Transformer with inductor, coil, and power conversion device

Abstract

To provide a transformer with an inductor which can improve productivity, and facilitates handling.SOLUTION: A transformer 1 with an inductor includes a transformer T having a first core part 10 and a first coil part 20, and an inductor L2 having a second core part 30 and a second coil part 40, wherein the first coil part 20 and the second coil part 40 are connected to each other, and at least the first coil part 20 and the first core part 40 are sealed with resins 171 and 172.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a transformer with an inductor, a coil, and a power conversion device.

Background Art

[0002] Conventionally, a transformer having a core portion and a coil portion is known (see, for example, Patent Document 1).

[0003] A conventional transformer T includes a first core portion 910 and a first coil portion 920 (see FIG. 8). The first core portion 910 is an EI core composed of an E core 911 and an I core 912. The first coil portion 920 has a primary side winding (not shown) and a secondary side winding (not shown), and is sealed with resin.

[0004] Such a transformer T is used to convert a voltage in a power conversion device (for example, a converter). That is, a conventional power conversion device converts the voltage input to the primary side winding by the transformer T and outputs it to the secondary side winding side, and outputs power to the outside through a rectifier circuit and an output filter circuit. The output filter circuit has an inductor and a capacitor.

[0005] The transformer T, the rectifier circuit SRC, and the inductor L2 of the output filter circuit in a conventional power conversion device can be configured as shown in FIG. 8. The inductor L2 has a second core portion (not shown) and a second coil portion 940. In a conventional power conversion device 900, the transformer T is connected to the rectifier circuit SRC, and is connected to the second coil portion 940 of the inductor L2 of the output filter circuit via a connection member 950 from the rectifier circuit SRC.

[0006] In the conventional transformer T, since the amount of heat generation is large, a metal heat sink 970 is disposed via a thermal pad 980, which is a heat dissipation resin, on the first core portion 910, and the heat generated from the transformer T is dissipated to a housing (not shown) via the thermal pad 980 and the heat sink 970. Further, the transformer T is fixed to the housing or the like by pressing the first core portion 910 together with the thermal pad 980 and the heat sink 970 using a metal bracket 960.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the conventional transformer T, since there are a large number of components for fixing and dissipating heat of the transformer T, there is a problem that the man-hours for operations such as screwing are large and it is difficult to increase productivity. In addition, there has been a demand for a transformer that is easier to handle and does not require the management of a plurality of components.

[0009] Further, in a power conversion device (for example, a converter) using such a transformer, in many cases, an inductor used for a noise filter or the like is connected in addition to the transformer. However, since it is necessary to attach them to the substrate as separate components, it has been desired to increase productivity also from this viewpoint.

[0010] Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a transformer with an inductor and a coil that can increase productivity and are easy to handle. Another object is to provide a power conversion device including such a transformer with an inductor or a coil.

Means for Solving the Problems

[0011] The first transformer with an inductor according to the present invention includes a transformer having a first core portion and a first coil portion, and an inductor having a second core portion and a second coil portion. The first coil portion and the second coil portion are connected, and at least the first coil portion and the first core portion are encapsulated with resin.

[0012] The second transformer with an inductor according to the present invention includes a transformer having a first core portion and a first coil portion, and an inductor having a second core portion and a second coil portion. The first coil portion and the second coil portion are connected, and both the first coil portion and the second coil portion are encapsulated with resin.

[0013] The coil according to the present invention has a core portion and a coil portion, and at least the coil portion and the core portion are encapsulated with resin. The core portion encapsulating resin for encapsulating the core portion is made of a material different from the coil portion encapsulating resin for encapsulating the coil portion.

[0014] The power conversion device according to the present invention includes a transformer, a switch circuit provided on the primary side of the transformer, a rectifier circuit provided on the secondary side of the transformer, and an inductor provided at the subsequent stage of the rectifier circuit. The transformer and the inductor are configured by the transformer with an inductor according to the present invention.

Advantages of the Invention

[0015] According to the first transformer with an inductor, the coil, and the power conversion device of the present invention, since at least the first coil portion and the first core portion are encapsulated with resin, components (such as heat sinks and brackets) for fixing the transformer T are unnecessary. Further, since the first coil portion and the first core portion are encapsulated with resin, man-hours for operations such as screwing are not required, and productivity can be increased. Further, since the first coil portion and the first core portion are encapsulated with resin, it is not necessary to manage a plurality of components, and handling becomes easy.

