JP5492123B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve used as a fuel injection valve for an engine.

  As this type of technology, the technology described in Patent Document 1 below is disclosed. This publication discloses a measuring plate in which nozzle holes are formed so as to penetrate in the axial direction. A swirl flow generating groove is formed on the upper surface of the measuring plate so as to be tangentially connected to the wall surface of the nozzle hole.

Japanese Patent No. 4154317

In the technique described in Patent Document 1, since the depth of the swirl flow generating groove is constant in the width direction, the fuel flow velocity in the nozzle hole is faster on the inner peripheral side than on the outer peripheral side, and is strong against the fuel. There was a risk that power could not be granted.
The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a fuel injection valve capable of imparting a strong turning force to the fuel.

In order to achieve the above object, in the present invention, the side surface of the radially outer communication path in which the fuel swirls in the swirl imparting chamber is defined as the first side surface, and the side surface of the radially inner communication path in which the fuel swirls in the swirl imparting chamber is defined as the first side surface. When the two side surfaces are formed, the first side surface side communication passage is a deep groove portion, the second side surface communication passage is a shallow groove portion, and the depth of the deep groove portion is deeper than the depth of the shallow groove portion , The swirl imparting chamber is continuously connected to the deep groove portion and the shallow groove portion of the communication passage, has a swirl groove formed along the side wall of the swirl impart chamber, and advances the depth of the swirl groove to the back of the swirl grant chamber. It was formed so as to become gradually shallower .

  According to the present invention, a strong turning force can be applied to the fuel.

It is an axial sectional view of the fuel injection valve of Example 1. It is an expanded sectional view near the nozzle plate of the fuel injection valve of Example 1. It is the top view which looked at the nozzle plate of Example 1 from the axial direction one end side. 3 is a perspective view of a swirl chamber according to Embodiment 1. FIG. 3 is a perspective view of a swirl chamber according to Embodiment 1. FIG. It is the figure which cut | disconnected the communicating path of Example 1 to the axial direction. It is the figure which cut | disconnected the communicating path of Example 1 in the width direction. It is the figure which cut | disconnected a part of swirl provision chamber of Example 1. 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. The fuel injection valve 1 is used for an automobile engine or the like.
The fuel injection valve 1 includes a magnetic cylinder 2, a core cylinder 3 accommodated in the magnetic cylinder 2, a valve element 4 slidable in the axial direction, and a valve shaft formed integrally with the valve element 4. 5, a valve seat member 7 having a valve seat 6 that is closed by the valve body 4 when the valve is closed, a nozzle plate 8 having an injection hole through which fuel is injected when the valve is opened, and a direction in which the valve body 4 is opened when energized And an electromagnetic coil 9 to be slid and a yoke 10 for inducing 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 tube housing portion 14 that houses the core tube body 3 on one end side from the thin wall portion 13, and a valve member 15 (valve 4, valve shaft 5, valve seat member on the other end side from the thin wall portion 13. 7) and is divided into a valve member accommodating portion 16 for accommodating. The thin portion 13 is formed so as to surround a gap portion between the core cylinder 3 and the valve shaft 5 in a state where the core cylinder 3 and the valve shaft 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.
The core cylinder 3 is formed in a cylindrical shape having a hollow portion 19 and is press-fitted into the core cylinder housing portion 14 of the magnetic cylinder 2. The hollow portion 19 accommodates a spring receiver 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 receiver 20.
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 shaft 5 has a large-diameter portion 22 and a small-diameter portion 23 whose outer shape is smaller than 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. A spring insertion hole 24 is formed at the end of the large diameter portion 22. A spring seat 25 having a smaller diameter than the spring insertion hole 24 is formed at the bottom of the spring insertion hole 24, and a stepped spring receiving portion 26 is formed. A fuel passage hole 27 is formed at the end of the small diameter portion 23. The fuel passage hole 27 communicates with the spring insertion hole 24. A fuel outflow hole 28 penetrating the outer periphery of the small diameter portion 23 and the fuel passage hole 27 is formed.
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 shaft 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 receiver 26 and the spring receiver 20 of the valve shaft 5 to urge the valve shaft 5 and the valve body 4 to the other end side. 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 core cylinder 3 of the magnetic cylinder 2. That is, the electromagnetic coil 9 is disposed on the outer periphery of the core cylinder 3. The electromagnetic coil 9 includes a bobbin 32 formed of a resin material and a coil 33 wound around the bobbin 32. The coil 33 is connected to the electromagnetic coil control device 55 via the connector pin 34. 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.

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 yoke 10 is connected to the magnetic cylinder 2 at the large-diameter portion 35 via the small-diameter portion 37 and the connecting core 38, that is, magnetically connected to the magnetic cylinder 2 at both ends of the electromagnetic coil 9. It becomes. 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.

When power is supplied to the electromagnetic coil 9 through the connector pin 34, a magnetic field is generated, and the valve body 4 and the valve shaft 5 are opened against the biasing force of the coil spring 29 by the magnetic force of the magnetic field.
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.
An O-ring 39 is provided on the outer periphery of one end of the magnetic cylinder 2, and an O-ring 40 is provided on the outer periphery of the small diameter portion 37 of the yoke 10.
A nozzle plate 8 is welded to the other end side of the valve seat member 7. The nozzle plate 8 is injected with a plurality of swirl chambers 41 that give a swirl (swirl flow) to the fuel, a central chamber 42 that distributes the fuel to each swirl chamber 41, and a fuel that has been swirled in the swirl chamber 41. An injection hole 44 is formed.

[Configuration of nozzle 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 nozzle plate 8 viewed from one axial end side. The cross section of the nozzle plate 8 in FIG. 2 is a cross section cut at the position of the straight line AA in FIG. The configuration of the nozzle plate 8 will be described with reference to FIGS.
A swirl chamber 41 and a central chamber 42 are formed on one side surface of the nozzle plate 8. The central chamber 42 is formed in a circular concave shape with a bottom on the concentric axis of the valve seat member 7.
Three swirl chambers 41 are formed at substantially equal intervals (120 ° intervals) in the circumferential direction of the nozzle plate 8, and each includes a communication path 45 and a swirl application chamber 46. The communication passage 45 is formed to extend in the radial direction of the central chamber 42. A swirling chamber 46 is formed at the tip of the communication path 45. The swirling chamber 46 is formed in a bottomed circular concave shape, and a side wall 46a is formed as an inner wall surface thereof. An injection hole 44, which is a cylindrical through hole, is formed on the bottom of the swirl application chamber 46 on the same axis as the side wall 46a of the swirl application chamber 46. A swirling groove 46b is formed along a side wall 46a of the swirl application chamber 46 at a part of the bottom of the swirl application chamber 46.

[Details of swirl room]
4 and 5 are perspective views of the swirl chamber 41, FIG. 6 is a view of the communication passage 45 cut in the axial direction, FIG. 7 is a view of the communication passage 45 cut in the width direction, and FIG. It is the figure which cut | disconnected the part. The configuration of the swirl chamber 41 will be described with reference to FIGS. In the first embodiment, the communication passage 45 is defined as a range (B range shown in FIG. 2) in which the start end is the central chamber 42 and the end is the approximate center of the injection hole 44. Further, the starting end is the end of the communication path 45, and the range of about 180 ° (the range of C in FIG. 2) along the side wall 46a of the swirl application chamber 46 is the swivel groove 46b.
The communication passage 45 is provided with a first side surface 45a located radially outward with respect to the direction of fuel swirling in the swirl imparting chamber 41 and a second side surface 45b located radially inside. . In the communication path 45, a deep groove portion 45c is formed on the first side surface 45a side, and a shallow groove portion 45d is formed on the second side surface 45b side.
The depth of the deep groove portion 45c is deeper than the depth of the shallow groove portion 45d. The depth of the deep groove portion 45c is formed so as to gradually become shallower toward the swirl application chamber 41. The depth of the shallow groove portion 45d on the second side surface 45b side is formed to be substantially the same as the depth of the central chamber 42, and is gradually deepened toward the deep groove portion 45c. Therefore, the width of the shallow groove portion 45d occupies substantially half of the width of the communication path 45 at the starting end of the communication path 45, and gradually decreases toward the swirl application chamber 41. Note that the width dimension of the shallow groove portion 45d may be the same as the width direction of the communication path 45 at the starting end of the communication path 45, or may be half or more of the width direction. In this case, it is possible to suppress a sudden change in the fuel flow.
The swirl groove 46b of the swirl imparting chamber 46 is continuous with the deep groove portion 45c and the shallow groove portion 45d at the connecting portion between the swirl imparting chamber 46 and the communication passage 45 (the end point of the communication passage 45 shown in the range B in FIG. 2). Is formed. That is, in the turning groove 46b, a deep groove portion 46c communicating with the deep groove portion 45c of the communication passage 45 and a shallow groove portion 46d communicating with the shallow groove portion 45d of the communication passage 45 are formed. The deep groove 46c of the swivel groove 46b is formed so that the depth becomes shallower as it goes deeper into the swirl imparting chamber 46, and finally the swirl at the end point of the swivel groove 46b shown in the range of C in FIG. It becomes the same depth as the bottom of the application chamber 46 and is integrated with the bottom.

