JP5316870B2 - Reactor and converter - Google Patents

Description

  The present invention relates to a reactor used for a DC-DC converter for an electric vehicle such as a hybrid vehicle. In particular, the present invention relates to a reactor that does not require an adhesive for assembling a core and has excellent assemblability.

  An electric vehicle such as a hybrid vehicle is equipped with a DC-DC converter that raises and lowers a DC voltage, and a reactor is one of the parts of this converter. Conventionally, a typical reactor has a structure in which an assembly in which a coil is arranged in an annular core is housed in a case, and a potting resin is filled in the case and sealed (for example, Patent Document 1). reference).

  The reactor described in Patent Literature 1 includes a track-shaped core (annular core) having a straight portion (intermediate core) and a curved portion (end core), a coil disposed on the straight portion of the core, a core, An intermediate case for storing the combined body with the coil and a case for storing the whole are provided. In this reactor, the linear portion of the core is covered with an inner bobbin (cylindrical bobbin), and a coil is wound around the outer side of the inner bobbin. In this reactor, both ends of the coil are sandwiched between outer bobbins (frame bobbins), and the curved portion of the core is exposed through the opening of the outer bobbin. Furthermore, since this reactor dissipates the heat generated in the reactor by energizing the coil, the case is used with the case installed on the heat sink.

JP 2008-28290 A

  However, the above-described conventional reactor has a problem that the assemblability is poor.

  Generally, in a conventional reactor, when assembling parts (intermediate core and end core) constituting a core into an annular shape, a holding jig that holds the positional relationship between the parts is used. And at the time of an assembly of a core, a core component is arrange | positioned in a predetermined position using a holding jig, and components are joined and fixed with an adhesive agent. The cylindrical bobbin and the frame bobbin are positioned with respect to the core by determining the positions of the intermediate core and the end core.

  In a conventional reactor in which core components are fixed to each other using an adhesive, an adhesive application operation and an adhesive curing operation are required, and therefore, an assembling operation requires a lot of time. In the conventional reactor, the gap length is designed in consideration of the thickness of the adhesive. However, since the thickness of the adhesive is roughly determined by the amount of adhesive applied, it is required to be applied in an appropriate amount and requires skill. For example, when the application amount is less than the appropriate amount, there is a problem that the gap length is shortened, and when the application amount is more than the appropriate amount, the adhesive protrudes between the gap material and the adjacent core piece.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a reactor that does not require an adhesive for assembling a core and has excellent assemblability.

  The reactor of the present invention includes a pair of coil elements that are arranged in parallel and connected to each other, a pair of intermediate cores on which the coil elements are arranged, and a pair of end cores that connect the ends of both intermediate cores. And an annular core having a bobbin for holding a coil element. The bobbin has a cylindrical bobbin that covers the outer periphery of the intermediate core, and a frame-shaped bobbin that comes into contact with the end face of the coil element. And the fitting part which mutually fits is provided in each of the end surface of a cylindrical bobbin, and one surface of the frame-shaped bobbin which opposes this surface. Moreover, at least one of the recessed part or convex part for positioning an edge part core is formed in the other surface of a frame-shaped bobbin. Furthermore, the positional relationship between the intermediate core and the end core is maintained without using an adhesive by fitting the cylindrical bobbin and the frame bobbin.

  According to this configuration, the positional relationship between the intermediate core and the end core is determined by fitting the cylindrical bobbin and the frame bobbin, and the positional relationship between the intermediate core and the end core is maintained. It does not require an adhesive for assembling the core and has excellent assemblability. Further, since the end core can be easily positioned with respect to the frame-shaped bobbin, a holding jig that has been indispensable in the past is not necessary.

  In a more preferred embodiment of the present invention, the cylindrical bobbin has a side surface formed with a slit that is open at one end in the axial direction and closed at the other end.

  When assembling the core, the axial direction of the cylindrical bobbin may be set up and down, and the intermediate core may be inserted into the cylindrical bobbin. At this time, according to the above configuration, the gripping means can be caused to enter the slit from the opening side of the slit while the side surface of the intermediate core is gripped by the gripping means, so that the intermediate core can be easily inserted. In addition, since the intermediate core can be inserted while maintaining the state of gripping the side surface of the intermediate core without dropping the intermediate core from one end side of the cylindrical bobbin, damage to the intermediate core due to dropping can be prevented. it can.

