JP4188979B2 - Leakage transformer - Google Patents

Description

  The present invention relates to a leakage transformer particularly suitable for use in a DC / DC inverter circuit constituting a lighting circuit of a backlight discharge lamp in a display device of a notebook personal computer, for example.

  A conventional transformer of this type is configured by superposing two cores, and winding a primary winding and a secondary winding around a plurality of columnar middle legs from one core to the other. Yes (see Patent Document 1).

JP 2002-75756 A (general)

  Although the transformer having the above configuration is small and thin, all the windings are wound around the middle leg, and when a small transformer is produced, fine work is required.

  The present invention has been made as a solution to the problems in the conventional leakage transformer as described above. The purpose of the present invention is to create a leakage transformer capable of facilitating work even when a small transformer is produced. It is to be.

The leakage transformer according to the present invention includes two bobbins around which a secondary winding is wound, two protrusions for arranging the two bobbins in parallel on an opening surface, and a position close to the two bobbins. A space for winding the primary winding; and a first core in which the space is formed, and the space formed in the first core is wound around the two protrusions as a core. a primary winding disposed Te, and a second core arranged opposite to the opening surface of the first core so as to cover the two projections, the space is a primary winding wound The two bobbins are present at positions where the two protrusions can be arranged in parallel with each other, and the primary winding includes the bottom surface of the first core and the bottom side flanges of the two hobbins. It is arrange | positioned between .

  The leakage transformer according to the present invention is characterized in that a groove is formed in a bottom surface portion from a base portion to a bottom portion of the two protrusions, and the primary winding is disposed in the groove.

  As described above, according to the present invention, a leakage transformer is created by attaching two bobbins each wound with a secondary winding to a protrusion protruding from the bottom surface of the first core. Can be performed very easily. Further, it is possible to avoid an increase in the size of the transformer by winding the primary winding around the two bobbins or in the lower space.

  Embodiments of a leakage transformer according to the present invention will be described below with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference numerals and redundant description is omitted.

  The leakage transformer according to the first embodiment of the present invention uses two bobbins 1 shown in FIGS. The two bobbins 1 are not exactly the same as shown in FIG. As shown in FIG. 2, the bobbin 1 is provided with a terminal 11 to which a secondary winding 5 is wound and to which a terminal end of the winding is connected. Further, the bobbin 1 includes a cylindrical portion 12 around which the winding is wound, an upper collar 14 projecting outward on the upper side of the cylindrical section 12, and a lower collar 15 projecting outward on the lower side of the cylindrical section 12. . A hole 13 is formed in the center of the cylindrical portion 12. The terminal 11 is provided so as to protrude outward from a terminal block 16 having a planar shape such as a trapezoid. The terminal block 16 is integrally formed on the lower surface of the lower collar 15 in the bobbin 1.

  5 to 8 show the first core 2. The first core 2 has a rectangular planar shape, and bobbin projections 21 and 21 to be inserted into the holes 13 of the bobbin 1 project from the bottom surface on the opening surface where the bobbin 1 is provided. In the vicinity of the position where 1 is disposed, a winding protrusion 22 and a positioning protrusion 23 are formed to protrude from the bottom surface at opposing positions.

  On the opening surface where the bobbin 1 is provided, a groove portion 24 for providing the primary winding 4 so as to make a round around the portion where the two bobbins 1 and 1 are arranged is substantially along an elliptical line segment. Is formed. As shown in FIG. 11, the primary winding 4 is wound around the two disposed bobbins 1, 1 and is wound around the winding projection 22. .

  A terminal block 25 provided with a terminal 26 to which a terminal portion of the primary winding 4 is connected is provided on the side portion of the first core 2 on the side where the winding projection 22 is formed. . Opposite to the first core 2 in the state where the bobbins 1 and 1 are provided, a lid is formed by the second core 3 so as to cover the opening side where the bobbins 1 and 1 are exposed.

  The second core 3 has a plate shape, and as shown in FIG. 9, the long side portions 3a and 3b have a zigzag shape so as to engage with the inner surface of the terminal block 16 and the terminal block 25, and the terminal It arrange | positions in the state pinched | interposed between the base 16 and the terminal block 25. FIG. The short side portion of the second core 3 is in contact with the short side portion of the first core 2 and is configured to be magnetically coupled to the first core 2.

