JP7122671B2 - Condensing optical unit, laser oscillator using the same, laser processing device, and abnormality diagnosis method for laser oscillator - Google Patents

Description

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

2. Description of the Related Art Conventionally, there has been known a laser processing apparatus that laser-processes a workpiece located at a remote location using a transmission fiber. In such a laser processing apparatus, a laser oscillator is provided inside, and the laser light emitted from the laser oscillator propagates through the core of the transmission fiber and reaches the workpiece from the laser light emission head connected to the transmission fiber. directed towards. 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 fits within 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 the laser diode, which is the excitation light source, may be damaged by the influence of the return light that is reflected at the processing point of the workpiece and returned into the transmission fiber.

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

JP 2012-179627 A

By the way, in a laser oscillator that condenses a laser beam with a condenser lens and enters it into a transmission fiber, if the condenser lens is dirty or damaged, or if the incident end of the transmission fiber into which the laser beam is incident is damaged, the laser beam Light output may decrease. In addition, even if the final output does not decrease much, the beam quality of the laser light may decrease and affect the processing quality.

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

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, a laser oscillator, and a laser processing apparatus using the same, which can specify the presence or absence of an internal abnormality and the location of the abnormality with a simple configuration. to provide. Another object of the present invention is to provide a method for diagnosing an abnormality of a laser oscillator that can identify the presence or absence of an internal abnormality and the location of the abnormality.

In order to achieve the above object, a condensing optical unit according to the present invention has a condensing lens in a housing for condensing laser light emitted from a laser light source, and the laser beam condensed by the condensing lens is provided. A condensing optical unit for causing light to enter a transmission fiber through a laser light emitting section, wherein the transmission fiber and/or the laser light are provided between the condensing lens and the laser light emitting section in the housing. A first light receiving section for receiving reflected light from the emitting section and a second light receiving section for receiving scattered light from the condensing lens are arranged with a predetermined gap therebetween, and in the housing, A first light-incidence limiting section for limiting incidence of the scattered light to the first light-receiving section and a second light-incidence limiting section for limiting incidence of the reflected light to the second light-receiving section are provided. It is characterized by

According to this configuration, it is possible to determine whether or not there is an abnormality in the condensing optical unit and to specify the location of the abnormality with a simple configuration.

A laser oscillator according to the present invention includes at least a laser light source that emits laser light, and the condensing optical unit that condenses the laser light and enters it into a transmission fiber.

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

Further, a laser processing apparatus according to the present invention comprises the above laser oscillator, a transmission fiber connected to the laser oscillator and guiding the laser light emitted from the laser oscillator, and attached to the output end of the transmission fiber. and a laser light emitting head.

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

A method for diagnosing an abnormality of a laser oscillator according to the present invention includes a laser light source and a condenser lens for condensing a laser beam emitted from the laser light source in a housing, and the laser beam condensed by the condenser lens. into a transmission fiber via a laser light emitting section, wherein the condenser optical unit includes the condenser lens in the housing and the laser A first light receiving section for receiving reflected light from the transmission fiber and/or the laser light emitting section and a second light receiving section for receiving scattered light from the condenser lens are provided between the light emitting section and the light emitting section . A first light-incidence restricting portion arranged at a predetermined interval and configured to restrict incident of the scattered light to the first light-receiving portion and an incident of the reflected light to the second light-receiving portion are provided in the housing. or the first optical guide path and the second optical guide path are arranged on the same side when viewed from the optical axis of the laser beam. , one end of which is attached to a housing located between the first optical guide path and the second optical guide path, and the reflected light from the transmission fiber and/or the laser light emitting portion is reflected to form the first light Unnecessary light is directed to each of the first light receiving section and the second light receiving section by causing the scattered light from the condenser lens to be reflected and incident on the second light guide path. A laser light emitting step of emitting the laser light, receiving the reflected light by the first light receiving section to obtain a first light receiving signal, and obtaining a first light receiving signal by receiving the reflected light with the first light receiving section 2 a received light signal acquiring step of receiving the scattered light by the light receiving unit and obtaining a second received light signal; and an abnormality determining whether or not there is an abnormality in the laser oscillator based on the first received light signal and the second received light signal. and a diagnostic step.

According to this method, it is possible to easily determine whether or not there is an abnormality in the condensing optical unit.

As described above, according to the condensing optical unit of the present invention, it is possible to determine whether there is an abnormality in the condensing optical unit and to specify the location of the abnormality with a simple configuration.

