JPH067984A - Laser beam welding method - Google Patents

Abstract

PURPOSE:To restrain the generation of plasma flames and to prevent the oxidation of the molten periphery by ejecting argon gas to the vicinity of a part irradiated with laser beam and helium gas to its periphery. CONSTITUTION:Argon gas is introduced into a 1st nozzle 17 and elected to the part 16 irradiated with laser beam 14 at a comparatively high speed. At the same time, helium gas is introduced into a 2nd nozzle 18 and ejected at a comparably low speed so that the part 16 irradiated with laser beam 14 is enclosed. The argon gas ejected to the irradiated part 16 generates plasma flames having a size suitable for weld and helium gas prevents the molten metal and the welded bead 19 from being oxidized at a part 16 to be irradiated. Though members 13a, 13b to be welded are of high laser beam reflecting material(Al, Cu, etc.), they can be welded easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam welding method for welding a highly reflective laser beam material such as aluminum with a laser beam such as a carbon dioxide gas laser.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view showing a structure of a gas spraying portion of an apparatus to which a conventional laser beam welding method of this kind disclosed in Japanese Patent Laid-Open No. 54-41247 is applied. In the figure, 1a and 1b are a pair of members to be welded but 2 is a laser beam that irradiates the welded portions of these members to be welded 1a and 1b, and 4 is a laser beam 2 that follows the welding process, The helium gas and the argon gas introduced from the helium gas introduction pipe 5 and the argon gas introduction pipe 6, respectively, in the gas blowing unit moving along the irradiation unit 3 of the laser beam 2 are shown from the blow-out port 7 to arrows 8 and 9, respectively. So as to spray the irradiation unit 3. Reference numeral 10 is an argon gas introduction pipe different from the argon gas introduction pipe 6,
The argon gas sprayed on the welding bead 12 is introduced as shown by the arrow 11.

In the gas spraying section of the conventional apparatus constructed as described above, the helium gas sprayed from the outlet 7 to the irradiation section 3 as shown by the arrow 8 is a metal vapor generated from the molten metal of the irradiation section 3. The generation of a plasma flame that absorbs the laser beam is suppressed by blowing away the laser beam, the argon gas indicated by the arrow 9 prevents the molten metal in the irradiation section 3 from being oxidized, and the argon gas indicated by the arrow 11 indicates that the welding is performed. The beads 12 are prevented from being oxidized.

[0004]

Since the conventional laser beam welding method is performed as described above, the irradiation part 3 is blown away with the metal vapor generated from the molten metal to generate a plasma flame which absorbs the laser beam. Helium gas is sprayed to suppress the welding, but the welded members 1a and 1b are made of aluminum, aluminum alloy,
In the case of high laser beam reflective materials such as copper and copper alloys,
In order to perform stable welding, it is necessary to generate an appropriate plasma flame.

However, since the helium gas is blown and the generation of the plasma flame is suppressed for the above reason, the welded portion is disturbed and stable welding becomes difficult. On the other hand, however, if argon gas that is easily turned into plasma is blown to generate a plasma flame, the plasma flame becomes too large and most of the laser beam is absorbed, making it difficult to form a molten pool and making welding difficult. There were problems such as.

The present invention has been made in order to solve the above problems, and provides a laser beam welding method capable of performing stable welding even when a member to be welded is a laser beam highly reflective material. The purpose is.

[0007]

[Means for Solving the Problems] Claim 1 according to the present invention
In the laser beam welding method, the welding is performed by spraying argon gas in the vicinity of the laser beam irradiation portion of the member to be welded and helium gas around the laser beam from substantially obliquely above.

Further, in the laser beam welding method according to a second aspect of the present invention, nitrogen gas is blown in the vicinity of the laser beam irradiation portion of the member to be welded and nitrogen gas or helium gas is blown around it in a substantially obliquely upward direction. While welding.

[0009]

In the laser beam welding method according to the first aspect of the present invention, since argon gas is blown in the vicinity of the laser beam irradiation portion, an appropriate plasma flame is generated to form a molten pool, and helium gas is surrounded by the molten pool. Since it is sprayed, the generation of plasma flame is suppressed and the oxidation around the molten pool is prevented.

In the laser beam welding method according to the second aspect of the present invention, since nitrogen gas is blown in the vicinity of the laser beam irradiation portion, a suitable plasma flame is generated to form a molten pool, and nitrogen gas or nitrogen gas is provided around it. Since helium gas is blown, generation of plasma flame is suppressed and oxidation around the molten pool is prevented.

[0011]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show the structure of a gas spraying part of an apparatus to which a laser beam welding method according to a first embodiment of the present invention is applied. FIG. 1A is a perspective view and FIG. In the figure, 13a and 13b are a pair of members to be welded which are abutted against each other, and are made of a laser beam highly reflective material such as aluminum, aluminum alloy, copper or copper alloy. 1
Reference numeral 4 denotes a laser beam irradiated to the welded portions of the members 13a and 13b to be welded, and 15 denotes a gas spraying portion that follows the laser beam 14 in accordance with the progress of welding and moves along the irradiation portion 16 of the laser beam 14. is there.

