JPS60143613A - Flat air-core coil - Google Patents

Abstract

PURPOSE:To contrive to enhance the space factor, and to obtain a flat air-core coil enabled to form the external shape of the coil in the prescribed size and shape, and enabled to flow a current higher than a printed coil by a method wherein an insulating layer is provided on one side of a conductive thin belt, an adhesive layer is provided on another side, and after wound around a core having the necessary shape, cut at the necessary thickness, and insulation treatment is performed. CONSTITUTION:A broad three layer thin belt (d) consisting of copper foil (a) having an insulating layer (b) on one side and an adhesive layer (c) on another side is formed. Then the necessary number of turns is wound around a pedestal type core 11. The wound belt thereof is put in a jig 12 having the necessary shape, and pressed strongly by a jig 13 having the necessary shape from the upside to be molded. After heated and cooled, the core 11 is drawn off from the three layer thin belt (d) using a forcing machine. The processes of cutting at the necessary thickness, washing, etching, etc. are performed, and insulation treatment of the cut edge faces is performed. The winding start and the winding end of the three layer thin belt (d) are led out finally to form terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive coil of a motor in which several trapezoidally wound coils are combined as a drive coil, or a flat air-core coil such as a coil used in a transformer, etc. be.

Conventional flat air-core coils of this type most commonly use an insulated wire with a circular cross section wound around a core of the desired shape and the required number of turns. As shown in Figure 1, even if a winding with the fewest voids is possible, the cross-sectional area is large compared to the required number of turns because the conductor 1 cannot occupy a high proportion of the cross-sectional area. There was a drawback.

That is, in FIG. 1, the radius of the wire including the insulation N2 is R.
I, if the radius of the conductor in the wire is R2, the ratio of the cross-sectional area occupied by the wire in the cross-sectional area is 3πR2"/6x Bar R12 x 1
00 -90.69%, which is an ideal value; in reality, spaces are created between the wires, so the value is lower than this.

The space factor of the conductor 2 in the wire varies slightly depending on the wire used, but for example, the conductor 2 is 0.17 m
When using copper wire with a diameter of
It is.

Therefore, the area ratio occupied by the conductor 2 in the cross section of the coil is:
Even in the ideal case, it is 90.69% x 69% #62%, but in reality it is usually around 50%, and at best it is only 60%, which is the space factor of the coil used in cassette record players etc. is also about 60%.

Therefore, as shown in FIG. 2, a method has also been proposed in which an insulating coated copper wire with a circular cross section is flattened using a roll machine or the like and then wound around a core.

In this case as well, since the material of the wire is an insulating coated copper wire, the space factor of the wire itself does not change, and therefore the space factor of the conductor as a coil cannot exceed 70%.

In addition, since the insulating layer is rolled with rolls, etc., if the aspect ratio of the cross section is increased, the insulating layer will be damaged and cause a short circuit between the eyebrows. However, since the insulation thickness is about 0.022 inch for a wire with a diameter of 0.17 nm, the thickness of the conductor becomes smaller than the thickness including the insulation layer, which results in a decrease in the space factor, which is preferable. do not have.

Furthermore, if the diameter of the conductor varies, this variation will be magnified and varied in the crushed wire, so that the entire wound coil may not fit within the specified center area, or the magnetic circuit may In the case of a coil used as a part of the magnet, the gap between the coil and the magnet increases in some areas, resulting in a decrease in magnetic efficiency.

Recently, printed coils have been developed in which a metal thin film is pasted on a thin insulating sheet, a predetermined pattern is printed on this thin film, or a metal thin film is left in a predetermined coil shape by photoresist treatment and etching. A method has been proposed in which a required number of insulating sheets are stacked on top of each other.

However, since this coil is formed as described above, the middle part of the metal thin film that becomes the coil requires a large dimension compared to the thickness of the thin film, as shown in FIG.
Due to the stacking of insulating sheets, it could not be used for coils that required a large number of turns.

In addition, when considering productivity, the thickness of the insulating sheet 4 is set to 0.
．． Since it is difficult to reduce the thickness to 01n or less, there remains a drawback that an improvement in the space factor cannot be expected.

The present invention eliminates these conventional drawbacks, improves the space factor, and makes it possible to make the outer shape of the coil constant in size and shape, allowing a higher current to flow than a printed coil. Another object of the present invention is to provide a high-efficiency, high-quality flat air-core coil that can increase the number of turns.

A further object of the present invention is to prevent corrosion of the conductive thin strip that becomes the coil layer in the process of removing glabellar short circuits caused by pars etc. that occur during the cutting process for manufacturing this. It is something to do.

That is, the coil of the present invention is made by forming an aFil ribbon by providing an insulating layer on one side and an adhesive layer on the other side of a conductive thin medium-wide band, and winding this around a core of a desired shape. This is then sealed by applying external pressure, cut to the required thickness, and then insulated.

This manufacturing process will be explained in more detail with reference to FIGS. 5 to IO.

In the first step, a diluted epoxy resin is applied as an insulating agent onto one side of a medium-wide copper foil a using a roll coater 6.

At this time, the coating thickness is set by adjusting the doctor knife 7 attached to the roll coater 6, and after the coating is applied, it is heated and dried with a heater 8, solidified, and wound onto a winding roll 9. The thickness of the insulating material after solidification is sufficient to provide the necessary electrical insulation.

In the second step, the take-up roll 9 is suspended so that the rotation direction of the take-up roll 9 is reversed, and the copper foil a is applied to the roll coater 6 with the adhesive layer facing upward. , Apply an adhesive made of diluted polyamide thermoplastic resin to the opposite side of the adhesive.

This is heated with heater 8, dried and solidified, and adhesive 1
As shown in FIG.
A medium-wide three-layer ribbon d is formed.

In the third step, the three-layer ribbon d is wound around the trapezoidal core 11 shown in FIG. 7 for a required number of turns while applying back tension.

Next, as a fourth step, the three-layer thin ribbon d wound around the core 11 is put into a jig 12 of a desired shape, and is strongly compressed and molded from above with a jig 13 of a desired shape. In the winding step of the process, the shape that swells toward the outer periphery and becomes the shape shown in Fig. 8 is changed to the shape shown in Fig. 9, where the inner and outer circumferences are parallel to each other in a process to make each wound layer tightly adhere. be.

In the fifth step, the molded three-layer ribbon d is placed in a jig 12.1.
3 is heated in a hot air drying oven 15 having a heater 14, and the adhesive layer C adheres to the copper foil a and the insulating layer A which was brought into close contact with each other in the fourth step by this heating and cooling.

The 6th process is the 3-layer ribbon d that has strong shape retention ability in the previous process.
The core 11 is extracted from the core 11 using a press-fitting machine.

The seventh step is a step of cutting the 3N thin strip d from which the core 11 has been removed to a required thickness, and the wire 16 and 3
Stress is applied between the wire 16 and the thin ribbon d, and the wire 16 is cut while moving back and forth.

In order to increase cutting efficiency, the 3N thin ribbon d may be fixed to a glass plate or the like with an adhesive and simultaneously cut using a large number of wires.

Step 8.9.10 is a step of cleaning the abrasive grains attached to the three-layer ribbon d after the cutting, and the cleaning is carried out using ultrasonic waves using Triclean, Guiflon, etc., which do not have a negative effect on the three-layer ribbon d. The washing machine 17 is used for drying, and the hot air drying oven 19 is used while heating at a lower temperature than the fifth step using the heater 1B.

The 11th step is nitric acid (HNO3), ferric chloride (FeC1)
l! 3) Etching is used to remove the short-circuit between the eyebrows of the 3N thin strip d due to copper powder during cutting or the spalling of the material of the copper foil a. The reason why nitric acid is used is that it does not adversely affect the insulating layer b and the adhesive layer C, including the subsequent steps.

The 12th and 13th steps are steps for removing the etching agent used in the previous step, and the cleaning is done by neutralizing the etching agent and then washing with water, or directly washing with water, and then drying with the heater 18.
This is carried out in a hot air drying oven 19 heated at the same temperature as in the 10th step.

The next 14th and 15th steps are insulation treatment steps for the cut end surface.
It is immersed in a bath 20 in which epoxy or polyamide is diluted and dried in a hot air drying oven 19 heated by a heater 18.

Finally, in step 16, the beginning and end of the three-layer ribbon d are pulled out to form a terminal.

In the coil of the present invention manufactured in this way, the copper foil a is insulated by the insulating layer and is tightly bonded by the adhesive layer C, so the space factor of the copper foil a is large. In addition to being easy to remove, the thickness of the copper foil a can be reduced to about several micrometers, so the number of turns can be increased.

Therefore, not only a high ampere turn can be obtained, but also high efficiency and high quality with constant thickness and shape can be obtained.

Moreover, in the coil of the present invention, since the 3N thin ribbon d has an insulating layer b formed on one side of the copper foil a and an adhesive layer C formed on the other side, the coil is wound between the winding layers in the third and fourth steps. close contact and the fifth
Adhesion can be performed through the process, and the core 11
Depending on whether the adhesive Nc or the insulating layer is on the inside, the inner layer will be exposed at the beginning of the winding, and the opposite layer will be exposed at the end of the winding, as shown in Figure 10. The copper foil a is never exposed at the beginning or end of winding.

Therefore, when etching is performed in the eleventh step, since the copper foil a is not exposed at the beginning and end of winding, it is not affected by the corrosive effect of etching.

Furthermore, even if some gaps are created between the eyebrows in step 3.4 and the etching solution infiltrates these gaps, the copper foil a in this area will have an adhesive layer C on one side of the gap and an insulating layer on the other side. Since the wire is covered with layers, there is no risk of wire breakage.

Incidentally, by using an adhesive insulating agent as the insulating layer and an adhesive insulating agent as the adhesive layer C, it is also possible to use the same material for both.

As mentioned above, the flat air-core coil of the present invention has a high space factor, high efficiency, and high quality. Since it is covered with an insulating layer,
The conductive ribbon is protected both at the beginning and end of the winding, and the etching process will not corrode the conductive ribbon at the beginning or end of the winding.

Furthermore, even if a gap is created between the winding eyebrows during the winding process, molding, or bonding process, and the etching liquid infiltrates during the etching process, it is protected against the risk of corrosion and disconnection, which reduces product yield. You can improve.

Also, when using the beginning and end of winding as terminals,
Since this part is not affected by corrosion or other negative effects, it is easy to pull it out, and it is also easy to remove the insulating and adhesive layers, especially since these layers are likely to melt due to the heat of soldering. If a suitable material is used, there is no need to remove it.

1 Moreover, if the same material is used for the insulating agent and the adhesive, both the first and second steps can be performed with the same machine, reducing equipment investment.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the space factor of a coil using a wire with a circular cross section, Figure 2 is an explanatory diagram of the cross section when the wire with a circular cross section is made flat, Figure 3 is a diagram of the coil shape, and Figure 4 is an explanatory diagram of the space factor of a coil using a wire with a circular cross section. The figure is an explanatory sectional view of a printed coil, FIG. 5 is a process diagram showing an example of the manufacturing process of the coil of the present invention, FIG. 6 is a sectional view of a three-layer ribbon, FIG. 7 is a side view of the core, and FIG. The figure is a side view of the product when it is wound, FIG. 9 is a side view of the product when it is molded, and FIG. 10 is an enlarged sectional view showing the beginning and end of the winding. a...Copper foil, b...Insulating layer, C...
...Adhesive layer, d...Three-layer ribbon. Patent applicant: Pioneer Corporation 2

Claims (1)

[Claims] By forming an insulating layer on one side of a conductive ribbon and an adhesive layer on the other side, an insulating layer and an adhesive layer are interposed,
The conductive ribbon is wound in the required number of turns in the desired shape, and one of the beginning and end of the conductive ribbon is coated with an insulating layer and the other with an adhesive layer, and the insulating layer and the adhesive layer are later removed. A flat air core coil characterized by: