JP6809345B2 - Laser processing equipment and laser processing method - Google Patents

Description

The present invention relates to a laser processing apparatus and a laser processing method.

The laser machining apparatus irradiates the workpiece with laser light to melt a part of the workpiece to perform cutting, and during this cutting, the melt can be removed from the workpiece with an assist gas. It is done. When cutting a work piece containing aluminum as a main component using such a laser processing device, the melt may solidify with the melt adhering to the back surface side of the work piece even if an assist gas is supplied. .. When the dross, which is a solidified product, adheres to the work piece, a step of removing the dross by hand or by using a removing device is required. On the other hand, there is known a technique for reducing the amount of dross adhering by using a mixed gas of nitrogen gas and oxygen gas as an assist gas (see, for example, Patent Document 1).

Japanese Patent No. 4869640

In the laser processing apparatus of Patent Document 1 described above, dross adheres by supplying a mixed gas of nitrogen gas and oxygen gas having a nitrogen gas concentration of 99.5% by volume to 99.9% by volume as an assist gas. There is a description that it can be reduced. However, Patent Document 1 does not mention the type of laser light. In recent years, a laser processing apparatus for cutting a workpiece by a laser beam output from a fiber laser has been provided. According to the experiment of the present inventor, when the workpiece is cut by the laser light output from such a fiber laser, if the mixing ratio of nitrogen gas and oxygen gas is set to the range shown in Patent Document 1, dross is generated. It was confirmed that a large amount of it adhered.

In view of the above circumstances, the present invention is laser processing capable of reducing the amount of dross adhered when cutting a workpiece containing aluminum as a main component by laser light output from a fiber laser. It is an object of the present invention to provide an apparatus and a laser processing method.

The laser processing apparatus according to the present invention is a laser processing apparatus that cuts a workpiece by supplying assist gas to the workpiece while irradiating the workpiece containing aluminum as a main component with laser light. A laser output unit equipped with a fiber laser that outputs light, an irradiation unit that collects the laser light from the laser output unit with the surface of the workpiece as a single focal point position, and an oxygen gas concentration of 0.7 as an assist gas. It is provided with a supply unit for supplying a mixed gas of nitrogen gas and oxygen gas, which is by volume% to 1.7% by volume, to the workpiece.

Further, the laser beam may have a wavelength of 1080 nm. In addition, a concentration sensor that measures the oxygen concentration or nitrogen concentration of the assist gas supplied from the supply unit, an adjustment unit that adjusts the concentration of oxygen gas or nitrogen gas in the assist gas, and an adjustment unit according to the measurement result of the concentration sensor. It may be provided with a control unit for operating the above. Further, the supply unit may supply a mixed gas of nitrogen gas and oxygen gas having an oxygen gas concentration of 1.0% by volume to 1.5% by volume to the workpiece as an assist gas. Further, the irradiation unit may collect the laser light so that the diameter of the laser light on the surface of the workpiece is approximately 100 μm. Further, a moving portion for moving the irradiation position of the laser beam with respect to the workpiece may be provided, and the relative speed between the workpiece and the laser beam due to the moving portion may be in the range of 5 m / min to 20 m / min. .. Further, the plate thickness of the work piece may be 1.5 mm to 4.0 mm.

Further, the laser processing method according to the present invention is a laser processing method for cutting a work piece by supplying an assist gas to the work piece while irradiating the work piece containing aluminum as a main component with laser light. , The laser light is output by the fiber laser, the output laser light is focused on the surface of the work piece as a single focal point position, and the concentration of nitrogen gas as an assist gas is 98.3% by volume to 99. Includes supplying the workpiece with a mixed gas of 3% by volume of nitrogen gas and oxygen gas.

The present inventor irradiates a laser beam output by a fiber laser to cut a work piece, and as an assist gas, nitrogen gas and oxygen having an oxygen gas concentration of 0.7% by volume to 1.7% by volume. It has been found that it is possible to reduce the amount of dross adhered by supplying a mixed gas with gas to the work piece. Therefore, according to the laser processing apparatus and the laser processing method according to the present invention, a mixed gas of nitrogen gas and oxygen gas having an oxygen gas concentration of 0.7% by volume to 1.7% by volume is processed as an assist gas. Since the supply unit for supplying the object is provided, it is possible to reduce the amount of dross adhered when cutting the workpiece by irradiating the laser beam output by the fiber laser.

