WO2012093419A1 - Core, coil and transformer - Google Patents

Abstract

A coil (1) which uses annular windings (10) or a core (20) for a transformer is formed using a wire-shaped magnetic member by way of an opening (11) in the centre of the annular windings (10) and a peripheral edge part (12) on the outside, in such a way that the peripheral length of the magnetic member bundle on the peripheral edge part (12) is greater than the radial length of the magnetic member bundle at the opening (11).

Description

Core, coil and transformer

This invention relates to a core and a coil or a transformer using the core.

In the tide of reducing global warming gas emissions, low carbon dioxide emissions have been accepted, and demand for electric vehicles has increased and has begun to spread.
This electric vehicle is equipped with a circuit to which a high voltage is applied, a circuit to which a large current is applied, and a coil (reactor) and a transformer corresponding to the high voltage and the large current are used everywhere.
Until now, the majority of high-voltage and high-current circuits are connected to the power source supplied from the AC power line. In this power line system application, coils and transformers are more efficient and smaller. Has been realized. However, when mounted for electric vehicles, further higher efficiency and smaller size are required.

Conventionally, in order to reduce the size of a coil and a transformer, a core made of a powdered magnetic material hardened with good high-frequency characteristics and a core made by stacking a plurality of magnetic materials with a high saturation magnetic flux density in a thin plate are used.
However, in general, materials with good high-frequency characteristics have low saturation magnetic flux density, and conversely, materials with high saturation magnetic flux density have inferior high-frequency characteristics, so it is necessary to select materials and configurations according to the desired characteristics. It was.
There are many conventional techniques related to the configuration of the coil and the transformer, and some of Patent Documents 1 to 4 are described below.

The transformer cut core according to Patent Document 1 relates to a core in which a thin plate made of amorphous metal is wound, and the outer surface of the core is sealed with a liquid-tight film so that the liquid does not enter a gap between the wound thin plates, and the shape is maintained. It is characterized by cutting after reinforcement.

The toroidal transformer according to Patent Document 2 uses a core in which a ribbon made of a magnetic material such as a silicon steel plate is wound in an annular shape, and performs cutting or drilling processing to reduce residual magnetic flux and make magnetic saturation difficult. It is characterized in that a part of the core is left unprocessed so that the core does not deform even if it is applied.

The reactor and the transformer according to Patent Document 3 use a cut core obtained by dividing an annular core formed of a dust magnetic material, and the material selection of a dust magnetic material compared to a core using a conventional silicon steel plate This makes it easier to control the magnetic characteristics.

The reactor according to Patent Document 4 uses a core wound with a silicon steel plate or a core formed by compacting ferrite or the like, and in order to enhance the heat dissipation effect, the core is arranged in four directions with respect to the coil. It is a feature.

JP-A-4-206909 JP 2006-140243 A JP 2006-344868 A JP 2010-192742 A

As described above, the magnetic properties of the core are required to have a high saturation magnetic flux density, good high frequency properties, etc., but there is a problem that both properties are in conflict and it is difficult to satisfy both properties at the same time. .

In order to increase the saturation magnetic flux density, a core such as a lump of iron (such as a silicon steel plate) is suitable because it is difficult to saturate, but metal iron has a low electrical resistance and eddy currents easily flow, so it can operate at high frequencies. It is difficult to use as. Therefore, when an iron-based magnetic material is used as a core, it is required to reduce the thickness of the magnetic material or reduce the width as a countermeasure for suppressing eddy currents in order to improve high-frequency characteristics. In the prior arts such as Patent Documents 1 to 4, eddy current suppression measures are taken by forming a core by stacking thin plate-shaped magnetic materials, but not only the thickness but also the width. There is no disclosure of a configuration using a narrow linear magnetic material.

On the other hand, in order to improve the high-frequency characteristics, a core made of a magnetic material powder with high electrical resistance is good because eddy current does not easily flow. However, a core made of powdered magnetic material has a non-magnetic substance content. Mostly, the saturation magnetic flux density is low. Therefore, when powder magnetic material is hardened and used as a core, it is necessary to make the core large in order to allow sufficient magnetic flux to pass. However, if this is done, the coil and transformer will also become large, making it unsuitable for electric vehicles. End up. In addition, since a typical ferrite core as a core obtained by solidifying a powder magnetic material is brittle, there is also a problem that it is easily broken by vibration or impact when it is mounted on an electric vehicle.

The present invention has been made to solve the above-mentioned problems, and has a high strength and a small and good core, and has a high mechanical strength using the core. The object is to obtain a small coil and a transformer with good characteristics.

The core according to the present invention uses a linear magnetic member, and arranges the magnetic member so as to pass through the opening on the center side of the annular winding and the outer peripheral edge, along the peripheral edge of the annular winding. The bundle of magnetic members thus arranged is wound so that the circumferential length is longer than the radial length of the bundle of magnetic members penetrating the opening of the annular winding.

The coil according to the present invention includes an annular winding formed by winding a conducting wire in an annular shape and the core attached to the annular winding.

The transformer according to the present invention includes an annular winding having a primary winding and a secondary winding formed by winding a conducting wire in an annular shape, and the core mounted on the annular winding.

