JPS62290116A - Manufacture of flat coil - Google Patents

Abstract

PURPOSE:To enable mass production by winding a metallic foil through an insulating layer and cutting the metallic foil through an electric discharge machining method. CONSTITUTION:A process in which an insulating layer is applied and formed to a metallic foil, a process in which the metallic foil to which the insulating layer is shaped is wound on the central axis, contact-bonded and a metallic-foil wound body 7 is prepared, and a process in which the wound body is cut in predetermined thickness through an electric discharge machining method in the direction orthogonal to the central axis 6 are provided. When the wound body 7 of the metallic foil on which the insulating layer is laminated is cut through the electric discharge machining method, the insulating layer is brought to the state in which it is projected slightly from the metallic foil on the cut surface, thus keeping insulation among the metallic foils. Consequently, the generation of defectives such as a short circuit is inhibited. According to the electric discharge machining method, the wound bodies 7 of the metallic foils can be cut collectively at the same time, thus remarkably improving productivity.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing flat coils used in motors, deflection yokes, transformers, etc. The present invention relates to a method of manufacturing a flat coil by cutting a wound body.

[Existing requirements of the invention]

The present invention comprises a step of forming an insulating layer on metal foil, a step of winding the metal foil provided with the insulating layer around a central axis while thermocompression bonding to create a metal foil wound body, and The purpose is to manufacture a flat coil with high reliability with good productivity by cutting the coil into a predetermined thickness by electrical discharge machining in a direction perpendicular to the central axis.

[Conventional technology]

Conventionally, motor coils and cathode ray tube deflection yokes have
Wire-wound coils in which copper wire is wound many times are generally used, but as devices become smaller, thinner so-called flat coils have been developed and put into practical use.

For example, sheet coils for flat motors are made by etching a copper foil laminated to an insulating sheet in a spiral shape with a line width of about 50 μm.This is used to make the motor thinner and smaller. He has contributed greatly.

However, although the sheet coil described above is extremely useful for thinning, it is difficult to mass produce because it requires extremely high precision etching technology, and it requires special technology so it can be easily produced anywhere. There's no way it can be done.

On the other hand, the idea of winding copper foil coated with an insulating film and slicing it to create a flat coil has been proposed, and various attempts have been made, but it is difficult to put it to practical use in terms of reliability and mass production. In particular, it is difficult to cut rolled copper foil to a specified thickness, and when cutting using mechanical means, lasers, etc., there is a risk that the cut surface will warp and short-circuit the coil. There is. The only way to solve this blurring of the cut surface is to polish the cut surface smoothly, but this process is surprisingly laborious and requires a huge amount of work time, so it is not suitable for mass production.

[Problem that the invention seeks to solve]

When attempting to cut a roll of copper foil into a flat coil in this way, conventional cutting methods do not have sufficient capacity to justify the cost, post-processing is difficult, and production costs are high. The reality is that it has not been mass-produced.

Therefore, an object of the present invention is to provide a method for manufacturing a flat coil that eliminates the drawbacks of the above-mentioned conventional methods. The purpose is to manufacture high quality coils with good productivity.

[Means for solving problems]

The inventors of the present invention have conducted various studies on the method of cutting a rolled body of metal foil, and as a result have come to the conclusion that the electric discharge machining method is preferable.The present invention is based on such findings. A step of forming an insulating layer on metal foil, and a step of winding the metal foil with the insulating layer around a central axis while thermocompression bonding to create a rolled metal foil body. and cutting the wound body to a predetermined thickness by electrical discharge machining in a direction perpendicular to the central axis.

[Effect]

When a rolled body of metal foil laminated with an insulating layer is cut by an electric discharge machining method, the insulating layer protrudes slightly from the metal foil at the cut surface, and insulation between the metal foils is maintained. Therefore, the occurrence of defects such as short circuits can be significantly suppressed.

Further, according to the electric discharge machining method described above, it is possible to simultaneously cut the wound body of metal foil at the same time, and productivity is dramatically improved.

〔Example〕

Hereinafter, the method for manufacturing a flat coil according to the present invention will be explained using specific examples.

To manufacture a flat coil, first, as shown in Figure 3, an adhesive layer that will serve as an insulating layer is laminated onto the copper foil (1). Polymer film such as polyimide film (2)
Laminate and sandwich this with two adhesive layers (3)
, (4) was coated.

Here, the thickness of the copper foil (1) is 35 μm, and the adhesive layer (
The thicknesses of 3) and (4) were each 6 μm, and a 13 μm thick polyimide film was used as the polymer film (2).

Note that the polymer film (2) is not necessarily required, and it is sufficient to simply coat both surfaces of the copper foil (1) with adhesive layers (3) and (4), as shown in FIG. 4, for example.

The polymer film (2) or the adhesive layers (3) and (4) are laminated onto the copper foil (1) using an apparatus as shown in FIG.
1) The polymer film (2) supplied from 1) is led to an adhesive applicator (12), and both sides of the film are coated with adhesive.Then, the adhesive is dried through a dryer (13).
After semi-curing a), the copper foil (1) fed from the unwinding roll (15) is bonded by the laminator (14), and the copper foil (1) is wound onto the winding roll (16).

Through the above steps, as shown in FIG. 2, a raw roll of a laminate (5) consisting of a copper foil (1), a polymer film (2), and adhesives N (3) and (4) is obtained.

Next, the raw fabric roll of this laminate (5) is rolled (16)
Then, as shown in FIG. 5, the pieces are cut to a predetermined width using cutter a (17), and each piece is rolled (18a).

(18b), (18c), and (18d).

Subsequently, as shown in Fig. 6, the laminate (5) produced in the above steps is fed out from the unwinding roll (19), and while applying back tension run by the tension roll (20), the central axis of the approximately triangular cross section is (6) to obtain a rolled body (7) of the laminate (5). In this embodiment, when winding the laminate (5) around the central shaft (6), a hot roll (22) that is energized by an air cylinder (21) is crimped from three sides, and the rolled body (7) is wound. The situation is being adjusted.

Further, at this point, the laminates (5) are bonded by the adhesive layers (3) and (4) by the pressure bonding of the hot roll (22). The external appearance of the obtained wound body (7) is shown in FIG.

The cross-sectional shape of the central axis (6) may be changed depending on the shape of the desired coil, and may be circular or oval.

It can be made into various shapes such as a rectangle or a polygon. In addition, a conductive metal rod such as a solder rod (
8) is attached as an electrode, and the laminated body (5) to be wound is attached as an electrode.
) is electrically connected to the innermost peripheral part of the coil so that it will become one of the lead-out electrodes when it is cut into a coil in the process described later.

Next, a solder rod (9) is connected along the end of the wound body (7) [the end of the winding of the laminated body (5)] so that when it is cut into a coil, it will become the other extraction electrode. . This solder rod (9) is easily formed by extruding solder in a softened state from the nozzle (23).

FIG. 9 is an external perspective view showing a state in which the solder rod (9) is attached along the negative side edge of the winding body (7). In this state, the winding body (7) of the copper foil (1) is ), the conductive metal rod (8) which becomes one electrode of the coil, and the solder rod (9) which becomes the other electrode, all the components of the coil are now assembled. Therefore, these are collectively referred to as a coil block (10).

The coil block (lO) obtained in the above steps was
As shown in Figure 0, first the rolled body (7) is placed in a heating furnace (24) and heated at a predetermined temperature to completely cure the adhesive layers (3) and (4) interposed between the eyebrows of the rolled body (7). do.

Next, as shown in FIG. 11, the coil block (
10) is cut at predetermined intervals by electrical discharge machining.

The electric discharge machining method described above is a non-contact machining method (energy machining method) that utilizes pulsed spark discharges at minute intervals in a dielectric liquid (cooling liquid) and the associated short arc discharges. It can also be referred to as abnormal consumption of metal at a point. This electric discharge machining method is normally used for processing conductors such as forming molds, but according to experiments conducted by the present invention, it also shows good results when cutting laminates of metal foil and insulating layers. There was found.

In order to perform the above electric discharge machining, the above coil block (10)
is immersed in the machining fluid (25) and pulsed power is applied from the plate electrodes (26) arranged at predetermined intervals (0.4 inch intervals in this example) in the longitudinal direction of the intermediate shaft (6). good. In this example, a power supply of 20 A and 40 to 50 V is used, and the peak current is 10 A, and the pulse width is 3 μs on and 6 μs off.
ec pulses M and B were given. Furthermore, water or a petroleum-based machining fluid (for example, kerosene) can be used as the machining fluid during electrical discharge machining.

In addition, in this embodiment, the central axis (6) of the coil block (10) is fixed to the rotating shafts (27) and (28), and
The wound body (7) was cut at a portion corresponding to each side of the triangular shape of the central axis (6) while rotating by 20 degrees.

The coil blocks (10) do not necessarily need to be cut one by one; for example, a plurality of coil blocks (10) are arranged in parallel as shown in FIG. The cutting may be performed using a shaped electrode (26). In fact, 10 coil blocks (10) were arranged, 11 plate-shaped electrodes (26) were arranged with a spacing of 0.4 dragons, and 100 coils were obtained by cutting them by electric discharge.

Alternatively, as shown in FIG. 13, the electrode (26a),
(26b) and (26c) are connected to the three sides (6) of the central axis (6) of the coil block (10) at an angle of 120°.
a), (6b), and (6c), and is wound around the central axis (6).
) may be cut simultaneously from three sides. Furthermore, when cutting with dimensions different from the electrode spacing, the electrodes can be fed by the required length and cut sequentially.

In any case, when performing the electrical discharge machining, it is necessary to ground the coil block (10) side. Therefore, the method for establishing this grounding is illustrated in Figures 1 to 14.

