JPH0569165A - Tig welding method in combination with laser beam - Google Patents

Abstract

PURPOSE:To provide the TIG welding method in combination with a laser beam where feed space of filler metal is secured and the occurrence of inside defects of a weld zone, etc., are prevented. CONSTITUTION:The laser beam welding side is constituted of an optical fiber 3 to transmit the laser beam 2, a condenser lens 5 and a hollow part of a hollow electrode 1 arranged on the same axis in front thereof. The TIG welding side is constituted of the hollow electrode 1 and an electrode fitting body 16. The optical fiber is protected by a fiber protecting tube 6 and fitted to lens housing 4, an irradiation part is formed of the optical fiber, the condenser lens and the lens housing and the optical fiber is inserted into the electrode fitting body, by which two welding means are formed into one system on the same axis. The electrode fitting body receives an electric current carried through a feeder 9 from a welding power source 7 which is passed to the hollow electrode and a TIG arc 22 is generated between the electrode 1 and welding base metal 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam combined TIG welding method used for welding various welded structures.

[0002]

2. Description of the Related Art TIG welding combined with laser light (hereinafter referred to as TIG welding)
The laser beam 2 is referred to as “laser welding”, and the laser beam 2 is focused through a condenser lens 5 and irradiated onto a portion (molten pool) 24 of the welding base material 23 whose surface is melted by TIG welding (FIG. 5). Alternatively, a method is used in which a molten pool 24 is formed in the welding base material 23 by using the focused laser beam 2 that has passed through the focusing lens 5, and the TIG arc 22 is applied to the molten pool 24. (FIG. 6) In the figure, 8 is a gas shield box for performing after-sealing, 20 _B is the shielding gas, and 21 is TI.
The shield cup of G and 25 show the welding directions, respectively.

[0003]

A feature of the conventional TIG laser welding method is that it has a wider bead width of TIG welding than laser welding and has a deeper penetration of laser welding than TIG welding. It is being adopted as a method for improving the welding efficiency in joint welding and the like. However, this method has a problem in that it is difficult to secure a space for supplying a filler material such as a welding wire if a space for the optical path of the laser beam and a space for the TIG torch is secured.

Further, while laser welding has a peculiar defect in which porosity and the like are present in the penetration tip, in TIG welding, the tip of the electrode is tapered in consideration of the arc directivity, so that a large current is produced. It was also difficult to improve the welding efficiency because there was a defect that the molten pool was disturbed by the excessive arc force accompanying the above and the internal defects were likely to occur. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laser light combined TIG welding method that secures a space for feeding the filler material and prevents the occurrence of internal defects in the welded portion.

[0005]

Therefore, in order to solve this problem, the present invention provides a welding method in which a TIG arc and a laser beam are used in combination, and the arc is formed between a hollow electrode for TIG welding. Is proposed to form a molten pool in the base material and irradiate a laser beam on the surface of the molten pool through the hollow portion of the hollow electrode.

[0006]

[Function] While the TIG arc and the laser light are generated coaxially, a space for feeding the filler material is secured, while
Internal defects that occur at high current and high output can also be prevented in a wide range of welding conditions by controlling a lens protective gas such as an inert gas that is the same as or different from the shielding gas.

[0007]

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings. In the description of the embodiments, the same members as the above-mentioned conventional members are designated by the same reference numerals, and duplicated description will be omitted.

FIG. 1 shows the entire structure of the present invention in cross section, and FIG. 2 is an enlarged cross sectional view of the main part of the present invention.
FIG. 3 shows the shape of the hollow electrode 1 used when a large current is used in plan view and semi-cut longitudinal section, and FIG. 4 shows the shape of the hollow electrode 1 for high speed welding in plan view and semi-cut vertical section. It is shown.

In this embodiment, as shown in FIG. 2, the laser welding side is provided with an optical fiber 3 for transmitting the laser beam 2, a condenser lens 5 for condensing the laser beam 2 emitted from the optical fiber 3, and in front of it. It is composed of the hollow portion 1a of the hollow electrode 1 arranged coaxially. On the other hand, the TIG welding side has a hollow electrode 1 and an electrode mounting body 1 to which the hollow electrode 1 is mounted.
6 and 6.

The optical fiber 3 is wholly protected by a fiber protection tube 6 and is attached to the lens housing 4 by a mounting screw. Fiber fixing metal fitting 2 on the injection side tip
Then, the lens housing 4 is fixed by 5 and is inserted and fixed at one end of the lens housing 4 to which the condenser lens 5 is attached. As a result, an irradiation section composed of the optical fiber 3, the condenser lens 5 and the lens housing 4 is formed, and is inserted into the electrode mounting body 16 to which the hollow electrode 1 is mounted. As a result, the two welding means are integrated into one system on the same axis. Further, the electrode mounting body 16 serves as a path for receiving a current supplied from the welding power source 7 through the power supply line 9 and reaching the hollow electrode 1 to generate the TIG arc 22 between the electrode 1 and the welding base material 23. The power supply line 9 is fixed to the electrode mounting body 16 with a mounting screw 10.

More specifically, the electrode mounting body 16 including the laser light irradiation portion composed of the optical fiber 3, the condenser lens 5 and the lens housing 4 has a tapered tip portion and a screw provided on the upper portion thereof. By the body 11
Inserted and tightened. The main body 11 is kept airtight by an O-ring 12 and has a cooling mechanism having a cooling water supply port and a discharge port 15. The electrode mounting body 16 and the lens housing 4 are cooled with cooling water 19. Further, the lens housing 4 is provided on the upper portion of the main body 11 by the electrode mounting body 1.
It is fixed by the body mounting screw 18 with the screw portion of 6.

At the bottom of the main body 11, a shield box 8 having a shield gas supply port 15 is provided with a shield gas 20 _A.
The shield mechanism to which the sintered alloy plate 17 is attached is fixed by screws in order to make the liquid flow into a narrow stream and improve the shield effect. The laser beam 2 is radiated to the welding base material 23 using these, and the hollow electrode 1
The TIG arc 22 is generated at the electrode mounting body 16
By controlling the lens gas 20 supplied through the lens gas supply hole 14 provided in the, stable welding with high welding efficiency is enabled, and the application range is ensured by securing a space for feeding a welding material such as a welding wire. I saw the improvement of.
In addition, the main body 11, the fiber protection tube 3, the body mounting screw 1
8. The protective tube mounting screw 26 is made of a material in consideration of insulation.

In the present embodiment, the focusing process of the laser beam 2 is performed through the hollow portion 1a of the hollow electrode 1 and the TIG arc 22 is generated in the welding base material 23 to generate the focused laser beam 2.
By irradiating with and establishing TIG laser welding on the same axis, it was possible to secure a space for feeding a filler material such as a welding wire. In addition, by controlling the lens protection gas 20 such as an inert gas of the same kind or different kind as the shield gas 20 _A using the hollow electrode 1, the internal defects generated at the time of large current and high output can be controlled in a wide range of welding conditions. Can be prevented by.

In the present embodiment, the hollow electrode 1 is used as the electrode for the TIG to secure the space for feeding the filler material such as welding wire, which has been difficult in the conventional TIG laser welding method. A condenser lens 5 and an optical fiber 3 for transmitting the laser light 2 are disposed coaxially above the hollow portion 1a so as to provide an optical path in the focusing process of the laser light 2, and two systems of TIG welding and laser welding are provided. The problem was solved by using a single coaxial welding system.

The occurrence of an internal defect caused by an excessive arc force due to a large current of TIG welding occurs in the focusing optical path of the laser light 2 in the hollow portion 1a of the hollow electrode 1 (from the condenser lens 5 to the tip of the hollow electrode). First, the condenser gas 5 side is sealed with the lens gas 20 mainly used for protecting the condenser lens, and the lens gas 20 is opened to the hollow portion 1a of the hollow electrode 1, or the lens gas 20 or
An arc 22 generated at the tip of the hollow electrode 1 is caused by flowing a different kind of inert gas and controlling it.
Control the spread of and prevent this with a proper arc force. By controlling the lens gas 20 to have a pulse-like intensity, the molten pool 24 is agitated, and internal defects such as porosity at the penetration tip portion peculiar to laser welding are floated and diffused to drastically reduce the occurrence. ..

On the other hand, in order to improve the welding efficiency by increasing the welding speed, so-called arc wandering in which the anode point of TIG welding becomes unstable and the arc 22 is disturbed can be stabilized by laser plasma. But,
In addition to this, the tip of the hollow electrode 1 is obliquely cut (shown in FIG. 4) to concentrate the arc 22 at the tip to prevent arc wandering. With the above-mentioned means, it is possible to secure a space for feeding a filler material such as a welding wire, and perform stable welding with sound and high welding efficiency.

[0017]

According to the present invention, a space for feeding a filler material such as a welding wire in TIG laser welding can be secured by arranging two welding means, laser welding and TIG welding, coaxially. A hollow electrode is used as the electrode for TIG welding, and the TIG arc can control the lens gas to make the arc force appropriate and prevent the occurrence of internal defects due to a large current. Also, by pulsing the lens gas, the molten pool is agitated to raise and diffuse defects such as porosity that occur at the bottom of the welded portion of laser welding, improve soundness, and stabilize by speeding up the shape of the hollow electrode tip. The effect of being able to be achieved is obtained by tilting.

[Brief description of drawings]

FIG. 1 is a side view showing an entire first embodiment of a welding method according to the present invention.

FIG. 2 is a cross-sectional view showing a welding torch portion of the first embodiment.

FIG. 3 is a plan view and a half-cut vertical sectional view showing a hollow electrode of the first embodiment.

FIG. 4 is a plan view and a half-cut vertical sectional view showing a hollow electrode according to a second embodiment.

FIG. 5 is an explanatory diagram showing an example of a conventional welding method.

FIG. 6 is an explanatory diagram showing an example of a conventional welding method.

[Explanation of symbols]

1 Hollow Electrode (Electrode) 1a Hollow Part 2 Laser Light 3 Optical Fiber 4 Lens Housing 5 Condenser Lens 6 Fiber Protective Tube 7 Welding Power Supply 8 Shield Box 9 Power Supply Line 10 Mounting Screw 11 Main Body 12 O-ring 13 Cooling Water Port (Supply / Discharge) 14 Lens gas supply hole 15 Shield gas supply port 16 Electrode mounting body 17 Sintered alloy plate 18 Body mounting screw 19 Cooling water 20 Lens gas 20 _A Shield gas 20 _B After shield gas 21 Shield cup 22 TIG arc 23 Welding base metal 24 Molten pool 25 Welding direction

Claims (1)

[Claims] 1. A welding method using TIG arc and laser light in combination, wherein an arc is generated between a hollow electrode for TIG welding to form a molten pool in a base metal,
A laser beam combined TIG welding method, characterized in that the surface of the molten pool is irradiated with laser light through the hollow portion of the hollow electrode.