JP2008258250A - Transformer with case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transformer with case wherein an insulation distance between a high-voltage terminal and a magnetic core as a part of a transformer can be ensured in a small-space range. <P>SOLUTION: The transformer is comprised of a pair of cores 21 made of a magnetic material, a bobbin 22 to which the magnetic cores 21 is assembled, and a high-voltage coil 25 and a low-voltage coil 24 wound around the bobbin 22. The transformer is housed in a box-like housing case 10, and the terminal 25a of the high-voltage coil 25 passes through a leading hole 17 on the upper face 11 of the housing case 10, and is led out along the side face 16 of thick wall for connection to the high-voltage terminal 28. The terminal 24a of the low-voltage coil 24 is led out from the side face 15 of opening and is connected to the low-voltage terminal 27. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to securing an insulation distance between a high voltage circuit that determines the size of a transformer and a magnetic core that is a component of the transformer.

  Generally, a transformer is always distinguished as a low voltage side coil and a high voltage side coil except for a transformation ratio of 1: 1, and terminals to which the terminals of the coil are connected are similarly classified. The low voltage side and the high voltage side in the coil portion can easily secure an insulation distance corresponding to the voltage by an interlayer tape made of an insulating tape, a barrier tape, or the like.

  However, for the terminals arranged on the bobbin, it is necessary to secure an insulation distance suitable for the set voltage value in advance, and the insulation distance between the high voltage side terminal and the magnetic core which is a component of the transformer is made of resin. A method of securing by the shape of the bobbin is common.

  In the transformer 100 shown in FIG. 6, the height of the spacer 109 located below the bobbin 102 is lowered by extending a part of the bobbin 102 on which the high-voltage side terminal 106 is disposed to the magnetic side. A sufficient insulation distance S1 between the core 103 and the solder portion 105 of the high-voltage side terminal 106 can be secured, and the transformer 100 can be thinned. (Patent Document 1)

  As another method, the transformer 110 shown in FIG. 7 refracts the insulation distance between the high voltage side terminal 116 and the magnetic core 113 by fitting the concave portion 114a of the cover 114 made of insulating resin and the convex portion 112a of the bobbin 112. Since it can be formed into a shape, it suppresses the enlargement of the transformer. (Patent Document 2)

JP 2003-142317 A (FIG. 1) JP 2006-228996 A (FIGS. 1 and 2)

  However, in the transformer structure of Patent Document 1 shown in FIG. 6, it is necessary to project part of the bobbin 102 provided with the high-voltage side terminal 106 outward, which increases the mounting area as a transformer. Was generated.

  In the transformer of Patent Document 2 shown in FIG. 7, the insulation distance is sufficient if the high voltage circuit is close to the terminal 116, but the high voltage circuit is located below the transformer 110 or around the transformer 110. Therefore, it is difficult to secure an insulation distance from the magnetic core 113 that is a conductive path to the low voltage circuit, and therefore, a design restriction is generated in the substrate circuit to which the transformer 110 is attached, which prevents high density of the circuit. It was.

  In view of the above problems, an object of the present invention is to provide a small-sized transformer that can secure a sufficient insulation distance between a high-voltage circuit and a magnetic core that is a component of the transformer and enables high-density circuit integration.

  The present invention provides a transformer comprising a high-voltage coil connected to a high-voltage circuit, a bobbin that winds one or more low-voltage coils connected to a low-voltage circuit, and a magnetic core incorporated in the bobbin. , Having an opening only on one side and above, and being combined with a storage case having a coil terminal and a circuit connection terminal below one side of the opening and the symmetrical side of the opening, the terminal of the high-voltage side coil is The transformer with a case is characterized in that it is led out from the upper opening of the storage case to a terminal located below the storage case, and the terminal of the low voltage side coil is led out to the terminal from the opening side surface of the storage case.

  According to the present invention, in the transformer with a case described above, the upper opening of the storage case is a lead-out hole through which only the terminal of the high voltage side coil passes.

