JP2019155450A - Shield device - Google Patents

Abstract

To provide a shield device capable of stably shielding laser beam for a long period.SOLUTION: A shield device 10 includes: a laser beam receiving section which receives laser beam; and a scattering substance jetting apparatus which is arranged on an upstream side of the laser beam receiving section in an advancing direction of laser beam and jets a scattering substance 50 to the path of laser beam. In the scattering substance jetting apparatus, the scattered scattering substance scatters laser beam and the scattered laser beam is received by the laser beam receiving section and is shielded.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shielding device that shields a laser.

  As a shielding device that shields a laser, there is a shielding device in which a flow path through which water flows is formed on a light receiving surface irradiated with a laser, and a transmission window through which the laser enters is provided in the flow path (for example, Patent Document 1). reference). This shielding device absorbs the laser with water and circulates the absorbed water to suppress the temperature rise in the region where the laser is incident.

JP-A-9-122963

  However, in the shielding device of Patent Document 1, if foreign matter adheres to the transmission window, the transmittance of the transmission window may decrease or the transmission window may be damaged.

  Therefore, an object of the present invention is to provide a shielding device that can stably shield a laser for a long time.

  The present invention is a shielding device, a laser light receiving unit that receives a laser, and a scattering material that is disposed upstream of the laser light receiving unit in a traveling direction of the laser and injects a scattering material into a path of the laser And an injection device.

  According to this configuration, the laser before reaching the laser light receiving unit can be scattered by the scattering material. Thereby, the output per unit area of the laser incident on the laser light receiving unit can be reduced. In addition, by injecting a scattering material, even if a foreign substance, for example, dross formed of a material processed by a laser adheres to the scattering material, the scattering material to which the foreign substance has adhered moves from the region irradiated by the laser. It is possible to suppress the foreign matter from being heated in the laser irradiation region and affecting other regions. Further, by scattering with a scattering material, it is possible to suppress the scattering material from absorbing a laser and heating to cause deformation or the like. Thereby, the laser can be shielded stably for a long time.

  The scattering material is preferably a transparent oxide. The scattering material preferably has an absorptance of 10% or less. The scattering material preferably has a diameter of 0.01 μm to 1000 μm. The scattering material can efficiently diffuse the laser by satisfying the above conditions.

  It is preferable that the shielding device further includes a circulation unit that circulates the scattering material. By circulating the scattering material in the circulation section, the scattering material can be used efficiently.

  It is preferable that the shielding device further includes a foreign matter collecting unit that removes foreign matters circulating in the circulation unit. By removing foreign matters mixed in the circulation path, the scattering material can be supplied to the region through which the laser passes with higher probability.

  The scattering material injection device preferably injects the scattering material together with a gas. The scattering material can be transported more safely by transporting and injecting the scattering material with gas.

  It is preferable that the scattering material ejecting apparatus ejects the scattering material together with a liquid. By transporting the scattering material with the liquid, the scattering material can be transported more easily, and the scattering material can be ejected more evenly.

  The laser is preferably a high-power laser having an output of kW order used in a processing machine. According to this configuration, the energy of the high-power laser can be efficiently diffused by the injection film, and the output per unit area can be reduced. Therefore, the present invention can be applied even if the laser is a high-power laser.

  It is preferable that the apparatus further includes a control unit that controls an injection amount of the scattering material injection device, and the control unit controls the injection amount based on a temperature of the laser light receiving unit. Thereby, it is possible to efficiently shield the laser while protecting the laser light receiving unit.

  The laser can be shielded stably for a long time.

FIG. 1 is a schematic diagram showing a schematic configuration of a laser processing unit having the shielding device of the present embodiment. FIG. 2 is a schematic diagram illustrating a schematic configuration of the shielding device according to the present embodiment. FIG. 3 is a flowchart illustrating an example of control of the shielding device according to the present embodiment. FIG. 4 is a schematic diagram illustrating a schematic configuration of a shielding device according to another embodiment.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined, and when there are a plurality of embodiments, the embodiments can be combined.

