JP2860463B2 - Air-assisted electromagnetic fuel injection valve - Google Patents

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 for a fuel injection device for an internal combustion engine of an automobile or the like.
In particular, the present invention relates to an air-assisted electromagnetic fuel injection valve in which air is blown toward fuel injected from an injection hole of an electromagnetic fuel injection valve to atomize the fuel.

[0002]

2. Description of the Related Art The first prior art of an air-assisted electromagnetic fuel injection valve is disclosed in Japanese Utility Model Laid-Open No. 5-47425. This is one in which an inner cap is arranged on the outer periphery of the valve seat, an outer cap is arranged on the outer periphery of the inner cap, and a slot for introducing air and an air passage groove connected to this slot are provided in the outer cap.

A second prior art of the air-assisted electromagnetic fuel injection valve is disclosed in Japanese Utility Model Laid-Open No. 54-169620. This is a bottomed cup-shaped cap fitted to the outer periphery of the valve seat and the tip of the valve seat.
An intake hole is formed in a side wall of the cap, and an ejection hole is formed in an inner bottom portion of the cap. The intake hole and the ejection hole are formed in a groove formed in a vertical direction along the side wall. It is connected by a groove drilled horizontally along the bottom.

[0004]

According to the first prior art, the fuel ejected from the injection hole of the valve seat is
Since air can be blown from a diagonal direction at a relatively distant position, good atomization of fuel can be achieved, and the fuel foam to be ejected can have an appropriate elliptical shape. Fuel can be supplied satisfactorily. However, since the air passage groove is formed by the inner cap and the outer cap, the number of parts and the number of assembling steps increase, and the manufacturing cost of the fuel injection valve cannot be reduced. Further, the diameter of the side of the valve seat is increased, which is not preferable.

On the other hand, according to the second conventional technique, the groove for supplying air is formed by the valve seat and the single cap, so that the manufacturing cost of the fuel injection valve can be reduced. However, air is blown at right angles to the fuel ejected from the injection hole of the valve seat through the groove. This is because the injection hole of the valve seat is formed in the vertical direction perpendicular to the bottom of the valve seat, and the groove opening to the injection hole of the cap is formed in the horizontal direction along the bottom of the valve seat. According to the above, air is blown from a direction perpendicular to the direction in which fuel is sprayed from the injection hole of the valve seat, and the air is blown at a position immediately after the outlet of the injection hole. The fuel foam spreads extensively, and the engine performance is adversely affected by the inability to effectively direct and supply the fuel to the intake valve, or by increasing the amount of fuel attached to the inner wall of the intake pipe. For example, it is a phenomenon of leaning of the air-fuel mixture during the engine acceleration operation due to a response delay of the attached fuel, or an excessively enriching phenomenon of the air-fuel mixture during the engine deceleration operation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been developed to provide an air-assisted electromagnetic fuel injection valve which is capable of optimally controlling a fuel foam of fuel ejected from an injection hole toward an engine and having a low manufacturing cost. The main purpose is to provide.

[0007]

In order to achieve the above object, an air-assisted electromagnetic fuel injection valve according to the present invention is configured such that a movable core is driven by energizing an electromagnetic coil disposed in a housing. An electromagnetic fuel injection valve that controls opening and closing of a valve seat hole of a valve seat arranged at a front end portion of a housing by a valve portion that moves integrally, and injects fuel from an injection hole located downstream of the valve seat hole. Perimeter 9 of sheet 9
E, the outer peripheral diameter C from the front end 9F toward the rear end 9C side.
Forms a conical protrusion 9G that gradually increases, while a cap 12 disposed on the outer periphery 9E of the valve seat 9 has a conical recess 12A that contacts the conical protrusion 9G of the valve seat 9.
An opening 12D that opens from the tip 12B of the conical recess 12A toward the tip 12C of the cap 12, an insertion hole 12G that opens from the rear end 12E of the conical recess 12A to the rear end 12F of the cap 12, and a conical recess. Outer circumference 12H from rear end 12E side of 12A to rear end 12F side of cap 12
A slit groove 12J that opens toward the
A is provided along the slope of the conical recess 12A, the tip of which is connected to the open hole 12D, the rear end of which is located at the tip 12C of the cap 12 and the rear end of which is connected to the slit groove 12J. Further, a plurality of positioning bosses 12L formed so as to protrude toward the tip A side, and the cap is fitted to the valve seat 9 so that the conical projection 9G of the valve seat 9 and the inclined groove of the cap 12 are formed. An air groove 20 having a leading end connected to the opening hole 12D and a rear end connected to the slit groove 12J is formed by the conical concave portion 12A including 12K.

According to the present invention, since the air groove is formed by the conical recess including the conical projection of the valve seat and the inclined groove of the cap, a single cap may be prepared.
Further, since air is blown obliquely from the injection hole of the valve seat at a position relatively far from the injection hole, the injected fuel foam can have an appropriate elliptical shape, Engine performance can be improved. or,
The positioning portion provided on the air-assisted electromagnetic fuel injection valve can be formed at a fixed position with respect to the positioning boss of the cap. According to this, an air groove can always be formed at a fixed position with respect to the air-assisted electromagnetic fuel injection valve. When the positioning part of the air-assisted electromagnetic fuel injection valve is attached to a fixed position of the intake pipe, the fuel foam ejected from the injection hole of the valve seat is always directed to a fixed position of the engine (intake pipe). Can be supplied.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the air-assisted electromagnetic fuel injection valve according to the present invention will be described below with reference to the drawings. 1 is a longitudinal sectional view of an air-assisted electromagnetic fuel injection valve, FIG. 2 is an enlarged longitudinal sectional view of a main part of a valve seat portion in FIG. 1, and FIG.
-An enlarged longitudinal sectional view of a main part of a valve seat part in X-ray,
FIG. 4 is an enlarged cross-sectional view taken along line YY of FIG.
FIG. 2 is an enlarged bottom plan view of FIG. 1. Note that, for ease of explanation, the front end refers to the lower side in the figure, and the rear end refers to the upper side in the figure. 1 has a bottom 1A on the rear end B side,
The housing is formed in a bottomed cylindrical shape with a magnetic material having an open end 1B. A first cylindrical portion 1C as a fixed core projects from the center of the bottom 1A toward the end A and flows from the center of the bottom 1A. Second cylindrical portion 1D as a road member
Project toward the rear end B side. Rear end 1 of second cylindrical portion 1D
A flow path 1G penetrates from E to a front end 1F of the first cylindrical portion 1C. The inner collar 2 is inserted and arranged in the flow channel 1G in the first cylindrical portion 1C, and the flow channel 1G in the second cylindrical portion 1D.
, A strainer 3 is arranged. In the flow path 1G, the inner collar 2 is disposed on the front end A side, and the strainer 3 is disposed on the rear end B side.

Reference numeral 4 denotes a coil bobbin formed of an insulating material. An electromagnetic coil 5 is wound around the coil bobbin, and a terminal 6 connected to the coil 5 projects from a rear end flange toward the rear end B. I do. Reference numeral 7 denotes a donut-shaped set collar which is made of a magnetic material and forms a pole piece. Reference numeral 8 denotes a valve stopper which is inserted into a small-diameter portion of a needle valve, which will be described later. A long groove 8A having a diameter slightly larger than the diameter of the small-diameter portion is formed from the outer periphery toward the center.

A valve seat 9 has a valve seat hole 9A formed on the inner front end thereof and an injection hole 9B formed further toward the front end A than the valve seat hole 9A. 9B is opened to the enlarged hole opened to the front end 9F. On the other hand, a guide hole 9D is formed from the valve seat hole 9A toward the rear end 9C of the valve seat 9. These guide holes 9D and valve seat holes 9
A, the injection hole 9B and the enlarged hole are formed concentrically. The outer end 9E of the valve seat 9 has a tip 9F
From the rear end 9C, a conical protrusion 9G whose outer diameter C gradually decreases is formed. The outer periphery of the rear end 9C of the valve seat 9 forms an enlarged flange.

Reference numeral 10 denotes a needle valve movably disposed in the valve seat 9. The needle valve 10 includes the following. The needle valve 10 has a valve portion 10 for opening and closing the valve seat hole 9A.
A, a pintle portion 10B protruding from the valve portion 10A toward the distal end A and inserted into the injection hole 9B to form a measuring gap with the injection hole 9B, and a guide portion at the rear end B side of the valve portion 10A. A guide portion 10C, which has the same shape as the cross section of the hole 9D and has a plurality of cutout surfaces formed on the outer periphery thereof, is movably disposed in the guide hole 9D, and is formed on the rear end B side of the guide portion 10C. It is formed of a locking flange 10D, a fitting projection 10E formed at the rear end, and a small diameter portion 10F formed between the fitting projection 10E and the locking flange 10D.

A fitting projection 10E formed at the rear end of the needle valve 10 has a movable core 11 having a cylindrical shape.
Are fitted and arranged integrally.

Reference numeral 12 denotes a cap which is disposed in contact with the outer periphery 9E including the conical projection 9G of the valve seat 9, and is composed of the following. Reference numeral 12A denotes a conical recess formed so as to be in contact with the conical projection 9G of the valve seat 9. An open hole 12D is opened from the tip 12B of the conical recess 12A toward the tip 12C of the cap 12. . Conical recess 1
An insertion hole 12G that abuts on the outer periphery 9E of the valve seat 9 is opened and formed from the rear end 12E of the 2A toward the rear end 12F of the cap 12. The conical recess 12A, the insertion hole 12
G is better shown in FIG.

A vertically elongated slit groove 12J is formed from the rear end 12E of the conical recess 12A toward the outer periphery 12H on the rear end 12F of the cap 12. This slit groove 12
J is open to the outer periphery 12H on the rear end 12F side of the cap 12, the rear end 12E of the conical recess 12A, and the insertion hole 12G.

Further, the conical concave portion 12A has a rear end 12E.
A slope groove 12K is formed substantially along the slope of the conical concave portion 12A toward the tip 12B. This inclined groove 12K is
The front end is connected to the opening hole 12D and opened, and the rear end is connected to the slit groove 12J and opened. The slit groove 12
J and two inclined grooves 12K are formed so as to face each other with the longitudinal axis of the cap 12 interposed therebetween. This slit groove 1
2J and the inclined groove 12K are well shown in FIG.

Further, a plurality of (two in this embodiment) positioning bosses 12L are provided on the tip 12C of the cap 12 so as to project further toward the tip A.

The air-assisted electromagnetic fuel injection valve is assembled as follows. The coil bobbin 4 is inserted and arranged from the opening of the front end 1B of the housing 1 toward the bottom 1A,
At this time, the terminal 6 projects toward the rear end B via a hole formed in the bottom 1A. Next, the set collar 7 is arranged at the tip of the coil bobbin 4. On the other hand, the guide hole 10C of the needle valve 10 is slidably disposed in the guide hole 9D of the valve seat 9, and the long groove of the valve stopper 8 is directed toward the small diameter portion 10F between the movable core 11 and the locking flange 10D. 8
A is inserted and arranged. Thus, the valve seat 9 having the needle valve 10 is disposed on the tip of the set collar 7. At this time, a spring 13 is contracted between the rear end of the movable core 11 and the front end of the inner collar 2. The rear end of the movable core 11 is arranged to face the front end 1F of the first cylindrical portion 1C, and the rear end of the locking flange 10D is arranged to face the front end of the valve stopper 8.

Next, the cap 12 is disposed on the outer periphery 9E of the valve seat 9. According to the above description, the set collar 7, the valve stopper 8, the valve seat 9, and the cap 12 are stacked and arranged on the locking step 1J provided at the intermediate portion in the housing 1. Is crimped inward with the front end 1B of the cap facing the cap 12.

In the state where the other components including the cap 12 are mounted and fixed in the air-assisted electromagnetic fuel injection valve, the outer periphery of the terminal 6 is determined with reference to the positioning boss 12L of the cap 12. The coupler 30 is formed by out-molding the outer periphery of the intermediate portion of the housing 1 including the housing 1, and a positioning portion (not shown) is integrally formed with the coupler 30. According to the above description, the positioning portion of the coupler 30 and the positioning boss 12L of the cap 12 are arranged at a fixed position.

When the coil 5 is not energized, there is a gap between the rear end of the movable core 11 and the front end 1F of the first cylindrical portion 1C, and between the rear end of the locking flange 10D and the front end of the valve stopper 8. A small gap (corresponding to an operation stroke) exists between them, but is not shown.

According to the fitting of the cap 12 to the outer periphery 9E of the valve seat 9 as described above, the insertion hole 12G of the cap 12 comes into contact with the cylindrical outer periphery 9E of the valve seat 9, and the conical recess 12A of the cap 12 is formed. Is the valve seat 9
Abuts on the conical projection 9G. The opening of the inclined groove 12K formed along the conical recess 12A of the cap 12 toward the conical recess 12A is formed by the conical projection 9G of the valve seat 9.
, An air groove 20 is formed which is inclined substantially along the inclination of the conical recess 12A. And this air groove 2
The leading end of the opening 0 is continuous with an opening 12D opening at the leading end 12C of the cap 12, while the trailing end is continuous with the slit groove 12J.

Next, the operation will be described. When the electromagnetic coil 5 is energized, the movable core 11 is attracted toward the tip 1F of the first cylindrical portion 1C against the spring force of the spring 13, and the rear end of the locking flange 10D of the needle valve 10 is The needle valve 10 is moved until it comes into contact with the tip of the stopper 8, whereby the valve portion 10 A of the needle valve 10 is moved to the valve seat hole 9 of the valve seat 9.
Release A. According to this, fuel supplied by a fuel pump (not shown) into the flow path 1G reaches the valve seat hole 9A through the outer periphery of the movable core 11, the small diameter portion 10F, the locking flange portion 10D, and the guide portion 10C. . The fuel flowing into the valve seat hole 9A is measured by a fuel gap formed by the pintle portion 10B and the injection hole 9B, and is ejected from the injection hole 9B into the open hole 12D of the cap 12 through the enlarged hole.

On the other hand, air is supplied to the slit groove 12J of the cap 12 in accordance with the ejection of the fuel. This air flows down in the air groove 20 from the slit groove 12J,
It flows out from the tip of the air groove 20 into the opening 12D of the cap 12.

According to the above description, the cap 12 is inserted from the injection hole 9B.
The fuel injected into the open hole 12D of the
The air is supplied obliquely through the nozzle and the air is collided at a position obliquely defined with respect to the fuel and at a position relatively distant from the injection hole 9B, so that the fuel is effectively atomized. As well as an appropriate fuel foam.

In the present invention, the conical projection 9G formed at the tip of the valve seat 9 and the cap 1
The inclined groove 12K formed in the second conical recess 12A forms an oblique air groove 20 substantially along the inclination of the conical recess 12A.
Is formed, a single cap 12 may be prepared, and the cap may be fitted and arranged on the outer periphery of the valve seat 9. According to this, the number of parts and the number of assembly steps can be reduced. Thus, the manufacturing cost can be reduced.

The air-assisted electromagnetic fuel injection valve according to the present invention has a predetermined engine (for example, an intake pipe and a fuel distribution pipe) based on a positioning portion of the coupler 30 (not shown).
The cap 12 including the air groove 20 is also arranged at a fixed position of the engine. Accordingly, the elliptical fuel foam formed by the air added from the air groove 20 formed in the cap 12 is accurately supplied to a predetermined position and direction of the engine.

[0028]

As described above, the air-assisted electromagnetic fuel injection valve according to the present invention has a conical projection formed at the tip of a valve seat and a conical recess of a cap disposed in contact with the outer periphery of the valve seat. With the inclined groove provided, an air groove intersecting with the longitudinal axis of the needle valve is formed, so that atomization of fuel can be achieved, the directivity of fuel to the intake valve is improved, and the inner wall of the intake pipe is formed. Fuel adhesion is suppressed, and in particular, the air groove is formed by the outer periphery of the valve seat and a single cap fitted to it, so that the number of parts and the number of assembly steps can be reduced, and the air-assisted electromagnetic fuel The manufacturing cost of the injection valve can be effectively reduced. According to the positioning boss formed at the tip of the cap, the air groove formed by the cap can be formed at a fixed position with respect to the reference position of the air-assisted electromagnetic fuel injection valve. When attached to a fixed position of the engine according to the reference position of the fuel injection valve, the elliptical fuel foam ejected from the air-assisted electromagnetic fuel injection valve accurately transfers fuel to a predetermined position. Can supply.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of an air-assisted electromagnetic fuel injection valve according to the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a main part of a valve seat portion in FIG.

FIG. 3 is an enlarged longitudinal sectional view of a main part of a valve seat portion taken along line XX of FIG. 1;

FIG. 4 is an enlarged transverse sectional view taken along line YY of FIG. 1;

FIG. 5 is an enlarged bottom plan view of FIG. 1;

[Explanation of symbols]

 Reference Signs List 9 Valve seat 9C Rear end of valve seat 9E Outer periphery of valve seat 9F Tip of valve seat 9G Conical projection 10 Needle valve 12 Cap 12A Conical recess 12D Opening hole 12G Insertion hole 12J Slit groove 12K Inclined groove 12L Positioning boss 20 Air groove

Continuation of the front page (56) References JP-A-4-279761 (JP, A) JP-A-7-1558537 (JP, A) JP-A-4-101059 (JP, A) JP-A-6-8761 (JP) , U) Shokai Sho 62-116170 (JP, U) Shokai Hei 4-105967 (JP, U) Shokai Hei 5-47425 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB Name) F02M 51/08 F02M 29/00 F02M 61/18 F02M 69/04

Claims (1)

(57) [Claims] 1. A movable core is driven by energization of an electromagnetic coil disposed in a housing, and a valve portion that moves integrally with the movable core opens and closes a valve seat hole of a valve seat disposed at a distal end of the housing. In an electromagnetic fuel injection valve that controls and injects fuel from an injection hole located downstream of a valve seat hole, an outer diameter C of the outer periphery 9E of the valve seat 9 gradually increases from a front end 9F to a rear end 9C. On the other hand, the cap 12 disposed on the outer periphery 9E of the valve seat 9 has a conical recess 12A in contact with the conical protrusion 9G of the valve seat 9, and a cap 12A formed from the tip 12B of the conical recess 12A. 12 tips 1
An open hole 12D opening toward 2C and a conical recess 12
An insertion hole 12G opening from the rear end 12E of the cap 12 to the rear end 12F of the cap 12, and a slit groove 1 opening from the rear end 12E of the conical recess 12A to the outer periphery 12H on the rear end 12F of the cap 12.
2J, an inclined groove 12K which is recessed in the conical concave portion 12A and substantially along the inclination of the conical concave portion 12A, a leading end of which is connected to the opening hole 12D, and a rear end of which is connected to the slit groove 12J, and a leading end 12C of the cap 12. And tip A more than tip 12C
A plurality of positioning bosses 12 protruding toward the side
L, and by fitting the cap to the valve seat 9,
The conical projection 9G of the valve seat 9 and the conical concave portion 12A including the inclined groove 12K of the cap 12 have an opening 1 at the tip.
Air groove 2 connected to 2D and rear end connected to slit groove 12J
An air-assisted electromagnetic fuel injection valve, wherein 0 is formed.