JPH09122962A - Laser beam machining head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defective machining, and to prevent an expensive condensing lens from being damaged. SOLUTION: In a laser beam working head 1, the laser beam LB is condensed by a condensing lens 5 provided in a machining head body 3, and a work W to be machined is irradiated with the condensed laser beam LB irradiated from a laser beam nozzle 7 provided on the tip of the machining head body 3, a protective glass 9 is provided in the machining head body 3 between the condensing lens 5 and the laser beam nozzle 7 in a horizontal direction approximately orthogonal to the optical axis C of the laser beam LB. A damage detecting sensor 25 to detect that the protective glass 9 is damaged is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing head used for welding a workpiece, for example.

[0002]

2. Description of the Related Art Conventionally, for example, Y for welding a work
As shown in FIG. 4, the AG laser processing head 101 includes a processing head body 103, and inside the processing head body 103, a condenser lens 105 that condenses the laser beam LB is provided. ing. Moreover, a laser nozzle 107 is detachably provided at the tip of the processing head body 103.

A transparent protective glass 109 for protecting the condenser lens 105 is provided inside the processing head main body 103 in the vicinity of the lower side of the condenser lens 105 to form a laser beam L.
It is fixedly provided in a horizontal state orthogonal to the optical axis C of B. An air blowing nozzle device 111 is provided at a part of the processing head 103 below the protective glass 109 (right part in FIG. 4). From an air blowing nozzle 113 provided at the tip of the air blowing nozzle device 111. Air is blown out.

With the above configuration, the laser beam LB oscillated from the laser oscillator (not shown) is processed by the processing head body 1.
After being condensed by the condenser lens 105 provided inside 03, it is irradiated toward the work W from the laser nozzle 107 through the protective glass 109, and the work W is laser-welded.

[0005]

By the way, when the above-mentioned conventional YAG laser processing head 101 is used for welding, the spatter returns to the inside of the laser nozzle 107 and damages the condenser lens 105. The expensive condensing lens 105 is protected by a protective glass 109 provided near the lower part. Moreover, the air blowing nozzle 11 of the air blowing nozzle device 111 is arranged so that spatter does not adhere to the protective glass 109 so much.
Air is blowing out from 3.

However, if the laser welding process is continued for a long time, spatter will adhere to the protective glass 109. Spatter cannot be removed from the protective glass 109 on the spot and must be replaced. Therefore, the protective glass 109 is treated as a consumable item.

However, in practice, if the grasshopper 109 adheres to the protective glass 109 to some extent, a defective processing occurs and the protective glass 109 breaks. The operator notices something abnormal after the processing failure occurs, or checks the state of the protective glass 109 when starting the processing.

Further, if the operator continues processing without noticing it, the expensive condenser lens 105 may be damaged.

An object of the present invention is to provide a laser processing head that does not cause processing defects and does not damage an expensive condenser lens.

[0010]

In order to achieve the above object, a laser processing head of the present invention according to claim 1 condenses a laser beam with a condensing lens provided inside the processing head body, and condenses the laser beam. A laser processing head that irradiates a workpiece to be processed with a laser beam provided from a laser nozzle provided at the tip of the processing head main body, inside the processing head main body between the condenser lens and the laser nozzle. The protective glass is provided in a horizontal state substantially orthogonal to the optical axis of the laser beam, and a damage detection sensor for detecting damage to the protective glass is provided.

Therefore, after the laser beam oscillated by the laser oscillator is condensed by the condenser lens provided in the processing head body, it passes through the protective glass and is directed from the laser nozzle provided at the tip of the processing head body to the workpiece. And is irradiated and the work is laser-welded, for example.

When laser welding is performed on the work, for example, spatters generated return to the inside of the laser nozzle and damage the condenser lens, so that the work is protected by the protective glass. The damage of the protective glass is detected by the damage detection sensor, so that the condensing lens is protected without being damaged and the processing defect does not occur.

According to a second aspect of the laser machining head of the present invention, in the laser machining head according to the first aspect, the damage detection sensor detects a pressure in the machining head body between the condenser lens and the protective glass. It is a pressure sensor that operates.

Therefore, the damage to the protective glass is detected by the pressure sensor detecting the pressure in the processing head body between the condenser lens and the protective glass, so that the condenser lens is protected and processed. It doesn't cause a defect.

A laser processing head according to a third aspect of the present invention is the laser processing head according to the first aspect, wherein the damage detection sensor detects the presence or absence of protective glass in the processing head body on the side surface of the protective glass. It is characterized by being a sensor.

Therefore, the damage of the protective glass is detected by detecting the presence / absence of the protective glass by the presence / absence detection sensor provided in the main body of the processing head, so that the condenser lens is protected and the defective processing is not caused. I'm done.

[0017]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a YAG laser processing head 1 as a laser processing head includes a processing head body 3. Inside the processing head body 3, a condenser lens 5 for condensing the laser beam LB is provided. Moreover, a laser nozzle 7 is detachably provided at the tip of the processing head body 3.

A transparent protective glass 9 is fixedly provided in the horizontal state orthogonal to the optical axis C of the laser beam LB inside the processing head body 3 near the lower part of the condenser lens 5. An air blowing nozzle device 11 is provided in a part of the processing head 3 below the protective glass 9 (right part in FIG. 1), and the air blowing nozzle 1 provided at the tip of the air blowing nozzle device 11.
Air is blown out from 3.