  FIG. 1 is a schematic diagram showing a schematic configuration of a laser processing unit having the shielding device of the present embodiment. FIG. 2 is a schematic diagram illustrating a schematic configuration of the shielding device according to the present embodiment.

  A laser processing unit 2 shown in FIG. 1 irradiates a laser from a laser irradiation head 4 to process a processing object 1. The laser processing unit 2 can perform various processes for removing a part of the processing object 1 such as cutting and drilling. Further, the laser processing unit 2 moves the laser to move the processing object so that the laser and the processing object move relatively even if the laser and the processing object move relatively. Alternatively, both the laser and the workpiece may be moved, and the laser and the workpiece may be moved relative to each other. As processing object 1, various materials, for example, concrete in which a reinforcing bar is arranged, are processed. Further, the workpiece 1 is not limited to concrete, and a member made of Inconel, Hastelloy, stainless steel, ceramic, steel, carbon steel, ceramics, silicon, titanium, tungsten, resin, plastics, glass, or the like is used. Can do. The processing object 1 includes fiber reinforced plastics such as CFRP (Carbon Fiber Reinforced Plastics), GFRP (Glass Fiber Reinforced Plastics), GMT (Glass Long Fiber Reinforced Plastics), iron alloys other than steel plates, Members made of various metals such as aluminum alloys and other composite materials can also be used.

  The laser processing unit 2 includes a laser irradiation head 4, a laser output device 6, a control device 8, and a shielding device 10. The laser irradiation head 4 irradiates the workpiece 1 with laser. The laser output device 6 is a device that outputs a laser. The laser output device 6 oscillates a laser having a plurality of wavelength bands. An example of the laser output device 6 is a semiconductor laser oscillator.

  The control device 8 controls the operation of each unit. The control device 8 adjusts various conditions of the laser output from the laser output device 6 and controls the operating conditions of the shielding device 10. The control device 8 also controls the movement of the relative position between the workpiece 1 and the laser processing unit 2.

  The shielding device 10 is disposed so as to face the laser irradiation head 4 with the workpiece 1 interposed therebetween. The shielding device 10 is disposed on the optical path of the laser irradiated from the laser irradiation head 4. The shielding device 10 is a device that shields a processing high-power laser output from the laser irradiation head 4. Here, since the high-power laser shielded by the shielding device 10 has an output of kW order and the irradiation energy of the laser is large, the shielding device 10 can efficiently absorb the irradiation energy of the high-power laser. It has become a thing.

  The shielding device 10 shown in FIG. 2 includes a housing 15, a first injection nozzle 16, a second injection nozzle 17, a laser receiving plate 18, a circulation unit 19, a control unit 20, and a foreign matter collection unit 22. The temperature sensor 24 is provided. The shielding device 10 has a function of injecting a large number of scattering materials 50 into a laser passage path to scatter the laser.

Here, the scattering material 50 is a material that scatters laser light, and is, for example, transparent such as glass beads, quartz, titania (TiO ₂ ), zirconia (ZrO ₂ ), barium oxide (BaO), and calcium oxide (CaO). Formed of an oxide. The scattering material 50 preferably has an absorptance of 10% or less, and more preferably an absorptance of 5% or less. It is even more preferable that the absorption rate is 2% or less. The reflectance of the scattering material 50 needs to be at least 3%, preferably 6% or more. By setting the absorptance and reflectance in the above ranges, the scattering material 50 can be prevented from being heated by the laser light, and the laser can be suitably scattered. The scattering material 50 is preferably a particle having a particle diameter (particle diameter) of 0.01 μm or more and 1000 μm, and more preferably a particle having a particle diameter (particle diameter) of 0.1 μm or more and 50 μm or less. Even more preferably, the particle diameter (particle diameter) is 1 μm or more and 10 μm or less. The particle scattering material 50 preferably has a particle size (particle diameter) of 1/100 to 500 times the wavelength of the laser L. The scattering material 50 can suitably scatter the laser by setting the particle size within the above range.

