JPH11789A - Emitting end nozzle of laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the reduction of gas momentum, to simplify the constitution and to facilitate the work of cutting or the like of the stock to be machined consisting of metal material of about 4-6 mm in plate thickness. SOLUTION: An emitting end nozzle 20 is composed of the inner nozzle 21 having a first nozzle hole 31 and an outer nozzle 23 installed coaxially to the central axis 22. An annular space 41 is formed between the outer periphery 39 of the inner nozzle 21 and the inner periphery 40 of the outer nozzle 23, and the second nozzle hole 42 externally encircling the first nozzle hole 31 is formed. Plural through holes 43 communicating the internal space 32 of the inner nozzle 21 and the annular space 41 are formed in the peripheral wall of the first nozzle part 29. The second nozzle hole 42 is approached to the central axis 22 as it advances to the downstream side in the jetting direction of the gas and moreover formed so as to incline in the direction crossing the central axis 22 at the lower side than the upper surface 47 of the stock 46 to be machined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emission end nozzle of a laser processing apparatus, and more particularly, to a plate thickness of 4 to 6 m.
The present invention relates to an emission end nozzle of a laser processing apparatus that can be suitably used for cutting a workpiece made of a ferrous or non-ferrous metal having a length of about m.

[0002]

2. Description of the Related Art FIG. 12 is a simplified cross-sectional view showing a typical prior art emission end nozzle 1. As shown in FIG. The emission end nozzle 1 is formed including a nozzle body 2 and a cap 3. A first nozzle hole 4 for injecting gas is formed at the tip of the nozzle body 2, and an inner space 6 facing the inner peripheral surface 5 of the nozzle body 2 is formed in a truncated cone shape. Cap 3
Is coaxially screwed to the nozzle body 2. An annular space 9 to which gas is supplied is formed between the inner peripheral surface 7 of the cap 3 and the outer peripheral surface 8 of the nozzle body 2, and a second nozzle hole 10 surrounding the nozzle hole 4 is formed. . The cap 3 is provided with a gas supply passage 11 communicating with the annular space 9 and extending outward in the radial direction.

When laser cutting is performed, the gas 12 guided to the internal space 6 coaxially with the laser beam is applied at high speed to the workpiece 1.
3 is sprayed on the upper surface. At this time, a gas having the same quality as the gas 12, for example, an O ₂ gas 14 is supplied from the gas supply path 11 into the annular space 9 from a path different from the gas 12, and the second nozzle hole 1
The gas is injected in a direction substantially parallel to the injection direction of the gas 12 from 0 to form an atmosphere of the gas 14 around the gas 12. In this way, the entrainment of air by the gas 12 is eliminated, and a decrease in the momentum of the gas 12 can be prevented.

Another conventional technique is disclosed in, for example,
-106376. In this conventional technique, in order to obtain the smoothness of the surface of the workpiece after laser ablation, a molten portion generated by melting the workpiece by laser irradiation is blown off by a gas from a nozzle,
The unevenness at the boundary with the adjacent irradiation pass after the ablation during multiple pass irradiation is eliminated.

[0005]

However, FIG.
In the prior art shown in FIG. 1, when cutting a workpiece 13 made of a metal material having a thickness of about 4 to 6 mm, the gas 1
Since the momentum of 2, 14 is insufficient, dross, which is a metal oxide, is not completely removed, and after the cutting operation, an operator must grind and remove the dross using a working tool such as a grinder. Is troublesome.

The inner peripheral surface 5 of the nozzle body 2 has a frusto-conical internal space 6 facing it, so that the flow velocity of the gas 12 rises with a sharp decrease in the sectional area, and the nozzle body 2 In this case, the pressure loss increases, the momentum of the gas decreases, and the dross cannot be completely removed.

Further, the supply paths of the gases 12 and 14 for the gases 12 and 14 in the inner space 6 and the annular space 9 must be provided separately in the nozzle body 2 and the cap 3, and the structure becomes complicated. Occurs.

In other conventional techniques, even if this conventional technique is applied to the above-described conventional technique, the dross is completely removed due to a shortage of gas momentum similarly to the above-described conventional technique. There is no problem.

SUMMARY OF THE INVENTION It is an object of the present invention to suppress a decrease in gas momentum and to simplify the structure.
An object of the present invention is to provide an emission end nozzle of a laser processing apparatus capable of facilitating operations such as cutting a workpiece made of a ferrous or non-ferrous metal having a size of about 6 mm.

