JP6101139B2 - Laser processing method and laser processing apparatus - Google Patents

Description

Embodiments described herein relate generally to a laser processing method and a laser processing apparatus.

  Laser cutting or water jet (WJ) cutting is used as a cutting process for metal materials, ceramics, FRP (fiber reinforced plastic), and the like. In laser cutting, laser light emitted from a laser oscillator is condensed by an optical system and irradiated onto a workpiece, and the irradiated portion is heated and melted. And it is the technique cut | disconnected by blowing off the fusion | melting part using assist gas, such as air and oxygen.

  On the other hand, WJ cutting is a technique in which water is sprayed onto a workpiece at a high pressure, and the sprayed portion is blown off and cut. There are cases where only water is used and cases where the abrasive is mixed with water. In the latter case, a polishing action is added to the kinetic energy of the jetted water, thereby improving the cutting ability.

  Furthermore, there is a cutting technique that combines laser and WJ. This cutting technique is used for the purpose of precisely processing a relatively thin workpiece such as a semiconductor substrate. In this method, the laser beam is propagated through the WJ, and the laser beam and the WJ are simultaneously applied to the processed portion, so that the cutting ability is increased, and the processed portion is cooled with water simultaneously with the cutting, so that a very clean cut surface can be obtained. .

  Further, since the processed portion is water-cooled simultaneously with the cutting, steam generated from the workpiece is hardly generated by heating. Therefore, when the workpiece is an activated metal or the like, the activated vapor is difficult to be generated and scattered. Therefore, there is little influence on the environment when cutting.

  Further, since the chips are contained in the wastewater resulting from WJ, the activated chips can be easily recovered by collecting the wastewater.

Katsunori Shiihara, 3 others, “Thick plate cutting method combining laser and water jet”, Summary of the National Conference of the Japan Welding Society, September 3, 2012, No. 91, p. 4-5

  When the workpiece is cut using the WJ having the laser propagated, it is necessary to apply the laser propagated to the WJ to the cutting path. Therefore, when a hollow workpiece such as a pipe or pipe is cut, it is necessary to rotate the workpiece in order to irradiate the workpiece along the cutting path with the WJ propagated by the laser. Alternatively, it is necessary to move the laser processing apparatus along the cutting path.

  However, when the workpiece is a pipe or pipe provided in a building or a large structure, it is difficult to rotate the workpiece. Further, when there is not enough space around the workpiece, it is difficult to move the laser processing apparatus along the cutting path of the workpiece, and it is difficult to cut the workpiece.

  It is an object of the present invention to provide a method for efficiently cutting a hollow workpiece using a liquid flow propagated by a laser.

In order to achieve the above object, the laser processing method according to the embodiment ejects a liquid flow in which a laser is propagated to a target portion, and irradiates the target portion with a laser using the liquid flow as a light guide material to cut the target portion. to a laser machining method, it is ejected airflow so as to follow the periphery of the liquid stream to propagate laser first Rutotomoni liquid flow is jetted against the target portion, through the first target portion a first cutting step of forming a first cutting slits have a width which can be liquid flow and air flow passes, it is passed through a first cutting slits in the liquid stream to propagate laser to propagate laser And a second cutting step for forming a second cutting slit penetrating the second target location, and ejecting the liquid flow to the second target location, wherein the second target location is the first Arranged at a distance from the target location , The first cutting slits and having a large slit width than the second cutting slits.

In order to achieve the above object, the laser processing apparatus of the embodiment ejects a liquid flow in which a laser is propagated to a target location, irradiates the target location with a laser using the liquid flow as a light guide material, and determines the target location. A laser processing apparatus that performs cutting processing, and controls each part of the laser processing apparatus to cut a first target location and a second target location that are spaced apart from the first target location. the a, the controller liquid flow through the first target portion by ejecting air current to follow the periphery of Rutotomoni liquid stream is ejected liquid stream to propagate laser to a first target location and first cutting slits to form a first passed through a cut slit liquid flow a second in which to propagate laser target portion to the liquid stream to propagate laser to have a width capable airflow passes The second target location It shall be controlled so that the slit width is a narrow second cutting slits than penetrating the first cutting slits.

