EP1296336A1 - Varnish-coated wire - Google Patents

Abstract

Lacquer-coated wire with two different lengths, perpendicular to each other Cross-section with axes consisting of a metal wire and a surrounding wire Lacquer coating comprising insulation and baking lacquer properties, in particular to produce electrical coils, the paint coating on the longer Cross-sectional axis assigned sides has a lower thickness than on the sides to be assigned to the shorter cross-sectional axis. The wire has a cross section an axis ratio of maximum 3: 1.

Process for the production of a wire with two cross sections of different lengths, perpendicular to each other, consisting of a metal wire and a varnish coating comprising the insulation and baking varnish properties surrounding it, the varnished coated wire having a round cross section being pressed onto a cross section with an axial ratio of maximum 3: 1 by means of a rolling process the wire can have an oval cross-section.

Description

The invention relates to a paint-coated wire with a non-circular cross-section, the two Axes of different lengths, normal to each other and made of a metal wire and a surrounding coating, the insulation and baking properties has, in particular for generating electrical coils, and a method to make the wire.

Lacquer-coated wires of round cross-section for the production of electrical coils are known. These wires are made of copper, aluminum or another metal or a metal alloy, and have an inner electrically insulating coating and arranged on this, an outer layer of baking varnish. The first, inner, paint coating, which consists of polyurethane or polyester amide serves for electrical insulation of the wire. The second, outer, layer of varnish called wire varnish by wire manufacturers is used to provide a mechanical connection between the windings and the winding layers. It is made from lacquers that subsequently soften the lacquer layer enable. The softening of the lacquer layer can be caused either by the action by heat or by the action of a chemical solvent. Lacquers based on polyvinyl butyral or polyamide are usually used.

In the description and claims, "circular" is always understood to be "circular", as "out of round" thus as "deviating from the circular cross-section". Essentially concern the non-circular cross-sections oval and rectangular cross-sections, the latter being rounded Have edges, thus the cross sections defined at the outset, the two different have long, normal axes.

Such wires are used for the production of electrical, self-supporting coils. However, these coils with a wire of round cross-section have the disadvantage that free spaces remain between the adjoining wires. These spaces require a reduced packing density, which affects the efficiency of the Reduce the device in which the coil is used. In addition, the individual lie Wires of such coils only at narrow contact lines, which also means that since such coils are exposed to electromechanical forces, the durability of such Coils is affected.

In an effort to produce more tightly packed coils, it is also known that the coils are made of paint-coated To produce wires of rectangular cross section. Such wires are obtained by deforming the metallic core accordingly and then using the insulation layers is provided.

The disadvantage of these coated wires with a metallic core of rectangular cross section is, however, that, due to the manufacturing process, the coatings are not applied to the metal core in a uniform thickness. The reason for this is the lack of symmetry of the square metal wire in connection with the Surface tension of the material of the coatings. For this reason, such Wire coatings with convex outer surfaces. If now such wires to coils are processed, adjacent wires touch only along relative Narrow lines of contact, whereby as with the coils, which consist of wires of round cross-section are produced, spaces remain between the individual wires. Since the lacquer coating and thus also the outer layer of baking lacquer on the wire in different thicknesses are distributed over the rectangular areas, and the Bake wires together in relatively narrow contact areas only the package cohesion of the individual wires in the coil is also not optimal. Thereby the service life and the mechanical self-bearing capacity of the coil become strong impaired.

The object of the invention is now to create a non-circular paint-coated wire, which does not have the mentioned disadvantages of these wires.

This object is achieved in that the wire is a lacquer coating has, which in a known manner from an inner electrically insulating lacquer layer and an outer layer of baking varnish, and that the varnish coating on the longer Cross-sectional axis assigned sides has a lower strength than on the the sides to be assigned to the shorter cross-sectional axis. According to an inventive Alternatively, the metal wire is surrounded by a single layer of lacquer that covers both the Has insulation properties as well as the baking varnish properties as a cross-sectional axis the side to be assigned are the areas of the surface that are designated on can be viewed as running parallel to a cross-sectional axis.

In an advantageous embodiment according to the invention, the wire has a cross section with an axis ratio of at most 3: 1, being rectangular or advantageously oval cross section.

The advantage of such a wire according to the invention is that its training enables the manufacture of an electrical coil in which the contiguous Lay the wires close together and bake them together over a large area. Through the The fact that the layer thickness of the lacquer coating on the wire matches that of the shorter ones Pages to be assigned to the cross-sectional axis are stronger, preferably much stronger, than on the sides to be assigned to the longer cross-sectional axis is in the production of Coils made of lacquer-coated wires, in particular oval cross-section, are possible the arrangement of the wires next to each other resulting gusset rooms with lacquer coating material to be filled in largely. The coil production takes place under Heating, so that paint coating material becomes plastic and so in particular in the area of the sides to be assigned to the shorter cross-sectional axes of the wire gusset spaces that form due to the increased amount of lacquer coating here can fill out. Due to the essentially uniform layer thickness is the lacquer coating on all sides or surfaces of the wire according to the invention a tight arrangement and caking of the varnished rectangular wires Cross-section guaranteed in the manufacture of coils in any case.

