JP2002239771A - Yag laser beam torch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a YAG laser beam torch with which a material to be machined is safely machined with the laser beam without bringing the nozzle of the laser torch continuously into contact with the material to be machined. SOLUTION: The emission end part 5 of an optical fiber which emits the YAG laser beam or a visible light beam is provided above an optical system for conversion, a first detection means, which detects the existence/nonexistence of the material W to be machined prior to the commencement of machining by non-contact or contact, and a second detection means, which detects the existence/nonexistence of the material to be machined during the machining by non-contact, are provided at the laser beam torch 1. The YAG laser beam torch is characterized by the fact that the laser torch is provided with a laser beam emission switch with which the YAG laser beam is emitted only when the material to be machined is detected prior to the commencement of the machining with the first detection means, and the machining is continuously performed only when the material to be machined is detected during the machining with the second detection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a YAG laser torch.

[0002]

2. Description of the Related Art For example, (a) Japanese Patent Publication No. 7-24943 and (b) Japanese Patent Application Laid-Open No. 9-57480 disclose a YAG laser torch used for welding or cutting a metal plate.

The former (a) is an emission end of an optical fiber (5) for guiding a laser beam from a laser oscillator (4) to a condenser lens (3) into a holding cylinder (2) having a nozzle (1) at the tip. (6) is provided, wherein the laser oscillator is oscillated only when the tip of the nozzle comes into contact with the workpiece (8).

In the latter (b), a laser head (1) having a condenser lens (5) is provided with an emission end (9) of an optical fiber for guiding laser light from a laser oscillator to the condenser lens. The contact (1
7) is provided so that the oscillation of the laser oscillator can be stopped when the contact and the workpiece (W) are out of contact with each other.

[0005]

In the above-mentioned (a), the YAG laser oscillator oscillates only when the laser torch is brought into contact with the workpiece with the hand switch provided on the holding cylinder turned on. The light is configured to exit from the laser torch.

Accordingly, in (a), the work is performed at the position where the hand switch is pressed, and is mainly used for discontinuous welding such as temporary fixing welding. When used for continuous welding, it is necessary to keep the hand switch turned on and to move the gripping cylinder back and forth while always pressing the tip of the nozzle against the workpiece. In this case, the movement may not be smooth due to the friction between the nozzle and the workpiece.

[0007] Also in the case of (b), the processing is performed in a state where the laser head is always in contact with the workpiece, and similarly, the movement may not be smooth.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a YAG laser torch capable of performing laser processing safely without bringing a nozzle of the laser torch into contact with a workpiece. To provide.

[0009]

As a means for solving the above-mentioned problems, a YAG laser torch according to claim 1 is a YA laser torch.
An optical fiber emitting end capable of emitting G laser light and visible light is provided above the converging optical system, and first detection means capable of non-contact detection or contact detection of the presence or absence of a workpiece before starting processing; A laser torch is provided with a second detection means capable of non-contact detection of the presence or absence of a workpiece during processing, and emits YAG laser light only when the first detection means detects the workpiece before the start of processing. The gist of the invention is that a laser emission switch for enabling the laser torch is provided in the laser torch.

A YAG laser torch according to claim 2 is
2. The YAG laser torch according to claim 1, wherein said first detecting means is for detecting visible light which receives reflected light from said processed material processing portion of visible light emitted from said optical fiber emitting end, which is capable of non-contact detection. An optical fiber is provided, and a visible light detector for detecting the presence or absence of the workpiece through the optical fiber for visible light detection is provided, and the second detecting means detects the YAG laser reflected light from the workpiece processing section. The gist of the invention is to provide an optical fiber for detecting a YAG laser beam for receiving light and an infrared detector for detecting the presence or absence of the workpiece through the optical fiber for detecting a YAG laser beam.

A YAG laser torch according to claim 3 is
3. The YAG laser torch according to claim 2, wherein the first and second detecting means are each a photodiode provided in the laser torch and capable of non-contact detection of light in a visible light region and infrared light. .

A YAG laser torch according to claim 4 is
2. The YAG laser torch according to claim 1, wherein the first detection means capable of detecting the contact is provided with a limit switch for detecting the contact of a workpiece, the second switch being provided on the laser torch.
The gist of the detection means is that a photodiode capable of non-contact detection of infrared light is provided on the laser torch.

[0013] A YAG laser torch according to claim 5 is
The YAG laser torch according to claim 2, wherein the first detecting means capable of non-contact detection is provided with a proximity sensor for detecting the presence of metal at the tip of the laser torch.

