JP2019201031A - Converging optical unit and laser oscillator using the same, laser processing device, and abnormality diagnostic method of laser oscillator - Google Patents

Abstract

To simply determine the presence of an abnormality of an inner part of a laser oscillator.SOLUTION: A converging optical unit 140 includes a conversing lens 142 that converses a laser beam LB in a housing 141, and makes the laser beam LB conversed with the conversing lens 142 to incident into a transmission fiber 200 via a quartz block 144. A photo diode 147 receiving a light reflected from the transmission fiber 200 and/or the quartz block 144 and a photo diode 148 receiving a scattering light from the conversing lens 142 are disposed with a prescribed interval between the conversing lens 142 and the quartz block 144 in the housing 141.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a condensing optical unit, a laser oscillator using the same, a laser processing apparatus, and a laser oscillator abnormality diagnosis method.

  2. Description of the Related Art Conventionally, there has been known a laser processing apparatus that uses a transmission fiber to laser process a workpiece at a remote location. In such a laser processing apparatus, a laser oscillator is provided inside, and laser light emitted from the laser oscillator propagates through the core of the transmission fiber and is transmitted from the laser light emission head connected to the transmission fiber to the workpiece. Irradiated toward. Further, when the laser light is incident on the transmission fiber, the beam diameter of the laser light is reduced to a spot diameter that can be accommodated in the core of the transmission fiber by a condensing lens provided in the laser oscillator.

  On the other hand, in a laser processing apparatus using a transmission fiber, there is a possibility that a laser diode as an excitation light source may be damaged due to the influence of return light that is reflected at a workpiece processing point and returns into the transmission fiber.

  Therefore, in Patent Document 1, the bend mirror provided in the laser light emitting head has an optical characteristic that allows a part of the laser light to pass therethrough, and the transmitted light that has passed through the bend mirror is incident on the absorber. A configuration is disclosed in which the scattered light from the light is detected by a light detection means to detect the laser light output and the return light from the workpiece.

JP 2012-179627 A

  By the way, in a laser oscillator that condenses laser light with a condensing lens and enters the transmission fiber, if there is dirt or damage on the condensing lens or damage at the incident end of the transmission fiber on which the laser light is incident, the laser The light output may decrease. Further, even when the final output does not decrease so much, there is a possibility that the beam quality of the laser beam is deteriorated and the processing quality is affected.

  However, when the configuration disclosed in Patent Document 1 is applied to the above laser oscillator, it is possible to determine whether the scattered light detected by the light detection means is caused by an abnormality in the condenser lens or an abnormality in the transmission fiber. It was difficult. For this reason, even if it is determined that some abnormality has occurred inside the laser oscillator based on the detection result of the light detection means, it is difficult to identify the abnormal part, and it takes time for maintenance work to increase productivity. There was a risk of lowering.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a condensing optical unit capable of specifying the presence / absence of an internal abnormality and an abnormal location with a simple configuration, and a laser oscillator and a laser processing apparatus using the same. It is to provide. Another object of the present invention is to provide a method for diagnosing an abnormality of a laser oscillator capable of specifying the presence / absence of an internal abnormality and an abnormal location.

  In order to achieve the above object, a condensing optical unit according to the present invention has a condensing lens for condensing laser light emitted from a laser light source in a housing, and the laser focused by the condensing lens. A condensing optical unit that causes light to be incident on a transmission fiber via a laser light emitting unit, wherein the transmission fiber and / or the laser light is disposed between the condensing lens and the laser light emitting unit in the housing. A first light receiving portion that receives reflected light from the emitting portion and a second light receiving portion that receives scattered light from the condenser lens are disposed at a predetermined interval.

  According to this configuration, it is possible to determine the presence / absence of an abnormality in the condensing optical unit with a simple configuration and to specify an abnormality location.

  In addition, a laser oscillator according to the present invention includes at least a laser light source that emits laser light, and the above-described condensing optical unit that condenses the laser light and enters the transmission fiber.

  According to this configuration, it is possible to easily identify an abnormal location inside the laser oscillator, and to repair or replace the target location. As a result, the beam quality of the laser beam can be maintained and the downtime of the laser oscillator can be reduced.

  Further, a laser processing apparatus according to the present invention is attached to the laser oscillator, a transmission fiber connected to the laser oscillator and guiding the laser beam emitted from the laser oscillator, and an output end of the transmission fiber. And at least a laser beam emitting head.

  According to this configuration, it is possible to easily identify an abnormal location inside the laser oscillator, and to repair or replace the target location. This can reduce the downtime of the laser processing apparatus. In addition, it is possible to maintain the beam quality of the laser beam and maintain a good processing quality.

  The abnormality diagnosis method for a laser oscillator according to the present invention includes a laser light source and a condensing lens for condensing the laser light emitted from the laser light source, and the laser light condensed by the condensing lens. And a condensing optical unit for making the converging optical unit incident on the transmission fiber via the laser light emitting unit, wherein the condensing optical unit includes the transmission fiber and / or the laser light emitting unit. A first light receiving part for receiving reflected light from the light source and a second light receiving part for receiving scattered light from the condenser lens, and a laser light emitting step for emitting the laser light; And receiving the reflected light to obtain a first received light signal, and receiving the scattered light at the second light receiving unit to obtain a second received light signal; a received light signal obtaining step; 2 With light reception signal Zui it, characterized in that a diagnosis step of determining the presence or absence of an abnormality in the laser oscillator.

  According to this method, the presence or absence of abnormality in the condensing optical unit can be easily determined.

