JP5889555B2 - Laser cutting method and laser cutting apparatus - Google Patents

Description

  The present invention relates to a laser cutting method and apparatus for irradiating a material to be cut with laser light, and cutting while injecting oxygen gas at and near the cutting point where the laser light is irradiated.

  Conventionally, when laser cutting a steel plate having a relatively large thickness, laser energy may be insufficient in the depth direction behind the steel plate surface. To compensate for this, high-purity oxygen gas is assisted near the cutting point. It is replenished as gas or shield gas to maintain the oxygen concentration on the back side in the plate thickness direction and cut by the heat of combustion reaction of iron and oxygen.

  For example, in Patent Document 1, a high oxygen concentration is secured in the vicinity of the cutting point, and the oxygen concentration on the rear side in the cutting progress direction is lowered from the cutting point, thereby adversely affecting the cut surface due to self-burning or the like due to excess oxygen. Techniques for preventing this have been proposed.

Japanese Patent No. 4183379

  However, in the technique of the above-mentioned Patent Document 1, since the oxygen concentration on the left and right sides in the cutting progress direction is high, there is a case where an adverse effect on the cut surface due to self-burning or the like due to excess oxygen may occur, and the cutting groove does not enter and contributes to cutting. Since there is always no oxygen gas, it is useless.

  In addition, adding a nozzle for injecting oxygen to the rear of the cutting progress direction has been conventionally performed, but the oxygen concentration in the vicinity of the cutting point maintains a substantially constant fingering property with respect to the cutting progress direction. Above, when changing the cutting progress direction, it is necessary to turn the nozzle in the cutting progress direction by a turning device or the like, or to rotate the material to be cut according to the directionality of the nozzle, the device is complicated, There was a problem that it was difficult to maintain the processing accuracy.

  The present invention solves the above-mentioned problems, and its object is to prevent adverse effects on the cut surface due to self-burning or the like due to excess oxygen, reduce oxygen gas that does not contribute to cutting, and maintain processing accuracy. It is an object of the present invention to provide a laser cutting method and a laser cutting device that can be used.

  The first configuration of the laser cutting method according to the present invention for achieving the above object is to irradiate a material to be cut with laser light and to inject oxygen gas at a cutting point where the laser light is irradiated and in the vicinity thereof. A laser cutting method for cutting, characterized in that the pressure of oxygen gas sprayed before and after the cutting progress direction from the cutting point is higher than the pressure of oxygen gas sprayed to parts other than before and after the cutting progress direction. And

The second configuration of the laser cutting method according to the present invention is a laser cutting method in which a material to be cut is irradiated with laser light, and cutting is performed while injecting oxygen gas at a cutting point where the laser light is irradiated and in the vicinity thereof. a is, the from the cutting point and the cutting point to inject oxygen gas only at the site before and after the cutting direction, and the cutting point and the oxygen gas to a site other than the front and rear cutting direction than the cutting point It is characterized by not injecting .

Further, a third configuration of the laser cutting method according to the present invention is characterized in that, in the second configuration, the gas to be injected to the cutting point and a portion other than before and after the cutting progress direction is cut off from the cutting point. And

In addition, a fourth configuration of the laser cutting method according to the present invention includes a single composition other than oxygen in the second configuration except for the cutting point and a portion other than before and after the cutting progress direction from the cutting point. A gas or a mixed gas not containing oxygen is injected.

  Further, the first configuration of the laser cutting device according to the present invention is a laser cutting device that irradiates a material to be cut with laser light and cuts while irradiating the laser beam with oxygen gas at and near the cutting point where the laser light is irradiated. And determining a plurality of nozzle ports provided around a nozzle port for emitting laser light, and nozzle ports arranged before and after the cutting point in the cutting progress direction from the plurality of nozzle ports. A high-pressure oxygen gas is supplied to the nozzle ports arranged before and after the cutting progress direction from the cutting point determined by the determining means and the nozzles arranged at sites other than before and after the cutting progress direction And gas supply means for supplying low-pressure oxygen gas to the mouth.