A YAG laser torch according to claim 6 is
2. The YAG laser torch according to claim 1, wherein the first detection means capable of detecting the contact is provided with a limit switch for detecting the contact of a workpiece, the second switch being provided on the laser torch.
The gist of the detection means is to provide a proximity sensor for detecting the presence of metal at the tip of the laser torch.

[0015]

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

FIG. 1 shows a first embodiment of a laser torch for a YAG laser according to the present invention. As shown in FIG. 1, an emission end 5 of an optical coaxial cable 3 having a plurality of optical fibers is appropriately fixed inside a holding tube 2 of a laser torch 1 shown generally.

At the center of the optical axis 7 at the above-mentioned emission end portion 5, a first YAG laser beam and a first
In order to detect reflected light of visible light from the processing portion on both sides of the optical axis center 7, return light (reflected light) of the YAG laser from the second optical fiber 11 and the processing portion is disposed. 3) Optical fiber 1 for detecting
3 are arranged.

A condensing optical system 15 composed of a plurality of lenses or the like for condensing the laser light LB emitted from the first optical fiber 9 is provided below the emission end 5 of the optical coaxial cable 3. It is provided. A protective window 17 is provided below the light-collecting optical system 15 to block dust from the processing part from reaching the light-collecting optical system 15.

A nozzle cone 1 is provided below the above-mentioned gripping cylinder 2.
9 is attached, and a nozzle tip 21 is detachably attached to the lower end of the nozzle cone 19.

The other end of the second optical fiber 11 is connected to a visible light detector (not shown), and similarly, the other end of the third optical fiber 13 is an infrared detector for detecting a YAG laser beam. (Not shown).

A laser emission switch 23 and a confirmation switch (not shown) for turning on or off the oscillation of a YAG laser oscillator (not shown) are provided on the side surface of the holding cylinder 2.

The laser emission switch 23 is connected to the YA
A shutter (not shown) for opening and closing the optical path of the laser beam in the G laser oscillator, and only when there is a detection signal from the visible light detector or the infrared detector for detecting the YAG laser light, and The shutter is opened only while the laser emission switch 23 is being pressed. That is, the laser emission switch 23 is provided only when the workpiece W is detected.

The above-described confirmation switch (not shown) turns on or off the oscillation of the YAG laser oscillator, and emits visible light from the first optical fiber 9 when the oscillation of the YAG laser oscillator is on. It is provided in.

The laser torch 1 is provided with a shield gas flow passage 25 communicating with the nozzle cone 19. The operation of the laser torch 1 of the above-described first embodiment in which the shield gas flow passage 25 is connected to a shield gas supply source (not shown) via a pipe (not shown) will be described below.

(1) The confirmation switch (not shown) is turned on, and the nozzle tip 21 at the tip of the laser torch 1 is brought closer to the workpiece W (FIG. 3A).

(2) When the workpiece W is present, the visible light emitted from the emission end portion 5 is condensed and irradiated on the workpiece W via the condensing optical system 15 and at the same time the workpiece W Reflected by W. A part of the reflected light is transmitted to the visible light detector via the condensing optical system 15 and the second optical fiber 11, and the presence or absence of the workpiece W is determined by the visible light detector (FIG. 3A). ).

(3) When the presence of the workpiece W is detected by the reflected light from the workpiece W, the laser emission switch 23 is pressed, and the YAG from the first optical fiber 9 is pressed.
The laser beam can be emitted, and the workpiece W can be welded.

(4) During the welding process, the YAG laser beam applied to the workpiece W is reflected, and a part of the reflected light is transmitted as return light to the infrared detector via the third optical fiber 13. Then, the determination of the presence or absence of the workpiece W is continuously performed (FIG. 3B).

In the above (3), when there is no reflected light from the workpiece W, it is determined that there is no workpiece W, and the YAG laser beam is not emitted even if the laser emission switch 23 is pressed (see the above description). (The shutter does not open.)

According to the laser torch 1 of the first embodiment as described above, the laser torch 1 is
It is not necessary to move the laser torch 1 and the workpiece W continuously because the laser torch 1 and the workpiece W do not become unstable, and stable continuous welding is possible.

The presence / absence of the workpiece W is detected in a non-contact manner.
Is pressed, the YAG laser beam is not emitted, and the detection of the presence or absence of the workpiece W is continued during the processing. If the workpiece W is not detected, YA
Since it is provided so as to block the emission of the G laser light, dangerous laser light is not irradiated to the operator and the surrounding people at the start of the processing and during the processing, and the processing is safe.

FIG. 4 shows a second embodiment of the laser torch for a YAG laser according to the present invention.

The laser torch 51 of the second embodiment
Has a photodiode 53 capable of detecting light in the visible light region and infrared light generated in a processed portion during welding processing, instead of the third optical fiber 13 for detecting return light (reflected light) of the YAG laser. It is provided outside the holding cylinder 2 and is provided so that the determination of the presence or absence of the workpiece W during the processing is continuously performed based on the light detection signal from the photodiode 53. Since the other configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The operation of the laser torch 51 according to the second embodiment will be described below.

(1) A confirmation switch (not shown) is turned on, and the nozzle tip 21 at the tip of the laser torch 51 is brought closer to the workpiece W (FIG. 5A).

(2) When the workpiece W is present, the visible light emitted from the emission end 5 is condensed on the workpiece W via the condensing optical system 15 and at the same time the workpiece W Is reflected by A part of the reflected light is transmitted to the visible light detector via the second optical fiber 11, and the presence or absence of the workpiece W is determined by the visible light detector (FIG. 5A).

(3) When the presence of the workpiece W is detected by the reflected light from the workpiece W, the laser emission switch 23 is pressed, and the YAG from the first optical fiber 9 is pressed.
The laser beam can be emitted, and the workpiece W can be welded.

(4) During the welding process, the presence or absence of the workpiece W is continuously determined by detecting the light emission (light and infrared in the visible light region) generated in the welded portion (FIG. 5B). ).

In the above (3), when there is no reflected light from the workpiece W, it is determined that the workpiece W does not exist, and even if the laser emission switch 23 is pressed, the YAG laser light is not emitted. This is the same as the first embodiment.

According to the laser torch 1 of the above-described second embodiment, the same effect as that of the first embodiment can be obtained.

FIG. 6 shows a third embodiment of the laser torch for a YAG laser according to the present invention.

As shown in FIG. 6, a laser torch 61 according to the third embodiment is a non-contact detection device using visible light according to the second embodiment as a means for detecting the presence or absence of a workpiece W before processing is started. In place of the means, a limit switch 63 is provided which is activated by pressing the tip of the laser torch 61 into contact with the workpiece W, and the detection of the presence or absence of the workpiece W during welding is performed according to the second embodiment. Similarly to the above, a photodiode 53 capable of detecting light in a visible light region and infrared light generated in a processed portion at the time of welding is provided outside the gripping cylinder 2.

The operation mechanism of the above-described limit switch 63 will be described below.

Referring to FIG. 6, a first cylindrical body 65 extending downward is fixed to the lower part of the gripping cylinder 2. The coupling mechanism between the gripping cylinder 2 and the first cylindrical body 65 includes, for example, a female screw provided at a lower portion of the gripping cylinder 2 in the embodiment, and a male screw provided at an upper portion of the first cylindrical body 65 is screwed to the female screw. It is provided so as to be connected and fixed.

The inner diameter of the nozzle cone 19 is slidably fitted in the outer diameter of the first cylindrical body 65 in the axial direction.
A second cylinder 67 extending upward from 9 is connected and fixed by “screw”.

The upper part of the above-mentioned second cylindrical body 67 is
It is slidably fitted to the lower outer diameter part. This gripping cylinder 2
The outer diameter portion is provided with a locking portion 69 which comes into contact with the upper portion of the second cylindrical body 67 and restricts the upward movement of the second cylindrical body 67.

The second cylinder 67 is provided with an engaging portion 71 that engages with the limit switch 63 and extends to the side of the gripping cylinder 2. A coil spring 73 for pressing the nozzle cone 19 downward (downward in FIG. 6) is provided inside the first cylindrical body 65.

The same parts as those in the first or second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the above configuration, when the nozzle tip 21 at the tip of the laser torch 61 abuts on the workpiece W, for example, and when the nozzle cone 19 is pressed upward against the coil spring 73, the nozzle Cone 1
The second cylinder 67 integrally connected to the second cylinder 9 moves upward, and the limit switch 63 is pressed by the engaging portion 71 of the second cylinder 67 to operate the limit switch 63.

Next, the operation of the laser torch 61 of the third embodiment during welding processing will be described.

(1) The confirmation switch (not shown) is turned on, and the laser torch 61 is held in hand and brought into contact with the workpiece W. When the laser torch 61 is further pressed against the workpiece W, the limit switch 63 is activated and the YAG
The laser beam can be emitted (FIG. 7A).

(2) Next, the laser emission switch 23 is pressed to start welding of the workpiece W. During the welding process, the presence or absence of the workpiece W is continuously determined by detecting the light emission (light in the visible light region and infrared light) generated in the welded portion by the photodiode 53 (FIG. 7B).