  As described above, according to the condensing optical unit of the present invention, it is possible to determine the presence / absence of abnormality of the condensing optical unit with a simple configuration and to specify the abnormal part.

It is a schematic diagram which shows the structure of the laser processing apparatus which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the internal structure of a condensing optical unit. It is a flowchart which shows the abnormality diagnosis procedure of the laser oscillator which concerns on Embodiment 1 of this invention. 10 is a schematic diagram showing an internal configuration of a condensing optical unit according to Modification Example 1. FIG. 10 is a schematic diagram illustrating an internal configuration of a condensing optical unit according to Modification 2. FIG. 10 is a schematic diagram illustrating an internal configuration of another condensing optical unit according to Modification 2. FIG. 10 is a schematic diagram illustrating an internal configuration of a condensing optical unit according to Modification 3. FIG. It is a flowchart which shows the abnormality diagnosis procedure of the laser oscillator which concerns on Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

(Embodiment 1)
[Configuration of laser processing equipment]
FIG. 1 shows a schematic diagram of a configuration of a laser processing apparatus according to the present embodiment, and FIG. 2 shows a schematic diagram of an internal configuration of a condensing optical unit. In the following description, the traveling direction of the laser beam LB toward the condensing optical unit 140 is the X direction, the arrangement direction of the plurality of laser modules 120 is the Y direction, and the direction orthogonal to the X direction and the Y direction is the Z direction. Sometimes called.

  The laser processing apparatus 1000 includes a laser oscillator 100, a transmission fiber 200, a laser light emission head 300, a control unit 400, a power source 500, and a display unit 600. The end portion of the laser oscillator 100 and the transmission fiber 200 where the laser light is incident (hereinafter simply referred to as the incident end. The end portion where the laser light of the transmission fiber 200 is emitted is hereinafter simply referred to as the emission end). Housed in the housing 110.

  The laser oscillator 100 includes a plurality of laser modules 120, a beam combiner 130, and a condensing optical unit 140. The laser module 120 is composed of a plurality of laser diodes or laser arrays that emit laser beams of different wavelengths, and laser beams synthesized in the laser module 120 are emitted from the respective laser modules 120.

  The beam combiner 130 combines the laser beams respectively emitted from the plurality of laser modules 120 into one laser beam (hereinafter referred to as laser beam LB) and outputs the combined laser beam to the condensing optical unit 140. Specifically, the optical axes of the respective laser beams are close to or coincide with each other, and are coupled so that the optical axes thereof are parallel to each other.

  As shown in FIG. 2, the condensing optical unit 140 includes a housing 141 and a condensing lens 142 disposed therein. The structure and function of each part of the condensing optical unit 140 will be described in detail later.

  With the laser oscillator 100 having such a configuration, it is possible to obtain a high-power laser processing apparatus 1000 whose laser light output exceeds several kW. Further, the laser oscillator 100 is supplied with electric power from a power source 500 described later to perform laser oscillation, and the laser beam LB is emitted from the emission end of the transmission fiber 200. In the present embodiment, the four laser modules 120 are mounted on the laser oscillator 100, but the present invention is not limited to this. The number of laser modules 120 mounted can be changed as appropriate depending on the output specifications required for the laser processing apparatus 1000 and the output specifications of the individual laser modules 120.

  The transmission fiber 200 is optically coupled to the condensing lens 142 of the condensing optical unit 140, and guides the laser light LB received from the laser oscillator 100 via the condensing lens 142 to the laser light emitting head 300. As shown in FIG. 2, the transmission fiber 200 includes a core 201 for guiding the laser beam LB in the axial center, and a clad 202 and an outer clad provided coaxially with the core 201 on the outer peripheral side of the core 201. 203. The core 201, the clad 202 and the outer clad 203 are made of quartz, respectively, but the clad 202 and the outer clad 203 are configured so that the refractive index thereof is lower than the refractive index of the core 201. 203 has a function of confining the laser beam LB in the core 201. The outer peripheral surface of the outer clad 203 is covered with a protective tube 204, and cooling water for cooling the transmission fiber 200 flows in the protective tube 204. However, instead of the protective tube 204, a coating for shielding external light and protecting the transmission fiber 200 from mechanical damage may be provided.

  The laser beam emission head 300 irradiates the laser beam LB guided by the transmission fiber 200 toward the outside. For example, in the laser processing apparatus 1000 illustrated in FIG. 1, the laser beam LB is emitted toward the workpiece W that is a processing target disposed at a predetermined position. By doing so, the workpiece W is laser processed.

  The control unit 400 controls the laser oscillation of the laser oscillator 100. Specifically, laser oscillation control of each laser module 120 is performed by supplying control signals such as output voltage and on-time to a power source 500 connected to the laser oscillator 100. It is also possible to individually control the laser oscillation for each laser module 120. For example, the laser oscillation output, on-time, etc. may be varied for each laser module 120. In addition, the control unit 400 includes a storage unit 410, and the storage unit 410 stores laser processing conditions, a processing operation program, and the like. Further, as will be described later, in the storage unit 410, a determination is made that first and second threshold values Th1 and Th2 described later are arranged in association with the characteristics of the laser module 120, the condensing lens 142, and the transmission fiber 200. The table is stored. The control unit 400 receives light reception signals from the photodiodes 147 and 148 (see FIG. 2) disposed in the condensing optical unit 140, and determines whether the laser oscillator 100 is abnormal based on the light reception signals. And it also functions as an abnormality diagnosis unit that identifies an abnormal part. The control unit 400 may control the operation of a manipulator (not shown) to which the laser beam emitting head 300 is attached. The laser oscillator 100 may be configured by the plurality of laser modules 120, the beam combiner 130, the condensing optical unit 140, and the control unit 400.

