JP2009246220A - Reactor, and bobbin for reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reactor which is reducible in size along a coil axis, and to provide a bobbin for the reactor which is suitable for structuring of such a reactor. <P>SOLUTION: The reactor includes a coil formed by spirally coiling a wire to be wound, a core which is fitted in the coil to be formed in an annular shape, and a frame-shaped bobbin 20F in which the core is fitted and which is brought into contact with both ends of the coil. A contact surface of the frame-shaped bobbin 20F for the coil has an inclined surface corresponding to the form of a coil end composed of the wiring. With this constitution, the frame-shaped bobbin 20F is brought into surface contact with the coil end. Consequently, no dead space is formed between the contact surface of the frame-shaped bobbin 20F and the coil end, and the size of the reactor along the coil axis is reducible. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a reactor used for components such as a converter and a bobbin used for the reactor.

  2. Description of the Related Art In recent years, converters that perform voltage step-up / step-down are used in hybrid vehicles that are becoming popular, and a reactor described in Patent Document 1 is known as one of the components of the converter.

  This reactor includes a ring-shaped core made of a magnetic material and a pair of coils formed on a part of the outer periphery of the core as main constituent members. Such a reactor is configured as follows, for example. A pair of coils are formed in advance by edgewise winding a series of rectangular wires. Both coils are arranged in parallel with each other via a connecting portion obtained by bending a part of a flat wire into a hairpin shape. This connecting portion is formed flush with the upper surface of the turn portion of the coil and is formed so as to protrude in the axial direction of the turn portion. On the other hand, the core is assembled. For example, the intermediate core pieces are bonded to each other through a gap plate between a plurality of intermediate core pieces made of a magnetic material, and a resin cylindrical bobbin is mounted around the core piece group. Next, the coil is fitted on the outer side of the intermediate core piece group on which the cylindrical bobbin is mounted. Subsequently, a substantially B-shaped frame-shaped bobbin made of resin is disposed at both ends of the coil, and the frame-shaped bobbin is fitted outside the end of the intermediate core piece group. The frame-shaped bobbin presses the coil that is going to spread by the spring back from both ends, and secures insulation between the coil and the core (end core piece described below). And the cyclic | annular core is formed by connecting the edge parts of an intermediate core piece group with an edge part core piece. Thereby, a part of the core is covered with the coil, and the remaining part is exposed from the coil.

JP 2008-28290 A Fig. 3

  However, the above configuration has a problem in that the size of the reactor cannot be sufficiently reduced due to the form of the frame bobbin.

  Conventionally used frame-shaped bobbins have a contact surface that comes into contact with an end portion of a coil and a plane that is orthogonal to the coil axis direction. On the other hand, since the coil is formed by winding a winding in a spiral shape, its end surface is not a plane orthogonal to the coil axis direction, but an inclined surface corresponding to the winding pitch of the winding. Therefore, when the conventional frame-shaped bobbin is disposed at the end of the coil, a dead space is formed between the contact surface of the frame-shaped bobbin and the coil end surface, which has been an obstacle for miniaturizing the reactor.

  Further, in the conventional frame bobbin, the contact surface and the coil end surface are in line contact, so that the stress applied to the frame bobbin acts locally at the point of line contact with the repulsion of the coil. For this reason, this stress cannot be received in a distributed manner across the entire contact surface of the frame-shaped bobbin, and the frame-shaped bobbin must be thickened to some extent in order to receive stress acting locally. As a result, the size of the reactor in the coil axis direction could not be reduced due to the occurrence of the dead space and the thickness of the frame bobbin itself.

  The present invention has been made in view of the above circumstances, and one of its purposes is a reactor capable of reducing the size in the coil axis direction, and a reactor bobbin that is optimal for constructing such a reactor. And to provide.

  The reactor of this invention achieves said objective by devising the shape of the contact surface of a frame-shaped bobbin.

  A reactor according to the present invention includes a coil formed by winding a winding in a spiral shape, a core that is fitted into the coil and formed into an annular shape, a frame-shaped bobbin that is fitted into the coil and is in contact with both ends of the coil, Is provided. And the contact surface with the coil in a frame-shaped bobbin is provided with the inclined surface corresponding to the form of the coil end part comprised by winding.

  According to this configuration, since the contact surface of the frame-shaped bobbin with the coil has an inclined surface corresponding to the form of the coil end portion, the frame-shaped bobbin can be brought into surface contact with the coil end surface. . Therefore, there is no dead space between the contact surface of the frame bobbin and the coil end surface, and the dimension of the reactor in the coil axis direction can be reduced.