[0016] According to the second transformer with an inductor and the power conversion device of the present invention, since both the first coil part and the second coil part are sealed with resin, the first coil part and the second coil part can be resin-sealed together. Therefore, the man-hour can be reduced as compared with the case where they are resin-sealed separately. Further, since the transformer and the inductor are resin-sealed together, the transformer and the inductor can be handled together, and the handling becomes even easier.

[0017] According to the first and second transformers with inductors and the power conversion device of the present invention, since the first coil part and the second coil part are connected, the transformer and the inductor can be handled together and do not need to be mounted on the substrate as separate components. As a result, also from this viewpoint, productivity can be increased and handling becomes easy.

Brief Description of Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0019] Hereinafter, the inductor-equipped transformer 1, coil, and power conversion device of the present invention will be described based on the embodiments shown in the drawings. Note that the embodiments described below do not limit the invention according to the claims. Also, not all of the various elements and their combinations described in the embodiments are essential for the solution means of the present invention.

[0020] [Embodiment 1] 1. Configuration of the power conversion device PCD and the inductor-equipped transformer according to Embodiment 1 First, the circuit configuration of the power conversion device PCD according to Embodiment 1 will be described. As shown in FIG. 1, the power conversion device PCD according to Embodiment 1 includes a line filter circuit LFC, a switch circuit SWC, a transformer T, a rectifier circuit SRC, and an output filter circuit FC. An AC input voltage is supplied to the power conversion device PCD from input terminals VP and VN.

[0021] The line filter circuit LFC is a filter circuit that removes noise generated from the power conversion device PCD and noise input from external devices via the input terminals. The line filter circuit LFC has an inductor L1 and capacitors C1, C2, C3, and C4. Capacitors C1 and C4 mainly attenuate normal-mode noise, and capacitors C2 and C3 reduce common-mode noise.

[0022] The switch circuit SWC converts to a high-frequency AC power supply. The switch circuit SWC has switch elements Q1, Q2, Q3, Q4, and is a full-bridge circuit in which the switch elements Q1 and Q3 connected in series and the switch elements Q2 and Q4 connected in series are connected in parallel. The midpoint between the switch element Q1 and the switch element Q3 is connected to one end of the primary winding T1 of the transformer T, and the midpoint between the switch element Q2 and the switch element Q4 is connected to the other end of the primary winding T1 of the transformer T. Note that the switch circuit SWC may be a half-bridge circuit or other appropriate switch circuit.

[0023] The transformer T includes a primary winding T1 on the input side and secondary windings T2 and T3 on the output side, and is a so-called center-tap type transformer to which a connection line Line is also connected at the midpoint between the secondary windings T2 and T3. One end of the secondary winding T2 is connected to the switch element Q5 of the rectifier circuit SRC. The other end of the secondary winding T2 and one end of the secondary winding T3 are connected and connected to the inductor L2 of the output filter circuit FC via the connection line Line. The other end of the secondary winding T3 is connected to the switch element Q6 of the rectifier circuit SRC.

[0024] The rectifier circuit SRC includes switch elements Q5 and Q6 and is a synchronous rectifier circuit that performs synchronous rectification. Note that the rectifier circuit SRC may be a rectifier circuit for asynchronous rectification.

[0025] The output filter circuit FC reduces high-frequency ripple and noise. The output filter circuit FC is a low-pass filter including an inductor L2 and a capacitor C5.

[0026] Next, with reference to FIG. 2, the configurations of the transformer T, the rectifier circuit SRC, and the output filter circuit FC in the power conversion device PCD according to Embodiment 1 will be described.

[0027] In the power conversion device PCD according to Embodiment 1, the transformer T, the rectifier circuit SRC, and the output filter circuit FC are composed of a substrate 90, a resin encapsulation 100, a second core portion 30, and a bracket 60 (see FIG. 2). Here, the resin encapsulation 100 and the second core portion 30 constitute a transformer 1 with an inductor.

[0028] The substrate 90 has a wiring board 91, electronic components 92, and a plurality of pin terminals 93.

[0029] The wiring board 91 is composed of an insulating substrate and a wiring pattern formed on the insulating substrate. The substrate 90 is connected to the terminal portions 112 and 152 that are connected to the secondary windings T2 and T3 of the transformer T of the resin encapsulation 100 by connection members (not shown). Also, the substrate 90 is connected to the terminal portion 163 of the inductor L2 of the resin encapsulation 100 by a connection member (not shown).