  In a more preferred embodiment of the present invention, the intermediate core is composed of a core piece and a gap material, and the positional relationship between the core piece and the gap material is maintained without using an adhesive.

  In the case of the above configuration, one of the core piece and the gap material may be plural. For example, the structure which arrange | positions a gap material in the both ends of a core piece, respectively, and the structure which interposes a gap material between two core pieces are mentioned, for example. In the latter case, no gap material is interposed between the intermediate core and the end core. A plurality of core pieces and gap materials may be provided. For example, two core pieces are used in the order of gap material-core piece-gap material-core piece-gap material, or three core pieces are used to form core piece-gap material-core piece-gap material. -The structure which arrange | positions in order of a core piece is mentioned. By configuring the intermediate core using a plurality of gap materials, it is possible to reduce individual gap lengths and reduce leakage magnetic flux in each gap.

  In the reactor of the present invention, the positional relationship between the intermediate core and the end core is determined by fitting the cylindrical bobbin and the frame bobbin, and the positional relationship between the intermediate core and the end core is maintained. It does not require an adhesive for assembling the core and has excellent assemblability.

1 is a schematic perspective view of a reactor according to a first embodiment. It is a schematic perspective view for demonstrating the coil element with which the reactor which concerns on Embodiment 1 is equipped. It is the schematic for demonstrating the core and bobbin with which the reactor which concerns on Embodiment 1 is equipped, (A) is a perspective view which shows the state which mounted | wore the bobbin to the core, (B) is a perspective view which shows a bobbin. It is. It is the schematic for demonstrating the cylindrical bobbin and frame bobbin with which the reactor which concerns on Embodiment 1 is equipped, (A) is a perspective view of a cylindrical bobbin, (B) is a perspective view of a frame bobbin It is. It is a schematic perspective view for demonstrating the reactor assembly method which concerns on Embodiment 1. FIG. It is the schematic for demonstrating the usage method of the reactor which concerns on Embodiment 1, (A) is a top view which shows the state which accommodated the reactor in the case, (B) is when storing a reactor in a case. It is a side view of the used leaf | plate spring.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Moreover, the same code | symbol is attached | subjected to the same member in the figure.

(Embodiment 1)
The reactor R1 according to the first embodiment will be described with reference to FIGS. Reactor R1 has a pair of coil elements 1, an annular core 2 having a pair of intermediate cores 2m on which each coil element 1 is disposed, and a pair of end cores 2s connecting the ends of both intermediate cores 2m; And a bobbin 3 for holding the coil element 1. The bobbin 3 includes a cylindrical bobbin 3m that covers the outer periphery of the intermediate core 2m, and a frame-shaped bobbin 3s that contacts the end surface of the coil element 1. Hereinafter, each configuration will be described in more detail.

  Each coil element 1 is formed by edgewise winding a rectangular winding. Further, the two coil elements 1 are arranged in parallel and connected to each other. Here, as shown in FIG. 2, the two coil elements 1 are formed by one winding. Specifically, the winding is bent in a U shape on the other end side in the axial direction of the coil element 1 so that the starting end 1s and the terminating end 1e of the winding are located on one end side in the axial direction of the coil element 1. By providing the bent portion 1u, both coil elements 1 are formed by a single winding.

  As shown in FIGS. 3 (A) and 5, the annular core 2 is connected to the ends of both intermediate cores 2m so as to connect the ends of the pair of intermediate cores 2m on which the coil elements are arranged. By arranging the partial core 2s, it is configured in an annular shape. The intermediate core 2m is a rectangular parallelepiped core component configured by sequentially arranging three core pieces 20 and two gap members g (see FIG. 5). On the other hand, the end core 2s has a surface to which the respective end surfaces of both the intermediate cores 2m are in contact with each other (hereinafter, this surface is referred to as a “core connection surface”). This is a core component having a trapezoidal cross section that decreases in width toward the surface (hereinafter, this surface is referred to as “rear surface”).

  Further, the core piece 20 and the end core 2s are made of a magnetic material, for example, a laminated body in which silicon steel plates are laminated, or a surface of a soft magnetic powder such as iron powder is subjected to insulation coating, and the powder is pressure-molded. It can be comprised with a compacting body. The gap material g is made of a non-magnetic material, and can be composed of, for example, a ceramic plate material such as glass epoxy resin or alumina, or a rubber plate material such as silicone rubber. When the gap material is made of an elastic material such as silicone rubber, the gap length can be adjusted by compressing the gap material from both sides, and even if the gap material has some dimensional error, the error can be absorbed. .

