JP3749352B2 - Nozzle in laser processing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nozzle in a laser processing machine particularly suitable for cutting a thick plate workpiece.
[0002]
[Prior art]
A conventional multiple nozzle generally includes an inner nozzle that irradiates a laser beam and ejects a laser gas, and an outer nozzle that ejects a shielding gas or a cooling fluid.
[0003]
Further, like the nozzle 101 shown in FIG. 9, an inner nozzle 103 and an outer nozzle 105 are provided, and a ring-shaped scanning sensor chip 107 attached to the outside of the outer nozzle 105 is also used. . Alternatively, although not shown in the figure, an outside nozzle among the multiple nozzles is used as a capacitive scanning sensor.
[0004]
[Problems to be solved by the invention]
However, with the multiple nozzles as shown above, although there is a temporary effect with respect to the cooling effect, particularly with regard to the processing of thick plates, it is not possible to obtain sufficient satisfaction with respect to the cooling effect and the processing of spatter and dross. There wasn't. In addition, since spatter and dross generated during piercing process adhere to the surface of the workpiece, when shifting from piercing process to normal cutting, the fixed object becomes an obstacle to the nozzle, making it impossible to make a smooth transition, In severe cases, there is a problem of causing interference or collision with the processing nozzle.
[0005]
Also, when the scanning sensor is mounted outside the nozzle, it is difficult to adjust the positional relationship between the nozzle and sensor chip each time the nozzle is replaced, etc. In order to avoid this, there is a problem that the machining area must be restricted by itself. Alternatively, when the capacitive scanning sensor is used for the nozzle outside the multiple nozzles, when cooling water is used, the cooling water sprayed from the gap between the inner nozzle and the outer nozzle spreads to the center of the nozzle by centrifugal force and spreads to the workpiece. In order to eject, cooling water enters the gap between the workpiece and the sensor part, and therefore, there is a problem that the function as a sensor cannot be sufficiently performed due to the influence of the relative dielectric constant of water.
[0006]
In addition, an effective multi-nozzle has not yet been used for piercing and normal machining in the processing of thick plates.
[0007]
The object of the present invention has been made by paying attention to the conventional techniques as described above, and can spray the cooling medium and easily peel off spatter, dross, etc. generated during processing from the surface of the workpiece and The object is to provide a nozzle in a laser processing machine that can be used as a scanning sensor.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an assist from between the inner nozzle and the middle nozzle of a multiple structure nozzle having a middle nozzle inside the outer nozzle and an inner nozzle inside the middle nozzle. on the workpiece surface by the centrifugal force by jetting while rotating mixing incombustible rust agent and air which has a clearance from the cooling effect provided between the outer nozzle and the middle nozzle with discharges gas By spraying in a state of spreading outward, the temperature of the workpiece is stabilized, and impurities such as spatter and molten metal debris generated on the workpiece surface during piercing or cutting are removed from the cutting path It is.
[0012]
The present invention also relates to a nozzle in a laser processing machine for performing laser processing by irradiating a workpiece with a laser beam oscillated by a laser oscillator, and an outer nozzle located outside and a predetermined inside the outer nozzle. And a middle nozzle whose tip is enlarged in a trumpet shape, and has an inner nozzle inserted therein with a predetermined interval. .
[0013]
Therefore, since the coolant and air blown from the gap provided between the outer nozzle and the middle nozzle spread along the outer shape of the middle nozzle, impurities on the workpiece surface are removed to the outside.
[0015]
In addition , assist gas or the like is jetted from a gap provided between the middle nozzle and the inner nozzle toward the workpiece machining position.
[0016]
Further, in the nozzle in the laser processing machine, the middle nozzle itself is an electrode of a capacitive scanning sensor, and the gap with the workpiece is detected and controlled at the tip portion.
[0017]
Therefore, even when cooling water is blown from the gap provided between the outer nozzle and the middle nozzle, the cooling water is blown outward by the outer shape of the middle nozzle, so the middle nozzle itself is used as a capacitive scanning sensor. This eliminates instability of the dielectric constant due to cooling water.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0019]
7 and 8 show the entire laser beam machine 1. Since the laser beam machine 1 is very general, a detailed description is omitted and only an outline will be described. This laser processing machine 1 has a laser oscillator 3 that emits a laser beam LB in the vicinity, and the laser beam LB emitted by the laser oscillator 3 is sent to the laser processing machine 1 through a plurality of bend mirrors 5.
