the inner electrode and a central angle α corresponding to the width of the outer peripheral surface of the inner electrode are set to have a relationship of α <β. The fuel injection valve integrated with a spark plug according to claim 1, wherein 3. The ignition plug integrated fuel injection valve according to claim 1, wherein the inner electrode has a tip on the inner peripheral surface side projecting from a tip on the outer peripheral surface side.