JPS6293Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention uses insulated wires, especially PFA, which has heat-resistant properties.
(Perfluoroalkoxyfluorocarbon) and PTFE
This relates to fluororesin insulated wires with a two-layer insulation structure of (Poly tetra fluoro ethylone).

Among fluororesin insulated wires, PTFE has the highest heat resistance and has the best electrical properties other than dielectric strength.
Insulated wire also had the following drawbacks.

PTFE is difficult to extrude because it does not melt under heat, and the batch method requires a special process of sintering after extrusion using the ram method, making continuous work on long lengths impossible.

When the extrusion diameter exceeds approximately 2 mm, distortion during extrusion increases and insulator cracks are likely to occur, making extrusion work extremely difficult.

Similarly, when the insulation thickness becomes thicker (1 mm or more), the distortion during extrusion becomes large, and furthermore, distortion due to the difference between the heat conduction surface and the conductor side during sintering, and distortion due to uneven vaporization of molding oil due to sintering. Insulator cracking during manufacturing due to factors such as thermal cycles during processing and use, and promotion of cracking due to external mechanical forces have recently been brought into close focus.

In addition, mechanical damage may occur due to factors such as disturbances in the conductor, oil on the conductor, foreign matter, gaps between conductor strands in stranded conductors, especially rope (composite) strands, etc.
Chemical strain occurs during PTFE extrusion and is a major problem in the generation of PTFE cracks.

Due to the combined effects of ~, it is required to remove irregularities at the bottom of the PTFE extrusion.

PFA is a material that exhibits almost the same heat resistance and electrical properties as PTFE, but because it is melt-extruded at high temperatures (over 400°C), if it is made thick, it may sag or bite into the conductor (stranded wire). There was a drawback to it.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, to facilitate the production of heat-resistant fluororesin-insulated wires with a conductor diameter of more than 2 mm and an insulation thickness of more than 1 mm, and to provide PFA with improved mechanical properties than wires insulated with PTFE alone. and
The object of the present invention is to provide an insulated wire having a two-layer structure of PTFE.

In other words, the gist of the present invention is a conductor, PFA applied on top of the conductor, and further applied directly on top of the conductor. PTFE
The insulated wire is characterized in that both insulators are thermally fused.

A specific example of the insulated wire of the present invention is shown in FIG. FIG. 1 is a cross-sectional view of the conductor 1.
It has a structure that is coated with PFA2 and further coated with PTFE3.

Conductor 1 can be anything such as a round wire or a flat wire, or a solid wire,
Either twisted wire is fine.

In any case, the structure shows a structure coated with PFA2 so that the surface is smooth.

PTFE3 may contain impurities such as minerals or oxides to improve wear resistance, or may have a structure of two or more layers of these and PTFE.

Furthermore, the melting point of PFA is 300 to 310°C, and the PTFE sintering temperature (near 400°C) fuses PFA and PTFE, making it possible to obtain an integrated structure.

An example of application of the present invention is shown in Fig. 2.

FIG. 2 shows a structure having an insulated wire core instead of the conductor 1 of FIG.

The wire cores are arranged in parallel with one core or multiple cores of two or more cores.
It is also good to change to a twisted structure (concentric, rectangular, etc.). In any case, the insulated wire core is coated with PFA2 to create a smooth shape that is easy to coat with PTFE3.

Is the insulator 4 of the insulated wire core generally made of the same material?
PFEP (hexafluoroethylene propylene), PE-TFE
(ethylene-tetrafluoroethylene copolymer) and other heat-resistant insulating materials.

The insulated wire of the present invention constructed as described above has the following advantages.

(1) PFA is the only material that fuses to PTFE,
This combination makes it possible to supply an insulated wire with an integrated insulator.

(2) It becomes easier to manufacture insulated wires with a PTFE conductor diameter of 2 mm or more and insulation thickness of 1 mm or more, which is a drawback of the conventional technology, and the cause of cracking can be eliminated.

(3) By increasing the amount of PFA coating on the conductor, the amount of PTFE extrusion per unit length can be reduced, making it possible to work on long lengths.

(4) PFA alone melts, but by covering it with PTFE, its heat resistance is equivalent to that of conventional PTFE.
It also has a positive effect on wear resistance, lubricity, etc., and its impact resistance is even better than that of conventional PTFE.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the insulated wire of the present invention, and FIG. 2 is a sectional view showing an application example. 1: Conductor, 2: PFA insulator, (jacket),
3: PTFE insulation (jacket), 4: Heat-resistant insulation.

Claims (1)

[Scope of utility model registration request] Conductor and PFA (perfluoroalkoxy fluororesin) as the primary insulator applied on it
and PTFE (tetrafluoroethylene polymer) as a secondary insulator applied directly thereon, and the primary and secondary insulators are fused together. Insulated wire.