JP2013021217A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor having improved vibration resistance.SOLUTION: A reactor (100) includes a coil (13a) and a bobbin (16) for supporting the coil (13a). The coil (13a) is formed by winding a conducting wire (12) around a core (14a) of the bobbin (16). Flanges (15a, 15b) are continuous with ends of the core (14a) of the bobbin (16). Biasing means (a leaf spring (17a)) for biasing the coil (13a) in an axial direction is disposed between the end flange (15a) and an end of the coil (13a). The coil (13a) is firmly fixed to the bobbin (16) by the leaf spring (17a).

Description

  The present invention relates to a reactor (passive element using a coil).

  The reactor is a passive element used for power factor improvement, harmonic current suppression (direct current smoothing), and the like. The reactor may also be used in a device that boosts a DC voltage.

  In recent years, hybrid cars and electric cars have been put into full-scale use, and the number of them used is rapidly increasing. Since hybrid vehicles and electric vehicles use a motor as a driving force, a reactor is provided in the drive circuit. In these automobiles, a large capacity reactor (a motor with high power consumption) is driven, and thus a large capacity reactor is required. The main component of the reactor is a coil, and a force that vibrates the reactor itself is generated by an alternating magnetic field generated when an alternating current is passed through the coil. In a hybrid vehicle or an electric vehicle, a large current flows through the reactor, so that the vibration force is increased. It is necessary to suppress the vibration of the coil against the force causing the self-excited vibration.

  One technique for improving the vibration resistance of electronic components such as reactors is called potting. Examples thereof are disclosed in Patent Document 1 and Patent Document 2. Potting means placing a reactor or other electronic component in the housing, and then injecting a fluid insulating material such as silicone resin (an insulator that solidifies later) into the housing, thereby filling all or part of the electronic component. Technology. Since the heat of the electronic component is diffused through the potting material, the potting material also contributes to cooling of the electronic component.

JP 2009-99793 A JP 2010-273422 A

  This specification provides the technique which improves the vibration resistance of a reactor.

  The force generated when the alternating current flows is a force that vibrates the coil in the axial direction. When the coil vibrates in the axial direction, adjacent conductors may be displaced from each other, or the conductors may slide to peel off the coating. Therefore, in the reactor disclosed in the present specification, the axial fixation of the coil is strengthened, thereby improving the vibration resistance of the reactor.

  In one aspect of the reactor disclosed in this specification, a bobbin around which a conducting wire is wound is provided. A coil is formed on the outer periphery of the bobbin. The bobbin has a core around which the coil is wound and a flange that extends to the end of the core and extends outward from the core. Further, the novel reactor disclosed in the present specification includes a biasing unit that biases the coil in the axial direction between the coil end portion and the end flange. In this reactor, the urging means presses the coil in the axial direction to strengthen the fixing of the coil, and the conductors (windings) forming the coil are displaced, or the conductors slide against each other to remove the coating. Is prevented.

  A suitable example of the biasing means is a curved leaf spring. In one embodiment of the leaf spring, both end portions thereof are in contact with one of the flange and the coil end portion, and the center portion of the leaf spring is in contact with the other of the flange and the coil end portion. In another preferred embodiment of the leaf spring, a cantilever leaf spring in which one end is supported by the flange and the other end abuts on the coil end may be used. Alternatively, in still another aspect, the bobbin flange itself may constitute the biasing means. In this case, a part of the flange is curved in the axial direction and protrudes toward the coil end, and the curved part (a part of the flange that is curved toward the coil end) is the coil end. Abut. The coil is pressed by the elastic force of the bending portion. Since such an urging means is created at the same time as bobbin molding, the urging means can be prepared at low cost. The urging means is preferably arranged at a symmetrical position with the coil center in between when the coil is viewed from the axial direction. Such an arrangement can bias the coil in a balanced manner and stably fix the coil.