[0030] The electronic components 92 at least include the switch elements Q5 and Q6 that constitute the rectifier circuit SRC and the capacitor C5 of the output filter circuit FC, and may also include other switch elements, capacitors, diodes, etc. The electronic components 92 are arranged on the wiring board 91 and constitute the rectifier circuit SRC. Also, one end of the capacitor C5 is connected to the rectifier circuit SRC, and the other end is connected to the second coil portion 40 of the inductor L2 to constitute the output filter circuit FC.

[0031] The plurality of pin terminals 93 are connected to the control electrodes etc. of the switch elements Q5 and Q6, and the tip portions constitute external terminals (gate signal terminals, sense terminals, etc.).

[0032] As shown in FIGS. 2, 4(a), and 4(b), the resin encapsulation 100 has a first core portion 10, a first coil portion 20, a second coil portion 40, and a connecting portion 50, and is resin-encapsulated. As shown in FIG. 4(b), the resin encapsulation 100 is at a height position at a predetermined interval from the height position of the wiring board 91, and the connecting portion 50 is located above the substrate 90 at a predetermined interval.

[0033] The first core portion 10 is made of a magnetic material, for example, ferrite. As shown in FIGS. 6 and 7, the first core portion 10 includes an E-core 11 having a central magnetic leg 13 extending from the center of a flat top plate portion and two external magnetic legs extending from the ends of the top plate portion parallel to the central magnetic leg, and a flat I-core 12. The central magnetic leg 13 is inserted into the central through hole of the first coil portion 20, and the two external magnetic legs are disposed outside the first coil portion 20. The first core portion 10 is encapsulated with a first core portion encapsulating resin 171 (see FIG. 3(b)).

[0034] The first coil portion 20 is a ring-shaped member having a through hole formed in the center. In the first coil portion 20, the central magnetic leg 13 of the first core portion 10 is inserted into the central through hole. The first coil portion 20 is formed with a terminal portion 132 connected to the primary side, and terminal portions 112 and 152 connected to the rectifier circuit SRC are formed on the opposite side of the primary side terminal portion 132 with the transformer T interposed therebetween.

[0035] As shown in FIG. 3(b), in the first coil portion 20, a primary coil 130 (T1) wound around the central magnetic leg 13 of the first core portion 10 a plurality of times is wound around the central portion. Also, a plate-shaped secondary winding T2 (first winding portion 111) is wound once around the central magnetic leg 13 via a first insulating member 120 from the primary coil 130, and a plate-shaped secondary winding T3 (second winding portion 151) is wound once around the central magnetic leg 13 via a second insulating member 140. A bobbin composed of the first insulating member 120 and the second insulating member 140 is formed on the inner peripheral side of the primary coil 130. The first coil portion 20 is encapsulated with a first coil portion encapsulating resin 172.

[0036] As shown in Fig. 4, the second coil portion 40 is a rectangular ring-shaped member with a through hole formed in the center. The second coil portion 40 is at substantially the same height position as the first coil portion 20 and is connected by a connecting portion 50 (see Fig. 4(b)). The second coil portion 40 has a fixing hole 42 for fixing to the housing and a terminal portion 41 for connecting to the substrate 90. As shown in Fig. 3(a), the second coil portion 40 is composed of a third winding portion 155 and a fourth winding portion 161. The second coil portion 40 is sealed with a second coil portion sealing resin 173.

[0037] The connecting portion 50 is a flat metal plate that connects the first coil portion 20 and the second coil portion 40. In Fig. 1, the connecting portion 50 constitutes a connection line Line between the center tap terminal of the transformer T and the inductor L2 (the second coil portion 40). The connecting portion 50 is sealed with a connecting portion sealing resin 174 (see Fig. 5). An opening 154 is formed near the center of the connecting portion 50, and it can be connected to the substrate 90 by a screw or the like (not shown).

[0038] The first core portion sealing resin 171, the first coil portion sealing resin 172, the second coil portion sealing resin 173, and the connecting portion sealing resin 174 may be different sealing resins, but in Embodiment 1, they are sealed together with the same sealing resin.

[0039] The specific internal structure of the resin-sealed body 100 will be described later.

[0040] The second core portion 30 is made of a magnetic material. As shown in Fig. 3(a), the second core portion 30 is an EE core formed by combining two E cores each having a central magnetic leg extending from the center of a flat top plate portion and two external magnetic legs extending from the ends of the top plate portion parallel to the central magnetic leg. The central magnetic leg is inserted into the through hole in the center of the second coil portion 40, and the two external magnetic legs are arranged outside the second coil portion 40. The second core portion 30 and the second coil portion 40 (described later) of the resin-sealed body 100 constitute the inductor L2.

[0041] The second core portion 30 is fixed to a housing (not shown) using a bracket 60. The bracket 60 is formed by bending a flat metal member or the like, and as shown in FIG. 2, has a rectangular flat base portion 61, side wall portions 62 protruding downward from both ends of the base portion 61, and fixing portions 63 formed by bending the ends of the side wall portions 62 in the horizontal direction. A pressing portion 64 for pressing the second core portion 30 is formed on the base portion 61. The pressing portion 64 is a leaf spring with a base end connected to the base portion 61 as a fulcrum. A screw insertion hole is formed in the fixing portion 63.

[0042] Next, the internal structure of the resin encapsulation body 100 will be described. As shown in FIGS. 6 and 7, the resin encapsulation body 100 includes a first plate 110, a first insulating member 120, a primary coil 130, a second insulating member 140, a second plate 150, a third plate 160, an E-core 11, and an I-core 12. The central magnetic leg 13 of the E-core 11 is inserted through openings formed in the first plate 110, the first insulating member 120, the primary coil 130, the second insulating member 140, and the second plate 150, respectively. Since the E-core 11 and the I-core 12 have already been described, the description thereof will be omitted.

[0043] The first plate 110 is composed of a single conductor plate and has a first winding portion 111, a terminal portion 112, and a connecting portion 113.

[0044] The first winding portion 111 has a substantially C shape in plan view with the rectifier circuit SRC side being open. The terminal portion 112 is drawn out from one end of the first winding portion 111 in a direction away from the first winding portion 111. The connecting portion 113 is drawn out from the other end of the first winding portion 111 in a direction away from the first winding portion 111. A circular opening 114 is formed in the central portion of the first winding portion 111, and the central magnetic leg 13 of the E-core 11 is inserted therethrough. The first plate 110 constitutes the secondary winding T2 (see FIG. 1) of the transformer T.

[0045] The first insulating member 120 is a member in a ring shape in plan view disposed between the first plate 110 and the primary coil 130. The first insulating member 120 is made of a substance having electrical insulation properties, for example, a resin having insulation properties and heat conductivity. It has an insulating member main body 121 provided with an opening 123 at the center, and a standing portion 122 erected upward (toward the second plate 150 side) along the opening 123 of the insulating member main body 121.

[0046] The primary coil 130 is formed by winding a linear conductor wire around the central magnetic leg 13 of the E-core 11 a plurality of times. One end and the other end of the primary coil 130 are each connected to the primary side switch circuit SWC via a terminal portion 132. Between the primary coil 130 and the central magnetic leg 13 of the E-core, a bobbin composed of the standing portion 122 of the first insulating member 120 and the standing portion 142 of the second insulating member 140 is disposed (see Fig. 3(b)).

[0047] The second insulating member 140 is a member in a ring shape in plan view disposed between the second plate 150 and the primary coil 130. The second insulating member 140 is made of a substance having electrical insulation properties, for example, a resin having insulation properties and heat conductivity. The second insulating member 140 is provided between the second winding portion 151 of the second plate 150 and the primary coil 130, and has an insulating member main body 141 provided with a first opening 144 at the center, and a standing portion 142 erected downward (toward the first plate 110 side) along the first opening 144 of the insulating member main body 141. The standing portion 122 of the first insulating member 120 and the standing portion 142 of the second insulating member 140 mate with each other to form a bobbin as shown in Fig. 3(b).

[0048] The second plate 150 is composed of a single conductor plate, and has a second winding portion 151, a terminal portion 152, a connecting portion 153, a third winding portion 155, and a connecting portion 156.

[0049] The second winding portion 151 has a substantially C-shaped planar view with the rectifier circuit SRC side being open, and an opening 154 is formed in the center. The terminal portion 152 is drawn out from one end of the first winding portion 151 in a direction away from the second winding portion 151. The terminal portion 152 is connected to the rectifier circuit SRC.

