JP2004311632A - Small coil and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small coil wherein coil a failure caused by a falling shock can be reduced and a manufacturing man-hour is reduced. <P>SOLUTION: A drum core 31 is made cylindrical, and a drum flange is not arranged on the end of the drum core 31 so that a wire winding can be attached by dropping the wire winding into the drum core 31. As a result, the manufacturing man-hour of the coil can be reduced. Since the drum core 31 and a ring core 32 are formed in an integrated body, the coil which can bear a shock by falling can be obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a small coil and a method for manufacturing the same, and more particularly, to a small coil used for a mobile phone and the like and a method for manufacturing the same.
[0002]
[Prior art]
This kind of small coil is used for a power supply of a mobile phone or the like, a voltage boosting / decreasing circuit for a display unit, and the like, and in particular, it is required to have a strength against an impact from its use environment.
[0003]
The general structure of this type of small coil is a cylindrical drum core, a cylindrical or box-shaped ring core that wraps and shields the drum core, a winding wound around the drum core, and winding start and end of the winding And a terminal plate for connecting the terminals. FIG. 8 shows a conventional example of the most basic configuration.
[0004]
The conventional coil 110 includes a coil section 130 shown in FIG. 8A and a box-shaped ring core 140 that wraps and shields the coil section 130 shown in FIG. 8B.
[0005]
A drum core 125 provided with a drum core flange 124 at an end shown in FIG. 9A and a terminal block 122 having terminal plates 121 connected to both ends shown in FIG. 9B are bonded or integrally formed. Thus, the bobbin 120 shown in FIG. 9B is formed. The terminal block 122 is provided with a ring core joint 123 to which the ring core 140 is connected. The winding 40 is wound around the drum core 125 of the bobbin 120 thus formed, and the winding start and end portions 41 are soldered or welded to the terminal plate 121 of the terminal block 122 to form the coil portion 130.
[0006]
The ring core 140 shown in FIG. 8B is mounted on the outer periphery of the coil section 130 shown in FIG. 8A so as to surround the coil section 130. FIG. 10 shows a state where the ring core 140 is mounted on the coil section 130. The ring core 140 is connected to the ring core joint 123 in the coil unit 130 by bonding. As shown in FIG. 8B, the ring core 140 has a hole 141 for preventing interference with the drum core flange 124 of the coil portion 130 and a winding start / end portion 41 of the winding so as not to interfere with the ring core 140. Is provided with a relief hole 142.
[0007]
Therefore, the winding was set in the winding machine after forming the coil portion 130, and the winding 40 was formed while winding the copper wire around the drum core 125.
[0008]
FIG. 11 shows a state where the coil 110 is mounted on a substrate. As shown in FIG. 11, the conventional coil 110 is mounted on a substrate 151 having a screw hole 152 to be screwed and soldered to form a substrate ASSY (assay: a state in which components are mounted on the substrate) 150. . As shown in FIG. 12, the board ASSY 150 shown in FIG. 11 is fixed to the housing 160 of the apparatus by screwing or fitting using a screw hole 152 provided on the board.
[0009]
FIG. 13 shows a substrate state when a drop impact is applied in the apparatus state shown in FIG.
In the state before the fall shown in FIG. 13A, the substrate 151 bends as shown in FIG. 13B at the moment of falling and colliding with the ground, and this bend tries to return immediately after the fall, but the coil 110 still falls. Since the force in the direction remains, the behaviors of the coil 110 and the substrate 151 are opposite to each other. Therefore, the internal drum core 125 cannot withstand the behavior and flakes off from the terminal block 122. When the coil 110 returns to the state after the drop shown in FIG. 13C, the drum core of the coil 110 is removed from the terminal block 122. I was
[0010]
Patent Literatures 1 to 4 below show inventions that prevent the problem that the drum core and the ring core fall off the mounting substrate even when an impact is applied to the drum core and the ring core.
[0011]
[Patent Document 1]
JP 2001-338817 A [Patent Document 2]
JP 2001-338818 A [Patent Document 3]
JP-A-2002-064023 [Patent Document 4]
Japanese Patent Application Laid-Open No. 2002-064024
[Problems to be solved by the invention]
A coil shown in FIG. 14 has been proposed as a coil having a structure that can withstand a drop impact. As shown in FIG. 14A, the terminal portion 220 of the coil 210 is press-fitted into or integrally formed with the ring core 232. Further, as shown in FIG. 14 (C), a drum core 231 having a drum core flange 233 and winding up a winding is integrally formed with a ring core 232 to form a ferrite core 230. Further, as shown in FIG. 14C, a winding 40 is wound around the internal drum core 231, and the winding start and end portions 41 are joined to the terminal portion 220 by soldering or welding.
[0013]
However, in the conventional winding method, since it is not possible to use a winding machine, it is extremely difficult to realize this component.