[0020]
The laser beam machine 1 includes a base 7, a post 9 fixed vertically at one end of the base 7, and a main body frame 11 supported by the post 9 in a horizontal cantilever shape above the base 7. Consists of. On the base 7, a fixed table 13 is provided for horizontally placing the workpiece W to be processed. On both the front and rear sides (upper and lower sides in FIG. 8) of the fixed table 13 are provided movable tables 15 that can be moved and positioned in the Y-axis direction (left and right direction in FIG. 8). A movable base 15 is connected, and a carriage base 17 that is moved and positioned in the Y-axis direction integrally with the movable table 15 is provided. The carriage base 17 is provided with an X-axis carriage 21 having a workpiece clamper 19 for gripping the workpiece W so that the interval can be adjusted. The X-axis carriage 21 can be moved and positioned in the X-axis direction.
[0021]
On the other hand, a processing head 23 is provided on the lower surface of the front end of the main body frame 11 (the right front end in FIG. 7), and the laser beam LB from the laser oscillator 3 is applied to the work W at the front end of the processing head 23. A nozzle 25 for irradiating is mounted.
[0022]
Accordingly, the X-axis carriage 21 holding the workpiece W is moved and positioned in the X-axis direction, and the carriage base 17 is moved and positioned in the Y-axis direction to position the machining position of the workpiece W below the nozzle 25. Laser processing is performed by irradiating the workpiece W with the laser beam LB.
[0023]
1 and 2 show a nozzle 25 attached to the tip of the processing head 23 described above. The nozzle 25 is a multiple nozzle, and has an outer nozzle 27 having a circular section on the outermost side, and a middle nozzle 29 having a circular section in the inner space of the outer nozzle 27. Further, the middle nozzle 29 has an inner nozzle 31 having a circular cross section, and has a triple structure.
[0024]
Since the flat portion 33 is provided at two locations on the outer periphery of the middle nozzle 29, gaps 35 are formed at two locations between the outer nozzle 27. Since a flat portion 37 is also provided on the outer periphery of the inner nozzle 31, a gap 39 is formed between the inner nozzle 31 and the middle nozzle 29. The tip 41 of the middle nozzle 29 located at the tip is formed in a trumpet shape.
[0025]
Therefore, a passage for ejecting liquid or gas is formed between the inner nozzle 31 and the middle nozzle 29, and between the middle nozzle 29 and the outer nozzle 27, and the gas or the like ejected from the gap 35 outwards. spread. Further, the assist gas is ejected from the gap 39.
[0026]
Next, a laser cutting method will be described with reference to FIGS.
[0027]
First, referring to FIG. 3, the nozzle gap H is made slightly larger (for example, 2.5 mm), and rust preventive water and air are mixed from the gap 35 formed between the outer nozzle 27 and the middle nozzle 29. Is sprayed on the surface of the workpiece W at a predetermined strength (for example, 3.5 kgf / cm ² ) as water spray. At this time, even if the rust preventive water evaporates, the rust preventive agent remains on the surface of the workpiece W, so that it is possible to prevent spatter and dross from directly adhering to the surface of the workpiece W.
[0028]
Next, referring to FIG. 4, the rust prevention water is stopped, and only air is discharged with the same large nozzle gap H from the gap 35 formed between the outer nozzle 27 and the middle nozzle 29 in the same manner as described above. The surface of the workpiece W is sprayed with strength (for example, assist gas is 0.4 kgf / cm ² and outer air is 1 kgf / cm ² ). Piercing is performed while blowing the spatter to the outside by this air. At this time, the spatter can be blown off from the surface of the workpiece W, although partially, by the rust preventive sprayed in the process shown in FIG.
[0029]
Referring to FIG. 5, the process shown in FIG. 3 described above is applied to the spatter and dross that have adhered to the surface of the workpiece W and could not be removed in the piercing process shown in FIG. Is completely removed by performing again at a strength of 6 (for example, assist gas is 6 kgf / cm ² , rust prevention water + outer air is 3.5 kgf / cm ² ).
[0030]
Referring to FIG. 6, after spatter and dross are completely removed, the tip 41 of the middle nozzle 29, which is a capacitive scanning sensor, and the nozzle gap H are corrected to an optimum value (for example, 1.5 mm) and confirmed. After that, the cutting process is started while spraying air or rust prevention water at a predetermined strength (for example, assist gas is 0.5 kgf / cm ² , rust prevention water + outer air is 3.5 kgf / cm ² from the gap 35). .