  As described above, the power supply 500 supplies power for performing laser oscillation to the laser oscillator 100, specifically, each of the plurality of laser modules 120. The power supplied to each laser module 120 may be made different according to a command from the control unit 400. The power source 500 may supply power to a movable part of the laser processing apparatus 1000, for example, the manipulator described above, or another power source (not shown) for the movable part of the laser processing apparatus 1000. ) May be supplied with power.

  The display unit 600 is configured to display an abnormal part of the laser oscillator 100 determined by the control unit 400. Note that data other than the above may be displayed on the display unit 600. For example, the output of the laser beam LB may be displayed. You may make it display simultaneously the process parameter and measured value at the time of laser processing. The display unit 600 usually includes a display device such as a cathode ray tube or a liquid crystal display.

[Internal configuration of condensing optical unit]
In the condensing optical unit 140, the condensing lens 142 disposed in the housing 141 condenses the laser light LB incident in the housing 141, and the condensed laser light LB has a predetermined magnification. To reduce the beam diameter. Further, the condensed laser beam LB enters the core 201 of the transmission fiber 200 through the connector 143 to which the incident end of the transmission fiber 200 is connected. The connector 143 has a quartz block (laser light emitting portion) 144 inside, and the end face of the quartz block 144 is fused to the incident end of the transmission fiber 200. As a result, the quartz block 144 is coupled to the transmission fiber 200 with a refractive index matching, so that irregular reflection or the like of the laser beam LB does not occur at the fused portion. The quartz block 144 and the incident end of the transmission fiber 200 may be joined with an adhesive that matches both refractive indexes.

  The housing 141 is formed with first and second light guide paths 145 and 146 each having an opening communicating with the inside at a predetermined interval. Further, a photodiode 147 (first light receiving portion) is provided on the other end side of the first light guide path 145, and a photodiode 148 (second light receiving portion) is provided on the other end side of the second light guide path 146, respectively. ing.

  The photodiode 147 receives light propagating through the first light guide path 145 and outputs an electrical signal (first light reception signal Sg1). The photodiode 148 receives light propagating through the second light guide path 146 and outputs an electrical signal (second light reception signal Sg2). The photodiodes 147 and 148 are mounted on the wiring boards 149 and 150, respectively, and attached to the housing 141. Further, the wiring boards 149 and 150 are connected to the control unit 400, respectively, and the first light reception signal Sg1 and the second light reception signal Sg2 are transmitted to the control unit 400 via the wiring boards 149 and 150.

  The condensing optical unit 140 has a first shielding plate 151 and a second shielding plate 152 each having one end attached to the inner surface of the housing 141.

  The first shielding plate 151 is made of a material that does not transmit the laser beam LB, for example, a metal material, and has one end on the inner surface of the housing 141 positioned between the photodiode 147 and the first light guide path 145 and the condenser lens 142. And a first upright portion 151a extending in a direction substantially perpendicular to the optical axis of the laser beam LB, and a first bent portion 151b extended from the other end of the first upright portion 151a by being bent toward the quartz block 144. It is configured. The first bent portion 151 b is provided to extend above the opening of the first light guide path 145. In the present embodiment, the angle between the first upright portion 151a and the first bent portion 151b is configured to be 90 °. However, the present invention is not particularly limited thereto, and as will be described later, the condenser lens 142 is configured. What is necessary is just to arrange | position so that the scattered light from may be shielded.

  The second shielding plate 152 is made of a material that does not transmit the laser beam LB, for example, a metal material, and has one end on the inner surface of the housing 141 located between the photodiode 148 and the second light guide path 146 and the quartz block 144. A second upright portion 152a that is attached and extends in a direction substantially perpendicular to the optical axis of the laser beam LB, and a second bent portion 152b that is bent toward the condenser lens 142 from the other end of the second upright portion 152a. It is configured. In addition, the second bent portion 152 b is provided to extend above the opening of the second light guide path 146. In the present embodiment, the angle between the second upright part 152a and the second bent part 152b is configured to be 90 °. However, the present invention is not particularly limited thereto, and as will be described later, the transmission fiber 200 and It suffices to be arranged so as to shield the reflected light from the quartz block 144.

  Here, functions of the photodiodes 147 and 148 will be described. Most of the laser light LB incident on the condensing optical unit 140 and collected by the condensing lens 142 propagates through the core 201 of the transmission fiber 200 via the quartz block 144, and the emission end of the transmission fiber 200. It is emitted from. However, as shown in FIG. 2, a part of the light is reflected from the housing 141 of the condensing optical unit 140 and returned without being emitted from the emission end of the transmission fiber 200. For example, the reflected light at the incident end face of the quartz block 144 (path I shown in FIG. 2), the reflected light at the incident end face of the core 201 (path II shown in FIG. 2), and the boundary between the clad 202 and the outer clad 203 There is reflected light (path I shown in FIG. 2). In addition, light (path IV shown in FIG. 2) that is reflected by the output end face of the transmission fiber 200 and returns inside the core 201 is also incident into the housing 141 of the condensing optical unit 140. In addition to these, if the condensing lens 142 is soiled or damaged, the laser light LB incident on the condensing lens 142 is not condensed at a predetermined focal point, but is scattered in another direction and is condensed into a condensing optical unit. 140 enters the housing 141 (path V shown in FIG. 2).

