JP2023082229A - Laser processing head and laser processing device - Google Patents

Abstract

Kind Code: A1 An object of the present invention is to appropriately determine when to perform maintenance of protective glass. Kind Code: A1 Infrared rays IR radiated from a protective glass 24 are reflected by an emission end face of a beam splitter 23. The detector 27 detects the amount of infrared rays IR reflected by the beam splitter 23 . The determination unit 31 determines the state of the protective glass 24 based on the detection value of the detection unit 27 . [Selection drawing] Fig. 2

Description

The present invention relates to a laser processing head and a laser processing apparatus.

Patent Literature 1 discloses a laser processing head to which protective glass is detachably attached. The protective glass protects the lens optical system so that spatters and fumes generated from the workpiece during laser processing do not adhere to the lens optical system.

JP 2019-42795 A

By the way, when the protective glass is dirty, the laser output is lowered, and the processing quality of the work deteriorates. Therefore, it is necessary to periodically perform maintenance work such as cleaning and replacement of the protective glass.

However, depending on how the laser processing head is used, the amount of dirt adhering to the protective glass may be greater than expected, and the laser output may drop before the period for regular maintenance of the protective glass has passed. .

The present invention has been made in view of the above points, and an object of the present invention is to enable appropriate determination of the maintenance timing of the protective glass.

The present invention is directed to a laser processing head that emits a laser beam to a work, and has taken the following solutions.

That is, the first invention comprises a transmission fiber for transmitting the laser beam, a collimator lens for parallelizing the laser beam transmitted by the transmission fiber, and a laser beam collimated by the collimator lens. a beam splitter for transmitting the laser beam condensed by the focus lens; protective glass disposed on the emission side of the beam splitter; emitted from the protective glass and reflected by the beam splitter and a determination unit that determines the state of the protective glass based on the detection value of the detection unit.

In the first invention, the infrared rays emitted from the protective glass are reflected by the beam splitter. The detector detects the amount of infrared rays reflected by the beam splitter. The judging section judges the state of the protective glass based on the detection value of the detecting section.

Specifically, when the protective glass is stained with spatters or fumes, the laser beam is applied to the stained portion to generate heat, which increases the amount of infrared rays emitted from the protective glass. Therefore, if the detector detects an increase in the amount of infrared rays, it can be determined that the protective glass is dirty or has an abnormality.

This makes it possible to appropriately determine when to perform maintenance such as cleaning or replacement of the protective glass.

According to a second aspect of the present invention, there is provided a condensing optical system disposed between the beam splitter and the detection section in the first invention, the condensing optical system condensing the infrared rays to the detection section. to

In the second invention, the infrared rays reflected by the beam splitter are condensed by the condensing optical system and emitted to the detection section. The condensing optical system is composed of, for example, a collimator lens and a focus lens.

As a result, it is possible to increase the amount of infrared rays detected by the detection unit and improve the detection accuracy.

In a third aspect based on the first or second aspect, the beam splitter is provided with an AR coat having the lowest reflectance of a processing wavelength for processing the workpiece.

In the third invention, the beam splitter is provided with an AR coat. The AR coat has the lowest reflectance for the processing wavelength for processing the workpiece.

This makes it easier for the laser light of the processing wavelength to pass through the beam splitter, and makes it easier for the beam splitter to reflect light other than the processing wavelength. Therefore, the detection accuracy can be improved by increasing the amount of infrared rays detected by the detection unit.

In a fourth aspect based on the third aspect, the AR coat has a higher reflectance on the longer wavelength side than the processing wavelength.

In the fourth invention, the AR coat has a higher reflectance for light on the longer wavelength side than the processing wavelength. As a result, far-infrared rays, which are light on the longer wavelength side, are more likely to be reflected by the beam splitter, making it easier to detect changes in the temperature state of the protective glass.

A fifth invention is a laser comprising: the laser processing head according to any one of the first to fourth inventions; and a laser oscillator connected to the incident end of the transmission fiber for oscillating laser light. processing equipment.

In a fifth invention, a laser beam oscillated by a laser oscillator is incident on the laser processing head according to any one of the first to fourth inventions through a transmission fiber, thereby operating a laser processing apparatus. I am trying to configure.

According to a sixth invention, in the fifth invention, a notification section is provided for performing a predetermined notification operation indicating the state of the protective glass based on the determination result of the determination section.

In the sixth invention, the notification section performs a predetermined notification operation based on the determination result of the determination section. For example, when the protective glass is soiled or abnormal, an alarm operation such as sounding an alarm buzzer, lighting an alarm lamp, or displaying an alarm message is performed.

