JPH0465746B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a droplet detachment technique for preventing spatter in consumable electrode arc welding.

[Background of the invention]

A problem that must be solved during consumable electrode arc welding work is the prevention of spatter. This spatter is a piece of molten metal that is formed by scattering droplets of molten metal during welding.
In order to prevent the occurrence of spatter, it is sufficient to eliminate short circuits between the welding wire and the welding area. In order to eliminate short circuits, the droplets can be separated and made into a spray state, but conventional methods for making the particles finer include changing the composition of the welding wire to improve the droplet detachment. There existed a method of generating a welding current using a pulsed power source and detaching the droplets using this pulse. However, these means do not completely separate the droplets, and in particular, forming one droplet per pulse using a pulsed power source is inconvenient because the range of pulse frequencies used is narrow.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method by which droplets can be detached regardless of the frequency of welding current.

[Means to achieve the purpose]

The present invention was made based on the fact that droplets can be detached regardless of the frequency of the welding current by forcibly applying vibration from the outside without relying on a pulsed power source. Ultrasonic vibration was adopted as a means of generating vibration from the outside. That is, vibration is applied to the welding wire by an ultrasonic oscillator, and droplets generated from the welding wire are separated by this vibration.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIG.
The welding wire 1 was once guided through a cylindrical wire guide 3 passing through the interior of the welding torch 2, and is held by a contact tip 4 present at the tip of the welding torch 2. A welding nozzle 5 is present around the contact tip 4 and sprays a shielding gas 6 sent along the welding wire 1. Now, the ultrasonic oscillator 7 is built into the welding torch 2 and indirectly applies vibration to the welding wire 1 via the wire guide 3.

Next, a comparison between the embodiment shown in Fig. 1 and the conventional example will be made in the third section.
This is done by drawing. That is, the conventional example is pulse welding in which one droplet is produced per pulse using a pulsed power source.
(At welding voltage 22V) Pulse frequency of welding current is 200
In a range other than ~300Hz, the amount of spatter generated increases rapidly, and spatter cannot be prevented. In contrast, this embodiment uses a pulse power source to
This is a combination of pulse 1 droplets and droplet detachment using ultrasonic vibration. The pulse wave number of welding current is
In the range of 200 to 300 Hz, the amount of spatter generated is further reduced, and even in the range other than 200 to 300 Hz, the amount of spatter generated is sufficiently low. Therefore, it has been found that the present embodiment can prevent the occurrence of spatter even in a range of welding current where the occurrence of spatter could not be prevented conventionally.

In addition, the welding current in the above conventional example and this example is a welding current of 200A, a voltage of 22V, and a welding speed.
1500mm/min, consumable electrode protrusion 15mm, welding gas
20ml/min at Ar80%, _CO2 20%, wire diameter 1.2φ,
The plate thickness is 3.2mm and the welding length is 200mm. Further, the ultrasonic frequency used in this example is 10 KHz, and the ultrasonic output is 1 KW.

[Other Examples]

In the above embodiments, the ultrasonic oscillator was built into the welding torch 2, but in other embodiments, as shown in FIG. The wire guide 3 may be provided so as to be in contact with the wire guide 3 existing around the wire guide 3.

〔Effect of the invention〕

According to the method for preventing spatter in consumable electrode type arc welding of the present invention, the generation of spatter can be effectively prevented even in a range of welding current pulse frequencies where spatter could not be prevented conventionally.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a welding torch showing one embodiment of the present invention, Fig. 2 is a rear view of the welding torch showing another embodiment, and Fig. 3 is the embodiment shown in Fig. 1 and a conventional example. This is a graph for comparison. 1... Welding wire, 2... Welding torch, 3...
Wire guide, 4... Contact tip, 5...
Welding nozzle, 6... Welding gas, 7... Ultrasonic oscillator.

Claims (1)

[Claims] 1. A method for preventing spatter in consumable electrode arc welding, which prevents spatter during welding work by applying ultrasonic vibration to a welding wire supplied as a consumable electrode.