JP2007149562A - Insulated conductor and electric coil using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulated conductor that has improved insulating properties, and can extend the life of equipment and reduce a leakage current in energization, and to provide an electric coil using the insulated conductor. <P>SOLUTION: The insulated conductor 1 has a conductor 2, and an insulating coating 3 formed on the conductor 2. The insulating coating 3 comprises a first resin layer 4 that is formed of a polyamideimide resin and covers the outer periphery of the conductor 2, and a second resin layer 5 that is formed of resin having higher extension properties than the polyamideimide resin and covers the outer periphery of the first resin layer 4. Therefore, when the insulated conductor 1 is bent and stranded, the second resin layer 5 follows the deformation of the insulated conductor 1, thus avoiding the generation of cracks in the insulating coating 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an insulated wire used for an electric coil of a motor, in particular, an insulated wire used as an electric coil for a drive motor integrated with a compressor, and an electric coil formed by the insulated wire.

  In recent years, systems for driving an electric compressor mounted on various devices such as an air conditioner blower, a refrigerator, and an automobile with an inverter power source are increasing. For example, an air conditioning system includes a heat exchanger, a compressor, a dryer, and a circulation system that connects these pipes. The compressor is integrated with a compressor for compressing a refrigerant and the compressor. Drive motor. And by driving the compressor with an inverter power supply, for example, at the time of starting, by operating the electric compressor at the maximum rotation, the maximum capacity of the air conditioning system can be drawn and the room temperature can quickly reach the set temperature. It becomes possible.

  In general, an insulated wire including a conductor and an insulating film formed on the conductor is used as a winding of the electric coil for the drive motor (insulated wire forming a coil winding). More specifically, for example, as shown in FIG. 14, a coating containing a polyamide-imide resin as a main component is applied to the surface of a copper wire that is a conductor 50 and baked to form an insulating film 51 on the copper wire. An insulated wire 52 in which is formed is disclosed. According to such a configuration, it is described that an insulated wire excellent in wear resistance and plasticity can be obtained (see, for example, Patent Document 1).

Further, as shown in FIG. 15, the surface of the copper wire as the conductor 53 is coated with an insulating paint containing a polyamide-imide resin several times and baked to form a first resin layer 54. On the surface of the first resin layer 54, an insulating paint containing polyamideimide is applied and baked to form a second resin layer 55. On the copper wire, the first and second resin layers 54, An insulated wire 57 in which an insulating film 56 made of 55 is formed is disclosed. The insulating paint forming the second resin layer 55 is added with a polyolefin dispersion in which an acid anhydride-modified polyolefin resin is dispersed in a xylene solvent. With such a configuration, the self-lubricating property is excellent. It is described that it is possible to obtain an insulated wire having an impregnating varnish fixing force equivalent to that of a non-self-lubricated wire (see, for example, Patent Document 2).
JP 2001-11312 A JP-A-5-217427

  However, in the conventional insulated wire, when the insulated wire is bent and wound, when the electric coil is formed, the insulating film may be cracked due to the stress acting on the insulating film. is there. As a result, there has been a problem that it is difficult to ensure good insulation in the insulated wire, and it is difficult to extend the life of equipment such as a drive motor in which the insulated wire is used.

  In addition, when an electric coil formed by winding an insulated wire is inserted into a slot formed in a stator core made of a magnetic core, etc., and the coil end is shaped by pressing, a crack occurs in the insulating film. May end up. As a result, there has been a problem in the insulated wire that good insulation cannot be ensured and the leakage current during energization increases.

  Accordingly, the present invention has been made in view of the above-described problems, and has an excellent insulating property, an insulated wire capable of extending the life of the device and reducing leakage current during energization, and the insulated wire. An object of the present invention is to provide an electric coil using the.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided an insulated wire comprising a conductor and an insulating film formed on the conductor, the insulating film covering the outer periphery of the conductor. And a second resin layer covering the outer periphery of the first resin layer, the first resin layer is formed of a polyamideimide resin, and the second resin layer is made of a polyamideimide resin. It is formed of a highly extensible resin.

