JP3817931B2 - Fluid injection valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid injection valve that injects and supplies liquid fuel such as gasoline as a spray.
[0002]
[Prior art]
Conventionally, as a fluid injection valve, for example, a fuel injection valve (Japanese Patent Laid-Open No. 3-78562, Japanese Patent Laid-Open No. 9-158736) has a slit-like fuel injection hole O at a small diameter tip T of a valve body B as shown in FIG. By forming in the direction, the fuel spray pattern was flattened, and the entire spray was easy to come into contact with air, and a relatively homogeneous spray was obtained.
[0003]
[Problems to be solved by the invention]
In the conventional fuel injection valve, both the spray angle and the injection amount are defined by the slit-like injection hole O. Therefore, when one is adjusted, the other also changes accordingly. There was a problem.
[0004]
In addition, since the conventional fuel injection valve is formed with the slit-shaped injection hole O at the small-diameter tip portion T of the valve body B, it is difficult to process the slit-shaped injection hole O and the productivity is not good. At the same time, since the size of the slit-shaped injection hole O strongly affects the spray shape, there is a problem that the required accuracy for processing is strict and is not suitable for mass production.
[0005]
Further, in the conventional fuel injection valve, since the injected fuel passes through the narrow space S and then flows into the wide slit-shaped nozzle hole O, only the central portion of the slit-shaped nozzle hole O is present. Therefore, the fuel stays at both ends in the longitudinal direction of the slit-like injection hole O, and this staying fuel becomes a deposit and accumulates in the injection hole O, and the shape of the spray is formed by the deposited deposit. There was a problem of changing.
[0006]
Therefore, the present inventor has provided a nozzle hole formed at the tip of the injection valve, a fluid supply passage provided inside the injection valve main body for supplying a fluid upstream of the nozzle hole, and between the nozzle hole upstream and the fluid supply passage. Whether the cross-sectional area of the communication path in the vicinity of one direction orthogonal to the axis of the injection valve is smaller than the cross-sectional area of the communication path in other regions. By adopting a configuration in which the communication passage is not provided, the flow of fuel from the communication passage is collided, and a flow force that spreads in a direction orthogonal to the collision portion is applied, so that the fan hole extends from the injection hole. Focusing on the technical idea of the present invention to inject fluid spray, and as a result of further research and development, it achieved a good flat fan-shaped spray pattern, suppressed deposit adhesion to the injection hole, Make manufacturing easier It has reached the present invention which achieves the goal.
[0007]
[Means for Solving the Problems]
The fluid injection valve of the present invention (the first invention described in claim 1) is a fluid supply that is provided inside the injection valve main body and supplies fluid upstream of the injection hole. A fluid injection valve having a passage and a needle that opens and closes a communication passage between the upstream of the injection hole and the fluid supply passage, and the cross-sectional area of the communication passage on the vicinity of one direction substantially orthogonal to the axis of the injection valve Or smaller than the cross-sectional area of the communication path in the region of or without providing a communication path ,
The communication passages are formed on a straight line facing each other and perpendicular to the longitudinal direction of the slit-shaped nozzle hole .
[0008]
(Operation of the invention)
In the fluid injection valve of the present invention having the above-described configuration, the fuel that has exited from the communication path formed on a straight line that is opposed to each other and orthogonal to the longitudinal direction of the slit-shaped nozzle hole as the needle rises is The fluid from the communication path that collides after flowing along the tip of the needle, branches off to the left and right and below along the outer peripheral wall of the needle, and expands in the longitudinal direction of the slit-shaped nozzle hole. The fluid spray which spreads in the shape of a fan from the said injection hole is given by giving the distribution force which spreads in the direction orthogonal to the said collision site | part, and is made to collide.
[0009]
That is, the fluid injection valve of the present invention has a configuration in which the fluid flow is increased in the direction in which it is desired to flatten the fluid spray, or the fluid passage itself is not provided, thereby suppressing the fluid inflow upstream of the nozzle hole. Inflow of fluid in the direction in which the spray is desired to be flattened is suppressed and extremely eliminated. Then, this direction is the direction with the smallest resistance for the fluid flowing in from the fluid passage, and the fluid flows positively in this direction, so that sufficient fluid is supplied in the flat direction.
[0010]
【The invention's effect】
The fluid injection valve of the present invention that exhibits the above-described action is a fluid spray that collides with a flow of fluid from the communication passage that extends in the longitudinal direction of the slit-shaped nozzle hole and spreads in a fan-shaped form from the slit-shaped nozzle hole. This produces an excellent flat fan-like spray pattern, suppresses deposit adhesion to the injection holes, and facilitates the manufacture of the injection valve.
[0011]
According to another invention (the second invention described in claim 2), in the fluid injection valve of the first invention, as shown in FIG. 1, the communication path is located in the vicinity of one direction orthogonal to the axis of the injection valve. Only provided.
[0012]
Further, according to another invention (third invention according to claim 3), in the injection valve of the first invention, as shown in FIGS. 2 and 3, only in the vicinity of one direction orthogonal to the axis of the injection valve, The communication path is not provided.
[0013]
Still another invention (the fourth invention according to claim 4) is the injection valve according to any one of the first to third inventions, wherein the injection hole has a lower end of the injection valve body with which the tip of the needle abuts. One direction perpendicular to the axis of the injection valve that is formed by a slit-shaped opening having a flat cross section formed in an orifice member that closes the circular opening of the conical surface and has a small cross-sectional area of the communication passage or no communication passage is provided. The slit-shaped longitudinal direction is positioned substantially in parallel.
[0014]
The fluid injection valves according to the second to fourth aspects of the invention exhibit substantially the same operational effects as the fluid injection valve of the first aspect of the invention.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0016]
(Embodiment)
A fuel injection valve as a fluid injection valve of the present embodiment is a fuel injection valve 1 for use in a direct injection gasoline engine, and is provided inside an injection valve main body 10 as shown in FIGS. A guide 2 for holding a body 3, an orifice member 4 provided at a tip of the injection valve body 10 and having an injection hole 41 extending in a radial direction of the injection valve body 10, and the injection valve body 10 and the guide 2 are formed so as to communicate with the injection hole 41 via the valve body 3 and collide with the flow of fuel flowing along the tip of the valve body 3 in the valve body axial direction. It consists of a plurality of opposed fuel passages 24 that apply a flow force that expands in the diameter direction of the injection holes that are orthogonal to each other.
[0017]
The fuel injection valve of the present embodiment is disposed in an internal combustion engine of a type in which liquid fuel such as gasoline is directly injected into a cylinder constituting a combustion chamber.
[0018]
The fuel injection valve 1 is constituted by a hollow cylindrical injection valve body 10 as shown in FIG. 4, and a conical surface 11 is formed on the inner wall of the lower end portion constituting the distal end portion of the injection valve body 1. A circular opening 12 is formed at the center of the lower end.
[0019]
As shown in FIGS. 4 to 7, the guide 2 has an outer diameter outer peripheral wall 21 inserted and fitted in the inner peripheral wall 13 of the injection valve main body 10 and the valve body is inserted in a reciprocating manner. The inner peripheral wall 22 is formed with a hollow cylindrical body 20, and a conical surface 23 that contacts the conical surface 11 of the injection valve body 10 is formed at the lower end.
[0020]
As shown in FIG. 5, the outer peripheral wall 21 of the guide 2 is formed in a bow shape on both sides, and two vertical fuel passages 25 are formed between the inner peripheral wall 13 of the injection valve body 10, Two fuel passages 24 are formed in a straight line so as to communicate with the vertical fuel passage 25 and face the conical surface 23.
[0021]
The valve body 3 is constituted by a needle 30 that is inserted in the inner peripheral wall 22 of the guide 2 so as to be able to reciprocate and that has a tip portion 31 in which two conical surfaces having different angles are formed at the tip.
[0022]
That is, the distal end portion 31 of the needle 30 is disposed below the two fuel passages 24 in a straight line formed so as to face the conical surface 23, and the inclination direction of the conical surface 23 of the fuel passage 24 is It is arrange | positioned so that the front-end | tip part 31 of the said needle 30 may be located on the extended line.
