JP2007250841A - Thin transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure which permits the winding end of a thick primary winding to be pulled back easily toward the terminal, is not increased in thickness, can be made low in height thereby, and is also not increased in mounting area. <P>SOLUTION: The structure includes a bobbin 22 consisting of a winding drum 30, terminal holders 34 which also serve for winding frames, and an intermediate winding frame. By winding a winding material 42 around the winding drum, a winding is formed. The end of the winding is connected to a terminal 32, and a magnetic core 24 is so arranged as to surround the side face of the winding. At a place away by a distance equivalent to the wire diameter of the winding material or above from the intermediate winding frame 36 near the winding end position on the side face of the winding drum of the bobbin, a projection 40 for pulling back the winding which projects by a length equivalent to the projecting length of the intermediate winding frame to the side or below is formed as an integral body of the bobbin. A groove 44 for the pulled-back wire is formed in the terminal holder outside the side face of the winding. The end of the winding is hooked on the projection, and then a portion 42a of the pulled-back wire is pulled back along the side face of the winding between the side face of the winding and the magnetic core toward the terminal, and is passed through the groove and finally is hooked up and connected to the terminal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thin transformer used for an inverter device, a high-voltage discharge circuit, and the like. More specifically, the present invention relates to a thin transformer having a structure in which the winding end of a winding material can be easily pulled back to the terminal side without increasing the thickness. It is.

  In a liquid crystal TV or a large liquid crystal monitor, generally four or more cold cathode tubes are used as a backlight. For example, in a 32-inch liquid crystal television, 16 cold cathode fluorescent lamps are arranged on the back surface of the liquid crystal panel at appropriate intervals to maintain the brightness of the entire screen. In the past, cold cathode fluorescent lamps were lit using the same number of inverter circuit units as the number of cold cathode fluorescent lamps. However, in such a configuration, the drive circuit is complicated and a large number of parts are used. It was difficult and expensive. Therefore, in recent years, as shown in FIG. 1, a system is used in which a plurality of (four in FIG. 1) cold cathode tubes 14 are turned on via the inverter transformer 12 at the output of one inverter circuit 10.

  An inverter transformer used in such an inverter circuit usually has a bobbin provided with a winding drum portion and a terminal holding portion, and a winding material is wound around the winding drum portion to thereby form a primary winding portion and a plurality of two windings. A next winding portion is formed, a winding terminal is connected to a terminal mounted on the terminal holding portion, and a magnetic core is arranged so as to surround a side surface of the winding body portion.

  However, in such an inverter transformer, as the output increases, it is necessary to increase the diameter of the winding material in order to increase the size of the magnetic core and reduce the heat generation. The increase in thickness is not negligible. This hinders the low profile of the inverter transformer. For this reason, the pullback line portion of the winding is arranged on the side surface of the bobbin winding body (that is, between the bobbin and the magnetic core) to reduce the height, but at this time, the winding may be unraveled. In addition, a complicated operation for wrapping the entire winding portion with an insulating tape or the like and fixing the pull-back line is required, which increases man-hours and material costs.

As a structure for solving such a problem, there has been proposed a transformer having a structure in which a protrusion is used to hook and return a winding terminal to the protrusion (see Patent Document 1). This is a structure in which a protrusion is formed on an intermediate winding frame part for winding separation provided in the middle of the bobbin, and the winding is hooked back on the protrusion. However, in such a structure, as the output voltage rises and the diameter of the winding material increases, the intermediate frame portion is thickened (length in the winding axis direction) in order to ensure the primary-secondary insulation distance. And a protrusion protrudes from the intermediate winding frame portion, so that it becomes longer in the width direction, and there is a problem that the mounting area increases accordingly. Furthermore, since it is necessary to work by removing the winding material from the winding body part in order to be hooked on the protrusion, the work is complicated and there is a possibility that the winding material is damaged.
Japanese Patent Laid-Open No. 5-283245

  The problem to be solved by the present invention is that there is no need to fix the winding part with an insulating tape or the like, the winding end of the winding part can be easily pulled back to the terminal direction, and the thickness (height dimension) increases. It is to realize a structure in which the overall height can be reduced so that the length (the longitudinal dimension of the magnetic core) and the width (the lateral dimension of the magnetic core) do not increase.