  Further, the heads of the bobbin projections 21, 21 formed on the first core 2, the heads of the winding projections 22 and the positioning projections 23, and the opening surface of the first core 2 are arranged opposite to each other. A magnetic gap is formed between the second core 3 and the second core 3. The width of the magnetic gap can be adjusted by changing the heights of the bobbin projections 21, 21, the winding projections 22, and the positioning projections 23. In this embodiment, the positioning protrusion 23 is formed at a position substantially opposite to the winding protrusion 22 so that the bobbins 1 and 1 are disposed at a fixed position on the opening surface of the first core 2. The bobbins 1 and 1 are formed with notches 31 that engage with the positioning protrusions 23.

  The leakage transformer configured as described above is created as follows. Two bobbins 1 around which the secondary winding 5 is wound are prepared. As shown in FIG. 1, the primary winding 4 is disposed in the groove portion 24 in the first core 2 provided with the terminal block 25. Next, the bobbin projections 21 and 21 are inserted into the holes 13 of the bobbins 1 and 1 around which the secondary winding 5 is wound, and the bobbins 1 and 1 are set on the first core 2. At this time, the bobbins 1 and 1 are set upside down from the state of FIG. 4 so that the lower eyelid 15 can be seen in the state of FIG. When mounted on a printed circuit board or the like, the outer surface of the first core 2 is on the upper side as shown in FIG. 10, and therefore the lower collar 15 is positioned on the lowermost side so as to face the printed circuit board.

  Subsequently, the irregularities formed on the long side portion 3b of the second core 3 are engaged with the inner edges of the terminal blocks 16, 16, and the irregularities formed on the other long side portion 3a are engaged with the terminal block 25. The first core 2 and the second core 3 are joined with an adhesive or the like and electromagnetically coupled to complete a leakage transformer. To do.

  Thus, according to the leakage transformer according to the first embodiment of the present invention, the secondary winding 5 is wound around the bobbin 1, and the bobbin 1 is set on the first core 2. The wire 5 can be incorporated, and the workability is excellent. Moreover, the primary winding 4 can be incorporated by arrange | positioning and winding the primary winding 4 in the groove part 24 in the 1st core 2, and it is excellent in workability | operativity. Then, the second core 3 is covered with the first core 2 like a lid so as to cover the opening side where the bobbins 1 and 1 are exposed, and the first core 2 and the second core 3 are coupled. Therefore, a leakage transformer can be easily created, and a transformer can be easily created. Since the leakage transformer is created by using the two bobbins 1 and 1 each having the terminal 11 to which the secondary winding is wound and to which the terminal end of the winding is connected, the creation can be performed very easily. . As described above, the leakage transformer of the present invention that uses two bobbins 1 is suitable as a leakage transformer that is used when a plurality of lamps are lit. In other words, using two bobbins 1 means having two secondary windings and means separately having secondary windings for supplying power to the two lamps. Therefore, in the present day when the backlight of a liquid crystal display device such as a notebook personal computer has multiple lamps, it means that one leakage transformer of the present invention can cope with two lamps.

  Further, as described above, a magnetic gap is formed between the inner surface of the second core 3 and the heads of the bobbin projections 21 and 21, the winding projections 22 and the positioning projections 23, Since the width of the gap can be adjusted by the height of the bobbin projections 21, 21, the winding projection 22, and the positioning projection 23, the coupling coefficient can be changed appropriately.

  The degree of coupling between each secondary winding and the primary winding can also be adjusted by changing the number of turns of the primary winding wound around the winding projection 22. Further, on the inner surface of the second core 3, a protrusion is formed so as to face the bobbin protrusions 21, 21, the winding protrusion 22 and the positioning protrusion 23 so that a magnetic gap is formed between the protrusions. May be. In addition, the degree of coupling between the first core 2 and the second core 3 can be changed by winding the primary winding around the positioning projection 23.

  Further, in the above-described embodiment, the notches 31 that engage with the positioning projections 23 are formed on the bobbins 1 and 1, but the notches 31 are not formed on the bobbins 1 and 1 as shown in FIG. And the corresponding positions of the positioning projections 23 are slightly cut away, and the flat side edges of the bobbins 1 and 1 are in contact with the cutout portions of the positioning projections 23. You may make it fix to the state which fits.

