JP6447223B2 - Surface mount inductor - Google Patents

Description

  The present invention relates to an inductor comprising a drum core, a ring core that houses the drum core, and a pair of external terminals disposed on the ring core.

  For a choke coil such as a DC / DC converter, a wound drum core is housed in a hole in the ring core, and a pair of external terminals formed by punching a metal plate into a desired shape and bending it on the exterior of the ring core An arranged inductor with a closed magnetic circuit structure is used. Such an inductor has a simple structure, and thus price competition is intense.

JP 2009-266554 A

In the inductor having the above-described closed magnetic circuit structure, the characteristic value of the inductor varies when the gap between the drum core and the ring core varies. If extra members or processes are added to suppress this variation, there is a problem that the price increases.
Therefore, an inductor having a simple and inexpensive structure and a structure that can be assembled with high accuracy is required.

  The surface-mount inductor according to the present invention includes a drum core having an upper collar and a lower collar at both ends of a winding shaft, a ring core having a hole penetrating an upper surface and a lower surface for housing the drum core, A pair of external terminals disposed on a side surface of the ring-type core, wherein the external terminal includes a side surface portion, an upper surface portion and a lower surface portion bent in the same direction at both ends of the side surface portion, and the side surface portion The bent portion between the lower surface portion and the lower surface portion is provided with a convex portion projecting inward, and the ridge line portion between the side surface and the lower surface of the ring core is provided with a concave portion that fits into the convex portion. The side surface portion and the lower surface portion of the external terminal sandwich the upper surface and the lower surface of the ring core, and the convex portion and the concave portion are fitted.

  According to the present invention, since the convex portion provided in the bent portion of the external terminal and the concave portion provided in the ring-type core are fitted and the external terminal is positioned, assembly can be performed with high accuracy.

It is a perspective view of the surface mount inductor of the present invention. It is a disassembled perspective view of the surface mount inductor of this invention. It is the longitudinal cross-sectional view of the surface mount inductor of this invention, and its partial enlarged view.

Hereinafter, an embodiment of a surface mount inductor according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of a surface mount inductor according to the present invention, and FIG. 2 is an exploded perspective view. 3A shows a longitudinal section at the position indicated by AA in FIG. 1, and FIGS. 3B and 3C are enlarged views of FIG. 3A, respectively. Is shown.

As shown in FIG. 1 to FIG.
A drum core 20 having an upper rod 22a and a lower rod 22b at both ends of the winding shaft 21, respectively.
Winding 40;
The ring-shaped core 30 is lower than the drum-shaped core and has a substantially square shape with chamfered corners in plan view, and is provided with a through hole 31 that penetrates the upper surface 32a and the lower surface 32b for housing the drum-shaped core 20. When,
The ring-shaped core 30 includes external terminals 50 and 50 which are arranged on opposite side surfaces 32c and 32d and to which end portions 41 and 41 of the winding 40 are respectively connected.

  The drum-type core 20 and the ring-type core 30 are made of ferrite, the winding 40 is made of a conductive wire insulated with polyurethane or the like, and the external terminal is formed by bending a metal plate punched into a desired shape.

  The upper surface 32a of the ring type core 30 is provided with grooves 33, 33 for pulling out the end portions 41, 41 of the winding 40 to the outer periphery of the drum type core 30, and the ridgeline between the opposite side surfaces 32c, 32d and the lower surface 32b. The part is provided with triangular recesses 34, 34, respectively.

  The external terminal 50 includes a side surface 51, a lower surface portion 52 provided at one end of the side surface portion 51, an upper surface portion 53 provided at the other end, and a connection provided in the side surface direction of the side surface portion 51. Part 56. The lower surface portion 52 and the upper surface portion 53 are bent at substantially right angles in the same direction with respect to the side surface portion 51, and are formed in a U-shaped cross section. The height of the side surface portion 51 is often formed higher than the height of the ring core 30.