  The photodiodes 147 and 148 are configured to receive these lights that have entered the housing 141 without passing through a normal optical path. Further, the first shielding plate 151 is provided at the above-described position, thereby preventing scattered light from the condenser lens 142 shown in the path V from being incident on the first light guide path 145 and eventually the photodiode 147. . On the other hand, the first shielding plate 151 does not prevent the reflected light from the transmission fiber 200 and / or the quartz block 144 shown in the paths I to IV from entering the first light guide path 145. For this reason, the photodiode 147 receives the reflected light from the transmission fiber 200 and / or the quartz block 144 incident on the first light guide path 145, and outputs the first received light signal Sg1 based on the reflected light.

  Similarly, the second shielding plate 152 is provided at the above-described position so that the reflected light from the transmission fiber 200 and / or the quartz block 144 is incident on the second light guide path 146 and eventually the photodiode 148. To prevent. On the other hand, the second shielding plate 152 does not prevent the scattered light from the condenser lens 142 from entering the second light guide path 146. Therefore, the photodiode 148 receives the scattered light from the condenser lens 142 that has entered the second light guide path 146, and outputs the second received light signal Sg2 based on the scattered light.

  As is clear from the above, the intensity of the reflected light from the transmission fiber 200 and / or the quartz block 144 and the intensity of the scattered light from the condenser lens 142 increase as the first light receiving signal Sg1 and the second light receiving signal Sg2 increase. It can be said that. In addition, the magnitude of the first light reception signal Sg1 corresponds to some abnormality that has occurred in the transmission fiber 200 and / or the quartz block 144, and the magnitude of the second light reception signal Sg2 has any magnitude that has occurred in the condenser lens 142. It corresponds to the abnormality.

[Laser oscillator abnormality diagnosis procedure]
FIG. 3 shows an abnormality diagnosis procedure for the laser oscillator according to this embodiment.

  First, power is supplied from the power source 500, the laser oscillator 100 is oscillated, and the laser beam LB is emitted (step S1). At this time, the transmission fiber 200 is connected to the condensing optical unit 140.

  Next, the first light reception signal Sg1 and the second light reception signal Sg2 are acquired based on the light incident on the photodiodes 147 and 148, respectively (step S2). The acquired first and second light reception signals Sg1 and Sg2 are sent to the control unit 400. Further, during or after the execution of step S2, the oscillation of the laser beam LB is stopped.

  The storage unit 410 of the control unit 400 stores a first threshold value Th1 and a second threshold value Th2 that are experimentally acquired in advance. The controller 400 determines whether or not the first light reception signal Sg1 is greater than the first threshold value Th1 (step S3).

  The first threshold value Th1 is a threshold value for determining whether or not the first light reception signal Sg1 is within the allowable range. If the first light reception signal Sg1 is larger than the first threshold value Th1, transmission is performed. The reflected light from the fiber 200 and / or the quartz block 144 is larger than the allowable range, and it is determined that some abnormality has occurred in the transmission fiber 200 and / or the quartz block 144. Similarly, the second threshold value Th2 is a threshold value for determining whether or not the second light reception signal Sg2 is within the allowable range, and the second light reception signal Sg2 is larger than the second threshold value Th2. For example, the scattered light from the condenser lens 142 is larger than the allowable range, and it is determined that some abnormality has occurred in the condenser lens 142. The first and second threshold values Th1 and Th2 are about three times as large as the first and second light receiving signals Sg1 and Sg2, respectively, when the condensing optical unit 140 is not abnormal. It is not limited to this. The specifications of the transmission fiber 200, the intensity and beam diameter of the laser beam LB, the size of the condenser lens 142, the size of the photodiodes 147 and 148, and the arrangement and shape of the first and second shielding plates 151 and 152, etc. Accordingly, this magnification can be changed as appropriate.

  If the determination result in step S3 is affirmative, the process proceeds to step S4, and it is determined whether or not the second light reception signal Sg2 is larger than the second threshold value Th2. If the determination result in step S4 is affirmative, the process proceeds to step S5, where all of the condenser lens 142, the quartz block 144, and the transmission fiber 200 are inspected to identify an abnormal location and repair and replace the location. . If the determination result in step S4 is negative, the process proceeds to step S6, in which the quartz block 144 and the transmission fiber 200 are inspected, an abnormal location is specified, and the location is repaired and replaced.

  On the other hand, if the determination result in step S3 is negative, the process proceeds to step S7 to determine whether or not the second light reception signal Sg2 is greater than the second threshold value Th2. If the determination result in step S7 is affirmative, the process proceeds to step S8, the condensing lens 142 is inspected, an abnormal part is specified, and the part is repaired and replaced. If the determination result in step S7 is negative, since it is determined that there is no abnormality in all of the condenser lens 142, the quartz block 144, and the transmission fiber 200, the abnormality diagnosis operation is terminated.

  In addition, you may make it display the determination result in step S3, S4, S7 on the display part 600. FIG.

[Effects]
The condensing optical unit 140 of this embodiment has a condensing lens 142 that condenses the laser light LB emitted from a plurality of laser modules 120 serving as laser light sources in a housing 141. The emitted laser beam LB is incident on the transmission fiber 200 through the quartz block 144 which is a laser beam emitting portion.

  In the condensing optical unit 140, a photodiode (first light receiving unit) 147 that receives reflected light from the transmission fiber 200 and / or the quartz block 144 between the condensing lens 142 and the quartz block 144 in the housing 141, and A photodiode (second light receiving unit) 148 that receives scattered light from the condenser lens 142 is disposed at a predetermined interval.

  By configuring the condensing optical unit 140 in this way, it is possible to determine the presence / absence of an abnormality in the condensing optical unit 140 with a simple configuration and to identify an abnormal part. In addition, since the abnormal part can be easily identified, the abnormal part can be repaired and replaced at an appropriate timing as necessary. In particular, it is relatively easy to remove and replace the transmission fiber 200 and the quartz block 144, but if the condensing lens 142 is damaged, it takes a lot of man-hours to adjust the position after the replacement.

  As described above, in the conventional technique disclosed in Patent Document 1, even if it can be determined that some abnormality has occurred in the laser oscillator 100, it is difficult to identify the abnormal part. For this reason, once it is determined that an abnormality has occurred, it is necessary to disassemble the laser oscillator 100 and inspect or replace all assumed parts.

  On the other hand, according to the present embodiment, since it is possible to easily identify which one of the transmission fiber 200 or the quartz block 144 and the condenser lens 142 is abnormal, for example, no abnormality has occurred in the condenser lens 142. If it is determined, the inspection and repair / replacement work is simplified, and the working time can be greatly shortened.

  Further, in the housing 141, a first shielding plate (first light incident limiting portion) 151 for limiting the incidence of scattered light from the condenser lens 142 to the photodiode 147, the transmission fiber 200 to the photodiode 148, and A second shielding plate (second light incidence limiting portion) 152 that restricts the incidence of reflected light from the quartz block 144 is disposed.

  Further, the housing 141 is formed with first and second light guide paths 145 and 146 each having an opening communicating with the housing 141 at one end, and the other ends of the first and second light guide paths 145 and 146 are formed. Photodiodes 147 and 148 are arranged on the side.

  The first shielding plate 151 includes a first upright portion 151a having one end attached to a portion of the housing 141 located between the first light guide path 145 and the condenser lens 142, and the other end of the first upright portion 151a. The first bent portion 151b extends by being bent toward the quartz block 144.

  The second shielding plate 152 is collected from the other end of the second upright portion 152a and the second upright portion 152a, one end of which is attached to the portion of the housing 141 located between the second light guide path 146 and the quartz block 144. The second bent portion 152b is bent toward the optical lens 142 and extends.

  According to the present embodiment, by providing the first shielding plate 151, scattered light from the condenser lens 142 can be prevented from entering the photodiode 147 through the first light guide path 145, and the photodiode 147. It is possible to increase the S / N ratio of the reflected light from the transmission fiber 200 and / or the quartz block 144 that is received at 1. The S / N ratio is the ratio of the signal (signal) and noise (noise). If the S / N ratio is high, the influence of noise in the transmission is small, and if the S / N ratio is small, the noise (noise). It shows that the influence of.

  Based on the light reception signal by the reflected light from the transmission fiber 200 and / or the quartz block 144 received by the photodiode 147, it is determined whether or not any abnormality has occurred in the transmission fiber 200 and / or the quartz block 144. It can be determined with high accuracy. In addition, since the first shielding plate 151 includes the first upright portion 151a and the first bent portion 151b, the scattered light from the condenser lens 142 can be more reliably prevented from being incident on the photodiode 147. it can.

  Further, by providing the second shielding plate 152, it is possible to prevent the reflected light from the transmission fiber 200 and / or the quartz block 144 from entering the photodiode 148 through the second light guide path 146, and the photodiode 148. The S / N ratio of the scattered light from the condenser lens 142 incident on the light can be increased. Thus, it can be accurately determined whether or not any abnormality has occurred in the condenser lens 142. In addition, since the second shielding plate 152 includes the second upright portion 152a and the second bent portion 152b described above, the reflected light from the transmission fiber 200 and / or the quartz block 144 is incident on the photodiode 148. Can be prevented more reliably.

  Further, the photodiode 147 and the photodiode 148 may be arranged on opposite sides of the optical axis of the laser beam LB.

  With this arrangement, the degree of freedom of arrangement of the first and second light guide paths 145 and 146 and the first and second shielding plates 151 and 152 in the housing 141 can be increased.

  The laser oscillator 100 of this embodiment includes at least a plurality of laser modules 120 that are laser light sources that emit laser light LB, and a condensing optical unit 140 that condenses the laser light LB and makes it incident on the transmission fiber 200. ing.

  According to the present embodiment, it is possible to identify an abnormal location inside the laser oscillator 100 with a simple configuration and to repair and replace the target part in the laser oscillator 100. As a result, the beam quality of the laser beam LB can be maintained, and the downtime of the laser oscillator 100 can be reduced.

  The laser oscillator 100 may further include an abnormality diagnosis unit that determines whether the laser oscillator 100 is abnormal based on the first and second light reception signals Sg1 and Sg2 received by the photodiodes 147 and 148, respectively. In this embodiment, the abnormality diagnosis unit corresponds to a function performed by the control unit 400.

  By doing in this way, the presence or absence and abnormality location of the laser oscillator 100 can be quickly identified.

  The laser processing apparatus 1000 according to the present embodiment includes a laser oscillator 100, a transmission fiber 200 that is connected to the laser oscillator 100 and guides the laser beam LB emitted from the laser oscillator 100, and an emission end of the transmission fiber 200. And at least a laser beam emitting head 300 attached thereto.

  According to the present embodiment, it is possible to identify an abnormal location inside the laser oscillator 100 with a simple configuration and to repair and replace the target part in the laser oscillator 100. Thereby, the downtime of the laser processing apparatus 1000 can be reduced. In addition, the beam quality of the laser beam LB can be maintained and good processing quality can be maintained.

  Further, in the abnormality diagnosis method for the laser oscillator 100 according to the present embodiment, a laser beam emission step (step S1) for emitting the laser beam LB and the reflected light from the transmission fiber 200 and / or the quartz block 144 are received by the photodiode 147. The first light receiving signal Sg1 is obtained, and the light receiving signal acquisition step (step S2) for obtaining the second light receiving signal Sg2 by receiving the scattered light from the condenser lens 142 with the photodiode 148, and the first light receiving signal Sg1 An abnormality diagnosis step (steps S3, S4, S7) for determining the presence or absence of abnormality in the laser oscillator 100 based on the second light reception signal Sg2.

  According to this method, the presence or absence of abnormality in the condensing optical unit 140 can be easily determined.

  In the abnormality diagnosis step, when the first light reception signal Sg1 is larger than the first threshold value Th1, it is determined that there is an abnormality in the transmission fiber 200 and / or the quartz block 144, and the second light reception signal Sg2 is the second. When it is larger than the threshold value Th2, it is determined that the condenser lens 142 is abnormal.

  According to this method, the abnormal part in the condensing optical unit 140 can be identified easily. This makes it possible to repair and replace an abnormal part at an appropriate timing, simplify inspection and repair replacement work, and greatly reduce the time.

<Modification 1>
FIG. 4 is a schematic diagram of the internal configuration of the condensing optical unit according to this modification. The configuration of the condensing optical unit 140 shown in the present modification example is that the first and second light guide paths 145a and 146a are inclined at a predetermined angle with respect to the optical axis of the laser beam LB, and The configuration of the condensing optical unit 140 shown in Embodiment 1 is different in that the second shielding plates 151 and 152 are omitted. In addition, about the member etc. similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted. Although not shown, the wiring boards 149 and 150 are connected to the control unit 400 in the same manner as shown in the first embodiment.

  In addition, as shown in FIG. 4, the first light guide path 145a is formed so as to be inclined so that the other end where the photodiode 147 is disposed is farther from the quartz block 144 than the opening communicating with the housing 141. Yes. In addition, the second light guide path 146 a is formed to be inclined so that the other end where the photodiode 148 is disposed is farther from the condensing lens 142 than the opening communicating with the housing 141.

  In other words, the first light guide path 145 a is inclined in a direction away from the quartz block 144, and the second light guide path 146 a is inclined in a direction away from the condenser lens 142.

  By forming the first and second light guide paths 145a and 146a in this manner, it is possible to prevent scattered light from the condenser lens 142 from entering the first light guide path 145a. Further, it is possible to prevent the reflected light from the transmission fiber 200 and / or the quartz block 144 from entering the second light guide path 146a. In other words, the first light guiding path 145a itself functions as a first light incident restricting section, and the second light guiding path 146a itself functions as a second light incident restricting section.

  According to this modification, the same effect as that shown in the first embodiment can be obtained. Further, since the first and second shielding plates 151 and 152 can be omitted, the number of components of the condensing optical unit 140 can be reduced, and the first and second light guide paths 145a and 146a, and thus the photodiodes 147 and 148 can be reduced. The degree of freedom of arrangement can be increased. Depending on the inclination angles of the first and second light guide paths 145a and 146a, unnecessary light incident on each of the first and second light guide paths 145a and 146a, for example, the first light guide path 145a is shielded from scattered light from the condenser lens 142. However, since this may be lower than the configuration shown in the first embodiment, it is necessary to pay attention to this point when actually manufacturing this configuration.

<Modification 2>
FIG. 5 is a schematic diagram of the internal configuration of the condensing optical unit according to this modification, and FIG. 6 is a schematic diagram of the internal configuration of another condensing optical unit. In addition, about the member etc. similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted. Although not shown, the wiring boards 149 and 150 are connected to the control unit 400 in the same manner as shown in the first embodiment.

  The configuration of the condensing optical unit 140 shown in this modification differs from the configuration of the condensing optical unit 140 shown in Embodiment 1 in the points described below.

  As shown in FIG. 5, the photodiode 147a has one end attached to the housing 141, and is disposed on the surface facing the quartz block 144 of the first shielding plate 153 extending substantially perpendicular to the optical axis of the laser beam LB. Has been. The photodiode 148a has one end attached to the housing 141, and is disposed on the surface of the second shielding plate 154 facing the condenser lens 142 that extends substantially perpendicular to the optical axis of the laser beam LB. In addition, although a plurality of photodiodes 147a and 148a are provided, one each may be provided.

  According to this modification, the photodiode 147a is disposed on the surface of the first shielding plate 153 facing the quartz block 144, so that the reflection from the transmission fiber 200 and / or the quartz block 144 incident on the photodiode 147a is achieved. The amount of light can be increased. Further, in the first shielding plate 153, the scattered light from the condenser lens 142 is shielded by the surface opposite to the surface where the photodiode 147a is disposed, so that the S / N ratio of the first light reception signal Sg1 can be maintained high. Similarly, by disposing the photodiode 148a on the surface of the second shielding plate 154 facing the condenser lens 142, the amount of scattered light from the condenser lens 142 incident on the photodiode 147a can be increased. it can. Further, in the second shielding plate 154, the reflected light from the transmission fiber 200 and / or the quartz block 144 is shielded by the surface opposite to the surface where the photodiode 148a is disposed, so that the S / N ratio of the second received light signal Sg2 Can be kept high.

  As shown in FIG. 6, the first shielding plate 153 may be inclined so as to approach the quartz block 144, and the second shielding plate 154 may be inclined so as to approach the condenser lens 142.