Thereby, the operator can determine the timing of maintenance such as cleaning or replacement of the protective glass based on the predetermined notification operation.

ADVANTAGE OF THE INVENTION According to this invention, the maintenance time of protective glass can be judged appropriately.

It is a schematic block diagram of the laser processing apparatus which concerns on this embodiment. It is a figure which shows the internal structure of a laser processing head. FIG. 4 is a graph showing the relationship between the wavelength of laser light incident on a beam splitter and the reflectance;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the following description of preferred embodiments is essentially merely an example, and is not intended to limit the present invention, its applications, or its uses.

<Configuration of laser processing device>
As shown in FIG. 1, the laser processing apparatus 1 includes a laser oscillator 10, a transmission fiber 11, a laser processing head 20, a robot 15, and a controller 30.

A laser oscillator 10 oscillates a laser beam LB. The laser oscillator 10 can use, for example, a solid-state laser light source, a gas laser light source, or a fiber laser light source. Alternatively, the laser oscillator 10 may be a semiconductor laser light source that directly uses light emitted from a semiconductor laser, or a semiconductor laser array that includes a plurality of laser light emitters.

A laser oscillator 10 is connected to an incident end of a transmission fiber 11 . A laser processing head 20 is connected to the output end of the transmission fiber 11 . A laser beam LB emitted from the laser oscillator 10 is transmitted to the laser processing head 20 via the transmission fiber 11 .

A laser processing head 20 is attached to the robot 15 . The laser processing head 20 can change the emission position and focal position of the laser beam LB with respect to the work W by operating the robot 15 .

A laser oscillator 10 , a laser processing head 20 , and a robot 15 are connected to the controller 30 . The control unit 30 controls the movement speed of the laser processing head 20 as well as the start and stop of the output of the laser beam LB, the output intensity of the laser beam LB, and the like.

The control unit 30 is connected to a notification unit 35 that performs a predetermined notification operation. The notification unit 35 performs a predetermined notification operation such as sounding an alarm buzzer, turning on an alarm lamp, or displaying an alarm message.

The control unit 30 has a determination unit 31 . Although details will be described later, the determination unit 31 determines the state of the protective glass 24 (see FIG. 2) of the laser processing head 20 .

<Configuration of laser processing head>
As shown in FIG. 2 , the laser processing head 20 has a collimator lens 21 , a focus lens 22 , a beam splitter 23 , a protective glass 24 and a detector 27 .

The collimator lens 21 collimates the laser beam LB emitted from the emission end of the transmission fiber 11 .

The focus lens 22 collects the laser beam LB collimated by the collimator lens 21 .

The beam splitter 23 transmits the laser beam LB condensed by the focus lens 22 . The beam splitter 23 is a plate-shaped optical element, and is arranged to form a predetermined angle (45 degrees in FIG. 2) with respect to the optical axis of the laser beam LB.

The protective glass 24 is arranged on the exit side of the beam splitter 23 . The protective glass 24 protects the beam splitter 23 so that fumes and spatter generated during laser processing of the work W do not adhere to the beam splitter 23 .

The laser beam LB condensed by the focus lens 22 passes through the beam splitter 23 and the protective glass 24 and is emitted to the work W. As shown in FIG.

An exit end face of the beam splitter 23 is provided with an AR coat 23a. Although details will be described later, the beam splitter 23 is configured to transmit the laser beam LB condensed by the focus lens 22 while reflecting the infrared rays IR emitted by the protective glass 24 .

A mirror 25 and a condensing optical system 26 are arranged between the beam splitter 23 and the detector 27 .

The mirror 25 is arranged at a position facing the exit end face of the beam splitter 23 . The mirror 25 is arranged to form a predetermined angle (45 degrees in FIG. 2) with respect to the optical axis of the infrared rays IR reflected by the beam splitter 23 .

The condensing optical system 26 has a collimator lens 26a and a focus lens 26b. The collimator lens 26 a collimates the infrared rays IR reflected by the mirror 25 . The focus lens 26b collects the infrared rays IR collimated by the collimator lens 26a. Infrared rays IR condensed by the focus lens 26 b are emitted to the detection section 27 .

The detection unit 27 is composed of, for example, an infrared sensor. The detector 27 detects the amount of infrared rays IR. A detection value of the detection unit 27 is sent to the control unit 30 .

