JP2006305615A - Aluminum welding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve removal effect of an oxidized film, to prevent welding irregularity caused by dust of an electrode wire, and to suppress puckering even in a high welding current. <P>SOLUTION: The welding equipment for aluminum comprises a welding torch composed of: a tip 9 which is designed to make a shielding gas A flow in a welding direction in a gap, wherein a gap is formed between an electrode wire 2 and a hole by preparing the hole for feeding the electrode wire 2 to a weld zone and by supplying an electric power from a welding power source to the electrode wire 2; an internal nozzle 8 which injects a shielding gas B from the outer periphery of the tip 9; and an external nozzle 7 which injects a shielding gas C from the outer periphery of the internal nozzle 8. The shielding gases A, B are a mixed gas of 50% Ar and 50% He, while the shielding gas C is a gas with 100% Ar. The flow rate of the shielding gas A is set at 0-5 L/min, while that of the shielding gases B, C is set at 25-60 L/min. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aluminum welding apparatus capable of increasing the efficiency of aluminum welding.

A high melting point oxide film (Al ₂ O ₃ ) is formed on the surface of the aluminum material, and this oxide film makes the welding arc unstable during welding of aluminum and causes many defects inside the weld. There's a problem.

  Conventionally, with respect to the above problems, a shield measure has been taken to prevent the entry of outside air by providing a nozzle for blowing an inert gas such as Ar gas or He gas to the welded portion around the electrode wire that is fed to the welded portion. ing.

  For example, Patent Document 1 discloses that the shielding effect and the welding performance are improved by multiplexing the nozzles and changing the gas types and flow rates of the outer nozzle and the inner nozzle.

JP-A-57-390815 (page 2-4, FIGS. 3 and 4)

In the aluminum welding apparatus described in Patent Document 1, the effect of removing the oxide film (Al ₂ O ₃ ) generated on the aluminum surface is not sufficient, and the guide for feeding the electrode wire to the welded portion There exists a problem that the welding nonuniformity by the dust which generate | occur | produces from the electrode wire in the chip | tip which becomes is generated.

  Further, when the welding current is increased in order to increase the penetration depth and width, there is a problem that an unstable phenomenon of welding called puckering occurs when the current exceeds about 350 A.

  The present invention has been made to solve the problems of the conventional aluminum welding apparatus as described above, improves the effect of removing the oxide film formed on the aluminum surface, and welds the electrode wire with dust. An object is to prevent unevenness and to suppress the occurrence of puckering even at a high welding current so that stable aluminum welding can be performed.

The aluminum welding apparatus according to the present invention has a hole for passing an electrode wire through a welded portion, supplies power from a welding power source to the electrode wire, and forms a gap between the electrode wire and the hole. A chip configured to flow the shield gas A at a predetermined flow rate in the direction of the welded portion in the gap,
An internal nozzle for injecting shield gas B at a predetermined flow rate from the outer periphery of the tip to the weld;
A welding torch provided with an external nozzle for injecting a shielding gas C at a predetermined flow rate from the outer periphery of the internal nozzle to the weld;
The shield gas A and shield gas B are mixed gas of Ar gas 50% and He gas 50%,
The shielding gas C is Ar gas 100%,
The flow rate of the shielding gas A exceeds 0 and 5 L / min or less,
The flow rates of the shield gas B and the shield gas C are 25 L / min or more and 60 L / min or less.

  According to the aluminum welding apparatus of the present invention, the effect of removing the oxide film is improved, welding unevenness due to the dust of the electrode wire is prevented, and further, the occurrence of puckering is suppressed even at a high welding current, and stable. Aluminum can be welded.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing the principle of removal of an aluminum oxide film during aluminum welding. As shown in FIG. 1, when a so-called reverse polarity (electrode wire 2 is + and aluminum 3 is-) of the welding power source (DC power source) 1 is applied to the electrode wire 2, + gas ions are generated. Collides with the oxide film 4 on the surface of the aluminum 3 to destroy the oxide film 4 and form the cleaning surface 5 in which the surface of the aluminum 3 is cleaned.

  FIG. 2 is a schematic diagram showing Embodiment 1 of the aluminum welding apparatus according to the present invention, and the welding torch guides the electrode wire 2 fed by the feeding roller 6 and energizes the electrode wire 2. Chip 9, an internal nozzle 8 for injecting shield gas B from the outer periphery of chip 9, and an external nozzle 7 for injecting shield gas C from the outer periphery of internal nozzle 8. A gap is provided to flow in the direction of the part.

