Transformer

Abstract

To provide a transformer capable of reducing an eddy current loss.SOLUTION: A transformer 1 includes: a core 2 having a central leg part 21 extending in a vertical direction and a side leg part extending in the vertical direction and provided away from the central leg part 21 in a left-right direction; a primary winding 3 wound around the central leg part 21; a secondary winding 4 provided away from the primary winding 3 in the vertical direction and wound around the central leg part 21; and a pass core 5 which is a pass core 5 forming a magnetic path of leakage magnetic flux together with the core 2 and extended in the left-right direction and provided between the primary winding 3 and the secondary winding 4. The pass core 5 is disposed such that a plurality of gaps are formed in a section of the magnetic path from the central leg part 21 to a side leg parts 22 through the pass core 5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a transformer. [Background technology]

[0002] There is known a transformer that includes a path core for magnetic flux leakage provided between a primary winding and a secondary winding (see, for example, Patent Document 1). In the transformer described in Patent Document 1, the path core protrudes from the central leg toward the side leg of two E-shaped cores facing each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 59-47722 Summary of the Invention [Problem to be solved by the invention]

[0004] In the transformer described in Patent Document 1, a gap is formed between the path core and the side legs. Of the magnetic flux generated by current flowing through the winding, leakage magnetic flux passes through a path that starts from the center leg, passes through the path core, gap, and side legs, and then returns to the center leg. Because magnetic flux passes through the path of least resistance, in the gap, the leakage magnetic flux passes closer to the winding than the extended portion of the path core. This can result in eddy current loss due to the leakage magnetic flux linking with the winding.

[0005] The present disclosure describes a transformer capable of reducing eddy current losses. [Means for solving the problem]

[0006] A transformer according to one aspect of the present disclosure includes a core having a central leg extending in a first direction and side legs extending in the first direction and spaced apart from the central leg in a second direction intersecting the first direction, a primary winding wound around the central leg, a secondary winding spaced apart from the primary winding in the first direction and wound around the central leg, and a path core forming a magnetic path for leakage magnetic flux together with the core, the path core extending in the second direction and being disposed between the primary winding and the secondary winding. The path core is arranged so that multiple gaps are formed in the section of the magnetic path that runs from the central leg through the path core to the side legs.

[0007] In this transformer, multiple gaps are formed in the section of the magnetic path of leakage magnetic flux that runs from the center leg through the path core to the side leg. The total gap length in the magnetic path is determined by the desired leakage inductance. Therefore, compared to a configuration with only one gap in the magnetic path, the length of each gap in the second direction (gap length) can be shortened, thereby reducing the leakage magnetic flux that interlinks with the primary winding or secondary winding. As a result, eddy current loss can be reduced.

[0008] The path core may include a plurality of segments spaced apart from one another and arranged in the second direction. With this configuration, a gap is formed between two adjacent segments, so that a plurality of gaps can be formed in the section extending from the central leg through the path core to the side legs.

[0009] The central leg may have a first protrusion that protrudes toward the side leg. When the direction of the magnetic path changes, the magnetic flux is more likely to take a shortcut. With the above configuration, leakage magnetic flux is more likely to pass through the first protrusion, thereby reducing the amount of leakage magnetic flux that takes a shortcut when the direction of the magnetic path changes. Therefore, the leakage magnetic flux that interlinks with the primary winding or secondary winding can be further reduced, and eddy current loss can be further reduced.

[0010] The transformer may further include a first adhesive layer disposed between a first segment closest to the central leg and the first protruding portion, and fixing the first segment to the first protruding portion. The gap between the first segment and the first protruding portion is close to the position where the magnetic path changes direction, making it easy for leakage flux to take a shortcut. This configuration allows the gap length between the first segment and the first protruding portion to be shorter than when a bobbin is used. This further reduces the leakage flux that takes a shortcut. This further reduces the leakage flux that interlinks with the primary winding or secondary winding, enabling further reduction in eddy current loss.