[0010]

According to a first aspect of the present invention, there is provided a laser processing head having a built-in condensing lens for converging a laser beam irradiated toward a workpiece and supplied with a gas. A first nozzle member formed coaxially with the first nozzle member and having a first nozzle hole formed on a central axis line through which laser light condensed by the condensing lens passes and which injects the gas. A second space, which is mounted and forms an annular space between the outer peripheral surface of the first nozzle member and the gas supply port, and injects gas from a second nozzle hole surrounding the first nozzle hole of the first nozzle member. In the emission end nozzle of the laser processing apparatus including the nozzle member, the first nozzle member has a plurality of through holes which are substantially parallel to the central axis thereof and communicate the internal space of the first nozzle member and the annular space. Formed at intervals in the direction A emission end nozzle of a laser machining apparatus characterized in that it is.

According to the present invention, the first nozzle member has a plurality of through-holes substantially parallel to the central axis thereof and communicating the internal space of the first nozzle member with the annular space at intervals in the circumferential direction. It is formed. Since the through holes are formed at intervals in the circumferential direction of the first nozzle member, the gas is guided into the annular space without lowering the strength of the first nozzle member, and the gas is injected from the second nozzle hole. can do. Further, since the central axis of each of the through holes is formed substantially parallel to the central axis of the first nozzle member, the gas facing each of the through holes easily passes through each of the through holes. The turbulence of the gas flow when passing through is reduced, and the decrease in the momentum of the gas in the annular space can be further reduced. Further, the gas is guided to the annular space through each through hole,
Since the gas is injected from the second nozzle hole, the configuration can be simplified as compared with a case where the gas supply path is individually supplied to the first and second nozzle members.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the second nozzle hole is arranged so as to be closer to the central axis of the first nozzle member toward the downstream side in the gas injection direction. It is characterized by being formed inclined.

According to the present invention, the second nozzle hole is formed so as to be inclined in a direction approaching the central axis of the first nozzle member as it becomes more downstream in the gas injection direction. Therefore the second
The gas injected from the nozzle hole can have a higher momentum as it approaches the central axis, and the gas injected from the first and second nozzle holes efficiently removes dross, which is a molten metal, and does not melt. And the cut surface is exposed, and the workpiece can be cut efficiently.

According to a third aspect of the present invention, in the configuration of the first or second aspect of the present invention, the second nozzle hole is closer to the center axis of the first nozzle member toward the downstream side in the gas injection direction. And is formed to be inclined below the upper surface of the workpiece in a direction intersecting the central axis.

According to the present invention, the gas injected from the second nozzle hole joins on the central axis below the upper surface of the workpiece. Therefore, even at a crossing position of the gas injected from the second nozzle hole even in a workpiece having a large thickness, it is possible to blow a higher momentum gas to the dross and sufficiently remove the dross below the position. And a good cut surface can be obtained.

According to a fourth aspect of the present invention, in the configuration of the first aspect of the present invention, the inner peripheral surface of the first nozzle member has a gas inside an inner space of the first nozzle member. It is characterized in that it is formed so as to protrude outward in the radial direction more than a virtual frustoconical surface connected to the opening end on the inflow side and the opening end on the gas outflow side facing the first nozzle hole.

According to the present invention, the inner peripheral surface of the first nozzle member has an opening end on the gas inflow side and an opening end on the gas outflow side facing the first nozzle hole in the internal space of the first nozzle member. The cross section of the flow path in the inner space of the first nozzle member is gradually reduced toward the gas injection direction because the flow path cross section is gradually reduced outward in the radial direction from the continuous virtual frusto-conical surface. Pressure loss due to the decrease in
Supplying gas to the first and second nozzle holes at a large flow rate;
Gas can be injected at high speed from the first and second nozzle holes. In this way, even if the thickness of the workpiece is large, dross can be removed by blowing a higher momentum gas from the upper surface to the lower surface of the workpiece.

According to a fifth aspect of the present invention, in the configuration of the first aspect of the present invention, the second nozzle hole is formed radially inward of each through hole. Features.

According to the present invention, the second nozzle hole is formed radially inward of each through hole. The gas injected from each through-hole is guided to the outer peripheral surface of the first nozzle member and the inner peripheral surface of the second nozzle member, and the flow path cross-sectional area becomes smaller as approaching the second nozzle hole. Thus, the gas pressure of the gas injected from each through-hole can be increased, and the gas can be injected from the second nozzle hole with a high momentum uniformly in the circumferential direction.

