JP4613036B2 - Leakage transformer - Google Patents

Description

  The present invention relates to a leakage transformer used in a lighting circuit or the like for lighting a backlight of a liquid crystal display device.

  A liquid crystal display device used for a TV monitor or a personal computer monitor includes a lighting circuit for lighting a backlight. In this lighting circuit, a leakage transformer is generally used to drive a liquid crystal display device by generating a high voltage. As this type of leakage transformer, for example, the one described in Patent Document 1 is known.

  The leakage transformer described in Patent Document 1 includes a core portion that houses a primary winding and a secondary winding to form a closed magnetic circuit, and performs electromagnetic induction between the primary winding and the secondary winding. To do. The core portion includes a pot-shaped lower core whose periphery is surrounded by side legs, and an upper core that closes the upper open surface of the lower core. The central leg is erected.

  In addition, an auxiliary leg that adjusts the coupling coefficient between the primary winding and the secondary winding by winding a part of the primary winding is provided at the base portion of the lower core, and the core portion has a horizontally long shape. ing.

  Furthermore, a terminal portion for connecting each end portion of the primary winding and the secondary winding is provided at an end portion in the longitudinal direction of the horizontally long core portion, and one of the end portions provided with the terminal portion is provided. Winding guiding grooves that communicate the terminal portion and the winding portion are provided.

JP 2003-124037 A

  By the way, in recent liquid crystal display devices, the area of the frame portion surrounding the liquid crystal display portion is reduced, so that the entire screen can be downsized even if the screen size is the same, and the thickness is reduced by reducing the thickness. It is required to be lightweight and compact. For this reason, the leakage transformer used in the lighting circuit is also required to be further downsized in order to reduce the mounting area on the circuit board.

  However, in the above-described conventional leakage transformer, since the lower core is a pot type, the periphery of the bobbin of the winding part is surrounded by the side legs, and the bobbin winding frame is smaller than the overall shape. The space could not be used effectively to make a high power transformer. In addition, there is a limit to downsizing the entire apparatus. In particular, when an auxiliary leg is provided for adjusting a coupling coefficient between the primary winding and the secondary winding by winding a part of the primary winding, the laterally long core portion has a short direction. It was difficult to narrow the width.

  Also, in the lower core, one end of the terminal portion is provided with a winding induction groove that communicates the terminal portion and the winding portion. The side legs had to be cut, the formwork for forming the core part had a complicated shape, and it was difficult to reduce manufacturing costs. In particular, in the case of a horizontally long core portion, the cut portions of the side legs are increased, the influence on the magnetic flux is increased, and it is difficult to ensure the capacity as designed.

  The present invention has been proposed in view of the above-described circumstances, and it is possible to reduce the mounting area by shortening the length in the width direction, and it is easy to manufacture and can reduce the manufacturing cost. The purpose is to provide a transformer.

In order to achieve the above-described object, the leakage transformer of the present invention includes a core portion that houses a primary winding and a secondary winding to form a closed magnetic circuit, and includes the primary winding and the secondary winding. In the leakage transformer that performs electromagnetic induction between
The core portion is supported on a gantry and includes a pair of side legs that are erected on both sides upward from the base portion, and a center leg that is erected within a distance between the pair of side legs. An E-type core, and an I-type core that closes an upper open surface of the E-type core,
The gantry is provided with a terminal portion connecting each end of the primary winding and the secondary winding on at least one side of the side surface portion having the pair of side legs of the E-type core,
The E-type core, the an outer peripheral portion of the central leg, with the primary winding and multistage bobbin wound by stacking the secondary winding down is provided, the side portions with side legs of said pair The side portions on both sides where the terminal portion is not provided are open,
Is characterized in that said opened the cradle and winding guiding groove for guiding the secondary winding to the multistage bobbin definitive on at least one of both side surfaces are provided.

