JPH09216083A - Laser beam machining head and laser beam machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily feed a welding wire in a laser beam welding even in case of providing a three-dimensional shape and executing the laser beam welding for a part of complicated shape. SOLUTION: A laser beam L is introduced to a ring-shaped converging lens optical system 140 in which a hole is formed in a center part, and a welding wire 111 is fed to the hole in the center part of the converging lens optical system 140 to converge the laser beam L by the converging lens optical system 140 and melt the welding wire 111.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a laser processing head and a laser processing method. More specifically, the present invention relates to a laser processing head for irradiating a welding wire with a laser beam and melting the welding wire and a laser processing method therefor, and is also applied to laser cladding or three-dimensional modeling with metal.

[0002]

2. Description of the Related Art Since laser light has a very high directivity and a large energy, it can be used for precision welding, cutting, drilling, surface modification, etc. by focusing on a small point. ing. In this case, pulse wave laser light (PW) or continuous wave laser light (CW) is used according to the difference in the material of the work and the processing method. In general, pulse wave laser light has a short duration, so it is suitable for drilling small holes and spot welding without affecting the surroundings. Suitable for processing such as welding.

A YAG laser oscillator, which is a type of solid-state laser oscillator, is a YAG (yttrium, aluminum, garnet) doped with Nd as a laser single crystal.
A crystal is used, and a laser beam having a wavelength of 1.064 μm is output as a pulse wave laser beam or a continuous wave laser beam. Since the YAG laser light is an infrared laser light having a wavelength of 1.064 μm, it can be transmitted by an optical fiber. As a result, in the welding device using the YAG laser oscillator, the laser light can be routed by the optical fiber, and the degree of freedom in design and arrangement is great.

When laser welding is performed by such a laser welding apparatus, it is possible to perform welding with a deep penetration depth in a narrow welding range. This is because the laser light has a very strong condensing property, and the laser light functions as a powerful concentrated heat source having an extremely high energy density.

In the laser welding, when the groove interval is relatively wide, the welding wire is fed to the beam irradiation point to melt the welding wire to form a molten pool.
The wire feeding direction was performed by inserting a welding wire from the front in the traveling direction.

On the other hand, in conventional laser cutting, metal powder is fed from a fixed angle in one direction above the optical axis of the laser beam, or it is formed into a film beforehand by thermal spraying or the like, and this is formed by the laser beam. A method of remelting, and a method of fixing a metal powder with a polymer solvent and then melting with a laser beam have been adopted.

[0007]

In the above-mentioned conventional laser welding apparatus, when performing welding of a complicated shape, the traveling direction is frequently changed. Therefore, the welding wire feeding direction is also continuous accordingly. Therefore, there is a problem that the handling of the welding wire is complicated. Furthermore, a processing method has been developed in which the laser beam is passed to the same location multiple times and the welding beads are piled up to build up the surface and form a three-dimensional shape. The traveling direction has to be continuously changed, which causes the same inconvenience as described above.

On the other hand, in the conventional apparatus for performing the cladding while feeding the metal powder, since the metal powder is fed from a constant direction, the cladding direction changes with respect to a complicated shape. It becomes difficult to stably supply the metal powder of No. 3 to the molten pool, and it is difficult to obtain a stable clad shape.

Further, in the conventional size for fixing metal powder with a polymer solvent, a device for spraying the solvent is required. Further, in this case, a device for applying a paste-like metal powder mixed with a solvent to the cladding target portion is required.

The present invention has been made in view of the above-mentioned prior art, and the welding wire can be easily fed and the laser can be easily fed in the laser welding of a complicated portion and in the laser processing for forming a three-dimensional shape. An object of the present invention is to provide a laser processing head and a laser processing method capable of always forming a stable clad shape in cladding.

[0011]

The structure of the present invention that achieves the above object has the following features.

1) The laser light is guided to a ring-shaped condenser lens optical system having a hole formed in the center thereof, and the laser light is condensed by the condenser lens optical system, and at the same time, the center of the condenser lens optical system. Melting this welding wire by feeding it into the hole in the section.

2) The laser light is guided to a ring-shaped condenser lens optical system having a hole formed in the center thereof, and the laser light is condensed by the condenser lens optical system, and the center portion of the condenser lens optical system. Melting the metal powder by feeding the metal powder through the holes in the.

3) In 1) or 2), the condensing lens protection means is provided on the condensing lens optical system on the side where the laser light is condensed.

4) Melting the welding wire or the metal powder to form a three-dimensional shape by using the laser processing head described in 1) or 2).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In one embodiment of the present invention, a welding wire is arranged in the center of a hollow condenser lens optical system, and the welding wire and the optical axis of laser light are coaxial with each other.
Laser welding can be performed while irradiating the welding wire with condensing laser light with a hollow condensing lens optical system. It is also possible to melt the welding wire and form a three-dimensional shape.