After the welding process is started (after the YAG laser is emitted), even if the limit switch 63 is turned off, the YA
The emission of the G laser is provided to continue. In other words, the YAG laser is provided so that the emission of the YAG laser continues even when the tip of the laser torch 61 and the workpiece W are separated from each other.

According to the laser torch 61 having the above configuration, even if the nozzle is separated from the workpiece W during the welding process, the process can be continued if the light emission generated in the welded portion continues. After the start of the welding process (after the emission of the YAG laser), the emission of the YAG laser light is stopped if there is no light emission in the welded portion.

FIG. 8 shows a fourth embodiment of the laser torch for a YAG laser according to the present invention.

As shown in FIG. 8, the laser torch 81 of the fourth embodiment is a means for detecting the workpiece W before the start of machining, and is provided around the nozzle tip 21 of the first embodiment as a capacitance type. The workpiece W is made of metal, and the proximity sensor 8
3 is provided so that the YAG laser beam can be emitted only when it is within the detection range of No. 3.

The means for detecting the workpiece W during processing is as follows:
This is the same as the first embodiment. Further, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

Next, the laser torch 8 of the fourth embodiment will be described.
1 will be described.

(1) The confirmation switch (not shown) is turned on, and the nozzle tip 21 at the tip of the laser torch 81 is brought closer to the workpiece W (FIG. 9A).

(2) The proximity sensor 83 uses the laser emission switch 23 only when the workpiece W is metal and the workpiece W is within the detection range of the proximity sensor 83.
Pressing allows emission of YAG laser light.

(3) During welding, the presence or absence of the workpiece W is continuously determined by detecting light emission (light in the visible light region and infrared light) generated in the welded portion (FIG. 9B). ).

According to the laser torch 81 having the above structure, the presence or absence of the workpiece W before the start of welding is determined by determining whether the workpiece is metallic or non-metallic, and the workpiece W whose presence is detected is within the detection range. YAG laser light can be emitted only when it is positioned, and light emission generated in the welded portion is detected during welding, so that even if the nozzle is separated from the workpiece W during welding, If the light emission generated in the welded portion continues, the processing can be continued.

Next, a fifth embodiment of the laser torch for a YAG laser according to the present invention will be described with reference to FIG.

As shown in FIG. 10, the laser torch 91 of the fifth embodiment is used as a means for detecting the presence or absence of a workpiece (metal or non-metal) W before the start of processing, similarly to the third embodiment. The tip of the laser torch 91 is processed W
Limit switch 6 which is activated by pressing against
3 and a proximity sensor 83 such as a capacitance type is provided around the nozzle tip 21 in the same manner as in the fourth embodiment, and a metal or non-metal workpiece W exists.
The workpiece W is located within the detection range of the proximity sensor 83.
Is provided so that the YAG laser beam can be emitted only when there is.

The same parts as those in the first, third and fourth embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

The operation of the laser torch 91 of the fifth embodiment will be described below.

(1) The confirmation switch (not shown) is turned on, and the nozzle tip 21 at the tip of the laser torch 91 is brought closer to the workpiece W (FIG. 11A).

(2) When the proximity sensor 83 at the tip of the laser torch 81 reaches the detection range and the workpiece W is metal, it detects that the workpiece W is present. If the workpiece W is non-metallic, it detects that the workpiece W is absent.

(3) When the tip of the laser torch 61 contacts the metal workpiece W and is further pressed to operate the limit switch 63, it is detected that the workpiece W is present (FIG. 11B).

(4) When the presence of the workpiece W is detected in the above (3), the YAG laser light can be emitted by pressing the laser emission switch 23.

(5) Even if the contact between the tip of the laser torch 91 and the workpiece W is separated during the welding process, if the workpiece W is within the detection range of the proximity sensor 83, the emission of the YAG laser beam is continued. So that continuous processing is possible.

According to the laser torch 91 having the above-described configuration, it is determined whether the material of the workpiece W is metal or non-metal before starting the welding process, and then whether the YAG laser beam can be emitted is determined by operating the limit switch 63. Therefore, the detection of the workpiece W can be performed reliably.

Further, the processing is started after the detection of the workpiece W, and even if the tip of the laser torch 91 is separated from the workpiece W during the processing, the workpiece W is detected by the proximity sensor 83.
Is within the detection range, the emission of the YAG laser light is provided so that continuous processing is possible.

[0074]

According to the first to third or fifth aspects of the present invention, the YAG laser beam is emitted only after the presence of the workpiece is confirmed by the first detecting means provided on the laser torch by non-contact detection. Since the laser beam can be emitted, the laser beam is not radiated to the operator and the surrounding humans, so that it is safe.

