JP2010267816A - Transformer and choke coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer and a choke coil capable of reducing eddy current loss effectively in a simple structure without complicating the manufacturing method. <P>SOLUTION: A center gap 6 is formed making the central leg 3a of a core body 1a come face to face with the central leg 3b of a core body 1b. Meanwhile, side gaps 7 and 8 are formed making the side legs 4a and 5a of the core body 1a come face to face with the side legs 4b and 5b of the core body 1b, respectively. The gap length (gs) of both side gaps 7 and 8 are configured to be greater than the gap length (gc) of the center gap 6 (gs>gc). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transformer and a choke coil, and more particularly to a structure of a gap provided in a core of the transformer and the choke coil.

  Conventionally, in a case where a gap is provided in a core in an outer iron type transformer or choke coil, a structure in which a gap is provided in a central leg portion is generally employed.

  On the other hand, in the case of a structure in which a gap is provided at the center leg, the magnetic flux flowing into and out of the gap flows wider than the cross section of the core, so that an eddy current is generated by interlinking with the windings arranged around the gap. There was a problem of increasing current loss.

  Therefore, in the converter transformer shown in Patent Document 1 below, when a gap is formed in the butt portion of the magnetic pole to which the winding of the EE type or UU type ferrite core is mounted, a taper portion is formed around the entire butt portion of the magnetic pole. The area of the end face of the butt portion of the magnetic pole is 70% to 80% of the cross-sectional area other than the taper portion, and the dimensions including the height and gap of both taper portions are 23% of the magnetic pole length for mounting the winding. A configuration is disclosed in which the amount of magnetic flux interlinked with the winding around the gap is reduced by setting to ˜50%, and eddy current loss is reduced.

Japanese Patent Laid-Open No. 4-188605

  However, in the technique disclosed in Patent Document 1, it is necessary to provide a taper portion at the magnetic pole butt portion, and the area of the end face of the magnetic pole butt portion falls within the specified range in relation to the cross-sectional area other than the taper portion. In addition, since the dimensions including the height of the taper portion and the gap must be within a specified range in relation to the magnetic pole length on which the winding is mounted, the manufacturing method is complicated, and the manufacturing time and manufacturing cost increase. There was a problem.

  The present invention has been made in view of the above, and provides a transformer and a choke coil that can effectively reduce eddy current loss with a simple structure without complicating the manufacturing method. With the goal.

  In order to solve the above-described problems and achieve the object, a transformer according to the present invention has a core constituted by a pair of core bodies, at least one of which has three legs, and the center leg of one core body In the transformer in which the primary winding and the secondary winding are mounted in a space region including the periphery of the core, the core includes a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body. A center gap formed between the side legs of the one core body and a pair of side gaps formed between the side legs or the yoke section of the other core body, The gap length of each side gap is configured to be larger than the gap length of the center gap.

  According to the present invention, it is possible to effectively reduce eddy current loss with a simple structure without complicating the manufacturing method.

  In the transformer according to the present invention, the ratio of the gap length of the center gap to the sum of the gap length of each side gap and the gap length of the center gap is in the range of 0.025 to 0.5. It is characterized by.

  According to the present invention, by setting the gap length ratio in the range of 0.025 to 0.5, an effect of reducing eddy current loss can be obtained for various types of cores. .

  Further, the transformer according to the present invention has a core constituted by a pair of core bodies, at least one of which has three leg portions, and a primary winding and a space in a space region including the periphery of the central leg portion of the one core body. In the transformer in which the secondary winding is mounted, the core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, A pair of side gaps formed between each side leg part of the other core body and the side leg part or yoke part of the other core body are provided, and the magnetic resistance of the gap part in each side gap is The center gap is configured to be larger than the magnetic resistance of the gap portion.

  According to the present invention, even if the end surfaces of the center gap and the side gap each have a complicated shape (for example, when having a taper), the gap length in each gap is determined using the criterion of magnetoresistance. The effect that can be determined is obtained.

  In the transformer according to the present invention, a spacer is inserted in each side gap, and no spacer is inserted in the center gap.

  According to the present invention, it is possible to obtain an effect that unnecessary stress is not generated between the central legs. Further, according to the present invention, even if there is some manufacturing error in the pair of core bodies constituting the core, it can be used as it is, and the transformer can be manufactured easily. can get.

