JP6818509B2 - Imaging method of laser processing position and laser processing equipment - Google Patents

Description

The present invention relates to a laser processing apparatus including an imaging means for capturing a laser processing position and a display means for displaying an image (video) captured by the imaging means. More specifically, even if the illumination at the laser processing position is too bright or too dark, the captured image (video) can be displayed on the display means with appropriate brightness. The method and the laser processing apparatus.

There is a laser processing apparatus for welding as an example of a laser processing apparatus. In this type of laser machining apparatus, the laser machining position is imaged by an imaging means when teaching the laser machining position or when confirming the positional relationship between the filler wire and the laser machining position. (See, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2013-128968 JP-A-2015-199127

By the way, a laser processing apparatus for welding is generally configured to include a laser processing head at the tip of a robot arm in, for example, an industrial robot. The direction in which the tip of the laser processing head is directed is various depending on the welding posture. The shape of the work to be laser-processed (welded) by the laser processing device is various, and the work is illuminated by indoor lighting.

Therefore, the machining position of the work includes a portion that is directly irradiated by the room lighting and is extremely bright, and a portion that becomes dark as a shadow of the work, the laser machining head, the robot arm, or the like. Therefore, when the laser processing position is imaged by the imaging means and the captured image (video) is displayed on the display means, for example, halation occurs, the image becomes dark, and it is difficult to display the image with appropriate brightness. ..

By the way, when displaying the image pickup screen on the display means, it is conceivable to adjust the brightness of the indoor lighting that illuminates the laser processing position of the work to an appropriate brightness. However, indoor lighting is usually provided in a plurality of places. Then, for example, when welding is performed near the corners of a work having a three-dimensional structure, the welding posture changes significantly. Therefore, shadows of the laser processing head, the robot arm, and the like may or may not be generated at the laser processing position due to the change in the welding posture. In addition, the reflected light from the laser processing position of the indoor lighting may or may not easily enter the imaging means frequently.

Therefore, it is difficult to adjust the brightness of the indoor lighting to an appropriate brightness.

The present invention has been made in view of the above-mentioned problems, and is laser processing including a laser processing head, an imaging means for capturing a laser processing position, and a display means for displaying an image captured by the imaging means. An illuminance sensor that detects the brightness of the laser processing position, and a shutter speed adjusting means that adjusts the shutter speed of the shutter provided in the imaging means according to the brightness detected by the illuminance sensor. With,
The shutter speed adjusting means includes a data table in which the detection value of the illuminance sensor and the shutter speed are previously associated with each other, and the data table corresponds to the type of laser nozzle to be attached / detached to / from the laser processing head in the laser processing apparatus. Is prepared.

Furthermore, when imaging the laser processing position by the imaging means provided in the laser processing apparatus, the detecting the brightness of the laser processing position by the illuminance sensor with the laser processing device, corresponding to the brightness detected by the illuminance sensor Then, the shutter speed of the shutter provided in the imaging means is adjusted for imaging, and the shutter speed is adjusted based on a data table in which the relationship between the brightness of the laser processing position and the shutter speed is previously associated. the data table, Ru provided corresponding to the type of the laser nozzle is removably replaced into the laser machining head in the laser processing device.

According to the present invention, the brightness of the laser processing position is detected by the illuminance sensor, and the shutter speed of the shutter provided in the imaging means is adjusted according to the detected brightness. Therefore, even when the brightness of the laser processing position is so bright that halation is likely to occur, the laser processing position can be imaged with appropriate brightness and displayed on the display means.

It is sectional drawing which shows the main structure of the laser processing head in the laser processing apparatus which concerns on embodiment of this invention. It is a functional block diagram.

Hereinafter, the laser processing apparatus according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional explanatory view of a main part of a laser processing head 1 in a laser processing apparatus (the overall configuration is not shown) according to an embodiment of the present invention. The laser processing head 1 is used, for example, provided at the tip of a robot arm in an industrial robot. Therefore, the laser machining head 1 is used by changing the directivity direction of the tip portion to various desired directions according to the shape and configuration of the work (not shown).

The laser processing head 1 is attached to the tip of a robot arm in an industrial robot (not shown) via an appropriate bracket (not shown), and the laser processing head 1 has a tubular housing box. 3 is provided. A lens holder 5 is provided in the housing box 3. The lens holder 5 is provided with a condensing lens 7 that condenses the laser beam LB.

A lighting housing 9 is provided in the lower part of the housing box 3. A cylindrical member 11 capable of transmitting the laser beam LB is provided in the lighting housing 9. The lower outer peripheral surface of the cylindrical member 11 is formed as a tapered surface having a smaller diameter on the lower side. On the upper side of the tapered surface, a tapered surface having an angle larger than the taper angle of the lower outer peripheral surface is formed. A plurality of point light sources 13 as illumination means for illuminating the laser processing position LP of the work W are arranged so as to come into contact with the lower side of the tapered surface having a large angle. The point light source 13 is composed of, for example, an LED. Therefore, the light from each point light source 13 is reflected on the outer peripheral surface (tapered surface) of the cylindrical member 11 and is directly irradiated downward. Then, for example, the brightness of the point light source 13 can be adjusted by adjusting the current value.

