JP6428485B2 - Surface mount inductor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a surface mount inductor in which a drum core is housed in a ring core and two metal terminals are arranged on the ring core.

  For a choke coil such as a DC / DC converter, a wound drum core is housed in a hole of a ring core, and a pair of metal terminals bent from a metal plate are arranged on the exterior of the ring core. An inductor is used.

JP 2009-266554 A JP 2006-135291 A

  Inductors with the above-mentioned closed magnetic circuit structure are highly price-competitive, and the characteristic values vary due to the gap between the drum core and ring core, so it is required to have a structure that can make the gap uniform with an inexpensive structure. ing.

  For example, Patent Document 1 discloses a surface-mount inductor in which a gap is constant by bending a part of a metal terminal and sandwiching the metal terminal between a ring-type core and a drum-type core. Further, Patent Document 2 discloses a surface mount inductor in which the gap is fixed by abutting the tip of the metal terminal against the outer periphery of the drum core.

  However, the surface-mount inductor disclosed in Patent Document 1 may cause a load on the ring core when the metal terminal is bent, and the ring core may be damaged. In addition, the surface mount inductor of Patent Document 2 has a problem that workability is poor because the metal terminals are bonded while adjusting the positions of the ring core and the drum core to a predetermined position using a jig or the like.

The surface mount inductor of the present invention is
A drum core having upper and lower rods at both ends of a winding shaft; a winding wound around the drum core; a ring core having a through hole for accommodating the drum core; It is arranged on the side surface of the ring-shaped core, is bent into a U-shaped cross section, and consists of a pair of metal terminals connected to the end of the winding,
A pair of recesses are provided at opposing positions on the outer periphery of the upper collar, and first protrusions are provided at the ends of the pair of metal terminals, respectively, and the projections of the one metal terminal. Is further provided with a second convex portion having a width smaller than that of the first convex portion, the first convex portion meshing with the concave portion, and the second convex portion at the bottom of the concave portion. It is characterized by abutting.

Further, the method for manufacturing the surface mount inductor of the present invention is as follows.
A step of winding a winding around a drum-type core when having an upper hook and a lower hook at both ends of the winding shaft, and a first convex portion which is bent into a U-shaped cross section and protrudes to the end portion of the ring-type core Bonding the first metal terminal provided with a predetermined position, housing the drum core in the ring core, and substantially the same shape as the first metal terminal in the ring core. Bonding a second metal terminal provided with a second protrusion narrower than the first protrusion that protrudes further than the first protrusion at a predetermined position; and the winding The both terminals are connected to the first metal terminal and the second metal terminal, respectively.

  According to the present invention, it is possible to provide a surface mount inductor that can be assembled with a simple structure with good workability and high accuracy, and a manufacturing method thereof.

It is a perspective view which shows one Example of the surface mount inductor of this invention. It is a disassembled perspective view which shows one Example of the surface mount inductor of this invention. It is a top view of the upper collar of a drum type core. It is an expanded view of a metal terminal. It is a top view of the surface mount inductor of this invention. It is a figure for demonstrating the assembly method of the surface mount inductor of this invention.

  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 10 of the present invention, and FIG. 2 is an exploded perspective view thereof. As shown in FIGS. 1 and 2, the surface-mount inductor 10 includes a drum core 20, a winding 40 wound around the drum core 20, a ring core 30 that houses the drum core 20,
It consists of a pair of metal terminals 50, 60 arranged to face the outer peripheral surface of the ring-type core 30.

The drum core 20 is made of ferrite, and has an upper collar 22 and a lower collar 23 at both ends of the winding shaft 21.
FIG. 3 is a plan view of the drum core 20. As shown in FIG. 3, concave portions 22 a and 22 b and concave portions 23 a and 23 b with rounded corners are provided at positions facing the outer peripheral surfaces of the upper collar 22 and the lower collar 23, respectively. The recesses 22a, 22b, 23a, and 23b have a width W and a depth L.

  The ring core 30 is made of ferrite and has a substantially octagonal columnar shape in plan view, and a through hole 31 for housing the drum core 20 is provided at the center.

  The winding 40 is composed of a self-bonding wire in which the outer periphery of a conductive wire insulated with polyurethane or the like is further coated with a self-bonding layer of polyamide or the like, and is fused after winding to prevent collapse. The drum core 20 and the winding 40 are fixed and positioned so as not to rotate.

  FIG. 4 is a development view for explaining the metal terminals 50 and 60 in detail.

The metal terminal 50 is made of a substantially T-shaped metal plate in plan view.
The side surface portion 51 which is a longitudinal end portion of the T-shape is bent along the outer periphery of the ring-shaped core to be formed into a square shape, and the upper surface portion 52 and the lower surface which are both ends of the T-shaped lateral direction. The portion 53 is bent and formed into a U-shape.
Convex tip of the side surface portion 51, connecting wire portion 51a for holding the terminal of the winding is provided folded, the front end of the upper surface portion 52, the corners are chamfered by a width W _A, the length L _A The convex portion 52a is further provided with a convex portion 52b that protrudes further from the convex portion 52a and is narrower than the convex portion 52a, with a width W _B and a length L _B rounded at the tip. Yes.

The metal terminal 60 is made of a substantially T-shaped metal plate in plan view.
The side surface portion 61 that is a longitudinal end portion of the T-shape is bent along the outer periphery of the ring-shaped core to be formed into a square shape, and the upper surface portion 62 and the lower surface that are both ends of the T-shape in the lateral direction. The part 63 is bent and formed into a U-shape.
A connecting portion 61a is provided at the front end of the side surface portion 61 so as to be folded and press the end of the winding, and a convex portion having a chamfered corner portion with a width W _A and a length L _B at the front end of the upper surface portion 62. A portion 62a is provided.

