JP2673760B2 - Litz wire and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a litz wire which is a high frequency electric wire used as a winding material for transformers and chokes, and a wiring material in equipment, and a method for manufacturing the same.

Conventionally, as a high frequency electric wire used for a winding material of a transformer or a choke, there has been a single wire whose center conductor is a metal such as copper, iron and brass and whose outer cover is covered with an insulating film such as formant and enamel, and also a single wire. There is a litz wire formed by twisting a plurality of the above-mentioned insulated single wires having a wire diameter of 0.02 to 0.5 mmφ for the purpose of suppressing the AC resistance due to the skin effect of the wire at a high frequency, which is a drawback of the above.

The single wire and the litz wire have a structure as shown in FIG. DESCRIPTION OF SYMBOLS 1 is a metal conductor, 2 is an insulating jacket, 3 is an insulating thin wire, 4 is a child bundle wire in which a plurality of insulating thin wires are twisted, 5 is a center child bundle wire, 6 is a parent bundle in which a plurality of child bundle wires are twisted A wire, 7 is a central bundle, and 8 is an insulating fiber such as Teflon. The single wire (B) is a single wire having a diameter of 0.2 mmφ to 3.2 mmφ and the material of the insulating jacket 2 is enamel. (A) Litz wire has a diameter of 0.02 mm
A large number of insulating thin wires 3 from φ to 0.5 mm are twisted to form a child bundle wire 4, and 5 to 7 pieces of this child wire bundle 4 are twisted to form a parent wire bundle 5 and further 5 to 7 of these parent wire bundles are twisted. Therefore, the exterior is covered with insulating fibers 8 such as Teflon, and the total number reaches several hundreds to several thousands.

[0004]

However, if these wires are used as a winding material such as a transformer or a choke operating at a high frequency or a wiring material through which a high-frequency current flows, the following problems occur. In the above conventional (B) single wire structure, as the frequency increases, the effect of the skin effect of the wire material increases, the AC resistance increases, and the loss of the transformer and choke increases. Similarly, in the litz wire structure of (A), the increase in AC resistance due to the skin effect of the wire is suppressed, but the frequency increases, so that the AC resistance is affected by the proximity effect between the central bundle and the surrounding bundle. As a result, the loss of transformers and chokes also increased.

[0005]

[Table 3]

Table 3 shows an example of AC resistance of each parent wire bundle of the litz wire of FIG. 8 (A) . Table 3 (a) is the absolute value of AC resistance, Table 3
(B) is the relative resistance value of the other parent bundling line when the AC resistance at each frequency of the parent bundling line (center conductor) located at the center is 100, and (c) of Table 3 is 1 kHz of each parent bundling line. AC resistance of 1
This is a relative resistance value when 00 is set. As shown in the table, there is little variation in resistance values other than the central parent bundle (central conductor), but the central parent bundle (central conductor) has a shorter line length than other parent bundles at low frequencies, so other parent bundles Less resistance than the wire,
At high frequencies, the resistance is higher than other parent bundle lines due to the proximity effect from other parent bundle lines. Similarly, there is the same problem with the center bundle. Conventionally, the litz wire has been used by peeling off the insulating film 2 and the insulating fiber 8 from all the bundled wires at both ends and soldering or short-circuiting them with a crimping terminal. for that reason,
The AC resistance of the litz wire was further increased because the AC resistance of the surrounding bundle wires increased due to the proximity effect due to the current flowing through the center bundle wires of the child and the parent. Further, in order to eliminate these influences, the central parent bundle line and the central child bundle line may be removed, but in many cases they cannot be visually discriminated, and they cannot be removed.
In particular, in the case of a large-diameter litz wire through which a large current flows, this is a particularly serious problem.

Therefore, in order to prevent the variation of the AC resistance between the bundle lines due to the central bundle line and to exert the parallelizing effect due to the bundle lines, there is a conventional litz wire having a structure shown in FIG. Here, reference numerals 6 and 8 are the same parts as those of FIG. 8 (A) , and 9 is an insulating core. With the litz wire having the structure shown in FIG. 9, it is possible to prevent an increase in the AC resistance of the central parent bundle wire portion, but since the insulating core is present, the conductor cross-sectional area occupying the cross-sectional area of the litz wire is shown in FIG. 8 (A) . There is a problem in that the size of the transformer, the size of the yoke, etc. becomes larger than the size of the transformer. In addition, there are problems that the price of the insulating core is high, the price of the litz wire rises, the flexibility of the insulating core is poor, and it is difficult to form a winding. Furthermore, replacing the sub-bundle wire with an insulating core further raises the price and deteriorates flexibility, and there is a problem that it cannot be used as a transformer winding or a wiring material.

In order to solve the above-mentioned problems, the present invention stops the use of the central bundle line of the parent bundle line and the child bundle line, thereby suppressing an inadvertent increase in AC resistance due to an increase in frequency, and The purpose of the present invention is to obtain a litz wire and its manufacturing method that reduce the loss in the choke winding and do not sacrifice the price and flexibility of the litz wire.

[0009]

According to the present invention, a plurality of bundled wires made of a plurality of insulating fine wires are twisted to form a child bundle, and a plurality of child bundles are twisted to form a parent bundle. In the litz wire, at the terminal portions at both ends, the center bundle of the child bundle located at the center of the child bundle and the center parent bundle located at the center of the parent bundle,
It electrically separates and insulates from other bundled wires, and electrically connects the bundled wires other than the central bundled wire of the child bundled wire and the parental wire bundle with the terminal portions at both ends. Insulating fibers at both ends of the litz wire composed of bundled wires are further separated in order from the parent bundled wire and the child bundled wire, and if visually distinguishable, the parental bundled wire and the center of the parent bundled wire Distinguish the bundles of wires, and if it cannot be visually distinguished, measure the resistance to make a distinction.
Except for the center parent bundle wire and the child bundle wire, only the other bundle wires are collectively soldered for the purpose of insulation removal, and the center parent bundle wire and the child bundle wires other than the center child bundle wire are attached to both terminals. The litz wire is manufactured by short-circuiting and cutting, leaving the insulating film portions of the central parent bundle wire and the central core bundle wire that have been removed.

[0010]

According to the present invention, by not using the central parent bundle wire or the central child bundle wire, the conventional litz wire having the central parent bundle wire or the central child bundle wire having the same wire diameter and the same number of wires (same cross-sectional area) is provided. In comparison, the effect of the proximity effect is small, AC resistance can be reduced, losses in transformer and choke windings can be reduced, and temperature rises in the windings can be prevented, so transformers and chokes can be made smaller.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of the manufacturing method of the present invention. In the drawing, (A) is a sectional view of the first Litz wire of the present invention, and (B) is a sectional view of the Litz wire manufactured in the final step. Is. Sign 1
8 are the same parts as those in FIG. The procedure of the manufacturing method of the present invention is as follows. The insulating fibers 8 at the terminals at both ends of the ordinary litz wire are loosened, and 5 to 7 parent bundle wires are individually separated. By visually checking the separated parent bundle lines, distinguish between the central parent bundle line and other surrounding parent bundle lines. In case of large diameter, it can be easily distinguished by visual inspection. In the case of a small diameter, it is not possible to distinguish visually, so proceed to the next step. In addition, separate the parent bundle lines and group them by child bundle lines.

Next, there is a step of removing the insulation of the insulating thin wires forming each bundle. When using insulation removal by chemicals, all the bundled wires are put on the chemicals together to remove the insulation film, and the next chemicals removal and solder coating process proceed. If the insulation is removed and the solder is applied at the same time due to the heat of the solder, the process using chemicals is omitted and the solder application process is performed. In the solder application process, if the center parent and child bundle lines are visible, only the center bundle lines of the parent and child are not subjected to solder application in the solder application process in advance. Apply solder only to the wires. If the center parent and child bundles are indistinguishable, apply solder to each child bundle. Therefore, the number of terminals in the terminal portions at both ends is twice the product of the number of parent bundle wires and the number of child bundle wires.

Next, each child bundle wire is bundled for each parent wire bundle, and the DC resistance of each parent wire bundle is measured by a precision resistance meter. The line with the lowest value of DC resistance or the line with the largest difference is the central parent bundle line, so it should be distinguished from other parent bundle lines. Next, it is a step of identifying the central bundle line. Separate each bundle line by the remaining remaining parent bundle lines except the central parent bundle line, and further divide child bundle lines belonging to the same parent bundle line. Measure the DC resistance of each strand with the precision ohmmeter and find the bundle with the lowest DC resistance or the largest difference. Since the child bundle line is the center child bundle line, it is distinguished from other child bundle lines. further,
Follow the same procedure to measure DC resistance for child bundles belonging to other parent bundles and find the center child bundle to distinguish it from other child bundles. Whether by visual inspection or resistance measurement, the center parent bundled wire and the child bundled wires other than the center child bundled wire, which are determined in this way, are short-circuited at both ends and used as each wiring material or transformer winding. .

When the center bundle lines are visually distinguished, the center parent bundle lines and the center core bundle lines that are removed by holding the front bundle lines are cut and left. In the case of resistance measurement, the remaining center parent bundle wire and center child bundle wire were cut off at the solder coating part of the terminal part, leaving only the insulating film part, and circulating current was generated between the individual wires forming the bundle wire. Prevent it from flowing. In FIG. 1, when visible, the central parent bundle line separating step and the terminal cutting / insulation recovery step are omitted since they are the same as in the case of non-visible.

[0015]

[Table 1]

Table 1 (a) shows the AC resistance at each frequency when normal parent litz wire is used as the basic parent wire bundle and each parent wire bundle is sequentially arranged in parallel with each other. Table 1 (b) shows AC resistances of the litz wire of the present invention when the parent bundle lines other than the central parent bundle line are used as basic parent bundle lines and the parent bundle lines are sequentially arranged in parallel. The last section also shows the AC resistance obtained by arranging the central parent bundle wires in parallel with ordinary Litz wire. When the central parent bundle line is present as in the conventional case, the resistance of the central parent bundle line is low at a low frequency, and therefore the AC resistance is lower than that in Table 1 (b) where the central parent bundle line of the present invention is not used. However, as the frequency increases, the central parent bundle has a greater proximity effect than other parent bundles, so the AC resistance increases and the AC resistance of other parent bundles increases due to the proximity effect of the current flowing in the central parent bundle. As a result of the mutual effect of increasing, the AC resistance is higher than that in the case where the wires other than the central parent bundle are arranged in parallel, and the ratio is up to about 120 at 100 kHz.
%. Furthermore, as the frequency increases, the central parent bundle has higher AC resistance than other parent bundles, so that almost no current flows and the central parent bundle includes the central parent bundle as compared to the case of parallelizing other than the central parent bundle. Even if they are paralleled, the AC resistance is only slightly low. Therefore, it is difficult for the normal litz wire structure shown in FIG. 8 (b) to reduce the resistance by paralleling at a high frequency. In the present invention, the AC resistance can be reduced up to about 20% at 100 kHz.

[0017]

[Table 2]

Table 2 shows the case of using the center wire bundle (conventional)
(A) and the case of not using (invention) (b) show the AC resistance increase rate. Here, the AC resistance at 1 kHz is 10
It was set to 0. In the present invention, the AC resistance can be reduced by up to about 20%. As shown in Table 2, the center bundle wire of the child bundle wire is also greatly involved in increasing the AC resistance. In the example of the table, the AC resistance increase rate is about 10% smaller. FIG. 2 shows the AC resistances of the case where the insulating thin wire is abbreviated and the case where it is cut open and B is left open, leaving the solder coating part of the central parent bundle wire. Center Shintabasen, cutting the both end portions of Chushinko wire bundles, with each insulation leaving the solder coating section insulation between the fine wire 3 without Fukusa times, the path of current flow at both ends are formed alternating Resistance increases. Therefore, the insulating thin wires of the central parent bundle wire and the central child bundle wire are cut at both ends so as to maintain insulation.

FIG. 3 shows a first embodiment of the present invention. Here, reference numerals 3, 4, 6 and 8 are the same parts as those of FIG. Reference numeral 12 is a central core bundle wire in which the color of the insulation thin wire is different from that of the other insulation bundle wires, and 13 is a center parent bundle wire in which the color of the insulation thin wire is different from that of the other insulation bundle wires. is there. In this example, the central parent bundle wire and the central child bundle wire are not found by DC resistance, but the central parent bundle wire and the central child bundle wire are different from other bundle wires in the insulation film 2 or the insulating thin wire color. By manufacturing a litz wire, the central parent bundle wire and the central child bundle wire can be easily distinguished visually from other bundle wires. According to this example, the center parent bundle wire and the center child bundle wire can be immediately found without measuring the DC resistance, so that it is not necessary to separately apply solder coating for each child bundle wire, and work efficiency can be significantly improved. it can. It should be noted that although the cost of strands increases slightly by using different colors, it does not pose a problem. Furthermore, since there is no solder coating process between the central parent bundle wire and the center strand bundle wire, insulation is maintained even at the terminals.
If it is opened as shown in FIG. 2, the increase in AC resistance is small. Therefore, it is not necessary to cut the terminal portions of the central parent bundle wire and the central child bundle wire again, so that the working process can be shortened.

FIG. 4 shows a second embodiment of the present invention. Here, reference numerals 4, 6 and 8 are the same parts as those in FIG.
Reference numeral 14 is a core wire bundle made of an insulating thin wire having a higher heat resistance than other insulating thin wires, and 15 is a central parent bundle wire made of an insulating thin wire having a higher heat resistance than the other insulating thin wires. This example is a litz wire characterized by having a heat-resistant insulating film that prevents the insulating film from peeling off due to the temperature during the solder coating process. By using the litz wire of this example, even if the solder coating process is performed collectively without paying attention to the central parent bundle wire and the central child bundle wire, the insulating coating is peeled off from the central parent bundle wire and the central child bundle wire. Since there is no solder, it is not possible to apply solder, and all other bundles can be soldered, so only other bundles can be electrically connected together in one step. Therefore, work efficiency can be significantly increased. Since there is no insulating film on the cut surfaces of the terminals at both ends, the central parent bundle wire, the central child bundle wire, and other bundle wires are electrically connected, and the AC resistance increases as in FIG. There's a problem. In this case, there is no problem because electrical insulation can be achieved by cutting the tip portion of the terminal portion again after the solder coating step.

FIG. 5 shows a third embodiment of the present invention. Here, reference numerals 4, 6 and 8 are the same parts as those in FIG.
Reference numeral 16 is a central core bundle wire using an insulating fine wire to which a normal solder does not adhere, and 17 is a central parent bundle wire using an insulating fine wire to which a normal solder does not adhere. This example is characterized in that the wire material of the central parent bundle wire and the central child bundle wire is changed to copper, and aluminum insulation fine wire to which solder does not adhere in the normal solder coating process or alloy insulation fine wire to which solder does not adhere It is a litz line.
By using the litz wire of this example, bundle wires other than the central parent bundle wire and the central core bundle wire can be
Although they are electrically connected by solder, the central parent bundle wire and the child bundle wire are not electrically connected because solder is not attached.
Although the insulation thin wires of the central parent bundle wire and the central child bundle wire are destroyed by the solder coating process and are electrically connected to other bundle wires by contact, the central parent bundle wire and the central child bundle wire are Since the resistivity of the aluminum or alloy wire used is 1.5 times higher than that of copper, the current flowing in the center is small, and the skin effect and proximity effect due to the center parent bundle wire and center child bundle wire are AC to other bundle wires. It rarely leads to increased resistance. In this example as well, the same effects as in the other examples such as shortening of the working process can be obtained.

FIG. 6 shows the AC resistance when the resistance of the central parent bundle line is increased. The figure also shows the characteristics when the central parent wire is an insulating core. The experiment was performed by connecting 1/2 and twice the DC resistance R of the litz wire in series with the central parent bundle wire and connecting it in parallel with other bundle wires via the resistance. As shown in the figure, the larger the resistance in series, the smaller the increase in AC resistance. Therefore, by using a material having a high resistivity for the central parent bundle wire and the central parent bundle wire, it is possible to suppress an increase in AC resistance due to the central parent bundle wire and the central child bundle wire. Further, the same effects as in the other embodiments such as shortening of the working process can be obtained.

FIG. 7 shows an embodiment of the present invention. In the conventional method of using the litz wire, since each bundle wire was electrically connected, it could not be directly connected to the grounded cooling fin or the like. Therefore, the litz wire had to radiate heat by itself. As shown in the structure of the conventional litz wire in Fig. 8, since the outermost insulating fiber is applied,
The heat was not released very efficiently. Therefore, the current density was reduced compared to the normal single wire. However, in the Litz wire of the present invention, since the central parent bundle line and the central child bundle line are not used, these bundle lines can be effectively used as a transfer means of heat generated inside the wire. The insulating thin wires forming these bundles have a low thermal resistance because they are made of metal, and can efficiently transfer heat because they are located at the center. FIG. 7 shows an example in which the central parent bundle wire and the central child bundle wire are directly connected to the cooling fins at the terminals. Here, reference numerals 4 to 8 are the same parts as those in FIG.
18 is a cooling fin. This embodiment can be applied to all litz wires shown in FIGS. 1, 3, 4, and 5. In addition, the explanation was given with the Litz wire having the parent bundle line and the child bundle line, but in the case of the Litz wire having the grandchild bundle line, the central grandchild bundle line should be the same as the central parent bundle line and the central child bundle line. Has the same effect.

[0024]

According to the present invention, since the litz wire in which the central parent wire and the central child wire are not used is constructed, it can be used as a wiring material for a high frequency power source (converter, inverter, etc.) and a winding material for a transformer or a choke. Even when used, the AC resistance can be reduced and the loss can be reduced. Further, the central parent bundle wire and the central bundle wire are made of a different wire material, insulating material, heat resistant material, and surface color different from those of other bundle wires, so that work efficiency can be significantly improved. In addition, by using a central parent wire or a central child wire that is not used electrically as a means for transporting heat generated inside the litz wire, the passing current density of the litz wire can be increased, and the transformer or choke winding The advantage that it can be miniaturized is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a litz wire manufacturing method of the present invention.

FIG. 2 is a diagram showing the relationship between the frequency and the AC resistance when the insulating thin wire of the central parent wire of the litz wire is short-circuited and opened.

FIG. 3 is a first embodiment of the present invention.

FIG. 4 is a second embodiment of the present invention.

FIG. 5 is a third embodiment of the present invention.

FIG. 6 is a relationship diagram between frequency and resistance when a resistance is connected to the center bundle of litz wires.

FIG. 7 is a perspective view of a fourth embodiment of the present invention.

FIG. 8 is a sectional view of the structure of a conventional litz wire, (A) is a litz wire, and (B) is a single wire.

FIG. 9 is a cross-sectional view of another conventional litz wire.

[Explanation of symbols]

1 Metallic conductor 2 Insulation sheath 3 Insulation thin wire 4 Insulating thin wire twisted multiple bundles 5 Central child bundle wire 6 Multiple parent bundle wire twisted 7 Central parent bundle wire 8 Teflon insulation Fiber 12 Core filament bundle with the color of the insulation filament different from that of other filament bundles 13 Core filament bundle with the color of the insulation filament different from that of other filament bundles 14 Other Central core bundle wire using insulation fine wire with higher heat resistance than the insulation fine wire 15 Central parent bundle wire using insulation fine wire with higher heat resistance than other insulation thin wires 16 Center using insulation fine wire to which ordinary solder does not adhere Bundled wire 17 Center parent bundled wire using insulating thin wire that ordinary solder does not adhere to

Claims (8)

(57) [Claims] 1. In a litz wire formed by twisting a plurality of bundled wires made up of a plurality of insulating thin wires to form a child bundle , a center wire bundle located at the center of the terminal portions at both ends is electrically separated from other bundle wires. The Litz wire is characterized in that it is electrically isolated and electrically connected, and the bundles other than the core bundle are electrically connected at the terminals at both ends. 2. A litz wire formed by twisting a plurality of bundle wires composed of a plurality of insulating thin wires into a child bundle wire, and further twisting a plurality of child bundle wires as a parent bundle wire, in which terminal portions at both ends are formed. in electrically isolation center parent wire bundle located Chushinko wire bundle and the center of Shintabasen you located in the heart of a child wire bundle from other wire bundles, medium
Litz wire, characterized in that electrically connecting the wire bundle other than heart child flux lines and the center Shintabasen centered terminal portions at both ends. 3. A plurality of insulated thin wires are twisted to form a child bundle, and a plurality of child bundles are twisted to form a parent bundle, and a plurality of the parent bundles are twisted, A step of loosening and removing the insulating fibers of both terminal portions of the litz wire provided with an insulating fiber on the outer periphery, a step of individually separating the parent bundle wires, a step of visually separating the central parent bundle wire and other parent bundle wires, process are summarized for each child bundled give away bundles line, previously centered Shintabasen and medium visually
Except for the core-child bundle wire, only the other bundle wires are collectively soldered for the purpose of insulating removal, the step of short-circuiting the child bundle wires other than the central parent bundle wire at each terminal of both ends, the removed central parent bundle A method for producing a litz wire, which comprises a step of cutting an insulating film portion of a wire and a core wire bundle, and cutting the wire. 4. The method of claim 3, center parent bundle line and the medium
Other processes, the each child flux lines to measure the resistance of each parent wire bundles bundled for each parent flux lines around the parent wire bundle if heart child flux lines can not be distinguished visually that solder applied to each child bundled The process of distinguishing from the parent bundle line of, the process of dividing into the child bundle lines belonging to the same parent bundle line other than the central parent bundle line, measuring the resistance of each child bundle line and distinguishing the center child bundle line from other child bundle lines , the step of shorting each across the wire bundle other than Kokorooya wire bundles and Chushinko wire bundle in which definite in the above step, the solder coating of the terminal portion of the central parent bundle line and Chushinko flux lines that did not shorted by the step A litz wire manufacturing method comprising a step of cutting a part and leaving an insulating film part. 5. The central child bundle line or the central parent according to claim 1 or 2.
The litz wire according to claim 1 or 2, wherein the bundle wire is a bundle wire made of an insulating thin wire having a color different from that of other bundle wires. 6. An insulating film having a higher heat resistance temperature than the solder melting point in the insulating thin line of the central element wire bundles and center parent flux lines of the central element wire bundles or claim 2 of claim 1 is provided, the other wire bundle 3. The litz wire according to claim 1, wherein the insulating thin wire is provided with an insulating film having a heat resistant temperature lower than a melting point of solder. 7. The core element bundle according to claim 1, 2 or 5 or 6.
7. The litz wire according to claim 1, wherein the conductor material of the wire or the central parent bundle wire has a resistivity higher than that of the conductor material of another bundle wire. 8. Among the claims 1 or 2 or 5 or 6 or 7
The litz wire according to any one of claims 1 to 2, 5 or 6 or 7, wherein a core-child bundle wire or a central parent bundle wire is attached to the heat dissipation plate.