[0011] The side legs may have second protrusions that protrude toward the center leg. This configuration allows leakage flux to more easily pass through the second protrusions, reducing the amount of leakage flux that takes a shortcut when the magnetic path changes direction. This further reduces leakage flux that interlinks with the primary winding or secondary winding, further reducing eddy current loss.

[0012] The transformer may further include a second adhesive layer disposed between the second segment, which is closest to the side leg, and the second protrusion, and which fixes the second segment to the second protrusion. The gap between the second segment and the second protrusion is close to the position where the magnetic path changes direction, making it easier for leakage flux to take a shortcut. This configuration allows the gap length between the second segment and the second protrusion to be shorter than when a bobbin is used. This further reduces leakage flux that takes a shortcut. This further reduces leakage flux that interlinks with the primary winding or secondary winding, enabling further reduction in eddy current loss.

[0013] The plurality of gaps may include a first gap closest to the central leg, a second gap closest to the side leg, and a third gap provided between the first and second gaps. The length of the first gap in the second direction and the length of the second gap in the second direction may be shorter than the length of the third gap in the second direction. With this configuration, the gap length is short in a location where leakage flux is likely to take a shortcut, thereby reducing the amount of leakage flux that takes a shortcut. Therefore, leakage flux linking with the primary winding or secondary winding can be further reduced, and eddy current loss can be further reduced. [Effects of the Invention]

[0014] According to the present disclosure, eddy current loss can be reduced. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a transformer according to one embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a diagram schematically showing paths of leakage magnetic flux in the transformer shown in FIG. [Figure 4] FIG. 4 is a diagram schematically showing the path of leakage magnetic flux in a transformer of a comparative example. [Figure 5] FIG. 5 is a cross-sectional view showing a schematic configuration of a transformer according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] A transformer according to one embodiment will be described in detail below with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted. An XYZ coordinate system may be shown in each drawing. The Y-axis direction is a direction intersecting (e.g., perpendicular to) the X-axis direction (second direction) and the Z-axis direction (first direction). The Z-axis direction is a direction intersecting (e.g., perpendicular to) the X-axis direction and the Y-axis direction. In the following description, as an example, the X-axis direction is defined as the left-right direction (width direction), the Y-axis direction is defined as the front-back direction (depth direction), and the Z-axis direction is defined as the up-down direction (height direction). The X-axis, Y-axis, and Z-axis directions are not limited to the above directions.

[0017] A schematic configuration of a transformer according to one embodiment will be described with reference to Figures 1 and 2. Figure 1 is a perspective view showing a schematic configuration of a transformer according to one embodiment. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. The transformer 1 shown in Figures 1 and 2 is a device that converts voltage, and includes a core 2, a primary winding 3, a secondary winding 4, a path core 5, and a bobbin 6. Note that the bobbin 6 is not shown in Figure 2.

[0018] The core 2 is a magnetic body that forms a magnetic path. The core 2 includes a central leg 21, a pair of side legs 22, and a pair of connecting portions 23. The central leg 21 and the pair of side legs 22 each extend in the up-down direction. The central leg 21 and the pair of side legs 22 are arranged substantially parallel to each other. The pair of side legs 22 are spaced apart from the central leg 21 in the left-right direction. The central leg 21 is arranged between the pair of side legs 22 in the left-right direction. The pair of connecting portions 23 connect the pair of side legs 22 and the central leg 21. Each connecting portion 23 has a flat plate shape. One connecting portion 23 connects one end of the central leg 21 to one end of each side leg 22. The other connecting portion 23 connects the other end of the central leg 21 to the other end of each side leg 22.

[0019] In this embodiment, the core 2 is an EI core composed of an E-shaped core member and an I-shaped core member, but the shape of the core 2 is not limited to this. The core 2 may be an EE core or a PQ core.

[0020] The primary winding 3 and the secondary winding 4 are formed by winding a long conductive material in a spiral shape. The primary winding 3 and the secondary winding 4 are wound around the central leg 21. The secondary winding 4 is provided spaced apart from the primary winding 3 in the up-down direction. In this embodiment, the primary winding 3 and the secondary winding 4 are edgewise coils formed by winding a flat copper wire in the width direction of the copper wire. The conductive material forming the primary winding 3 and the secondary winding 4 is not limited to a flat copper wire.