According to the present invention, a core having a high strength can be obtained by arranging a linear magnetic member to configure the core. In addition, the cross-sectional area of each magnetic member is reduced to reduce the loss in high-frequency operation, and the magnetic member covers a wide area of the annular winding to reduce magnetic flux leakage. Can be obtained. Furthermore, even if the linear magnetic member is divided, there is little deterioration in characteristics, so the linear magnetic member is divided into a plurality of pieces and wound around the annular winding, or the core formed by winding in advance is divided into the annular winding. It can be manufactured by various methods such as mounting on a wire, and can be easily manufactured.

In addition, according to the present invention, the coil or transformer is configured using the above-described core having high strength, small size, and good characteristics. Therefore, the coil or transformer having high mechanical strength, small size, and good characteristics. A transformer can be obtained.

It is an external appearance perspective view which shows the structure of the coil which concerns on Embodiment 1 of this invention. In the coil which concerns on Embodiment 1, it is an external appearance perspective view which shows the state which started winding the linear magnetic member to the cyclic | annular winding. It is an external appearance perspective view which shows the structural example of the conventional toroidal coil. It is sectional drawing which cut | disconnected the coil which concerns on Embodiment 1 along the AA line of FIG. 3 is an external perspective view showing an example of a bobbin used for the coil according to Embodiment 1. FIG. It is sectional drawing which cut | disconnected the coil which concerns on Embodiment 2 of this invention in the position corresponded to the BB line of FIG. It is a figure which shows the modification of the coil which concerns on Embodiment 2. FIG. It is sectional drawing which cut | disconnected the coil which concerns on Embodiment 2 in the position corresponded to the BB line | wire of FIG. 1, and shows an example of a spacer. It is sectional drawing which cut | disconnected the forward transformer which concerns on Embodiment 3 of this invention in the position corresponded to the BB line of FIG. It is sectional drawing which cut | disconnected the flyback transformer which concerns on Embodiment 3 in the position corresponded to the BB line of FIG. It is a block diagram which shows the structure of the electric power system of the electric vehicle to which the coil or the transformer which concerns on Embodiment 4 of this invention is applied. 6 is an external perspective view showing an example of a through hole provided in a coil according to Embodiment 4. FIG.

Hereinafter, in order to explain the present invention in more detail, modes for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
As shown in FIG. 1, the coil 1 is a wire arranged so as to pass through an annular winding 10 formed by winding a conducting wire in an annular shape, an opening 11 on the center side of the annular winding 10, and an outer peripheral edge 12. And a core 20 made of a magnetic material. In the first embodiment, a linear magnetic member is wound around the annular winding 10 as shown in FIG. 2 to form the core 20 as shown in FIG. In the illustrated example, the linear magnetic member is in a turbulent winding state. However, the winding method is arbitrary, and any winding method that can ensure a cross-sectional area corresponding to the passing magnetic flux is sufficient. For example, the linear magnetic member is wound in a layered state. There may be.
In the following description, the coil 1 using the core 20 will be described as an example, but the same applies to a transformer using the core 20.

The coil 1 according to the first embodiment is similar in appearance to a configuration in which the positional relationship between a core and a winding of a general toroidal coil is exchanged.
For reference, FIG. 3 shows a general toroidal coil 100 configured by winding a single conducting wire (winding 120) around the annular core 110 a plurality of times. With respect to the toroidal coil 100, the coil 1 of the first embodiment replaces the positional relationship between the core and the conductive wire, arranges the annular winding 10 instead of the position of the annular core 110 of the toroidal coil 100, and A core 20 is formed by winding a linear magnetic member instead of the position.
In the toroidal coil 100, it is necessary to wind one seamless wire (winding 120) in order to pass an electric current, but the core 20 of the first embodiment at the same position has a magnetic flux. However, it is not necessary to magnetically connect the linear magnetic member of the core 20 by special means. For this reason, even if a plurality of short linear magnetic members are wound around each other to form the set of cores 20, mutual connection is unnecessary and the characteristics are not deteriorated. Although details will be described in the second embodiment, the characteristics are not deteriorated even if the core 20 is cut and divided.

In the case of the toroidal coil 100, in order to obtain good characteristics with little leakage of magnetic flux, the annular core 110 formed by winding a magnetic member made of ferrite, dust, or iron-based thin plate (or strip) is variously sized. It is used for various purposes. Since the winding 120 is wound so as to pass through the opening 111 opened in the center of the annular core 110 and the peripheral edge 112 of the outer peripheral edge, the peripheral edge of the winding 120 is reduced to reduce magnetic flux leakage on the peripheral edge 112 side. If it winds by aligning so that it may mutually contact on the part 112 side, the opening part 111 side will be a messy dense winding. Therefore, it is difficult to wind the winding 120 on the opening 111 side.
In addition, due to the configuration of winding the winding 120, a high flexibility is required for the conducting wire to be used, and a thick wire cannot be used. In addition, it is difficult to use a wire having a square cross section in order to increase the space factor. Further, since the winding 120 needs to be electrically connected, it is inefficient to wind a plurality of short conducting wires into one conducting wire while connecting them in the middle.
Therefore, if attention is paid to the conducting wire to be used, the toroidal coil 100 is not suitable for high power.

