CS257353B1 - Polygonal flexible cord - Google Patents

Abstract

The solution relates to the field of electrical engineering. The subject of the solution is a flexible multi-core shielded cord for devices operating in thermally and mechanically demanding environments. The essence of the solution is that between the silicone rubber insulation of the cord core and the shielding there is a separation layer made of woven fabric impregnated with methylphenylsiloxane varnish, resistant to puncture and flexible at the vulcanization temperatures of the silicone rubber sheath of the cord.

Description

257353

BACKGROUND OF THE INVENTION The present invention relates to a multi-core flexural resistance resistant to thermal and mechanical bending stress.

Multicore flexible cords are thermally and mechanically demanding environments with a temperature of about 180 ° C and insulation and silicon rubber sheath. They serve to supply the devices operating in the premises as, for example, metallurgical, welding, robotized work and the like. Especially in heavy operations where strong sources of interference are present, it is necessary to prevent the penetration of interfering electromagnetic signals into individual core cores. Therefore, the polygonal cord is shielded in the form of mesh from tinned Cu drums. In order to increase the resistance of the cord to the bending stress, it is necessary to insert a separating layer between the core and the braid to prevent piercing of the insulation of the cores by the braids of the braid. the core, which in the bending and mechanical retraction of the cord lama. Another source of failure is the bonding of individual strands. Tests and practice have shown that neither silicone rubber isolation nor the previously used release liner materials have sufficient puncture resistance. The thermoplastic materials used so far are unsuitable because the thermoplastics destroy the elasticity of the cord at a temperature of 250-300 ° C. When using the polytetrafluoroethylene tapes on the twine wrap, the tapes are shrunk in the subsequent production step and the exposed areas under the shield are formed. Nowadays, a commonly used non-impregnated glass tape has the serious disadvantage that, when subjected to mechanical stress, the non-impregnated glass web causes abrasion of the soft silicone rubber insulation, in the thinning areas of the insulation there is increased electrical loading and conductive bonding. core cores with shielding. As a result, all these disturbances lead to the cords being removed, or to the cords. a corded device.

The above-mentioned disadvantages are eliminated by the invention, the object of which is a polygonal sleeve with increased resistance to thermal and mechanical stress, formed from a core insulated with silicone rubber, cores coiled around a core with the same insulation, separation layer, shielding and silicone rubber sheath wherein the separating layer is a glass tissue tape impregnated with a methylphenylsiloxane pressurized crosslinked dihydric fatty acid phosphate.

The main effect of the invention is that the multicore cord is resistant to cyclic bending stress in that the separating layer prevents puncture of the insulating layer by shielding drots. The bending tests have shown that the cords of the invention meet a mechanical stress of 100,000 cycles. The tolerability of the silicone insulation of the asiloxane impregnating agent results in a very good elasticity of the cord, which is retained even after curing of the jacket at 250-300 ° C, and which is due to the increased slip of the separation layer on the insulating layer. A further advantage is that due to the increased electrical strength of the 6 kV separation layer, the electrical strength of the web will also increase. The cord lifetime of the invention is about 10 times that previously used.

In the accompanying drawing, an example 7 of a vein flexible cord of the invention is shown. It is formed from a core 1 of tin-plated copper drills, insulated with silicone rubber. Around the core, 2 of the same material as the core 1 is deposited, on which a separating tape 3 of a glassy fabric impregnated with methylphenylsiloxane varnish is wound and there is a shield 4 of tinned Cu drots. The cord is wrapped with a silicone rubber jacket 5. The outer cord diameter is 9.2 mm.

The following example of a particular embodiment of a 27-core flexible cord explains the essence of the solution, but does not exhaust all possibilities of embodiment, nor does it limit the scope of its protection:

A 0.5 mm thick isolation of silicone rubber is extruded on a 0.5 mm2 core formed from tinned Cu drums. The extrusion speed is 50 inm / min, vulcanization temperature 270 ° C. Veins are deposited around the core. The veins are of the same material and are clad in 3 positions. The first semi-ha - 3 veins - twisting left; second position— 9 veins - right turn; third position - 15th - twisted left. On the last third position, a methylphenylsiloxane impregnated separating glass strip is wound, wound in one direction at 4 meters per minute in two layers. Separation tape primers, 50% overlap. Above the separating strip there is a shielding from tinned Cu drotics of 24 x 11 X 0.12 mm mesh. The cord protection is a silicone rubber jacket extruded on a continuous vulcanization line; extrusion rate 9 m / min, vulcanization temperature 290 ° C. The mantle thickness is 1.5 mm. The outer diameter of the cord is 16 mm.

For flexural tests, cords are subjected to bending mechanical stress of 100,000 cycles.

The multicore flexible silicone rubber compositions of the present invention are useful in the electrical industry in high thermal and mechanical environments.

Claims (1)

257353 5 ARTICLE Multi-core flexible cord with increased resistance against thermal and mechanical stress formed from a core insulated with silicone rubber, lined with coiled core with the same insulation, separating layer, shielding and silicone rubber coating, characterized by that the separating layer (3) is a glass cloth tape impregnated with methylphenylsiloxane lacquer crosslinked with divalent metal salts of fatty acids. 1 sheet of drawings