JPH106009A - Shield gas welding equipment that also serves as a heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch between a shielding gas and a heating gas so that welding and distortion removal by welding can be performed by the same shielding gas welding apparatus 1 and 2, and the shielding gas welding is also used as a heating apparatus. Provide equipment. SOLUTION: In a shield gas welding apparatus 1 or 2 for performing welding while supplying a shield gas supplied from a shield gas supply source 14 from a tip of a welding torch 10 to a welding portion, a heating gas supply source 15 and a heating gas supply source are provided. Gas supply source 1
5. A shielding gas welding apparatus which also serves as a heating apparatus including supply gas switching devices 13, 4 to 6 for switching the heating gas to the shielding gas and supplying the same to the welding torch 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielding gas welding device which also serves as a heating device, and more particularly to a method for switching between a shielding gas and a heating gas so that the same shielding gas welding device performs welding and distortion removal by welding. The present invention relates to a shielding gas welding device which also serves as a heating device.

[0002]

2. Description of the Related Art In conventional shield gas welding, a method for correcting distortion generated in a welded product due to welding heat will be described with reference to FIGS. In FIG. 4, the electric welding torch 50 is mounted on a mounting bracket 51, and a mounting portion 51a of the mounting bracket 51 is mounted on the tip of an arm 52a of a welding robot 52 shown in FIG. The shield gas supply section 50a of the electric welding torch 50 is connected to a shield gas cylinder 54 using an inert gas such as carbon dioxide gas or argon gas via an opening / closing cock 53 to constitute a shield gas welding device.

[0003] By using the shield gas welding apparatus, two boom brackets 57 are provided on the upper surface of a frame body 56 constituting a turning frame 55 of a hydraulic excavator.
FIG. An appropriate amount of shielding gas adjusted by the on-off valve 53 connected to the shielding gas cylinder 54 is supplied to the electric welding torch 50 via the shielding gas supply part 50a of the electric welding torch 50.
When the K portion of the revolving frame 55 is electrically welded in a state where the molten metal is supplied, the molten metal in the welded portion is covered with the shielding gas, so that the oxidation of the molten metal is prevented and the welding quality is improved.

In such electric welding, since a welded product is thermally deformed by a large amount of welding heat, the welding leg length is kept as short as possible to perform multi-layer welding, or a low heat source by argon gas welding is used to heat the welded product. Deformation is suppressed, but this method has a limit in terms of securing welding strength when it comes to a welded product having a thick plate structure such as a construction machine part. Therefore, as shown by a chain line in FIG. 6A, when a reverse strain corresponding to the thermal deformation of the welded product is given to the welded product in advance by a welded product fixing jig (not shown), the welded product becomes M , M, a method of correcting the thermal deformation of a welded product having a regular shape as shown by a solid line due to thermal deformation.

[0005]

However, in the welding operation, the cost of the jig for fixing the welded product increases, especially when the welded product has a thick plate structure, and the amount of reverse strain given to the welded product in advance is not stable. There were problems such as the inability to completely remove distortion.

[0006] The present invention has been made in view of the above problems, and by switching the shielding gas supplied to the shielding gas welding apparatus to a heating gas after welding is completed,
It is an object of the present invention to provide a shield gas welding device that can also be used as a heating device and that can correct welding and thermal distortion due to welding by the same shield gas welding device.

[0007]

In order to achieve the above object, a first invention of a shield gas welding apparatus which also serves as a heating apparatus according to the present invention is supplied from a shield gas supply source. In a shielding gas welding apparatus that performs welding while supplying a shielding gas from a welding torch tip to a welding portion, a heating gas supply source, and a heating gas of the heating gas supply source are switched to the shielding gas to the welding torch. And a supply gas switching device for supplying.

According to the first aspect of the present invention, when welding is performed while the shield gas supplied from the shield gas supply source by the supply gas switching device is supplied from the tip of the welding torch to the weld portion during the shield gas welding, Since the molten metal is covered by the shielding gas, the oxidation of the molten metal is prevented, and the welding quality is improved. After the welding is completed, the shielding gas supplied to the welding torch at the time of welding is switched to a heating gas by a supply gas switching device, and the heat distortion generated in the welded product by the flame of the heating gas burning at the tip of the welding torch is reduced. By heating a required portion of the welded product that can be effectively removed and applying reverse strain, the thermal distortion generated in the welded product can be reliably removed.

According to a second aspect of the present invention, in the first aspect, the welding torch is an electric welding torch and heats an arc between a welding rod and a welded product. It is characterized in that it is a means for igniting utility gas.

According to the second aspect of the invention, when thermal distortion generated in the welded article after the completion of welding is removed by the combustion heat of the heating gas, it is not necessary to separately provide an ignition means for the heating gas, so that the apparatus is simplified. Be transformed into

A third invention of a shield gas welding apparatus which also serves as a heating apparatus according to the present invention is characterized in that in the first and second inventions, the welding torch is driven by a welding robot.

According to the third aspect of the present invention, when the thermal distortion generated in the welded article after the welding is completed is removed by the combustion heat of the heating gas, the welding torch is driven by the welding robot.
By accurately heating a required portion that can effectively remove the thermal distortion generated in the welded product, the dimensional accuracy of the welded product can be significantly improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a shield gas welding apparatus which also serves as a heating apparatus according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a view showing a first embodiment of a shielding gas welding apparatus which also serves as a heating apparatus according to the present invention. An electric welding torch 10 is mounted on a mounting bracket 11.
The mounting portion 11a of the mounting bracket 11 is mounted on the tip of the arm 52a of the welding robot 52 shown in FIG. A gas supply unit 10a of the electric welding torch 10 is provided with a shield gas cylinder 14 using an inert gas such as carbon dioxide gas or argon gas, a propane gas, a butane gas, an acetylene gas, or the like, via an on-off valve 12 and a supply gas switching valve 13. The shield gas welding device 1 is connected to a combustion gas cylinder 15 using an active gas and an oxygen cylinder 16. The solenoids 12 a and 13 a of the on-off valve 12 and the supply gas switching valve 13 are controlled by a controller 18 that inputs a command of a switching switch 17.

Using the shielding gas welding apparatus 1,
A welding operation for attaching the two boom brackets 19 to the upper surface of the frame main body 21 constituting the turning frame 20 of the hydraulic excavator will be described with reference to FIG. When the opening operation of the on-off valve 12 and the connection of the shield gas to the supply gas switching valve 13 are commanded by the changeover switch 17, the controller 18 outputs to the solenoids 12 a and 13 a, the on-off valve 12 is at the position a, and the supply gas switching valve 13 is Switch to position a. Therefore, the shielding gas of the shielding gas cylinder 14 is supplied to the electric welding torch 10 via the supply gas switching valve 13 and the opening / closing valve 12 via the gas supply section 10a of the electric welding torch 10. In this state, when the electric welding of the P portion of the revolving frame 20 is performed by the electric welding torch 10, the molten metal in the welded portion is covered with the shielding gas, so that the oxidation of the molten metal is prevented and the welding quality is improved.

In such electric welding, a large amount of welding heat causes the revolving frame 20 to be thermally deformed in a direction indicated by an arrow Q from a state indicated by a chain line in FIG.

After completion of welding, when the opening and closing of the on-off valve 12 and the connection of the combustion gas to the supply gas switching valve 13 are commanded by the change-over switch 17, the controller 18 outputs to the solenoids 12a and 13a, and the on-off valve 12
In the position, the supply gas switching valve 13 is switched between the position b and the position c according to a command of the changeover switch 17. Therefore, the combustion gas of the combustion gas cylinder 15 and the oxygen gas cylinder 1
The oxygen of No. 6 is supplied to the electric welding torch 10 via the supply gas switching valve 13 and the on-off valve 12 via the gas supply unit 10 a of the electric welding torch 10 at a ratio according to the command of the changeover switch 17. . In this state, the electric welding torch 1
When an arc is generated between a welding wire (not shown) and the turning frame 20, the combustion gas is ignited by the arc heat and a flame is generated at the tip of the electric welding torch 10.

