JP2015063898A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve capable of accelerating atomization of a fuel injected from an injection hole and making an injection direction stationary.SOLUTION: An orifice hole 42 smaller in diameter than a downstream opening portion 48 of a valve seat member 7 is formed on one end of an intermediate plate 41, while a transverse passage hole (communication passage) 45 continuous to the orifice hole 42 and larger in diameter than the orifice hole 42 is formed on the other end of the orifice hole 42. The orifice hole 42 is formed to have a smaller diameter than a range in which one end (internal plate 41-side end) of a fuel injection hole 44 of a nozzle plate 8 is open, and a disturbance generation unit 49 generating disturbance in a fuel that passes through the communication passage 45 is formed on a side surface of the communication passage 45 connecting the downstream opening portion 48 of the valve seat member 7 to the injection hole 44 of the nozzle plate 8, the side surface being opposed to the injection hole 44.

Description

  The present invention relates to a fuel injection valve.

  As this type of technique, a technique described in Patent Document 1 below is disclosed. Patent Document 1 discloses a device in which a plurality of protrusions are formed on a surface of an orifice plate on which an orifice through which fuel is injected is formed, which faces the needle valve. When the fuel collides with the projections or when the fuel passes between the projections, the fuel flow is disturbed, and the energy of the disturbance promotes atomization of the fuel spray injected from the orifice. .

JP 11-093807 A

In the technique described in Patent Document 1, since a plurality of protrusions are provided on the surface of the orifice plate that faces the needle valve, the flow of fuel passing through the orifice is only a disturbed flow, and the fuel injection direction is constant. There was a risk of not becoming.
The present invention has been focused on the above-mentioned problems, and its object is to provide a fuel injection valve capable of promoting atomization of fuel injected from an injection hole (orifice) and stabilizing the injection direction. Is to provide.

  In order to achieve the above object, in the present invention, the fuel passing through the communication passage is disposed on the side surface facing the opening of the injection hole of the communication passage connecting the opening of the valve seat member and the injection hole of the nozzle plate. A disturbance generating part for generating a disturbance was formed.

  Therefore, in the present invention, it is possible to promote atomization of the fuel injected from the injection hole and to stabilize the injection direction.

1 is an axial sectional view of a fuel injection valve of Example 1. FIG. 2 is an enlarged cross-sectional view of the vicinity of a nozzle plate of a fuel injection valve of Example 1. FIG. FIG. 3 is a plan view of the intermediate plate of Example 1 as viewed from the other end side. FIG. 3 is a perspective view of the intermediate plate of Example 1 cut in the axial direction. 2 is a cross-sectional view of an intermediate plate of Example 1. FIG. It is the image figure which showed the flow of the fuel in the horizontal passage hole of a comparative example. FIG. 3 is an image diagram showing a flow of fuel in a lateral passage hole of Example 1. 6 is a perspective view of an intermediate plate of Example 2. FIG. FIG. 6 is a perspective view of an intermediate plate of Example 2 cut in the axial direction. 6 is a sectional view of an intermediate plate of Example 2. FIG. 6 is a plan view of an intermediate plate of Example 3 as viewed from the other end side. FIG. 6 is a perspective view of an intermediate plate of Example 3 cut in the axial direction. FIG. 6 is a cross-sectional view of an intermediate plate of Example 3. FIG.

Example 1
The fuel injection valve 1 according to the first embodiment will be described.
[Configuration of fuel injection valve]
FIG. 1 is an axial sectional view of the fuel injection valve 1. This fuel injection valve 1 is a so-called low-pressure fuel injection valve that is used in a gasoline engine for automobiles and injects fuel into an intake manifold. In the following, in FIG. 1, the upper side of the fuel injection valve 1 is referred to as one end, and the lower side of the paper is referred to as the other end.
The fuel injection valve 1 includes a magnetic cylinder 2, a fixed core 3 accommodated in the magnetic cylinder 2, a valve element 4 slidable in the axial direction, and a movable core 5 formed integrally with the valve element 4. A valve seat member 7 having a valve seat 6 closed by the valve body 4 when the valve is closed, a nozzle plate 8 having a fuel injection hole 44 through which fuel is injected when the valve is opened, and the movable core 5 and the valve body when energized It has an electromagnetic coil 9 that slides 4 in the valve opening direction, and a yoke 10 that induces magnetic flux lines.

