Magnetic component and power converter using same

Abstract

The present invention provides a magnetic component comprising: a magnetic core (12) with an annular portion surrounding window sections (12a, 12b); one or more windings wound around the annular portion of the magnetic core (12); and a cooling plate (7) which is provided passing through the window sections (12a, 12b) and overlapping the windings, is formed from metal, and cools the windings. The cooling plate (7) has a main section (71), which is the portion overlapping the windings, and a first cooling section (72) and a second cooling section (73) that protrude from the main section (71). Each of the first cooling section (72) and the second cooling section (73) is at least thermally connected to a cooler. The first cooling section (72) and the second cooling section (73) protrude from respective portions of the main section (71) on both sides of the window sections (12a, 12b). A pathway surrounding the magnetic core (12) by way of the main section (71), the first cooling section (72), the cooler, and the second cooling section (73) has at least one insulating section, the pathway being electrically insulated by the insulating section.

Description

Magnetic component and power converter using same

[0001] The present disclosure relates to a magnetic component and a power converter using the same.

[0002] Due to recent environmental regulations and technological advances surrounding automobiles, various classes of electrically powered vehicles, such as electric vehicles and hybrid vehicles, have been developed and are becoming increasingly popular. An electrically powered vehicle using a motor as a drive source is generally equipped with multiple power converters. Power converters equipped in electrically powered vehicles include a charger that converts commercial AC voltage into DC voltage to charge a high-voltage battery, an inverter that converts DC power from the high-voltage battery into AC power for the motor, and a DC-DC converter (SDC) that converts DC voltage from the high-voltage battery into DC voltage (e.g., 12 V) for an auxiliary battery. Converters such as the charger and SDC described above are equipped with magnetic components, such as a transformer and a reactor. From the perspectives of securing vehicle space and cost in electrically powered vehicles, there is a demand for smaller and less expensive magnetic components and power converters.

[0003] A transformer, which is a magnetic component, transmits power from a primary winding to a secondary winding by linking a magnetic flux generated by passing a current through the primary winding with a current loop formed in the secondary winding. A configuration for reducing the size and cost of a transformer has been disclosed (see, for example, Patent Document 1). In the configurations disclosed in Embodiments 1 and 2 of Patent Document 1, a heat dissipation plate having multiple bent portions is attached to the transformer. The winding and the heat dissipation plate are wound around a magnetic core, and the core heat dissipation plate is positioned parallel to and immediately adjacent to the magnetic core. The multiple bent portions are formed by bending portions of the heat dissipation plate. The tip portions of the bent portions are embedded in a potting resin material.

[0004] With this configuration, the heat dissipation plate is positioned in close proximity to the windings, so heat generated in the windings and magnetic core is transferred to the heat dissipation plate. The transferred heat is dissipated into the potting resin material through the bent portions of the heat dissipation plate, allowing the windings and magnetic core to be made smaller. Because the windings and magnetic core are made smaller, raw material costs are reduced, allowing for lower costs for magnetic components.

[0005] In this configuration, if a fixing part is placed at the tip of the bent part and the fixing part is connected to a metal housing, the heat from the heat dissipation plate can be directly transferred to the housing. Because the heat from the heat dissipation plate can be directly transferred to the housing, the heat dissipation characteristics of the transformer can be further improved. The more fixing parts there are, the more heat dissipation paths to the housing there are, so the heat dissipation characteristics of the transformer can be further improved.

[0006] Patent No. 6525360

[0007] The transformer structure of Patent Document 1 includes a heat dissipation plate, which improves the transformer's heat dissipation characteristics. Furthermore, providing a heat dissipation path to the housing further improves the transformer's heat dissipation characteristics. However, in a transformer with this structure, a current loop is formed that passes through the heat dissipation plate and the housing and circulates around the legs of the magnetic core, separate from the secondary winding. This current loop generates magnetic flux within the magnetic core. The generated magnetic flux cancels out the magnetic flux generated by the transformer's primary winding, preventing a portion of the power from the transformer's primary winding from being transmitted to the secondary winding, thereby reducing the transformer's performance. The above-described configuration poses a problem: it is difficult to improve the transformer's heat dissipation characteristics without reducing the transformer's performance.

[0008] Furthermore, the phenomenon in which the current loop that passes through the heat dissipation plate and the housing and circulates around the legs of the magnetic core cancels out the magnetic flux inside the magnetic core also occurs when the magnetic component is a reactor. A reactor is a magnetic component that can have a high L value by passing a current through its windings and generating magnetic flux inside the magnetic core. However, when a current loop is generated that passes through the heat dissipation plate and the housing and circulates around the legs of the magnetic core, this current loop cancels out the magnetic flux inside the magnetic core, just like a transformer, reducing the L value and thereby reducing the reactor's functionality. The above-mentioned configuration poses a problem: it is difficult to improve the reactor's heat dissipation characteristics without reducing the reactor's functionality.

[0009] Therefore, an object of the present disclosure is to obtain a magnetic component having high heat dissipation characteristics without degrading functionality, and a power converter using the same.

[0010] The magnetic component of the present disclosure comprises a magnetic core having an annular portion surrounding a window portion, one or more windings wound around the annular portion of the magnetic core, and a cooling plate that passes through the window portion, overlaps the windings, is made of metal, and cools the windings, the cooling plate having a main body portion that overlaps the windings, and a first cooling portion and a second cooling portion that protrude from the main body portion, each of the first cooling portion and the second cooling portion being at least thermally connected to a cooler, and each of the first cooling portion and the second cooling portion protruding from each of the portions of the main body portion on both sides of the window portion, the path surrounding the magnetic core by the main body portion, first cooling portion, cooler, and second cooling portion having at least one insulating portion, and the path being electrically insulated by the insulating portions.

[0011] According to the magnetic component of the present disclosure, there is provided a magnetic core having an annular portion surrounding a window portion, one or more windings wound around the annular portion of the magnetic core, and a cooling plate that penetrates the window portion, overlaps the windings, is made of metal, and cools the windings, the cooling plate having a main body portion that overlaps the windings, and a first cooling portion and a second cooling portion that protrude from the main body portion, each of the first cooling portion and the second cooling portion being at least thermally connected to a cooler, and each of the first cooling portion and the second cooling portion protruding from each of the portions of the main body portion on both sides of the window portion, the path that surrounds the magnetic core by the main body portion, the first cooling portion, the cooler, and the second cooling portion has at least one insulating portion, and since the path is electrically insulated by the insulating portion, the current flowing in the path and the generation of magnetic flux caused by the current flowing are suppressed, and the magnetic flux generated by the current flowing in the windings is not reduced, so that a magnetic component with high heat dissipation characteristics can be obtained by the cooling plate without degrading the function of the magnetic component, and a power converter using the same.