  According to this configuration, since the second resin layer is made of a resin having higher extensibility than the polyamide-imide resin that forms the first resin layer, an electric coil is formed by winding the insulated wire. At this time, since the second resin layer follows the deformation of the insulated wire by the processing jig, it is possible to avoid the occurrence of cracks in the insulating film. As a result, since it is possible to ensure good insulation in the insulated wire, it is possible to extend the life of equipment in which the insulated wire is used.

  In addition, for example, when an electric coil made of an insulated wire wound around a stator core made of a magnetic core or the like is pressed and shaped, it has higher extensibility than the polyamide-imide resin that forms the first resin layer Due to the second resin layer formed of resin, the insulating film is easily stretched. Therefore, it is possible to avoid the occurrence of cracks in the insulating film, and as a result, it is possible to extend the life of the equipment in which the insulated wire is used.

  In addition, for example, when an electric coil made of an insulated wire wound around a stator core made of a magnetic core or the like is pressed and shaped, the insulated wire may be bent. The second resin layer formed of a resin having higher extensibility than the polyamideimide resin to be formed generates wrinkles in the insulating film on the inner side of the bend, and the stress acting on the insulating film is relieved. Can be avoided. Therefore, since the workability of the insulating film is improved, it can be avoided that the insulating film is cracked. As a result, since it is possible to ensure good insulation in an insulated wire, it is possible to provide an electric coil with a small leakage current when energized, and the safety of equipment in which the insulated wire is used is improved. It is possible to improve and extend the life. Further, since the shapeability when the electric coil is pressed is excellent, the electric coil can be reduced in size, and as a result, the mounting property to a device such as a compressor is improved.

  Invention of Claim 2 is the insulated wire of Claim 1, Comprising: Resin which comprises a 2nd resin layer is a polyimide resin, It is characterized by the above-mentioned. According to the same configuration, the polyimide resin is, for example, a second resin that forms an insulating film because the relative dielectric constant is smaller than that of a polyamideimide resin, a polyesterimide resin, a polyester resin, a urethane resin, and a polyvinyl formal resin. By using the polyimide resin for the layer, the capacitance of the electric coil is reduced. Therefore, the leakage current of the electric coil during energization can be further reduced, and the safety of the device in which the insulated wire is used can be further improved and the life can be further extended.

  Invention of Claim 3 is an insulated wire of Claim 1 or Claim 2, Comprising: An insulating film is formed with resin with higher lubricity than resin which comprises a 2nd resin layer, 2nd It further has the 3rd resin layer which coats the perimeter of this resin layer.

  According to this configuration, it becomes possible to easily insert an insulated wire into a slot formed in a stator core made of a magnetic core or the like, so that stress on the insulating film can be reduced and more in the slot. It becomes possible to insert an insulated wire. As a result, the efficiency and output of a device (for example, a drive motor) in which an insulated wire is used can be improved. Moreover, since the stress to an insulating film reduces, the insulation performance of an insulated wire can improve and the safety | security of an insulated wire can be improved. Moreover, workability | operativity at the time of forming the apparatus using an insulated wire will improve. In addition, for example, when the second resin layer is formed by multiple baking coatings, the interface of the resin constituting the second resin layer is easily peeled off, but the outer periphery of the second resin layer is the third By covering with the resin layer, the third resin layer functions as a protective layer for the second resin layer having high peelability.

  The invention described in claim 4 is the insulated wire according to claim 3, wherein the resin forming the third resin layer is a polyamide-imide resin. According to this configuration, since the polyamideimide resin has excellent friction resistance, by using the polyamideimide resin in the third resin layer that is the outermost layer of the insulated wire, the friction resistance of the insulated wire is increased. It becomes possible to improve the property.

  According to a fifth aspect of the present invention, there is provided an electric coil comprising the insulated electric wire according to any one of the first to fourth aspects. According to the structure, since it is set as the structure provided with the insulated wire in any one of Claim 1 thru | or 4, the electric coil which has the same effect as the insulated wire in any one of Claim 1 thru | or 4 Can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, favorable insulation can be ensured in an insulated wire, and the lifetime of the apparatus in which the said insulated wire is used and the reduction of the leakage current at the time of electricity supply can be aimed at.

(First embodiment)
Hereinafter, a preferred embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing the structure of an insulated wire according to the first embodiment of the present invention. As shown in FIG. 1, the insulated wire 1 is, for example, a winding of an electric coil for a drive motor integrated with an electric compressor mounted on various devices such as a blower of an air conditioner, a refrigerator, or an automobile ( Insulated electric wire forming a coil winding) and the like, and has a conductor 2 and an insulating film 3 formed on the conductor 2. Further, the insulating film 3 includes a first resin layer 4 that covers the outer periphery of the conductor 2 and a second resin layer 5 that covers the outer periphery of the first resin layer 4.

  When forming an electric coil using the insulated wire 1, as shown in FIG. 2, first, as a first step, the insulation from the bobbin (not shown) around which the insulated wire 1 is wound. By pulling out the electric wire 1 and rotating the reel structure 7 having the movable reel 6, the insulated wire 1 is wound to the movable reel 6 via the coil supply nozzle 8 to form an annular electric coil 9. .

  Next, as a second step, the outer periphery of the formed annular electric coil 9 is formed into a concavo-convex shape to form a star coil. More specifically, as shown in FIG. 3, the forming moving frame 10 is inserted between the moving reels 6 holding the electric coil 9, and the coil is pushed in the radial direction from the outside of the electric coil 9 to be fixed. By pressing the coil against the frame 11, the annular electric coil 9 is formed into a star shape.

  Next, as a third step, as shown in FIG. 4, the first electric coil 9 a formed into the above-mentioned star shape is inserted into the slot 13 formed in the stator core 12 made of a magnetic core or the like. The stator core 12 is inserted in a state where it is mounted on an insertion jig (not shown), and the stator core 12 is wound by the first electric coil 9a. And as a 4th process, the coil shaping for making easy insertion of the 2nd, 3rd electric coils 9b and 9c inserted into the slot 13 with respect to the inserted 1st electric coil 9a next. A process is performed. By this coil shaping step, the high space factor electric coil 9 can be formed in multiple layers. The first to fourth electric coils 9a to 9c are inserted by repeating the first to fourth steps described above three times.

  Then, as a fifth step, the coil ends 14 to 16 of the inserted first to third electric coils 9a to 9c are pressed into the direction of the shaft for the drive motor (the direction of the arrow X in the figure). ). More specifically, as shown in FIG. 5, for example, for the first electric coil 9 a, the rising portion 14 a of the coil end 14 is moved in the left-right direction (in the drawing, the coil end 14 indicated by a virtual line). The rising portion 14a is pressed and deformed from the direction of arrow Z in the figure so as to escape in the directions of arrows Y1 and Y2, and the height thereof is shaped low. And the coil ends 14-16 shown in FIG. 6 are shape | molded by shaping by the same press work also about each coil end 15, 16 of the 2nd, 3rd electric coils 9b, 9c. Moreover, the stator core 12 wound by the first to third electric coils 9a to 9c can be obtained.

  The conductor 2 is not particularly limited as long as the necessary transmission capacity can be secured. For example, copper wire, tin-plated copper wire, aluminum wire, aluminum alloy wire, steel core Aluminum wire, copper fly wire, nickel-plated copper wire, silver-plated copper wire, copper-covered aluminum wire, etc. can be used.

  In addition, the resin forming the first resin layer 4 of the insulating film 3 is not particularly limited as long as it has high adhesion to the conductor 2 and has high insulation and heat resistance. Polyamideimide resin, A polyimide resin, a polyesterimide resin, a H-type polyester resin, or the like can be suitably used. In addition, resin with high adhesiveness with the conductor 2 is, for example about polyamideimide resin, adhesiveness with the conductor 2 is general-purpose polyamideimide resin (For example, Hitachi Chemical Co., Ltd. make, brand name HI-405H) HI-401D, etc. (for example, trade names HI-400A, HI-407A, etc., manufactured by Hitachi Chemical Co., Ltd.).

  In addition, these resin may be used independently and may be used in combination of 2 or more type. Moreover, it is good also as a structure which uses resin which added adhesiveness imparting agents (For example, amino resins, such as a melamine, heterocyclic mercaptan, etc.).

  The first resin layer 4 is formed, for example, by applying a polyamide-imide insulating paint on the surface of a conductor 2 made of a copper wire having a diameter of 1.0 mm and baking at 450 ° C. for about 1 minute. It is formed by coating.

  Moreover, in ordinary vehicle-mounted and indoor air conditioners, since the refrigerant often contains water of 300 ppm or more, a resin having high insulating properties is preferable even in a liquid phase environment containing a large amount of water, From the viewpoint of the insulating property, a polyamideimide resin is particularly preferably used in the present embodiment.

  Here, the present embodiment is characterized in that the second resin layer 5 of the insulating film 3 is formed of a resin having higher extensibility than the polyamide-imide resin that forms the first resin layer 4. With such a configuration, when forming the electric coil 9 by winding the insulated wire 1, the second resin layer 5 follows the deformation of the insulated wire 1 by the processing jig. Can be avoided. As a result, since it becomes possible to ensure good insulation in the insulated wire 1, it becomes possible to extend the life of equipment (for example, the above-described drive motor) in which the insulated wire 1 is used. .

  Here, the term “extensibility” refers to tensile elongation. For example, the tensile elongation of polyimide resin is about 60%, which is higher than the tensile elongation of polyamideimide resin (about 30%). It can be said that it is a resin having higher extensibility than the polyamide-imide resin. In the present embodiment, the tensile elongation is preferably 40% or more.

  In addition, since the second resin layer 5 is formed of a resin having higher extensibility than the polyamide-imide resin that forms the first resin layer 4, the electric coil including the insulated wire 1 that is wound on the stator core 12. When the 9 is pressed and shaped, the second resin layer 5 makes the insulating film 3 easily stretched. Accordingly, the stress acting on the insulating film 3 during press working is relieved and the workability of the insulating film 3 is improved, so that it is possible to avoid the occurrence of cracks in the insulating film 3, and as a result, It is possible to extend the life of equipment in which the insulated wire 1 is used.

  In addition, for example, when the electric coil 9 made of the insulated wire 1 is pressed and shaped, the insulated wire 1 may be bent, but it is more extensible than the polyamide-imide resin that forms the first resin layer 4. Due to the second resin layer 5 formed of resin, wrinkles are generated in the insulating film 3 on the inner side of the bend, and the stress acting on the insulating film 3 is relieved, so that cracking of the film can be avoided. Therefore, since the workability of the insulating film 3 is improved, it can be avoided that the insulating film 3 is cracked. As a result, since it becomes possible to ensure good insulation in the insulated wire 1, it becomes possible to reduce the leakage current of the electric coil 9 during energization, and the safety of the equipment in which the insulated wire 1 is used. As a result, the service life can be improved and the service life can be extended. In addition, since the shapeability when the electric coil 9 is pressed is excellent, the electric coil 9 can be reduced in size, and as a result, the mountability to a device such as a compressor is improved.

Note that the leakage current I between the electric coil 9 and the stator core 12 in which the electric coil 9 is wound as referred to here is, for example, an electrostatic capacity of the electric coil 9 when applied using an inverter power source as a power source. When C is C, when the insulating material between the electric coil 9 and the stator core 12 is not taken into consideration, the relationship is I∝C. Further, the capacitance C is between the dielectric constant ε (expressed as ε = ε ₀ ε _S where the dielectric constant of the space is ε ₀ and the relative dielectric constant of the insulating film 3 is ε _S ). a, is related to Shiarufaipushiron, by using the winding of the relative dielectric constant epsilon _S is less insulating film 3, it is possible to reduce the leakage current I.

  The resin for forming the second resin layer 5 is not particularly limited as long as it can generate wrinkles in the insulating film 3 on the inner side when the insulated wire 1 is bent. An etherimide resin, a polyether sulfone resin, a polyether ether ketone resin, a polyphenyl sulfone resin, a polysulfone resin, and the like can be suitably used. Among these resins, it is particularly preferable to use a polyimide resin. This is because the polyimide resin is smaller in relative dielectric constant than, for example, polyamide imide resin, polyester imide resin, polyester resin, urethane resin, and polyvinyl formal resin, so that the second resin layer 5 constituting the insulating film 3 is used. In addition, the capacitance C of the electric coil 9 is reduced by using the polyimide resin. Therefore, for example, the leakage current I of the electric coil 9 when energized by the inverter power supply can be further reduced, and the safety of the device in which the insulated wire 1 is used is further improved and the life is further extended. This is because it becomes possible to plan.

  In addition, these resin may be used independently and may be used in combination of 2 or more type. Moreover, it is good also as a structure which forms the said 2nd resin layer 5 by multiple layers of resin (namely, multilayered structure by a polyimide resin) by performing baking coating several times.

  In addition, the second resin layer 5 is formed, for example, by applying a polyimide insulating coating on the surface of the first resin layer 4 and baking at 450 ° C. for about 1 minute. It is formed by coating.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 7 is a cross-sectional view showing the structure of an insulated wire according to the second embodiment of the present invention. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, the electric coil forming method, the method of winding the stator core with the electric coil, and the coil end shaping method described as the first to fifth steps in the first embodiment are also described in the first. Since it is the same as that of embodiment, detailed description is abbreviate | omitted here.

  In the present embodiment, as shown in FIG. 7, in the insulated wire 1 shown in FIG. 1, a third resin layer 17 that covers the outer periphery of the second resin layer 5 is provided, and the third resin layer 17 is provided. Is characterized in that it is formed of a resin having higher lubricity than the resin forming the second resin layer 5. With such a configuration, the electric coil 9 made of the insulated wire 1 can be easily inserted into the slot 13 formed in the stator core 12, so that the stress on the insulating film 3 can be reduced, and the inside of the slot 13 can be reduced. More insulated wires 1 can be inserted. As a result, the efficiency and output of a device (for example, a drive motor) in which the insulated wire 1 is used can be improved. Moreover, since the stress to the insulating film 3 is reduced, the insulation performance of the insulated wire 1 can be improved, and the safety of the insulated wire 1 can be improved. Moreover, workability | operativity at the time of forming the apparatus in which the insulated wire 1 is used will improve.

  In addition, as described above, when the second resin layer 5 is formed by a plurality of baking coatings, for example, with the polyimide resin described above, the interface of the resin constituting the second resin layer 5 is easily peeled off. However, by covering the outer periphery of the second resin layer 5 with the third resin layer 17, the third resin layer 17 functions as a protective layer for the second resin layer 5 having high peelability. Become.

  The resin that forms the third resin layer 17 of the insulating film 3 is not particularly limited as long as it is a resin having higher lubricity than the resin that forms the second resin layer 5. For example, polyamideimide resin, nylon Resins and the like can be suitably used. The resin having high lubricity is, for example, a polyamide-imide resin, and the second resin has slipperiness when the electric coil 9 made of the insulated wire 1 is inserted into the slot 13 formed in the stator core 12. It refers to a polyamide-imide resin that is higher than a general-purpose polyimide resin that forms the layer 5 (for example, product name Pyre-MLRC5057 manufactured by IST Co., Ltd.).

  Of these resins, it is particularly preferable to use a polyamideimide resin as the resin forming the third resin layer 17. This is because the polyamide-imide resin has excellent friction resistance, and therefore the polyamide-imide resin is used for the third resin layer 17 that is the outermost layer of the insulated wire 1, whereby the friction resistance of the insulated wire 1 is obtained. This is because the property is improved.

  In addition, these resin may be used independently and may be used in combination of 2 or more type. Moreover, it is good also as a structure which forms the 3rd resin layer 17 with the polyamideimide resin with high adhesiveness with the conductor 2 which forms the above-mentioned 1st resin layer 4. FIG.

  The third resin layer 17 is formed by, for example, applying a polyamide-imide insulating paint on the surface of the second resin layer 5 and baking it at 450 ° C. for about 1 minute. It is formed by covering the outer periphery.

  Below, this invention is demonstrated based on an Example and a comparative example. In addition, this invention is not limited to these Examples, These Examples can be changed and changed based on the meaning of this invention, and they are excluded from the scope of the present invention. is not.

Example 1
(Production of insulated wires)
On the surface of the conductor 2 made of a copper wire having a diameter of 1.0 mm, a polyamide-imide insulating paint (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked at 450 ° C. for about 1 minute. A first resin layer 4 having a thickness of 0.03 mm covering the outer periphery of the conductor 2 was formed. Next, a polyimide insulating coating (product name: Pyr-ML) manufactured by IST Co., Ltd. is applied to the surface of the first resin layer 4 and baked at 450 ° C. for about 1 minute. Then, the second resin layer 5 having a thickness of 0.005 mm covering the outer periphery of the first resin layer 4 was formed, and the insulated wire 1 having the insulating film 3 having a thickness of 0.035 mm was produced.

(Wrinkle / crack determination test)
Next, as shown in FIG. 8, one end 1 a of the manufactured insulated wire 1 was attached and fixed to the attachment member 18, and the insulated wire 1 was suspended. Next, as shown in FIG. 9, the insulated wire 1 is bent to form a ring portion 1 c on the insulated wire 1 and moved to the other end 1 b of the insulated wire 1 in the direction of arrow W in the figure. A load member 20 placed on a possible carrier 19 was attached, and a kink portion 21 was formed on the insulated wire 1. An enlarged view of the kink portion 21 is shown in FIG. Then, the load member 20 attached to the other end 1b of the insulated wire 1 is moved (lowered) at a constant speed (about 50 mm / min) in the direction of the arrow W in the state where the load member 20 is placed on the loading platform 19. It was. Then, the load carrier 19 is moved until the load member 20 is separated from the load carrier 19, and when the load member 20 is in a natural fall state, the insulating film on the bent inner side 3 d (see FIG. 10) of the kink portion 21. The occurrence of wrinkles in 3 and the presence or absence of cracks were determined. In addition, generation | occurrence | production of a wrinkle and generation | occurrence | production of a crack were observed using the microscope (OLYMPUS Co., Ltd. make, brand name BX60). Further, the load member 20 applied three types of loads of 13N, 15N, and 20N to the insulated wire 1. In addition, the judgment index is: ○: Wrinkles are generated in the insulating film 3 on the inner side 3d of bending, or no crack is generated, ×: Wrinkles are not generated in the insulating film 3 on the inner side of bending 3d , Or performed with cracks. The results are shown in Table 1.

(Dielectric breakdown voltage test)
The kink part 21 of the insulated wire 1 produced in the above-described wrinkle / crack determination test is immersed in a mixed solution of glycerin and saturated saline, and between the conductor 2 of the insulated wire 1 and the mixed solution of glycerin and saturated saline, An AC voltage having a waveform close to a sine wave of 50 Hz or 60 Hz was applied to measure the breakdown voltage. At this time, one end 1a and the other end 1b of the insulated wire were prevented from being immersed in the above-mentioned mixed solution. The AC voltage was uniformly increased at a speed of 500 V / sec, and the dielectric breakdown detection current was 5 mA. In addition, the initial voltage (that is, the voltage when the load is 0N) is measured, and the above-described load member 20 is used to insulate the insulated wire 1 by applying four types of loads of 10N, 15N, 20N, and 25N. The breakdown voltage was measured. The above results are shown in FIG.

(Example 2)
On the surface of the conductor 2 made of a copper wire having a diameter of 1.0 mm, a polyamide-imide insulating paint (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked at 450 ° C. for about 1 minute. A first resin layer 4 having a thickness of 0.027 mm covering the outer periphery of the conductor 2 was formed. Next, a polyimide insulating coating (product name: Pyr-ML) manufactured by IST Co., Ltd. is applied to the surface of the first resin layer 4 and baked at 450 ° C. for about 1 minute. The second resin layer 5 having a thickness of 0.005 mm that covers the outer periphery of the first resin layer 4 was formed. Next, a polyamide-imide insulating coating (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied to the surface of the second resin layer 5 and baked at 450 ° C. for about 1 minute. A third resin layer 17 having a thickness of 0.003 mm covering the outer periphery of the resin layer 5 was formed, and an insulated wire 1 having an insulating film 3 having a thickness of 0.035 mm was produced. Next, a wrinkle / crack determination test and a dielectric breakdown voltage test were performed under the same conditions as in Example 1 described above. The above results are shown in Table 1 and FIG.