Further, the second configuration of the laser cutting device according to the present invention is to irradiate the material to be cut with laser light, and only at the cutting point where the laser light is irradiated and at the front and back portions in the cutting progress direction from the cutting point. A laser cutting device that injects oxygen gas and cuts the oxygen gas without injecting the oxygen gas to the cutting point and other portions before and after the cutting progress direction than the cutting point, around a nozzle port that emits laser light. A plurality of nozzle ports provided; a determination unit that determines a nozzle port disposed before and after the cutting point in the cutting progress direction from the plurality of nozzle ports; and a nozzle port that emits the laser light and the determination Oxygen gas is supplied only to the nozzle ports arranged before and after the cutting point determined by the means in the cutting progress direction , and oxygen gas is supplied to the cutting point and other parts before and after the cutting point in the cutting direction. Supply And having no gas supply means.

Further, a third configuration of the laser cutting device according to the present invention is that, in the second configuration, the gas supply means injects gas to a portion other than the cutting point and the front and rear of the cutting progress direction from the cutting point. It is characterized by blocking.

According to a fourth configuration of the laser cutting apparatus of the present invention, in the second configuration, the gas supply means is configured to provide oxygen other than oxygen at the cutting point and other portions before and after the cutting progress direction than the cutting point. A gas having a single composition or a mixed gas not containing oxygen is injected.

  According to the first configuration of the laser cutting method of the present invention, the pressure of the oxygen gas injected before and after the cutting progress direction from the cutting point is the pressure of the oxygen gas injected to a part other than the front and rear of the cutting progress direction. Higher than the cutting point, before and after the cutting progress direction, while ensuring a wide gas width in the cutting progress direction by jetting high-pressure oxygen gas and suppressing dross remaining, Reduce the pressure of the oxygen gas injected to the part, narrow the gas width on the left and right sides of the cutting progress direction, and suppress the excessive oxidation combustion reaction of the cut surface on the left and right sides of the cutting progress direction to deform the cutting groove It can suppress, generation | occurrence | production of dross, and generation | occurrence | production of the taper formed in the cut surface of the plate | board thickness direction back side of a to-be-cut material can be suppressed, and a perpendicular | vertical flat cut surface can be formed. Further, as compared with a case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

According to the second configuration of the laser cutting method of the present invention, the oxygen gas is injected only to the cutting point and the site before and after the cutting progress direction from the cutting point , and the cutting point and the cutting point are cut. by not inject oxygen gas at a site other than the front and rear in the traveling direction, the front and rear cutting direction from the cutting point and the cutting point, while suppressing the residual dross by normal oxidative combustion reactions, cutting points and the cutting By not injecting oxygen gas to the part other than before and after the cutting progress direction from the point , excessive oxidation combustion reaction of the cut surface on the left and right sides of the cutting progress direction can be suppressed, and dross generation can be suppressed. It is possible to form a vertical and flat cut surface by suppressing the occurrence of a taper formed on the cut surface on the far side in the plate thickness direction of the cutting material. Further, as compared with a case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

According to the third configuration of the laser cutting method of the present invention, the cutting of the cutting point and the gas sprayed to the part other than the front and back of the cutting progress direction from the cutting point is interrupted, and the fourth of the laser cutting method of the present invention. According to the above configuration, by injecting a gas having a single composition other than oxygen or a mixed gas not containing oxygen to the cutting point and a portion other than before and after the cutting progress direction from the cutting point , the cutting point and before and after the cutting direction than the cutting point, while suppressing the residual dross by normal oxidative combustion reaction, or not at all injected shielding gas to a site other than the front and rear cutting direction from the cutting point and the cutting point By injecting a gas having a single composition other than oxygen or a mixed gas containing no oxygen as the shielding gas, excessive oxidation combustion reaction on the cut surface on the left and right sides of the cutting progress direction is suppressed, and dross generation is prevented. Suppression To it is possible, it is possible to form a vertical flat cut surface by suppressing the occurrence of taper formed on the cut surface of the plate thickness direction rear side of the workpiece. Further, as compared with a case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

  According to the first configuration of the laser cutting device of the present invention, the determination unit determines the nozzle ports arranged before and after the cutting point in the cutting progress direction from the plurality of nozzle ports, and the gas supply unit A high-pressure oxygen gas is supplied to nozzle ports arranged before and after the cutting progress direction from the cutting point, and a low-pressure oxygen gas is supplied to nozzle ports arranged at positions other than before and after the cutting progress direction. I can do it. As a result, before and after the cutting point in the cutting progress direction, the injection of high-pressure oxygen gas ensures a wide gas width in the cutting progress direction and suppresses dross remaining, while injecting to parts other than before and after the cutting progress direction. Lowering the pressure of the oxygen gas to be performed, narrowing the gas width on the left and right sides of the cutting progress direction to suppress excessive oxidation combustion reaction of the cut surface on the left and right sides of the cutting progress direction, and suppressing deformation of the cutting groove, The generation of dross can be suppressed, and the generation of a taper formed on the cut surface on the back side in the thickness direction of the material to be cut can be suppressed to form a vertical and flat cut surface. Further, as compared with a case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

According to the second configuration of the laser cutting device according to the present invention, the determining means determines the cutting point and the nozzle ports arranged before and after the cutting progress direction from the cutting point among the plurality of nozzle ports, The gas supply means supplies oxygen gas only to the cutting point and the nozzle openings arranged before and after the cutting point in the cutting progress direction , and to the cutting point and the part other than the cutting point in the cutting progress direction than the cutting point. Oxygen gas can not be supplied . Thus, by not injecting the cut point and injecting an oxygen gas only before and after the cutting direction than the cutting point and the cutting point and the oxygen gas to a site other than the front and rear cutting direction than the cutting point, Before and after the cutting direction from the cutting point and the cutting point, while suppressing the residual dross by normal oxidative combustion reactions, inject oxygen gas at a site other than the front and rear cutting direction from the cutting point and the cutting point By not doing so, it is possible to suppress excessive oxidation combustion reaction of the cut surface on the left and right sides in the cutting progress direction, to suppress the generation of dross, and to form a taper formed on the cut surface on the back side in the plate thickness direction of the material to be cut It is possible to form a vertical and flat cut surface by suppressing the occurrence of. Further, as compared with a case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

According to the 3rd structure of the laser cutting device which concerns on this invention, the gas injected to parts other than before and after a cutting | disconnection point and this cutting progress direction is interrupted | blocked, and 4th of the laser cutting device which concerns on this invention According to the above configuration, by injecting a gas having a single composition other than oxygen or a mixed gas not containing oxygen to the cutting point and a portion other than before and after the cutting progress direction from the cutting point, the cutting point and before and after the cutting direction than the cutting point, while suppressing the residual dross by normal oxidative combustion reaction, or not at all injected shielding gas to a site other than the front and rear cutting direction from the cutting point and the cutting point By injecting a gas having a single composition other than oxygen or a mixed gas containing no oxygen as the shielding gas, excessive oxidation combustion reaction on the cut surface on the left and right sides of the cutting progress direction is suppressed, and dross generation is prevented. Suppression To it is possible, it is possible to form a vertical flat cut surface by suppressing the occurrence of taper formed on the cut surface of the plate thickness direction rear side of the workpiece. Further, as compared with a case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

It is a block diagram which shows the structure of the laser cutting device which concerns on this invention. It is a schematic explanatory view showing the configuration of gas supply means connected to a plurality of nozzle ports arranged at equal intervals around the nozzle port that emits laser light on the same circle centered on the nozzle port. It is a schematic explanatory drawing explaining a mode that the nozzle opening before and behind a cutting progress direction is selected rather than a cutting point corresponding to the change of a cutting progress direction. (A) is sectional explanatory drawing explaining the effect | action of the shield gas injected from the nozzle opening before and behind a cutting progress direction rather than a cutting point, (b) is injected from the nozzle opening before and behind a cutting progress direction rather than a cutting point. Cross-section explanatory drawing explaining the subject at the time of interrupting the shield gas which cuts off, (c) Cross-sectional explanation explaining the effect | action at the time of interrupting the shield gas injected from the nozzle port of the right and left side of a cutting progress direction rather than a cutting | disconnection point FIG. 4D is a cross-sectional explanatory diagram for explaining a problem caused by the shield gas injected from the left and right nozzle ports in the cutting progress direction from the cutting point.

  An embodiment of a laser cutting method and a laser cutting device according to the present invention will be specifically described with reference to the drawings.

