JPS6289590A - Manufacture of fuel jet nozzle - Google Patents

Abstract

PURPOSE:To manufacture a product having the high reliability at low cost by irradiating a laser beam, forming continuously plural minute holes in a prescribed special shape at the prescribed position of a nozzle base material, and also immersing it in an electrolyte. CONSTITUTION:The direction of the laser beam 1 is positioned so as to be opposed to the prescribed position of a nozzle base material 2, the minute hole 41 is pierced, and subsequently, the direction of the laser beam 1 is changed so as to be opposed to the prescribed position of the nozzle base material 2 being adjacent to its minute hole 41, and a minute hole 42 is pierced continuously. Thereafter. plural minute holes 41, 42, 43... are formed continuously in a prescribed shape. Also, said material is immersed in an electrolyte and a burr left between the minute holes is melted and removed. In this way, a nozzle having the excellent accuracy can be manufactured at the low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application In diesel engines, etc., the spray particles sprayed from the nozzle hole of the injection nozzle begin to disperse from the periphery due to air friction, and the entire spray particle has a diameter of about 2 to 50 μm. It is divided into particles, and the size becomes larger as you go from the tip to the root, and from the periphery to the center. However, while it is not necessarily bad for large particles to hit the hot piston and cylinder walls, incomplete combustion occurs when large particles adhere to the cooled walls, so it is important to make sure that the atomization is appropriate depending on the shape of the combustion chamber. The injection distance and spread angle were necessary.

Therefore, the appropriate atomization injection reach depending on the shape of the combustion chamber,
It has been desired to obtain a fuel injection nozzle that has a special shape to achieve a widening angle and also has a small hole diameter to reduce the size of the spray particles to prevent incomplete combustion.

The present invention relates to a method of manufacturing a fuel injection nozzle having a special injection hole shape.

Prior Art In the conventional manufacturing method of this type of fuel injection nozzle,
One round hole was drilled with a thin drill, and multiple round holes were drilled in N formations.

In addition, even if a special nozzle hole shape consisting of a series of micro holes is formed to achieve appropriate atomization depending on the shape of the combustion chamber, continuous micro holes cannot be machined with a drill. In some cases, electrical discharge machining was used for drilling, but this made the drilling operation difficult and could lead to large holes.

Problems to be solved by the invention By the way, the injection holes of the fuel injection nozzle are minute.
Its shape and area have a great influence on engine performance.
When drilling with a thin drill, the hole diameter often changed due to wear of the cutting edge, and in the case of one round hole, the hole diameter became large to provide the necessary fuel to the combustion chamber, resulting in large spray particles. Therefore, an attempt was made to obtain a specially shaped nozzle hole by electric discharge machining, but such a nozzle hole has an irregular shape and a large area, resulting in improper mixing of fuel and air. This resulted in a negative impact on engine performance. In addition, with special nozzle holes consisting of a series of microholes, burrs occur in the continuous part of the microholes, and even when drilling, burrs occur in the light passing through the nozzle hole, and the resulting burrs are used as is without processing. In this case, the shape changes due to wear of the burr over time, changing the characteristics, and as mentioned above, this has a negative effect on engine performance.

The present invention is a method for manufacturing a special nozzle hole shape that improves engine performance, and furthermore, allows quick and inexpensive processing to produce a fuel injection nozzle with a small hole diameter, and extremely easily forms a nozzle hole shape with high combustion efficiency. The present object is to provide a novel method for manufacturing a fuel injection nozzle that can be used.

Means for Solving the Problems In the method for manufacturing a fuel injection nozzle of the present invention, first, the direction of the laser beam is positioned to face a predetermined position of the nozzle material, and then the direction of the laser beam is positioned to face the predetermined position of the nozzle material. After drilling a microhole at the position by irradiation with a laser beam, and then changing the direction of the laser beam and positioning it so that it faces the predetermined position of the nozzle material adjacent to the microhole,
The next microhole is drilled by irradiation with a laser beam,
Manufacture of a fuel injection nozzle characterized by forming a nozzle hole of a predetermined special shape by continuously drilling a plurality of microholes in the nozzle material in the same manner as the previously drilled microholes. It's a method.