  FIG. 13 shows a state where the second core 3 in the second embodiment of the leakage transformer in a state where the second core 3 is removed is removed. As is apparent from FIGS. 14 to 16, the first core 2 </ b> A constituting the leakage transformer has a substantially quadrangular planar shape, and two protrusions 21, 21 are formed so as to protrude from the bottom surface to the opening surface side. . On the opening surface side of the first core 2 </ b> A, a groove 31 is formed that makes one turn along a substantially elliptical line segment along the outer peripheral portion. The bottom surface of the groove 31 is a lower surface than the bottom surface 34 in the periphery of the base portion of the two protrusions 21 and 21. The first core 2A is not provided with the winding projections 22 and the positioning projections 23 formed on the first core 2 of the leakage transformer in the first embodiment.

  Bobbins 1A and 1A around which the secondary winding 5 is wound are arranged in parallel on the two protrusions 21, respectively. The bobbins 1A and 1A have the same configuration as the bobbin 1 shown in FIGS. 3 and 4 except that the planar shapes of the upper and lower collars 14 and 15 are circular.

  Except for the configuration described above, the leakage transformer of the second embodiment has the same configuration as that of the first embodiment. The leakage transformer according to the second embodiment is produced as follows. Two bobbins 1A around which the secondary winding 5 is wound are prepared. As shown in FIG. 13, the primary winding 4 is wound around the groove 31 in the first core 2 </ b> A provided with the terminal block 25. Next, the bobbin projections 21 and 21 are inserted into the holes 13 of the bobbins 1A and 1A around which the secondary winding 5 is wound, and the bobbins 1A and 1A are set on the first core 2A. At this time, the state shown in FIG. 13 is obtained, and the lower eyelid 15 of the bobbins 1A and 1A is visible.

  Next, as in the first embodiment shown in FIG. 9, the irregularities formed on the long side 3b of the second core 3 are engaged with the inner edges of the terminal blocks 16, 16, and the other Engage the unevenness formed on the long side 3a with the inner edge of the terminal block 25 and join them with an adhesive or the like, and also join the first core 2A and the second core 3 with an adhesive or the like. Then, the leakage transformer is completed by electromagnetic coupling.

  The same effect as that of the first embodiment can also be obtained by the leakage transformer according to the second embodiment. The first core 2A employed in the leakage transformer according to the second embodiment is free from the winding projections 22 and the positioning projections 23, so that the first core 2A can be easily manufactured. The winding work of the winding 5 is also facilitated.

  FIG. 17 shows a state where the second core 3 in the third embodiment of the leakage transformer is removed. As is apparent from FIGS. 18 to 20, the first core 2 </ b> B constituting the leakage transformer has a substantially quadrangular planar shape, and two protrusions 21, 21 are formed protruding from the bottom surface to the opening surface side. . A step 32 is formed at the base of these protrusions 21, 21. The step portion 32 constitutes a base portion that connects the base portions of the two protrusions 21 and 21. A bottom surface portion that is one step lower than the step portion 32 is a groove 33. In other words, a groove 33 is formed in a bottom surface portion connected from the base portion of the two protrusions 21 and 21 via the step portion 32.

  The primary winding 4 is wound around the bottom portion of the first core 2 </ b> B around the step portions 32, 32 formed at the base portions of the two protrusions 21, 21. The primary winding 4 is arrange | positioned at the groove part 33 in the bottom face of the 1st core 2B. Moreover, the primary winding 4 is arrange | positioned as shown in FIG. 20 between the upper collar 14 and the said groove part 33 in the two hobbins 1A and 1A. The first core 2B is not provided with the winding projections 22 and the positioning projections 23 formed on the first core 2.

  The other configuration of the third leakage transformer is the same as that of the leakage transformer according to the second embodiment. In the leakage transformer according to the third embodiment, except that the primary winding 4 is wound around the step portions 32 and 32 formed at the base portions of the two protrusions 21 and 21 so as to go around. It is created in the same manner as the leakage transformer according to the second embodiment. The leakage transformer according to the third embodiment can achieve the same effect as that of the second embodiment.

