JPS63213207A - Insulated electric conductor and its manufacture - Google Patents

Abstract

PURPOSE:To improve mechanical strength and easiness of molding together with insulation performance by providing insulating property by means of an insulating tape in which a composite consisting of an insulating film and an insulating fiber braid excellent in mechanical strength and impregnated with hardening resin. CONSTITUTION:Insulating fiber braids 2 are arranged up and down so as to hold an insulating tape therebetween for being impregnated with thermosetting epoxy resin 3 in order to be made in a partial bridging condition by controlling heating temperature and heating time. The insulating tape 4 obtained in this way is pasted on a superconductive wire 5 to make it in a coil form. At this time, thermosetting epoxy resin 3 of the insulating tape 4 is in the partial bridging condition so as to be easy for molding. The insulating tape 4 sticks firmly to the super conductive wire 5 by hardening thermosetting epoxy resin 3 after coil molding is finished so that the mutual insulating fiber braids 2 as well as the insulating fiber braids 2 and the insulating tape 1 also stick firmly to each other for obtaining a superconductive coil made en bloc. Thereby, large mechanical strength, easy molding and sure insulation can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a combination of an insulating film with excellent insulating properties and an insulating fiber braid with excellent mechanical strength, which is edged with an insulating tape impregnated with a curable resin. The present invention relates to an insulated electrical conductor and a method for manufacturing the same.

[Background technology]

Insulators used in electrical machines are required to have late-edge performance, mechanical strength, and ease of molding. In particular, as superconducting technology has advanced in recent years, strict requirements have been placed on insulating materials for superconducting wires. For example, it is desirable to have mechanical strength that can withstand the large electromagnetic force of superconducting magnets, moldability that makes it easier to insulate superconducting wires, and excellent insulation properties that ensure insulation.

[Problem that the invention seeks to solve]

However, for electrical insulating materials, mechanical strength and ease of molding are contradictory performances, and increasing mechanical strength makes molding difficult, so emphasis is placed on ease of molding.
This leads to disadvantages such as a decrease in mechanical strength, such as the inability to withstand the large electromagnetic force of superconducting magnets.

Means for Solving Problem C] The present invention has been made in view of the above, and in order to have mechanical strength that can withstand the large electromagnetic force of a superconducting magnet, be easy to mold, and provide reliable insulation. The present invention provides an electrical conductor insulated by an insulating tape made of a combination of an insulating film with excellent insulating properties and an insulating fiber braid with excellent mechanical strength impregnated with a curable resin, and a method for producing the same.

Hereinafter, the insulated electrical conductor of the present invention and its manufacturing method will be explained in detail.

〔Example〕

FIG. 1(a), (bl shows the first embodiment of the present invention,
Figure 1 (al) shows a polyimide insulating film 1 with a thickness of 25 μm, an insulating fiber braid 2 with a thickness of 100 μm using aramid, which is an insulating fiber with high mechanical strength, these insulating films 1 and the insulating The insulating tape 4 is made of a thermosetting epoxy resin 3 that is impregnated after combining the insulating fiber braids 2. That is, the insulating fiber braids 2 are arranged one above the other so as to sandwich the insulating tape 1, and are heated to It is impregnated with a curable epoxy resin 3 and brought into a partially crosslinked state (semi-cured state S) by controlling the heating temperature and heating time.

The insulating tape 4 thus obtained is attached to the superconducting wire 5 to form a coil as shown in FIG. 1(b). At this time,
l! Since the thermosetting epoxy resin 3 of li & chi 14 is in a partially crosslinked state, molding is easy. After the coil molding is completed, the thermosetting epoxy resin 3 is cured (full cured) so that the insulating tape 4 is firmly adhered to the superconducting wire 5, and the two insulating fiber braids and the insulating fiber braid 2 are
An integrated superconducting coil is obtained by strongly adhering the superconducting coil and the insulating tape 1. According to this superconducting coil, even if the space between the insulating fiber braids 2 is forced apart, the insulating film 1 sandwiched between them ensures the insulation between the superconducting wires, so that the reliability is maintained. It gets expensive.