By the way, the loss due to the eddy current of the annular core 110 is high when an iron-based thin plate (or strip-like) magnetic material is used, and when a ferrite (a core obtained by solidifying a powder of a magnetic material having a high electric resistance) is used. Low. The saturation magnetic flux density is high when an iron-based thin plate (or strip) is used, and is low when ferrite is used. In addition, a dust-molded core (a core obtained by solidifying a magnetic material powder having low electrical resistance with an insulating material) exhibits intermediate characteristics between iron and ferrite.
Therefore, in general, for high frequency operation, ferrite is selected in order to reduce loss due to eddy current. However, since this core has a low saturation magnetic flux density, the annular core 110 is enlarged for high power. There is a need. On the contrary, in order to cope with high power, an iron-based thin plate (or strip) magnetic material with a high saturation magnetic flux density is selected. However, since this core tends to generate eddy current, it is a plate for high-frequency operation. It is necessary to reduce the thickness. Therefore, as a core corresponding to high frequency and high power, a powder-molded core having intermediate characteristics between the two is often selected.
If the width of the iron-based belt-like magnetic material is reduced to a linear shape, it can be used for further high frequency use. The toroidal coil 100 may be difficult to use for high frequency and high power.

As described above, in the general toroidal coil 100, there are few choices of the conducting wire and the magnetic member, and the difficulty in winding the conducting wire becomes a bottleneck, and a coil (or transformer) suitable for high frequency and high power applications is configured. It is hard to do.

Therefore, in the coil 1 of the first embodiment, a linear magnetic member is wound around an annular winding 10 formed by winding a conducting wire (for example, a copper wire with an insulating coating, hereinafter referred to as an insulating copper wire). The core 20 is formed. Since there is no need to wind the winding around the core unlike the toroidal coil 100, a conducting wire having a large cross-sectional area can be used as the conducting wire constituting the annular winding 10, and a high-power winding can be easily configured. it can. Moreover, since the length of the conducting wire can be minimized by making the shape of the winding simple, the winding resistance can be reduced and the loss in the annular winding 10 can be reduced.
As the conducting wire of the annular winding 10, a conducting wire having an arbitrary shape such as a circular or quadrangular cross section can be used. In the example of FIGS. 1 and 2, a rectangular copper wire is used as a conducting wire, and the annular winding 10 is formed by edgewise winding the rectangular copper wire. Thereby, the space factor of a coil | winding can be raised and the small coil 1 is realizable.
On the other hand, since a conducting wire having a circular cross-sectional shape is inexpensive, an inexpensive coil 1 can be realized by using a conducting wire having a circular cross-section.
In addition, the winding method and shape of the annular winding 10 are arbitrary, and the shape of the winding may be cylindrical or flat.

By using a thin and flexible wire (wire) as a linear magnetic member constituting the core 20, the core 20 can be easily brought into close contact with the annular winding 10, thereby reducing the leakage of magnetic flux. it can. Moreover, since the eddy current is hardly generated by making the wire thin, the high frequency characteristics are improved.
As the magnetic material of the linear magnetic member, an iron-based magnetic material and an amorphous magnetic material can be used. If the core 20 is formed of, for example, an iron-based wire containing silicon having a high saturation magnetic flux density, the coil 1 can be made small. For example, if it is formed of an amorphous wire such as an amorphous material having a small iron loss, the magnetic characteristics are good, so that the coil 1 having good characteristics can be realized. The breakdown of iron loss includes loss of power due to eddy currents and loss of power lost when the magnetic poles in the magnetic material are reversed. Amorphous linear magnetic members have the latter loss. It is effective for reduction.

Furthermore, if the surface of the linear magnetic member is insulated (increasing electrical resistance), the current (vortex) that flows through the linear magnetic member is insulated from each other at the part where the linear magnetic members are in contact with each other when wound. Since the current is not transmitted to the adjacent linear magnetic member, the high frequency characteristics are further improved. As an insulating material for the linear magnetic member, for example, an inorganic insulating material used for a silicon steel plate, a polyurethane resin, a polyester resin, a polyamide resin, or the like used for an insulating copper wire can be used. If a resin-based insulating material is applied to the magnetic member, it can be processed in the same manner as a general insulating copper wire, and it is not necessary to construct a new technique for the magnetic member.

As described above, the core 20 is formed by forming a magnetic material having a high saturation magnetic flux density into a linear shape (wire shape), so that the magnetic flux in the core can be made high density, and a large magnetic flux can be passed even with a small cross-sectional area. Therefore, the core 20 can be made small. Further, since the individual cross-sectional areas of the linear magnetic members are small in diameter, loss in high frequency operation can be reduced and frequency characteristics can be improved. Furthermore, since the magnetic member is thin and supple, the strength of the core 20 can be made higher than that of the brittle ferrite core and the compacted core.
Then, by combining the core 20 with the annular winding 10 adapted to high power using a thick conducting wire, the coil 1 having high mechanical strength, small size and good characteristics can be configured.

Further, since a linear material is used as the magnetic member constituting the core 20, it is easy to wind and can be stacked in layers, so that it is arranged so as to penetrate the opening 11 of the annular winding 10. The cross-sectional shape of the bundle of linear magnetic members (hereinafter referred to as the opening penetrating portion 21) is different from the cross-sectional shape of the bundle of linear magnetic members (hereinafter referred to as the peripheral routing portion 22) arranged along the peripheral edge 12. It can be shaped.

Therefore, for example, as shown in FIG. 1, linear magnetic members can be arranged from the opening portion 11 of the annular winding 10 to the peripheral portion 12 in a substantially radial manner. FIG. 4 shows a cross-sectional view of the coil 1 shown in FIG. 1 cut along the line AA. In the example of FIG. 4, the surface around which the linear magnetic member is wound is covered with a bobbin 30 such as resin among the outer surface of the annular winding 10 and insulated between the annular winding 10 and the core 20. The members are arranged. Details of the bobbin 30 will be described later.
As shown in FIG. 4, the cross-sectional shape of the opening penetrating portion 21 is made into a substantially circular shape, and the cross-sectional shape of the other peripheral routing portion 22 is made into a substantially circular shape excluding a portion for drawing out the winding start and winding end of the annular winding 10 (I.e., the opening penetrating portion 21 and the peripheral routing portion 22 are made of the same number of linear magnetic members, but the circumferential direction of the peripheral routing portion 22 is determined from the radial length d of the opening penetrating portion 21. The bundle of the linear magnetic members on the peripheral edge 12 side spreads over a wide range, and most of the peripheral edge 12 can be covered with the core 20.
Thereby, the leakage magnetic flux emitted from the annular winding 10 can be reduced, and the characteristics of the coil 1 can be further improved. Although not shown in the drawing, a linear magnetic member is also arranged in the part where the winding start and end of the annular winding 10 are drawn out, so that the core 20 covers almost the entire peripheral edge 12, that is, the peripheral arrangement. You may make it the cross-sectional shape of the measure part 22 become a substantially annular shape.

In contrast to a linear magnetic member, a strip-like magnetic member used for a conventional coil cannot be wound radially as shown in FIG. 4, and several layers are wound at the same position. Become. For this reason, the outer surface of the annular winding 10 has a wider portion exposed without being covered by the core of the belt-like magnetic member as in the shape of Patent Document 4, and the magnetic flux generated by the annular winding 10 is likely to leak, and the coil 1 characteristic deteriorates. Further, the cross-sectional area of the linear magnetic member can be made smaller than the cross-sectional area of the belt-like magnetic member, and the linear magnetic member is advantageous for reducing eddy current when operating at a high frequency.

In general, if a coil (or transformer) has the same rating, the winding and core for high-frequency operation can be made smaller than the winding and core for low-frequency operation. In high-frequency operation, the magnetic characteristics of the linear magnetic member are inferior to those of the ferrite core, and it cannot be denied that the amount of heat generation increases. However, the coil 1 of the first embodiment has the core 20 disposed outside. The heat dissipation effect on the heat generation of the core 20 is superior to the core of the type in which the annular core 110 is disposed inside the winding 120 such as the toroidal coil 100 as shown in Patent Document 4 above.
Therefore, in high frequency operation, the heat generation amount of the core 20 increases due to the inferior magnetic characteristics, but the heat generation can be easily transmitted to the outside by directly contacting the core 20 disposed on the outside with the case of the device. As a result, a small and easy-to-handle coil 1 can be configured.

In order to maintain the shape of the core 20 after formation, it is desirable that the linear magnetic members are fixed to each other. Therefore, for example, an adhesive that is bonded by high-temperature treatment may be applied to the linear magnetic member in advance and wound to form the core 20, and then heated to bond adjacent linear magnetic members to each other. In addition, some insulated copper wires, which are coil wires, are coated with an adhesive for performing the same processing, and it is not necessary to construct a new technique for the magnetic member.
Of course, means other than the method of adhering the linear magnetic member by applying the adhesive and performing high temperature treatment may be used for adhering or fixing the linear magnetic member.

Further, as shown in FIG. 4, the core 20 may be formed by covering the surface of the annular winding 10 with a bobbin 30 that is an insulating member and winding a linear magnetic member around the bobbin 30. FIG. 5 shows an example of the bobbin 30. The bobbin 30 is formed by forming a cylindrical resin member into a C shape, and cutting a part thereof (for example, a portion along the axial direction of the cylinder as shown by a one-dot chain line in FIG. 5) Attach to 10. The presence of the bobbin 30 does not damage the annular winding 10 when winding the linear magnetic member of the core 20. In addition, a short circuit between the annular winding 10 and the core 20 can be prevented. Furthermore, the insulation between the conducting wire of the annular winding 10 and the core 20 becomes high, and the highly reliable coil 1 can be realized.

As described above, according to the first embodiment, the core 20 attached to the annular winding 10 formed by winding the conducting wire in an annular shape uses a linear magnetic member, and the magnetic member is disposed on the center side of the annular winding 10. The circumferential length l of the peripheral routing portion 22 arranged along the peripheral edge 12 of the annular winding is arranged so as to pass through the opening 11 and the outer peripheral edge 12 of the annular winding. The opening penetrating part 21 penetrating the part 11 was wound so as to be longer than the radial length d. For this reason, the core 20 with high strength can be obtained. In addition, the cross-sectional area of each magnetic member is reduced in diameter, so that loss in high-frequency operation can be reduced, and the magnetic member can cover a wide area of the annular winding 10 to reduce magnetic flux leakage. 20 can be obtained. Further, even if the linear magnetic member is divided, there is little deterioration in characteristics, so that a plurality of short linear magnetic members can be used, and the winding work can be facilitated.
Then, by mounting the core 20 having a high strength and a small and good characteristic on the annular winding 10 to constitute the coil 1 or the transformer, the mechanical strength is high and the small and the good characteristic is obtained. The coil 1 or the transformer can be realized.

