JP2000024785A - Method and device for light guide trouble detection of laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for light guide trouble detection of a laser beam machine capable of inexpensively and easily detect of cutting of an optical fiber used for a laser beam machine. SOLUTION: When laser machining is conducted by irradiating a work with a laser beam generated by a laser oscillator 13 and guided to a machining head 19, ultraviolet rays generated by irradiating the work with the laser beam are detected by a suitable number of sensors S1, S2, S3, S4 arranged at prescribed positions, a comparison discriminating means discriminates generation of trouble of the light guide 21 from a change in the ultraviolet rays quantity. In the case the comparison discriminating means discriminates generation of trouble in the light guide 21, a command part 11 stops the laser beam oscillator 13 based on a signal from the comparison discriminating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a light guide path failure of a laser beam machine for detecting a failure in a light guide path leading to a processing head for irradiating a laser beam generated by a laser generator onto a workpiece. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, in a YAG laser beam machine, a laser beam generated by a laser generator is generally guided to a machining head using an optical fiber as a light guide path.

[0003] In order to detect a failure such as a breakage of the optical fiber, as shown in FIG.
May be coated with a conductive coating material 103 and covered with a protective coating 105, or as shown in FIG.
In general, an infrared sensor 113 is provided in the optical fiber emitting section 111 as shown in FIG.

[0004]

However, in such a conventional technique, when the above-mentioned conductive coating material 103 or the conductive wire 109 is used, the optical fiber becomes expensive. There is a problem. In addition, when the infrared sensor 113 is used, the structure of the optical fiber emission unit 111 is complicated because the infrared sensor 113 is incorporated, which hinders miniaturization of the apparatus.

SUMMARY OF THE INVENTION An object of the present invention is to pay attention to the above-mentioned conventional techniques, and to easily and inexpensively detect a fault such as a cutout of an optical fiber used in a laser beam machine. It is an object of the present invention to provide a method and an apparatus for detecting a light guide path failure of a laser beam machine which can be realized.

[0006]

According to a first aspect of the present invention, there is provided a method for detecting a failure in a light guide path of a laser beam machine, the method comprising: irradiating a workpiece with laser light generated by a laser generator. In the method of detecting a failure in a light guide path leading to a processing head for performing laser processing, the processing head irradiates a laser beam to a work, and an ultraviolet ray generated from the work irradiated with the laser light is disposed at a predetermined position. If the amount of ultraviolet light detected by the sensor does not increase despite laser light being generated by the laser generator, it is determined that a failure has occurred in the light guide path. It is assumed that.

Accordingly, when the laser beam generated by the laser generator is guided to the processing head through the light guide path and is irradiated on the work, and the laser processing is performed, the ultraviolet light generated by irradiating the work with the laser light is irradiated at a predetermined position. Are detected by an appropriate number of sensors disposed in the optical waveguide, and the occurrence of a failure in the light guide path is determined from the change in the amount of the ultraviolet light. That is, if the amount of ultraviolet light detected by the sensor does not increase even though the laser light is being generated by the laser generator, it is determined that a failure has occurred in the light guide path.

According to a second aspect of the present invention, there is provided an apparatus for detecting a failure in a light guide path of a laser beam machine. And an appropriate number of sensors arranged around the work on which the laser processing is performed and detecting ultraviolet light generated from the work, and determining a failure in the light guide path from the amount of ultraviolet light detected by the sensor. And comparison determining means.

Therefore, when the laser beam generated by the laser generator is guided to the processing head by the light guide path and is irradiated on the work, and the laser processing is performed, the ultraviolet light generated by irradiating the work with the laser light is irradiated at a predetermined position. Are detected by an appropriate number of sensors arranged in the above, and the comparison and determination means determines the occurrence of a failure in the light guide path from the change in the amount of the ultraviolet light. That is, when the amount of ultraviolet light detected by the sensor does not increase even though the laser light is being generated by the laser generator, the comparing and determining means determines that a failure has occurred in the light guide path.

According to a third aspect of the present invention, there is provided a light guide path failure detection apparatus for a laser beam machine, wherein the comparison and determination means is connected to the comparison and determination means. A command unit for commanding to stop the laser generator when it is determined that a failure in the light guide path has occurred.

Therefore, when the comparison and determination means determines that a failure has occurred in the light guide path from the change in the amount of ultraviolet light, the command section stops the laser generator based on a signal from the comparison and determination means.

[0012]

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

FIG. 1 shows an entire laser processing apparatus 3 to which a light guide path failure detection apparatus 1 (see FIG. 2) for a laser processing machine according to the present invention is applied. This laser processing device 3
Is provided with a safety enclosure 5 all around to prevent laser light from leaking to the surroundings, and performs laser processing inside the safety enclosure 5. The safety enclosure 5 is provided with a door 7 for loading / unloading a worker or a work, and the door 7 is provided with a view window 9 for monitoring the inside during the work. Outside the safety enclosure 5, a control panel 11, which is a command unit for controlling each device inside, is provided.

A laser generator 13 having a laser power supply and a laser oscillator is provided inside the safety enclosure 5. A processing robot 15 which is a laser processing machine is provided near the center of the inside of the safety enclosure 5, and a processing head 19 is attached to a tip of an arm 17 which freely moves and rotates the processing robot 15. . A laser beam is sent from the laser generator 13 to the processing head 19 through an optical fiber 21 as an example of a light guide path, and irradiates a workpiece to perform laser processing such as welding or cutting.

