JP2000038974A - Fluid injection nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid injection nozzle capable of injecting fluid uniformly in a wide range with its configuration made simple. SOLUTION: Six injection holes 15a are formed over an injection plate 15 in such a way as to be disposed to the identical circumference around the axial line of a needle valve 20. Each injection hole 15a is formed up while being inclined by a different angle with respect to the axial line of a fuel injection valve, and as the whole, the injection holes are directed to the direction inclined with respect to the axial line of the fuel injection valve. Here in this place, the thickness of the injection hole plate is t, the diameter of each injection hole 15a is d, and the widening angle of a spray injected out of each injection hole is ω. In this case, if t/d is changed, the value of ω is increased to the extent that sprays injected out of the respective injection holes 15a are overlapped with one another in a range of t/d<=1.5. At this point, the sprays of fuel are formed into a hollow circular shape in the cross section of the whole of the sprays. Therefore, atomized fuel can thereby be uniformly injected in a wide range without providing a mechanism forming a revolving flow with its configuration simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid ejection nozzle for ejecting a fluid over a wide range.

[0002]

2. Description of the Related Art For example, in a fuel injection valve for injecting fuel into a cylinder of an engine, fuel injected from an injection hole of a fuel injection nozzle is reduced in view of reduction of fuel consumption and reduction of harmful substances in exhaust gas. It is important to atomize. Further, in the case of a fuel injection valve for an in-cylinder direct injection type engine, it is necessary to diffuse the fuel injected from the injection hole into the combustion chamber of each cylinder immediately below the injection hole, so it is important to increase the spray angle.

[0003] For example, a valve member for opening and closing the injection hole is provided on the upstream side of the injection hole, and a separate member is provided, and a through hole is formed in the separate member in a direction intersecting the axis of the fuel injection valve, thereby forming an injection hole. 2. Description of the Related Art There is known a fuel injection valve that forms a swirl flow in an inflowing fuel flow and enlarges a spray angle by using centrifugal force of the swirl flow. The member that forms the swirling flow may be formed integrally with the valve member.

[0004]

However, if a mechanism for forming a swirling flow is provided separately or integrally with the valve member on the upstream side of the injection hole, the structure of the fuel injection nozzle in the fuel injection valve is complicated. There's a problem.

An object of the present invention is to provide a fluid ejecting nozzle which ejects a fluid uniformly over a wide range with a simple structure.

[0006]

According to a first aspect of the present invention, there is provided a fluid injection nozzle, wherein the injection hole plate is provided with a plurality of injection holes penetrating the injection hole plate in the thickness direction. Is t and the diameter of the injection hole is d, t / d ≦ 1.5
It is. As a result, the spray angle of the fluid ejected from each injection hole is increased, so that even if the angle of inclination of each injection hole is adjusted and the entire spray angle of the spray injected from the plurality of injection holes is increased, each of the injection angles is different from each injection hole. The spray that is sprayed is connected. Therefore, by adjusting the plate thickness of the injection hole plate and the diameter of each injection hole, a fluid can be injected uniformly over a wide area with a simple configuration without providing a member that forms a swirling flow separately from or integrally with the valve member. it can.

[0007] When the pressure p of the fluid injected from the injection hole is high, the fluid spray is atomized. Further, when four or more injection holes are formed, fluid sprays ejected from each injection hole are easily connected. Therefore, the fluid is sprayed uniformly over a wide area.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 shows a fuel injection valve using a fluid injection nozzle according to one embodiment of the present invention. The fuel injection valve 10 shown in FIG. 1 is fitted to a mounting hole of the engine head by screwing a cylinder screw 50 as a mounting member to the engine head.

A housing 11 of the fuel injection valve 10 and a valve body 13 are connected by a retaining nut 12 with a spacer 14 interposed therebetween. The needle valve 20 as a valve member is housed in the valve body 13 so as to be able to reciprocate.
The distal end surface 20a of the needle valve 20 is formed flat as shown in FIG. 1, and the distal end surface 20a and the injection hole plate 15 form a disk-shaped fuel chamber 40. The valve body 13, the injection hole plate 15, and the needle valve 20 constitute a fuel injection nozzle as a fluid injection nozzle.

The injection hole plate 15 is welded to the valve body 13, and as shown in FIG. 1, six injection holes 15a are formed on the same circumference having a diameter of 0.6 mm with respect to the axis of the needle valve 20.
Are formed. The diameter d of each injection hole 15a is 0.2 mm. The contact portion 20b is formed in a tapered shape at the tip of the needle valve 20 on the injection hole side, and the contact portion 20b is formed in the valve seat 13a.
The fuel is injected from the injection hole 15a by being separated from the nozzle.

The injection holes 15a are formed at different angles with respect to the axis of the fuel injection valve 10, and are generally inclined with respect to the axis of the fuel injection valve 10, in this embodiment, in FIG. It faces the direction inclined to the right. The cap 16 covers the outer periphery of the injection hole plate 15.

The injection hole 15a is formed so as to be directed in a direction inclined as a whole with respect to the axis of the fuel injection valve 10. The in-cylinder direct injection engine as in this embodiment for directly injecting fuel into the cylinder of the engine. In this case, the fuel is injected in a predetermined direction in the cylinder even if the mounting direction of the fuel injection valve is limited.

