JPS5919608B2 - How to create an oxide film on copper strands - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Background and Purpose As an example of strand insulation for power cable conductors, it has been proposed to form a thin copper oxide film on the surface of copper strands.

This copper oxide film can be made, for example, by immersing a copper conductor in an oxidizing solution. Even if the copper strands are directly immersed in the oxidizing solution using this chemical oxidation method, there are not many gaps between the copper strands, so when creating a copper oxide film on the surface of the copper strand conductor, the internal The problem is whether the oxidation treatment can be performed uniformly down to the strands.

In particular, compression-molded segments used for stranded conductors of high-voltage, large-capacity cables have very few gaps between strands, making uniform oxidation treatment difficult. This invention makes it possible to uniformly oxidize even the stranded wires of compression molded segments as described above.

Construction of the Invention The preformed stranded copper wire is immersed in an oxidizing solution in an untwisted state.

Then, the gaps between the strands widen, allowing the processing liquid to penetrate inside. Embodiments (FIGS. 1 and 2) 10 is a compression molded segment of stranded copper wire with a loose pitch (twist) and a fan-shaped cross section (FIG. 2).

12 is an oxidation bath, 14 is an oxidation treatment liquid (for example, a mixed aqueous solution of sodium chlorite and caustic soda, etc.), and 16 is a seal.

18 is a take-up caterpillar that advances the copper strands in the direction of arrow 19.

20 is a reduction gear thereof, 22 is a clutch, 24 is a line shaft, 26 is a reduction gear, and 28 is a drive motor.

30A and 30B are twist return devices and have the same structure.

32 is its casing, 34 is a rotating ring, and 36 is a bearing.

38 are three free-rotating guide rolls (Fig. 2).
These support the stranded wire 10 from three sides.

40 is a mounting hood for these (omitted in FIG. 1).

42 is a free drive, 44 is a torque limiter, 46A, 4
6B is a clutch that has a brake and can also be reversed.

Effect: If both the untwisting devices 30A and 30B are left free, both rotating rings 34 rotate at the same speed and in the same direction due to the twisting of the stranded wire 10.

Also, even if the same rotation as this rotation is applied externally,
There is no change in the twist of the copper stranded wire 10. Therefore, if a difference is created in the rotational phase of the twisting devices 30A and 30B, the twisting between the twisting devices 30A and 30B is restored.

Specifically, for example, do the following. 1) First, first, disconnect both clutches 46A and 46B, and tighten the return device 30.
Make both A and B free.

2) Disengage the clutch 22 of the take-up caterpillar 18.

At the same time, the twist return device 30B is locked. 3) Engage the clutch 46A and turn the twister 30A in the opposite direction.

Then, the tension is restored between the tension restoring devices 30A and 30B. 4) Engage clutches 22 and 46B and continue driving in that state.

In this way, the stranded wire 10 is continuously untwisted and passed through the oxidizing bath funnel 12 in this state.

Therefore, gaps are created between the strands, and the treatment liquid 14 penetrates into the interior, allowing for easy oxidation treatment. Note that when the stranded wire 10 leaves the untwisting device 30B, it returns to its original state due to its own elasticity. The amount of untwisting may be less than the preform pitch of the stranded wire 10.

Even with that much space, there is enough space between the strands. Also, the take-up speed of the take-up caterpillar 18 and the twisting return device 30
If the rotational speeds of A and B are not synchronized, the twist will be in a state different from the steady state, and more rotational load will be applied to the return devices 30A and 30B. At that time, by adjusting the load with the torque limiter 44, a constant state can be maintained. By restoring the effect of the invention, gaps between the strands are created, so
Even in cases such as compression molded segments, an oxide film can be formed uniformly throughout the interior.

In addition, a segment having a fan-shaped cross section is sandwiched and supported from three sides by three free-rotating guide rolls 38 at two points appropriately spaced from each other, and these are used to untwist the copper stranded wire 10. Therefore, a rotational force around the axis can be applied to the copper stranded wire 10 to sufficiently untwist the copper stranded wire without interfering with the running of the copper stranded wire.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of a device used to carry out the present invention;
FIG. 2 is a cross-sectional view of - in FIG. 1. 10...Copper stranded wire, 12...Oxidation bath, 14...Oxidation treatment liquid, 30A, B...
...Twisting device, 38...Guide roll.

Claims (1)

[Claims] 1. A continuously running compression-molded copper stranded wire with a fan-shaped cross section is supported by three free-rotating guide rolls from three sides at two points at appropriate intervals, and these guide rolls are used. Then, at the two support points, untwist the copper strands to widen the gap between the strands,
A method for forming an oxide film on a stranded copper wire, comprising passing the stranded copper wire through an oxidation treatment solution while widening the gap between the strands.