  Here, the E-type core is formed by winding a part of the primary winding between the central leg and any one of the pair of side legs, and the primary winding and the 2 An auxiliary leg for adjusting the coupling coefficient of the secondary winding may be provided, and an auxiliary bobbin for winding the primary winding may be provided on the outer periphery of the auxiliary leg.

  In addition, the terminal portion is provided on the pedestal located on both of the side portions having the pair of side legs, and the terminal portion provided on one side portion is used as a winding start side of the winding, and the other side surface is provided. The terminal part provided in the part can be the winding end side of the winding.

Further, the E-type core can be configured such that the base portion has a substantially rectangular shape and the terminal portions are provided on the pedestals located at both ends of the base portion in the longitudinal direction.

  Moreover, it is possible to provide a guide portion for guiding the winding from the winding guiding groove toward the terminal portion on the back side of the gantry.

  The plurality of flanges constituting the winding frame of the multi-stage bobbin can be configured such that notches are provided at positions facing the winding guide groove in the vertical direction.

The leakage transformer according to the present invention is adjacent to the side surface portion having the pair of side legs of the E-type core, and opens the side surface portions on both sides where the terminal portion is not provided . The winding portion can be disposed to the full width. Therefore, as compared with a conventional leakage transformer having a winding portion of the same size, the length in the width direction between both open side surfaces can be shortened, and the leakage transformer can be reduced in size. .

  Further, since the primary winding and the secondary winding are wound around the multi-stage bobbin, this can also shorten the length of the bobbin in the width direction, which can contribute to the downsizing of the leakage transformer. .

  Further, in the core portion, there is no side leg at the portion where the winding guiding groove is provided, so that it is not necessary to cut the side leg, and the core portion can be easily formed.

  In addition, the open side part that does not have side legs is designed from the beginning, and the side legs provided on the other side parts have few cut parts, so ensure the capacity as designed. Can do.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a leakage transformer according to the present invention will be described using specific examples shown in the drawings.

<Example 1>
1 to 4 show a leakage transformer according to a first embodiment of the present invention. FIG. 1 is a perspective view of the leakage transformer, FIG. 2 is a perspective view of the leakage transformer with the I-type core removed, and FIG. Is a bottom view of the leakage transformer, and FIG. 4 is a longitudinal sectional view of the leakage transformer.

  As shown in FIGS. 1 to 4, the leakage transformer 10 according to the first embodiment is configured by attaching a core portion made of a magnetic member on an insulating base 20.

The core portion is a member that houses the primary winding 90 and the secondary winding 100 to form a closed magnetic circuit, and is supported on the gantry 20 and is a pair that is erected upward from the base portion 31. E-type core 30 having a central leg 33 disposed within a distance between the side legs 32a and 32b and the pair of side legs 32a and 32b, and an I-type core 40 that closes the upper open surface of the E-type core 30. And has. Here, the E-type core 30 and the I-type core 40 are formed using, for example, ferrite.

  A two-stage bobbin 50 is attached to the E-shaped core 30 so that the primary winding 90 and the secondary winding 100 are vertically stacked and wound around the outer periphery of the central leg 33. The two-stage bobbin 50 is configured such that the secondary winding 100 is wound on the lower stage side and the primary winding 90 is wound on the upper stage side. The two-stage bobbin 50 includes a lower flange 51, an intermediate flange 52, and an upper flange 53 in order from the lower side.

  In the two-stage bobbin 50, the lower flange 51 is integrated with the upper surface of the gantry 20, and the lower winding and the primary winding 90 are wound around the secondary winding 100 by the intermediate flange 52. The upper side is isolated from the upper side, and the upper flange 53 supports the I-type core 40 from the lower side. Further, positioning portions 54 a and 54 b that fit into positioning grooves 41 provided in the I-type core 40 are provided on the upper surface of the upper flange portion 53. In this embodiment, the two-stage bobbin 50 is molded integrally with the gantry 20, but the two-stage bobbin 50 may be formed separately from the gantry 20.

  Further, the gantry 20 located on the side surface having the pair of side legs 32a and 32b is provided with terminal portions 60a and 60b for connecting the respective ends of the primary winding 90 and the secondary winding 100. . Further, the E-type core 30 is open at the side surface adjacent to the side surface having the pair of side legs 32a and 32b, that is, the side surface not provided with the terminal portions 60a and 60b. Winding induction grooves 70 a and 70 b communicating from the outer peripheral portion of the central leg 33 toward the side surface of the gantry 20 are provided on the side surface portion. The winding guiding grooves 70 a and 70 b are portions into which a winding nozzle (not shown) is inserted when the secondary winding 100 is wound around the lower step portion of the two-step bobbin 50.

  Further, a part 90a of the primary winding 90 is wound around the E-type core 30 between the central leg 33 and one side leg (the left side leg 32b in FIGS. 1 and 2). An auxiliary leg 34 for adjusting the coupling coefficient between the winding 90 and the secondary winding 100 is provided, and an auxiliary bobbin 80 for winding a part 90 a of the primary winding 90 is provided on the outer peripheral portion of the auxiliary leg 34. Is attached. The auxiliary bobbin 80 includes a lower auxiliary hook 81 located on the substantially same plane as the intermediate hook 52 of the two-stage bobbin 50, and an upper auxiliary located on the same plane as the upper hook 53 of the two-stage bobbin 50. And a collar portion 82.

  As described above, the terminal portions 60a and 60b are provided on the gantry 20 located on the side surface portion having the pair of side legs 32a and 32b, and four terminal pins 61b are provided on the side surface portion on the auxiliary leg 34 side. To 61e and two tie terminals 61a and 61f provided obliquely projecting from both sides of these terminal pins 61b to 61e, respectively, and two terminal pins 62a and 62d on the other side surface portion. And two linking terminals 62b and 62c provided so as to protrude from the interval between the terminal pins 62a and 62d.

  Further, as shown in FIG. 3, guide walls 21a to 21d for guiding windings between the winding guiding grooves 70a and 70b and the terminal portions 60a and 60b are provided on the rear surface of the gantry 20. By the guide walls 21a to 21d, the winding is easily and reliably guided between the winding guiding grooves 70a and 70b and the terminal portions 60a and 60b, and the winding is disconnected or short-circuited by contact with another member. Etc. can be prevented.

  The guide walls 21a to 21d are not provided on the rear surface of the gantry 20, but the guide grooves are provided on the rear surface of the gantry 20, so that the winding is guided between the winding guiding grooves 70a and 70b and the terminal portions 60a and 60b. You may form the guide part which guide | induces.

  In this embodiment, the terminal portion 60a provided on one side surface portion (for example, the binding pin 62c on the upper right side in FIG. 3) is the winding start side of the winding, and the terminal portion 60b provided on the other side surface portion. (For example, the binding pin 61a on the lower left side in FIG. 3) is the winding end side of the winding. Here, in particular, only in the secondary winding 100 where a high voltage is generated, the winding start side and the winding end side of the winding may be distributed to the left and right. In this way, by dividing the winding start side and winding end side to the left and right without providing them on the same side surface portion, it is possible to prevent dielectric breakdown in the winding (especially the secondary winding 100).

  Moreover, as shown in FIGS. 1 and 2, the upper auxiliary hook 82 and the mount 20 of the auxiliary bobbin 80 are provided with winding hooks 83 and 22 for hooking the primary winding 90, respectively. By tensioning the primary winding 90 between the winding hooks 83 and 22, tension is applied to the primary winding 90. Thus, by applying tension to the primary winding 90, there is no possibility that the primary winding 90 is loosened and contacts the secondary winding 100 to cause a short circuit.