Further, according to the first embodiment, since the surface of the linear magnetic member is subjected to insulation (increasing electrical resistance), eddy current flowing through the adjacent linear magnetic member can be suppressed. Thus, the coil 1 or the transformer having good characteristics can be realized.

According to the first embodiment, a small coil 1 or a transformer can be realized by using an iron-based magnetic material having a high saturation magnetic flux density as the linear magnetic member.
Further, by using an amorphous magnetic material having good magnetic properties as the linear magnetic member, the coil 1 or the transformer having good properties can be realized.

Further, according to the first embodiment, the coil 1 is configured to include the bobbin 30 provided between the annular winding 10 and the core 20, so that the annular winding 10 is damaged when the linear magnetic member is wound. There is nothing. In addition, a short circuit between the annular winding 10 and the core 20 can be prevented. Further, the insulation between the annular winding 10 and the core 20 is enhanced. Therefore, a highly reliable coil 1 or transformer can be realized.

Further, according to the first embodiment, an inexpensive coil 1 or transformer can be realized by making the conducting wire used for the annular winding 10 into a conducting wire having a substantially circular cross section.
Moreover, the space factor of a coil | winding can be made high and the small coil 1 or a transformer can be implement | achieved by making the conducting wire used for the cyclic | annular winding 10 into a conducting wire containing a rectangular wire with a substantially square cross section.

Embodiment 2. FIG.
FIG. 6 is a cross-sectional view of coil 1 according to Embodiment 2 of the present invention cut at a position corresponding to line BB in FIG. In FIG. 6, parts that are the same as or equivalent to those in FIGS. 1 to 5 are given the same reference numerals, and descriptions thereof are omitted.
In the first embodiment, the core 20 is formed by winding the linear magnetic member around the annular winding 10. However, in the second embodiment, the core 20 previously wound with the linear magnetic member is used as a cut core. Thus, it is cut and divided so that it can be easily attached to the annular winding 10. The core 20 has a three-dimensional shape such as a so-called PQ type core, EP type core, or pot type core.

For example, a core winding bobbin 40 formed by forming a cylindrical resin member into a C shape is prepared. The core winding bobbin 40 has the same shape as the bobbin 30 shown in FIG. 5, for example, and is used as a dummy for the annular winding 10 in the second embodiment. The core 20 is formed by winding a linear magnetic member so as to pass through a portion corresponding to the opening 11 of the annular winding 10 and a portion corresponding to the peripheral edge 12 of the core winding bobbin 40. Then, both the core winding bobbin 40 and the core 20 are cut in the circumferential direction (for example, along the AA line shown in FIG. 1 or along the alternate long and short dash line of the bobbin 30 shown in FIG. 5). Subsequently, the annular winding 10 is sandwiched between the core 20 divided into two parts and the bobbin 40 for winding the core, the two cut portions are brought into contact with each other, and fixed back to the original shape. The coil 1 in which is inserted can be easily manufactured.

Therefore, the coil is more easily wound than the winding of the winding 120 constituted by one continuous lead wire from the start to the end of winding, which is performed in the toroidal coil 100 as shown in FIG. 3 of the first embodiment. 1 can be produced.
As described in the first embodiment, since the magnetic flux circulates not only in the magnetic member but also in the space, it is not necessary to magnetically connect the linear magnetic member of the core 20 by special means. Therefore, the characteristics are not deteriorated even if the divided core 20 is used.

Further, since the linear magnetic member can be bent, the core 20 can also be bent. Therefore, after forming the core 20 with a winding jig corresponding to the core winding bobbin 40, a part of the core 20 is cut open. For example, the opening penetrating portion 21 having a substantially circular cross section is cut in the circumferential direction, and conversely, the peripheral routing portion 22 having a substantially circular cross section is cut in the circumferential direction. And if the cross section of this incision part is opened and the clearance gap is opened like bending the core 20, the cyclic | annular winding 10 can be inserted in this core 20 similarly to a cut core. Then, after inserting the annular winding 10 from the incision site of the core 20, if both cross sections of the incision site are butted and fixed to the original shape, the coil 1 in which the annular winding 10 is inserted into the core 20 is obtained. Easy to produce.

In order to facilitate the cutting or cutting operation, it is desirable to fix at least the cutting site or the cutting site with an adhesive member or a resin member before cutting or cutting the core 20.

Further, when winding a linear magnetic member using a winding jig such as a C-shaped core winding bobbin 40, one nozzle (cylinder tip for supplying the linear magnetic member) is used. When it is difficult to form the core 20 by continuously winding it seamlessly with a wire, a partial core is formed with a plurality of wires using a plurality of nozzles, and they are combined into one piece. The core 20 may be formed. At this time, it is not necessary to connect a plurality of magnetic members, and it is not necessary to align the winding direction in the same direction.