  A laser cutting device 1 shown in FIG. 1 emits a laser beam 3a generated by a laser oscillator 3 from a nozzle port 4 of a laser cutting torch 16 to irradiate a material 2 to be cut such as a steel plate and the laser beam 3a. Cutting is performed while injecting oxygen gas to the irradiated cutting point 2a and its vicinity. Along with the laser beam 3a, around the central nozzle port 4 for emitting high-purity oxygen gas as an assist gas around the laser beam 3a, as shown in FIGS. Twelve (plural) nozzle ports 5a to 5l arranged at equal intervals on the same circle. Corresponding to the cutting progress direction, nitrogen gas, argon gas, helium gas among the various gases having high purity oxygen gas or single composition other than oxygen from the nozzle ports 5a to 5l selected as appropriate. Inert gas such as is injected at a predetermined pressure, or shielding gas injection is blocked.

  Of the plurality of nozzle ports 5a to 5l, the control unit 6 serving as a determination unit that determines the nozzle ports 5 arranged before and after the cutting point 2a in the direction of arrow a in FIG. The control unit 6 acquires cutting progress direction information from the cutting direction information of the specific figure stored in the NC data storage unit 7 that stores NC (numerical control) data designed in advance, and the cutting is performed. From the advancing direction information, the nozzle ports 5 arranged before and after the cutting advancing direction indicated by the arrow a direction or the arrow b direction in FIG.

  For example, when cutting in the direction of the arrow a in FIG. 3, the nozzle ports 5 arranged before and after the cutting point 2 a in the plurality of nozzle ports 5 a to 5 l are arranged at a position closer to the cutting point 2 a than the cutting point 2 a. The nozzle ports 5a to 5c arranged in front of the cutting progress direction and the nozzle ports 5g to 5i arranged behind the cutting point 2a in the cutting progress direction are selected. When cutting in the direction of the arrow b in FIG. 3, the cutting progress is made more than the cutting point 2 a as the nozzle opening 5 arranged before and after the cutting point 2 a among the plurality of nozzle openings 5 a to 5 l. The nozzle openings 5d to 5f arranged in the front of the direction and the nozzle openings 5j to 5l arranged behind the cutting point 2a in the cutting progress direction are selected.

  Then, the gas supply unit 8 serving as a gas supply means supplies high-pressure oxygen gas to the nozzle ports 5 arranged before and after the cutting point 2a determined by the control unit 6 in the cutting progress direction, and the cutting progress. Low-pressure oxygen gas is supplied to the nozzle ports 5 that are disposed at portions other than the front and rear directions. In the present embodiment, the gas supply unit 8 includes an oxygen gas supply source 11, an inert gas supply source 12, a gas type switching device 10, a traveling direction pressure regulator 13 b provided in the pressure regulating unit 13, and a lateral pressure. It has a regulator 13c, a solenoid valve 14 and the like.

  The gas pressure supplied to the nozzle ports 4, 5 a to 5 l by the gas supply unit 8 is set in advance according to the material and plate thickness of the material to be cut 2, and stores gas pressure data. Stored in the unit 9. And the control part 6 is supplied to the nozzle port 5 arrange | positioned by parts other than the front and back of a cutting | disconnection progress direction by the gas type switching apparatus 10 based on the pressure information of various gas memorize | stored in the gas pressure data storage part 9. FIG. The shield gas is selectively switched from the oxygen gas supply source 11 or the inert gas supply source 12 such as nitrogen gas, argon gas, or helium gas. The oxygen gas supply source 11 and the inert gas supply source 12 are configured by a gas cylinder (not shown), a factory gas pipe, or the like.

  Instead of the inert gas supply source 12, various gas supply sources having a single composition other than oxygen and various mixed gas supply sources not containing oxygen may be appropriately selected. For example, when a steel material such as a steel plate is laser-cut, oxygen gas or nitrogen gas is jetted as a shielding gas from the nozzle ports 5a to 5l selected as appropriate in accordance with the cutting progress direction.

  Specific examples of the mixed gas that does not include oxygen ejected from the nozzle port 5 disposed on the left and right sides of the cutting progress direction, which is a part other than the front and rear of the cutting progress direction from the cutting point 2a, include flammability such as methane gas and propane gas. A gas or a gas obtained by mixing an inert gas such as nitrogen gas, argon gas, or helium gas for controlling reactivity with these combustible gases can also be used.