  The casing 15 is formed in a rectangular box shape, and accommodates therein a first injection nozzle (scattering substance injection apparatus) 16, a second injection nozzle (scattering substance injection apparatus) 17, and a laser receiving plate 18. Yes. The housing 15 has an opening 25 through which a laser is introduced. The opening 25 is formed through the side surface of the housing 15. In addition, the housing 15 has a collection portion 26 that collects the scattering material 50 used in the first injection nozzle 16 and the second injection nozzle 17 on the lower side inside. A circulation unit 19 is connected to the collection unit 26.

  The first injection nozzle 16 injects the scattering material 50 toward the collection unit 26 in the housing 15 to form an injection film 35. The first injection nozzle 16 has a slit opening (outlet) 32 formed therein. The first injection nozzle 16 is attached to the ceiling inside the housing 15, is a direction orthogonal to the laser irradiation direction, and extends in the longitudinal direction with the horizontal direction as the longitudinal direction. The scattering material 50 supplied to the first injection nozzle 16 spreads over the longitudinal direction of the first injection nozzle 16. The slit opening 32 serves as an outlet for injecting the scattering material 50 supplied into the first injection nozzle 16 together with the transport fluid for transporting the scattering material 50, and is provided on the lower surface side of the first injection nozzle 16. Yes. The slit opening 32 is formed to extend in the longitudinal direction of the first injection nozzle 16. When a large number of scattering materials 50 are supplied to the first injection nozzle 16, the large number of scattering materials 50 are spread over the longitudinal direction of the first injection nozzle 16 and are injected from the slit openings 32. A large number of scattering materials 50 ejected from the slit openings 32 become curtain-shaped ejection films 35 having surfaces orthogonal to the laser irradiation direction. In the spray film 35, the scattering material 50 is dispersed in a region.

  The spray film 35 formed by the first spray nozzle 16 is irradiated with a laser. In the injection film 35, the scattering material 50 flows from the upper side to the lower side in the vertical direction. That is, the spray film 35 flows from the upper ceiling side inside the housing 15 toward the lower collecting portion 26 inside the housing 15. The jet film 35 scatters the laser with the scattering material 50 dispersed inside. The spray film 35 has a thickness of 10 mm, which is a thickness in the laser irradiation direction. The film thickness of the spray film 35 is preferably 10 mm or more. The upper limit of the film thickness of the spray film 35 is more preferably determined from the design because the apparatus becomes larger as the film thickness increases. Moreover, it is preferable that the flow rate of the injection film 35 is 2 m / s or more and 28 m / s or less. The spray film 35 preferably has a particle density (volume ratio) of the scattering material 50 of 0.0001 or more, and more preferably 0.001 or more. By setting the particle density within the above range, the laser can be suitably scattered.

  The second injection nozzle 17 has basically the same structure as the first injection nozzle 16, and in the housing 15, the scattering material 50 is injected toward the collection portion 26 to form an injection film 36. Yes. The second injection nozzle 17 has a slit opening (outlet) 32 formed therein. The second injection nozzle 17 is arranged side by side with the first injection nozzle 16 in the laser irradiation direction, and is arranged upstream of the first injection nozzle 16 in the irradiation direction. In other words, the first injection nozzle 16 is disposed downstream of the second injection nozzle 17 in the irradiation direction. A suitable range of the second injection nozzle 17 is the same as that of the first injection nozzle 16.

  The laser receiving plate 18 is a member that receives a laser whose output per unit area is attenuated by being diffused by the injection film 35 and the injection film 36 formed by the first injection nozzle 16 and the second injection nozzle 17. The laser receiving plate 18 is, for example, a metal plate using metal. The laser receiving plate 18 shields the laser inside the housing 15 by receiving the laser. In the laser receiving plate 18, a laser receiving region is a laser receiving unit. The laser receiving plate 18 is preferably provided with a cooling mechanism that reduces the temperature of the surface irradiated with the laser. For example, the laser receiving plate 18 may be formed with a cooling flow path through which the cooling medium flows, and the cooling medium may flow through the cooling flow path. The laser receiving plate 18 can have high durability by being provided with a mechanism for reducing the temperature. In the present embodiment, the laser light receiving portion that receives the laser is the plate-shaped laser receiving plate 18, but it is sufficient to receive the laser, and the shape is not limited to the plate.