FIG. 14A shows the coil block (10) placed on a conductive metal fixture (29), and this fixture (29)
9) is grounded.

FIG. 14B shows a coil block (1
0) is placed on a fixture (29) and grounded. However, a groove (29a) is provided in the fixture (29), and a liquid conductive material such as mercury is placed in the groove (29a). (
30) to ensure a good grounding condition even when the cutting progresses.

FIG. 14C shows a method in which a central shaft (6) to be inserted into the center of the coil block (10) is made of a conductive metal or the like, and the ground is directly connected to the central shaft (6).

The fourteenth scheme is a method of connecting the ground to the solder rod (9) disposed along the negative edge of the winding body (7).

Of course, in the drawing, the ground is connected to the solder rod (9), but it may be connected to the conductive metal rod (8) located at the innermost part of the wound body (7).

By the electric discharge machining method described above, the coil block (10) is formed into a coil (31) having a predetermined thickness, as shown in FIG.
) is cut off. FIG. 16 shows the external appearance of the flat coil (31) taken out after removing the central shaft (6).

The obtained flat coil (31) has a circular part (31a) of copper foil and an insulating layer, and terminal electrodes (31b) and (31c).
The copper foil (1) was extremely thin, and the laminated state of the copper foil (1) was dense, making it useful as a motor coil.

Furthermore, when the present inventors observed the cut surface obtained by the electrical discharge machining using a microscope, surprisingly, as shown in FIG.
) The adhesives Ji (3), (4) ) were in a state of protruding from the copper foil (1), and the insulation between the laminated copper foils (1) was completely maintained.

The protrusion of the insulating layer (32) may be left as is, but in order to ensure the width accuracy of the flat coil (31),
Using a wrapping device (33) as shown in FIG.
You can remove it by doing research.

The flat coil (31) produced through these processes is subjected to a terminal masking process, a resin coating process, and an inductance process as necessary.

After undergoing inspection processes such as continuity resistance and insulation tests, the resulting flat coil (6) is incorporated into the motor.
31) with a diameter of approximately 2711. A flat motor with approximately 2 fins of FE size was fabricated.

〔Effect of the invention〕

As is clear from the above description, in the present invention,
The coil is made by winding the metal foil with an insulating layer interposed in between and cutting it using the electric discharge machining method.
It is possible to produce coils in large quantities.

Further, according to the present invention, insulation between the layers of the metal foil to be wound is ensured, and it is possible to manufacture a highly reliable flat coil with almost no occurrence of defects such as short circuits.

Furthermore, the method of the present invention does not require special techniques or a high degree of sensitivity, and is an extremely simple method, so it can be said that it has high practical value in this respect as well.

[Brief explanation of drawings]

Figures 1 to 18 are fuller models to which the present invention is applied.
An example of a method for manufacturing a coil is shown in the order of the steps. Figure 1 is a schematic diagram showing the process of forming an insulating layer on copper foil,
The figure is a perspective view of the appearance of the raw coil with an insulating layer attached, Figure 3 is an enlarged sectional view of the main part of the raw coil, and Figure 4 is an enlarged cross-section of the main part of the raw coil when no polymer film is used. Figure 5 is a schematic diagram showing the cutting process of the original coil, Figure 6 is a schematic diagram showing the process of winding around the central shaft, and Figure 7 is an external perspective view of the wound body wound around the central shaft. , Fig. 8 is an external perspective view showing the process of connecting solder rods that become electrodes, Fig. 9 is an external perspective view of the coil block, and Fig. 10 is a partially broken view of the heating furnace used to heat-cure the adhesive layer. A front view, FIG. 11 is a schematic side view showing the cutting process by electric discharge machining, FIG. 12 is a schematic perspective view showing the arrangement of electrodes for cutting coil blocks together and at the same time, and FIG. 13 is a coil block. Fig. 14A to Fig. 14 are schematic diagrams showing how to connect the ground to the coil block, and Fig. 15 is an external perspective view showing the coil block after cutting. , FIG. 16 is an external perspective view of the obtained flat coil, FIG. 17 is an enlarged sectional view showing the vicinity of the cut surface by electric discharge machining, and FIG. 18 is a partially cutaway perspective view showing the lapping device. 1...Copper foil 3.4...Adhesive layer 6...Central shaft 7...Wound body Patent applicant Sony Chemical Corporation Representative Patent attorney Koike Mima Sakae Tamura - Figure 1 1 Figure 2 Figure 3 Figure 4 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 C Figure 14 D J] Figure 15 Figure 17 Figure 16 Figure 18 Procedural amendment (voluntary) September 4, 1986

Claims (1)

[Claims] A step of forming an insulating layer on a metal foil, a step of winding the metal foil provided with the insulating layer around a central axis while thermocompression bonding, and creating a metal foil wound body, A method for manufacturing a flat coil, comprising the step of cutting the rotating body to a predetermined thickness by electrical discharge machining in a direction perpendicular to the central axis.