JP2006294736A - Low profile coil and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low profile coil which is high in inductance and compact in size and its manufacturing method. <P>SOLUTION: The low profile coil is comprised of a core 3 that is square and of a non-divided type, paired bobbins 1 and 10 that are located on facing sides among four sides of the square shapes, and windings wound around the bobbins. The bobbins 1 and 10 are wound while they are turned by using a winding as an axis, the windings wound around the bobbins 1 and 10 are connected, and the winding wound around the respective bobbin generates magnetic flux in the same direction within a closed magnetic circuit of the core 3 with respect to the same current. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a low profile coil used for consumer electronics, industrial electronic equipment, and the like, and a method for manufacturing the same, and particularly to a low profile coil suitable for choke coils, transformers, and common mode choke coils used in AD converters and the like. About.

  Conventionally, this type of coil is wound around only one place of a closed magnetic circuit core to form a coil. As an example, a conventional choke coil is shown in a front view in FIG. 1 is a combination type bobbin, its central axis is perpendicular to the plane of the figure, 2 is a base, 3 is a square-shaped core (magnetic core), and although not shown, when viewed from above A square shape appears and 4 is a terminal pin. Thus, the winding is applied to one of the straight portions of the core 3 via the bobbin 1. A line filter having a similar structure is disclosed in Patent Document 1 and the like.

JP-A-8-138952

  In recent years, a high inductance is required for this type of coil, and a low profile with a low height is required for miniaturization of equipment. Conventionally, however, this type of coil is wound only at one location of the closed magnetic circuit core as shown in FIG. 4, so that it is necessary to increase the bobbin and wind many copper wires in order to obtain a high inductance. Since the copper wire overlaps many layers, the outer diameter of the coil is increased, and the height direction and the width direction are increased, so there is a limit to downsizing of the device.

  Therefore, an object of the present invention is to provide a low-profile coil having a high inductance and a small size in the height direction, and a method for manufacturing the same.

  In order to solve the above problems, a low-profile coil according to the present invention comprises a non-divided magnetic core having a square shape and a pair of bobbins located on opposite sides of the four sides of the square shape. And a low-profile coil including a winding wound around the bobbin, wherein the bobbin is wound while rotating around the side, and the winding wound around the two bobbins forming the pair. The wires are connected, and the winding wound around each bobbin generates a magnetic flux in the same direction in the closed magnetic path of the magnetic core for the same current.

  The winding wound around the pair of bobbins may be formed of a continuous conducting wire having no connection portion.

  The bobbin may include a gear, and may be rotated and driven by a gear mechanism that meshes with and engages with the gear.

  The bobbin may be provided with a gear serving as a part of a gear structure that can be wound synchronously in order to wind the bobbin with a conducting wire continuous to the pair of bobbins.

  And the manufacturing method of the low profile type coil of the present invention comprises: a non-divided magnetic core having a square shape; a bobbin that is located on opposite sides of the four sides of the square shape; In a method for manufacturing a low-profile coil comprising a winding wound around a bobbin, one end of a certain length of conducting wire is wound around one bobbin, and the one bobbin is wound around the side as an axis. The method further comprises a step of winding the other end of the conducting wire around the other bobbin and rotating the other bobbin to wind.

  In the low profile coil of the present invention, the winding portion is divided and provided at the first and second positions, so that the height direction becomes lower than that of the conventional coil, and a low profile coil can be provided. Further, by dividing the winding portion into the first and second positions, the distributed capacity existing between the windings is reduced and the high frequency characteristics are improved.

  Further, the common mode choke coil to which the present invention is applied is wound so as to cancel the magnetic flux, and the high frequency characteristics are improved. Further, by dividing the winding portion into the first and second positions, the heat radiation area can be widened and the temperature rise can be suppressed.

  In addition, since a bobbin that can rotate around the winding position of the magnetic core is used, a manufacturing method using automatic winding becomes possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view showing a low profile coil in which the present invention is applied to a common mode choke coil. 1 and 10 are bobbins, 2 is a base, 3 is a U-shaped core, 4 is a terminal pin, 5 is a base stand-off. As described above, when viewed from the front, the two bobbins 1 and 10 have a glasses shape. FIG. 2 is a right side view of the low profile coil of the present invention, and 6 is a copper wire wound around a bobbin. FIG. 3 is a bottom view thereof. Although the plan view is omitted, the core 3 has a square shape when viewed from above.

  As shown in FIGS. 1 and 2, the low-profile coil of the present invention includes a U-shaped ferrite core 3, bobbins 1 and 10, a copper wire 6, a base 2, and pins 4.

  The combination type bobbin 1 and bobbin 10 are respectively attached to a square-shaped core 3, wound, and attached to a base 2.

  In order to wind the copper wire around the bobbin 1, the bobbin 1 is rotated by a gear (mechanism of a gear that rotates in mesh with the gear provided in the bobbin 1), which is tangled with the bobbin 1 and interlocked with the bobbin 1. It is wound around the bobbin 1. In order to wind around the other bobbin 10, a copper wire having a specified length is drawn, the end is cut, the cut end is entangled with the bobbin 10, the bobbin 10 is rotated and wound. . The direction of the rotation is a direction in which the magnetic flux in the closed magnetic path of the core is strengthened against the same current flowing through the copper wire. Each end previously wound after winding is wound on the pin 4 (see the binding 9 in FIG. 3), and the pin 4 is soldered to obtain the low profile coil of the present invention. Note that the winding 7 and the winding 8 shown in FIG. 3 are wound in directions that cancel out the magnetic fluxes generated from each other.

  In the manufacturing method described above, the copper wire can be cut into a predetermined length, and both bobbins can be rotated in synchronization to perform winding. In addition, it may replace with the gear mechanism which rotates a bobbin, and you may wind using the rotation mechanism by the bobbin collar and a pulley.

  More specifically, one end of a copper wire cut to a certain length in a coil that can be automatically wound by rotating the bobbin itself with a bobbin that is divided into two parts on a rectangular closed magnetic path core. Is wound around the first divided bobbin, the first divided bobbin is rotated by half of the specified total number of times, and is laminated and wound to the extent that it is used up to the center of the copper wire that has been cut to a fixed length, to form the first winding part, Next, the other half of the copper wire end extending from the first winding part is bound to the second divided bobbin, and the second divided bobbin is rotated so that the number of turns is the same as that of the first winding part. The height direction is lowered by dividing into a glass shape at the first winding portion and the second winding portion.

  As described above, by using a square-shaped closed magnetic circuit core, the winding part is divided into two parts and provided on two opposite sides of the square shape, thereby reducing the height and reducing the inductance. Not only was this possible, but the distributed capacity existing between the windings was reduced and the high-frequency characteristics were improved. Also, heat generation from the windings became easier and the current capacity could be increased. In addition, since the bobbin is rotatable, automatic winding with a common mode choke coil is possible. Furthermore, as a result of combining the glasses-like winding portions having two winding portions, the high-frequency characteristics of the common mode choke coil could be improved.

  In the above embodiment, as shown in FIG. 3, the common mode choke coil in which half of the winding 8 and half of the winding 7 are wound around each of the bobbins 1 or 10 has been described. The effectiveness of the present invention is apparent also for the choke coil.

  The low profile coil of the present invention can be used as a choke coil for EMI countermeasures of the power supply unit.

The front view which shows the low profile coil of this invention. The right view of the low profile coil of this invention. The bottom view of the low profile coil of this invention. The front view of the conventional choke coil.

Explanation of symbols

1,10 Bobbin 2 Base 3 Core 4 Pin 5 Base standoff 6 Copper wire 7, 8 Winding 9 Tying

Claims (5)

  A low profile type comprising: a B-shaped non-divided magnetic core; a pair of bobbins located on opposite sides of the four sides of the B-shaped; and a winding wound around the bobbin In the coil, the bobbin is wound while rotating around the side, the windings wound around the two bobbins forming the pair are connected, and the winding wound around each bobbin is A low-profile coil that generates a magnetic flux in the same direction in a closed magnetic circuit of the magnetic core for the same current.   2. The low profile coil according to claim 1, wherein the winding wound around the pair of bobbins comprises a continuous conducting wire having no connection portion.   The low-profile coil according to claim 1 or 2, wherein the bobbin includes a gear, and is rotated and wound by a gear mechanism that meshes with and engages with the gear.   4. The low profile according to claim 2, wherein the bobbin includes a gear that is part of a gear structure that can be wound synchronously so that the bobbin is wound with a continuous wire on the bobbin that forms the pair. Type coil.   A low profile type comprising: a B-shaped non-divided magnetic core; a pair of bobbins located on opposite sides of the four sides of the B-shaped; and a winding wound around the bobbin In the coil manufacturing method, one end of a certain length of the conducting wire is entangled with one bobbin, the one bobbin is wound around the side as an axis, and the other end of the conducting wire is entangled with the other bobbin, A method of manufacturing a low profile coil, comprising the step of rotating the other bobbin to wind.

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