Since the presence or absence of the workpiece during processing is also detected by the second detecting means in a non-contact manner, it is not necessary to continuously move the laser torch in contact with the workpiece during welding. In addition, the movement of the laser torch does not become unstable due to friction with the workpiece. Therefore, continuous welding can be stably performed.

When the laser torch is detached from the workpiece during processing, the emission of the YAG laser light can be stopped by using the second detecting means.

According to the invention of claim 4 or claim 6,
The detection means for the presence or absence of the workpiece W before the start of processing temporarily detects the contact only at the time of detection. After the detection is confirmed, the emission of the YAG laser continues even if the contact with the workpiece W is released. It is provided to do. Therefore, claims 1 to
The same effect as the third or fifth aspect of the invention can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of a YAG laser torch according to the present invention.

FIG. 2 is a view as seen from an arrow A in FIG.

FIG. 3 is a use state diagram of the YAG laser torch of the first embodiment. (A) Before processing, (b) During processing.

FIG. 4 is an explanatory view of a second embodiment of the YAG laser torch according to the present invention.

FIG. 5 is a use state diagram of a YAG laser torch according to a second embodiment. (A) Before processing, (b) During processing.

FIG. 6 is an explanatory view of a third embodiment of the YAG laser torch according to the present invention.

FIG. 7 is a diagram illustrating a use state of a YAG laser torch according to a third embodiment. (A) Before processing, (b) During processing.

FIG. 8 is an explanatory view of a fourth embodiment of the YAG laser torch according to the present invention.

FIG. 9 is a diagram showing a use state of a YAG laser torch according to a fourth embodiment. (A) Before processing, (b) During processing.

FIG. 10 is an explanatory view of a fifth embodiment of the YAG laser torch according to the present invention.

FIG. 11 is a view showing a usage state of a YAG laser torch according to a fifth embodiment. (A) Before processing, (b) During processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 51, 61, 81, 91 Laser torch 2 Grasping cylinder 3 Optical coaxial cable 5 Emission end part 7 Optical axis center 9 First optical fiber 11 Second optical fiber 13 Third optical fiber 15 Condensing optical system 17 Protection window 19 Nozzle cone 21 Nozzle tip 23 Laser emission switch 25 Shield gas flow passage 53 Photodiode 63 Limit switch 65 First cylinder 67 Second cylinder 69 Engagement part 71 Engagement part 73 Coil spring 83 Proximity sensor LB Laser light

Claims (6)

[Claims] An optical fiber emitting end capable of emitting a YAG laser beam and a visible light is provided above a converging optical system, and the presence or absence of a workpiece before starting machining can be detected in a non-contact or contact manner. A laser torch is provided with a first detecting means and a second detecting means capable of non-contact detection of the presence or absence of a workpiece during processing, and the YAG is provided only when the first detecting means detects the workpiece before starting the processing. A YAG laser torch characterized in that a laser emission switch for enabling emission of laser light is provided on the laser torch. 2. The YAG laser torch according to claim 1, wherein the first detection means capable of non-contact detection receives a reflected light of the visible light emitted from the optical fiber emission end from the workpiece processing portion. And a visible light detector for detecting the presence or absence of the workpiece through the visible light detecting optical fiber is provided, and the second detection unit is configured to detect the presence or absence of the workpiece from the workpiece processing unit. YA
A YAG laser torch comprising: a YAG laser light detecting optical fiber for receiving a G laser reflected light; and an infrared detector for detecting the presence or absence of the workpiece through the YAG laser light detecting optical fiber. 3. The YAG laser torch according to claim 2, wherein each of the first and second detecting means is a photodiode provided on the laser torch and capable of non-contact detection of light in a visible light region and infrared light. YAG
Laser torch. 4. The YAG laser torch according to claim 1, wherein the first detecting means capable of detecting the contact is provided with a limit switch for detecting the contact of the workpiece, and the second detecting means detects infrared rays. A YAG laser torch, wherein a photodiode capable of detecting contact is provided on the laser torch. 5. The YAG laser torch according to claim 2, wherein said first detection means capable of non-contact detection is provided with a proximity sensor for detecting the presence of metal at the tip of the laser torch. 6. The YAG laser torch according to claim 1, wherein said first detecting means capable of detecting contact is provided with a limit switch for detecting contact of a workpiece, and said second detecting means is provided with metal. A YAG laser torch characterized in that a proximity sensor for detecting a pressure is provided at the tip of the laser torch.