JPS62206778A - Uniform diameter joint of cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for connecting conductors of cables, such as rubber-plastic insulated cables, with the same diameter.

Conventionally, to connect the conductors of rubber/plastic insulated cables with the same diameter, a cylindrical copper sleeve is attached to the two cable conductors to be connected against each other, and compressive force is applied from the outer periphery to integrate the side conductors. It is done by doing. However, this method has the fatal problem that the radially compressed conductor stretches in the axial direction.
Not suitable for use in junction boxes subject to dimensional restrictions.

Therefore, when connecting cable conductors of the same diameter in a location subject to dimensional restrictions, the ends of each cable conductor to be connected are cut at an angle with respect to the axial direction of the conductor, and the cut surface is After applying flux to the outer periphery of the conductor near the cut surface, each conductor is butted against each other, and the two conductors are brazed with silver brazing material. After that, the brazed part is finished to have the same diameter as the conductor. It is done by doing.

However, with this method, it is necessary to remove the glassy flux before silver brazing.
This removal work was extremely troublesome.

Incidentally, if this glass-like flux is not completely removed, the tensile strength and conductivity of the conductor connection will decrease significantly.
In some cases, it is of no use.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for connecting cable conductors of the same diameter, which eliminates the drawbacks of the prior art described above and can significantly improve workability.

That is, the gist of the present invention is to cut the terminal of each small cape conductor to be connected at an angle with respect to the axial direction of the conductor,
Furthermore, after hot-dip plating copper brazing material on this cut surface and the outer periphery of the conductor near the cut surface, each cable conductor is faced and butted together, and both conductors are brazed with copper brazing material, and then the brazed portion is The goal is to finish it to the same diameter as the conductor.

Note that the thickness of the hot-dip plating of the steel brazing filler metal is not particularly limited, but it is usually preferable to set it to about 111rB.

Furthermore, the cutting angle of the cable conductor terminal varies depending on the strength of the brazing material and the conductor. In Figure 1 of the attached drawings,
Cable conductors 2 and 2' are joined with copper brazing material 1, and the tip of conductor 2 is at (90-ψ)0 with respect to the conductor axis.
is cut off. Now, when a certain force acts in the axial direction, tensile stress σ and shear stress τ act on the (90-ψ)0 plane. At this time, the following relational expression holds between τ and σ.

τ−1/2・(σ +σ2)・sin 2ψσ1:
X-axis stress σ2: Y-axis stress dr/dψ−1 (σ +σ2) cos 2ψdτ/d
When ψ-0, τ is maximum.

・°・ cos 2ψ−0 2ψ−90° , °9 ψ−45° Therefore, if 2ψ >90', the strength of the copper brazing filler metal will be dominant, and if 2ψ <90'', the strength of the conductor will dominate. Generally, the tensile strength σCu of copper (i.e. conductor) and the tensile strength σp of copper solder are a Cu -26kg/
mm, ap -23kg/mm2te, so 2ψ
Therefore, 90° is good.

In other words, it is better for the cutting angle to be close to perpendicular to the conductor axis, but considering the workability of copper brazing, it is impossible to make it so close to perpendicular, and based on the inventor's experimental experience, It is preferable to set it to about 2ψ−60° (ψ−30°).

Next, referring to FIGS. 2 and 3 of the attached drawings,
An embodiment of the method for connecting cable conductors with the same diameter according to the present invention will be described.

First, about 300 nV of each insulating layer 4, 4' was removed at the terminal part of the rubber/plastic insulated cable (here, a cross-linked polyethylene insulated cable with conductor size 1X30001IllI12 is used) 3, 3- to be connected, and exposed. The tip of each cable conductor 2, 2' is 6 points relative to the conductor axis.
Cut at an angle of 0" and cut the side conductor 2.2" at the tip of the cut surface 5,
5- and the conductor outer circumference 6, about 10111ffl from the cut surface.
6- is plated with copper brazing material 1' to a thickness of about 1 av. (3rd
(See figure) Thereafter, a half-split type water cooler 7, 7' is installed on each of the conductors 2, 2' at a position approximately 100 mm away from the tip of the cut portion of the conductor.

After installing the water cooler 7.7, attach the fixing jig 8 to the U band 9.9
' and U bolt 10.10 = each cable 3.3
'Mounted between each other, thus both cable conductors 2, 2'
Butt them together and expose the conductor axis. Note that at this time, the ends of the cut surfaces of the conductor are in contact with each other. Thereafter, water piping hoses (not shown) are connected to the water inlets 11, 11'' and water outlets 12, 12' provided on the water coolers 7, 7''.

After that, 0.21)/See in the water cooler 7.7'
While flowing the above cooling water, heat the end butting portions of the side conductors 2 and 2' using a TIG welder (not shown) to melt the steel brazing material 1' and melting a similar steel brazing material 1 there. It's crowded. In addition, the welding current during TIG welding is 75 to 10
0 ampere is suitable.

In addition, since it is necessary to braze the conductor butting portions on the back side, that is, on the lower side in the figure, the fixing jig 8
is designed to make the work easier.

When copper brazing begins, steel brazing filler metal is sequentially supplied to the conductor abutting portions, and finally the brazing material is raised to about 2 cm above the outer diameter of the conductors 2, 2'. After the brazing work is completed, the cable fixing jig 8 and the water cooler 7°7'' are dismantled and removed, and the brazing parts are finished to have the same diameter as the conductor using a mechanical tool, and the work is completed.

In this embodiment, the water coolers 7 and 7' are used, but this is because the insulating layer 4.
This is to prevent it from being applied to 4'.

For example, in the case of a crosslinked polyethylene insulation layer, the maximum operating temperature is usually 90°C. Therefore, in this case, the conductor surface temperature at the end of the insulating layer must be at most 90° C., and the use of the water cooler 7.7- is extremely effective in ensuring this temperature.

Now, according to the method for connecting cable conductors of the same diameter according to the present embodiment, which is carried out as described above, after hot-dip plating a copper brazing material on the cut surface of the cable conductor cut at an angle and on the outer periphery of the conductor in the vicinity thereof, Since the butt parts of these two conductors are brazed with copper brazing material, unlike the case of conventional silver brazing, there is no need to remove the glassy flux, so overall workability is improved. Significantly improved.

As described above, the present invention improves all the difficulties in the prior art at once, and it can be said that its industrial value is extremely large.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the same-diameter connection portion of cable conductors, Fig. 2 is an explanatory diagram of an embodiment of the same-diameter connection method for cable conductors of the present invention, and Fig. 3 is a longitudinal cross-sectional view of an embodiment of the cable conductor of the present invention having the same diameter. FIG. 3 is a perspective view showing the state of copper brazing on the tip of a cable conductor in one embodiment of the connection method. 1: Copper brazing material, 1″: Copper brazing part, 2.2-: Cable conductor, 3, a-: Cable, 4.4-: Insulating layer, S, S-: Cut surface, a, a-: Conductor outer periphery near the cut surface, 7.7-: Water cooler, 8: Fixing jig, 9.9-: U band, 10, 10-: U bolt, xi, 1i-: Water Inlet, 12.12-: Water outlet.

Claims (1)

[Claims] (1) Cut the end of each cable conductor to be connected at an angle to the axial direction of the conductor, and then hot-dip plate copper brazing material on the cut surface and the outer periphery of the conductor near the cut surface, and then A method for connecting cable conductors with the same diameter, characterized by facing each other, butting them together, brazing both conductors with a copper brazing filler metal, and then finishing the brazed part to have the same diameter as the conductor.