Here, the modification of the coil 1 is demonstrated using FIG. FIG. 7A shows a modification of the core 20, and FIG. 7B shows a cross-sectional view of the core 20 mounted on the annular winding 10.
For example, a C-shaped core winding bobbin 40 (not shown in FIG. 7) is divided into two parts above and below C, and a wire rod is wound around the upper half core winding bobbin to form the partial core 25. Then, another wire is wound around the core winding bobbin in the lower half of C to form the partial core 26, and the two partial cores 25, 26 are combined into one core 20. Furthermore, the partial cores 25 and 26 may be cut and divided into divided partial cores 25a, 25b, 26a, and 26b.
In the case of this configuration, as shown in FIG. 7B, the opening penetrating portion 21 is formed by combining a plurality of partial cores 25 and 26 so that the cross-sectional shape becomes one substantially circular shape. Moreover, the peripheral arrangement | positioning part 22 combines several partial cores 25 and 26 so that a cross-sectional shape may become a substantially annular | circular shape (part).
In the opening 11 of the annular winding 10, the annular winding 10 can be made small (small diameter) by reducing the gap between the inner diameter of the annular winding 10 and the opening penetrating portion 21. Further, in the peripheral portion 12 of the annular winding 10, the linear magnetic member covers the peripheral portion 12 with a uniform thickness, thereby reducing the leakage of magnetic flux generated by the annular winding 10 and reducing the outer diameter ( That is, the outermost diameter of the core 20 can be made small. Therefore, the coil 1 can be made small and have good characteristics.

The core winding bobbin 40 may be used only for winding the linear magnetic member, and may be removed after the core 20 is cut or incised. In the case of this configuration, as shown in FIG. 4, a resin bobbin 30 may be mounted around the annular winding 10 in advance. Thereby, when mounting | wearing the core 20 cut | disconnected or cut | disconnected to the annular winding 10, this annular winding 10 is not damaged. In addition, a short circuit between the annular winding 10 and the core 20 can be prevented. Furthermore, the insulation between the conducting wire of the annular winding 10 and the core 20 becomes high, and the highly reliable coil 1 can be realized.

Furthermore, an insulating member (spacer) for providing a magnetic interval may be sandwiched between the cut portion or the cut portion of the core 20. FIG. 8 shows an example of the spacer 50. The coil 1 shown in FIG. 8 is a cross-sectional view cut at a position corresponding to the line BB shown in FIG. When the cut surfaces 23 and 24 of the core 20 divided into two are brought into contact with each other, a plate-like spacer 50 is sandwiched between the cut surfaces 23 and 24. The spacer 50 becomes a magnetic air gap (gap) for adjusting the inductance, or a magnetic air gap (gap) for avoiding the saturation of the core 20.
Further, the above-described bobbin 30 is also attached to the annular winding 10.

As described above, according to the second embodiment, the linear magnetic member is pre-wound into a shape to be routed via the opening 11 and the peripheral edge 12 of the annular winding 10, and is cut or partially cut. An incision was made to form the core 20. For this reason, dividing the core 20 facilitates the operation of inserting the annular winding 10 into the core 20, and the coil 1 or the transformer having a small size and good characteristics can be easily manufactured.
Moreover, you may make it comprise the set of core 20 using the some partial cores 25 and 26 wound beforehand by the linear magnetic member, and the winding operation | work of the core 20 becomes easy.

In addition, according to the second embodiment, since the spacer 50 for setting the magnetic interval is provided at the portion where the cut surfaces 23 and 24 of the core 20 are cut or cut out, the adjustment of the inductance is easy. Thus, the coil 1 or the transformer that is hard to be magnetically saturated can be realized.

Further, according to the second embodiment, since the surface of the linear magnetic member is covered with the adhesive member, the linear magnetic materials can be fixed to each other, and the core 20 can be cut or incised and bent. The coil 1 or the transformer can be easily manufactured.

Further, according to the second embodiment, since the bobbin 30 provided between the annular winding 10 and the core 20 is provided, the annular winding 10 is not damaged when the divided core 20 is mounted. Moreover, since the short circuit between the annular winding 10 and the core 20 can be prevented and the insulation between the annular winding 10 and the core 20 can be increased as in the first embodiment, the highly reliable coil 1 or A transformer can be realized.

Embodiment 3 FIG.
In the third embodiment, a case where a forward or flyback transformer is configured using the annular winding 10 and the core 20 shown in the first and second embodiments will be described.

First, a forward transformer will be described.
FIG. 9 is a cross-sectional view of the forward transformer 1a according to the third embodiment cut at a position corresponding to the line BB in FIG. In FIG. 9, parts that are the same as or equivalent to those in FIGS. 1 to 8 are given the same reference numerals, and descriptions thereof are omitted.
In this forward transformer 1a, a primary winding 13 and two secondary windings 14 sandwiching the primary winding 13 constitute an annular winding 10, and a core 20 is connected to the annular winding 10. It is attached.
Since the core 20 has the same configuration as the core 20 according to the first and second embodiments, detailed description thereof is omitted. Further, as the conductive wires (for example, insulated copper wires) constituting the primary winding 13 and the secondary winding 14, conductive wires having a substantially circular cross section may be used as in the first and second embodiments. However, a substantially rectangular conducting wire may be used. Further, the primary winding 13 and the secondary winding 14 are respectively covered with an insulating bobbin 30 as shown in FIG. 8 to improve the insulation between the primary winding 13 and the secondary winding 14. May be.

