JP2006187059A - Method and apparatus for impregnating insulation varnish - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for insulation treatment of a coil capable of preventing varnish from being attached at a core by means of a drip-impregnation process by using varnish with various viscosities in an impregnating process, and more efficiently performing manufacture of the coil by omitting a trimming process for removing varnish hardened objects. <P>SOLUTION: This insulation varnish impregnating treatment device 1 includes a coil preheating means 2 for heating a coil for electric appliance made by an iron core and a winding wound around the iron core, a first varnish impregnating means 3 for impregnating low viscosity varnish in the coil, a second varnish impregnating means 4 for impregnating a high viscosity varnish in the coil, a varnish curing means 5 for curing the varnish impregnated in the coil by heating the coil, and a coil retaining/rotating unit having a chuck mechanism which can retain the coil and rotate the coil at a shaft core in the coil preheater, the varnish impregnating device and the varnish curing device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a method and apparatus for insulating general industrial and consumer coils (motors, generators, etc.), improving the workability of the insulating process and shortening the coil manufacturing time and improving the manufacturing efficiency. The present invention relates to an insulating varnish impregnation treatment method and an impregnation treatment apparatus.

  Conventionally, in a coil such as a stator coil, a varnish insulation process is performed to protect the winding. This insulation process gives the coil various functions such as physical support, transmission of heat generation to the slot wall, wire pinholes and processing flaw cover, in addition to winding insulation.

  The insulation treatment of the varnish includes, for example, a preheating process for preheating the coil, an impregnation process for impregnating the coil with the varnish, and a curing process for heating and curing the varnish attached to the coil.

  Examples of methods for impregnating coils with varnish include immersion impregnation method (dipping), dripping impregnation method (drip), rotary impregnation method, vacuum impregnation method, etc. These methods depend on the application, type of coil to be processed and process. It was properly used. Recently, electrical appliances (motors, generators, etc.) have increased in the coil line area, taped on the outer packaging, and interstitial paper between the poles. (Penetration) is lowered and it is difficult to sufficiently impregnate, and various conditions have been studied in order to improve the impregnation property of the coil.

  By the way, although the insulation treatment varnish used for the impregnation of the coil is roughly classified into a solvent type varnish treatment and a solventless varnish treatment, most of the solvent varnish used in the immersion impregnation method has a nonvolatile content of 20 to 70% by mass. The remainder is volatile matter (solvent). At this time, in order to improve the varnish impregnation property, it is often used by further diluting with a solvent or the like, but in this case, the amount of resin that actually adheres to the winding is very small, and the desired adhesion amount is achieved by one impregnation. I can't do it.

  On the other hand, it is conceivable to increase the non-volatile content in order to increase the adhesion amount, but the viscosity of the varnish increases and impregnation becomes worse, and it becomes difficult to penetrate into the minute gaps between the windings in the slot. The amount of adhesion only on the surface will increase. In addition, it becomes difficult for the varnish to impregnate the inside of the slot or the inner side of the interphase paper, and the purpose of varnish treatment cannot be achieved. In any case, in the drying process, the solvent contained in the total amount of varnish is scattered by 30% by mass or more, and the amount of resin adhering to the impregnated winding is reduced, or there are many voids inside the slot. Sometimes it became.

  In order to improve this, when the coil is immersed in the varnish, the winding is energized and heated to cause the varnish to gel, thereby increasing the amount of varnish adhering to the winding body. (For example, refer to Patent Document 1).

  On the other hand, solvent-free varnish may be used instead of solvent-type varnish. In this case, if the amount of varnish adhesion is increased, the viscosity of the varnish is increased to reduce the dripping flow, or the varnish curing speed is increased. It is possible to speed up. However, if the viscosity of the varnish is increased, it is difficult to penetrate into the minute gaps between the windings in the slot, and the amount of adhesion increases only on the iron core surface. On the other hand, when the curing speed of the varnish is increased, the pot life of the varnish remaining in the container is shortened, which is very disadvantageous in terms of workability and economy.

The dripping impregnation method is a method developed to avoid the above-mentioned drawbacks, in which a preheated coil is rotated or rotated at an angle, and a varnish that hardens in a short time is dropped onto the winding from the top. It is. The varnish dripped onto the upper part of the winding penetrates between the windings by capillary action and does not gel until reaching the end of the winding, but hardens quickly after penetration. This method is an excellent method capable of adjusting the adhesion amount of the cured product, and is a method capable of thick coating by selecting a resin component.
JP-A-7-39120

  However, in recent years, in order to increase the reliability of the coil, in order to increase the amount of varnish impregnated, including the method of energizing and heating the winding to gel the varnish, a large amount of varnish is dripped into the coil. In many cases, varnish overflows from the slot and a lot of varnish adheres to the core.

  In this case, a trimming process to remove the excess cured varnish adhering to the core is required, and it takes a lot of time for the work, making full use of the original advantage of dripping impregnation (no varnish is attached to the extra part). Since it was not cut, an impregnation treatment method for more efficiently producing the coil has been demanded.

  Therefore, as a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention, as a varnish impregnation step, a first varnish impregnation step and a coil end portion that impregnate the windings in the slot using varnishes having different viscosities. By combining with the second varnish impregnation step for impregnating the varnish, it is possible to prevent the varnish from overflowing from the inside of the slot and adhere the cured varnish to the core, and there is no need to remove the adhered varnish cured product. The present invention has been completed by finding an impregnation treatment method and an impregnation treatment apparatus.

  That is, the insulating varnish impregnation method of the present invention includes a coil preheating step for preheating an electric device coil comprising an iron core and a winding wound around the iron core, and a varnish impregnation step for impregnating the preheated coil with varnish. An insulating varnish impregnation treatment method comprising a varnish curing step in which the varnish adhering to the coil is heated and cured by the varnish impregnation step, wherein the varnish impregnation step removes the low-viscosity varnish penetrating into the windings inside the coil slot. It comprises a first varnish impregnation step for impregnating the coil portion, and a second varnish impregnation step for impregnating the coil end portion with a high viscosity varnish having a higher viscosity than the low viscosity varnish.

  Further, the insulation varnish impregnation apparatus of the present invention includes a coil preheating means for preheating an electrical equipment coil comprising an iron core and a winding wound around the iron core, and the preheated coil penetrates the winding inside the coil slot. First varnish impregnation means for impregnating the low-viscosity varnish, second varnish impregnation means for impregnating the preheated coil with a high-viscosity varnish having a higher viscosity than the low-viscosity varnish, low-viscosity varnish and high-viscosity adhered to the coil And varnish curing means for heating and curing the varnish.

  According to the insulation varnish impregnation treatment method and impregnation treatment apparatus of the present invention, by using a specific impregnation treatment method, the varnish does not overflow from the inside of the slot and adhere to the core. Since the trimming process to be removed can be omitted to reduce the number of processes, the workability can be improved and the coil can be manufactured efficiently.

  Hereinafter, an insulating varnish impregnation treatment method and an impregnation treatment apparatus of the present invention will be described with reference to the drawings.

(First embodiment)
First, the insulating varnish impregnation processing apparatus of the present invention will be described in detail with reference to FIGS. FIG. 1 is a diagram schematically showing a configuration of an insulating varnish impregnation processing apparatus, and FIG. 2 is a cross-sectional view showing a coil holding / rotating unit provided in the insulating varnish impregnation processing apparatus of FIG.

  The varnish impregnation treatment apparatus 1 of the present invention includes a coil preheating means 2 for preheating a coil, a first varnish impregnation means 3 for impregnating a coil with a low viscosity varnish, and a second varnish impregnation for impregnating a coil end portion with a high viscosity varnish. It is a batch type apparatus comprising means 4 and varnish curing means 5 for curing the attached varnish.

  The function of the varnish impregnation processing apparatus 1 is to rotate the stator coil 23 formed in the shape of a ring (circular tube) used for the stator of the motor (by rotating the rotating shaft 16 (in the Sl direction), the coil itself is also rotated. Rotating at the axis of the coil), a varnish, which is an insulating material, is dropped and impregnated into the winding portion (coil portion) 23a of the stator coil 23.

  The coil preheating means 2 heats the stator coil 23 and preheats it to about 90 to 110 ° C. At this time, examples of the coil preheating means include heating means such as an energization heating means, an induction heating means, and a hot air heating means, and these can be used alone or in combination.

  The first varnish impregnation means 3 is a unit for dripping and impregnating a low-viscosity varnish into the winding portion 23a of the stator coil 23 that has been preheated, and performing an insulation treatment by infiltrating the varnish into the winding inside the slot. . Therefore, the first varnish impregnation means is preferably a nozzle that can drop and supply a low-viscosity varnish to the winding portion 23a.