[Action]
When the fuel enters the communication path 45, the flow velocity of the fuel flowing through the portion contacting the first side surface 45a and the second side surface 45b of the communication path 45 is slower than the flow velocity of the fuel flowing through the middle of the communication path 45. This is because friction with the first side surface 45a and the second side surface 45b occurs.
The first side surface 45a is continuous with the side wall 46a of the swirl imparting chamber 46 in a tangential direction, but the second side surface 45b is connected to the swirl groove 46b of the swirl imparting chamber 46 so that the second side surface 45b is disconnected. It consists of. Therefore, the fuel passing through the communication path 45 flows to the first side surface 45a side rather than the second side surface 45b. Therefore, when flowing into the swirl imparting chamber 46, the amount of fuel flowing into the communication path 45 flows more to the side wall 46a side of the swirl imparting chamber 46 than the injection hole 44 side, and the fuel can sufficiently swirl and is strong A turning force can be applied.

  Due to the above characteristics, if the cross-sectional area of the communication path 45 is formed constant, the flow rate of the fuel flowing on the first side surface 45a side becomes slower than the flow rate of the fuel flowing on the second side surface 45b side. That is, the fuel flow rate radially inward with respect to the direction in which the fuel swirls in the swirl imparting chamber 46 is relative to the fuel flow rate radially outward in the direction in which the fuel swirls in the swirl imparting chamber 46. Get faster. Therefore, the fuel cannot sufficiently swirl in the swirl imparting chamber 46, and a strong swirling force (swirl force) cannot be imparted to the fuel.

Therefore, in the fuel injection valve 1 of the first embodiment, the deep groove portion 45c is formed on the first side surface 45a side of the communication passage 45, the shallow groove portion 45d is formed on the second side surface 45b side, and the depth of the deep groove portion 45c is reduced to the shallow groove portion 45d. It was formed to be deeper than the depth.
Therefore, a larger amount of fuel in the communication passage 45 can flow toward the 45a side of the first side surface than the second side surface 45b. A larger amount of fuel that has flowed into the swirl application chamber 46 can flow toward the side wall 46a than the injection hole 44 side of the swirl application chamber 46. Accordingly, the fuel can sufficiently swirl in the swirl imparting chamber 46, and a strong swirling force can be imparted to the fuel.

Further, since the shallow groove portion 45d is on the second side surface 45b side, the fuel that has passed through the communication passage 45 can be prevented from flowing directly to the injection hole 44, and fuel with weak turning force is injected from the injection hole 44. Can be suppressed.
Further, in the fuel injection valve 1 of the first embodiment, the deep groove portion 45c of the communication passage 45 is formed so as to become gradually shallower toward the swirl application chamber 46.
Therefore, an upward component (a component in a direction away from the bottom of the swirl application chamber 46) can be applied in the direction of the flow rate of the fuel flowing into the swirl application chamber 46, so that the fuel is injected at the bottom of the swirl application chamber 46. It tends to flow away from the hole 44. Therefore, the swirl force can be sufficiently imparted to the fuel in the swirl imparting chamber 46 before the fuel enters the injection hole 44.

Further, in the fuel injection valve 1 of the first embodiment, the shallow groove portion 45d of the communication passage 45 is formed so as to gradually become deeper toward the deep groove portion 45c.
Therefore, the change in the flow direction of the fuel in the width direction in the communication passage 45 can be gradually changed toward the deep groove portion 45c, and a sudden change in the flow direction of the fuel in the communication passage 45 can be suppressed. Generation of turbulent flow can be suppressed.
In the fuel injection valve 1 of the first embodiment, the swirl imparting chamber 46 is continuously connected to the deep groove portion 45c and the shallow groove portion 45d of the communication passage 45, and the swirl groove 46b is formed along the side wall 46a of the swirl impart chamber 46.
Therefore, the flow rate of the fuel radially outside the swirl direction of the fuel in the swirl chamber 46 can be made larger than the flow rate of the fuel radially inside the swirl direction of the fuel. Accordingly, the fuel can sufficiently swirl in the swirl imparting chamber 46, and a strong swirling force can be imparted to the fuel.
Further, in the fuel injection valve 1 according to the first embodiment, the depth of the swivel groove 46b is formed so as to gradually become shallower as it goes deeper into the swirl application chamber 46.
Therefore, an upward component can be given in the direction of the flow velocity of the fuel flowing into the swirl imparting chamber 46, so that the fuel tends to flow away from the injection hole 44 formed at the bottom of the swirl imparting chamber 46. Therefore, the swirl force can be sufficiently imparted to the fuel in the swirl imparting chamber 46 before the fuel enters the injection hole 44.

[effect]
The effects of the fuel injection valve 1 of the first embodiment are listed below.
(1) A valve body 4 provided slidably, a valve seat 6 on which the valve body 4 sits when the valve is closed, and a valve seat member 7 having a downstream opening 48 on the downstream side, and a valve seat member 7 is connected to the downstream opening 48 of the central chamber 42 having a cylindrical inner surface, and is formed on the downstream side of the central chamber 42, and has a cylindrical side wall 46a. The swirl application chamber 46 for applying force, the injection hole 44 formed in a cylindrical shape at the bottom of the swirl application chamber 46 and penetrating to the outside, and connected to the swirl application chamber 46 in the tangential direction of the swirl application chamber 46, In the fuel injection valve 1 provided with the communication passage 45 that communicates the swirl application chamber 46 and the central chamber 42, the side surface of the communication passage 45 that is radially outward with respect to the direction in which the fuel swirls in the swirl application chamber 46 The first side surface 45a is the side of the communication passage 45 that is radially inward with respect to the direction in which the fuel swirls in the swirl chamber 46. Is the second side surface 45b, the communication path 45 on the first side surface 45a side is the deep groove part 45c, the communication path 45 on the second side surface 45b side is the shallow groove part 45d, and the depth of the deep groove part 45c is the shallow groove part 45d. It was formed to be deeper than the depth of.
Therefore, the flow rate of the fuel on the first side surface 45a side can be made larger than the flow rate of the fuel on the second side surface 45b side. Accordingly, the fuel can sufficiently swirl in the swirl imparting chamber 46, and a strong swirling force can be imparted to the fuel.
Further, since the shallow groove portion 45d is on the second side surface 45b side, the fuel that has passed through the communication passage 45 can be prevented from flowing directly to the injection hole 44, and fuel with weak turning force is injected from the injection hole 44. Can be suppressed.

(2) The deep groove 45c of the communication passage 45 is formed so as to become gradually shallower toward the swirl imparting chamber 46.
Therefore, an upward component (a component in a direction away from the bottom of the swirl application chamber 46) can be applied in the direction of the flow rate of the fuel flowing into the swirl application chamber 46, so that the fuel is injected at the bottom of the swirl application chamber 46. It tends to flow away from the hole 44. Therefore, the swirl force can be sufficiently imparted to the fuel in the swirl imparting chamber 46 before the fuel enters the injection hole 44.
(3) The shallow groove portion 45d of the communication path 45 is formed so as to gradually become deeper toward the deep groove portion 45c.
Therefore, the change in the fuel flow direction in the width direction in the communication passage 45 can be gradually changed toward the deep groove portion 45c, and a sudden change in the fuel flow direction in the communication passage 45 is suppressed, and turbulence is generated. Can be suppressed.

