JPH0770259B2 - Litz wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is improved in that it is possible to improve the high frequency gain, at the same time improve the space factor at the time of winding, and further to prevent the dislocation of the wires. It is about the litz wire.

[Prior Art] A litz wire made by twisting an enamel wire into a multi-conductor has been used for a long time in high-frequency communication devices and the like. This is because when the frequency of the applied current is high, AC resistance increases due to the skin effect and loss increases, so the conductor is divided into multiple pieces by using an enamel wire with an insulating film, and the conductor is subdivided by this. Thus, the skin current is divided to prevent the increase of the AC resistance.

In recent years, the frequency of inverter control has become higher and higher due to the miniaturization, high performance, and energy saving of electric devices, and the improvement of image quality in the deflection yoke of TVs etc.
The demand for the above litz wire is increasing due to higher FBT drive frequency.

The litz wire is made by twisting a large number of enameled wires as described above, and regardless of whether the twisting method is concentric twist, collective twist, or composite twist, distortion at the time of twisting at the time of terminal cutting is once There is a problem that the wires tend to come apart when they are released, and the terminal treatment at the time of coil winding becomes very troublesome.

In addition to the problem of the above terminal treatment, if it is easy to disperse as described above, the twisted shape of the electric wire will be crushed at the corner when winding this on a rectangular bobbin, and it will be difficult to wind smoothly. There are also problems.

Therefore, the Applicant, in the litz wire formed by twisting the enamel wire into a plurality of strands, at least one of the strands is constituted by a self-bonding enamel wire, and the self-bonding enamel wire is used as a normal enamel wire. We separately proposed a litz wire that can solve the above problems by placing it between wires.

[Problems to be Solved by the Invention] Although the problem of wire strand breakage, which can be said to be fatal for the Litz wire, has been solved by the above, there is still a problem with the Litz wire that the space factor decreases. There is.

That is, the conventional litz wire has a conductor 1 and an enamel film 2
The enamel strands 1A, 1A obtained by coating the above were usually concentrically twisted, aggregated twisted or compound twisted as shown in FIG. 5 to form a twisted wire having a circular cross section as a whole.

When such a stranded wire having a circular cross section is wound, the space factor is inevitably lowered, which is a large bottleneck for the downsizing and labor saving of the aforementioned devices.

In order to improve the space factor, it has been proposed that the litz wires are twisted and then rolled into a rectangular shape as shown in FIG. However, when the wire is forcibly deformed in this way, a very large stress is applied to the wire 1A located particularly in the central portion, and the elongation and strain of the enamel film 2 become large, and the film 2 is cracked. There is a large possibility that the pinholes are generated and the insulation reliability is impaired, which is a practical problem.

An object of the present invention is to solve the above-mentioned problem of the space factor in the litz wire, and to provide a novel litz wire which is excellent in the space factor and at the same time, which can solve the problem of the strand dislocation. .

[Means for Solving the Problem] The gist of the present invention is a litz wire configured such that the entire cross section is a rectangular flat stranded wire, and the litz wire is an enamel having a circular cross section. A plurality of wires are arranged and twisted in two horizontal rows, and either side of the upper and lower horizontal two rows of enameled wires is formed by a self-bonding enameled wire and The adjacent enamelled wires are fused to each other via the fusible enameled wire, and moreover, the short side direction of the flat stranded wire is rolled and deformed as a whole in a rolling reduction range of 5 to 40%. It is on the characteristic Litz line.

In the present invention, the flat twisted wire is rolled only in the direction of the short side in order to improve the space factor further by flattening the strands together.

Furthermore, the reason for limiting the rolling reduction to 5 to 40% is 5
% Or less, the flat rolling is not sufficient and the space factor is not significantly improved. On the other hand, if it is 40% or more, the wire enamel wire and the wire self-bonding enamel wire will be damaged. is there.

[Operation] The litz wire of the present invention does not forcibly roll a twisted wire having a circular cross section into a rectangular shape unlike the litz wire of the conventional example, but instead of twisting the twisted wire into two rows. Since the strands are arranged and twisted so as to have a rectangular cross section, an unreasonable stress is not applied, and as a result, a litz wire having an excellent space factor and easy winding can be obtained.

Then, either side of the pair of enameled wires in the upper and lower horizontal rows is composed of the self-bonding enameled wire, and the adjacent wires are fused by the self-bondable enameled wire. Therefore, even if the terminal of the litz wire is cut, there is no variation, and as a result, the terminal continuous workability is excellent.

Further, since the whole flat wire is rolled and deformed in the direction of the short side in the range of the rolling reduction of 5 to 40%, all the constituent wires are flat-rolled, and the space factor of the wire is further improved.

[Examples] Hereinafter, the present invention will be described with reference to Examples.

FIG. 1 is an end view of a litz wire according to an embodiment of the present invention.

In FIG. 1, 1 is a conductor, 1A is a normal enamel wire, 1B is a self-bonding enamel wire, 2 is an enamel coating, 3 is a self-bonding coating, and 10 'is a rolled flat stranded wire. It is a litz wire of one example.

As shown in FIG. 2, the litz wire 10 'of the embodiment of the present invention, which is a rolled flat type twisted wire, sends the enamel strands 1A, 1B from the delivery bobbins 21, 21 of the delivery device 20. Then, the flat shape is twisted in the flat-angle twisting die 22, and then the whole shape is adjusted by passing through the forming die 24, and is wound by the winder 25.

By doing so, the enamel strands 1A and 1B having the enamel coating 2 on the conductor 1 as shown in FIG. 3 are twisted in two rows as shown in the figure, and the entire cross section has a rectangular flat shape. A stranded wire 10 is obtained.

As can be seen from FIG. 3, the enameled wires that are paired vertically and horizontally in two rows are composed of the self-bonding enameled wire 1B on either side.

The self-bonding enamel wire 1B comprises a conductor 1 on which an enamel coating 2 is provided, and a self-bonding coating 3 provided thereon.

Then, as shown in FIG. 3, a heating device 23 (which may be electrically heated) is installed and self-fused. By doing so, it is possible to completely prevent the strands from becoming distorted during twisting.

Next, as shown in FIG. 4, using the rolling roll 26, the flat type twisted wire 10 is pressure-rolled in the range of a reduction rate of 5 to 40% from the short side direction.

By doing so, a litz wire 10 'of one embodiment of the present invention, which is a rolled flat type twisted wire as shown in FIG. 1, can be obtained.

By performing the rectangular rolling in this way, the space factor can be further improved.

The flat stranded wire 10 has a space factor of 60% before rolling, but it can be improved to 85% after being flat-rolled at a rolling reduction of 40%.

It was also confirmed by experiments that no mechanical load is applied within the range of the rolling reduction of 5 to 40%, and the cracks and pinholes of the resulting litz wire can be eliminated.

When the rolling reduction was 5% or less, the rectangular rolling was not sufficient, and as a result, the space factor was not significantly improved. On the contrary, when the rolling reduction is 40% or more, the work deterioration is severe, and as a result, the wire cracks and pinholes occur.

In addition, the enamel wire used for these has a conductor diameter of 0.
2mm Polyurethane enameled wire with 2 types of insulation thickness defined by JIS-C-3003 (2 UEW 0.2) and polyurethane enameled wire with 3 types of insulation thickness defined by JIS-C-3003 JI
Self-bonding enameled wire (2 BB-3 UEW 0.2) with a bonding layer so that it has the two types of insulation thickness specified in S-C-3003.
After arranging them in 7 layers in 2 layers and manufacturing 14 flat stranded wires, each was wound on a square bobbin and no crushing phenomenon was seen at the corners, and good winding performance was obtained. Was found to show.

[Effects of the Invention] As described above, according to the litz wire of the present invention, the coil winding property is excellent because it is not subjected to abnormal stress during manufacturing, the variation can be completely suppressed even when the terminal is cut, and the coil space is occupied. The rate can be remarkably improved, and it is very useful industrially.

[Brief description of drawings]

FIG. 1 is an end view of a litz wire according to an embodiment of the present invention, FIG. 2 is an explanatory view of a manufacturing apparatus thereof, and FIG. 3 is a flat mold obtained in an intermediate process of manufacturing a litz wire according to an embodiment of the present invention. End view of stranded wire,
FIG. 4 is an explanatory view showing how the flat type twisted wire is rolled, and FIGS. 5 and 6 are end views showing two conventional examples. 1: Conductor, 1A: Normal enamel wire, 1B: Self-bonding enamel wire, 2: Enamel film, 3: Self-bonding film, 10: Flat stranded wire, 10 ′: Rolled flat stranded wire.

Claims (1)

[Claims] 1. A litz wire having a flat cross-section having a rectangular cross section as a whole, wherein the litz wire has a plurality of enameled wires having a circular cross section in two rows. The self-bonding enamel wire is provided on either side of the enamel wire, which is formed by twisting in an array and is paired in the upper and lower two rows. The litz wire is characterized in that the adjacent strands are fused together, and the flat type stranded wire is rolled and deformed in the short side direction within a rolling reduction range of 5 to 40%.