JP2000228313A - Coil component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component which is manufacturable at a minimum cost by shortening its manufacturing time, and simplifying its construction. SOLUTION: A bobbin made of resin is provided with a winding drum 1b having core inserting holes 1c. A coil 2 is wound around the drum 1b. The legs of split cores 3 are inserted into the core-inserting holes 1c. Projecting strip-like portions 10b to be press-welded to the backs of the cores 3 are formed on the internal surfaces of both end board portions 10a of a case 10 which is opposed in a direction perpendicular to that of the core-inserting holes 1c. The protruded strip portions 10b of the case 10 are press-welded to the back surfaces of the cores 3, and the case 10 is fitted onto the bobbin 1 fitted with the coil 2 and the cores 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component used as a choke coil or a transformer, and more particularly to a coil component using a split core.

[0002]

2. Description of the Related Art As an example of a conventional coil component using a split type core, there is one shown in a side view of FIG. 2C and an end view of FIG. 2D. In this coil component, a terminal 5 is fixed to a flange portion 1a at both ends, a winding 2 is applied to a winding drum 1b of a bobbin 1, and a core insertion hole 1 penetratingly provided in the winding drum 1b.
c, the legs of the split cores 3 and 3 are inserted from both sides and mounted, and the cores 3 and 3 are mounted on the bobbin 1 with the U-shaped elastic metal fitting 4 so as to sandwich the cores 3 and 3. It is.

A sectional view of FIG. 2E is disclosed in Japanese Patent Application Laid-Open No. 9-115.
744 discloses another example of a conventional coil component, in which a bobbin 6, a winding 7, and a core 8 are entirely formed of a molding resin 9.
It is covered by.

[0004]

As shown in FIGS. 2 (C) and 2 (D), the structure in which the core 3 is fixed by the metal fittings 4 is a step of attaching the metal fittings 4 and the protection after the metal fittings 4 are attached. Since a varnish impregnation step for the varnish and a drying step after the varnish impregnation are required, the production process becomes complicated and the cost increases.

On the other hand, as shown in FIG. 2E, in the case where the bobbin 6, the winding 7 and the core 8 are sealed with the molding resin 9, the characteristics are deteriorated due to the stress on the core 8 when the molding resin 9 is cured. In addition, since the management of the filling process of the mold resin 9 (stirring time, temperature, etc.) is complicated, it is used only for special applications, and the price of the coil increases.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a coil component capable of reducing cost by reducing the manufacturing time and simplifying the structure.

Another object of the present invention is to provide a coil component which has a simple structure, can securely fix the core, and does not cause deterioration in characteristics.

[0008]

According to a first aspect of the present invention, there is provided a coil component including a bobbin provided with a winding body having a core insertion hole, a winding provided on the winding body, and a leg in the core insertion hole. Both end plate portions of a case including a split core to be inserted, and a bottom-opening case fitted to the split core and the bobbin from above, and facing in a direction perpendicular to the direction of the core insertion hole. On the inner surface of the core, a ridge that presses against the back of the core is formed in the vertical direction, and the ridge of the case presses against the back of the core to fit the case onto the bobbin on which the winding and the core are provided. It is characterized by being combined.

As described above, if the protruding ridge provided on the inner surface of the end plate portion of the core is pressed against the back surface of the core, the contact surface between the core and the case at the end plate portion is reduced, and the end plate portion is formed. Combined with the elasticity of the core, even if a dimensional error occurs in the core and the case due to manufacturing, the range of the pressing force can be widened, and the core can be held in the case with an appropriate pressure that does not become excessive or excessive. It is possible to suppress the occurrence of a gap between the split cores due to an excessively small value and a change in the inductance value due to an excessively large value. In addition, since the pressing force of the core against the case does not become excessive, the fitting operation of the case to the core is easy, and the manufacturing is easy and short.

[0010] In the coil component according to the second aspect, the interval between the ridges formed on the inner surfaces of the both end plates of the case is P1 in the first aspect, and the whole of the split core is oriented in the core insertion hole direction. Assuming that the external dimensions are P2, the ratio of P1 / P2 is 0.
It is characterized by being set to 95 or more and 0.99 or less.

When the ratio P1 / P2 is less than 0.95, when the case is pressed into the bobbin, a load is applied to the bases of the two ridges provided on the inner surface of the case, and the case is broken. If the ratio P1 / P2 exceeds 0.99, the pressing force between the ridge of the case and the core is weakened, and the electrical characteristics are degraded.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a coil component according to the present invention will be described below. FIGS. 1A to 1C are bottom views each showing an example of a case used for the coil component of the present invention.
It is a side view and an end view. 1 (D) and 1 (E) are a side view and an end view, respectively, showing the main body of the coil component of the present invention. 1 (D) and (E), FIG. 2 (C),
The same reference numerals as in (D) denote portions that exhibit an equivalent function. The bobbin 1 is a resin molded product, includes a winding drum 1b having a core insertion hole 1c, and has flanges 1a at both ends of the winding drum 1b. The terminal 5 is fixed to the flange 1a in a direction orthogonal to the core insertion hole 1c. In addition, the mounting structure and shape of the terminal 5 can be variously changed.

A winding 2 is applied to a bobbin 1b of the bobbin 1. The legs of the U-shaped split core 3 are inserted from both sides into the core insertion hole 1c of the bobbin 1. Collar 1
A projection 1d serving as a fixing means for retaining the case 10 is formed at a lower portion of the end surface of the portion a. Each projection 1d is
The upper surface is formed in a tapered shape to facilitate the fitting of the case 10.