With the above structure, the laser beam LB oscillated from the laser oscillator (not shown) is processed by the processing head body 3.
After being condensed by the condensing lens 5 provided inside, the workpiece W is irradiated with the laser beam from the laser nozzle 7 through the protective glass 9, and the workpiece W is laser-welded.

When the work W is laser-welded, spatter is generated, and the spatter returns to the inside of the laser nozzle 7 and tries to adhere to the protective glass 9, but the protective glass 9
Is fixed in a horizontal state orthogonal to the optical axis C of the laser beam LB, and the air blowing nozzle device 11
The air is blown out from the air blowing nozzle 13 so that it does not adhere to the protective glass 9.

However, if laser welding is performed for a long time,
Sputters may adhere to the protective glass 9, and eventually the protective glass 9 may be damaged and damage the condenser lens 5. Therefore, in order to prevent damage to the protective glass 9, a pressure detection sensor 1 as a damage detection sensor that detects the internal pressure between the condenser lens 5 and the protective glass 9.
5 is connected to the right side wall of the processing head body 3 in FIG. 1 via a joint 17 and a pipe 19. Moreover, an air source (not shown) is connected to the pressure sensor 15 via the pipe 21.

With the above structure, when air is supplied from an air source (not shown) to the inside between the condenser lens 5 and the protective glass 9 through the pipes 21, 19 and the joint 17, the internal air pressure is measured by the pressure sensor 15. Is constantly detected by. Therefore, since the pressure sensor 15 can accurately and easily detect that the constantly detected air pressure falls below a certain value, it is possible to detect that the protective glass 9 is damaged due to this drop in air pressure. You can Thus, the condenser lens 5 can be protected without damaging the condenser lens 5. Further, it is possible to perform processing without causing processing defects. Assist gas may be used instead of air.

FIGS. 2 and 3 show another example which replaces FIG. 2 and 3, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the overlapping parts will be omitted.

In FIG. 2, on the right side wall of the processing head body 3 on which the protective glass 9 is provided, for example, a micro switch 23 as a presence / absence detecting sensor for detecting the presence / absence of the protective glass 9 as a damage detecting sensor is provided. Has been.

With the above structure, if the micro switch 23 is ON, for example, it is always detected that the protective glass 9 is present. Therefore, if the micro switch 23 is OFF, it is possible to detect the absence of the protective glass 9. You can
Therefore, it is possible to accurately and easily detect that the protective glass 9 is damaged. Consequently, the condenser lens 5 can be protected without damaging the condenser lens. Further, it is possible to perform processing without causing processing defects.

In FIG. 3, a photoelectric sensor 25 as a presence / absence detecting sensor for detecting the presence / absence of the protective glass 9 is provided on the upper right side of the processing head main body 3 provided with the protective glass 9 and is protected. A reflection plate 27 is provided on the lower left side of the processing head body 3 on which the glass 9 is provided.

With the above structure, if the protective glass 9 is present, the light from the photoelectric sensor 25 passes through the protective glass 9 and is received by the reflecting plate 27, and the returning light is again received by the photoelectric sensor 25. If it is lost or damaged, the detection level of the return light returning to the photoelectric sensor 25 rises, so that the damage to the protective glass 9 can be accurately and easily detected. Consequently, the condenser lens 5 can be protected without damaging the condenser lens 5. Further, it is possible to perform processing without causing processing defects.

The present invention is not limited to the above-described embodiment, but can be implemented in other modes by making appropriate changes. In FIG. 3, a light receiving device may be provided instead of the reflection plate 27. Further, any sensor other than the photoelectric switch 25 may be used as long as it changes when light passes through the protective glass 9 and when light does not pass therethrough.

[0030]

As can be understood from the examples of the above-described embodiments, according to the inventions of claims 1, 2 and 3, for example, a pressure sensor and a presence / absence detection sensor are provided as damage detection sensors in the machining head body. Since the damage to the protective glass can be accurately and easily detected, the condenser lens can be protected without being damaged, and processing can be performed without causing processing defects.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a laser processing head according to an example of an embodiment for carrying out the present invention.

FIG. 2 is a front sectional view of a laser processing head showing another example of the present invention.

FIG. 3 is a front sectional view of a laser processing head showing another example of the present invention.

FIG. 4 is a front sectional view of a conventional laser processing head.

[Explanation of symbols]

 1 YAG laser processing head (laser processing head) 3 Processing head body 5 Condensing lens 7 Laser nozzle 9 Protective glass 15 Pressure sensor (damage detection sensor) 23 Micro sensor (damage detection sensor) 25 Photoelectric sensor (damage detection sensor) LB laser beam

Claims (3)

[Claims] 1. A laser beam is condensed by a condenser lens provided inside the machining head body, and the condensed laser beam is directed from a laser nozzle provided at the tip of the machining head body to a workpiece to be machined. A laser processing head for irradiating the protective glass is provided inside the processing head body between the condenser lens and the laser nozzle in a horizontal state orthogonal to the optical axis of the laser beam. A laser processing head comprising a damage detection sensor for detecting damage to a laser. 2. The laser processing head according to claim 1, wherein the damage detection sensor is a pressure sensor that detects a pressure inside the processing head body between the condenser lens and the protective glass. 3. The damage detection sensor is a presence / absence detection sensor for detecting the presence / absence of protective glass on a processing head body on a side surface of the protective glass.
The laser processing head described.