JP4987657B2 - Small step-up transformer - Google Patents

Description

  The present invention relates to a small step-up transformer used in, for example, an optical device such as a camera or a small electronic device.

  A choke coil having a pot-type core and a rivet-type core includes, for example, a pot-type core composed of a top wall and a side wall integrally formed with the top wall, a bottom plate, and the bottom plate, as shown in Patent Document 1. A rivet-type core comprising a magnetic core portion standing at the center thereof, a coil fitted to the magnetic core portion, and a U-shaped terminal fixed to the bottom plate.

  In the choke coil disclosed in Patent Document 1, a spacer made of a nonmagnetic material is interposed between the inner surface of the top wall of the pot-type core and the upper end surface of the magnetic core portion of the rivet-type core to form a magnetic path gap. ing. That is, the inductance of the choke coil is set by adjusting the thickness of the spacer made of a nonmagnetic material.

  Moreover, for example, as shown in Patent Document 2, a pot-type core composed of a top wall and a side wall integrally formed with the top wall, a bottom plate, and a bottom plate that is integrally provided with the bottom plate at the center thereof, and an upper end There is known a small step-up transformer including a rivet-type core composed of a magnetic core part having a flange part at a part, a coil fitted to the magnetic core part, and a terminal fixed to the bottom plate.

In this small step-up transformer of Patent Document 2, a pot-type core is divided into left and right parts so that the top surface of each top wall and the top surface of the collar part are flush with each other, and the inner peripheral surface of the top wall opening and the collar part A first gap forming portion is provided between the outer peripheral surfaces of the pot-type cores, and a lower end surface of each side wall of the pot-type core and an upper surface of the bottom plate of the rivet-type core are opposed to each other, and a second gap-forming portion is provided therebetween. It is provided and the inductance of the coil is set.
Japanese Patent No. 3581350 JP 2006-313841 A

  In Patent Document 1, in a choke coil, a spacer made of a nonmagnetic material is interposed between an inner surface of a top wall of a pot type core and an upper end surface of a magnetic core portion of a rivet type core to form a magnetic path gap. However, the inner surface of the top wall of the pot type core and the upper end surface of the magnetic core part of the rivet type core, that is, the gap forming part of the magnetic path are surrounded by the side wall of the pot type core.

  Therefore, when assembling the choke coil, it is difficult to set the inductance of the choke coil by putting spacers with different thicknesses in and out of the gap forming part of the magnetic path surrounded by the side wall of the pot-type core, and it takes time for assembly. This is a cause of cost increase.

  In the small step-up transformer of Patent Document 2, the gap of the magnetic path can be selectively formed by the first and second gap forming portions and the coil inductance can be adjusted, but the gap is insufficient and the inductance value is limited. is there.

  The present invention has been made paying attention to the above circumstances, and an object thereof is to provide a small step-up transformer capable of easily and accurately positioning a ring core and a drum core and suppressing variations in coil inductance. It is in.

  It is another object of the present invention to provide a small step-up transformer that can easily perform coil terminal processing on a binding terminal and can improve work efficiency.

In order to solve the object, the invention according to claim 1 is made of a synthetic resin material, a pedestal provided with a plurality of binding terminals on a peripheral side portion, a top wall, and a side wall integrally formed with the top wall. The top wall has a circular fitting hole, the side wall has a ring core mounted on the pedestal, and a magnetic core portion, and a flange portion is provided at each of both ends of the magnetic core portion. A drum core in which one flange portion located on the pedestal side is placed on the pedestal and the other flange portion located on the ring core side is fitted in the fitting hole of the ring core; and the magnetic core portion The pedestal is provided on a flat surface on which one of the flanges of the drum core is placed, and on the two side portions facing each other with the flat surface interposed therebetween. A protruding wall projecting upward from the position of the surface, and provided on the flat surface, and the drum core is placed on the flat surface. At least two first positioning protrusions that abut against the peripheral wall of one flange portion of the drum core and restrict lateral movement of the ring core, and a wall surface of the protruding wall that faces the flat surface. The left and right corners of the concave fitting part and the bottom part of the concave fitting part, the left and right corners and the bottom of the concave fitting part are in contact with the peripheral surface of one flange part of the drum core, and And a second positioning protrusion that restricts movement in a lateral direction different from the direction, and the ring core is one of the flanges positioned on the pedestal side of the drum core that contacts the first positioning protrusion. A pair of side walls that contact the first positioning protrusion from the side opposite to the side on which the part abuts, and a magnetic path gap is formed between the ring core and the drum core to set the coil inductance Characterized by It is the type step-up transformer.

The invention according to claim 2 is the small step-up transformer according to claim 1, wherein the binding terminal has a tapered portion in which a base end side of a portion where the coil is wound is narrow and wide toward a tip end portion. The terminal of the said binding terminal to which the said coil is wound is provided with the habit which goes to the said base side.

  According to the first aspect of the present invention, the first and second positioning protrusions provided on the pedestal can easily and accurately position the ring core and the drum core, and the variation in coil inductance can be suppressed.

  According to the second aspect of the present invention, it is possible to easily perform the terminal processing of the coil with respect to the binding terminal and to improve the work efficiency.

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

  1 to 7 show a first embodiment of a small step-up transformer. As shown in FIGS. 1 to 7, the small step-up transformer 10 includes a pedestal 11, a ring core 12, and a drum core 13. The pedestal 11 has a rectangular shape integrally formed of a synthetic resin material. The opposite two side portions are provided with protruding walls 14 protruding upward, and the other two side portions are flat portions flush with the upper surface. 15 is formed.

  Each of the flat portions 15 of the pedestal 11 has a substantially equilateral triangular shape, and a first positioning protrusion 16 is formed in a symmetrical and integral manner with protrusions with the top portion 16a facing outward and the flat portion 16b facing inward. ing. On the side surfaces of the protruding wall 14 facing each other, recessed portions 17 that are notched in a rectangular shape are provided. A second positioning projection 18 is formed which includes three portions of the left and right corners 17a and the bottom 17b of the recessed portion 17. The first and second positioning protrusions 16 and 18 are configured to position the ring core 12 and the drum core 13 with respect to the base 11 by a method described later.

  Further, a rough surface 19 is formed on the upper surface of the pedestal 11 by embossing or the like. Further, a tap terminal 20 is provided on the peripheral side of the pedestal 11 on the protruding wall 14 side, and a binding terminal 21 is provided on both sides of the tap terminal 20. A plurality of mounting terminals 22 are provided on the peripheral side portion of the base 11 on the flat portion 15 side.

  The tap terminal 20 is formed in a divergent shape in which the proximal end portion 20a to which the coil 23 is entangled is narrow and wide toward the distal end portion 20b. It is formed as follows.

  The binding terminal 21 is formed in a tapered portion 21c on one side so that the proximal end portion 21a to which the coil 23 is wound is narrow and the distal end portion 21b is wide, and the wound coil 23 is connected to the distal end of the binding terminal 21. It is formed so as not to escape from the portion 21b. Furthermore, the taper portion 21c is provided with a coil end processing groove 24 having an edge 24a that peels off the insulating coating of the coiled coil 23. The coil end processing groove 24 has a very narrow width of, for example, 0.15 mm, and the insulating coating of the coil 23 is peeled off due to the friction between the coil 23 and the edge 24a, and is electrically connected to the binding terminal 21. It has come to be.

  The ring core 12 has, for example, a square top wall 25 of 5.8 × 5.8 mm, and a cut surface 25a (for example, for instructing the direction of the small step-up transformer 10) at one corner thereof. A cut width of 1.0 mm) is formed. In addition, a pair of side walls 26 (height is, for example, 2.0 mm) that are integral with the top wall 25 and narrower than the top wall 25 are provided on both sides of the lower surface of the top wall 25. A circular recess 27 is provided on the lower surface of the top wall 25, and an arc recess 27 a is formed along the curvature of the recess 27 on the inner surfaces of the pair of side walls 26 facing each other. Further, a circular fitting hole 28 is provided in the central portion of the top wall 25.

  The drum core 13 is integrally provided with a first flange 29 and a second flange 30 at both upper and lower ends of a cylindrical magnetic core portion 13a. The outer diameter of the first flange portion 29 is slightly smaller than the inner diameters of the recessed portion 27 and the fitting hole 28, and the first flange portion 29 is fitted inside the recessed portion 27 and the fitting hole 28. The second collar part 30 is formed to have a slightly smaller diameter than the first collar part 29.

  The coil 23 is wound around the magnetic core portion 13a. The coil 23 has a primary winding wound on the inner layer and the outer layer, and a secondary winding wound on the intermediate layer. The tap terminal 20 and the binding terminal 21 are connected.

  When fixing the second flange 30 of the drum core 13 to the pedestal 11, an adhesive is applied to the rough surface 19 formed by embossing or the like on the upper surface of the pedestal 11, and the second ridge of the drum core 13 is applied. The part 30 is adhered and fixed. At this time, a part of the outer peripheral surface of the second flange part 30 abuts on the flat surface part 16b of the two first positioning protrusions 16, and another part of the outer peripheral surface of the second flange part 30 is two. The second positioning protrusion 18 abuts on the left and right corners 17a and the bottom 17b of the recessed part 17 of the recessed part 17. Accordingly, the drum core 13 is positioned at a total of eight locations, and the movement of the drum core 13 in the lateral direction is restricted.

  After fixing the drum core 13 to the pedestal 11, the middle of the coil 23 wound around the magnetic core portion 13 a is entangled with the tap terminal 20, and the terminal of the coil 23 is entangled with the tangling terminal 21. The terminal 20 is formed in a divergent shape, and the binding terminal 21 has a tapered portion 21c. Therefore, it is possible to prevent the coiled coil 23 from being pulled toward the peripheral wall side of the pedestal 11 and coming out from the tip side of the tap terminal 20 and the binding terminal 21. Furthermore, since the middle and the end of the coil 23 wound around the magnetic core portion 13a are attached to the upper surface and the side surface of the projecting wall 14 of the base 11, the projecting wall 14 serves as a guide, and the number of antenna lines in the coil 23 is reduced. The reliability can be improved without fear of disconnection.

  Next, when the ring core 12 of the drum core 13 is fitted and the side wall 26 of the ring core 12 is bonded and fixed to the upper surface of the pedestal 11, the circular arc recess 27 a of the ring core 12 abuts on the top 16 a of the first positioning protrusion 16. The positioning of the lateral direction of the ring core 12 is restricted. At this time, since the circular arc recess 27a of the ring core 12 and the top portion 16a of the first positioning protrusion 16 are in pressure contact with each other, the top portion 16a is crushed and the ring core 12 is reliably positioned. Therefore, a magnetic path gap 31 for setting the inductance of the coil 23 is formed between the outer peripheral surface of the first flange portion 29 of the ring core 12 and the inner peripheral surface of the fitting hole 28 of the drum core 13, thereby suppressing variation in inductance. can do.

  Next, a method for assembling a small step-up transformer will be described.

  First, an adhesive is applied to the upper surface of the pedestal 11, and the drum core 13 around which the coil 23 is wound is placed on the upper surface of the pedestal 11. Specifically, the second flange 30 of the drum core 13 is fixed to the pedestal 11. After the pedestal 11 and the drum core 13 are coupled, the pedestal 11 is chucked to the chuck mechanism of the winding machine with the pedestal 11 and the drum core 13 facing sideways. Then, the coil 23 is wound around the magnetic core portion 13a of the drum core 13, the ends of the coil 23 are entangled with the tap terminal 20 and the binding terminal 21, and the binding portion is soldered.

  Next, when an adhesive is applied to the lower surface of the side wall 26 of the ring core 12 and the ring core 12 is fitted to the drum core 13, the fitting hole 28 of the ring core 12 is fitted to the first flange 29 of the drum core 13. Therefore, the coil 23 is covered by the side wall 26 of the ring core 12, and the ring core 12, the drum core 13, and the pedestal 11 are integrally coupled to complete the small step-up transformer 10.

  As described above, when the base 11 and the drum core 13 are assembled and when the base 11 and the ring core 12 are assembled, the drum core 13 and the ring core 12 are positioned by the first positioning protrusion 16 and the second positioning protrusion 18. Therefore, the first flange 29 and the fitting hole 28 are fitted concentrically, the positioning of both is simple, and the assembly workability is improved. Further, a magnetic path gap 31 for setting the inductance of the coil 23 is formed between the outer peripheral surface of the first flange portion 29 of the ring core 12 and the inner peripheral surface of the fitting hole 28 of the drum core 13, thereby suppressing variation in inductance. can do.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine the component covering different embodiment suitably.

  The small step-up transformer of the present invention can be used for optical devices such as cameras and small electronic devices such as mobile phones.

The perspective view of the small step-up transformer which shows the 1st Embodiment of this invention. The front view of the small step-up transformer of the embodiment. The back view of the small step-up transformer of the embodiment. Sectional drawing which shows the small step-up transformer of the embodiment, and follows the AA line of FIG. Sectional drawing which shows the small step-up transformer of the embodiment, and follows the BB line of FIG. The perspective view of the state which showed the small pressure | voltage rise transformer of the same embodiment, and fixed the drum core to the base. The perspective view of the tap terminal of a base and a binding terminal which shows the small step-up transformer of the embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Base, 12 ... Ring core, 13 ... Drum core, 13a ... Magnetic core part, 16 ... 1st positioning protrusion, 18 ... 2nd positioning protrusion, 21 ... Binding terminal, 24a ... Edge, 24 ... Coil terminal Processing groove, 25 ... Top wall, 26 ... Side wall, 28 ... Fitting hole, 29 ... First flange, 30 ... Second flange, 31 ... Magnetic path gap

Claims (2)

A base made of a synthetic resin material and provided with a plurality of binding terminals on the peripheral side portion;
A ring core having a top wall and a side wall configured integrally with the top wall, having a circular fitting hole in the top wall, and the side wall being placed on the pedestal;
The magnetic core portion has a flange portion at each of both ends of the magnetic core portion, and one flange portion positioned on the pedestal side is placed on the pedestal and the other flange portion positioned on the ring core side. A drum core that is fitted into the fitting hole of the ring core;
A coil wound around the magnetic core part;
Consists of
The pedestal has a flat surface on which one flange of the drum core is placed;
A projecting wall provided on the two opposite side portions with the flat surface interposed therebetween and projecting upward from the position of the flat surface;
At least two first positioning protrusions provided on the flat surface and restricting lateral movement of the ring core by contacting the peripheral wall of one flange portion of the drum core when the drum core is placed on the flat surface. And
The protruding wall includes left and right corner portions of a recessed fitting portion formed on a wall surface facing the flat surface and a bottom portion of the recessed fitting portion, and one flange of the drum core is formed on the left and right corner portions and the bottom portion of the recessed fitting portion. A second positioning protrusion that abuts the peripheral surface of the portion and restricts movement in the lateral direction different from the lateral direction at the plurality of locations;
Further, the ring core is a pair of abutting against the first positioning protrusion from a side opposite to a side where the one flange located on the pedestal side of the drum core abutting against the first positioning protrusion is abutted. With side walls,
A small step-up transformer in which a magnetic path gap is formed between the ring core and the drum core to set the inductance of the coil.   The binding terminal has a taper portion that is narrow at a base end side of a portion to which the coil is wound and is widened toward a distal end portion, and an end of the binding terminal at which the coil is wound is the base. The small step-up transformer according to claim 1, further comprising a habit toward the side.

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