JP3036339U - Multilayer insulated wire for high frequency transformer winding - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a multi-layer insulated wire for winding suitable for a high-frequency transformer and the like. [Structure] A plurality of magnet wires 1 are focused in a substantially parallel shape and in a circular cross section to form a focusing conductor 2. Next, a first extruded layer 3a of heat resistant resin is provided on the outer circumference. Next, the resin temperature of the layer 3a is cooled to a temperature not higher than 1/2 of the resin melting temperature, and then the second heat-resistant resin extruded layer 3b is provided on the outer periphery of the layer 3a. Next, after cooling the resin temperature of the layer 3b to a temperature of ½ or less of the resin melting temperature, the layer 3b is cooled.
A third heat resistant resin extruded layer 3c is provided on the outer periphery of the. 3 above
The multilayer insulated wire 4 for high frequency transformer winding is formed by retaining any of the two insulating layers so as to maintain the specified withstand voltage characteristics. [Effect] As an insulated wire for transformer winding conforming to various safety standards such as IEC and UL, it is possible to suppress heat generation of the switching transformer even when the switching frequency is increased.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to an insulated wire for winding suitable for a high frequency transformer, a high frequency reactor or a high frequency coil used for a switching power supply of electronic equipment.

[0002]

[Prior art]

 Generally, a magnet wire is used as an insulated wire for a winding of a switching power supply, in which a single wire conductor is coated with an insulating layer of polyurethane resin, polyester resin, or the like. Safety transformers such as switching power supplies are subject to the following restrictions based on various safety standards such as IEC (International Electrotechnical Commission) or UL (Standards of Underwriter's Laboratories, Inc.). (1) Guarantee the dielectric strength between layers of wires and between the primary and secondary windings with a specified insulating film. (2) To secure the creepage distance between the winding and the core, perform space insulation with an insulator between the winding and the core. This limits the winding space. (3) When pulling out the lead wire from the pin terminal, it is necessary to insulate it with an insulating tube.

Due to such restrictions on safety standards, it is difficult to downsize a transformer when using a magnet wire in a single wire state, and the number of parts and man-hours for performing various insulation treatments are required, resulting in cost reduction. As a result, there was a problem that it was difficult to obtain a more compact and high-performance transformer. Therefore, the inventors of the present invention have proposed to use a three-layer insulated wire for the winding of the transformer as described in Japanese Utility Model Application No. 2-49801 (Japanese Utility Model Application No. 3-110721), and the IEC or UL etc. It is possible to meet safety standards.

[0004]

[Problems to be solved by the device]

 Switching power supplies have come to be applied with high frequencies of several tens KHz to several hundreds KHz for the switching frequency in order to improve switching efficiency. However, in the above high frequency band, the eddy current loss in the conductor of the transformer winding and the loss due to the skin effect become prominent, which causes an increase in the heat generation of the transformer. There is a fear that the characteristics of the above will deteriorate.

The present invention has been made to solve the above problems, and it is intended to reduce the heat generation amount of a transformer even if the above-mentioned various safety standards are satisfied and the switching frequency is in a high frequency band. It is an object of the present invention to provide an insulated electric wire for a transformer winding capable of being manufactured.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a focusing conductor in which a plurality of magnet wires are bundled in a substantially circular shape in a circular cross section, or a focusing conductor in which a plurality of magnet wires are twisted and focused in a circular cross section. A high-frequency transformer formed by providing at least three insulation layers made of a heat-resistant resin extruded layer on the outer periphery of the core, and maintaining the specified withstand voltage characteristics with any two insulating layers of the three layers. A multi-layer insulated electric wire for winding, wherein the at least three extruded layers of heat-resistant resin are a first extruded layer extruded on the outer periphery of the focusing conductor, and a heat-resistant resin of the first extruded layer. Second extruded layer extruded onto the outer periphery of the first extruded layer after cooling to a temperature not higher than 1/2 of the melting temperature of the resin, and a heat-resistant resin of the second extruded layer. Is cooled to a temperature below 1/2 of the melting temperature of the resin. In Third ing from extruded layer of the high-frequency transformer winding multilayer insulated wire that is extruded onto the outer periphery of the second extruded layer (hereinafter referred to as multilayer insulated wire) from. If cooling is performed with water, air cooling is preferable because it may cause swelling when the next layer is extruded due to moisture adhering to the surface, but water cooling is not a hindrance.

As the magnet wire of the present invention, there is used a wire such as a copper wire, a copper alloy wire, or a single wire conductor such as tin or solder-plated copper wire provided with an insulating layer such as polyurethane resin or polyester resin. To be Although conductor structure is selected appropriately according to the specifications of the transformer, a conductor cross-sectional area consisting of a plurality of magnet wire, primarily conductor in the range of 0.032mm ² (AWG 32) from 0.52mm ² (AWG20) is used To be The bundling conductor of the present invention may be one in which a plurality of the magnet wires are bundled in a substantially circular shape in cross section, or a plurality of the magnet wires may be collectively twisted, concentric twisted, or litz twisted. It may be twisted and bundled into a circular cross section.

