JP6652349B2 - Laser processing apparatus and laser processing method - Google Patents

Description

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

  As a technique for modifying the surface of a metal material, shot peening, water jet peening, and laser peening are generally known. Laser peening irradiates the material surface with a high-power pulsed laser and confines the plasma generated by ablation on the material surface to the material surface by painting or water film, etc., so that shock waves generated from the plasma pressure are directed to the material side. This is a technique for modifying the surface of a metal material by transmitting it.

  When water is used to confine the plasma, a method of irradiating a laser in water, a method of supplying water to a material surface to form a water film, and the like are used. When a paint or the like is used to confine the plasma, pretreatment such as painting is performed in advance to confine the plasma pressure generated on the material surface and perform a surface modification treatment of the metal material.

  The laser peening method using water to confine the plasma pressure is difficult to apply to materials such as iron and steel which are easily oxidized by water. Processing such as performing a drying treatment after construction is required. Further, when construction is performed underwater, there is a problem that dimensional restrictions may be applied to the applied member, and it is necessary to immerse in the water to an unnecessary range.

  Further, as a pretreatment, a method of obtaining a laser peening effect without using water by coating a sheet for transmitting laser and containing generated plasma on a material surface has been proposed (for example, Patent Document 1). 1).

  However, in the above-described method, the coating may be peeled off by a plasma generated by the laser irradiation in a range beyond the peening effect, and it may be difficult to continuously perform the application. Further, when it is desired to perform the repetitive processing in order to superimpose the laser peening effect, it is necessary to perform the pre-processing coating again.

  Further, the sheet for transmitting the laser beam and containing the plasma is formed in a belt shape, and the sheet is slid to the work surface by a feeding portion in which the sheet is concentrically wound and a winding portion for winding the sheet after laser irradiation. At the same time, there has been proposed a laser peening apparatus for blowing a gas to press a sheet against a work surface (for example, see Patent Document 2). In this laser peening apparatus, since laser irradiation is performed while supplying a sheet for transmitting laser light and confining plasma, repetition of pretreatment is unnecessary.

  However, this laser peening apparatus is applicable when the main body of the apparatus needs to follow the construction target and has a sufficiently wide plane, but it is difficult to construct only the tip of the parts etc. In the case of, the peening effect may not be sufficiently obtained because the irradiation density cannot be kept constant. Further, since the sheet is configured to be pressed against the construction surface by the gas supplied from the inner surface of the head, there is a possibility that the pressure on the construction surface of the sheet becomes insufficient and the confinement of plasma becomes insufficient.

JP 2006-159290 A JP 2014-176870 A

  As described above, conventionally, when performing laser peening, there are limitations on the method of construction such as continuous construction and the construction target, and there is a case where desired treatment cannot be performed due to insufficient confinement of plasma pressure. was there.

  The present invention has been made in view of the above-described conventional circumstances, and an object of the present invention is to provide a laser processing apparatus and a laser processing method capable of suppressing insufficient confinement of plasma pressure.

One mode of the laser processing apparatus includes a laser oscillator for oscillating laser light to irradiate the processing target member, a ball lens for condensing the laser light and guiding the laser light to the processing target member, and being pressed by the ball lens. A medium holding mechanism that holds a medium disposed between the ball lens and the member to be processed, a holding mechanism that rotatably holds the ball lens, and a medium holding mechanism that is provided in the medium holding mechanism. A medium supply mechanism for supplying the medium disposed between the member to be processed, a detection mechanism for detecting a rotation state of the ball lens, and a medium supply mechanism based on the rotation state detected by the detection mechanism. And a medium supply control mechanism for controlling a supply state of the medium .

One embodiment of a laser processing method is a laser processing method of performing surface treatment by irradiating a laser beam to a member to be processed, and oscillating the laser light to irradiate the member to be processed with a laser oscillator. A step of causing the laser light oscillated by an oscillator to enter a ball lens to condense the light, a step of arranging a medium that transmits the laser light between the ball lens and the member to be processed, and A step of pressing the member to make contact with the member to be processed, a step of changing the irradiation position of the laser beam on the member to be processed while rotating the ball lens, and detecting the ball lens rotation state by a detection mechanism. And a step of controlling the supply state of the medium based on the rotation state detected by the detection mechanism .