[0014]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small coil that can reduce coil defects due to a drop impact and that reduces the number of manufacturing steps, and a method for manufacturing the same.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 provides a cylindrical drum core, a ring core formed integrally with the drum core and wrapping and shielding the drum core, and a cylindrical drum core wound by a winding machine. And a terminal plate to which the winding start and end lines of the winding are connected, and a resin filled in the ring core to fix the winding to the drum core. It is characterized by the following.
[0016]
According to a second aspect of the present invention, in the first aspect of the present invention, the end of the drum core opposite to the connection portion with the ring core projects from a resin filled in the ring core, and an opening provided on the bottom surface of the ring core. Characterized by being connected to a bottom plate that closes off.
[0017]
According to a third aspect of the present invention, in the first or second aspect, the terminal plate has one end of the terminal plate embedded and fixed in a side surface of the ring core.
[0018]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the bottom plate has a cutout for preventing contact with a winding connected to the terminal plate.
[0019]
According to a fifth aspect of the present invention, a cylindrical drum core and a ring core that wraps and shields the drum core are integrally formed, and the winding wound by the winding machine is mounted by dropping the winding into the cylindrical drum core. In order to fix the wire to the drum core, the ring core is filled with resin, and the winding start and end winding wires are connected to the terminal plate.
[0020]
According to a sixth aspect of the present invention, in the invention of the fifth aspect, an end provided on a bottom surface of the ring core is formed by projecting an end of the drum core opposite to a connection portion with the ring core from resin filled in the ring core. It is characterized in that it is connected to a bottom plate closing the part.
[0021]
According to a seventh aspect of the present invention, in the fifth or sixth aspect, the terminal plate has one end of the terminal plate embedded and fixed in a side surface of the ring core.
[0022]
The invention according to claim 8 is the invention according to any one of claims 5 to 7, characterized in that the bottom plate has a notch for preventing contact with a winding connected to the terminal plate.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a small coil of the present invention and a method of manufacturing the same will be described in detail with reference to the accompanying drawings. 1 to 7 show an embodiment of a small coil of the present invention and a method of manufacturing the same.
[0024]
First, the configuration of the coil according to the first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of the coil of the present embodiment, FIG. 2 is a component configuration diagram, FIG. 3 is a rear view of the coil, and a perspective view of the ferrite core with a side wall removed.
[0025]
The coil 10 according to the first embodiment includes a ferrite core 30 formed by integrally forming a cylindrical drum core 31 and a box-shaped ring core 32 that encloses and shields the drum core 31, and the drum core 31 and the ring core 31. At the same time, it is composed of two left and right terminal plates 20 each having one end embedded and fixed on both side surfaces of the ring core 32 and a winding 40 wound around the drum core 31.
[0026]
As shown in FIG. 2B, the winding 40 is mounted on the drum core 31 by dropping the winding 40 wound by a winding machine or the like onto the drum core 31 as shown in FIG. 2A. Is done. As described above, since the drum core 31 of the present embodiment is not provided with the drum core flange shown in FIG. 9, the winding wound by the winding machine can be directly dropped into the drum core 31. Then, the end of the wire at the start and end of winding is welded or soldered to the terminal plate 20.
[0027]
Further, the winding 40 mounted on the drum core 31 is fixed by filling the inside of the ring core 32 with a resin 50 as shown in FIG.
[0028]
Next, a configuration when the coil is mounted on a substrate will be described with reference to FIGS. FIG. 4 shows a state in which the substrate is mounted, and FIG. 5 shows a state in which a coil is incorporated in a housing of the apparatus.
[0029]
As shown in FIG. 4, the coil 10 according to the present embodiment is mounted on a substrate 51 having a screw hole 52 to be screwed, and is fixed to the substrate 51 by soldering to form a substrate ASSY5. Further, as shown in FIG. 5, the board ASSY 50 is fixed to the housing 60 of the apparatus by screwing or sandwiching it using a screw hole 52 provided in the board 51.
[0030]
As described above, the coil 10 of the present embodiment can be mounted by dropping the winding into the drum core 31 because the drum core 31 has a cylindrical shape and no drum core flange is provided at the end. Therefore, the number of manufacturing steps of the coil can be reduced.
[0031]
Further, by integrating the drum core 31 and the ring core 32, it is possible to provide a coil that can withstand the impact of falling.
[0032]
Next, the coil of the second embodiment will be described in detail with reference to FIGS. FIG. 6 shows a perspective view of the back surface of the coil of the present embodiment, and FIG. 7 shows the configuration of the ferrite plate.
[0033]
As shown in FIG. 6, in the coil 10 of the present embodiment, the amount of the resin 50 for fixing the winding 40 is slightly smaller than that of the first embodiment, and the top surface 80 of the drum core 31 is smaller than the resin 50. The ferrite core 30 has a protruding shape, and the bottom of the ferrite core 30 is sealed by a bottom plate (ferrite plate) 90.