  The shield gas A and the shield gas B are mixed gases in which Ar gas and He gas supplied from the Ar gas tank 12 and He gas tank 11 are Ar gas 50% + He gas 50% by a gas mixer, and the shield gas C is Ar gas. The gas is 100% Ar gas supplied from the tank 12.

  The flow rate of shield gas A exceeds 0 and 5 L / min or less, and the flow rates of shield gas B and shield gas C are 25 L / min or more and 60 L / min or less.

  FIG. 3 is a cross-sectional view showing a state in which dust 10 is generated from the electrode wire 2 in the chip 9, and as shown in FIG. 3A, the edge of the chip 9 on the insertion side of the electrode wire 2 and the electrode wire 2 Slid to generate dust 10 and the feeding speed of the electrode wire 2 becomes unstable. As a result, welding may become unstable. However, as shown in FIG. By flowing the shielding gas A through the gap between the electrode wire 2 and the dust wire 10 is pushed out from the gap, the feeding speed of the electrode wire 2 is stabilized.

  The flow rate of the shield gas A is set to exceed 0 in order to make the inside of the gap positive so as not to involve outside air, and is 5 L / min or less so as not to affect the arc generated from the electrode wire 2. To do.

  Further, the flow rates of the shielding gas B and the shielding gas C need to be 25 L / min or more in order to maintain the shielding property. If the flow rates of the shield gas B and the shield gas C are excessively increased, outside air is involved. Therefore, the flow rates of the shield gas B and the shield gas C are set to 60 L / min or less so as not to involve outside air.

  Further, the shield gas A and the shield gas B affect the penetration depth and penetration shape of the weld. According to the experiments by the present inventors, the shielding gas A and the shielding gas B are mixed gas of Ar gas 50% + He gas 50%, so that the puckering phenomenon is suppressed even at a welding current exceeding 350 A. It has been found that welding with a deep mold penetration and a wide penetration can be obtained stably.

  Thus, even if the welding current exceeds 350 A, the bottom-bottom-type penetration can be stably obtained by mixing 50% He gas with the Ar shielding gas, and the mixed shielding gas when the arc is generated. It is assumed that the thermal conductivity is increased and the thermal energy is increased by increasing the speed of movement of the atoms in the shield gas, thereby promoting the cleaning phenomenon and stabilizing and suppressing puckering.

  As described above, according to the aluminum welding apparatus of the first embodiment, the effect of removing the oxide film is improved, welding unevenness due to dust of the electrode wire is prevented, and even at a high welding current exceeding 350 A, Stable aluminum welding with suppressed puckering can be achieved.

  The aluminum welding apparatus according to the present invention can be effectively used for welding thick aluminum members.

It is a schematic diagram which shows the principle of the aluminum oxide film removal at the time of aluminum welding. It is a schematic diagram which shows Embodiment 1 of the welding apparatus of the aluminum which concerns on this invention. FIG. 6 is a cross-sectional view showing a state where dust 10 is generated from the electrode wire 2 in the chip 9.

Explanation of symbols

1 welding power source, 2 electrode wire, 3 aluminum, 4 oxide film,
5 Cleaning surface, 6 Feeding roller, 7 External nozzle, 8 Internal nozzle,
9 chips, 10 dust, 11 He tank, 12 Ar tank,
A, B, C Shield gas.

Claims (1)

It has a hole through which the electrode wire is passed through the welded portion, and power is supplied from the welding power source to the electrode wire, and a gap is formed between the electrode wire and the hole. A tip that allows the shield gas A to flow at a predetermined flow rate in the direction of the weld,
An internal nozzle for injecting shield gas B at a predetermined flow rate from the outer periphery of the tip to the weld;
A welding torch provided with an external nozzle for injecting a shielding gas C at a predetermined flow rate from the outer periphery of the internal nozzle to the weld;
The shield gas A and shield gas B are mixed gas of Ar gas 50% and He gas 50%,
The shielding gas C is Ar gas 100%,
The flow rate of the shielding gas A exceeds 0 and 5 L / min or less,
An aluminum welding apparatus, wherein the flow rate of the shielding gas B and the shielding gas C is 25 L / min or more and 60 L / min or less.

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