  The biasing means is also preferably used in combination with a conventional potting technique. That is, the space between at least a part of the coil and the housing that houses the coil may be filled with the potting material. Furthermore, when either one of the urging means and the potting is strong, it is also preferable to make the potted portion half or less of the coil when viewed from the axial direction. Such a structure can significantly reduce the amount of potting material used and reduce the cost of the reactor itself. Further, in addition to potting, a sheet-like insulating / heat dissipating material such as a heat dissipating sheet is also suitable when disposed between the lower surface of the coil and the case.

It is a typical side view of a reactor. It is a typical top view of a reactor. It is a figure of a flange when it sees in the direction of arrow III of FIG. It is a figure which shows the other example of a biasing means. It is a typical side view of the 1st modification. It is a typical side view of the 2nd modification. It is a typical side view of the 3rd modification. It is a typical side view of the 4th modification. It is a typical side view of the 5th modification. It is a typical side view of the 6th modification.

  Preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view of a reactor 100 according to the first embodiment. FIG. 2 is a schematic top view of the reactor 100. FIG. 1 shows a cross section of only the housing 2, and other parts are depicted as side views. The hatching attached to the housing 2 in FIG. 1 represents the cross section of the housing 2. Moreover, illustration of the housing | casing 2 and a potting material is abbreviate | omitted in FIG. In the coordinate system in the figure, the X and Y axes indicate the horizontal direction, and the Z axis indicates the vertical direction. From the coordinate axes shown in FIGS. 1 and 2, the correspondence between the orientation of the reactor 100 depicted in FIG. 1 and the orientation of the reactor 100 depicted in FIG. 2 will be understood.

  As can be understood from FIG. 2, in the reactor 100, the bobbin 16 around which the conducting wire 12 is wound is constituted by two cores 14a and 14b and flanges 15a and 15b. The two cores 14a and 14b are arranged in parallel, and both ends thereof are connected by flanges 15a and 15b. The bobbin 16 is made of resin, and the cores 14a and 14b are hollow. The core 20a passes through the inside of the core 14a, and the core 20b passes through the inside of the core 14b. As is apparent from the figure, the “flange” of the bobbin is a portion that continues to the end of the cores 14a and 14b around which the conducting wire 12 is wound, and a portion that extends outward from the cores 14a and 14b in the radial direction. means.

  The conductive wire 12 is wound around the bobbin 16 to form the coils 13a and 13b. The conducting wire 12 is wound around one core 14a and then wound around the other core 14b. A coil 13a is formed by the conductive wire 12 wound around the core 14a, and a coil 13b is formed by the conductive wire 12 wound around the core 14b. In the present embodiment, the conducting wire 12 is a flat wire.

  Support brackets 22 are attached to four locations outside the flanges 15a and 15b (outside in the bobbin axial direction). Bolt holes are formed in the support fitting 22. The bobbin 16 is fixed to the housing 2 by a bolt 24 through the metal fitting 22. It should be noted that reference numerals are omitted for the left side support bracket and bolt in FIG. 1 and the support bracket and bolt other than the lower right side in FIG.

  As shown in FIG. 1, the lower half of the coil 13a (13b) is covered (potted) with an insulating silicon resin P. That is, the space between the lower half of the coil 13a (13b) and the housing 2 is filled with the silicon resin P (potting material). In FIG. 2, the casing 2 and the silicone resin P (potting material) are not shown. In FIG. 1, an arrow indicating the potting depth is marked on the left side of the reactor 100. The upper end of the arrow indicating the potting depth H is just at the position reaching the center line of the coil 13a.

  As shown in FIGS. 1 and 2, leaf springs 17a and 17b are inserted into the gap between the flange 15a of the bobbin 16 and the end of the coil 13a. The leaf spring 17a is a curved leaf spring made of metal. The leaf spring 17a is curved in an arcuate shape. Both ends of the leaf spring 17a are in contact with the flange 15a, and the central portion is in contact with the end of the coil 13a. The leaf spring 17b has a similar shape. The leaf springs 17a and 17b are compressed and inserted between the flange 15a and the end of the coil 13a. That is, the leaf springs 17a and 17b press the coil 13a toward the opposite flange 15b in the axial direction.