[0050] The connecting portion 153 is connected to the second winding portion 151 via a step portion 158 and extends linearly in a direction away from the second winding portion 151. Then, it bends in a crank shape on the second coil portion side (the third winding portion 155 side) and is connected to the third winding portion 155.

[0051] The third winding portion 155 has an angular ring shape in planar view and is wound in the opposite direction to the second winding portion 151. An opening 157 is formed in the center, and the central magnetic leg of the second core portion 30 is inserted therethrough. The connecting portion 156 is connected to the tip of the third winding portion 155 via a step portion 158 and is connected to the connecting portion 162 of the third plate 160.

[0052] The third plate 160 is composed of a single conductor plate and has a fourth winding portion 161, a connecting portion 162, and a terminal portion 163.

[0053] The fourth winding portion 161 has a substantially square shape in planar view with the rectifier circuit SRC side being open, and an opening 164 is formed in the center. The connecting portion 162 is formed at one end of the fourth winding portion 161 and is connected to the connecting portion 156 of the second plate 150. The terminal portion 163 is formed at the other end of the fourth winding portion 161 in a state of being bent outward in planar view. The terminal portion 163 is connected to the external terminal of the power conversion device PCD and the capacitor C5.

[0054] Therefore, in the transformer 1 with an inductor, the first coil portion 20 includes a first winding portion 111 and a second winding portion 151 wound around the first core portion 10 (central magnetic leg 13), a primary coil 130 disposed between the first winding portion 111 and the second winding portion 151 and wound around the first core portion 10, a first insulating member 120 disposed between the first winding portion 111 and the primary coil 130, and a second insulating member 140 disposed between the second winding portion 151 and the primary coil 130.

[0055] Further, the second coil portion 40 includes third winding portions 155 and 161 wound around the second core portion 30. The second coil portion 40 also includes a connecting portion 153 connecting the second winding portion 151 and the third winding portion 155, and the second winding portion 151, the connecting portion 153, and the third winding portion 155 are formed of the same conductor plate (second plate 150).

[0056] 2. Effects of the Transformer 1 with an Inductor and the Power Conversion Device PCD According to Embodiment 1 According to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, at least the first core portion 10 and the first coil portion 20 are sealed with the first core portion sealing resin 171 and the first coil portion sealing resin 172, so that components (such as heat sinks and brackets) for fixing the transformer T are unnecessary. Also, since the first core portion 10 and the first coil portion 20 are sealed with the first core portion sealing resin 171 and the first coil portion sealing resin 172, the man-hours for operations such as screwing are not required, and productivity can be increased. Further, since the first coil portion 20 and the first core portion 10 are sealed with the first core portion sealing resin 171 and the first coil portion sealing resin 172, it is not necessary to manage a plurality of components, and handling becomes easy. In addition, since it is resin-sealed, there is also an effect that heat generated from the first coil portion 20 and the first core portion 10 can be easily dissipated to the outside through the sealing resin.

[0057] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, since both the first coil portion 20 and the second coil portion 40 are sealed with the first coil portion sealing resin 172 and the second coil portion sealing resin 173, the first coil portion 20 and the second coil portion 40 can be resin-sealed together. Therefore, the man-hour can be reduced as compared with the case where they are resin-sealed separately. Further, since the transformer and the inductor are resin-sealed together, the transformer and the inductor can be handled together, and the handling becomes even easier.

[0058] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, since the first coil portion 20 and the second coil portion 40 are connected, the transformer T and the inductor L2 can be handled together and do not need to be attached to the substrate as separate components. As a result, also from this viewpoint, the productivity can be increased and the handling becomes easy.

[0059] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, since the first coil portion 20 and the second coil portion 40 are connected, they can be directly conducted with the inductor L2 without passing through the substrate 90. Therefore, there is no need to connect from the transformer T to the substrate once or connect from the substrate to the inductor L2 via a separate connecting member in order to connect the transformer T and the inductor L2 as in the case of a conventional power conversion device, and the man-hour and the number of components can be reduced. Further, since the transformer T and the inductor L2 are directly connected via the connecting portion, there is no need to secure an area for arranging a connection area and a connecting member with the transformer T or the inductor L2 on the substrate 90, and the mounting area on the substrate 90 can be effectively utilized. Further, since the connecting portion 50 is arranged on the substrate 90, electronic components can also be arranged below the connecting portion 50, and the mounting area on the substrate 90 can be more effectively utilized.