  The drum core 20 is accommodated in the hole 31 of the ring core 30 so that the bottom surface of the drum core 20 and the lower surface of the ring core 30 are in the same plane. 30. The terminals 41a and 41b of the winding 40 are disposed on the opposing side surfaces of the winding 40, and are electrically connected by soldering, welding, or the like between the folded connection portions 51a and 61a.

Since the side surface of the ring-type core 30 on which the metal terminals 50 and 60 are arranged is set lower than the height of the drum-type core 20, the bottom surface of the ring-type core 30 and the lower arm of the drum-type core 20 are set as the same plane. When the ring core 30 is housed in the through hole 31, the upper collar 22 of the drum core 20 protrudes from the upper surface portions 52 and 62 of the metal terminals 50 and 60, and the convex portions 52 a and 52 b of the metal terminal 50 and the metal terminal 60. The convex part 62a contacts the outer peripheral surface of the upper collar 22.
At this time, the convex portion 52a of the metal terminals 50 and 60, the width _{W A} of 62a are recesses 21a of the drum core 20, since wider than the width W of the 21b, the convex portions 52a, 62a are meshed in recesses 21a, 21b At that time, the rotation of the drum core 20 is restricted.
The width _{W b} of the projecting portion 52b of the metal terminal 50 is narrower than the width W of the recess 20b of the drum core 20, the tip of the second protrusion 52b is in contact with the bottom of the recess 22a, the drum core 20 regulates the position of the metal terminals 50, 60 in the facing direction (see FIG. 5).

The above-described surface mount inductor 10 can be assembled with high accuracy because the positions of the drum core 20 and the ring core 30 are regulated, and the gap can be made constant.
Further, since the drum core 20 and the winding 40 are positioned so as not to rotate and the terminals 41a and 41b of the winding 40 are fixed to the metal terminals 50 and 60, they are not easily displaced after assembly.

  In the above-described embodiment, the drum core 20 is provided with the recesses 23a and 23b in the lower collar 23 in the same manner as the upper collar 22. However, the vertical direction may or may not be generated.

  Next, the manufacturing method of the surface mount inductor of this invention is demonstrated. FIG. 6 is a cross-sectional view for explaining a part of the assembly process.

First, the winding 20 is wound around the drum core 20 a predetermined number of times, and exposed to warm air to fuse the winding. Further, the metal terminal 60 is bonded to a predetermined position of the ring type core 30.
Next, the ring core 30 is accommodated in the through-hole 31 so that the protrusion 62 a of the metal terminal 60 fits into the recess 22 b of the drum core 20.
Then, as shown in FIG. 6, the ring-shaped core 30 is placed on a jig 70 having a wall and a placement surface, and the placement surface is inclined by θ ° so that the metal terminal 60 is pressed against the wall. Then, the metal terminal 50 is bonded to the side surface of the ring core 40 so that the convex portion 52b of the metal terminal fits into the concave portion 22a of the drum core 20.
Finally, the terminals 41a and 41b of the winding 40 are respectively connected to the connecting portion 51a of the metal terminal 50 and the connecting portion 61a of the metal terminal 60 to be electrically connected.

The above-described method for manufacturing a surface-mount inductor has good workability because the ring-type core 30 is housed in the drum-type core 20 to which only the metal terminals 60 having short projections are bonded.
Further, by assembling using a jig whose mounting surface is inclined, it is possible to position and assemble by a simple method without using a complicated jig.

DESCRIPTION OF SYMBOLS 10 Surface mount inductor 20 Drum type core 21 Winding shaft 22 Upper collar 23 Lower collar 22a, 22b, 23a, 23b Recess 30 Ring type core 31 Through-hole 33 Recess 40 Winding 41a, 41b Terminal 50, 60 Metal terminal 52, 62 Upper surface Portions 53 and 63 Lower surface portions 51a and 61a Connection portions 52a and 62a Convex portions 52b Second convex portions 70

Claims (4)

A drum core having upper and lower ridges at both ends of the winding shaft;
A winding wound around the drum core;
A ring type core having a through hole for accommodating the drum type core;
It is disposed on the side surface of the ring-shaped core, and is formed of a pair of metal terminals that are bent into a U-shaped cross section and connected to the end of the winding.
A pair of recesses are provided at opposing positions on the outer periphery of the upper collar,
First protruding portions that protrude from the end portions of the pair of metal terminals are respectively provided.
The convex portion of the one metal terminal is further provided with a second convex portion that is narrower than the first convex portion,
The surface-mount inductor, wherein the first convex portion meshes with the concave portion, and the second convex portion is in contact with the bottom of the concave portion. The surface mount inductor according to claim 1, wherein the winding is a self-bonding wire. A step of winding a winding around a drum-type core with an upper rod and a lower rod at both ends of the winding shaft;
Bonding a first metal terminal, which is bent into a U-shaped cross section and provided with a first convex portion protruding at an end, to a ring-shaped core at a predetermined position;
Storing the drum core in a ring core;
The ring-shaped core is provided with a second convex portion that is substantially the same shape as the first metal terminal and that protrudes further than the first convex portion and is narrower than the first convex portion. Adhering the metal terminals to a predetermined position;
A method for manufacturing a surface-mount inductor comprising a step of connecting both ends of the winding to the first metal terminal and the second metal terminal, respectively. The method for manufacturing a surface-mount inductor according to claim 3, further comprising a step of fusing the winding after the step of winding the winding.

Images