JPH0655228U - choke coil - Google Patents

Abstract

(57) [Abstract] [Purpose] With regard to a smoothing choke coil used in a switching regulator or the like, a structure is simplified and miniaturized without the need for a bobbin and an insulating film. [Structure] A choke coil having a structure in which a coil is inserted between split cores and combined, wherein an insulating core is used as a core, and one core has a pair of external terminals provided with a coil soldering portion. Positioning and mounting, through the hole formed near the center leg on the bottom surface of the core, solder the winding start end inside the coil to one external terminal, and solder the winding end end outside the coil to the other external terminal. Attach and fix.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a smoothing choke coil used in a switching regulator or the like.

[0002]

[Prior art]

 Conventionally, as this type of choke coil, for example, there is one shown in FIG. 4 has a structure in which a wire 43 is wound around a bobbin 42 having an external terminal 41 and cores 44 and 45 are attached. Further, as a choke coil capable of being surface-mounted on a printed circuit board, there is one shown in FIG. 5, for example.

FIG. 5 is an assembly exploded view of a choke coil. A coil 51 is formed by using a rectangular copper wire without using a bobbin, and external terminals 52 are soldered to the inner and outer coil ends, respectively, and divided into two parts. It is assembled between the E-shaped cores 53 and 54. Further, as shown in FIG. 6, an insulating film 62 is provided to insulate the core, which is a conductor, and an insulating film 61 is inserted to insulate the coil 51 from the external terminal 52.

[0004]

[Problems to be solved by the device]

 However, such a conventional choke coil has the following problems. First, in the choke coil of FIG. 4, a bobbin is required to wind the wire, and the bobbin cannot be miniaturized by the thickness of the bobbin. Further, in the choke coil of FIGS. 5 and 6, an insulating film is required to insulate the core from the coil and the coil from the external terminal, and there is a problem that the structure becomes complicated accordingly.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a choke coil which has a simple structure and can be miniaturized without requiring a bobbin and an insulating film.

[0006]

[Means for Solving the Problems]

 In order to achieve this object, the present invention is configured as follows. The reference numerals in the drawings of the embodiments are also shown. First, the present invention is intended for a choke coil having a structure in which the coil 1 is inserted between the divided cores 6 and 9 and combined.

In the present invention, the choke coil having such a structure uses insulating cores 6 and 9, and the soldering portion 10 of the coil 1 is provided at both ends of the coil housing portion of one core 6. Positioning and mounting a pair of external terminals 4a, 4b equipped with, through the hole 5 formed near the central leg on the bottom surface of the core, the winding start end 2 inside the coil is fixed by soldering to one external terminal 4a. Further, the winding end 3 on the outside of the coil is fixed to the other external terminal 4b by soldering.

Here, a lead-out groove 15 for drawing out the coil winding start end 2 to the external terminal 4 a is formed following the hole 5 on the bottom surface of the core that penetrates the coil 1.

[0009]

[Action]

 According to the choke coil of the present invention having such a configuration, since an insulating core, for example, a nickel-based ferrite core is used, the insulating film provided between the core and the coil can be eliminated. . Also, between the coil and the external terminal, since the coil is soldered and fixed to the external terminal via the insulating core, it is not necessary to use the insulating film in the same manner. Further, since the bobbin is not used, the structure can be simplified and the size can be further reduced by eliminating the need for the insulating film.

[0010]

【Example】

 FIG. 1 is an exploded view showing an embodiment of the present invention. In FIG. 1, the choke coil of the present invention is basically composed of a coil 1, an E-type ferrite core 6 and an I-type ferrite core 9. The coil 1 has a coil shape formed by winding a rectangular copper wire with an insulating coating, for example, urethane. The inner winding start end 2 of the coil 1 is bent downward at a right angle, and the outer winding end end 3 is also bent downward at a right angle. The inner winding start end 2 is bent with a sufficient length so that it can be pulled out to the outside.

Such a coil 1 is incorporated between an E-type ferrite core 6 on the lower side and an I-type ferrite core 9 on the upper side. The E-type ferrite core 6 and the I-type ferrite core 9 use nickel-based ferrite cores in order to secure the performance as an insulator. The E-type ferrite core 6 located on the lower side has a columnar leg portion 16 standing upright in the center, a wall portion 17 standing upright on both sides of the leg portion 16, and a columnar portion inside the wall portion 17. The legs 16 are provided with concentric hollow portions 18 so that the coil 1 can be assembled from above.

A hole 5 is formed in the E-type ferrite core 6 near the base of the leg portion 16. The winding start end 2 on the inside of the coil 1 is inserted into the hole 5 and pulled out to the outside. A pair of external terminals 4a and 4b are mounted on both sides of the E-type ferrite core 6 on the opening side.

The external terminals 4a and 4b are formed with soldering portions 10 on the outside as shown in the sectional view of the coil assembled state with respect to the E-type ferrite core 6 of FIG. The tip of the winding start end 2 of the coil 1 drawn through the hole 5 of the E-type ferrite core 6 is fitted into the coil 10, and the winding end of the coil 1 is fitted to the soldering portion 10 of the external terminal 4b. The tips of the ends 3 are fitted and fixed by soldering.

Here, a lead-out groove 15 is formed on the bottom surface of the E-type ferrite core 6 following the hole 5, and the winding start end 2 of the coil 1 penetrating the hole 5 extends along the lead-out groove 15. The winding start end 2 of the coil 1 is prevented from protruding from the bottom surface of the E-type ferrite core 6 by pulling it out. Referring again to FIG. 1, positioning grooves 7 and 8 are formed in the mounting portions of the external terminals 4a and 4b on both sides of the E-type ferrite core 6. The positioning groove 7 is formed at two positions on the end surface of the core, and the engaging pieces 13 formed by bending both sides of the external terminals 4a and 4b are fitted into the positioning groove 7 as is apparent from the bottom view shown in FIG.

Further, the positioning groove 8 in the E-type ferrite core 6 of FIG. 1 is also formed on the back surface side, and as shown in FIG. 2, the protrusion of the engaging piece 11 formed above and below the external terminals 4a and 4b. The portion fits into the positioning groove 8 for positioning. Next, the assembly of the choke coil in the above embodiment will be described. First, as shown in FIG. 1, a coil 1 in which a rectangular copper wire having an insulating coating such as urethane is wound is made, and the coil 1 is fitted into the leg portion 16 of the E-type ferrite core 6. At this time, the winding start end 2 on the inner side of the coil 1 is fitted into the hole 5 and taken out through the pull-out groove 15 on the back surface as shown in FIG.

Subsequently, the external terminals 4a and 4b are attached to the positioning grooves 7 and 8 on both sides of the E-type ferrite core 6 as shown in the drawing. Then, as shown in FIG. 2, the tip of the winding start end 2 of the coil 1 pulled out from the lead-out groove 15 is fitted into the soldering portion 10 of the external terminal 4a, and similarly the soldering portion 10 of the external terminal 4b is inserted. The tip of the winding end 3 on the outside of the coil 1 is fitted into the inside.

Subsequently, the E-type ferrite core 6 to which the coil 1 and the external terminals 4a and 4b are assembled is put in a solder layer and the bottom side is immersed in the molten solder, so that the inside of the soldering portion 10 of the external terminals 4a and 4b. As shown in FIG. 2, the winding start end 2 and the winding end end 3 of the coil 1 can be soldered and fixed to the external terminals 4a and 4b by injecting the molten solder into and pulling it up from the solder layer.

When the assembly on the E-type ferrite core 6 side is completed in this way, finally the I-type ferrite core 9 shown in FIG. The coil is completed. In the above embodiment, the positioning grooves 7 and 8 are provided for positioning the external terminals 4a and 4b with respect to the E-type ferrite core 6, but holes may be formed instead of the grooves. .

Further, in the above embodiment, the coil 1 is wound with a flat copper wire having an insulating coating, but a plurality of round magnet wires having an insulating coating are used instead of the flat copper wire. The coil 1 may be made using strip-shaped copper wires formed by bonding and fixing in parallel. Furthermore, a single wire of a round magnet wire coated with an insulating film may be wound and adhered and fixed to the shape of the coil 1.

Further, in the above embodiment, the E-type ferrite core 6 and the I-type ferrite core 9 are taken as an example of the two-divided core, but two E-type ferrite cores may be used. Of course.

[0021]

[Effect of device]

 As described above, according to the present invention, since the choke coil can be made without using the bobbin, the choke coil can be downsized. In addition, since the coil and external terminal are mounted separately on the insulating core, there is no risk of contact between the coil and external terminal, and there is no need to use an insulating film, so the structure is simple and the insulation reliability is high. Can be improved and cost can be reduced. Furthermore, the winding start end and the winding end end of the coil and each external terminal can be fixed by soldering by passing the solder dip layer while the external terminal and coil are assembled to the core. The connection process can be significantly shortened compared to the case.

[Brief description of drawings]

FIG. 1 is an exploded view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the present invention.

FIG. 3 is a bottom view of the present invention.

FIG. 4 is an explanatory view of a conventional choke coil using a bobbin.

FIG. 5 is an assembly exploded view of a conventional choke coil that does not use a bobbin.

6 is an explanatory view of an insulating structure of a coil portion in the conventional example of FIG.

[Explanation of symbols]

 1: coil 2: winding start end 3: winding end end 4a, 4b: external terminal 5: hole 6: E-type ferrite core 7, 8: positioning groove 9: I-type ferrite core 10: solder receiving portion 11, 12, 13 : Engagement piece 15: Pull-out groove

Claims (2)

[Scope of utility model registration request] 1. A choke coil having a structure in which a coil is inserted between divided cores and combined, wherein an insulating core is used as the core, and coil solder is provided at both ends of a coil housing portion of the one core. Positioning and mounting a pair of external terminals having a mounting portion, through the hole formed in the vicinity of the central leg of the bottom surface of the core through soldering the winding start end inside the coil to the one external terminal, A choke coil having a winding end outside the coil fixed to the other external terminal by soldering. 2. The choke coil according to claim 1, wherein a lead-out groove for drawing the coil to an external terminal is formed following a hole on the bottom surface of the core that penetrates the coil.