<Modification 3>
FIG. 7 is a schematic diagram of the internal configuration of the condensing optical unit according to this modification. In addition, about the member etc. similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted. Although not shown, the wiring boards 149 and 150 are connected to the control unit 400 in the same manner as shown in the first embodiment.

  The configuration of the condensing optical unit 140 shown in this modification differs from the configuration of the condensing optical unit 140 shown in Embodiment 1 in the points described below.

  As shown in FIG. 7, the first light guide path 145 and the second light guide path 146 are arranged on the same side as viewed from the optical axis of the laser light LB. One end of a third shielding plate (third light limiting portion) 155 is attached to a portion of the housing 141 located between the first light guiding path 145 and the second light guiding path 146, and the third shielding is provided. The plate 155 is provided so as to extend into the housing 142. The third shielding plate 155 is made of a material that reflects the laser beam LB, for example, a metal material.

  According to this modification, the third shielding plate 155 is disposed between the first light guide path 145 and the second light guide path 146 that are arranged adjacent to each other with a predetermined interval, thereby transmitting the transmission fiber. The reflected light from 200 and / or the quartz block 144 is reflected by the third shielding plate 155 and enters the first light guide path 145, and the scattered light from the condenser lens 142 is reflected by the third shielding plate 155. To the second light guide path 146. Thus, unnecessary light can be shielded from each of the photodiodes 147 and 148, and the S / N ratio of the first and second light reception signals Sg1 and Sg2 can be increased. In addition, the number of parts can be reduced as compared with the configuration shown in the first embodiment, and the degree of freedom of arrangement of the first and second light guide paths 145 and 146, and thus the photodiodes 147 and 148 can be increased.

(Embodiment 2)
FIG. 8 shows an abnormality diagnosis procedure for the laser oscillator according to this embodiment. Steps S12 and S13 shown in FIG. 8 and steps S1 and S2 shown in FIG. Further, steps S15 to S20 shown in FIG. 8 and steps S3 to S8 shown in FIG.

  In the present embodiment, the configuration of the condensing optical unit 140 and the like is the same as the configuration shown in the first embodiment and the first to third modifications. On the other hand, in the flowchart shown in FIG. 8, the determination table is prepared (step S11), and the first and second threshold values Th1 and Th2 are respectively called from the determination table (step S14). Different from the flowchart shown.

  As described above, the first and second threshold values Th1 and Th2 are changed according to various conditions. For example, the first threshold value Th1 can be changed even if the transmission fiber 200 having a different diameter of the core 201 is used. . Further, the first and second threshold values Th1 and Th2 can be changed only by changing the intensity of the laser beam LB.

  On the other hand, it is common for the laser processing apparatus 1000 to perform laser processing with different light intensities, or to replace the transmission fiber 200 and perform laser processing with different beam diameters. It is also possible to replace the condenser lens 142 and the like and use other parts as they are.

  In such a case, obtaining the first and second threshold values Th1 and Th2 each time is a very laborious operation.

  Therefore, in this embodiment, various conditions that can be used in the laser oscillator 100 and the laser processing apparatus 1000, for example, the laser module 120 and the beam combiner 130 that emit the transmission fiber 200 and the laser beam LB, and the condenser lens 142 are used. The first and second threshold values Th1 and Th2 are obtained in advance for each combination in the case where variations such as types or characteristics are extracted. Then, the threshold values Th1 and Th2 are arranged in association with the above conditions, a determination table is prepared, and the determination table is stored in the storage unit 410. In the actual abnormality diagnosis, the first and second threshold values Th1 and Th2 that match the actual conditions are called from the determination table, and based on these, whether there is an abnormality in the components in the condensing optical unit 140 and the transmission fiber 200 In addition, the abnormal part is specified.

  By doing so, it is possible to accurately determine the presence or absence of abnormality in the components in the condensing optical unit 140 and the transmission fiber 200 in response to a change in the specifications of the laser oscillator 100 and the laser processing apparatus 1000, and the abnormal location. Can be specified.

(Other embodiments)
In the first and second embodiments including the first to third modifications, the laser beam emitted from the plurality of laser modules 120 is coupled by the beam combiner 130 to emit the laser beam LB. For example, the laser beam LB may be emitted from one laser light source.

  2, 4, and 7 show the configuration in which one each of the first and second light guide paths 145 and 146 and the photodiodes 147 and 148 are provided. You may make it provide. In that case, the abnormal part can be specified more finely based on the light reception signal output from each photodiode. For example, a plurality of sets of second light guide paths 146 and photodiodes 148 are provided around the optical axis of the laser beam LB, so that a contamination spot or a damage spot of the condenser lens 142 is specified in detail, and inspection or repair work is performed. Can be shortened.

  The condensing optical unit of the present invention is useful for application to a laser oscillator used in a laser processing apparatus or the like because it can easily determine the presence or absence of internal abnormality and specify an abnormal location.

