CN209343798U - A kind of multi-twisted litz wire, reactor and production device for medium and high frequency electric - Google Patents

Abstract

The application discloses a multi-twisted Litz wire for medium and high frequency electrical use, a reactor and a manufacturing device, which relate to the technical field of cable equipment, including a bundle-shaped protective layer and a wire core, the bundle-shaped protective layer is arranged around the surface outside the wire core, and the wire The core includes a plurality of helically twisted Litz strands, each Litz strand includes a plurality of mutually insulated and helically twisted wires, and the cross-section of the bundle-shaped protective layer and the wire core is roughly rectangular. The double-stranded Litz wire with a pitch-shaped cross-section makes the coil wound by it smaller in volume, stronger in strength and less prone to loosening.

Description

A kind of multi-twisted litz wire, reactor and production device for medium and high frequency electric

technical field

The utility model relates to the technical field of cable equipment, in particular to a double-twisted litz wire for medium and high-frequency electricity, a reactor and a manufacturing device.

Background technique

In the prior art, the winding wires of medium and high frequency electrics are made of flat wire materials, which have large eddy current loss and great bending force during winding, especially when the bending radius is small, it is easy to cause surface cracking, and the bending of large cross-section flat wires is more difficult, affecting performance of the winding wire.

Contents of the invention

The technical problem mainly solved by the utility model is the technical problem of large eddy current loss of the flat wire material in the winding of medium and high frequency electrics.

According to the first aspect, an embodiment provides a multi-twisted Litz wire for medium and high frequency electrical use, including a bundle-shaped protective layer with a rectangular structure, and a plurality of helically twisted Litz strands are arranged in the bundle-shaped protective layer ; Each Litz strand includes a plurality of mutually insulated and helically twisted wires; the cross-sections of the multiple helically twisted Litz strands are generally rectangular.

Further, the wire core includes 7 litz strands.

Further, each litz strand includes 29 wires.

Further, the wire is a magnet wire.

Further, the diameter of the magnet wire is less than 0.5 mm.

Further, the material of the beam-shaped protective layer is Dupont paper.

Further, the thickness of the beam-shaped protective layer is not greater than 0.05 mm.

According to the second aspect, an embodiment provides a medium and high frequency electrical reactor, including:

It includes a magnetic shielding cylinder and a coil; the coil includes the litz wire described in the first aspect.

Further, the wire is an enameled wire.

According to a third aspect, an embodiment provides a manufacturing device for double-stranded litz wires for medium and high frequency electrical use, including a stranding machine for helically stranding the wires; the stranding machine includes stranding rollers, The material of the stranding roller includes polytetrafluoroethylene.

According to the above-mentioned embodiment, a kind of multi-twisted Litz wire for medium and high-frequency electrical use, reactor and manufacturing device, since the multi-twisted Litz wire with a square cross-section is used, the coil wound by it is smaller in volume, stronger in strength and not easy to be wound. loose.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a multi-stranded litz wire in an embodiment;

Fig. 2 is a side view of the wire core of the multi-stranded Litz wire in an embodiment;

Fig. 3 is a schematic diagram of the structure of a reactor in an embodiment;

Fig. 4 is a schematic cross-sectional view of seven Litz strands being helically twisted into one strand in an embodiment;

Fig. 5 is a schematic diagram of the structure of the square die of the square machine in one embodiment;

Fig. 6 is a cross-sectional schematic diagram of a square die of a square machine in an embodiment;

Fig. 7 is a structural schematic diagram of a twisting machine for helically twisting wires in an embodiment.

Detailed ways

The utility model will be described in further detail below through specific embodiments in conjunction with the accompanying drawings. Wherein, similar elements in different implementations adopt associated similar element numbers. In the following implementation manners, many details are described for better understanding of the present application. However, those skilled in the art can readily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the application are not shown or described in the description, this is to avoid the core part of the application being overwhelmed by too many descriptions, and for those skilled in the art, it is necessary to describe these operations in detail Relevant operations are not necessary, and they can fully understand the relevant operations according to the description in the specification and general technical knowledge in the field.

In addition, the characteristics, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be exchanged or adjusted in a manner obvious to those skilled in the art. Therefore, various sequences in the specification and drawings are only for clearly describing a certain embodiment, and do not mean a necessary sequence, unless otherwise stated that a certain sequence must be followed.

The serial numbers assigned to components in this document, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any sequence or technical meaning. The "connection" and "connection" mentioned in this application all include direct and indirect connection (connection) unless otherwise specified.

At present, on the coils of medium and high frequency electrical appliances, bundled wires (also called Litz wires) made of multi-strand insulated wire bundles are mostly used. The use of Litz wires can reduce various problems caused by leakage flux on the coils at medium and high frequencies. an additional loss. At present, the single-strand insulated wires used in Litz wires can be twisted together with several thousand strands of enameled wires with a small diameter, such as 0.01mm enameled wires. However, because the twisted Litz wire is circular, when winding the coil, on the one hand, the wound coil is relatively large, and the circular wire takes up a large space, resulting in a large volume and weight of the designed and manufactured equipment, and the entire coil The losses will be increased and uneconomical. On the other hand, because it is a round wire, the strength of the wound coil is not enough, especially the vertically running coil, which is easy to loose. Although this problem can be avoided by adopting squared litz wires, in the prior art, the squared litz wires are all single-strand, and the diameter of the litz wires is relatively large, all of which are greater than 0.5 mm. Therefore, when the wire diameter is small, it is easy to cause the enameled wire to break or the insulating varnish to be damaged when the stranded Litz wire is pressed into a square, causing a short circuit.

In the embodiment of the utility model, the double twisted Litz wire with a distance-shaped cross section is used, so that the coil wound by it has smaller volume, greater strength and is not easy to loose.

Embodiment one:

Please refer to FIG. 1 , which is a schematic cross-sectional view of a multi-twisted Litz wire in an embodiment, which is a multi-twisted Litz wire for medium and high frequency electrical use, including a bundle-shaped protective layer 10 and a wire core 20 . The bundle-shaped protective layer 10 is arranged around the outer surface of the wire core 20 . In one embodiment, the material of bundle-shaped protective layer 10 is Dupont paper, and Dupont paper comprises two kinds of materials, and a kind of is high-density polyethylene material (Tyvek, Tyvek strong), and another kind is meta-aramid fiber material ( Nomex, Nomex). Tyvek is a high-density polyethylene made of high-density polyethylene that is processed into continuous filaments by thermal melting and then thermally bonded by using flash evaporation technology. This unique technology allows Tyvek to combine paper, The material properties of film and fabric are combined, waterproof, breathable, light weight, strong, tear-resistant, puncture-resistant, high reflectivity, diffuse reflectivity, UV resistance, unique texture and touch, environmentally friendly, recyclable, and compatible Various printing technologies and most digital printing technologies are suitable for various processing techniques. As an insulating material, Nomax is widely used in various electrical equipment and electronic fields, such as electrical insulation of motors, transformers, household appliances, electric tools and small heating, ventilation and air conditioning equipment. In one embodiment, the bundle-shaped protective layer 10 has a thickness of 0.05 mm. The wire core 20 includes a plurality of helically stranded Litz strands, and each Litz strand includes a plurality of wires insulated from each other and helically stranded. The cross-sections of the bundle-shaped protective layer 10 and the wire core 20 are substantially rectangular.

Please refer to FIG. 2 , which is a side view of a core of a multi-stranded Litz wire in an embodiment. In an embodiment, the core 20 includes 7 Litz strands, and each Litz strand includes 29 wires 201 . In one embodiment, the wire 201 is a magnet wire with a diameter less than 0.5 mm. Electromagnetic wire, also known as winding wire, is an insulated wire used to manufacture coils or windings in electrical products. Magnet wire must meet a variety of usage and manufacturing process requirements. The electromagnetic wire used for the coil includes its shape, specification, ability to work at high temperature for a short time and for a long time, as well as withstand strong vibration and centrifugal force at high speed in some occasions, withstand corona and breakdown under high voltage, and special Chemical corrosion resistance in the atmosphere, etc. Magnet wires for winding include the requirements to withstand stretching, bending, and abrasion during winding and embedding, as well as swelling, erosion, etc. during dipping and drying. Magnet wires can be classified by their basic composition of conductive core and electrical insulation. It is usually divided into enameled wire, wrapped wire, enameled wrapped wire and inorganic insulated wire according to the insulating material and manufacturing method used in the electrical insulation layer. In one embodiment, the magnet wire used for the wire 201 is an enameled wire.

The multi-twisted Litz wire disclosed in the embodiment of the present application adopts the multi-twisted Litz wire with a square cross-section, so that the coil wound by it has a smaller volume, greater strength and is not easy to loose.

Embodiment two:

Please refer to FIG. 3 , which is a schematic structural diagram of a reactor in an embodiment, including a magnetic shielding cylinder 31 and a coil 30 . The reactor adopts a magnetically shielded air-core oil-immersed method, wherein the coil 30 is formed by winding multiple-twisted Litz wires as described in the embodiments. The reactor in the power grid is an air-core coil without magnetic material. It can be arranged in three assembly forms: vertical, horizontal and zigzag according to needs. When a short circuit occurs in the power system, a large short-circuit current will be generated. It is very difficult to maintain the dynamic stability and thermal stability of electrical equipment if it is not restricted. Therefore, in order to meet the interrupting capacity requirements of some circuit breakers, reactors are often connected in series at the outlet circuit breaker to increase the short-circuit impedance and limit the short-circuit current. Due to the use of reactors, when a short circuit occurs, the voltage drop on the reactor is relatively large, so it also plays a role in maintaining the voltage level of the busbar, so that the voltage fluctuation on the busbar is small, ensuring that the user's electrical equipment on the non-fault line Stability of operation.

In one embodiment, the double-stranded Litz wire of the coil 30 includes 203 magnet wires, each of which has a diameter of 0.2 mm and a length of 3500 meters. Further, the magnet wire can be selected with a diameter less than 0.5 mm. In one embodiment, the magnet wires are enameled wires, and the 203 enameled wires are divided into 7 groups, with 29 enameled wires forming a group. Each group of enameled wires is helically stranded with a twisting machine to form one litz strand, that is, a total of 7 litz strands. Among them, when stranding enameled wires, the material of the rollers of the stranding machine is nylon. Since the nylon material is soft in texture, when a wire with a certain tension (especially a thinner wire) passes through the roller, it is easy to cause partial material damage to the roller. Deformation, causing the friction between the roller and the enameled wire to increase, resulting in damage to the insulating varnish. In this embodiment, the rollers of the stranding machine used for enameled wire stranding are selected from polytetrafluoroethylene rollers. The polytetrafluoroethylene rollers have high hardness, smoothness, and low friction, and will not deform when the enameled wire passes through the rollers. The enamelled wire is therefore not damaged. When twisting, the 29 wire reels must be strictly synchronized with the twisting machine, and the 29 enameled wires are twisted in a clockwise spiral structure. The length error of any one of the twisted Litz strands is within 1%, and the speed of the twisting machine should not be too fast during twisting, generally not exceeding 5 meters per minute. After stranding, samples should be taken for inspection, and if the error is >1%, it will be regarded as unqualified. Then 7 strands of Litz strands are helically twisted to form a large strand of core, that is, double twisted Litz wire. As shown in Figure 4, it is a cross-sectional schematic diagram of seven Litz strands being helically twisted into one strand in one embodiment. In one embodiment, the twisting method is centered on one of the seven Litz strands, and the rest Twist in a clockwise helical configuration. Similarly, the 7 wire reel machines and stranding machines must be strictly synchronized, and the speed should not be too fast, generally not exceeding 4 meters per minute. Then, wrap a layer of plastic film in a clockwise direction with a plastic film winding machine at the outlet end of the stranding machine where the 7 Litz strands are helically stranded, to prevent the enameled wire from being damaged during pressing. Generally, the mold for pressing the square is metal. When the stranded litz wire passes through the four corners of the square mold, the outer wire of the litz wire will be subjected to greater pressure and friction force. It will cause deformation of the outer wire and damage to the paint. The twisted Litz wire is not a single wire or a few fixed wires in the outer layer, but with the twisting spiral, each enameled wire in the Litz wire changes position continuously according to the twisting sequence, so as the length of the Litz wire Growth, each enameled wire will appear on the outer layer according to the twisting pitch, that is, each enameled wire will appear many times at the four corners of the metal pressing die. The longer the length of the litz wire, the greater the probability of occurrence. The degree of damage to the enameled wire is also greater. Therefore, there will be a large number of broken wires and short circuits between wires caused by damage to the paint leather in the formed litz wire. In the embodiment of this application, a layer of 0.05mm insulating film is half-folded on the stranded circular litz wire before pressing, and the outer layer is stressed when the circular litz wire wrapped with insulating film passes through the pressing die The film is always the film, and the size of the mold is adjusted to the size of the Litz wire wrapped around the insulating layer after squaring, so that the damage to the enameled wire can be avoided during the squaring process, and the size of the litz wire after squaring will not be increased. Then remove the film. Then the wire core is squared, and the litz wire wrapped in plastic film is squared with a squarer, so that the cross-sectional area of the wire core is roughly rectangular.

As shown in FIG. 5 and FIG. 6 , it is a schematic structural view and a schematic cross-sectional view of a square die of a square machine in an embodiment, including four rollers 61 and a square opening 62 surrounded by four rollers 61 . When pressing the square, the size of the square opening 62 set by the square machine is 2.7 mm * 3.7 mm, and the speed of the square is no more than 4 meters per minute. The same coil machine and the square machine must be strictly synchronized. In one embodiment, the square opening 62 is a square. The plastic film is removed after pressing. Finally, wrap a layer of Dupont paper with a thickness of 0.05 mm in a clockwise direction with a paper winding machine for the bundle shape and protection of the Litz wire. In one embodiment, Dupont paper is half-wrapped to bundle and protect the finished litz wire. The size of the rectangular section of the finished litz wire is 2.7mm*3.7mm, and the length is more than 3400 meters. This completes the production of multi-stranded litz wire. The terminal of the multi-twisted Litz wire disclosed in the present application is to electrically connect the terminals of each enameled wire together by welding. This kind of multi-twisted litz wire greatly improves the qualification rate of fixed-shaped litz wire with small wire diameter, and its internal enameled wire breakage rate is less than 1.4%, and there is no short circuit. The Q value of the reactor wound with this kind of multi-twisted Litz wire can reach more than 300, which reduces the loss and provides the possibility for the miniaturization of the reactor. Large, the Q value can only be around 100.

Embodiment three:

As shown in Figure 7, it is a structural schematic diagram of a twisting machine for helically twisting wires in an embodiment, including a honeycomb plate 81, a comb plate 82, a wire distribution frame 83, a pay-off roller 84, and a wire separation wire 85, pay-off frame 86, tension roller 87, swing frame 88 and rotating shaft 89. A pay-off frame 86 , a wire-distributing frame 83 and a honeycomb board 81 are arranged in sequence from front to back, and the pay-off frame 86 is a tension pay-off frame 86 . The top bar of the wire distribution frame 83 is arranged horizontally and perpendicular to the pay-off frame 86 , and the wire distribution frame 83 is provided with a comb-shaped plate 82 that can slide along the top bar of the wire distribution frame 83 . The litz wires protrude from the tension pay-off frame 86 and bifurcate to form multiple parallel wires 85 , all parallel wires 85 reach the honeycomb board 81 through the comb plate 82 . Wherein, the tension roller 87 includes a roller, and the material of the roller includes polytetrafluoroethylene. The PTFE roller has high hardness, smoothness and low friction, and will not deform when the enameled wire passes through the roller, so the enameled wire will not be damaged.

The above uses specific examples to illustrate the utility model, which is only used to help understand the utility model, and is not intended to limit the utility model. For those skilled in the technical field to which the utility model belongs, some simple deduction, deformation or replacement can also be made according to the idea of the utility model.

Claims (10)

1. A kind of multi-twisted litz wire for medium and high frequency electrical use, it is characterized in that, comprises bundle-shaped protective layer and wire core, and described bundle-shaped protective layer is arranged around the surface outside described wire core; Described wire core includes multiple A helically twisted litz strand; each strand of the litz strand includes a plurality of insulated and helically twisted wires; the bundle-shaped protective layer and the wire core are both roughly rectangular in cross-section. 2. The litz wire according to claim 1, wherein the core comprises 7 litz strands. 3. Litz wire according to claim 2, characterized in that each said litz strand comprises 29 wires. 4. Litz wire according to claim 3, characterized in that the wire is a magnet wire. 5. Litz wire according to claim 4, characterized in that the diameter of the magnet wire is less than 0.5 mm. 6. The litz wire according to claim 1, characterized in that, the material of the bundle-shaped protective layer is Dupont paper. 7. The litz wire according to claim 6, characterized in that, the thickness of the bundle-shaped protective layer is not greater than 0.05 mm. 8. A reactor for medium and high frequency electrical use, characterized by comprising a magnetic shielding cylinder and a coil; the coil comprises the litz wire according to any one of claims 1 to 7. 9. The reactor according to claim 8, wherein the wire is an enameled wire. 10. A manufacturing device for double-stranded litz wires for medium and high frequency electrical use, characterized in that it includes a twisting machine for helically twisting the wires; the twisting machine includes rollers, and the material of the rollers includes poly Tetrafluoroethylene.