[0031]
From the above results, the rust preventive water and air are mixed with the cooling medium ejected from the nozzle 25 and strongly blown onto the surface of the workpiece W, so that the temperature of the workpiece is stabilized and a cooling effect is given. Spatter and dross on the W surface can be removed and rust prevention treatment can be performed.
[0032]
Further, by using multiple nozzles 25, cooling can be performed constantly, and appropriate processing can be performed in piercing processing and normal cutting processing.
[0033]
In addition, since the tip of the middle nozzle 29 used as a part of the nozzle 25 has a trumpet shape, even when cooling water is used, the cooling water can be expelled from the tip of the middle nozzle 29, and the influence of the relative dielectric constant of water. You can copy without receiving.
[0034]
The present invention is not limited to the embodiment of the invention described above, and can be implemented in other modes by making appropriate modifications. That is, mere water, nonflammable oil or powder can be used instead of the rust preventive water used in the above-described embodiment.
[0035]
Moreover, the numerical value of the discharge force shown in the above-described embodiment of the present invention is an example, and the present invention is not limited to this.
[0036]
【The invention's effect】
As described above, according to the present invention, the nonflammable rust preventive agent having a cooling effect and air are mixed from the gap provided between the outer nozzle and the middle nozzle, and particularly on the thick plate work surface. The temperature of the workpiece is stabilized by spraying in a spread state. Thereafter, impurities such as spatter and molten metal debris generated on the workpiece surface during piercing or cutting of the assist gas from the gap provided between the middle nozzle and the inner nozzle can be removed.
[0038]
In addition, according to the present invention, the coolant and air blown from the gap provided between the outer nozzle and the middle nozzle spread along the outer shape of the middle nozzle, so that impurities on the surface of the workpiece, particularly thick plates, can be reliably ensured. Can be removed to the outside. Thereby, since an impurity is not involved, an appropriate cutting process can be performed.
[0039]
Further , it is possible to inject assist gas or the like from the gap provided between the middle nozzle and the inner nozzle toward the workpiece processing position, and appropriate cutting processing can be performed.
[0040]
Further, even when spraying cooling water from the gap formed between the outer nozzle and the middle nozzle, the cooling water by the outer shape of the middle nozzles are blown outwardly, the cooling water if used as a sensor scanning the middle nozzle tip It is possible to eliminate the instability of the dielectric constant due to.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a nozzle in a laser beam machine according to the present invention.
FIG. 2 is a plan view seen from the direction II in FIG.
FIG. 3 is a cross-sectional view showing a process of a processing method by a laser processing machine according to the present invention.
FIG. 4 is a cross-sectional view showing the steps of a processing method using a laser processing machine according to the present invention.
FIG. 5 is a cross-sectional view showing the steps of a processing method using a laser processing machine according to the present invention.
FIG. 6 is a cross-sectional view showing the steps of a processing method using a laser processing machine according to the present invention.
FIG. 7 is a front view showing a laser processing machine to which the processing method by the laser processing machine according to the present invention is applied.
8 is a plan view seen from the direction VIII in FIG. 7. FIG.
FIG. 9 is a cross-sectional view showing a conventional multiple nozzle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Laser processing machine 3 Laser oscillator 25 Nozzle 27 Outer nozzle 29 Middle nozzle 35 Gap 39 Gap 41 Tip part (copy sensor)
W Work LB Laser beam

Claims (3)

Comprises a middle nozzle inside the outer nozzle, the middle nozzle and the outer nozzle while ejecting an assist gas from between the inner nozzle and the middle nozzles of the nozzle of the multi-layered structure comprising an inner nozzle to the inside of the middle nozzle Mixing non-flammable rust preventive agent with cooling effect and air from the gap provided between them and blowing them while rotating, and spraying them in a state of spreading outward on the workpiece surface by the centrifugal force, the temperature of the workpiece And further removing impurities such as spatter and molten metal debris generated on the workpiece surface during piercing or cutting from the cutting path.   A nozzle in a laser processing machine for performing laser processing by irradiating a workpiece with a laser beam oscillated by a laser oscillator, and having an outer nozzle positioned outside and a predetermined gap inside the outer nozzle A nozzle in a laser processing machine, comprising a middle nozzle that is positioned and has a tip that is enlarged in a trumpet shape, and the middle nozzle includes an inner nozzle that is inserted at a predetermined interval inside. .   3. The nozzle in a laser beam machine according to claim 2, wherein the middle nozzle itself is an electrode of a capacitive scanning sensor, and the gap between the middle nozzle and the workpiece is detected and controlled.

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