BRIEF DESCRIPTION OF THE DRAWINGS 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. 4 is a flow chart showing an abnormality diagnosis procedure for a laser oscillator according to Embodiment 1 of the present invention; FIG. 5 is a schematic diagram showing the internal configuration of a condensing optical unit according to Modification 1; FIG. 11 is a schematic diagram showing the internal configuration of a condensing optical unit according to Modification 2; FIG. 11 is a schematic diagram showing the internal configuration of another condensing optical unit according to Modification 2; FIG. 11 is a schematic diagram showing an internal configuration of a condensing optical unit according to Modification 3; 9 is a flow chart showing an abnormality diagnosis procedure for a laser oscillator according to Embodiment 2 of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its applicability or its uses.

(Embodiment 1)
[Configuration of laser processing device]
FIG. 1 shows a schematic diagram of the configuration of a laser processing apparatus according to this embodiment, and FIG. 2 shows a schematic diagram of the 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 and Y directions is the Z direction. I may call

A laser processing apparatus 1000 includes a laser oscillator 100 , a transmission fiber 200 , a laser beam emitting head 300 , a control section 400 , a power supply 500 and a display section 600 . What is the end of the laser oscillator 100 and the transmission fiber 200 where the laser light is incident (hereinafter simply referred to as the input end, and the end of the transmission fiber 200 from which the laser light is emitted is simply referred to as the output end)? Housed in housing 110 .

The laser oscillator 100 has 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.

The beam coupler 130 couples the laser beams emitted from the plurality of laser modules 120 into one laser beam (hereinafter referred to as laser beam LB) and emits it to the condensing optical unit 140 . Specifically, the optical axes of the respective laser beams are brought close to each other or coincident with each other, and are coupled so that their optical axes are parallel to each other.

As shown in FIG. 2, the condensing optical unit 140 has 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 detailed later.

By configuring the laser oscillator 100 in this way, it is possible to obtain a high-power laser processing apparatus 1000 with a laser light output exceeding several kW. Also, the laser oscillator 100 is supplied with power from a power source 500 to be described later, performs laser oscillation, and emits a laser beam LB from the emission end of the transmission fiber 200 . Although four laser modules 120 are mounted on the laser oscillator 100 in this embodiment, the present invention is not particularly limited to this. The number of mounted laser modules 120 can be appropriately changed according to the output specifications required for the laser processing apparatus 1000 and the output specifications of individual laser modules 120 .

The transmission fiber 200 is optically coupled to the condenser lens 142 of the condenser optical unit 140 and guides the laser beam LB received from the laser oscillator 100 through the condenser lens 142 to the laser beam emitting head 300 . Further, as shown in FIG. 2, the transmission fiber 200 includes a core 201 for guiding the laser beam LB to 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 each made of quartz. 203 has the function of confining the laser beam LB within the core 201 . The outer cladding 203 has an outer peripheral surface covered with a protective tube 204 , and cooling water for cooling the transmission fiber 200 flows through the protective tube 204 . However, instead of the protective tube 204, a coating may be provided for shielding external light and protecting the transmission fiber 200 from mechanical damage.

The laser light emitting head 300 emits the laser light LB guided by the transmission fiber 200 toward the outside. For example, in the laser processing apparatus 1000 shown in FIG. 1, a laser beam LB is emitted toward a work W, which is an object to be processed arranged at a predetermined position. By doing so, the workpiece W is laser-processed.

The control unit 400 controls 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 the power supply 500 connected to the laser oscillator 100 . It is also possible to individually control laser oscillation for each laser module 120 . For example, each laser module 120 may have a different laser oscillation output, ON time, or the like. The control unit 400 also has a storage unit 410, and the storage unit 410 stores laser processing conditions, operating programs for processing, and the like. Further, as will be described later, in the storage unit 410, first and second threshold values Th1 and Th2 described later are arranged in association with the characteristics of the laser module 120, the condenser lens 142, and the transmission fiber 200. table is stored. The control unit 400 also receives light reception signals from the photodiodes 147 and 148 (see FIG. 2) provided in the light condensing optical unit 140, and determines whether or not there is an abnormality in the laser oscillator 100 based on the light reception signals. It also functions as an abnormality diagnosis section that identifies the location of an abnormality. Also, the control unit 400 may control the operation of a manipulator (not shown) to which the laser light emitting head 300 is attached. Note that the laser oscillator 100 may be composed of a plurality of laser modules 120 , beam couplers 130 , condensing optical units 140 and controller 400 .

The power supply 500 supplies power for laser oscillation to the laser oscillator 100 , specifically, to each of the plurality of laser modules 120 , as described above. The power supplied to each laser module 120 may be varied according to a command from the control unit 400 . Further, the power supply 500 may supply power to the movable parts of the laser processing apparatus 1000, such as the manipulator, or another power supply (not shown) may be provided for the movable parts of the laser processing apparatus 1000. ) may be supplied with power.

The display unit 600 is configured to display the abnormal location of the laser oscillator 100 determined by the control unit 400 . Note that the display unit 600 may display data other than the above. For example, the output of laser light LB may be displayed. The processing parameters and measured values for laser processing may be displayed at the same time. The display unit 600 usually includes a display device such as a cathode ray tube or liquid crystal display.

[Internal configuration of condensing optical unit]
In the condensing optical unit 140, the laser beam LB incident on the casing 141 is condensed by the condensing lens 142 arranged in the casing 141, and the condensed laser beam LB is converted to a predetermined magnification. to reduce the beam diameter. Also, the condensed laser beam LB enters the core 201 of the transmission fiber 200 via 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, and the laser beam LB is prevented from being irregularly reflected at this fused portion. Alternatively, the quartz block 144 and the incident end of the transmission fiber 200 may be bonded together with an adhesive that matches the refractive indices of both.

First and second light guide paths 145 and 146 having openings communicating with the interior at one end thereof are formed in the housing 141 at predetermined intervals. 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. ing.

The photodiode 147 receives the light propagated through the first optical guide path 145 and outputs an electric signal (first received light signal Sg1). The photodiode 148 receives the light propagated through the second optical guide path 146 and outputs an electrical signal (second received light signal Sg2). Photodiodes 147 and 148 are mounted on wiring boards 149 and 150 respectively and attached to housing 141 . Also, the wiring boards 149 and 150 are connected to the control unit 400 respectively, and the first light receiving signal Sg1 and the second light receiving signal Sg2 are sent to the control unit 400 via the wiring boards 149 and 150 .

The condensing optical unit 140 also 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, such as 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 . is attached, 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 extending from the other end of the first upright portion 151a toward the quartz block 144 are bent. It is configured. Also, the first bent portion 151 b is provided to extend above the opening of the first optical guide path 145 . In this embodiment, the angle between the first vertical portion 151a and the first bent portion 151b is 90°. It is sufficient if it is arranged so as to shield the scattered light from.

The second shielding plate 152 is made of a material that does not transmit the laser beam LB, such as a metal material, and has one end on the inner surface of the housing 141 positioned 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 and extends from the other end of the second upright portion 152a toward the condenser lens 142. It is configured. Also, the second bent portion 152b is provided to extend above the opening of the second optical guide path 146 . In this embodiment, the angle between the second straight portion 152a and the second bent portion 152b is 90°, but the angle is not limited to this. / Or it may 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 that is incident on the condensing optical unit 140 and condensed by the condensing lens 142 propagates through the core 201 of the transmission fiber 200 via the quartz block 144, and reaches the output end of the transmission fiber 200. emitted from However, as shown in FIG. 2, part of the light is not emitted from the emission end of the transmission fiber 200, but is reflected back into the housing 141 of the condensing optical unit 140. FIG. For example, reflected light from the incident end surface of the quartz block 144 (path I shown in FIG. 2), reflected light from the incident end surface of the core 201 (path II shown in FIG. 2), and the boundary between the clad 202 and the outer clad 203 There are reflected light (path I shown in FIG. 2) and the like. Further, the light reflected by the output end face of the transmission fiber 200 and returning inside the core 201 (path IV shown in FIG. 2) also enters the housing 141 of the condensing optical unit 140 . Apart from these, if the condensing lens 142 is dirty or damaged, the laser beam LB incident on that portion will not be condensed at a predetermined focal point, and will be scattered in different directions, resulting in the condensing optical unit 140 (path V shown in FIG. 2).

Photodiodes 147 and 148 are configured to receive these lights that enter housing 141 without passing through normal optical paths. Also, the first shielding plate 151 is provided at the above-described position to prevent the scattered light from the condenser lens 142 shown in the path V from entering the first light guide path 145 and thus 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 indicated by paths I to IV from entering the first optical guide path 145 . Therefore, the photodiode 147 receives reflected light from the transmission fiber 200 and/or the quartz block 144 that has entered the first optical guide path 145, and outputs the first received light signal Sg1 based on this reflected light.