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that confinement of plasma pressure becomes inadequate.

FIG. 1 is a diagram illustrating an overall schematic configuration of a laser processing apparatus according to a first embodiment. FIG. 2 is a diagram illustrating a schematic configuration of a main part of the laser processing apparatus in FIG. 1. FIG. 2 is a diagram illustrating a schematic configuration of a main part of the laser processing apparatus in FIG. 1. FIG. 5 is a diagram illustrating a schematic configuration of a main part of a laser processing apparatus according to a second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an overall schematic configuration of a laser processing apparatus 100 according to the first embodiment.

  As shown in FIG. 1, the laser processing apparatus 100 includes a torch 1 for irradiating a laser beam 30 to a construction target 20. A casing 3 is provided inside the torch 1, and a casing 4 is provided inside the casing 3. A microchip laser oscillator 5 and an optical system 6 for shaping a laser beam 30 emitted from the microchip laser oscillator 5 into parallel light are provided in the housing 4. Further, a protective glass 7 is provided at an exit portion of the housing 4 for the laser light 30.

  A guide mechanism 8 for controlling the attitude of the housing 4 is provided between the housing 4 and the casing 3. A ball lens 9 that condenses the laser beam 30 and guides the laser beam 30 to the construction target 20 is provided at an exit portion of the laser beam 30 of the torch 1. The ball lens 9 is rotatably held by a ball lens holding mechanism 10. Generally, the ball lens 9 can have a short focal point, and can focus the laser beam 30 at a close position. The material of the ball lens 9 is preferably a material that can transmit the laser beam 30 efficiently and is hardly damaged. For example, sapphire or the like can be suitably used.

  In the laser processing apparatus 100, a transparent resin such as silicon or the like is used as a medium that is pressed by the ball lens 9 and disposed between the ball lens 9 and the object 20 in order to transmit the laser beam 30 and confine the plasma. And a tape-shaped medium 11 composed of a band-shaped (tape-shaped) sheet. The laser processing apparatus 100 includes a medium supply / recovery mechanism 12 for supplying and recovering the tape-shaped medium 11, and in this embodiment, the medium supply / recovery mechanism 12 functions as a medium holding mechanism for holding the medium. I have. The medium supply / recovery mechanism 12 includes a reel around which the tape-shaped medium 11 is wound, a reel for winding the tape-shaped medium 11, a motor for rotating these reels, and the like. The tape supply medium 11 is supplied from the medium supply / recovery mechanism 12 between the ball lens 9 and the processing target 20, and the tape supply medium 11 after passing the laser beam 30 and used for confining the plasma is supplied and recovered. Collected by the mechanism 12.

  In FIG. 1, reference numeral 13 denotes a control unit for controlling the entire operation of the laser processing apparatus 100, and reference numeral 14 denotes a laser control for supplying light or electricity to the microchip laser oscillator 5 to oscillate the laser light 30. Department. Reference numeral 15 denotes a posture sensor for detecting the posture (inclination) of the torch 1.

  In the laser processing apparatus 100 having the above-described configuration, excitation light or electricity for emitting the laser light 30 is supplied from the laser control unit 14 to the microchip laser oscillator 5, and the laser light 30 is repeatedly oscillated with a predetermined number of pulses. Is done. The laser light 30 emitted from the microchip laser oscillator 5 is shaped into parallel light by the optical system 6, passes through the protective glass 7, is condensed by the ball lens 9, and then passes through the tape-shaped medium 11. Irradiation is performed on the construction target 20.

  At this time, the ball lens 9 is substantially pressed by the ball lens 9 by maintaining the ball lens 9 in contact with the tape medium 11. As a result, the tape-shaped medium 11 is brought into contact with the surface of the processing target 20, and the processing target 20 is irradiated with the laser beam 30 in this state. Thereby, the plasma generated by the irradiation of the laser beam 30 is reliably confined by the tape-shaped medium 11, and peening can be reliably performed. That is, it is possible to suppress the confinement of the plasma pressure from becoming insufficient.

  When the torch 1 is moved, the ball lens 9 is moved while rotating while the ball lens 9 is in contact with the tape-shaped medium 11 and pressed. The ball lens holding mechanism 10 is provided with a rotation detection mechanism that detects the state of rotation of the ball lens 9. Then, based on a detection signal from the rotation detection mechanism, the control unit 13 detects whether or not the torch 1 has moved and the moving speed. The movement of the torch 1 may be performed manually by an operator or by a driving mechanism such as a robot.

  The medium supply / recovery mechanism 12 automatically adjusts the supply and recovery speed of the tape-shaped medium 11 in accordance with the moving speed of the torch 1 detected by the control unit 13. The tape-shaped medium 11 is supplied between the ball lens 9 and the object 20 through the outside of the casing 3 in the torch 1 and is collected.

  Further, when the movement of the torch 1 is stopped, when the traveling direction is changed, or the like, the change in the rotation state of the ball lens 9 is detected by the rotation detection mechanism of the ball lens holding mechanism 10 so that the control unit 13 Can be detected. The control unit 13 controls on / off of the oscillation of the laser beam 30 by the microchip laser oscillator 5 based on the detection result. Further, in accordance with a change in the progress state of the torch 1, the unused surface of the tape-shaped medium 11 is supplied between the ball lens 9 and the construction target 20 so that the tape-shaped medium 11 is Control supply and recovery.

  FIG. 2 and FIG. 3 are enlarged views of the tip portion of the torch 1. As shown in FIGS. 2 and 3, in the laser processing apparatus 100 of the present embodiment, when performing laser peening by irradiating the flat plate-like construction target 20 with the laser beam 30, for example, the state shown in FIG. 2. When the torch 1 is tilted as shown in FIG. 3, the controller 13 detects the tilt and drives the guide mechanism 8 to keep the posture constant so that the housing 4 does not tilt. Note that the inclination of the torch 1 is detected based on a detection signal from a posture sensor 15 disposed on the torch 1 as shown in FIG. By adopting such a configuration, even when the torch 1 is tilted, it is possible to suppress a change in the irradiation interval of the laser light 30, and to irradiate the construction object 20 with the laser light 30 at a set density. Can be.

  Note that the ball lens holding mechanism 10 can be provided with a cleaning mechanism for cleaning the ball lens 9. In addition, an optical sensor is provided in the ball lens holding mechanism 10, and the degree of deterioration of the ball lens 9 can be detected by detecting light transmitted through the ball lens 9 or light irregularly reflected by the ball lens 9. For example, the light transmitted through the ball lens 9 is detected to determine the transmittance, and whether the reduction (that is, the attenuation) of the transmittance exceeds a predetermined value (for example, 5%) depends on whether the ball lens 9 is replaced due to deterioration. Can be detected. By using sapphire as the material of the ball lens 9, the durability of the lens is improved, and stable peening can be performed for a long time.

  As described above, according to the laser processing apparatus 100 of the present embodiment, it is possible to continuously perform the construction without requiring any pretreatment. Further, since the laser light 30 oscillated from the microchip laser oscillator 5 is condensed by the ball lens 9, the torch 1 can be reduced in size, and the ball lens 9 contacts the tape-shaped medium 11. Since the construction can be performed while rotating, the degree of freedom in the construction can be improved, and the restriction on the construction target can be eased.

  Further, by maintaining the ball lens 9 in contact with the tape-shaped medium 11, the tape-shaped medium 11 can be prevented from peeling off and floating, and the plasma generated by the irradiation of the laser beam 30 can be reliably removed. It can be confined by the tape-shaped medium 11. That is, it is possible to suppress insufficient confinement of the plasma pressure, and to perform desired peening. In this embodiment, a ball lens holding mechanism 10 for rotatably holding the ball lens 9 and a medium supply / recovery mechanism 12 for supplying and recovering the tape-shaped medium 11 are provided. What is necessary is just to be able to maintain the state in which the ball lens 9 is in contact with the tape-shaped medium 11 by being configured to be pressed between the ball lens 9 and disposed between the ball lens 9 and the installation target 20. In this case, the hole lens holding mechanism 10 does not have to be configured to hold the ball lens 9 rotatably, and the medium holding mechanism 12 that supplies and recovers the tape-shaped medium 11 is omitted as the medium holding mechanism. What is necessary is just to have the mechanism which hold | maintains so that the tape-shaped medium 11 may be arrange | positioned between the ball lens 9 and the to-be-processed object 20 so that it may be pressed by the ball lens 9.

  Next, a laser processing apparatus 101 according to a second embodiment will be described with reference to FIG. The laser processing apparatus 101 of the present embodiment uses a gel-like medium 111 as a medium that is pressed between the ball lens 9 and disposed between the ball lens 9 and the object 20 to confine plasma.

  As shown in FIG. 4, the laser processing apparatus 101 according to the second embodiment supplies a gel medium 111 between the ball lens 9 and the object 20 and supplies a gel having a function of cleaning the ball lens 9. Cleaning lines 112a and 112b are provided, and the gel supply cleaning lines 112a and 112b constitute a medium holding mechanism. Since the other configuration is the same as that of the laser processing apparatus 100 according to the first embodiment, the corresponding portions are denoted by the same reference numerals, and redundant description will be omitted.

  In the laser processing apparatus 101, the laser light 30 emitted from the microchip laser oscillator 5 is formed into parallel light by the optical system 6, passes through the protective glass 7, is condensed by the ball lens 9, and then is gelled. The light is transmitted to the construction target 20 through the medium 111.

  At this time, the gel lens 111 is substantially pressed by the ball lens 9 by maintaining the ball lens 9 in contact with the gel medium 111. As a result, the gel medium 111 is brought into contact with the object 20 to be processed, and the laser light 30 is applied to the object 20 in this state. Thereby, the plasma generated by the irradiation of the laser beam 30 is reliably confined by the gel-like medium 111, and peening can be reliably performed. That is, it is possible to suppress the confinement of the plasma pressure from becoming insufficient.

  When the torch 1 is moved, the ball lens 9 is moved while rotating while the ball lens 9 is in contact with the gel medium 111 and pressed. The ball lens holding mechanism 10 is provided with a rotation detection mechanism that detects the state of rotation of the ball lens 9. Then, based on a detection signal from the rotation detection mechanism, the control unit 13 detects whether or not the torch 1 has moved and the moving speed. When the torch 1 stops, the oscillation of the laser beam 30 from the microchip laser oscillator 5 stops.

  The control unit 13 automatically adjusts the supply amount of the gel medium 111 supplied from the gel medium supply mechanism (not shown) through the gel supply cleaning lines 112a and 112b according to the detected moving speed of the torch 1. The supply of the gel medium 111 from the gel supply / cleaning lines 112a and 112b and the cleaning of the ball lens 9 by the gel supply / cleaning lines 112a and 112b are switched according to the moving direction of the torch 1.

  That is, the gel medium 111 is supplied from the front side with respect to the moving direction of the torch 1, and the ball lens 9 is washed on the rear side. For example, as shown by an arrow in FIG. 4, when the torch 1 moves rightward, the gel-like medium 111 is supplied from the gel supply cleaning line 112a on the front side with respect to the moving direction, and the gel supply cleaning on the rear side. In the line 112b, the ball lens 9 is cleaned. In addition, when the moving direction of the torch 1 is changed and the torch 1 moves leftward in FIG. 4, the gel medium 111 is supplied from the gel supply washing line 112b on the front side with respect to the moving direction, and the gel on the rear side is supplied. In the supply cleaning line 112a, the ball lens 9 is cleaned.

  Thereby, the laser beam 30 is always transmitted through the clean surface of the ball lens 9 and is irradiated on the construction target 20. The cleaning of the ball lens 9 is performed by supplying a liquid capable of removing the gel medium 111, such as water or another solvent.

  In the laser processing apparatus 101 according to the second embodiment, the same effects as those of the laser processing apparatus 100 according to the above-described first embodiment can be obtained. In the laser processing apparatus 101 according to the second embodiment, a gel medium 111 is used. Therefore, peening can be performed continuously without stopping laser oscillation when the traveling direction of the torch 1 is changed. In addition to the gel-like medium 111, a liquid medium having a low viscosity, such as ink, can be used in the same manner.

  Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

  DESCRIPTION OF SYMBOLS 1 ... Torch, 3 ... Casing, 4 ... Case, 5 ... Microchip laser oscillator, 6 ... Optical system, 7 ... Protective glass, 8 ... Guide mechanism, 9 ... Ball lens, 10 ... ... Ball lens holding mechanism, 11 ... Tape medium, 12 ... Medium supply / recovery mechanism, 13 ... Control unit, 14 ... Laser control unit, 15 ... Attitude sensor, 20 ... Construction target, 30 ... Laser Light, 100, 101... Laser processing apparatus, 111... Gel medium, 112a, 112b.

Claims (8)

A laser oscillator for oscillating laser light to irradiate the member to be processed,
A ball lens that focuses the laser light and guides the laser light to the member to be processed;
A medium holding mechanism that holds a medium that is pressed by the ball lens and that is disposed between the ball lens and the member to be processed;
A holding mechanism for rotatably holding the ball lens,
A medium supply mechanism that is provided in the medium holding mechanism and supplies the medium disposed between the ball lens and the member to be processed;
A detection mechanism for detecting a rotation state of the ball lens;
A medium supply control mechanism that controls a supply state of the medium from the medium supply mechanism based on the rotation state detected by the detection mechanism;
A laser processing apparatus comprising: A laser oscillator for oscillating laser light to irradiate the member to be processed,
A ball lens that focuses the laser light and guides the laser light to the member to be processed;
A medium holding mechanism that holds a medium that is pressed by the ball lens and that is disposed between the ball lens and the member to be processed;
A holding mechanism for rotatably holding the ball lens,
A medium supply mechanism that is provided in the medium holding mechanism and supplies the medium disposed between the ball lens and the member to be processed;
A detection mechanism for detecting a rotation speed of the ball lens;
A laser irradiation control mechanism that controls irradiation timing of the laser light based on the rotation speed detected by the detection mechanism,
A laser processing apparatus comprising: The laser processing apparatus according to claim 2,
A rotation state detection mechanism for detecting a rotation state of the ball lens,
A laser processing apparatus, comprising: a medium supply control mechanism that controls a supply state of the medium from the medium supply mechanism based on the rotation state detected by the rotation state detection mechanism. A laser oscillator for oscillating laser light to irradiate the member to be processed,
A ball lens that focuses the laser light and guides the laser light to the member to be processed;
A medium holding mechanism that holds a gel or liquid medium that is disposed between the ball lens and the member to be processed and pressed by the ball lens;
A cleaning mechanism for cleaning the ball lens,
A laser processing apparatus comprising: The laser processing apparatus according to any one of claims 1 to 4 ,
A housing for housing the laser oscillator,
A casing for housing the housing,
Interposed between the housing and the casing, an attitude control mechanism that maintains the attitude of the housing constant,
A laser processing apparatus comprising: A laser oscillator for oscillating laser light to irradiate the member to be processed,
A ball lens that focuses the laser light and guides the laser light to the member to be processed;
A medium holding mechanism that holds a medium pressed between the ball lens and the member to be processed by being pressed by the ball lens;
A housing for housing the laser oscillator,
A casing for housing the housing,
And a posture control mechanism interposed between the housing and the casing to maintain the posture of the housing constant. A laser processing method of performing surface treatment by irradiating a laser beam to a member to be processed,
Oscillating the laser light to irradiate the member to be processed by a laser oscillator,
A step of collecting the laser light oscillated by the laser oscillator by causing the laser light to enter a ball lens,
Arranging a medium that transmits the laser light between the ball lens and the member to be processed;
A step of pressing the medium by the ball lens to abut the member to be processed;
Changing the irradiation position of the laser beam to the member to be processed while rotating the ball lens,
Detecting the ball lens rotation state by a detection mechanism;
Controlling the supply state of the medium based on the rotation state detected by the detection mechanism,
A laser processing method comprising: A laser processing method of performing surface treatment by irradiating a laser beam to a member to be processed,
Oscillating the laser light to irradiate the member to be processed by a laser oscillator,
A step of collecting the laser light oscillated by the laser oscillator by causing the laser light to enter a ball lens,
Disposing a medium that transmits the laser light between the ball lens and the member to be processed;
A step of pressing the medium by the ball lens to abut the member to be processed;
A case for housing the laser oscillator, and a posture control mechanism interposed between the casing for housing the housing, a step of maintaining the posture of the housing constant,
A laser processing method comprising:

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