  In addition, since the contact surface of the frame bobbin and the coil end surface can be brought into surface contact, the stress applied to the frame bobbin due to the repulsion of the coil can be distributed and received in a wide area of the contact surface. The thickness of the bobbin can be reduced. Therefore, downsizing of the reactor in the coil axis direction can be realized even by thinning the frame-shaped bobbin.

  On the other hand, the reactor bobbin of the present invention is used for a reactor including a coil formed by winding a winding in a spiral shape and a core that is fitted into the coil and formed in an annular shape. The bobbin has a frame shape in which the core is fitted and is in contact with both ends of the coil, and the contact surface of the bobbin with the coil is an inclined surface corresponding to the form of the coil end formed by the winding. It is characterized by providing.

  According to this configuration, the contact surface of the frame-shaped bobbin and the end surface of the coil can be brought into surface contact in the same manner as the reactor of the present invention described above. Thereby, the dead space between the frame-shaped bobbin and the coil end surface can be eliminated, and the frame-shaped bobbin itself can be thinned. As a result, the reactor can be downsized.

  According to the reactor of this invention, the dimension of the coil axial direction in a reactor can be made small.

  Moreover, according to the reactor bobbin of the present invention, it is possible to construct a reactor having a reduced size in the coil axis direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Based on FIGS. 1-8, the frame-shaped bobbin and reactor of this invention are demonstrated. The reactor of this invention has the main characteristics in the form of a frame-shaped bobbin, and the basic composition of the coil and core which comprise a reactor is common in the past. However, prior to describing the frame-shaped bobbin of the present invention, the configuration of the coil that contacts the frame-shaped bobbin will be described.

<Coil>
As shown in FIG. 1, the coil 10 is formed by spirally winding a rectangular copper wire (winding) having an insulating coating in an edgewise manner, and is arranged in parallel in a direction orthogonal to the axial direction. It consists of a pair of second coils 10B. The first and second coils 10A and 10B are coils having the same number of turns and a substantially rectangular shape when viewed from the axial direction. Further, both the coils 10A and 10B are constituted by a single winding without a joint. That is, on one end side of the coil 10, the start end 11 and the end end 12 of the winding are drawn upward, and on the other end side of the coil 10, the first coil 10A and the first coil 10A are connected via the connecting portion 13 bent in a hairpin shape. The second coil 10B is connected. With this configuration, the winding directions of the first coil 10A and the second coil 10B are the same. The both end surfaces of the coil 10 are provided with surfaces that are inclined with respect to the coil axis direction in accordance with the winding pitch of the winding.

<Frame bobbin>
On the other hand, the frame-shaped bobbin 20 is disposed at both ends of the coil and has a function of pressing the coil. More specifically, the frame-shaped bobbin 20F (FIGS. 2 to 4) that abuts on one end surface (starting end 11 and end 12 side) of the coil 10 and the other end surface of the coil (connecting portion 13 side). Frame-shaped bobbin 20B (FIGS. 5 to 8). The greatest feature of these frame-shaped bobbins is that the contact surface with the coil end surface has an inclined surface according to the form of the coil end surface. Hereinafter, each of the frame bobbins 20F and 20B will be described in order.

  First, the frame-shaped bobbin 20F has a substantially B-shaped substrate frame 24 having two rectangular openings 22, a partition 26 provided between both openings 22 of the substrate frame 24, and the substrate frame 24 from each opening 22. And a protruding frame portion 28 protruding in the thickness direction.

  One surface (FIG. 2A) of the substrate frame 24 is a contact surface that contacts one end surface of each coil, and the other surface (FIG. 2B) is a non-contact surface. Here, the contact surface has a shape adapted to the shape of the one end surface of the coil. Specifically, as shown in FIG. 3, among the contact surfaces of the substrate frame 24, the right side portion of the figure becomes the contact surface with the first coil 10A (FIG. 1) and gradually increases in the clockwise direction. It is composed of an inclined surface so as to be thick. For example, as shown in FIG. 4 (A), the DD cross section of FIG. 3 is configured such that the upper part is thinner and thicker toward the lower side, and the CC cross section of FIG. 3 is as shown in FIG. 4 (B). In addition, the lower part is thin and the thickness is increased toward the upper part. The left side portion of the contact surface of the substrate frame 24 is a contact surface with the second coil 10B (FIG. 1), and is configured with an inclined surface so as to gradually increase in the clockwise direction. Yes. For example, as shown in FIG. 4C, the BB cross section in FIG. 3 is configured such that the upper part is thin and thicker toward the lower side, and the FF cross section in FIG. 3 is as shown in FIG. In addition, the lower part is thin and the thickness is increased toward the upper part.