  The circulation unit 19 circulates the scattering material 50 accumulated in the collection unit 26 of the housing 15 to the first injection nozzle 16 and the second injection nozzle 17. The circulation unit 19 includes a circulation channel 41 and a pump 42 provided in the circulation channel 41. One of the circulation channels 41 is connected to the collection unit 26 of the housing 15, and the other is connected to the first injection nozzle 16 and the second injection nozzle 17. The pump 42 sends the scattering material 50 accumulated in the collection unit 26 toward the first injection nozzle 16 and the second injection nozzle 17. The pump 42 conveys the scattering material 50 together with the gas (conveying fluid). The gas may be air, but is preferably an inert gas.

  The control unit 20 controls the operation of each part of the shielding device 10 and controls the operation of the shielding device 10. Specifically, the control unit 20 operates the pump 42 to supply the scattering material 50 toward the first injection nozzle 16 and the second injection nozzle 17, or to stop the operation of the pump 42. The supply of the scattering material 50 to the first injection nozzle 16 and the second injection nozzle 17 is stopped. The temperature sensor 24 detects the temperature of the laser light receiving portion that is a region of the laser receiving plate 18 that receives the laser. The temperature sensor 24 may directly detect the temperature of the light receiving unit, but measures the temperature at an arbitrary position of the laser receiving plate 18 and calculates based on the result and the positional relationship between the measurement position and the laser light receiving unit. By doing so, the temperature of the light receiving unit can be detected.

  The foreign matter collecting unit 22 removes foreign matter that is mixed in the circulating scattering material 50 and has a particle size larger than that of the scattering material 50. The foreign matter collection unit 22 is disposed in the collection unit 26 of the housing 15. The foreign matter collection unit 22 is a mesh that covers a part of the flow path of the collection unit 26. The foreign matter collecting unit 22 has a larger mesh diameter than the scattering material 50. As a result, the scattering material 50 circulating in the circulation unit 19 passes through the foreign matter collection unit 22. In addition, foreign matters larger than the diameter of the mesh are collected by the foreign matter collecting unit 22.

  When the shielding device 10 is irradiated with a laser such as a high-power laser from the laser irradiation head 4 of the laser processing unit 2, the irradiated laser is introduced into the housing 15 through the opening 25 of the housing 15. The Even when the laser output from the laser irradiation head 4 of the laser processing unit 2 passes through the processing object 1 and attenuates and enters the shielding device 10, it does not pass through the processing object 1 and directly enters the shielding device 10. It may be incident. The laser introduced into the housing 15 first intersects with the injection film 36 formed by the second injection nozzle 17. The laser passes through the ejection film 36. The laser that has passed through the spray film 36 intersects the spray film 35 formed by the first spray nozzle 16. The laser crosses the spray film 36 and then crosses the spray film 35, and is scattered by the scattering material 50 dispersed in the spray films 35 and 36. The laser that is scattered by the scattering material 50 and whose output per unit area is attenuated enters the laser receiving plate 18 and is shielded by the laser receiving plate 18.

  As described above, the shielding device 10 can scatter the laser before entering the laser receiving plate 18 with the scattering material 50 by injecting the scattering material 50 onto the region before reaching the laser receiving plate 18. . Thereby, the output per unit area of the laser incident on the laser receiving plate 18 can be reduced. Further, even when foreign matter, for example, dross formed of a material processed by a laser adheres to the scattering material 50 by spraying the scattering material 50, the scattering material 50 to which the foreign matter has adhered is irradiated from the region irradiated with the laser. Since it moves, it can suppress that a foreign material is heated in a laser irradiation area | region, and affects another area | region. Further, by scattering with the scattering material 50, it is possible to suppress the scattering material 50 from absorbing the laser and heating to cause deformation or the like. Thereby, the laser can be shielded stably for a long time. Further, it is possible to apply a high-power laser by diffusing the laser with the jet film 35 and the jet film 36.

  Further, the shielding device 10 can efficiently use the scattering material 50 by circulating the scattering material 50 in the circulation unit 19. Further, the shielding device 10 can remove foreign matters mixed in the circulation path by providing the foreign matter collecting portion 22 that removes the foreign matters circulating in the circulation portion 19. Thereby, the scattering material can be supplied to the region through which the laser passes with higher probability.

  The shielding device 10 can transport the scattering material more safely by transporting and injecting the scattering material with gas. Specifically, since it is possible to suppress the component to evaporate from being irradiated to the laser, it is possible to suppress adverse effects of the fluid being conveyed. Further, the medium can be easily replenished and managed.

  Next, an example of control of the shielding device 10 will be described with reference to FIG. FIG. 3 is a flowchart illustrating an example of control of the shielding device according to the present embodiment. The control unit 20 detects the temperature of the light receiving unit based on the detection result of the temperature sensor 24 (step S12). The control unit 20 determines whether the temperature of the light receiving unit is equal to or lower than the first threshold (step S14). When it is determined that the temperature of the light receiving unit is equal to or lower than the first threshold (Yes in Step S14), the control unit 20 decreases the circulation amount of the scattering material 50. As a result, the number of scattering materials 50 in the laser path is reduced (step S16). When it is determined that the temperature of the light receiving unit is not equal to or lower than the first threshold (No in Step S14), the control unit 20 determines whether the temperature of the light receiving unit is equal to or higher than the second threshold (Step S18). Here, the second threshold is a temperature higher than the first threshold. When it determines with the temperature of a light-receiving part being more than a 2nd threshold value (it is Yes at step S18), the control part 20 increases the circulation amount of the scattering material 50 (step S20). This increases the number of scattering materials 50 in the laser path. When it is determined that the temperature of the light receiving unit is not equal to or higher than the second threshold (No in Step S18), that is, when the temperature is higher than the first threshold and lower than the second threshold, the control unit 20 ends the process.

  The shielding device 10 can maintain the laser receiving plate 18 in a predetermined temperature range by controlling the injection amount of the scattering material 50 based on the temperature of the temperature sensor 24. Accordingly, an appropriate amount of the scattering material 50 can be ejected while protecting the laser receiving plate 18.

  The control unit 20 can control the circulation amount by changing the flow rate of the pump 42. Further, the control unit 20 may adjust the circulation speed or the density of the scattering material 50 to be conveyed. Moreover, the shielding apparatus 10 may change the width (distance in the laser traveling direction) for injecting the scattering material 50.

  Moreover, in the said embodiment, although injection of the scattering material 50 was controlled based on temperature, you may control based on the output of a laser. In this case, the injection amount of the scattering material 50 may be increased or decreased based on the output of the laser output from the laser irradiation head 4, the output of the laser output from the laser irradiation head 4, and the processing object 1. The injection amount of the scattering material 50 may be increased or decreased based on the thickness and material.

  FIG. 4 is a schematic diagram illustrating a schematic configuration of a shielding device according to another embodiment. The shielding device 10 a shown in FIG. 4 transports the scattering material 50 with the transport liquid 52 and jets the transport liquid 52 together with the scattering material 50. In the shielding device 10a, the first spray nozzle 16 and the second spray nozzle 17 spray the carrier liquid 52 together with the scattering material 50 as the spray films 35a and 36a. The collection unit 26 collects the ejected scattering material 50 and the carrier liquid 52. The pump 42 is a device capable of transporting a liquid in which particles are mixed, and transports the scattering material 50 and the transport liquid 52.

  The shielding device 10a forms jet films 35a and 36a in which the scattering material 50 is dispersed in the carrier liquid 52 in the laser passage path. It is preferable that the carrier liquid 52 and the scattering material 50 are ejected at a flow velocity at which no gas flows into the first ejection nozzle 16, the second ejection nozzle 17, and the ejection films 35a and 36a.