The gas spraying portion 15 is a member to be welded 13
The first cylindrical shape is arranged so as to be inclined upward by a predetermined angle with respect to a and 13b, has an inner diameter of 1 to 5 mm, and has an argon gas introduced from the introduction port 17a therein.
No. 17 and the first nozzle 17 are arranged concentrically with and surround the first nozzle 17 and have an inner diameter of 10
It is formed with a cylindrical second nozzle 18 which is formed to be about 20 mm and into which helium gas is introduced from the introduction port 18a, and the tip of the first nozzle 17 is opened so as to face the irradiation section 16. However, the peripheral edge of the tip of the second nozzle 18 is 3
It is arranged so as to face the surfaces of the members to be welded 13a and 13b with a gap of ˜5 mm and cover the irradiation portion 16.

Next, the operation of the gas spraying section of the apparatus to which the laser beam welding method according to the first embodiment having the above-mentioned structure is applied will be described. First, the argon gas introduced into the first nozzle 17 from the introduction port 17a is blown toward the irradiation portion 16 of the laser beam 14 at a relatively high speed, as indicated by an arrow A in the figure. On the other hand, at the same time, the helium gas introduced into the second nozzle 18 from the introduction port 18a is blown at a relatively low speed so as to surround the irradiation portion 16 of the laser beam 14 as shown by an arrow B in the figure.

The argon gas blown to the irradiation section 16 generates a plasma flame of a size suitable for welding, and the helium gas blown around the plasma flame is melted in the irradiation section 16. Since the metal and the welding bead 19 are prevented from being oxidized, the member to be welded 1
Even if 3a and 13b are made of a highly reflective laser beam material, welding can be performed easily.

Example 2. Needless to say, the same effect can be obtained even when the welding is performed while supplying the filler wire 20 from the filler wire nozzle 21 as shown in FIG.

Embodiment 3. Further, in each of the above embodiments, the first nozzle 17 and the second nozzle 18 are fixedly integrated, but the first nozzle 17 and the second nozzle 18 are combined.
If the distance between the tip opening and the irradiation unit 16 is adjusted within a range of about 7 to 30 mm, the size of the plasma frame to be generated is adjusted to the welding scale or the like. Therefore, it becomes possible to perform finer control. Both nozzles 17 and 18 are less likely to absorb the laser beam 14, and a material such as copper or copper alloy having a high thermal conductivity is suitable.

Embodiment 4. Further, in each of the above-mentioned embodiments, argon gas is added in the vicinity of the laser beam irradiation portion of the member to be welded,
Welding is performed by spraying helium gas from diagonally above the periphery, but welding is performed while spraying nitrogen gas near the laser beam irradiation part of the welded member and helium gas or nitrogen gas around it. Even if it does so, it goes without saying that the nitrogen gas improves the absorption rate of the laser beam by a chemical reaction with the member to be welded, as well as the same effects as those of the above-mentioned respective examples, and because it is cheap, the laser beam is cheap at a low cost. It becomes possible to perform welding, and it has an excellent economical effect.

[0018]

As described above, according to the present invention, the welding is performed while spraying the argon gas or the nitrogen gas in the vicinity of the laser beam irradiating portion of the member to be welded and the helium gas in the vicinity thereof from substantially obliquely above. Because I chose
It is possible to provide a laser beam welding method capable of stable welding even when the member to be welded is a laser beam highly reflective material.

[Brief description of drawings]

FIG. 1 shows a structure of a gas spraying part of an apparatus to which a laser beam welding method according to a first embodiment of the present invention is applied, in which (A) is a perspective view and (B) is a sectional view.

FIG. 2 is a sectional view showing a configuration of a gas spraying section of an apparatus to which a laser beam welding method according to a second embodiment of the present invention is applied.

FIG. 3 is a cross-sectional view showing a configuration of a gas spraying section of an apparatus to which a conventional laser beam welding method is applied.

[Explanation of symbols]

 13a, 13b Members to be welded 14 Laser beam 15 Gas spraying portion 16 Irradiation portion 17 First nozzle 18 Second nozzle 19 Weld bead

Claims (2)

[Claims] 1. A laser beam welding method for irradiating and welding a member to be welded made of a highly reflective laser beam with a laser beam, wherein argon gas is provided in the vicinity of the laser beam irradiation portion of the member to be welded, and its periphery. The laser beam welding method is characterized in that the helium gas is welded while being sprayed from substantially diagonally above. 2. A laser beam welding method for irradiating a member to be welded, which is made of a highly reflective laser beam, with a laser beam to perform welding, wherein nitrogen gas is provided in the vicinity of the laser beam irradiation portion of the member to be welded, and its periphery. A laser beam welding method, characterized in that the welding is performed while spraying nitrogen gas or helium gas from substantially diagonally above.