  As shown in FIG. 2, leaf springs 17c and 17d are similarly inserted in the gap between the flange 15b and the end of the coil 13b. The shape of the leaf springs 17c and 17d is the same as that of the leaf spring 17a. As shown in FIG. 2, the gap between the flange 15b and the coil 13b at the position of the leaf spring 17c is one width of the conductor 12 than the gap between the flange 15b and the coil 13b at the position of the leaf spring 17d. Only big. For this reason, the leaf spring 17c is curved larger than the leaf spring 17d.

  FIG. 3 shows the flange 15b when viewed from the direction indicated by the arrow III in FIG. Dashed lines indicated by symbols Pos_2 and Pos_4 indicate locations where the leaf springs 17c and 17d are disposed. A symbol Cb indicates the center of the coil 13b. As is apparent from FIG. 3, the leaf springs 17c and 17d are disposed at symmetrical positions with the coil center Cb interposed therebetween when the coil is viewed from the axial direction. The arrangement of the leaf springs 17a and 17b is the same, and is arranged at a symmetrical position with the center of the coil 13a interposed therebetween. With such an arrangement of leaf springs, the coils are biased equally in the axial direction. As is clear from FIG. 3, the cross sections of the bobbin cores 14a and 14b are rectangular. Therefore, the coils 13a and 13b also have a rectangular cross section. The cores 14a and 14b are hollow, and the cores 20a and 20b are inserted therethrough.

  The coil spring 13 a is pressed in the axial direction by the leaf springs 17 a and 17 b and is firmly fixed to the bobbin 16. The coil 13 b is urged in the axial direction by the leaf springs 17 c and 17 d and is firmly fixed to the bobbin 16. Since the leaf springs 17a to 17d firmly fix the coils 13a and 13b, it is not necessary to cover the entire coils 13a and 13b with a potting material in order to obtain sufficient vibration resistance. In this embodiment, as shown in FIG. 1, it is sufficient to bury half of the coils 13a and 13b with silicon resin P (potting material) to ensure the desired vibration resistance. This reactor 100 can save the amount of potting material than before by adopting the leaf springs 17a to 17d.

  With reference to FIG. 4, an alternative to the leaf spring will be described. Hereinafter, the term “biasing means”, which is a generic concept of “plate spring”, is used as a general term for the leaf spring 17 and its alternatives. FIG. 4A shows the leaf spring 17 of the embodiment shown in FIG. The urging means shown in FIG. 4B is a cantilever type leaf spring 217. In the plate spring 217, a flat metal plate and a curved metal plate are connected to each other at one end. One end of the curved metal plate (the end joined to the other metal plate) is supported by the flange 15, and the other end is in contact with the coil 13.

  The biasing means shown in FIGS. 4C to 4F is formed by bending a part of the flange 15. FIG. 4C is a part of the flange 15 and is curved so that a region facing the end of the coil 13 protrudes toward the coil. In other words, the areas Pos_1, Pos_2, Pos_3 and Pos_4 in FIG. The elastic force of the bending portion 317 biases the coil 13 in the axial direction. In FIG. 4C, both ends of the curved portion 317 are connected to the flat portion of the flange 15. In FIG. 4 (D), it is a part of the flange 15 and is curved so that a region facing the end of the coil 13 protrudes toward the coil, but one end of the curved part 417 is a flat portion of the flange 15. It is separated from. That is, the curved portion 417 has a cantilever shape. The other end of the bending portion 417 is in contact with the coil 13, and the elastic force of the bending portion 417 biases the coil 13 in the axial direction.