The block diagram which shows the outline | summary of the laser processing apparatus of 1st Embodiment. The longitudinal cross-sectional view parallel to the laser processing apparatus and the piping central axis of piping in 1st Embodiment. (A) A schematic diagram of a water jet in a stable state, (b) a schematic diagram of a water jet in the form of water droplets, and (c) a schematic diagram of a water jet having an enlarged diameter. The perspective view of piping in which the 1st cutting slit was formed. The jet route of the water jet of the 1st cutting step in a 1st embodiment. The longitudinal section parallel to the piping central axis of piping in the middle of cutting in a 1st embodiment. The water jet ejection path of the first cutting step in the second embodiment. The longitudinal cross-sectional view parallel to the water jet and the piping center axis | shaft of piping in 4th Embodiment. The longitudinal cross-sectional view parallel to the piping center axis | shaft of the water jet and piping in 5th Embodiment during cutting | disconnection.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
A first embodiment will be described with reference to FIGS. FIG. 1 is a block diagram showing an outline of the laser processing apparatus according to the first embodiment. FIG. 2 is a longitudinal sectional view parallel to the central axis of the laser processing apparatus and the pipe during cutting in the first embodiment. FIG. 3A is a schematic diagram of a water jet in a stable state, FIG. 3B is a schematic diagram of a water jet in the form of water droplets, and FIG. 3C is a water jet with an expanded diameter. It is a schematic diagram of a jet. FIG. 4 is a perspective view of a pipe in which a first cutting slit is formed. FIG. 5 is a water jet ejection path of the first cutting step in the first embodiment. FIG. 6 is a longitudinal sectional view parallel to the pipe central axis of the pipe in the middle of cutting in the first embodiment.

  In addition, the to-be-processed object which is the target object cut | disconnected in this embodiment shall be the piping 2 provided in facilities, such as a nuclear power station, in the perpendicular direction. In the present embodiment, it is assumed that the liquid flow is formed of water. And the liquid flow formed with water is called a water jet (WJ).

(Constitution)
Hereinafter, the configuration of the present embodiment will be described. The laser processing apparatus 10 of this embodiment is demonstrated using FIG.

  The laser processing apparatus 10 includes a laser oscillator 11 that emits a laser L, and an optical transmission unit 12 that transmits the laser L to a construction head 13. The construction head 13 is a mechanism that ejects WJ to the pipe 2 from the outside of the pipe 2. The construction head 13 is provided on the outer side of the pipe 2 so that the jet hole 21 for jetting WJ faces the pipe 2. The laser L transmitted to the construction head 13 enters the WJ and propagates through the WJ. When WJ is ejected to the pipe 2, the laser L is also irradiated to the pipe 2. A portion of the pipe 2 that is irradiated with the water flow W and the laser L is referred to as a processing point.

  Connected to the construction head 13 are a water supply means 14 for supplying water for forming the WJ and a gas supply means 15 for supplying a gas for forming an airflow R that flows around the WJ.

  In addition, the laser processing apparatus 10 includes a processing position measuring unit 18 that detects the position of a processing point during cutting and transmits the information to the control unit 19. The position of the machining point measured by the machining position measuring means 18 is a distance (machining distance) from the machining position measuring means 18 to the machining point.

  Further, the laser processing apparatus 10 has a construction head moving means 16 that moves the construction head 13 relative to the pipe 2. The construction head moving means 16 can move the construction head 13 in the horizontal direction and the vertical direction, and can turn the construction head 13 so that the WJ ejected from the construction head 13 rotates. It is.

  The machining position measuring means 18, the laser oscillator 11, the optical transmission means 12, the water supply means 14, the gas supply means 15, and the construction head moving means 16 are all connected to the control unit 19. Based on the processing distance information obtained by the processing position measuring means 18, the control unit 19 operates the laser oscillator 11, the water supply means 14, the gas supply means 15, the optical transmission means 12, the construction head moving means 16, and the like. To control.

