Insulated electric wire, coil using the same, thickness variation insulating tape used in the manufacture of the insulated electric wire, and method for manufacturing the same

Abstract

Provided is an insulated electric wire, a coil using the same, a thickness-variable insulation tape used in the production of the insulated electric wire, and a production method thereof, which can increase a partial discharge inception voltage and prevent deterioration of an insulator, and can achieve a slot fill factor that is not deteriorated. The above problems are solved by the following insulated electric wire, which is a coil-use insulated electric wire (10) having a conductor (1) and an insulating cover (2, 3) provided on the outer periphery of the conductor (1), wherein the insulated electric wire includes a thicker insulating cover (3) for a portion where a voltage becomes high when wound into a coil and partial discharge is likely to occur, and a thinner insulating cover (2) for a portion where a voltage does not become high and partial discharge is not likely to occur, and the thicker insulating cover (3) and the thinner insulating cover (2) are repeatedly provided at arbitrary intervals. The above problems are solved by the following coil, which is a coil (40) obtained by winding the above insulated electric wire (10), wherein the insulating cover (3) of the insulated electric wire (10) at a portion where partial discharge is likely to occur is thicker, and the insulating cover (2) of the insulated electric wire (10) at a portion where partial discharge is not likely to occur is thinner.

Description

Technical Field

[0001] This invention relates to an insulated wire whose thickness can be arbitrarily changed in order to increase the initiation voltage of partial discharge (corona discharge), a coil using the insulated wire, a thickness-variable insulating tape used in the manufacture of the insulated wire, and a method thereof. Background Technology

[0002] Insulated wires are used in various products. In particular, when insulated wires are used as windings for coils in rotating electrical equipment such as motors, they are used under high voltage. At this time, severe partial discharge (corona discharge) sometimes occurs on the surface of the insulation. This partial discharge is caused by localized temperature increases or the generation of ozone or ions, leading to accelerated deterioration of the insulation. The occurrence of partial discharge can shorten the lifespan of equipment using its components.

[0003] In recent years, the increasing demand for small, high-power electric motors has created a need for coils capable of increasing applied voltage. However, increasing the applied voltage leads to higher voltage applied to the coil, making partial discharge more likely. To address this problem, it is desirable to increase the voltage at which partial discharge occurs (called the partial discharge initiation voltage). To raise this voltage, methods have been employed, such as thickening the insulation coating of enameled wire, thickening the insulation coating based on resin extrusion, and lowering the dielectric constant of foamed insulation coatings. However, regardless of the method, the slot fill factor of the coil winding or the coating strength decreases, and there are limits to increasing the partial discharge initiation voltage.

[0004] Partial discharge is prone to occur when a high voltage is applied to the "lap joint" of the stator slot conductor section (the slot conductor section refers to the section in which wires are arranged) of the electric motor. To solve this problem, for example, Patent Documents 1 and 2 describe methods to suppress partial discharge by changing the thickness and material of the insulation material in the slot conductor section and the lap joint of the insulated wire.

[0005] Specifically, Patent Document 1 describes a method in which, after winding and shaping a conductor into a coil, an insulating layer is formed in each portion that becomes the slot conductor portion and the overlapping portion, and the thickness of each insulating layer is varied. Furthermore, Patent Document 2 describes a method in which the relative permittivity of the overlapping portion along the length of the insulated wire is lower than that of the slot conductor portion along the length of the insulated wire by adjusting the total volume of air bubbles in the resin forming the insulating layer.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2008-236924

[0009] Patent Document 2: Japanese Patent Application Publication No. 2015-138678 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] However, manufacturing insulated wires with insulation layers that provide the insulation performance required for coil design necessitates a significant amount of time and complex processes in the aforementioned methods. Furthermore, it is difficult to manufacture insulated wires with insulation sheaths of varying thicknesses to achieve the insulation performance required for coil design using enameling baking methods or resin extrusion methods.

[0012] The present invention was made to solve the above-mentioned problems, and its object is to provide an insulated wire, a coil using the insulated wire, a thickness-variable insulating tape used in the manufacture of the insulated wire, and a method thereof, which can be manufactured without a large amount of time and complex procedures, can increase the partial discharge initiation voltage and prevent the deterioration of the insulator, and can achieve a constant slot fill factor.

[0013] Solution for solving the problem

[0014] (1) The insulated wire of the present invention is an insulated wire having a conductor and an insulating cover disposed on the outer periphery of the conductor, characterized in that the insulated wire includes a thicker insulating cover and a thinner insulating cover, and the thicker insulating cover and the thinner insulating cover are repeatedly disposed at arbitrary intervals.

[0015] According to the present invention, since thicker and thinner insulating covers are repeatedly provided at arbitrary intervals, it is possible, for example, to thicken the insulating covers in areas prone to partial discharge or requiring higher insulation withstand voltage. As a result, for example, the partial discharge initiation voltage at the overlap can be increased, or the insulation withstand voltage in areas requiring higher insulation withstand voltage can be increased. Furthermore, for example, the insulating covers in slot conductor portions or areas where insulation withstand voltage is not required can be thinned, thereby improving the slot fill factor without causing it to deteriorate. Since these portions are repeatedly provided at arbitrary intervals, for example, in the case of a coil preferably used in a three-phase induction motor, a thinner insulating cover can be formed in the slot conductor portion of the motor, and a thicker insulating cover can be formed in the overlap portion of the connecting slot conductor portion of the motor where high voltage is applied.

[0016] In the insulated wire of the present invention, the thicker insulating cover and the thinner insulating cover are formed by winding an insulating strip having thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. According to the present invention, by winding the aforementioned thicker insulating strip around the outer periphery of the conductor, it is possible to form an insulated wire having thicker and thinner insulating covers repeatedly provided at arbitrary intervals.

[0017] In the insulated wire of the present invention, the thicker insulating sheath and the thinner insulating sheath are configured to have different visual distinguishability. According to the present invention, by setting the visual distinguishability to differ according to the thickness of the insulating sheath, the thinner insulating sheath and the thicker insulating sheath can be distinguished. Therefore, during coil manufacturing, the thinner insulating sheath and the thicker insulating sheath can be distinguished by operators, discrimination sensors, etc., making the coil manufacturing process easier.

[0018] In the insulated wire of the present invention, the thickness-varying insulation tape is composed of a substrate tape and an adhesive tape bonded to one main surface of the substrate tape, or of a substrate tape, an adhesive tape bonded to one main surface of the substrate tape, and a cover tape further bonded to the adhesive tape in a manner that covers the adhesive tape. According to the present invention, the thickness-varying insulation tape can be made into a simple structure consisting of a substrate tape and an adhesive tape, or into a so-called sandwich structure consisting of a substrate tape, an adhesive tape, and a cover tape.

[0019] In the insulated wire of the present invention, the thickness-varying insulating tape further comprises an adhesive layer formed on one main surface of the substrate tape and the adhesive tape, or on the other main surface of the substrate tape. The thickness-varying insulating tape, initially wound around the outer periphery of the conductor, is wound such that the adhesive layer is on the inner side (conductor side or outer side). Further thickness-varying insulating tapes provided on the aforementioned thickness-varying insulating tape are wound such that the adhesive tape side and the adhesive layer are both on the inner side. According to the present invention, the other main surface of the substrate tape on the planar side can be firmly bonded to the conductor. Furthermore, in the case of further overlapping winding, the further thickness-varying insulating tapes provided on the thickness-varying insulating tape are wound such that the adhesive tape side and the adhesive layer are both on the inner side, thereby making the appearance of the insulating coating uniform and smooth. This has the effect of preventing snagging on jigs used in processing such as manufacturing coils using insulated wires, and suppressing damage during processing. In addition, to facilitate the peeling of the insulating cover, the varying thickness insulating tape initially wound around the outer periphery of the conductor can be achieved by making the adhesive layer the outer side.

[0020] In the insulated wire of the present invention, a thickness-variable insulating tape is wound around the outer periphery of the conductor, and other thickness-variable or constant-thickness insulating tapes are also wound around the outer periphery of the thickness-variable insulating tape, and the thicker insulating cover and the thinner insulating cover are repeatedly wound. According to the present invention, it is possible to configure an insulated wire that has multiple thickness-variable insulating tapes wound around it to further thicken the thicker insulating cover, thereby improving the insulation withstand voltage, and an insulated wire that has a constant-thickness insulating tape wound around it to further thicken the thinner insulating cover, thereby adjusting the slot fill factor.

[0021] In the insulated wire of the present invention, when other insulating tapes of varying thickness are further wound on top of the aforementioned thickness-variable insulating tape, the thicker regions of the other thickness-variable insulating tapes are overlapped and wound onto the already formed thicker insulating sheath. According to the present invention, since the thicker regions of the other thickness-variable insulating tapes are overlapped and wound onto the already formed thicker insulating sheath, the thicker insulating sheath can be further thickened.

[0022] In the insulated wire of the present invention, when other insulating tapes of varying thickness or constant thickness are further overlapped on top of the aforementioned insulating tapes of varying thickness, the other insulating tapes of varying thickness and the constant thickness insulating tapes are overlapped by changing the winding direction of the insulating tapes of varying thickness. According to the present invention, when multiple insulating tapes are overlapped, since the aforementioned insulating tapes are overlapped by changing the winding direction, the thickness of the insulating sheath can be made uniform and the surface smooth. This has the effect of preventing snagging on jigs used in processing such as manufacturing coils using insulated wires, and suppressing damage during processing.

[0023] In the insulated wire of the present invention, the thicker insulating sheath has tapered portions at both ends. According to the present invention, the tapered portions of the thicker insulating sheath allow the thicker insulating sheath to smoothly transition into a thinner insulating sheath, which has the effect of preventing snagging on jigs used in processing such as manufacturing coils with insulated wires, and suppressing damage during processing.

[0024] In the insulated wire of the present invention, it is preferable that the taper ratio of the tapered portion is 0.5 / 1000 or more and 150 / 1000 or less. By setting the taper ratio within this range, an appropriate insulation thickness can be obtained, and good insulation properties can be achieved.

[0025] In this case, the thicker insulating layer and the thinner insulating layer are formed by winding a thickness-varying insulating tape with thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. In the thickness-varying insulating tape, the boundary line between the thicker and thinner regions is formed obliquely relative to the length direction of the thickness-varying insulating tape. According to the present invention, the abrupt change in the outer diameter of the insulated wire at the boundary portion of the thickness-varying insulating tape can be reduced. As a result, the amount of change in outer diameter is reduced, allowing for a smoother surface. This has the effect of preventing snagging on jigs used in processing such as manufacturing coils with insulated wires, and suppressing damage during processing.

[0026] In the insulated wire of the present invention, when the winding angle of the thickness-varying insulation strip relative to the length direction of the conductor is set as θ1, the angle of the boundary line between the thicker and thinner regions relative to the length direction of the thickness-varying insulation strip is set as θ2, and the angle formed by the boundary line of the thickness-varying insulation strip and the length direction of the conductor is set as θ3, θ1 is in the range of 10° to 60°, and θ2 is in the range of 10° to 90°, and the winding is performed in a direction where θ2 is larger than θ3. Particularly preferred is that θ3 is 0°.

[0027] In the insulated wire of the present invention, an extruded resin layer is also provided as an insulating outer sheath.

[0028] (2) The coil of the present invention is a coil obtained by winding the insulated wire of the present invention described above. The insulated wire includes a portion having a thicker insulating cover and a portion having a thinner insulating cover, and the thicker insulating cover and the thinner insulating cover are repeatedly arranged at arbitrary intervals.

[0029] According to the present invention, since a coil is obtained by winding an insulated wire with a thicker insulating sheath and a thinner insulating sheath repeatedly arranged at arbitrary intervals, it is possible to use, for example, an insulated wire with a thicker insulating sheath in areas prone to partial discharge or areas requiring higher insulation withstand voltage. As a result, it is possible to design a coil that, for example, increases the partial discharge initiation voltage at the overlap or increases the insulation withstand voltage in areas requiring higher insulation withstand voltage. In addition, by using, for example, an insulated wire with a thinner insulating sheath in areas where the slot conductor portion or the insulation withstand voltage is not required, the slot fill factor can be improved without deteriorating.

