JP4735721B2 - Method for machining nozzle hole in injector and machining apparatus therefor - Google Patents

Description

The present invention relates to a method for machining an injection hole in an injector and a machining apparatus therefor .

Conventionally, wire electrical discharge machining has been used for narrow groove machining portions that require precision machining in various mechanical parts.
However, wire electrical discharge machining is not necessary if the machining site is machining from the outside, but if the machining site is an internal part of the product, combined with the fact that a pilot hole through which the wire wire passes is essential. Wire passage is necessary, and wiring processing is difficult with a fine and complicated shape.

  On the other hand, as disclosed in Patent Document 1, when a narrow groove is machined in a so-called water jet laser machining method, scanning with laser light and high-pressure water is repeated a plurality of times.

Japanese Patent Laid-Open No. 11-320526

Certainly, the water jet laser machining has an advantage that cannot be obtained by the electric discharge machining described above, but in the method described in Patent Document 1, the water jet laser machining is repeatedly performed a plurality of times. Nevertheless, the processing wall roughness is 6 to 12 μm, and satisfactory processing accuracy is not obtained.
As a cause of this, even when scanning with laser light and high-pressure water multiple times, the laser power value does not attenuate much compared to the input value near the processing surface, but the power attenuation in the deep part The rate seems to be large. Since this water jet laser processing method uses a thin water jet as a laser waveguide, the water jet reaches the deep part while interfering with the wall surface in the ultra-fine width. In this case, the water jet is disturbed and the effectiveness is considered to be reduced. That is, it seems that the surface roughness in the vicinity of the abyss tends to be rougher than in the vicinity of the surface of the workpiece.
The present invention, which has been proposed above background, during processing by processing with rocking the workpiece, thereby improving the machining accuracy, the injection holes in the injectors processing method and for its An object is to provide a processing apparatus.

In order to solve the above problems, the invention described in claim 1, with respect to the injector (10), a processing method of the nozzle hole (16) in the injector (10) for forming a nozzle hole (16) When laser processing is performed on a portion where the nozzle hole (16) is to be formed, the injector (10) is irradiated with laser light so that the central axis of the portion where the nozzle hole (16) is to be formed coincides with the vertical axis. By placing the machining table (8) on the machining table (8) so that the points coincide with each other, and then repeatedly swinging the machining table (8) at a predetermined angle and at a constant speed in the left-right direction with one point on the center axis as the rocking center. A fan-shaped processed part is formed .

Thus, at the site to form a nozzle hole (16) to the injector (10), by swinging the injector (10), since the laser beam is irradiated in a swing range of the injector (10), cross fan A shaped nozzle hole (10) is formed.

Further , by processing the nozzle hole (16) of the injector (10) into a fan shape in cross section, the injector (10) can be sprayed at a wide angle without resistance during fuel spraying, and the spray performance has been improved. Can be.

Further, at the site to form a nozzle hole (16) to the injector (10), about a vertical axis, by swinging the injector (10), the nozzle hole (10) for expanding the cross-sectional sector-shaped form Is done.
By performing such rocking processing, the moving speed V ₂ of the laser beam irradiation point is lower than the moving speed V ₁ of the laser beam irradiation point near the surface in the vicinity of the deep part of the nozzle hole. By doing so, the degree of processing can be maintained at a predetermined level even if the power value of the laser beam is reduced. That is, since the laser beam irradiation points are densely packed and overlapped in the vicinity of the deep part, the finished surface of the machined surface is improved.

In the invention according to claim 2, laser processing, injector supplies high pressure water from the high-pressure water supply (6) irradiates a laser beam from the laser generator (2), these laser light and high-pressure water from the nozzle It is water jet laser processing that performs processing by irradiating and jetting (10).

As a result, the water column (5) is ejected from the nozzle and the laser beam is irradiated, so that a beam mark is formed at a portion where the nozzle hole (16) is to be formed, and a processing groove having a corresponding groove width is formed. Is done.

The invention described in claim 3 is obtained by the device invented a method invention of claim 1, injection holes in the injectors to (10), injector (10) for forming a nozzle hole (16) ( 16) is a processing apparatus, which performs laser processing on a portion where a laser generator (2), a laser head (3), an optical fiber (4) connecting them, and a nozzle hole (16) are to be formed. in making, provided with a machining table (8) for performing processing with rocking by placing the injector (10), the center of the site to be formed an injector (10), the injection hole (16) After placing the machining table (8) on the machining table (8) so that the axis coincides with the vertical axis and the laser beam irradiation point coincides, the machining table (8) has a predetermined point on the central axis as a swing center. By swinging at a constant speed in the left and right angles, the fan shape And forming a working site.

Thus, basically the same effect as that of the method invention of claim 1 is obtained, and the injection hole (16) is formed by swinging the processing table (8) on which the injector (10) is placed. at the site to be laser light is irradiated by the oscillating range, as a result, the portion to be formed injection hole (16), it is formed in an sectional fan-shaped injection hole (16).

The invention according to claim 4 is an apparatus invention according to the method invention of claim 2, and the processing apparatus includes a high-pressure water supply unit (6) that generates high-pressure water as a water column (5), and high-pressure water. A nozzle (7) for jetting as a water column, and irradiating the laser beam from the laser generator (2) and supplying high-pressure water from the high-pressure water supply unit (6). and while swinging the injector (10) machining table (8) placing the, wherein the TURMERIC line irradiation and injected in working at the site to form a nozzle hole (16) in the injector (10) And

As a result, the water column (5) is ejected to the portion of the injector (10) where the injection hole (16) is to be formed, and the laser beam is irradiated to form a beam mark, and a cross-sectional fan having a corresponding groove width is formed. A shaped groove is formed.

  In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

At the site to form a nozzle hole in the injector, by swinging the injector, it is possible to form a cross-section fan-shaped injection hole, without resistance during fuel spray and the spray performance can be wide-angle spraying It is possible to manufacture an injector with improved efficiency.

It is typical structure explanatory drawing which showed an example of the water jet laser processing apparatus used when implementing the processing method of the nozzle hole which is a narrow groove in the injector as a mechanism component concerning this invention. It is principal part explanatory drawing which shows an example of the injector as an object of the mechanism components which comprise a to-be-processed object. It is the top view seen from the upper part of the injector shown in FIG. It is the diagram which showed the irradiation range of the laser beam which is a process range processed with the water jet laser processing apparatus shown in FIG. It is the diagram which showed the irradiation range of the laser beam which is a processing range at the time of moving a process part at a fixed speed.

An example of the water jet laser processing apparatus 1 used when implementing the processing method of the injection hole which is a narrow groove in the injector as a mechanism component concerning this invention is shown.
The water jet laser processing apparatus 1 (hereinafter, the laser processing apparatus 1) upon the mechanical parts (injector) to the machining area (described later) to form a fine groove (nozzle hole), forming a fine groove (nozzle hole) When laser processing is performed on a portion to be processed, processing is performed while swinging a mechanical component (injector) .
That is, the laser processing apparatus 1 includes a laser generating unit 2 that generates laser light, a laser head 3 that narrows the generated laser light to a desired diameter, an optical fiber 4 that connects the laser beam and leads the laser light, A high-pressure water supply unit 6 that supplies high-pressure water for the water column 5 to be jetted around the laser head 3 and a nozzle 7 that jets the high-pressure water as the water column 5 are provided.
Moreover, the laser processing apparatus 1 has the processing table 8 which hold | maintains the workpiece W so that rocking is possible. The high-pressure water supply unit 6, the laser generation unit 2, and the processing table 8 described above are connected to a control panel (not shown) for controlling them.
The processing performed by the laser processing apparatus 1 as described above forms water column 5 by spraying water onto the processing site of the workpiece W held swingably on the processing table 8, and the water column 5. The laser beam is irradiated through the inside.

Here, as an object of the mechanical component 10 including the workpiece W, for example, an injector can be given as an example, as shown in FIG.
Although not described in detail, the mechanical component 10 (hereinafter referred to as an injector 10) includes a cylindrical nozzle body 11 on the fuel injection tip side, and a lid portion 12 that is a workpiece W that can be fitted to the tip of the nozzle body 11, It has the attachment part 13 attached to an injector main body (illustration omitted) in the rear-end side.

The nozzle body 11 has a circular cross section and extends in the axial direction, and a needle-like needle valve 14 is inserted into the hollow portion 11a so as to be movable in the axial direction.
Moreover, the cover part 12 has the substantially cone-shaped dome part 15 in which the front end side has a space inside as shown in the figure. A frustum-shaped valve seat portion 15 a is formed in the inner space of the dome portion 15.

At the tip of the dome portion 15, a different-diameter nozzle hole 16 having a length l that penetrates the dome portion 15 in the thickness direction is formed. The injection hole 16 is partitioned by a pair of left and right side walls 16a and a horizontal wall 16b as shown in FIG. The groove width h of the different-diameter nozzle hole 16 is constant over the entire length. The groove width h is set to 40 μm to 200 μm.
On the other hand, as shown in FIG. 2, the width is widened from w1 on the inner peripheral surface side to w2 on the outer peripheral surface side, and the different-diameter injection hole 16 has a fan-shaped vertical cross-sectional shape. Therefore, the left and right side walls 16a have an elongated rectangular shape, but the lateral wall 16b has a fan shape. In this case, w2 on the outer peripheral surface side, which is the maximum width, is set to 0.6 to 2 mm.

  The needle valve 14 has an outer diameter smaller than the inner diameter of the guide hole 11a of the nozzle body 10, and an annular fuel flow passage 17 is defined between them. Further, the needle valve 14 has a valve portion 18 seated on the valve seat portion 15a in the inner space of the dome portion 15 at the tip thereof. The needle valve 14 is moved back and forth in the axial direction (up and down in FIG. 1). When the needle valve 14 moves upward, the valve portion 18 moves away from the valve seat portion 15a and opens the different diameter nozzle hole 16. As a result, the fuel in the fuel flow passage 17 is injected from the different-diameter injection holes 16 in a fan-shaped spray distribution shape.

Next, a processing procedure of the irregular injection hole 16 that is a fine groove in the lid 12 at the tip of the nozzle body 11 of the injector 10 using the water jet laser processing apparatus 1 will be described.
First, the lid 12 that is the workpiece W is held on the machining table 8. In this case, in the processing table 8, the placement surface of the lid portion 12 that is the top workpiece is initially in a substantially horizontal state, and when the lid portion 12 is placed on the placement surface, the center of the lid portion 12 is placed. The axis coincides with the vertical axis, and coincides with the laser beam from the laser generator 2 and the water column 5 from the high-pressure water supply unit 6 in the water jet laser processing apparatus 1 (neutral state).

Next, an operation command is given to the processing table 8, the high-pressure water supply unit 6, and the laser generation unit 2 by the control panel in the laser processing apparatus 1, and water is supplied to a portion where the deformed injection hole 16 of the lid 12 is to be formed. The water column 5 is formed by jetting, and the laser beam is irradiated through the water column 5.
As a result, the high-pressure water for the water column 5 from the high-pressure water supply unit 6 hits the portion where the deformed injection hole 16 of the lid 12 should be formed through the nozzle 7 as the water column 5 from the vertical axis direction.
On the other hand, the laser light emitted from the laser generator 2 is guided to the laser head 3 through the optical fiber 4 from the laser generator 2 and is reduced to a desired diameter, and along the water column 5, the water column 5 and the lid 12. It is led to the part where the irregular injection hole 16 is to be formed.
Here, the machining table 8 is swung by a predetermined angle by a drive mechanism (not shown) with the vertical axis as the center, that is, with one point on the central axis in the inner space of the dome portion 15 as the swing center (see FIG. 1). Oscillating at a constant speed.
As a result, the laser beam along with the water column 5 is irradiated from the starting point in the neutral state of the processing table 8 to the portion to be formed with the deformed nozzle hole 16 of the lid portion 12 as shown in FIG. Based on the swinging motion of the processing table 8, the desired irregularly shaped injection hole 16 is penetrated and irradiated in a fan shape on the left and right.