The following (1) to (4) are outlines of the current flowing in the primary winding 13 of the forward transformer 1a, the generated magnetic flux, and the current flowing in the secondary winding.
(1) Current is passed through the primary winding 13 (2) A magnetic field is generated in the vicinity of the primary winding 13 in response to energization of the primary winding 13 (3) Magnetic flux generated by the primary winding 13 (4) The magnetic flux generated by the primary winding 13 is balanced with the magnetic flux generated by the secondary winding 14. Therefore, the current flowing through the primary winding 13 Is determined by the magnitude of the current flowing through the secondary winding 14.

As described in (3) above, in the forward transformer 1a, since the magnetic fluxes generated by the primary winding 13 and the secondary winding 14 cancel each other, the large magnetic flux generated by the primary winding 13 does not spread outside. Therefore, since a large magnetic flux does not reach the core 20, the core 20 is hardly magnetically saturated. Therefore, the core 20 having a small cross-sectional area can be used.

Accordingly, when used as the forward transformer 1a, electric energy is transmitted from the primary winding 13 to the secondary winding 14 via the magnetic field generated by the primary winding 13 and the secondary winding 14, and therefore, as shown in FIG. As shown in the figure, two secondary windings 14 are arranged on the front and back sides of the primary winding 13 so as not to disturb the magnetic fluxes of the two, and the cores are covered so as to cover the front and back sides of the pair of secondary windings 14. A configuration in which 20 is arranged is preferable.

On the other hand, when the positions of the primary winding 13 and the secondary winding 14 are switched (configuration of a flyback transformer 1b in FIG. 10 described later), the magnetic flux generated by the primary winding 13 toward the core 20 is 2 It becomes difficult to cancel out by the magnetic flux generated by the next winding 14. Therefore, the magnetic flux generated by the primary winding 13 on the core 20 side passes through the core 20. Therefore, an inappropriately large core 20 must be used as the forward transformer 1a so that magnetic saturation does not occur in this portion.

Next, a transformer for flyback will be described.
FIG. 10 is a cross-sectional view of the flyback transformer 1b according to Embodiment 3 cut at a position corresponding to the line BB in FIG. In FIG. 10, the same or corresponding parts as in FIGS. 1 to 9 are denoted by the same reference numerals and description thereof is omitted.
In the flyback transformer 1b, a secondary winding 14 and two primary windings 13 sandwiching the secondary winding 14 constitute an annular winding 10, and the annular winding 10 includes a core 20 It comes with wearing. Since the core 20 has the same configuration as the core 20 according to the first and second embodiments, detailed description thereof is omitted. Further, as the conductive wires (for example, insulated copper wires) constituting the primary winding 13 and the secondary winding 14, conductive wires having a substantially circular cross section may be used as in the first and second embodiments. However, a substantially rectangular conducting wire may be used. Further, the primary winding 13 and the secondary winding 14 are respectively covered with an insulating bobbin 30 as shown in FIG. 8 to improve the insulation between the primary winding 13 and the secondary winding 14. May be.

The following (1) to (5) are outlines of the current flowing in the primary winding 13 of the flyback transformer 1b, the generated magnetic flux, and the current flowing in the secondary winding.
(1) Current is passed through the primary winding 13 (2) A magnetic field is generated in the vicinity of the primary winding 13 in response to energization of the primary winding 13 (3) Magnetic flux generated by the primary winding 13 (4) Stop energization of the primary winding 13 (5) The magnetic energy stored in the core 20 appears as electrical energy in the primary winding 13 and the secondary winding 14. In the flyback transformer 1b, energy (electric power) is transmitted by taking out the electric energy that has appeared in (5) above.

As described in (3) above, since the electric energy flowing into the primary winding 13 is once stored in the core 20 as magnetic energy, the core 20 needs to have a sufficient cross-sectional area to hold the magnetic energy.
Further, if the gap between the core 20 and the primary winding 13 is narrowed, the magnetic flux generated by the primary winding 13 can easily flow into the core 20 and can be efficiently stored, improving the characteristics of the flyback transformer 1b. To do.

On the other hand, when the positions of the primary winding 13 and the secondary winding 14 are exchanged as shown in FIG. 9 (configuration of the forward transformer 1a), the forward current of the secondary winding 14 flowing through the stray capacitance causes A part of the magnetic flux generated by the primary winding 13 is canceled, and a part of the magnetic flux does not reach the core 20 and is not stored as magnetic energy. Therefore, even if the core 20 having an appropriate cross-sectional area is used as the flyback transformer 1b, sufficient power cannot be transmitted from the primary winding 13 to the secondary winding.

As described above, according to the third embodiment, the annular winding 10 having the primary winding 13 and the secondary winding 14 formed by winding a conducting wire and the core 20 attached to the annular winding 10 are provided. In the transformer, in particular, the secondary winding 14 is divided into two layers, and the primary winding 13 is sandwiched between the two layers of the secondary winding 14 to constitute the forward transformer 1a. For this reason, since the secondary winding 14 cancels and reduces the magnetic flux which the primary winding 13 emits around, the core 20 can be reduced in size. Therefore, a small forward transformer 1a can be realized.

According to the third embodiment, the primary winding 13 is divided into two layers, and the flyback transformer 1b is configured with the secondary winding 14 sandwiched between the two primary windings 13. It may be. In the case of this configuration, since the primary winding 13 is disposed in the vicinity of the core 20, the magnetic flux generated by the primary winding 13 can be easily stored in the core 20, and the flyback transformer 1b having good characteristics can be realized.

Embodiment 4 FIG.
FIG. 11 is a block diagram showing the configuration of the electric power system of electric vehicle 200. An electric vehicle 200 including a main battery 202 and a motor 204 includes a charger 201 that supplies power from the AC power source to the main battery 202, an inverter 203 that supplies power from the main battery 202 to the motor 204, and a sub battery from the main battery 202. And a step-down converter 205 that charges the battery 206 and supplies electric power to the vehicle-mounted electrical component 207.

Since the coil 1 or transformer shown in the first to third embodiments is small and has high rigidity, the AC / DC converter is provided between the AC power source and the main battery 202 to insulate the AC power source from the DC power source of the electric vehicle 200. (Charger 201), which is suitable for use as a vehicle-mounted component such as a DC / DC converter (step-down converter 205) provided between the main battery 202 and the sub-battery 206 to insulate both batteries.

In order to attach the coil 1 or the transformer to a fixed position on the device side, for example, a through hole through which a bolt (fixing tool) is inserted may be provided in the opening through portion 21 of the core 20. Since the core 20 forming the through hole is made of a linear magnetic member, it has high rigidity and can be directly fixed using a bolt or the like.
FIG. 12 shows an example of the through hole. In the example of FIG. 12, a cylindrical sleeve 60 is passed through the opening penetrating portion 21 of the core 20 to form a through hole. If a bolt is inserted into the sleeve 60 and tightened to the equipment side, the coil 1 can be fixed, and the assembly work of the coil 1 becomes easy.

In addition to the above, within the scope of the invention, the invention of the present application can be freely combined with each embodiment, modified any component of each embodiment, or omitted any component in each embodiment. Is possible.

As described above, the core according to the present invention can be miniaturized while increasing the mechanical strength by winding a linear magnetic member, and can cope with high voltage and high power. Suitable for use in coils or transformers.

1 coil, 1a forward transformer, 1b flyback transformer, 10 annular winding, 11 opening, 12 peripheral edge, 13 primary winding, 14 secondary winding, 20 core, 21 opening through part, 22 peripheral routing part , 23, 24 cut surface, 25, 26 partial core, 25a, 25b, 26a, 26b split partial core, 30 bobbin, 40 core bobbin, 50 spacer, 60 sleeve, 100 toroidal coil, 110 annular core, 111 opening Part, 112 peripheral part, 120 winding, 200 electric vehicle, 201 charger, 202 main battery, 203 inverter, 204 motor, 205 step-down converter, 206 sub-battery, 207 in-vehicle electrical components.

Claims (18)

A core mounted on an annular winding formed by winding a conducting wire in an annular shape;
A linear magnetic member is used, and the magnetic member is routed so as to pass through the opening on the center side and the outer peripheral edge of the annular winding, and is arranged along the peripheral edge of the annular winding. A core having a circumferential length of a bundle of magnetic members longer than a radial length of the bundle of magnetic members penetrating through the opening of the annular winding. 2. The core according to claim 1, wherein the core is formed in advance so as to route the magnetic member via an opening and a peripheral edge of the annular winding, and then cut or partially cut. The described core. 3. The core according to claim 2, wherein the core is divided into a plurality of parts. 3. The core according to claim 2, wherein a magnetic gap is provided at a portion where the cut or incised cross sections of the core are abutted with each other. The core according to claim 1, wherein the surface of the magnetic member is insulated. The core according to claim 1, wherein an adhesive member is applied to the surface of the magnetic member. The core according to claim 1, wherein the magnetic member is an iron-based magnetic material. The core according to claim 1, wherein the magnetic member is an amorphous magnetic material. The core according to claim 1, wherein a gap for inserting a fixture is provided in the bundle of magnetic members penetrating the opening of the annular winding. The core according to claim 1, wherein the core is applied to a coil used for a vehicle-mounted device or a transformer used for a vehicle-mounted device. An annular winding formed by winding a conducting wire in an annular shape;
A coil comprising the core according to claim 1 attached to the annular winding. The coil according to claim 11, wherein the conductor used for the annular winding is a conductor having a substantially circular cross section. 12. The coil according to claim 11, wherein the conducting wire used for the annular winding is a conducting wire including a rectangular wire having a substantially rectangular cross section. An annular winding having a primary winding and a secondary winding formed by winding a conducting wire in an annular shape;
A transformer comprising the core according to claim 1 attached to the annular winding. 15. The transformer according to claim 14, wherein the secondary winding is divided into a plurality of layers, and the primary winding is sandwiched between the secondary windings of the plurality of layers to constitute a forward transformer. . 15. The flyback transformer according to claim 14, wherein the primary winding is divided into a plurality of layers, and the secondary winding is sandwiched between the primary windings of the plurality of layers to constitute a flyback transformer. Trance. 15. The transformer according to claim 14, wherein the conducting wire used for the annular winding is a conducting wire having a substantially circular cross section. 15. The transformer according to claim 14, wherein the conducting wire used for the annular winding is a conducting wire including a rectangular wire having a substantially rectangular cross section.

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