  The present invention includes a winding drum portion, a terminal holding portion that serves as a winding frame that is positioned at both ends of the winding drum portion, and holds a terminal, and an intermediate winding reel portion that is located in the middle of the winding portion and defines a winding region. A structure having a bobbin, forming a winding part by winding a winding material around the winding body part, connecting a winding terminal to the terminal, and arranging a magnetic core so as to surround a side surface of the winding part. In the transformer, in the vicinity of the winding end position on the side surface of the bobbin body of the bobbin, at a position separated from the intermediate winding part by a distance equal to or larger than the wire diameter of the winding material, the protrusion below the protruding length to the side of the intermediate winding part A long winding pull-back projection is formed integrally with the bobbin, and a pull-back wire groove is formed outside the side surface of the winding portion of the terminal holding portion, and a winding terminal portion of the winding material is formed on the projection. Hook and pull the part of the return line along the side of the winding part and between the magnetic core toward the terminal And a flat transformer, characterized in that so as to connect tied to terminal through the grooves of the terminal holding portion.

  For example, the winding drum portion has a rectangular tube structure into which a part of the magnetic core is inserted, and the protrusion is a plate-like piece parallel to the intermediate winding frame portion, and the winding material is formed from the intermediate winding frame portion. The shape is cut away so that the lower end is positioned by the wire diameter and the lower end is positioned above the lower surface of the winding body by the wire diameter of the winding material.

  The transformer is, for example, an inverter transformer for driving a cold-cathode tube having a primary winding section and a high-voltage secondary winding section partitioned by an intermediate winding section, and the high-voltage secondary winding section includes a plurality of separators separated by separators. The structure is divided into small winding regions and each wound with a thin single wire. In such an inverter transformer, a protrusion is formed on a winding body portion of a primary winding portion wound with a thick stranded wire.

  In the thin transformer according to the present invention, since the pullback line is arranged on the side surface (between the bobbin and the magnetic core) of the bobbin winding portion, it is possible to prevent an increase in the dimension in the height direction and realize a low profile. . In addition, since a protrusion is provided, the winding terminal portion of the winding material is hooked on this protrusion, and the portion of the pullback line is pulled back along the side surface of the winding body portion. The workability can be improved. Since the groove of the terminal holding part of the bobbin through which the return line is passed is provided outside the side surface of the winding part, the return line does not rest on the upper surface side of the winding part, and the binding work to the terminal is easy Yes. Furthermore, in the present invention, since the position of the protrusion is set on the side surface of the winding drum portion, it is possible to prevent an increase in mounting area due to the increase in the size of the bobbin in the vertical and horizontal directions, and the winding material is removed from the winding drum portion. Since there is no need to perform the winding operation, the operation is easy in that respect, and there is no possibility of damaging the winding material.

  FIG. 2 is a plan view showing an embodiment of a thin transformer according to the present invention. FIG. 3 is an explanatory view of the bobbin provided with the winding, in which A shows the bottom, B shows the xx cross section, and C shows the front and the enlarged main parts. This is an example of an inverter transformer for driving a cold cathode tube having a primary winding portion and a plurality (six in this case) of high-voltage secondary winding portions.

  As shown in FIG. 2, the thin transformer 20 includes a combination of a bobbin 22 provided with a winding and a magnetic core 24 disposed so as to surround a side surface of the winding portion. As shown in FIG. 3, the bobbin 22 is positioned between the winding body 30 and the winding part 30 and the terminal holding part 32 serving as a winding frame which is located at both ends of the winding body 30 and holds the terminal 32. The structure is provided with an intermediate winding frame portion 36 that divides the region into a primary side region and a secondary side region. Here, the secondary side region is divided into six small winding regions by five separators 38. . In addition, the said winding trunk | drum 30 is a square cylinder structure in which a part of magnetic core is inserted (refer B of FIG. 3).

  In the present invention, in the vicinity of the winding end position on the side surface of the winding body portion 30 of the bobbin 22 (therefore, in the vicinity of the intermediate winding portion 36), the intermediate winding portion 36 is separated by a distance equal to or larger than the wire diameter of the winding material. A protrusion 40 for retracting the winding having a projection length equal to or less than the projection length to the side of the intermediate winding frame 36 is formed integrally with the bobbin 22. Here, the protrusion 40 is a plate-like piece parallel to the intermediate winding frame portion 36, and is located apart from the intermediate winding frame portion 36 by the wire diameter of the winding material 42, and the lower end of the winding drum portion 30. The shape is notched so as to be positioned above the lower surface by the wire diameter of the winding material 42 (see particularly the enlarged view of FIG. 3C). Further, a pull-back line groove 44 is formed outside the side surface of the winding portion of the bottom surface of the terminal holding portion 34 of the bobbin 22. Accordingly, the pull-back wire groove 44 is deeper than the wire diameter of the winding material 42 and wider than the wire diameter, and has a groove cross-sectional shape that completely fits the winding material 42, and extends from end to end of the terminal holding portion 34. Is formed.

  The primary winding is wound around the winding body portion of the primary winding portion by a thick twisted wire as many times as necessary. At the end of winding, the end portion of the winding material 42 is hooked on the protrusion 40, the portion 42a of the return line is pulled back toward the terminal along the side surface of the winding portion, and entangled with the terminal 32 through the groove 44 of the terminal holding portion. Connect with. Each secondary winding is wound around each small winding region of the secondary winding portion with a winding material 46 made of a thin single wire, and each winding end is connected to a terminal and connected by a solder dip.

  The magnetic core 24 includes a combination of a rod-shaped core 50 and a square frame-shaped core 52. The core material may be, for example, a ferrite material such as nickel or a metal magnetic material. The rod-shaped core 50 has a rectangular cross section, and has a size that can be inserted into the winding body 30 of the bobbin 22. The square frame-shaped core 52 is combined so as to surround the outer periphery of the primary winding portion and the secondary winding portion of the bobbin 22 and to face the rod-shaped core 50 at both ends of the bobbin 22.

  With such a structure, the pull-back wire portion 42a is disposed on the side surface (between the winding portion and the magnetic core) of the winding body portion 30 of the bobbin 22, so that an increase in thickness can be prevented and a reduction in height is achieved. realizable. In addition, since the winding is simply hooked on the protrusion and the winding is pulled back along the side surface of the winding body, there is no need to perform extra work such as attaching and fixing a tape, thereby improving workability. be able to. Since the protrusion is formed on the side surface of the winding drum portion, it is only pulled back after winding up to the vicinity of the intermediate winding frame portion, and the operation is simplified. And since the part other than the projection can be used as a winding region, it is possible to effectively use the space, and it is not necessary to increase the thickness of the intermediate winding frame part for securing insulation, and the mounting area can be reduced. Is possible. Further, since the groove of the bobbin through which the portion of the pullback line passes is provided outside the side surface of the winding body portion, the pullback wire does not get on the winding portion and can be easily tangled to the terminal.

Explanatory drawing which shows an example of the cold cathode tube lighting circuit by the conventional inverter. The top view which shows one Example of the thin transformer which concerns on this invention. Explanatory drawing of the bobbin which gave winding.

Explanation of symbols

20 transformer 22 bobbin 24 magnetic core 30 winding body part 32 terminal 34 terminal holding part 36 intermediate winding frame part 40 projection 44 groove

Claims (3)

A bobbin provided with a winding drum portion, a terminal holding portion that serves as a winding frame that is located at both ends of the winding drum portion, and an intermediate winding frame portion that is located in the middle of the winding portion and divides the winding region. In a transformer having a structure in which a winding part is formed by winding a winding material around the winding body part, a winding terminal is connected to the terminal, and a magnetic core is disposed so as to surround a side surface of the winding part.
Winding with a projecting length equal to or less than the projecting length to the side of the intermediate winding frame part at a position separated from the intermediate winding frame part by a distance equal to or greater than the wire diameter of the winding material in the vicinity of the winding end position on the side surface of the bobbin body of the bobbin A wire pull-back projection is formed integrally with the bobbin, and a pull-back wire groove is formed on the outer side of the winding portion side surface of the terminal holding portion. A thin transformer characterized in that a wire portion is pulled back in the direction of a terminal along a side surface of a winding portion with a magnetic core and is connected to a terminal through a groove of a terminal holding portion.   The winding drum portion has a rectangular tube structure into which a part of a magnetic core is inserted, and the protrusion is a plate-like piece parallel to the intermediate winding frame portion, and the wire diameter of the winding material from the intermediate winding frame portion 2. The thin transformer according to claim 1, wherein the thin transformer is located so as to be separated by a distance, and the lower end is notched so as to be higher than the lower surface of the winding body portion by the wire diameter of the winding material. The transformer is an inverter transformer for driving a cold cathode tube having a primary winding section and a high-voltage secondary winding section partitioned by an intermediate winding frame, and the high-voltage secondary winding section is divided into a plurality of small regions by a separator. The thin transformer according to claim 1 or 2, wherein the thin transformer is divided and wound by a thin single wire, and a protrusion is formed on a winding body portion of a primary winding portion wound by a thick stranded wire.

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