[0021] Each of the primary winding 3 and the secondary winding 4 is wound with a conductive material so that there is a predetermined number of turns per layer. In this embodiment, each of the primary winding 3 and the secondary winding 4 is wound with a conductive material in five layers, with two turns per layer, but the number of layers and the number of turns per layer of the primary winding 3 and the secondary winding 4 can be changed as appropriate. Note that a layer in a winding means a predetermined number of turns of the conductive material, and corresponds to the layer in the cross section shown in FIG. 2.

[0022] The path core 5 is a magnetic material that, together with the core 2, forms a magnetic path MP (see FIG. 3) for leakage magnetic flux. The path core 5 extends in the left-right direction and is provided between the primary winding 3 and the secondary winding 4 in the up-down direction. The path core 5 is arranged so that multiple gaps are formed in a section S. The section S is a section of the magnetic path MP that runs from the central leg 21 through the path core 5 to the side leg 22. Note that a gap refers to a portion of the magnetic path MP where magnetic material is missing. In this embodiment, each gap is formed by an air layer or a part of the bobbin 6.

[0023] Specifically, the path core 5 includes a plurality of segments between the central leg 21 and each side leg 22. The segments are spaced apart and arranged in the left-right direction. In this embodiment, the path core 5 includes three segments (segments 51, 52, and 53) between the central leg 21 and each side leg 22. The three segments are arranged in the following order from the central leg 21 toward the side legs 22: segment 51 (first segment), segment 52, and segment 53 (second segment). Of the three segments, segment 51 is the segment closest to the central leg 21. Segment 52 is the segment located in the middle of the three segments. Segment 53 is the segment closest to the side legs 22.

[0024] A gap G1 (first gap) is formed between the divider 51 and the central leg 21. A gap G2 (third gap) is formed between the divider 51 and the divider 52. A gap G3 (third gap) is formed between the divider 52 and the divider 53. A gap G4 (second gap) is formed between the divider 53 and the side leg 22. In other words, the multiple gaps formed in the section S include gap G1, gap G2, gap G3, and gap G4. Of the multiple gaps formed in the section S, gap G1 is closest to the central leg 21. Of the multiple gaps formed in the section S, gap G4 is closest to the side leg 22. Gaps G2 and G3 are provided between gap G1 and gap G4 in the left-right direction.

[0025] The length of gap G1 in the left-right direction (gap length L1) is approximately the same as the length of gap G4 in the left-right direction (gap length L4). The length of gap G2 in the left-right direction (gap length L2) is approximately the same as the length of gap G3 in the left-right direction (gap length L3). Gap length L1 is shorter than both gap lengths L2 and L3, and gap length L4 is shorter than both gap lengths L2 and L3. The leakage inductance of transformer 1 is determined according to the sum of the lengths (gap lengths) of the gaps provided on magnetic path MP along magnetic path MP. Therefore, the gap length of each gap formed in section S is determined so as to obtain the desired leakage inductance.

[0026] The bobbin 6 is a member that holds the primary winding 3 and the secondary winding 4. The bobbin 6 is made of an insulating material. Examples of insulating materials that can be used to form the bobbin 6 include resins such as plastic. The bobbin 6 electrically separates the primary winding 3 and the secondary winding 4 from the core 2, and also electrically separates the primary winding 3 and the secondary winding 4 from the core 2. The bobbin 6 houses the path core 5. The bobbin 6 holds each of the segments while fixing the position of each segment. Instead of using the bobbin 6, the core 2, primary winding 3, secondary winding 4, and path core 5 may be held by an integrated injection mold formed by injection molding, or the core 2, primary winding 3, secondary winding 4, and path core 5 may be held by potting.

[0027] Next, the effects of the transformer 1 will be described with reference to Figures 3 and 4. Figure 3 is a diagram schematically showing the path of leakage magnetic flux in the transformer shown in Figure 1. Figure 4 is a diagram schematically showing the path of leakage magnetic flux in a transformer of a comparative example. For ease of explanation, the ratio of the dimension in the X-axis direction to the dimension in the Z-axis direction in Figures 3 and 4 is different from that in Figure 2. The transformer 100 shown in Figure 4 differs from the transformer 1 mainly in that it includes a core 102 and a path core 105 instead of the core 2 and the path core 5.

[0028] The core 102 is an EE core composed of two E-shaped core members. A path core 105 is provided between a central leg 121 of the two core members. The path core 105 extends from the central leg 121 toward side legs 122 on both sides. A gap Gc is formed between the tip of the path core 105 and each side leg 122. The length of the gap Gc in the left-right direction (gap length Lc) is substantially equal to the total gap length of the multiple gaps formed in the section S of the transformer 1 (the total of gap length L1, gap length L2, gap length L3, and gap length L4).

[0029] In the transformer 100, a magnetic flux is generated when a current flows through the primary winding 3. Of this, leakage magnetic flux passes through a path (magnetic path) that starts from the center leg 121 of the core 102, passes through the path core 105, the gap Gc, the side leg 122, and the connecting portion 123, and then returns to the center leg 121. Because magnetic flux passes through the path of minimum resistance, the leakage magnetic flux passes closer to the primary winding 3 at the gap Gc than the extended portion of the path core 105. This may result in eddy current loss due to the leakage magnetic flux interlinking with the primary winding 3. Similarly, leakage magnetic flux generated when a current flows through the secondary winding 4 of the transformer 100 passes closer to the secondary winding 4 at the gap Gc than the extended portion of the path core 105. This may result in eddy current loss due to the leakage magnetic flux interlinking with the secondary winding 4.

[0030] On the other hand, in the transformer 1, multiple gaps (gap G1, gap G2, gap G3, and gap G4) are formed in the section S. That is, to obtain a desired leakage inductance, it is necessary to provide gaps with a gap length approximately equal to the gap length Lc of the gap Gc in the transformer 100. In the transformer 1, however, the gaps are dispersed so that the total gap length is approximately equal to the gap length Lc. In the transformer 1, leakage magnetic flux generated by a current flowing through the primary winding 3 passes through a path (magnetic path MP) from the center leg 21, through gap G1, partition 51, gap G2, partition 52, gap G3, partition 53, gap G4, side leg 22, and connecting portion 23 in this order, and returns to the center leg 21.

[0031] Here, the shorter the gap length of the gap provided in section S, the smaller the amount of magnetic flux passing through the gap nearer to the primary winding 3 than the extended portion of the path core 5 (segment). The sum of gap length L1, gap length L2, gap length L3, and gap length L4 is substantially equal to gap length Lc. Therefore, the gap length of each gap formed in section S is shorter than gap length Lc. Therefore, in each of gaps G1, G2, G3, and G4, the amount of magnetic flux passing nearer to the primary winding 3 than the extended portion of the path core 5 (segment) is smaller than the amount of magnetic flux passing nearer to the primary winding 3 than the extended portion of the path core 105 in gap Gc of the transformer 100. As a result, the amount of leakage magnetic flux (magnetic flux density) interlinking with the primary winding 3 is reduced in the transformer 1 compared to the transformer 100.

[0032] Furthermore, in the transformer 1, the positions at which the leakage flux interlinks with the primary winding 3 are dispersed, so the magnetic flux density of the leakage flux interlinking with the primary winding 3 is further reduced compared to the transformer 100. Similarly, in the transformer 1, the magnetic flux density of the leakage flux interlinking with the secondary winding 4 is reduced compared to the transformer 100. Since eddy current loss is proportional to the square of the magnetic flux density, it is possible to reduce eddy current loss compared to the transformer 100.

[0033] By arranging the divided bodies 51, 52, and 53 in the left-right direction and spaced apart from each other, a gap is formed between two divided bodies adjacent to each other in the left-right direction, thereby forming a plurality of gaps (gap G1, gap G2, gap G3, and gap G4) in the section S.