  Details of each component will be described below. First, the laser oscillator 11 will be described. The laser L emitted from the laser oscillator 11 is preferably a laser with a small attenuation of energy in water, and is a YAG laser second harmonic (wavelength 532 nm) in this embodiment. However, it is only necessary that the laser L finally irradiated to the workpiece 2 has sufficient energy for processing, and any laser that irradiates a laser having sufficient energy even when attenuation by water is added. . For example, a YAG laser fundamental wave (wavelength 1064 nm), a UV laser (wavelength 355 nm), a fiber laser (wavelength 1070 nm), or the like can be used.

  The optical transmission means 12 is an optical transmission system constituted by optical system parts such as a lens, a mirror, a telescope, and an optical fiber so as to transmit the laser L from the laser oscillator 11 to the construction head 13. Only a single mirror is shown. The laser L may be guided from the laser oscillator 11 to the construction head 13 using an optical fiber instead of a mirror as the light transmission means 12.

  The water supply means 14 is connected to the construction head 13 via a water supply pipe 22 and supplies water to the construction head 13 by a pump or the like and pressurizes it. The water supplied to the construction head 13 may be newly supplied from the outside, or the waste water ejected as WJ may be reused. A part of the water supplied to the construction head 13 in this embodiment is obtained by reusing waste water. The water supply means 14 has a waste water circulation mechanism 23 for reusing waste water.

  For example, as shown in FIG. 2, the wastewater circulation mechanism 23 is filtered by a wastewater tray 24 for collecting wastewater provided around the pipe 2, a filtration unit 26 that removes impurities from the wastewater in the wastewater tray 24, and A wastewater circulation pump 25 that circulates wastewater to the construction head 13 is provided. Impurities are cutting wastes and the like generated during the cutting process.

  The waste water circulation pump 25 may be directly connected to the construction head 13 to circulate the waste liquid. Alternatively, as shown in FIG. 2, the wastewater circulation pump 25 may be connected to the water supply unit 14 and circulate the waste liquid to the construction head 13 via the water supply unit 14.

  The gas supply means 15 is connected to the construction head 13 via a gas supply pipe 27 as shown in FIG. The gas supplied from the gas supply means 15 is preferably an inert and light gas. In this embodiment, helium gas is used.

  The processing position measuring means 18 is provided in the construction head 13 so as to face the pipe 2 and is, for example, a distance sensor using a laser or a distance sensor using an ultrasonic wave. If the distance sensor is a laser, it is possible to measure the machining distance by emitting a machining distance measuring laser, receiving a reflection from the machining point, and measuring a time difference between light emission and light reception. Similarly, in the case of sensors using ultrasonic waves, the processing distance is measured by transmitting the ultrasonic waves for measuring the processing distance, receiving the reflection from the processing point, and measuring the time difference between transmission and reception. Is possible.

  Hereinafter, the configuration of the construction head 13 will be described with reference to FIG. A water chamber 29 as a liquid storage means is formed in the construction head 13. A water supply pipe 22 is connected to the water chamber 29 and is filled with water supplied from the water supply means 14 via the water supply pipe 22. The water chamber 29 is provided with a WJ ejection nozzle 17 that opens toward the pipe 2. The opening of the WJ ejection nozzle 17 is an ejection hole 21. The water filled in the water chamber 29 is ejected from the ejection hole 21 and ejected to the pipe 2 as WJ.

  Further, a gas nozzle 28 is provided in the vicinity of the WJ jet nozzle 17 and the gas nozzle 28 opens toward the WJ. Gas is supplied to the gas nozzle 28 from the gas supply means 15 through the gas supply pipe 27, and the gas is ejected around the WJ. The gas ejected around the WJ forms an air flow R that follows the WJ.

  One gas nozzle 28 may be provided around the WJ ejection nozzle 17, or a plurality of gas nozzles 28 may be provided. When a plurality of gas nozzles 28 are provided around the WJ ejection nozzle 17, a more uniform air flow R is formed around the WJ. In the present embodiment, it is assumed that four gas nozzles 28 are provided around the WJ jet nozzle 17 at equal intervals.

  Further, the gas nozzle 28 may be a nozzle that is provided outside the periphery of the WJ jet nozzle 17 and opens concentrically with the WJ jet nozzle 17. The position and shape of the gas nozzle 28 are preferably determined as appropriate so that a uniform air flow R can be formed around the WJ.

  The construction head 13 is provided with a condensing optical system 30 and a window 31. The window 31 is provided in the water chamber 29 in a watertight manner, and is located between the water chamber 29 and the condensing optical system 30. The laser L transmitted to the construction head 13 by the optical transmission means 12 is condensed by the condensing optical system 30, passes through the water in the water chamber 29 through the window 31, and passes through the ejection hole 21 of the WJ ejection nozzle 17. Is incident on the WJ.

(WJ and laser current R propagated through laser L)
Hereinafter, the relationship between the WJ through which the laser L is propagated and the airflow R will be described. First, how the airflow R is formed will be described. In FIG. 2, the water chamber 29 is filled with water, and the water in the water chamber 29 is ejected as WJ from the ejection hole 21 and is injected into the pipe 2. The water chamber 29 is pressurized and the flow rate of WJ is fast. Since the pressure around the fluid flowing at high speed becomes low (Bernoulli's theorem), the gas ejected from the gas nozzle 28 flows so as to follow around the WJ and forms an air flow R.

  Next, how the laser L propagates through the WJ will be described. WJ has a role as a light guide material for propagating the laser L from the construction head 13 to the processing point. An incident NA (numerical aperture) of the laser L is determined by the laser oscillator 11 and the condensing optical system 30. By adjusting the configurations of the laser oscillator 11 and the condensing optical system 30, the incident NA of the laser L can be adjusted and the laser L can be incident on the WJ.

  The laser L incident on the WJ passes through the inside of the WJ, and is totally reflected at the interface between the WJ and the periphery of the WJ (the surface of the WJ) due to a difference in refraction angle, and is turned back into the WJ. The laser L propagates in the WJ while repeating total reflection in the WJ. And the laser L is irradiated to the process point in which WJ is injected. The processing point is melted by the energy of the laser L, and the melted portion is blown off by the force of WJ and is removed from the processing point as cutting waste 29, and at the same time, the processing point is cooled by WJ. Cutting processing proceeds by melting by laser L, removal of cutting waste by WJ, and cooling of processing points.

  Next, the relationship between WJ and airflow R will be described. An appropriate amount of airflow R has the effect of stabilizing the state of WJ. The state of the WJ being stable means that the diameter of the WJ is constant and the WJ is columnar as shown in FIG. When the state of the WJ is stable, the laser L is totally reflected on the surface of the WJ, and propagates in the WJ while maintaining energy substantially. The laser L can sufficiently heat and melt the processing point, and the melted portion is removed from the processing point by WJ and cooled, and the cutting process of the pipe 2 proceeds.

  On the other hand, when there is no appropriate amount of airflow R around WJ, the state of WJ is difficult to stabilize. In particular, the WJ state becomes unstable as the distance from the ejection hole 21 increases. For example, WJ does not have a columnar shape, but has a droplet shape that continuously flows as shown in FIG. Alternatively, as shown in FIG. 3C, the diameter of WJ may be larger than the diameter near the ejection hole 21, and the laser L may not be totally reflected. The laser L is not totally reflected at the portion where the WJ is not columnar, and part or all of the laser L is emitted to the outside of the WJ. Then, the energy of the laser L irradiated to the processing point is reduced, the heating at the processing point is insufficient, the amount of melting is reduced, the cutting speed is lowered, and the cutting efficiency is lowered. Or it becomes impossible to cut.

(Laser cutting method and action)
Hereinafter, the laser processing method of the laser processing apparatus 10 in this embodiment is demonstrated. In addition, the path | route which moves the construction head 13 with respect to a to-be-processed body and performs a cutting process is called the cutting path 34, and the groove | channel produced in the cutting path 34 by the laser cutting process is called a cutting slit. The cutting slit refers to both a groove penetrating the workpiece and a groove not penetrating the workpiece. In the cutting slit, a direction parallel to the cutting path 34 and a direction perpendicular to the cutting depth direction are referred to as a slit width direction, and the width of the cutting slit in the slit width direction is referred to as a slit width.

  Further, a portion of the pipe 2 where the WJ through which the laser L is propagated can be directly ejected from the outside of the pipe 2 is referred to as a first wall surface 2a. A portion of the pipe 2 that is separated from the WJ that propagates the laser L by the first wall surface and cannot eject the WJ that propagates the laser L from the outside is referred to as a second wall surface 2b.

  First, a first cutting step is performed. In the first cutting step, the WJ and the airflow R propagated by the laser L are ejected to the first wall surface 2a. Then, as shown in FIGS. 2 and 4, a first cutting slit 32 is formed along a cutting path 34 that penetrates the first wall surface 2 a.

  When the first cutting slit 32 is formed, the WJ that has propagated the laser L is ejected to the pipe 2 as shown in FIG. The WJ propagating the laser L is ejected to the pipe 2 so as to repeatedly reciprocate in parallel with the cutting path 34, and is ejected while shifting the ejection position in the slit width direction.

  And the 1st cutting slit 32 is formed so that it may be the slit width which WJ and the airflow R which propagated the laser L can pass through. The slit width of the first cutting slit 32 is assumed to be 1.5 to 2 times the diameter of WJ, for example.

  After the first cutting slit 32 penetrates the first wall surface 2a, the second cutting step is performed. In the second cutting step, the WJ and airflow R propagated by the laser L are passed through the first cutting slit 32, and the WJ and airflow R propagated by the laser L are passed through the second wall surface 2b to the inner surface side of the pipe 2. And a second cutting slit 33 penetrating the second wall surface 2b is formed.

  Since the slit width of the first cutting slit 32 is a sufficient distance for the air flow R following the WJ and the WJ to pass, the air flow R can reach the processing point in the second cutting step. . Therefore, WJ can propagate the laser L well to the processing point in the second cutting step, and the second cutting slit 33 can be formed quickly and efficiently.

By forming the cutting slit so that the first cutting slit 32 and the second cutting slit 33 are connected, the pipe 2 can be cut so as to be divided.

  While the first cutting step and the second cutting step are performed, a waste water circulation step is performed. In the wastewater circulation step, the wastewater tray 24 collects wastewater resulting from WJ, the filtration unit 26 removes the cutting waste from the wastewater, and the wastewater circulation pump 25 conveys the wastewater from which the cutting waste has been removed to the water supply means 14. . Then, the waste water from which the cutting waste has been removed is again ejected as WJ from the construction head 13 and used for forming WJ.

  Further, while the first cutting step and the second cutting step are being performed, a machining position measuring step is performed as needed. In the machining position measuring step, the machining position measuring means 18 measures the machining distance and transmits the information to the control unit 19. Then, the control unit 19 determines the pipe 2 based on the diameter and thickness of the pipe 2 given in advance, the information such as the initial positions of the construction head 13 and the pipe 2, and the processing distance information received from the processing position measuring means 18. Grasping the position of the machining point at. For example, the control unit 19 can detect that the first cutting slit 32 has penetrated the first wall surface 2 a based on the information of the processing position measuring means 18.

  The machining position measuring means 18 is preferably provided in front of or behind the ejection hole 21 in the moving direction of the construction head 13. Then, even when the diameter of the pipe 2 is large, the laser or ultrasonic wave irradiated from the processing position measuring means 18 can pass through the first slit and reach the processing point of the second wall surface. It is possible to measure the machining distance also in the second cutting step.

  Further, the processing position measuring means 18 may be capable of controlling the directivity of the irradiated laser or ultrasonic wave. Then, it becomes possible to accurately irradiate the processing point with a laser or ultrasonic wave for measuring the processing distance, and it becomes possible to measure the processing distance more accurately.

  Note that the cutting of the pipe 2 in the laser processing apparatus 10 is automatically performed by the control unit 19 controlling the operation of each part of the laser processing apparatus 10. The control unit 19 automatically determines the execution of the first cutting step or the second cutting step based on the position of the processing point in the pipe 2. And operation | movement of each part of the laser processing apparatus 10 is controlled so that a 1st cutting step or a 2nd cutting step may be implemented.