(4) The swirl imparting chamber 46 is continuously connected to the deep groove portion 45c and the shallow groove portion 45d of the communication passage 45, and the swirl groove 46b is formed along the side wall 46a of the swirl impart chamber 46.
Therefore, the flow rate of the fuel radially outside the swirl direction of the fuel in the swirl chamber 46 can be made larger than the flow rate of the fuel radially inside the swirl direction of the fuel. Accordingly, the fuel can sufficiently swirl in the swirl imparting chamber 46, and a strong swirling force can be imparted to the fuel.
(5) The depth of the swirling groove 46b of the swirl imparting chamber 46 is formed so as to gradually become shallower as it goes deeper into the swirl imparting chamber 46.
Therefore, an upward component can be given in the direction of the flow velocity of the fuel flowing into the swirl imparting chamber 46, so that the fuel tends to flow away from the injection hole 44 formed at the bottom of the swirl imparting chamber 46. Therefore, the swirl force can be sufficiently imparted to the fuel in the swirl imparting chamber 46 before the fuel enters the injection hole 44.

[Other Examples]
As described above, the present invention has been described based on the first embodiment. However, the specific configuration of each invention is not limited to each embodiment, and even if there is a design change or the like without departing from the gist of the invention. Are included in the present invention.
In the fuel injection valve 1 of the first embodiment, three swirl chambers 41 are formed, but the number of swirl chambers 41 may be changed as appropriate according to the design of the fuel injection amount.
In the fuel injection valve 1 of the first embodiment, the injection hole 44 is formed concentrically with the side wall 46a of the swirl application chamber 46. However, the injection hole 44 may be disposed at a different position as long as it is the bottom of the swirl application chamber 46. good.
In the fuel injection valve 1 of the first embodiment, the swirl chamber 46 is formed in a circular concave shape, but the outer peripheral shape may be a spiral shape, an involute curve shape, or the like.

1 Fuel injection valve
4 Disc
6 Valve seat
7 Valve seat member
8 Nozzle plate
41 Swirl room
42 Central room
44 injection hole
45 passage
45a 1st side
45b Second side
45c Deep groove
45d shallow groove
46 Swirl grant room
46a Side wall
46b Swivel groove
48 Downstream opening

Claims (3)

A valve body slidably provided;
A valve seat on which the valve body sits when the valve is closed, and a valve seat member having an opening on the downstream side;
A central chamber communicating with the opening of the valve seat member and having a cylindrical inner surface;
A swirl imparting chamber that is formed on the downstream side of the central chamber, has a cylindrical inner surface, and swirls fuel to impart a swirl force;
An injection hole formed in a cylindrical shape at the bottom of the swirl application chamber and penetrating to the outside;
The communication path connecting the swirl application chamber and the central chamber with the swirl application chamber in the tangential direction of the swirl application chamber,
In a fuel injection valve equipped with
A side surface of the communication path that is radially outward with respect to the direction in which the fuel swirls in the swirl chamber is a first side surface, and a side surface of the communication path that is radially inward with respect to the direction in which the fuel is swirled in the swirl chamber. Is the second side surface, the communication path on the first side surface side is a deep groove part, the communication path on the second side surface side is a shallow groove part, and the depth of the deep groove part is greater than the depth of the shallow groove part. To form deeper ,
The swirl application chamber is connected continuously to the deep groove portion and the shallow groove portion of the communication path, and has a swirl groove formed along a side wall of the swirl application chamber,
The fuel injection valve characterized in that the swivel groove is formed such that the depth of the swirl groove gradually becomes shallower as it goes deeper into the swirl chamber . The fuel injection valve according to claim 1, wherein
The fuel injection valve, wherein the deep groove portion is formed so as to gradually become shallower toward the swirl application chamber. The fuel injection valve according to claim 1 or 2,
The fuel injection valve, wherein the shallow groove portion is formed so as to gradually become deeper toward the deep groove portion.

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