JPH02194508A - Choke coil - Google Patents

Abstract

PURPOSE:To easily adjust an inductance and to change it continuously by a method wherein two core bodies whose peripheral edge parts of cylinder end faces having concentric recessed parts toward the inside are turned relatively and are set to a desired gap state. CONSTITUTION:Two core bodies 2, 3 made of a magnetic material such as a ferrite are formed cylindrical; concentric recessed parts 2a, 3a are formed from end faces on one side; sinusoidal waves 2b, 3b are formed at outer protruding parts. These two core bodies 2, 3 are arranged and installed in such a way that they are faced by keeping a gap on an axial line. A coil 4 is wound on a bobbin 5 which is installed at inside protruding parts 2e, 3e and which is housed at the recessed parts 2a, 3a. A spacer 6 made of a heat-resistant phenolic resin is sandwiched and held between tip parts of inside protruding parts 2f, 3f of both core bodies and is used for a coarse adjustment operation. For a fine adjustment operation, the core bodies 2, 3 are turned relatively and the gap is changed and adjusted; thereby, a desired inductance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a 1,000-row coil used in ballasts and the like.

(Prior Art) This type of choke coil as shown in FIG. 5 is generally used. In other words, a bobbin D has an E-shaped core A and an I-shaped core B made of a magnetic material such as ferrite to form a mouth-shaped core, and a coil C is wound around the central piece of the E-shaped core.
is inserted. E is a spacer made of heat-resistant resin, and an appropriate number of spacers are connected to both cores A in order to obtain a predetermined inductance fS.
, B.

Further, axially symmetric types as shown in FIGS. 6 and 7 have also been proposed. Zunawara] Ato is composed of two Niffer bodies G and G that have approximately the same shape, and a bobbin D is accommodated in the recess of both bodies GG, and a coil C is wound around this. There is.

A spacer E for obtaining a predetermined inductance is inserted and held between the long ends of both core bodies G, G.

In order to obtain a desired inductance, the conventional choke coils as described above are prepared by preparing a plurality of spacers and adjusting the laminated thicknesses of these spacers while changing them.

(Problems to be Solved by the Invention) For conventional choke coils, as mentioned above, multiple spacers are inserted and the laminated thickness is changed while the inductance is measured, so it is difficult to maintain a predetermined inductance. The adjustment process is troublesome, and the inductance that is adjusted through such an adjustment process can only be obtained in stages due to the thickness of the spacer.

The present invention was proposed to improve the above-mentioned drawbacks, and its purpose is to provide a choke coil whose inductance can be easily adjusted and whose inductance can be changed continuously.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a substantially cylindrical shape, a concentric recess is formed inward from one end surface, and the peripheral edge of the end surface is waved. A core in which two core bodies formed in a shape are arranged with the concave portions facing each other, a coil wound around the inward convex portions of both core bodies, and a coil wound around the inward convex portions of the two core bodies. and a spacer inserted between the parts,
A choke coil characterized in that both core bodies are rotated relatively around an axis to change a gap state between the outer convex portions of both core bodies, and both core bodies are fixed in a desired gap state. This is a feature of the invention.

It is desirable that the two core bodies have the same shape, but they may have different shapes, and a through hole may be formed in the center of each core body for centering the two core bodies in the inductance adjustment process.

(Function) According to the present invention, based on the relative phase relationship between the two core bodies, the gap between the outer convex portions is continuous from a substantially uniform state to a minimum gap state where both cores are in contact with each other. changes,
Therefore, the inductance, which is inversely proportional to the square of the gap length of the magnetic path, is continuously changed. In this case, the thickness of the spacer is constant and the core body is simply rotated relative to each other to adjust to a desired gap state, that is, a predetermined inductance, so inductance adjustment can be performed extremely easily.

(Example) Next, an example of the present invention will be described. It should be noted that the embodiments are merely illustrative, and it goes without saying that various changes and improvements may be made without departing from the spirit of the present invention.

1 to 4 show embodiments of the present invention. In the figure, 1 is a core, and 2 is made of a magnetic material such as ferrite.
It consists of 2.3 core bodies. The two core bodies 2.3 in this embodiment are of the same shape.

That is, each core body 2.3 has a cylindrical shape, with concentric recesses 2a, 3a formed from one end surface, and sinusoidal waves 2b, 3b formed on the outward convex portion. 2 like this
The core bodies 2.3 are arranged so as to face each other with a gap on the axis.

2C and 3C are through holes for the centering shaft of the inductance adjustment jig, and may be omitted if a jig that does not require a centering shaft is used. 4 is a hole wound around the inner convex portions 2e and 3e. The coil is wound around the pobbin 5 housed in both the recesses 2a and 3a.

6 is a spacer made of heat-resistant phenolic resin with a thickness of 1.
As two fans, it is held between the tips of the inner convex portions 2f and 3f of both core bodies. This spacer 6 is for rough adjustment.

For fine adjustment, set the gap as shown in Figure 3 to be the maximum, and adjust the core body 2.
, 3 relative to each other, the gap can be made smaller as shown in FIG. By adjusting the gap in this way, a desired inductance can be obtained.

In the above configuration, when the core 1 has a predetermined inductance value of 230 μH, for example, each core body 2,
3 has an outer diameter of 26 mm, a height of 11-1, a large concave diameter of 21 mm, a small concave diameter of 12 m, an average concave depth of 8 m, and a sine wave amplitude of 1.5 mm.
, when the outward convex portion was provided with 8 cycles, an adjustment width of about 20 μH was obtained.

(Effects of the Invention) The choke coil of the present invention has two cores each having a substantially cylindrical shape, with a concentric recess formed inward from one end surface, and a wavy peripheral edge of the end surface. a core arranged with the concave portions facing each other; a coil wound around the inward convex portions of both core bodies; and a spacer inserted between the inward convex portions of the two core bodies. By providing this, the inductance can be adjusted extremely easily by simply rotating the core body relatively to match the desired inductance.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the choke coil of the present invention, Fig. 2 is an exploded perspective view thereof, Fig. 3 is a perspective view when the gap is large, and Fig. 4 is a perspective view when the gap is small. FIG. 5 is an exploded perspective view of a conventional choke coil, FIG. 6 is a vertical sectional view of another conventional example, and FIG. 7 is an exploded perspective view thereof. 1... Core 2, 3... Core body 2a, 3
a-Concave portion 2b, 3b-Wave 2c, 3cm through hole 2f, 3f-Inward convex portion 4...Coil
5...Bobbin 6...Space diagram

Claims (1)

[Claims] A core comprising two core bodies each having a substantially cylindrical shape, having a concentric recess formed inward from one end surface, and a peripheral edge of the end surface formed in a wave shape, with the recesses facing each other. and a coil wound around the inward convex portions of the two core bodies, and a spacer inserted between the inward convex portions of the two core bodies; A choke coil characterized in that both core bodies are fixed in a desired gap state by rotating them relative to each other to change a gap state between the outer convex portions of both core bodies.