By the way, as described above, when the laser beam is irradiated with the water column 5 to the portion where the deformed injection hole 16 of the lid portion 12 is to be formed under the swinging motion of the processing table 8, the power value of the laser beam is appropriate. Even if it is an input value, since the power value in actual processing is surface> deep, the surface roughness in the vicinity of the deep tends to deteriorate.
However, by implementing the oscillation process as described above, syntan area around the moving speed V ₂ of the irradiation point of the laser beam, as compared to the moving speed V ₁ of the irradiation point of the laser beam on the surface closer By lowering, the processing degree can be maintained at a predetermined level even when the power value of the laser beam is lowered.
In other words, the vicinity of the deep part is dense and overlaps in a narrower range of laser beam irradiation points, leading to an improvement in the finished surface.

  On the other hand, in the processing that is not oscillating as described above, as shown in FIG. 5, the moving speed V of the laser beam irradiation point is near the surface even though the laser power is attenuated near the deep part. It can be easily understood that the machining capability cannot follow and the deterioration of the surface roughness is inevitable because it is the same as the side.

Above, carrying out the machining process that written to the present invention, as the target of mechanical parts having a workpiece W, cited injector 10, a fine groove in the lid part 12, the processing procedure of the profiled injection hole 16 However, as a matter of course, the target of the mechanical part including the workpiece W is not limited to the injector 10, and various mechanical parts (vaporizer ejection holes, fluid flow rate adjusting orifices, printing machines having fine grooves) are included. An injection nozzle or the like is also possible.

DESCRIPTION OF SYMBOLS 1 Water jet laser processing apparatus 2 Laser generating part 3 Laser head 4 Optical fiber 5 Water column 6 High pressure water supply part 7 Nozzle 8 Processing table 10 Injector 11 Nozzle body 11a Hollow part 12 Lid part 13 Attachment part 14 Needle valve 15 Dome part 15a Valve Seat part 16 Injection hole 16a Side wall 16b Horizontal wall 17 Fuel flow path 18 Valve part 19 Needle W Workpiece h Groove width

Claims (4)

A method of processing the injection hole (16) in the injector (10) for forming the injection hole (16) with respect to the injector (10),
When performing laser processing on the site to be forming the injection hole (16), the injector (10) to initially center axis of the portion to be formed the injection hole (16) coincides with the vertical axis, and, Place on the processing table (8) so that the irradiation point of the laser beam coincides,
Next, the machining table (8) is repeatedly rocked at a predetermined angle and at a constant speed in the left-right direction with one point on the central axis as the rocking center, thereby forming a fan-shaped machining portion. The injection hole machining method in the injector . In the laser processing, laser light is irradiated from the laser generator (2) and high-pressure water is supplied from the high-pressure water supply unit (6), and these laser light and high-pressure water are supplied from the nozzle (7) to the injector (10). 2. The method of processing an injection hole in an injector according to claim 1, wherein the processing is performed by water jet laser processing that performs processing by irradiation and injection. To the injector (10), a processing device of the injection holes (16) in the injector (10) for forming a nozzle hole (16),
A laser generator (2) for generating laser light;
A laser head (3) for narrowing the generated laser light to a desired diameter;
An optical fiber (4) for connecting the laser generator (2) and the laser head (3) to guide laser light;
A processing table (8) for performing processing while placing and swinging the injector (10) when performing laser processing on a portion where the nozzle hole (16) is to be formed ;
The injector (10) is placed on the processing table (8) so that the central axis of the portion where the nozzle hole (16) should be formed coincides with the vertical axis and the irradiation point of the laser beam coincides. The fan-shaped machining part is formed by repeating rocking of the machining table (8) at a predetermined angle and a constant speed in the left-right direction with one point on the central axis as a rocking center. Processing device for injection holes in an injector . The processing device includes:
A high-pressure water supply unit (6) for supplying high- pressure water for a water column (5) sprayed around the laser beam to the laser head (3) ;
A nozzle (7) for injecting high-pressure water as a water column (5);
Further comprising
While irradiating the laser beam from the laser generator (2) and supplying high-pressure water from the high-pressure water supply unit (6), the laser light and high-pressure water are supplied to the processing table (8) by the injector (10). while by placing swung to, the injector according to claim 3, characterized in that for machining irradiation and injected in the site to be forming the injection hole (16) before SL injector (10) Injection hole processing equipment.

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