[0030] In this coil, it is preferable that the insulation sheath of the insulated wire in the portion where the voltage is high and partial discharge is prone to occur has a thicker insulation sheath, while the insulation sheath of the insulated wire in the portion where the voltage is not high and partial discharge is not prone to occur has a thinner insulation sheath. According to the present invention, since the insulation sheath of the insulated wire in the portion where partial discharge is prone to occur is thicker, for example, the partial discharge initiation voltage at the overlap portion can be increased, and since the insulation sheath in the portion where partial discharge is not prone to occur is thinner, the slot fill factor can be improved without the slot fill factor deteriorating. Since the above-mentioned portions are repeatedly arranged at arbitrary intervals, for example, in the case where it is preferably used as a coil for a three-phase induction motor, a thinner insulation sheath can be provided for the slot conductor portion of the motor, and a thicker insulation sheath can be provided for the portion where high voltage is applied at the overlap portion of the connecting slot conductor portion of the motor.

[0031] (3) The thickness-varying insulating tape of the present invention is characterized by being composed of an insulator and having alternating thinner and thicker portions. According to the present invention, by winding such a thickness-varying insulating tape around the outer periphery of a conductor, an insulating covering consisting of thicker and thinner portions can be formed on the outer periphery of the conductor.

[0032] In the thickness-varying insulating tape of the present invention, the thickness of the thicker portion is 1.5 times or more and 8 times or less than the thickness of the thinner portion. According to the present invention, since the thickness of the thicker portion of the thickness-varying insulating tape is within the above-mentioned range, the work efficiency is good when the thickness-varying insulating tape is wound around the outer periphery of the conductor, and it can be configured as an insulating cover with sufficient thickness difference.

[0033] In the thickness-varying insulating tape of the present invention, the thicker portion is colored. According to the present invention, the thicker portion can be easily identified during the operation of winding the thickness-varying insulating tape, etc. Furthermore, when the thickness-varying insulating tape is wound around the outer periphery of a conductor, the thicker portion of the insulating covering formed on the outer periphery of the conductor can be designated as the colored portion.

[0034] In the thickness-varying insulating tape of the present invention, the thinner portion is composed of a substrate tape, and the thicker portion is composed of the substrate tape and an adhesive tape bonded to one main surface of the substrate tape. According to the present invention, a simple structure can be formed without complex processes.

[0035] In the thickness-varying insulating tape of the present invention, the thinner portion is formed by overlapping a substrate tape and a cover tape, and the thicker portion includes an adhesive tape sandwiched between the substrate tape and the cover tape and bonded to a main surface of the substrate tape. According to the present invention, a simple structure can be formed without complex processes; furthermore, by using the cover tape, the winding performance when wound around the outer periphery of the conductor can be improved.

[0036] In the thickness-varying insulating tape of the present invention, the adhesive tape is colored. According to the present invention, the thicker portion of the thickness-varying insulating tape can be colored with a simple construction that does not require complex processes.

[0037] In the thickness-varying insulating tape of the present invention, the substrate tape and the adhesive tape are made of insulating materials with the same heat resistance temperature. According to the present invention, the heat resistance temperature of the thickness-varying insulating tape can be made uniform, which is preferable in terms of the overall heat resistance of the wire when used as an insulating sheath for insulated wires.

[0038] In the thickness-varying insulating tape of the present invention, the boundary line between the thicker portion and the thinner portion is formed obliquely relative to the length direction of the thickness-varying insulating tape. According to the present invention, when the thickness-varying insulating tape is wound around a conductor, the insulated wire with respect to the boundary portion of the thickness variation of the winding thickness-varying insulating tape can reduce abrupt changes in its outer diameter. As a result, the amount of change in outer diameter is reduced, thereby enabling a smoother surface.

[0039] The thickness-varying insulating tape of the present invention functions as an insulating covering provided on the outer periphery of the conductor constituting an insulated wire.

[0040] (4) The method for manufacturing the thickness-varying insulating tape of the present invention is a method for manufacturing a thickness-varying insulating tape composed of an insulator and repeatedly having thinner and thicker portions, characterized in that the method for manufacturing the thickness-varying insulating tape is any one of the methods (a) to (b) below.

[0041] (a) The following method: temporarily bonding an adhesive substrate tape, which becomes the thicker portion, to a substrate tape that becomes the thinner portion; removing the adhesive substrate tape in a predetermined shape; and setting the remaining portion of the adhesive substrate tape as the thicker portion.

[0042] (ii) The following method: bonding an adhesive tape, which is formed into a predetermined shape and constitutes the thicker portion, to a substrate tape, which constitutes the thinner portion.

[0043] (iii) The following method: adhesive tape cut to a predetermined width to form the thicker portion is bonded to a substrate tape forming the thinner portion and then cut, or the adhesive tape is cut simultaneously with the heating and stamping process.

[0044] (iv) The following method: temporarily bond an adhesive substrate tape to the process tape to form the thicker portion, remove the adhesive substrate tape in a predetermined shape and set the remaining portion of the adhesive substrate tape as the thicker portion, bond a base material tape to the second tape that forms the thicker portion to form the thinner portion, and finally remove the process tape.

[0045] According to the present invention, it is possible to manufacture an insulating tape of varying thickness, which consists of a substrate tape and an adhesive tape, wherein the substrate tape is composed of a thinner portion and the adhesive tape is composed of a thicker portion bonded to a main surface of the substrate tape by means of an adhesive layer.

[0046] In the manufacturing method of the thickness-variable insulating tape of the present invention, a step of bonding a cover tape to the adhesive tape is further included. According to the present invention, it is possible to provide a sandwich structure in which a cover tape covering the entire adhesive tape is provided through an adhesive layer.

[0047] The effects of the invention

[0048] According to the present invention, it is possible to provide an insulated wire capable of increasing the partial discharge initiation voltage, preventing insulator deterioration, and maintaining a constant slot fill factor, as well as a coil for an electric motor made using the insulated wire. Furthermore, according to the present invention, it is possible to provide a thickness-variable insulation tape used in the manufacture of an insulated wire composed of a thicker insulation sheath and a thinner insulation sheath, and a method for manufacturing the thickness-variable insulation tape. Attached Figure Description

[0049] Figure 1 This is a perspective view showing an example of an insulated wire according to the present invention.

[0050] Figure 2 This is a schematic diagram illustrating an example of an insulating tape with varying thickness.

[0051] Figure 3 This is a schematic diagram used to illustrate the construction of thicker and thinner regions that make up an insulating tape with varying thickness.

[0052] Figure 4 This is an example of a cross-sectional view of an insulating tape with varying thickness. Figure 4 (A) is a thickness-variable insulating tape with an adhesive tape on a substrate tape. Figure 4 (B) is a thickness-varying insulating tape with an adhesive tape on a substrate tape and a cover tape thereon.

[0053] Figure 5 This is a longitudinal sectional view showing the structure of the insulating cover in the first embodiment.

[0054] Figure 6 This is a longitudinal sectional view showing the structure of the insulating cover in the second embodiment.

[0055] Figure 7 This is a longitudinal sectional view showing the structure of the insulating cover in the third embodiment.

[0056] Figure 8 This is a longitudinal sectional view showing the structure of the insulating cover in the fourth embodiment.

[0057] Figure 9 This is a structural diagram showing an example of the shape of an insulating tape. Figure 9 (A) is an example where the boundary between the thicker and thinner regions is orthogonal to the length direction of the strip. Figure 9 (B) is an example where the boundary between the thicker and thinner regions is at a predetermined angle θ2 relative to the length direction of the strip.

[0058] Figure 10 It is Figure 9 Example (B) shows a configuration where the strip is wound relative to the conductor at a predetermined winding angle θ1. Figure 10 (A) is an example of winding in a direction where the angle θ3 between the boundary line of the strip and the length direction of the conductor is smaller than the angle θ2 between the boundary line of the strip. Figure 10 (B) is an example of winding in a direction where the angle θ3 between the boundary line of the strip and the length direction of the conductor is larger than the angle θ2 between the boundary line of the strip.

[0059] Figure 11 It is Figure 9 The example shown in (B) where the strip is wound relative to the conductor at a predetermined winding angle θ1 is an example where the strip's dividing line angle θ2 is the same as the strip's winding angle θ1 and the angle θ3 formed by the dividing line and the conductor's length direction is 0°.

[0060] Figure 12 This is an external diagram showing an example of a folded shape. Figure 12 (A) is an example of half-overlapping insulation tape with varying thickness. Figure 12 (B) is an example of an insulation tape with a thickness variation of one-third overlap.

[0061] Figure 13 This is a structural unfolded diagram of the coil used in a three-phase induction motor.

[0062] Figure 14 This is a process diagram illustrating an example of a method for manufacturing the thickness-varying insulating tape of the present invention.

[0063] Figure 15 This is a process diagram illustrating another example of the manufacturing method of the thickness-varying insulating tape of the present invention.

[0064] Figure 16 This is a process diagram illustrating yet another example of the manufacturing method of the thickness-varying insulating tape of the present invention.

[0065] Figure 17 This is a process diagram illustrating yet another example of the manufacturing method of the thickness-varying insulating tape of the present invention.

[0066] Figure 18 This is a process diagram illustrating yet another example of the manufacturing method of the thickness-varying insulating tape of the present invention. Detailed Implementation

[0067] The insulated wire, coil, insulating tape with varying thickness, and manufacturing method thereof according to the present invention will be described with reference to the accompanying drawings. Furthermore, the present invention can be modified in various ways as long as it possesses its technical features, and is not limited to the manner described below and the accompanying drawings.

[0068] [Insulated wires]

[0069] like Figure 1 , Figures 5-8 As shown, the insulated wire 10 of the present invention is an insulated wire 10 having a conductor 1 and insulating coverings 2 and 3 disposed on the outer periphery of the conductor 1. The insulated wire 10 is characterized by comprising: a thicker insulating covering 3 for portions where the voltage increases and partial discharge is prone to occur during winding into a coil, and a thinner insulating covering 2 for portions where the voltage remains constant and partial discharge is less likely to occur. The thicker insulating covering 3 and the thinner insulating covering 2 are repeatedly provided at arbitrary intervals. Figure 13 As shown in the coil structure unfolded diagram, the coil 40 obtained by winding such an insulated wire 10 is configured such that the insulating sheath 3 of the insulated wire 10 is thicker in the part where the voltage is high and partial discharge is likely to occur, and the insulating sheath 2 of the insulated wire 10 is thinner in the part where the voltage is not high and partial discharge is unlikely to occur.

[0070] In the insulated wire 10 of the present invention, since the insulating sheath 3 of the insulated wire is thicker in areas where partial discharge is prone to occur, the partial discharge initiation voltage at the overlap portion can be increased, for example. Since the insulating sheath 2 of the insulated wire is thinner in areas where partial discharge is not prone to occur, the slot fill factor can be improved without deteriorating. Since the above-mentioned portions are repeatedly arranged at arbitrary intervals, for example, in the case of a coil 40 for a three-phase induction motor, a thinner insulating sheath 2 can be formed in the slot conductor portion of the motor, and a thicker insulating sheath 3 can be formed in the overlap portion of the connecting slot conductor portion of the motor where a high voltage is applied. As a result, an insulated wire and a coil for a motor made using the insulated wire can be provided, which can increase the partial discharge initiation voltage and prevent the insulation from deteriorating, and can achieve a stable slot fill factor.

[0071] The following is an explanation of each structure.

[0072] (conductor)

[0073] The conductor 1 is not particularly limited to being the center conductor of the insulated wire 10, especially the insulated wire 10 for coils; it can be any type of conductor, regardless of material or twisting structure. For example, conductor 1 can be a conductor consisting of a single wire extending along its length, a conductor consisting of multiple twisted wires, or a conductor configured as Litz wire. The type of wire is not particularly limited to a highly conductive metal, but copper wire, copper alloy wire, aluminum wire, aluminum alloy wire, copper-aluminum composite wire, and other highly conductive metal conductors, or wires with plating applied to the surface of the aforementioned metal conductors, are preferred. From the viewpoint of coils, copper wire and copper alloy wire are particularly preferred. As plating, solder plating, tin plating, gold plating, silver plating, nickel plating, etc., are preferred. Furthermore, the term "conductor" or "wire" also includes components covered by an enameled layer for insulation and anti-oxidation purposes, as described in this invention. There are no particular restrictions on the cross-sectional shape of the wire; it can be a wire with a circular or roughly circular cross-section, or a wire with a rectangular cross-section.

[0074] The cross-sectional shape of conductor 1 is not particularly limited; it can be circular (including elliptical) or rectangular, etc. It is desirable that the cross-sectional dimensions of conductor 1 be as large as possible to reduce resistance (AC resistance, conductor resistance), thereby making it a preferred conductor for coil applications. For example, the outer diameter of a circular wire can be approximately 0.05 mm to 4 mm. In the case of a rectangular wire, the shorter side can be approximately 0.3 mm to 5 mm, and the longer side approximately 0.5 mm to 10 mm. The cross-sectional dimensions of conductor 1 can be appropriately selected depending on the application of the coil; however, the smaller the cross-sectional dimensions, the more necessary it is to improve the tightness of the adhesion and the positioning accuracy of the insulating coverings 2 and 3, which will be described later.

[0075] (Insulating components)

[0076] like Figure 1 As shown, insulating sheaths 2 and 3 are disposed on the outer periphery of conductor 1. The insulating sheaths include: a thicker insulating sheath 3 used in areas where the voltage increases during winding into a coil and partial discharge is prone to occur, and a thinner insulating sheath 2 used in areas where the voltage remains constant and partial discharge is less likely to occur. These insulating sheaths are repeatedly disposed at arbitrary intervals. For example, the insulating sheath 3 in areas prone to partial discharge can increase the partial discharge initiation voltage at the overlap, while the insulating sheath 2 in areas less prone to partial discharge can, for example, improve the slot fill factor while maintaining a stable slot fill factor.

[0077] The materials for insulating coverings 2 and 3 are not particularly limited, but materials such as those used in insulating tapes, such as polyethylene resin, polyester resin (PET, PEN, etc.), polyimide resin, polyamide resin, polyamide-imide resin, polystyrene resin, polyphenylene sulfide resin, and PEEK (polyether ether ketone), are preferred. Alternatively, conductive materials such as aluminum foil, copper foil, or metal foils plated with tin, nickel, or gold may be used. Furthermore, the resin materials can be low-dielectric-constant fluorinated resins such as PFA, ETFE, and FEP used as dielectric materials, or polyolefin resins such as polyphenylene ether resin, polypropylene, polyester resin, and polyacrylic acid resin.

[0078] The thickness of the thinner insulating cover 2 is preferably in the range of 2 μm to 500 μm, and the thickness of the thicker insulating cover 3 is preferably thicker than the thinner insulating cover 2 and is in the range of 4 μm to 1000 μm. The respective thicknesses are set according to the characteristics of the coil of the insulated wire 10. In the thinner insulating cover 2, it is desirable to have a thickness that at least meets the required insulation withstand voltage, typically preferably 2 μm or more. On the other hand, in the thicker insulating cover 3, it is desirable to have a thickness that at least meets the insulation withstand voltage required to raise the required partial discharge initiation voltage, typically preferably 4 μm or more. Furthermore, the thickness of the thicker insulating cover 3 is at least 1.5 times and less than 8 times the thickness of the thinner insulating cover 2, preferably at least 2 times and less than 7 times.

[0079] Preferably, the insulating covers 2 and 3 are visually distinct from each other. Specifically, the visual distinctiveness of the insulating covers 2 and 3 can be achieved by varying their respective colors, patterns, and textures. By making the insulating covers 2 and 3 visually distinct, the thinner insulating cover 2 and the thicker insulating cover 3 can be distinguished. Therefore, during coil manufacturing, operators and sensors can differentiate between the thinner insulating cover 2 and the thicker insulating cover 3, making the coil manufacturing process easier. Furthermore, considering the ease of manufacturing when using the thickness-varying insulating tape 20 (described later), it is preferable to make the color of the thicker insulating cover 3 darker than the thinner insulating cover 2, or to color the thicker insulating cover 3 while leaving the thinner insulating cover 2 uncolored.

[0080] like Figure 1 (A) Figure 1As shown in (B), a tapered portion 3a is formed between the thinner insulating cover 2 and the thicker insulating cover 3, specifically between the main body portion 3b. The tapered portion 3a is formed such that its thickness increases from the boundary between it and the thinner insulating cover 2 to the boundary between it and the main body portion 3b. The thicker insulating cover 3 has a main body portion 3b, and tapered portions 3a are provided at both ends of the main body portion 3b along the length direction of the insulated wire 10. Because the thicker insulating cover 3 has tapered portions 3a, the change in the outer diameter of the insulated wire 10 is reduced, allowing for a smoother change in the thickness of the insulating cover. This has the effect of preventing snagging on jigs used in processing such as manufacturing coils using the insulated wire 10, and suppressing damage during processing.

[0081] In addition, with Figure 1 Compared to the method shown in (A), Figure 1 The method shown in (B) is an insulated wire 10 in which the length of the tapered portion 3a is formed to be longer. In this way, by making the tapered portion 3a longer, the amount of change in the outer diameter of the insulated wire 10 can be reduced, thereby making the thickness of the insulation cover change more smoothly.

[0082] For the tapered portion 3a, the taper ratio (defined as "difference in tapered diameter / axial length of the tapered portion") is preferably in the range of 0.5 / 1000 or more and 150 / 1000 or less. When the taper ratio is less than 0.5 / 1000, the axial length of the tapered portion 3a becomes too long, making it difficult to achieve an appropriate insulation thickness. Furthermore, when the taper ratio is greater than 150 / 1000, the change in outer diameter from the thinner insulating cover 2 to the thicker insulating cover 3 is significant, causing problems with insulation properties. A taper ratio of 1.0 / 1000 to 100 / 1000 is more preferable.

[0083] (Insulating tape with varying thickness)

[0084] like Figure 2 As shown, in the thickness-varying insulating tape 20, there are tape portions 21 (also called thinner sections 21.) that are thinner regions B and tape portions 22 (also called thicker sections 22.) that are thicker regions A, at predetermined intervals. In other words, the thinner sections 21 and thicker sections 22 are alternated. Here, "alternate" means that the thinner sections 21 and thicker sections 22 alternate. Figure 3 As shown, "alternation" can refer to alternation at fixed intervals (spacing) or alternation at irregular intervals. The "predetermined interval" can be set within the range of several millimeters to several meters, and can be arbitrarily set according to the intended use of the insulated wire.

[0085] Figure 3This is a schematic diagram used to illustrate the construction of the thinner portion 21 and the thicker portion 22. For example... Figure 3 As shown, there are no particular limitations on the repetition method; various methods can be used. For example, Figure 3 Example (A) illustrates a case where the intervals P1, P2, and P3 (also called distances) between the thicker portions 22a, 22b, and 22c are not constant. The interval P1 between the thicker portions 22a and 22b can be set to be longer than the intervals P2 between the thicker portions 22b and 22c, and the interval P3 between the thicker portions 22c and 22a. In this case, the lengths L1, L2, and L3 along the length direction of the thicker portions 22a, 22b, and 22c are set to be constant. Furthermore, Figure 3 Example (B) illustrates the case where the lengths of the thicker portions 22a, 22b, and 22c are not constant. The length L1 of the thicker portion 22a can be set to be longer than the length L2 of the other thicker portions 22b. In this case, the interval P1 between the thicker portions 22a and 22b, and the interval P2 between the thicker portions 22b and 22c, are set to constant.

[0086] like Figure 3 As shown, the length of the thicker portion 22 along its longitudinal direction and / or the spacing between the thicker portions 22 can be arbitrarily set. The spacing P1 between the thicker portions 22a and 22b can be set to a distance different from the spacing P2 between the thicker portions 22b and 22c and / or the spacing P3 between the thicker portions 22c and 22a. Furthermore, the lengths L1, L2, and L3 of the thicker portions 22a, 22b, and 22c along their longitudinal direction can also be set to non-fixed lengths. As a result, for example, adjustments can be made to the position of the thickened insulating covering to increase insulation, thus increasing design freedom. Furthermore, as... Figure 9 As shown in (B), the thicker part 2 can also be set as an inclined line shape. In this case, the intervals P1 and P2 can be set as the intervals of the thicker part 22 in the length direction X of the belt.

[0087] By winding such a thickness variation of insulating tape 20... Figure 1 The outer periphery of the conductor 1 shown is thus formed into an insulated wire 10 with insulating sheaths 2 and 3 formed on the outer periphery of the conductor 1, and thinner insulating sheaths 2 and thicker insulating sheaths 3 are repeatedly provided at arbitrary intervals. In detail, [the following text is missing from the original extract]. Figure 2 The strip 21 shown is wound around the outer periphery of the conductor 1, thereby forming a thinner insulating cover 2, and the strip 22 is wound around the outer periphery of the conductor 1, thereby forming a thicker insulating cover 3.

[0088] Regarding thickness, it is preferable that the thickness of the strip portion 22, which is the thicker region A, is 1.5 times or more but less than 8 times the thickness of the strip portion 21, which is the thinner region B. When the thickness of the strip portion 22 is less than 1.5 times the thickness of the strip portion 21, there is a risk that the thickness of the thicker insulating cover 3 formed by winding the strip portion 22 around the outer periphery of the conductor 1 cannot be sufficiently thick relative to the thinner insulating cover 2 formed by winding the strip portion 21 around the outer periphery of the conductor 1. Furthermore, when the thickness of the strip portion 22 exceeds 8 times the thickness of the strip portion 21, bending and wrinkling of the insulating strip 20 are likely to occur when the strip portion 22 is wound around the outer periphery of the conductor 1, potentially resulting in an uneven appearance after winding. More preferably, the thickness of the strip portion 22, which is the thicker region A, is 2 times or more but less than 7 times the thickness of the strip portion 21, which is the thinner region B.

[0089] Regarding the spacing between the thinner region B (strip 21) and the thicker region A (strip 22), when manufacturing a coil using an insulated wire 10 formed by winding a thickness-variable insulation strip 20 around the outer periphery of the conductor 1, the spacing is designed based on whether and to what extent the thinner insulation sheath 2 and the thicker insulation sheath 3 need to be spaced. In this design, the width, winding spacing, and overlap of the thickness-variable insulation strip 20 are taken into account, but... Figure 2 As shown, an example is a strip 22 with a length of 60mm to 80mm provided along the length direction, spaced at intervals of 40mm to 60mm.

[0090] like Figure 4 As shown in (A), the thickness-varying insulating tape 20 includes: a substrate tape 23 having two main surfaces F1 and F2, and an adhesive tape 24 bonded to one main surface F1 of the substrate tape 23 by means of an adhesive layer 25, which is a simple structure that does not require complicated processes.

[0091] The substrate tape 23 forms a tape portion 21 that is a thinner region B, and the substrate tape 23 and the adhesive tape 24 form a tape portion 22 that is a thicker region A. By winding the thickness-varying insulating tape 20 around the outer periphery of the conductor 1, the portion wound from the tape portion 21 forms a thinner insulating cover 2, and the portion wound from the tape portion 22 forms a thicker insulating cover 3. No adhesive layer is provided on the other main surface F2 of the substrate tape 23.

[0092] On the other hand, an adhesive layer 26 is provided on the adhesive tape 24. Additionally, an adhesive layer 26 is also provided on the adhesive tape side of the tape portion 21 where the adhesive tape 24 is not attached, i.e., on a main surface F1 of the substrate tape 23. In this thickness-varying insulating tape 20, since the adhesive layer 26 is provided on both the adhesive tape side of the tape portion 21 (i.e., on a main surface F1 of the substrate tape 23) and the adhesive tape 24, the side with the adhesive layer 26 is the conductor side (inner side) and it is wound around the outer periphery of the conductor 1.

[0093] Alternatively, although not illustrated, the adhesive layer 26 can be disposed on the other main surface F2 of the substrate strip 23, which is the flat side, instead of on the adhesive strip 24 of the adhesive strip's side S1. In this case, the flat side S2 of the substrate strip 23, i.e., the other main surface F2 of the substrate strip 23, is the conductor side and is wound around the conductor.

[0094] like Figure 4 As shown in (B), the thickness-varying insulating tape 20 is a so-called sandwich structure consisting of a substrate tape 23, an adhesive tape 24 bonded to a main surface F1 of the substrate tape 23 by means of an adhesive layer 25, and a cover tape 27 that completely covers the adhesive tape 24 through the adhesive layer 25a. With this structure, the thickness-varying insulating tape 20 can be manufactured with a simple construction that does not require complex processes. Furthermore, by using the cover tape 27, the winding properties to the conductor 1 can be improved.

[0095] The substrate tape 23 and the cover tape 27 constitute a tape portion 21 forming a thinner region B, while the substrate tape 23, the adhesive tape 24, and the cover tape 27 constitute a tape portion 22 forming a thicker region A. An adhesive layer 26 is provided on the other main surface F2 of the flat surface S2 of the substrate tape 23. On the other hand, no adhesive layer is provided on the cover tape 27. In this thickness-varying insulating tape 20, the adhesive layer 26 is provided on the other main surface F2 of the flat surface S2 of the substrate tape 23, so that the adhesive layer 26 side is the conductor side (inner side) and is wound around the outer periphery of the conductor 1. Alternatively, although not shown, the adhesive layer 26 can be provided on the cover tape 27 instead of on the flat surface S2 of the substrate tape 23, i.e., the other main surface F2 of the substrate tape 23. In this case, the adhesive tape surface S1 is the conductor side and is wound around the conductor.

[0096] Like this Figure 4 (A) Figure 4As shown in (B), the adhesive layer 26 is provided on either the face side S1 of the adhesive tape or the planar side S2 of the substrate tape. Furthermore, the thickness-varying insulating tape 20 initially wound around the outer periphery of the conductor 1 is wound such that the planar side S2 of the substrate tape is on the inside (conductor side) or outside, and the adhesive layer 26 is on the inside. Further thickness-varying insulating tapes 20 provided on this thickness-varying insulating tape 20 are wound such that the face side S1 of the adhesive tape is on the inside, and the adhesive layer 26 is on the inside. This allows the planar side S2 of the substrate tape to be firmly bonded to the conductor. Moreover, in the case of further overlapping winding, further thickness-varying insulating tapes 20 provided on the thickness-varying insulating tape 20 are wound such that the face side S1 of the adhesive tape is on the inside (conductor side), and the adhesive layer 26 provided thereon is on the inside, thereby making the appearance of the insulating cover uniform and smooth. Therefore, it has the following effect: it prevents the jig used in the processing of coils made with insulated wire 10 from getting caught, and it can suppress the occurrence of damage during processing.

[0097] Furthermore, the thickness-variable insulation tape 20 can be wound with the adhesive layer 26 positioned on the outer side opposite to the conductor side. In this case, since it is not firmly bonded to the conductor 1, the insulating coverings 2 and 3 formed by the thickness-variable insulation tape 20 are easy to peel off during end processing.

[0098] Preferably, the substrate tape 23 and the adhesive tape 24 are made of insulating materials with the same heat resistance temperature. Since the substrate tape 23 and the adhesive tape 24 have the same heat resistance temperature, the heat resistance of the insulating coverings 2 and 3 is also the same. This homogenizes the heat resistance temperature of the thickness-varying insulating tape 20, and therefore the heat resistance temperatures of the insulating coverings 2 and 3 become the same or approximately the same, which is preferable in terms of the overall heat resistance of the insulated wire. Furthermore, "same heat resistance temperature" means that it is the same as the "upper limit of the operating temperature of the insulating materials used in electrical appliances" stipulated in Appendix 11 of the Electrical Appliance Safety Law enacted by the Ministry of Economy, Trade and Industry of Japan.

[0099] Adhesive layers 25 and 26 are preferably made of thermoplastic resins such as acrylic, polyester, polyurethane, polyimide, PVC, and EVA, or thermosetting resins such as epoxy and bismaleimide. It is desirable that the thickness of adhesive layers 25 and 26 be, for example, in the range of 0.2 μm or more and 50 μm or less, and particularly preferably in the range of 0.5 μm or more and 40 μm or less.

[0100] For adhesive layers 25 and 26, an adhesive coating made by dissolving the aforementioned resin in an organic solvent can be applied to a predetermined thickness (e.g., 2 μm) using a coating apparatus such as gravure printing to form the adhesive layer. Furthermore, such an adhesive layer can be provided not only between the substrate tape 23 and the adhesive tape 24 (adhesive layer 25), but also between the substrate tape 23 and the cover tape 27 (adhesive layer 25a), or on one of the insulating tapes 20 with varying thicknesses (S1 or S2) as adhesive layer 26.

[0101] The thicknesses of the thinner insulating sheath 2 and the thicker insulating sheath 3 can be arbitrarily designed based on the degree of overlap (wrapping) of the strip portions 21 and 22 around the conductor 1, and the thickness of the strip further wrapped around the outer side of the strip portions 21 and 22. For example, when the strip portion 21 is wound in a 1 / 2 overlap, such as... Figures 5-7 As shown, the tape portion 21 has a double-layer structure; therefore, it is generally preferable that the thickness of the tape portion 21 is half the thickness of the thinner insulating cover 2 intended to be. Furthermore, when the tape portion 21 is wound in a 2 / 3 overlap, as... Figure 8 As shown, the strip 21 has a three-layer structure, so it is generally preferable that the thickness of the strip 21 is 1 / 3 of the thickness of the thinner insulating cover 2 intended to be obtained. Furthermore, in the case where the strip 21 is formed by providing an adhesive layer 26 on the other main surface F2 of one side (flat surface) S2 of the substrate strip 23, since the thickness including the adhesive layer 26 is the thickness of the strip 21, the thickness of the substrate strip 23 is designed taking into account the thickness of the adhesive layer 25. Additionally, as... Figures 6-8 As shown, in the case where a constant-thickness insulating tape 30 or a variable-thickness insulating tape 20 is wound further outward from tape portions 21 and 22, the thickness of tape portion 21, which becomes a thinner insulating cover 2, is achieved by adding the thickness of tape portion 21 to the tape portion 21, which is the thinner insulating cover 2, to the thickness of the tape portion 21, which is the outermost layer of the constant-thickness insulating tape 30 or the variable-thickness insulating tape 20, and the thickness of the adhesive layer used to bond the tape portion 21. In other words, in the case where a constant-thickness insulating tape 30 or a variable-thickness insulating tape 20 is wound further outward from tape portions 21 and 22, the thickness of the thinner insulating cover 2 is achieved by adding the thickness of the tape portion 21, which is the outermost layer of the constant-thickness insulating tape 30 or the variable-thickness insulating tape 20, and the thickness of the adhesive layer used to bond the tape portion 20.

[0102] Since the strip 22 is also wound around the outer periphery of the conductor 1, the thickness of the strip 22 is the sum of the thickness of the substrate strip 23, the thickness of the adhesive strip 24, and the thickness of the adhesive layer 25 disposed between the substrate strip 23 and the adhesive strip 24. Its thickness is designed according to the overlap of the strip 22. For example, when the strip 22 is wound in a 1 / 2 overlap, such as... Figures 5-7 As shown, the tape portion 22 has a double-layer structure; therefore, it is generally preferable that the thickness of the tape portion 22 is half the thickness of the intended thicker insulating cover 3. Furthermore, when the tape portion 22 is wound in a 2 / 3 overlap, as... Figure 8 As shown, the strip 22 has a three-layer structure; therefore, it is generally preferred that the thickness of the strip 22 be one-third of the thickness of the thinner insulating cover 3 intended to be obtained. Additionally, as... Figures 6-8 As shown, in the case where a constant-thickness insulating tape 30 or a variable-thickness insulating tape 20 is wound further out of tape portions 21 and 22, the thickness of tape portion 22, which forms the thicker insulating cover 3, is achieved by adding the thickness of tape portion 22 to the tape portion 22, which forms the thicker insulating cover 3, to the thickness of the tape portion 22, which is bonded to the tape portion 22. In other words, in the case where a constant-thickness insulating tape 30 or a variable-thickness insulating tape 20 is wound further out of tape portions 21 and 22, the thickness of the thicker insulating cover 3 is achieved by adding the thickness of the tape portion 22, which forms the thicker insulating cover 3, to ...0, which forms the thicker insulating cover 3, to the thickness of the tape portion 20, which forms the thicker insulating cover 3, to the thickness of the tape portion 20, which forms the thicker insulating cover 3, to the thickness of the tape portion 20, which forms the thicker insulating cover 3, to the thickness of the tape portion 20, which forms the thicker insulating cover 3, to the thickness of the tape portion 20, which forms the thicker insulating cover 3

[0103] Furthermore, in the case where the adhesive layer 26 is provided on either the face side S1 of the adhesive tape 24 or the face side (planar side S2) of the substrate tape 23 to form the tape portion 22, since the thickness including the adhesive layer 26 becomes the thickness of the tape portion 22, the thickness of the tape portion 22, i.e. the thickness of the substrate tape 23, the thickness of the adhesive tape 24, and the thickness of the adhesive layer 25 provided between the substrate tape 23 and the adhesive tape 24 are designed with consideration of the thickness of the adhesive layer 26.

[0104] Preferably, the adhesive layer 26 is disposed on any one side (S1 or S2) of the insulating tape 20 with varying thickness. When the adhesive layer 26 is disposed on the other main side F2 of the planar side S2, which serves as the substrate tape, this side S2 can be bonded to the outer periphery of the conductor 1. When the adhesive layer 26 is disposed on the adhesive tape side S1, this side S1 can be bonded to the outer periphery of the conductor 1. Which side S1 or S2 is disposed on the conductor side and wound can be arbitrarily selected, but for example... Figure 7As shown, preferably, for the initially wound thickness-varying insulating tape 20, an adhesive layer 26 is provided on the other main surface F2 of the planar side S2 of the substrate tape, and the planar side S2 of the substrate tape is set as the conductor side and wound. For the thickness-varying insulating tape 20 that is overlapped and wound thereon, an adhesive layer 26 is provided on the adhesive tape side S1, and the adhesive tape side S1 is set as the conductor side and wound. As a result, the planar side S2 of the substrate tape can be bonded to the conductor 1, and even when overlapping is performed, each thickness-varying insulating tape 20 can be bonded, and the appearance of the insulating cover can be uniform and smooth.

[0105] Furthermore, the adhesive layer 26 of the thickness-varying insulating tape 20 can be positioned on the outer side opposite to the conductor side and wound. In this case, since the thickness-varying insulating tape 20 is not firmly bonded to the conductor 1, the insulating coverings 2 and 3 formed by the thickness-varying insulating tape 20 are easy to peel off during end processing.

[0106] Preferably, the thickness-varying insulation tape 20 is set to a predetermined width corresponding to the diameter of the conductor 1, so as to facilitate winding around the conductor 1. Its width is not particularly limited, but can be set to approximately 2 to 15 times the diameter of the conductor 1. The thickness-varying insulation tape 20 can be formed by cutting a large sheet of material for making the thickness-varying insulation tape into a predetermined width. Therefore, a thickness-varying insulation tape 20 that is particularly suitable for easy winding of insulated wires 10 for coils can be provided.

[0107] The thickness variation of the insulating tape 20 can be achieved through the process described later. Figures 14-17 The various methods illustrated herein are not particularly limited. For example, (1) a strip of the same size can be glued to the substrate strip 23, and then the portion of the strip that is set as the thinner insulating cover 2 can be removed, leaving the remaining portion as adhesive strip 24. Removal can be performed by pulling open a slit in the strip and peeling it off. Alternatively, (2) an adhesive strip 24 of a predetermined length can be glued to the substrate strip 23. Alternatively, (3) a strip of the same size can be glued to a peelable strip, and then the portion of the strip that is set as the thinner insulating cover 2 can be removed, leaving the remaining portion as adhesive strip 24, and the substrate strip 23 can be glued to the adhesive strip 24, and finally the peelable strip can be removed.

[0108] Here, the structure used to achieve different visually distinguishable states by changing the colors of the insulating coverings 2 and 3 will be described.

[0109] The thinner insulating sheath 2 is mainly composed of Figure 2 The thinner region B, consisting of the strip 21, and the thicker insulating sheath 3, mainly composed of... Figure 2The thicker region A is formed by the strip portion 22. Therefore, it is possible to form the strip portion 22, which mainly constitutes the thicker insulating cover 3, to have different visual recognizability from the strip portion 21, which mainly constitutes the thinner insulating cover 2. Here, an example is to make the color of the thicker insulating cover 3 darker than the color of the thinner insulating cover 2, or to color the thicker insulating cover 3 while leaving the thinner insulating cover 2 uncolored.

[0110] By coloring the thicker region A of the strip 22, the thicker insulating covering 3, which is mainly composed of the strip 22, can be colored. Specifically, in order to color the strip 22 with a simple structure that does not require complex processes, it is sufficient to color either or both of the adhesive layer 25 and the adhesive tape 24. For coloring the adhesive layer 25 and the adhesive tape 24, coloring materials such as red, blue, green, yellow, and orange can be used, but red is preferred to improve visibility. Pigments and dyes are not considered as coloring materials. Furthermore, at this time, the thinner region B of the strip 21 is not colored, thus the thinner insulating covering 2, which is mainly composed of the strip 21, is in an uncolored state.

[0111] As described above, by making the colors of the belt portion 21 and the belt portion 22 different, and as Figures 5-7 This allows the insulating coverings 2 and 3 located on the outer periphery of conductor 1 to be visually distinguishable in different states. Specifically, since the strip 22 mainly constitutes the thicker insulating covering 3, coloring the strip 22 makes the thicker insulating covering 3 appear colored. Conversely, since the strip 21 mainly constitutes the thinner insulating covering 2, leaving the strip 21 uncolored allows for the creation of an insulating covering 2 with a different color from the insulating covering 3. Therefore, the thinner insulating covering 2 and the thicker insulating covering 3 can be distinguished, and during coil manufacturing, operators or sensors can differentiate between them, simplifying the coil manufacturing process.

[0112] (Constant thickness insulating tape)

[0113] like Figure 6 and Figure 8 As shown, the constant-thickness insulating tape 30 is a tape of constant thickness that is preferably wound in the reverse direction based on the thickness-variable insulating tape 20. This constant-thickness insulating tape 30 uses a resin tape with an adhesive layer. By winding this constant-thickness insulating tape 30 around the outer periphery of the thickness-variable insulating tape 20, the appearance of the insulating cover can be made uniform and smooth, and the thickness-variable insulating tape 20 can be covered and protected. The constant-thickness insulating tape 30 is wound with the adhesive layer side facing the thickness-variable insulating tape 20 side.

[0114] Preferably, the constant thickness insulating tape 30 is made of the same material as the base material tape 23 constituting the aforementioned thickness-variable insulating tape 20. The thickness of the constant thickness insulating tape 30 is not particularly limited to the thickness required to ensure the insulation withstand voltage of the tape portion 21 and tape portion 22 after winding. For example, it can be set to approximately 0.002 mm to 0.1 mm.

[0115] An adhesive layer constituting the constant thickness insulating tape 30 is provided on one side of the constant thickness insulating tape 30. The adhesive layer can be made of the same material as the adhesive layers 25 and 26 constituting the aforementioned variable thickness insulating tape 20. The constant thickness insulating tape 30 is arranged horizontally with the adhesive layer side as the inner side (variable thickness insulating tape side), and bonding is performed at this time or after by heating or the like. Thus, the constant thickness insulating tape 30 can be bonded to the variable thickness insulating tape 20 located below it. The thickness of the adhesive layer is not particularly limited, but it can be set to approximately 0.001 mm to 0.05 mm, for example. Furthermore, when the tape portion 21 and the tape portion 22 are different colors, it is preferable that the constant thickness insulating tape 30 is made of an uncolored transparent or semi-transparent insulating tape.

[0116] (Wrapping angle and winding method)

[0117] Next, refer to Figures 9-11 The winding angle and winding method are explained. Figure 9 This is a structural diagram showing an example of the shape of the insulating tape 20 with varying thickness. Figure 9 (A) is an example of a shape in which the boundary line 19 between the thicker region A (strip 22) and the thinner region B (strip 21) is orthogonal to the length direction X of the thickness-varying insulating strip 20. Figure 9 (B) is an example where the boundary line 19 between the tape portion 22 and the tape portion 21 is at a predetermined angle θ2 relative to the length direction X of the thickness-varying insulating tape 20. Thus, the angle θ2 can be a right angle relative to the length direction X, or it can be an angle less than that right angle (i.e., the angle when the boundary line 19 between the tape portion 22, which is the thicker region A, and the tape portion 21, which is the thinner region B, is formed to be inclined relative to the length direction X of the thickness-varying insulating tape 20).

[0118] When angle θ2 is a right angle, such as Figure 1 As shown in (A), the portion where the thinner insulating sheath 2 changes to the thicker insulating sheath 3 becomes a shorter tapered portion 3a, and the change in diameter produces a slight step difference. On the other hand, when the angle θ2 is less than 90°, as... Figure 1As shown in (B), the portion where the thinner insulating cover 2 changes to the thicker insulating cover 3 becomes a longer tapered portion 3a. As the angle θ2 decreases, the change in diameter decreases, the tapering becomes gentler, and the step difference is eliminated. Furthermore, if the angle θ2 is made too acute, it becomes difficult to manufacture the thickness-varying insulating tape 20 itself. Therefore, it is desirable for the angle θ2 to be set in the range of about 10° to 90°, and more preferably in the range of 15° to 60°.

[0119] Figure 10 Yes Figure 9 The example shown in (B) is an example of a thickness-varying insulating tape 20 wound relative to conductor 1 at a predetermined winding angle θ1. Figure 10 (A) is an example where the winding direction is such that the angle θ3 between the dividing line 19 of the thickness-varying insulation tape 20 and the length direction X of the conductor 1 is smaller than the angle θ2 of the dividing line 19 of the thickness-varying insulation tape 20. On the other hand, Figure 10 (B) is an example where the winding direction is such that the angle θ3 between the boundary line 19 of the thickness-varying insulation tape 20 and the length direction X of the conductor 1 is larger than the angle θ2 between the boundary line 19 of the thickness-varying insulation tape 20. Furthermore, θ1 is the angle between the length direction X of the conductor 1 and the length direction of the thickness-varying insulation tape 20.

[0120] exist Figure 10 In the example shown, with such Figure 10 Compared to the case shown in (B) where the winding occurs in a direction where θ2 < θ3, as Figure 10 As shown in (A), the winding along a direction where θ2 > θ3 reduces the abrupt change in the outer diameter of the insulated wire 10 wound around the boundary line 19 of the thickness-varying insulation tape 20. As a result, the amount of change in outer diameter is smaller, allowing for a smoother change in the thickness of the covering. In particular, this is advantageous when using a thickness-varying insulation tape 20 with a large thickness variation, as it reduces the abrupt change in the outer diameter of the insulated wire 10. Furthermore, in Figure 10 In the example, for instance, when θ1 is set to 20° and θ2 is set to 45°, in Figure 10 In (A), θ3 is approximately 25°. Figure 10 In (B), θ3 is approximately 65°. Compared to the case where θ3 is 65°, when θ3 is 25°, the thickness variation in the length direction X changes along the dividing line 19, thus allowing it to change gradually. As a result, the abrupt change in outer diameter can be reduced, making the change in outer diameter smoother. Furthermore, it is desirable to set the winding angle θ1 to a range of 10° to 60°, more preferably a range of 15° to 40°.

[0121] In addition, such as Figure 11As shown, the most preferred setting is that angle θ3 is 0°. That is, when... Figure 9 When the thickness-varying insulating tape 20 shown in (B) is wound relative to the conductor 1 at a predetermined winding angle θ1, the angle θ2 of the dividing line 19 of the thickness-varying insulating tape 20 is the same as the winding angle θ1 of the thickness-varying insulating tape 20. Therefore, the angle θ3 between the dividing line 19 and the longitudinal direction X of the conductor 1 can be 0°. The thickness of the insulating sheath of the insulated wire 10 after winding the thickness-varying insulating tape 20 varies along the dividing line 19. Therefore, the change in the outer diameter of the insulated wire 10 in the longitudinal direction X can be minimized, thus reducing the step difference caused by the change in outer diameter and making the change in outer diameter smoother. Specifically, with... Figure 1 Compared to the method shown in (A), the preferred method is... Figure 1 As shown in (B). Furthermore, as... Figure 10 and Figure 11 In that way, when Figure 9 When the tape shown is wound around the conductor, the bandwidth and / or angle θ1 to θ3 of the thickness-varying insulating tape 20 used are adjusted, thereby allowing the taper ratio to be set appropriately.

[0122] (First Embodiment)

[0123] Figure 5 The insulated wire 10A of the first embodiment shown is constructed by winding an insulating tape 20 of varying thickness around the outer periphery of the conductor 1 in a 1 / 2-fold loop, repeating the thinner insulating sheath 2 and the thicker insulating sheath 3. Furthermore, Figure 12 (A) is an external view of an insulated wire 10A in which the thickness-varying insulation tape 20 is wound in a 1 / 2 stack. In the figure, the solid line shows the edge of the thickness-varying insulation tape 20, and the dashed line shows the step of the thickness-varying insulation tape 20 within the same tape.

[0124] By winding the tape portions 21 and 22 of the thickness-varying insulating tape 20 around the conductor 1, a thinner insulating sheath 2 and a thicker insulating sheath 3 are formed. At this time, as... Figure 5 As shown, a small step is created at the transition portion of the edge of the thickness-varying insulating strip 20.

[0125] In this structure, by coloring the strip 22 that constitutes the thicker insulating cover 3, it is possible to... Figure 12 The insulating cover 3 of (A) is partially colored, while the insulating cover 2 is not colored, so that the visual recognizability of the insulating cover 2 and 3 is different, and the thicker insulating cover 3 and the thinner insulating cover 2 can be easily identified.

[0126] (Second Implementation)

[0127] Figure 6 The insulated wire 10B of the second embodiment shown is constructed by winding a thickness-variable insulation strip 20 in half-lap around the outer periphery of the conductor 1, and then further winding a thickness-constant insulation strip 30 in half-lap around the outer periphery of the thickness-variable insulation strip 20, repeating the process of thinner insulation covering 2 and thicker insulation covering 3. The winding direction of the thickness-variable insulation strip 20 and the winding direction of the thickness-constant insulation strip 30 can be the same or opposite, but are preferably opposite. When the directions are opposite, the thickness of the insulation covering can be made uniform and smooth. Furthermore, reference numeral 31 indicates the overlap portion, and reference numeral 32 indicates the non-overlap portion. This has the effect of preventing snagging on jigs used in processing such as manufacturing coils with insulated wires, and suppressing damage during processing. In addition, Figure 12 (B) is an external view of the insulated wire 10B in which the outermost layer of constant thickness insulation tape 30 is wound in a 1 / 3 stack. In the figure, the solid line shows the edge of the constant thickness insulation tape 30, and the dashed line shows the step of the constant thickness insulation tape 30 within the same tape.

[0128] By winding a constant-thickness insulating tape 30 around the outer periphery of a variable-thickness insulating tape 20, a thinner insulating cover 2 and a thicker insulating cover 3 are formed. At this time, as... Figure 6 As shown, the constant-thickness insulating tape 30 is affected by the step difference between the tape portion 21 and tape portion 22 of the underlying thickness-varying insulating tape 20, and a step difference is generated in the overlapping portion 31 and the non-overlapping portion 32. In such a structure, by coloring the tape portion 22 constituting the thicker insulating cover 3 and using an uncolored transparent or translucent insulating tape for the constant-thickness insulating tape 30, it is possible to... Figure 12 Part of the insulating cover 3 of (B) is colored, while part of the insulating cover 2 is uncolored. As a result, the visual distinguishability of the insulating covers 2 and 3 is different, and the thicker part of the insulating cover 3 and the thinner part of the insulating cover 2 can be easily identified.

[0129] (Third Implementation)

[0130] Figure 7 The insulated wire 10C of the third embodiment shown is constructed such that: an insulating tape 20A of varying thickness is wound in half-lap around the outer periphery of the conductor 1; and another insulating tape 20B of varying thickness is further wound in half-lap around the outer periphery of the insulating tape 20A, repeating the process of thicker insulating sheath 3 and thinner insulating sheath 2. In this case, as... Figure 7As shown, the thicker regions A of the other varying thickness insulating tapes 20B are overlapped and wound onto the already formed thicker insulating sheath 3. This allows the already thick insulating sheath 3 to be further thickened. As shown in this third embodiment, multiple varying thickness insulating tapes 20 (20A, 20B) can be wound to further thicken the already thick insulating sheath 3, thus forming an insulated wire 10 with improved insulation withstand voltage.

[0131] Furthermore, the thicker insulating sheath 3 is mainly composed of the strip portion 22 of the insulating tape 20 with varying thickness, but as Figure 7 As shown in section α, there are also cases where the strip portion 21 of the thickness-varying insulating tape 20 (20B) constitutes a part of the thicker insulating cover 3. That is, the thicker insulating cover 3 does not necessarily have to be composed solely of the strip portion 22 of the thickness-varying insulating tape 20, and may also include the strip portion 21 in part. Similarly, the thinner insulating cover 2 does not necessarily have to be composed solely of the strip portion 21 of the thickness-varying insulating tape 20, and may also include the strip portion 22 in part.

[0132] (Fourth implementation)

[0133] Figure 8 The insulated wire 10D of the fourth embodiment shown is constructed such that: a thickness-variable insulation strip 20 is wound in 2 / 3 stacks around the outer periphery of the conductor 1, and a thickness-constant insulation strip 30 is further wound in 1 / 3 stacks around the outer periphery of the thickness-variable insulation strip 20, and the thinner insulation sheath 2 and the thicker insulation sheath 3 are repeatedly wound. By winding the thickness-variable insulation strip 20 in 2 / 3 stacks, it is formed by overlapping three layers. As a result, a thicker insulation sheath 3 can be formed. Overlapping winding can result in up to 4 layers or more, but if it is up to 2 / 3 stacks, it is easier to prevent winding slack and winding deviation, especially in the thicker insulation sheath 3, and manufacturing can be carried out stably. Therefore, three layers or less are preferred. Furthermore, in the 2 / 3 stacks, the thickness-variable insulation strip 20 and / or the thickness-constant insulation strip 30 are wound simultaneously with each 2 / 3 stack, thus ultimately resulting in three layers.

[0134] (Other structures)

[0135] An insulating sheath (not shown) made of extruded resin may also be provided on the outermost periphery of the insulated wire 10, as needed. This insulating sheath is located on... Figure 1The outer periphery of the insulated wire 10 shown only needs to be insulating, and its material is not particularly limited. As the constituent resin of the insulating sheath, various resins suitable for resin extrusion can be used, such as fluorinated resins like PFA, ETFE, and FEP, vinyl chloride resins, polyolefin resins like polyethylene, and polyester resins like polyethylene terephthalate. The thickness of the insulating sheath can be set, for example, in the range of approximately 0.05 mm to 1.0 mm. Furthermore, when the insulated sheaths 2 and 3 are to have different identifiabilities, the extrusion resin is preferably a colorless transparent or translucent material.

[0136] [coil]

[0137] Figure 13 This is a structural unfolded view of the coil 40 of the present invention. The coil 40 is a coil obtained by winding the insulated wire 10 of the present invention as described above. It is characterized in that the insulating sheath 3 of the insulated wire 10 in the part where the voltage is high and partial discharge is prone to occur is thicker, and the insulating sheath 2 of the insulated wire 10 in the part where the voltage is not high and partial discharge is not prone to occur is thinner.

[0138] In such a coil 40, since the insulation sheath 3 of the insulated wires in areas prone to partial discharge is thicker, for example, the partial discharge initiation voltage at the overlap can be increased. Since the insulation sheath 2 of the insulated wires in areas less prone to partial discharge is thinner, the slot fill factor can be increased without deteriorating. Because the above-mentioned portions are repeatedly arranged at arbitrary intervals, for example, in the case of a coil preferably used for a three-phase induction motor, a thinner insulation sheath 2 can be formed in the slot conductor portion of the motor, and a thicker insulation sheath 3 can be formed in the overlap portion of the connecting slot conductor portion of the motor where a high voltage is applied.

[0139] Figure 13 This is a structural development diagram of the coil 40 used in a three-phase induction motor. In this structural development diagram, it includes circumferential conductor portions E1 to E9, straight conductor portions PS1 to PS10, the front portion of the circumferential conductor portion E1M to E9M, the stepped unformed portion KA1 to KA9, the rear portion of the circumferential conductor portion E1N to E9N, and the bent ends SS1 and SS2. In this case, the thinner insulating sheath 2 of the insulated wire 10 is disposed in the straight conductor portions PS1 to PS10. On the other hand, the thicker insulating sheath 3 of the insulated wire 10 is disposed in the circumferential conductor portions E1 to E9.

[0140] Therefore, by using a thinner insulating sheath 2 on the insulated wires disposed in the stator slot conductors to withstand the applied phase voltage, the slot fill factor of the coil winding can be improved. Furthermore, in the case of a three-phase induction motor, since each phase voltage is applied to the stator slot conductors, the overlap portion connecting the stator slot conductors approaches or contacts the overlap portion of other phases, applying the phase-to-phase voltage of the other phases to the overlap portion; specifically, applying a line-to-line voltage (√3 times the phase voltage) to the overlap portion. As a result, although partial discharge is prone to occur at the overlap portion, by using a thicker insulating sheath 3 on the overlap portion of the stator slot conductors to which the line-to-line voltage is applied, the partial discharge initiation voltage at the overlap portion can be increased.

[0141] At this time, due to the different visual recognizability of the thinner insulating cover 2 and the thicker insulating cover 3 of the insulated wire 10, which are configured to correspond to each configuration, the insulating cover 2 and 3 can be clearly distinguished respectively, thus improving the configuration workability.

[0142] [Manufacturing method for insulating tape with varying thickness]

[0143] The method for manufacturing the thickness-variable insulating tape 20 of the present invention is a method for manufacturing a tape that repeatedly has a thinner portion 21 and a thicker portion 22. The method is not particularly limited, but examples can be given. Figures 14-16 The method.

[0144] (one) Figure 14 The method shown is as follows: a substrate tape 24' is temporarily bonded to a thinner substrate tape 23, the substrate tape 24' is removed in a predetermined shape, and the remaining portion of the substrate tape 24' is set as the adhesive tape 24 (the thicker portion 22).

[0145] First, such as Figure 14 As shown in (A), an adhesive substrate strip 24' of the same size is temporarily bonded to a thinner substrate strip 23. The temporary bonding can be performed using various methods without particular limitation; examples include temporary bonding using an adhesive, and temporary bonding by lamination and heat. The type and thickness of the adhesive are as described above. The adhesive can be applied to the substrate strip 23, the adhesive substrate strip 24', or both strips 23 and 24. From a visually perceptible point of view, it is preferable to apply the colored adhesive to the adhesive strip 24.

[0146] When the adhesive is a tack adhesive, temporary bonding is achieved by applying pressure; however, when the adhesive is a heat-adhesive adhesive, temporary bonding is achieved by applying pressure and heating simultaneously. Alternatively, the adhesive can be supplied by flowing between the two tapes during bonding. Lamination is performed by hot lamination, for example, by applying pressure using hot rollers while heating to achieve temporary bonding.

[0147] like Figure 14 (B) Figure 14 As shown in (C), after temporary bonding, the adhesive tape 24 is left while the rest is removed. As a removal method, a blade is inserted from the adhesive substrate tape 24' side to form a cut 53, and the outer side of the portion surrounded by the cut 53 is peeled off and removed. The length and shape of the removal can be determined by the size and shape of the cutting blade. By continuously pulling open the cut 53 using the cutting blade, the removed portion can be continuously formed.

[0148] Furthermore, it is preferable that, when temporarily bonding the thinner substrate strip 23 and the adhesive substrate strip 24', the substrate strip 23 and the adhesive substrate strip 24' are bonded by temporary bonding as described above. This temporary bonding can be performed such that, by adjusting the applied pressure and / or heating temperature, the thinner substrate strip 23 and the adhesive substrate strip 24' can be easily peeled off after being bonded together in an overlapping manner. Additionally, after the adhesive tape 24 is made by temporary bonding, the thinner substrate strip 23 and the adhesive tape 24 can be formally bonded by applying pressure and / or heating.

[0149] (two) Figure 15 The method shown is as follows: an adhesive tape 24, which is formed into a predetermined shape and is a thicker portion 22, is bonded to a thinner substrate tape 23. First, as... Figure 15 As shown in (A), prepare substrate tape 23. Next, as... Figure 15 As shown in (B), multiple adhesive tapes 24 of a predetermined size are prepared, or multiple adhesive tapes 24 are bonded to the process tape 51 using any light bonding method. Furthermore, the process tape 51 is shown with a dashed line to indicate that the use of the process tape 51 is arbitrary. Finally, as... Figure 15 As shown in (C), multiple adhesive tapes 24 are directly bonded to the substrate tape 23 at predetermined intervals using any bonding method.

[0150] (three) Figure 16 The method shown is as follows: the cut adhesive tape 24”, which is cut to a predetermined width and becomes the thicker portion 22, is bonded to the substrate tape 23, which becomes the thinner portion, and then cut, or cut simultaneously with the bonding heating and stamping. First, as Figure 16 As shown in (A), prepare substrate tape 23. Next, as... Figure 16 As shown in (B), an adhesive strip 24” is prepared to be cut to a predetermined width and, while extending a predetermined length along the width direction of the substrate strip 23, is adhered to a position consistent with the width of the substrate strip 23. Finally, as shown in (B), Figure 16As shown in (C), the cut adhesive tape 24” is directly bonded to the substrate tape 23 at predetermined intervals and then cut, or cut simultaneously with the bonding heating and stamping.

[0151] (Four) Figure 17 The method shown is as follows: an adhesive substrate strip 24' that forms a thicker portion 22 is overlapped and bonded onto the process strip 51; the adhesive substrate strip 24' is removed in a predetermined shape and the remaining portion of the adhesive substrate strip 24' is set as the adhesive strip 24 (the thicker portion 22); a thinner substrate strip 23 is bonded onto the adhesive strip 24 that forms the thicker portion 22; and finally, the process strip 51 is removed.

[0152] For this method, firstly, as Figure 17 As shown in (A), a preparation process tape 51 is prepared, and an adhesive substrate tape 24' is bonded thereto by means of an adhesive layer 52. From a visually identifiable point of view, it is preferable that a colored adhesive layer 25 is provided on the other side of the adhesive substrate tape 24'. Therefore, the adhesive substrate tape 24' is bonded to the process tape 51 such that adhesive layers 52 and 25 are provided on both sides. The process tape 51 does not constitute the thickness-varying insulating tape 20 of the present invention, but is only used in the manufacturing process, although it can also remain in its set state as a peelable protective tape that is peeled off during use. As the process tape 51, it can be the same tape as the substrate tape 23, or a resin tape other than that. The thickness of the process tape 51 is not particularly limited as long as it does not hinder the manufacturing process. Regarding the adhesive layers 52 and 25, as for the adhesive force, it is preferable that the adhesive force of the adhesive layer 52 on the side of the process tape 51 that is finally peeled off is weaker than the adhesive force of the adhesive layer 25 on the side that is bonded to the substrate tape 23. This perspective guides the selection of adhesive types.

[0153] Next, as Figure 17 (B) Figure 17 As shown in (C), with Figure 14 Similarly, in the temporary bonding method, after temporary bonding, the adhesive substrate strip 24' is removed in a predetermined shape, and the remaining portion of the adhesive substrate strip 24' is designated as adhesive strip 24 (the thicker portion 22). As a method, such as... Figure 17 As shown in (B), a cut 53 is formed by inserting a blade into the self-adhesive substrate tape 24' side, as... Figure 17 As shown in (C), the outer side of the portion surrounded by the cut 53 is peeled off and removed. The length and shape of the removal can be determined by the size and shape of the cutting blade. By continuously pulling open the cut 53 using the cutting blade, the removed portion can be continuously formed.

[0154] Next, as Figure 17As shown in (D), a thinner substrate strip 23 is bonded to the adhesive strip 24, which is the thicker portion 22. Since an adhesive layer 25 is provided on the adhesive strip 24, the substrate strip 23 can be bonded thereto, and bonding can be achieved by applying pressure and / or heating.

[0155] Finally, as Figure 17 As shown in (E), the process belt 51 is removed. Furthermore, as described above, the process belt 51 can also be kept in its installed state and configured as a peelable protective belt that is peeled off during use.

[0156] Furthermore, in each of the manufacturing methods described in (a) to (iv) above, the following step may also be included: bonding the cover strip 27 to the adhesive strip 24, which becomes the thicker portion 22, using an adhesive layer 25a. Thus, as Figure 4 (B) and Figure 18 As shown, it can be configured as a so-called sandwich structure consisting of a substrate strip 23, an adhesive strip 24 bonded to a main surface F1 of the substrate strip 23 by means of an adhesive layer 25, and a cover strip 27 that covers the adhesive strip 24 entirely through the adhesive layer 25a.

[0157] As explained above, the thickness-varying insulating tape 20 of the present invention allows for repeated variations in tape thickness, making it particularly suitable for applications such as parts requiring different properties at intervals. The thickness-varying insulating tape 20 manufactured using the methods described in (a) to (iv) above can be bonded to parts and components, for example, increasing the strength and insulation of the thicker portion 22 compared to the thinner portion 21, and is expected to be applicable in various uses. Furthermore, this method is time-efficient and requires no complicated operations. The manufactured tape can be distributed and sold as a rolled-up tape.

[0158] Example

[0159] The invention will be illustrated more specifically by way of examples. The invention is not limited to the following examples, and those skilled in the art can make various changes, modifications, and alterations within the scope of the invention.

[0160] [Example 1]

[0161] The insulated wire in Example 1 is Figure 5 The insulated wire 10A of the first embodiment shown has a copper wire with a diameter of 1.0 mm wound around its outer periphery. Figure 4 The insulated wire 10A is shown in (A) with varying thickness insulation tape 20. Here, it is assumed that the tape portion 22 of the insulated wire 10A is colored.

[0162] The thickness-varying insulating tape 20 is an insulating tape in which an adhesive tape 24 with a thickness of 25 μm and a length of 65 mm is bonded to a substrate tape 23 with a thickness of 12 μm at 40 mm intervals using a colored adhesive layer 25 with a thickness of 2 μm. An adhesive layer 26 is provided on the main surface F1 of the adhesive tape side S1 of the thickness-varying insulating tape 20. The thickness-varying insulating tape 20 is wound around the conductor 1 in a half-lap (1 / 2 lap) manner with the adhesive tape side S1 facing the conductor 1 side.

[0163] In the obtained insulated wire 10A, the total average thickness of the tape portion 21, which is the thinner insulating cover 2, including the adhesive layer 26, is 23 μm, and the total average thickness of the colored tape portion 22, which is the thicker insulating cover 3, including the colored adhesive layer 25 and the adhesive layer 26, is 62 μm. In the obtained insulated wire 10A, the average diameter of the thicker portion of the insulating cover is 1.12 mm, and the average diameter of the thinner portion of the insulating cover is 1.05 mm. The thickness and average diameter are shown in Table 1. By winding the wire 1 with the convex portion of the adhesive tape side S1 as the inside, the surface of the insulated wire 10A becomes a smooth surface, so it is more preferable to use it as a coil. At this time, since the average diameter difference between the thicker insulating cover 3 and the thinner insulating cover 2 of the insulated wire 10A is 0.07mm, it is difficult to visually identify the insulating covers 2 and 3. However, as in this embodiment, by coloring the thicker insulating cover 3, the visual recognizability of the insulating covers 2 and 3 is made different, thereby making it easy to identify the thicker insulating cover 3 and the thinner insulating cover 2.

[0164] [Example 2]

[0165] The insulated wire in Example 2 is Figure 6 The insulated wire 10B of the second embodiment shown has a copper wire with a diameter of 1.0 mm wound around its outer periphery. Figure 4 The diagram (A) shows an insulated wire 10B with a varying thickness insulation strip 20 and a constant thickness insulation strip 30. Here, the structure is shown where the strip portion 22 of the insulated wire 10B is colored.

[0166] The thickness-variable insulation tape 20 is an insulation tape in which colored adhesive tape 24, 25 μm thick and 65 mm long, is bonded to a substrate tape 23, 12 μm thick, at 40 mm intervals using a colored adhesive layer 25 with a thickness of 2 μm. An adhesive layer 26 is provided on the main surface F2 of the substrate tape on the planar side S2 of the thickness-variable insulation tape 20. The thickness-variable insulation tape 20 is wound in a double layer on the conductor 1 with the adhesive tape side S1 facing the conductor 1 side. The thickness-constant insulation tape 30 is a transparent insulation tape with a 2 μm thick adhesive layer on a 9 μm thick tape. The thickness-constant insulation tape 30 is wound in a 1 / 3-fold roll, in the opposite direction to the thickness-variable insulation tape 20, with the adhesive layer side facing the inside.

[0167] In the obtained insulated wire 10B, the total average thickness of the tape portion 21, which is the thinner insulating cover 2, including the adhesive layer 26, is 40 μm, and the total average thickness of the tape portion 22, which is the thicker insulating cover 3, including the colored adhesive layer, is 78 μm. In the obtained insulated wire 10B, the average diameter of the thicker portion of the insulating cover is 1.16 mm, and the average diameter of the thinner portion of the insulating cover is 1.08 mm. The thickness and average diameter are shown in Table 1. At this time, the color of the colored tape portion 22, which is the thicker insulating cover 3, can be identified by the transparent, constant-thickness insulating tape 30. By coloring the thicker insulating cover 3, the visual recognizability of the insulating covers 2 and 3 is made different, thereby making it easy to distinguish the portion of the thicker insulating cover 3 and the portion of the thinner insulating cover 2.

[0168] [Example 3]

[0169] The insulated wire in Example 3 is Figure 7 The insulated wire 10C of the third embodiment is made by winding a copper wire with a diameter of 1.0 mm around its outer periphery. Figure 4 The insulated wire 10C is shown in (A) with a thickness variation insulation tape 20. Here, it is assumed that the tape portion 22 of the insulated wire 10C is colored.

[0170] The thickness-varying insulating tape 20 is an insulating tape in which colored adhesive tape 24, 25 μm thick and 65 mm long, is bonded to a substrate tape 23, 12 μm thick, at 40 mm intervals using a colored adhesive layer 25 with a thickness of 2 μm. In the initially wound thickness-varying insulating tape 20A, an adhesive layer 26 is provided on the planar side S2 of the substrate tape. For the thickness-varying insulating tape 20B wound on the thickness-varying insulating tape 20A, an adhesive layer 26 is provided on the adhesive tape side S1. The thickness-varying insulating tape 20A is wound in a double layer on the conductor 1 with the substrate tape 23 side facing the conductor 1 side. The thickness-varying insulating tape 20B, wound on the thickness-varying insulating tape 20A in the opposite direction, is wound on the conductor 1 with a 1 / 3 overlap and in a winding direction opposite to that of the thickness-varying insulating tape 20A.

[0171] In the obtained insulated wire 10C, the total average thickness including the adhesive layer in the tape portion 21, which is the thinner insulating cover 2, is 43 μm, and the total average thickness including the adhesive layer in the colored tape portion 22, which is the thicker insulating cover 3, is 113 μm. In the obtained insulated wire 10C, the average diameter of the thicker portion of the insulating cover is 1.23 mm, and the average diameter of the thinner portion of the insulating cover is 1.09 mm. The thickness and average diameter are shown in Table 1. At this time, by coloring the tape portion 22, the thicker portion of the insulating cover 3 can be identified, and the portions of the thicker insulating cover 3 and the thinner portion of the insulating cover 2 can be easily identified.

[0172] [Example 4]

[0173] The insulated wire 10D in Example 4 is Figure 8 The insulated wire 10D of the fourth embodiment shown is an insulated wire 10D in which an insulating strip 20 of varying thickness and an insulating strip 30 of constant thickness are wound around the outer periphery of a copper wire with a diameter of 1.0 mm. Here, it is designed so that the strip portion 22 of the insulated wire 10D is colored.

[0174] The thickness-variable insulation tape 20 is an insulation tape in which colored adhesive tape 24, 25 μm thick and 65 mm long, is bonded at 40 mm intervals to a substrate tape 23, 12 μm thick, using a colored adhesive layer 25 with a thickness of 2 μm. An adhesive layer 26 is provided on the planar side S2 of the substrate tape of the thickness-variable insulation tape 20. The thickness-variable insulation tape 20 is wound three times, with the substrate tape 23 side facing the conductor 1 side, overlapping the conductor 1. The thickness-constant insulation tape 30 is an insulation tape with a 2 μm thick adhesive layer on a 9 μm thick tape. The thickness-constant insulation tape 30 is wound with the adhesive layer side facing the inside, overlapping the conductor 1 by 1 / 3, and wound in the opposite direction to the winding of the thickness-variable insulation tape 20.

[0175] In the obtained insulated wire 10D, the total average thickness including the adhesive layer in the strip portion 21, which is the thinner insulating cover 2, is 61 μm, and the total average thickness including the adhesive layer in the colored strip portion 22, which is the thicker insulating cover 3, is 133 μm. In the obtained insulated wire 10D, the average diameter of the thicker portion of the insulating cover is 1.27 mm, and the average diameter of the thinner portion of the insulating cover is 1.12 mm. The thickness and average diameter are shown in Table 1. At this time, the colored strip portion 22, which is the thicker insulating cover 3, can be identified through the transparent, constant-thickness insulating strip 30, and the portions of the thicker insulating cover 3 and the thinner insulating cover 2 can be easily identified.

[0176] [Example 5]

[0177] The insulated wire of Example 5 is the same as that of Example 3. Figure 7 The insulated wire 10C of the third embodiment shown is similar, but in embodiment 5, the thickness variation insulation tape 20 is made thinner than in embodiment 3. Its average thickness and average diameter are shown in Table 1.

[0178] [Example 6]

[0179] In the insulated wire of Example 6, the same as that of Example 1 is used to manufacture the wire. Figure 5 Following the insulated wire 10A of the first embodiment shown, an extruded resin layer formed of ETFE resin is provided on its outer periphery as an insulating outer sheath. Its average thickness and average diameter are shown in Table 1.

[0180] [Example 7]

[0181] The insulated wire in Example 7 is the same as that in Example 2. Figure 6 The insulated wire 10B shown in the second embodiment, however, uses a thickness-variable insulation tape 20 instead of the standard insulation tape. Figure 4 The thickness variation of the insulating tape 20 in the so-called sandwich structure shown in (B) is illustrated here. Here, it is assumed that the tape portion 22 of the insulated wire 10B is colored.

[0182] The thickness-variable insulating tape 20 of the sandwich structure includes: a 6 μm thick substrate tape 23, a 25 μm thick colored adhesive tape 24 bonded to the substrate tape 23 by means of a 2 μm thick colored adhesive layer 25, and a 6 μm thick cover tape 27 that completely covers the adhesive tape 24 with a 2 μm thick adhesive layer 25a. The thickness-constant insulating tape 30 is a transparent insulating tape with a 2 μm thick adhesive layer on a 9 μm thick tape. The thickness-constant insulating tape 30 is wound in a 1 / 3 stack, with the adhesive layer side facing inward, and in the opposite direction to the thickness-variable insulating tape 20.

[0183] In this insulated wire, the total average thickness of the thinner portions is 43 μm, and the total average thickness of the thicker portions is 81 μm. Their thicknesses and average diameters are shown in Table 1. At this point, the color of the colored strip 22, which constitutes the thicker insulating sheath 3, can be identified through the transparent, constant-thickness insulating strip 30. Therefore, the portions of the thicker insulating sheath 3 and the thinner insulating sheath 2 can be easily distinguished.

[0184] [Compare Examples 1 and 2]

[0185] Comparative Example 1 is an enameled wire with a baked-on coating of varnish having an insulation sheath thickness of 0.04 mm. In Comparative Example 2, two constant-thickness insulation tapes 30, identical to those used in Example 2, were used, and these two constant-thickness insulation tapes 30 were wound in opposite directions with a 1 / 2 overlap. The thickness and outer diameter are shown in Table 1.

[0186] [Determination of Partial Discharge Initiation Voltage]

[0187] The partial discharge voltages of the insulated wires of Examples 1-7 and Comparative Examples 1 and 2 were measured. The samples were designed with two twisted shapes according to Japanese Industrial Standard JIS C3216-5. The partial discharge voltages were measured according to IEC 60034-18 using an Adphox XT-350PB39b measuring instrument. The results are shown in Table 1.

[0188] [Table 1]

[0189] Table 1

[0190]

[0191] ※) Tape 20 is an insulation tape with varying thickness.

[0192] 30 refers to a constant thickness insulating tape of 30.

[0193] [Evaluation Results]

[0194] In the insulated wire of Example 1, the thinner portion of the insulating sheath is thinner than the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is about 1.5 times thicker than the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 35% compared to Comparative Example 1. In the insulated wire of Example 2, the thinner portion of the insulating sheath is the same as the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is about twice thicker than the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 53% compared to Comparative Example 1. In the insulated wire of Example 3, the thinner portion of the insulating sheath is approximately the same as the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is about 2.8 times thicker than the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 87% compared to Comparative Example 1. In the insulated wire of Example 4, the thinner portion of the insulating sheath is about 1.5 times the thickness of the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is about 3.3 times the thickness of the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 135% compared to Comparative Example 1. In the insulated wire of Example 5, the thinner portion of the insulating sheath is about 0.87 times the thickness of the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is about 1.5 times the thickness of the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 35% compared to Comparative Example 1. In the insulated wire of Example 6, the thinner portion of the insulating sheath is about 1.8 times the thickness of the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is about 2.5 times the thickness of the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 73% compared to Comparative Example 1. In the insulated wire of Example 7, the thinner portion of the insulating sheath is approximately the same as the sheath of the insulated wires of Comparative Examples 1 and 2, and the thicker portion of the insulating sheath is approximately twice that of the sheath of the insulated wires of Comparative Examples 1 and 2. The partial discharge initiation voltage increased by 54% compared to Comparative Example 1.

[0195] On the other hand, the insulation thickness of the insulated wire in Comparative Example 2 is that of a typical wound insulated wire, which is roughly the same as that of the insulated wire in Comparative Example 1, i.e., an enameled wire with a baked-on varnish coating of about 0.04 mm. Compared to the insulated wire in Comparative Example 1, the partial discharge initiation voltage of the insulated wire in Comparative Example 2 increased by about 20%.

[0196] As described above, it is evident that the partial discharge initiation voltage of the thicker portion of the insulating sheath in Examples 1-7 is increased compared to Comparative Examples 1 and 2. By employing this thicker portion in, for example, the "lap" portion of the connecting stator slot conductor of an electric motor, the partial discharge initiation voltage can be increased. In particular, in coils using fine wires with a conductor cross-sectional dimension of approximately 1.0 mmφ, as in the embodiments, it is necessary to improve the tightness of the insulating sheath relative to the conductor and the positioning accuracy of the thicker portion of the insulating sheath to correspond to the overlap portion of the coil. In such cases, in the insulated wire of the present invention, since the difference in the thickness of its insulating sheath is repeatedly formed at predetermined intervals, the coil manufacturing process can be simplified.

[0197] Explanation of reference numerals in the attached figures

[0198] 1. Conductor; 2. Thinner insulating sheath; 3. Thicker insulating sheath; 3a. Tapered portion; 3b. Main body; 10. 10A-10D. Insulated wire; 19. Boundary line between thicker and thinner areas; 20. 20A, 20B. Insulating tape with varying thickness; 21. Tape section (thinner portion); 22. 22a, 22b, 22c. Tape section (thicker portion); 23. Substrate tape; 24. Adhesive tape; 24'. Adhesive substrate tape; 24”. Adhesive tape after being cut; 25. Adhesive layer; 25a. Adhesive layer; 26. Adhesive layer; 27. Cover tape; 30. Constant thickness insulating tape; 31. Overlap; 32. Non-overlap; A. Thicker area; B. Thinner area; F1. One main surface of the substrate tape; F2. The other main surface of the substrate tape; S1. Adhesive tape S2, Planar side of substrate tape; L1, L2, L3, Length in the longitudinal direction of the thicker portion; P1, P2, P3, Spacing between the thicker portions; θ1, Winding angle of the thickness-varying insulation tape relative to the longitudinal direction of the conductor; θ2, Angle of the boundary line between the thicker and thinner regions relative to the longitudinal direction of the thickness-varying insulation tape; θ3, Angle between the boundary line of the thickness-varying insulation tape and the longitudinal direction of the conductor; 40, Coil structure; E1~E9, Circular conductor section; PS1~PS10, Straight conductor section; E1M~E9M, Front part of the circumferential conductor section; KA1~KA9, Stepped unformed part; E1N~E9N, Rear part of the circumferential conductor section; SS1, SS2, Bending end; 51, Process tape; 52, Adhesive layer (adhesive layer); 53, Cut.

Claims

1. An insulated wire, comprising a conductor and an insulating sheath disposed around the outer periphery of the conductor, characterized in that, Thicker and thinner insulating sheaths are repeatedly arranged at arbitrary intervals. The thicker and thinner insulating sheaths are formed by winding an insulating tape with varying thicknesses of thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. The thickness-varying insulating tape is composed of a substrate tape and an adhesive tape bonded to one main surface of the substrate tape, or it is composed of a substrate tape, an adhesive tape bonded to one main surface of the substrate tape, and a cover tape further bonded to the adhesive tape in a manner that covers the adhesive tape. The thickness-varying insulating tape also has an adhesive layer, which is formed on one main surface of the substrate tape and on the adhesive tape, or on another main surface of the substrate tape. The thickness-varying insulating tape initially wound around the outer periphery of the conductor is wound such that the adhesive layer is on the inside, i.e., the conductor side or the outside. Further, other thickness-varying insulating tapes are provided on the thickness-varying insulating tape and wound such that the adhesive tape side is on the inside and the adhesive layer is on the inside.

2. The insulated wire according to claim 1, wherein, The conductor is wound with an insulating tape of varying thickness, and other insulating tapes of varying thickness or constant thickness are also wound around the outer periphery of the insulating tape of varying thickness, and the thicker insulating cover and the thinner insulating cover are repeated.

3. The insulated wire according to claim 2, wherein, In the case where other insulating tapes of varying thickness are further wound on top of the aforementioned thickness-variable insulating tape, the thicker areas of the other thickness-variable insulating tapes are overlapped and wound onto the already formed thicker insulating cover.

4. The insulated wire according to claim 1, wherein, In the case where other insulating tapes of varying thickness or constant thickness are further overlapped on top of the aforementioned insulating tape of varying thickness, the other insulating tapes of varying thickness and the constant thickness insulating tape are overlapped by changing their winding direction with the insulating tape of varying thickness.

5. The insulated wire according to claim 1, wherein, The thicker insulating sheath has tapered portions at both ends.

6. The insulated wire according to claim 4, wherein, The thicker insulating cover and the thinner insulating cover are formed by winding an insulating tape with a thickness variation having thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. In the thicker insulating tape, the boundary line between the thicker and thinner regions is formed obliquely with respect to the length direction of the thicker insulating tape.

7. The insulated wire according to claim 6, wherein, When the winding angle of the thickness-varying insulating tape relative to the length direction of the conductor is set as θ1, the angle of the dividing line between the thicker region and the thinner region relative to the length direction of the thickness-varying insulating tape is set as θ2, and the angle formed by the dividing line of the thickness-varying insulating tape and the length direction of the conductor is set as θ3, θ1 is in the range of 10° to 60°, and θ2 is in the range of 10° to 90°, the winding is performed in the direction where θ2 is larger than θ3.

8. The insulated wire according to claim 7, wherein, The value of θ3 is 0°.

9. An insulated wire, comprising a conductor and an insulating sheath disposed around the outer periphery of the conductor, characterized in that, Thicker and thinner insulating sheaths are repeatedly arranged at arbitrary intervals. The thicker and thinner insulating sheaths are formed by winding an insulating tape with varying thicknesses of thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. A varying-thickness insulating tape is wound around the outer periphery of the conductor. Other varying-thickness or constant-thickness insulating tapes are also wound over and over this varying-thickness insulating tape, with the thicker and thinner insulating layers alternating repeatedly. In the case where other insulating tapes of varying thickness are further wound on top of the aforementioned thickness-variable insulating tape, the thicker areas of the other thickness-variable insulating tapes are overlapped and wound onto the already formed thicker insulating cover.

10. An insulated wire, comprising a conductor and an insulating sheath disposed around the outer periphery of the conductor, characterized in that, Thicker and thinner insulating sheaths are repeatedly arranged at arbitrary intervals. The thicker and thinner insulating sheaths are formed by winding an insulating tape with varying thicknesses of thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. The thickness-varying insulating tape is composed of a substrate tape and an adhesive tape bonded to one main surface of the substrate tape, or it is composed of a substrate tape, an adhesive tape bonded to one main surface of the substrate tape, and a cover tape further bonded to the adhesive tape in a manner that covers the adhesive tape. In cases where other insulating tapes of varying thickness or constant thickness are further overlapped on top of the aforementioned insulating tape of varying thickness, the other insulating tapes of varying thickness and the constant thickness insulating tape are overlapped by changing their winding direction relative to the insulating tape of varying thickness. The thicker insulating cover and the thinner insulating cover are formed by winding an insulating tape with a thickness variation having thicker and thinner regions at predetermined intervals around the outer periphery of the conductor. In the thicker insulating tape, the boundary line between the thicker and thinner regions is formed obliquely with respect to the length direction of the thicker insulating tape.

11. The insulated wire according to claim 10, wherein, When the winding angle of the thickness-varying insulating tape relative to the length direction of the conductor is set as θ1, the angle of the dividing line between the thicker region and the thinner region relative to the length direction of the thickness-varying insulating tape is set as θ2, and the angle formed by the dividing line of the thickness-varying insulating tape and the length direction of the conductor is set as θ3, θ1 is in the range of 10° to 60°, and θ2 is in the range of 10° to 90°, the winding is performed in the direction where θ2 is larger than θ3.

12. The insulated wire according to claim 11, wherein, The value of θ3 is 0°.

13. A coil obtained by winding an insulated wire according to any one of claims 1 to 12, characterized in that, The insulated wire includes a portion with a thicker insulating sheath and a portion with a thinner insulating sheath, and the thicker insulating sheath and the thinner insulating sheath are repeatedly arranged at arbitrary intervals.

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