SU872099A1 - Current feed tip to electric-arc welding torches - Google Patents

Description

(54) CURRENT SUPPORTING TIP FOR ELECTRIC WELDING BURNERS

Of course, it relates to welding technology and can be used in semi-automatic welding machines and automatic machines for applying current to a moving welding wire.

The main reasons for reducing the durability of the current-carrying tips are the uneven distribution of the current and the mechanical pressure of the moving wire along the length of the contact zone. The most electrically, thermally and mechanically loaded is the lower portion of the tip fl.

The closest in technical essence to the invention is a current-carrying tip to torches for electric arc welding, comprising a housing and a current-carrying element in it in the form of an insert consisting of alternating sleeves made of a material with high and low electrical conductivity, for example sleeves, assembled from copper current-carrying rings, separated by guiding elements from solid materials (cobalt alloys, tool steels or ceramics. The durability of a known device ensures Since due to the fact that the guiding elements are evenly distributed over the entire height of the liner and prevent wear of the current-carrying rings when the wire is moving, in the case of their manufacture from ceramics that has dielectric properties, the current is uniformly distributed throughout the contact fruit. Since the current supplying rings are thus connected through the housing to an electrical parallel circuit 2J.

The disadvantages of this tip are the difficulty of making

P and the breakdown of contact between the wire and the current-carrying rings due to the clogging of the longitudinal channel of the liner with metal particles forming

with teasers; moving wire on a firm surface directed the coros of the elements. The breakdown of the contact by wire and the current lead of the sh4 and element w leads to a decrease in the quality of welded joints.

The purpose of the invention is to improve the quality of welded joints by increasing the reliability of the current supply to the welding wire.

This is achieved by the fact that in the current-feeding tip to the torches for electric arc welding, comprising a housing and a current-supporting element in the form of an input with alternating layers of a material with high and low electrical conductivity, the insert is made whole of polymetallic material, and the height of the layer with low electrical conductivity equal to twice the height of diffusion penetration of a metal with a high conductivity into a metal with a low conductivity, and the height of the layer with a high conductivity equal to

ti - a / s)

where h is the height of the layer with high electrical conductivity, mm;

- liner length, mm;

the number of pairs of layers, the height of the layer with a low elekki the troconductivity, mm. The polymetallic material can be made with layers of metals that are unlimitedly soluble in one another in a solid state.

Polymetallic material can be made with layers of copper and nickel.

. FIG. depicts a mouthpiece, a general view; in fig. 2 - electrical circuit diagram of the current source - mouthpiece. The mouthpiece includes a housing 1 with a thread on its outer surface. A current-carrying element is placed in the housing. The element is in the form of a cylindrical liner 2 with a longitudinal channel for guiding the electrode wire 3, made of a polymetallic material with alternating layers 4 and 5, some of which have a high and a different low electrical conductivity.

Since dissimilar metadles that are included in a polymetallic composition during its manufacture necessarily go through a stage of joint deformation, they have a discontinuity of electrical conductivity in the direction crossing the interface at the interface of metals throughout its length. As a result of the diffusion mixing of the metals included in the composition, the electrical conductivity of their interface decreases. In the case of the manufacture of multilayer compositions of metals, unlimitedly soluble in each other, such as copper-nickel, at the interface as a result of interdiffusion a continuous series of solid solutions of various concentrations, s with high specific resistance, is formed. With increasing temperature, the electrical resistance of copper-nickel alloys of the same composition increases slightly and is determined mainly by the concentration of the components included in the composition. With equal content of components, 50% of the resistivity of the alloys is maximum and is 55, i.e. 32 oa5 higher than the specific resistivity of copper (specific resistivity of copper - 1,724 µOhm-cm).

Alloys with equal concentrations of copper and nickel, which have the highest specific electrical resistance, are located directly at the fusion line. -. As the distance from the f line increases, the concentrations of copper and nickel sharply decrease.

The height of the layers with low electrical conductivity is determined by the length of the boundaries; the zone in which the mutual penetration of the metals into each other occurs as a result of diffusion.