By eliminating gaps between adjacent wires and that All-round solid caking of the wires will increase the stability of the electrical Coil and thus their lifespan compared to the previously known coils with a square cross-section wire increased by up to 50%, thus quite considerably.

The invention also relates to a method for producing a wire with a non-circular shape Cross-section that has two axes of different lengths that are normal to each other and from a metal wire and a lacquer coating surrounding it, the insulation and has baking varnish properties. According to the invention, this method is characterized in that that the paint-coated wire of round cross-section by means of rolling is pressed on a cross section with an axis ratio of maximum 3: 1. According to In a preferred embodiment, the wire is pressed onto an oval cross section.

Surprisingly, it was found that pressing the coated wire up to to this maximum extent is possible without affecting the paint coating and to achieve a substantially uniform coating thickness on the individual Surfaces of the wire.

The inventive method is preferably carried out such that the paint-coated Wire of round cross-section between two appropriately spaced rollers is carried out. It is essential that the nip is set in such a way that the ratio of the two differently long, perpendicular to each other cross-sectional axes 3: 1 of the deformed wire is not exceeded.

Fig. 1 einen herkömmlich beschichteten Draht runden Querschnittes,

Fig. 2 eine aus einem Draht gemäß Fig. 1 hergestellte elektrische Spule,

Fig. 3 einen bekannten lackbeschichteten Draht rechteckigen Querschnittes,

Fig. 4 eine aus dem Draht gemäß Fig. 3 hergestellte elektrische Spule,

Fig. 5 einen erfindungsgemäßen Draht ovalen Querschnittes,

Fig. 6 eine aus dem Draht gemäß Fig. 5 hergestellte elektrische Spule,

Fig. 7 eine erfindungsgemäße elektrische Spule in Draufsicht,

Fig. 8 einen Schnitt entlang der Linie VIII-VIII der Fig. 7,

Fig. 9 einen Schnitt entlang der Linie IX-IX der Fig. 7 und

Fig. 10 einen Schnitt entlang der Linie X-X der Fig. 7 zeigen.

The subject matter of the invention is explained in more detail in the drawing, the scale being on an extremely high scale for the sake of clarity

1 shows a conventionally coated wire of round cross section,

2 shows an electrical coil made from a wire according to FIG. 1,

3 shows a known lacquer-coated wire of rectangular cross section,

4 is an electrical coil made of the wire of FIG. 3,

5 an oval cross-section wire according to the invention,

6 is an electrical coil made of the wire of FIG. 5,

7 is an electrical coil according to the invention in plan view,

8 shows a section along the line VIII-VIII of FIG. 7,

Fig. 9 is a section along the line IX-IX of Fig. 7 and

Fig. 10 show a section along the line XX of Fig. 7.

The invention is explained in more detail, for example, on the basis of coated wires, the lacquer coating each of an inner electrically insulating insulation layer and an outer layer of baked varnish is built up. Instead of the two-layer structure Lacquer coating on the metal wire can also be a single-layer lacquer coating are used, which have insulation and baking varnish properties at the same time.

Fig. 1 shows a conventional paint-coated wire of round cross-section, the Metal wire 1 'is coated with an inner electrically insulating lacquer layer 2'. about This lacquer layer 2 'is an outer, second baking lacquer layer 3' arranged that a connection between the wires of electrical coils made from them. A such a coil 4 'is shown in Fig. 2. The touching coated wires 1 'are along relatively narrow lines of contact with one another, each via the baking lacquer layer connected. However, there are free spaces between the wires 1 ' 6 ', which entail a reduced packing density.

Fig. 3 shows a paint-coated wire 1 "rectangular cross-section corresponding to date known prior art. Such coated wires are becoming more conventional Made in such a way that a metal wire of round cross-section pressed or pressed and is deformed into a wire 2 "rectangular cross-section. On the deformed metal wire 2 "will then be an electrically insulating coating 3" and then a baked varnish layer 4 "applied. Due to the lack of symmetry in the cross section essentially rectangular wire 2 ", these wires have coatings due to the manufacturing process in non-uniform thickness, with the wires particularly on their Broad sides, coatings 3 ", 4" sometimes irregularly convex outer surfaces exhibit.

This creates conventionally manufactured products of this type Wires to 5 "electrical coils between the turns or layers of turns again free spaces 6 ", which have a reduced packing density and stability the electrical coil.

5 shows a wire 1 of oval cross section produced according to the invention a metal wire 2, an electrically insulating coating 3 enveloping it and an outer baking lacquer layer 4 applied thereon. Through a continuous gentle pressing of a lacquer-coated wire of round cross-section, according to the the given symmetry can be produced with lacquer coatings of uniform thickness is on an oval cross section with a ratio of the two different lengths, Finally, perpendicular cross-sectional axes of maximum 3: 1 points the coated wire 1 thus pressed has coatings on all sides in a stepless manner uniform strength. The surface of the coating is essentially smooth. The electrically insulating coating 3 and the outer baking lacquer layer 4 each have average thicknesses between 5 and 10 µm.