  21 and 22 show the first core 2C employed in a modification of the third leakage transformer. A groove 35 is formed along the outer peripheral portion of the first core 2C so as to make one round as a substantially elliptical line segment. The bottom surface of the groove 35 is a belt-like bottom surface portion connecting the base portions of the two protrusions 21 and 21. The surface is lower than 36. The primary winding 4 is disposed between the upper collar 14 and the groove 35 in the two hobbins 1A and 1A as shown in FIG. In the leakage transformer according to the modification of the third embodiment, the primary winding 4 is arranged in the groove 35 formed below the two protrusions 21 and 21 and is wound. It is produced in the same manner as the leakage transformer according to the embodiment. Also with the leakage transformer according to this modification, the same effect as that of the third embodiment can be obtained.

  As described above, according to the above-described embodiment, the leakage transformer is created by attaching the two bobbins wound with the secondary windings to the protrusions protruding from the bottom surface of the first core. It can be made very easily. In addition, when the primary winding is wound and disposed in a groove provided around or below the two bobbins, the groove becomes a space for the winding, so that an increase in size of the transformer can be avoided. .

The top view of the state which removed the 2nd core in the leakage transformer which concerns on 1st Example of this invention. FIG. 10 is a cross-sectional view of the leakage transformer of FIG. 1 taken along the line AA with the second core attached, and is a cross-sectional view of the leakage transformer according to the present invention shown in FIG. The top view of the bobbin used for the leakage transformer which concerns on 1st Example of this invention. BB sectional drawing of the bobbin used for the leakage transformer shown by FIG. The top view of the 1st core used for the leakage transformer which concerns on 1st Example of this invention. CC sectional drawing of the 1st core used for the leakage transformer shown by FIG. The top view which looked at the 1st core used for the leakage transformer which concerns on 1st Example of this invention from the outer side. FIG. 6 is a DD cross-sectional view of a first core used in the leakage transformer shown in FIG. 5. The top view seen from the 2nd core side in the leakage transformer which concerns on 1st Example of this invention. The top view seen from the 1st core side in the leakage transformer which concerns on 1st Example of this invention. The top view for showing the winding state of the secondary winding in the leakage transformer concerning the 1st example of the present invention. The top view of the state which removed the 2nd core in the leakage transformer which concerns on the 1st Example of this invention which employ | adopted the bobbin which changed the shape. The top view of the state which removed the 2nd core in the leakage transformer which concerns on the 2nd Example of this invention. The top view of the 1st core used for the leakage transformer which concerns on the 2nd Example of this invention. FF sectional drawing of the 1st core used for the leakage transformer shown by FIG. In EE sectional drawing of FIG. 13, sectional drawing of the state which attached the 2nd core. The top view of the state which removed the 2nd core in the leakage transformer which concerns on the 3rd Example of this invention. The top view of the 1st core used for the leakage transformer which concerns on the 3rd Example of this invention. FIG. 19 is an HH sectional view of the first core used in the leakage transformer shown in FIG. 18. FIG. 18 is a cross-sectional view showing a state where the second core is attached in the GG cross-sectional view of FIG. The top view of the 1st core used for the leakage transformer which concerns on the modification in the 3rd Example of this invention. FIG. 22 is a cross-sectional view taken along the line II of the first core shown in FIG. 21. FIG. 18 is a cross-sectional view taken along the line GG in the leakage transformer of FIG. 17 that is configured using the first core of FIG.

Explanation of symbols

1 bobbin
2, 2A-2C first core
3 Second core
3a, 3b Long side
4 Primary winding
5 Secondary winding
11 terminals
12 tube
13 holes
14 upper arm
15 Shimojo
16 terminal block
21 Bobbin protrusion
22 Winding protrusion
23 Positioning protrusion
24 groove
25 Terminal block
26 terminals
31 groove
32 steps
33 groove
34 Bottom
35 groove
36 Bottom

Claims (2)

Two bobbins around which the secondary winding is wound;
Two projections for arranging the two bobbins side by side on the opening surface and a space for winding the primary winding at a position close to the two bobbins are formed. The core,
A primary winding wound around the two protrusions in the space formed in the first core and arranged so as to circulate ;
A second core disposed opposite to the opening surface of the first core so as to cover the two protrusions,
The space exists at a position where the two bobbins can be arranged in parallel with the two protrusions after the primary winding is wound ,
The leakage transformer according to claim 1, wherein the primary winding is disposed between a bottom surface of the first core and the bottom side rods of the two hobbins . The leakage transformer according to claim 1, wherein a groove is formed in a bottom surface portion from a base portion to a bottom portion of the two protrusions, and the primary winding is disposed in the groove .

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