  Further, the transformer according to the present invention has a core constituted by a pair of core bodies, at least one of which has three leg portions, and a primary winding and a space in a space region including the periphery of the central leg portion of the one core body. In the transformer in which the secondary winding is mounted, the core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, A pair of side gaps formed between each side leg portion of the other core body and the side leg portion or yoke portion of the other core body are provided, and the gap length of each side gap and the center gap are provided. The gap lengths are configured to be approximately equidistant, and magnetic members having different permeability are inserted into the side gaps and the center gap, and are inserted into the side gaps. Permeability of the gas member, characterized in that it is configured to be smaller than the magnetic permeability of the magnetic member inserted into the center gap.

  According to the present invention, a configuration in which the magnetic gap length of each side gap is larger than the magnetic gap length of the center gap can be simplified even when the gap lengths of the center gap and each side gap are equal. This is realized by the technique, and the effect that the eddy current loss generated in the winding can be effectively reduced is obtained.

  Further, the transformer according to the present invention has a core constituted by a pair of core bodies, at least one of which has three leg portions, and a primary winding and a space in a space region including the periphery of the central leg portion of the one core body. In the transformer in which the secondary winding is mounted, the core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, A pair of side gaps formed between each side leg of the other core body and the side leg or yoke of the other core body, and a magnetic member is inserted only into each side gap; The magnetic member has a magnetic permeability such that the magnetic resistance of the gap portion in the center gap is larger than the magnetic resistance of the gap portion in each side gap.

  According to the present invention, even if the gap length of the center gap is configured to be larger than the gap length of each side gap, the magnetic gap length of each side gap is the magnetic gap of the center gap. The effect of being able to determine a configuration that is larger than the gap length by using a standard called magnetoresistance and to realize a configuration that can effectively reduce eddy current loss generated in the winding by a simple method. Is obtained.

  The transformer according to the present invention is characterized in that the gap length of each side gap and the gap length of the center gap are substantially equidistant.

  According to the present invention, it is possible to reduce the work man-hour of the transformer.

  The choke coil according to the present invention has a choke core constituted by a pair of core bodies, at least one of which has three leg portions, and is wound around a space region including the periphery of the central leg portion of the one core body. The choke core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, and the one choke core. A pair of side gaps formed between each side leg portion of the core body and each side leg portion or yoke portion of the other core body are provided, and the gap length of each side gap is equal to the center gap. It is configured to be larger than the gap length.

  According to the present invention, eddy current loss can be effectively reduced with a simple structure without complicating the manufacturing method.

  According to the transformer of the present invention, there is an effect that eddy current loss can be effectively reduced with a simple structure without complicating the manufacturing method.

FIG. 1 is a diagram illustrating a structure of a transformer according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a magnetic field distribution around a gap obtained by simulation. FIG. 3 is a diagram illustrating the relationship between the winding loss and the gap length obtained by simulation. FIG. 4 is a diagram illustrating a range in which the loss calculation is performed in the simulation result. FIG. 5 is a diagram illustrating the structure of the transformer according to the second embodiment of the present invention. FIG. 6 is a diagram for explaining one method for providing the center gap and the side gap shown in the first and second embodiments. FIG. 7 is a diagram for explaining another method different from the method shown in FIG. FIG. 8 is a diagram illustrating an example when the method illustrated in FIG. 7 is applied to an EI type core. FIG. 9 is a diagram illustrating the structure of the transformer according to the fourth embodiment of the present invention. FIG. 10 is a diagram illustrating the relationship between the winding loss and the relative permeability ratio obtained by simulation.

  Hereinafter, a transformer according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a structure of a transformer according to a first embodiment of the present invention. More specifically, FIG. 1 (a) is a cross-sectional view of a transformer core made of a magnetic material (hereinafter simply referred to as “core”), and FIG. 1 (b) is shown in FIG. 1 (a). It is the arrow view seen from the AA line.

  In FIG. 1, the core 10 according to the first embodiment is configured by using core bodies 1 a and 1 b having the same structure, for example, as an ER type core. The core bodies 1a and 1b are composed of a linear yoke portion 2 (2a and 2b) and side leg portions 4 (4a and 4b) that are erected from both ends of the yoke portion 2 in a direction perpendicular to the longitudinal direction of the yoke portion 2. ), 5 (5a, 5b), and a central leg 3 (3a, 3b) standing substantially parallel to the side legs 4, 5 from the approximate center of the yoke part 2. Further, the center leg 3 is a cylindrical body having a circular cross section as shown in the figure, and the side legs 4 and 5 have a structure in which the side surface on the side of the center leg 3 has a concave shape with a curvature. Although not shown, a primary winding and a secondary winding for functioning as a transformer are wound or mounted around the center leg 3.

  In addition, the core body 1a and the core body 1b have the leg portions of the central leg portion 3 and the side leg portions 4 and 5 abutted to each other, and the end surfaces of the central leg portion 3 and the leg portions 4 and 5 of the side leg portions 4 and 5 respectively. The end faces are arranged with a predetermined distance. That is, the center gap 6 is formed in the core 10 by abutting the central leg portion 3a of the core body 1a and the central leg portion 3b of the core body 1b, and the side legs 4a of the core body 1a and the side legs of the core body 1b are formed. The side gap 7 is formed by abutting the portion 4b, and the side gap 8 is formed by abutting the side leg portion 5a of the core body 1a and the side leg portion 5b of the core body 1b. However, there is a relationship of gc <gs between the gap length gc of the center gap 6 and the gap lengths gs of the side gaps 7 and 8 (assumed to be equal here).

  In FIG. 1, an ER type core is shown as an example, but the ER type core is not limited to the ER type. Other than the ER type, for example, an EE type, EER type, RM type, P type, EPC type, or PQ type core may be used as a core constituted by a pair of core bodies having three legs. Moreover, both do not need to have three legs, and as a core constituted by a pair of core bodies having one leg having three legs, for example, an EI type or ET / FT type is used. It doesn't matter. That is, any core can be applied as long as at least one core is constituted by a pair of core bodies having three legs.

  FIG. 2 is a diagram illustrating an example of a magnetic field distribution around a gap obtained by simulation. In this simulation, in order to consider the influence of the primary winding 60 and the secondary winding 62 mounted between the central leg 53 and the side legs 54 due to the magnetic field generated by the center gap 56 and the side gap 58, 3 having only the center gap 56 (FIG. 2A), having the center gap 56 and the side gap 58 (FIG. 2B), and having only the side gap 58 (FIG. 2C). The two cases are shown in contrast. 2A to 2C, the alternate long and short dash line 70 indicates the center of the core. Further, as a magnetic field distribution around the gap, attention is paid to a rectangular region 72 including the primary winding 60 and the secondary winding 62, and the magnetic field distribution in the rectangular region 72 is enlarged to each of FIGS. 2 (a) to 2 (c). Shown on the right.

  Next, the magnetic field distribution around the gap will be considered. First, in the case of having only the center gap 56, as shown in FIG. 2A, the magnetic field around the gap is large and the magnetic field distribution is widened. In other words, the leakage magnetic flux in the gap portion is large, and it is understood that the eddy current loss is increased by interlinking with the primary winding 60 and the secondary winding 62 (hereinafter simply referred to as “winding”).

  In the case where only the side gap 58 is provided, as shown in FIG. 2C, the magnetic field distribution around the gap shows almost the same spread as in the case where only the center gap 56 is provided. However, since there is no winding in the right half of the side gap 58, it can be seen that the influence of causing an eddy current loss by interlinking with the winding is smaller than when only the center gap 56 is provided.

  On the other hand, in the case where both the center gap 56 and the side gap 58 are provided, the magnetic field distribution around each gap has a case where only the center gap 56 and a case where only the side gap 58 are provided, as shown in FIG. In comparison, it is clearly smaller. That is, it can be seen that the influence of eddy current loss linked to the winding around each gap is smaller than when only the center gap 56 is provided and when only the side gap 58 is provided.

  FIG. 3 is a diagram illustrating the relationship between the winding loss and the gap length obtained by simulation. In FIG. 3, the horizontal axis represents the ratio of the gap length of the center gap to the sum (= gc + gs) of the gap length of the side gap (= gs) and the gap length of the center gap (= gc) (= gc / (gc + gs)) The vertical axis represents the copper loss ratio generated in the winding when the center gap is provided (gap ratio = 1) is 1. In this simulation, iron loss generated in the core is not considered.

  In FIG. 3, the curve connecting the “diamond” points indicates the loss (copper loss) of the space surrounded by the outer legs, and the curve connecting the “square” points is not surrounded by the outer legs. A space loss (copper loss) is shown, and a curve connecting “triangle” points indicates the sum of both losses (hereinafter referred to as “total copper loss”). Here, the “space surrounded by the outer legs” is an internal space of the core surrounded by two virtual planes including the side surfaces of the yoke portion and the side legs. For example, in the case of an ER core, as shown in FIG. 4 (a), it is an internal space of the core whose cross section is a region 20 indicated by hatching. In addition, the “space not surrounded by the outer legs” is outside the “space surrounded by the outer legs”. For example, if it is an ER core, it is indicated by hatching as shown in FIG. This is an internal space of the core having a cross section of the region 22. Note that the widths of the region 22 in the longitudinal direction and the short direction are widths set to determine a range for calculating the loss of the winding, and can be set to an arbitrary width according to the calculated accuracy.

  According to the simulation result of FIG. 3, it can be seen that there is a region where the total copper loss is minimized when the gap ratio is 0 to 0.2. The first reason why such a minimum region exists is that the leakage magnetic flux due to the center gap and the leakage magnetic flux due to the side gap are opposite to each other. This is probably because the eddy current is reduced. The cancellation of the leakage magnetic flux does not occur when the gap ratio = 0 (that is, only the side gap), and does not occur even when the gap ratio = 1 (that is, only the center gap). Therefore, it can be explained that there is a point where the total copper loss is minimized when the gap ratio has a certain value with the center gap and the side gap. This can also be understood from the magnetic field distribution around the gap shown in FIG.

  The second reason for the existence of the minimum region as described above is considered to be because the influence on the winding is different between the center gap and the side gap. Specifically, the center gap causes an eddy current to flow through the winding through 360 °, but the side gap is limited to a range of about 90 to 180 ° (for example, small for the ER type and large for the PQ type). . Therefore, the eddy current generated in the winding can be reduced by reducing the influence of the center gap.

  Here, if it is assumed that the range in which the eddy current flows in the winding is the same between the center gap and the side gap, for the first reason, when the gap length of the center gap and the gap length of the side gap are equal, that is, the gap The optimum length is considered when the ratio = 0.5. Therefore, it can be explained that there is a point where the total copper loss is minimized when the gap length of the side gap is larger than the gap length of the center gap.

  According to the simulation result of FIG. 3, the total copper loss is reduced by about 50% at the minimum point of the total copper loss (gap ratio≈0.05) compared to the case of only the center gap (gap ratio = 1). In addition, the total copper loss can be reduced by about 30% even when the gap length of the center gap and the gap length of the side gap are equal (gap ratio = 0.5).

  In the simulation result of FIG. 3, the gap ratio≈0.05 is shown as the minimum point of the total copper loss, but the gap ratio is not necessarily at this point. The important point is that the total copper loss is reduced as compared with the prior art. In the simulation results of FIG. 3, when the gap ratio = 0.5, the total copper loss can be reduced by about 25% compared to the gap ratio = 1. It is no exaggeration to say that there is an effect of reducing copper loss.

  In addition, the simulation result of FIG. 3 is an example of the ER core, and in the other types of cores, the minimum point of the total copper loss is somewhat shifted. Even in the case of the ER core, the minimum point of the total copper loss is shifted due to the difference in the cross-sectional area of each gap portion or the configuration of the magnetic circuit. Therefore, the minimum value of the gap ratio has a value (0.025) within “−50%” of 0.05 which is the minimum point of the simulation result as a lower limit, and has a value larger than this value. In other words, it can be said that the gap ratio is surely obtained even for various types of cores, which can surely reduce the total copper loss.

  As described above, according to the transformer of the first embodiment, the gap between the pair of side gaps formed by abutting each side leg portion of one core body with the side leg portion or yoke portion of the other core body. Since the length is configured to be larger than the gap length of the center gap formed by abutting the central leg part of one core body and the central leg part or yoke part of the other core body, the manufacturing method There is an effect that eddy current loss generated in the winding can be effectively reduced with a simple structure without being complicated.

Embodiment 2. FIG.
FIG. 5 is a diagram illustrating the structure of the transformer according to the second embodiment of the present invention. Parts that are the same as or equivalent to those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. In the transformer of the second embodiment, as shown in FIG. 5, spacers 26 and 28 are inserted into the side gaps 7 and 8, respectively. Note that nothing is inserted in the center gap 6.

  The core body 1a and the core body 1b are fixed by the spacers 26 and 28 inserted in the side gaps 7 and 8, respectively, but the central leg portions 3a and 3b are not in contact with each other. Therefore, unnecessary stress does not occur in the central leg portions 3a and 3b, and there is no concern that the performance is deteriorated due to a crack in a part of the central leg portions 3a and 3b. Furthermore, since the thickness of the spacers 26 and 28 can be adjusted as appropriate, even if there are some manufacturing errors in the core bodies 1a and 1b, they can be used as they are. Therefore, the transformer can be easily manufactured.

  The spacers 26 and 28 inserted into the side gaps 7 and 8 have substantially the same performance as the transformer described in the first embodiment if a material having a relative permeability of about 1 is used. Become. However, as the spacers 26 and 28, those having a relative permeability exceeding 1 or 1 or less may be inserted. In addition, the point which inserts things with relative permeability other than about 1 is demonstrated in Embodiment 4 mentioned later.

  As described above, according to the transformer of the second embodiment, only the pair of side gaps formed by abutting each side leg portion of one core body with the side leg portion or yoke portion of the other core body. Since the spacer is inserted, an effect that unnecessary stress is not generated between the central legs can be obtained.

  Further, according to the transformer of the second embodiment, even if there is some manufacturing error in the pair of core bodies constituting the transformer core, it can be used as it is, so that the transformer can be manufactured easily. The effect of being able to be obtained.

Embodiment 3 FIG.
In the third embodiment, a method of providing the center gap and the side gap in the transformer core shown in FIGS. 1 and 5 will be described. FIG. 6 is a diagram for explaining one method for providing the center gap and the side gap shown in the first and second embodiments.

  The technique shown in FIG. 6 is that the side leg portions 4a and 5a in the core body 1a and the end portions of the side leg portions 4b and 5b in the core body 1b are evenly cut away, so that each gap length gs of the side gap becomes the center. A structure that is larger than the gap length gc of the gap is realized. By adopting this method, the core body 1a and the core body 1b have the same structure, so that there is an advantage that it is not necessary to prepare two kinds of core bodies. In addition, when a plurality of core members (for example, electromagnetic steel plates) are stacked to form an EE type core, there is no need to worry that a core body is manufactured by combining wrong core members.

  FIG. 7 is a diagram for explaining another method different from the method shown in FIG. The technique shown in FIG. 7 is to remove each end of each side leg (side leg 4a, 5a in FIG. 7) of one core body (core body 1a in FIG. 7) evenly. A structure in which the length gs is larger than the gap length gc of the center gap is realized. If this method is adopted, the scraping work can be performed only on one core body, so that the number of work steps can be reduced as compared with the method shown in FIG.

  The transformer core shown in FIG. 8 has a central leg portion 3a and side leg portions 4a and 5a on one core body 1a, and the other core body has only a yoke portion 2. Also in this case, similarly to the method shown in FIG. 7, the gap length gs of the side gap is changed to the gap length gc of the center gap by evenly scraping the ends of the side legs 4a and 5a of the one core body 1a. A larger structure can be realized.

Embodiment 4 FIG.
FIG. 9 is a diagram illustrating the structure of the transformer according to the fourth embodiment of the present invention. Parts that are the same as or equivalent to those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. In the transformer of the fourth embodiment, as shown in FIG. 8, the gap length of the center gap 16 and the gap lengths of the side gaps 17 and 18 are configured to be approximately equidistant. A magnetic member 36 having a magnetic permeability μs2 is inserted, and magnetic members 37 and 38 having a relative magnetic permeability μs3 are inserted into the side gaps 17 and 18, respectively. However, there is a relationship of μs2> μs3 between the relative permeability μs2 of the magnetic member 36 inserted into the center gap 16 and the relative permeability μs3 of the magnetic members 37 and 38 inserted into the side gaps 17 and 18.

  In FIG. 7, an ER type core is shown as an example, but the ER type core is not limited to the ER type as in the first embodiment. That is, for example, an EE type, an EER type, an RM type, a P type, an EPC type, a PQ type, an EI type, or an ET / FT type is used which is constituted by a pair of core bodies each having three legs. It is possible.

  In the first embodiment, the gap length of the side gap is configured to be larger than the gap length of the center gap. However, the important point of this technique is that the leakage magnetic flux due to the side gap, the leakage magnetic flux due to the center gap, It is to make a compromise between. In the first embodiment, it can be explained that the magnetic flux has been compromised by adjusting the gap length of each gap portion without inserting a magnetic member (that is, relative permeability = 1).

  On the other hand, adjusting the gap length of each gap portion is technically equivalent to changing the magnetic resistance in each gap portion. Here, a large gap length means a large magnetoresistance. Further, since the relative permeability is inversely proportional to the magnetic resistance, when the gap length is equal, the smaller the relative permeability of the magnetic member to be inserted, the larger the magnetic resistance. Therefore, if a magnetic member having a small relative permeability is inserted into the side gap, a transformer equivalent to that in the first embodiment can be configured even when the gap length is equal.

  FIG. 10 is a diagram illustrating the relationship between the winding loss and the relative permeability ratio obtained by simulation. In FIG. 9, the horizontal axis represents the ratio (relative permeability ratio) between the relative permeability (μs3) of the magnetic member inserted into the side gap and the relative permeability (μs2) of the magnetic member inserted into the center gap. Represents the copper loss ratio generated in the winding when the relative permeability ratio (μs 3 / μs 2) is “1913”. In this simulation, since the relative magnetic permeability of the core bodies 1a and 1b is “1913”, the case of μs3 / μs2 = 1913 corresponds to the case where only the center gap is provided in the transformer of the first embodiment. .

  In FIG. 10, the curve connecting the “diamond” points indicates the loss (copper loss) of the space surrounded by the outer legs, and the curve connecting the “square” points is not surrounded by the outer legs. The space loss (copper loss) is shown, and the curve connecting the “triangle” points shows the total copper loss. These definitions are the same as those in FIG.

  According to the simulation result of FIG. 10, it can be seen that there is a region where the total copper loss is minimized when the relative permeability ratio is 0.1 to 0.2. The total copper loss can be reduced by about 50% compared to the case of μs 3 / μs 2 = 1913 corresponding to the case where only the center gap is provided. Further, at the minimum point of the total copper loss, the relative permeability ratio = 1, that is, when a magnetic material having the same relative permeability is inserted in the center gap and the side gap (the case of the air gap also corresponds to this case). Compared to the above, the total copper loss can be reduced by about 25%. The reason why such a minimum region exists is the same as in the first embodiment, because the eddy current generated in the winding is reduced by canceling out the magnetic flux linked to the winding. .

  In the present embodiment, the gap length of the center gap and the gap length of each side gap are configured to be approximately equidistant, but this is not restrictive. In particular, as the relative permeability of the magnetic material to be inserted into each gap portion can be selected arbitrarily, the center gap gap length is theoretically larger than the gap length of each side gap. It may be a configuration. The important point is that the magnetic resistance of the gap portion in each side gap is configured to be larger than the magnetic resistance of the gap portion in the center gap. That is, even if the gap length of the center gap is configured to be larger than the gap length of each side gap, by appropriately selecting the relative permeability of the magnetic material to be inserted into each gap portion, It is possible to configure so that the magnetic resistance of the gap portion is larger than the magnetic resistance of the gap portion in the center gap.

  As described above, according to the transformer of the fourth embodiment, a pair of side gaps formed by abutting each side leg portion of one core body with the side leg portion or yoke portion of the other core body, A magnetic member having a different relative permeability is inserted into the center gap formed by abutting the central leg portion of one core body with the central leg portion or yoke portion of the other core body, and is inserted into each side gap. Since the relative permeability of the member is configured to be smaller than the relative permeability of the magnetic member inserted into the center gap, it is possible to effectively reduce the eddy current loss generated in the winding. .

  In addition, as shown in FIG. 8, if the gap length of each side gap and the gap length of the center gap are configured to be approximately equidistant, an effect that the work man-hour of the transformer can be reduced is obtained.

  Further, according to the transformer of the fourth embodiment, the center gap formed by abutting the central leg portion of one core body with the central leg portion or the yoke portion of the other core body, and each side of the other core body When configuring a transformer core provided with a pair of side gaps formed by abutting the leg part and the side leg part or yoke part of the other core body, magnetic members are inserted only into each side gap, and Since the relative magnetic permeability of the member can be configured such that the magnetic resistance of the gap portion in the center gap is larger than the magnetic resistance of the gap portion in each side gap, the gap length of the center gap is larger than the gap length of each side gap. Even if the configuration is large, the magnetic gap length of each side gap is larger than the magnetic gap length of the center gap. Formation can be determined using the criterion that the magnetic resistance effect is obtained in that the structure capable of effectively reducing eddy current loss generated in the windings can be realized by a simple technique.

  Note that the technique of determining the gap length of each gap portion using the standard of magnetoresistance can also be applied to the transformer of the first embodiment. For example, it is a transformer that does not insert a magnetic member as in the first embodiment (that is, a transformer having an air gap), and the end face in each gap portion of the center gap or the side gap has a complicated shape (for example, has a taper). Even if it is a core), it is possible to determine the gap length in each gap using the criterion of magnetoresistance.

  In the first to fourth embodiments, at least one has a transformer core constituted by a pair of core bodies having three leg portions, and is primary in a spatial region including the periphery of the central leg portion of one core body. Although a transformer having a winding and a secondary winding has been described, it may be applied to a choke coil in which a winding is wound or mounted in a space region including the periphery of the central leg of one core body. It is possible to obtain the same effect as in the case of a transformer.

  As described above, the transformer and choke coil according to the present invention are useful as an invention that can effectively reduce eddy current loss with a simple structure without complicating the manufacturing method.

1a, 1b Core body 2 Yoke part 3, 3a, 3b, 53 Central leg part 4, 4a, 4b, 5, 5a, 5b, 54 Side leg part 6, 16, 56 Center gap 7, 8, 17, 18, 58 Side gap 10 core (transformer core)
26, 28 Spacer 36, 37, 38 Magnetic member 60 Primary winding 62 Secondary winding

Claims (8)

At least one has a transformer core constituted by a pair of core bodies having three leg portions, and a primary winding and a secondary winding are mounted in a space region including the periphery of the central leg portion of the one core body. In the transformer
The transformer core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, each side leg portion of the one core body, and the A pair of side gaps formed between the side legs or yokes of the other core body,
A transformer characterized in that a gap length of each side gap is configured to be larger than a gap length of the center gap.   The ratio of the gap length of the center gap to the sum of the gap length of each side gap and the gap length of the center gap is in the range of 0.025 to 0.5. Transformer. At least one has a transformer core constituted by a pair of core bodies having three leg portions, and a primary winding and a secondary winding are mounted in a space region including the periphery of the central leg portion of the one core body. In the transformer
The transformer core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, each side leg portion of the other core body, and the A pair of side gaps formed between the side legs or yokes of the other core body,
A transformer characterized in that a magnetic resistance of a gap portion in each side gap is larger than a magnetic resistance of a gap portion in the center gap.   The transformer according to claim 1, wherein a spacer is inserted in each side gap, and no spacer is inserted in the center gap. At least one has a transformer core constituted by a pair of core bodies having three leg portions, and a primary winding and a secondary winding are mounted in a space region including the periphery of the central leg portion of the one core body. In the transformer
The transformer core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, each side leg portion of the other core body, and the A pair of side gaps formed between the side legs or yokes of the other core body,
The gap length of each side gap and the gap length of the center gap are substantially equidistant, and a magnetic member having a different relative permeability is inserted into each side gap and the center gap, and A transformer configured such that a relative permeability of a magnetic member inserted into each side gap is smaller than a relative permeability of a magnetic member inserted into the center gap. At least one has a transformer core constituted by a pair of core bodies having three leg portions, and a primary winding and a secondary winding are mounted in a space region including the periphery of the central leg portion of the one core body. In the transformer
The transformer core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, each side leg portion of the other core body, and the A pair of side gaps formed between the side legs or yokes of the other core body,
A magnetic member is inserted only in each side gap, and the magnetic member has a relative magnetic permeability such that the magnetic resistance of the gap portion in the center gap is larger than the magnetic resistance of the gap portion in each side gap. Transformer characterized by being configured.   The transformer according to claim 6, wherein the gap length of each side gap and the gap length of the center gap are substantially equidistant. In the choke coil in which at least one has a choke core constituted by a pair of core bodies having three leg portions, and a winding is mounted in a space region including the periphery of the central leg portion of the one core body,
The choke core includes a center gap formed between a central leg portion of the one core body and a central leg portion or a yoke portion of the other core body, each side leg portion of the one core body, and the A pair of side gaps formed between each side leg or yoke of the other core body,
A choke coil characterized in that a gap length of each side gap is configured to be larger than a gap length of the center gap.

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