Further, when the wavelength of the laser light is 1080 nm, the wavelength of 1080 nm is the main wavelength of the laser light output by the fiber laser, and even when the laser light of this wavelength is used, the amount of dross adhered can be reliably reduced. it can. In addition, a concentration sensor that measures the oxygen concentration or nitrogen concentration of the assist gas supplied from the supply unit, an adjustment unit that adjusts the concentration of oxygen gas or nitrogen gas in the assist gas, and an adjustment unit according to the measurement result of the concentration sensor. When the control unit for operating the above is provided, the concentration of nitrogen gas in the assist gas can be automatically adjusted within the above range, and the amount of dross adhered can be easily and surely reduced. Further, when the supply unit supplies a mixed gas of nitrogen gas and oxygen gas having an oxygen gas concentration of 1.0% by volume to 1.5% by volume as an assist gas to the work piece, the amount of dross adhered is increased. It can be 0 or almost 0. Further, even when the laser beam is focused by the irradiation unit so that the diameter of the laser beam on the surface of the workpiece is approximately 100 μm, the amount of dross adhered can be reliably reduced. Further, even when a moving portion for moving the laser beam irradiation position with respect to the workpiece is provided and the relative speed between the workpiece and the laser beam due to the moving portion is in the range of 5 m / min to 20 m / min. , The amount of dross adhered can be surely reduced. Further, when the plate thickness of the work piece is 1.5 mm to 4.0 mm, the amount of dross adhered can be reliably reduced.

It is a schematic diagram which shows an example of the laser processing apparatus which concerns on this embodiment. It is a figure which shows an example of the laser beam which irradiates a work piece with a laser processing apparatus. It is a figure which shows an example of the cut part at the time of processing a workpiece by using a laser processing apparatus. It is a graph which shows the relationship between the nitrogen concentration and the dross amount adhering to a work piece for each relative velocity of a work piece and a laser beam when the work piece is machined by a laser processing apparatus. It is a graph which shows the relationship between the nitrogen concentration and the amount of dross adhering to a work piece for each plate thickness of a work piece when the work piece is machined by a laser processing apparatus. It is a flowchart which shows an example of the laser processing method which concerns on this Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to this. Further, in the drawings, in order to explain the embodiment, the scale is appropriately changed and expressed, such as drawing a part in a large or emphasized manner. In each of the following figures, the directions in the figure will be described using the XYZ coordinate system. In this XYZ coordinate system, a plane parallel to the horizontal plane is defined as an XY plane. An arbitrary direction parallel to the XY plane is referred to as the X direction, and a direction orthogonal to the X direction is referred to as the Y direction. Further, the direction perpendicular to the XY plane is referred to as the Z direction. In each of the X direction, the Y direction, and the Z direction, the direction of the arrow in the drawing is the + direction, and the direction opposite to the direction of the arrow is the − direction.

FIG. 1 is a diagram showing an example of a laser processing apparatus according to an embodiment. The laser processing apparatus 100 can emit the laser beam L to cut the workpiece W. As shown in FIG. 1, the laser processing apparatus 100 includes a laser head 10, a laser output unit 20, a head moving unit (moving unit) 30, an assist gas supply unit (supply unit) 40, and a control unit 50. The laser head 10 is connected to the laser output unit 20, and converges the laser light L output from the laser output unit 20 and emits the laser light L toward the workpiece W.

The laser head 10 has a head body 11 and a nozzle 12. The head main body 11 can be moved in the X direction, the Y direction, and the Z direction by the head moving portion 30. The head body 11 has an irradiation unit 13 for irradiating the laser beam L. The irradiation unit 13 has a collimating lens 13a, a protective glass 13b, and a condensing lens 13c. The collimating lens 13a forms the laser light L diverged and emitted from the tip of the optical transmitter 22 of the laser output unit 20 described later as parallel light. Although FIG. 1 shows one optical element (lens) as the collimating lens 13a, a plurality of optical elements may be used in combination.