  Although not shown, the gantry 20 and the two-stage bobbin 50 integrated therewith are provided with insertion holes for inserting the side legs 32a and 32b, the central leg 33, and the auxiliary leg 34 of the E-type core 30. It has been. Further, although not shown in FIGS. 1 and 2, a winding hook portion for hooking the primary winding 90 is provided on the rear side of the gantry 20 as well as the front side of the gantry 20.

<Example 2>
5 to 8 show a leakage transformer according to a second embodiment of the present invention. FIG. 5 is a perspective view of the leakage transformer, FIG. 6 is a perspective view of the leakage transformer with the I-type core removed, and FIG. FIG. 8 is a perspective view of the gantry and the two-stage bobbin, and FIG.

As shown in FIGS. 5 and 6, the leakage transformer 210 according to the second embodiment has substantially the same configuration as the leakage transformer 10 according to the first embodiment, but the shape of the two-stage bobbin 250 is slightly different. .

  Hereinafter, with respect to the leakage transformer 210 according to the second embodiment, the two-stage bobbin 250 having a configuration different from that of the first embodiment will be described in detail, and the other portions will be described with the same reference numerals as those of the first embodiment. Omitted.

  As shown in FIGS. 5 to 8, the leakage transformer 210 according to the second embodiment has a primary winding 90 and a secondary winding 100 stacked vertically on the outer periphery of the center leg 33 of the E-type core 30. A rotating two-stage bobbin 250 is attached. In the two-stage bobbin 250, the secondary winding 100 is wound on the lower stage side, and the primary winding 90 is wound on the upper stage side. The two-stage bobbin 250 includes a lower flange 251, an intermediate flange 252 and an upper flange 253 in order from the lower side.

  In the two-stage bobbin 250, the lower flange 251 is integrated with the upper surface of the mount 20, and the lower winding and the primary winding 90 are wound around the secondary winding 100 by the intermediate flange 252. The upper side is isolated from the upper side, and the upper flange 253 supports the I-type core 40 from the lower side. In addition, positioning portions 254 a and 254 b that fit into positioning grooves 41 provided in the I-type core 40 are provided on the upper surface of the upper flange portion 253. In this embodiment, the two-stage bobbin 250 is molded integrally with the gantry 20, but the two-stage bobbin 250 may be formed separately from the gantry 20.

In the two-stage bobbin 250, winding guide grooves 70a and 70b are provided on the gantry 20 integrated with the lower flange portion 251. Further, intermediate flange portions facing the winding induction grooves 70a and 70b. The cutout portions 255a, 255b, 256a, and 256b are provided in the 252 and the upper flange portion 253 . By the notches 255 and 256, the winding can be guided more easily and reliably. The winding guiding grooves 70 a and 70 b communicate from the outer peripheral portion of the central leg 33 of the E-type core 30 toward the side surface of the gantry 20.

  The gantry 20 is provided with two winding hooks 22 for hooking the primary winding 90. Further, as shown in FIG. 7, the base 20 and the two-stage bobbin 50 integrated therewith are inserted through the side legs 32 a and 32 b, the center leg 33, and the auxiliary legs 34 of the E-type core 30. Holes 23a, 23b, 24, and 25 are provided.

<Other embodiments>
In each of the above embodiments, a two-stage bobbin is attached to the outer periphery of the central leg, the primary winding is wound on the upper stage side, and the secondary winding is wound on the lower stage side. A multi-stage bobbin having a stage or more may be used, and the secondary winding may be wound in a plurality of stages.

  The E-type core and the I-type core are formed of ferrite, but the core forming material is not limited to this, and can be selected from other general core materials. For example, permalloy It is possible to use materials such as sendust and iron carbonyl, and it is also possible to use a dust core obtained by compression molding these fine powders.

  Further, the coupling coefficient between the primary winding and the secondary winding may be adjusted by providing a gap between the upper surface of the center leg of the E-type core and the upper surface of the auxiliary leg and the I-type core.

