Laser processing equipment

Abstract

The present invention provides a laser processing apparatus equipped with a nozzle capable of suppressing contamination of protective glass. [Solution] The laser processing apparatus according to the present disclosure is a laser processing apparatus 1 comprising a laser processing head 10 that irradiates a workpiece W with laser light LB and a side nozzle 40 that ejects gas introduced from an inlet 41 into the optical path between the laser processing head 10 and the workpiece W from a slit-shaped nozzle 42, wherein the inlet 41 of the side nozzle 40 introduces gas from a direction inclined with respect to the direction of gas ejection from the nozzle 42, and the flow path 43 that guides the gas introduced from the inlet 41 to the nozzle 42 has a first flow path 43a that guides the gas from the inlet 41 to the nozzle 42 in the longitudinal direction of the nozzle 42, and a second flow path 43b that guides the gas that has flowed out of the first flow path 43a to the nozzle 42, and the inner shape of the first flow path 43a becomes narrower as it moves away from the inlet 41 in the direction of gas introduction.

Description

Technical Field

[0001] This disclosure relates to a laser processing apparatus.

Background Art

[0002] When processing a workpiece using a laser processing apparatus, there is a risk that spatter scattered from the processing point on the workpiece or fumes generated by sublimation of the metal contained in the workpiece may adhere to the optical system such as the mirror and lens of the laser processing head. Therefore, in order to protect the optical system from spatter, fumes, etc., a protective glass is provided on the laser processing head. However, if spatter, fumes, etc. adhere to this protective glass, there is a risk that the laser processing apparatus may not be able to appropriately focus the laser light on the processing point on the workpiece.

[0003] In order to protect the protective glass from spatter, fumes, etc., for example, Patent Document 1 discloses a laser processing apparatus provided with a nozzle that injects gas from one side toward the other side so as to cross the optical path of the laser light. This laser processing apparatus prevents spatter, fumes, etc. from adhering to the protective glass by flowing gas in a direction crossing the optical path of the laser light from the nozzle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] From the perspective of reducing carbon dioxide emissions, it is necessary to reduce the amount of gas supplied to the nozzle. However, if the amount of supplied gas decreases, the amount of gas ejected from the nozzle also decreases, which may cause contamination of the protective glass by spatter and fumes that pass through the ejected gas. Therefore, there is a need for a nozzle that can ensure a sufficient ejection volume even when the amount of gas supplied to the nozzle is reduced.

[0006] This invention was made to solve these problems and provides a laser processing apparatus equipped with a nozzle capable of suppressing contamination of protective glass. [Means for solving the problem]

[0007] The laser processing apparatus according to this disclosure comprises a laser processing head that irradiates a workpiece with laser light and a side nozzle that ejects gas introduced from an inlet into the optical path between the laser processing head and the workpiece from a slit-shaped nozzle, wherein the inlet of the side nozzle introduces the gas from a direction inclined with respect to the direction of gas ejection from the nozzle, and the flow path that guides the gas introduced from the inlet to the nozzle has a first flow path that guides the gas from the inlet in the longitudinal direction of the nozzle to the nozzle, and a second flow path that guides the gas that has flowed out of the first flow path to the nozzle, and the inner shape of the first flow path becomes narrower as it moves away from the inlet in the direction of gas introduction. As a result, the side nozzle can make the flow velocity of the gas ejected from the nozzle uniform along the longitudinal direction of the nozzle.

[0008] The width of the second flow path, as viewed from the longitudinal direction of the nozzle, may widen and then narrow as it approaches the nozzle. The gas introduced into the side nozzle is rectified at the point where the second flow path widens. Therefore, the side nozzle can reduce the pressure loss of the gas.

[0009] The side nozzle comprises a plurality of outlets, and the plurality of outlets may be arranged in one or more rows along the longitudinal direction of the outlets. By arranging a plurality of outlets, the side nozzle can increase the flow velocity of the gas ejected from the outlets.

[0010] The width of the second flow path, as viewed from the short side of the nozzle, may widen as it approaches the nozzle. This allows the side nozzle to eject gas over a wide area in the longitudinal direction of the nozzle.

[0011] The side nozzle has an external air passage separate from the flow path, and the external air passage is provided so as to sandwich the second flow path when viewed from the short side direction of the nozzle outlet, and both ends of the external air passage are connected to the outside air, and when the gas is ejected from the nozzle of the side nozzle, the outside air may be ejected from one end of the external air passage provided near the nozzle outlet. As a result, the flow velocity of the gas ejected from the nozzle outlet increases due to the outside air ejected from one end of the external air passage. [Effects of the Invention]

[0012] The present invention provides a laser processing apparatus equipped with a nozzle capable of suppressing contamination of protective glass. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a diagram showing the configuration of the laser processing apparatus according to this disclosure. [Figure 2] Figure 2 is a perspective view of the side nozzle according to Embodiment 1. [Figure 3] Figure 3 shows a side view of the side nozzle according to Embodiment 1 (top image) and a bottom view of the side nozzle according to Embodiment 1 (bottom image). [Figure 4] Figure 4 shows a side nozzle according to Embodiment 1 (upper figure) and a side nozzle according to Embodiment 2 (lower figure). [Figure 5] Figure 5 is a cross-sectional view taken along the VV cutting line in the lower part of Figure 4. [Figure 6]Figure 6 shows the fluid analysis results for the side nozzle according to Embodiment 1 (upper figure) and the fluid analysis results for the side nozzle according to Embodiment 2 (lower figure). [Modes for carrying out the invention]

[0014] The following describes specific embodiments of this disclosure in detail with reference to the drawings. However, this disclosure is not limited to the following embodiments. Also, for clarity, the following descriptions and drawings have been simplified as appropriate.

[0015] (Embodiment 1) <Configuration of laser processing equipment> First, with reference to Figure 1, the configuration of the laser processing apparatus according to this embodiment 1 will be described. Figure 1 is a diagram showing the configuration of the laser processing apparatus according to this disclosure. The laser processing apparatus 1 is a device for performing laser processing such as welding, cutting, drilling, and marking on a workpiece W. The laser processing apparatus 1 comprises a laser processing head 10, a laser oscillator 20, a gas supply unit 30, a side nozzle 40, and a processing point nozzle 50.

[0016] The laser processing head 10 is for irradiating the workpiece W with laser light LB. The laser processing head 10 includes an optical system (not shown) and protective glass. The optical system is for focusing and refracting the laser light transmitted from the laser oscillator 20 via an optical fiber cable in order to irradiate the workpiece W. The optical system includes, for example, lenses, mirrors, and filters. The protective glass is provided on the laser processing head 10 to prevent spatter scattered when the workpiece W melts during laser processing, and fumes from the sublimation of metal contained in the workpiece W, from adhering to the optical system. The laser processing head 10 may also be mounted on a robot, for example. In this case, the position of the laser processing head 10 relative to the workpiece W can be changed by operating the robot.

[0017] The laser oscillator 20 is connected to the laser processing head 10 via an optical fiber cable. The laser oscillator 20 emits laser light LB to the optical fiber cable by oscillation. The laser oscillator 20 emits the laser light LB in response to an output command signal for commanding the output of the laser light LB and the like, which is input by a laser oscillator control unit not shown. The laser oscillator 20 can use, for example, a solid laser light source, a gas laser light source, a fiber laser light source, etc. as the light source.

[0018] The gas supply unit 30 pumps gas to the housing 11, the side nozzle 40, and the nozzle 50 for the processing point by a pump not shown. The gas supplied by the gas supply unit 30 is not limited to air, and may be other gases such as nitrogen.

[0019] The housing 11 is attached near the emission port of the laser processing head 10. The housing 11 is arranged to cover the emission port and the protective glass, and suppresses foreign matters such as spatter and fume from adhering to the protective glass. A flow path for supplying gas is provided in the housing 11. The gas supplied to the housing 11 generates an air flow AR1 by being ejected from a predetermined position of the housing 11. The air flow AR1 suppresses foreign matters such as spatter and fume from adhering to the protective glass. Note that the laser processing head 10 of the present disclosure may not be provided with the housing 11.