  Further, as a specific example of a gas having a single composition other than oxygen injected from the nozzle port 5 disposed on the left and right sides in the cutting progress direction, which is a portion other than before and after the cutting progress direction from the cutting point 2a, nitrogen gas, An inert gas such as argon gas or helium gas can be used.

  A pressure adjusting unit 13 converts an electrical signal into a gas pressure signal based on a control signal from the control unit 6. Inside the pressure adjusting unit 13, the pressure of 99.5 mol% or more high-purity oxygen gas supplied to the central nozzle port 4 as an assist gas around the laser beam 3a from the oxygen gas supply source 11 is adjusted. An assist gas pressure regulator 13a is provided. The pressure of oxygen gas supplied to the central nozzle port 4 is set to 0.02 MPa to 0.2 MPa.

  Further, 99.5 mol of oxygen is supplied from the oxygen gas supply source 11 to the nozzle port 5 arranged before and after the cutting point 2a determined by the control unit 6 in the cutting progress direction. A traveling direction pressure regulator 13b for regulating the pressure of oxygen gas having a purity of at least% is provided. The pressure of the oxygen gas supplied to the nozzle ports 5 arranged before and after the cutting progress direction from the cutting point 2a is set to 0.02 MPa to 0.2 MPa.

  Further, the pressure adjusting unit 13 has an oxygen gas supply source 11 switched by the gas type switching device 10 or an inert gas supply source 12 from the cutting point 2a determined by the control unit 6 in the cutting progress direction. For lateral adjustment of the pressure of high-purity oxygen gas of 99.5 mol% or higher or inert gas of high purity of 99.5 mol% or higher supplied to the nozzle port 5 disposed at a position other than the front and rear. A pressure regulator 13c is provided. The pressure of the oxygen gas supplied to the nozzle port 5 arranged at a portion other than the front and rear in the cutting progress direction from the cutting point 2a is set to 0.0 MPa to 0.1 MPa, and the front and rear in the cutting progress direction from the cutting point 2a. The pressure of the inert gas supplied to the nozzle port 5 disposed at a location other than is set to 0.0 MPa to 0.5 MPa.

  The pressure adjustment unit 13 gasses an electric signal based on a control signal from the control unit 6 corresponding to each of the assist gas pressure regulator 13a, the traveling direction pressure regulator 13b, and the side pressure regulator 13c. An electro-pneumatic regulator (electro-pneumatic transformer) can be used to convert the pressure signal. The electropneumatic regulator controls the gas pressure continuously. The pressure adjustment unit 13 uses a manual pressure regulator instead of the electropneumatic regulator, and constitutes at least one of a pressure regulator for assist gas 13a, a pressure regulator for traveling direction 13b, and a side pressure regulator 13c. May be.

  In the case where oxygen gas is supplied to both the nozzle ports 5 arranged before and after the cutting point 2a in the cutting progress direction and the nozzle ports 5 arranged at positions other than the cutting point 2a and before and after the cutting direction. In this case, the pressure of the oxygen gas supplied to the nozzle ports 5 arranged before and after the cutting direction 2 is set to be more lateral than the cutting point 2a set by the traveling direction pressure regulator 13b. Is set so as to be higher than the pressure of the oxygen gas supplied to the nozzle port 5 disposed at a portion other than the front and rear in the cutting progress direction than the cutting point 2a set by the above.

  Actually, the material to be cut 2 is an SS400 steel plate with a plate thickness of 16 mm and a laser output of 6 kW. Oxygen gas with a pressure of 0.03 MPa is jetted from the nozzle port 5 arranged before and after the cutting point 2a in the cutting progress direction. FIG. 4C shows a result of laser cutting by injecting oxygen gas having a pressure of 0.01 MPa from the nozzle port 5 arranged on the left and right sides of the cutting progress direction, which is a part other than the front and rear of the cutting progress direction from the point 2a. A good cut surface having no taper 2c was obtained.

