JPH0740448B2 - SZ twisted wire-shield method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a method for manufacturing a high voltage cable, and more particularly to an SZ twisted wire shield method for SZ twisting a shield wire on the high voltage cable.

Conventional technology and problems Conventionally, for example, a high voltage cable of 154 KV is wrapped with a shielded wire such as a copper tape or a copper wire in order to improve the electric characteristics of the cable. A phenomenon in which the shielded wire buckles when a bending action is applied to the wire is found, and in recent years a shielded wire is provided by SZ twisting in order to prevent such a buckling phenomenon of the shielded wire, a so-called "SZ twisted wire shield method". Was developed.

An apparatus for carrying out the SZ twisted wire shield method is illustrated in FIG. In this device, a cable C penetrates through a central portion, and a fixed eye plate 2 having an annular guide hole for guiding a plurality of shielded wires S is provided on the outer peripheral portion, and a cable similar to the fixed eye plate 2. C has a penetrating center portion, and an outer peripheral portion is provided with a reversing eye plate 4 which has a guide hole for guiding a plurality of shield wires S in an annular shape and is supported so as to be capable of reciprocating rotary movement.
A plurality of shielded wires S are SZ twisted by reversing movement of the reversing eye plate 4 in a predetermined cycle on the outer periphery of the cable C which is fed at a predetermined speed through the fixed eye plate 2 and the reversing eye plate 4. Wrapped around. The SZ twisted shielded wire is fixed to the outer circumference of the cable by a holding tape T supplied from a taping head (not shown) which rotates around the cable C at a constant speed.

Further, in the SZ twisted wire shield device having such a structure, the distance between the position P where the shield wire S contacts the cable C and fixes the shield wire S to the cable C and the reversing eye plate 4 are extremely large. They cannot be brought close to each other and must be separated by a predetermined distance l or more. Therefore, even if the reversing eye plate 4 is reversed by a predetermined angle, there is a distance 1 from the reversing eye plate 4 to the shield wire winding position P. Therefore, the reversing eye plate 4 is wound before the shield wire S is wound up to the predetermined reversing angle. However, there is a problem that the reversal angle of the shielded wire S is reduced and the shielded wire floats or twists are disturbed. More specifically, even if the reversing angle of the reversing eye plate 4 is 270 degrees, the winding angle of the shield wire S around the cable C is usually 180 degrees or less, and in the worst case, it is 90 degrees. There was a time when it did not reach.

If the reversing eye plate 4 is rotated by 270 degrees or more in order to compensate for such a decrease in the wrapping angle of the shield wire S, a harmful effect may occur when the shield wire S is broken. There are restrictions on growth.

It is an object of the present invention to provide an SZ twisted wire shield method capable of reliably fixing a shield wire with a holding tape and eliminating floating or twist disturbance of the shield wire.

Means for Solving the Problems The above objects are achieved by the SZ twisted wire shield method according to the present invention. In summary, the present invention applies an inversion motion to a shield wire with an inversion eye plate and attaches the shield wire to the SZ cable.
In the SZ twisted wire shield method in which the SZ twist of the shielded wire is then held on the cable with a pressing tape in the SZ twisted wire shield method, the reversal eye plate is shorter than the reversing reciprocating time at each reversal of the reversing eye plate. The SZ twisted wire shield method is characterized by stopping for a predetermined time. According to a preferred embodiment of the present invention, the stop time of the reversing eye plate is 1/10 to 1/5 of the reciprocating reciprocating time, particularly preferably 1/7 to 1/6.

Next, the SZ twisted wire shield method according to the present invention will be described in more detail with reference to FIGS.

As described above, the reversing eye plate 4 is provided on the outer circumference of the cable C which is fed at a predetermined speed through the fixed eye plate 2 and the reversing eye plate 4.
The plurality of shielded wires S are wound with SZ twist by reversing the movement in a predetermined cycle. More specifically, when the position shown in FIG. 1 is used as the reference position, the reversing eye plate 4 is first moved clockwise from the reference position, in the present embodiment.
Rotate 180 degrees. The shield wire S is wound around the cable C from the reference position to the maximum winding point A, that is, θ ₁ , for example, 135 degrees by the 180 ° clockwise rotational movement of the reversing plate (FIG. 2).

Next, as shown in FIG. 3, the reversing eye plate 4 rotates counterclockwise by 180 degrees, returns to the reference position, and is further reversed counterclockwise by 180 degrees. As a result, the shield wire S is wound around the cable C from the reference position to the maximum winding point B, that is, θ ₂ , for example, 135 degrees (FIG. 4).

Despite the winding movement of the shield wire S, in the conventional SZ twisted wire shield method, the reversing eye plate 4 is immediately reversed at the reversing position shown in FIGS. 1 and 4, that is, the shield wire S. The points A and B are reversed before they are pressed by the presser tape P, and therefore, when the shield wire is reversed, the winding is returned from the maximum winding positions A and B, and the winding angle. However, as mentioned above, it has decreased considerably.

According to the present invention, at the reversing position, that is, the position where the shielded wire S is maximally wound around the cable C, the reversing eye plate is stopped for a predetermined time shorter than the reversing reciprocating time, and the above A The points B and B are completely wound with the holding tape T. The stop time of the reversing plate is selected in relation to the revolving speed of the reversing plate and the pressing tape head around the cable C.
When the rpm and the rotational speed of the tape head are 60 rpm, the time is preferably 1.5 to 2 seconds.

Stopping of the rotary eye plate 4 can be suitably performed by incorporating a clutch mechanism in the drive system of the rotary eye plate 4 and controlling the clutch mechanism.

EFFECTS OF THE INVENTION The SZ twisted wire shield method according to the present invention is configured to stop the reversing eye plate at each reversing of the reversing eye plate as described above for a predetermined time shorter than the reversing reciprocating time. It is possible to significantly increase the winding angle of the shielded wire around the cable without increasing the reversal angle and securely fix the shielded wire to the cable with a holding tape to prevent floating or twisting disorder of the shielded wire. Have a profit

[Brief description of drawings]

1 (A) and (B) to 4 (A) and (B)
FIG. 4A is a front view and a side view of a reversing plate part for explaining the functions of the cable, the reversing plate, the shield wire, and the holding tape in the SZ twisted wire shielding method according to the invention. FIG. 5 is a front view of the eye plate portion of the SZ twisted wire shield device. 2: Fixed eye plate 4: Reverse eye plate C: Cable S: Shield wire T: Presser tape

Claims (2)

[Claims] 1. A ZZ twist in which a shield wire is applied with an inversion motion by an inversion eye plate to wind the shield wire around the cable with an SZ twist, and then the SZ twist of the shield wire is held on the cable with a pressing tape. In the wire shield method, the SZ twisted wire shield method is characterized in that the inversion eye plate is stopped for a predetermined time shorter than the inversion reciprocation time at each inversion of the inversion eye plate. 2. The stop time of the reversing eye plate is 1/10 of the reciprocating reciprocating time.
The method according to claim 1, which is ˜1 / 5.