In addition, as a second invention, the fuel injection nozzle manufactured above is formed into a predetermined special shape by irradiating the fuel injection nozzle with a laser beam and making a plurality of microholes in a row in the nozzle material. The residue from drilling the micro holes forms burrs between adjacent micro holes, and the nozzle material with the burred nozzle holes is immersed in an electrolytic solution, and the electrolyte is flowed through the nozzle holes. This method of manufacturing a fuel injection nozzle is characterized in that it dissolves and removes dust and forms a nozzle hole that will not be deformed even by high-pressure spray in a high-temperature combustion chamber.

Effect: Therefore, by machining with a laser beam, micro holes that cannot be drilled with a drill can be formed, and during laser machining, the fuel injection nozzle is fixed and the laser beam is moved, or the laser beam is fixed and the fuel injection nozzle is rotated. After that, injection holes with a predetermined special shape are formed by irradiation with a laser beam, and by forming the special shape, an appropriate atomization injection reach and spread angle can be obtained according to the shape of the combustion chamber of the engine. This will improve performance.

In addition, the combustion chamber of the engine is high temperature, and the injection pressure of the fuel flowing out of the injection hole of the fuel injection nozzle is small. Some burrs were melted and deformed, changing the shape of the nozzle hole and changing its characteristics. Therefore, in order to prevent these problems, burrs are removed in advance using an electrolytic solution or the like.

Embodiment FIG. 1 is an explanatory diagram of a method of manufacturing a fuel injection nozzle according to the first invention.

In the first step of the manufacturing method, the direction of the laser beam 1 is set at a predetermined position of the nozzle material 2, preferably its virtual axis 3.
It is positioned so that it intersects with and has a predetermined angle θ. As shown in FIGS. 2, 3, and 4, its predetermined position is determined by the type of shape of the nozzle hole 4 to be formed, and the predetermined angle θ is determined by the position of the curved surface of the nozzle material 20.

Such positioning includes two cases in which the position of the laser beam 1 is fixed and the position of the nozzle material 2 is freely changeable, and the virtual axis 3 is adjusted so as to intersect with the laser beam 1;
Conversely, there are cases where the position of the nozzle material 2 is fixed, and the position of the laser beam l, that is, its optical system, is freely changeable and adjusted so that it intersects with the virtual axis 3.

Note that the reason for positioning so as to intersect with the virtual axis 3 is to ensure that fuel is evenly injected from the nozzle holes 4 formed at a plurality of locations.

In the second step of the manufacturing method, after the previous step, the nozzle material 20 is irradiated with the laser beam 1 positioned at a predetermined position to form microholes 41.41a.

41b is perforated. The irradiation may be performed in one shot or divided into multiple shots depending on the thickness of the nozzle material. However,
In the latter case, where the thickness is too thick to drill in one shot, burrs will be formed within the thickness of the nozzle material 2.

In the third step, the microhole 41.41a drilled in the previous step
The nozzle material 20 is positioned at a predetermined position adjacent to the nozzle material 20, preferably by changing the direction of the laser beam so that it intersects with the virtual axis 3 and has a predetermined angle, and the microhole 42 is irradiated with the laser beam. 42a is drilled. When the microhole 42.42a is drilled, the predetermined position of the microhole 42.42a is close enough to be continuous with the microhole 41.41a drilled in the previous step.

In the fourth step, the determined nozzle material 2 is
A microhole 41.0 is formed at a predetermined position by irradiation with the laser beam 1.
42.431'', 41a, 42a, 43a...
- are continuously drilled to form a nozzle hole of a predetermined special shape. However, burrs 5 remaining from drilling the microholes are present between these microholes, and a burred nozzle hole 4 is formed.

As described above, the types of shapes of the nozzle holes 4 formed by using a laser beam are determined in order to achieve an appropriate atomization injection reach and spread angle depending on the shape of the combustion chamber of the engine. In addition to the machining shape shown in FIG. 2 and the machining shape shown in FIG. 3, the shape shown in FIG.
There are also shapes such as C1 (, Y shape, L shape, cross shape, etc.).

In addition, as shown in FIG. 4, the micro holes 41b, 42b, 43b@- drilled by the laser beam are not continuous with each other but are drilled independently and close to each other to form the nozzle hole 4b of the micro hole group. good.

Next, a method for manufacturing a fuel injection nozzle according to the second aspect of the present invention will be described.

A burr 5 exists in the nozzle hole 4 of a predetermined special shape, which is formed by continuously forming microholes 41, 42, 43, etc., drilled in the nozzle material 2 by irradiation with the laser beam 1, and the nozzle hole with burrs is formed. It was the nozzle material 2 forming the nozzle 4.

Therefore, in order to permanently remove the burrs, as shown in Fig. 6, the nozzle material 2 on which the burred nozzle holes are formed is immersed in an electrolytic solution, and the electrolytic solution is injected into the burred nozzle holes 4 and permeates. let In this case, by making the support frame 7 holding the nozzle material 2 also serve as an electrode, the burr 5 in the nozzle hole 4 protrudes and is likely to come into contact with the electrolyte and will be eluted first.

As the electrolytic solution 6 circulates through the nozzle hole 4 in this way, all the burrs inside the nozzle hole are removed, as shown in Fig. 7, and wear due to burrs due to changes over time is removed. There is no change in the shape of the nozzle hole.

As a result of the above-mentioned effects of the invention, according to the method for manufacturing a fuel injection nozzle described in the detailed description of the present invention, ■ there is no change in the hole diameter due to wear of the cutting edge unlike in general drilling, and ■ machining is completed instantly. Therefore, the processing cost is low, and (1) small holes can be formed in a series of predetermined special shapes other than round holes to facilitate drilling freely.

Furthermore, according to the method for manufacturing a fuel injection nozzle according to the second aspect of the present invention, burr wear that occurs due to aging in the burr-equipped nozzle hole is eliminated, and therefore, the surface area of the spray shape due to the burr wear decreases, etc. This eliminates changes in the characteristics of the diesel engine and increases the reliability of diesel engines using it.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the direction of the laser beam and the positioning state of the nozzle material when carrying out the method for manufacturing a fuel injection nozzle according to the first invention, and FIG. FIG. 3 is a front view of the main part of the first embodiment of the fuel injection nozzle with raised holes, FIG. 3 is a front view of the main part of the second embodiment of the same fuel injection nozzle, and FIG. FIG. 7 is a front view of main parts of a third embodiment. FIG. 5 is a state diagram of an example of the shape of the nozzle hole of the fuel injection nozzle as described above, and (a
l is the Y-shape phase diagram, (bl is the L-shape phase diagram, (C1
is a cross-shaped state diagram. FIG. 6 is an explanatory diagram of a method of manufacturing a fuel injection nozzle according to the second invention, and FIG. 7 is a front view of the main part of the fuel injection nozzle completed by the same manufacturing method. 1.-Laser beam, 2.. Nozzle material 3a*Virtual axis line, 4.. Nozzle hole, 41, 42, 43...Minor hole, 41a, 42a, 43a11@.e.Minor hole, 41b
9.42b, 43b, , , , Micropore, 50. Bali, 6. . (1 other person) ＾kaguchi → Metezen ζ %゛mo＼ 1gin

Claims (1)

[Claims] 1. When drilling the injection hole in the injection nozzle, first, the direction of the laser beam (1) is positioned to face a predetermined position of the nozzle material (2), and then the nozzle material (2) is ) is irradiated with the laser beam (1) to make a microhole (41), and then the laser beam (l) is irradiated with the laser beam (l) so as to face a predetermined position of the nozzle material (2) adjacent to the microhole (41). ) After changing the direction and positioning, the laser beam (1) is irradiated in the same way to drill a microhole (42) that is continuous to the previously drilled microhole (41). In this way, a plurality of micro holes (41) (42) (43)... are formed in the nozzle material (2).
A method of manufacturing a fuel injection nozzle characterized by forming a nozzle hole of a predetermined special shape by continuously drilling holes. 2. When drilling the injection hole in the injection nozzle, a plurality of micro holes (41), (42), (43), and
... are continuously drilled to form a predetermined special shape, and the remainder from the drilling of both microholes that exists between adjacent microholes of the special shape nozzle forms a burr, and the nozzle with the burr is A method for manufacturing a fuel injection nozzle, characterized in that the formed nozzle material (2) is immersed in an electrolytic solution (6), and the electrolytic solution is allowed to permeate the mound to dissolve and remove burrs in the nozzle hole.