That is, the plurality of point light sources 13 have a function of illuminating the laser machining position LP of the work W. Therefore, the illuminance at the laser processing position can be adjusted by adjusting the brightness of the point light source.

An air ejection housing 15 for ejecting air that blows spatter and the like outward is provided in the lower portion of the lighting housing 9, and a protective glass is provided between the air ejection housing 15 and the illumination housing 9. 17 is provided so as to be removable and replaceable. A laser nozzle 21 is detachably provided at the lower end of the tubular nozzle holder 19 provided in the lower portion of the air ejection housing 15. Therefore, the illumination of the laser processing position LP by the plurality of point light sources 13 is performed through the nozzle openings 21A of the laser nozzle 21.

The laser machining head 1 is provided with a CCD camera 23 on the outer surface of the housing box 3 as an example of an imaging means for imaging the laser machining position LP of the work W. A reflector 25 is provided in the housing box 3 in order to image the laser processing position LP by the CCD camera 23.

More specifically, the housing box 3 is provided with a mirror holder 27 that is movable in a direction orthogonal to the optical axis of the laser beam LB (direction perpendicular to the paper surface in FIG. 1). The mirror holder 27 is provided with an inclined reflecting mirror 25 that reflects the reflected light from the laser processing position LP toward the CCD camera 23. Therefore, the laser processing position LP can be imaged by the CCD camera 23. The imaging by the CCD camera 23 is performed through the nozzle port 21A of the laser nozzle 21.

By the way, when the work W is irradiated with the laser beam LB to perform laser processing on the work W, the mirror holder 27 is retracted from the optical path of the laser beam LB. Then, when the CCD camera 23 takes an image of the laser processing position LP, it is moved and positioned in the optical path of the laser light LB. That is, the mirror holder 27 is moved forward and backward with respect to the optical path of the laser beam LB by the operation of an actuator (not shown) such as a fluid pressure cylinder.

An illuminance sensor 29 for detecting the brightness of the laser processing position LP when the CCD camera 23 takes an image of the laser processing position LP is provided. The illuminance sensor 29 is provided in the laser processing head 1. The illuminance sensor 29 may have a function of detecting the brightness of the laser processing position LP through the nozzle port 21A of the laser nozzle 21, and can be provided at a desired position in the laser processing head 1.

In the present embodiment, the illuminance sensor 29 is provided in the mirror holder 27. That is, the illuminance sensor 29 is located at a detection position for detecting the brightness of the laser processing position LP when the CCD camera 23 images the laser processing position LP, and is not when the laser processing position LP is not imaged. It is located at the detection position. In other words, the illuminance sensor 29 is movably provided between a detection position and a non-detection position. Therefore, the illuminance sensor 29 can be protected from the reflected light of the laser beam LB from the laser machining position LP at the time of laser machining of the work W.

As understood from the above description, when the laser processing position LP is imaged by the CCD camera 23 as the imaging means, the brightness of the laser processing position LP can be detected by the illuminance sensor 29. Therefore, it is also possible to adjust the brightness of the laser processing position LP by adjusting the brightness of the point light source 13 to adjust the brightness of the laser processing position LP to an appropriate brightness.

However, for example, when the indoor lighting is very bright and the laser processing position LP is too bright, it is difficult to adjust the brightness of the laser processing position LP to an appropriate brightness. Therefore, in such a case, when the laser processing position is imaged by the CCD camera 23 and the image of the laser processing position LP is displayed on the display means (not shown in FIG. 1) provided in the laser processing apparatus, halation occurs. Is likely to occur, and the image tends to be white.

Further, when the portion of the laser processing position LP becomes dark, for example, as a shadow, the image may become black. In this case, it is also possible to deal with this by illuminating the laser processing position LP with the plurality of point light sources 13.

As described above, the brightness of the laser machining position LP changes variously depending on the lighting direction and brightness of the indoor lighting, the work W's posture, the welding posture, and the shadows of the robot arm, the laser machining head, and the like. Is what you do. Therefore, for example, if the brightness of the indoor lighting is adjusted in order to prevent halation from occurring, the brightness of the laser processing position LP may become darker than necessary in some cases. Therefore, it is difficult to always adjust the brightness of the laser processing position LP to an appropriate brightness.

Therefore, in the present embodiment, the amount of light entering the image sensor (for example, CCD, CMOS) in the image pickup means 23 such as a CCD camera is always kept substantially constant, and the image becomes pure white or becomes pure black. In order to prevent this from happening, the image of the laser processing position LP is always displayed on a display means such as a monitor in an easy-to-see manner.