From such coated wires 1 according to the invention rectangular or oval cross-section constructed electrical coils 5, as e.g. are shown in Fig. 6, have an extremely high packing density, since the coated wires 1 with their outer Baking layers 4 without or at least to a large extent without the formation of free spaces Bake on all sides and are connected to each other. This results in there is also a very high level of stability and thus the service life of this self-supporting Coils 5.

The invention makes it possible to have a disadvantage of non-circular cross-section wires Eradicate use of electrical coils. Such wires tend to stick to the Break places where they leave the coil assembly. You are in this much more fragile than round wires. The reason for this vulnerability is probably in the increased selective dynamic stresses in this area, the non-circular Oppose wires with less resistance than round ones, but the causes are not researched in the final analysis.

As shown in FIGS. 7 to 10, it is possible through the inventive method, the To produce coils from a wire 1 'in the area in which it is from the (not shown) Connection point is freely led to the coil (section X-X, Fig. 10), the loop 7, and in an initial area 8 on the coil 9, which does not exceed one turn and preferably less than half a turn, to leave it round and only the actual one To produce bobbins from the wire 1 designed according to the invention. In the illustrated In the exemplary embodiment, the transition from the round wire 1 'to the non-circular takes place Wire 1 in the area between the cutting planes VIII-VIII and IX-IX, as in FIG. 8 and 9 can be seen.

This is possible because the wire is round until the coil is wound and only during the feed is deformed for winding. For the non-round wires according to the status In terms of technology, it would be completely hopeless to make the core uneven over the wire length train and then look for and use the appropriate positions. It is only through this embodiment of the invention that it is possible to coil them together electrical leads in one piece, but with different over the length of the wire To produce a cross-section and thus the most suitable cross-sectional shape for the respective position to provide.

In practice, this is done in such a way that the round wire end is used in automatic coil production is gripped by the manipulator with the intended excess length to the winding point is guided, and that during this feed movement the form rollers are delivered in such a way that part of the first turn of the coil 9 consists of round wire 1 ', while the remaining and the further turns consist of non-circular wire 1. On analog Way, the form rolls are brought apart when the wire's place towards you from which round wire should be present on the finished spool again.

The invention thus relates both to a coil made from a wire according to the invention, the is characterized in that the coil body essentially out of wire Cross-section exists and that at least one of the feed wires (loop) round to the coil Cross-section and over a maximum of one turn, preferably a maximum of half Winding with a round cross section is part of the coil body; as well as a process for Production of such a coil, which is characterized in that between the supply reel for the round wire and the guide device for feeding the wire form rollers for deformation of the wire are arranged at the run-up point on the coil, between an active position in which they push the wire through and an inactive position, in which the wire runs through and remains round, is adjustable, and that the form rollers are in the active position when sections of the wire pass through from which the coil body is formed and that they are brought into the inactive position, when passing through wire sections from which a loop or the transition from the coil is formed into a loop.

Claims (8)

Lacquer-coated wire with a non-circular cross-section, which has two axes of different lengths, normal to each other, and consists of a metal wire and a surrounding, insulation and baking lacquer, possibly multi-layer lacquer coating, in particular for producing electrical coils, characterized in that the lacquer coating on the sides to be assigned to the longer cross-sectional axis have a lower thickness than to the sides to be assigned to the shorter cross-sectional axis. Wire according to claim 1, characterized in that the wire has a cross section with an axial ratio of at most 3: 1. Wire according to one of claims 1 or 2, characterized in that it has alternating round and non-circular sections over its length. Method for producing a wire according to one of claims 1 or 2, characterized in that a lacquer-coated wire with a round cross section is pressed onto a cross section with an axial ratio of at most 3: 1 by means of the rolling process. Method according to claim 3, characterized in that the wire is pressed onto an oval cross section. A method for producing a wire according to claim 3, characterized in that a lacquer-coated wire of round cross-section is pressed into a cross-section with an axial ratio of at most 3: 1 in the non-circular sections by means of the rolling process and is not pressed in the round sections. Coil made of a wire according to claim 3, characterized in that the coil body consists essentially of wire of non-circular cross-section and at least one of the supply wires to the coil has a round cross-section and is part of the coil body over a maximum of one turn, preferably a maximum of half a turn, with a round cross-section , A method of manufacturing a coil according to claim 7, characterized in that between the supply reel for the round wire and the guide device for feeding the wire to the run-up point on the coil, form rollers for deforming the wire are arranged between an active position in which they compress the passing wire and an inactive position in which the wire passes and remains round, and that the form rollers are in the active position when passing through portions of the wire from which the bobbin is formed and that they are in the inactive position brought when wire sections pass through, from which a loop or the transition from the coil to the loop is formed.

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