[0034] When the direction of the magnetic path MP changes, the magnetic flux is likely to take a shortcut. For example, the magnetic flux is likely to take a shortcut between the center leg 21 and the path core 5 (i.e., gap G1) and between the path core 5 and the side leg 22 (i.e., gap G4). For example, when leakage magnetic flux generated by a current flowing through the primary winding 3 travels from the center leg 21 to the path core 5, it does not turn around the corner formed by the center leg 21 and the extended portion of the path core 5, but tends to pass through an air layer closer to the primary winding 3 than the corner. Similarly, when leakage magnetic flux generated by a current flowing through the primary winding 3 travels from the path core 5 to the side leg 22, it does not turn around the corner formed by the side leg 22 and the extended portion of the path core 5, but tends to pass through an air layer closer to the primary winding 3 than the corner.

[0035] To address this problem, in the transformer 1, the gap length L1 of the gap G1, through which leakage flux is likely to take a shortcut, is shorter than both the gap length L2 and the gap length L3, so that the leakage flux that takes a shortcut at the gap G1 can be reduced. Similarly, the gap length L4 of the gap G4, through which leakage flux is likely to take a shortcut, is shorter than both the gap length L2 and the gap length L3, so that the leakage flux that takes a shortcut at the gap G4 can be reduced. Therefore, the leakage flux that links with the primary winding 3 and the leakage flux that links with the secondary winding 4 can be further reduced, and eddy current loss can be further reduced.

[0036] Next, a schematic configuration of a transformer according to another embodiment will be described with reference to Fig. 5. Fig. 5 is a cross-sectional view showing the schematic configuration of a transformer according to another embodiment. Transformer 1A shown in Fig. 5 differs from transformer 1 mainly in that it includes core 2A instead of core 2 and further includes adhesive layer 7 (first adhesive layer) and adhesive layer 8 (second adhesive layer). Core 2A differs from core 2 mainly in that it includes central leg 21A instead of central leg 21 and a pair of side legs 22A instead of a pair of side legs 22.

[0037] The central leg 21A includes a main body 21a and a pair of protrusions 21b (first protrusions). The main body 21a is a portion corresponding to the central leg 21. The pair of protrusions 21b are provided on both the left and right side surfaces of the main body 21a. The right protrusion 21b is provided on the right side surface of the main body 21a and protrudes from the main body 21a toward the right side leg 22A. The left protrusion 21b is provided on the left side surface of the main body 21a and protrudes from the main body 21a toward the left side leg 22A. The length in the left-right direction of the protrusions 21b (protrusion height) is, for example, equal to or less than half the left-right clearance between the primary winding 3 or the secondary winding 4 and the main body 21a.

[0038] Each side leg 22A includes a main body 22a and a protrusion 22b (second protrusion). The main body 22a is a portion corresponding to the side leg 22. The protrusion 22b is provided on the surface of the main body 22a facing the central leg 21A, and protrudes from the main body 22a toward the central leg 21A. The length in the left-right direction of the protrusion 22b (protrusion height) is, for example, equal to or less than half the left-right clearance between the primary winding 3 or secondary winding 4 and the main body 22a.

[0039] The adhesive layer 7 is provided between the divided body 51 and the protruding portion 21b, and fixes the divided body 51 to the protruding portion 21b. Specifically, the adhesive layer 7 is sandwiched between the surface of the divided body 51 facing the central leg portion 21A and the tip surface of the protruding portion 21b. The adhesive layer 7 is made of, for example, an epoxy resin adhesive. The adhesive that makes up the adhesive layer 7 may contain a soft magnetic material. In this embodiment, the gap G1 is made of the adhesive layer 7.

[0040] The adhesive layer 8 is provided between the divided body 53 and the protruding portion 22b, and fixes the divided body 53 to the protruding portion 22b. Specifically, the adhesive layer 8 is sandwiched between the surface of the divided body 53 facing the side leg portion 22A and the tip surface of the protruding portion 22b. The adhesive layer 8 is made of, for example, an epoxy resin adhesive. The adhesive that makes up the adhesive layer 8 may contain a soft magnetic material. In this embodiment, the gap G4 is made of the adhesive layer 8.

[0041] The transformer 1A also has the same configuration as the transformer 1, and thus has the same effects as the transformer 1.

