JPH0726814Y2 - Tubular ferrite sintered body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a tubular ferrite sintered body used for a noise prevention filter of a data line, and more specifically, it has a large strength against external force such as compression. The present invention relates to a tubular ferrite sintered body.

[Prior Art] Conventionally, tubular ferrite sintered bodies have been widely used in fields such as communication and information processing.

For example, it is used as a noise prevention filter for reducing radiation noise from a data line by passing a flat cable through a tubular ferrite sintered body.

This tubular ferrite sintered body has an integral structure formed in a tubular shape with a plurality of long plate-shaped wall portions, and each of the plate-shaped wall portions has a rectangular cross section in a direction perpendicular to the longitudinal direction. It was

FIG. 4 is a perspective view showing an example of a conventional tubular ferrite sintered body.

In FIG. 4, the wall portion of the tubular ferrite sintered body includes plate-shaped wall portions 41, 41 ′ and plate-shaped wall portions 42, 42 ′ that are parallel to each other and have a substantially uniform thickness, and are adjacent to each other. The wall portion has a so-called integral structure that shares the boundary portion and has no dividing line.

This tubular ferrite sintered body is small and light in weight, such as industrial equipment to be incorporated.
The tubular ferrite sintered body itself is becoming smaller and lighter.

[Problems to be solved by the invention] However, as is well known, since the ferrite sintered body is a very fragile substance, the tubular ferrite sintered body itself becomes a brittle material due to the reduction in size and weight, and the handling is difficult. It has a drawback that it becomes difficult and it is not suitable for use in receiving external force.

Therefore, the technical problem of the present invention is to provide a compact and lightweight tubular ferrite sintered body with practically sufficient strength.

[Means for Solving the Problems] The inventors of the present invention have made earnest studies regarding the strength of the conventional tubular ferrite sintered body, and found that the cross-sectional shape of the tubular ferrite sintered body in the direction perpendicular to the longitudinal direction is tubular ferrite sintered body. The present invention has been made in view of the remarkable influence on the strength of the union.

According to the present invention, a ferrite sintered body is formed in a tubular shape with at least three plate-shaped wall portions extending in the longitudinal direction, and the outer contour side of the cross section perpendicular to the longitudinal direction has at least two lengths, short and long. In the united body, a tubular ferrite sintered body is obtained, in which the outer surface of the plate-shaped wall portion including the long side of the plurality of plate-shaped wall portions is curved outwardly convex.

[Operation] In the present invention, one of the plurality of plate-shaped wall portions forming the tubular ferrite sintered body is formed into a tubular shape by making the cross-sectional shape perpendicular to the longitudinal direction of the plate-shaped wall portion a so-called bridge shape. This is a ferrite sintered body with practically sufficient strength.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the tubular ferrite sintered body of the present invention.

The tubular ferrite sintered body shown in FIG. 1 has an integral structure having plate-shaped wall portions 11 and 11 'and plate-shaped wall portions 12 and 12' facing each other. The plate-shaped wall portion 12 has a flat inner surface, and the outer surface facing the inner surface is a cylindrical surface with a protruding central portion in the width direction. The plate-shaped wall portion 12 moves from both sides to the central portion. As the thickness increases, the thickness gradually increases.

On the other hand, the plate-shaped wall portion 12 'is a flat plate having a substantially uniform thickness. This sintered body has a longitudinal direction of 40 mm, the inner dimension of the cross section in the direction perpendicular to the longitudinal direction is 3 mm in length, 24 mm in width, and the outer dimension is 5 mm in height, 26 mm in width.
The cylindrical surface has a shape with a radius of curvature of 146 mm.

A compression test was performed to measure the strength of the above-mentioned tubular ferrite sintered body.

A surface opposite to the cylindrical surface of the tubular ferrite sintered body was supported at two points at intervals of 20 mm in the longitudinal direction as fulcrums, and a load was applied by line contact to the apex of the arcuate tubular ferrite sintered body in the longitudinal direction. .

The load was a compressive load of 1 mm per second, and the compression pressure at which the plate surface 12 having the cylindrical surface of the tubular ferrite sintered body at which breakage occurred was measured using a strain gauge and found to be 2.9 kgf.

Next, another embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a perspective view showing another embodiment of the present invention.

The tubular ferrite sintered body shown in FIG. 2 has an integral structure having plate-shaped wall portions 21 and 21 'and plate-shaped wall portions 22 and 22' which are opposed to each other. A convex curved surface forms a cylindrical surface, while the plate-shaped wall portion 22 'is a flat plate having a substantially uniform thickness.

In this sintered body, the inner dimension of the cross section in the longitudinal direction of 40 mm, the longitudinal direction and the direction perpendicular to the longitudinal direction is 3 mm in length, 24 mm in width, and the inner side surface of the plate-shaped wall portion 22 is a cylindrical surface having a radius of curvature of 145 mm.

On the other hand, the outer dimension is 5 mm in length, 26 mm in width, and the outer surface of the plate-shaped wall portion 22 is a cylindrical surface having a radius of curvature of 146 mm.

In order to measure the strength of the above-mentioned tubular ferrite sintered body, a plate-like wall portion 22 having a cylindrical surface is formed by the same method as in the first embodiment.
The compression pressure at which fracture occurred was 2.4 kgf.

FIG. 3 is a perspective view showing still another embodiment of the tubular ferrite sintered body of the present invention.

The tubular ferrite sintered body shown in FIG. 3 has an integral structure having plate-shaped wall portions 31 and 31 'and plate-shaped wall portions 32 and 32' that face each other. The curved surfaces project in opposite directions to form a cylindrical surface.

This sintered body has a longitudinal direction of 40 mm, the inner dimension of the cross section in the direction perpendicular to the longitudinal direction is 3 mm in the longitudinal direction, and the inner side surfaces of the plate-like wall portions 32 and 32 'are cylindrical surfaces having a radius of curvature of 145 mm.

On the other hand, the outer dimension is 5 mm in length, and the outer surfaces of the plate-shaped wall portions 32 and 32 'are cylindrical surfaces having a curvature radius of 146 mm.

In order to measure the strength of the above-mentioned tubular ferrite sintered body, one of the plate-shaped wall portions 32 and 32 'having a cylindrical surface is supported by a fulcrum having the same curvature as the outer cylindrical surface, and the other is the same as in the first embodiment. When a compression pressure at which a plate-shaped wall portion having a cylindrical surface facing the supporting surface was fractured was measured by the same method, it was 2.4 kgf.

As a comparative example, the strength of the conventional tubular ferrite sintered body shown in FIG. 4 was measured.

This sintered body has a shape having a longitudinal direction of 40 mm and a cross-sectional inside dimension in a direction perpendicular to the longitudinal direction of 5 mm in length and 26 mm in width.

The strength of the tubular ferrite sintered body according to the above-mentioned comparative example was measured by the same method as in the first example, and was 1.8 kgf, confirming the usefulness of the present invention.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the spirit of the present invention.

For example, in each of the above-mentioned examples, a so-called rectangular columnar tubular ferrite sintered body is shown, but if the other two or three examples are given, the present invention is applied to a triangular columnar or pentagonal columnar tubular ferrite sintered body. Even in this case, it can be easily estimated that the same effect as that of the embodiment of the present invention can be obtained.

It goes without saying that the composition of ferrite itself is not limited in the present invention.

[Effects of the Invention] As described above, according to the tubular ferrite sintered body of the present invention, at least one of the plurality of plate-shaped wall portions has an outer surface that is convexly curved outward, and is highly resistant to external force. Since it exhibits resistance, it has an effect that it has practically sufficient strength even when it is made smaller and lighter, which is extremely useful in industry.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the tubular ferrite sintered body of the present invention, FIG. 2 is a perspective view showing another embodiment of the tubular ferrite sintered body of the present invention, and FIG. FIG. 4 is a perspective view showing yet another embodiment of the inventive tubular ferrite sintered body, and FIG. 4 is a perspective view showing an example of a conventional tubular ferrite sintered body. In the figure, 11,11 ', 12,12', 21,21 ', 22,22', 31,31 ', 32,3
2 ', 41,41', 42,42 '…… Plate-shaped wall.

Claims (1)

[Scope of utility model registration request] 1. A ferrite sintered body having a tubular shape having at least three plate-shaped wall portions extending in the longitudinal direction, and having two different lengths of an outer contour side of a cross section perpendicular to the longitudinal direction of at least two. In the body, the tubular ferrite sintered body is characterized in that the outer surface of the plate-shaped wall portion including the long side of the plurality of plate-shaped wall portions is convexly curved outward.