JPH04118193A - Device for monitoring protective glass of laser beam machine - Google Patents

Abstract

PURPOSE:To observe the contamination of protective glass by providing the device for monitoring the protective glass in the laser beam machine having the protective glass for a condenser lens. CONSTITUTION:The laser machine which irradiates a work 4 with a laser beam 6 condensed by the condenser lens 2 and processes the work by providing the protective glass 3 for protecting the condenser lens 2 is provided with the device which is disposed with a reflecting mirror 7 for forming the positional relation to set the surface of the protective glass 3 on the work side as the focal position of the condenser lens 2 and is used to view the protective glass 3 by using the reflecting mirror 7 through the condenser lens 2. The distinct observation of the contents and degree of the contamination of the rear surface of the protective glass is possible in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a protective glass monitoring device for laser processing equipment.
In particular, the present invention relates to a monitoring device for a protective glass of a laser processing apparatus that can observe dirt and damage on a protective glass provided in a laser emitting section during processing.

[Conventional technology]

A protective glass is disposed in a laser beam emitting section of a laser processing device in order to protect the lens from sputtering and the like from a workpiece. However, if the protective glass itself becomes dirty or damaged, the transmittance of the laser beam will decrease, resulting in a decrease in laser beam output to the workpiece and machining defects, so it is important to always keep the protective glass in the optimal condition. need to be maintained. For this purpose, it is necessary to periodically inspect the condition of the protective glass.

An example of a device for inspecting the protective glass of a conventional laser processing device is disclosed in Japanese Patent Application Laid-Open No. 60-27489. This conventional device is equipped with a detection device that is placed opposite to the tip hole of the nozzle of the laser welding device and has the function of projecting light and receiving the reflected light. It is configured to detect dirt, compare the detection signal with a reference value in a determination circuit, determine whether the state of the protective glass is good or bad, and output the result to an output device. In this device, a tip hole of a nozzle through which laser light is emitted is used to irradiate light onto a protective glass, and the reflected light is taken in to detect an obstacle that obstructs the transmission of laser light through the protective glass. Therefore, in the configuration of this protective glass inspection apparatus, laser processing is performed periodically when laser processing is not performed.

[Problem to be solved by the invention]

According to the conventional device described above, the following first to fifth problems occur.

First, it is not possible to detect dirt on the protective glass during laser processing due to restrictions on the placement of the detection device, which requires looking into the protective glass through a hole at the tip of the nozzle, and restrictions on how to retrieve information about dirt. There is a problem. It is very important to be able to inspect the protection glass for dirt during laser processing, since it is necessary to know the dirt status of the protection glass quickly and at an appropriate timing.

Second, since the level signal related to dirt detected by the detection device is simply compared with a specified reference value, there is a problem in that the content of the dirt on the protective glass cannot be known. In other words, it is not possible to know whether the dirt is caused by large spatters or powdery dirt. When the types of machining or workpieces are different, or when fine machining is performed, it is necessary to obtain accurate information about the contents of contamination.

Thirdly, it is difficult to detect any damage such as cracks in the protective glass.

Fourthly, since the configuration is such that the dirt information on the protective glass is extracted through the tip hole of the nozzle, which is like a pinhole that emits the laser beam, the range on the protective glass that can be detected by the detection device is limited. There is a problem in that only a very narrow area on the protective glass can be detected. According to conventional devices, it is practically impossible to see dirt on the entire surface of the protective glass.

Fifth, dirt on the protective glass is detected only as an obstacle by using light reflection, and the judgment circuit only compares the detection signal with a specified value to judge whether it is good or bad. The problem is that it is not possible to know exactly.

Further, in the laser processing apparatus, it is desirable to be able to observe the contamination state of the protective glass during laser processing, and also to simultaneously observe the processing state of the workpiece by the laser beam.

In view of the above-mentioned problems, an object of the present invention is to be able to accurately and easily observe the contamination state of the protective glass even during laser processing, and to accurately know the content and extent of the contamination state of the protective glass. It is an object of the present invention to provide a protective glass monitoring device for a laser processing device, which is capable of detecting dirt on the entire surface of the protective glass.

Another object of the present invention is to provide a protective glass monitoring device for a laser processing apparatus that can simultaneously observe the dirty state of the protective glass and the processed state of the processed portion of the workpiece.

[Means to solve the problem]

A first protective glass monitoring device for a laser processing device according to the present invention is configured to perform laser processing by focusing laser light emitted from a laser oscillator with a condensing lens and irradiating it onto a workpiece, In a laser processing device equipped with a protective glass for protecting the condensing lens between the condensing lens and the workpiece, the positional relationship is such that the surface of the protective glass on the workpiece side is the focus position of the condensing lens. Place a reflective mirror to form
It is arranged to provide a device for viewing the protective glass through the condensing lens and using a reflective mirror.

A second protective glass monitoring device for a laser processing apparatus according to the present invention is characterized in that, in the first configuration, a hole is formed at a portion of the reflecting mirror through which the laser beam passes.

A third protective glass monitoring device for a laser processing apparatus according to the present invention has the second configuration in which the device for viewing the protective glass allows the device to view the protective glass and monitors the workpiece through the hole of the reflection mirror. It is characterized by being configured so that the machined surface can be viewed.

A fourth protective glass monitoring device for a laser processing device according to the present invention has the following configuration:
It is characterized in that the reflecting mirror is formed of a convex mirror.

A fifth protective glass monitoring device for a laser processing device according to the present invention has the following configuration:
It is characterized in that the protective glass is monitored during laser processing.

A sixth protective glass monitoring device for a laser processing device according to the present invention has the following configuration:
It has a mechanism that allows the reflective mirror to be taken in and out, and is characterized in that the reflective mirror is taken out during laser processing, and the reflective mirror is installed at a predetermined location and monitored during non-laser processing.

A seventh protective glass monitoring device for a laser processing apparatus according to the present invention is provided with a mirror protection member that protects the reflecting mirror in the second or third configuration, and the mirror protection member is configured to be freely put in and taken out. It is characterized by

A protective glass monitoring device for a laser processing device according to an eighth aspect of the present invention has the configuration of any one of the first to seventh structures.
The device for viewing the protective glass is characterized by comprising a camera and a monitor device.

[Effect]

The protective glass monitoring device for laser processing equipment according to the present invention employs an optical system configuration for observing the protective glass through a condensing lens that condenses laser light and irradiates it onto the workpiece, and observes the protective glass. Preferably, a camera, which is an imaging device, and a monitor device are used as a device for this purpose, and reflective mirrors are arranged in a predetermined arrangement relationship so that the camera can obtain an image of the lower surface of the protective glass. . In practice, the reflective mirror is placed approximately midway between the protective glass and the workpiece.

The reflecting mirror may be a normal mirror, but it is preferably formed into a ring shape with a hole through which the laser beam passes. With such a shape, the reflecting mirror can be maintained at its installation position even when processing is performed using laser light. When monitoring the protective glass with the monitor device, the content and degree of dirt on the protective glass can be observed in the area determined by the reflective mirror, and the machined surface of the workpiece can be observed in the area determined by the hole. can be observed. In particular, such observations can be made during laser processing. Of course, it can also be carried out during non-processing.

According to a configuration in which the protective glass is viewed through a condenser lens using a reflective mirror and a device for viewing the protective glass, it is possible to clearly observe dirt in a considerably wide area on the lower surface of the protective glass using the field of view determined by the reflective mirror. It's now possible. In particular, if the reflecting mirror is formed of a convex mirror, it is possible to see the entire lower surface of the protective glass. In this way, information on dirt, damage, etc. on the protective glass can be accurately obtained.

Furthermore, in order to prevent the reflective mirror itself from getting dirty, a structure that allows it to be taken in and out is adopted, or a shutter member is provided. According to this, a clear image of the protective glass etc. can always be obtained.

〔Example〕

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

FIG. 1 shows a first embodiment of a protective glass monitoring device for a laser processing apparatus according to the present invention. In this figure, 1 indicates a part of the laser processing apparatus, and is a nozzle from which laser light is emitted. A condensing lens 2 for converging laser light onto a predetermined surface of a workpiece is disposed within the nozzle 1, and a protective glass 3 is disposed below the condensing lens 2 in the figure. A hole 1a is formed at the tip of the nozzle 1, and laser light is emitted to the outside from this hole 1a. A workpiece 4 is placed opposite the hole 1a at the tip of the nozzle 1. The protective glass 3 is attached to the nozzle 1 using a slit and an attachment groove, and can be taken in and out at will, and by using this configuration, the protective glass 3 that has become heavily soiled can be replaced.

5 is a laser oscillator, and a laser beam 6 is output from the laser oscillator 5. The laser beam 6 output from the laser oscillator 5 is reflected toward the condenser lens 2 by a reflecting mirror 7 that reflects only the laser beam. The laser beam heading toward the condenser lens 2 is focused by the condenser lens 2, and then passes through the protective glass 3.
, passes through the hole 1a, and is irradiated to a predetermined location on the workpiece 4. The laser beam 6 is set to be focused at the location of the workpiece 4 by the condensing action of the condensing lens 2.

A flat reflecting mirror 8 is disposed on the inner surface of the wall 1b around the hole 1a at the tip of the nozzle 1.

The reflecting mirror 8 has a ring-shaped front surface, and the hole in the center coincides with the hole 1a, and its diameter is a. Further, the placement position of the reflective mirror 8 is set so that the distance between the lower surface of the protective glass 3 and the reflective surface of the reflective mirror 8 is approximately equal to the distance between the reflective surface of the reflective mirror 8 and the surface of the workpiece 4. be done. That is, the reflective mirror 8 is disposed at a substantially intermediate position between the protective glass 3 and the workpiece 4. This arrangement creates a relationship between the protective glass 3 and the condensing lens 2 such that the lower surface of the protective glass 3 is at the focal point of the condensing lens 2.

For such a reflecting mirror 8, the lens 2 of the reflecting mirror 7
An optical camera 9 is placed at a position opposite to the side, and the camera 9
The image reflected on the reflection mirror 8 is captured. The reflecting mirror 7 reflects the laser beam 2 as described above, but transmits the light for imaging. Therefore, the camera 9 can capture an image reflected on the reflection mirror 8 and an image of the surface to be processed that can be seen through the hole 1a. The image information of the reflecting mirror 8 captured by the camera 9 is given to the monitor device 10 and displayed on the screen 10a of the monitor device 10.

FIG. 2 shows an image displayed on the screen 10a of the monitor device 10. In FIG. 2, reference numeral 11 is an image showing the machined surface of the workpiece 4 that can be seen through the hole of the reflecting mirror 8 and the hole 1a at the tip of the nozzle 1. 12 is a reflecting mirror 8
This is an image projected on the screen, which shows the state of the lower surface of the protective glass 3. In this way, with the monitor device 10, the machining state of the machined surface of the workpiece 4 can be observed in the area 11,
The content and degree of dirt on the lower surface of the protective glass 3 in the area 12;
Furthermore, damage etc. can be observed. According to the above configuration, since the camera 9 is configured to take in the image to be monitored from the upper side of the condenser lens 2 in the drawing, the processing state and the protective glass 2 can be monitored by the monitor device 10 during laser processing. It becomes possible to observe the state of contamination. In addition, in the configuration shown in FIG. 1, a mirror having a flat reflective surface and a central hole is used as the reflecting mirror 8, so the central part of the protective glass 3 cannot be seen. A considerably wide area can be seen around the periphery of the glass 3. In addition, in the above-mentioned structure, since the reflective mirror 8 was provided which was set so that the lower surface of the protective glass 3 was in particular the focal position, the image of the lower surface of the protective glass 3 could be clearly seen. If the reflecting mirror 8 is not provided, the condition of the lower surface of the protective glass 3 cannot be clearly seen due to the lens action of the condensing lens 2.

Next, a second embodiment of the present invention will be described based on FIG.

FIG. 2 is a sectional view showing a portion of the nozzle 1.
The same parts as those shown in the figures are given the same reference numerals. In this embodiment, instead of the ring-shaped reflecting mirror 8, a reflecting mirror 18 having a convex reflecting surface is provided. By forming the reflective surface of the reflective mirror 18 in a convex shape in this manner, the range that can be captured by the camera 9, that is, the range of the protective glass 3 that can be seen in the area 12 of the monitor device 10 is expanded. By appropriately forming a convex reflective surface, almost the entire lower surface of the protective glass 3 can be seen. In FIG. 3, numeral 19 indicates the observable range.

FIG. 4 shows a third embodiment of the invention. In the embodiments described above, a configuration was shown in which the protective glass 3 could be observed especially during processing by the laser processing apparatus. This embodiment shows a configuration for observing the protective glass 3 exclusively during times other than laser processing.

The basic configurations of the camera 9, monitor device 10, etc. are the same as in the previous embodiment, so illustration thereof will be omitted.

In this embodiment, a reflecting mirror 2 corresponding to the reflecting mirror 8 is used.
There are 8. The reflective mirror 28 is large and formed into a flat plate shape, has a reflective surface on its upper surface, and can be freely attached using a slit formed in the nozzle 21 and a groove. According to the above configuration, during laser processing, the reflecting mirror 28 is taken out to perform the laser processing, and during non-laser processing, the reflecting mirror 28 is inserted, and the monitor device 10 monitors dirt, etc. on the lower surface of the protective glass 3. Try to observe. In this case, although the processed surface of the workpiece 4 cannot be seen, the entire lower surface of the protective glass 3 can be observed. Also, during laser processing, there is a reflection mirror 28 for observation.
Since these are removed, they will not be contaminated by spatter during processing. Note that 29 is the observation range of the protective glass.

Next, a fourth embodiment of the present invention will be described based on FIGS. 5 and 6. This embodiment is characterized in that a mirror protection member such as a shutter or an aperture for protecting the reflection surface of the reflection mirror 8 is provided in the structure of the first embodiment. The illustrated mirror protection member 13 is a shutter type protection member. Two slits are formed at opposing positions at the tip of the nozzle 1, and from these slits, as shown in FIG. 6, the mirror protection member halves 13A and 13B are separated into two.
configured to insert. Actually mirror protection member 1
Although an opening/closing device for opening and closing 3 is required, this device can be designed arbitrarily, so illustration thereof is omitted. When the mirror protection member halves 13A and 13B are integrated, they partially have the same shape as the mirror in the first embodiment. That is, it has a ring-like shape with a predetermined hole in the center, which covers the reflective surface of the reflective mirror 8, thereby making it possible to prevent the reflective surface from becoming dirty.

Note that in the present invention, a monitor device 1 using a TV system is provided.
Although the configuration is configured to monitor at 0, it is also possible to configure a viewfinder to allow visual observation. In addition to simply displaying images on the monitor device 10, by attaching an image processing device, the image information obtained by the camera 9 can be analyzed through image processing, and the dirt status of the protective glass 3 can be quantitatively or numerically analyzed. It is also possible to configure the system to make a determination based on the following information.

Although various embodiments have been described above, it goes without saying that the embodiments can be combined in any desired manner.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a clear image can be obtained over a wide range of the protective glass,
Therefore, the content and extent of dirt on the lower surface of the protective glass can be clearly observed, and further information on damage can be obtained. When a convex reflective mirror is used, the entire surface of the protective glass can be observed. In particular, according to the present invention, it is possible to observe the state of dirt on the protective glass not only when laser processing is not being performed but also when laser processing is being performed, and it is possible to quickly and easily observe the state of dirt on the protective glass when laser processing is being performed. It is possible to obtain appropriate judgment. With a configuration that uses a ring-shaped reflective mirror, it is possible to obtain information about dirt on the protective glass and the condition of the machined surface of the workpiece with a single monitor, making it extremely efficient to monitor important aspects of processing operations. You can get information. In addition, if the reflecting mirror is made to be freely removable or if a shutter member is provided, the reflecting mirror itself can be prevented from becoming dirty.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a first embodiment of a protective glass monitoring device for a laser processing device according to the present invention, FIG. 2 is a diagram showing an image of a display screen of a monitor device, and FIG. 4 is a sectional view of essential parts showing a third embodiment of the protective glass monitoring device; FIG. 5 is a sectional view of essential parts showing a fourth embodiment of the protective glass monitoring device; FIG. 6 is a front view of the mirror protection member. [Explanation of symbols] 1.21・ 1a・・e 2・・Fist 3・−・・ 4・・ 5・・φ・ 6・・ 7・・1 8.18°9・・Nozzle Tip hole of nozzle Condensing lens Protective glass Workpiece Laser oscillator Laser light reflecting mirror Reflection mirror Camera 10 Monitor device 11 Area showing the processed surface 12 Protective glass Area 13 showing shutter member

Claims (8)

[Claims] (1) A laser beam emitted from a laser oscillator is condensed by a condenser lens and irradiated onto the workpiece to perform laser processing, and the laser beam is condensed between the condenser lens and the workpiece. In a laser processing apparatus equipped with a protective glass for protecting an optical lens, a reflecting mirror is arranged such that a surface of the protective glass on the workpiece side is a focal point of the condensing lens, and A protective glass monitoring device for a laser processing device, comprising a device for viewing the protective glass through an optical lens and using the reflective mirror. (2) The protective glass monitoring device for a laser processing device according to claim 1, wherein the reflective mirror has a hole formed at a location through which the laser beam passes. (3) In the protective glass monitoring device for a laser processing apparatus according to claim 2, the device for viewing the protective glass not only views the protective glass, but also allows the machined surface of the workpiece to be viewed through the hole of the reflective mirror. A protective glass monitoring device for a laser processing device, characterized in that the device is configured to monitor the protective glass of a laser processing device. (4) The protective glass monitoring device for a laser processing device according to any one of claims 1 to 3, wherein the reflective mirror is a convex mirror. (5) The protective glass monitoring device for a laser processing device according to any one of claims 1 to 4, wherein the protective glass is monitored during laser processing. . (6) The protective glass monitoring device for a laser processing device according to any one of claims 1 to 4, further comprising a mechanism that allows the reflective mirror to be taken in and out, and the reflective mirror is taken out during laser processing and is not 1. A protective glass monitoring device for a laser processing device, characterized in that a reflective mirror is installed at a predetermined location for monitoring during laser processing. (7) The protective glass monitoring device for a laser processing apparatus according to claim 2 or 3, wherein a mirror protection member for protecting the reflecting mirror is provided, and the mirror protection member is configured to be freely put in and taken out. Equipment protective glass monitoring device. (8) In the protective glass monitoring device for a laser processing apparatus according to any one of claims 1 to 7, the device for viewing the protective glass is constituted by a camera and a monitor device. Protective glass monitoring device for processing equipment.