An arbitrary position inside the safety enclosure 5;
For example, at points S1 to S4 in FIG. 1, sensors S1, S2, S3, which constitute the light guide path failure detection device 1 of the laser beam machine,
S4 is provided, and the sensors S1, S2, S3, and S4 detect ultraviolet light generated when the laser light emitted from the processing head 19 hits the work.

FIG. 2 shows the configuration of a light guide path failure detecting device 1 for a laser beam machine according to the present invention. Safety enclosure 5
, A plurality of sensors S1, S2,
S3 and S4 are connected via an amplifier 23 to a comparison circuit 25 which is a comparison determination means. When a work is irradiated with laser light during welding or cutting, ultraviolet light is generated. Therefore, the ultraviolet light is received by sensors S1, S2, S3, and S4, and the amount of received light is transmitted to a comparison circuit 25. If the amount of ultraviolet rays increases during the laser emission by 13, it can be confirmed that the laser beam passes through the optical fiber 21 which is the light guide path without any obstacle and is irradiated on the work.

On the other hand, if the increase in the amount of ultraviolet light is not detected by the sensors S1, S2, S3, and S4 during laser emission by the laser generator 13, a failure occurs in the optical fiber 21 and laser light is applied to the work. It is determined that irradiation has not been performed normally. In this case, upon receiving a signal from the comparison circuit 25, the control panel 11 generates an alarm signal and stops the laser processing apparatus 3.

From the above results, the inexpensive UV sensor S
The failure of the existing optical fiber 21 can be detected by using 1, S2, S3, and S4, so that work efficiency can be improved and work safety can be ensured. In addition, since it is not always necessary to provide the optical fiber 21 at the emission portion, the size of the processing robot 15 as a laser processing machine can be reduced.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. That is, the sensor S
The numbers and arrangement positions of 1, S2, S3, and S4 are not limited to the positions shown in FIG. 1, and may be provided at appropriate positions.

[0020]

As described above, in the method of detecting a light guide path failure of a laser beam machine according to the first aspect of the present invention, the laser light generated by the laser generator is guided to the processing head by the light guide path and irradiated onto the work. When performing laser processing, ultraviolet light generated by irradiating the workpiece with laser light is detected by an appropriate number of sensors arranged at predetermined positions, and the occurrence of a failure in the light guide path is determined from the change in the amount of ultraviolet light. I do.
That is, if the amount of ultraviolet light detected by the sensor does not increase despite the laser light being generated by the laser generator, it is determined that a failure has occurred in the light guide path,
The failure of the light guide path can be reliably detected at low cost. As a result, work efficiency can be improved and work safety can be ensured. Further, since it is not always necessary to provide the laser beam on the processing head, the size of the laser processing machine can be reduced.

According to a second aspect of the present invention, there is provided an apparatus for detecting a failure in a light guide path of a laser beam machine. Ultraviolet light generated by irradiating the work with light is detected by an appropriate number of sensors arranged at predetermined positions, and the comparison and determination means determines the occurrence of a failure in the light guide path from the change in the amount of ultraviolet light. In other words, if the amount of ultraviolet light detected by the sensor does not increase even though the laser light is being generated by the laser generator, the comparison and determination means determines that a failure has occurred in the light guide path, so that it is cheap and reliable. An optical path failure can be detected. As a result, work efficiency can be improved and work safety can be ensured. Further, since it is not always necessary to provide the laser beam on the processing head, the size of the laser processing machine can be reduced.

In the light guide path failure detection device for a laser beam machine according to the third aspect of the present invention, when the comparison / determination means determines that a failure has occurred in the light guide path based on a change in the amount of ultraviolet light, the comparison / determination means outputs the signal. Since the command unit stops the laser generator based on the signal, it is possible to secure work safety and improve work efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the entirety of a laser processing apparatus using a light guide path failure detection device according to the present invention.

FIG. 2 is a block configuration diagram of a light guide path failure detection device of the laser beam machine according to the present invention.

FIG. 3 is a sectional view showing a conventional optical fiber.

FIG. 4 is a perspective view showing another conventional optical fiber.

FIG. 5 is a cross-sectional view showing still another conventional optical fiber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light guide path failure detection apparatus 11 Control panel (command part) 13 Laser generator 19 Processing head 21 Optical fiber (light guide path) 25 Comparison circuit (comparison determination means) S1, S2, S3, S4 Sensor

Claims (3)

[Claims] In a method for detecting a failure in a light guide path leading to a processing head for performing laser processing by irradiating a laser beam generated by a laser generator to a workpiece, the processing head irradiates the workpiece with laser light. Ultraviolet light generated from the work irradiated with the laser light is detected by an appropriate number of sensors arranged at a predetermined position, and the amount of the ultraviolet light detected by the sensor increases despite the laser light being generated by the laser generator. If not, it is determined that a failure has occurred in the light guide path. 2. A failure detection device for a light guide path for irradiating a laser beam generated by a laser generator onto a work and guiding the work to a processing head for laser processing, wherein the failure detection device is disposed around the work on which the laser processing is performed. A laser comprising: an appropriate number of sensors for detecting ultraviolet rays generated from the workpiece; and comparison determining means for determining a failure in the light guide path based on an amount of the ultraviolet rays detected by the sensor. Light guide path failure detection device for processing machines. A command unit connected to the comparison / determination means for instructing the laser generator to stop when the comparison / determination means determines that a failure in the light guide path has occurred;
The light guide path failure detecting device for a laser beam machine according to claim 2, further comprising: