JP2024046330A - Insulated wire, coil, electric/electronic device, and manufacturing method of electric/electronic device - Google Patents

Abstract

To provide an insulated wire which can sufficiently remove an insulated film from a conductor surface in a short time while suppressing residue of soot and a resin on a conductor surface by irradiation with a laser beam without blending a foreign matter such as transition metal oxide particles with the insulated film, when an end film is combusted and removed using a laser beam instead of mechanical removal of the end film, a coil using the insulated wire, an electric/electronic device having the coil, and a manufacturing method of the electric/electronic device.SOLUTION: An insulated wire 1 has at least a conductor 10, and an insulated coating layer A containing an insulated resin layer arranged so as to be brought into contact with the conductor 10, wherein in the insulated coating layer A, a content of an organic solvent having a flash point of 0 to 50°C and a boiling point of lower than 150°C is 500 to 20,000 ppm.SELECTED DRAWING: Figure 1

Description

The present invention relates to insulated wires, coils, electrical and electronic devices, and methods for manufacturing electrical and electronic devices.

Insulated electric wires have been used in electrical devices for some time now. In the conventional insulated electric wires, for example, a varnish containing polyamide-imide, polyimide, heat-resistant polyester, polyester-imide, or the like is applied to a conductor and baked to form an insulating coating around the conductor.
In electric and electronic devices such as motors and transformers, for example, an insulated wire is processed into a hairpin shape to form a segment coil, and the segment coil is pushed into a slot in a stator core, and the ends of the segment coil (insulated wire) protruding from the stator core are welded together to electrically connect them. In order to perform this welding, it is necessary to remove the insulating coating (end coating) covering the end of the segment coil to expose the conductor. A method of removing this end coating by mechanical cutting and removal using press processing or the like is known. However, with this cutting and removal method, not only the insulating coating but also the surface layer of the conductor part is scraped off, which causes a problem of reducing the cross-sectional area of the conductor. In addition, problems arise in terms of manufacturing efficiency, such as the need to dispose of shavings of the metal conductor and wear on the mold used in the press processing.
Instead of mechanically removing the end coating, a technique has been proposed in which the end coating is burned off and removed using a laser beam. For example, Patent Document 1 describes that, in manufacturing a rotating device in which an insulated electric wire is wound around an insulated armature, the insulating coating of the insulated electric wire contains transition metal oxide particles that absorb laser beams and generate heat, so that the insulating coating of the end portion of the insulated electric wire can be easily removed by irradiating the insulated electric wire with a laser beam.

Japanese Patent Application Publication No. 2010-15907

In the technique described in Patent Document 1, it is necessary to prepare a slurry in which a relatively large amount of transition metal oxide particles are uniformly dispersed in a resin varnish prior to forming an insulating film, which limits the improvement of work efficiency. be. Additionally, if the insulating film contains a large amount of transition metal oxide particles with physical properties different from those of the insulating resin, the adhesion between the insulating film and the conductor and the adhesion between the layers that make up the insulating film will decrease. This is also a concern.

The present invention relates to a technology for burning and removing end coatings using laser light instead of mechanically removing the end coating, and aims to provide an insulated electric wire that makes it possible to sufficiently remove the insulating coating from the conductor surface in a short time by irradiating it with laser light without mixing foreign matter such as transition metal oxide particles into the insulating coating. Another aim of the present invention is to provide a coil using this insulated electric wire, an electric/electronic device having this coil, and a method for manufacturing this electric/electronic device.

The above problem of the present inventors is solved by the following means.
[1]
It has at least a conductor and an insulating coating layer A including an insulating resin layer disposed in contact with the conductor, and in the insulating coating layer A, an organic solvent having a flash point of 0 to 50° C. and a boiling point of less than 150° C. Insulated wire with a content of 500 to 20,000 ppm.
[2]
The insulated wire according to [1], which has an insulating coating layer B surrounding the insulating coating layer A in which the content of the organic solvent is less than 500 ppm.
[3]
The insulated wire according to [2], wherein the insulating coating layer B is an enamel layer and/or an extrusion coating layer.
[4]
The insulated wire according to any one of [1] to [3], wherein the insulating coating layer A is an enamel layer.
[5]
The insulated wire according to any one of [1] to [4], wherein the insulating coating layer A has a thickness of 3 to 50 μm.
[6]
The insulated wire according to any one of [1] to [5], wherein the content of oxygen atoms in the polymer constituting the insulating coating layer A is 10 at % or more.
[7]
The insulated wire according to any one of [1] to [6], wherein the insulating coating layer A contains polyimide and/or polyamideimide.
[8]
The insulated wire according to any one of [1] to [7], wherein the conductor contains copper or aluminum.
[9]
A coil using the insulated wire according to any one of [1] to [8].
[10]
An electrical/electronic device having the coil according to [9].
[11]
The electric/electronic device according to [10], wherein the electric/electronic device is a transformer.
[12]
a step of removing the end film of the segment of the insulated wire according to any one of [1] to [8] by laser light irradiation;
Processing the segment from which the end film has been removed into a coil shape to form a segment coil, and incorporating the segment into a slot of a stator core;
A method for manufacturing electrical/electronic equipment, the method comprising the step of welding the ends of the segment coils to electrically connect them.
[13]
A step of processing the segment of the insulated wire according to any one of [1] to [8] into a coil shape to form a segment coil, and incorporating the segment coil into a slot of a stator core;
removing the end coating of the segment coil incorporated in the slot of the stator core by laser beam irradiation;
A method for manufacturing electrical/electronic equipment, the method comprising the step of welding the ends of the segment coils to electrically connect them.

In the present invention and this specification, a numerical range expressed using "to" means a range including the numerical values before and after "to" as the lower and upper limits. For example, when it is described as "A to B", the numerical range is "A or more and B or less".
In the present invention, "ppm" is based on mass.

In the present invention and this specification, the term "insulating resin layer" means a layer formed by one layer formation process, and a layer formed by one layer formation process is counted as one layer. For example, an enamel layer (I) formed by applying and baking a resin varnish once is one insulating resin layer, and when an enamel layer (II) is formed on this enamel layer (I) by applying and baking a varnish of the same or different resin as the enamel layer (I), a laminated structure of two insulating resin layers, enamel layers (I) and (II), is obtained. Also, when a thermoplastic resin is extrusion coated once on the enamel layer (I) instead of the enamel layer (II) to form an extrusion coating layer (III), a laminated structure of two insulating resin layers, enamel layer (I) and extrusion coating layer (III), is obtained. In addition, when a thermoplastic resin is extruded once onto the enamel layer (II) to form an extrusion coating layer (III), a laminate structure of three insulating resin layers, namely, the enamel layer (I), the enamel layer (II), and the extrusion coating layer (III), is obtained.
In the present invention and this specification, the term "insulating coating" refers to the entire insulating resin layer that constitutes the insulated wire. In addition, in the present invention and this specification, the term "insulating coating layer" refers to a layer unit consisting of one or more insulating resin layers that constitute the insulating coating. In the present invention and this specification, the term "insulating coating" is composed of one or more (preferably two or more) "insulating coating layers", and the "insulating coating layer" is composed of one or more "insulating resin layers".

In the insulated wire of the present invention, the insulating film can be sufficiently removed from the conductor surface in a short time by laser light irradiation without adding foreign substances such as transition metal oxide particles to the insulating film. Therefore, in a coil or an electric/electronic device using the insulated wire of the present invention, conductor loss is suppressed, the electrical connection is good, and the performance is further improved. Further, the method for manufacturing electrical/electronic equipment of the present invention is a suitable method for manufacturing the above-mentioned electrical/electronic equipment of the present invention.

1 is a cross-sectional view schematically showing a configuration example of an insulated wire according to an embodiment of the present invention. FIG. 4 is a cross-sectional view illustrating a schematic configuration example of an insulated wire according to another embodiment of the present invention. 1 is a schematic perspective view showing a preferred embodiment of a stator used in an electric/electronic device of the present invention; 1 is a schematic perspective view showing a preferred embodiment of a stator used in an electric/electronic device of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing one form of a method for manufacturing electric/electronic equipment according to the present invention.

[Insulated wire]
The insulated wire of the present invention has at least a conductor and an insulating coating layer A including an insulating resin layer disposed in contact with the conductor. The insulating coating layer A contains an organic solvent having a flash point of 0 to 50° C. and a boiling point of less than 150° C., and the content of the organic solvent in the insulating coating layer A is 500 to 20,000 ppm.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below except as specified in the present invention. Furthermore, the description of the conductor, resin varnish, insulating resin layer, insulating coating layer, organic solvent, etc. explained with reference to the drawings below is not limited to the form according to the drawings below, and is not limited to the configuration of the present invention or matters specifying the invention. It is applied as an explanation.

Figure 1 is a cross-sectional view showing a schematic configuration example of an insulated electric wire 1 according to one embodiment of the present invention. The insulated electric wire 1 has a conductor 10 and an insulating coating layer A that contacts the conductor 10 and covers the circumferential surface of the conductor 10. The insulating coating layer A may have a single-layer structure of one insulating resin layer, or a multi-layer structure in which two or more insulating resin layers are laminated. In the embodiment of Figure 1, the insulating coating layer A serves as an insulating film. Below, the insulated electric wire 1 of this embodiment will be described in order, starting with the conductor 10.

<Conductor>
The conductor 10 can be a wide variety of conductors commonly used in insulated wires, and is usually a metal conductor. The metal conductor preferably contains copper or aluminum, and a copper wire or an aluminum wire is preferably used. Although the conductor 10 shown in FIG. 1 has a rectangular (flat) cross-sectional shape, the cross-sectional shape is not particularly limited, and may be, for example, a circular shape.
In order to suppress partial discharge from the corners, the rectangular conductor 10 is preferably shaped with R-chamfered corners (with a radius of curvature r) as shown in Fig. 1. The radius of curvature r is preferably 0.6 mm or less, and more preferably 0.2 to 0.4 mm.
The size of the conductor 10 is not particularly limited. In the case of a rectangular conductor, the width (long side) of the rectangular cross-sectional shape is preferably 1 to 5 mm, more preferably 1.4 to 4.0 mm, and the thickness (short side) is preferably 0.4 to 3.0 mm, more preferably 0.5 to 2.5 mm. The ratio of the length of the width (long side) to the thickness (short side) (thickness:width) is preferably 1:1 to 1:4. In the case of a conductor with a circular cross-sectional shape, the diameter is preferably 0.3 to 3.0 mm, more preferably 0.4 to 2.7 mm.

<Insulating coating layer A>
The insulating coating layer A may be an enamel layer formed by applying a resin varnish containing an insulating resin (insulating polymer) onto the conductor 10 and baking it, or may be an extrusion coating layer formed by extrusion coating a thermoplastic resin. Preferably it is an enamel layer. When the insulating coating layer A is an enamel layer, a thermosetting resin or a thermoplastic resin such as polyetherimide can be used to form the enamel layer, and the enamel layer formed by curing the thermosetting resin can be used to form the enamel layer. preferable. Examples of thermosetting resins used for forming the enamel layer include polyimide (PI), polyurethane, polyamideimide (PAI), thermosetting polyester (PEst), H-type polyester (HPE), polybenzimidazole, and polyesterimide ( PEsI), melamine resin, and epoxy resin, and one or more of these can be used. Among these, polyimide, polyamideimide, H type polyester, or polyesterimide is preferred.

The polyimide is not particularly limited, and ordinary polyimides such as fully aromatic polyimides and thermosetting aromatic polyimides can be used. For example, commercially available products (product name: U-imide (manufactured by Unitika Ltd.) and product name: U-Varnish (manufactured by Ube Industries Ltd.)) can be used. Alternatively, a polyamic acid solution obtained by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine in a polar solvent in a conventional manner can be used, and imidized by a heat treatment during baking when coating.

The above-mentioned H-type polyester refers to an aromatic polyester in which the resin has been modified by adding a phenolic resin or the like, and has a heat resistance class of H-type. An example of a commercially available H-type polyester is the product name: Isonel 200 (manufactured by Schenectady International, USA).

The organic solvent of the resin varnish used to form the insulating coating layer A, which is the enamel layer, can be any organic solvent commonly used in this type of resin varnish. Examples include amide solvents such as N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and N,N-dimethylformamide (DMF), as well as organic solvents with a boiling point of 150°C or higher, such as dimethylsulfoxide (DMSO). From the viewpoint of varnish stability due to hydrogen bonding with the resin, it is preferable for the organic solvent to contain an aprotic solvent, and it is more preferable for it to contain DMAc and/or NMP.

In the present invention, the resin varnish contains a desired amount of an organic solvent having a flash point of 0 to 50°C and a boiling point of less than 150°C (hereinafter referred to as organic solvent a). By forming the insulating coating layer A using such a resin varnish, the organic solvent a can be contained in the insulating coating layer A in a content of 500 to 20,000 ppm. Note that organic solvent a is liquid at 25° C. and 1 atm.
The flash point of organic solvent a is preferably 5 to 45°C, more preferably 10 to 40°C. Further, the boiling point of the organic solvent a is preferably 140°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower. The organic solvent a may be used alone or in combination of two or more. Further, the boiling point of the organic solvent a is preferably 70°C or higher, more preferably 80°C or higher, more preferably 90°C or higher, and also preferably 100°C or higher. The boiling point range of organic solvent a is preferably 70 to 150°C, more preferably 80 to 140°C, even more preferably 90 to 130°C, and even more preferably 100 to 120°C.
The flash point means the flash point determined by the tag sealing method based on JIS K 2265-1 (2007). Moreover, the boiling point is the boiling point at an external pressure of 0.1 MPa (1 atm).
Specific examples of the organic solvent a include lower alcohols such as methanol, ethanol, butanol, and pentanol, and aromatic hydrocarbons such as xylene and toluene. Can be used. Organic solvent a is preferably alcohol, more preferably monoalcohol.
In the resin varnish for forming the insulating coating layer A, the content of the organic solvent a is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, and even more preferably 1 to 10% by mass.

The content of organic solvent a in the insulating coating layer A is preferably 600 to 10,000 ppm, more preferably 650 to 8,000 ppm, even more preferably 700 to 6,000 ppm, even more preferably 750 to 4,000 ppm, and even more preferably 800 to 2,000 ppm.

The thickness of the insulating coating layer A is preferably 100 μm or less, more preferably 60 μm or less, even more preferably 50 μm or less, and even more preferably 40 μm or less. Further, the thickness of the insulating coating layer A is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, and still more preferably 10 μm or more. The preferred range of the thickness of the insulating coating layer A is 1 to 100 μm, more preferably 3 to 60 μm, even more preferably 3 to 50 μm, still more preferably 5 to 40 μm, and also preferably 10 to 40 μm.