As the heat-resistant resin used for the insulating layer made of the extruded layer of the heat-resistant resin of the present invention, for example, various fluorine resins or various engineering plastics are used. Further, if necessary, in order to clearly identify each insulating layer, each insulating layer resin may be used by coloring each layer in a different hue by a method such as using a resin having a different hue.

[0009]

[Action]

 The converging conductor of the present invention is one in which a plurality of magnet wires are converged in a substantially parallel and circular cross section, or a plurality of magnet wires are twisted together to be a circular cross section. Since they are insulated from each other, the generation of eddy currents can be suppressed low, and the increase in high frequency resistance due to eddy current loss can be suppressed. In addition, the surface area of the focusing conductor is significantly larger than that of a single wire conductor, so that the increase in loss due to the skin effect can be significantly improved. In addition, when a plurality of the magnet wires are bundled in a substantially parallel and circular cross section, or when a plurality of the magnet wires are twisted and bundled into a circular cross section, a conductor to be used is used when the twist pitch is increased. It is possible to shorten the twisted length of the coil and reduce the DC resistance of the coil accordingly.

In addition, each extruded layer of at least three layers of the heat resistant resin of the present invention is cooled to a temperature of half or less of the melting temperature of the resin after extruding the heat resistant resin of each layer. After that, since the extruded layer is obtained by sequentially repeating the step of forming the next layer by extrusion, there is no adhesion between the extruded layers and it is possible to distinguish between the layers. Therefore, it can be seen that each of the three insulating layers is independent and separable.

The meaning that each of the three insulating layers is independent and separable means that each insulating layer is individually peelable and exists as one independent layer. As a method for removing the insulating layer, there are a method of using a stripper, a method of removing a slit scratch on the insulating layer, a method of burning and removing the insulating layer with a hot blade, and the like. On the other hand, the coating of the magnet wire is formed by applying insulating paint to the outer circumference of the conductor multiple times and baking, but a single insulating layer is formed by the entire coating, and it is not possible to separate each layer. Since it is possible, it is not recognized as a multi-layer insulated wire. In the present invention, the magnet wire is also used, but it is not intended to be used as a multi-layer electric wire in the state of a single wire, but it is used as an insulated wire constituting a focusing conductor.

In addition, the multilayer insulated wire of the present invention is provided with at least three insulating layers made of extruded layers of heat-resistant resin, and any two insulating layers among the three layers have a specified withstand voltage characteristic. Since it is formed so as to hold the dielectric strength, it is possible to hold the dielectric strength (3.75 KV in the case of IEC 950) specified by safety standards, for example. Therefore, it is recognized as an insulated wire for winding that has sufficient insulation characteristics in terms of safety standards, and is released from the many restrictions imposed on the aforementioned transformer.

[0013]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment. Embodiment 1 FIG. 1 is a sectional view showing an embodiment of the multilayer insulated wire of the present invention. As the magnet wire 1, a 0.10 mm type 2 polyurethane copper wire with a finishing outer diameter of 0.120 mm was used. 19 polyurethane copper wires were bundled into a circular cross-section in a substantially parallel manner, and a focusing conductor 2 with a focusing outer diameter of 0.60 mm was used. Was formed. Next, fluorinated ethylene propylene resin (FEP) (Teflon 100 J, trade name of Mitsui DuPont Fluorochemicals Co., Ltd.) colored in red as the primary insulating layer 3a is extruded on the outer periphery of the focusing conductor 2 at a temperature of 310 ° C. After extruding to a thickness of about 0.06 mm, the extruded FEP was air-cooled to 120 ° C. to provide a first extruded layer. Next, a natural color FEP is extruded on the outer periphery of the first extruded layer 3a as a secondary insulating layer 3b at a temperature of 310 ° C to a thickness of about 0.06 mm, and then the temperature of the extruded FEP is increased to 120 ° C. Air-cooled to provide a second extruded layer. Further, blue colored FEP is extruded on the outer periphery of the second extruded layer 3b as a tertiary insulating layer 3c at a temperature of 310 ° C. to a thickness of about 0.06 mm, and then the extruded FEP is air-cooled to a room temperature. Then, the third extruded layer was provided to manufacture the multilayer insulated wire 4.