That is, in the present embodiment, the imaging condition adjusting device 31 (see FIG. 2) for adjusting the imaging conditions of the imaging means 23 is provided according to the brightness of the laser processing position LP. The imaging condition adjusting device 31 is composed of, for example, a microcomputer, and includes a CPU 33, a RAM 35, and a ROM 37. The imaging condition adjusting device 31 adjusts the shutter speed of the shutter in the imaging means 23 according to the illuminance (brightness) of the laser processing position LP detected by the illuminance sensor 29.

Therefore, the illuminance sensor 29 is connected to the imaging condition adjusting device 31. Then, a shutter speed adjusting means 39 for adjusting the shutter speed of the shutter in the imaging means 23 is provided corresponding to the detected value (brightness) of the illuminance sensor 29. The imaging condition adjusting device 31 has a detection value (brightness) of the illuminance sensor 29 and a shutter speed in order to adjust the shutter speed in accordance with the brightness (illuminance) detected by the illuminance sensor 29. A data table 41 in which the relationship is experimentally obtained in advance is provided.

By the way, when the laser processing position LP of the work W is imaged by the imaging means 23, the image is taken through the nozzle port 21A of the laser nozzle 21. Further, when the brightness of the laser machining position LP is detected by the illuminance sensor 29, it is performed through the nozzle port 21A. Here, when the type of the laser nozzle 21 is changed, the size of the nozzle port 21A also changes.

Therefore, when the brightness of the laser processing position is detected by the illuminance sensor 29, if the size of the nozzle opening 21A is changed instead of the laser nozzle 21, it is equivalent to the change in the aperture. Therefore, even if the brightness of the laser processing position LP is the same, if the laser nozzle 21 is replaced, the value detected by the illuminance sensor 29 will change. Therefore, the data table 41 is provided according to the type of laser nozzle that is attached to and detached from the laser processing head 1.

In the above configuration, for example, when the nozzle 21 provided in the laser machining head 1 is directed to the laser machining position LP of the work W for teaching, the laser machining position is determined by the illuminance sensor 29 provided in the laser machining head 1. The brightness of the LP is detected. Then, when the brightness of the laser processing position LP is detected, the shutter speed corresponding to the brightness detected by the illuminance sensor 29 is referred to with reference to the data table 41 corresponding to the nozzle 21 mounted on the laser processing head 1. Is searched.

Then, the shutter speed adjusting means 39 adjusts the shutter speed of the imaging means 23 to the searched shutter speed. Therefore, the imaging of the laser processing position LP by the imaging means 23 is performed at the adjusted shutter speed. In this case, when the laser processing position LP is very bright, the shutter speed is adjusted to a high-speed shutter, and when it is dark, the shutter speed is adjusted to a low-speed shutter.

Therefore, when the laser processing position LP is imaged, the amount of light input to the image sensor (not shown) in the image pickup means 23 can always be maintained (maintained) substantially constant regardless of the brightness of the laser processing position LP. It is a thing. Therefore, when displaying an image (image) on the display means 43, the screen of the display means 43 is not too bright or too dark, and can always be displayed with appropriate brightness.

As understood from the above description, according to the present embodiment, when the laser machining position LP of the work W is imaged, the brightness of the laser machining position LP is detected by the illuminance sensor 29. Then, the shutter speed of the shutter provided in the imaging means 23 is adjusted to an appropriate speed according to the detected brightness. Therefore, the amount of light entering the imaging means 23 can be made substantially constant regardless of the brightness or darkness of the laser processing position LP. That is, the image of the laser processing position LP can be imaged in a stable and easy-to-see state.

1 Laser processing head 9 Lighting housing 13 point light source (lighting means)
19 Nozzle holder 21 Laser nozzle 21A Nozzle mouth 23 CCD camera (imaging means)
25 Reflector 29 Illuminance sensor 31 Imaging condition adjustment device 39 Shutter speed adjustment means

Claims (2)

A laser processing apparatus including a laser processing head, an imaging means for capturing a laser processing position, and a display means for displaying an image captured by the imaging means.
An illuminance sensor that detects the brightness of the laser processing position and
A shutter speed adjusting means for adjusting the shutter speed of the shutter provided in the imaging means according to the brightness detected by the illuminance sensor, and a shutter speed adjusting means.
Equipped with a,
The shutter speed adjusting means includes a data table in which the detection value of the illuminance sensor and the shutter speed are associated in advance.
The data table is a laser processing apparatus characterized in that the data table is provided corresponding to the type of laser nozzle that is attached to and detached from the laser processing head in the laser processing apparatus. When imaging the laser processing position with the imaging means provided in the laser processing device
Wherein detecting the brightness of the laser processing position by the illuminance sensor with the laser processing device,
The shutter speed of the shutter provided in the imaging means is adjusted to image according to the brightness detected by the illuminance sensor.
The shutter speed is adjusted based on a data table in which the relationship between the brightness of the laser processing position and the shutter speed is previously associated.
The data table, the method of imaging a laser processing position, wherein Rukoto provided corresponding to the type of the laser nozzle is removably replaced into the laser machining head in the laser processing device.

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