[0020]

FIG. 1 is a sectional view showing a configuration of an emission end nozzle 20 of a laser processing apparatus according to an embodiment of the present invention. The emission end nozzle 20 includes an inner nozzle 21 as a first nozzle member and an outer nozzle 23 as a second nozzle member mounted coaxially with the center axis 22 of the inner nozzle 21. The inner nozzle 21 includes a large-diameter cylindrical portion 25 in which a male screw 24 is engraved in the direction of the central axis 22, and a flange 2 formed to extend radially outwardly from the lower end of the large-diameter cylindrical portion 25.
6 and the large-diameter cylindrical portion 2
A small-diameter tube portion 28 having a diameter smaller than 5 and having a screw 27 engraved on the peripheral wall thereof, and a frustoconical and cylindrical shape connected to the lower end of the small-diameter tube portion 28 and extending downward in the direction of the central axis 22. And a first nozzle portion 29. Also, a straight line 22a parallel to the central axis 22 by the inner peripheral surfaces of the large-diameter cylindrical portion 25, the flange 26, the small-diameter cylindrical portion 28, and the first nozzle portion 29, and a line perpendicular to the central axis 22 including the gas inflow-side open end 33a. The inner peripheral surface 3 of the inner nozzle 21 having a radius R on a vertical plane including the center axis 22 and the straight line 22a around an intersection P between the center axis 22 and a horizontal line 22b orthogonal to the straight line 22a on one plane.
0 is formed.

The inner nozzle 21 has a first nozzle hole 31 formed on the center axis 22 through which a laser beam 96 to be described later passes and which injects a gas such as air.
Here, the inner peripheral surface 30 has a radius larger than a virtual frusto-conical surface 34 which is continuous with the opening end 33a on the gas inflow side and the opening end 33b on the gas outflow side facing the first nozzle hole 31 in the inner space 32 of the inner nozzle 21. It is formed to be convexly outward in the direction. The outer peripheral portion 26a of the flange 26 is knurled.

As shown in FIG. 3, the outer nozzle 23 is formed with a flange 35 having an outer diameter substantially equal to that of the flange 26, and a cylindrical portion 37 in which a female screw is engraved in the direction of the central axis 22, and a cylindrical portion. A second nozzle portion 38 formed in a truncated cone shape and extending in the direction of the central axis 22 surrounding the first nozzle portion 29 and connected to the lower end portion of the first nozzle portion 29 is formed. The outer peripheral portion 35a of the flange 35 is subjected to knurling. The inner nozzle 21 and the outer nozzle 23 are screwed together by a male screw of the small-diameter cylindrical portion 28 and a female screw of the cylindrical portion 37. The first
An annular space 41 to which gas is supplied is formed between an outer peripheral surface 39 of the nozzle portion 29 and an inner peripheral surface 40 of the second nozzle portion 38, and a second nozzle surrounding the first nozzle hole 31. A hole 42 is formed. A plurality of through holes 43 substantially parallel to the central axis 22 and communicating the internal space 32 and the annular space 41 are formed in the peripheral wall of the first nozzle portion 29 at intervals in the circumferential direction. Here, one end face 44 of the inner nozzle 21 in the direction of the central axis 22 and one end face 45 of the outer nozzle 23 in the direction of the central axis 22 are formed so as to be included in the same virtual horizontal plane. The second nozzle holes 42 are formed radially inward of the respective through holes 43. The annular space 41 includes:
The gas inflow side is formed to be wide and the gas outflow side is formed to be narrow, and the flow path cross-sectional area becomes smaller as approaching the second nozzle hole 42. The second nozzle hole 42 is closer to the central axis 22 of the inner nozzle 21 as it goes downstream in the gas injection direction, and the upper surface 4 of a workpiece 46 described later.
7 is formed to be inclined below the center axis 22 in a direction intersecting the central axis 22.

A workpiece 46 on which a process such as cutting is performed is disposed below the emission end nozzle 20 at a distance d, for example, 1 between the upper surface 47 and one end surface 44, 45 of the emission end nozzle 20 in the direction of the central axis 22. They are arranged facing each other with an interval of about 2 mm. The workpiece 46 is made of a ferrous metal or a non-ferrous metal such as aluminum.

The length L1 of the first nozzle hole 31 in the direction of the central axis 22 is, for example, about 2 mm.
Is about 10 mm, for example, and the length L3 of the flange 26 in the direction of the central axis 22 is
Is, for example, about 2 mm, and the length L4 of the small-diameter cylindrical portion 28 in the direction of the central axis 22 is, for example, about 5 mm, and the length L5 of the first nozzle portion 29 in the direction of the central axis 22 is L5.
Is, for example, about 10 mm. The diameter D1 of the first nozzle hole 31 is about 2 mm, the distance D2 connecting the central axes of the through holes 43 on one diameter line is, for example, about 10 mm, and the outer diameter D3 of the large-diameter cylindrical portion 25 is For example, 1
The radius R of the inner peripheral surface 30 of the inner nozzle 21 is, for example, about 50 mm. Work material 46
Is selected to be about 4 to 6 mm.

FIG. 2 is a bottom view showing the appearance as viewed from below the inner nozzle 21. Outer diameter D of the flange 26
4 is, for example, about 22 mm,
Is about 16 mm, for example, and the outer diameter D6 of the one end face 44 in the direction of the central axis 22 is, for example, 4 mm.
It is about. The diameter D7 of each through hole 43 is, for example, 2 mm.
A radius line passing through the central axis 22 of the inner nozzle 21 and passing through the central axis of one through hole 43, and another through hole passing through the central axis 22 of the inner nozzle 21 and adjacent to the through hole 43. The angle θ formed by one radial line passing through the central axis of 43 is, for example, about 45 °, and the angle θ is appropriately selected according to the number of through holes 43.

FIG. 3 is a sectional view showing the structure of the outer nozzle 23. Referring also to FIG. 1, the inner nozzle 2 is provided in a truncated conical internal space 48 facing the inner peripheral surface 40.
The first first nozzle portion 29 is inserted into the annular space 41.
Is formed, and the gas outlet side opening 49 of the second nozzle portion 38 is formed.
Is formed with the second nozzle hole 42 surrounding the first nozzle hole 31.

The length L6 of the flange 35 in the direction of the central axis 22 is, for example, about 2 mm. The length L7 of the cylindrical portion 37 excluding the flange 35 in the direction of the central axis 22 is, for example, about 3 mm. The length L8 of the 38 in the direction of the central axis 22 is, for example, about 10 mm. The outer diameter D8 of the flange 35 is, for example, about 22 mm, the outer diameter D9 of the cylindrical portion 37 excluding the flange 35 is, for example, about 21 mm, and the diameter D1 of the opening 49 is
0 is, for example, about 5 mm, and the outer diameter D11 of the second nozzle portion 38 near the opening 49 is, for example, about 7 mm. The inner nozzle 21 and the outer nozzle 23 are made of, for example, oxygen-free copper.

FIG. 4 is a cross-sectional view showing the structure of a laser processing head 60 of a laser processing apparatus provided with the emission end nozzle 20. The laser processing head 60 is formed including the emission end nozzle 20 and the head main body 61. The head main body 61 has a mounting cylinder 62 to which the inner nozzle 21 is detachably mounted, and a bag which is engaged with an outward flange 63 formed on the mounting cylinder 62 and is screwed to an external thread of the adjustment cylinder 64. Nut 65, lock nuts 66, 67
And a holding cylinder 69 to which the adjusting cylinder 64 is fixed by bolts 68.
0 is attached to the base 71.
The flange of the base 71 is fixed to the X-Y
It is detachably attached to a flange 74 of an attachment member 73 such as a table or a wrist of an industrial robot.

FIG. 5 is a horizontal sectional view of the mounting cylinder 62 of the head main body 61 in FIG. A female screw 76 is engraved on the bottom 75 of the mounting cylinder 62, and the male screw 24 formed at the upper end of the inner nozzle 21 is detachably screwed thereto. A cooling water passage 77 is formed in the bottom 75 as shown in FIG.
The cooling water supplied from the connection port 78 is discharged from the other connection port 79, and the bottom 75 is cooled, so that the emission end nozzle 20 including the inner nozzle 21 and the outer nozzle 23 is cooled.

FIG. 6 is a horizontal sectional view of the holding cylinder 69 taken along the line VI-VI in FIG. A cooling water passage 80 is also formed in this holding cylinder 69, and cooling water from one connection port 81 cools the holding cylinder 69 through the cooling water passage 80 and is discharged from the other connection port 82. You.

A holding wheel 84 is housed in the holding hole 83 of the holding cylinder 69. With reference to FIG.
Are formed in a trapezoidal cylindrical portion 85 that fits tightly into the inner peripheral surface of the storage hole 83 of the retaining cylindrical body 69, a retaining portion 87 that forms a room 86 radially inward from the inner peripheral surface, and formed below the same. And a receiving portion 88 having an inward flange shape. Receiving part 8
8, an injection hole 89 is formed. On the receiving portion 88,
The lens holding ring 90 is supported, and the condenser lens 9 is placed thereon.
4 is disposed on the periphery of the condensing lens 91, and a spring holding member 94 is screwed into the holding ring 84 via a spring 93 to move the condensing lens 91 up and down in FIG. Is adjustable. Two lens holding rings 90,
Reference numeral 92 denotes a soft synthetic resin, for example, a fluororesin such as Teflon (trade name).

For example, a laser beam 95 from a carbon dioxide laser source passes through the inside of the mounting member 73, is condensed by the condenser lens 91, follows a path indicated by reference numeral 96, passes through the exit end nozzle 20, Irradiation is performed on the workpiece 46 to perform a cutting process or the like. Here, the converging point 51 of the condensed laser beam 96 is, as shown in FIG.
6 is present between the upper surface 47 and a horizontal plane passing through the center in the plate thickness direction. Referring to FIG. 4, a connection port 97 is formed on the side of holding cylinder 69, from which gas is supplied.
Through the injection hole 89 to the lower surface of the condenser lens 91 in FIG. 4, thereby cooling the condenser lens 91, and the injected gas is supplied to the space 98 below the condenser lens 91 of the head main body 61. Supplied within.

A cooling gas, for example, a gas of the same type as the above-mentioned gas is supplied to the base 71 from the connection port 99 and is injected from the nozzle 100 into the space 101 to form the condenser lens 91.
The condenser lens 91 is cooled by being sprayed onto the upper surface of the lens.

The mounting cylinder 62 is vertically displaced by adjusting the cap nut 65, whereby the distance between the first and second nozzle holes 31, 42 in the emission end nozzle 20 and the workpiece 46 is optimally set. The laser beam 95 can be adjusted so that the focal point of the laser beam 95 coincides with the workpiece 46 or the gas injection region is set accurately. This adjustment may be automated using a distance sensor or the like.

FIG. 7 shows the exit end nozzle 2 of the laser processing apparatus.
FIG. 2 is a system diagram illustrating a supply path of a gas supplied to a zero. In the laser processing head 60, a gas supply source 105
The gas can be supplied by opening the on-off valve 106 interposed in the pipe 107 and connecting the connection end 107a of the pipe 107 to the connection port 97.

FIG. 8 is a system diagram showing a schematic configuration of the laser processing apparatus 110. The laser processing device 110 includes a laser light generating unit 111, a light guiding unit 112, and a laser processing head 60. The laser light generating means 111 has, for example, a laser light 95 having an output of 2.5 kW and a wavelength of 10.6 μm.
Gas laser oscillator 11 capable of continuously irradiating
3 is included. The light guide 112 is provided between the laser beam generator 111 and the laser processing head 60, and the light guide 112 is provided with a plurality of high reflection mirrors 114. The laser beam 95 generated by the laser beam generator 111 is totally reflected by a plurality of high reflection mirrors 114 provided in the light guide 112 and guided to the laser processing head 60. The laser beam 95 guided to the laser processing head 60 is condensed in the laser processing head 60, and is emitted while the gas is ejected from the emission end nozzle 20. As a result, the laser beam irradiated portion of the upper surface 47 of the workpiece 46 is melted, and the laser beam 9 is removed while forming the cut surface 46a by removing dross by gas.
6 is moved in the cutting direction A1.

FIG. 9 shows an emission end nozzle 2 of the laser processing apparatus.
FIG. 9 is a simplified cross-sectional view for describing an operation when cutting a workpiece 46 using 0. Referring to FIGS. 1 to 8 as well, laser light 95 is condensed by condensing lens 91, and condensed laser light 96 is irradiated onto workpiece 46 from first nozzle hole 31. The gas supplied from the connection port 97 is jetted to the condenser lens 91 and the condenser lens 9
1 is supplied to the internal space 32 after being cooled. The gas supplied to the internal space 32 flows from the opening end 33a on the gas inflow side toward the opening end 33b on the gas outflow side. A part of this gas passes through each through hole 43 and is injected into the annular space 41, and the remaining gas flows from the first nozzle hole 31 to the workpiece 46 as the first gas 118, for example, 3 to 5 kg. / Cm ² . At the same time, the gas injected into the annular space 41 is supplied to the first nozzle 29
Is guided by the outer peripheral surface 39 and the inner peripheral surface 40 of the second nozzle portion 38, and is injected from the second nozzle hole 42 as the second gas 119.

The irradiated portion of the upper surface 47 of the workpiece 46 irradiated with the condensed laser beam 96 is melted, and the dross, which is the molten metal in the irradiated portion, is removed by the first gas 118 to remove the unmelted cut surface. Expose. The first gas 118 is surrounded by the second gas 119, and the second gas 119 joins from the upper surface 47 of the workpiece 46 at a position of t1, for example, about 4 mm in the thickness direction, and the second gas 119 at this position t1. Has the highest momentum. When cutting the workpiece 46, the dross is removed at the position of t1 by the second gas 119 opposite to the cutting direction A1. In this manner, the cutting process is performed on the first nozzle hole 31.
The workpiece 46 is irradiated with the laser beam 96 collected from the
Is melted and the dross is blown off and removed by the first and second gases 118 and 119 in the direction of arrow A2.

FIG. 10 shows the first and second gases 118 and 119 injected from the emission end nozzle 20 of the laser processing apparatus.
FIG. 4 is a diagram showing a pressure distribution of FIG. FIG. 10A is a pressure distribution diagram in the diameter direction of the emission end nozzle 20 at a position about 2 mm downstream from the tip of the emission end nozzle 20 in the gas injection direction, and FIG. FIG. 7 is a pressure distribution diagram in the diameter direction of the emission end nozzle 20 at a position about 6 mm downstream from the tip in the gas injection direction. The vertical line 120 in the figure indicates the center of the nozzle. In FIG. 10A, the first gas 118 is surrounded by the second gas 119, the pressure of the first gas 118 is maintained, and the first gas 118
It can be seen that the entrainment of air by the air is prevented. In FIG. 10B, it can be seen that the first gas 118 and the second gas 119 are merged, and that the pressures of the first and second gases 118 and 119 are substantially constant in a wide area. Therefore, referring also to FIG. 9, near the upper surface 47 of the workpiece 46, the dross near the upper surface 47 can be removed without the second gas 119 affecting the momentum of the first gas 118. In the vicinity of t1, the first gas 118 and the second gas 119 merge, and a high momentum gas is blown to the dross, so that the dross below the position can be sufficiently removed. Even in this case, a good cut surface can be obtained, and cutting can be easily performed.

FIG. 11 shows the first gas 118 and the second gas 11.
9 is a diagram showing a flow rate relative ratio to the flow rate of the flow rate of the flow rate to the flow rate of the flow rate 9; FIG. The straight line B in FIG.
The flow rate relative ratio of the gas 118 is shown, and the straight line C is the second gas 11.
9 shows a relative flow rate of 9; In order to cut the workpiece 46 satisfactorily, the relative flow rate of the first gas 118 is 20 to 60.
%, And the relative flow rate of the second gas 119 is 40 to 40%.
It is chosen to be about 80%. If the relative flow rate of the first gas 118 is selected to be less than 20%, the momentum necessary for removing dross near the upper surface 47 of the workpiece 46 cannot be obtained, and the dross cannot be sufficiently removed. , Cutting becomes difficult. When the relative flow rate of the first gas 118 exceeds 60%, the relative flow rate of the second gas 119 becomes 40%.
%, The momentum of the second gas 119 at the position t1 is insufficient, so that dross cannot be completely removed, causing a problem that the dross must be ground by a grinder after the cutting operation. Therefore, the relative flow rates of the first and second gases 118 and 119 are 20 to 60.
% And about 40 to 80%, and particularly preferably 50%. When the thickness of the workpiece 46 increases, the cutting process can be performed by increasing the flow rate of the second gas 119 within the above-described range.

The flow rates and flow rates of the first and second gases 118, 119 can be adjusted according to the opening amounts of the first and second nozzle holes 31, 42. The adjustment is shown in FIG.
With reference to, the opening amount of the second nozzle hole 42 of the emission end nozzle 20 can be changed by changing the size of the opening 49 on the downstream side in the gas injection direction of the outer nozzle 23. By using a plurality of outer nozzles 23 having different sizes, the flow velocity and the flow rate can be easily adjusted, which is convenient.

As described above, since the through holes 43 are formed at intervals in the circumferential direction of the inner nozzle 21, the gas is introduced into the annular space 41 without reducing the strength of the inner nozzle 21. , The second gas 119 can be injected from the second nozzle hole 42. Further, since the central axis of each of the through holes 43 is formed substantially parallel to the central axis 22 of the inner nozzle 21, the gas facing each of the through holes 43 easily passes through each of the through holes 43. Each through hole 43
The turbulence of the gas flow when passing through is reduced, and the decrease in the momentum of the gas in the annular space 41 can be further reduced. Further, the gas is guided to the annular space 41 through each through hole 43, and the first and second nozzle holes 31, 4 are provided.
Since the first and second gases 118 and 119 are injected from the second nozzle, the configuration can be simplified as compared with the case where the gas supply path is individually supplied to the inner nozzle 21 and the outer nozzle 23.