  As shown in FIGS. 3A and 3B, the bobbin 3 is configured by fitting a cylindrical bobbin 3m and a frame bobbin 3s to each other. An intermediate core 2m is held on the inner periphery of the cylindrical bobbin 3m, and a coil element is mounted on the outer periphery of the cylindrical bobbin 3m. Further, as shown in FIG. 4 (A), the cylindrical bobbin 3m has a rectangular tube shape, and is provided with a fitting recess 31 at each corner of both end surfaces. Further, a slit 35 is formed on the side surface of the cylindrical bobbin 3m. The slit 35 is open at one end in the axial direction and closed at the other end.

  On the other hand, as shown in FIG. 4B, the frame-shaped bobbin 3s is provided with a fitting convex portion 32 corresponding to the fitting concave portion 31 of the cylindrical bobbin end surface on the surface facing the end surface of the cylindrical bobbin 3m. ing. The frame-shaped bobbin 3s has a substantially flat outer shape, and has two openings 34 through which end portions of the respective intermediate cores penetrate. A convex frame 33 for positioning the end core 2s with respect to the frame bobbin 3s is formed on the surface on which the end core 2s is disposed (see FIG. 3A). The convex frame 33 is formed in a shape that surrounds three outer peripheral edges of the core connection surface of the end core 2s. The cylindrical bobbin 3m and the frame-shaped bobbin 3s can maintain the positional relationship with each other by fitting the fitting concave portion 31 and the fitting convex portion 32 provided on each of them.

  The cylindrical bobbin 3m and the frame bobbin 3s are made of an insulating material and can be made of a resin such as polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polytetrafluoroethylene (PTFE), or the like.

  A specific example of the method for assembling the reactor R1 will be described with reference to FIG. First, one end core 2s is attached to one frame-shaped bobbin 3s (lower side in the figure). Specifically, by sliding the frame-shaped bobbin 3s from the opening side of the convex frame 33 and fitting the end core 2s into the convex frame 33 with the core connection surface of the end core 2s facing upward. Install. At this time, one end core 2s is positioned with respect to one frame-shaped bobbin 3s.

  Next, the cylindrical bobbin 3m is attached to one frame-shaped bobbin 3s. Specifically, the fitting recess 32 of the cylindrical bobbin 3m is fitted to the fitting projection 32 of the frame-shaped bobbin 3s with the axial direction of the cylindrical bobbin 3m being the vertical direction and the opening side of the slit 35 facing upward. Install by fitting 31. At this time, the positional relationship between the one frame-shaped bobbin 3s and the cylindrical bobbin 3m is maintained by fitting the one frame-shaped bobbin 3s and the cylindrical bobbin 3m.

  Next, the intermediate core 2m is inserted into the inner periphery of the cylindrical bobbin 3m. Specifically, the core piece 20 and the gap material g are sequentially inserted and stacked on the inner periphery of the cylindrical bobbin 3m. At this time, the core piece 20 and the gap material g are not joined with an adhesive, and the intermediate core 2m (the core piece 20 and the gap material g) is held on the inner periphery of the cylindrical bobbin 3m. Further, the lower end portion of the intermediate core 2m passes through the opening of the one frame-shaped bobbin 3s, and the lower end surface of the intermediate core 2m is in direct contact with the core connection surface of the one end core 2s. Furthermore, since the slit 35 of the cylindrical bobbin 2m opens upward, it is possible to insert the intermediate core 2m while holding the side surface of the intermediate core 2m, and the insertion work of the intermediate core 2m is safe and easy. Can be done.

  Next, the coil element (not shown) is mounted on the outer periphery of the cylindrical bobbin 3m with the bent portion side facing down.

  Finally, the other frame bobbin 3s is attached to the cylindrical bobbin 3m, and the other end core 2s is attached to the other frame bobbin 3s. The specific method for attaching the other frame-shaped bobbin is the same as that for the other frame-shaped bobbin, and is therefore omitted. At this time, the positional relationship between the other frame-shaped bobbin 3s and the cylindrical bobbin 3m is maintained by fitting the other frame-shaped bobbin 3s and the cylindrical bobbin 3m. Further, the upper end portion of the intermediate core 2m passes through the opening of the other frame-shaped bobbin 3s, and the upper end surface of the intermediate core 2m directly contacts the core connection surface of the other end core 2s. Furthermore, the other end core 2s is positioned with respect to the other frame-shaped bobbin 3s.