[0020] The side nozzle 40 ejects gas to generate an air current AR2. The side nozzle 40 is sometimes also called an air knife. The side nozzle 40 ejects gas onto the optical path of the laser beam LB between the laser processing head 10 and the workpiece W to generate a substantially planar air current AR2. The air current AR2 blows away spatter, fumes, etc. that scatter from the processing point W0 toward the laser processing head 10 during laser processing. Therefore, the side nozzle 40 can suppress spatter, fumes, etc. from reaching the laser processing head 10 by the air current AR2. Here, in order to suppress foreign matter blown away by the air current AR2 from adhering to the workpiece W, it is preferable that the air current AR2 does not overlap with the workpiece W. The configuration of the side nozzle 40 will be described in detail later.

[0021] The nozzle 50 for the processing point is arranged at a position closer to the workpiece W than the side nozzle 40. The nozzle 50 for the processing point ejects gas to generate an air current AR3. The nozzle 50 for the processing point generates an air current AR3 within a substantially conical range so as to cover the processing point W0. The air current AR3 blows away fumes generated from the workpiece W during laser processing. Therefore, the nozzle 50 for the processing point can suppress fumes from reaching the laser processing head 10 by the air current AR3. From the viewpoint of suppressing the decline of the functions of each air current, it is preferable that the ranges of the air current AR2 and the air current AR3 do not overlap with each other. Note that the side nozzle 40 may be used instead of the nozzle 50 for the processing point. Also, the laser processing head 10 of the present disclosure may not be provided with the nozzle 50 for the processing point.

[0022] <Configuration of Side Nozzle> Subsequently, referring to FIGS. 2 and 3, the configuration of the side nozzle 40 will be described. FIG. 2 is a perspective view of the side nozzle according to Embodiment 1. FIG. 3 is a side view of the side nozzle according to Embodiment 1 in the upper figure and a bottom view of the side nozzle according to Embodiment 1 in the lower figure. The side nozzle 40 includes an inlet 41, an outlet nozzle 42, and a flow path 43. In FIGS. 2 and 3, the outer contour of the side nozzle 40 is indicated by a two-dot chain line, and the gas flowing through the side nozzle 40 is indicated by a solid line.

[0023] In the following explanation, the xyz 3D Cartesian coordinate system will be used as appropriate. In this embodiment 1, the longitudinal direction of the nozzle 42 is the x-direction, the short direction of the nozzle 42 is the y-direction, and the normal direction of the nozzle 42 is the z-direction.

[0024] The inlet 41 is an opening for introducing gas from the gas supply unit 30 into the side nozzle 40. More specifically, the inlet 41 introduces gas into the side nozzle 40 from a direction inclined with respect to the direction of gas ejection from the outlet 42 (+z direction). In this embodiment 1, the inlet 41 is provided in the yx plane with respect to the side nozzle 40. The inlet 41 is connected to the gas supply unit 30 via a pipe P.

[0025] The nozzle 42 is a slit-shaped opening for ejecting gas introduced into the side nozzle 40. The gas ejected from the nozzle 42 becomes the airflow AR2 shown in Figure 1. Multiple nozzles 42 are provided in the side nozzle 40. These multiple nozzles 42 are arranged in one or more rows along the longitudinal direction (x direction) of the nozzle 42. By arranging multiple nozzles 42, the side nozzle 40 can increase the flow velocity of the gas ejected from the nozzles 42.

[0026] Multiple nozzles 42 are formed by dividing an opening in the side nozzle 40 into multiple sections by partition walls C provided at predetermined intervals. The partition walls C are formed by pressing a part of the side nozzle 40, but are not limited to this. For example, the partition walls C may be formed by screw fastening. Alternatively, the nozzles 42 may be formed by machining or other methods. Note that the side nozzle 40 may also be used as a nozzle 42 by leaving the opening as is, rather than dividing the opening into multiple nozzles 42.

[0027] The flow path 43 is provided within the side nozzle 40 and guides the gas introduced from the inlet 41 to the outlet 42. The flow path 43 comprises a first flow path 43a that guides the gas from the inlet 41 to the outlet 42 in the longitudinal direction (+x direction) of the outlet 42, and a second flow path 43b that guides the gas flowing out of the first flow path 43a to the outlet 42. As shown in the upper part of Figure 3, the first flow path 43a is located on the -z side of the dotted line in the flow path 43, and the second flow path 43b is located on the +z side of the dotted line. In this embodiment 1, the dotted line in the upper part of Figure 3 indicates the position where the flow path 43 is divided into the first flow path 43a and the second flow path 43b, but this position is not particularly limited.

[0028] As shown in Figure 3, the inner shape of the first flow path 43a narrows as it moves away from the inlet 41 in the direction of gas introduction (+x direction). This allows the flow path 43 to guide a large amount of gas to the outlet 42 near the inlet 41 (-x direction side). Therefore, the side nozzle 40 can reduce the difference between the flow velocity of the gas ejected from the outlet 42 near the inlet 41 (-x direction side) and the flow velocity of the gas ejected from the outlet 42 far from the inlet 41 (+x direction side). In other words, the side nozzle 40 can make the flow velocity of the gas ejected from the outlet 42 uniform along the longitudinal direction (x direction) of the outlet 42.

[0029] As shown in Figure 2, the width of the second flow path 43b, viewed from the longitudinal direction (x direction) of the nozzle 42, widens once towards the nozzle 42 (+z direction) and then narrows. As a result, the gas introduced into the side nozzle 40 is straightened at the widened portion of the second flow path 43b. This allows the side nozzle 40 to reduce the pressure loss of the gas as it passes through the flow path 43.

[0030] As shown in the upper part of Figure 3, the width of the second flow path 43b, viewed from the short side direction (y direction) of the nozzle 42, widens towards the nozzle 42 (+z direction). This allows the side nozzle 40 to eject gas over a wider area relative to the longitudinal direction (x direction) of the nozzle 42.

[0031] As described above, the side nozzle 40 according to this embodiment 1 can make the flow velocity of the gas ejected from the nozzle 42 uniform along the longitudinal direction (x direction) of the nozzle 42. Furthermore, the side nozzle 40 can more effectively straighten the gas passing through the flow path 43, thereby reducing pressure loss. Therefore, even if the amount of gas supplied into the side nozzle 40 decreases, the side nozzle 40 can eject gas with sufficient flow velocity over a wide area along the longitudinal direction (x direction) of the nozzle 42, thus suppressing contamination of the protective glass.

[0032] (Embodiment 2) This section will describe the laser processing apparatus according to Embodiment 2. The laser processing apparatus according to Embodiment 2 has the same configuration as the laser processing apparatus according to Embodiment 1, except for the side nozzle 40. Therefore, this section will describe the configuration of the side nozzle 40 according to Embodiment 2.

[0033] <Side nozzle configuration> Below, another example of a side nozzle will be described using Figures 4 and 5. Figure 4 shows a side nozzle according to Embodiment 1 in the upper figure and a side nozzle according to Embodiment 2 in the lower figure. Figure 5 is a cross-sectional view taken along the VV cutting line in the lower figure of Figure 4. As shown in Figure 4, the side nozzle 40 according to Embodiment 2 is further equipped with an outside air utilization section 44 in addition to the side nozzle 40 according to Embodiment 1. The side nozzle 40 according to Embodiment 2 has two outside air utilization sections 44. The two outside air utilization sections 44 are provided on the side nozzle 40 so as to sandwich the second flow path 43b. Note that the outside air utilization section 44 may be on only one side.

[0034] The outside air utilization unit 44 is equipped with an outside air passage 45. The outside air passage 45 is a separate passage from the passage 43 and is not connected to the passage 43. Multiple outside air passages 45 are formed by dividing the inside of the outside air utilization unit 44, for example, with multiple partition walls. As shown in Figure 5, these multiple outside air passages 45 are arranged so as to sandwich the second passage 43b when viewed from the short side direction (x direction) of the nozzle 42. Alternatively, the outside air passage 45 may be one outside air passage 45 per outside air utilization unit 44, without dividing it into multiple passages with partition walls.

[0035] Both ends of the outside air channel 45 are connected to the outside air. As shown in Figure 5, one end of the outside air channel 45 (the +z direction side) is located near the nozzle 42. The other end of the outside air channel 45 (the -z direction side) is located on the opposite side of the outside air channel 45 from the one end (the +z direction side). The shape of both ends of the outside air channel 45 is triangular, but is not limited to this. The shape of both ends of the outside air channel 45 may be any shape such as circular, elliptical, polygonal, or rectangular.

[0036] Figure 6 shows the fluid analysis results for a side nozzle according to Embodiment 1 (upper figure) and a side nozzle according to Embodiment 2 (lower figure). Fluid analysis refers to analysis using computational fluid dynamics (CFD) with a computer, for example. Figure 6 shows the fluid analysis results in a cross-sectional view of the side nozzle 40 as seen from the longitudinal direction (x direction) of the nozzle outlet 42. In the fluid analysis results, the distribution of flow rate (unit, for example, m / s) is indicated by different colors.

[0037] As shown in the fluid analysis results in Figure 6, when the gas introduced into the side nozzle 40 is ejected from the nozzle 42, outside air is introduced into the outside air channel 45 from the other end (-z direction side) of the outside air channel 45. The outside air introduced into the outside air channel 45 is then ejected from one end (+z direction side) of the outside air channel 45. This outside air flow occurs in the outside air channel 45 because a negative pressure is generated near the nozzle 42 when the gas introduced into the side nozzle 40 is ejected from the nozzle 42. The outside air ejected from one end (+z direction side) of the outside air channel 45 increases the flow velocity of the gas ejected from the nozzle 42.

[0038] As explained above, with the side nozzle 40 according to this second embodiment, the outside air ejected from one end (+z direction side) of the outside air passage 45 increases the flow velocity of the gas ejected from the nozzle 42. Therefore, even if the amount of gas supplied into the side nozzle 40 decreases, the side nozzle 40 can eject gas at a sufficient flow velocity, thereby suppressing contamination of the protective glass.

[0039] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0040] 1 laser processing device, 10 laser processing heads, 11 housings, 20 Laser oscillator, 30 Gas supply unit, 40 Side nozzle, 41 Inlet, 42 spout, 43 flow path, 43a first flow path, 43b second flow path, 44 Outside air utilization section, 45 Outside air flow path, 50 Nozzle for processing point, AR1, AR2, AR3 Airflow, C Bulkhead, LB Laser beam, P Pipe, W workpiece, W0 machining point

Claims

1. A laser processing head that irradiates the workpiece with laser light, A laser processing apparatus comprising: a side nozzle that ejects gas introduced from an inlet into the optical path between the laser processing head and the workpiece from a slit-shaped nozzle, The inlet of the side nozzle introduces the gas from a direction inclined with respect to the direction of gas ejection from the nozzle. The flow path that guides the gas introduced from the inlet to the outlet has a first flow path that guides the gas from the inlet in the longitudinal direction of the outlet relative to the outlet, and a second flow path that guides the gas that flows out from the first flow path to the outlet. The inner shape of the first flow path is narrowed as it moves away from the inlet in the direction of gas introduction. Laser processing equipment.

2. The width of the second flow path, as viewed from the longitudinal direction of the nozzle, widens once and then narrows as it approaches the nozzle. The laser processing apparatus according to claim 1.

3. The side nozzle is equipped with multiple nozzles, The multiple nozzles are arranged in one or more rows along the longitudinal direction of the nozzles. The laser processing apparatus according to claim 1 or 2.

4. The width of the second flow path, as viewed from the short side of the nozzle, widens as it approaches the nozzle. The laser processing apparatus according to claim 3.

5. The side nozzle has an external air channel separate from the flow channel, The aforementioned outside air passage is provided so as to sandwich the second passage when viewed from the short side direction of the nozzle, Both ends of the aforementioned outside air passage are connected to the outside air. When the gas is ejected from the outlet of the side nozzle, the outside air is ejected from one end of the outside air passage provided near the outlet. The laser processing apparatus according to claim 4.

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