JP2005072261A - Low profile transformer and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a low profile transformer which is assembled easily and reduced in size and profile thereof, and also provide a low profile transformer. <P>SOLUTION: Flanges 4 having a terminal board 6 to which pin terminals 5 are implanted are respectively formed to both ends of a hollow type winding trunk 3, and an internal leg 7 consisting of a molding core is inserted into the hollow winding trunk 3 of a coil bobbin 1 in which the coil 2 is wound to the external circumference of the winding trunk 3. Moreover, the low profile transformer is assembled by providing a lower core 8 formed of the molding core to the lower side of the coil bobbin 1, by arranging the lower surface of each end portion 7a of the internal leg 7 projected from the winding trunk 3 to the predetermined position on the lower core 8, by providing an upper core 9 consisting of the molding core opposing to the lower core 8 to the upper part of the coil bobbin 1, and by arranging the upper core 9 to the predetermined position for the internal leg 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a low profile transformer used in consumer electronic equipment and a low profile transformer.

  In recent years, various electronic devices are required to be downsized and space-saving, and accordingly, components are required to be similar, and a transformer, which is a main component of a power supply circuit, is no exception.

  Usually, a transformer secures the core cross-sectional area and secures the winding space, which leads to power. However, the core cross-sectional area cannot be secured to reduce the height of the transformer, making it difficult to achieve the desired one. Become.

  In general, many cores used in transformers are obtained by attaching an I-type iron core to an E-type iron core, and a transformer is formed by winding a coil around the center leg of the E-type core.

  In such a type of transformer, if the core middle leg is made thick in order to increase the core cross-sectional area, the transformer cannot be reduced in height. Further, when the width of the core middle leg is increased, the floor area of the transformer is increased.

  As the core shape, an I-type core and two square cores are combined, a coil is wound around the outer circumference of the I-type core, and the square cores are respectively arranged above and below the upper and lower sides. If the coil is positioned in the letter-shaped core, the height can be reduced.

  As a transformer using such a core structure, for example, Japanese Patent Publication No. 53-46244 exists.

When manufacturing this transformer, the steel strip formed by cutting a magnetic steel sheet having a thickness into a required width is continuously and mechanically wound in an annular shape to form a wound core with a required thickness. Separately, the same magnetic steel sheet pieces as the wound iron cores cut into strips are laminated to make a rod-shaped auxiliary core equal to the height of the wound iron core, and two of the above-mentioned wound iron cores and one auxiliary core are prepared. Auxiliary cores are placed in positions that bisect the wound cores in the longitudinal direction between the opposing winding layers of the winding cores, and the laminated surfaces of the auxiliary cores and the wound layers of both winding cores are joined orthogonally. Prior to fixing with the clamping tool, the auxiliary core is wound with an insulating material to form primary and secondary wires, and the auxiliary core is inserted and fixed between the two wound cores. Manufactured.
Japanese Patent Publication No.53-46244

  The core of this transformer has to cut electromagnetic steel sheets to a predetermined width and laminate them in a predetermined shape. In this case, since the core consists of three types, there is a problem that manufacturing is complicated.

  In addition, it has a configuration in which an auxiliary core is arranged at a position that bisects the wound core in the longitudinal direction between the opposite wound layer surfaces of the two wound cores, and in this case, no positioning means is particularly taken, There has been a problem that it is necessary to pay attention to positioning and assembling, and there is a variation in characteristics when there is variation in positioning for each product.

  Furthermore, the laminated surface of the auxiliary core and the wound layer surface of the both-winding iron cores must be joined orthogonally and fixed with a clamping tool, and there is a problem that assembly is complicated.

  The present invention has been proposed in view of the above, and an object of the present invention is to provide a method for manufacturing a low-profile transformer that is easy to assemble and a low-profile transformer manufactured thereby.

  According to the first aspect of the present invention, the flange 4 having the terminal block 6 in which the pin terminals 5 are planted at both ends of the hollow winding drum 3 is formed, and the coil 2 is provided on the outer periphery of the winding drum 3. A lower core 8 made of a frame-shaped molded core having an opening at the center is provided at the lower part of the coil bobbin 1 wound, and a middle leg 7 of the molded core is inserted into the wound body 3, The upper core 9 made of a frame-shaped molded core having an opening at the center is incorporated at a predetermined position on each end portion 7a of the middle foot 7 protruding from 3, thereby achieving the above object.

  In the transformer according to claim 2, flanges 4 each having terminal blocks 6 in which pin terminals 5 are implanted are formed at both ends of a hollow winding drum portion 3, and a coil 2 is provided on the outer periphery of the winding drum portion 3. A coil bobbin 1 wound, a middle leg 7 made of a molded core that is inserted into the winding drum portion 3 and each end portion 7a projects outward from the winding drum portion 3, and a lower portion of the coil bobbin 1 are provided. A lower core 8 made of a frame-shaped molded core having an opening at the center where each end portion 7a of the middle foot 7 is provided at a predetermined position; and an upper portion of the coil bobbin 1; 7 is provided at a predetermined position on each end portion 7a, and is provided with an upper core 9 formed of a molded core having an opening in the center and spaced from the lower core 8 so as to face the lower core 8.

  According to a third aspect of the present invention, the upper surface of the coil 4 wound around the flange 4 and the winding drum portion 3 of the coil bobbin 1 is located in the upper core 9, and the upper core 9. It is set as the structure which does not protrude from the upper surface.

  According to the first and second aspects, since the middle leg 7 and the upper and lower cores 9 and 8 having an opening in the center are formed of a molded core, it is easier to incorporate than the wound layer type, and the core is the middle leg. Even if it is a three-point partial configuration of a pair of letter-shaped cores, it is easy to assemble and has excellent mass productivity.

  Moreover, a transformer can be assembled by inserting the middle leg 7 into the winding body 3 of the coil bobbin 1 and providing the upper and lower cores 9 and 8 on the coil bobbin 1. In this case, the coil bobbin 1 also functions as a positioning member. In addition, the cores can be easily integrated with each other.

  According to the third aspect, since the upper and lower cores 9 and 8 are provided at the lower part and the upper part of the coil bobbin 1, the increase in dimension in the height direction can be suppressed as much as possible, and the height can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view of an embodiment of the present invention, and FIG. 2 is an assembled perspective view.

  In these drawings, reference numeral 1 denotes a coil bobbin made of a molded product of insulating resin. The coil bobbin 1 has a hollow winding body 3 around which a coil 2 is wound on the outer periphery and both ends of the winding body 3. A flange 4 is formed, and a terminal block 6 is provided on the lower outer side of the flange 4 so as to project in the bobbin axial direction, and an appropriate number of pin terminals 5 are implanted in the lower part.

  Reference numeral 7 denotes a middle leg that is inserted into the hollow portion of the winding drum portion 3 and is formed by molding, for example, ferrite. The hollow part of the winding drum part 3 is formed horizontally long in order to reduce the height in the state shown in the figure. The middle leg 7 made of a molded core is formed in a shape corresponding to the shape of the window of the hollow portion so that it can be inserted into the hollow portion of the winding drum portion 3, and a cross-sectional area is secured. When the middle foot 7 is inserted into the winding drum portion 3, each end portion 7 a in the length direction protrudes outward from the outer end of the terminal block 6.

Reference numeral 8 denotes a lower core made of a molded core. The lower core 8 has a substantially rectangular shape with an opening at the center, and is arranged orthogonally to a pair of opposite long side passages 8a at the ends thereof. It is made of the same material as that of the middle foot 7. Each terminal block 6 of the coil bobbin 1 is positioned on the lower core 8 side, and the outer periphery of the lower part of the coil bobbin 1 is surrounded by the lower core 8. That is, the length dimension L ₁ inside the side path 8 b on the short side of the lower core 8 is formed to be substantially equal to the dimension L ₁ between the outer ends of the terminal blocks 6 of the coil bobbin 1. Further, the length dimension L ₂ between the inner surfaces of the opposite short-side side paths 8 b is formed to be substantially equal to the length dimension L ₂ of the terminal block 6 orthogonal to the axial direction of the coil bobbin 1, and the lower part of the coil bobbin 1. Can be stored in a space portion inside the lower core 8. The length dimension of the flange 4 is also formed equally to the length dimension L ₂ of the terminal block 6.

Further, the length L ₃ of the middle leg 7 is formed to be equal to the length L ₃ of the side path 8 b on the short side of the lower core 8 disposed on the lower side, and is a terminal block below the coil bobbin 1. When the lower core 8 is incorporated on the 6th side, the lower surfaces of both end portions 7a of the middle leg 7 are joined to predetermined positions on the side path 8a on the long side of the lower core 8.

  In FIGS. 1 and 2 again, reference numeral 9 denotes an upper core which is disposed on the upper side of the coil bobbin 1 and has a substantially square-shaped center, and the upper core 9 is also formed of a molded core and has a pair of long sides. Side passage 9a and short side passage 9b, and the flange 4 of the coil bobbin 1 is accommodated in the inner space.

  Next, an assembly example of the present invention will be described.

  First, the coil 2 is wound around the winding body portion 3 of the coil bobbin 1, and the lead wire (not shown) has a lead groove (not shown) formed in the terminal block 6 of the coil bobbin 1, as is well known. It is entangled at the base of a predetermined pin terminal 5 and connected by soldering.

  Next, the middle leg 7 is inserted into the winding body part 3 of the coil bobbin 1, and the middle leg both ends 7 a protruding from both ends of the winding body part 3 are on the long side of the lower core 8 provided at the lower part of the coil bobbin 1. It is arranged opposite to a predetermined position on the side path 8a.

  Next, the upper core 9 is provided on the outer periphery of the upper portion of the coil bobbin 1. The upper core 9 is arranged to be opposed to a predetermined position on both end portions 7 a of the middle leg 7 protruding from the winding body portion 3.

  A predetermined portion of each core is joined and integrated through an adhesive (not shown).

  When assembling, the coil bobbin 1 functions as a positioning member, and a middle leg 7 of a predetermined shape and size is inserted into the winding body 3 of the coil bobbin 1 having a predetermined shape and size. In the process in which the core 8 is provided and the upper core 9 is incorporated above the core bobbin 1, the middle leg 7, the lower core 8, the upper core 9, etc. can be arranged at appropriate positions, and the coil bobbin 1 The members such as the foot 7, the lower core 8, and the upper core 9 can be integrated with each other.

  After the assembly, as shown in FIG. 2, the upper surface of the flange 4 of the coil bobbin 1 and the upper surface of the coil 2 are accommodated in a space portion inside the upper core 9 so as not to protrude upward from the upper surface of the upper core 9. Is preferable from the viewpoint of reducing the height.

  FIG. 3 shows a side view of the transformer assembled in this way. The pin terminal 5 protrudes downward from the lower surface of the lower core 8 and is inserted into a pin terminal insertion hole (both not shown) on the mounting surface, and the transformer is mounted on the mounting surface.

  In the transformer configured as described above, when a current is passed through the coil 2, a magnetic flux is generated. The magnetic flux is ¼ each of the lower core 8 and the upper core 9 arranged in the vertical direction of the middle foot 7. The flow is distributed in the magnetic path, and the outer dimensions in the plane are suppressed as much as possible. Further, since the coil bobbin 1 is positioned in the upper core 9 and the lower core 8, the dimension in the height direction can be suppressed.

  Further, since the magnetic flux of the middle leg 7 is divided into four via the upper and lower cores 9 and 8 respectively disposed above and below the middle leg 7, the leakage magnetic flux can also be suppressed small.

The disassembled perspective view of Example 1 of this invention is shown. The assembly perspective view of 1 of the Example is shown. The side view of the assembly state of the Example of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coil bobbin 2 Coil 3 Winding drum part 4 Flange 5 Pin terminal 6 Terminal block 7 Middle leg 7a End part 8 Lower core 8a Long side side path 8b Short side side path 9 Upper core

Claims (3)

Flange (4) having terminal blocks (6) in which pin terminals (5) are implanted at both ends of a hollow winding body (3) is formed, and a coil is formed on the outer periphery of said winding body (3). A lower core (8) comprising a frame-shaped molded core having an opening in the center is provided at the lower part of the coil bobbin (1) around which (2) is wound,
Insert the middle leg (7) of the molded core into the winding body (3),
Incorporating an upper core (9) made of a frame-shaped molded core having an opening in the center at a predetermined position on each end (7a) of the middle leg (7) protruding from the winding body (3). A manufacturing method of a low profile transformer characterized by the above. Flange (4) having terminal blocks (6) in which pin terminals (5) are implanted at both ends of a hollow winding body (3) is formed, and a coil is formed on the outer periphery of said winding body (3). A coil bobbin (1) around which (2) is wound;
A middle leg (7) composed of a molded core inserted into the winding body (3) and each end (7a) projecting outward from the winding body (3),
A lower core (8) comprising a frame-shaped molded core provided at a lower portion of the coil bobbin (1) and having an opening at the center where each end (7a) of the middle foot (7) is provided at a predetermined position. When,
A center provided at an upper portion of the coil bobbin (1) and provided at a predetermined position on each end portion (7a) of the middle foot (7), and disposed opposite to the lower core (8). A low-profile transformer comprising an upper core (9) made of a molded core having an opening in the top. The upper surface of the coil (2) wound around the flange (4) of the coil bobbin (1) and the winding body (3) is located in the upper core (9), and the upper core (9). 9) A low profile transformer that does not protrude from the upper surface.

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