Similarly, the second shielding plate 152 is provided at the position described above to prevent the reflected light from the transmission fiber 200 and/or the quartz block 144 from entering the second light guide 146 and thus 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 optical guide path 146, and outputs the second received light signal Sg2 based on this 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 scattered light from the condenser lens 142 increases as the first light receiving signal Sg1 and the second light receiving signal Sg2 increase. It can be said that The magnitude of the first received light signal Sg1 corresponds to some abnormality occurring in the transmission fiber 200 and/or the quartz block 144, and the magnitude of the second received light signal Sg2 corresponds to some abnormality occurring in the condenser lens 142. corresponds to the anomaly.

[Laser Oscillator Abnormal Diagnosis Procedure]
FIG. 3 shows an abnormality diagnosis procedure for a laser oscillator according to this embodiment.

First, power is supplied from the power supply 500 to cause the laser oscillator 100 to oscillate and emit a laser beam LB (step S1). At this time, the transmission fiber 200 is connected to the condensing optical unit 140 .

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

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

The first threshold Th1 is a threshold for determining whether the first light receiving signal Sg1 is within the allowable range. If the first light receiving signal Sg1 is greater than the first threshold Th1, the transmission If the reflected light from fiber 200 and/or quartz block 144 is greater than the allowable range, it is determined that something is wrong with transmission fiber 200 and/or quartz block 144 . Similarly, the second threshold Th2 is a threshold for determining whether or not the second light reception signal Sg2 is within the allowable range. 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 . Note that the first and second threshold values Th1 and Th2 are approximately three times the values of the first and second received light signals Sg1 and Sg2 when the optical condensing unit 140 is normal. 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, 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 to determine whether or not the second received light signal Sg2 is greater than the second threshold value Th2. If the determination result in step S4 is affirmative, the process advances to step S5 to inspect all of the condenser lens 142, the quartz block 144 and the transmission fiber 200, identify the location of the abnormality, and repair or replace the location. . If the determination result in step S4 is negative, the process proceeds to step S6, where the quartz block 144 and the transmission fiber 200 are inspected to identify the location of the abnormality, and the location is repaired or 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 received light signal Sg2 is greater than the second threshold value Th2. If the determination result in step S7 is affirmative, the process advances to step S8, where the condenser lens 142 is inspected to identify the location of the abnormality, and the location is repaired or replaced. If the determination result in step S7 is negative, it is determined that there is no abnormality in all of the condenser lens 142, quartz block 144, and transmission fiber 200, and the abnormality diagnosis operation is terminated.

Note that the determination results in steps S3, S4, and S7 may be displayed on the display unit 600. FIG.

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

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

By configuring the condensing optical unit 140 in this way, it is possible to determine whether or not there is an abnormality in the condensing optical unit 140 and to specify the location of the abnormality with a simple configuration. In addition, since the location of the abnormality can be easily identified, the location of the abnormality can be repaired or 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 condenser lens 142 is damaged, it takes a lot of man-hours to adjust the position after replacement.

As described above, in the conventional technique disclosed in Patent Document 1, even if it can be determined that some kind of abnormality has occurred inside the laser oscillator 100, it is difficult to identify the location of the abnormality. Therefore, once it is determined that an abnormality has occurred, it has been necessary to disassemble the laser oscillator 100 and inspect or replace all possible parts.

On the other hand, according to the present embodiment, it is possible to easily identify which of the transmission fiber 200 or the quartz block 144 and the condenser lens 142 has an abnormality. If it is determined as such, the inspection and repair/replacement work can be simplified, and the work time can be greatly shortened.

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

Further, the housing 141 is formed with first and second light guide paths 145 and 146 each having an opening communicating with the inside of 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 two sides, respectively.

The first shielding plate 151 has a first upright portion 151a, one end of which is 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. and a first bent portion 151 b that is bent and extends toward the quartz block 144 .

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

According to this 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 optical guide path 145 , and the photodiode 147 The signal-to-noise ratio of light reflected from the transmission fiber 200 and/or the quartz block 144 received at is increased. The S/N ratio is the ratio of signal and noise. This indicates that the influence of

Whether or not any abnormality has occurred in the transmission fiber 200 and/or the quartz block 144 is determined based on the received light signal of the reflected light from the transmission fiber 200 and/or the quartz block 144 received by the photodiode 147. Accurate determination is possible. In addition, since the first shielding plate 151 is composed of the above-described first upright portion 151a and first bent portion 151b, scattered light from the condenser lens 142 is more reliably prevented from entering the photodiode 147. 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 optical guide path 146. It is possible to increase the S/N ratio of scattered light from the condenser lens 142 incident on the . As a result, it is possible to accurately determine whether or not the condenser lens 142 is abnormal. In addition, since the second shielding plate 152 is composed of the above-described second upright portion 152a and second bent portion 152b, reflected light from the transmission fiber 200 and/or the quartz block 144 is incident on the photodiode 148. can be prevented more reliably.