  Next, a specific example of how to use the reactor R1 will be described with reference to FIG. When the reactor R1 is used, for example, it is housed in a case 50 as shown in FIG. 6 (A), and fixing brackets (for example, bolts) are inserted into insertion holes 50h formed at the four corners of the case 50, for example, a heat sink. Install in the heat dissipation mechanism. Here, the back surface of one end core 2s is brought into contact with the case 50, and the other end core 2s is pressed toward the one end core 2s between the back surface of the other end core 2s and the case 50. A pressing member (leaf spring 51) is inserted. As shown in FIG. 6B, the leaf spring 51 is substantially S-shaped. Thus, by applying a pressing force in the direction in which the end cores approach each other using a pressing member such as a leaf spring, the gap length is prevented from changing due to external factors such as vibration and impact. be able to.

  Alternatively, the case 50 may be filled with a potting resin and the reactor R1 may be sealed with the potting resin. Examples of the potting resin include an epoxy resin, a urethane resin, a silicon resin, and an unsaturated polyester resin.

  As described above, in the reactor of the present invention, one frame-shaped bobbin and the cylindrical bobbin are fitted together, and the cylindrical bobbin and the other frame-shaped bobbin are fitted together, and these are integrated. The bobbin positional relationship is maintained. Therefore, the positional relationship between the intermediate core held by the cylindrical bobbin and the end core attached to the frame bobbin is determined by fitting the cylindrical bobbin and the frame bobbin, and the intermediate core and the end part are determined. The positional relationship with the core is maintained. Moreover, the periphery of the intermediate core (core piece and gap material) is held by the cylindrical bobbin and is sandwiched between the end cores from both sides. And the reactor of this invention is excellent in assemblability, since core components are not fixed using an adhesive agent, and also alignment of core components is unnecessary.

  Note that the present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention. For example, you may change suitably the shape of the fitting part provided in a cylindrical bobbin and a frame-shaped bobbin, a position, and a number. Further, the shape for positioning the end core of the frame-shaped bobbin may be appropriately changed, and may be a concave portion (concave frame) in addition to a convex portion (convex frame).

  The reactor of the present invention can be suitably used for, for example, a DC-DC converter for an electric vehicle such as a hybrid vehicle.

R1 reactor
1 Coil element
1s Start 1e End 1u Bend
2 cores 2m intermediate core 2s end core
20 Core piece g Gap material
3 bobbin 3m cylindrical bobbin 3s frame bobbin
31 Fitting recess 32 Fitting protrusion 33 Convex frame
34 Opening 35 Slit
50 Case 50h Insertion hole 51 Leaf spring

Claims (4)

An annular core having a pair of coil elements arranged in parallel and connected to each other; a pair of intermediate cores on which the respective coil elements are arranged; and a pair of end cores connecting the ends of both intermediate cores; A reactor comprising a bobbin for holding a coil element,
The intermediate core is composed of a plurality of core pieces and a gap material,
The bobbin has a cylindrical bobbin that covers the outer periphery of the intermediate core, and a frame-shaped bobbin that abuts against an end surface of the coil element,
Each of the end surface of the cylindrical bobbin and the one surface of the frame-shaped bobbin facing the surface is provided with a fitting portion that fits each other.
On the other surface of the frame-shaped bobbin, at least one of a concave portion or a convex portion for positioning the end core is formed ,
In the opposite part of the side surface of the cylindrical bobbin, a slit is formed in which one end side in the axial direction is opened and the other end side is closed ,
By the fitting of the cylindrical bobbin and the frame-shaped bobbin, the positional relationship between the intermediate core and the end core and the positional relationship between the core piece and the gap member are maintained without using an adhesive. A reactor characterized by   The frame bobbins have a pair and abut against both end faces of the coil element,
  The reactor according to claim 1, wherein one end of the cylindrical bobbin is fitted to one of the frame-shaped bobbins, and the other end of the cylindrical bobbin is fitted to the other of the frame-shaped bobbins. .   The reactor according to claim 1 or 2, wherein the core piece of the intermediate core is formed of a compacted body.   The converter provided with the reactor of any one of Claims 1-3.

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