When the insulating coating layer A is an enamel layer and has a thickness of, for example, about 10 μm or more, the insulating coating layer A usually has a multi-layer structure of two or more layers. In other words, it is a layer formed by applying and baking a resin varnish two or more times. In the present invention, the content of organic solvent a in the insulating coating layer A is 500 to 20,000 ppm means that the content of organic solvent a is 500 to 20,000 ppm in all insulating resin layers that make up the insulating coating layer A.

When the insulating coating layer A contains the above-mentioned specific amount of the organic solvent a, the removal efficiency of the insulating film by laser light irradiation is greatly improved. The reason for this is not clear, but because organic solvent a has a low flash point of 0 to 50°C and a relatively low boiling point of less than 150°C, oxygen generated from the resin decomposed by the amount of heat applied during laser beam irradiation. This is thought to be due to the fact that the fire spread of the resin is promoted by acting together with the above.

In addition to the organic solvent a, the insulating coating layer A usually contains other organic solvents contained in the varnish (organic solvents other than the organic solvent a, for example, organic solvents typically used in the above-mentioned resin varnishes). The content of the other organic solvents in the insulating coating layer A is preferably 1000 to 20000 ppm, more preferably 2000 to 18000 ppm, even more preferably 3000 to 15000 ppm, and even more preferably 4000 to 13000 ppm.
In the insulating coating layer A, the total content of organic solvent a and organic solvents other than organic solvent a (total content of organic solvents in the insulating coating layer A) is preferably 2000 to 40000 ppm, more preferably 3000 to 30000 ppm, even more preferably 4000 to 20000 ppm, and still more preferably 5000 to 15000 ppm.

In the above description, the insulating coating layer A has been described in detail as an enamel layer, but the insulating coating layer A may be an extrusion coating layer. In this case, the insulating coating layer A can be formed by extrusion coating the conductor surface by incorporating an organic solvent containing at least organic solvent a into the thermoplastic resin to be extrusion coated. As the thermoplastic resin that is the material for forming the extrusion coating layer, a wide variety of thermoplastic resins that are commonly used as insulating resin layers of insulated wires can be used. For example, polyamide (PA) (nylon), polyacetal (POM), polycarbonate (PC), polyphenylene ether (including modified polyphenylene ether), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), In addition to general-purpose engineering plastics such as and ultra-high molecular weight polyethylene, polysulfone (PSF), polyethersulfone (PES), polyphenylene sulfide (PPS), polyarylate (U polymer), polyetherketone (PEK), polyaryletherketone ( PAEK), tetrafluoroethylene/ethylene copolymer (ETFE), polyetheretherketone (PEEK) (including modified polyetheretherketone (modified PEEK)), tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA) , polytetrafluoroethylene (PTFE), thermoplastic polyimide resin (TPI), and super engineering plastics such as liquid crystal polyester, as well as polymer alloys based on polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), ABS/ Examples include polymer alloys containing the above engineering plastics, such as polycarbonate, nylon 6,6, aromatic polyamide resin (aromatic PA), polyphenylene ether/nylon 6,6, polyphenylene ether/polystyrene, and polybutylene terephthalate/polycarbonate. These resins may be used alone or in combination of two or more resins. The thermoplastic resin preferably includes at least one of polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), and nylon 6,6 (nylon 66, PA66).

As the polyether ether ketone, for example, commercially available products such as KetaSpire KT-820 (manufactured by Solvay Specialty Polymers) and PEEK450G (manufactured by Victrex Japan) can be used.

The insulating coating layer A preferably has an oxygen atom content (the ratio of the number of oxygen atoms to the total number of atoms constituting the polymer, also referred to as the oxygen atomic ratio) of 10 atomic % or more (preferably 10.5 atomic % or more) in the polymer constituting the insulating coating layer A. By having an oxygen atomic ratio of 10 atomic % or more, the thermal decomposition of the insulating coating layer A by laser peeling, which will be described later, is promoted, and soot is less likely to remain. Many polyimides or polyamideimides have a structure with an oxygen atomic ratio of 10 atomic % or more, and are preferable as a constituent material of the insulating coating layer A. Therefore, the insulating coating layer A preferably contains polyimide and/or polyamideimide, and more preferably consists of polyimide and/or polyamideimide. The oxygen atom content in the polymer constituting the insulating coating layer A is usually 15 atomic % or less, and is also preferably 14 atomic % or less.

2 is a cross-sectional view showing a schematic configuration example of an insulated wire 2 according to another embodiment of the present invention. The insulated wire 2 has a conductor 20, an insulating coating layer A that contacts the conductor 20 and coats the outer peripheral surface of the conductor 20, and an insulating coating layer B that coats the outer peripheral surface of the insulating coating layer A. The conductor 20 is the same as the conductor 10 described in the embodiment of FIG. 1, and the preferred embodiment is also the same. The insulating coating layer A is the same as the insulating resin layer A described in the embodiment of FIG. 1, and the preferred embodiment is also the same. The insulating coating layer B may have a single layer structure like the insulating coating layer A, or may have a multi-layer structure in which two or more insulating resin layers are laminated. In the embodiment of FIG. 2, the insulating coating layer A and the insulating coating layer B are combined to form an insulating coating. The insulating coating layer B, which is characteristic of this embodiment, will be described below.