Since the heating temperature of the current-carrying tips is about 50 Cpc, and the duration of their work does not exceed 100 hours, the length of the dimeter interface of the copper-nickel bimetal selected on the concentration distribution curve at a peak of 100 hours is 0.25 mn. In the case of a multilayer composition, where the nickel interlayer is between the copper layers, the height of the nickel layer is equal to twice the diffusion zone of SS of copper to nickel and is 0.5 mm. The height of a layer with high electrical conductivity depends on the length of the current-carrying liner, the number of layers in the polymechanical composition, and the following short-term dependence is chosen: K4Uh) -h ig-V-in / Itz, where h 7 is the height of the layer with high conductivity; the length of the current-conducting input breathing; the number of pairs of layers with high and low electrical conductivity,, 3, 4, 5j is the height of a layer with low electrical conductivity; Number of pairs of layers in a polymetallic composition: it depends on the size of the current-carrying liner and the length of the interface between the circuits, i.e. on the nature of the metals, the entry of the PCCP into the composition, and varies from 2 to 5. This is due to the fact that with AND the proposed design of the tip does not make sense, since the current distribution is not evenly distributed over the contact area. With an increase in the number of pairs of layers and the high layer with a high electrical conductivity decreases, for example, at the length of the supply copper-nickel liner current, the height of the copper layer is determined by (h) formula hg and equals ne -0, 5 mm, and h -0 3 mm, with. Further decrease in the number of pao layers in the Wnenecoo6pa3Ho polymetallic composition, because as a result of interdiffusion, high resistivity alloys are formed on both sides of the interface, which leads to a decrease in the electrical conductivity of the layer by an amount equal to twice zone height diff The penetration of metal with low electrical conductivity into metal with high electrical conductivity, deterioration of the reliability of the current wire to the welding wire. The mouthpiece works as follows: Electrical current IQ (Fig. 2), the passage through the body of the mouthpiece 1 is transmitted to the insert 2. Since the boundaries are. Insertion of the metal section has a high resistivity, the current IQ, in accordance with the first Kirchhoff law, is uniformly distributed between layers 4 with the highest electrical conductivity on components 1, It ,, 1, the value of which

 2 resistances When they are determined

echch) -

Claims (2)

And when the liner 2 is in contact with the moving wire 3, the X., 1-1-x currents are summed to the value of IQ. As a result of uniformly dividing the current over the contact area, the current density passing through the lower, more loaded section of the liner will significantly decrease. The total resistance of the liner will simultaneously decrease, since it will be determined by the formula of parallel connection of conductors / fto-silR ii where R. - resistance contribution | sh1a; - resistance of an individual layer. Thus, the use of a current-carrying element in the form of a cylindrical sleeve of polymetallic material with alternating layers of high and low electrical conductivity in the design of the muncture and the use of intermediate layers of small thickness in the material of the liner instead of solid guide elements in the known tip to form The interface of metals of alloys with high electrical resistivity provides a reliable supply of current to the welding wire. Claim 1. Current-carrying tip to the hot-wire for electric arc welding, comprising a case, a current-carrying element in it in the form of an insert with alternating layers of a material with high and low electrical conductivity, characterized in that, in order to increase the quality of welded joints by increasing the reliability of the supply of current to the welding wire, the insert is made of a polymetallic material, and the height of the layer with low electrical conductivity is equal to twice the height of the diffusion penetration of the metal with high electrical conductivity in the metal with low electrical conductivity, and the height of the layer with high electrical conductivity is equal to where h is the height of the layer with high electrical conductivity, mm; L liner length, mm; n is the number of pairs, layers, 2-5, Nc is the height of the layer with low electrical conductivity, mm. 2. A tip to the torch for electric arc welding according to claim 1, characterized in that the polymetallic material is made with layers of metals that are indefinitely stretched into one another in a solid state. 3. Tip to the torch for electric arc welding on PP. 1 and 2, in that the polymetallic material is made with layers of copper and nickel. Sources of information taken into account in the examination 1. Znbertschteyn BM. and others. Durable current lead tips. Automatic welding torches. Welding, 1975, 4, p. 61. 2. Patent of France 1478099, cl. At 23 K, 04.21.67 (prototype). BUT l j; "G fe.2