DESCRIPTION OF SYMBOLS 100 Laser oscillator 120 Laser module 130 Beam combiner 140 Condensing optical unit 141 Case 142 Condensing lens 143 Connector 144 Quartz block (laser beam emission part)
145 1st light guide path 145a 1st light guide path (1st light incident control part)
146 Second light guide path 146a Second light guide path (second light incident limiting portion)
147, 147a Photodiode (first light receiving portion)
148, 148a Photodiode (second light receiving portion)
151, 153 First shielding plate (first light incident limiting portion)
151a First upright portion 151b First bent portions 152, 154 Second shielding plate (second light incident limiting portion)
152a Second upright portion 152b Second bent portion 155 Third shielding plate (third light incident limiting portion)
200 Transmission fiber 300 Laser light emitting head 400 Control unit 410 Storage unit 500 Power supply 600 Display unit 1000 Laser processing apparatus W Workpiece

Claims (14)

Condensing optics that has a condensing lens for condensing the laser light emitted from the laser light source in the housing, and causes the laser light condensed by the condensing lens to enter the transmission fiber via the laser light emitting portion A unit,
A first light receiving unit that receives reflected light from the transmission fiber and / or the laser light emitting unit between the condensing lens and the laser light emitting unit in the housing, and scattering from the condensing lens. A condensing optical unit, characterized in that a second light receiving portion for receiving light is disposed at a predetermined interval. The condensing optical unit according to claim 1,
In the housing, a first light incident limiting unit for limiting the incidence of the scattered light to the first light receiving unit, and a second light incident limiting unit for limiting the incidence of the reflected light to the second light receiving unit, A condensing optical unit characterized in that is provided. The condensing optical unit according to claim 2,
The housing is formed with first and second light guide paths each having an opening communicating with the inside of the housing.
The first and second light receiving parts are disposed on the other end sides of the first and second light guide paths, respectively.
The first light incident restricting portion includes a first upright portion having one end attached to a housing located between the first light guide path and the condenser lens, and the laser beam from the other end of the first upright portion. A first bent portion that is bent and extended toward the light emitting portion;
The second light incident restricting portion includes a second upright portion having one end attached to a housing located between the second light guide path and the laser light emitting portion, and the other end of the second upright portion. A condensing optical unit comprising a second bent portion that is bent toward the condensing lens and extends. The condensing optical unit according to claim 2,
The housing is formed with first and second light guide paths each having an opening communicating with the inside of the housing.
The first and second light receiving parts are disposed on the other end sides of the first and second light guide paths, respectively.
By forming the first light guide path to be inclined so that the other end is farther from the laser light emitting part than the opening, the first light incident restricting part is configured,
The second light incident restricting portion is configured by forming the second light guide path so that the other end is farther from the condensing lens than the opening. Optical unit. The condensing optical unit according to claim 2,
The first light receiving portion is disposed on a surface facing the laser light emitting portion of the first light incident limiting portion having one end attached to the housing,
The condensing optical unit, wherein the second light receiving unit is disposed on a surface of the second light incident restricting unit, one end of which is attached to the housing, facing the condensing lens. In the condensing optical unit according to claim 5,
The first light incident limiting portion is inclined so as to approach the laser light emitting portion,
The condensing optical unit, wherein the second light incident restricting portion is inclined so as to approach the condensing lens. The condensing optical unit according to any one of claims 2 to 6,
The condensing optical unit, wherein the first light receiving unit and the second light receiving unit are disposed on opposite sides of the optical axis of the laser beam. The condensing optical unit according to claim 1,
The housing is formed with first and second light guide paths each having an opening communicating with the inside of the housing.
The first and second light receiving parts are disposed on the other end sides of the first and second light guide paths, respectively.
The first light guide path and the second light guide path are disposed on the same side as viewed from the optical axis of the laser beam,
A condensing optical unit comprising a third light restricting portion having one end attached to a casing located between the first light guiding path and the second light guiding path. A laser light source for emitting laser light;
9. A laser oscillator comprising at least the condensing optical unit according to claim 1, wherein the laser light is condensed and incident on a transmission fiber. The laser oscillator according to claim 9, wherein
A laser oscillator, further comprising: an abnormality diagnosing unit that determines whether or not the laser oscillator is abnormal based on light reception signals received by the first and second light receiving units, respectively. A laser oscillator according to claim 9 or 10,
A transmission fiber connected to the laser oscillator for guiding the laser beam emitted from the laser oscillator;
A laser processing apparatus comprising at least a laser beam emission head attached to an emission end of the transmission fiber. The housing has a laser light source and a condensing lens for condensing the laser light emitted from the laser light source, and the laser light condensed by the condensing lens is transmitted to the transmission fiber via the laser light emitting unit. A method for diagnosing abnormality of a laser oscillator comprising a condensing optical unit to be incident,
The condensing optical unit includes a first light receiving unit that receives reflected light from the transmission fiber and / or the laser beam emitting unit, and a second light receiving unit that receives scattered light from the condensing lens. And
A laser beam emitting step for emitting the laser beam;
The first light receiving unit receives the reflected light to obtain a first light receiving signal, and the second light receiving unit receives the scattered light to obtain a second light receiving signal; and
An abnormality diagnosis method for a laser oscillator, comprising: an abnormality diagnosis step for determining presence / absence of an abnormality in the laser oscillator based on the first light reception signal and the second light reception signal. In the laser oscillator abnormality diagnosis method according to claim 12,
In the abnormality diagnosis step, when the first light reception signal is larger than a first threshold value, it is determined that there is an abnormality in the transmission fiber and / or the laser beam emitting unit, and the second light reception signal is a second value. A method for diagnosing abnormality of a laser oscillator, characterized in that, when the value is larger than a threshold value, it is determined that the condenser lens is abnormal. In the laser oscillator abnormality diagnosis method according to claim 13,
A determination table preparation step of preparing a determination table in which the first and second threshold values associated with at least one type and / or characteristic of the transmission fiber, the laser light source, and the condenser lens are arranged; Prepared,
In the abnormality diagnosis step, the first and second light reception signals acquired in the light reception signal acquisition step are compared with the first and second threshold values of the determination table, respectively. An abnormality diagnosis method for a laser oscillator, characterized by specifying a location.

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