[0012] 18 is a perspective view showing an outline of a transformer according to embodiment 1. FIG. 19 is an exploded perspective view showing a transformer according to embodiment 1. FIG. 20 is a perspective view showing an outline of a magnetic core of the transformer according to embodiment 1. FIG. 21 is a side view of the magnetic core of the transformer according to embodiment 1. FIG. 22 is an exploded perspective view showing a coil body of the transformer according to embodiment 1. FIG. 23 is a perspective view showing a primary winding of the transformer according to embodiment 1. FIG. 24 is a perspective view showing a secondary winding of the transformer according to embodiment 1. FIG. 25 is a perspective view showing an insulating plate of the transformer according to embodiment 1. FIG. 26 is a perspective view showing another insulating plate of the transformer according to embodiment 1. FIG. 27 is a perspective view showing a primary winding and an insulating plate of the transformer according to embodiment 1. FIG. 28 is a perspective view showing a secondary winding and an insulating plate of the transformer according to embodiment 1. FIG. 29 is a perspective view showing a cooling plate of the transformer according to embodiment 1. FIG. 21 is a perspective view showing an outline of a power converter according to embodiment 1. FIG. 22 is a plan view showing a main part of the power converter according to embodiment 1. FIG. 23 is a cross-sectional view of the power converter cut at the A-A cross section position of FIG. 14. FIG. 24 is a plan view showing a main part of the power converter according to embodiment 1. FIG. 25 is a perspective view showing a cooling plate of a transformer of a comparative example. FIG. 26 is a cross-sectional view of the power converter of the comparative example cut at the B-B cross section position of FIG. 18. Fig. 1 is a side view showing a main part of another transformer according to embodiment 1. Fig. 2 is a plan view showing a cooling plate of a transformer according to embodiment 2. Fig. 3 is a plan view showing a cooling plate of a transformer according to embodiment 3. Fig. 4 is a cross-sectional view showing a main part of the transformer according to embodiment 3. Fig. 5 is a plan view showing a cooling plate of a transformer of a comparative example.

[0013] Hereinafter, magnetic components and power converters according to embodiments of the present disclosure will be described with reference to the drawings. Note that the same or equivalent members and parts in each drawing will be denoted by the same reference numerals.

[0014] 1 is a perspective view showing an outline of a transformer 1 according to embodiment 1, FIG. 2 is an exploded perspective view showing the transformer 1, FIG. 3 is a perspective view showing an outline of a magnetic core 12 of the transformer 1, FIG. 4 is a side view of the magnetic core 12 of the transformer 1 as viewed in the Y direction, FIG. 5 is an exploded perspective view showing a coil body 2 of the transformer 1, FIG. 6 is a perspective view showing a primary winding 3 of the transformer 1, FIG. 7 is a perspective view showing a secondary winding 5 of the transformer 1, FIG. 8 is a perspective view showing an insulating plate 4 of the transformer 1, FIG. 9 is a perspective view showing an insulating plate 6 of the transformer 1, and FIG. 10 is a perspective view showing the primary winding 3 of the transformer 1 and the insulating plate FIG. 11 is a perspective view showing the secondary winding 5 and insulating plate 6 of the transformer 1. FIG. 12 is a perspective view showing the cooling plate 7 of the transformer 1. FIG. 13 is a perspective view showing a schematic of a power converter 200. FIG. 14 is a plan view showing a main part of the power converter 200 shown in FIG. 13, showing the transformer 1 and its surroundings. FIG. 15 is a cross-sectional view of the power converter 200 taken along the A-A cross section in FIG. 14, showing only the magnetic core 12. FIG. 16 is a plan view showing a main part of the power converter 200 shown in FIG. 13, showing the cooling plate 7 and its surroundings. The power converter 200 is, for example, a step-down DC-DC converter that converts the DC voltage of a DC power source into a secondary-side DC voltage insulated by the transformer 1 and outputs the DC voltage to a load such as a battery. The power converter 200 is not limited to a step-down converter, and may be another power converter such as a step-up converter.

[0015] <Configuration of Power Converter 200> An outline of an example configuration of the power converter 200 will be described. The power converter 200 is connected to a DC power supply on the input side and to a load such as a low-voltage battery on the output side. The power converter 200 includes an input capacitor that smoothes the input voltage of the inverter circuit, an inverter circuit having a power semiconductor and converting the input DC voltage to an AC voltage and supplying it to a primary winding 3, a transformer 1 having a primary winding 3 and a secondary winding 5 that converts the voltage of the AC power output from the inverter circuit and outputs it, a rectifier circuit that rectifies the AC voltage output from the secondary winding 5, and a smoothing capacitor and a reactor that smooth the output of the rectifier circuit. The transformer 1 and the reactor are magnetic components.

[0016] As shown in Fig. 13, the power converter 200 includes a housing 9 that houses components such as a transformer 1 and serves as a cooler for cooling the components. Fig. 13 shows only the transformer 1 and the housing 9 as components of the power converter 200, and the other components are omitted for simplicity of explanation. The housing 9 is made of a metal such as aluminum. The housing 9 may have a refrigerant flow path through which a refrigerant such as water flows.

[0017] <Transformer 1> The transformer 1, which is a magnetic component, will be described with reference to FIGS. 1 to 12. As shown in FIG. 2, the transformer 1 includes a magnetic core 12 having an annular portion surrounding windows 12a and 12b, one or more windings (not shown in FIG. 2) wound around the annular portion of the magnetic core 12, and a metal cooling plate 7 that passes through the windows 12a and 12b, overlaps the windings, and cools the windings. A closed magnetic circuit (described later) is formed in the annular portion of the magnetic core 12. In this embodiment, as shown in FIG. 5, the transformer 1 has multiple windings, and a coil body 2 having multiple windings, namely a primary winding 3 and a secondary winding 5, is formed. Details of each component constituting the transformer 1 will be described below.

[0018] First, the magnetic core 12 will be described. As shown in FIG. 3 , the magnetic core 12 includes an I-shaped core 10 and an E-shaped core 11. The magnetic core 12 is formed of a magnetic material such as ferrite. The magnetic core 12 includes a center leg 11a around which a winding is wound and which extends in the direction of the winding center axis of the winding; outer legs 11b and 11c that are not wound with a winding and are spaced apart from the center leg 11a; and beam portions 10a and 11d that connect the center leg 11a and the outer legs 11b and 11c across the winding. The coil body 2 is disposed so as to surround the center leg 11a of the E-shaped core 11. In this embodiment, the center leg 11a and the outer legs 11b and 11c are formed in a rectangular parallelepiped shape. The shapes of the center leg 11a and the outer legs 11b and 11c are not limited thereto and may be, for example, cylindrical.

[0019] By abutting the center leg 11a and outer legs 11b and 11c of the E-shaped core 11 against the I-shaped core 10, a magnetic core 12 having two annular portions is formed, as shown in FIG. 4 . One annular portion is formed by the center leg 11a, beam portion 10a, outer leg portion 11b, and beam portion 11d, and the other annular portion is formed by the center leg 11a, beam portion 10a, outer leg portion 11c, and beam portion 11d. A winding is wound around the center leg 11a, which constitutes the annular portion. Closed magnetic circuits 101 and 102 are provided in each annular portion. The closed magnetic circuits 101 and 102 are indicated by dashed lines in FIG. 4 . In this embodiment, the magnetic core 12 has two outer legs 11b and 11c, and therefore has two closed magnetic circuits 101 and 102. The configuration of the magnetic core 12 is not limited to this, and the magnetic core 12 may have one outer leg and one closed magnetic circuit. In this embodiment, the magnetic core 12 is composed of the I-shaped core 10 and the E-shaped core 11, but this is not limiting. The magnetic core 12 may be composed of two E-shaped cores 11, and the center leg and outer leg of each of the two E-shaped cores 11 may be butted together to form the magnetic core 12.

[0020] As shown in FIG. 2 , the center leg 11a is passed through the central hole 2a provided in the center of the coil body 2, and then the I-shaped core 10 and the E-shaped core 11 are brought into contact with each other to form the transformer 1. Then, adhesive tape 13 is wound around the magnetic core 12 in the longitudinal direction, thereby fixing the I-shaped core 10 to the E-shaped core 11, as shown in FIG. 1 . Here, directions are defined. The direction of the winding center axis extending from the center leg 11a is the Z-direction. The short side direction of the center leg 11a, which is perpendicular to the Z-direction and extends from the center leg 11a to the outer leg 11c, is the X-direction. The longitudinal direction of the center leg 11a, which is perpendicular to the Z-direction and the X-direction, is the Y-direction. In each figure, the direction indicated by each arrow is one side, and the opposite direction is the other side. The first outer leg 11b is disposed on the other side of the middle leg 11a in the X direction, and the second outer leg 11c is disposed on one side of the middle leg 11a in the X direction.

[0021] 4 is a view of the magnetic core 12 viewed from the other side in the Y direction. Closed magnetic circuits 101 and 102 are paths through which magnetic flux flows within the magnetic core 12. The closed magnetic circuit 101 is a path through which magnetic flux flows from the center leg 11 a to the outer leg 11 b, and the closed magnetic circuit 102 is a path through which magnetic flux flows from the center leg 11 a to the outer leg 11 c. The closed magnetic circuit 101 is formed to surround the window 12 a, and the closed magnetic circuit 102 is formed to surround the window 12 b.

[0022] 13 , the housing 9 has a cooling surface 9a to which the magnetic core 12 is thermally connected. In this embodiment, for example, thermally conductive grease is applied to the other surface of the E-shaped core 11 in the Z direction, and the E-shaped core 11 is thermally connected to the cooling surface 9a. When the grease solidifies, the transformer 1 is fixed to the housing 9.

[0023] Next, the coil body 2 will be described. As shown in FIG. 5 , the coil body 2 includes a cooling plate 7, a secondary winding 5, an insulating plate 6, a primary winding 3, and an insulating plate 4 stacked in this order from one side in the Z direction. The cooling plate 7 is integrated by being partially exposed and then covered with a molding resin 8 shown in the upper part of FIG. 5 . A gap is provided between the cooling plate 7 and the secondary winding 5, and this gap is filled with the molding resin 8. The molding resin 8 is an insulating resin material such as epoxy resin. In this embodiment, as shown in FIG. 2 , the cooling plate 7 is partially exposed, but this is not limiting. The cooling plate 7 may be entirely covered with the molding resin 8. Even when the cooling plate 7 is entirely covered with the molding resin 8, the effects of the present disclosure, described below, can be similarly obtained. When the cooling plate 7 is partially exposed, the heat dissipation characteristics of the cooling plate 7 can be improved.

[0024] As shown in FIG. 5 , the primary winding 3 and the secondary winding 5 have through holes surrounding the center leg 11 a. The primary winding 3 has a central hole 3 a as a through hole, and the secondary winding 5 has a central hole 5 a as a through hole. The windings are formed in a curved plate shape on a plane and wound around the magnetic core 12 in a circular or spiral shape. In this embodiment, both the primary winding 3 and the secondary winding 5 are spirally formed and wound multiple times around the magnetic core 12. Each winding is formed by punching a sheet metal such as copper or aluminum using a press die or the like so as to have a predetermined number of turns and winding width. The cross section of each winding is rectangular. As shown in FIGS. 6 and 7 , a gap is provided between adjacent windings in the XY plane, forming a spiral shape.

[0025] The shape of the windings is not limited to a plate shape, and the windings may be round wire or other shapes. By forming the windings in a plate shape, unlike when the windings are round wire or other shapes, it is possible to increase the mutual facing surfaces between the primary winding 3 and the secondary winding 5 via the insulating plate 6, and between the secondary winding 5 and the cooling plate 7. Because the mutual facing surfaces between the respective windings and between the secondary winding 5 and the cooling plate 7 are increased, the thermal resistance between them is reduced, and the cooling effect of each winding can be improved. Because the cooling effect of each winding is improved, the transformer 1 and the power converter 200 can be made smaller and less expensive.

[0026] In this embodiment, both the primary winding 3 and the secondary winding 5 are spirally wound, but this is not limiting. Either or both of the primary winding 3 and the secondary winding 5 may be formed in an annular shape with a predetermined winding width per turn and wound around the magnetic core 12. Even when either or both of the primary winding 3 and the secondary winding 5 are annular, the effects of the present disclosure, which will be described later, can be similarly obtained.

[0027] As shown in FIG. 6, the primary winding 3 has a terminal 3b at its inner end and a terminal 3c at its outer end. As shown in FIG. 7, the secondary winding 5 has a terminal 5b at its inner end and a terminal 5c at its outer end. The terminals 3b, 3c and 5b, 5c are formed by bending the ends of the primary winding 3 and the secondary winding 5 at right angles. The terminals 3b, 3c and 5b, 5c protrude from the molded resin 8 as shown in FIG. 2. The terminals 3b, 3c are connected to an inverter circuit. The terminals 5b, 5c are connected to a rectifier circuit.

[0028] In this embodiment, the primary winding 3 has eight turns and the secondary winding 5 has six turns, but the number of turns of each winding is not limited to this. In this embodiment, the power converter 200 is a step-down DC-DC converter. Therefore, the transformer 1 is configured as a step-down transformer in which the secondary winding 5 has fewer turns than the primary winding 3. In this embodiment, one primary winding 3 and one secondary winding 5 are provided, but the number of primary windings 3 and one secondary winding 5 is not limited to this. The primary winding 3 and the secondary winding 5 may be configured by providing multiple primary windings 3 and multiple secondary windings 5 ​​and connecting the multiple windings on the inner or outer circumferential side.

[0029] In this embodiment, the transformer 1 having multiple windings, i.e., the primary winding 3 and the secondary winding 5, is shown as a magnetic component, but the magnetic component is not limited to this. A reactor having a single winding may also be a magnetic component. For example, by removing the secondary winding 5, the transformer 1 can be used as a reactor.

