JP4855227B2 - Choke coil unit and power device using the same - Google Patents

Description

  The present invention relates to a choke coil used for a high-current power device of several tens of A or more, and a power device using the same.

  Generally, in a power device with a large current of several tens of A or more, a choke coil is used for applications such as power source smoothing and noise filter. As the choke coil, conventionally, a cross-section circular electric wire or a rectangular electric wire having a large wire diameter is used. For example, a choke coil according to the prior art described in Patent Document 1 has a configuration in which a rectangular electric wire is laminated in a glasses shape and wound.

Japanese Patent Laid-Open No. 07-130560

  By the way, a choke coil wound with a flat wire to allow a large current is large and heavy. For this reason, the terminal portion connecting the choke coil and other components is likely to be loosened due to vibration during transportation or the like. Moreover, since the flat electric wires are laminated and wound, it is difficult to dissipate heat generated by the flat electric wires. As a countermeasure, if a rectangular electric wire with a large cross-sectional area is used to suppress the temperature rise of the choke coil, there is a problem that it becomes larger and heavier.

  The present invention has been made in order to solve the above problems, and has a high vibration resistance, excellent heat dispersion and heat dissipation, and can use a low-cost electric wire with a thin wire diameter. It aims at providing a coil unit and a power apparatus using the same.

In order to achieve the above object, a choke coil unit according to a first invention includes a plurality of choke coils formed by winding an electric wire around a ring-shaped magnetic core, and a printed circuit board on which these choke coils are mounted. And an air path mechanism that covers each of the choke coils and the printed circuit board, the choke coils are arranged in a triangular lattice pattern on the printed circuit board, and the choke coils and the printed circuit board are The position where the adhesive is fixed by adhesive and the adhesive is fixed by the adhesive guides the wind flowing between the choke coil and the printed circuit board from the inlet to the outlet of the air passage mechanism toward the center of the choke coil. As described above, the air passage mechanism is characterized by being on the exit side .
The choke coil unit according to the second invention includes a plurality of choke coils formed by winding an electric wire around a ring-shaped magnetic core, a printed circuit board on which these choke coils are mounted, each of the choke coils, An air passage mechanism that covers the printed circuit board, the choke coils are arranged in a triangular lattice pattern on the printed circuit board, and the choke coils and the printed circuit board are bonded and fixed with an adhesive, The air path mechanism is composed of an air path guide case, and the air path guide case is supported by a plurality of pillars erected on the printed circuit board, and each of the pillars is arranged in three adjacent triangular lattices. It is characterized in that it is provided at a position that becomes the center of gravity of an equilateral triangle formed by the centers of two choke coils.

According to the first invention, the vibration resistance is improved by the dispersion of weight and the vibration absorbing effect of the adhesive as the vibration preventing member due to the arrangement of the choke coils arranged in a triangular lattice shape. In addition, the choke coil is covered with an air path mechanism, and the adhesive acts as a wall, so that the wind strikes the choke coil. Thereby, since dispersion | distribution of heat_generation | fever and heat dissipation improve, it becomes possible to provide the low-cost choke coil unit using an electric wire with a thin wire diameter.
Further, according to the second invention, each support column supporting the air path guide case constituting the air path mechanism is an equilateral triangle formed by the centers of three adjacent choke coils arranged in the triangular lattice shape. Since it is provided at the position where it becomes the center of gravity, it is possible to improve the vibration resistance by dispersing the weight and absorbing the vibration stress. Further, the stagnation of the wind flow is eliminated and the cooling performance is further improved.

Embodiment 1 FIG.
FIG. 1 is a plan view showing a portion of the choke coil unit omitted in Embodiment 1 of the present invention, FIG. 2 is a side view showing a portion of the choke coil unit, and FIG. 3 is an electrical view of the choke coil unit. It is an equivalent circuit diagram.

  The choke coil unit according to the first embodiment covers a plurality of (six in this example) choke coils 1, a printed circuit board 2 on which these choke coils 1 are mounted, and each choke coil 1 and printed circuit board 2. An air path guide case 3 as an air path mechanism is provided.

  Each choke coil 1 is configured by winding an electric wire 6 made of a copper wire or the like having a circular cross section and a thin wire diameter around a ring-shaped magnetic core 5, and each choke coil 1 is a printed circuit board. 2 are arranged in a state where the axis of the magnetic core 5 is orthogonal to the substrate 2 and dispersed in a triangular lattice shape in plan view. Then, both end portions of the electric wire 6 wound around each magnetic core 5 are fixed and electrically connected to a wiring pattern 7 of copper foil formed on the printed circuit board 2 with solder 8.

  In this case, as shown in FIG. 3, the choke coils 1 are electrically connected to each other in parallel by a wiring pattern 7, and the pair of choke coils 1 are connected in series. ing.

  Thereby, since the electric wire 6 is divided and wound around the plurality of magnetic cores 5, the heat generated from each choke coil 1 can be suppressed by dispersing the current flowing through each choke coil 1. In addition, since each choke coil 1 is dispersed and arranged in a plane, the weight of each choke coil 1 is lighter than that in the case of using a single choke coil 1 as in the prior art, and is resistant to vibration. Improves.

  Moreover, since the wiring pattern 7 is formed on the printed circuit board 2 in a planar manner, it not only serves to electrically connect the respective choke coils 1 but also serves to disperse the heat generated by the choke coils 1. . Further, generally, the choke coil 1 has a problem that the noise removal capability is lowered when it is affected by the leakage magnetic flux generated by other components, but the wiring pattern 7 is formed on the printed circuit board 2 as described above. Thus, the wiring pattern 7 serves as an electromagnetic shield plate and can shield the leakage magnetic flux.

  As a method of fixing each choke coil 1 to the printed circuit board 2 with the solder 8, a plurality of choke coils 1 can be soldered to the printed circuit board 2 at once by applying flow soldering or the like. Even if there are a plurality of them, the assembly property does not deteriorate.

  The air guide case 3 is made of metal or resin, and is supported by a plurality of support columns 9 erected on the printed circuit board 2 and arranged in parallel with the printed circuit board 2. In particular, when the air path guide case 3 is made of metal, this serves as an electromagnetic shield plate, which has an advantage that the leakage magnetic flux to the choke coil 1 can be shielded.

  Each column 9 is made of metal or resin, and is fixed between the printed board 2 and the air guide case 3 by screwing or soldering. When soldering between the support 9 and the printed board 2, the support 9 can be handled by plating with a metal that can be soldered or a metal that can be soldered. In addition, when both the air guide case 3 and the support 9 are conductive, even when the support 9 is erected on the wiring pattern 7 by interposing an insulating material between the connection parts of the both 3, 9 Since the column 9 and the air path guide case 3 can be electrically insulated from each other, it is possible to prevent a short circuit through the column 9 and the air path guide case 3.

  The choke coil 1 is cooled by flowing air between the printed circuit board 2 and the air path guide case 3. In this case, the cooling air is preferably forced convection using a cooling fan. Alternatively, the printed circuit board 2 may be arranged perpendicular to the ground so that an upward air flow is generated between the two and 3 naturally. Good.

  When air is passed between the printed circuit board 2 and the air path guide case 3 as described above, the cooling air can be obtained by arranging the choke coils 1 in a triangular lattice pattern as in the first embodiment. As shown by the broken lines in FIG. 4, since the gas flows along the outer peripheral surface of each choke coil 1, the outer peripheral surface of the choke coil 1 can be uniformly cooled. Moreover, since the printed circuit board 2 simultaneously serves as an air path guide, it is cooled by this cooling air. Therefore, the wiring pattern 7 through which the heat generated by the choke coil 1 is conducted is also cooled at the same time.

  In the first embodiment, since the choke coils 1 are dispersed in series and parallel and cooled, local heat generation is unlikely to occur as described above, but local heat generation occurs in the portion fixed by the solder 8. And stress due to vibration or the like is likely to occur, so that solder cracks are likely to occur. In particular, the stress on the soldered portion increases in proportion to the magnitude of displacement between the printed circuit board 2 and the choke coil 1 caused by vibration or the like.

  Therefore, in the first embodiment, in addition to soldering the choke coil 1 to the printed circuit board 2, the choke coil 1 and the printed circuit board 2 are fixedly bonded using the silicon adhesive 11. In this case, as shown in FIG. 5, the position where each choke coil 1 and the printed board 2 are bonded and fixed is preferably on the leeward side of each choke coil 1 so that the wind can be efficiently guided to the center of the choke coil 1. .

  As a result, the silicon adhesive 11 reduces the displacement of the printed circuit board 2 and the choke coil 1 to absorb stress due to vibrations and the like, and also serves to guide the cooling air to the center of the choke coil 1. Coolability is further improved.

  As described above, in this embodiment, the vibration resistance is improved by the weight dispersion and the vibration stress absorption effect of the silicon adhesive 11. Further, since the wind also flows through the central portion of the choke coil 1 which is difficult to be cooled to improve the cooling performance of the choke coil 1, the choke coil unit using the low-cost choke coil 1 using the wire 6 having a thin wire diameter is used. Can be configured.

Embodiment 2. FIG.
FIG. 6 is a side view showing a part of the choke coil unit according to Embodiment 2 of the present invention, and FIG. 7 is an explanatory view schematically showing the arrangement position of the support column 9 that supports the airway guide case 3.