  The present invention is the above transformer with a case, wherein a three-layer insulated wire is used for the high voltage side coil connected to the high voltage circuit.

  The present invention is the above transformer with a case, characterized in that the insulation distance between the terminal connected to the high voltage circuit and the magnetic core of the transformer in the storage case is 10 mm or more.

  Further, the present invention is the above transformer with a case, wherein the resin thickness of the storage case is 0.5 mm or more.

  In the present invention, the transformer is housed in a substantially box-shaped case, and the terminal of the high voltage side coil is led out to the terminal in a refractive manner, so that a sufficient insulation distance of the magnetic core as a component can be secured to the transformer for the high voltage circuit In addition to improving the reliability, it is possible to achieve high density of circuits on the transformer mounting board, and it is possible to reduce the size of devices and equipment that use the circuits.

  An embodiment of a transformer with a case according to the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing an embodiment of a transformer with a case of the present invention, FIG. 2 is a cross-sectional view of the transformer with a case of the present invention shown in FIG. 1, and FIGS. 3 and 4 are shown in FIGS. It is a perspective view of a transformer with a case of the present invention.

  The transformer with a case according to the present invention includes a core 21 made of a magnetic material, a bobbin 22 incorporating the magnetic core 21, a high-voltage coil 25 and a low-voltage coil 24 wound around the bobbin 22. It is a function.

  The above transformer is housed in a box-shaped storage case 10, and the structure of the storage case 10 is as follows. The bottom surface 14 in which the high voltage side terminal 28 and the low voltage side terminal 27 are embedded, the opening side surface 15 on the low voltage side terminal 27 side, and the thick wall side surface on the high voltage side terminal 28 side that is thicker than the other side surfaces 12 and 13. The storage case 10 is composed of 16 and an upper surface 11 having an outlet hole 17 that is an opening.

  Each coil terminal drawn out from the transformer contained in the storage case 10 has a terminal 25 a of the high-voltage side coil 25 drawn out along the thick wall side surface 16 through the lead-out hole 17 in the upper surface 11 of the storage case 10. To the high voltage side terminal 28. Further, the terminal 24 a of the low voltage side coil 24 is pulled out from the opening side surface 15 and connected to the low voltage side terminal 27.

  The transformer with a case of the present invention secures an insulation distance including a creepage distance and a spatial distance between the high-voltage side terminal 28 and the core 21 which is a member of the transformer by the structure shown in FIGS. The necessary insulation distance can be obtained by the vertical distance Dp and horizontal distance Dh of the thick wall side surface 10 and the space distance Dc between the lead-out hole 17 of the storage case 10 and the magnetic core 21. It is a thing.

  Further, the storage case 10 is provided with a wall on the side surface except the opening side surface 14 on the low voltage side terminal 27 side, and the high voltage circuit in the circuit board can be provided under the transformer with the case of the present invention. It enables high density circuit design.

  Further, by using a three-layer insulated wire for the high voltage side coil 25 of the transformer, an interlayer tape between the coils becomes unnecessary, and the insulation with respect to electricity is high, so that the reliability of the transformer with a case of the present invention is improved. .

  The transformer with a case shown in FIGS. 1 to 4 described above was produced. The size of the transformer stored in the storage case 10 is 8 mm × 8 mm and the height is 5 mm. The storage case 10 has an outer dimension of 11 mm × 11 mm and a height of 7 mm (terminal dimensions are not included). The dimensions inside the case that houses the transformer are 9mm x 9.5mm and the height is 5.5mm. The thickness of the bottom surface 14 is 1.1 mm, and the thickness of the side surfaces 12 and 13 is 5.5 mm. The thickness of the thick wall side surface 16 is 2 mm. The thickness of the upper surface 11 was 0.5 mm.

  The insulation distance between the high voltage side terminal 28 and the magnetic core 21 in the transformer with a case of the present invention manufactured as described above is the vertical dimension Dp of the thick wall side surface 16 (the high voltage side coil 25 connected to the high voltage side terminal 28). (From the conductive portion of the terminal 25a) is 5.7 mm, the horizontal dimension Dh of the thick wall side surface 16 is 2 mm, the space dimension Dc from the lead-out hole 17 to the magnetic core 21 is 3 mm, and the high voltage side terminal 36 and the magnetic core 21 An insulation distance of 10 mm or more could be secured.

  Further, the thickness of the planted portion 28a of the high voltage side terminal 28 provided on the bottom surface 14 of the storage case 10 and the inside of the case, and the side walls 12 and 13 could each ensure a dimension of 0.5 mm or more.

  As described above, the case-equipped transformer of the present invention was able to secure a sufficient insulation distance between the high-voltage side terminal 28 and the magnetic core 21 of the transformer while being small.

  FIG. 5 shows another embodiment of the present invention, and is a perspective view of a storage case according to the transformer with a case of the present invention. The storage case 30 of FIG. 5 is provided with a slit 36 for leading out the coil terminal above the thick wall side surface 32 on the high voltage side terminal 34 side so that the coil terminal does not protrude above the height of the storage case 30. Further, by forming a protrusion 37 protruding in the horizontal outward direction on the thick wall side surface 32, the insulation distance reduced by the slit 36 is increased.

  Further, the storage case 30 of FIG. 5 has an opening on the upper surface, and makes it easier to lead out the coil terminal than the storage case 10 shown in FIGS.

  In the above-described transformer with a case of the present invention, a combination magnetic core such as EE and EI has been described. However, the transformer housed in the storage case according to the present invention does not limit the shape and the number of coils, and has a toroidal shape. Even if the magnetic core is used, the same effect as that of the present invention can be obtained, and the bobbin 21 described in the present invention can be used by removing the terminal from the existing bobbin.

  This is a technology that enables miniaturization of transformers used in various electric and electronic devices.

It is a top view of the transformer with a case of the present invention. It is AA sectional drawing of FIG. 1 of the trans | transformer with a case of this invention. It is a perspective view of a transformer with a case of the present invention. It is a perspective view of a transformer with a case of the present invention. It is a perspective view of another storage case which concerns on the small transformer with a case of this invention. It is a figure explaining the insulation distance with the high voltage side terminal of the conventional transformer. It is a figure explaining the insulation distance with the high voltage side terminal of another conventional transformer.

Explanation of symbols

10: Storage case 11: Upper surface 12, 13: Side surface 14: Bottom surface 15: Opening side surface 16: Thick wall side surface 17: Lead-out hole 21: Magnetic core 22: Bobbin 24: Low voltage side coil 24a: Low voltage side coil terminal 25: High voltage side coil 25a: High voltage side coil terminal 27: Low voltage terminal 28: High voltage side terminal 28a: High voltage side terminal planting part

Claims (5)

A transformer comprising a high voltage side coil connected to the high voltage circuit, a bobbin that winds one or more low voltage side coils connected to the low voltage circuit, and a magnetic core incorporated in the bobbin, It has an opening only in the upper part, and is combined with a storage case having a coil terminal and a circuit connection terminal below one side of the opening and the symmetrical side surface thereof, and the terminal of the high voltage side coil is located above the storage case. A transformer with a case, wherein the transformer is led out from the opening to a terminal located below the housing case, and the terminal of the low voltage side coil is led out to the terminal from the opening side surface of the housing case. 2. The transformer with a case according to claim 1, wherein the upper opening of the storage case is a lead-out hole through which only the terminal of the high voltage side coil passes. The transformer with a case according to claim 1 or 2, wherein a three-layer insulated wire is used for a high-voltage side coil connected to a high-voltage circuit. 4. The transformer with a case according to claim 1, wherein an insulation distance between a terminal connected to the high voltage circuit and a magnetic core of the transformer in the storage case is 10 mm or more. 5. The transformer with a case according to claim 1, wherein the resin thickness of the storage case is 0.5 mm or more.

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