[0034]
The bottom plate (ferrite plate) 90 has a cutout portion 91 so as not to interfere with the winding start / end portions 41 of the dropped winding 40 as shown in FIG.
[0035]
The bottom plate (ferrite plate) 90 having such a shape is fixed to the top surface portion 80 of the drum core 30 with an adhesive or the like. Or, it is sandwiched between the bottoms of the ferrite core 30.
[0036]
With the coil 10 having such a shape, the magnetic flux generated when a current flows through the coil can be optimally transmitted to the ferrite core 30 via the bottom plate (ferrite plate) 90, and the magnetic flux generated from the coil Can be confined in the coil 10.
[0037]
The above embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.
[0038]
【The invention's effect】
As is apparent from the above description, in the present invention, since the drum core is formed in a cylindrical shape and the drum core flange is not provided at the end of the drum core, it can be mounted by dropping the winding into the drum core. Therefore, the number of manufacturing steps of the coil can be reduced.
[0039]
Further, by integrating the drum core and the ring core, it is possible to provide a coil that can withstand the impact of falling.
[0040]
The end of the drum core opposite to the connection with the ring core protrudes from the resin filled in the ring core, and is connected to the bottom plate that closes the opening provided on the bottom surface of the ring core. It is possible to optimally transmit the magnetic flux generated when the magnetic flux is generated to the drum core via the bottom plate, and confine the magnetic flux generated from the coil in the coil.
[Brief description of the drawings]
FIG. 1A is a schematic perspective view showing a configuration of a first embodiment of the present invention, and FIG.
FIG. 2 is a diagram for explaining a procedure for mounting a winding 40 to a drum core 31.
FIG. 3 is a diagram illustrating a state where the coil 10 according to the first embodiment is viewed from the back surface.
FIG. 4 is a diagram showing a state where the coil 10 is mounted on a substrate.
FIG. 5 is a diagram showing a state where the coil 10 is incorporated in a housing of the device.
FIG. 6 is a diagram illustrating a state where a coil 10 according to a second embodiment is viewed from the back surface.
FIG. 7 is a diagram showing an overview of a ferrite plate.
8A is a schematic diagram showing a configuration of a conventional coil unit 130, and FIG. 8B is a schematic diagram showing a configuration of a conventional ring core 140. FIG.
9A is a schematic view showing a configuration of a conventional drum core 125, and FIG. 9B is a schematic view showing a configuration of a conventional bobbin 120. FIG.
FIG. 10 is a diagram showing an outline shape of a conventional coil 110.
FIG. 11 is a view showing a state where a conventional coil is mounted on a substrate.
FIG. 12 is a diagram showing a state in which a conventional coil 110 is incorporated in a housing of an apparatus.
FIG. 13 is a diagram for explaining an impact on a component when the component falls.
FIG. 14 is a schematic view showing a configuration of a conventional coil 210.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Coil 20 Terminal board 30 Ferrite core 31 Drum core 32 Ring core 32
40 winding

Claims (8)

A cylindrical drum core,
A ring core formed integrally with the drum core and wrapping and shielding the drum core;
A winding wound by a winding machine and mounted by being dropped into the cylindrical drum core,
A terminal plate to which the winding start and end lines of the winding are connected,
In order to fix the winding to the drum core, a resin filled in the ring core,
A small coil characterized by having: The end portion of the drum core opposite to the connection portion with the ring core protrudes from the resin filled in the ring core, and is connected to a bottom plate closing an opening provided on a bottom surface of the ring core. The small coil according to claim 1, wherein The small coil according to claim 1, wherein the terminal plate has one end of the terminal plate embedded and fixed in a side surface of the ring core. The small coil according to any one of claims 1 to 3, wherein the bottom plate has a notch for preventing contact with a winding connected to the terminal plate. A cylindrical drum core and a ring core that wraps and shields the drum core are integrally formed,
The winding wound by the winding machine is mounted by dropping into the cylindrical drum core,
In order to fix the winding to the drum core, filling the ring core with resin,
A method for manufacturing a small coil, comprising: connecting a winding start and end line of the winding to a terminal plate. An end portion of the drum core opposite to a connection portion with the ring core protrudes from the resin filled in the ring core, and is connected to a bottom plate closing an opening provided on a bottom surface of the ring core. The method for manufacturing a small coil according to claim 5, wherein 7. The method for manufacturing a small coil according to claim 5, wherein the terminal plate has one end of the terminal plate embedded and fixed in a side surface of the ring core. The method for manufacturing a small coil according to any one of claims 5 to 7, wherein the bottom plate has a notch for preventing contact with a winding connected to the terminal plate.

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