(Example 3)
On the surface of the conductor 2 made of a copper wire having a diameter of 1.0 mm, a polyamide-imide insulating paint (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked at 450 ° C. for about 1 minute. A first resin layer 4 having a thickness of 0.027 mm covering the outer periphery of the conductor 2 was formed. Next, a polyimide insulating coating (product name: Pyr-ML) manufactured by IST Co., Ltd. is applied to the surface of the first resin layer 4 and baked at 450 ° C. for about 1 minute. The second resin layer 5 having a thickness of 0.005 mm that covers the outer periphery of the first resin layer 4 was formed. Next, on the surface of the second resin layer 5, as a lubricating polyamide-imide insulating coating, a coronate is used with respect to 50 parts by weight of a solid content of amidoimide varnish (trade name HI-400, manufactured by Hitachi Chemical Co., Ltd.). A mixture of 2503 (manufactured by Nippon Urethane Co., Ltd.) with a solid content of 50 parts by weight and 3 parts by weight of polyethylene wax (manufactured by Mitsui Petrochemical Co., Ltd., product name 220P) was applied, and about 1 at 450 ° C. Baking was performed for a minute to form a third resin layer 17 having a thickness of 0.003 mm covering the outer periphery of the second resin layer 5, and an insulated wire 1 having an insulating film 3 having a thickness of 0.035 mm was produced. . Next, a wrinkle / crack determination test and a dielectric breakdown voltage test were performed under the same conditions as in Example 1 described above. The above results are shown in Table 1 and FIG.

(Comparative Example 1)
On the surface of the conductor 50 made of a copper wire having a diameter of 1.0 mm, a polyamide-imide insulating paint (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked at 450 ° C. for about 1 minute. An insulated wire 52 having an insulating film 51 having a thickness of 0.035 mm covering the outer periphery of the conductor 50 was produced. Next, a wrinkle / crack determination test and a dielectric breakdown voltage test were performed under the same conditions as in Example 1 described above. In Comparative Example 1, as described later, in the dielectric breakdown voltage test, the insulation performance could not be maintained when a load of 15 N was applied. A dielectric breakdown voltage test was performed by applying two types of loads, 10N and 15N. The above results are shown in Table 1 and FIG.

(Comparative Example 2)
On the surface of the conductor 53 made of a copper wire having a diameter of 1.0 mm, a polyamide-imide insulating paint (trade name HI-405, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked at 450 ° C. for about 1 minute. A first resin layer 54 having a thickness of 0.032 mm covering the outer periphery of the conductor 53 was formed. Next, on the surface of the first resin layer 54, as a self-lubricating polyamide-imide insulating coating, a coronate is used as a solid content of 50 parts by weight of an amidoimide varnish (trade name HI-400, manufactured by Hitachi Chemical Co., Ltd.). A mixture of 2503 (manufactured by Nippon Urethane Co., Ltd.) with a solid content of 50 parts by weight and 3 parts by weight of polyethylene wax (manufactured by Mitsui Petrochemical Co., Ltd., product name 220P) was applied, and about 1 at 450 ° C. A second resin layer 55 having a thickness of 0.003 mm that covers the outer periphery of the first resin layer 54 was formed by baking for a minute, and an insulated wire 57 having an insulating film 56 having a thickness of 0.035 mm was produced. . Next, a wrinkle / crack determination test and a dielectric breakdown voltage test were performed under the same conditions as in Example 1 described above. In Comparative Example 2, as described later, in the dielectric breakdown voltage test, when a load of 15 N was applied, the insulation performance could not be maintained. A dielectric breakdown voltage test was performed by applying two types of loads, 10N and 15N. The above results are shown in Table 1 and FIG.

  As can be seen from Table 1, when a load of 13 N was applied, wrinkles were generated in the insulating films 3, 51, and 56 on the bent inner side in any of Examples 1 to 3 and Comparative Examples 1 and 2. In addition, no cracks occurred. However, when a load of 15 N or 20 N is applied, in each of Examples 1 to 3, wrinkles 30 (see FIG. 11) are generated in the insulating film 3 on the bent inner side 3d, and cracks are generated. However, in Comparative Examples 1 and 2, in any case, the insulating films 51 and 56 on the bent inner sides 51d and 56d are not wrinkled, but cracks are generated, and the bent inner sides 51d and The surfaces of the insulating films 51 and 56 of 56d were broken, and the peeling portion 58 (see FIG. 12) was generated.

  As can be seen from FIG. 13, when a load of 10 N was applied, the insulation performance of about 10 kV was obtained in any of Examples 1 to 3 and Comparative Examples 1 and 2. However, when a load of 15 N was applied, in Examples 1 to 3, the insulation performance of about 10 kV was maintained in any case, but in Comparative Examples 1 and 2, as described above, In this case, the insulating films 51 and 56 on the bent inner sides 51d and 56d are cracked, and the surfaces of the insulating films 51 and 56 on the bent inner sides 51d and 56d are ruptured to generate the peeling portion 58. The performance could not be maintained.