<Insulating coating layer B>
The insulating coating layer B is not particularly limited as long as the content of the organic solvent a is less than 500 ppm, and may be an enamel layer, an extruded coating layer, or a combination of an enamel layer and an extruded coating layer. The content of the organic solvent a in the insulating coating layer B is preferably 400 ppm or less, more preferably 300 ppm or less, even more preferably 200 ppm or less, and also preferably 100 ppm or less. It is also preferable that the insulating coating layer B does not contain the organic solvent a. That is, in the formation of the insulating coating layer A, a resin varnish or an extruded coating material containing the organic solvent a is used, whereas in the formation of the insulating coating layer B, it is not necessary to contain the organic solvent a. Therefore, as the organic solvent used in the resin varnish or the like used in the formation of the insulating coating layer B, the above-mentioned organic solvents normally used in the resin varnish can be used as they are.

When the insulating coating layer B is an extruded coating layer, it can be formed by extruding a thermoplastic resin onto the outer peripheral surface of the insulating coating layer A, for example, using a co-extruder. The extruded coating layer may be formed using an organic solvent or the like and a thermoplastic resin. For example, the thermoplastic resin described in the extruded coating layer of the insulating coating layer A can be used as this thermoplastic resin.

The insulating coating layer B may be formed by applying and baking a resin varnish onto the insulating coating layer A. In this case, the insulating coating layer B may be an enamel layer made of a thermoplastic resin, or an enamel layer made by curing a thermosetting resin, and is preferably an enamel layer made by curing a thermosetting resin. Examples of resins used to form the enamel layer include the resins described for the enamel layer of the insulating coating layer A.

The process for forming the insulating coating layer B itself can employ a general method for forming an insulating resin layer for an insulated electric wire.

The thickness of the insulating coating layer B is not particularly limited, and can be, for example, 1 to 200 μm, may be 3 to 150 μm, and is preferably 5 to 120 μm. Furthermore, when the insulating coating layer B is an enamel layer, the thickness is preferably 5 to 50 μm, more preferably 5 to 40 μm, and even more preferably 10 to 30 μm.

The ratio (D2/D1) of the thickness of the insulating coating layer A (D2) to the total thickness (D1) of the insulating coating layer A and the insulating coating layer B is preferably 0.01 to 0.7, more preferably 0.02 to 0.7, more preferably 0.1 to 0.7, more preferably 0.15 to 0.6, and even more preferably 0.2 to 0.5.

The resin varnish, insulating resin layer, and insulating coating layer used in the present invention may contain various additives such as bubble nucleating agents, antioxidants, antistatic agents, ultraviolet light inhibitors, light stabilizers, fluorescent whitening agents, pigments, dyes, compatibilizers, lubricants, reinforcing agents, flame retardants, crosslinking agents, crosslinking assistants, plasticizers, thickeners, viscosity reducers, and elastomers, to the extent that the additives do not affect the properties.

[Method of manufacturing insulated wire]
The insulated wire of the present invention can be produced by forming an insulating coating layer A on the outer periphery of a conductor and, if necessary, sequentially forming an insulating coating layer B. The method of forming an enamel layer by applying and baking a resin varnish and the method of forming an extrusion coating layer are themselves widely known in the technical field of insulated wires, and the insulated wire of the present invention can be obtained by appropriately applying a conventional method, except for forming the insulating coating layer A so as to leave a specific amount of organic solvent a.

In the present invention, in order to cause a specific amount of the organic solvent a to remain in the formed insulating coating layer A, the baking conditions for the resin varnish described above, etc. can be adjusted as appropriate.
For example, the content (residual amount) of organic solvent a increases when the passing time is shortened and the furnace temperature is lowered among the baking conditions. Further, by baking using a baking furnace with a short furnace length, the heating time is shortened even if the set temperature is the same, so the content of the organic solvent a can be effectively adjusted to a desired amount. Such a method for controlling the amount of residual solvent itself is widely known among those skilled in the art, and the amount of residual solvent can be controlled to a desired amount by appropriately adjusting the manufacturing conditions.

[Applications of insulated wire]
The insulated wire of the present invention can be preferably processed into a coil and used in fields that require high voltage resistance and heat resistance, such as various electrical devices. Electrical/electronic equipment using this coil is not particularly limited. A preferred embodiment of such electric/electronic equipment is a transformer. Further, for example, a rotating device (for example, a drive motor of a hybrid vehicle or an electric vehicle) including the stator 30 shown in FIG. 3 can be mentioned. This rotating device can have the same configuration as a normal rotating device except that it includes the stator 30.
The stator 30 can have the same configuration as a normal stator except that the wire segments 34 (segment coils 34) are formed of the insulated wire of the present invention. That is, the stator 30 has a stator core 31 (stator core 31) and a wire segment 34 made of the insulated wire of the present invention, for example, as shown in FIG. It has a coil 33 which is connected to each other. Here, the electric wire segment 34 may be incorporated into the slot 32 singly, but preferably as a set of two as shown in FIG. In this stator 30 , a coil 33 is housed in a slot 32 of a stator core 31 , and the coil 33 is formed by connecting electric wire segments 34 bent as described above with their two open end portions 34 a alternately connected. At this time, the open ends 34a of the wire segments 34 may be connected and then stored in the slots 32. Alternatively, after the insulating segments 34 are stored in the slots 32, the open ends 34a of the wire segments 34 may be bent. You can also connect it by

[Manufacturing methods for electrical and electronic equipment]
The method for manufacturing an electric/electronic device of the present invention includes the steps of segmenting the insulated wire of the present invention described above and removing the end coating of the segment by irradiating it with laser light, processing the segment from which the end coating has been removed into a coil shape to form a segment coil, and incorporating the segment coil into a slot of a stator core, and welding the ends of the segment coil from which the coating has been removed to electrically connect them. An example of each of these steps, including the steps before and after these steps, will be described with reference to the drawings.

Figure 5 is an explanatory diagram that shows a schematic diagram of one embodiment of the method for manufacturing electrical and electronic devices of the present invention. Note that the method for manufacturing electrical and electronic devices of the present invention is not limited to the following embodiment except as specified in the present invention.

FIG. 5 shows a step of shortening the insulated wire (segmentation step), a film removal step of removing the film at the end of the obtained segment coil, and an assembly step of assembling the segment coil into the slot of the stator core. This shows a welding/powder coating process in which the ends of the segment coils from which the film has been removed are welded together, and the welded parts are powder coated (insulating coated). Each of these steps will be explained below.

<Shortening process>
In the shortening step, the insulated wire 1 wound around the roller R is cut at predetermined intervals, thereby obtaining the insulated wire 1 shortened to a predetermined dimension.

<Film Removal Process>
In the coating removal step, the insulating coating at the end of the shortened insulated electric wire 1 is burned (pyrolyzed) by irradiation with laser light and removed to expose the conductor 10 at the end. Methods for removing the insulating coating by irradiation with laser light are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 6-38330, 2001-309521, and 2005-285755.
The coating removal step of the present invention may be performed by a laser device. The laser device may have, for example, a laser oscillator and be configured to be capable of outputting laser light with a power of several kW. Alternatively, the laser device may have, for example, a plurality of semiconductor laser elements therein and be configured to be capable of outputting multimode laser light with a power of several kW as the total output of the plurality of semiconductor laser elements.
The laser device may have various laser light sources such as a fiber laser, a YAG (Yttrium Aluminum Garnet) laser, a disk laser, etc. The laser device may output a continuous wave of laser light or a pulse of laser light.

In the present invention, the insulating coating layer A of the insulated wire 1 contains 500 to 20,000 ppm of organic solvent a with a flash point of 0 to 50°C and a boiling point of less than 150°C, which makes it possible to sufficiently remove the insulating coating from the surface of the conductor 10 in a short time. In addition, the reduction in the conductor cross-sectional area caused by excessive removal of the surface layer of the conductor 10, which was a problem in the conventional mechanical cutting method, is suppressed. In addition, no shavings of the conductor 10 are generated, and there is no need to worry about wear on the mold used in the press processing. Therefore, it is possible to effectively improve the performance and manufacturing efficiency of coils or electric/electronic devices using the insulated wire.

<Assembly process>
In the assembly process, the insulated wire 1, from whose end the insulating coating has been removed, is bent into a hairpin shape to produce the segment coil 34. Next, the segment coil 34 is inserted into the slot 32 of the stator core 31, and the segment coil 34 protruding from the surface of the stator core 31 is twisted.

<Welding/powder coating process>
In the welding/powder coating process, the open end 34a of one segment coil 34 and the open end 34a of the other segment coil 34 are welded and electrically connected. The weld area is then coated with an insulating powder coating, and the weld area is coated with an insulating material.

Through each of the above steps, the desired electrical/electronic device can be obtained.
Note that the order of the above <film removal step> and the above <incorporation step> may be reversed. That is, after the <shortening step> described above, the segments of the insulated wire may be processed into a coil shape to form a segment coil, and the segment coil may be assembled into the slot of the stator core, and then the end coating of the segment coil may be removed by laser light irradiation. .
Regarding the above embodiments, the present invention provides the following method for manufacturing electrical/electronic equipment.

a step of removing a coating on an end of the segment of the insulated electric wire of the present invention by irradiating the end with a laser beam;
A step of forming the segment from which the end coating has been removed into a coil shape to form a segment coil and incorporating the segment coil into a slot of a stator core;
and welding the ends of the segment coils together to electrically connect them.

A step of forming a segment coil by processing the segment-shaped insulated electric wire of the present invention into a coil shape and incorporating the segment coil into a slot of a stator core;
removing an end coating of the segment coil incorporated in the slot of the stator core by irradiating it with laser light;
and welding the ends of the segment coils together to electrically connect them.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[Preparation of insulated wire]
<Example 1>
In Example 1, an insulated wire 2 shown in FIG. 2 was produced.
As the conductor 10, a copper wire having a rectangular cross section was used.
For forming the insulating coating layer A, a die having a shape similar to that of the insulating coating layer A formed on the conductor 10 was used. A polyimide resin varnish was coated on the surface of the conductor 10 using the die, and the conductor was passed through a hot air circulation furnace with a furnace length of 10 m and a furnace temperature of 500° C. at a speed that gave a passing time of 10 to 20 seconds. This was repeated three times to form an insulating coating layer A with a thickness of 15 μm.
For forming the insulating coating layer B, a die having a shape similar to that of the insulating coating layer B formed on the insulating coating layer A was used. The polyamide-imide resin varnish was coated on the surface of the insulating coating layer A using the die, and passed through a hot air circulation furnace with a furnace length of 10 m and a furnace temperature of 500° C. at a speed that gave a passing time of 10 to 20 seconds. Ta. By repeating this three times, an insulating coating layer B having a thickness of 15 μm was formed.
In Example 1, the polyimide resin varnish used to form the insulation coating layer A was based on a commercially available polyimide resin varnish (manufactured by Unitika, trade name: Uimide), and n-butanol was mixed therein as an organic solvent a. I used the one I made.
Further, as the polyamide-imide resin varnish used for forming the insulating coating layer B, a commercially available polyamide-imide resin varnish (manufactured by Showa Denko Materials, trade name: HI406) was used.
In Example 1, the ratio of the thickness (D2) of insulation coating layer A to the total thickness (D1) of insulation coating layer A and insulation coating layer B (thickness ratio, D2/D1) is 0. It was 50.

Example 2
An insulated wire 2 was produced in the same manner as in Example 1, except that the total thickness (D1) of the insulating coating layer A and the insulating coating layer B was not changed and the ratio (D2/D1) of the thickness of the insulating coating layer A to D1 was set to 0.20.

Example 3
An insulated wire 2 was produced in the same manner as in Example 2, except that the commercially available polyimide resin varnish used in forming the insulating coating layer A was changed to the commercially available polyamideimide resin varnish, and the commercially available polyamideimide resin varnish used in forming the insulating coating layer B was changed to the commercially available polyimide resin varnish. Note that n-butanol was mixed into the polyamideimide resin varnish as the organic solvent a.

Example 4
An insulated wire 2 was produced in the same manner as in Example 3, except that the coating and baking process in forming the insulating coating layer A was repeated six times to make the insulating coating layer A 30 μm thick, and the insulating coating layer B was an extruded coating layer having a thickness of 100 μm.
The ratio of the thickness (D2) of the insulating coating layer A to the total thickness (D1) of the insulating coating layer A and the insulating coating layer B (film thickness ratio, D2/D1) was set to 0.23.
In forming the extrusion coating layer, an extruder screw with a full flight of 30 mm, L/D = 20, and a compression ratio of 3 was used. Polyetheretherketone (PEEK) (manufactured by Solvay, product name: KT-800) was used as the thermoplastic resin, and extrusion coating was performed at 370°C (extrusion die temperature) using an extrusion die so that the outer shape of the cross section of the extrusion coating layer was similar to the shape of the conductor 10, and an insulating coating layer B with a thickness of 100 µm was formed on the outside of the insulating coating layer A.

Example 5
An insulated wire 2 was produced in the same manner as in Example 4, except that the commercially available polyamideimide resin varnish was changed to a polyetherimide resin varnish and the thickness of the insulating coating layer A was set to 10 μm. The ratio (D2/D1) of the thickness of the insulating coating layer A (D2) to the total thickness (D1) of the insulating coating layer A and the insulating coating layer B was set to 0.09.
In forming the insulating coating layer A, polyetherimide (PEI) (product name: Ultem 1010, manufactured by Sabic Innovative Plastics) was dissolved in N-methyl-2-pyrrolidone (NMP), and n-butanol was further mixed as organic solvent A to prepare a polyetherimide resin varnish. Next, this varnish was coated on the surface of the conductor 10 using a die having a similar shape to the shape of the conductor 10, and the conductor was passed through a baking furnace having a length of 10 m and an internal temperature of 500° C. at a speed giving a passage time of 15 seconds, thereby forming an insulating coating layer A made of polyetherimide having a thickness of 10 μm.

<Comparative example 1>
In Example 4, an insulated wire was produced in the same manner as in Example 4, except that the insulating film was only an extruded PEEK coating layer (thickness: 100 μm).

<Comparative Example 2>
An insulated wire was produced in the same manner as in Example 5, except that in forming the insulating coating layer A in Example 5, the organic solvent a was not mixed into the polyetherimide resin varnish.

<Comparative example 3>
In Example 4, an insulated wire was produced in the same manner as in Example 4, except that a commercially available polyamide-imide resin varnish was used as it was (without adding organic solvent a) to form the insulating coating layer A. did.

[Measurement of organic solvent content in insulation coating layer A]
Regarding the insulated wires according to Examples and Comparative Examples, the insulation coating layer B was peeled off from the insulation coating layer A using a knife, and then the insulation coating layer A was peeled off from the conductor 10 using a knife. Accurately measure 3 mg of the peeled insulation coating layer A, thermally decompose it at a thermal decomposition temperature of 400°C, measure the volatilized organic solvent by gas chromatography analysis, and determine the organic solvent species and their content. did. The results are shown in Table 1.

[Laser peel test]
The insulated wires according to the examples and comparative examples were made into segments with a length of 70 mm, and the insulating film covering the ends was removed by irradiating with infrared laser light with a wavelength of 1070 nm (output: 300 W, speed: 1500 mm/s). did. The time required for the insulation film to be completely removed within 10 mm from the end of the insulated wire was measured. The results are shown in Table 1.

(Note to Table 1)
"PAI", "PI", "PEEK", and "PEI" in Table 1 mean "polyamideimide", "polyimide", "polyetheretherketone", and "polyetherimide", respectively.
The "film thickness ratio" in Table 1 means the ratio (D2/D1) of the thickness (D2) of the lower layer to the total thickness (D1) of the lower layer and the upper layer.

As shown in Table 1, the time required to remove the insulating coating of the insulated wire of the comparative example by laser light irradiation was 18 to 20 seconds, whereas the time required to remove the insulating coating of the insulated wire 2 of the example by laser light irradiation was 0.5 to 1 second. From this result, it was found that the time required to remove the insulating coating of the insulated wire 2 of the example by laser light irradiation was significantly reduced.

[Measurement of carbon atom concentration]
Next, in the segments of the insulated wires according to the examples and comparative examples in which the laser peeling test was performed, the carbon atom concentration (atomic %, at%) on the surface of the conductor peeled off by laser light irradiation was measured. Specifically, the conductor surface is analyzed by energy dispersive X-ray spectroscopy (EDS), and the total number of carbon atoms, oxygen atoms, and copper atoms present on the conductor surface is 100%. The carbon atom number concentration was calculated by conversion. The measurement results are shown in Table 2.
(Judgment criteria for carbon atom number concentration)
◎: Carbon atom concentration is less than 25% ○: Carbon atom concentration is 25% or more and less than 50% △: Carbon atom concentration is 50% or more

[Welding strength test]
For the insulated electric wires according to the examples and comparative examples on which the laser peeling test was carried out, the conductors at the exposed ends of two segments were welded together, and the weld strength was measured. The test results are shown in Table 2. The welding was carried out by irradiating a laser beam.
In measuring the weld strength, both ends of two welded insulated electric wires were gripped and pulled in opposite directions, and the load (N) was measured when the weld broke.
(Weld strength test criteria)
△: Weld strength is less than 500N. ◯: Weld strength is 500N or more and less than 700N. ◎: Weld strength is 700N or more.

As shown in Table 2, insulated wires 2 according to Examples 1 to 4, in which the oxygen atomic percentage of the resin constituting the insulation coating layer A is 10 atomic % or more, and the insulation coating layer A contains a specific amount of organic solvent a. It was found that the soot remaining on the conductor surface caused by laser peeling was suppressed and the welding strength was further increased.

1, 2... Insulated wire, 10, 20... Conductor, A, B... Insulating coating layer.

Claims (13)

It has at least a conductor and an insulating coating layer A including an insulating resin layer disposed in contact with the conductor, and in the insulating coating layer A, an organic solvent having a flash point of 0 to 50° C. and a boiling point of less than 150° C. Insulated wire with a content of 500 to 20,000 ppm. The insulated wire according to claim 1, having an insulating coating layer B around the insulating coating layer A, the insulating coating layer B having an organic solvent content of less than 500 ppm. The insulated wire according to claim 2, wherein the insulating coating layer B is an enamel layer and/or an extruded coating layer. The insulated wire according to claim 3, wherein the insulating coating layer A is an enamel layer. The insulated wire according to claim 4, wherein the thickness of the insulating coating layer A is 3 to 50 μm. The insulated wire according to claim 5, wherein the content of oxygen atoms in the polymer constituting the insulating coating layer A is 10 atomic % or more. The insulated wire according to claim 6, wherein the insulating coating layer A contains polyimide and/or polyamideimide. The insulated wire of claim 7, wherein the conductor comprises copper or aluminum. A coil using the insulated wire according to any one of claims 1 to 8. An electric/electronic device having the coil according to claim 9. The electrical/electronic device according to claim 10, wherein the electrical/electronic device is a transformer. A step of removing the end film of the segment of the insulated wire according to any one of claims 1 to 8 by laser light irradiation,
Processing the segment from which the end film has been removed into a coil shape to form a segment coil, and incorporating it into a slot of a stator core;
A method for manufacturing electrical/electronic equipment, the method comprising the step of welding the ends of the segment coils to electrically connect them. A step of processing the segment of the insulated wire according to any one of claims 1 to 8 into a coil shape to form a segment coil, and incorporating the segment coil into a slot of a stator core;
removing the end coating of the segment coil incorporated in the slot of the stator core by laser beam irradiation;
A method for manufacturing electrical/electronic equipment, the method comprising the step of welding the ends of the segment coils to electrically connect them.

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