JPH0715667Y2 - Double shield gas nozzle for arc welding - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shield gas nozzle used for carbon dioxide arc welding, MAG welding, and MIG welding used for processing metal structures.

(Prior Art) Single and double shielded gas nozzles used for gas shielded arc welding are generally made of copper or copper alloy, and most of them are plated with chrome.

However, gas shielded arc welding has a problem of spattering in which molten particles are scattered, and spatter S adheres to the welding nozzle 7 as shown in FIG. That is, the adhered spatter narrows the tip hole of the welding nozzle to make the gas shield state incomplete, or to make a short circuit electrically in contact with the welding wire,
Further, the spattered mass that has adhered and grown on the outside of the welding nozzle is in contact with the base metal during fillet welding and in-groove welding, thus impairing the welding operation.

Even in the double shield, a nozzle made of copper or copper alloy is generally used as the inner nozzle, and the above-mentioned problems occur similarly to the single nozzle. As a means for solving this problem of spatter, Japanese Utility Model Laid-Open No. 58-111175 discloses a welding nozzle consisting entirely of a ceramic nozzle and Japanese Utility Model Laid-Open No. 61-82782 discloses a fiber nozzle in the circumferential and longitudinal directions of the ceramic nozzle. Nozzles in which a material is buried and Japanese Utility Model Laid-Open No. 55-111681 disclose a nozzle in which a large number of holes for discharging a shield gas are provided in an inner nozzle and an outer nozzle.

(Problems to be Solved by the Invention) Since the copper and copper alloy nozzles shown above are made of metal, they have excellent durability, but have the drawback that spatter adheres frequently. Also, the publication cited above is made of ceramic, and since it does not easily react with spatter, it has very little adhesion of spatter and is not suitable for gas shield welding in a special posture such as continuous welding or upward welding by a robot. Although effective, it has the drawback of being slightly inferior in impact resistance and durability to those made of metal and being easily cracked.

In addition, the metal double shield gas nozzles that have been used in the past are generally water-cooled, which not only complicates the hose around the nozzle, but also increases the weight of the nozzle as a whole and makes it difficult to remove it. It is expensive and expensive.

Further, even in the automatic welding by robots, etc., whose application is rapidly expanding in recent years, from the viewpoint of performing continuous welding for a long time, the adhesion of spatter to the nozzle as described above and the accompanying equipment Preventing damage is one of the important technical challenges.

The present invention has been made in view of the above, and its purpose is for gas shielded arc welding, which is difficult to attach spatter, has good peeling property, can prevent short circuit phenomenon, and can be manufactured at low cost. A dual shield gas nozzle is provided.

(Means for Solving the Problem) In the present invention, a welding double shield gas nozzle used for gas shielded arc welding, a welding tip 3 for feeding a welding wire 4 and the welding tip 3 are fixed. The inner nozzle 1 is arranged on the outer circumference of the welding tip mounting portion 8, and the outer nozzle 2 is further arranged on the outer circumference of the inner nozzle 1. The welding tip 3 and the portion between the welding tip mounting portion 8 and the inner nozzle 1 are A first gas passage space through which the shield gas flows from the shield gas discharge hole 9 provided in the welding tip attachment portion 8 to the object to be welded is formed, and the space between the inner nozzle 1 and the outer nozzle 2 is the outer side. A second gas passage space through which the shield gas flows from the shield gas introducing pipe 10 connected to the nozzle 2 to the object to be welded is formed, and the inner nozzle 1 is made of ceramics and the outer nozzle is made of ceramics. Nozzle 2
Is a double shield gas nozzle for arc welding, characterized by being made of copper or copper alloy.

(Operation) The configuration and operation of the present invention will be described in detail with reference to the drawings.

FIG. 1 (a) is a longitudinal section of the nozzle of the present invention, and FIG. 1 (b) is a plan view thereof.

The welding tip 3 for feeding the welding wire 4 is concentrically surrounded by the first gas passage space through which the shielding gas flows from the shielding gas discharge hole 9 provided in the welding tip attachment portion 8. A cylindrical inner nozzle 1 made of ceramics, and a cylindrical trumpet shape connected to a shield gas introducing pipe 10 made of copper or a copper alloy concentrically surrounding a second gas passage space around the inner nozzle. The outer nozzle 2 is arranged.

Since the inner nozzle 1 is made of ceramics, it does not easily react with spatter. In addition, the adhesion of spatter is very small compared to the conventional nozzle made of copper or copper alloy, and even if the spatter adheres, it can be easily removed by hand. Further, it becomes possible to prevent a short circuit phenomenon between the tip and the object to be welded.

In the double shield gas nozzle, the purpose of the outer nozzle is originally to improve the shield property, and it is particularly used for shielding the groove bottom of thick plate welding and improving the shield property when the weld pool is large.

Also in the present invention, the purpose of the outer nozzle 2 is almost the same, but it also serves to protect the inner nozzle 1. Outer nozzle 2
Since the nozzle tip is away from the arc point, there is almost no spatter adhesion. Therefore, the material of the outer nozzle is more suitable than the nozzle made of copper or copper alloy, which is durable and has excellent thermal conductivity and workability. It can protect the inner nozzle and improve the shield property, and the double shield The result is a sound weld with no defects. Further, since the inner nozzle and the outer nozzle of the double shield gas nozzle can be separated from each other, if the inner nozzle is damaged due to spatter or the like, only the inner nozzle needs to be replaced, which is inexpensive.

(Example) A steel plate having a plate thickness of 50 mm was welded in a downward posture using the groove shown in Fig. 3 under the following test materials and the welding conditions shown in Table 1. The welding results are shown in Table 2.

Specimen steel: SM-50B 50mmt (backing metal 12.7mmt) Wire: JIS YGW-11 1.6mmφ Shielding gas: CO ₂ inside: 25l / min Outside: 25l / min As is clear from the results shown in Table 1, in the case of the nozzle of the present invention, the amount of spatter deposited was very small, and a sound weld having no defects was obtained.

For reference, the nitrogen content analysis result of the weld metal in the case of the double nozzle is as low as 0.0070 to 0.0085%, but it is as high as 0.0180 to 0.0195% in the case of the single nozzle.

In this experiment, since the welding length was 500 mm and 11 passes were welded, the arc time was 22 to 23 minutes, but the nozzle of the present invention has very little spatter adhered during this time and it is absolutely necessary to clean the nozzle during installation. There wasn't. Further, in the nozzle of the present invention, the short path phenomenon with the base material due to the spatter adhesion did not occur during welding. However, when the inner nozzle was a copper nozzle, a short path phenomenon occurred.

(Effect of the invention) By using the nozzle of the present invention, the inner nozzle can be protected and the shield property can be improved, and the double shield can not only provide a sound weld without defects but also prevent spatter from adhering. The peelability is also good, and the short-circuit phenomenon between the tip and the work piece can be prevented. As a result, the durability of the gas shield nozzle and the continuous welding time can be greatly improved. became.

In addition, the conventional double shield nozzle made of copper had to be water-cooled due to the radiant heat of the arc.
Water cooling becomes unnecessary, and the double shield nozzle can be simplified and lightened.

[Brief description of drawings]

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the double shield nozzle for gas shielded arc welding of the present invention, and FIG.
FIG. 2B is a plan view of this nozzle as seen from the tip side, FIG. 2 is a vertical sectional view of a conventional gas shield welding nozzle, and FIG. 3 shows the groove shape used in the embodiment. 1 ... Inner nozzle, 2 ... Outer nozzle 3 ... Welding tip, 4 ... Wire 5 ... Attachment, 6 ... Welding torch 7 ... Welding nozzle, 8 ... Welding tip mounting section 9 ... Shield gas discharge Hole, 10 ... Shield gas introduction tube S ... Sputtering, G ... Shield gas

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Otoguro Yasuaki Otoguro 5-10-1 Fuchinobe, Sagamihara-shi, Kanagawa Nippon Steel Corp. 2nd Technical Research Institute (56) References 62-127372 , U)

Claims (1)

[Scope of utility model registration request] 1. A welding double shield gas nozzle for use in gas shielded arc welding, comprising a welding wire (4).
Welding tip (3) for feeding and welding tip (3)
The inner nozzle (1) is arranged on the outer circumference of the welding tip mounting portion (8) to which is adhered, and the outer nozzle (2) is further arranged on the outer circumference of the inner nozzle (1), and the welding tip (3) and Between the welding tip attachment part (8) and the inner nozzle (1), a shield gas flows from a shield gas discharge hole (9) provided in the welding tip attachment part (8) to the object to be welded. A gas passage space is formed between the inner nozzle (1) and the outer nozzle (2), and the shield gas flows from the shield gas introduction pipe (10) connected to the outer nozzle (2) to the object to be welded. A double shield gas nozzle for arc welding, characterized in that a second gas passage space is formed, the inner nozzle (1) is made of ceramics, and the outer nozzle (2) is made of copper or a copper alloy.