  FIG. 4E is a part of the flange 15 and a region facing the end of the coil 13 is curved in a direction away from the coil. Two pins 517 b extend from the curved portion 517 a toward the coil 13. The pin 517b is also integrally formed with the flange 15 similarly to the curved portion 517. The elastic force of the bending portion 517a biases the coil 13 through the pin 517b. In FIG. 4E, both ends of the curved portion 517 a are connected to the flat portion of the flange 15. The urging means in FIG. 4 (F) has substantially the same shape as the urging means in FIG. 4 (E), but one end of the bending portion 617a is separated from the flat portion of the flange 15, and the bending portion 617a is a piece. Have a possession. The elastic force of the bending portion 617a biases the coil 13 via the pin 617b. The flange 15 is made of resin and is formed by injection molding. Therefore, the urging means shown in FIGS. 4C to 4F is formed simultaneously with the flange by injection molding.

  FIG. 5 shows a first modification of reactor 100. Reactor 101 in FIG. 5 is different from reactor 100 in FIG. 1 in the range in which potting material P is filled. In the reactor 101 of FIG. 5, the range from the bottom surface of the housing 2 to the lower end of the coil 13 is filled with the potting material P. Further, on the outside of the bobbin 16 in the axial direction, the range from the bottom surface of the housing 2 to the lower end of the support fitting 22 is filled with the potting material P. In the reactor 100 of FIG. 1, the head of the bolt 24 is covered with the potting material P. However, in the reactor 101 of FIG. 5, the head of the bolt 24 is exposed.

  FIG. 6 shows a second modification of reactor 100. Reactor 102 in FIG. 6 is filled with potting material P in the range from the lower surface of housing 2 to the lower end of coil 13a. In the axial direction of the coil, only the range corresponding to the axial width W of the coil 13 is filled with the potting material P.

  FIG. 7 shows a third modification of reactor 100. The reactor 103 in FIG. 7 covers the entire coil with another insulating resin P2 separately from the potting material P1 filling the lower half of the coil. Although the insulating resin P2 covers the entire coil 13 and the bobbin 16, the insulating resin P2 is drawn only around the coil 13 and the bobbin 16 for easy understanding in FIG. In this embodiment, before the assembly of the coil 13 and the bobbin 16 is assembled to the casing, the entire assembly is covered with the insulating resin P2, and then the assembly is assembled to the casing, and the potting material P1 is filled. In this aspect, in order to cover the entire coil with the insulating resin P2, a leaf spring having smaller spring stiffness than the leaf springs 17a to 17d used in the reactor 100 of FIG. 1 may be employed.

  FIG. 8 shows a fourth modification of reactor 100. The reactor 104 in FIG. 8 is an example in which the range from the bottom surface of the housing 2 to the lower end of the coil 13 is filled with the first potting material P1, and the upper half of the coil 13 is covered with another second potting material P2. It is. The reactor 104 in FIG. 8 corresponds to the reactor 101 shown in FIG. 5 with the second potting material P2 on the upper side of the coil added. In the reactor 104, the head of the bolt 24 that fixes the bobbin 16 to the housing 2 is exposed.

  FIG. 9 shows a fifth modification of reactor 100. The reactor 105 in FIG. 9 is a range from the bottom surface of the housing 2 to the lower end of the coil 13, and only the range corresponding to the width W of the coil 13 in the axial direction is filled with the first potting material P1. In this example, the upper half of 13 is covered with another second potting material P2. The reactor 105 in FIG. 9 corresponds to the reactor 102 shown in FIG. 6 with the second potting material P2 on the upper side of the coil added.

  FIG. 10 shows a sixth modification of reactor 100. In the reactor 106 of FIG. 10, leaf springs are disposed at both ends of the coil 13. A leaf spring 17a is inserted between the right end of the coil 13 and the flange 15a, and a leaf spring 17e is inserted between the left end of the coil 13 and the flange 15b. In FIG. 10, the leaf spring is also disposed on the other side of the core 14 of the bobbin 16. That is, the leaf springs are disposed at symmetrical positions on both ends of the coil with the center of the coil interposed therebetween.