[0030] As shown in FIG. 5 , the insulating plates 4 and 6 have through holes surrounding the center leg portion 11 a. The insulating plate 4 has a central hole 4 a as a through hole, and the insulating plate 6 has a central hole 6 a as a through hole. The insulating plates 4 and 6 are molded into a plate shape using an insulating resin material such as epoxy resin. As shown in FIG. 8 , the insulating plate 4 has a first groove 4 b for positioning the primary winding 3. As shown in FIG. 9 , the insulating plate 6 has a second groove 6 b for positioning the secondary winding 5. As shown in FIG. 10 , when forming the coil body 2, the primary winding 3 is fitted into the first groove 4 b. As shown in FIG. 11 , when forming the coil body 2, the secondary winding 5 is fitted into the second groove 6 b.

[0031] As shown in Fig. 12 , the cooling plate 7 has a main body 71 that overlaps the winding, and a first cooling portion 72 and a second cooling portion 73 that protrude from the main body 71. As shown in Fig. 14 , the first cooling portion 72 and the second cooling portion 73 are each at least thermally connected to a housing 9 that serves as a cooler. In this embodiment, as shown in Fig. 12 , the first cooling portion 72 has a first fixing portion 72a that is a portion of the first cooling portion 72 fixed to the housing 9, an extension portion 72b that is a portion extending toward the housing 9, and a bent portion 72c that causes the extension portion 72b to extend toward the housing 9. Similarly, the second cooling portion 73 has a second fixing portion 73a that is a portion of the second cooling portion 73 fixed to the housing 9, an extension portion 73b that is a portion extending toward the housing 9, and a bent portion 73c that causes the extension portion 73b to extend toward the housing 9. The bent portion 72 c and the bent portion 73 c are exposed from the molding resin 8 .

[0032] The main body 71 overlapping the winding is thermally connected to the winding. The first fixing portion 72a is fixed to the cooling surface 9a, and the second fixing portion 73a is fixed to the cooling surface 9a. The first fixing portion 72a and the second fixing portion 73a are fixed to the cooling surface 9a by, for example, screw fastening. With this configuration, heat generated in the winding can be transferred to the housing 9 via the cooling plate 7, thereby improving the heat dissipation characteristics of the transformer 1.

[0033] The cooling plate 7 is made of a metal such as aluminum or copper. A central hole 7a is provided in the center of the main body 71, which is a through-hole surrounding the middle leg 11a. The main body 71 is a portion indicated by a dashed rectangle having four vertices 71a, 71b, 71c, and 71d. The main body 71 is formed in a plate shape parallel to the XY plane. A line segment 712 connecting the vertices 71b and 71c and a line segment 714 connecting the vertices 71a and 71d are parallel to the Y direction and face each other outside the window portions 12a and 12b of the magnetic core 12. The line segment 714 is located on the outer leg 11b side as viewed from the middle leg 11a, and the line segment 712 is located on the outer leg 11c side as viewed from the middle leg 11a. A line segment 711 connecting the vertices 71a and 71b and a line segment 713 connecting the vertices 71c and 71d are parallel to the X direction and face each other with the windows 12a and 12b of the magnetic core 12 interposed therebetween.

[0034] In this embodiment, the main body 71 of the cooling plate 7 has cuts 71e and 71f arranged parallel to the X direction. Cut 71e divides the portion of the main body 71 between the middle leg 11a and the outer leg 11b in the Y direction. Cut 71f divides the portion of the main body 71 between the middle leg 11a and the outer leg 11c in the Y direction. When viewed in the Z direction, cut 71e is positioned to overlap with the window 12a, and cut 71f is positioned to overlap with the window 12b.

[0035] When a current flows through the primary winding 3 or the secondary winding 5, a magnetic field is generated inside the magnetic core 12, and magnetic flux interlinks with the central hole 7a of the cooling plate 7, generating an induced current that circulates around the middle leg 11a in the main body 71 of the cooling plate 7. Providing at least one of the cutouts 71e and 71f can prevent induced current, or a so-called one-turn short. In this embodiment, both the cutouts 71e and 71f are provided because they are provided as insulating portions, which will be described later.

[0036] In this embodiment, as described above, the magnetic core 12 is thermally connected to the cooling surface 9a, and the first and second cooling units 72 and 73 each have a portion extending toward the cooling surface 9a, and the first and second cooling units 72 and 73 are thermally connected to the cooling surface 9a. With this configuration, the first and second cooling units 72 and 73 are disposed adjacent to the magnetic core 12 that is thermally connected to the cooling surface 9a, thereby enabling the miniaturization of the transformer 1. Furthermore, the heat dissipation path by the first and second cooling units 72 and 73 is shortened, thereby improving the heat dissipation characteristics of the transformer 1.

[0037] <Comparative Example> Prior to describing the arrangement of the first cooling section 72 and the second cooling section 73 and the insulating section, which are essential components of this disclosure, a comparative example will be described using FIGS. 17 to 19 . FIG. 17 is a perspective view showing the cooling plate 20 of a comparative example transformer 1a. FIG. 18 is a plan view showing an outline of a comparative example power converter 200a, illustrating the magnetic core 12, the cooling plate 20, and their surroundings. FIG. 19 is a cross-sectional view of the comparative example power converter 200a taken along the B-B cross section (a cross section parallel to the X direction) of FIG. 18, illustrating only the magnetic core 12. The comparative example transformer 1a has the cooling plate 7 of the transformer 1 replaced with the cooling plate 20. Because the configuration other than the cooling plate 20 is the same as that of the transformer 1, the same reference numerals are used for the other components. The magnetic flux distribution within the magnetic core 12 of the comparative example transformer 1a during operation will now be described.

[0038] First, the cooling plate 20 will be described. As shown in FIG. 17 , the cooling plate 20 has a main body 21, which is a portion overlapping the winding, and a first cooling portion 22 and a second cooling portion 23 protruding from the main body 21. As shown in FIG. 18 , the first cooling portion 22 and the second cooling portion 23 are each thermally connected to the housing 9. In the comparative example, as shown in FIG. 17 , the first cooling portion 22 has a first fixing portion 22a, which is a portion of the first cooling portion 22 fixed to the housing 9, an extension portion 22b, which is a portion extending toward the housing 9, and a bent portion 22c, which causes the extension portion 22b to extend toward the housing 9. Similarly, the second cooling portion 23 has a second fixing portion 23a, which is a portion of the second cooling portion 23 fixed to the housing 9, an extension portion 23b, which is a portion extending toward the housing 9, and a bent portion 23c, which causes the extension portion 22b to extend toward the housing 9.

[0039] The cooling plate 20 is made of a metal such as aluminum or copper. A central hole 20a is provided in the center of the main body 71, which is a through-hole surrounding the middle leg 11a. The main body 21 is a portion indicated by a dashed rectangle having four vertices 21a, 21b, 21c, and 21d. The main body 21 is formed in a plate shape parallel to the XY plane. A line segment 212 connecting vertices 21b and 21c and a line segment 214 connecting vertices 21a and 21d are parallel to the Y direction and face each other outside the window portions 12a and 12b of the magnetic core 12. The line segment 214 is located on the outer leg 11b side as viewed from the middle leg 11a, and the line segment 212 is located on the outer leg 11c side as viewed from the middle leg 11a. Furthermore, line segment 211 connecting vertices 21a and 21b and line segment 213 connecting vertices 21c and 21d are parallel to the X direction and face each other across windows 12a and 12b of magnetic core 12. To prevent an induced current circulating around center leg 11a from occurring in main body 21, cutout 21e is formed in main body 21. In the comparative example, cutout 21e is parallel to the Y direction and is provided at a position overlapping midpoint 211a of line segment 211.

[0040] The magnetic flux distribution within the magnetic core 12 when current flows through the primary winding 3 of the transformer 1a will be described. The magnetic flux when current flows from terminal 3b to terminal 3c of the primary winding 3 is shown in Figure 19 by dashed arrows superimposed on the closed magnetic circuits 101 and 102. A counterclockwise magnetic flux 31 is generated in the closed magnetic circuit 101, and a clockwise magnetic flux 32 is generated in the closed magnetic circuit 102. At this time, as shown in Figure 18, a current loop 90a is formed in a path that surrounds the outer leg 11b of the magnetic core 12 by the main body 21, first cooling unit 22, housing 9, and second cooling unit 23. In Figure 18, the outer leg 11b is indicated by hatching. Because the magnetic flux 31 passing through the center leg 11a interlinks with this current loop 90a, according to Lenz's law, a counterclockwise current flows through the current loop 90a when viewed from the Z direction. 19, a magnetic flux 33 is generated in the closed magnetic circuit 101 of the magnetic core 12. Note that a portion of the magnetic flux 33 interlinks with the outer leg 11c, but this is omitted for simplicity of explanation.

[0041] 19, part of the magnetic flux 31 generated by the current flowing through the primary winding 3 is canceled out by the magnetic flux 33 generated by the current loop 90a, and therefore the magnetic flux linking the secondary winding 5 is reduced, and therefore part of the power of the primary winding 3 is not transmitted to the secondary winding 5. That is, in the transformer 1a shown in the comparative example, similar to the description of the problem in Patent Document 1, if a cooling plate 20 is provided to improve the heat dissipation characteristics of the transformer 1a, the magnetic flux 31 generated by the current flowing through the primary winding 3 is reduced, and part of the power of the primary winding 3 is not transmitted to the secondary winding 5, and therefore the function of the transformer 1a is reduced.

[0042] <Arrangement of First Cooling Unit 72 and Second Cooling Unit 73 and Insulating Unit> The arrangement and insulating unit of the first cooling unit 72 and the second cooling unit 73, which are essential parts of the present disclosure, will be described. As shown in FIG. 12 , the first cooling unit 72 and the second cooling unit 73 each protrude from a portion of the main body 71 on both sides of the window portions 12a and 12b. In this embodiment, the first cooling unit 72 and the second cooling unit 73 face each other in the Y direction, and the first cooling unit 72 and the second cooling unit 73 protrude from a portion of the main body 71 on the other side in the X direction. The first cooling unit 72 is provided on the side of the vertex 71a of the main body 71, and the second cooling unit 73 is provided on the side of the vertex 71d of the main body 71. The path surrounding the magnetic core 12 by the main body 71, the first cooling unit 72, the housing 9, and the second cooling unit 73 has at least one insulating unit, and the path is electrically insulated by the insulating unit. In this embodiment, the insulating portions are cut portions 71 e and 71 f of the main body portion 71, which cut between the main body portion 71 on both sides of the window portions 12 a and 12 b. In this embodiment, the portion of the magnetic core 12 that is surrounded by the path is the outer leg portion 11 b.

[0043] The distribution of magnetic flux within the magnetic core 12 when current flows from terminal 3b to terminal 3c of the primary winding 3 shown in Figure 6 is described below. The magnetic flux when current flows is shown in Figure 15 by dashed arrows superimposed on the closed magnetic circuits 101 and 102. Current flowing through the primary winding 3 generates magnetic flux flowing from the center leg 11a to the outer legs 11b and 11c. A counterclockwise magnetic flux 14 is generated in the closed magnetic circuit 101, and a clockwise magnetic flux 15 is generated in the closed magnetic circuit 102. At this time, as shown in Figure 16, if the cutoff portions 71e and 71f were not present, a current loop 90 would be formed in the path surrounding the magnetic core 12 by the main body 21, first cooling portion 22, housing 9, and second cooling portion 23. However, because the cutoff portions 71e and 71f are provided, the current loop 90 is cut off, and therefore no current loop 90 is formed. Since the current loop 90 is not formed, unlike the transformer 1a of the comparative example, the current flowing through the current loop 90a of the comparative example and the generation of the magnetic flux 33 due to the current loop 90a can be prevented.

[0044] Because the generation of magnetic flux 33 caused by the current loop 90a is suppressed, the magnetic flux 14 generated by the current flowing through the primary winding 3 does not decrease, and therefore the power of the primary winding 3 can be transmitted to the secondary winding 5 without loss of power. Unlike the comparative example transformer 1a, the transformer 1 can transmit the power of the primary winding 3 to the secondary winding 5 without loss, even when a cooling plate 7 is provided to improve heat dissipation characteristics. Because the power of the primary winding 3 can be transmitted to the secondary winding 5 without loss, the transformer 1 and the power converter 200 using the same can be obtained, with high heat dissipation characteristics, without degrading the functionality of the transformer 1. Because the transformer 1 has high heat dissipation characteristics, the transformer 1 can be miniaturized. Because the transformer 1 is miniaturized, the cost of the transformer 1 can be reduced.

[0045] In this embodiment, the cutouts 71e and 71f are provided as the insulating portions. However, the configuration of the insulating portions is not limited to this. When the cutouts 71e and 71f are provided as the insulating portions, the insulating portions can be provided in the main body 71, eliminating the need for additional insulating portions, thereby reducing the cost of the transformer 1. Furthermore, the insulating portions can be formed simultaneously with the manufacture of the cooling plate 7, thereby improving the productivity of the transformer 1.

[0046] Even when the secondary winding 5 is removed and the transformer 1 is used as a reactor, it is possible to prevent a decrease in the magnetic flux generated in the magnetic core 12 due to the current flowing through the primary winding 3, just like the transformer 1. Since the decrease in the magnetic flux generated in the magnetic core 12 can be prevented, a decrease in the L value of the reactor can be prevented. Therefore, a reactor with high heat dissipation characteristics can be obtained without degrading the reactor's functionality.