  In the second cutting step, WJ that contributes to the formation of the second cutting slit 33 is WJ that propagates the laser well due to the presence of the air flow R. That is, when the distance required for the air flow R to pass through when the WJ passes through the first cutting slit 32 is not sufficiently secured between the WJ and the first cutting slit 32, the WJ Does not contribute to the formation of the second cutting slit 33. Therefore, as shown in FIG. 6, the slit width of the second cutting slit 33 is smaller than the slit width of the first cutting slit 32.

(effect)
Hereinafter, effects of the laser processing method and the laser processing apparatus 10 according to the present embodiment will be described. In the laser processing method of the present embodiment, the slit width of the first cutting slit 32 is sufficiently wide to allow the WJ and the airflow R that have propagated the laser L to pass therethrough. Therefore, the second cutting slit 33 can be efficiently formed, and the pipe 2 can be cut efficiently. Therefore, even the pipe 2 that is fixed to a facility or the like and does not have a sufficient space for moving the laser processing apparatus around it can be efficiently cut.

  In addition, when the pipe 2 is a radioactive pipe installed in a nuclear power plant or the like, the pipe can be cut efficiently, so that the work time can be shortened and the amount of exposure of workers Can be reduced.

  Further, since the laser processing apparatus 10 can automatically perform the pipe cutting process, it is possible to further reduce the exposure amount of the worker.

  Further, since the WJ cools the processing point simultaneously with the melting by the laser L, the vaporized pipe 2 is hardly generated. Therefore, the burden on the environment can be reduced.

  Moreover, the laser processing apparatus 10 includes a waste water circulation mechanism 23, and can reduce the amount of waste water. Furthermore, since the activated cutting waste is caught in the wastewater, it is difficult to scatter and can be recovered by the wastewater treatment mechanism 23. Therefore, the burden on the environment can be reduced.

  The cutting position measuring means 18 measures not only the processing distance but also the distance (cutting depth) from the surface of the pipe 2 on the side where the WJ is jetted to the processing point, and the diameter and thickness of the pipe 2. It is good also as a structure which is possible. Then, even if the wall thickness, the initial position of the construction head 13 and the pipe 2 and the like cannot be grasped in advance, the control unit 19 determines the machining point in the pipe 2 from the information on the diameter, processing distance, and cutting depth of the pipe 2. It becomes possible to grasp the position.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings. FIG. 7 is a water jet ejection path in the first cutting step of the present embodiment. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  In the present embodiment, when the first cutting slit 32 is formed in the first cutting step, the WJ propagating the laser L is ejected while being weaved along the cutting path 34 in the pipe 2 as shown in FIG. Let When the WJ is ejected while weaving the pipe 2, the WJ is repeatedly reciprocated in the slit width direction of the first cutting slit 32 while the WJ is ejected while shifting the ejection position in the direction parallel to the cutting path 34. That is.

  Moreover, the construction head moving means 16 in the present embodiment includes an ultrasonic transducer that vibrates the construction head 13 in a direction parallel to the slit width direction. By moving the construction head 13 along the cutting path 34 while vibrating the construction head moving means 16 in the slit width direction with an ultrasonic vibrator, the WJ can be ejected while weaving along the cutting path 34. . In the second cutting step, the ultrasonic transducer is stopped.

  The laser cutting device 10 and the laser cutting method according to the present embodiment have the same effects as those of the first embodiment. Moreover, in the laser cutting device 10 in this embodiment, it is necessary to control the moving direction of the construction head moving unit 16 in the slit width direction by setting the amplitude of the ultrasonic transducer to a desired width. Disappear. Therefore, it is possible to simplify the structure of the control part 19 and the construction head moving means 16. Therefore, the installation space of the laser cutting device 10 can be reduced.

(Third embodiment)
Hereinafter, a third embodiment will be described. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment and 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  The diameter of WJ ejected to the pipe 2 in the first cutting step of the present embodiment is larger than the diameter of WJ ejected to the pipe 2 in the second cutting step. The diameter of WJ can be changed by adjusting the diameter of the ejection hole 21 and the pressurization of the water supply means 14 to the water chamber 29. In addition, the energy density of the laser L that is propagated to the WJ and applied to the processing point is controlled so that the energy density at which the cutting is performed most efficiently at the processing point. The energy density can be changed by adjusting the laser transmitter 11, the optical transmission means 12, and the condensing optical system 13.

