JPH09213540A - Molded electric-apparatus coil and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molded electric-apparatus coil whose crack resistance is increased by a method wherein every block coil is constituted in such a way that a conductor which is formed by executing a strand insulating operation is wound on an aluminum conductor in which the ratio of its thickness to its width in its cross section has a specific value and which has a specific thickness. SOLUTION: An aluminum conductor 2 has a thickness of 1.5 to 3mm, the ratio of its thickness to its width is 1:8 to 1:20, its cross section has a flat oval shape, and a strand insulating operation is executed to its outer circumference. Twin coils are constituted by using the aluminum conductor 2, and a plurality of block coils 5 are formed. The plurality of block coils 5 are piled up via respective spacers, and aluminum 4 crimp terminals to which lead-out terminal bosses 9 are brazed are attached to the winding start lead end 4 of the block coil 5 at the uppermost state and to the winding finish lead end 4 of the block coil 5 at the lowermost stage. The winding finish and winding start lead ends 4 of the block coils 5 are overlapped in such a way that chevron- shaped groove parts are engaged, they are connected by aluminum crimp sleeves 7 so as to be mold-molded integrally by using a molding resin 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded electric coil formed by integrally molding a block coil formed by winding an aluminum conductor with a resin, and a method for manufacturing the molded electric coil.

[0002]

2. Description of the Related Art Molded electric appliances such as mold transformers are made by integrally molding an electromagnetic coil with a molding resin, and are therefore excellent in fire resistance, self-extinguishing ability, and other disaster prevention properties. It is widely used mainly in public facilities such as underground malls.

Molded electric coils generally have a structure in which an electromagnetic coil is integrally cast by a vacuum pressure casting (VPI) method. In this case, in order to improve crack resistance, which is the most technical problem, a conductor is used. Is an aluminum conductor whose linear expansion coefficient is close to that of the molding resin, and when the current capacity is large, a rectangular conductor having a better space factor than a round wire is used.

FIG. 7 is a partial cross-sectional view of a conventional molded electric coil 14, in which a flat rectangular aluminum conductor 15 is used as a conductor, and a block coil 25 is continuously wound in multiple layers.
Are stacked in multiple stages, and the lead-out ends 16 are connected by aluminum brazing to form a coil for one phase. In the figure, 17 is an external lead terminal, and 18 is a molding resin.

Since the block coil 25 has a large potential difference between the stages, an interstage insulator 19 is inserted to provide insulation between the stages. A glass net 20 is wound around each block coil 25.

FIG. 8 shows a partial cross-sectional view of another molded electric coil 21. The conductor is an aluminum sheet conductor 22.
The block coils 26 are formed by winding through the interstage insulator 19, and the block coils 26 are connected by cold-pressing a copper strip ribbon 23 to an aluminum sheet conductor 22 and connecting the copper strip ribbons 23 to each other. Crimp each other with the crimp terminal 24 1
The coils for the phases are formed. In addition, the block coil 26
A glass net 20 is wound around the.

[0007]

In the molded electric coil as described above, the interstage insulator 19 is inserted between the stages of the block coils 25 and 26. In this case, the interstage insulator 19 is inserted. In order to prevent the cracks from developing from the upper and lower ends and propagating, it is necessary to take measures such as winding and reinforcing the entire block coil with a high-strength fiber material such as the glass net 20. There were many problems.

In the case of the block coil 25 using the aluminum rectangular conductor 15, each block coil 25
In connection, the lead ends 16 of the winding start and the end of each block coil 25 are connected by aluminum brazing. In this case, however, it is necessary to tie the lead ends 16 together beforehand, and to prevent fire. In order to use it, to prevent the welding spatter from scattering on the sound coil,
There is a problem that workability is poor because it is necessary to braze the coil while curing it.

Further, each block coil 26 when the block coil 26 is formed by using the aluminum sheet conductor 19
The copper coil ribbons 23 are cold-pressed to the ends of the aluminum sheet conductors 19 and the copper coil ribbons 23 are crimped with crimp terminals 24 to connect the block coils 2 to each other.
6 are connected. In this case, each block coil 2
Equipment for cold-pressing both ends of the winding start and the winding of No. 6 is required, and equipment for crimping the crimp terminal 24 is also required.

