JPS63194873A - Conduit tube for welding - Google Patents

Abstract

PURPOSE:To prevent the plating drop of a wire and the defective wire feeding caused by the blocking of the tube inside by having the coating layer consisting of the materials excellent in wear resistance and lubricity at the part brought into contact with the welding wire of the conduit tube for welding. CONSTITUTION:A coating layer 8 may be formed on either of the inner surface 7a front face, the all surface of the tube 7 made with a metal made fine wire 71 being wound in coils, namely of only the zone coming into contact with the welding wire 2 of the inner surface 7a, the outer surface and inner surface. As for the material of this coating layer 8 there are no special limitations if it has excellent wear resistance and lubricity and it is that which contains one kind or two kinds of a polytetrafluoroethylene and molybdenum disulfide concretely.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is applicable to old G (Meta) using welding wire, for example.
1Inert Ga5) Welding, ↑IG (Tungst
en Inert Ga5) Inert gas for welding etc.
The present invention relates to a welding conduit tube used as a guide member for welding wire in arc welding.

(Prior Art) Conventionally, for example, in inert gas arc welding such as MIG welding, it has been common to use a welding device as shown in FIG. 3, for example.

That is, in the figure, a welding wire 2 wound around a wire reel 1 is fed to a welding part A by a pair of feed rolls 4.5 operated by a wire feed motor 3, and the tip 2a of the wire 2 and An arc is generated between the base metal 6 and welding is performed continuously.

In such a welding device, a metal conduit tube 7 is used to guide the welding wire 2 being fed, and the welding wire 2 is fed to the welding part A through the tube 7. This conduit duplex 7 is usually
As shown in FIG. 4, a thin metal wire 71 is wound into a coil shape to obtain flexibility.

(Problem to be Solved by the Invention) However, as the welding wire 2 passes through the conduit tube 2, the inner circumferential surface of the tube 7 and the wire 2 do not easily slip, so they come into contact with each other, and the wire 2 comes into contact with the welding wire 2. The plating formed on the surface of the wire 2 may fall off, and the fallen plating may accumulate inside the tube 7 and obstruct the movement of the wire 2. As a result, it is not possible to maintain a constant gap between the wire 2 and the base metal at the welding part, resulting in problems such as instability of the arc.

The present invention has been made in view of the above-mentioned conventional problems.It has good slippage between the wire and the welding wire, prevents the wire from falling off, and prevents the occurrence of poor wire feeding during continuous welding. The purpose is to provide a conduit tube for welding that is prevented.

(Means for Solving the Problems) According to the present invention, in order to achieve the above object, in a welding conduit tube that guides a welding wire, at least a portion that comes into contact with the welding wire has wear resistance and lubricity. It has a coating layer made of a superior material.

The welding conduit tube of the present invention has a coating layer made of a material with excellent wear resistance and lubricity on at least the contact surface with the welding wire, specifically, the inner peripheral surface.

The coating layer of the welding conduit tube of the present invention will be explained below with reference to FIG. In addition, in the figure, the third
Components that are the same as those in the figures and FIG. 4 are designated with the same reference numerals. In other words, as shown in FIG. 1(al), this coating layer 8 is the front surface of the inner surface 7a of the tube 7 (FIG. 1(al), the entire surface That is, the inner surface 7a and the outer surface 7b (first
It may be formed only in the region 7c of the inner surface that contacts the welding wire 2 (FIG. 1C).

In addition, as mentioned above, the material of this coating layer 8 is as follows:
It is not particularly limited as long as it has excellent wear resistance and lubricity, but specifically, it contains one or two of polytetrafluoroethylene (PTFE) and molybdenum disulfide (MoS2). Machine oil, grease, turbine oil, etc. can also be used.

These substances are used by mixing with a suitable base. Examples of the base include acrylic resin, polyvinyl alcohol resin, polyester resin, epoxy resin, melamine resin, and polyamideimide resin. The blending ratio of the above substances to these base materials is, for example, PTFE
In the case of 0.5% by weight or more, in the case of M OS z, 0.5% by weight or more.
The triple arsenic content is preferably at least %.

Further, it is desirable that the thickness of the coating layer 8 be 5 μm or more in order to increase the life of the conduit tube.

(Example) Examples 1 to 6, Comparative Example 1 Various substances shown in Table 1 were added to acrylic resin in a commercially available welding conduit tube (length 3 m) so that the content was 5.0% by weight. The mixture was coated (coating layer thickness: 20 μm), and Δ, B, and C type coated tubes were prepared corresponding to the coated areas shown in Figure 1 (al to tc+), and the following was applied to each type of tube. A continuous welding test was conducted under the following conditions.Then, the time until wire feeding failure occurred was measured for three tubes of each type, and the results are shown in Table 1.

Conduit Tube As shown in Figure 2, welding wire 2 fed from wire reel 1 by feed roll 4.5 is connected to two tubes of diameter 3Qc+++ on a plane making 90 degrees to each other as shown. The feed resistance was intentionally increased by passing the conduit tube 7 with loops 7d, 7e.

Welding wire J Is Z33 1 2 YGWI I
(1.2mmφ) (Chemical composition) C: 0.06% by weight 3i: 0.75% by weight Mn: 1.73% by weight P: o, ot3 times % S: 0.011% by weight Fe: remainder Welding conditions Welding current: 300A Air voltage: 32 ■Welding
Speed = 60ω/min Shielding gas: C01 (flow rate 20#/m1n) Electrode-base metal gap: 20mm Polarity: DC reverse polarity (DCRP) In addition, in the above continuous welding test, in order to eliminate the influence of Welding was interrupted every 30 minutes to remove spatter adhering to the nozzle (hereinafter referred to as "interval").

(Left below) Examples 7 to 13 Continuous welding tests were conducted in the same manner as in Examples I to 6 above, with the contents of PTFE and MoS2 varied as shown in Table 2, and the results are shown in Table 2. Indicated.

The thickness of all coating layers was 20 μm, and the coating type was A type.

(Left below) Examples 14 to 24 The content ratio of PTFE and MoS and the thickness of the coating layer were adjusted to the third level.
Continuous welding tests were conducted in the same manner as in Examples 1 to 6 above, with various changes as shown in the table, and the results are shown in Table 3. In addition, all covered types were classified as B type.

(Left below) As is clear from Tables 1 to 3 above, the continuous welding time for tubes with a coating layer is much longer than for conventional uncoated tubes, especially for PTFE and/or
Particularly excellent are those coated with a substance containing MoS or MoS. Furthermore, it was confirmed that it is effective to form the coating layer on the front surface of the tube (Table 1). on the other hand,
From the relationship between the content of PTFE and host and the continuous welding time, it is found that the content of PTFE is 0.5% by weight or more, Mo5
It is clear that a t content of 0.3% by weight or more is particularly effective (Table 2). Furthermore, the thickness of the coating layer is 5% by weight or more.
μm or more is preferable in order to increase the life of the tube (
Table 3).

(Effects of the Invention) As explained above, according to the present invention, at least the portion of the welding conduit tube that comes into contact with the welding wire has a coating layer made of a material with excellent wear resistance and lubricity. Sliding between the welding wire and the conduit tube is improved, preventing the plating on the wire from falling off, and preventing poor wire feeding due to blockage in the tube.

[Brief explanation of the drawing]

Fig. 1 is a partially enlarged cross-sectional view showing the structure of the welding conduit tube of the present invention, Fig. 2 is a conceptual block diagram showing the wire feeding mechanism used in the embodiment of the present invention, and Fig. 3 is inert gas welding. FIG. 4 is a conceptual block diagram showing the structure of the apparatus, and a partially enlarged sectional view showing the structure of a conventional welding conduit tube. 2... Welding wire, 7... Conduit tube, 8
...Covering layer.

Claims (5)

[Claims] (1) A welding conduit tube that guides a welding wire, the welding conduit tube having a coating layer made of a material with excellent wear resistance and lubricity at least in a portion that comes into contact with the welding wire. (2) Claim 1, characterized in that the substance with excellent wear resistance and lubricity contains polytetrafluoroethylene and/or molybdenum disulfide.
Conduit tube for welding as described in section. (3) The content of the polytetrafluoroethylene is 0
．． The welding conduit tube according to claim 2, characterized in that the content is 5% by weight or more. (4) The welding conduit tube according to claim 2, wherein the molybdenum disulfide content is 0.3% by weight or more. (5) The welding conduit tube according to claim 1, wherein the thickness of the coating layer is 5 μm or more.