[0023]
As shown in FIGS. 4 and 8, the orifice member 4 is constituted by a disk-like member attached to the lower end of the injection valve body 10, and is formed in a straight line formed on the conical surface 23 of the guide 2. In addition, slit-like injection holes 41 whose longitudinal directions are perpendicular to the two fuel passages 24 are formed.
[0024]
The slit-shaped injection hole 41 is set to be smaller than the diameter of the circular opening 12 formed in the lower end central portion of the injection valve main body 10, and the tip end portion 31 of the valve body 3 A space 5 having a predetermined cross-sectional area and volume is formed between the orifice member 4 and the orifice member 4.
[0025]
Since the cross-sectional area of the space 5 and the cross-sectional area of the circular opening 12 formed at the center of the lower end of the injection valve body 1 are set sufficiently larger than the opening area of the slit-like injection hole 41 of the orifice member 4. The fuel from the fuel passage 24 is most narrowed in the slit-like injection hole 41, so that the fuel passes uniformly in the longitudinal direction of the slit-like injection hole 41.
[0026]
In the fuel injection valve of the present embodiment configured as described above, fuel is supplied from the upper part of the injection valve, and the two vertical parts formed between the guide 2 as the flow path guide and the injection valve body 10. It is guided along the fuel passage 25 to the tip of the injection valve.
[0027]
That is, the flow path guide 2 has the outer peripheral walls 21 on both sides in the left-right direction cut into a bow shape as shown in FIG. 5, and the fuel passage 24 is formed from both side planes from the center of the two cut surfaces. Is formed.
[0028]
As shown in FIG. 4, the flow path guide 2 is inserted into the distal end portion of the injection valve main body 10, and the conical surface 23 at the lower end of the flow path guide 2 and the conical surface 11 inside the injection valve front end are in close contact with each other. Therefore, the fuel guided to the tip of the injection valve main body 10 is introduced into the space 5 inside the tip of the injection valve through the two fuel passages 24 of the flow path guide 2.
[0029]
Since the fuel passages 24 are formed in a straight line so as to face each other, the fuel that has exited the fuel passages 24 flows along the tip of the valve body 3 and collides with it. It branches and expands to the left and right and downward along the outer peripheral wall of the tapered tip 31 and expands in the longitudinal direction of the injection hole 41 perpendicular to the valve body axial direction formed in the orifice member 4.
[0030]
In the injection valve according to the present embodiment, the nozzle hole 41 is formed in a slit-like elongated hole, so that the colliding fuel liquid spreads in the longitudinal direction of the nozzle hole 7 and is ejected as a fan-shaped spray.
[0031]
In the fuel injection valve of the present embodiment having the above-described effect, the flow of fuel flowing along the outer peripheral wall of the tapered distal end portion 31 of the valve body 3 is collided by the plurality of opposed fuel passages 24 and formed in the orifice member. A flow force that expands in the diameter direction of the injection holes perpendicular to the valve body axis direction is applied to inject fuel spray that spreads in a fan shape from the injection holes, realizing a good flat fan-shaped spray pattern The effect of doing.
[0032]
That is, the fuel passage 24 allows fuel to flow as two flows facing each other along the conical surface of the needle 30 in which the tip 31 is conical, and the conical surface of the tip 31 of the needle 30 The elongated hole is formed in the central portion of the orifice member 4 as a thin plate nozzle member that is formed so as to collide near the apex and is attached to the tip of the body as the injection valve body 10 on which the needle 30 slides. Since the injection hole 41 is opened, the fuel is spread in a fan shape, so that a good flat fan-shaped spray pattern is realized.
[0033]
Further, the fuel injection valve of the present embodiment allows the fuel to pass uniformly over the longitudinal direction of the slit-like injection holes 41 in order to realize a good flat fan-like spray pattern, so that deposits to the injection holes are not caused. In addition to suppressing adhesion, fuel stays at both ends in the longitudinal direction of the slit as in the past, and this staying fuel deposits and accumulates in the nozzle hole, and the shape of the spray changes due to this deposited deposit. It has the effect of eliminating the problem of being lost.
[0034]
That is, the cross-sectional area of the space 5 and the cross-sectional area of the circular opening 12 formed at the center of the lower end of the injection valve body 1 are set sufficiently larger than the opening area of the slit-like injection hole 41 of the orifice member 4. Therefore, the fuel from the fuel passage 24 is most narrowed in the slit-like injection hole 41, so that the fuel passes uniformly in the longitudinal direction of the slit-like injection hole 41. It suppresses adhesion of deposits, and suppresses changes in the shape of the spray due to the deposited deposits.
[0035]
Furthermore, the fuel injection valve of the present embodiment has an effect that the injection hole is a slit-like elongated hole having a simple shape, and thus is easier to process than a conventional slit nozzle.
[0036]
In addition, the fuel injection valve of the present embodiment can be welded to the nozzle tip by laser welding after the nozzle hole is manufactured by the orifice member 4 which is a thin plate member separate from the nozzle, so that the productivity is high. Play.
[0037]
Furthermore, in the fuel injection valve of the present embodiment, the fuel from the fuel passage 24 facing the fuel collides with the flow of the fuel flowing along the outer peripheral wall of the tapered tip 31 of the valve body 3, in the longitudinal direction of the injection hole. Since the fuel is uniformly expanded and introduced into the injection hole 41 and the fuel uniformly passes through the entire injection hole of the injection hole 41, there is no fuel retention portion. .
[0038]
The above-described embodiments have been illustrated for the purpose of explanation, and the present invention is not limited thereto. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the description of the drawings. Modifications and additions can be made without departing from the technical idea of the present invention.
[0039]
In the above-described embodiment, an example in which the spray holes are slit-like elongated holes has been described in order to realize a good flat fan-shaped spray pattern as an example. If it is a substantially circular hole having a shape or a predetermined diameter, the spread angle is slightly reduced, but a mode of forming a fan-shaped spray can be employed.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a communication path of a fluid injection valve of the present invention.
FIG. 2 is a schematic view showing a communication path of a fluid injection valve according to another invention.
FIG. 3 is a perspective view showing a communication path of a fluid injection valve according to another invention.
4 is a partial longitudinal sectional view taken along line IV-IV in FIG. 8 showing the tip of the fuel injection valve according to the embodiment of the present invention.
FIG. 5 is a bottom view showing a guide of the fuel injection valve of the present embodiment.
FIG. 6 is a longitudinal sectional view showing a guide of the present embodiment.
7 is a longitudinal sectional view taken along line VII-VII in FIG.
FIG. 8 is a bottom view showing the orifice member of the present embodiment.
FIG. 9 is a partial longitudinal sectional view showing a tip portion of a conventional fuel injection valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel injection valve 2 Guide 3 Valve body 4 Orifice member 10 Injection valve main body 24 Fuel passage 41 Injection hole

Claims (4)

An injection hole formed at the tip of the injection valve, a fluid supply passage provided inside the injection valve main body for supplying fluid upstream of the injection hole, and a communication passage between the upstream of the injection hole and the fluid supply passage are opened and closed. In a fluid injection valve having a needle, the cross-sectional area of the communication path in the vicinity of one direction substantially orthogonal to the axis of the injection valve is made smaller than the cross-sectional area of the communication path in other regions, or a communication path is provided. no and with,
The fluid injection valve according to claim 1, wherein the communication passages are formed on a straight line facing each other and orthogonal to the longitudinal direction of the slit-shaped nozzle hole . 2. The fluid injection valve according to claim 1, wherein the communication passage is provided only in the vicinity of one direction orthogonal to the axis of the injection valve. 2. The fluid injection valve according to claim 1, wherein no communication passage is provided only in the vicinity of one direction orthogonal to the axis of the injection valve. The fluid injection valve according to any one of claims 1 to 3,
The injection hole is configured by a slit-shaped opening having a flat cross section formed in an orifice member that closes a circular opening of a lower end conical surface of the injection valve body with which the tip of the needle abuts, and a cross-sectional area of the communication path is A fluid injection valve characterized in that a slit-shaped longitudinal direction is positioned substantially parallel to one direction orthogonal to the axis of the injection valve that is small or has no communication passage.

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