[0060] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, since the first coil portion sealing resin 172 that seals the first coil portion 20 and the second coil portion sealing resin 173 that seals the second coil portion 40 are made of the same material, they can be resin-sealed together, and the working process becomes easy.

[0061] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, since the first coil portion 20, the second coil portion 40, and the connecting portion 50 are sealed with the same resin, they can be resin-sealed together including the connecting portion 50, and the working process becomes even easier.

[0062] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, since the first coil portion sealing resin 172 is made of the same material as the first core portion sealing resin 171, they can be resin-sealed together.

[0063] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, the first coil portion 20 includes a first first winding portion 111 and a second winding portion 151 wound around the first core portion 10, a primary coil 130 disposed between the first first winding portion 111 and the second winding portion 151 and wound around the first core portion 10, a first insulating member 120 disposed between the first first winding portion 111 and the primary coil 130, and a second insulating member 140 disposed between the second winding portion 151 and the primary coil 130. The second coil portion 40 has third winding portions 155 and 161 wound around the second core portion 30, and includes a connecting portion 153 that connects the second winding portion 151 and the third winding portion 155. Since the second winding portion 151, the connecting portion 153, and the third winding portion 155 are formed of the same conductor plate (second plate 150), the transformer 1 with an inductor can be formed with a simple configuration. Further, since the connecting portion 153 is at the same height position as the second winding portion 151 and the third winding portion 155, it can be disposed above the substrate, and electronic components can be disposed below the connecting portion 153 on the substrate 90.

[0064] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, between the primary coil 130 and the first core portion 10, there are arranged a bobbin formed by the first insulating member 120 and the second insulating member 140, and a first core portion sealing resin 171 for sealing the first core portion 10. Therefore, the primary coil 130 and the first core portion 10 can be surely insulated. Also, it is possible to prevent the primary coil 130 wound a plurality of times from coming apart.

[0065] Further, according to the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, between the third winding portion 155 and the second core portion 30, only the second coil portion sealing resin 173 for sealing the second coil portion 40 is arranged. Therefore, in the inductor L2, the second coil portion 40 and the second core portion 30 can be insulated by resin sealing without forming a bobbin.

[0066] [Embodiment 2] The transformer with an inductor and the power conversion device according to Embodiment 2 basically have the same configuration as the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1, but are different from the transformer 1 with an inductor and the power conversion device PCD according to Embodiment 1 in that the first core portion sealing resin for sealing the first core portion is made of a material different from the first coil portion sealing resin for sealing the first coil portion.

[0067] The configuration of Embodiment 2 has the same configuration as the configuration of FIGS. 2 to 7. However, in Embodiment 2, the first core portion sealing resin 171 for sealing the first core portion 10 is made of a material different from the first coil portion sealing resin 172 for sealing the first coil portion 20. In this case, the first core portion sealing resin 171 can have higher elasticity and vibration resistance than the first coil portion sealing resin 172, or a material with low elasticity can be used.

[0068] Further, the coefficient of linear expansion of the first core portion sealing resin 171 is closer to the coefficient of linear expansion of the material (e.g., ferrite) constituting the first core portion 10 than the coefficient of linear expansion of the first coil portion sealing resin 172, and the coefficient of linear expansion of the first coil portion sealing resin 172 is closer to the coefficient of linear expansion of the material (e.g., copper) constituting the first coil portion 20 than the coefficient of linear expansion of the first core portion sealing resin 171.

[0069] Thus, the inductor - attached transformer and the power conversion device according to Embodiment 2 are different from the inductor - attached transformer 1 and the power conversion device PCD according to Embodiment 1 in that the first core portion sealing resin that seals the first core portion is made of a different material from the first coil portion sealing resin that seals the first coil portion. However, similar to the case of the inductor - attached transformer 1 and the power conversion device PCD according to Embodiment 1, since at least the first coil portion 20 and the first core portion 10 are sealed with the resins 171 and 172, components (heat sinks, brackets, etc.) for fixing the transformer T are not required. Also, since the first coil portion 20 and the first core portion 10 are sealed with the resins 171 and 172, the man - hours for operations such as screwing are not necessary, and productivity can be increased. Further, since the first coil portion 20 and the first core portion 10 are sealed with the resins 171 and 172, it is not necessary to manage a plurality of components, and handling becomes easy.