FIG. 2 shows a second embodiment of the present invention, in which an insulating fiber braid 2 is arranged so as to wrap an insulating film 1, impregnated with a thermosetting epoxy resin 3, and made into a partially cross-linked state to form an insulating tape 4. get.

FIG. 3 shows a third embodiment of the present invention, in which an insulating fiber braid 2 is arranged only on one side of an insulating film 1, and a thermosetting epoxy resin 3 is impregnated therein. In this embodiment as well, after the insulating tape 4 is applied to the superconducting wire, it is wound into a coil and subjected to a hardening (full cure) treatment.

In each of the above embodiments, the insulating film 1 is not only the above-mentioned polyimide film that can be used widely from high temperatures to extremely low temperatures, but also mylar tape, Nomex (a nonwoven fabric made of aromatic polyamide, a trade name of DuPont, USA), and polyester film. As the insulating fiber braid, fibers such as aramid, Dacron (polyester fiber, trade name of DuPont, USA), etc., which have high mechanical strength, can be used. Additionally, a nonwoven polyester fabric combined with an insulating film and impregnated with a resin can also be used for applications that do not require much strength, although the mechanical strength is slightly reduced. It goes without saying that the implementation state of the present invention is not limited to the embodiments, and that variations in the positional relationship between the insulating film and the insulating fiber braid also fall within the scope of the present invention. Further, two or more layers of insulating films and insulating fiber braids may be alternately combined.

〔Effect of the invention〕

As explained above, according to the insulated electrical conductor and the manufacturing method thereof of the present invention, an insulating film with excellent insulation properties and an insulating fiber braid with excellent mechanical strength are combined,
Since the insulation is performed using an insulating tape impregnated with a curable resin, the mechanical strength is high, molding is easy, and insulation can be ensured.

[Brief explanation of the drawing]

FIG. 1 (al and fbl are explanatory diagrams of the first embodiment of the present invention,
FIG. 2 is an explanatory diagram of a second embodiment of the invention, and FIG. 3 is an explanatory diagram of a third embodiment of the invention. Explanation of symbols 1 ... Insulating film 2 ... Insulating fiber braid 3 ... Curing resin 4 ... Insulating tape 5 ... superconducting wire

Claims (5)

[Claims] (1) Consisting of an insulating film (including non-woven fabric, etc.) mainly having insulating properties and an insulating fiber braid (including non-woven fabric, etc.) mainly having mechanical strength, the insulating film and the insulating fiber braid are An insulated electrical conductor comprising: an insulating tape formed by impregnating a laminate with a curable resin and integrating the same; and an electrical conductor insulated by the insulating tape. (2) The insulated electrical conductor according to claim 1, wherein the insulating fiber braid is arranged so as to wrap the insulating film. (3) The insulating film is made of an insulating material having good insulation properties at extremely low temperatures, such as polyimide or mylar, and the insulating fiber braid is made of an insulating material with high mechanical strength, such as aramid or Dacron. An insulated electrical conductor according to claim 1 or 2, characterized in that: (4) A laminate of an insulating film and an insulating fiber braid is impregnated with a curable resin, the curable resin of the laminate is semi-cured (partially cross-linked) and overlapped with an electrical conductor; A method for manufacturing an insulated electrical conductor, characterized in that the curable resin of the laminate is fully cured (completely crosslinked) to integrate the laminate and the electrical conductor. (5) The insulating film is an insulating material having good insulation properties at extremely low temperatures, such as polyimide or mylar; the insulating fiber braid is an insulating material with high mechanical strength, such as aramid or Dacron; 5. The method of manufacturing an insulated electrical conductor according to claim 4, wherein the curable resin is a thermosetting epoxy resin, and the electrical conductor is a superconducting coil.