1 is a perspective view of a leakage transformer according to a first embodiment of the present invention. The perspective view of the state which removed the I-type core in the leakage transformer which concerns on Example 1 of this invention. The bottom view of the leakage transformer which concerns on Example 1 of this invention 1 is a longitudinal sectional view of a leakage transformer according to Embodiment 1 of the present invention. The perspective view of the leakage transformer which concerns on Example 2 of this invention. The perspective view of the state which removed the I type core in the leakage transformer which concerns on Example 2 of this invention. The perspective view of the mount frame and 2 step | paragraph bobbin which concern on Example 2 of this invention. The partially expanded view which expands and shows the collar part of the 2 step | paragraph bobbin which concerns on Example 2 of this invention.

Explanation of symbols

10 Leakage transformer (Example 1)
20 Base 21a, 21b Guide wall 22, 83 Winding hook 23a, 23b, 24, 25 Insertion hole 30 E-type core 31 Base part 32a, 32b Side leg 33 Central leg 34 Auxiliary leg 40 I-type core 41 Positioning groove 50 2 Corrugated bobbin 51 Lower flange 52 Intermediate flange 53 Upper flange 54a, 54b Positioning portion 60a, 60b Terminal portions 61b-e, 62a, 62d Terminal pins 61a, 61f, 62b, 62c Tying terminals 70a, 70b Winding induction Groove 80 Auxiliary bobbin 81 Lower auxiliary hook 82 Upper auxiliary hook 90 Primary winding 90a Coupling coefficient adjusting primary winding 100 Secondary winding 210 Leakage transformer (Example 2)
250 Two-stage bobbin 251 Lower flange 252 Intermediate flange 253 Upper flange 254a, 254b Positioning portion 255, 256 Notch

Claims (6)

In a leakage transformer that includes a core portion that houses a primary winding and a secondary winding to form a closed magnetic circuit, and performs electromagnetic induction between the primary winding and the secondary winding,
The core portion is supported on a gantry and includes a pair of side legs that are erected on both sides upward from the base portion, and a center leg that is erected within a distance between the pair of side legs. An E-type core, and an I-type core that closes an upper open surface of the E-type core,
The gantry is provided with a terminal portion connecting each end of the primary winding and the secondary winding on at least one side of the side surface portion having the pair of side legs of the E-type core,
The E-type core, the an outer peripheral portion of the central leg, with the primary winding and multistage bobbin wound by stacking the secondary winding down is provided, the side portions with side legs of said pair The side portions on both sides where the terminal portion is not provided are open,
Leakage transformer, characterized in that said opened the cradle and winding guiding groove for guiding the secondary winding to the multistage bobbin definitive on at least one of both side surfaces are provided.   The E-type core is configured such that a part of the primary winding is wound between the central leg and one of the pair of side legs to thereby form the primary winding and the secondary winding. The leakage transformer according to claim 1, wherein an auxiliary leg for adjusting the coupling coefficient is provided, and an auxiliary bobbin for winding the primary winding is provided on an outer peripheral portion of the auxiliary leg. The terminal portion is provided on the pedestal located on both side portions having the pair of side legs, and the terminal portion provided on one side portion is used as a winding start side of the winding, and the other side portion is provided on the other side portion. according to claim 1 or 2, wherein leakage transformer, characterized in that the terminal part provided with winding end side of the winding. It said E-shaped core, together with said base portion has a substantially rectangular shape, according to claim 1 to 3, characterized in that the terminal unit to the mount located in the longitudinal ends of the base bottom portion is provided The leakage transformer of any one of these. The leakage transformer according to any one of claims 1 to 4 , wherein a guide portion for guiding a winding from the winding guiding groove toward the terminal portion is provided on a back side of the mount. Plural flange portions constituting the winding frame of the multi-bobbin, at a position opposed to the vertical direction as the winding guiding groove, one of claims 1 to 5, each notch is characterized by being provided The leakage transformer of any one of Claims.

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