[0070] Also, according to the inductor - attached transformer and the power conversion device according to Embodiment 2, since the first core portion sealing resin 171 has higher elasticity than the first coil portion sealing resin 172, the first core portion 10 using a brittle magnetic material (e.g., ferrite) can be protected from external impacts.

[0071] Also, in the transformer with an inductor and the power conversion device according to the second embodiment, the linear expansion coefficient of the first core portion sealing resin 171 is closer to the linear expansion coefficient of the material (for example, ferrite) constituting the first core portion 10 than the linear expansion coefficient of the first coil portion sealing resin 172, and the linear expansion coefficient of the first coil portion sealing resin 172 is closer to the linear expansion coefficient of the material (for example, copper) constituting the first coil portion 20 than the linear expansion coefficient of the first core portion sealing resin 171. By adopting such a configuration, when the temperature rises, the difference between the linear expansion coefficient of the core (for example, ferrite) and the linear expansion coefficient of the coil (copper) can be alleviated, and it is possible to prevent the core (for example, ferrite) from cracking due to the difference in the linear expansion coefficient. On the other hand, since the linear expansion coefficient of the first coil portion sealing resin 172 is closer to the linear expansion coefficient of the material (for example, copper) constituting the first coil portion 20 than the linear expansion coefficient of the first core portion sealing resin 171, a resin having high heat dissipation performance can be used.

[0072] Note that the transformer with an inductor and the power conversion device according to the second embodiment have the same configuration as the transformer with an inductor 1 and the power conversion device PCD according to the first embodiment, except that the first core portion sealing resin that seals the first core portion is made of a material different from the first coil portion sealing resin that seals the first coil portion. Therefore, they have the corresponding effects among the effects that the transformer with an inductor 1 and the power conversion device PCD according to the first embodiment have.

[0073] As described above, the present invention has been described based on the above embodiments, but the present invention is not limited to the above embodiments. It can be implemented in various aspects without departing from the spirit thereof. For example, the following modifications are also possible.

[0074] (1) The positions, connections, numbers, etc. described in the above embodiments (including each modification example. The same applies hereinafter.) are examples, and can be changed within a range that does not impair the effects of the present invention.

[0075] (2) In the above-described Embodiment 2, one type of the first coil portion sealing resin was used, but the present invention is not limited thereto. Two types of the first coil portion sealing resin may be used. In this case, it is preferable to use a resin having a coefficient of linear expansion close to that of the material (e.g., copper) of the first coil portion 20 on the first coil portion 20 side, and use a resin having the coefficient of linear expansion of the first core portion 10 on the first core portion 10 side. By adopting such a configuration, the difference in the coefficients of linear expansion between copper and ferrite can be alleviated, and the ferrite can be prevented from cracking.

[0076] (3) In the above-described embodiments, the first coil portion, the first core portion, the connecting portion, and the second coil portion were resin-sealed, but the present invention is not limited thereto. In addition to the first coil portion, the first core portion, the connecting portion, and the second coil portion, the second core portion may also be resin-sealed. By adopting such a configuration, the bracket used for attaching the second core portion to the housing becomes unnecessary, and a transformer with an inductor that is easier to handle is obtained.

[0077] (4) In the above-described embodiments, the first coil portion, the first core portion, the connecting portion, and the second coil portion were resin-sealed, but the present invention is not limited thereto. Only the first coil portion and the first core portion may be resin-sealed, or only the second coil portion and the second core portion may be resin-sealed. By adopting such a configuration, it is possible to prevent the first core portion from cracking due to the difference in the coefficients of linear expansion between the first coil portion and the first core portion (the same applies to the second coil portion and the second core portion).

[0078] (5) In the above-described embodiments, the first coil portion, the first core portion, the connecting portion, and the second coil portion were resin-sealed, but the present invention is not limited thereto. The connecting portion does not necessarily need to be resin-sealed.

[0079] (6) In each of the above embodiments, the first coil portion, the first core portion, the connecting portion, and the second coil portion are resin-sealed, but the present invention is not limited thereto. Only the first coil portion and the second coil portion may be resin-sealed. By adopting such a configuration, two coils can be handled collectively, and a transformer with an inductor that is easy to handle can be obtained.

[0080] (7) In each of the above embodiments, an inductor of an output filter circuit (choke coil) is used as the inductor, but the present invention is not limited thereto. As the inductor, an inductor other than the choke coil of the output filter circuit may be used.

Explanation of Reference Numerals

[0081] 1... Transformer with inductor, 10... First core portion, 20... First coil portion, 30... Second core portion, 40... Second coil portion, 50... Connecting portion, 100... Resin-sealed body, 111... First winding portion, 120... First insulating member, 130... Primary-side coil, 140... Second insulating member, 142... Bobbin, 151... Second winding portion, 155... Third winding portion, 161... Fourth winding portion, 171... First core portion sealing resin, 172... First coil portion sealing resin, 173... Second coil portion sealing resin, 174... Connecting portion sealing resin, T... Transformer, L2... Inductor

Claims

1. A transformer having a first core portion and a first coil portion, and an inductor having a second core portion and a second coil portion, wherein the first coil portion and the second coil portion are connected, and at least the first coil portion and the first core portion are encapsulated with resin, characterized in that it is a transformer with an inductor.

2. The transformer with an inductor according to claim 1, characterized in that the second coil portion is also encapsulated with resin.

3. The transformer with an inductor according to claim 2, characterized in that the first coil portion encapsulating resin for encapsulating the first coil portion is made of the same material as the second coil portion encapsulating resin for encapsulating the second coil portion.

4. Further comprising a connecting portion connecting the first coil portion and the second coil portion, The transformer with an inductor according to claim 3, characterized in that the first coil portion, the second coil portion, and the connecting portion are encapsulated with the same resin.

5. The transformer with an inductor according to any one of claims 1 to 4, characterized in that the first coil portion encapsulating resin for encapsulating the first coil portion is made of a material different from the first core portion encapsulating resin for encapsulating the first core portion.

6. The transformer with an inductor according to claim 5, characterized in that the first core portion encapsulating resin has higher elasticity than the first coil portion encapsulating resin.

7. The linear expansion coefficient of the first core portion encapsulating resin is closer to the linear expansion coefficient of the material constituting the first core portion than the linear expansion coefficient of the first coil portion encapsulating resin, The transformer with an inductor according to claim 5, characterized in that the linear expansion coefficient of the first coil portion encapsulating resin is closer to the linear expansion coefficient of the material constituting the first coil portion than the linear expansion coefficient of the first core portion encapsulating resin.

8. The transformer with an inductor according to any one of claims 1 to 4, characterized in that the first coil portion encapsulating resin for encapsulating the first coil portion is made of the same material as the first core portion encapsulating resin for encapsulating the first core portion.

9. The first coil portion has a first winding portion and a second winding portion wound around the first core portion, a primary-side coil disposed between the first winding portion and the second winding portion and wound around the first core portion, a first insulating member disposed between the first winding portion and the primary-side coil, and a second insulating member disposed between the second winding portion and the primary-side coil, The second coil portion has a third winding portion wound around the second core portion It further has a connecting portion that connects the first winding portion or the second winding portion and the third winding portion. The inductor-equipped transformer according to any one of claims 1 to 4, wherein the first winding portion or the second winding portion, the connecting portion, and the third winding portion are formed of the same conductor plate.

10. Between the primary coil and the first core portion, there are arranged a bobbin formed by the first insulating member and the second insulating member, and a first core portion sealing resin for sealing the first core portion. The inductor-equipped transformer according to claim 9, wherein only a second core portion sealing resin for sealing the second core portion is arranged between the third winding portion and the second core portion.

11. The inductor-equipped transformer according to any one of claims 1 to 4, wherein the second core portion is also sealed with resin.

12. A transformer having a first core portion and a first coil portion, An inductor having a second core portion and a second coil portion, The first coil portion and the second coil portion are connected, An inductor-equipped transformer, characterized in that both the first coil portion and the second coil portion are sealed with resin.

13. Having a core portion and a coil portion, At least the coil portion and the core portion are sealed with resin, The core portion sealing resin for sealing the core portion is made of a material different from the coil portion sealing resin for sealing the coil portion.

14. A transformer, A switch circuit provided on the primary side of the transformer, A rectifier circuit provided on the secondary side of the transformer, An inductor provided at the subsequent stage of the rectifier circuit, and The power conversion device is characterized in that the transformer and the inductor are configured by the inductor-equipped transformer according to claim 1 or 12, or the transformer or the inductor is configured by the coil according to claim 13.

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