  The second varnish impregnation means 4 impregnates the coil end portion by dripping or dipping the high viscosity varnish on the coil end side of the winding portion 23a of the preheated stator coil 23 to impregnate the coil end portion. It is. As the second varnish impregnation means, when a high viscosity varnish is dropped and supplied to the winding portion 23a, it is preferably a nozzle, and when the winding portion is immersed and impregnated in the varnish, It is preferable that it is an immersion tank which can accommodate a varnish.

  When these first and second varnish impregnation means perform the first impregnation treatment and then the second impregnation treatment, the first varnish impregnation means 3 and the second varnish impregnation means. 4 may be arranged separately. In the case of simultaneous operation, the first varnish impregnation means 3 is arranged on the slot side of the coil end portion so that the varnish can easily penetrate into the winding inside the slot. The varnish impregnation means 4 of 2 is arrange | positioned at the coil end side (outside) of the 1st varnish impregnation means 3 so that a coil end part may be impregnated.

  The varnish curing means 4 heats and cures the varnish impregnated in the winding portion 23a of the stator coil 23. Here, as means for heating the winding portion 23a of the coil, the coil is connected to the coil via a lead wire. In addition to energization heating that energizes and heats, ultraviolet (UV) irradiation, hot air heating, and the like can be mentioned, and it is preferable that a temperature sensor is provided so as not to heat above a predetermined temperature.

  At this time, the varnish gelling means for gelling the varnish by heating between the first varnish impregnation means 3 and the second varnish impregnation means 4 at a temperature lower than the curing means, for example, 80 to 170 ° C. May be provided. By providing the varnish gelling means, it is possible to prevent the varnish impregnated in the coil from flowing down and out of the coil.

  In addition, it is preferable to provide a coil cooling means for cooling the stator coil 23 in which the varnish is heated and cured at the winding portion 23a after the varnish hardening means. The coil preheating means 2, the varnish hardening means 5, and the coil cooling means are provided in the coil cooling means. A plurality of fans may be provided as air conditioning equipment.

  As shown in FIG. 2, the coil holding / rotating unit 6 includes a chuck mechanism 21 that rotatably holds the stator coil 23 and a driving force transmission mechanism 20 that transmits power for driving the chuck mechanism 21. ing. The driving force transmission mechanism 20 is mainly provided with a pair of main bearings 11 and auxiliary bearings 15 that rotatably support a rotating shaft 12 described later, and a sprocket 14 that applies a rotating force to the rotating shaft 12.

  The pair of main bearings 11 and auxiliary bearings 15 are attached to the mounting base 10. A collar 13 for positioning the sprocket 14 is interposed between the pair of main bearings 11 on the mounting base 10. The sprocket 14 applies a rotational force that rotates the rotating shaft 12 in the direction of the arrow S1.

  The chuck mechanism 21 has a coil insertion member 22, and after inserting the coil insertion member 22 into the iron core 23 b, the coil can be chucked by switching the pressure contact state between the insertion member and the iron core. .

  Next, the insulating varnish impregnation method of the present invention will be described with reference to the insulating varnish impregnation apparatus 1 in FIG. 1 and the drawing showing the coil impregnation method in FIG.

  First, in the preheating step, the coil is heated to a temperature at which the coil preheating means 2 can remove moisture from a workpiece such as a chuck, aligning, and improve the impregnation of varnish, for example, about 90 to 110 ° C. At this time, the coil can be heated by using a heating method such as energization heating, induction heating, or hot air heating alone, or can be heated by combining them. The combination of heating methods is preferably energization + induction heating or energization + hot air heating.

  Next, in the first varnish impregnation step and the second varnish impregnation step, the preheated coil (stator) is cantilevered by an inner diameter chuck, and the chuck is kept horizontal as shown in FIG. In this state, the first varnish 31 is dropped from the first nozzle 30 onto the winding portion 23a, and the varnish is impregnated in the slot of the coil and the inside of the interphase paper at the coil end portion. The first varnish impregnation step and the second varnish impregnation step of impregnating the coil end portion are simultaneously performed by the dropping impregnation method in which the second varnish 33 is dropped from the second nozzle 32 onto the winding portion 23a.

  In this varnish impregnation step, the first varnish is intended to impregnate the inside of the slot and the second varnish impregnates the coil end portion. Therefore, the first nozzle 30 is disposed on the core side of the winding portion 32a. The second nozzle is disposed closer to the coil end than the first nozzle.

  In this embodiment, the first varnish impregnation step and the second varnish impregnation step are performed at the same time. However, after the first varnish impregnation step is performed first, the second varnish impregnation step may be performed. In this case, the first nozzle and the second nozzle may be arranged in the same manner as shown in FIG. 3, and the first nozzle and the second nozzle are separately arranged and the respective steps are performed. Also good.

  The viscosity of the varnish used in the first varnish impregnation step is preferably 0.01 to 0.2 Pa · s, particularly preferably 0.05 to 0.1 Pa · s. If the viscosity is less than 0.01 Pa · s, the varnish does not adhere to the coil and flows out from the lower part, and if it exceeds 0.2 Pa · s, the impregnation into the coil is deteriorated.

  The viscosity of the varnish used in the second varnish impregnation step is preferably 0.5 to 20.0 Pa · s, and particularly preferably 1.0 to 5.0 Pa · s. If this viscosity is less than 0.5 Pa · s, the amount of varnish adhering to the coil end decreases, and if it exceeds 20.0 Pa · s, the varnish does not become a coating film.

  Therefore, in the first varnish impregnation step of the present invention, by using a low-viscosity varnish, the impregnation treatment can be performed to the inside of the coil slot, and in the second varnish impregnation step, a high-viscosity varnish is used. Thus, the coil end portion can be impregnated while preventing the varnish from flowing down, and the workability is excellent.

  In this varnish impregnation step, the coil can be heated within a period of 10 minutes at a temperature of 100 to 170 ° C. after dropping the varnish in the first varnish impregnation step, and the varnish is gelled by performing such heating. Therefore, the adhesion of the varnish to the core edge (end surface and side surface of the core) is reduced, and trimming can be further easily omitted. Moreover, since the adhesion amount of a varnish can be increased simultaneously, productivity can also be improved.

  After the impregnation, the coil proceeds to a varnish curing process, in which the varnish adhering to the coil is heated in the varnish curing means 4 to be completely cured. The heating temperature at this time is preferably about 100 to 170 ° C., and this heating is performed by conducting current heating to the coil using the current heating means 5. By performing the electric heating, the curing process can be completed in a shorter time than the conventional heating method.

  In this varnish curing step, the varnish is cured by heating using a heating method such as energization heating, UV irradiation, or hot air heating. At this time, heating using these methods in combination (for example, energization + hot air heating, UV + (Electric heating) can also be performed, and by performing combined heating, it is preferable in that the curing time can be further shortened compared to using electric heating alone, and all of electric heating, UV irradiation, and hot air heating are combined. It can also be done.

  Moreover, as a varnish used for the varnish impregnation processing method of this invention, both a solvent-free varnish and a water-soluble varnish can be used, and unless it is contrary to the objective of this invention, it will not specifically limit. Specifically, an unsaturated polyester resin or an epoxy ester resin is used for the insulating varnish used in the present invention.

  The unsaturated polyester resin used in the present invention can be obtained by reacting an acid component containing an unsaturated dibasic acid with an alcohol component.

  Acid components used here include phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, adipic acid and other fatty acids, soybean oil fatty acid, linseed oil fatty acid, The thing which mixed multiple types of fatty acids, such as coconut oil fatty acid, tall oil fatty acid, rice bran oil fatty acid, is mentioned, These can be used individually or in mixture of 2 or more types.

  The alcohol component used here is propylene glycol, neopentyl glycol, 1,4-butadienediol, 1,6-hexanediol, 1,6-cyclohexanedimethanol, glycerol monoallyl ether, trimethylolpropane monoallyl ether, pentaerythritol. Examples include dihydric alcohols such as diallyl ether, trivalent or higher alcohols such as glycerin, trimethylolpropane, tris-2-hydroxyethyl isocyanurate, pentaerythritol triallyl ether, and these are used alone or in combination of two or more. can do.

  The epoxy ester resin used here is obtained by reacting an acid component and an epoxy component with an esterification catalyst. Examples of the acid component used here include unsaturated monobasic acids such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, and sorbic acid, and phthalic acid, phthalic anhydride, isophthalic acid, hexahydrophthalic anhydride as necessary. A dibasic acid such as acid or adipic acid can be mixed and used.

  Any epoxy component may be used as long as it has two or more epoxy groups in one molecule, and the molecular structure, molecular weight and the like are not particularly limited and can be widely used. Specific examples include epoxy resins having aromatic groups such as bisphenol type, novolac type, and biphenyl type, epoxy resins obtained by glycidyl etherification of polycarboxylic acids, and alicyclic epoxy resins obtained by condensation of cyclohexane derivatives and epoxy. These can be used alone or in admixture of two or more.

  For these two types of resin compositions, there are aromatic monomers such as styrene, vinyltoluene and divinylbenzene as reactive monomers, 2HEMA, polyalkylene oxide diacrylate derivative: triethylene glycol di (meth) acrylate Acrylic monomers such as tetraethylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate can be used. These can be used alone or in combination of two or more.

  Next, the varnish used in the present invention is blended with an organic peroxide to cure the resin component. Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxide, and acetyl peroxide. . Examples thereof include methyl ethyl ketone peroxide, acyl peroxide, cumene peroxide and the like, and these can be used alone or in combination of two or more.

  The varnish used in the present invention can also be mixed with an insulating powder. Examples of the insulating powder include metal oxide powders such as silica powder, alumina powder and magnesia powder, and metal water such as aluminum hydroxide and magnesium hydroxide. Oxide powder can be used. By putting the insulating powder into the second varnish, it becomes more suitable as a varnish having a high viscosity and adhering to the coil end.

  In addition to this, the varnish also contains a curing accelerator such as a metal salt of naphthenic acid or octylic acid, a polymerization inhibitor such as hydroquinone, methoquinone, pt-butylcatechol, pyrogallol, a colorant, and an anti-settling agent, as necessary. An agent or the like can also be mixed.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a diagram for explaining a method for impregnating a coil with a low-viscosity varnish, and FIG. 5 is a diagram for explaining a method for impregnating a coil end with a high-viscosity varnish.

  In this embodiment, as the first varnish impregnation means 3 in FIG. 1, the first nozzle 30 for dropping the low-viscosity varnish as shown in FIG. 4 is used, and as the second varnish impregnation means 4 in FIG. As shown in FIG. 5, a dipping tank 34 for dipping and impregnating the high-viscosity varnish into the coil end portion and a second nozzle 32 for dropping the high-viscosity varnish are provided. This embodiment is the same as the first embodiment except that a varnish impregnation method using both immersion and dripping is used.

  In the varnish impregnation step in the second embodiment, the first varnish impregnation step and the second varnish impregnation step are completely separate steps. In the first varnish impregnation step, the low viscosity varnish 31 is dropped from the nozzle 30. To impregnate the inside of the slot.

  Next, the second varnish impregnation step is performed, and the second varnish impregnation step is to impregnate the varnish so that the coil that has been held horizontally in the other steps is held vertically. is there. In order to achieve such verticality, a joint can be provided on the shaft 12 that supports the coil, and the joint can be bent when entering the varnish impregnation process. As a result, the coil itself can be continuously rotated.

  In this way, the coil is held vertically, and one coil end portion is immersed in the high viscosity varnish in the varnish impregnation tank 34, and the other coil end portion is provided with a high viscosity varnish from the nozzle 32. By impregnating the varnish with the dropping impregnation method in which 33 is dropped, a coil with good impregnation properties that makes use of the advantages of the conventional immersion impregnation method and the dropping impregnation method can be obtained. That is, the varnish can be impregnated quickly and sufficiently by this method.

  The present invention can improve the varnish impregnation property to the coil and obtain a safe and highly productive insulating varnish not only in the batch type described in the above embodiment but also in the case of the continuous type.

  The present invention will be described below with reference to examples.

Example 1
The impregnation treatment was performed by the varnish impregnation apparatus shown in FIG. 1 using the varnish impregnation method shown in FIG. First, a coil having a winding diameter of 0.8 mm, a line area ratio of 70%, and a total coil weight of 12 kg was preheated to 100 ° C. by heating with hot air, and the preheated coil was dropped and impregnated with low-viscosity varnish A. The blended high viscosity varnish B was dropped and impregnated into the coil end. The coil to which the varnish was attached was heated to 130 ° C. by hot air heating and cured to obtain a coil impregnated with an insulating coil.

(Example 2)
The impregnated coil was treated by the same operation as in Example 1 except that a varnish gelling step for heating to 150 ° C. by hot air heating was provided between the first varnish impregnation step and the second varnish impregnation step. Got.

(Example 3)
The impregnation-treated coil was obtained in the same manner as in Example 2 except that the impregnation treatment was performed using the varnish C containing no insulating powder instead of the high-viscosity varnish B.

  Table 1 summarizes the varnishes, impregnation methods, and curing methods used in the examples.

(Comparative Example 1)
The varnish impregnation apparatus shown in FIG. 1 was used to impregnate the coil end portion using the varnish impregnation method shown in FIG. First, a coil having a winding diameter of 0.8 mm, a line area ratio of 70%, and a total coil weight of 12 kg was preheated to 100 ° C. by hot air heating, and the preheated coil was dropped and impregnated with low viscosity varnish A. The coil to which the varnish was attached was heated to 130 ° C. by hot air heating and cured to obtain a coil impregnated with an insulating coil.

(Comparative Example 2)
Except for performing the impregnation treatment of the coil using only the low-viscosity varnish A, the treatment was performed in the same manner as in Example 1 to obtain an impregnated coil.

  In Comparative Examples 1 and 2, the coil was obtained by increasing the amount of dripping so that the same amount of varnish as in Example was adhered.

  Table 2 summarizes the varnishes, impregnation methods, and curing methods used in the comparative examples.

  In addition, the characteristic and structure of varnish A, B, and C used by the Example and the comparative example are as showing next.

[Varnish A]: Viscosity (25 ° C.) 0.08 Pa · s, Gel time 240 seconds Varnish A was manufactured by mixing 100/1 TVB2129L (main agent) / TEC9637K (curing agent) manufactured by Kyocera Chemical Co., Ltd. It consists of epoxy ester resin (soy oil fatty acid, dicyclopentadiene, ethylene glycol, synthesized by adding hydroquinone to tetrahydrophthalic acid) and reactive diluent (styrene), manganese naphthenate, leveling agent, A foaming agent is added.

[Varnish B]: Viscosity (25 ° C.) 2.0 Pa · s, gel time 240 seconds Varnish B was manufactured by mixing 100/1 TVB2470 (main agent) / TEC9637K (curing agent) manufactured by Kyocera Chemical Co., Ltd. The content of the composition is epoxy ester resin (synthetic oil by adding hydroquinone to soybean oil fatty acid, dicyclopentadiene, ethylene glycol), air-drying resin (Neopol 8414), reactive diluent (triethylene glycol di ( (Meth) acrylate), silica (average particle size 3 μm), manganese naphthenate, leveling agent and antifoaming agent.

[Varnish C] Viscosity (25 ° C.) 3.0 Pa · s, gel time 240 seconds Varnish C is manufactured by mixing TVB2470H (main agent) / TEC9637K (curing agent) manufactured by Kyocera Chemical Co., Ltd. at 100/1. There are epoxy ester resin (soybean oil fatty acid, dicyclopentadiene, ethylene glycol, synthesized by adding hydroquinone), air drying resin (Neopol 8414), reactive diluent <triethylene glycol di (meta ) Acrylate), manganese naphthenate, leveling agent and antifoaming agent.

(Test example)
For the coils obtained by insulation treatment in the examples and comparative examples, the treatment appearance, the amount of varnish attached, the varnish exudation to the core, the coating thickness of the coil end, and the varnish filling rate in the slot were evaluated, respectively. The coils were evaluated. The results are shown in Tables 1 and 2.

[Coil processing appearance]
Based on visual appearance, it was determined according to the following criteria.
○: Cured, x: Uncured part was observed [Amount of varnish attached]
The coil weight before and after varnish application was measured and calculated from the difference.
[Vanishing into the core]
Based on visual appearance, the presence or absence of seepage was confirmed.
[Coil end coating thickness]
The thickness of the cured varnish peeled when the coil was loosened was measured with a micrometer.
[Vanity filling rate in slot]
The coil was cut and the cut surface was visually confirmed and judged.

  From the above results, it was found that by using a specific varnish impregnation treatment method, it was possible to sufficiently achieve the impregnation into the slot, to have a large amount of varnish adhesion, and to have a good appearance in a short manufacturing time.

The figure which showed roughly the composition of the insulation varnish impregnation processing equipment Sectional drawing which showed the coil holding and rotation unit with which the varnish impregnation apparatus of FIG. The figure which showed the 1st and 2nd varnish impregnation process of a coil end The figure which showed the 1st varnish impregnation process of a coil end The figure which showed the 2nd varnish impregnation process of a coil end

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Insulation varnish impregnation processing apparatus, 2 ... Coil preheating means, 3 ... 1st varnish impregnation means, 4 ... 2nd varnish impregnation means, 5 ... Varnish hardening means, 6 ... Coil holding | maintenance / rotation unit, 12 ... Rotation shaft , 20 ... Driving force transmission mechanism, 21 ... Chuck mechanism, 22 ... Coil insertion member, 23 ... Stator coil, 23a ... Winding part (coil part), 23b ... Iron core, 30 ... First nozzle, 31 ... Low viscosity varnish 32 ... second nozzle 33 ... high viscosity varnish 34 ... varnish dipping bath

Claims (13)

A coil preheating step for preheating an electric device coil comprising an iron core and a winding wound around the iron core, a varnish impregnation step for impregnating the preheated coil with varnish, and a varnish attached to the coil by the varnish impregnation step An insulating varnish impregnation treatment method comprising a varnish curing step of curing by heating,
The varnish impregnation step includes a first varnish impregnation step of impregnating a coil portion with a low-viscosity varnish that penetrates into the winding in the slot of the coil, and a high-viscosity varnish having a higher viscosity than the low-viscosity varnish. And a second varnish impregnation step for impregnating the varnish.   The second varnish impregnation step performs the first varnish impregnation step of dripping and impregnating the winding in the slot using the low viscosity varnish, and then dripping and impregnating the coil end portion using the high viscosity varnish. The insulating varnish impregnation method according to claim 1, wherein a varnish impregnation step is performed.   In the varnish impregnation step, after performing the first varnish impregnation step of dripping and impregnating the winding in the slot using the low viscosity varnish, the second end of the coil end is immersed and impregnated using the high viscosity varnish. The insulating varnish impregnation method according to claim 1, wherein a varnish impregnation step is performed.   In the varnish impregnation step, the low-viscosity varnish is supplied from the first nozzle, and at the same time, the high-viscosity varnish is supplied from the second nozzle disposed closer to the coil end than the first nozzle. The method for impregnating an insulating varnish according to claim 1.   The viscosity of the low-viscosity varnish at 25 ° C is 0.01 to 0.2 Pa · s, and the viscosity of the high-viscosity varnish at 25 ° C is 0.5 to 20.0 Pa · s. 5. The insulating varnish impregnation method according to any one of 1 to 4.   The insulating varnish impregnation method according to any one of claims 1 to 5, wherein the low-viscosity varnish and the high-viscosity varnish are unsaturated polyester resins or epoxy ester resins.   The method for impregnating an insulating varnish according to any one of claims 1 to 6, wherein the high-viscosity varnish contains an insulating powder.   The insulating varnish impregnation method according to any one of claims 1 to 7, wherein the first and second varnish impregnation steps are performed while the coil is energized and heated. A coil preheating means for preheating an electric device coil comprising an iron core and a winding wound around the iron core;
First varnish impregnation means for impregnating the preheated coil with a low-viscosity varnish that penetrates into the winding inside the slot of the coil;
A second varnish impregnation means for impregnating the preheated coil with a high viscosity varnish having a higher viscosity than the low viscosity varnish;
Varnish curing means for heating and curing the low viscosity varnish and the high viscosity varnish attached to the coil,
An insulating varnish impregnation treatment apparatus characterized by comprising:   10. The insulating varnish impregnation apparatus according to claim 9, wherein the first varnish impregnation means and the second varnish impregnation means comprise a nozzle for supplying the varnish dropwise.   11. The insulation varnish impregnation according to claim 9 or 10, wherein the coil preheating means, the varnish impregnation means and the varnish hardening means have a chuck mechanism capable of holding the coil and rotating the coil about its axis. Processing equipment.   10. The first varnish impregnation means comprises a nozzle for supplying varnish by dripping, and the second varnish impregnation means comprises a nozzle for supplying varnish by dripping and a dipping tank for accommodating the varnish. The insulation varnish impregnation processing apparatus as described.   The coil preheating means, the varnish impregnation means, and the varnish curing means have a chuck mechanism that can hold the coil and rotate the coil about its axis, and the chuck mechanism is the second varnish impregnation means. 13. The insulation varnish impregnation apparatus according to claim 12, wherein the coil is held so that an axis of the coil is perpendicular to a horizontal plane.

Images