  The shielding device 10a ejects the carrier liquid 52 together with the scattering material 50 through the ejection films 35a and 36a. Since the energy of the high-power laser can be efficiently absorbed by ejecting the carrier liquid, the present invention can be applied even if the laser is a high-power laser.

  The shielding device 10a can transport the scattering material more easily by transporting the scattering material with the liquid, and can spray the scattering material more evenly. The carrier liquid 52 is water, but may be any liquid as long as it can absorb laser irradiation energy. The carrier liquid 52 is preferably a non-flammable and non-volatile liquid such as water.

  Moreover, the shielding apparatus 10 and the shielding apparatus 10a may be provided with the collection unit 26 and the circulation system of the first injection nozzle 16 and the second injection nozzle 17 separately to inject different scattering substances. For example, scattering materials having different particle diameters may be ejected. Thereby, even when the wavelength of the laser changes, the laser can be suitably scattered. Further, the shielding device 10 and the shielding device 10a may be provided with scattering materials having different particle diameters in a tank or the like, and may circulate and switch the scattering materials to be ejected according to conditions.

  In the present embodiment, the second injection nozzle 17 is provided on the upstream side of the first injection nozzle 16, but only the first injection nozzle 16 may be provided, and the injection nozzles may be provided in three stages in the laser traveling direction. . Further, as in the present embodiment, the first injection nozzle 16 and the second injection nozzle 17 are provided with a slit opening 32 having a long slit on a surface orthogonal to the laser traveling direction, thereby allowing the scattering material 50 to pass through the laser path. The spray films 35, 36, 35 a, and 36 a intersecting with each other can be formed. The spray films 35, 36, 35a, and 36a may be formed. Moreover, the 1st injection nozzle 16 and the 2nd injection nozzle 17 are good also as one opening.

DESCRIPTION OF SYMBOLS 1 Processing object 2 Laser processing unit 4 Laser irradiation head 6 Laser output device 8 Control apparatus 10, 10a Shielding device 15 Housing | casing 16 1st injection nozzle 17 2nd injection nozzle 18 Laser receiving plate 19 Circulation part 20 Control part 22 Foreign material capture Collection part 24 Temperature sensor 25 Opening 26 Collection part 32 Slit opening 35, 35a, 36, 36a Spray film 41 Circulation flow path 42 Pump 50 Scattering substance 52 Carrier liquid

Claims (10)

A laser receiver for receiving the laser;
A scattering material injection device that is disposed upstream of the laser light receiving unit in the traveling direction of the laser and injects scattering material into the laser path;
The shielding device, wherein the scattering material ejecting device scatters the laser with the scattering material ejected to the laser path, and receives and shields the scattered laser with the laser light receiving unit.   The shielding apparatus according to claim 1, wherein the scattering material is a transparent oxide.   The shielding apparatus according to claim 1, wherein the scattering material has an absorptance of 10% or less.   The shielding apparatus according to claim 1, wherein the scattering material has a diameter of 0.01 μm or more and 1000 μm or less.   5. The shielding apparatus according to claim 1, further comprising a circulation unit that circulates the scattering material.   The shielding apparatus according to claim 5, further comprising a foreign matter collecting portion that removes the foreign matter circulating through the circulation portion.   The said scattering substance injection apparatus injects the said scattering substance with gas, The shielding apparatus as described in any one of Claim 1 to 6 characterized by the above-mentioned.   The said scattering substance injection apparatus injects the said scattering substance with a liquid, The shielding apparatus as described in any one of Claim 1 to 6 characterized by the above-mentioned.   The shielding apparatus according to any one of claims 1 to 8, wherein the laser is a high-power laser having an output of a kW order used in a processing machine. A control unit for controlling an injection amount of the scattering material injection device;
The shielding device according to any one of claims 1 to 9, wherein the control unit controls the ejection amount based on a temperature of the laser light receiving unit.

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