[0047] In the present embodiment, the first cooling section 72 and the second cooling section 73 face each other in the Y direction and protrude from the other side of the main body section 71 in the X direction, but the arrangement of the first cooling section 72 and the second cooling section 73 is not limited to this. The arrangement of the first cooling section 72 and the second cooling section 73 in the present embodiment is such that they cut off the current loop formed around the outer leg section 11 b. The first cooling section 72 and the second cooling section 73 may be arranged on one side and the other side of the main body section 71 in the Y direction, respectively, and cut off the current loop formed around the beam section 11 d.

[0048] <Modification> A modification of the transformer 1, which is provided with insulating parts different from the disconnecting parts 71e and 71f of the transformer 1 shown previously, will be described with reference to Fig. 20. Fig. 20 is a side view showing a main part of another transformer 1 according to embodiment 1, showing the first cooling part 72 and its surroundings from the other side in the X direction. In this modification, the insulating part is a heat dissipation member 16 made of an insulating material provided between the housing 9 and one or both of a first fixing part 72a, which is the part of the first cooling part 72 fixed to the housing 9, and a second fixing part 73a, which is the part of the second cooling part 73 fixed to the housing 9.

[0049] The heat dissipation member 16 is a heat-conductive sheet such as a silicone rubber sheet or a urethane rubber sheet. Even if the heat dissipation member 16 is made of an insulating material without providing the cutting portions 71e and 71f, the current loop formed around the magnetic core 12 can be cut. Because the insulating portion is the heat dissipation member 16, the thermal resistance between the cooling plate 7 and the housing 9 is reduced, thereby further suppressing the temperature rise of the winding. While FIG. 20 shows an example in which the heat dissipation member 16 is provided between the first fixing portion 72a and the housing 9, this is not limiting. The heat dissipation member 16 may also be provided between the second fixing portion 73a and the housing 9. Alternatively, the heat dissipation member 16 may be provided only between the second fixing portion 73a and the housing 9.

[0050] When the current loop is cut by the heat dissipation member 16 made of insulating material instead of by the cutting portion, there is no need to provide the cutting portions 71e and 71f in the main body portion 71, and therefore the area of ​​the main body portion 71 is enlarged, thereby improving the heat dissipation characteristics of the transformer 1 by the cooling plate 7. Details of the improvement in the heat dissipation characteristics of the transformer 1 will be described below.

[0051] The magnetic core 12 of the transformer 1 generates heat due to iron loss during operation. Therefore, in a transformer 1 having the cutoff portions 71e and 71f, the portions of the primary winding 3 and secondary winding 5 that overlap with the cutoff portions 71e and 71f, as viewed from the Z direction, are affected by the heat generated by the magnetic core 12 via the cutoff portions 71e and 71f, resulting in a rise in temperature. Furthermore, the portions where the cutoff portions 71e and 71f are located do not have a cooling plate 7 with excellent heat dissipation properties as viewed from the Z direction, and therefore the primary winding 3 and secondary winding 5 cannot be cooled by the cooling plate 7, further increasing the temperatures of the primary winding 3 and secondary winding 5. On the other hand, in a configuration in which the current loop is cut by the heat dissipation member 16, the cutoff portions 71e and 71f are not provided. Therefore, in the configuration in which the current loop is cut by the heat dissipation member 16, when viewed from the Z direction, the primary winding 3 and secondary winding 5 do not face the magnetic core 12, and since the cooling plate 7 is arranged between the primary winding 3 and secondary winding 5 and the magnetic core 12, the primary winding 3 and secondary winding 5 are cooled by the cooling plate 7, thereby improving the heat dissipation characteristics of the transformer 1.

[0052] As described above, the transformer 1 according to the first embodiment includes the magnetic core 12 having an annular portion surrounding the window portions 12a and 12b, one or more windings wound around the annular portion of the magnetic core 12, and the cooling plate 7 made of metal that passes through the window portions 12a and 12b and overlaps the windings to cool the windings. The cooling plate 7 has a main body portion 71 that overlaps the windings, and a first cooling portion 72 and a second cooling portion 73 that protrude from the main body portion 71. Each of the first cooling portion 72 and the second cooling portion 73 is at least thermally connected to the housing 9. Each of the cooling plates 7 protrudes from the portions of the main body 71 on both sides of the windows 12a, 12b, and the path surrounding the magnetic core 12 by the main body 71, the first cooling section 72, the housing 9, and the second cooling section 73 has at least one insulating section, and because the path is electrically insulated by the insulating section, the current flowing through the path and the generation of magnetic flux caused by the current are suppressed, and the magnetic flux generated by the current flowing through the winding is not reduced. Therefore, the cooling plate 7 allows for a transformer 1 with high heat dissipation characteristics and a power converter 200 using the same to be obtained without degrading the functionality of the transformer 1. Because the transformer 1 has high heat dissipation characteristics, it can be made smaller. Because the transformer 1 can be made smaller, it can be made less expensive.

[0053] When the insulating portions are cut portions 71e and 71f of the main body 71, which are formed by cutting between the main body 71 on both sides of the windows 12a and 12b, the insulating portions can be provided in the main body 71, eliminating the need for additional insulating portions and reducing the cost of the transformer 1. Furthermore, the insulating portions can be formed simultaneously with the manufacture of the cooling plate 7, thereby improving the productivity of the transformer 1.

[0054] When the insulating portion is a heat dissipation member 16 made of an insulating material provided between the housing 9 and one or both of the first fixing portion 72a, which is the portion of the first cooling portion 72 fixed to the housing 9, and the second fixing portion 73a, which is the portion of the second cooling portion 73 fixed to the housing 9, there is no need to provide cutting portions 71e, 71f in the main body portion 71, and therefore the area of ​​the main body portion 71 is enlarged, thereby improving the heat dissipation characteristics of the transformer 1 by the cooling plate 7.

[0055] When the windings are formed into a curved plate shape on a plane and wound around the magnetic core 12 in a ring or spiral shape, forming the windings into a plate shape makes it possible to increase the mutual facing surfaces between the primary winding 3 and secondary winding 5 via the insulating plate 6, and between the secondary winding 5 and cooling plate 7, unlike when the windings are round wires or the like. Because the mutual facing surfaces between the respective windings and between the secondary winding 5 and cooling plate 7 increase, the thermal resistance between them decreases, thereby improving the cooling effect of each winding. Because the cooling effect of each winding is improved, the transformer 1 and the power converter 200 can be made smaller and less expensive.

[0056] The power converter 200 according to the first embodiment includes the magnetic components described above and a housing 9 that is a cooler having a cooling surface 9a to which the magnetic core 12 is thermally connected, and the first cooling unit 72 and the second cooling unit 73 each have a portion that extends toward the cooling surface 9a. Because the first cooling unit 72 and the second cooling unit 73 are thermally connected to the cooling surface 9a, the first cooling unit 72 and the second cooling unit 73 are disposed adjacent to the magnetic core 12 that is thermally connected to the cooling surface 9a, thereby enabling a reduction in the size of the transformer 1. Furthermore, because the heat dissipation path by the first cooling unit 72 and the second cooling unit 73 is shortened, the heat dissipation characteristics of the transformer 1 can be improved.

