JP2985285B2 - Electromagnetic fuel injection valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic fuel injection valve for injecting fuel into an internal combustion engine.

(Prior art)

2. Description of the Related Art As a conventional electromagnetic fuel injection valve, there is an electromagnetic fuel injection valve in which air from an intake pipe is used to improve atomization of fuel.
FIG. 5 shows a characteristic portion of the structure.

In FIG. 5, a needle valve 7 has a valve body 6.
The needle valve 7 is slidably disposed within the needle valve 7.
Controls the opening and closing of the fuel flowing through the valve body 6 while being separated from and attached to the tapered seat surface 63 formed on the valve body 6. A pintle 74 is formed at the tip of the needle valve 7 in the injection hole 62 formed in the valve body 6, and a spray is formed by a conical surface 76 formed continuously with the pintle 74. At the tip of the valve body 6 is attached a sleeve 8 having a tapered guide hole 81 for defining spray. The sleeve 8 has an air hole 82 for introducing air in the radial direction. Between the valve body 6 and the sleeve 8, there is arranged a ring nozzle 90 for guiding the air introduced from the air hole 82 to the periphery of the pintle 74.

With this configuration, the air that has passed through the air holes 82 of the sleeve 8 collides with the spray through the gap formed by the sleeve 8, the ring nozzle 90, and the valve body 6,
It promotes atomization of spray.

[Problems to be solved by the invention]

However, this tip portion is exposed to the intake system, and when the back-flowing combustion gas flows backward, the air holes 82 are formed, so that the back-flowing combustion gas easily flows into the injection holes 62, and the pintle 74 and the injection holes 62 Residue adheres to the metering section between the above and the injection amount is reduced.

In view of the above, an object of the present invention is to provide an electromagnetic fuel injection valve in which the injection amount does not decrease even if a backflow of the blowback combustion gas occurs.

[Means for solving the problem]

As a means for solving the above-mentioned problems, the present invention provides a valve body having an injection hole, and controls a fuel which is electromagnetically driven and flows through the valve body. A needle valve having a cylindrical pintle that performs fuel metering in cooperation with the hole, a sleeve having an air hole on the outer peripheral side, which is disposed on an end side where the injection hole of the valve body is formed, A ring nozzle disposed between the sleeve and the valve body, and a spacer disposed between the valve body and the ring nozzle, for changing a relative position between the pintle and the ring nozzle, A gap is formed between the ring nozzle and the sleeve, and between the ring nozzle and the spacer, to allow communication between the air hole and the injection hole. Employing an electromagnetic fuel injection valve according to claim.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, a housing 1 of a fuel injection valve 100 that operates electromagnetically has a stepped cylindrical shape, and a spool 2 around which an electromagnetic coil 3 is wound is disposed in a large diameter portion of the housing 1.

A fixed iron core 4 penetrates the spool 2 from above in the figure, and a flange portion protruding from a cylindrical wall of the fixed iron core 4.
41 is fixed by caulking the upper opening end of the housing 1. A 0 ring 10 for sealing is provided between the spool 2 and the fixed iron core 4,
An O-ring 11 for sealing is installed between the two.

A power supply connector 5 is integrally formed of resin on the upper surface of the housing 1. The power supply connector 5 is used to connect the electromagnetic coil 3 to an electronic control unit (not shown) by a cable (not shown).
Are connected to the electromagnetic coil 3 by lead wires.

The movable core 14 is formed of a magnetic material and is movably disposed in the housing 1. This movable core
14 is electromagnetically driven against the urging force of the compression coil spring 15 by energizing the electromagnetic coil 3. The urging force of the compression coil spring 15 acting on the movable core 14 is adjusted by an adjusting member 42 inserted into the fixed core 4, and is fixed by caulking after the adjustment.

A valve body 6 is fixed by caulking to a small diameter portion of the housing 1 via a spacer 61, and a tapered seat surface 63 and an injection hole 62 are provided below the valve body 6, as shown in FIG. Is formed.

The housing 1 and the valve body 6 are formed with introduction passages 12 and 66 for introducing fuel, respectively. The introduction passages 12 and 66 receive supply of relatively low-pressure fuel from a fuel pump (not shown). Fuel filter 1 at inlet
3,64 are arranged.

The needle valve 7 is connected to the movable core 14,
The valve reciprocates in the valve body 6 in conjunction with the movable core 14. The needle valve 7 is attached to and detached from the seat surface 63 of the valve body 6, and controls the injection of fuel from the injection holes 62 located downstream of the seat surface 63. Also,
A stopper 70 is formed substantially at the center of the needle valve 7 so as to face the spacer 61. The needle valve 7 has a cylindrical portion 71 located in a fuel reservoir in the valve body 6, a seat portion 72 detachable from a seat surface 63, and a conical surface 73. A pintle 74 having a columnar shape at a position, a constricted portion 75 formed to be inclined and narrowed from the pintle 74, a conical surface 76 formed to be inclined and expanded from the constricted portion, and a tip portion 77 are formed in series. It is formed.

A sleeve 8 forming a tapered guide hole 81 is press-fitted and fixed to the end of the valve body 6 where the injection hole 62 is formed. An air hole 82 is formed in the sleeve 8 in the radial direction, and a ring nozzle 90 for guiding the air introduced from the air hole 82 to the periphery of the pintle 74 is disposed between the valve body 6 and the sleeve 8. . In addition, the ring nozzle 90
A spacer 91 is arranged between the valve body 6 and the valve body 6.

The valve body 6 and the spacer 91 are formed of stainless steel having corrosion resistance.

 Next, the operation of the present embodiment having the above configuration will be described.

When a current pulse is applied from an electronic control unit (not shown) through the connector pin 51, the fixed core 4 is magnetized, whereby the movable core 14 moves upward in the figure against the urging force of the spring 15, and The needle valve 7 moves upward by several tens of microns, and a gap is generated between the seat portion 72 and the seat surface 63 of the needle valve 7.

The fuel passes through the gap, passes between the conical surface 73 of the needle valve 7 and the seat surface 63 of the valve body 6 and passes through the injection hole.
It is metered by the gap between 62 and pintle 74.

On the other hand, the air introduced from the intake system passes through the air holes 82, and then, the sleeve 8, the ring nozzle 90, and the spacer 91.
By this, it is introduced around the pintle 74 through the gap formed and mixed with the metered fuel to promote atomization. This fuel flows along the conical surface 76 of the needle valve 7
Sprayed at a spray angle of 20-30 °.

Here, since the fuel injection valve 100 is arranged in the intake system, when the blowback combustion gas is generated, the residue adheres around the pintle 74 and the injection hole 62. In particular, when the air holes 82 are formed in the sleeve 8, the blown back combustion gas flows easily, and the amount of the adhered residue is large.

3 and 4 show the state where the residue D around the pintle 74 has adhered. FIG. 3 shows the valve closed state and FIG. 4 shows the valve open state. 5 shows the case of the prior art, and the right half shows the case of the present embodiment.

As is clear from FIGS. 3 and 4, in this embodiment, a spacer is provided between the ring nozzle 90 and the valve body 6.
By arranging 91, the metering passage S cooperates with the injection hole 62.
No residue adheres to the periphery of the pintle 74 of the needle valve 7 which forms the above, and the injection amount does not decrease.

The present inventors, with the electromagnetic fuel injection valve 100 of the present embodiment,
When an experiment was performed for a running distance of about 10,000 km, it was confirmed that the decrease in the injection amount was about one-tenth or less as compared with the conventional example shown in FIG.

Further, since the spray angle by the conical surface 76 changes (spray angle increases) due to the arrangement of the spacer 91, the angle of the rectifying hole 81 of the sleeve 8 is set accordingly so that the spray does not collide.

In addition, since it has a simple configuration in which the spacer 91 is disposed, no special processing is required for the structure of the conventional injection valve, and its versatility is extremely high.

〔The invention's effect〕

As described above, according to the present invention, with a simple configuration in which a spacer that changes the relative position between the pintle and the ring nozzle is disposed between the valve body and the ring nozzle, residue adheres around the pintle. In addition, it is possible to effectively prevent a decrease in the injection amount caused by the above-described operation, and it is possible to obtain an excellent effect that the versatility is extremely high without requiring any special processing for the structure of the conventional injection valve. .

[Brief description of the drawings]

1 to 4 relate to an embodiment of the present invention. FIG. 1 is a cross-sectional view showing the entire structure, FIG. 2 is an enlarged view of a part II in FIG. 1, and FIGS. FIG. 3 shows the state of adhesion of the residue in comparison with the conventional case, FIG. 3 shows the state when the valve is closed, FIG. 4 shows the state when the valve is closed, and FIG. 5 is an enlarged view showing a characteristic portion of the conventional type. 6 …… Valve body, 62 …… Injection hole, 7 …… Needle valve,
74 Pintle, 8 Sleeve, 82 Air hole, 90 Ring nozzle, 91 Spacer.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriyasu Onihara 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (72) Inventor Yoshihiko Ito 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Nihon Denso Incorporated (72) Inventor Masaru Kitakita 1-1-1 Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References Japanese Utility Model Sho-59-123661 (JP, U) (58) Field surveyed .Cl. ⁶ , DB name) F02M 51/08 F02M 61/04-61/06 F02M 61 / 18,69 / 04

Claims (1)

(57) [Claims] A valve body having an injection hole, which controls electromagnetically driven fuel flowing through the valve body, and which is located at the tip thereof in the injection hole and cooperates with the injection hole. A needle valve having a cylindrical pintle for metering fuel; a sleeve disposed on an end portion on which an injection hole of the valve body is formed; and a sleeve having an air hole on an outer peripheral side; and the sleeve and the valve body. A ring nozzle arranged between the valve body and the ring nozzle, and a spacer for changing a relative position between the pintle and the ring nozzle, the ring nozzle and the sleeve And a gap between the air nozzle and the injection hole is formed between the ring nozzle and the spacer. .