  On the other hand, the non-contact surface of the substrate frame 24 is configured by a plane orthogonal to the axial direction of the opening 22. In this example, the upper corner of the substrate frame 24 from which the starting end 11 and the terminal end 12 (FIG. 1) of the coil are drawn is formed at a substantially right angle, and the lower corner of the substrate frame 24 is bent to the coil 10 (FIG. 1). It is formed in an arc shape along.

  Near the center of the substrate frame 24, there is a partition portion 26 composed of protrusions extending in the height direction. The partition part 26 is fitted between the first coil and the second coil, and maintains the interval between the two coils.

  Further, the protruding frame portion 28 is interposed between the core and the coil 10 (FIG. 1), and is used to position the coil 10 coaxially with respect to the core.

  Next, the frame-shaped bobbin 20B is formed by a substantially E-shaped substrate edge 21, a flat base portion 23 protruding upward in the direction perpendicular to the substrate edge 21, and a substrate edge 21 and the flat base portion 23. A projecting frame portion 27 projecting from the pair of openings 25 in the thickness direction of the substrate edge 21, and a partition portion 29 provided between the openings 25 in the substrate edge 21.

  The frame-shaped bobbin 20B is different from the frame-shaped bobbin 20F in that a flat base part 23 is provided. A coil connecting portion 13 (FIG. 1) is disposed on the flat base portion 23.

  Here, one surface (FIG. 5A) of the substrate edge 21 is a contact surface that contacts one end surface of each coil, and the other surface (FIG. 5B) is a non-contact surface. This abutting surface has a shape that matches the shape of the one end surface of the coil 10. Specifically, as shown in FIG. 6, among the contact surfaces of the substrate edge 21, the right side portion in the figure becomes the contact surface with the second coil 10 </ b> B and gradually increases in thickness clockwise. It consists of an inclined surface. For example, as shown in FIG. 7A, the DD cross section of FIG. 6 is configured such that the upper part is thin and thicker as it goes downward, and the CC cross section of FIG. 6 is as shown in FIG. In addition, the lower part is thin and the thickness is increased toward the upper part. Further, of the contact surface of the substrate edge 21, the left portion in the figure is a contact surface with the first coil 10A, and is configured with an inclined surface so as to gradually increase in thickness clockwise. For example, as shown in FIG. 7C, the BB cross section in FIG. 6 is configured so that the upper part is thin and thicker toward the lower side, and the FF cross section in FIG. 6 is as shown in FIG. 7D. In addition, the lower part is thin and the thickness is increased toward the upper part.

  These frame-shaped bobbins 20F and 20B can be obtained by casting a resin material. As a specific resin material, a material having excellent insulation and heat resistance that does not soften with respect to the use temperature of the reactor is preferable. For example, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), epoxy and the like can be mentioned.

<Reactor>
The frame-shaped bobbin having the above-described configuration forms a reactor by combining a core with a coil already described.

  Here, as shown in FIG. 8, the core 30 is configured using a total of six intermediate core pieces 32, a pair of end core pieces 34, and a total of four gap plates 36. The intermediate core piece 32 and the end core piece 34 can be formed of a compacted body of magnetic powder or a laminate of electromagnetic steel plates, and the gap plate 36 can be formed of a nonmagnetic material such as alumina.

  First, a rectangular gap plate 36 is interposed between the three block-shaped intermediate core pieces 32 and joined with an adhesive to form an intermediate core piece group, and a pair of core piece groups are prepared.

  Next, a cylindrical bobbin (not shown) is disposed outside each core piece group. The cylindrical bobbin is a member for positioning the coil 10 coaxially with respect to the core piece group. Usually, a known cylindrical bobbin formed into a square pipe shape by combining a pair of divided pieces having a U-shaped cross section can be used.

  Next, the coil 10 is fitted on the outside of the intermediate core piece group on which the cylindrical bobbin is mounted. That is, one core piece group is arranged in the first coil 10A, and the other core piece group is arranged in the second coil 10B.

  Subsequently, the frame-shaped bobbin 20F is attached to the ends of the coils 10A and 10B, that is, one end side, and the frame-like bobbin 20B is attached to the other end side. At this time, the projecting frame portions 28 and 27 of the frame-shaped bobbins 20F and 20B are arranged in series with the cylindrical bobbin and are interposed between the intermediate core piece group and the coils 10A and 10B. Further, the connecting portion 13 of the coil 10 is arranged on the upper part of the flat base portion 23 of the frame-shaped bobbin 20B.

  And a pair of edge part core piece is arrange | positioned so that both frame-shaped bobbins 20F and 20B may be pinched | interposed, and these are joined to the edge part of a core piece group with an adhesive agent. The end core piece 34 is a flat block having a size connecting between a pair of core pieces, that is, an area substantially equal to the frame-shaped bobbins 20F and 20B. Thereby, the annular core 30 is formed.

  As described above, since the frame-shaped bobbins 20F and 20B of the present invention have an inclined surface adapted to the end face of the coil, the abutting face and the end face of the coil can be brought into surface contact, and a dead space between both faces Is not formed. In addition, by bringing the contact surface and the coil end surface into surface contact, the stress applied to the frame bobbins 20F and 20B due to the repulsion of the coil 10 can be distributed and received over a wide area of the contact surface. The thickness of the bobbins 20F and 20B can be reduced. As a result, the dimensions of the reactor in the coil axis direction can be reduced. Furthermore, by increasing the contact area between the coil 10 and the frame-shaped bobbins 20F and 20B, the heat of the coil 10 can be easily radiated through the bobbins 20F and 20B.

  For example, the frame-shaped bobbins 20F and 20B according to the present invention are each made thinner by about 2.2 to 2.3 mm than a conventional frame-shaped bobbin having a uniform thickness and a plane that is perpendicular to the coil axis direction. be able to. Therefore, when both the frame-shaped bobbins 20F and 20B are combined, a space of about 4.5 mm can be used for reducing the size of the reactor. Of course, this space may be used effectively for the arrangement of other members to increase the design freedom of the reactor.

<Other configurations>
At least one of the following configurations can be further added to the reactor according to the above embodiment.

(Case)
The case houses the above-described assembly of the coil and the core, and dissipates heat from the assembly through the case. This case is usually a container having a front, back, left, and right side surfaces and a bottom surface, and an open top. As a constituent material of the case, a metal material having high heat dissipation such as aluminum or aluminum alloy can be suitably used. However, in the reactor of the present invention, the assembly of the core and the coil may be used as it is as a reactor without being housed in the case, or may be housed in the case. If the case is not used, the reactor can be downsized. On the other hand, when the case is used, it is easy to mechanically protect the core and coil assembly. Usually, the sealing material described below is filled between the assembly and the case.

(Encapsulant)
The encapsulant covers the periphery of the coil and core assembly and provides mechanical protection for the assembly. In addition, the functions of the sealing material include absorbing vibration generated when the reactor is excited, and mechanically and electrically protecting the coil by covering it. In addition, when a case is used, the function of further increasing the insulation between the coil and the case, the function of holding the components such as the core and the coil housed in the case, or the heat of the coil is conducted to the case. It also has a function to make it. Of course, when the case is not used, the assembly of the coil and the core may be covered with a sealing material. As this sealing material, an insulating material that does not soften at the maximum temperature reached by the core or coil can be suitably used. For example, an epoxy resin, a urethane resin, etc. are mentioned.

  Next, a frame-shaped bobbin having a configuration different from that of the first embodiment will be described with reference to FIG. FIG. 9 shows a state in which the cylindrical bobbin 20M is disposed between the pair of frame-shaped bobbins 20F and 20B, and one intermediate core piece 32 is inserted into the cylindrical bobbin 20M.