The upper surface portion 53 is divided into a first upper surface portion 53a and second upper surface portions 53b and 53b disposed on both side surfaces of the first upper surface portion 53a.
The first upper surface portion 53a is formed in a cross-sectional shape in which an intermediate portion is bent in a direction, and the first upper surface portion 53a is bent from the side surface portion 51 at an acute angle from a right angle.
An edge 55 that is further bent upward is provided at the tip of the second upper surface portion 53b.
A claw portion 57 that is further bent and bent is provided at the tip of the connecting portion 56.
Triangular ribs 54 are provided on the ridge lines of the side surface 51 and the lower surface 52.

The drum core 20 around which the winding 40 is wound pulls the terminal portions 41 and 41 out of the grooves 32 and 32, respectively. The lower surface 32b of the ring core 30 and the lower surface of the lower collar 22b of the drum core 20 Are accommodated in the hole 31 of the ring-type core 30 so as to be on the same plane.
At this time, since the height of the drum core 20 is higher than the height of the ring core 30, the upper collar 22 a of the drum core 20 protrudes from the upper surface of the ring core 30.

The external terminals 50 and 50 are disposed on the side surfaces 32c and 32d of the ring core 30 facing each other so that the triangular ribs 54 are fitted in the recesses 34, respectively.
At this time, in the external terminal 50, the lower surface portion 52 is prevented from being opened by the triangular ribs 54, and the first upper surface portion 53 a is often bent at an acute angle to exert a spring force. The ring-shaped core 30 is sandwiched so that the fitting with the ring is in close contact. Further, the edge 55 abuts on the outer peripheral surface of the upper collar 22a of the drum core 20 to regulate the position of the drum core 20.

  The terminal part 41 is arrange | positioned at the nail | claw part of the external terminal 50, and is electrically connected by soldering etc. FIG.

In the above-described surface mount inductor, the triangular rib 54 and the concave portion 34 are fitted and positioned, and the edge 55 of the second upper surface portion 53b abuts on the outer peripheral surface of the upper collar 20a of the drum core 20 so that the drum type Since the position of the core is restricted, it can be assembled with high accuracy.
Further, since the edge portion 55 is sandwiched between the drum core 20 and the ring core 30, it is not necessary to bend a part of the external terminal after being attached to the ring core 30. Furthermore, since it is not on the path of the closed magnetic circuit, an eddy current is not generated in the edge 55 and the characteristics of the inductor are not deteriorated.

DESCRIPTION OF SYMBOLS 10 Surface mount inductor 20 Drum type core 21 Winding axis 22a Upper collar 22b Lower collar 30 Ring type core 31 Hole 32a Upper surface 32b Lower surface 32c, 32d Side surface 33 Groove 34 Recess 40 Winding 41 Terminal portion 50 External terminal 51 Side surface portion 52 Lower surface portion 53, 53a, 53b Upper surface part 54 Convex part 55 Edge part 56 Connecting part 57 Claw part

Claims (4)

A drum core having upper and lower ridges at both ends of the winding shaft;
A ring-type core having a hole penetrating the upper surface and the lower surface for housing the drum-type core;
A pair of external terminals disposed on the side surface of the ring core;
The external terminal is composed of a side surface portion, an upper surface portion and a lower surface portion that are bent in the same direction at both ends of the side surface portion,
The bent portion of the side surface portion and the lower surface portion is provided with a convex portion protruding inward,
The ridge line portion between the side surface and the lower surface of the ring core is provided with a concave portion that fits into the convex portion,
The surface mounting characterized in that the side surface portion and the lower surface portion of the external terminal sandwich the upper surface and the lower surface of the ring core, and the convex portion and the concave portion are fitted. Inductor. The surface-mount inductor according to claim 1, wherein the convex portion is a triangular rib. The surface-mount inductor according to claim 1, wherein the upper surface portion of the external terminal sandwiches the ring-type core by an urging force. The lower surface of the drum core and the lower surface of the ring core are arranged to be aligned, and the upper collar of the drum core protrudes from the upper surface of the ring core,
The tip portion of the upper surface portion is further bent upward,
The surface mount inductor according to any one of claims 1 to 3, wherein a surface of a tip portion of the upper surface portion is in contact with an outer peripheral surface of the upper collar to regulate a position of the drum core.

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