JPH0568076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for connecting conductors, and particularly to a method for connecting conductors suitable for connecting conductors for large-sized formed cables.

[Technical Background of the Invention and Problems Therein] Conventionally, methods for connecting conductors include a method using a compression sleeve and a method using welding.

The method using a compression sleeve does not require heating during connection and does not deteriorate the insulator, but on the other hand, the outside diameter of the connection part is larger than the outside diameter of the conductor, so the finished outside diameter is large, and the mechanical It has the disadvantage that its physical and electrical properties tend to deteriorate.

On the other hand, in the welding method, as shown in Figure 3a, the ends of a pair of conductors 1 and 1' are butted together,
The abutting portions are cut out in a letter-shape, or as shown in FIG. 2B, the abutment portions are cut out in an X-shape, and the built-up portions 2 and 2' are formed by TIG welding, respectively.

In this case, in TIG welding, an arc is not generated unless the welding torch is brought close to the workpiece, so
The cut angle of the cut section must be large, which inevitably increases the welding time, making the insulator more susceptible to deterioration due to heat, and especially in the case of large-sized conductors, the rate of heat diffusion increases. Therefore, the welding connection had the disadvantage of requiring considerable skill.

Furthermore, since the welding area becomes large, oxides and slag are likely to be included, and the properties of the joint are not fully satisfactory.

[Object of the Invention] The present invention has been made to solve the above-mentioned drawbacks, and it is possible to shorten the welding time, reduce the thermal influence on the insulator, and place the welding part in an inert gas atmosphere. It is an object of the present invention to provide a method for connecting conductors that can be maintained and obtain a good connection.

[Summary of the Invention] That is, the method for connecting conductors of the present invention involves arranging a pair of conductors having end faces substantially perpendicular to the central axis to face each other with a predetermined distance apart on the central axis, and connecting the opposite portions of the two conductors. The outer periphery is surrounded by a splittable cylindrical body made of a heat-resistant material that does not have wettability with molten metal and has an opening on one side, and a welding rod is inserted into the space through the opening of the cylindrical body. Both conductors
The method is characterized in that the cylindrical body is removed after MIG welding.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a welded part showing the conductor connection method of the present invention, and FIG. 2 is a sectional view taken along line A-A'.

As shown in the figure, a pair of copper stranded wire conductors 1 of the same size, each of which has an end face cut along a plane substantially perpendicular to the axis of the conductor,
1' are arranged facing each other on the same axis, and the end faces to be connected are supported by a cylinder 3 with a distance of 5 to 10 mm.

The cylindrical body 3 is made of a refractory material that is not wettable with molten metal such as carbon material or ceramic, and is divided into two by a surface 3a that includes the axis of the conductor, and has a rotating pin 4 at one end. , the other end is tightened with fixing members 6, 6 which can be fixed with bolts and nuts 5.

This cylindrical body 3 has a semicircular space 3c that surrounds a spaced part disposed opposite to a hollow part 3b having an inner diameter approximately equal to the outer diameter of the conductors 1, 1' with an inner diameter slightly larger than the outer diameter of the conductors. , an opening 3d connected to this
The pair of conductors 1 and 1' are supported by the hollow parts 3b and 3b.

After supporting the pair of conductors 1 and 1' with the cylinder 3 and tightening the cylinder 3 with the fixing members 6 and 6 as described above, the welding rod 7 is inserted through the opening 3d.
Perform MIG welding.

The above MIG welding is a well-known method in which an arc is generated between a metal electrode wire and a base metal in an inert gas atmosphere, and the base metal and electrode wire are melted by the arc heat, forming a welded part. Since the arc heat is concentrated and strong, the welding is deep, and copper has good thermal conductivity, so it is particularly effective for welding copper, aluminum, and their alloys. Note that the space 3c of the pair of twisted copper wire conductors to be connected is supported by the cylinder 3.
By disposing a short copper wire 8 inside the welding rod and bringing the welding rod into contact with the short copper wire 8, it is possible to easily generate an arc at the start of welding.

In addition, MIG welding has an extremely high welding speed,
Due to its high efficiency compared to TIG welding, it is suitable for welding large-sized conductors and can significantly reduce welding time (for example, for a ^3000mm2 copper conductor, the 30-45 minutes of conventional TIG welding is replaced by 3-5 minutes). minutes).

In addition, in the case of a large-sized conductor, the insulator 9,
9 can be made smaller,
The cylindrical body 3 can also be easily removed after welding.

Furthermore, according to MIG welding, since the current density is extremely high, fine droplets are projected from the electrode at high speed, resulting in ripples on the bead surface.
Not only does it form an extremely small, smooth and beautiful bead, but the arc has strong directionality, so it has the advantage of being easy to weld in any position, whether facing downwards, vertically, or upwards.

After welding, the cylindrical body 3 is removed and the burr on the welded part is ground to complete the connection.

By using the above welding method, the cylindrical body 3 plays the role of preventing molten copper from flowing out and as a gas seal, and since the space containing the welded part is slightly larger than the outer diameter of the conductor, the slush is placed in this area. It can be extruded and a good connection can be obtained.

[Effects of the Invention] As explained above, according to the method for connecting conductors by MIG welding of the present invention, there is no need to make V or Since this is carried out in a gas-sealed state, there is no entrainment of oxides or sludge, and therefore a connection having good electrical and mechanical properties can be obtained. Additionally, since the thermal effect on the insulator can be reduced, the cylindrical body can be easily removed after welding.

[Brief explanation of drawings]

Fig. 1 is a side view of a welded part showing an embodiment of the connection method of the present invention, Fig. 2 is a sectional view taken along line A-A', and Figs. FIG. 1, 1'...Conductor, 3...Cylinder, 3a...Opening, 6...Fixing member, 7...Welding rod.

Claims (1)

[Claims] 1. A pair of conductors having end faces substantially perpendicular to the central axis are opposed to each other with a predetermined distance apart on the central axis,
The outer peripheries of the opposing parts of both conductors are surrounded by a splittable cylinder made of a heat-resistant material that does not have wettability with molten metal and having an opening on one side, and the opening of the cylinder is inserted into the space between the two conductors. A method for connecting conductors, the method comprising: inserting a welding rod into the conductors to perform MIG welding on both conductors, and then removing the cylinder.