The condensing lens 13c condenses the laser beam L formed in parallel light by the collimated lens 13a with the surface Wa of the workpiece W as the single focal point position, and forms a spot S on the surface of the workpiece W. The protective glass 13b is arranged on the nozzle 12 side with respect to the condenser lens 13c, and prevents the melt from adhering to the condenser lens 13c when the workpiece W is melted and scattered by the laser beam L. FIG. 2 is a diagram showing an example of a spot S formed on the surface of the workpiece W. As shown in FIG. 2, the spot S has a circular shape, but is not limited to this, and may have another shape such as an elliptical shape, an oval shape, or a polygonal shape. The condensing lens 13c condenses the laser beam L so that the diameter R of the spot S on the surface Wa of the workpiece W is, for example, approximately 100 μm. Although FIG. 1 shows one optical element as the condenser lens 13c, a plurality of optical elements may be used in combination.

The nozzle 12 has a nozzle port 15. A conical trapezoidal tubular body with a small diameter on the tip side is used, and is attached to the lower end of the head body 11. The nozzle 12 emits the laser beam L focused by the condenser lens 13c from the nozzle opening 15 toward the workpiece W. The diameter of the nozzle 12 decreases toward the tip according to the focused laser beam L. The nozzle 12 may be replaceable. The nozzle 12 is formed in a circular shape in a cross section parallel to the XY plane, but is not limited to this, and may be an elliptical shape, an oval shape, or a polygonal shape.

Further, the nozzle 12 is connected to the assist gas supply unit 40 via the gas supply pipe 44 described later. The nozzle 12 discharges the assist gas G supplied from the assist gas supply unit 40 via the gas supply pipe 44 from the nozzle port 15 toward the workpiece W. The nozzle 12 functions as a emitting portion of the laser beam L and also functions as a discharging portion of the assist gas. The single nozzle 12 is not limited to emitting the laser beam L and discharging the assist gas G. For example, the laser beam L may be emitted from the nozzle 12, and the assist gas G may be discharged from a member different from the nozzle 12.

The laser output unit 20 includes a laser oscillator 21 and an optical transmitter 22. The laser output unit 20 is, for example, a fiber laser. The laser oscillator 21 includes a light source (not shown) that emits excitation light, amplifies the excitation light, and emits, for example, laser light L having a wavelength of 1080 nm. The laser oscillator 21 can adjust the output of the laser beam L based on the control of the control unit 50. The laser oscillator 21 emits the laser beam L to the optical transmitter 22. For example, an optical fiber or the like is used in the optical transmitter 22, and the laser beam L emitted from the laser oscillator 21 is transmitted to the irradiation unit 13 of the laser head 10.

The head moving unit 30 moves the laser head 10 in the X direction, the Y direction, and the Z direction. The head moving portion 30 is composed of, for example, a gantry that can move in the X direction, a slider that can move in the Y direction with respect to the gantry, and an elevating portion that can move in the Z direction with respect to the slider. The head moving unit 30 can move the laser head 10 to a predetermined position in the X direction, the Y direction, and the Z direction by driving each drive source, and can position the laser head 10 at an arbitrary position on the workpiece W. .. However, the configuration of the head moving unit 30 is not limited to this, and any configuration capable of moving the laser head 10 can be applied, for example, the laser head 10 is held by a robot arm, a manipulator, or the like. It may be a configuration.

The assist gas supply unit 40 includes a nitrogen gas supply source 41, an oxygen gas supply source 42, an adjustment unit 43, a gas supply pipe 44, and a concentration sensor 17. The nitrogen gas supply source 41 supplies the nitrogen gas constituting the assist gas to the adjusting unit 43. As the nitrogen gas supply source 41, for example, a nitrogen gas cylinder, an existing nitrogen gas line in a factory or the like is used. The oxygen gas supply source 42 supplies the oxygen gas constituting the assist gas to the adjusting unit 43. The oxygen gas supply source 42 may be configured to supply air, for example, as long as it can supply a gas containing oxygen gas.

The adjusting unit 43 mixes the nitrogen gas supplied from the nitrogen gas supply source 41 with the oxygen gas supplied from the oxygen gas supply source 42 to generate the assist gas G. The adjusting unit 43 adjusts the concentration of nitrogen gas in the assist gas G by adjusting the flow rate of the nitrogen gas supplied from the nitrogen gas supply source 41 and the flow rate of the oxygen gas supplied from the oxygen gas supply source 42. To do. The adjustment by the adjusting unit 43 is performed, for example, by increasing the flow rate of oxygen gas from the state of supplying only nitrogen gas.