Also, the photodiode 147 and the photodiode 148 may be arranged on opposite sides of each other with the optical axis of the laser beam LB interposed therebetween.

With such an arrangement, the degree of freedom in arrangement of the first and second light guide paths 145 and 146 and the first and second shielding plates 151 and 152 within 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 beams LB, and a condensing optical unit 140 that collects the laser beams LB and causes them to enter 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 repair or 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 section that determines whether there is an abnormality in the laser oscillator 100 based on the first and second light receiving signals Sg1 and Sg2 received by the photodiodes 147 and 148, respectively. It should be noted that, in the present embodiment, the abnormality diagnosis section corresponds to the function of the control section 400 .

By doing so, it is possible to quickly identify the presence or absence of an abnormality in the laser oscillator 100 and the location of the abnormality.

Further, the laser processing apparatus 1000 of the present embodiment includes a laser oscillator 100, a transmission fiber 200 connected to the laser oscillator 100 and guiding the laser beam LB emitted from the laser oscillator 100, and an output end of the transmission fiber 200. and an attached laser light emitting head 300 .

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

Further, the abnormality diagnosis method for the laser oscillator 100 of the present embodiment includes a laser light emitting step (step S1) of emitting the laser light LB, and a photodiode 147 receiving reflected light from the transmission fiber 200 and/or the quartz block 144. a light receiving signal obtaining step (step S2) of obtaining a first light receiving signal Sg1 by obtaining a first light receiving signal Sg1, and obtaining a second light receiving signal Sg2 by receiving the scattered light from the condenser lens 142 with the photodiode 148; and an abnormality diagnosis step (steps S3, S4, S7) for determining whether or not there is an abnormality in the laser oscillator 100 based on the second received light signal Sg2.

According to this method, it is possible to easily determine whether or not there is an abnormality in the condensing optical unit 140 .

Further, 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 If it is larger than the threshold Th2, it is determined that the condenser lens 142 is abnormal.

According to this method, it is possible to easily identify an abnormal location in the condensing optical unit 140 . As a result, it is possible to repair or replace an abnormal portion at an appropriate timing, and the inspection and repair/replacement work can be simplified and significantly shortened.

<Modification 1>
FIG. 4 shows 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 this modified example is that the first and second optical guide paths 145a and 146a are inclined at a predetermined angle with respect to the optical axis of the laser beam LB, and the first and second light guide paths 145a and 146a The configuration differs from that of the condensing optical unit 140 shown in the first embodiment in that the second shielding plates 151 and 152 are omitted. Note that members and the like that are the same as those in the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted. Also, although not shown, wiring boards 149 and 150 are connected to the controller 400 in the same manner as in the first embodiment.

Further, as shown in FIG. 4, the first optical guide path 145a is inclined so that the other end where the photodiode 147 is disposed is further away from the quartz block 144 than the opening communicating with the housing 141. there is Further, the second optical guide path 146 a is formed to be inclined so that the other end where the photodiode 148 is arranged is further away from the condenser lens 142 than the opening communicating with the inside of the housing 141 .

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

By forming the first and second light guide paths 145a and 146a in this way, it is possible to prevent scattered light from the condenser lens 142 from entering the first light guide path 145a. Also, reflected light from the transmission fiber 200 and/or the quartz block 144 can be prevented from entering the second optical guide path 146a. In other words, the first light guide path 145a itself functions as a first light incidence limiting section, and the second light guide path 146a itself functions as a second light incidence limiting section.

According to this modified example, the same effects as shown in the first embodiment can be obtained. In addition, since the first and second shielding plates 151 and 152 can be omitted, the number of parts of the condensing optical unit 140 can be reduced, and the first and second light guide paths 145a and 146a and 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, the shielding performance of the unnecessary light incident thereon, for example, the scattered light from the condenser lens 142 for the first light guide path 145a However, it may be lower than the configuration shown in the first embodiment, so it is necessary to pay attention to this point when actually manufacturing this configuration.

