JP2011062036A - Varnish treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a varnish treatment method which controls varnish supply properly to make masking unnecessary, causes no varnish pool, precisely control the amount of varnish impregnating in a coil, and eliminate the need of unnecessary varnish removal work, thereby reducing the amount of use of varnish materials and work processes to cut down overall costs. <P>SOLUTION: While a flatly placed coil 1 is rotated horizontally, varnish is dropped to a treatment spot of the coil 1 to impregnate it therein. Subsequently, the coil 1 impregnated with the varnish is set vertically, and is rotated vertically to cause the varnish to cure and dry. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coil varnish treatment method intended to fix a coil, and to insulate the coil and dissipate heat in the coil.

An alternator (alternator) for automobiles, ships, and the like employs a stator composed of a stator core and a stator coil. The stator is fixed and the rotor is rotated to generate an alternating current to charge the battery. Is going. The stator coil is coated and impregnated with varnish for the purpose of fixing to prevent insulation change due to slight vibration during power generation and preventing heat accumulation of the coil.

FIG. 2 is a schematic diagram of a conventional example showing a varnish treatment method for a coil. In this processing method, the coil 1 is placed in an upright state, and masking 2 is applied to a portion where it is difficult for the varnish to adhere. Then, the coil 1 is immersed in a bat in which varnish is stored, and impregnation and coating are performed. Thereafter, the masking is removed and the excess varnish is removed, and finally, the drying is performed in a dryer.

FIG. 3 is a schematic diagram of another conventional example showing a varnish treatment method for a coil. In this treatment method, the varnish is dropped and impregnated while the coil 1 is placed flat and rotated laterally. Subsequent drying is carried out while horizontally rotating while flat.

Moreover, the following technique is shown by the "varnish processing method" of patent document 1. FIG. In other words, after the preheating, in the first supply step, the stator core is held horizontally, varnish is injected from the upper surface of the upper coil end, and the varnish that flows through the impregnation reaches the outside of the lower coil end protruding from the lower end surface of the stator core. The varnish is supplied while controlling the supply amount so as to gel before. Thereafter, the stator core on which the coil is mounted is reversed at intervals equal to or longer than the time when the varnish gels. And in the 2nd supply process after a reversal process, a supply amount is controlled and varnish is supplied so that gelation may start in the vicinity of the position where gelation started in the 1st supply process. Thereafter, the varnish impregnated in the coil is heat-cured.

JP 2008-109732 A

The conventional varnish treatment method described with reference to FIG. 2 has the trouble of masking before the treatment, and the varnish is excessively attached, and thus there is a difficulty that a step of removing the excess varnish is required.

In the processing method described with reference to FIG. 3, the operation is simplified as compared with the processing method illustrated in FIG. However, since a varnish pool that is a lumpy lump occurs, the exact amount of varnish impregnation into the coil cannot be grasped, and there is a risk of insufficient fixing of the coil due to insufficient varnish processing amount, insufficient heat dissipation function There is.

According to the varnish treatment method described in Patent Document 1, varnish treatment time can be shortened, varnish impregnation variation to the coil can be prevented, and trimming to remove excess varnish after varnish treatment It is described that it is possible to reduce the trouble. However, there are problems that the number of work processes is large and the process work itself is complicated and difficult to manage.

By properly controlling the supply of varnish, the present invention does not require masking and does not accumulate varnish, and can accurately manage the amount of varnish impregnation into the coil, and also eliminates unnecessary varnish removal work to make varnish material It aims at providing the varnish processing method which can aim at the cost reduction by the usage-amount reduction and work process reduction.

In order to solve the above-mentioned problems, the varnish treatment method of the present invention is such that a horizontally placed coil is rotated horizontally while dripping and impregnating the varnish into the main part of the coil treatment, and then the varnish-impregnated coil is placed vertically, The varnish is cured and dried while rotating.
The coil is preferably preheated. Moreover, it is preferable to perform the dripping impregnation of the varnish by intermittent dropping since the dropping amount can be easily adjusted.

According to the varnish treatment method of the present invention, since an appropriate amount of varnish is dripped and impregnated only in a portion where coil treatment is required, masking is not required and varnish accumulation can be eliminated. As a result, the amount of varnish impregnation into the coil can be accurately managed, and further, unnecessary varnish removal work is not necessary, so it is possible to reduce costs by reducing the amount of varnish material used and working processes. Become.

The conceptual diagram which shows an example of the varnish processing method concerning this invention Outline diagram of conventional example showing varnish treatment method for coil Schematic diagram of another conventional example showing a varnish treatment method for a coil

In the varnish treatment method according to the present invention, the coil 1 is preferably preheated in the dryer 3 as shown in FIG. Preheating can remove moisture from the surface of the coil 1 and improve the fluidity of the varnish dripped onto the coil 1. Further, the preheating temperature (coil surface temperature) can be appropriately determined in consideration of the time until the subsequent dripping impregnation, the size of the coil 1, the viscosity of the varnish, the curing temperature, and the like.

Next, as shown in FIG. 1B, the coil 1 is placed flat on the rotating body 4 and rotated laterally. In this state, a varnish made of epoxy resin or the like is dropped and impregnated only in the main part of the coil. Although continuous dripping is possible as the dropping impregnation method, intermittent dropping is advantageous because fine adjustment is easier.

The coil 1 after the varnish treatment needs to satisfy the vibration durability specification of the motor to be formed. For this purpose, the dropping amount, dropping time, dropping interval, and the like are adjusted. However, since these vary depending on the heat capacity, size, etc. of the coil 1 to be processed, the appropriate values are obtained by considering them individually.

By placing the varnish on a flat surface, it can be selectively dropped only on the main impregnation, and masking is unnecessary. Further, by adjusting the dropping amount, dropping time, dropping interval and the like, the coil 1 is impregnated with an appropriate amount of varnish, so that unnecessary varnish removal work as a subsequent step becomes unnecessary. It is possible to accurately control the amount of impregnation into the water.

Next, as shown in FIG. 1 (c), the coil 1 impregnated with varnish is placed in a drying furnace 5. In the case of using a solvent varnish or an aqueous varnish, the solvent or water is removed and the varnish is cured, and in the case of a solventless varnish, the varnish is cured.

In the drying furnace 5 of the next step, the coil 1 is placed vertically and rotated vertically. By doing so, it is possible to cure the impregnated varnish in a state of being uniformly distributed in the coil 1.

Here, in general, the temperature in the drying furnace 5 is usually higher in the upper layer portion and lower in the lower layer portion. Therefore, by placing a plurality of coils 1 on a conveyor or a hanger (not shown) and circulating in the drying furnace 5 in the vertical direction, the thermal history of each coil 1 is adjusted to be approximately the same, and the varnish curing time is averaged. It can also be made.

  The varnish treatment method of the present invention is suitable for a stator coil attached to an alternator for automobiles, ships, etc., but also for various motor coils for power generation, construction, business use, home use, etc. Regardless of its small size, it can be used sufficiently.

DESCRIPTION OF SYMBOLS 1 ... Coil, 2 ... Masking, 3 ... Dryer, 4 ... Rotating body, 5 ... Drying furnace.

Claims (3)

Varnish treatment characterized by dripping and impregnating varnish into the coil's main processing parts while horizontally rotating a horizontally placed coil, then placing the varnish-impregnated coil vertically, and curing and drying the varnish while vertically rotating the coil. Method. The varnish treatment method according to claim 1, wherein the coil is preheated. The varnish treatment method according to claim 1 or 2, wherein the varnish is dropped and impregnated by intermittent dropping.