The magnetic cylinder 2 is made of a metal pipe or the like formed of a magnetic metal material such as electromagnetic stainless steel, and is stepped as shown in FIG. 1 by using means such as deep drawing or pressing or grinding. It is integrally formed in a cylindrical shape. The magnetic cylinder 2 has a large-diameter portion 11 formed on one end side and a small-diameter portion 12 having a smaller diameter than the large-diameter portion 11 and formed on the other end side.
The small diameter portion 12 is formed with a thin portion 13 that is partially thinned. The small-diameter portion 12 includes a core cylinder housing portion 14 that houses the fixed core 3 on one end side from the thin-walled portion 13, and a valve member 15 (valve body 4, movable core 5, valve seat member 7 on the other end side from the thin-walled portion 13). ) And a valve member accommodating portion 16 for accommodating. The thin portion 13 is formed so as to surround a gap portion between the fixed core 3 and the movable core 5 in a state where the fixed core 3 and the movable core 5 described later are accommodated in the magnetic cylinder 2. The thin wall portion 13 increases the magnetic resistance between the core tube housing portion 14 and the valve member housing portion 16, and magnetically blocks between the core tube housing portion 14 and the valve member housing portion 16.
The inner diameter of the large-diameter portion 11 constitutes a fuel passage 17 for sending fuel to the valve member 15, and a fuel filter 18 for filtering the fuel is provided at one end of the large-diameter portion 11. A pump 47 is connected to the fuel passage 17. The pump 47 is controlled by a pump control device 54. An O-ring 39 is provided on the outer periphery of one end portion of the large-diameter portion 11 to connect to the piping of a pump that sends fuel.
The fixed core 3 is formed in a cylindrical shape having a hollow part 19 and is press-fitted into the core cylinder housing part 14 of the magnetic cylinder 2. The hollow portion 19 accommodates a spring receiving member 20 fixed by means such as press fitting. A fuel passage 43 penetrating in the axial direction is formed at the center of the spring receiving member 20.
The movable core 5 has a large-diameter portion 22 and a small-diameter portion 23 whose outer shape is smaller than the large-diameter portion 22. A fluid receiving portion 28 and a spring insertion hole 24 are formed on one end side of the large diameter portion 22.

The valve body 4 is integrally fixed to the tip of the small diameter portion 23 by welding. In addition, the black semicircle and black triangle in a figure have shown the welding location. The outer shape of the valve body 4 is formed in a substantially spherical shape, and has a fuel passage surface 21 cut in parallel with the axial direction of the fuel injection valve 1 on the circumference.
The valve seat member 7 includes a substantially conical valve seat 6, a valve body holding hole 30 formed on the one end side from the valve seat 6 so as to be substantially the same as the diameter of the valve body 4, and one end opening side from the valve body holding hole 30. An upstream opening 31 having a larger diameter and a downstream opening 48 that opens to the other end of the valve seat 6 are formed. The valve seat 6 is formed so that the diameter decreases from the valve body holding hole 30 toward the downstream opening 48 so that the cross-sectional shape is about 45 °, and the valve body 4 is attached to the valve seat 6 when the valve is closed. Sit down. An intermediate plate 41 and a nozzle plate 8 are welded to the other end side of the valve seat member 7. A plurality of fuel injection holes 44 are formed in the nozzle plate 8. The fuel injection hole 44 is formed so as to be inclined with respect to the axial direction of the nozzle plate 8, and the other end side opening is positioned on the radially outer side of the nozzle plate 8 with respect to the one end side opening. .

The movable core 5 and the valve body 4 are accommodated in the magnetic cylinder 2 so as to be slidable in the axial direction. A coil spring 29 is provided between the spring receiving portion 26 of the movable core 5 and the spring receiving member 20, and urges the movable core 5 and the valve body 4 to the other end side. That is, the coil spring 29 biases the movable core 5 and the valve body 4 in the valve closing direction. The valve seat member 7 is inserted into the magnetic cylinder 2 and fixed to the magnetic cylinder 2 by welding.
An electromagnetic coil 9 is inserted into the outer periphery of the fixed core 3 of the magnetic cylinder 2. That is, the electromagnetic coil 9 is disposed on the outer periphery of the fixed core 3. The electromagnetic coil 9 includes a coil 33 wound around an insulator formed of a resin material. The coil 33 is connected to the electromagnetic coil control device 55 via the connector pin 34.

The yoke 10 has a hollow through-hole, and has a large-diameter portion 35 formed on one end opening side, a medium-diameter portion 36 formed with a smaller diameter than the large-diameter portion 35, and a diameter smaller than the medium-diameter portion 36. It is composed of a small diameter portion 37 formed on the end opening side. The small diameter portion 37 is fitted on the outer periphery of the valve member housing portion 16. An electromagnetic coil 9 is accommodated on the inner periphery of the medium diameter portion 36. A connecting core 38 is disposed on the inner periphery of the large diameter portion 35.
The connecting core 38 is formed in a substantially C shape by a magnetic metal material or the like. The large diameter portion 35 and the magnetic cylinder 2 are connected by the connecting core 38. That is, the yoke 10 is connected to the magnetic cylinder 2 at the small diameter portion 37 and the large diameter portion 35, and is magnetically connected to the magnetic cylinder 2 at both ends of the electromagnetic coil 9. A protector 52 for holding the O-ring 40 for connecting the fuel injection valve 1 to the intake port of the engine and protecting the tip of the magnetic cylinder is attached to the tip of the yoke 10 on the other end side.

As shown in FIG. 1 of the fuel injection valve 1, most of the fuel injection valve 1 is covered with a resin cover 53. The portion covered with the resin cover 53 is from the portion excluding one end portion of the large-diameter portion 11 of the magnetic cylindrical body 2 to the electromagnetic coil 9 installation position of the small-diameter portion 12 to the medium-diameter portion 36 of the electromagnetic coil 9 and the yoke 10. Between the outer periphery of the connecting core 38 and the large-diameter portion 35, the outer periphery of the large-diameter portion 35, the outer periphery of the medium-diameter portion 36, and the outer periphery of the connector pin 34. The tip of the connector pin 34 is formed by opening a resin cover 53 so that the connector of the control unit can be inserted.
When power is supplied to the electromagnetic coil 9 via the connector pin 34, a magnetic field is generated, and the valve body 4 and the movable core 5 are opened against the biasing force of the coil spring 29 by the magnetic force of the magnetic field. Thereby, the fuel supplied from the pump is injected into the combustion chamber of the engine.
When power is supplied to the electromagnetic coil 9 via the connector pin 34, a magnetic field is generated, and the valve body 4 and the movable core 5 are opened against the biasing force of the coil spring 29 by the magnetic force of the magnetic field.
The electromagnetic coil control device 55 energizes the coil 33 of the electromagnetic coil 9 to energize the fuel injection valve 1 in accordance with the timing of injecting fuel into the combustion chamber calculated based on the information from the crank angle sensor that detects the crank angle. Open the valve.

[Configuration of intermediate plate]
FIG. 2 is an enlarged cross-sectional view of the vicinity of the nozzle plate 8 of the fuel injection valve 1. FIG. 3 is a plan view of the intermediate plate 41 as viewed from the other end side. FIG. 4 is a perspective view of the intermediate plate 41 cut in the axial direction. FIG. 5 is a cross-sectional view of the intermediate plate 41.
On one end side of the intermediate plate 41, an orifice hole 42 having a diameter smaller than the diameter of the downstream opening 48 of the valve seat member 7 is formed. Further, on the other end side of the orifice hole 42, a lateral passage hole 45 that is continuous with the orifice hole 42 and has a larger diameter than the orifice hole 42 is formed. The orifice hole 42 is formed to have a smaller diameter than a range where one end side (the intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 opens. The lateral passage hole 45 is formed to have a larger diameter than a range in which one end side (intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 opens. In other words, one end side (intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 is opened at a position radially outside the orifice hole 42 and radially inside the lateral passage hole 45. .
A large number of dimples formed in a substantially spherical shape are formed in a step portion between the orifice hole 42 and the lateral passage hole 45 and facing the fuel injection hole 44 (hereinafter simply referred to as a step portion 46). A portion 49 is formed.
The intermediate plate 41 is formed by pressing, and the orifice hole 42, the lateral passage hole 45, and the dimple portion 49 are simultaneously formed in one pressing process.

[Action]
(Fuel flow when opening / closing valve)
When the electromagnetic coil 9 is not energized, the movable core 5 is urged away from the fixed core 3 by the coil spring 14, and the valve body 4 is seated on the valve seat 6. As a result, the passage of fuel between the valve body 4 and the valve seat 6 is blocked, and no fuel is injected from the fuel injection hole 44.
When the electromagnetic coil 9 is energized, a magnetic field is generated between the electromagnetic coil 9, the fixed core 3, and the movable core 5, and the movable core 5 is attracted to the fixed core 3 side and fixed against the urging force of the coil spring 14. Move to the core 3 side. As a result, the valve body 4 is separated from the valve seat 6, so that the fuel passes between the valve body 4 and the valve seat 6. The fuel that has passed between the valve body 4 and the valve seat 6 flows toward the center through the downstream opening 48, and the flow velocity increases when it flows into the orifice hole 42 of the intermediate plate 41 having a narrow flow path. When the fuel flows into the lateral passage hole 45 from the orifice hole 42, the flow spreads radially outward from the center. At this time, the fuel is disturbed by the dimple portion 49 provided in the step portion. Since the disturbed fuel flow is injected from the fuel injection hole 44, atomization of the fuel spray can be promoted by the energy of the disturbance.

(Stabilization of fuel injection direction)
When the flow of fuel flowing into the fuel injection hole 44 is a turbulent flow, atomization of the injected fuel spray is promoted, but the injection direction may not be constant. FIG. 6 is an image diagram showing the flow of fuel when the dimple portion 49 is formed on the lower surface of the lateral passage hole 45 (the surface on the side where the opening of the fuel injection hole 44 is formed). When the dimple portion 49 is provided on the lower surface of the lateral passage hole 45, only the disturbed fuel flow flows into the fuel injection hole 44. As a result, the fuel injection direction may not be constant as described above.
FIG. 7 is an image diagram showing the flow of fuel when the dimple portion 49 is formed on the upper surface of the lateral passage hole (side surface facing the opening of the fuel injection hole 44) as in the first embodiment. When the dimple portion 49 is provided on the upper surface, a disturbance is generated on the upper layer side of the fuel flowing through the lateral passage hole 45, but the disturbance is not generated on the lower layer side and rectification occurs. For this reason, the disturbed flow and rectification flow into the fuel injection hole 44, and atomization of the fuel spray can be achieved by the energy of the turbulence, and the injection direction can be stabilized by rectification.

[effect]
(1) A valve seat member 7 having a valve body 4 provided so as to be openable and closable, a valve seat 6 on which the valve body 4 sits when the valve is closed, and a downstream opening portion 48 (opening portion) opened downstream of the valve seat 6 And a nozzle plate 8 having a fuel injection hole 44 (injection hole) that communicates with the downstream opening 48 and penetrates in the plate thickness direction, and an orifice hole 42 that connects between the downstream opening 48 and the fuel injection hole 44. The dimple portion 49 is provided in the lateral communication hole 45 (communication path) and the side surface (step portion 46) of the lateral communication hole 45 facing the fuel injection hole 44 and generates a disturbance in the fuel passing through the lateral communication hole 45. (Disturbance generating part).
Therefore, the disturbed flow and rectification flow into the fuel injection hole 44, and the atomization of the fuel spray can be achieved by the energy of the turbulence and the injection direction can be stabilized by the rectification.
(2) An orifice hole 42 connected to the downstream opening 48 and having a smaller diameter than the downstream opening 48, and a lateral passage formed continuously with the orifice hole 42 and larger in diameter than the orifice hole 42 An intermediate plate 41 having a hole 45 is provided, and the fuel injection hole 44 on the side of the intermediate plate 41 is located radially outside the orifice hole 42 and radially inward from the lateral passage hole 45. The portion 49 is provided on the side surface facing the fuel injection hole 44 of the stepped portion 46 between the orifice hole 42 and the lateral passage hole 45.
Therefore, since the diameter of the orifice hole 42 of the intermediate plate 41 is smaller than the diameter of the downstream opening 48 of the valve seat member 7, the flow velocity of the fuel flowing into the orifice hole 42 can be increased, and the fuel Atomization of fuel spray injected from the injection hole 44 can be achieved.
(3) A dimple portion 49 formed in a dimple shape is provided as a disturbance generating portion.
Therefore, the disturbance generating part can be easily formed.

