Method of production of welding wire

Details Method of production of welding wire Method of production of welding wire

1998-11-20

2000-06-27

Butler, Rodney A.

Metal deforming

With cleaning, descaling, or lubrication of work or product

Lubricating

72224, B21B 4502, B21B 1310

Patent

active

060792434

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates to a method for production of welding wires of small diameters such as solid wires and cored wires ensuring particular smooth feeding to welding torches through conduit tubes during welding operation.


BACKGROUND ART

Conventionally in welding such as CO.sub.2 gas shielded arc welding and MIG welding, solid wires and cored wires of small diameters such as 0.8 to 1.6 mm are used. Solid wires are homogeneous through the diameter and cored wires are filled with fluxes and other materials in the core of a steel tube shell (also called flux cored wires). These welding wires are provided in spools or, for requirement of continuous supply of long wires, in pail packs. In the usual welding operation, a wire feeding machine set near to the spool and/or the pail pack produces a driving force on the wires, and then feeds out the wires through a conduit tube as far as to the electrode tip in a welding torch at the welding position. The wire feeding machine is composed of a wire-feeding roller driven by a motor and a free-rotating pinch roller to grip and press the wire between the wire-feeding roller. At the central part of the conduit tube which contacts the wire, a liner made by spiral steel wires is provided as a flexible guide for the wire.
Though the conduit tube is usually in a length of 3 to 6 m, for welding of wide areas a tube as long as 20 m is required, and the length of conduit tube is selected in accordance with distance to the welding position. By proper choice of the long conduit tube, welding operation can be easily conducted by moving only a light-weight welding torch even in a narrow space and a high or low place such as when field welding for ship building.
On the other hand, the long conduit tube has a problem of increased resistance in feeding of welding wires. Wires are pushed into the liner inside of the conduit tube by a driving force of the feeding machine, and are subjected to the resistance in feeding due to friction created by contact with the inside wall of the liner. Although for a straight conduit tube high feeding forces are not required, for a conduit tube with a small radius of curvature or with a number of deflection positions, the resistance to feeding is large (especially when the tube is long). In order to perform stable welding operation without the occurrence of defects, it is necessary to feed the welding wire at a predetermined constant speed to the welding spot; that is, good feeding performance is necessary. However, if the resistance to feeding is high, the balance with the driving force of the feeding machine is difficult to maintain, leading to bad feeding performance.
Application of some lubricants is necessary to reduce the feeding resistance of wires through the conduit tubes. For this purpose solid lubricants such as MoS.sub.2 are applied to the liner of the conduit tube. However, since the effects are not satisfactory, application of additional lubricants like oil on the surface of wires is necessary. The application of oil on wires could be made in the neighborhood of the wire feeding machine, but accurate control of the coating amount of oil requires an excessive burden on the welding operators, and it is difficult in the actual welding operation. If the amount of oil is not enough, naturally satisfactory lubrication cannot be achieved resulting in bad welding performance. On the other hand if the amount of oil is excessive, slipping occurs between the wire and the wire-feeding roller leading to unstable wire feeding speed, and also an increase in hydrogen content by pick-up in weld metal is anticipated. In addition, since the wire driven out of the feeding roller is subjected to compression, in order to prevent of buckling, the wire is lead into a guide tube connected to the conduit tube immediately after departure from the wire feeding roller. Thus application of oil on the wire must be done before the entry into the feeding roller, so the problem of slipping is inevitable.
Accordingly, makers of welding wire

REFERENCES:
patent: 3380278 (1968-04-01), Dilling

Affiliated with

Also associated with

Rating

Method of production of welding wire does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of production of welding wire, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of production of welding wire will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1774189