The case 10 is a resin molded product, and is shown in FIG.
As shown in (A) to (C), the rear surface of the core 3 is in contact with the inner surface of the both end plate portions 10a which form a lower surface opening and face in a direction perpendicular to the direction of the core insertion hole 1c. The ridge 10b is formed vertically. The case 1
A hole 10d for fitting the protrusion 1d is provided at a position corresponding to the protrusion 1d in the end plate portion 10a. In the present embodiment, a mounting piece 10c projecting downward is formed in order to facilitate the fitting when fitting into the assembly including the bobbin 1 having the winding 2 and the core 3 of the case 10 to facilitate the fitting. The attachment piece 10c is provided with a hole 10d in a hole for preventing the attachment piece 10c from being detached.

As shown in the side view of FIG. 2A and the end view of FIG.
The case 10 is fitted to the bobbin 1 provided with the winding 2 and the core 3 while being compressed by pressing the ridge 10b of the bobbin 1 on the back surface of the core 3, and the hole 10d of the case 10 is The case 10 is fixed to the bobbin 1 by being fitted to the protrusion 10e.

As described above, if the case 10 is fitted to the assembly of the bobbin 1 and the core 3 having the windings 2 while compressing the ridges 10b, the case 10 can be fitted with a relatively small force. The divided core 3 can be reliably sandwiched with an appropriate force.

Here, as shown in FIG.
As shown in FIG. 1 (D), the interval 1 between 0b and 10b is P1, and the external dimension of the entire split type cores 3 and 3 in the direction of the core insertion hole 1c is P2, and the ratio of P1 / P2 is 0.95. As described above, it is preferable to set the value to 0.99 or less.

Since the outer dimension P2 depends on the size of the frame at the time of molding the core, the variation is 0.1% or less of the outer dimension P2.
Also for the interval P1 between b, the variation is 0.1% of P1.
It is as follows.

In consideration of such variations, the ridges 1
0b, the ratio P of the distance P1 between the 10b and the external dimension P2
When 1 / P2 is less than 0.95, when the case 10 is press-fitted into the assembly of the bobbin 1 and the core 3 having the winding 2, a load is applied to the base of the two ridges 10 b provided on the inner surface of the case 10. And it breaks.

When the ratio P1 / P2 exceeds 0.99, the pressure contact force between the ridge 10b of the case 10 and the core 3 is weakened, and as shown in FIG.
% Or more.

In the above embodiment, the protrusion 1d is provided on the end face of the flange 1a. However, a protrusion is provided on the side surface of the flange 1a, and a hole is formed in the side plate 10e of the case 10 to fit the protrusion. You may.

[0022]

According to the first aspect of the present invention, the case has a projection formed on the inner surface of both end plates facing in a direction perpendicular to the direction of the core insertion hole, the projection being in contact with the back surface of the core. ,
The ridge of the case is crimped to the back of the core to fit the case to the bobbin provided with the winding and the core, so that the core is held by the case with an appropriate pressure that does not become excessive or excessive. It is possible to suppress the occurrence of a gap between the split cores due to an excessively small pressing force and a change in the inductance value due to an excessively large pressing force. In addition, since the pressing force of the core against the case does not become excessive, the fitting operation of the case to the core becomes easy, and the manufacturing is easy and short. As described above, the manufacturing time is shortened, and the protection of the core, the windings, and the like is realized by the case, and the structure is simplified.

According to the second aspect, in the first aspect, the interval between the ridges formed on the inner surfaces of the both end plates of the case is P1, and the outer shape of the entire split core in the core insertion hole direction. Since the dimension is set to P2 and the ratio of P1 / P2 is set to 0.95 or more and 0.99 or less, the yield does not decrease due to cracking of the case and the like, and the electrical characteristics do not deteriorate and are stable. Quality coil parts can be provided.

[Brief description of the drawings]

FIGS. 1A to 1C are a bottom view, a side view, and an embodiment, respectively, showing an embodiment of a case used for a coil component of the present invention.
FIGS. 2D and 2E are a side view and an end view, respectively, showing one embodiment of the main body of the coil component of the present invention.

FIGS. 2A and 2B are a side view and an end view, respectively, showing an embodiment of the coil component of the present invention, FIGS.
(D) is a side view and an end view showing an example of a conventional coil component, and (E) is a cross-sectional view showing another example of the conventional coil component.

FIG. 3 is a diagram illustrating a ratio P1 / when a distance between protrusions formed on the inner surfaces of both end plate portions of the case is P1 and an outer dimension of the entire split core in the core insertion hole direction is P2. P
FIG. 3 is a diagram showing a relationship between the ratio 2 and the rate of change of the inductance value.

[Description of Signs] 1: bobbin, 1a: flange, 1b: winding drum, 1c: core insertion hole, 1d: protrusion, 2: winding, 3: core, 5: terminal, 1
0: case, 10a: end plate, 10b: ridge, 10
c: mounting piece, 10d: hole, 10e: side plate

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01F 27/26 H01F 37/00 G 30/00 15/02 N 37/00 31/00 G

Claims (2)

[Claims] 1. A bobbin having a winding drum having a core insertion hole, a winding wound on the winding drum, a split core having legs inserted into the core insertion hole, and a split core. And a bottom-opening case that is fitted to the bobbin from above, and a protrusion that presses against the inner surface of both end plates of the case that faces in a direction perpendicular to the direction of the core insertion hole against the back surface of the core. A coil component, wherein a ridge portion is formed in a vertical direction, and a ridge portion of the case is pressed against a back surface of the core to fit the case to a bobbin provided with a winding and a core. 2. The case according to claim 1, wherein a distance between ridges formed on inner surfaces of both end plates of the case is P1, and an outer dimension of the entire split core in the core insertion hole direction is P2. A coil component wherein the ratio of P1 / P2 is set to 0.95 or more and 0.99 or less.