  Also in the second embodiment, as in the first embodiment, the air passage guide case 3 is supported by a plurality of support columns 9 erected on the printed circuit board 2. Each column 9 is provided at a position where the distances from the centers of the adjacent choke coils 1 are equal, that is, at the position of the center of gravity of the adjacent choke coils 1. In addition, the shape of the support | pillar 9 in this case may be either a cylindrical shape as shown in FIG. 8A or a polygonal shape as shown in FIG.

  By providing the support column 9 at the position of the center of gravity and fixing the printed circuit board 2 and the air path guide case 3, stress due to vibration or the like is uniformly distributed throughout the printed circuit board 2 and the air path guide case 3. Further, the post 9 absorbs vibration stress in a direction perpendicular to the printed circuit board 2 where solder cracks are likely to occur.

  Further, when the cooling air is made to flow, the vicinity of the center of gravity of each choke coil 1 becomes a stagnation point of the wind, and the cooling air may hardly flow to this position. However, in the second embodiment, since the support 9 is disposed at this stagnation point, the stagnation point of the cooling air can be eliminated and the cooling air can be guided by the support 9. Thereby, uniform cooling air along the outer periphery of each choke coil 1 can be generated.

  Then, the heat generated in each choke coil 1 can be dispersed along the route of the wiring pattern 7 → the support column 9 → the airway guide case 3. In particular, when the wiring pattern 7 and the support 9 are soldered, the thermal resistance of the connecting portion is reduced, and the effect of dispersing the heat generated in the choke coil 1 is increased. Effective in the center.

As described above, in the second embodiment, the vibration resistance is improved by the weight dispersion and the absorption effect of the vibration stress. Further, the stagnation of the wind flow is eliminated, and the cooling performance is further improved as compared with the case of the first embodiment.
Since other configurations and operational effects are the same as those of the first embodiment, detailed description thereof is omitted here.

In the first and second embodiments, not only the plurality of choke coils 1 but also other electric components are mounted on the printed circuit board 2 at the same time, and the choke coil 1 and the other electric components are connected to each other by the wiring pattern 7. A power device can also be configured by connection. In this way, product assembly is facilitated and the entire power device can be made compact.
In the first and second embodiments, the air path guide case 3 is used as the air path mechanism. However, the air path guide case 3 is not necessarily in a case shape as long as the air can flow efficiently through the choke coil 1. .

It is a top view which abbreviate | omits and shows the choke coil unit in Embodiment 1 of this invention. It is a side view which shows a part of the choke coil unit. It is an electrical equivalent circuit diagram of the choke coil unit. It is explanatory drawing which shows the flow of the wind around a choke coil in Embodiment 1 of this invention. It is a side view which shows the position which fixes a silicon adhesive agent in Embodiment 1 of this invention. It is a side view which shows a part of choke coil unit in Embodiment 2 of this invention. It is explanatory drawing which shows the arrangement position of the support | pillar which supports an airway guide case in Embodiment 2 of this invention. It is a perspective view which shows an example of the shape of the support | pillar in Embodiment 2 of this invention. It is explanatory drawing which shows the flow of the wind around the support | pillar in Embodiment 2 of this invention.

Explanation of symbols

1 choke coil, 2 printed circuit board, 3 airway guide case (airway mechanism),
5 magnetic core, 6 electric wire, 7 wiring pattern, 8 solder, 9 strut,
11 Silicone adhesive.

Claims (3)

A plurality of choke coils formed by winding an electric wire around a ring-shaped magnetic core, a printed board on which these choke coils are mounted, and an air path mechanism that covers each of the choke coils and the printed board, Each choke coil is arranged in a triangular lattice pattern on the printed circuit board, and the choke coil and the printed circuit board are bonded and fixed with an adhesive. The choke coil unit is characterized in that it is on the outlet side of the air path mechanism so as to guide the air flowing between the air path mechanism and the printed circuit board from the inlet to the outlet of the air path mechanism toward the central portion of the choke coil. . A plurality of choke coils formed by winding an electric wire around a ring-shaped magnetic core, a printed board on which these choke coils are mounted, and an air path mechanism that covers each of the choke coils and the printed board, Each choke coil is arranged in a triangular lattice pattern on the printed circuit board, and each choke coil and the printed circuit board are bonded and fixed with an adhesive, and the air path mechanism includes an air path guide case. The airway guide case is supported by a plurality of support columns erected on the printed circuit board, and each of the support columns has a center of gravity of an equilateral triangle formed by the centers of three adjacent choke coils arranged in a triangular lattice pattern. A choke coil unit characterized by being provided at a position. A power device comprising the choke coil unit according to claim 1 or 2, wherein another electric component is mounted on the printed board in addition to the choke coil.

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