(Example 2)
The fuel injection valve 1 according to the second embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
[Configuration of intermediate plate]
FIG. 8 is a perspective view of the intermediate plate 41. FIG. 9 is a perspective view of the intermediate plate 41 cut in the axial direction. FIG. 10 is a sectional view of the intermediate plate 41.
On one end side of the intermediate plate 41, an orifice hole 42 having a diameter smaller than the diameter of the downstream opening 48 of the valve seat member 7 is formed. Further, on the other end side of the orifice hole 42, a lateral passage hole 45 that is continuous with the orifice hole 42 and has a larger diameter than the orifice hole 42 is formed. The orifice hole 42 is formed to have a smaller diameter than a range where one end side (the intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 opens. The lateral passage hole 45 is formed to have a larger diameter than a range in which one end side (intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 opens. In other words, one end side (intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 is opened at a position radially outside the orifice hole 42 and radially inside the lateral passage hole 45. .
An annular ring in which a plurality of concentric grooves are formed on a surface (hereinafter simply referred to as a stepped portion 46) between the orifice hole 42 and the lateral passage hole 45 and facing the fuel injection hole 44. A groove 50 is formed.
[effect]
(4) An annular groove portion 50 formed by concentrically cutting a plurality of grooves is provided as the disturbance generating portion.
Therefore, a disturbance can be generated equally for the fuel flowing in any direction with respect to the fuel flowing in the radial direction in the lateral passage hole 45 after passing through the orifice hole.

Example 3
The fuel injection valve 1 according to the third embodiment will be described. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
[Configuration of intermediate plate]
FIG. 11 is a plan view of the intermediate plate 41 as viewed from the other end side. FIG. 12 is a perspective view of the intermediate plate 41 cut in the axial direction. FIG. 13 is a sectional view of the intermediate plate 41.
On one end side of the intermediate plate 41, an orifice hole 42 having a diameter smaller than the diameter of the downstream opening 48 of the valve seat member 7 is formed. Further, on the other end side of the orifice hole 42, a lateral passage hole 45 that is continuous with the orifice hole 42 and has a larger diameter than the orifice hole 42 is formed. The orifice hole 42 is formed to have a smaller diameter than a range where one end side (the intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 opens. The lateral passage hole 45 is formed to have a larger diameter than a range in which one end side (intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 opens. In other words, one end side (intermediate plate 41 side) of the fuel injection hole 44 of the nozzle plate 8 is opened at a position radially outside the orifice hole 42 and radially inside the lateral passage hole 45. .
A step portion between the orifice hole 42 and the lateral passage hole 45 and facing the fuel injection hole 44 (hereinafter simply referred to as a step portion 46) is a straight line having a plurality of grooves formed in a straight groove shape. A groove 51 is formed.
[effect]
(5) As the disturbance generating portion, a straight groove portion 51 formed by cutting a plurality of grooves into a straight groove shape is provided.
Therefore, the disturbance generating part can be easily formed.

[Other Examples]
As described above, the present invention has been described based on the first to third embodiments. However, the specific configuration of each invention is not limited to the first to third embodiments and does not depart from the gist of the present invention. Such design changes are included in the present invention.
Although examples of the dimple portion 49, the annular groove portion 50, and the linear groove portion 51 are shown as the disturbance generating portions formed in the step portion 46 of the intermediate plate 41, other shapes may be used.

4 Disc
6 Valve seat
7 Valve seat member
42 Orifice hole (communication path)
44 Fuel injection holes
45 Horizontal communication hole (communication path)
46 steps
48 Downstream opening (opening)
49 Dimple part (disturbance generation part)
50 annular groove
51 Straight groove

Claims (5)

A valve body provided to be capable of opening and closing; and
A valve seat member having a valve seat on which the valve body sits when the valve is closed, and an opening opening on the downstream side of the face seat;
A nozzle plate communicating with the opening and having an injection hole penetrating in the thickness direction;
A communication path connecting between the opening and the injection hole;
A disturbance generating part that is provided on a side surface of the communication path facing the injection hole and generates a disturbance in the fuel passing through the communication path;
The fuel injection valve characterized by providing. In the fuel injection valve according to claim 1,
An intermediate plate having an orifice hole connected to the opening and having a smaller diameter than the opening, and a lateral passage hole formed continuously with the orifice and having a larger diameter than the orifice hole Provided,
The intermediate plate side of the injection hole is radially outer than the orifice hole and opens at a position radially inner than the lateral passage hole,
The communication path is composed of the orifice hole and the lateral path hole,
The fuel injection valve according to claim 1, wherein the disturbance generating portion is provided on a side surface of the step portion between the orifice hole and the lateral passage hole facing the injection hole. In the fuel injection valve according to claim 1 or claim 2,
The fuel injection valve, wherein the disturbance generating portion is formed in a dimple shape. In the fuel injection valve according to claim 1 or claim 2,
The fuel injection valve, wherein the disturbance generating part is formed in an annular groove shape. In the fuel injection valve according to claim 1 or claim 2,
The fuel injection valve, wherein the disturbance generating part is formed in a straight groove shape.

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