Further, as the second nozzle hole 42 is located on the downstream side in the gas injection direction, the center axis 2 of the inner nozzle 21
2, the second gas 119 can have a higher momentum as it approaches the central axis 22, and the first and second gases 11.
8, 119, the dross can be efficiently removed, the unmelted cut surface is exposed, and the workpiece 46 can be cut efficiently. Further, since the second gas 119 joins on the central axis 22 below the upper surface 47 of the workpiece 46, even if the workpiece 46 has a large thickness, the second gas 1
At the crossing position t1 of 19, a higher momentum gas is blown to the dross to sufficiently remove the dross below the position t1, and a good cut surface 46a
Can be obtained.

Further, the inner peripheral surface 30 of the inner nozzle 21
Is formed in the inner space 32 of the inner nozzle 21 so as to project radially outward from a virtual frustoconical surface 34 which is continuous with an opening end 33a on the gas inflow side and an opening end 33b on the gas outflow side facing the first nozzle hole 31. Since it is formed to be curved and the cross-sectional area of the flow passage in the inner space 32 of the inner nozzle 21 gradually decreases in the gas injection direction, the pressure loss due to the decrease in the cross-sectional area of the flow passage can be reduced. The gas is supplied to the first and second nozzle holes 31 and 42 at a large flow rate,
And the first and second gases 11 from the second nozzle hole 42.
8,119 can be injected at high speed. In this way, even if the thickness of the workpiece 46 is large, dross can be removed by blowing the higher momentum first and second gases 118 and 119 from the upper surface 47 to the lower surface 50 of the workpiece 46.

Further, the second nozzle holes 42 are provided with the respective through holes 43.
The gas injected from each through-hole 43 is guided to the outer peripheral surface 39 of the first nozzle portion 29 and the inner peripheral surface 40 of the second nozzle portion 38, and the second nozzle Since the cross-sectional area of the flow passage becomes smaller as approaching the hole 42, the gas pressure of the gas injected from each through-hole 43 in the annular space 41 is increased, and the second nozzle hole 42 is formed with a high momentum in the circumferential direction. , The second gas 119 can be injected.

In the embodiment of the present invention shown in FIGS. 1 to 11, the gas injected from the emission end nozzle 20 is air, but when the workpiece 46 is a ferrous metal, the gas is oxygen. And when it is a non-ferrous metal such as stainless steel or aluminum, the gas may be an inert gas such as nitrogen and argon.

[0047]

According to the first aspect of the present invention, the first nozzle member has a plurality of through holes which are substantially parallel to the central axis thereof and communicate the internal space of the first nozzle member with the annular space. It is formed at intervals in the direction. Since the through holes are formed at intervals in the circumferential direction of the first nozzle member, the gas is guided into the annular space without lowering the strength of the first nozzle member, and the gas is injected from the second nozzle hole. can do. Further, since the central axis of each of the through holes is formed substantially parallel to the central axis of the first nozzle member, the gas facing each of the through holes easily passes through each of the through holes. The turbulence of the gas flow when passing through is reduced, and the decrease in the momentum of the gas in the annular space can be further reduced. Further, since the gas is introduced into the annular space through each through hole and the gas is injected from the first and second nozzle holes, the gas supply path is configured as compared with the case where the gas supply path is individually supplied to the first and second nozzle members. Can be simplified.

According to the second aspect of the present invention, the second nozzle hole is formed so as to be inclined in a direction approaching the central axis of the first nozzle member toward the downstream side in the gas injection direction.
Therefore, the gas injected from the second nozzle hole can have a higher momentum as it approaches the central axis, and the gas injected from the first and second nozzle holes efficiently removes dross, which is a molten metal. Thus, the unmelted cut surface is exposed, and the workpiece can be cut efficiently.

According to the third aspect of the present invention, the gas injected from the second nozzle hole joins on the central axis below the upper surface of the workpiece. Therefore, even at a crossing position of the gas injected from the second nozzle hole even in a workpiece having a large thickness, it is possible to blow a higher momentum gas to the dross and sufficiently remove the dross below the position. And a good cut surface can be obtained.

According to the fourth aspect of the present invention, the inner peripheral surface of the first nozzle member has a gas outflow side facing the opening end on the gas inflow side and the first nozzle hole in the internal space of the first nozzle member. Is formed so as to protrude radially outward from the virtual frusto-conical surface that is continuous with the opening end of the first nozzle member, and the decrease in the cross-sectional area of the flow path in the internal space of the first nozzle member in the gas injection direction is slow. It is possible to reduce the pressure loss due to the decrease in the flow path cross-sectional area, supply the gas to the first and second nozzle holes at a large flow rate, and inject the gas at a high speed from the first and second nozzle holes. it can. In this way, even if the thickness of the workpiece is large, dross can be removed by blowing a higher momentum gas from the upper surface to the lower surface of the workpiece.