<Detection of dirt on protective glass>
By the way, when the protective glass 24 is dirty, the laser output is lowered, and the processing quality of the workpiece W is deteriorated. Therefore, it is necessary to periodically perform maintenance work such as cleaning and replacement of the protective glass 24 .

Here, the inventor of the present application has found that when the protective glass 24 is stained by spatters or fumes, the laser beam LB is applied to the stained portion to generate heat, and the infrared rays emitted from the protective glass 24 It was noted that the amount of infrared rays in IR increased.

Therefore, in the present embodiment, the state of the protective glass 24 can be determined by detecting the amount of infrared rays IR emitted from the protective glass 24 .

Specifically, an AR coat 23a is provided on the output end face of the beam splitter 23 . As shown in FIG. 3, the AR coat 23a has the lowest reflectance for the processing wavelength for processing the workpiece W. As shown in FIG.

As a result, the beam splitter 23 facilitates transmission of the laser beam LB of the processing wavelength, while the beam splitter 23 facilitates the reflection of the infrared light IR, which is light having a wavelength other than the processing wavelength.

Also, the AR coating 23a has a high reflectance on the longer wavelength side than the working wavelength. As a result, far-infrared rays, which are light on the long wavelength side, are more likely to be reflected by the beam splitter 23, and changes in the temperature state of the protective glass 24 can be more easily detected.

The infrared rays IR reflected by the beam splitter 23 are reflected by the mirror 25 and enter the condensing optical system 26 . In the condensing optical system 26 , the infrared rays IR are condensed and emitted to the detector 27 . This makes it possible to increase the amount of infrared rays IR detected by the detection unit 27 and improve the detection accuracy.

The detector 27 detects the amount of infrared rays IR. A detection value of the detection unit 27 is sent to the control unit 30 .

The control unit 30 has a determination unit 31 . The determination unit 31 determines the state of the protective glass 24 based on the detection value of the detection unit 27 . Here, the state of the protective glass 24 refers to a state in which dirt adheres to the protective glass 24, a state in which the light absorption rate of the protective glass 24 changes, and thermal distortion occurs.

The determination unit 31 determines that an abnormality such as dirt adheres to the protective glass 24 occurs when the detection value of the detection unit 27 is larger than a predetermined threshold value. As the threshold value, for example, the amount of infrared rays IR radiated from the protective glass 24 in the initial state where dirt is not attached may be used.

The notification unit 35 performs a predetermined notification operation indicating the state of the protective glass 24 based on the determination result of the determination unit 31 . For example, when the protective glass 24 is soiled or abnormal, an alarm operation such as sounding an alarm buzzer, turning on an alarm lamp, or displaying an alarm message is performed.

Thereby, the operator can determine the timing of maintenance such as cleaning or replacement of the protective glass 24 based on the predetermined notification operation.

INDUSTRIAL APPLICABILITY As described above, the present invention is extremely useful and has high industrial applicability because it is possible to obtain the highly practical effect of being able to appropriately determine the maintenance timing of the protective glass.

1 laser processing device 10 laser oscillator 11 transmission fiber 20 laser processing head 21 collimator lens 22 focus lens 23 beam splitter 23a AR coat 24 protective glass 26 condensing optical system 27 detection unit 31 determination unit 35 notification unit IR infrared ray LB laser beam W work

Claims (6)

A laser processing head that emits a laser beam to a work,
a transmission fiber that transmits the laser light;
a collimator lens for collimating the laser light transmitted by the transmission fiber;
a focus lens for condensing the laser beam collimated by the collimator lens;
a beam splitter that transmits the laser light condensed by the focus lens;
a protective glass disposed on the exit side of the beam splitter;
a detection unit that detects the amount of infrared rays emitted from the protective glass and reflected by the beam splitter;
and a determination unit that determines the state of the protective glass based on the detection value of the detection unit. In claim 1,
A condensing optical system arranged between the beam splitter and the detection unit,
A laser processing head, wherein the condensing optical system condenses the infrared rays and emits the infrared rays to the detection unit. In claim 1 or 2,
The laser processing head, wherein the beam splitter is provided with an AR coat having the lowest reflectance for a processing wavelength for processing the workpiece. In claim 3,
The laser processing head, wherein the AR coat has a higher reflectance on the longer wavelength side than the processing wavelength. A laser processing head according to any one of claims 1 to 4;
and a laser oscillator that is connected to the incident end of the transmission fiber and that oscillates laser light. In claim 5,
A laser processing apparatus comprising a notification unit that performs a predetermined notification operation indicating the state of the protective glass based on the determination result of the determination unit.

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