Example 2 As the magnet wire 1, a type 2 polyester copper wire having a finished outer diameter of 0.120 mm was prepared. Using 10 mm, 19 polyester copper wires were bundled in a circular cross-section at a twist pitch of 24 mm to form a bundled conductor 2 having a bundled outer diameter of 0.60 mm. Thereafter, in the same manner as in Example 1, the first extruded layer (primary insulating layer) 3a, the second extruded layer (secondary insulating layer) 3b, and the third extruded layer (tertiary insulating layer) were formed on the outer periphery of the focusing conductor 2. The insulating layer 3 composed of the layer 3c was provided to manufacture the multilayer insulated electric wire 4.

Separation / Confirmation Test of Insulating Layer Regarding the multilayer insulated electric wires obtained in Example 1 and Example 2, a method for forming slit scratches on the surface of each layer of the insulating layer 3 of the multilayer insulated electric wire 4 or The insulation layer was separated and confirmed by a method using a stripper. As a result, it was confirmed that the insulating layers 3a, 3b and 3c could be easily separated by any of the above-mentioned methods, and that each layer was independent.

Withstand Voltage Characteristic Test Regarding the multilayer insulated electric wires of Examples 1 and 2, samples with each insulating layer provided were sampled and the outer diameter and withstand voltage characteristics were tested. No difference was observed between Example 1 and Example 2.

[0017]

[Table 1]

In the above table, note (1) is the breakdown voltage for 10 mmφ mandrel winding (with 15 turns winding). As is clear from Table 1, the insulated wire having the above structure withstands the withstand voltage characteristic of IEC950 standard, that is, 3.75 KV · 1 minute.

Transformer temperature rise test A switching transformer using the three-layer insulated wire of Example 1 of the present invention as a secondary winding and a switching transformer using a Class 0 polyurethane copper wire 0.60 mm as a secondary winding. Was manufactured in the same manner except the above. For a switching transformer with an oscillation frequency of 50 kHz used for a switching power supply with an output of 136 W, these switching transformers are operated at an output voltage of 161 V and 0.5 A, and the surface temperature of the winding of the switching transformer at that time is determined by the thermistor temperature. It measured using the meter. The results are shown in Table 2.

[0020]

[Table 2]

As is clear from Table 2, the switching transformer using the multi-layer insulated wire of the present invention has a temperature of 7.7 ° C. lower than that of the conventional transformer using the magnet wire in the single wire state. I understand.

[0022]

[Effect of the invention]

 The multi-layer insulated wire of the present invention uses a focusing conductor in which a plurality of magnet wires are focused in a substantially parallel shape and a circular cross section, or a focusing conductor in which a plurality of magnet wires are twisted and focused in a circular cross section. As a result, the heat generated by eddy current loss and skin effect loss generated in the conductor is significantly reduced, and it is possible to suppress the heat generation of the switching transformer even when the switching frequency is increased, and as a result, the switching power supply The efficiency can be improved.

In addition, the multilayer insulated wire of the present invention is provided with at least three insulating layers made of extruded layers of heat-resistant resin, and any two of the three insulating layers have specified withstand voltage characteristics. Since it is formed so as to be held, it becomes possible to hold the dielectric strength (3.75 KV in the case of IEC 950) specified by safety standards, for example. Therefore, it is recognized as an insulated wire for winding that has sufficient insulation characteristics in terms of safety standards, and is released from the many restrictions imposed on the aforementioned transformer. The practical effect is extremely large.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a multi-layer insulated wire for high frequency transformer winding of the present invention.

[Explanation of symbols]

 1 Magnet Wire 2 Focusing Conductor 3 Insulating Layer 3a Primary Insulating Layer (First Extruded Layer) 3b Secondary Insulating Layer (Second Extruded Layer) 3c Tertiary Insulating Layer (Third Extruded Layer) 4 For High Frequency Transformer Winding Multi-layer insulated wire

Claims (1)

[Utility model registration claims] 1. A heat-resistant resin is provided on the outer periphery of a focusing conductor obtained by focusing a plurality of magnet wires substantially in a circular shape in cross section, or a focusing conductor obtained by twisting a plurality of magnet wires in a circular shape in cross section. A multi-layer insulated wire for high-frequency transformer winding, wherein at least three insulating layers consisting of extruded layers are provided, and any two insulating layers of the three layers are formed to maintain the specified withstand voltage characteristics. In addition, the at least three extruded layers of the heat-resistant resin are the first extruded layer extruded on the outer periphery of the focusing conductor, and the temperature of the heat-resistant resin of the first extruded layer is the melting temperature of the resin. The temperature of the second extruded layer extruded on the outer periphery of the first extruded layer after being cooled to a temperature of ½ or less and the temperature of the heat resistant resin of the second extruded layer is 1 of the melting temperature of the resin. On the outer periphery of the second extruded layer after being cooled to a temperature of 1/2 or less A multi-layer insulated wire for a high-frequency transformer winding, which comprises a third extruded layer extruded into