[0042] As described above, when the orientation of the magnetic path MP changes, the magnetic flux is likely to take a shortcut. In the transformer 1A, the central leg 21A has the protrusion 21b, so that the leakage magnetic flux is likely to pass through the protrusion 21b, which has a higher magnetic permeability than the air layer. This makes it possible to reduce the leakage magnetic flux that takes a shortcut when the orientation of the magnetic path MP changes. This further reduces the leakage magnetic flux that links with the primary winding 3 and the secondary winding 4, making it possible to further reduce eddy current loss.

[0043] In the transformer 1A, the side legs 22A have the protrusions 22b, which allow leakage flux to easily pass through the protrusions 22b, which have a higher magnetic permeability than the air layer. This reduces the amount of leakage flux that takes a shortcut when the direction of the magnetic path MP changes. This further reduces the leakage flux that links with the primary winding 3 and the secondary winding 4, making it possible to further reduce eddy current loss.

[0044] The gap between the divided body 51 and the protruding portion 21b (i.e., the gap G1) is close to the position where the direction of the magnetic path MP changes, making it easy for leakage flux to take a shortcut. In the transformer 1A, the divided body 51 is fixed directly to the protruding portion 21b by the adhesive layer 7 without using the bobbin 6, so the gap length L1 of the gap G1 between the divided body 51 and the protruding portion 21b can be made shorter than when the bobbin 6 is used. This makes it possible to further reduce leakage flux that takes a shortcut. Therefore, it is possible to further reduce the leakage flux that links with the primary winding 3 and the secondary winding 4, making it possible to further reduce eddy current loss.

[0045] The gap between the divided body 53 and the protruding portion 22b (i.e., gap G4) is close to the position where the direction of the magnetic path MP changes, making it easy for leakage flux to take a shortcut. In the transformer 1A, the divided body 53 is fixed directly to the protruding portion 22b by the adhesive layer 8 without using the bobbin 6, so the gap length L4 of the gap G4 between the divided body 53 and the protruding portion 22b can be made shorter than when the bobbin 6 is used. This further reduces leakage flux that takes a shortcut. Therefore, the leakage flux linking with the primary winding 3 and the leakage flux linking with the secondary winding 4 can be further reduced, making it possible to further reduce eddy current loss.

[0046] Although the embodiments of the present disclosure have been described in detail above, the transformer according to the present disclosure is not limited to the above embodiments.

[0047] For example, the transformer 1 may further include an adhesive layer provided between the central leg 21 and the divided body 51, and the divided body 51 may be fixed to the central leg 21 by the adhesive layer. The transformer 1 may further include an adhesive layer provided between the side leg 22 and the divided body 53, and the divided body 53 may be fixed to the side leg 22 by the adhesive layer.

[0048] The transformer 1, 1A may further include an adhesive layer provided between the divided body 51 and the divided body 52, and the divided body 52 may be fixed to the divided body 51 by the adhesive layer. Similarly, the transformer 1, 1A may further include an adhesive layer provided between the divided body 52 and the divided body 53, and the divided body 52 may be fixed to the divided body 53 by the adhesive layer.

[0049] In the transformer 1A, the core 2A does not necessarily have to include either the protruding portion 21b or the protruding portion 22b.

[0050] As long as a desired leakage inductance is obtained, the gap length L1, the gap length L2, the gap length L3, and the gap length L4 may be changed as appropriate.

[0051] In the transformer 1, 1A, the path core 5 may include two divided bodies, or may include four or more divided bodies.

[0052] The path core 5 does not have to be divided into sections S. For example, the path core 5 may have a plate-like shape extending in the left-right direction. In this case, in the transformer 1, the path core 5 is spaced apart from each of the center leg 21 and the side leg 22. The sum of the gap length between the path core 5 and the center leg 21 and the gap length between the path core 5 and the side leg 22 is set to obtain a desired leakage inductance. Similarly, in the transformer 1A, the path core 5 is spaced apart from each of the center leg 21A and the side leg 22A. The sum of the gap length between the path core 5 and the center leg 21A and the gap length between the path core 5 and the side leg 22A is set to obtain a desired leakage inductance. Even with this configuration, compared to the transformer 100, the leakage flux linking with the primary winding 3 and the leakage flux linking with the secondary winding 4 can be reduced, thereby reducing eddy current loss.

