JPS6226990Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to a junction box for power cables, particularly a stiffening layer at the junction of a single-core corrugated aluminum sheathed cable.

(b) Prior art Figure 1 shows a conventionally used connection box for a single-core corrugated aluminum sheathed cable, with cable core 1
The outer periphery of the insulating reinforcing paper 2 laminated on the outer periphery of the connection part is covered with a metal sheet shield tube 3, and annealed copper wire 4 is tightly wound around the tapered surfaces of both ends. Together with this, they constitute the Shiyahei layer. The winding start end of the annealed copper wire 4 is brought into contact with the end of a temporary oil stopper pipe 5 caulked to the outer periphery of the cable core 1.

The above-mentioned temporary oil stopper pipe 5 is fixed by lead parts 7 and 8 formed on the outer periphery of the aluminum sheath 6.

In addition, in the figure, 9 indicates a spacer and 10 indicates an outer box.

(c) Problems to be solved by the invention The annealed copper wire 4 mentioned above has its winding start end in contact with the end of the temporary oil stopper pipe 5 to prevent it from slipping.
If there is an unbalance in the axial force due to thermal stress or the like acting on the two cables connected at the connection part of the cable core 1, the unitary structure group consisting of the cable core 1 and the cable core connection part integral therewith, A relative shift may occur between the aluminum cover 6, the temporary oil stopper pipe 5 and the outer box 10, which are integrally structured groups.
If such a shift occurs, there is a risk that the annealed copper wire 4 will be disturbed, or that the insulation reinforcing paper 2 and the cable core 1 will be relatively shifted, resulting in a decrease in the insulation effect.

(d) Means for solving the problem In order to solve the above problem, this invention separates the temporary oil stopper part and the winding start end support part of the annealed copper wire from each other, and connects the winding start end support part to the cable core. It is integrally formed on the top.

That is, this invention forms a reinforcing insulating paper layer on the cable core in a power cable junction box in which an annular sealing member for temporary oil stopper is fixed to the cable sheath between the end of the cable sheath and the cable core. , the sealing member is formed of an elastic body, the sealing member is brought into close contact with the reinforcing insulating paper layer by elastic force, and the winding start end of the annealed copper wire constituting the stiffening layer is attached to the end of the reinforcing insulating paper layer. The structure is such that they are in contact with each other.

(E) Embodiment An embodiment of this invention will be explained based on FIGS. 2 and 3. Note that the same parts as in the conventional example are indicated by the same reference numerals.

In the junction box according to this invention, the cable core 1 is connected between the insulation reinforcing paper layer 2 and the aluminum sheath 6.
A reinforcing insulating paper layer 11 is formed on the outer periphery of the reinforcing insulating paper layer 11, and a gap g is provided between one end of the reinforcing insulating paper layer 11 and the end of the aluminum sheath 6, which is larger than the relative deviation between the aluminum sheath 6 and the cable core 1 that is expected in the usage condition. , the other end is formed into a tapered surface, and the winding start end of the annealed copper wire 4 forming the thin layer is brought into contact with the tapered surface.

In addition, as shown in FIG. 3, the sealing member 12 used in this invention is made by bending an elastic material such as rubber into two layers: an inner wall 13 and an outer wall 1.
4, and a mounting flange 15 is formed at the end of the outer peripheral wall 14. The inner circumferential wall 13 is formed via a bent portion 16 at the end opposite to the flange 15, and its inner diameter d ₁ is formed to be slightly smaller than the outer diameter d ₂ (see FIG. 2) of the reinforcing insulating paper layer 11. Ru.

As shown in FIG. 2, the sealing member 12 described above is inserted through the reinforcing insulating paper layer 11, and its inner circumferential wall 13 is tightly attached by its own elastic force. The seal member 12 is attached by a mounting bracket 17 whose flange 15 is fixed to the aluminum cover 6, and a support bracket 18 having a shape that follows the flange 15, the outer peripheral wall 14, and the bent portion 16 is attached to the opposite side of the seal member 12. The sealing member 12 is coupled to the flange 15 along with the mounting fitting 17, and the sealing member 12 is supported by the supporting fitting 18.

(e) Effects As described above, this invention abuts the winding start end of the annealed copper wire of the shielding layer against the end of the reinforcing insulating paper layer formed on the cable core, and the sealing member is attached to the cable sheath made of aluminum or the like. By fixing it to the end of the cable and making the inner circumferential wall elastically adhere to the reinforcing insulating paper layer, the integrated structure group consisting of the cable core and cable core connection part, the cable sheath, and the outer If an axial force is applied that causes the unitary structure group consisting of the box and the temporary oil stopper to shift relative to each other,
Since the seal member and the reinforcing insulating layer are kept oil-tight only by the elastic force of the seal member, they can easily shift. In addition, the reinforcing insulating paper layer that supports the winding start of the annealed copper wire moves together with the cable core, so there is no effect of relative misalignment.
Therefore, no winding disorder occurs.

[Brief explanation of the drawing]

Figure 1 is a partially omitted sectional view of a conventional junction box;
The figure is a partially omitted sectional view of a junction box according to this invention, and FIG. 3 is a partially omitted sectional view of a sealing member used in this invention. 1...Cable core, 2...Insulating reinforcement paper, 3
. . . Shiyahei tube, 4 . . . Annealed copper wire, 6 . . . Aluminum covering, 11 .

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a power cable junction box provided with an annular seal member for temporary oil stopper fixed to the cable sheath between the end of the cable sheath and the cable core, reinforcement on the cable core. Annealed copper forming an insulating paper layer, forming the sealing member from an elastic body, bringing the sealing member into close contact with the reinforcing insulating paper layer by elastic force, and forming a flexible layer at the end of the reinforcing insulating paper layer. A power cable junction box characterized in that the winding start end of the wire is brought into contact with the wire. (2) The scope of the utility model registration claim, characterized in that a gap is provided between the reinforcing insulating paper layer and the end of the cable sheath, which is larger than the relative deviation between the cable sheath and the cable core that is expected in the usage state. The power cable junction box according to paragraph 1.