  As can be seen from FIG. 13, when a load of 20 N was applied, the insulation performance of about 8 kV was maintained in any of Examples 1 to 3. In addition, when a load of 25 N was applied, the wrinkle 30 was generated in the insulating film 3 on the bent inner side 3d in any of the first to third embodiments, but cracks were also generated. Since the surface of the insulating coating 3 was broken and a peeling portion (not shown) corresponding to the above-described peeling portion 58 was generated, the insulating performance could not be maintained.

  This is because, in each of Examples 1 to 3, the second resin layer 5 of the insulating film 3 is formed of a polyimide resin having a higher extensibility than the polyamide-imide resin that forms the first resin layer 4. It is considered that this is because the stress acting on the insulating film 3 is relieved when a load of 15 N or 20 N is applied due to the generation of the wrinkle 30, and the insulation performance can be maintained. .

  On the other hand, in Comparative Example 1, since the insulating film 51 is formed of only a polyamideimide resin having a lower extensibility than the polyimide resin described above, when a load of 15N or 20N is applied, This is probably because the acting stress was not relaxed. Also in Comparative Example 2, although the insulating film 56 is composed of two layers, since the insulating film 56 is formed of only a polyamideimide resin having a lower extensibility than the above-described polyimide resin, As in the case, it is considered that the stress acting on the insulating film 56 was not relaxed when a load of 15N or 20N was applied.

  Examples of utilization of the present invention include insulated wires used for motor coils and the like, particularly insulated wires used as coils for drive motors integrated with a compressor, and electric coils formed by the insulated wires. Is mentioned.

It is sectional drawing which shows the structure of the insulated wire which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the process of forming a cyclic | annular electric coil with the insulated wire which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the process of shape | molding a cyclic | annular electric coil in a star shape. It is a figure for demonstrating the process which inserts the electric coil shape | molded by the star shape in the slot formed in the stator core, and winds a stator core with an electrical coil. It is a figure for demonstrating the process of shaping the coil end of the electric coil inserted in the slot of a stator core. It is a figure which shows the stator core wound by the electric coil by which the coil end was shaped. It is sectional drawing which shows the structure of the insulated wire which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating a wrinkle / crack determination test, and is a figure which shows the state which attached and fixed the end part of the insulated wire to the attachment member, and suspended the insulated wire. It is a figure for demonstrating a wrinkle and a crack determination test, and is a figure which shows the state which formed the kink part in the insulated wire. It is an enlarged view of the kink part shown in FIG. It is the elements on larger scale which show the wrinkle which generate | occur | produced inside the bending of an insulating film. It is the elements on larger scale which show the peeling part which generate | occur | produced inside the bending of the insulating film. It is a figure which shows the result of a dielectric breakdown voltage test. It is sectional drawing which shows the structure of the conventional insulated wire. It is sectional drawing which shows the structure of the conventional insulated wire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulated electric wire, 2 ... Conductor, 3 ... Insulating film, 3d ... Inside bent side of kink part, 4 ... 1st resin layer, 5 ... 2nd resin layer, 17 ... 3rd resin layer, 21 ... Kink part 30 ... Wrinkles

Claims (5)

  A conductor and an insulating film formed on the conductor, wherein the insulating film includes a first resin layer covering an outer periphery of the conductor and a second resin layer covering an outer periphery of the first resin layer. The first resin layer is made of a polyamideimide resin, and the second resin layer is made of a resin having a higher extensibility than the polyamideimide resin. Insulated wire.   The insulated wire according to claim 1, wherein the resin constituting the second resin layer is a polyimide resin.   The insulating film further includes a third resin layer formed of a resin having a higher lubricity than the resin constituting the second resin layer and covering the outer periphery of the second resin layer. The insulated wire according to claim 1 or claim 2.   The insulated wire according to claim 3, wherein the resin forming the third resin layer is a polyamide-imide resin.   An electric coil comprising the insulated wire according to any one of claims 1 to 4, wherein the insulated wire is wound.

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