JPS62126607A - Variable inductance coil - Google Patents

Abstract

PURPOSE:To enable the titled coil to be miniaturized and thin-formed by a method wherein a movable core is provided on a part of turning body mounted to cover the surface of a coil fixed on a substrate such as a printed board etc. so that the overlapped area of movable core and a core of fixed coil may be changed by the rotation of turning body so as to change the inductance. CONSTITUTION:A variable chip coil 2 mounted on a printed board 1 is composed of a lower fixed mold body 3 and a turning mold boy 4 covering the surface of the fixed mold body 3. The fixed mold body 3 is mold-formed of a coil 14 comprising a fixed core 5 and windings 6 buried in the fixed mold body 3. The turning mold body 4 is internally mold-formed of a movable core 11 comprising a semicircular magnetic material. In such a constitution, the turning mold body 4 is turned so that the overlapped space of inner movable core 11 with the core 5 of coil 14 inside the fixed mold body 3 i.e. the space of movable core 11 covering the fixed core 5 may be changed so as to change the inductance.

Description

[Detailed description of the invention] [Table of contents] - Overview - Field of industrial application - Prior art - Problems to be solved by the invention - Means for solving the problems - Effects - Examples - Effects of the invention [Overview] A coil consisting of a core and a winding is fixed on a substrate such as a printed board, the upper surface of the coil is covered with a rotating body having a rotating shaft adjacent to the coil, and a part of the rotating body is made of magnetic material. A variable inductance coil configured as, for example, a semicircular movable core, in which the overlapping area of the movable core and the core of the fixed coil can be varied by rotating the rotating body.

[Industrial application field]

The present invention relates to a coil consisting of a core and a winding, and particularly to a variable inductance structure thereof.

[Conventional technology]

A conventional variable inductance coil is shown in FIG. A winding 22 is applied to a bobbin 21 provided on a base 20. The ends of winding 22 are connected to electrodes 23. A movable core 24 is screwed into the center of the pobbin 21 along its axis. When the movable core 24 is rotated by engaging a driver or the like in the groove 25 on its upper surface, it moves in the vertical direction as shown by arrow B, and the amount of insertion into the bobbin can be varied. Conventionally, the inductance of the coil was made variable by using such a screw-type movable core 24.

[Problem that the invention seeks to solve]

In the conventional variable inductance coil described above, since the movable core moves up and down (perpendicular to the base), the space up to the maximum movement of the movable core is required for mounting components, and the height of the coil becomes substantially higher. It was not possible to make the parts thinner.

The present invention has been made in view of the drawbacks of the prior art described above, and an object of the present invention is to provide a variable inductance coil that allows the coil to be made smaller and thinner.

[Means for solving problems]

In order to achieve the above object, in the present invention, a coil consisting of a core and a winding is fixed on a substrate, the upper surface of the coil is covered with a rotating body having a rotation axis adjacent to the coil, and a part of the rotating body is is constructed as a movable core made of a magnetic material, and the overlapping area between the movable core and the core of the fixed coil is variable.

[For production]

By rotating the rotating body, a movable core provided on the rotating body rotates and moves, and the area (overlapping area) covering the upper surface of the core of the coil on the substrate changes. This changes the inductance of the coil.

〔Example〕

FIG. 1 shows an embodiment of the present invention. The tat diagram is a top view, (
Figure b1 is a sectional view. The variable chip type coil 2 mounted on the printed board 1 is composed of a lower fixed molded body 3 and a rotary molded body 4 covering the upper surface of the fixed molded body 3. The fixed molded body 3 is molded with a coil 14 consisting of a fixed core 5 and a winding 6 buried therein.

Electrodes 7 and 8 connected to the internal winding 6 are provided on both sides of the fixed molded body 3, and these electrodes 7.8 are bonded and fixed onto the pad patterns 9 and 10 of the printed board 1 by soldering or the like. A molded body 3 is fixed onto a printed board 1. The rotary molded body 4 is molded with a semicircular movable core 11 made of a magnetic material embedded therein. The rotation axis 12 of the rotary molded body 4 is coaxial with the center of the fixed molded body 3, and the coil 14 inside the fixed molded body 3
Adjacent to. The rotary molded body 4 can be rotated in the direction of arrow A with respect to the fixed molded body 3 by engaging a screwdriver or the like with a groove 13 on the rotation axis at the center of the upper surface thereof. By rotating the rotary mold body 4 in this way, the movable core 11 inside the rotary mold body 4 is rotated.
The overlapping area between the coil 14 and the core 5 inside the fixed molded body 3, that is, the area where the movable core 11 covers the fixed core 5 changes, and therefore the inductance changes.

In the embodiment, the coil 14 and the movable core 11 are configured as a molded body, but the coil 14 may be fixed on a printed board without being embedded in the molded body, and the movable core 11 may be configured as a molded body. A magnetic material layer may be formed, for example, in a semicircular shape by vapor deposition or the like on the lower surface.

The variable inductance structure having the above configuration can also be applied to a transformer having two coils.

Further, the coil may be in the form of a planar coil.

〔Effect of the invention〕

As explained above, in the variable inductance coil according to the present invention, a movable core is provided on a part of the rotating body that covers the upper surface of the coil fixed on a substrate such as a printed board, and the movable core is movable by the rotation of the rotating body. The inductance is changed by changing the overlapping area between the core and the coil core.

Therefore, by making the rotating body thinner, the height of the entire coil can be lowered, making it possible to make the variable coil smaller and thinner. Further, if a planar coil is used as the coil, the thickness can be further reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a variable inductance coil according to the present invention, and FIG. 2 is a perspective view of a conventional variable inductance coil. DESCRIPTION OF SYMBOLS 1... Printed board, 2... Variable chip type coil, 3... Fixed mold body, 4... Rotating mold body,
5... Fixed core, 6... Winding wire, 11...
・Movable core, 12...rotating shaft, 14...coil. (Q) Configuration diagram s1 of the embodiment of the present invention

Claims (1)

[Claims] 1. A coil consisting of a core and a winding is fixed on a substrate,
A rotating body having a rotation axis adjacent to the coil covers the upper surface of the coil, a part of the rotating body is configured as a movable core made of a magnetic material, and the overlapping area between the movable core and the core of the fixed coil is variable. variable inductance coil. 2. The variable inductance coil according to claim 1, wherein the coil is embedded in a molded body, and the rotating body is formed as a molded body having a semicircular core inside. 3. The variable inductance coil according to claim 1, wherein the rotating body is disk-shaped, and a magnetic material layer is provided on the lower surface of the rotating body to form a semicircular core.