  Further, the rigidity of the left leaf spring 17e is stronger than that of the right leaf spring 17a, so that the gap Gb between the coil 13 and the flange 15b is larger than the gap Ga between the coil 13 and the flange 15a. It has become. It is also preferable to arrange urging means at both ends of the coil as in the reactor 106 of FIG.

  Points to be noted regarding the reactor of the embodiment will be described. As shown in FIG. 3, in the reactor 100, the urging means (plate spring 17) is disposed at two symmetrical positions (Pos_2 and Pos_4) with the coil center Cb interposed therebetween. The location of the biasing means may be two locations, Pos_1 and Pos_3 in FIG. Furthermore, the urging means may be arranged at four places (Pos_1, Pos_2, Pos_3, and Pos_4) surrounding the coil center Cb.

  As shown in FIG. 2, at the upper end portion of the coil 13b, the conducting wire 12 is drawn out halfway, so that the width of the gap between the coil end portion and the flange 15b is different between the right side and the left side of the coil 13b. When the gap widths are different as described above, it is also preferable to dispose urging means corresponding to the gap width. Specifically, a stronger biasing means may be arranged at a location where the gap width is larger than at a location where the gap width is small. More specifically, when the spring rigidity is the same, a spring having a natural length longer than that of a spring disposed at a position where the gap width is small may be disposed at a position where the gap width is large.

  The biasing means is not limited to a part of a metal leaf spring or a resin flange. For example, the biasing means may be made of a rubber material. The conducting wire forming the coil is not limited to a flat wire, and may be a round wire. As is apparent from FIG. 3, the coils 13a and 13b of the reactor 100 have a rectangular cross section. The coil cross-sectional shape is not limited to a rectangle, and may be a circle.

  The bobbin 16 is not limited to resin. The cores 20a and 20b passing through the center of the coil are typically a metal mainly composed of iron. The cores 20a and 20b may be made of a magnetic material such as iron, nickel, and cobalt mixed with a ceramic or epoxy resin insulating material such as silica or alumina. As a potting material, an epoxy resin, a urethane resin, or the like may be used in addition to an insulating silicon resin. As the potting material, a material having an insulating property and a fluidity at the beginning but having a property of decreasing the fluidity when time passes is used. Furthermore, since the potting material also contributes to the heat dissipation of the coil, it is preferable that the potting material is a substance having a high thermal conductivity.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Housing 12: Conductive wires 13a, 13b: Coils 14a, 14b: Cores 15a, 15b: Flange 16: Bobbins 17a, 17b, 17c, 17d, 17e: Leaf springs (biasing means)
20a, 20b: Cores 100, 101, 102, 103, 104, 105, 106: Reactors 217, 317, 417, 517, 617: Energizing means

Claims (6)

  A reactor comprising biasing means for biasing the coil in an axial direction between an end of the coil wound around the bobbin and an end flange of the bobbin.   The reactor according to claim 1, wherein a space between at least a part of the coil and a housing that houses the coil is filled with a potting material.   The reactor according to claim 2, wherein a portion of the coil covered with the potting material is equal to or less than half of the coil as viewed from the axial direction.   The reactor according to any one of claims 1 to 3, wherein the urging means is disposed at a symmetrical position across the coil center when the coil is viewed from the axial direction.   The biasing means is a curved leaf spring, both ends of the leaf spring are in contact with one of the flange and the coil end, and the center of the leaf spring is in contact with the other of the flange and the coil end. The reactor of any one of Claim 1 to 4 characterized by these.   The biasing means is a part of a flange of the bobbin, a part of the flange is curved and protrudes toward the coil end, and the curved part is in contact with the coil end. The reactor according to any one of 1 to 4.

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