As the assist gas G, the adjusting unit 43 generates, for example, a mixed gas having a concentration of oxygen gas of 0.7% by volume to 1.7% by volume. In this case, the concentration of nitrogen gas in the assist gas G is about 98.3% by volume to 99.3% by volume. The adjusting unit 43 can generate, for example, a mixed gas having an oxygen gas concentration of 1.0% by volume to 1.5% by volume as the assist gas G. In this case, the concentration of nitrogen gas in the assist gas G is about 98.5% by volume to 99.0% by volume. The adjusting unit 43 supplies the generated mixed gas to the nozzle 12 of the laser head 10 via the gas supply pipe 44.

The gas supply pipe 44 supplies the assist gas G adjusted by the adjusting unit 43 into the nozzle 12. The concentration sensor 17 is arranged in a part of the gas supply pipe 44. The concentration sensor 17 measures the oxygen concentration or the nitrogen concentration of the assist gas G supplied to the nozzle 12. As the concentration sensor 17, a known oxygen concentration meter, nitrogen concentration meter, or the like is used. In the present embodiment, the concentration sensor 17 uses an oxygen concentration meter that measures the oxygen concentration. The concentration sensor 17 outputs the measurement result to the control unit 50. The concentration sensor 17 and the control unit 50 are connected wirelessly or by wire. The concentration sensor 17 is not limited to being arranged in a part of the gas supply pipe 44. For example, the density sensor 17 may be arranged in the nozzle 12 or in the adjusting unit 43. Further, as the concentration sensor 17, a nitrogen concentration meter for measuring the nitrogen concentration may be used instead of the oxygen concentration meter. Further, it is optional whether or not the density sensor 17 is installed, and the density sensor 17 may not be installed.

The control unit 50 controls the operations of the laser oscillator 21, the head moving unit 30, the assist gas supply unit 40 (adjusting unit 43), and the like. The control unit 50 has an arithmetic processing unit such as a CPU (Central Processing Unit) and a storage device such as a main storage device and an auxiliary storage device (not shown). The storage device stores various information such as various programs such as a processing program and processing conditions of the workpiece W. The control unit 50 reads a machining program from a storage device or the like, operates the laser head 10, the head moving section 30, the adjusting section 43, etc. according to this machining program, and cuts a part of the workpiece W by the laser beam L to produce a product. To form. The machining program includes the output of laser light L and the assist gas G according to the machining conditions such as the material and thickness of the workpiece W, in addition to the moving path and moving speed of the laser head 10 that conform to the dimensions of the product. The ejection amount of the assist gas G, the nitrogen concentration of the assist gas G, the oxygen concentration, and the like may be included.

In the present embodiment, the workpiece W is a plate-shaped member containing aluminum as a main component. The plate thickness t of the workpiece W is, for example, 1.5 mm to 4.0 mm. The workpiece W is processed while being placed on the processing pallet P. The processing pallet P has, for example, a sawtooth-shaped, wavy, or sword-shaped mounting portion Pa on which the workpiece W is placed. The processing pallet P can convey the workpiece W in a state where the workpiece W is placed on the upper end of the mounting portion Pa.

FIG. 3 is a diagram showing an example of a cut portion when the workpiece W is machined by using the laser machining apparatus 100. As shown in FIG. 3, when cutting the workpiece W using the laser processing apparatus 100, a part of the workpiece W is melted from the surface Wa of the workpiece W by the laser beam L, and this melt is formed. Is blown downward by the assist gas G. However, there is a case where the melt is solidified with the melt adhering to the back surface Wb side of the workpiece W. When the solidified dross D remains on the workpiece W, for example, a step of removing the dross D by hand or by using a removing device is required.

On the other hand, the present inventor irradiates the laser beam L output by the laser output unit 20 (fiber laser) to cut the workpiece W, and the concentration of the oxygen gas as the assist gas G is 0.7. By supplying a mixed gas of nitrogen gas and oxygen gas, which is by volume% to 1.7% by volume, to the workpiece W, the amount of dross adhered (height H shown in FIG. 3; hereinafter, referred to as dross amount). It was found that it is possible to reduce.).

FIG. 4 shows the relationship between the nitrogen concentration and the amount of dross adhering to the workpiece when the workpiece W is machined by the laser machining apparatus 100 according to the present embodiment. It is a graph which shows for each relative velocity. The vertical axis of FIG. 4 shows the amount of dross (unit: mm), and the horizontal axis shows the nitrogen concentration (unit:%). Note that FIG. 4 shows a case where the plate thickness t of the workpiece W is 1.5 mm.

As shown in FIG. 4, when the relative velocities of the workpiece W and the laser beam L are 5 m / min, 10 m / min, 15 m / min, and 20 m / min, the assist gas G is used in all cases. It is confirmed that the amount of dross (that is, the length of the adhering dross) is about 0.03 mm or less in the range where the concentration of oxygen gas is 0.7% by volume to 1.7% by volume.

Further, as shown in FIG. 4, when the relative speeds of the workpiece W and the laser beam L are 5 m / min, 10 m / min, 15 m / min, and 20 m / min, the oxygen of the assist gas G is oxygen. It is confirmed that the amount of dross adhered is about 0.01 mm or less in the range where the gas concentration is 1.0% by volume to 1.5% by volume. Further, when the relative velocity between the workpiece W and the laser beam L is 10 m / min, the amount of dross is in the range where the oxygen gas concentration of the assist gas G is 1.0% by volume to 1.5% by volume. It is confirmed that it becomes almost 0 mm.

Specifically, when the relative velocity between the workpiece W and the laser beam L is 5 m / min, the oxygen gas concentration of the assist gas G is in the range of 0.7% by volume to 1.7% by volume. It is confirmed that the dross amount is about 0.03 mm or less. Further, it is confirmed that the dross amount is about 0.01 mm in the range where the oxygen gas concentration of the assist gas G is 1.0% by volume to 1.5% by volume.

Further, when the relative velocity between the workpiece W and the laser beam L is 10 m / min, the amount of dross is in the range where the oxygen gas concentration of the assist gas G is 0.7% by volume to 1.7% by volume. It is confirmed that it is about 0.02 mm or less. Further, it is confirmed that the amount of dross becomes almost 0 mm in the range where the concentration of the oxygen gas of the assist gas G is 1.0% by volume to 1.5% by volume, and almost no dross remains.

Further, when the relative velocity between the workpiece W and the laser beam L is 15 m / min, the amount of dross is in the range where the oxygen gas concentration of the assist gas G is 0.7% by volume to 1.7% by volume. It is confirmed that it is about 0.02 mm or less. Further, it is confirmed that the amount of dross adhered is about 0.01 mm in the range where the oxygen gas concentration of the assist gas G is 1.0% by volume to 1.5% by volume.

Further, when the relative velocity between the workpiece W and the laser beam L is 20 m / min, the dross amount is in the range where the oxygen gas concentration of the assist gas G is 0.7% by volume to 1.7% by volume. It is confirmed that it is about 0.02 mm or less. Further, it is confirmed that the dross amount is about 0.01 mm in the range where the oxygen gas concentration of the assist gas G is 1.0% by volume to 1.5% by volume.

FIG. 5 shows the relationship between the nitrogen concentration and the amount of dross adhering to the workpiece W when the workpiece W is machined by the laser machining apparatus 100 according to the present embodiment for each plate thickness t of the workpiece W. It is a graph shown in. The vertical axis of FIG. 5 shows the amount of dross (unit: mm), and the horizontal axis shows the nitrogen concentration (unit:%). Note that FIG. 5 shows a case where the relative speed between the workpiece W and the laser beam L is 10 m / min.

As shown in FIG. 5, when the plate thickness t of the workpiece W is 1.5 mm, 2.0 mm, and 4.0 mm, the oxygen gas concentration of the assist gas G is 0.7 volume in any case. It is confirmed that the amount of dross (that is, the length of the adhering dross) is about 0.1 mm or less in the range of% to 1.7% by volume.

Specifically, when the plate thickness t of the workpiece W is 1.5 mm, the amount of dross is about in the range where the oxygen gas concentration of the assist gas G is 0.7% by volume to 1.7% by volume. It is confirmed that it is 0.03 mm or less. Further, it is confirmed that the amount of dross becomes almost 0 mm in the range where the concentration of the oxygen gas of the assist gas G is 1.0% by volume to 1.5% by volume, and almost no dross remains.

Further, when the plate thickness t of the workpiece W is 2.0 mm, the dross amount is about 0.08 mm in the range where the oxygen gas concentration of the assist gas G is 0.7% by volume to 1.7% by volume. It is confirmed that: Further, it is confirmed that the dross amount is about 0.02 mm in the range where the oxygen gas concentration of the assist gas G is 1.0% by volume to 1.5% by volume%.

Further, when the plate thickness t of the workpiece W is 4.0 mm, the dross amount is about 0.1 mm in the range where the oxygen gas concentration of the assist gas G is 0.7% by volume to 1.7% by volume. It is confirmed that: Further, it is confirmed that the dross amount is about 0.05 mm in the range where the oxygen gas concentration of the assist gas G is 1.0% by volume to 1.5% by volume.

Next, the operation of the laser processing apparatus 100 described above will be described with reference to FIG. In the explanation of the flowchart of FIG. 6, FIGS. 1 to 3 are appropriately used. The control unit 50 executes the set machining program and operates the laser head 10 to start cutting the workpiece W. The control unit 50 may control the laser machining apparatus 100 in an integrated manner. In this case, the control unit 50 also controls operations such as loading or unloading of the workpiece W with respect to the machining region of the laser machining apparatus 100. That is, the movement of the processing pallet P on which the workpiece W is placed may also be controlled by the control unit 50.

The workpiece W is carried into the machining area of the laser machining apparatus 100 in a state of being placed on the machining pallet P. The control unit 50 causes the adjusting unit 43 to adjust a mixed gas having an oxygen gas concentration of 0.7% by volume to 1.7% by volume as the assist gas G, and causes the nozzle 12 to adjust the mixed gas via the gas supply pipe 44. To supply. As shown in FIG. 6, the assist gas G is discharged from the nozzle 12 and supplied to the surface Wa of the workpiece W (step ST01). The control unit 50 may control the adjustment unit 43 so that the concentration of oxygen gas is in the range of 1.0% by volume to 1.5% by volume.

In this state, the concentration sensor 17 measures the concentration of nitrogen gas or oxygen gas of the assist gas G supplied from the adjusting unit 43 to the nozzle 12 (step ST02). In step ST02, the concentration sensor 17 measures the concentration of the assist gas G supplied to the nozzle 12, that is, the nitrogen gas or oxygen gas of the assist gas G immediately before being supplied to the workpiece W, thereby causing the assist gas. The concentration of nitrogen gas or oxygen gas contained in G can be measured with high accuracy. The measurement result measured by the concentration sensor 17 is output to the control unit 50.

The control unit 50 determines whether or not the measurement result by the concentration sensor 17 is a value in the set range (step ST03). In step ST03, the control unit 50 calculates the oxygen gas concentration based on the measurement result. When the calculation result is in the range of, for example, 0.7% by volume to 1.7% by volume, the control unit 50 determines that the measurement result of the concentration sensor 17 is in the set range (YES in step ST03). Further, when the calculation result is out of the range of, for example, 0.7% by volume to 1.7% by volume, the control unit 50 determines that the measurement result of the concentration sensor 17 is not in the set range (NO in step ST03). The control unit 50 may make the above determination by setting the setting range of the oxygen gas concentration to 1.0% by volume to 1.5% by volume.

When the control unit 50 determines that the measurement result of the concentration sensor 17 is not within the set range (YES in step ST03), the control unit 50 causes the adjustment unit 43 to adjust the concentration of nitrogen gas or oxygen gas of the assist gas G (step ST04). In step ST04, for example, when the calculation result of the oxygen gas concentration based on the measurement result of the concentration sensor 17 exceeds 1.7% by volume (or 1.5% by volume), the control unit 50 determines the oxygen gas concentration of the assist gas G. The adjusting unit 43 is controlled so as to reduce.

Further, for example, when the calculation result of the oxygen gas concentration described above is less than 0.7% by volume (or 1.0% by volume), the control unit 50 increases the oxygen gas concentration of the assist gas G so as to increase the oxygen gas concentration 43. To control. The adjusting unit 43 adjusts the nitrogen gas concentration or the oxygen gas concentration of the assist gas G under the control of the control unit 50, and supplies the adjusted assist gas G to the nozzle 12 (step ST04). It should be noted that steps ST01 to ST04 may be executed after steps ST05 and ST06, which will be described later, or may be executed at the same time. That is, the assist gas G may be supplied and the oxygen gas or nitrogen gas concentration may be adjusted after the laser output unit 20 outputs from the laser light L, or the assist gas may be output from the laser light L from the laser output unit 20 at the same time. The supply of G and the adjustment of the oxygen gas or nitrogen gas concentration may be carried out.

On the other hand, when the control unit 50 determines that the measurement result of the concentration sensor 17 is within the set range (YES in step ST05), the control unit 50 drives the laser oscillator 21 of the laser output unit 20 and outputs the laser beam L from the laser oscillator 21. (Step ST05). In step ST05, the laser oscillator 21 emits the output laser light L to the optical transmitter 22. The laser light L is transmitted from the optical transmitter 22 to the irradiation unit 13 of the laser head 10.

In the laser head 10, the irradiation unit 13 collects the laser light L transmitted from the optical transmitter 22 and irradiates the surface Wa of the workpiece W as a spot S having a diameter of about 100 μm (step ST06). The spot S of the laser beam L may be set by the condenser lens 13c of the irradiation unit 13, or may be set by the height of the laser head 10 with respect to the workpiece W (depending on the position in the Z direction). When the laser beam L is irradiated by ST06, the cutting process of the workpiece W is started (step ST07).

In step ST07, the control unit 50 irradiates the workpiece W with the laser beam L from the laser head 10 with the workpiece W placed on the machining pallet P, and applies the assist gas G adjusted as described above. Supply. In this state, the control unit 50 cuts the workpiece W by moving the laser head 10 relative to the workpiece W in the X or Y direction, for example, at a moving speed of 5 m / min to 20 m / min. Process. The workpiece W is cut by the laser beam L and then carried out from the laser processing apparatus 100 while being placed on the processing pallet P, for example.

As described above, the laser processing apparatus 100 and the laser processing method according to the present embodiment are a mixture of nitrogen gas and oxygen gas having an oxygen gas concentration of 0.7% by volume to 1.7% by volume as the assist gas G. Since the assist gas supply unit 40 that supplies gas to the workpiece W is provided, the amount of dross adhered when the workpiece W is cut by irradiating the laser beam L output by the laser output unit 20 (fiber laser). Can be reduced. This makes it possible to reduce or eliminate post-treatment such as deburring after cutting the workpiece W, and improve processing efficiency.

Although the embodiments have been described above, the present invention is not limited to the above description, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the case where the wavelength of the laser beam L is 1080 nm has been described as an example, but the present invention is not limited to this. For example, the wavelength of the laser beam L may be another value in the range of 1030 nm to 1100 nm.

Further, in the above-described embodiment, the configuration in which one density sensor 17 is arranged has been described as an example, but the present invention is not limited to this. For example, the concentration sensor 17 may be arranged in a plurality of places such as the nozzle 12 and the adjusting unit 43 in addition to the gas supply pipe 44.

Further, in the above-described embodiment, when adjusting the concentration of oxygen gas or nitrogen gas in the assist gas G, a case where the adjustment unit 43 is controlled by the control unit 50 according to the measurement result of the concentration sensor 17 will be described as an example. However, it is not limited to this. For example, the control unit 50 is based on the flow rate of nitrogen gas supplied from the nitrogen gas supply source 41 to the adjustment unit 43 and the flow rate of oxygen gas (or air) supplied from the oxygen gas supply source 42 to the adjustment unit 43. The concentration of oxygen gas or nitrogen gas may be estimated, and the adjusting unit 43 may be controlled based on the estimation result. Further, the control unit 50 is not limited to controlling the adjustment unit 43, and for example, the adjustment unit 43 may be manually operated by an operator to adjust the concentration of oxygen gas or nitrogen gas of the assist gas G. Good. In this case, the value of the concentration sensor 17 is displayed by, for example, a display unit or the like, and the operator may operate the adjusting unit 43 while observing this display to adjust the concentration of oxygen gas or nitrogen gas of the assist gas G. ..

