JP2007311480A - Inverter transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an inverter transformer that reduces manufacturing costs while enhancing a coupling degree between a primary winding and a secondary winding. <P>SOLUTION: The inverter transformer 1 is composed so that the primary winding 2 is directly wound around a winding shaft of an insulating I-type core 4A and an insulating bobbin 6 is arranged around which the secondary winding 3 is wound so as to cover the primary winding 2. It is also composed so as to form each groove which is for leading out each end 2a, 2b of the primary winding 2 wound around the winding shaft to the outside, in a thick shaft 42A of the I-type core 4A. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inverter transformer used in a DC / AC inverter circuit for discharging and lighting a cold cathode discharge lamp (CCFL) for backlights of various display panels used in, for example, notebook personal computers and liquid crystal televisions.

  Conventionally, as this type of inverter transformer, those described in Patent Documents 1 and 2 below are known.

  The inverter transformer described in Patent Document 1 below has a primary winding and a secondary winding arranged coaxially with respect to one bobbin, and the inverter transformer described in Patent Document 2 below is 1 A small-diameter bobbin around which the primary winding is wound is arranged inside a large-diameter bobbin around which the secondary winding is wound so that the secondary winding and the secondary winding are positioned concentrically. Is.

JP 2004-31647 A JP 2005-327977 A

  Since the inverter transformer described in Patent Document 1 requires only one type of bobbin, it is possible to reduce the manufacturing cost spent on the mold cost and the like, but the primary winding and the secondary winding are arranged side by side. Since the arrangement is adopted, there is a problem that the magnetic path length becomes long and the degree of coupling between the primary winding and the secondary winding decreases.

  On the other hand, since the inverter transformer described in Patent Document 2 adopts a configuration in which the primary winding is disposed inside the secondary winding, the magnetic path length becomes short, and the primary winding and the secondary winding. However, since two types of bobbins having different diameters are required, it is difficult to reduce the manufacturing cost.

  This invention is made | formed in view of such a situation, and while providing the coupling degree of a primary winding and a secondary winding, it can provide the inverter transformer which can suppress manufacturing cost. Objective.

An inverter transformer according to the present invention is an inverter transformer for lighting a discharge lamp, comprising a primary winding, a secondary winding electromagnetically coupled to the primary winding, and a core through which magnetic flux passes.
Winding the primary winding directly on the core;
The secondary winding is wound through an insulating member so as to cover the primary winding wound around the core.

The core includes a winding shaft portion around which the primary winding is wound, and a thick shaft portion provided at both ends of the winding shaft portion and formed thicker than the winding shaft portion,
At least one of the thick shaft portions may be formed with a groove portion for drawing out the primary winding wound around the winding shaft portion from the winding shaft portion.

The inverter transformer according to the present invention is an inverter transformer for lighting a discharge lamp, comprising a primary winding, a secondary winding electromagnetically coupled to the primary winding, and a core through which magnetic flux passes.
The core is formed of an insulating magnetic material, and a winding shaft portion on which the primary winding is wound directly, and a winding shaft portion provided on each end of the winding shaft portion, respectively. With a thick shaft portion formed thicker,
At least one of the thick shaft portions is formed with a groove portion for pulling out the starting end portion and the terminal end portion of the primary winding wound around the winding shaft portion from the winding shaft portion,
A hollow bobbin around which the secondary winding is wound is disposed so as to cover the primary winding wound around the winding shaft portion.

  The core may be a combination of an I-type core having the winding shaft portion inserted through the bobbin and a U-type core disposed outside the bobbin.

  In the present invention, the core can be formed of a nickel-based magnetic material.

  According to the inverter transformer of the present invention, the primary winding is wound directly around the core, and the secondary winding is wound via the insulating member so as to cover the primary winding. As a result, the magnetic path length can be shortened as compared with the configuration in which the primary winding and the secondary winding are arranged side by side, so the degree of coupling between the primary winding and the secondary winding is increased. It is possible to increase.

  In addition, since the primary winding is wound directly around the core, a bobbin for winding the primary winding becomes unnecessary, so that a small diameter bobbin for the primary winding and a large for the secondary winding are used. Manufacturing costs can be reduced compared to those requiring a diameter bobbin.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an inverter transformer according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view (partially cut away) of an inverter transformer according to an embodiment of the present invention, and FIG. 2 is a perspective view thereof (a state where a secondary winding is not wound). 3 is a perspective view from the bottom side of the I-type core shown in FIG. 1, and FIG. 4 is a bottom view thereof (a state where the primary winding is wound). In the following description, the direction of the X axis of the three-dimensional orthogonal coordinate system shown in FIG. 2 is the front and back (the direction of the arrow is forward), the direction of the Y axis is the left and right (the direction of the arrow is right), The direction is referred to as up and down (the direction of the arrow line is up). Further, the three-dimensional orthogonal coordinate system in the other figures is shown so that the directions of the respective axes coincide with those in FIG.

  The inverter transformer 1 of this embodiment is used in a DC / AC inverter circuit that discharges and lights a cold cathode discharge lamp (CCFL) for backlights of various display panels used in, for example, notebook computers and liquid crystal televisions. As shown in FIG. 1, the primary winding 2, the secondary winding 3 electromagnetically coupled to the primary winding 2, and the primary winding 2 and the secondary winding 3 are passed through. It comprises a core 4 through which magnetic flux passes and a bobbin terminal block 5 made of an insulating material such as plastic.

  The bobbin terminal block 5 includes a hollow bobbin 6 around which the secondary winding 3 is wound, and first and second terminal blocks 7A and 7B disposed on both left and right ends of the bobbin 6, respectively. They are formed integrally with each other. The bobbin 6 has end rods 61 respectively disposed on the left and right ends thereof, and a plurality (six in this embodiment) of partition rods 62 disposed between the pair of end rods 61. The secondary winding 3 is wound around a winding region divided into a plurality of sections (seven in this embodiment) by the partition rods 62. Each partition rod 62 is formed with a notch 63 (see FIG. 2) for passing the secondary winding 3 to an adjacent winding section. Meanwhile, the first terminal block 7A holds three primary terminals 8A to 8C and one secondary terminal 9A, and the second terminal block 7B has one secondary terminal. A side terminal 9B and one spare terminal 10 are held, and each end portion of the secondary winding 3 is connected to each binding portion 9a of the secondary side terminals 9A and 9B. ing.

  The core 4 is formed of a magnetic material, for example, ferrite (in addition, a material such as permalloy or sendust, or a dust core obtained by compression molding these fine powders can be used). The core 4A and the U-shaped core 4B are combined.

  As shown in FIG. 3, the I-type core 4 </ b> A includes a prismatic winding shaft portion 41, and a thick shaft formed thicker than the winding shaft portion 41 provided at both left and right ends of the winding shaft portion 41. The portions 42A and 42B are formed integrally with each other, and two groove portions 43A and 43B extending in parallel with each other in the left-right direction are formed on the bottom surface of the thick shaft portion 42A. By using a core made of a magnetic material having a high insulation resistance, such as nickel, for the I-type core 4A, the primary winding 2 can be wound directly as shown below. .

  That is, as shown in FIG. 4, the winding shaft portion 41 is configured such that the primary winding 2 is wound directly, and the primary winding 2 wound around the winding shaft portion 41. The starting end portion 2a and the terminal end portion 2b are drawn out to the outside via the groove portions 43A and 43B and connected to any one of the primary side terminals 8A to 8C. 2, the I-type core 4A around which the primary winding 2 is wound is inserted and held in the hollow portion 64 of the bobbin 6, as shown in FIG. 64, and the thick shaft portions 42A and 42B are partially inserted into the hollow portion 64 on opposite sides). In this state, as shown in FIG. 1, when the secondary winding 3 is wound around the bobbin 6, the secondary winding 3 is connected to the I-type core 4A via the bobbin 6 as an insulating member. Will be arranged so as to cover the primary winding 2 wound around.

  On the other hand, as shown in FIG. 1, the U-shaped core 4B is disposed outside the bobbin 6, and its left and right end portions 44A and 44B are connected to the left and right thick shaft portions 42A and 42B of the I-shaped core 4A. They are configured to be connected to each other (may be connected via an air gap for leakage inductance adjustment). Thereby, a magnetic path C through which the magnetic flux passing through the primary winding 2 and the secondary winding 3 passes when the inverter transformer 1 is driven is formed inside the core 4. The U-shaped core 4B can use a core made of a magnetic material having a low insulation resistance, such as manganese, in addition to the above-described nickel-based core.

  Thus, according to the inverter transformer 1 of the present embodiment, since the secondary winding 3 is wound via the insulating bobbin 6 so as to cover the primary winding 2, the primary windings 2 and 2 The length of the magnetic path C can be shortened compared with the case where the next winding 3 is arranged side by side. Therefore, the degree of coupling between the primary winding 2 and the secondary winding 3 can be increased.

  Further, since the primary winding 2 is wound directly around the I-type core 4A, a bobbin for winding the primary winding 2 becomes unnecessary. Therefore, compared with the case where the bobbin for winding the primary winding 2 is used, the manufacturing cost can be reduced and the assembling work is facilitated. Further, the size can be reduced by the thickness of the bobbin for the primary winding.

  In the above embodiment, the groove portions 43A and 43B are formed in only one (thick shaft portion 42A) of the left and right thick shaft portions 42A and 42B, but the same groove portion is formed in the other thick shaft portion 42B. May be. Further, the overall shape and cross-sectional shape of the core can be changed as appropriate.

  Further, as the I-type core 4A, it is possible to use a core made of a magnetic material having a low insulation resistance, such as a manganese-based material, with improved insulation.

The top view (partially fractured) of the inverter transformer which concerns on one Embodiment 1 is a perspective view of the inverter transformer shown in FIG. 1 (secondary winding is not installed). The perspective view from the bottom face side of the I-type core shown in FIG. Bottom view of I-type core with primary winding wound

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter transformer 2 Primary winding 2a Start end part 2b (primary winding) End part 3 Secondary winding 4 Core 4A I type core 4B U type core 5 Bobbin terminal block 6 Bobbin 7A 1st terminal block 7B 2nd terminal block 8A-8C Primary side terminal 9A, 9B Secondary side terminal 9a Tying part 10 Spare terminal 41 Winding axis part 42A, 42B Thick axis part 43A, 43B Groove part 44A, 44B ( End 61 of U-shaped core End 鍔 62 Partition ６３ 63 Notch C Magnetic path

Claims (5)

In an inverter transformer for lighting a discharge lamp, comprising a primary winding, a secondary winding electromagnetically coupled to the primary winding, and a core through which magnetic flux passes,
Winding the primary winding directly on the core;
An inverter transformer, wherein the secondary winding is wound through an insulating member so as to cover the primary winding wound around the core. The core includes a winding shaft portion around which the primary winding is wound, and a thick shaft portion provided at both ends of the winding shaft portion and formed thicker than the winding shaft portion,
The groove portion for pulling out the primary winding wound around the winding shaft portion from the winding shaft portion is formed on at least one of the thick shaft portions. Inverter transformer. In an inverter transformer for lighting a discharge lamp, comprising a primary winding, a secondary winding electromagnetically coupled to the primary winding, and a core through which magnetic flux passes,
The core is formed of an insulating magnetic material, and a winding shaft portion on which the primary winding is wound directly, and a winding shaft portion provided on each end of the winding shaft portion, respectively. With a thick shaft portion formed thicker,
At least one of the thick shaft portions is formed with a groove portion for pulling out the starting end portion and the terminal end portion of the primary winding wound around the winding shaft portion from the winding shaft portion,
An inverter transformer, comprising: a hollow bobbin around which the secondary winding is wound so as to cover the primary winding wound around the winding shaft portion.   The core is a combination of an I-type core having the winding shaft portion inserted through the bobbin and a U-type core disposed outside the bobbin. 3. The inverter transformer according to 3. The inverter transformer according to any one of claims 1 to 4, wherein the core is formed of a nickel-based magnetic material.

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