In a laser processing head according to another embodiment of the present invention, a laser beam is condensed by a ring-shaped condenser lens optical system having a hole formed in a central portion thereof to be guided to a cladding portion, and It is configured to melt the metal powder fed through the hole at the center of the condenser lens system. As a result, a constant amount of metal powder is always supplied to the beam optical axis even if the cladding direction changes.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. A laser processing head 100 according to an embodiment of the present invention is shown in FIG. In this embodiment, the welding wire 111 is arranged inside the cylindrical lens holder 110, and the condenser lens optical system 140 is arranged outside the welding wire 111.

That is, at the top of the lens holder 110,
A welding wire supply device 150, in which the welding wire 111 is wound and stored, is attached.
The welding wire 111 fed from 0 descends the lens holder 110 and is fed from the tip (lower end) of the lens holder 110 toward the base material 50. On the outer peripheral surface of the lens holder 110, a reflecting film made of gold is applied, and a plurality of lenses 141 to 145 and a protective glass 146 are mounted as a condenser lens optical system 140.

The lenses 141 to 145 each have a hole formed in the center thereof, are fitted on the outer peripheral surface of the lens holder 110, and are arranged side by side in the axial direction of the lens holder 110. Further, the protective glass 146 is used for the lenses 141 to 14
It is fitted in the lens holder 110 at a position closer to the front end than 5.

A total reflection mirror 132 is obliquely attached to the lens holder 110 directly above the condenser lens optical system 140. This total reflection mirror 13
2 is for refracting the laser light L generated by the YAG laser device 120 and guided by the optical fiber 131, and guiding it to the condenser lens optical system 140.

Therefore, the lenses 141 to 145 of the condensing lens optical system 140 condense the laser light L reflected by the total reflection mirror 132 and incident on the tip of the welding wire 111 to melt it. The surface portion of the base material 50 is laser-welded.

In the laser processing head 100 having such a structure, the welding wire 111 is fed through the inner circumference of the lens holder 110 and the lens holder 11
The laser light L is condensed by the condenser lens optical system 140 arranged on the outer peripheral surface of 0, and the welding wire 111 is melted, so that the base material 50 can be laser-welded.

Moreover, since the optical axis of the laser light L and the welding wire 111 are coaxially arranged, the welding wire 111 is accurately fed to the converging point of the laser light L. 111 melts reliably to form a symmetrical molten pool, which enables highly accurate laser welding. In particular, in the past, since the welding wire 111 was fed from the front in the traveling direction of the laser light L, the handling of the welding wire 111 was complicated in the case of laser welding with a complicated shape, but this embodiment Then, since the welding wire supply device 150 and the condenser lens optical system 140 have an integrated structure, the handling of the welding wire 111 becomes extremely easy.

Further, the same effect can be obtained when a three-dimensional shape is formed on the surface by welding bead by passing the laser beam to the same place plural times.
It is extremely easy to handle the welding wire 111.

Since the outer peripheral surface of the lens holder 110 is coated with a gold coat, the laser light L is not absorbed by the lens holder 110, and the lens holder 110 does not generate heat by the laser light L. .

Further, the protective glass 146 is replaced by the lens 141.
Since it is located on the tip side of the lenses 141 to 145, the dirt due to welding may adhere to the protective glass 146 but not to the lenses 141 to 145.
~ 145 can be prevented from becoming dirty. When the protective glass 146 becomes dirty, the protective glass 146
And the protection glass 146 is replaced.

Furthermore, in the example of FIG. 1, the YAG laser device is adopted as the laser device, but other types of laser devices may be used. When another type of laser device is used, a reflecting mirror or the like is used instead of the optical fiber 131 so that the laser light L is guided.

Another embodiment of the present invention will be described with reference to FIG. As shown in the figure, this laser processing head 201
Is the metal powder 2 inside the cylindrical lens holder 202.
03, and the condenser lens optical system 204 is arranged on the outside thereof. A metal powder supply device 205 containing a metal powder 203 is connected to the upper part of the lens holder 202, and the metal powder 203 fed from the metal powder supply device 205 descends in the lens holder 202 to provide a tip of the lens holder 202. It is fed from the section toward the base material 206.

On the outer peripheral surface of the lens holder 202, a reflecting film of gold coating is applied and the condenser lens optical system 2
As a reference numeral 04, a plurality of lenses 207 to 211 and one protective glass 212 are attached. Lens 207-2
11 has a hole formed in the center thereof, is fitted on the outer peripheral surface of the lens holder 202, and is arranged side by side in the axial direction of the lens holder 202. Also, the protective glass 2
12 is fitted in the lens holder 202.