Further, in the above-described embodiment, a case where the irradiation unit 13 collects the laser beam L so that the diameter R of the spot S of the laser beam L on the surface Wa of the workpiece W is approximately 100 μm is given as an example. As described above, the present invention is not limited to this, and the diameter R of the spot S may be set to 100 μm or less, or the diameter R of the spot S may be set to 100 μm or more.

Further, in the above-described embodiment, the relative speed between the workpiece W by the head moving portion 30 and the spot S of the laser beam L has been described by taking as an example a range of 5 m / min to 20 m / min. Not limited. The relative velocity between the workpiece W and the spot S of the laser beam L may be 5 m / min or less, or 20 m / min or more. Further, in the above-described embodiment, the configuration in which the laser head 10 moves with respect to the workpiece W by the head moving portion 30 has been described as an example, but the present invention is not limited to this. For example, the workpiece W may be moved with respect to the laser head 10, or both the laser head 10 and the workpiece W may be moved.

Further, in the above-described embodiment, the case where the plate thickness t of the workpiece W is 1.5 mm to 4.0 mm has been described as an example, but the present invention is not limited to this. The plate thickness t of the workpiece W may be 1.5 mm or less, or 4.0 mm or more.

D ... Dross G ... Assist gas L ... Laser light R ... Diameter S ... Spot t ... Plate thickness W ... Work piece Wb ... Back side 10 ... Laser Head 11 ... Head body 12 ... Nozzle 13 ... Irradiation unit 15 ... Nozzle port 17 ... Density sensor 20 ... Laser output unit 30 ... Head moving unit (moving unit)
40 ... Assist gas supply unit (supply unit)
43 ... Adjustment unit 44 ... Gas supply pipe 50 ... Control unit 100 ... Laser processing device

Claims (8)

A laser processing device that cuts the work piece by supplying assist gas to the work piece while irradiating the work piece containing aluminum as a main component with laser light.
A laser output unit including a fiber laser that outputs the laser beam,
An irradiation unit that collects the laser light from the laser output unit with the surface of the work piece as a single focal point position.
A laser processing apparatus including a supply unit for supplying a mixed gas of nitrogen gas and oxygen gas having a concentration of oxygen gas of 0.7% by volume to 1.7% by volume as the assist gas to the work piece. The laser processing apparatus according to claim 1, wherein the laser beam has a wavelength of 1080 nm. A concentration sensor that measures the oxygen concentration or nitrogen concentration of the assist gas supplied from the supply unit, and
An adjusting unit that adjusts the concentration of oxygen gas or nitrogen gas in the assist gas,
The laser processing apparatus according to claim 1 or 2, further comprising a control unit that operates the adjusting unit according to the measurement result of the concentration sensor. The supply unit supplies a mixed gas of nitrogen gas and oxygen gas having an oxygen gas concentration of 1.0% by volume to 1.5% by volume to the work piece as an assist gas, according to claims 1 to 1. The laser processing apparatus according to any one of 3. The laser processing apparatus according to any one of claims 1 to 4, wherein the irradiation unit collects the laser light so that the diameter of the laser light on the surface of the work piece is approximately 100 μm. .. A moving portion for moving the irradiation position of the laser beam with respect to the workpiece is provided.
The laser processing apparatus according to any one of claims 1 to 5, wherein the relative speed between the work piece and the laser beam by the moving portion is in the range of 5 m / min to 20 m / min. The laser processing apparatus according to any one of claims 1 to 6, wherein the plate thickness of the workpiece is 1.5 mm to 4.0 mm. A laser processing method in which an assist gas is supplied to a work piece while irradiating a work piece containing aluminum as a main component with a laser beam to cut the work piece.
Outputting laser light with a fiber laser and
Focusing the output laser light on the surface of the work piece as a single focal point position
A laser processing method comprising supplying a mixed gas of nitrogen gas and oxygen gas having a concentration of oxygen gas of 0.7% by volume to 1.7% by volume as the assist gas to the work piece.

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