<Modification 2>
FIG. 5 shows a schematic diagram of the internal configuration of a condensing optical unit according to this modification, and FIG. 6 shows a schematic diagram of the internal configuration of another condensing optical unit. Note that members and the like that are the same as those in the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted. Also, although not shown, wiring boards 149 and 150 are connected to the controller 400 in the same manner as in the first embodiment.

The configuration of the condensing optical unit 140 shown in this modified example differs from the configuration of the condensing optical unit 140 shown in the first embodiment in the following points.

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

According to this modification, by arranging the photodiode 147a on the surface of the first shielding plate 153 facing the quartz block 144, the reflection from the transmission fiber 200 and/or the quartz block 144 incident on the photodiode 147a is The amount of light can be increased. In addition, since the surface of the first shielding plate 153 opposite to the surface on which the photodiode 147a is provided shields the scattered light from the condenser lens 142, the S/N ratio of the first received light signal Sg1 can be kept high. Similarly, by arranging the photodiode 148a on the surface of the second shielding plate 154 facing the condensing lens 142, it is possible to increase the amount of scattered light from the condensing lens 142 that enters the photodiode 147a. can. In addition, since the second shielding plate 154 shields the reflected light from the transmission fiber 200 and/or the quartz block 144 on the surface opposite to the surface on which the photodiode 148a is arranged, the S/N ratio of the second received light signal Sg2 is can be kept high.

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

<Modification 3>
FIG. 7 shows a schematic diagram of the internal configuration of the condensing optical unit according to this modification. Note that members and the like that are the same as those in the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted. Also, although not shown, wiring boards 149 and 150 are connected to the controller 400 in the same manner as in the first embodiment.

The configuration of the condensing optical unit 140 shown in this modified example differs from the configuration of the condensing optical unit 140 shown in the first embodiment in the following points.

As shown in FIG. 7, the first optical guide path 145 and the second optical guide path 146 are arranged on the same side when viewed from the optical axis of the laser beam LB. In addition, one end of a third shielding plate (third light restricting portion) 155 is attached to a portion of the housing 141 located between the first light guide path 145 and the second light guide path 146. Plate 155 is provided to extend into housing 142 . Also, the third shielding plate 155 is made of a material that reflects the laser beam LB, such as a metal material.

According to this modified example, by disposing the third shielding plate 155 between the first optical guide path 145 and the second optical guide path 146 which are arranged adjacent to each other with a predetermined interval, the transmission fiber 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 scattered light from the condenser lens 142 is reflected by the third shielding plate 155 . and enters the second optical guide path 146 . As a result, the photodiodes 147 and 148 can be shielded from unnecessary light, and the S/N ratios of the first and second received light signals Sg1 and Sg2 can be increased. Moreover, compared to the configuration shown in the first embodiment, the number of parts can be reduced, and the degree of freedom in arranging the first and second optical guide paths 145 and 146 as well as the photodiodes 147 and 148 can be increased.

(Embodiment 2)
FIG. 8 shows an abnormality diagnosis procedure for a laser oscillator according to this embodiment. Note that steps S12 and S13 shown in FIG. 8 and steps S1 and S2 shown in FIG. 3 are the same, respectively, so description thereof will be omitted. Further, since steps S15 to S20 shown in FIG. 8 and steps S3 to S8 shown in FIG. 3 are the same, the description thereof will be omitted.

In this embodiment, the configuration of the condensing optical unit 140 and the like is the same as the configuration shown in the first embodiment and modified examples 1-3. On the other hand, in the flow chart shown in FIG. 8, preparation of the determination table (step S11) and calling of the first and second threshold values Th1 and Th2 from the determination table (step S14) are similar to those shown in FIG. It is different from the flow chart shown.

As described above, the first and second thresholds Th1 and Th2 are changed according to various conditions. For example, the first threshold Th1 can be changed only by using a transmission fiber 200 having a core 201 with a different diameter. . Also, 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, in the laser processing apparatus 1000, it is common to perform laser processing with different light intensities, or to perform laser processing with different beam diameters by exchanging the transmission fiber 200. , the condensing lens 142, etc., may be replaced, and other parts may be used as they are.

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

Therefore, in this embodiment, various conditions that can be used in the laser oscillator 100 and the laser processing apparatus 1000, for example, the transmission fiber 200, the laser module 120 and the beam coupler 130 that emit the laser beam LB, and the condenser lens 142 are extracted, and the first and second thresholds Th1 and Th2 are obtained in advance for each combination when these are changed. Then, the thresholds 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 judgment table, and based on these, the presence or absence of abnormality in the parts in the optical condensing unit 140 and the transmission fiber 200 is determined. is determined, and the location of the abnormality is specified.

By doing so, it is possible to accurately determine whether or not there is an abnormality in the parts in the optical condensing unit 140 and the transmission fiber 200 in response to changes in the specifications of the laser oscillator 100 and the laser processing apparatus 1000, and to determine the location of the abnormality. can be specified.

(Other embodiments)
In Embodiments 1 and 2, including Modifications 1 to 3, the laser beams emitted from the plurality of laser modules 120 are combined by the beam combiner 130 to emit the laser beam LB. The present invention is not limited to this, and for example, the laser light 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 optical guide paths 145, 146 and the photodiodes 147, 148 are provided, but the configuration is not particularly limited to this, and a plurality of each may be provided. You may make it provide. Also, in that case, it is possible to identify the abnormal location in more detail based on the received light signal output from each photodiode. For example, by providing a plurality of sets of the second light guide path 146 and the photodiode 148 around the optical axis of the laser beam LB, the contaminated or damaged portions of the condenser lens 142 can be specified in detail, and inspection or repair work can be performed. can be shortened.

INDUSTRIAL APPLICABILITY The condensing optical unit of the present invention can easily determine the presence or absence of an internal abnormality and specify the location of the abnormality.

100 laser oscillator 120 laser module 130 beam combiner 140 condensing optical unit 141 housing 142 condensing lens 143 connector 144 quartz block (laser light emitting part)
145 First optical guide path 145a First optical guide path (first light incidence limiting portion)
146 Second light guide path 146a Second light guide path (second light incidence limiting portion)
147, 147a photodiode (first light receiving part)
148, 148a photodiode (second light receiving part)
151, 153 first shielding plate (first light incidence limiting part)
151a First upright portion 151b First bent portions 152, 154 Second shielding plate (second light incidence limiting portion)
152a Second upright portion 152b Second bent portion 155 Third shielding plate (third light incidence 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 device W Work

Claims (13)

Condensing optics having a condensing lens in a housing for condensing laser light emitted from a laser light source, and causing the laser light condensed by the condensing lens to enter a transmission fiber via a laser light emitting section being a unit
A first light receiving section for receiving reflected light from the transmission fiber and/or the laser light emitting section, and scattering from the collecting lens, between the condensing lens and the laser light emitting section in the housing. A second light receiving portion that receives light is arranged at a predetermined interval ,
In the housing, a first light incidence limiting section for limiting incidence of the scattered light to the first light receiving section and a second light incidence limiting section for limiting incidence of the reflected light to the second light receiving section are provided. A condensing optical unit, characterized in that is arranged . The collection optical unit of claim 1 , wherein
The housing is formed with first and second light guide paths each having an opening at one end that communicates with the housing,
The first and second light receiving portions are arranged on the other end sides of the first and second optical guide paths, respectively, and the first light incidence limiting portion is provided between the first optical guide path and the condensing lens. composed of a first upright portion having one end attached to a housing located therebetween and a first bent portion extending from the other end of the first upright portion by bending toward the laser light emitting portion,
The second light-incidence restricting portion includes a second upright portion, one end of which is attached to a housing positioned between the second light guide path and the laser light emitting portion, and a second upright portion that extends from the other end of the second upright portion. and a second bent portion extending toward the condenser lens. The collection optical unit of claim 1 , wherein
The housing is formed with first and second light guide paths each having an opening at one end that communicates with the housing,
The first and second light receiving portions are arranged on the other end side of the first and second optical guide paths, respectively, and the first optical guide path is arranged such that the other end is further away from the laser light emitting portion than the opening. is formed at an angle to configure the first light incidence limiting portion,
The light condensing, wherein the second light entrance limiting section is configured by forming the second light guide path so that the other end is further away from the condensing lens than the opening. optical unit. The collection optical unit of claim 1 , wherein
the first light receiving unit is disposed on a surface facing the laser light emitting unit of the first light incidence limiting unit, one end of which is attached to the housing;
The light-condensing optical unit, wherein the second light-receiving section is arranged on a surface facing the condensing lens of the second light-incidence limiting section, one end of which is attached to the housing. 5. The condensing optical unit according to claim 4 ,
The first light incidence limiting section is inclined so as to approach the laser light emitting section,
The condensing optical unit, wherein the second light incidence limiter is inclined so as to approach the condensing lens. In the condensing optical unit according to any one of claims 1 to 5 ,
A condensing optical unit, wherein the first light receiving portion and the second light receiving portion are arranged on opposite sides of each other with the optical axis of the laser beam interposed therebetween. A condensing lens for condensing laser light emitted from a laser light source is provided in a housing, and the laser light condensed by the condensing lens is incident on a transmission fiber via a laser light emitting section. an optical unit,
A first light receiving section for receiving reflected light from the transmission fiber and/or the laser light emitting section, and scattering from the collecting lens, between the condensing lens and the laser light emitting section in the housing. A second light receiving portion that receives light is arranged at a predetermined interval,
The housing is formed with first and second light guide paths each having an opening at one end that communicates with the housing,
The first and second light receiving portions are arranged on the other end sides of the first and second optical guide paths, respectively, and the first optical guide path and the second optical guide path are separated from the optical axis of the laser beam. are located on the same side as seen,
A third light incidence limiting part having one end attached to a housing located between the first light guide path and the second light guide path , wherein reflection from the transmission fiber and/or the laser light emitting part is provided. Light is reflected by the third light incidence limiting section and enters the first light guide path, and scattered light from the condenser lens is reflected by the third light incidence limiting section and is guided by the second light guide path. A condensing optical unit, wherein unnecessary light is shielded from each of the first light receiving section and the second light receiving section by the third light incidence limiting section so that the unnecessary light is incident on a path . a laser light source that emits laser light;
8. A laser oscillator, comprising at least a condensing optical unit according to claim 1 or 7 , for condensing the laser light and causing it to enter a transmission fiber. The laser oscillator according to claim 8 ,
The laser oscillator, further comprising an abnormality diagnostic section that determines whether or not there is an abnormality in the laser oscillator based on the received light signals respectively received by the first and second light receiving sections. a laser oscillator according to claim 8 ;
a transmission fiber connected to the laser oscillator and guiding the laser light emitted from the laser oscillator;
and a laser beam emitting head attached to the emitting end of the transmission fiber. A laser light source and a condensing lens for condensing the laser light emitted from the laser light source are provided in a housing, and the laser light condensed by the condensing lens is sent to a transmission fiber through a laser light emitting section. A method for diagnosing an abnormality of a laser oscillator, comprising:
the condensing optical unit includes a first light receiving section that receives reflected light from the transmission fiber and/or the laser light emitting section between the condensing lens and the laser light emitting section in the housing; and a second light receiving unit that receives the scattered light from the condenser lens is arranged at a predetermined interval,
In the housing, a first light incidence limiting section for limiting incidence of the scattered light to the first light receiving section and a second light incidence limiting section for limiting incidence of the reflected light to the second light receiving section are provided. is located, or
The first optical guide path and the second optical guide path are arranged on the same side as viewed from the optical axis of the laser beam,
One end is attached to a housing located between the first optical guide path and the second optical guide path, and the reflected light from the transmission fiber and/or the laser light emitting section is reflected to the first optical guide path. Unnecessary light is shielded from each of the first light receiving section and the second light receiving section by reflecting scattered light from the condensing lens and entering the second light guide path. A third light incidence limiting portion is provided to
a laser beam emitting step of emitting the laser beam;
a light receiving signal obtaining step of obtaining a first light receiving signal by receiving the reflected light with the first light receiving unit and obtaining a second light receiving signal by receiving the scattered light with the second light receiving unit;
An abnormality diagnosis method for a laser oscillator, comprising: an abnormality diagnosis step for determining whether or not there is an abnormality in the laser oscillator based on the first light reception signal and the second light reception signal. In the abnormality diagnosis method for a laser oscillator according to claim 11 ,
In the abnormality diagnosis step, if the first received light signal is larger than a first threshold value, it is determined that there is an abnormality in the transmission fiber and/or the laser light emitting section, and the second received light signal is the second received light signal. A method for diagnosing an abnormality of a laser oscillator, comprising determining that the condenser lens is abnormal when the value is greater than a threshold value. In the abnormality diagnosis method for a laser oscillator according to claim 12 ,
further comprising a decision table preparation step of preparing a decision table in which the first and second threshold values associated with the types and/or characteristics of at least one 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 obtained in the light reception signal obtaining step are compared with the first and second threshold values of the determination table, respectively, to determine whether there is an abnormality in the laser oscillator. A method for diagnosing an abnormality in a laser oscillator, comprising identifying a location.

Images