JPS5932093Y2 - variable inductance element - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a variable inductance element used in parts of communication equipment, etc., and in particular, the present invention relates to a variable inductance element used in parts such as communication devices, and in particular, a through hole formed by a magnetic material in one of two magnetic materials constituting a magnetic core. By providing a small hole and a groove, and fitting and fixing a flanged nut having an elastic model protrusion on the body and a protrusion that engages with the groove in the hole, the number of steps required to apply adhesive to the flanged nut is reduced. A variable inductance that makes it possible to make the inductance characteristics that change according to the screwing amount of the magnetic core screw smooth and regular by eliminating the axial center of the through hole and matching the axial center of the flanged nut. Regarding elements.

FIG. 1 is a sectional view showing the structure of a conventionally used variable inductance element.

In the figure, the magnetic core 1 is composed of two identical magnetic bodies 1A and 1.
The magnetic bodies 1A and 1B have a shape in which one ends of two large and small coaxial cylinders are connected by an annular flat plate.

The other ends of the magnetic bodies 1A and 1B are in contact with each other and the magnetic core 1
It consists of

A coil 2 is installed in an annular space formed by the inner periphery of the large cylinder and the outer periphery of the small cylinder of the magnetic core 1, and a notch 3 (not shown) is provided in a part of the large cylinder. Then, the terminal of the coil winding is taken out from the notch 3.

The magnetic core 1 is formed by the inner periphery of the small cylinders of the magnetic bodies 1A and 1B.
A through hole 4 is formed in the center of the hole 4, and a flanged nut 5 is fitted and fixed to one end of the through hole 4.

The flanged nut 5 consists of a collar 5A and a body 5B, and is provided with a female thread 5C inside.

A screw 6 with a magnetic core inserted from the other end of the through hole 4 of the magnetic core 1 is screwed into the female screw 5C.

The magnetic core screw 6 is a non-magnetic screw 6A, and a cylindrical magnetic body 6.
B: It is cut out from the flare 60 of the elastic body.

The variable inductance element having the above configuration changes the inductance value by rotating the screw 6 with a magnetic core and changing the magnetic resistance in the gap of the through hole 4 of the magnetic core 1. Whether or not shows a regular and smooth change depends on whether the axis of the through hole 4 of the magnetic core 1 and the axis of the magnetic body 6B of the screw 6 with a magnetic core are accurately aligned. .

In other words, as shown in FIG. 2, in a variable inductance element in which the axis of the through hole 4 and the axis of the magnetic body 6B are exactly aligned, the inductance curves with respect to the number of screw rotations. On the other hand, when the axis of the magnetic body 6B is eccentric or inclined with respect to the axis of the through hole 4, it changes smoothly and regularly as shown in curve a. Shows regular changes.

The mismatch between the axis of the magnetic body 6B and the axis of the through hole 4 is caused by machining errors of the magnetic core 1, machining errors of the flanged nut 5, and magnetic core screws 6.
This can also occur due to machining errors, etc., but the biggest influence is due to mismatch between the axis of the through hole 4 and the axis of the flanged nut 5 due to errors in fitting the flanged nut 5 to the through hole 4, etc. It is.

Conventionally, the flanged nut 5 was fitted and fixed into the through hole 4 after applying adhesive to the outer periphery of the body 5B.

Therefore, the outer diameter of the body 5B of the flanged nut 5 is smaller than the inner diameter of the through hole 4 by the thickness of the adhesive to be applied. The axial center of the nut 4 and the axial center of the flanged nut 5 have a drawback that they are eccentric as shown in FIG.

Furthermore, in order to prevent the above-mentioned drawbacks, a flanged nut 5 as shown in FIG. 4 is used.

That is, in the figure, a plurality of protrusions 5D parallel to the axes are provided on the outer periphery of the body 5B of the flanged nut 5, and the outer diameter of the protrusions 5D is equal to the inner diameter of the through hole 4. Finished with extremely precise fitting dimensions.

When this conventional flanged nut 5 is fitted into the through hole 4,
It is intended that the axial center of the through hole 4 and the axial center of the flanged nut 5 be correctly aligned by highly accurate fitting between the outer diameter of the protrusion 5D and the inner diameter of the through hole 4'.

However, even with this method, if there is an error in the machining dimensions or if the pushing pressure when fitting the flanged nut 5 into the through hole 4 is uneven, the protrusions may
A large force is applied to D, causing plastic deformation of the protrusion 5D as shown in FIG. 5, resulting in eccentricity as shown in FIG. On the other hand, problems such as the inclination of the axial center of the flanged nut 5 occur, resulting in the disadvantage that the inductance characteristics change irregularly.

Furthermore, as described above, in the past, adhesive was used to fit and fix the flanged nut 5 into the through hole 4, which resulted in a drawback of increased man-hours and material costs, resulting in an increase in cost.

The present invention aims to eliminate the above-mentioned drawbacks of the conventional variable inductance element, to provide a variable inductance element whose inductance characteristics change regularly and smoothly, and whose cost is low.

In this invention, the inner diameter of the annular flat plate that is the end face of one of the two magnetic bodies constituting the coil is made smaller than the inner diameter of the through hole, and the coil is formed by the inner peripheral surface of the annular flat plate. The above purpose is achieved by providing a groove in the hole to be inserted, further providing an elastic wedge-shaped protrusion on the body of the flanged nut and a protrusion that engages with the groove, and fitting and fixing the flanged nut into the hole. They are distant relatives.

Embodiments of the present invention will be described below based on the drawings.

FIG. 7 is a cross-sectional view showing how the magnetic core and the flanged nut of the variable inductance element according to the present invention are fitted together; FIG. 8 is a cross-sectional view of one of the two magnetic bodies forming the magnetic core; 9 is a perspective view thereof, FIG. 10 is a front view of the flanged nut, FIG. 11 is a perspective view thereof, and FIG. 12 is a sectional view of the whole.

In FIGS. 8 to 12, the annular flat plate serving as the end face of one of the two magnetic bodies forming the magnetic core 1, 1A, has an inner diameter smaller than the diameter of the through hole 4. , the hole 7 formed by the inner circumference has a groove 7A parallel to the axis.
is provided.

The flanged nut 5 has a collar 5A and a body 5B, and is provided with a female thread 5C inside, and the body 5B has a plurality of elastic wedge-shaped projections 5E and 1 (four in this embodiment). A protrusion 5F parallel to each axis is provided.

The outer diameter of the wedge-shaped protrusion 5E gradually increases in the direction of the flange 5A, and forms an end surface perpendicular to the axis at a portion sized from the flange.

The dimensions are approximately the same as the thickness t of the magnetic body 1A.

The outer diameter of the barrel 5B of the flanged nut 5 is finished to have exact fitting accuracy with respect to the inner diameter of the hole 7.

If the flanged nut 5 is pushed into the hole 7 while the protrusion 5F is engaged with the groove 7A, the wedge-shaped protrusion 5E will reduce its outer diameter due to its elasticity, and the collar 5A of the flanged nut 5 will fit into the end surface of the magnetic body 1A. When it comes into contact with the magnetic body 1A, the wedge-shaped protrusion 5E returns to its original shape due to its elasticity and is fitted and fixed in the hole 7 of the magnetic body 1A as shown in FIG.

Since the dimension is almost the same as the dimension t as described above, the flanged nut 5 after fitting does not move in the axial direction with respect to the magnetic body IA, and the groove 7A and the protrusion 5F engage with each other. Therefore, the flanged nut 5 is completely fixed to the magnetic body 1A without rotating about the axis.

In addition, since the fitting precision between the hole 7 and the body 5B of the flanged nut 5 is high, the axis of the hole 7 and the axis of the flanged nut 5 are perfectly aligned, so that the flanged nut 5 is fitted with a magnetic core screw. 6 are screwed together, the axis of the magnetic body 6B and the axis of the through hole 4 (see Fig. 1)
, so the changes in inductance characteristics are regular and smooth.

Further, as described above, according to the present invention, since no adhesive is used to fit and fix the magnetic body 1A and the flanged nut 5, it is possible to reduce material costs and labor costs.

In the embodiments described above, the magnetic bodies 1A and 1B have a shape in which one ends of two large and small cylinders are connected by an annular flat plate, but the shape of the magnetic bodies is not necessarily limited to the above embodiments, and may be changed as appropriate. A large hollow prism with a cross-sectional shape,
It is clear that the present invention can be effectively implemented in a shape in which one end of a small coaxial hollow cylinder is connected with a flat plate.

As described above, the present invention has the effect of improving the performance of a variable inductance element and reducing its cost.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the structure of a conventionally used variable inductance element, Figure 2 is a graph showing the change in inductance with respect to the amount of screwing in of a screw with a magnetic core, and Figure 3 is the eccentricity of the through hole and flanged nut. Figure 4 is a perspective view of a conventionally used flanged nut, Figure 5 is a diagram showing the state of plastic deformation of the protrusion of the flanged nut, and Figure 6 is a diagram showing the axis of the through hole and the flanged nut. Figure 7 is a cross-sectional view showing how the magnetic core of the variable inductance element according to the present invention is fitted to the flanged nut, and Figures 8 and 9 are magnetic. 10 and 11 are a front view and a perspective view of the flanged nut, and FIG. 12 is a sectional view of the entire body. 1...Magnetic core, IA, IB...Magnetic material,
2... Coil, 4... Through hole, 5...
... Nut with flange, 5A... Tsuba, 5B...
...Body, 5C...Female thread, 5D...Protrusion, 5E...Cuneiform protrusion, 5F...Protrusion, 6...・Screw with magnetic core, 6A... screw,
6B...magnetic material, 6C...flare,
7...hole, 7A...groove.

Claims (1)

[Scope of utility model registration request] A magnetic core formed by two magnetic bodies, a coil and a flanged nut each attached to an annular space and a through hole formed by the two magnetic bodies, and a screw with a magnetic core screwed into the flanged nut. In the variable inductance element, the end face of one end of the magnetic tube of 1 joined with a flat plate is formed into a flange-like shape having a hole smaller than the through hole and a groove parallel to the axis provided in the hole. 1. A variable inductance element, characterized in that the variable inductance element is molded, and a flanged nut having a plurality of elastic wedge-shaped protrusions on the body and a protrusion that engages with the groove is fitted and fixed in the hole.