The present invention has been made in view of the above problems, and a first object thereof is to provide a molded electric coil excellent in crack resistance without using an interstage insulator. is there. A second object of the present invention is to provide a molded electric coil and a method for manufacturing the molded electric coil, which facilitates the connection work between the block coils.

[0011]

According to the molded electric coil of claim 1, since the block coil is formed by winding the flat aluminum conductor having the wire insulation, the potential difference between the windings of the conductor is reduced. Since it is small and can be sufficiently insulated by wire insulation, it is not necessary to use an interstage insulator. As a result, the occurrence of cracks due to the use of the interstage insulating material is eliminated, the crack resistance can be improved, and the work of winding the glass net for preventing the development of cracks is eliminated.

According to the molded electric coil according to the second aspect, the lead-out end is located on the outer periphery of the block coil, and it is formed in a V shape and connected by crimping. There is no need to work while curing the coil.

According to the molded electric coil according to the fifth aspect of the present invention, it is possible to perform the work of forming the lead-out end of the block coil into a dogleg shape by a crimping machine. Therefore, when the aluminum sheet conductor and the copper ribbon are cold-welded to each other. There is no need to install pressure welding equipment.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view of a molded electric coil according to the present invention, and FIG. 2 is a partial sectional view of a block coil. 1 and 2, the aluminum conductor 2 has a flat oval shape with a thickness of 2 mm, a width of 24 mm, and chamfered corners to form a curved surface. Insulation 3 is applied. The aluminum conductor 2 is used to form a twin coil to form a plurality of block coils 5. In the twin coil, for example, the aluminum conductor 2 is wound inward in order of 1, 2, ...
In order to form the block coil 5B over the lowermost step at the innermost circumference, the block coil 5B is formed by winding in the order of 11, 12, ... Similarly, two block coils are sequentially formed by twin coil winding, and the plurality of block coils 5 are stacked via a spacer (not shown).
The lead-out ends 4 of the winding start and the winding end of each block coil 5 are located at the outermost circumference of each block coil 5, and the wire insulation 3 is peeled off from each block coil 5 to form a dogleg shape. As shown in FIG. 3, aluminum crimp terminals 6 having brazing lead-out terminal bosses 9 are attached to the winding start lead-out end 4 of the uppermost block coil 5 and the winding end lead-out end 4 of the lowermost block coil 5 by crimping. And is configured as an external lead terminal. As shown in FIGS. 4 and 5, the winding ends and winding start ends 4 of the adjacent block coils 5 are overlapped with each other so that the V-shaped groove portions are meshed with each other and are crimped by an aluminum crimp sleeve 7. To be done.

The molded electric coil 1 is obtained by integrally molding the plurality of block coils 5 thus constructed with the molding resin 8. According to this structure, the potential difference between the turns (between steps) of the aluminum conductor 2 is small, and a predetermined insulation can be secured by the wire insulation 3 and the molding resin 8 provided around the aluminum conductor 2. There is no need to provide an interstage insulator or cover the entire coil with a glass net. As a result, the occurrence and development of cracks due to the use of inter-stage insulators can be eliminated, and crack resistance can be improved, and the work involved in inserting inter-stage insulators and auxiliary work such as glass net winding work is eliminated, making the coil simpler. Be able to manufacture.

In addition, since the aluminum conductor 2 is formed in an oval cross section, the edge portion where the stress of the mold resin 8 concentrates is eliminated, and the occurrence of cracks can be further reduced.

Further, the lead-out end 4 of each block coil 5 is connected to an aluminum crimp sleeve or aluminum crimp terminal 6 by crimping, but since it is not necessary to make brazing connection as in the conventional case, welding spatter does not occur, There is no need to perform connection work while curing the coil. Moreover, a highly reliable connection is possible.

In the above embodiment, the molding jig for molding the lead-out end 4 into a dogleg shape was not described in detail.
As this molding jig, a die 1 for molding as shown in FIG.
By attaching 3 to the crimping head of the crimping machine and pressurizing with this, it is possible to easily form a dogleg shape.
Therefore, both the molding and the pressure bonding can be performed by sharing the aluminum pressure bonding machine and exchanging only the die.

In the above embodiment, the case where the aluminum conductor 2 is a conductor having a thickness of 2.0 mm and a width of 24 mm has been described. The cross-sectional area of this conductor is 47 mm
² and 7.7 mmφ round wire, or 1.0 x 47
mm aluminum sheet conductor and has the same cross section,
Current capacities in excess of amperes can be obtained. The thickness-width ratio of this conductor is 1:12, and in order to form a coil for one phase by stacking block coils of twin coils, this ratio is desirable. However, practically, the thickness of the aluminum conductor is determined based on the fact that the wire insulation can be formed by winding, that it has the strength to withstand compression by vertical tightening, and that it can be shaped like a dogleg. 1.5 to 3.0 mm is suitable. Further, the width of the aluminum conductor is 12 to 30 mm, which is suitable for forming a dogleg shape and the shape of the aluminum conductor to be inserted into the crimp terminal by molding. Therefore, the thickness-width ratio of the aluminum conductor is 1: 8 to 1: 2.
0 is suitable.

[0020]

The molded electric coil and the method for manufacturing the same formed as described above have the following effects. (1) Since the insulation between the steps is carried out only by the wire insulation and the resin, the crack resistance is excellent without using the insulation between the steps. (2) The connection of the lead end of each block coil is
Since they are bent in a dogleg shape and crimped by tying them together with an aluminum sleeve or aluminum crimp terminal, the work can be performed relatively easily as compared with the brazing work, and a highly reliable connection is possible. (3) Since the crimping machine can be used to form the dogleg shape of the lead-out end of the block coil and the connection of the lead-out end, it is not necessary to separately prepare equipment such as cold pressure welding, and manufacturing is further facilitated. Become.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a molded electric coil according to an embodiment of the present invention.

FIG. 2 is a partial sectional view showing a block coil portion.

FIG. 3 is an enlarged view showing a connecting portion between a lead end of a block coil and an aluminum crimp terminal.

FIG. 4 is an enlarged view showing a connecting portion between the lead-out ends of the block coil.

FIG. 5 is an enlarged view showing a state where the lead ends of the block coil are connected to each other by an aluminum crimp sleeve.

FIG. 6 is a perspective view showing a die attached to the crimping machine.

FIG. 7 is a partial sectional view showing an example of a conventional molded electric coil.

FIG. 8 is a partial cross-sectional view showing another example of a conventional molded electric coil.

[Explanation of symbols]

1 ... Molded electric coil, 2 ... Aluminum conductor, 4 ...
Lead end, 5, 5A, 5B ... Block coil, 7 ... Aluminum crimp sleeve, 8 ... Mold resin, 9 ... Lead-out terminal boss.

Claims (5)

[Claims] 1. A molded electric coil formed by stacking a plurality of block coils formed by winding aluminum conductors in multiple stages, connecting the lead-out ends of each block coil, and molding the resin with a resin, wherein each block coil has a cross section. Thickness to width ratio is 1: 8 to 1:20 and thickness is 1.5 to 3m
A molded electric coil formed by winding a conductor formed by applying a wire to an aluminum conductor of m. 2. The molded electric coil according to claim 1, wherein the plurality of block coils are composed of twin coils and the lead-out end is arranged on the outer peripheral side. 3. The block coils are connected by forming the winding start end and the winding end start end into a dogleg shape, tying them together, and crimping them with an aluminum crimping sleeve. Molded electric coil of. 4. The external lead terminal of the block coil is formed by crimp-connecting to the lead-out end of the block coil shaped like a dogleg using an aluminum crimp terminal to which a lead terminal boss is brazed. The molded electric coil according to claim 1. 5. The V-shaped molding of the lead end of the aluminum conductor is performed by using the same machine as the crimping machine for crimping the aluminum crimping terminal and exchanging only the dice. 1. The method for manufacturing a molded electric coil according to 1.