The movable core 30 is fixed to the end of the needle valve 20 opposite to the injection hole by laser welding or the like. Fixed core 31
Is disposed on the inner periphery of the housing 11 so as to face the movable core 30 in the axial direction. The fixed core 31 is fixed to the end of the housing 11 on the side opposite to the injection hole by laser welding or the like. The spring 21 urges the movable core 30 in the injection hole closing direction, and the urging force of the spring 21 is set by adjusting the axial position of the adjusting pipe 22 when the fuel injection valve 10 is assembled. FIG. 2 of the fixed core 31
The fuel that has flowed in from the upper opening in the above is removed by a filter 23 from foreign matter in the fuel, and is introduced into the fuel injection valve 10.

The coil 32 is wound around a spool 33 and disposed between the housing 11 and the fixed core 31 in the radial direction. The connector 35 is resin-molded on the housing 11 and the fixed core 31. A power receiving pin 36 attached to the connector 35 is electrically connected to the coil 32 and supplies power to the coil 32.

When the power to the coil 32 is turned off, the spring 2
Since the needle valve 20 is seated on the valve seat 13a and closes the injection hole 15a by the urging force of 1, the fuel injection is not performed from the injection hole 15a. When energization of the coil 32 is turned on, the movable core 30 is attracted to the fixed core 31 side against the urging force of the spring 21 due to the magnetic force generated in the coil 32. At this time, the needle valve 20 is lifted together with the movable core 30 and the needle valve 20 is separated from the valve seat 13a.
Fuel is injected from 5a.

Next, the number of the injection holes 15a is 6, the thickness of the injection hole plate 15 is t, the diameter d of the injection holes 15a is 0.2 mm, and as shown in FIG. FIG. 3B shows the relationship between t / d and ω when the spread angle of the spray injected is ω and the plate thickness t is changed in the range of 0.1 to 1.2 mm. The fuel injection pressure p is set to 12 MPa, and the spread angle of the entire spray injected from the six injection holes 15a is set to 30 to 35 °.

As can be seen from FIG. 3B, t / d is 2
Ω rapidly increases from the point where it becomes smaller. At t / d = 1.5, ω = 13 °, and at this time, the sprays sprayed from the respective injection holes 15a are respectively connected,
A hollow circular fuel spray is formed in the cross section of the entire spray.
FIG. 4 shows a schematic shape of the entire spray at t / d = 1.5 and ω = 13 °. The spread angle θ of the entire spray shown in FIG. 4A is θ = 35 °. FIG. 4B shows a schematic cross-sectional shape of the entire spray at a position at a distance L = 40 mm from the fuel injection valve 10.

In the above embodiment showing the embodiment of the present invention described above, the plate thickness t of the injection hole plate 15 and the injection hole 15a
By adjusting the diameter d, atomized fuel can be uniformly injected over a wide range with a simple configuration without providing a mechanism for forming a swirling flow. Therefore, in the in-cylinder direct injection type engine of this embodiment, fuel consumption can be reduced, and harmful substances in exhaust gas can be reduced.

In the above embodiment, the fuel injection pressure p is set to 12MP.
However, if the pressure is set within a range of 5 MPa ≦ p ≦ 20 MPa, the spray injected from each injection hole is connected, and the fuel spray becomes a hollow circular fuel spray in the cross section of the entire spray.

If the number of injection holes is four or more, the spray injected from each injection hole is connected to form a fuel spray having a hollow circular shape as a whole. By adjusting the angle of inclination of the injection hole, it is also possible to form a solid circular spray in the cross section of the entire spray.

In the above embodiment, the fluid injection nozzle of the present invention is applied to the fuel injection nozzle of the fuel injection valve. However, the present invention is applicable to any type of fluid injection nozzle as long as the fluid is injected uniformly over a wide range. May be.

[Brief description of the drawings]

FIG. 1A is a schematic sectional view showing a fuel injection nozzle according to one embodiment of the present invention, and FIG. 1B is a plan view of an injection hole plate viewed from a fuel upstream side.

FIG. 2 is a sectional view showing a fuel injection valve according to one embodiment of the present invention.

FIG. 3A is a schematic diagram showing a spray shape according to the present embodiment, and FIG. 3B is a diagram showing the spraying spread and t / d when the plate thickness of the injection hole plate is t and the diameter of the injection hole is d. FIG. 9 is a characteristic diagram illustrating a relationship with an angle ω.

FIG. 4A is a schematic front view showing the overall shape of the spray according to the present embodiment, and FIG. 4B is a cross-sectional view taken along line BB of FIG.

[Explanation of symbols]

Reference Signs List 10 fuel injection valve 11 housing 13 valve body (fluid injection nozzle) 13a valve seat 15 injection hole plate (fluid injection nozzle) 15a injection hole 20 needle valve (valve member, fluid injection nozzle)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G066 AA02 AB02 AD12 BA03 BA17 BA23 CC06U CC14 CC20 CC24 CC27 CC48 CC57 CD29 CD30 CE22

Claims (1)

[Claims] A valve body provided with a valve seat on an inner wall surface forming a fluid passage; a valve member for opening and closing the fluid passage by detaching from the valve seat and seating on the valve seat; An injection hole plate which is disposed downstream of the fluid and has a plurality of injection holes penetrating in the plate thickness direction. When the plate thickness of the injection hole plate is t and the diameter of the injection hole is d, t / d ≦ 1.5, and the fluid pressure p injected from the injection hole is 5 MPa ≦ p ≦
20 MPa, the number of the injection holes is 4 or more, and the cross-sectional shape of the fluid spray injected from each of the plurality of injection holes is a hollow circular shape or a solid circular shape as a whole. Fluid injection nozzle.