  The slit width of the first cutting slit 32 can be formed more quickly because the diameter of the WJ ejected to the processing point in the first cutting step is large. Therefore, according to the laser processing method of the present embodiment, the working time can be further shortened, and the exposure amount of the worker can be further reduced. Further, the laser processing method of the present embodiment has the same effect as that of the first embodiment.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to FIG. FIG. 8 is a longitudinal sectional view parallel to the central axis of the water jet and the pipe being cut in the fourth embodiment.

  In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment thru | or 3rd Embodiment, and the overlapping description is abbreviate | omitted.

  In the first cutting step and the second cutting step of the present embodiment, WJ propagated by the laser L is ejected from the construction head 13 at an elevation angle. Then, as shown in FIG. 8, the first cutting slit 32 and the second cutting slit 32 are formed at an elevation angle when viewed from the construction head 13 on the projection plane parallel to the central axis of the pipe 2.

  Here, the relationship between the wastewater existing near the processing point and WJ will be described. There is waste water that is water jetted as WJ in the vicinity of the processing point, but the waste water is pushed away from the vicinity of WJ by the momentum of jetting WJ. However, if the momentum of the WJ is weak, or if the vicinity of the processing point is narrow and the waste water stays in the vicinity of the processing point, the WJ cannot push the waste water, and the waste water interferes with the WJ. Then, since the surface of the WJ disappears in the portion interfering with the wastewater, the laser L is emitted to the outside of the WJ before reaching the processing point, the cutting process does not proceed, and the cutting efficiency is lowered.

  In this embodiment, since the 1st cutting slit 32 and the 2nd cutting slit 32 are formed in an elevation angle, the waste water in a cutting slit flows into the exterior of a cutting slit according to gravity. Therefore, in the present embodiment, the pipe 2 can be efficiently cut even when the pipe 2 is thick and the cutting depth of the cutting slit is deep.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to FIG. FIG. 9 is a longitudinal sectional view parallel to the central axis of the water jet and the pipe being cut in the fifth embodiment.

  In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment thru | or 4th Embodiment, and the overlapping description is abbreviate | omitted.

  In the first cutting step and the second cutting step of the present embodiment, as shown in FIG. 8, the WJ that has propagated the laser L is ejected from the construction head 13 at a depression angle. The WJ can obtain a gravitational acceleration, and the momentum of the WJ ejected to the processing point increases by the gravitational acceleration. Therefore, WJ can push more waste water near the processing point. Therefore, it is possible to reduce the hindrance of the cutting process by wastewater, and in this embodiment, it is possible to cut the pipe 2 efficiently.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. Moreover, the combination of embodiment may be sufficient. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, the pipe 2 is not limited to a pipe installed in the vertical direction. The present invention can also be applied to piping installed at a horizontal direction or other angles, bent portions of piping, and the like. In the present embodiment, the target portions to be cut are the first wall surface 2a and the second wall surface 2b, and the cutting target portions are set in one structure. However, the target portion to be cut may extend over a plurality of targets, and the present invention can be applied to two plates that are stacked at intervals. In addition, when the pipe 2 is a pipe installed in the horizontal direction, waste liquid accumulates inside the pipe 2, and it is considered that the waste liquid and WJ interfere with each other and the cutting process is hindered in the second cutting step. Therefore, a device for preventing the wastewater from interfering with the WJ is necessary. For example, it is possible to prevent the wastewater from interfering with the WJ by increasing the flow velocity of the WJ ejected to the pipe 2 in the second cutting step. Further, by inserting a pipe or the like for sucking waste water into the pipe 2 from the first cutting slit 32, it is possible to prevent the waste water from interfering with the WJ.

  Further, the workpiece is not limited to piping provided at a nuclear power plant or the like. It may be a pipe provided in another facility. Moreover, other than piping may be sufficient if it is hollow. Further, the constituent material of the workpiece is not limited to carbon steel, and may be various metals, ceramics, resins, and the like.

