JPH082992Y2 - choke coil - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION This invention relates to a choke coil which is used for preventing electromagnetic noise generated in an electronic device or the like, propagates through a wire or propagates in the air, and particularly prevents electromagnetic noise. The present invention relates to a choke coil having a wide usable frequency band effective for

[0002]

2. Description of the Related Art Electromagnetic noise (hereinafter referred to as noise) generated from an electronic device has a wide range of frequency components such as 10 KHz to 1 GHz, and these noises affect the function of other electronic devices, Alternatively, the device itself may be affected by the noise of other devices, and with the progress of digitalization of devices, prevention of noise has become an important issue. Generally, as a simple and effective effect for noise prevention, a normal mode choke coil is used for normal mode noise and a common mode choke coil is used for common mode noise.
In order to obtain the impedance required to prevent noise in such a wide frequency band, these choke coils require a large inductance in the low frequency region and a corresponding inductance in the high frequency region. In other words, it is necessary to use, as the magnetic core used for these choke coils, a magnetic core having a large relative permeability in the low frequency region and a very large relative permeability in the high frequency region. However, in general, a magnetic material having a high relative magnetic permeability characteristic has a characteristic that the relative magnetic permeability value does not extend to a high frequency region and deteriorates in a low frequency region, and a magnetic material having a low relative magnetic permeability characteristic has a high characteristic. It has the characteristic of retaining a high value up to the frequency band, but the inductance value is low in the low frequency range. Therefore, there is no magnetic material having a relative magnetic permeability characteristic that satisfies the above requirements with one kind of magnetic core. Therefore, as a countermeasure, for example, a coil in which a magnetic core in a low frequency band is wound,
Also, choke coils having multiple frequency characteristics, such as a coil wound around a magnetic core in a high frequency band, are used in cascade connection, and an air core coil without a magnetic core is connected especially in a high frequency range. It has been customary to take measures to obtain the required impedance characteristics in a wide frequency band.

[0003]

In the conventional structure, a plurality of iron-core or air-core choke coils each having a separate winding are connected in series to obtain the required impedance characteristics in a wide frequency band. As a result, the mounting space is increased and each coil is wound independently.Therefore, even if the coil is wound on the machine, the bobbin setting time on the machine and the lead wire end It took a long time for processing and required a plurality of bobbins, which was inevitably expensive. The present invention provides a choke coil that can be used in a wide frequency withstanding range by eliminating these conventional drawbacks.

[0004]

The features for obtaining a conventional wide frequency band choke coil are as follows. That is, an intermediate portion of a tubular coil bobbin having a through hole for passing a magnetic core and a plurality of collars for split winding including a collar provided at both ends of the through hole, and a plurality of coil winding outer peripheral surfaces surrounded by the collar. By cutting off a part of the outer peripheral surface surrounded by the collar to form a coil bobbin having a conductive portion communicating with the internal through hole of the coil bobbin, the through hole is divided in the bobbin length direction and the through hole is formed. In the conductive portion formed so as to be conductive with, in the conductive portion and the through hole, a plurality of endless magnetic cores having a square shape with different magnetic permeability and different frequency characteristics of the relative magnetic permeability are incorporated. That is, a plurality of magnetic cores are attached to one coil bobbin, and the winding outer peripheral surface of each magnetic core is wound so that the directions of the magnetic fluxes generated by the respective windings match in the through holes. , Connect each winding in series Characterized in that a choke coil form.

That is, the present invention is 1. One of the outer peripheral surfaces of the tubular coil bobbin, which has a through hole and a plurality of flanges provided at both ends, and a plurality of coil winding outer peripheral surfaces surrounded by the flange, which is surrounded by the intermediate flange. A conductive portion is provided to connect the through hole into which the magnetic core is incorporated by cutting the portion to divide the through hole in the bobbin length direction, and the relative magnetic permeability and the relative permeability are provided in the conductive portion and the through hole. A plurality of magnetic cores having square and endless magnetic circuits with different frequency characteristics of magnetic susceptibility are inserted and arranged, and the direction of the magnetic flux generated by each winding is a through hole on the winding outer peripheral surface of each magnetic core. The choke coil is characterized in that windings are provided so as to coincide with each other, and the windings are connected in series. 2. Multiple square shapes,
The choke coil according to claim 1, wherein one set of endless magnetic cores is an air core.

[0006]

A coil bobbin having a coil winding outer peripheral surface partitioned by a plurality of collars, penetrating the inside of the coil winding outer peripheral surface at the center of the flange end surface, and providing a magnetic leg of the magnetic core with a through hole. A conducting portion for incorporating an I-shaped core of a UI-shaped magnetic core obtained by cutting off a part of the outer peripheral surface for coil winding is provided in a part of the middle, and one coil bobbin has a relative magnetic permeability and a relative magnetic permeability. Magnetic cores having different frequency characteristics are incorporated, and windings wound around the respective magnetic cores are connected in cascade to form an inductance having a wide withstand frequency characteristic of the frequency value of the inductance. Also, to prevent the two magnetic cores incorporated in the conducting part from contacting each other, the magnetic cores are separated by providing a gap with a non-magnetic spacer, and the magnetic fields created when currents flow in the respective windings have the same direction. By connecting the lead wire of the terminal to, a choke coil for preventing electromagnetic noise having a high inductor value in a high frequency tolerance region is formed.

[0007]

1 is a perspective view showing an example of a coil bobbin used in a choke coil of the present invention. This coil bobbin is a cylindrical coil bobbin formed by a through hole 1 penetrating both ends of the bobbin, a collar 2 at both ends and a bobbin supporting portion 10, and the bobbin supporting portion 10 is a horizontal magnet. Supports the core stably. The winding is wound on the coil winding outer peripheral surface 3 surrounded by the collar. Further, a part of the coil winding outer peripheral surface surrounded by the collar at the middle portion of the present coil bobbin is cut off to form a conducting portion 4 which is electrically connected to the through hole 1. FIG. 2 is a perspective view showing a first embodiment using the coil bobbin shown in FIG. 1 in the choke coil of the present invention. One coil bobbin has different relative permeability-frequency characteristics and different dimensions. The UI-shaped magnetic cores 6 and 7 are individually attached (the winding is not shown). The magnetic cores are UI-shaped magnetic cores, which are formed by I-shaped magnetic cores 6a and 7a and U-shaped magnetic cores 6b and 7b, respectively. In FIG. 2, two types of I-shaped magnetic cores 6a and 7a are the conductive portions. 4, the U-shaped magnetic cores 6b and 7b have one leg portion inserted into the through hole 1 to form a square and endless magnetic core. When the winding is performed only on one side of the square-shaped magnetic core as shown in FIG. 2, even if the I-shaped magnetic core is inserted through the through hole and a part of the leg portion of the U-shaped magnetic core is arranged in the conducting portion, The effect is the same. In addition, one set of magnetic cores 7 is attached only to a part of the conduction portion and the through hole portion, and the other is used as an air core, and each coil winding outer peripheral surface 3 is attached.
By winding and connecting to the coil, a composite coil of an iron core and an air core can be obtained (not shown).

FIG. 3 is a perspective view showing another embodiment of the choke coil according to the present invention, in which winding is carried out on two sides of a square-shaped magnetic core facing each other. The coil bobbins A and B are used, the I-shaped magnetic core is arranged in the conducting portion of the two coil bobbins A and B, and the U-shaped magnetic core has a through hole 1
a and 1b are inserted. In this example, the windings 8a and 8b and the windings 9a and 9 are provided on both legs of the U-shaped magnetic core 7b of the UI magnetic core 7.
b are wound continuously, and U of the UI type magnetic core 6
Windings 8b and 9b are wound around both legs of the character-shaped magnetic core 6b. The windings 8a and 8b and the windings 9a and 9b are wound so that the directions of the magnetic fluxes in the through holes are the same. A series of windings 8a, 8b and windings 9a, 9b that are completely equal and independent, and have different winding directions when viewed from the input side or the output side are common mode choke type choke coils. When the winding directions are the same, the windings 8b and 9b or the windings 8a and 9a function as a normal mode choke coil. 2 and 3, I for forming the UI-shaped magnetic cores 6 and 7
It is desirable that the joints of the U-shaped core and the U-shaped magnetic core are closely joined so that no magnetic gap is generated. Therefore, they are fixed with elastic clips or tapes, and then impregnated with resin or the like. It is normal to In addition, a non-magnetic spacer is inserted between the magnetic cores so that the magnetic fluxes generated in the UI magnetic cores 6 and 7 juxtaposed in the conducting portion do not affect each other. The space 11 is provided and arranged. The windings of the individual magnetic cores are connected to the terminals 5 shown in FIGS. 2 and 3, and even if the two terminals 5 provided in the conducting portion are previously connected inside the conducting portion, or are mounted on the printed circuit board. Even if they are sometimes connected by a conductor pattern, the windings of the coil bobbins A and B may be continuously performed without relaying the terminals at the conducting portions. The embodiment of the present invention has been described with reference to an example in which the coil bobbin is provided with one conducting portion that is electrically connected to the through hole. It is natural that a choke coil having a wide same wave number band can be constructed by combining them.

[0009]

As is apparent from the above embodiments, according to the present invention, a composite coil requiring at least two or more coil bobbins in the conventional structure can be realized with only one coil bobbin. The winding machine only needs to be set once, and continuous winding is possible. Therefore, a cheaper coil bobbin can be provided, and at the same time, the coil bobbin A. By integrating B, a large inductance value can be obtained in a smaller mounting space, and there are great advantages in economics and size reduction.

[Brief description of drawings]

FIG. 1 is an external perspective view of a coil bobbin used in the choke coil of the present invention.

FIG. 2 is an external perspective view showing an embodiment of the choke coil of the present invention.

FIG. 3 is an external perspective view showing a second embodiment of the choke coil of the present invention.

[Explanation of symbols]

 1, 1a, 1b through hole 2 collar 3 outer peripheral surface for coil winding 4 conduction part 5 terminal 6, 7 UI type magnetic core 6a, 7a I type magnetic core 6b, 7b U-shaped magnetic core 8a, 9a, 8b, 9b winding Wire 10 Bobbin support 11 Air gap A, B Coil bobbin

Claims (2)

[Scope of utility model registration request] 1. A cylindrical coil bobbin having a through hole and a plurality of flanges provided at both ends and a plurality of coil winding outer peripheral surfaces surrounded by the flange, and an outer periphery surrounded by the intermediate collar. By providing a conductive portion that is conductive with a through hole incorporating a magnetic core by cutting off a part of the surface, the through hole is divided in the bobbin length direction, and the relative permeability in the conductive portion and the through hole, And a plurality of magnetic cores having a square and endless magnetic circuit with different frequency characteristics of relative permeability are inserted and arranged, and the direction of the magnetic flux generated by each winding on the winding outer peripheral surface of each magnetic core. A choke coil is characterized in that windings are formed so that the above-mentioned windings coincide with each other in the through holes, and the windings are connected in series. 2. The choke coil according to claim 1, wherein one set of a plurality of square-shaped and endless magnetic cores is an air core.