  In addition, as a material to be cut 2, an SS400 steel plate having a thickness of 25 mm and a laser output of 6 kW, an oxygen gas having a pressure of 0.025 MPa was injected from the nozzle port 5 arranged before and after the cutting point 2a in the cutting progress direction. Laser at a pressure of 0.0 MPa (that is, the shield gas on the left and right sides in the cutting progress direction is cut off) from the nozzle ports 5 arranged on the left and right sides in the cutting progress direction, which are portions other than the front and rear sides of the cutting progress direction than 2a. As a result of cutting, a good vertical cut surface having no taper 2c and a 30 ° groove cut surface as shown in FIG. 4C were obtained.

  Further, an SS400 steel plate as the material to be cut 2 is 28 mm thick, the laser output is 4 kW, oxygen gas having a pressure of 0.05 MPa is jetted from the nozzle port 5 arranged in front of and behind the cutting point 2a, and the cutting point 2a. As a result of laser cutting by injecting oxygen gas with a pressure of 0.015 MPa from the nozzle port 5 arranged on the left and right sides in the cutting progress direction, which is a part other than the front and back in the cutting progress direction, as shown in FIG. A good cut surface without the taper 2c was obtained.

  On the downstream side of the advancing direction pressure regulator 13b and the side pressure regulator 13c, there is provided an electromagnetic valve 14 for circulating / blocking the shield gas supplied to the nozzle ports 5a to 5l. In the present embodiment, as shown in FIG. 2, the nozzle ports 5a and 5g provided at positions shifted from each other by 180 degrees around the central nozzle port 4 are opened and closed by the electromagnetic valve 14c, and similarly, the nozzle ports 5b and 5h. Is opened and closed by the electromagnetic valve 14d, the nozzle ports 5c and 5i are opened and closed by the electromagnetic valve 14e, the nozzle ports 5d and 5j are opened and closed by the electromagnetic valve 14f, and the nozzle ports 5e and 5k are similarly opened and closed by the electromagnetic valve 14a. Similarly, the nozzle ports 5f and 5l are opened and closed by the electromagnetic valve 14b.

  Thereby, by operating one electromagnetic valve 14 by the control signal of the control unit 6, a pair of nozzle ports 5 arranged before and after the cutting progress direction from the cutting point 2a, or cutting progress from the cutting point 2a. The pair of left and right nozzle ports 5 arranged at portions other than the front and rear of the direction can be opened and closed at a time, and the number of electromagnetic valves 14 can be reduced.

  FIG. 4 (a) shows a state in which no dross 15 remains at the bottom of the cutting groove 2b of the workpiece 2 due to the action of the shield gas sprayed from the nozzle ports 5 before and after the cutting point 2a in the cutting progress direction. . FIG. 4 (b) shows that dross 15 remains at the bottom of the cutting groove 2b of the material 2 to be cut when the shield gas injected from the nozzle ports 5 before and after the cutting direction 2a is cut off from the cutting point 2a. Indicates. FIG. 4C shows a state in which the cut surface of the cutting groove 2b is formed to be vertical and flat when the shield gas sprayed from the nozzle ports 5 on the left and right sides in the cutting progress direction from the cutting point 2a is cut off. FIG. 4D shows a state in which the taper 2c is generated at the lower part of the cutting groove 2b by the shield gas injected from the nozzle ports 5 on the left and right sides in the cutting progress direction from the cutting point 2a.

  According to the above configuration, the control unit 6 serving as a determination unit determines the nozzle ports 5 disposed before and after the cutting point 2a in the cutting progress direction from the plurality of nozzle ports 5 that inject the shield gas, and gas The supply unit 8 supplies high-pressure oxygen gas to the nozzle ports 5 disposed before and after the cutting progress direction with respect to the cutting point 2a, and the low-pressure oxygen gas is supplied to the nozzle ports 5 disposed at positions other than before and after the cutting progress direction. Oxygen gas can be supplied. As a result, before and after the cutting progress direction from the cutting point 2a, as shown in FIG. 4A, a wide gas width is secured in the cutting progress direction by jetting high-pressure oxygen gas to suppress the remaining of the dross 15. On the other hand, the pressure of the oxygen gas injected to the part other than before and after the cutting progress direction is lowered, and as shown in FIG. The excessive oxidation combustion reaction of the cut surface on the side can be suppressed, the deformation of the cutting groove 2b can be suppressed, the generation of dross 15 can be suppressed, and it is formed on the cut surface on the far side in the plate thickness direction of the material 2 to be cut. It is possible to form a vertical and flat cut surface by suppressing the generation of the taper 2c. Further, compared to the case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point 2a, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

  In the present embodiment, when the material to be cut 2 is irradiated with the laser beam 3a and the cutting is performed while injecting oxygen gas to the cutting point 2a where the laser beam 3a is irradiated and its vicinity, the cutting progresses more than the cutting point 2a. The pressure of the oxygen gas injected before and after the direction is higher than the pressure of the oxygen gas injected to portions other than before and after the cutting progress direction. The pressure of the oxygen gas sprayed before and after the cutting progress direction from the cutting point 2a is higher than the pressure of the oxygen gas sprayed to a part other than the front and back of the cutting progress direction, so that the cutting progress direction is higher than the cutting point 2a. Before and after, as shown in FIG. 4 (a), the injection of high pressure oxygen gas ensures a wide gas width in the cutting progress direction and suppresses the remaining of the dross 15, while injecting it to parts other than the front and rear in the cutting progress direction. As shown in FIG. 4 (c), the gas width on the left and right sides in the cutting progress direction is narrowed to suppress excessive oxidation combustion reaction on the cut surfaces on the left and right sides in the cutting progress direction. Thus, the deformation of the cutting groove 2b can be suppressed, the generation of the dross 15 can be suppressed, and the generation of the taper 2c formed on the cut surface on the back side in the plate thickness direction of the material to be cut can be suppressed to be vertical and flat. A cut surface can be formed.

  As another configuration, the gas supply unit 8 may supply oxygen gas only to the nozzle ports 5 arranged before and after the cutting point 2a determined by the control unit 6 in the cutting progress direction. At that time, it is possible to shut off the gas injected to the part other than before and after the cutting progress direction by the electromagnetic valve 14, or a gas having a single composition other than oxygen, or oxygen at a part other than before and after the cutting progress direction. It is also possible to inject a mixed gas that does not contain.

  According to the above configuration, the control unit 6 serving as the determination unit determines the nozzle ports 5 arranged before and after the cutting point 2a in the cutting progress direction from the plurality of nozzle ports 5, and the gas supply unit 8 performs the cutting. Oxygen gas can be supplied only to the nozzle ports 5 arranged before and after the point 2a in the cutting progress direction. Thereby, by injecting oxygen gas only before and after the cutting progress direction from the cutting point 2a, before and after the cutting progress direction than the cutting point 2a, while suppressing the remaining of the dross 15 by a normal oxidation combustion reaction, By not injecting oxygen gas to parts other than before and after the cutting progress direction, it is possible to suppress excessive oxidative combustion reaction of the cut surface on the left and right sides of the cutting progress direction and to suppress the generation of dross 15, It is possible to form a vertical and flat cut surface by suppressing the generation of the taper 2c formed on the cut surface on the far side in the plate thickness direction. Further, compared to the case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point 2a, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

  Also, the gas to be injected to the parts other than before and after the cutting progress direction is shut off, or the gas having a single composition other than oxygen or the mixed gas not containing oxygen is injected to the parts other than before and after the cutting progress direction. As a result, before or after the cutting point 2a in the cutting progress direction, the remaining of the dross 15 is suppressed by a normal oxidative combustion reaction, and no shield gas is injected to any part other than before and after the cutting progress direction. By injecting a gas having a single composition other than oxygen or a mixed gas not containing oxygen, the excessive oxidation combustion reaction of the cut surface on the left and right sides in the cutting progress direction is suppressed, and the generation of dross 15 is suppressed. It is possible to suppress the generation of the taper 2c formed on the cut surface on the back side in the plate thickness direction of the material 2 to be cut, thereby forming a vertical and flat cut surface. Further, compared to the case where oxygen gas having the same pressure is injected in all directions in the vicinity of the cutting point 2a, adverse effects on the cut surface due to self-burning or the like due to excess oxygen can be reduced on the left and right sides in the cutting progress direction.

  In this embodiment, the gas consumption can be reduced by injecting only the gas necessary for laser cutting. Moreover, since the gas distribution optimum for laser cutting can be formed, the processing quality can be improved. Further, with respect to the oxygen concentration in the vicinity of the cutting point 2a, it is necessary to turn the laser cutting torch 16 or rotate the workpiece 2 in order to maintain a substantially constant fingering property in the cutting progress direction. There is no effect on machining accuracy.

  As an application example of the present invention, the present invention can be applied to a laser cutting method and apparatus for irradiating a material to be cut with laser light, and cutting while injecting oxygen gas at and near the cutting point where the laser light is irradiated.

DESCRIPTION OF SYMBOLS 1 ... Laser cutting apparatus 2 ... Material to be cut 2a ... Cutting point 2b ... Cutting groove 2c ... Taper 3 ... Laser oscillator 3a ... Laser beam 4 ... Nozzle port 5, 5a-5l ... Nozzle port 6 ... Control part (determination means)
7: NC data storage unit 8: Gas supply unit (gas supply means)
9 ... Gas pressure data storage
10… Gas type switching device
11… Oxygen gas supply source
12… inert gas source
13… Pressure adjustment section
13a ... Pressure regulator for assist gas
13b ... Pressure regulator for the direction of travel
13c… Side pressure regulator
14, 14a-14f ... Solenoid valve
15 ... Dross
16 ... Laser cutting torch

Claims (8)

A laser cutting method of irradiating a material to be cut with laser light, and cutting while injecting oxygen gas to the cutting point where the laser light is irradiated and in the vicinity thereof,
A laser cutting method, characterized in that the pressure of oxygen gas injected before and after the cutting progress direction is higher than the pressure of oxygen gas injected to parts other than the cutting point before and after the cutting point. A laser cutting method of irradiating a material to be cut with laser light, and cutting while injecting oxygen gas to the cutting point where the laser light is irradiated and in the vicinity thereof,
Not to inject than said cutting point and the cutting point to inject oxygen gas only at the site before and after the cutting direction, and the cutting point and the oxygen gas to a site other than the front and rear cutting direction than the cutting point A featured laser cutting method. The laser cutting method according to claim 2, wherein a gas sprayed to the cutting point and a portion other than before and after the cutting progress direction is cut off from the cutting point . The gas having a single composition other than oxygen or a mixed gas not containing oxygen is sprayed to the cutting point and a portion other than before and after the cutting progress direction from the cutting point . Laser cutting method. A laser cutting device that irradiates a material to be cut with laser light and cuts oxygen gas at a cutting point where the laser light is irradiated and in the vicinity thereof,
A plurality of nozzle openings provided around the nozzle openings for emitting laser light;
Judgment means for judging the nozzle ports arranged before and after the cutting point in the cutting progress direction from among the plurality of nozzle ports;
A high-pressure oxygen gas is supplied to the nozzle ports arranged before and after the cutting progress direction from the cutting point determined by the determining means, and the low pressure is applied to the nozzle ports arranged at sites other than before and after the cutting progress direction. Gas supply means for supplying oxygen gas of
A laser cutting device comprising: While irradiating the material to be cut with laser light, oxygen gas is injected only to the cutting point where the laser light is irradiated and to the front and back portions of the cutting progress direction from the cutting point, and more than the cutting point and the cutting point. A laser cutting device for cutting without spraying oxygen gas to parts other than before and after in the cutting progress direction ,
A plurality of nozzle openings provided around the nozzle openings for emitting laser light;
Judgment means for judging the nozzle ports arranged before and after the cutting point in the cutting progress direction from among the plurality of nozzle ports;
Oxygen gas is supplied only to the nozzle port that emits the laser light, the cutting point determined by the determination unit, and the nozzle port arranged before and after the cutting point in the cutting progress direction , and the cutting point and the cutting point Gas supply means that does not supply oxygen gas to sites other than before and after the cutting progress direction from the cutting point ;
A laser cutting device comprising: The laser cutting apparatus according to claim 6, wherein the gas supply unit cuts off the gas to be injected to the cutting point and a portion other than the front and rear sides of the cutting progress direction from the cutting point . The gas supply means injects a gas having a single composition other than oxygen or a mixed gas not containing oxygen to the cutting point and a portion other than before and after the cutting progress direction from the cutting point. The laser cutting device according to claim 6.

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