  The frame-shaped bobbins 20F and 20B according to the first embodiment are configured to be used for a pair of coils 10 arranged in parallel through a connecting portion 13 in a series of windings, and a flat base portion 23 for arranging the connecting portion 13 is used. Although one frame-shaped bobbin 20B is provided, the frame-shaped bobbins 20F and 20B of this example are different from the frame-shaped bobbin of Example 1 in that they do not have a flat base portion. That is, the frame-shaped bobbins 20F and 20B of this example are used for welding type coils. For the welding type coil, for example, a pair of first and second coils each composed of independent windings are prepared, both coils are arranged in parallel, and the winding ends of each coil are connected to one end side of the coil. This is a coil (not shown) connected by welding. For example, the leading end of the first coil is the leading portion 20FS of the frame-shaped bobbin 20F, the terminal end of the coil 10A is the leading portion 20BE of the frame-shaped bobbin 20B, and the terminal end 12 of the second coil 10B is the leading portion 20FE of the frame-shaped bobbin 20F. In addition, the starting end of the coil 20F may be disposed on the lead-out portion 20BS of the frame-shaped bobbin 20B. Therefore, since the welding location is provided at the upper part of the turn of the coil 10, it is not necessary to provide a flat base part for arranging the coil connection part in the frame-like bobbins 20F and 20B of this example.

  Also in the configuration of this example, each contact surface of both frame-shaped bobbins 20F and 20B has an inclined surface adapted to the end surface of the coil 10, so that the frame-shaped bobbins 20F and 20B are similar to the first embodiment. The contact surface and the coil end surface can be brought into surface contact. As a result, it is possible to avoid the formation of a dead space between the contact surface and the coil end surface, and it is possible to reduce the size of the reactor by reducing the thickness of each frame-shaped bobbin 20F, 20B.

  Each of the above-described embodiments can be appropriately changed without departing from the gist of the present invention, and the present invention is not limited to the above-described configuration. For example, the winding of the coil is not limited to a rectangular wire, and may be a wire having a circular or polygonal cross section. In that case, the shape of the contact surface of the frame-shaped bobbin may be changed in accordance with the surface shape of the winding. Moreover, you may change suitably the external shape and number of an intermediate | middle core piece or an edge part core piece. In addition, a core without a gap material may be used.

  The coil of the present invention can be used as a component of a reactor, and the reactor of the present invention can be used as a component such as a converter. In particular, it can be suitably used as a reactor for automobiles such as hybrid cars and electric cars.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a coil used in a reactor of the present invention related to Example 1. It is a perspective view of this invention frame-shaped bobbin 20F which concerns on Example 1, (A) shows a contact surface side, (B) shows a non-contact surface side. (A) is a front view of this invention frame-shaped bobbin 20F which concerns on Example 1, (B) is the bottom view. (A) is a sectional view taken along the line DD in FIG. 3, (B) is a sectional view taken along the line CC in FIG. 3, (C) is a sectional view taken along the line BB in FIG. 3, and (D) is a diagram. 3 is a cross-sectional view taken along line FF in FIG. It is a perspective view of this invention frame-shaped bobbin 20B which concerns on Example 1, (A) shows a contact surface side, (B) shows a non-contact surface side. (A) is the front view of this invention frame-shaped bobbin 20B which concerns on Example 1, (B) is the bottom view. (A) is a cross-sectional view taken along the line DD in FIG. 6, (B) is a cross-sectional view taken along the line CC in FIG. 6, (C) is a cross-sectional view taken along the line BB in FIG. FIG. 6 is a cross-sectional view of FIG. It is assembly explanatory drawing of this invention reactor which concerns on Example 1. FIG. It is an assembly perspective view of the present invention frame shape bobbin concerning Example 2. FIG.

Explanation of symbols

10 coils
10A 1st coil 10B 2nd coil
11 Start 12 End 12 Connection
20, 20F, 20B Frame bobbin
22 Opening 24 Board frame 26 Partition 28 Projection frame
21 Board edge 23 Flat base 25 Opening 27 Projection frame 29 Partition
20FS, 20FE, 20BS, 20BE drawer
20M cylindrical bobbin
30 cores
32 Intermediate core piece 34 End core piece 36 Gap plate

Claims (2)

A reactor comprising a coil formed by winding a winding in a spiral shape, a core that is inserted into the coil and formed into an annular shape, and a frame-shaped bobbin that is fitted into the coil and abuts on both ends of the coil. ,
The reactor in which the contact surface with the coil in the said frame-shaped bobbin is provided with the inclined surface corresponding to the form of the coil end part comprised by winding. A reactor bobbin used for a reactor including a coil formed by winding a winding in a spiral shape and a core that is fitted into the coil and formed in an annular shape,
This bobbin has a frame shape in which the core is fitted and is in contact with both ends of the coil.
A bobbin for a reactor, wherein a contact surface of the bobbin with a coil includes an inclined surface corresponding to a form of a coil end portion constituted by a winding.

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