[0053] (Addendum) [Article 1] a core having a central leg portion extending in a first direction and side legs extending in the first direction and spaced apart from the central leg portion in a second direction intersecting the first direction; a primary winding wound around the center leg; a secondary winding wound around the central leg and spaced apart from the primary winding in the first direction; a path core that forms a magnetic path of leakage magnetic flux together with the core, the path core extending in the second direction and provided between the primary winding and the secondary winding; Equipped with The path core is arranged so that a plurality of gaps are formed in a section of the magnetic path extending from the center leg through the path core to the side leg.

[0054] [Clause 2] The transformer described in clause 1, wherein the path core includes a plurality of segments spaced apart from each other and arranged in the second direction.

[0055] [Article 3] 3. The transformer of claim 2, wherein the central leg has a first protrusion protruding toward the side leg.

[0056] [Article 4] The transformer described in clause 3 further comprises a first adhesive layer provided between a first division body among the plurality of division bodies that is closest to the central leg and the first convex portion, and fixing the first division body to the first convex portion.

[0057] [Article 5] The transformer according to any one of clauses 2 to 4, wherein the side legs have second protrusions that protrude toward the central leg.

[0058] [Article 6] The transformer described in clause 5 further comprises a second adhesive layer provided between a second division of the plurality of divisions that is closest to the side leg and the second convex portion, and fixing the second division to the second convex portion.

[0059] [Article 7] the plurality of gaps include a first gap closest to the central leg, a second gap closest to the side leg, and a third gap provided between the first gap and the second gap; The transformer according to any one of clauses 1 to 6, wherein the length of the first gap in the second direction and the length of the second gap in the second direction are shorter than the length of the third gap in the second direction. [Explanation of symbols]

[0060] 1...transformer, 2, 2A...core, 3...primary winding, 4...secondary winding, 5...path core, 7...adhesive layer (first adhesive layer), 8...adhesive layer (second adhesive layer), 21, 21A...central leg, 21b...convex portion (first convex portion), 22, 22A...side leg, 22b...convex portion (second convex portion), 51...divided body (first divided body), 52...divided body, 53...divided body (second divided body), G1...gap (first gap), G2...gap (third gap), G3...gap (third gap), G4...gap (second gap).

Claims

1. a core having a central leg portion extending in a first direction and side legs extending in the first direction and spaced apart from the central leg portion in a second direction intersecting the first direction; a primary winding wound around the center leg; a secondary winding spaced apart from the primary winding in the first direction and wound around the central leg; a path core that forms a magnetic path for leakage magnetic flux together with the core, the path core extending in the second direction and being provided between the primary winding and the secondary winding; Equipped with The path core is arranged so that a plurality of gaps are formed in a section of the magnetic path extending from the center leg through the path core to the side leg.

2. The transformer according to claim 1 , wherein the path core includes a plurality of divided bodies spaced apart from each other and arranged in the second direction.

3. The transformer according to claim 2 , wherein the central leg has a first protrusion that protrudes toward the side leg.

4. 4. The transformer according to claim 3, further comprising a first adhesive layer provided between a first division closest to the central leg among the plurality of divisions and the first protrusion, the first adhesive layer fixing the first division to the first protrusion.

5. The transformer according to any one of claims 2 to 4, wherein the side legs have second protrusions that protrude toward the central leg.

6. 6. The transformer according to claim 5, further comprising a second adhesive layer provided between a second division of the plurality of divisions that is closest to the side leg and the second convex portion, the second adhesive layer fixing the second division to the second convex portion.

7. the plurality of gaps include a first gap closest to the central leg, a second gap closest to the side leg, and a third gap provided between the first gap and the second gap; The transformer according to any one of claims 1 to 4, wherein a length of the first gap in the second direction and a length of the second gap in the second direction are shorter than a length of the third gap in the second direction.

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