JPH04295175A - Fuel injection nozzle - Google Patents

Abstract

PURPOSE:To perform excellent mixture of fuel and intake air by forming spray, formed in the shape of a fan in a vertical and a lateral direction, in any direction. CONSTITUTION:Four sets of adjoining injection nozzles 24a and 24b of a plurality of injection nozzles 24 communicated to a fuel inflow passage 21 are peripherally formed in an axially aligned state in a lower end part 23 of a poppet valve 22 having a fuel inflow passage 21 and slidably located on a nozzle body 26. The two injection nozzles 24a and 24b are inclined so that they cross each other in an opening position 25 opened and closed through slide of the poppet valve 22. This constitution forms horizontally flat spray L1 in all directions, promotes mixture with air through squish, and achieves uniform and excellent combustion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection nozzle for injecting fuel into a combustion chamber of an internal combustion engine.

0002

2. Description of the Related Art Various types of fuel injection nozzles have been proposed as devices for appropriately injecting fuel into the combustion chamber of a diesel engine or the like.

Among these, a Junkers type nozzle as shown in FIGS. 11 and 12 is known as a single-hole fuel injection nozzle. The fuel is guided to a nozzle hole 4 formed at the lower end of the nozzle body 3 to form a fuel spray L that is jetted downward. That is, by colliding fuel from two directions, a flat fan-shaped spray L is formed.

As a multi-hole fuel injection nozzle, there is a poppet valve type nozzle as shown in FIG. This injection nozzle includes a nozzle body 12 attached to a holder 11.
and a poppet valve 13 provided slidably in the axial direction within the nozzle body 12, and a plurality of nozzle holes 15 are formed at the tip of the poppet valve 13 in communication with a fuel inflow path 14. A piston 16 that engages with the upper end of the poppet valve 13 when fuel is fed under pressure from the fuel inlet passage 14
is pushed and the poppet valve 13 moves downward against the spring 17, thereby opening the nozzle hole 15 and injecting fuel through the gap with the nozzle body 12. The shape of the spray M from this nozzle is conical.

[0005]

[Problem to be solved by the invention] In order to obtain good combustion, the spray must be distributed evenly in all directions.
It is necessary to promote mixing with the air taken into the combustion chamber. For this purpose, the fan-shaped spray L of the Junkers type nozzle described above is preferable as the spray shape, but since it has a single hole, it is difficult to distribute the spray uniformly within the combustion chamber. Furthermore, although the above-mentioned poppet valve type nozzle forms the spray M in any direction, since it is cone-shaped, there is a problem in terms of diffusion.

[0006] Therefore, a configuration that can form fan-shaped spray radially is most desirable, but in order to achieve more uniform mixing, it is required to be able to appropriately combine vertical and horizontal fan-shaped patterns.

In view of the above circumstances, the present invention was devised to provide a fuel injection nozzle that can form vertical and horizontal fan-shaped sprays in any direction.

[0008] As a prior art to be compared with the present invention,
"Hole-type injection nozzle for diesel engines" (1986)
-88074). In this proposal, nozzle holes that are opened and closed by needle valves are formed at the tip of the nozzle body so as to intersect in the circumferential direction at the outlet, thereby creating a fan-shaped spray that spreads in the axial direction. However, with this proposal, it is difficult to form a fan-shaped spray that spreads horizontally. That is, if an attempt is made to form nozzle holes that intersect in the axial direction for this purpose, the seat surface between the needle valve and the nozzle body becomes large, and there is a concern about fuel sealing performance. Therefore, it is considered that the combination of fan-shaped spray is insufficient to achieve mixing with air.

[0009]

[Means for Solving the Problems] The present invention provides a poppet valve having a fuel inflow channel and a poppet valve that is slidably provided in a nozzle body. These two nozzle holes are arranged around the axial or circumferential direction, and are formed so that these two nozzle holes intersect at the opening position opened and closed by the sliding of the poppet valve, or at a radially outward position thereof. be.

0010

[Operation] With the above structure, the two nozzle holes that intersect in the axial direction open when the poppet valve slides to form a fan-shaped spray that spreads horizontally. Furthermore, the two nozzle holes that intersect in the circumferential direction form a fan-shaped spray that spreads in the axial direction. These fan-shaped sprays are appropriately combined and mixed with the air in the combustion chamber.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show a first embodiment of a fuel injection nozzle according to the present invention.

This fuel injection nozzle has a fuel inlet passage 21 at a lower end 23 of a poppet valve 22 having a fuel inlet passage 21.
Adjacent two of the plurality of nozzle holes 24 communicating with the
24b are aligned in the axial direction and arranged around the periphery, and these two nozzle holes 24a, 24b are formed to intersect at an opening position 25 which is opened and closed by sliding of the poppet valve 22.

The poppet valve 22 is slidably accommodated in an axial hole 27 formed in a nozzle body 26, and has a fuel inlet passage 21 extending along the axial center formed therein.

A head 29 is formed at the lower end 23 of the poppet valve 22 and is appropriately bulged out from the stem 28 above, and the upper surface 30 is connected to the lower end 31 of the nozzle body 26.
It is designed to be seated and engaged. The opening position 25 of the nozzle hole 24 is formed in the stem portion 28 directly above the head 29. Therefore, when the poppet valve 22 is relatively moved downward, the head 29 separates from the lower end 31 of the nozzle body 26, so that the stem portion 28 directly above it is exposed, and the nozzle hole 24 is substantially closed. It is designed to be opened.

The nozzle holes 24 are arranged radially around the nozzle 24 in a total of four sets of two, spaced at equal intervals. Of the nozzle holes in each set, the upper nozzle holes 24a are inclined downward, and the lower nozzle holes 24b are inclined upward, so that they are formed in a horizontal V-shape when viewed in longitudinal section. In this embodiment, these nozzle holes 24
The inclination of the spray L1 is set so that the spray L1 that is formed has a slightly downward fan shape with a central angle of about 90 degrees in plan view.

Next, the operation of the embodiment will be explained.

When fuel at a predetermined pressure is supplied to the fuel inlet passage 21, the poppet valve 22 slides downward against a spring (not shown). Due to this sliding, the head 29 is separated from the lower end 31 of the nozzle body 26, and the nozzle holes 24a of each set are separated.
, 24b are opened. Then, the fuel flows through the fuel inflow path 21
When ejecting from the nozzle holes 24a and 24b at the opening position 25, it is collided in two directions, up and down.
As shown in FIG. 2, a fan-shaped spray L1 that is flat in the horizontal direction
The shape will be .

In the combustion chamber (not shown) to which this spray L1 is supplied, the spray L1 and intake air are mixed due to air turbulence such as squish formed in the compression stroke and swirl formed in the intake stroke. is promoted and burned.

In this way, the lower end 23 of the poppet valve 22
Two adjacent nozzle holes 24a, 24b of the plurality of nozzle holes 24 are aligned in the axial direction and provided around the circumference, and these two nozzle holes 24a, 24
b are formed to intersect at the opening position 25, a horizontally flat fan-shaped spray L1 is obtained, and compared to the cone-shaped spray of a conventional poppet valve nozzle, the fuel distribution is extremely uniform, especially when squishing. Mixing with intake air is promoted, resulting in good combustion. Furthermore, since the nozzle holes 24 are opened and closed by the sliding of the poppet valve 22, even if the nozzle holes 24 are arranged in the axial direction as in this embodiment, the valves will not work like a hole-type nozzle with a needle valve. There are no concerns about the sealing performance of the seat surface.

Since the four sets of nozzle holes 24 are formed facing in all directions, a more uniform fuel distribution can be achieved compared to the conventional single-hole Junkers type nozzle.

Furthermore, by changing the inclination and crossing angle of the two nozzle holes 24a and 24b, the thickness, spread angle (center angle), etc. of the fan-shaped spray L1 can be appropriately selected.

The point where the axes of the nozzle holes 24a and 24b intersect is not limited to the position on the outer surface of the poppet valve 22, but may be located radially outward in the vicinity thereof.

3 and 4 show a second embodiment of the present invention, in which two adjacent nozzle holes 43a, 43b are arranged in four sets in the circumferential direction at the lower end 42 of a poppet valve 41. They are aligned and formed to intersect at the opening position 44. That is, the nozzle holes 43a, 43b of each set are inclined so as to approach each other as they go radially outward. Therefore, the spray L2 has a fan shape that is flat in the axial direction (vertical direction), and in this embodiment, it has a shape that extends approximately 60 degrees when viewed from the side. With this configuration, the fuel is sufficiently diffused in the axial direction within the combustion chamber, and is easily evenly distributed and mixed by the swirl, which is air turbulence in the circumferential direction, contributing to good combustion.

Other structures and functions are the same as those of the first embodiment, so the same reference numerals are used and explanations thereof will be omitted.

Next, a third embodiment of the present invention will be described with reference to FIGS. 5 and 6.

In this embodiment, the nozzle holes 24 and 43 of the first and second embodiments are provided together, and the nozzle holes 24a intersect with each other in the axial direction at the lower end 52 of the poppet valve 51.
, 24b and nozzle holes 43a, 43b intersecting in the circumferential direction, two sets each, a total of four sets, are arranged alternately and at equal intervals.

[0028] With this configuration, the flat fan-shaped sprays L1 and L2 are distributed vertically and horizontally, and the fuel and intake air are well mixed due to air turbulence such as squish and swirl. Uniform and good combustion is achieved. The other configurations and operations are the same as those of the previous embodiment.

Furthermore, in the above embodiment, the intersecting nozzle holes 24
, 43 is shown, but the fuel injection nozzle may be arranged in parallel with a conventional nozzle hole. For example, as shown in FIGS. 7 and 8, the lower end 62 of the poppet valve 61 includes a nozzle hole 63 that forms a cone-shaped spray M, and nozzle holes 24a and 24b that form a fan-shaped spray L1 that spreads in the horizontal direction. Alternatively, as shown in FIGS. 9 and 10, a cone-shaped spray M is provided at the lower end 72 of the poppet valve 71.
and a fan-shaped spray L2 that spreads in the axial direction.
A possible configuration is such that the nozzle holes 43a and 43b forming the nozzle holes 43a and 43b are arranged alternately around the circumference.

These modified embodiments also provide a more uniform fuel distribution than conventional poppet valve type nozzles or Junkers type nozzles. Other configurations and effects are the same as those in the first to third embodiments, so the same reference numerals are given and explanations are omitted.

[0031]

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

[0032] At the lower end of the poppet valve, which has a fuel inflow path and is slidably provided on the nozzle body, two adjacent nozzle holes communicating with the fuel inflow path are installed in the axial or circumferential direction. These two nozzle holes are aligned and arranged so that they intersect at the opening position opened and closed by the sliding of the poppet valve or at the radially outward position of the opening position, so that a fan-shaped spray that spreads horizontally or vertically is generated. It will be formed in the desired direction,
Mixing with air is promoted to achieve uniform and good combustion.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a fuel injection nozzle according to the present invention.

FIG. 2 is a sectional view taken along line A-A in FIG. 1;

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB in FIG. 3;

FIG. 5 is a cross-sectional view showing a third embodiment of the present invention.

6 is a sectional view taken along the line CC in FIG. 5. FIG.

FIG. 7 is a cross-sectional view showing a modified embodiment of the present invention.

8 is a sectional view taken along the line DD in FIG. 7; FIG.

FIG. 9 is a cross-sectional view showing another modified embodiment of the present invention.

FIG. 10 is a sectional view taken along the line E-E in FIG. 9;

FIG. 11 is a longitudinal sectional view showing a Junkers type nozzle, which is a conventional fuel injection nozzle.

FIG. 12 is a view taken along line FF in FIG. 11;

FIG. 13 is a longitudinal sectional view showing a poppet valve type nozzle which is another conventional fuel injection nozzle.

[Explanation of symbols]

21 Fuel inflow path 22 Poppet valve 23 Lower end portions 24a, 24b Two adjacent nozzle holes 25 Opening position

Claims (1)

[Claims] Claim 1: At the lower end of a poppet valve having a fuel inlet passage and slidably provided in a nozzle body, two adjacent nozzle holes of a plurality of nozzle holes communicating with the fuel inlet passage are connected in an axial direction or A fuel injection nozzle characterized in that the two nozzle holes are aligned in the circumferential direction and are formed so that these two injection holes intersect at an opening position opened and closed by sliding of the poppet valve or at a position radially outward thereof. .