According to the fifth aspect of the present invention, the second nozzle hole is formed radially inward of each through hole. The gas injected from each through-hole is guided to the outer peripheral surface of the first nozzle member and the inner peripheral surface of the second nozzle member, and the flow path cross-sectional area becomes smaller as approaching the second nozzle hole. Thus, the gas pressure of the gas injected from each through-hole can be increased, and the gas can be injected from the second nozzle hole with a high momentum uniformly in the circumferential direction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an emission end nozzle 20 of a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is a bottom view showing the appearance of the inner nozzle 21 as viewed from below.

FIG. 3 is a sectional view showing a configuration of an outer nozzle 23.

FIG. 4 is a cross-sectional view illustrating a configuration of a laser processing head 60 of a laser processing apparatus including the emission end nozzle 20.

5 is a mounting cylinder 62 of the head main body 61 in FIG.
5 is a horizontal cross-sectional view as viewed from a section line VV in FIG.

FIG. 6 is a section line VI-V of the holding cylinder 69 in FIG. 4;
It is the horizontal sectional view seen from I.

FIG. 7 is a system diagram showing a supply path of a gas supplied to an emission end nozzle 20 of the laser processing apparatus.

FIG. 8 is a system diagram showing a schematic configuration of the laser processing apparatus 110.

FIG. 9 is a simplified cross-sectional view for explaining an operation when cutting the workpiece 46 using the emission end nozzle 20 of the laser processing apparatus.

FIG. 10 is a diagram showing a pressure distribution of first and second gases 118 and 119 injected from an emission end nozzle 20 of the laser processing apparatus.

FIG. 11 is a diagram showing a flow rate relative ratio between a first gas 118 and a second gas 119.

FIG. 12 is a simplified cross-sectional view showing a typical exit end nozzle 1 of the related art.

[Explanation of symbols]

 Reference Signs List 20 Outgoing end nozzle 21 Inner nozzle 23 Outer nozzle 30 Inner peripheral surface 31 First nozzle hole 32 Internal space 33a Open end on gas inflow side 33b Open end on gas outflow side 34 Virtual frustoconical surface 41 Annular space 42 Second nozzle hole 43 Transparent Hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mamoru Nishio 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe City, Hyogo Prefecture Inside the Kobe Plant of Kawasaki Heavy Industries, Ltd. (72) Inventor Satoru Kawabuchi Wadayama, Hyogo-ku, Kobe City, Hyogo Prefecture 2-1-1-18, Kawasaki Heavy Industries, Ltd. Hyogo Plant

Claims (5)

[Claims] 1. A condensing lens for condensing a laser beam emitted toward a workpiece is built in, coaxially mounted on a laser processing head to which gas is supplied, and condensed by the condensing lens. The first nozzle hole through which the laser beam passes and the gas is injected is formed on the center axis.
The nozzle member and the first nozzle member are coaxially mounted on the first nozzle member.
A second nozzle member that forms an annular space between the outer peripheral surface of the nozzle member and the gas supply hole and that injects gas from a second nozzle hole surrounding the first nozzle hole of the first nozzle member. In the emission end nozzle of the laser processing apparatus, the first nozzle member is provided with a plurality of through-holes substantially parallel to the central axis thereof and communicating the internal space of the first nozzle member and the annular space at circumferential intervals. An emission end nozzle of a laser processing apparatus characterized by being formed by: 2. The laser processing apparatus according to claim 1, wherein the second nozzle hole is formed so as to be inclined in a direction approaching the central axis of the first nozzle member as the downstream side in the gas injection direction. Exit nozzle of the device. 3. The second nozzle hole is closer to the central axis of the first nozzle member toward the downstream side in the gas injection direction, and is inclined below the upper surface of the workpiece in a direction intersecting the central axis. The emission end nozzle of the laser processing device according to claim 1, wherein the emission end nozzle is formed by forming the nozzle. 4. An inner peripheral surface of the first nozzle member is a virtual frustoconical surface connected to an opening end on the gas inflow side and an opening end on the gas outflow side facing the first nozzle hole in the internal space of the first nozzle member. The emission end nozzle of the laser processing apparatus according to any one of claims 1 to 3, wherein the emission end nozzle is formed so as to be curved more radially outward. 5. The emission end nozzle of a laser processing apparatus according to claim 1, wherein the second nozzle hole is formed radially inward of each through hole.