[0057] Second Embodiment A transformer 1 according to a second embodiment will now be described. Fig. 21 is a plan view showing a cooling plate 40 of the transformer 1 according to the second embodiment. The transformer 1 according to the second embodiment is configured with a cooling plate 40 instead of the cooling plate 7 shown in Fig. 12 of the first embodiment.

[0058] The cooling plate 40 of this embodiment will be described. In FIG. 21 , the window portions 12a and 12b are provided at the positions indicated by the dashed lines. The main body portion 71 is provided at the window portions 12a and 12b and on both sides of the window portions 12a and 12b. Both the first cooling portion 72 and the second cooling portion 73 protrude from the portion of the main body portion 71 on one side of the window portions 12a and 12b, and do not protrude to the main body portion 71 on the other side of the window portions 12a and 12b. In the cooling plate 7 shown in Embodiment 1, the second cooling portion 73 is provided on one side of the first cooling portion 72 in the Y direction, sandwiching the window portions 12a and 12b. However, in the cooling plate 40, the second cooling portion 73 is provided on the vertex 71b side of the main body portion 71, which is not sandwiched between the window portions 12a and 12b and the first cooling portion 72. Furthermore, the cutting portion 71e provided in the cooling plate 7 is not provided in the cooling plate 40. The cut portion 71f is provided to prevent a one-turn short circuit.

[0059] With this configuration, a current loop is not formed in the path surrounding the magnetic core 12 by the main body 71, the first cooling unit 22, the housing 9, and the second cooling unit 23, preventing the generation of magnetic flux 33 due to the current loop. Since the generation of magnetic flux due to the current loop is suppressed, the magnetic flux 14 generated by the current flowing through the primary winding 3 is not reduced, and the power of the primary winding 3 can be transmitted to the secondary winding 5 without loss of power. Even if the transformer 1 is provided with a cooling plate 40 to improve heat dissipation characteristics, the power of the primary winding 3 can be transmitted to the secondary winding 5 without loss of power. Because the power of the primary winding 3 can be transmitted to the secondary winding 5 without loss of power, the transformer 1 and the power converter 200 using the same can be obtained, with high heat dissipation characteristics, without degrading the functionality of the transformer 1.

[0060] Furthermore, unlike the cooling plate 7, the cooling plate 40 does not require the cut portion 71e. Therefore, the area of ​​the main body portion 71 of the cooling plate 40 does not decrease due to the formation of the cut portion 71e, and therefore the deterioration of the heat dissipation characteristics of the transformer 1 can be suppressed. Since the deterioration of the heat dissipation characteristics of the transformer 1 is suppressed, the components constituting the transformer 1 can be made smaller. Furthermore, the cooling plate 40 does not require the heat dissipation member 16 provided between the housing 9 and one or both of the first fixing portion 72a of the first cooling portion 72 and the second fixing portion 73a of the second cooling portion 73, and therefore the cost of the transformer 1 can be reduced.

[0061] Third Embodiment A transformer 1 according to a third embodiment will now be described. Fig. 22 is a plan view showing a cooling plate 50 of the transformer 1 according to the third embodiment, in which the outline of the secondary winding 5 placed on the cooling plate 50 is indicated by a dashed line, and Fig. 23 is a cross-sectional view showing the main part of the transformer 1, in which the coil body 2 is viewed in the X direction. The transformer 1 according to the third embodiment is configured with a cooling plate 50 instead of the cooling plate 7 shown in Fig. 12 of the first embodiment.

[0062] 22 , the portion of main body 71 separated by cuts 71e and 71f on the other side in the Y direction is designated as cut 71g, and the portion of main body 71 separated by cuts 71e and 71f on one side in the Y direction is designated as cut 71h. The outline of main body 71 is indicated by a dashed line. In this embodiment, cut 71e passes through the midpoint of line segment 714 and is parallel to the X direction, while cut 71f passes through the midpoint of line segment 712 and is parallel to the X direction. While only the outline of secondary winding 5 is shown in FIG. 22 , the outline of primary winding 3 and the outline of secondary winding 5 coincide when viewed in the Z direction.

[0063] In the path surrounding the magnetic core 12 by the main body 71, the first cooling unit 72, the housing 9, and the second cooling unit 73, the length from the cutoff portion 71e to the first fixed portion 72a, which is the portion of the first cooling unit 72 fixed to the housing 9, is equivalent to the length from the cutoff portion 71e to the second fixed portion 73a, which is the portion of the second cooling unit 73 fixed to the housing 9. Similarly, the length from the cutoff portion 71f to the first fixed portion 72a of the first cooling unit 72 is equivalent to the length from the cutoff portion 71f to the second fixed portion 73a of the second cooling unit 73. "Equivalent" means that the design lengths are the same, and the difference in length is within the tolerance range, within the range of manufacturing error.

[0064] Before describing the effects of the configuration shown in FIG. 22 , a comparative example will be described using FIG. 24 . FIG. 24 is a plan view showing cooling plate 60 of a transformer of the comparative example. Cooling plate 60 is configured by moving both cut portions 71e and 71f of cooling plate 50 the same distance to the other side in the Y direction, and the cut portions after movement are designated as cut portions 71i and 71j. The portion of main body 71 divided by cut portions 71i and 71j on the other side in the Y direction is designated as divided portion 71k, and the portion of main body 71 on one side in the Y direction is designated as divided portion 71l. The outline of main body 71 is indicated by a dashed line. For ease of explanation, the reference numerals for components other than the cut portions and divided portions are the same in FIGS. 22 and 24 .

[0065] In the comparative example, the length from the cut portion 71i to the first fixed portion 72a of the first cooling portion 72 is not equal to the length from the cut portion 71i to the second fixed portion 73a of the second cooling portion 73, and the length from the cut portion 71i to the first fixed portion 72a is shorter. Similarly, the length from the cut portion 71j to the first fixed portion 72a of the first cooling portion 72 is not equal to the length from the cut portion 71j to the second fixed portion 73a of the second cooling portion 73, and the length from the cut portion 71j to the first fixed portion 72a of the first cooling portion 72 is shorter. Therefore, when viewed in the Z direction, the area of ​​the divided portion 71l is larger than the area of ​​the divided portion 71k. Because the area of ​​the divided portion 71l is larger than the area of ​​the divided portion 71k, the heat transferred from the winding of the divided portion 71l is greater than the heat transferred from the winding of the divided portion 71k. Because each of the divided portions 71k and 71l has only one fixed portion that is thermally connected to the housing 9, the temperature of the winding on the side of the divided portion 71l, to which a large amount of heat is transferred, becomes higher than the temperature of the winding on the side of the divided portion 71k. As shown in Figure 24, if the lengths from the cut portion to the fixed portion that is thermally connected to the housing 9 are not equal, the heat of the winding on the side that has a longer length from the cut portion to the fixed portion that is thermally connected to the housing 9 will be less likely to be dissipated via the cooling plate 60, resulting in a rise in the temperature of the winding.

[0066] 22 , when the length from cutoff portion 71e to first fixed portion 72a is equal to the length from cutoff portion 71e to second fixed portion 73a, and the length from cutoff portion 71f to first fixed portion 72a is equal to the length from cutoff portion 71f to second fixed portion 73a, the area of ​​split portion 71g and the area of ​​split portion 71h are equal when viewed in the Z direction. Therefore, the amount of heat transferred from the winding overlapping split portion 71g to split portion 71g is equal to the amount of heat transferred from the winding overlapping split portion 71h to split portion 71h, so the temperature of the winding on one side of the split portion does not increase. Because the temperature of the winding on one side of the split portion does not increase, the maximum temperature of the winding is suppressed, allowing the transformer 1 to be made smaller.

[0067] In this embodiment, the length from cut portion 71 e to first fixed portion 72 a is equal to the length from cut portion 71 e to second fixed portion 73 a, and the length from cut portion 71 f to first fixed portion 72 a is equal to the length from cut portion 71 f to second fixed portion 73 a. By arranging each fixed portion at an equal distance from both cut portions 71 e and 71 f in this manner, the effect of suppressing the maximum temperature of the winding is increased.

[0068] In this embodiment, the cooling plate 50 is disposed parallel to the windings, and the projected area of ​​the main body 71 of the cooling plate 50 is equal to or larger than the projected area of ​​the windings when viewed in the direction of the winding central axis. As shown in Fig. 23 , the cooling plate 50 is disposed parallel to the primary winding 3 and the secondary winding 5. As shown in Fig. 22 , the projected area of ​​the main body 71 is larger than the projected areas of the primary winding 3 and the secondary winding 5 when viewed in the Z direction, which is the direction of the winding central axis. The projected area of ​​the main body 71 is not limited to this, and the projected areas of the primary winding 3 and the secondary winding 5 and the main body 71 may be equal to each other.

[0069] With this configuration, the primary winding 3 and the secondary winding 5 are disposed directly below the cooling plate 50, minimizing the distance between the cooling plate 50 and each point on the primary winding 3 and the secondary winding 5, thereby enabling the transformer 1 to have high heat dissipation characteristics. Furthermore, because the transformer 1 can have high heat dissipation characteristics, the components of the transformer 1 can be made smaller. Because the components of the transformer 1 are made smaller, the cost of the transformer 1 can be reduced.

[0070] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0071] 1, 1a transformer, 2 coil body, 2a central hole, 3 primary winding, 3a central hole, 3b, 3c terminal portion, 4 insulating plate, 4a central hole, 4b first groove portion, 5 secondary winding, 5a central hole, 5b, 5c terminal portion, 6 insulating plate, 6a central hole, 6b second groove portion, 7 cooling plate, 7a central hole, 71 main body portion, 71a, 71b, 71c, 71d vertex, 711, 712, 713, 714 line segment, 71e, 71f cut portion, 71g, 71h division portion, 71i, 71j cut portion, 71k, 71l division portion, 72 first cooling portion, 72a first fixed portion, 72b extension portion, 72c bent portion, 73 second cooling portion, 73a second fixed portion, 73b Extension portion, 73c Bent portion, 8 Molded resin, 9 Housing, 9a Cooling surface, 10 I-shaped core, 10a Beam portion, 11 E-shaped core, 11a Center leg portion, 11b, 11c Outer leg portion, 11d Beam portion, 12 Magnetic core, 12a, 12b Window portion, 13 Adhesive tape, 14, 15 Magnetic flux, 16 Heat dissipation member, 20 Cooling plate, 20a Central hole, 21 Main body portion, 21a, 21b, 21c, 21d Vertex, 211, 212, 213, 214 Line segment, 211a Midpoint, 21e Cutting portion, 22 First cooling portion, 22a First fixing portion, 22b Extension portion, 22c Bent portion, 23 Second cooling portion, 23a Second fixing portion, 23b Extension portion, 23c Bent portion, 31, 32, 33 magnetic flux, 40 cooling plate, 50 cooling plate, 60 cooling plate, 90, 90a current loop, 101, 102 closed magnetic circuit, 200, 200a power converter

Claims

1. A magnetic component comprising: a magnetic core having an annular portion surrounding a window portion; one or more windings wound around the annular portion of the magnetic core; and a cooling plate which passes through the window portion and is overlapped on the windings, made of metal, and cools the windings, wherein the cooling plate has a main body portion which is a portion overlapping with the windings, and a first cooling portion and a second cooling portion protruding from the main body portion, each of the first cooling portion and the second cooling portion being at least thermally connected to a cooler, each of the first cooling portion and the second cooling portion protruding from each of portions of the main body portion on both sides of the window portion, a path surrounding the magnetic core by the main body portion, the first cooling portion, the cooler, and the second cooling portion has at least one insulating portion, and the path is electrically insulated by the insulating portion.

2. A magnetic component comprising: a magnetic core having an annular portion surrounding a window portion; one or more windings wound around the annular portion of the magnetic core; and a cooling plate which passes through the window portion, is made of metal and overlaps the windings, and cools the windings, wherein the cooling plate has a main body portion which is a portion overlapping the windings, and a first cooling portion and a second cooling portion protruding from the main body portion, each of the first cooling portion and the second cooling portion being at least thermally connected to a cooler, and both of the first cooling portion and the second cooling portion protruding from a portion of the main body portion on one side of the window portion and not protruding to the other side of the window portion.

3. A magnetic component according to claim 1, wherein the insulating portion is a cut portion of the main body that cuts between the main body on both sides of the window portion.

4. A magnetic component as described in claim 3, wherein the length of the path from the cut portion to a first fixed portion, which is the portion of the first cooling section fixed to the cooler, is equivalent to the length from the cut portion to a second fixed portion, which is the portion of the second cooling section fixed to the cooler.

5. A magnetic component as described in claim 1, wherein the insulating portion is a heat dissipation member made of an insulating material and arranged between the cooler and one or both of a first fixing portion which is a portion of the first cooling portion fixed to the cooler and a second fixing portion which is a portion of the second cooling portion fixed to the cooler.

6. A magnetic component according to any one of claims 1 to 5, wherein the winding is formed into a curved plate shape on a plane and wound around the magnetic core in a circular or spiral shape.

7. A magnetic component as claimed in any one of claims 1 to 6, wherein the cooling plate is arranged parallel to the winding, and the projected area of ​​the main body of the cooling plate when viewed in the direction of the winding central axis is equal to or larger than the projected area of ​​the winding.

8. A power converter comprising: a magnetic component as defined in any one of claims 1 to 7; and a cooler having a cooling surface to which the magnetic core is thermally connected, wherein the first cooling section and the second cooling section each have a portion extending in the direction of the cooling surface, and the first cooling section and the second cooling section are thermally connected to the cooling surface.

Images