  Further, the liquid flow may be WJ or may be formed of a liquid other than water as long as the laser L can be propagated. Further, even if the liquid absorbs the laser L, it is sufficient if it can propagate a laser having a sufficient output at the processing point.

  Further, when the WJ is rotated, the construction head moving means 16 does not move the construction head 13 but the WJ jet nozzle 17 may be rotated. In that case, it is necessary to adjust the laser oscillator 11, the condensing optical system 30, etc. so that the laser L may enter the WJ.

2... Piping 2 a... First wall 2 b... Second wall 10... Laser processing device 11... Laser oscillator 12. Optical transmission means 13 ... construction head 14 ... water supply means 15 ... gas supply means 16 ... construction head moving means 17 ... WJ jet nozzle 18 ... Processing position measuring means 19 ... Control unit 20 ... Processing point 21 ... Eject hole 22 ... Water supply pipe 23 ... Wastewater circulation Mechanism 24 ... Waste water tray 25 ... Waste water circulation pump 26 ... Filtration mechanism 27 ... Gas supply piping 28 ... Gas nozzle 29 ... Water chamber 30... Condensing optical system 31... Window 32... First cutting slit 33. Tsu door 34 ..... cutting path L ····· laser WJ ····· water jet R ····· airflow

Claims (9)

A laser processing method of jetting a liquid flow in which a laser is propagated to a target location, irradiating the target location with the liquid flow as a light guide material, and cutting the target location.

It is ejected airflow so as to follow the periphery of Rutotomoni the liquid flow is ejected liquid stream obtained by propagating the laser with respect to the first target portion, the liquid flow and the air flow through the first target portion a first cutting step of forming a first cutting slits have a width but can pass,
The liquid stream obtained by propagating the laser is passed through the first cutting slits in the liquid stream to propagate the laser is ejected with respect to the second target portion, the second penetrating the second target portion A second cutting step for forming a cutting slit of
The laser processing method, wherein the second target portion is arranged at a distance from the first target portion, and the first cutting slit has a slit width larger than that of the second cutting slit. The liquid flow ejected to the first target location in the first cutting step has a cross section perpendicular to the flow direction, rather than the liquid flow passing through the first cutting slit in the second cutting step. The laser processing method according to claim 1, wherein the diameter of the laser is large. The laser processing method according to claim 1, wherein the liquid flow is ejected to the target portion at an elevation angle. The laser processing method according to claim 1, wherein the liquid flow is ejected to the target portion at a depression angle. The flow velocity of the liquid flow ejected to the second target location in the second cutting step is higher than the flow velocity of the liquid stream ejected to the first target location in the first cutting step. The laser processing method according to claim 1, which is fast. The laser processing method according to any one of claims 1 to 5, further comprising a processing position measuring step of measuring a position of a processing point that is a portion where the liquid flow is ejected in the target portion. The waste liquid circulation step which collects the waste liquid resulting from the liquid flow, removes cutting waste from the waste liquid, and uses the waste liquid from which the cutting waste has been removed for forming the liquid flow is provided. The laser processing method according to claim 6. A laser processing apparatus for ejecting a liquid flow in which a laser is propagated to a target location, irradiating the target location with a laser using the liquid flow as a light guide material and cutting the target location,
In order to cut the first target location and the second target location spaced apart from the first target location, a control unit that controls each part of the laser processing apparatus,
Wherein the control unit through said first target portion in the air flow to the jet so as to follow the periphery of the allowed Rutotomoni the liquid flow ejected liquid stream to propagate the laser to the first target portion the liquid to form a first cutting slits have a width in which the flow and the air flow can pass,
The liquid flow propagated through the laser passes through the first cutting slit, and the liquid flow propagated through the laser is ejected to the second target location, penetrating through the second target location, and The said laser processing apparatus controlled to form the 2nd cutting slit whose slit width is narrower than a 1st cutting slit. A tray unit for collecting waste liquid resulting from the liquid flow;
A filtration unit for removing cutting waste from the waste liquid collected in the tray unit;
The laser processing apparatus of Claim 8 provided with the waste liquid circulation pump which circulates the said waste liquid from which the said cutting waste was removed to the construction head which ejects the said liquid flow.

Images