As shown in FIG. 2D, when the R portion of the revolving frame 20 is heated by the flame at the tip of the electric welding torch 10, the revolving frame 20 changes from the state shown by the dashed line to the arrow S.
The thermal deformation of the revolving frame 20 is corrected in the reverse direction in the direction shown in FIG. When the work for correcting the thermal deformation of the revolving frame 20 is completed, the changeover switch 17 causes the solenoid 12a of the on-off valve 12 to open and close the on-off valve 12
When a command to close is output, the on-off valve 12 switches to the position b, so that the supply gas switching valve 13 is in any position.
The gas cylinders 14 to 16 are cut off from the gas supply unit 10a of the electric welding torch 10. Further, when the pre-heating work before welding is required, such as a high-tensile steel plate, the work may be switched to the welding work after heating the work, contrary to the thermal deformation correction work of the turning frame 20. .

FIG. 3 is a view showing a second embodiment of a shielding gas welding apparatus which also serves as a heating apparatus according to the present invention. Components common to those of the first embodiment shown in FIG. ,
A description thereof will be omitted, and only different portions will be described.
The gas supply unit 10a of the electric welding torch 10 is connected to a shielding gas cylinder 14 using an inert gas such as carbon dioxide gas or argon gas via an electromagnetic switching valve 4 and propane gas, butane gas, and acetylene gas via an electromagnetic switching valve 5. The shield gas welding apparatus 2 is configured by connecting to a combustion gas cylinder 15 using an active gas such as the above, and to an oxygen cylinder 16 via an electromagnetic on-off valve 6. The solenoids 4a, 5a, 6a of the solenoid valves 4, 5, 6 are controlled by a controller 18a which inputs a command of a changeover switch 17a. The welding operation of attaching the two boom brackets 19 to the upper surface of the frame main body 21 constituting the turning frame 20 of the hydraulic excavator shown in FIG. The description is omitted because it is the same as the embodiment.

In each of the above embodiments, when the shield gas welding device also serving as the heating device according to the present invention is used as the heating device, the welding torch is replaced with the electric welding torch 10 to explain the ignition device for the combustion gas. However, it is not limited to this.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of a shield gas welding apparatus which also serves as a heating apparatus according to the present invention.

FIG. 2 is a view showing a shield gas welding method using the welding apparatus of FIG. 1;

FIG. 3 is a view showing a second embodiment of a shield gas welding apparatus which also serves as a heating apparatus according to the present invention.

FIG. 4 is a view showing a conventional welding apparatus.

FIG. 5 is a view showing a conventional welding robot.

FIG. 6 is a view showing a conventional shield gas welding method.

[Explanation of symbols]

 The element name of the claim is described in parentheses after the member name. REFERENCE SIGNS LIST 1 shield gas welding device 1st embodiment 2 shield gas welding device 2nd embodiment 4, 5, 6 solenoid on-off valve 4a, 5a, 6a solenoid 10 electric welding torch (welding torch) 10a gas supply unit 11 mounting bracket 11a Mounting part 12 On-off valve 13 Supply gas switching valve 12a, 13a Solenoid 14 Shield gas cylinder (shield gas supply source) 15 Combustion gas cylinder (combustion gas supply source) 16 Oxygen cylinder 17, 17a Changeover switch 18, 18a Controller 19 Boom bracket 20 Swivel Frame (welded product) 21 Frame body

Claims (3)

[Claims] A shield gas welding apparatus for performing welding while supplying a shield gas supplied from a shield gas supply source to a welding portion from a tip of a welding torch, wherein a heating gas supply source and a heating gas supply source are provided. A supply gas switching device for switching a heating gas to the shielding gas and supplying the gas to the welding torch, the shielding gas welding device also serving as a heating device. 2. The shielding gas according to claim 1, wherein the welding torch is an electric welding torch, and an arc between the welding rod and the welded product is used as a heating gas ignition means. Welding equipment. 3. The shielding gas welding apparatus according to claim 1, wherein the welding torch is driven by a welding robot.