A total reflection mirror 213 is obliquely attached to the lens holder 202 directly above the condenser lens optical system 204. The total reflection mirror 213 is generated by the YAG laser device 214, and the optical fiber 215 is used.
The laser light L guided by is refracted and guided to the condenser lens optical system 204.

Therefore, the lenses 207 to 211 of the condensing lens optical system 204 condense the laser light 216 reflected by the total reflection mirror 213 and incident on the feeding portion of the metal powder 203 on the base material 206. The metal powder 203 is melted and laser-sprayed on the surface of the base material 206.

In the laser processing head 201, the metal powder 203 is fed and shielded by the metal powder supply gas 216 through the inner periphery of the lens holder 202, and the condenser lens optical system 204 arranged on the outer peripheral surface of the lens holder 202. This enables laser spraying of the base material 206. Moreover, since the metal powder 203 is accurately fed to the converging point of the laser light L, the metal powder 203 is surely melted to form a symmetrical molten pool, which enables highly accurate laser spraying. Becomes In particular, conventionally, since the metal powder 203 was fed from the outer peripheral side of the laser light L, the handling of the laser processing head 201 was complicated in the case of laser spraying with a complicated shape, but in the present embodiment, Since the metal powder supply device 205 and the condenser lens optical system 204 have an integrated structure, the handling of the metal powder 203 becomes extremely easy.

Further, when the laser beam L is passed to the same place a plurality of times, a similar effect can be obtained even when a three-dimensional shape in which the surface is raised by the thermal spray beads is formed, and the metal powder 203 can be easily handled. It's extremely easy.

Since the outer peripheral surface of the lens holder 202 is coated with a gold-coated reflective film, the laser light L is not absorbed by the lens holder 202, and the lens holder 202 generates heat due to the laser light L. Absent.

Further, the protective glass 212 is attached to the lens 207.
Since it is located on the tip side of the lenses 207 to 211, the dirt caused by thermal spraying may adhere to the protective glass 212, but does not adhere to the lenses 207 to 211 and does not adhere to the lenses 207.
~ 211 can be prevented from becoming dirty.

When the protective glass 212 becomes dirty, the protective glass 212 is cleaned or replaced.

In this embodiment, as a laser device, YAG is used.
Although the laser device 214 is employed, other types of laser devices may be used. When another type of laser device is used, a reflecting mirror or the like is used instead of the optical fiber 215 to guide the laser light L.

[0039]

As described above in detail, according to the present invention, by arranging the optical axis of the laser beam and the welding wire coaxially, the welding wire can be accurately applied to the converging point of the laser beam. It was possible to form a symmetrical molten pool by supplying the laser and to perform highly accurate laser welding. Furthermore, when welding complicated shapes or when forming a three-dimensional shape, the handling of the welding wire becomes extremely easy.

Further, by using this processing head, it is possible to stably feed the metal powder to the beam irradiation section. Furthermore, even if the cladding direction changes, a constant amount of metal powder is always fed to the beam optical axis, so not only can a stable clad shape be formed, but the metal powder feeding unit and laser optical system can also be used. By being integrated,
The processing head can be made compact.

Thus, it becomes possible to freely select the cladding direction, which is indispensable for forming a three-dimensional complex shape, and to approach the narrow portion by making the processing head compact.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a laser processing head according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a laser processing head according to another embodiment of the present invention.

[Explanation of symbols]

 50 base material 100 laser processing head 110 lens holder 111 welding wire 120 YAG laser device 131 optical fiber 132 total reflection mirror 140 condensing lens optical system 141 to 145 lens 146 protective glass 150 welding wire supply device 201 laser processing head 202 lens holder 203 Metal powder 204 Condenser lens optical system 205 Metal powder supply device 206 Base material 207 to 211 Lens 212 Protective glass 213 Total reflection mirror 214 YAG laser device 215 Optical fiber 216 Metal powder supply gas

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Akabane 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard

Claims (4)

[Claims] 1. A laser light is guided to a ring-shaped condenser lens optical system having a hole formed in the center thereof, and the laser light is condensed by the condenser lens optical system, and at the same time, the center of the condenser lens optical system. A laser processing head characterized in that the welding wire is melted by feeding the welding wire into the hole of the portion. 2. A laser light is guided to a ring-shaped condenser lens optical system having a hole formed in the central portion thereof, the laser light is condensed by the condenser lens optical system, and the central portion of the condenser lens optical system. A laser processing head characterized in that the metal powder is melted by feeding the metal powder through the holes of the. 3. The laser according to claim 1, further comprising means for protecting the condenser lens on the side of the condenser lens optical system for condensing the laser light. Processing head. 4. By using the laser processing head according to any one of [Claim 1] or [Claim 2], the welding wire or the metal powder is melted to form a three-dimensional shape. Characterized laser processing method.