JPH0124976Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an LC coaxial filter in which a magnetic material serving as an inductance element and a capacitor are coaxially provided.

Conventionally, in order to prevent malfunctions caused by noise pollution generated from various industrial or household electronic and electrical equipment or noise that enters these equipment,
Use by incorporating into the input/output connector of equipment, etc.
LC coaxial filters are known.

Figure 1 shows a conventional example of this type of LC coaxial filter, in which a plurality of cylindrical magnetic bodies 2 made of ferrite beads etc. are placed inside the inner diameter of a cylindrical dielectric ceramic capacitor 1. The rod-shaped through conductor 3 is inserted into the through hole 2a of the magnetic body 2, and the through conductor 3 is connected to the electrode connecting bodies 4, 5.
It has a structure in which it is electrically connected to the electrode of the capacitor 1. The ceramic capacitor 1 has an outer circumferential electrode 6 and two inner circumferential electrodes 7, 8 separated from each other by a gap _g1 in the center, and the inner circumferential electrodes 7, 8 are connected to both end surfaces in the axial direction. The electrode connectors 4, 5 are attached to the lead electrodes 9, 10 formed by leading out the electrodes 4, 5.
The structure is such that they are connected and fixed by means such as soldering.

The conventional LC coaxial filter described above has an inductance due to the magnetic material 2, as shown in Figure 2.
At both ends of L ₁ , electrodes 6-7 of the ceramic capacitor 1,
This is an equivalent circuit in which capacitors C ₁ and C ₂ between 6 and 8 are connected, respectively, and functions as a low-pass filter.

However, this conventional LC coaxial filter
A magnetic capacitor 1, a magnetic material 2, a through conductor 3,
Since the structure is such that the electrode connectors 4 and 5 are assembled as separate parts, the number of parts and the number of assembly steps are large, making assembly troublesome and costly.
Further, the electrical and mechanical connection strength between the electrode connectors 4 and 5 and the lead electrodes 9 and 10 or the through conductor 3 was weak, resulting in a lack of reliability. Furthermore, since the through conductor 3 is supported on the ceramic capacitor 1 by the electrode connectors 4 and 5, which are separate parts, the through conductor 3 is likely to become eccentric due to misalignment of the electrode connectors 4 and 5, machining errors, etc. However, there was also the drawback that assembly accuracy was reduced. In particular, when used as a component of a multi-pole input/output connector, if the through conductor 3 is eccentric as described above, excessive external force may be applied to the through conductor 3 when another female connector is mated and connected. In addition, accidents such as bending of the through conductor 3, peeling of the electrode connectors 4 and 5 from the lead electrodes 9 and 10, or damage to the ceramic capacitor 1 are likely to occur, and reliability is likely to be impaired.

Further, the electrode connectors 4 and 5 are connected to lead electrodes 9 and 10.
Since it is soldered and fixed so as to cover almost the entire surface of the
The soldering area is narrow, the soldering strength is insufficient, and the above-mentioned drawbacks are more likely to occur.

The present invention eliminates the above-mentioned conventional drawbacks, has a small number of parts, is easy to assemble, is inexpensive, and has high reliability in electrical and mechanical connections of various parts, and does not cause eccentricity of through conductors. The purpose is to provide a difficult-to-use LC coaxial filter.

In order to achieve the above object, the LC coaxial filter according to the present invention has two inner circumferences separated from each other by an outer circumference electrode and a central cap on the outside of a cylindrical magnetic body through which a through conductor is passed. A capacitor having an electrode is coaxially provided, opposite ends of the two inner peripheral electrodes are led out to both end faces in the axial direction of the magnetic body to form lead electrodes, and a header part is provided on one end side. On the other end side of the through conductor,
An LC coaxial type filter in which a washer-like fastener is inserted between the header part and the magnetic body from both ends, and the fastener is brought into contact with one of the lead electrodes and soldered. , the fastener is on a surface that comes into contact with one of the lead electrodes,
A protrusion that fits and contacts the inner diameter surface of the magnetic body is coaxially formed around the shaft hole through which the through conductor passes, and a cutout is provided around the periphery, and solder is applied to the lead electrode through the cutout. It is characterized by being attached and fixed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically described below with reference to the accompanying drawings, which are examples. Figure 3 is related to the present invention.
FIG. 3 is a front sectional view of an LC coaxial filter. In the figures, the same reference numerals as in FIG. 1 indicate the same or constituent parts. The magnetic body 2 is formed into a cylindrical shape, and the ceramic capacitor 1 is integrally sintered around the outer periphery of the magnetic body 2. With this structure, the number of parts and assembly man-hours are reduced, making assembly easier.
The magnetic capacitor 1, which is a fragile material, has a structure reinforced by the magnetic body 2, thereby preventing damage and cracking of the ceramic capacitor 1, and by making the ceramic capacitor 1 thinner or having a longer axial length. , increase the acquisition capacity or inductance,
Effects such as improved filter action can be obtained. Electrodes 7 and 8 of the magnetic capacitor 1 are provided at the interface between the magnetic body 2 and the ceramic layer, and lead electrodes 9 and 10 are led out to both end faces of the magnetic body 2 in the axial direction.

Through holes 2a of the magnetic body 2 are penetrated with through conductors 3 which are electrically connected to the electrodes 7 and 8 of the magnetic capacitor 1, respectively. The through conductor 3 is made of a round bar-shaped metal material, and has a disk-shaped header portion 11 integrally formed at one end thereof. Header part 11
is formed into a disk shape with a diameter slightly smaller than the outer diameter of the magnetic body 2 and larger than its inner diameter, and the magnetic capacitor 1
Continuing from the inner circumferential electrode 7 , the lead electrode 9 is brought into contact with a lead electrode 9 led out from one end surface of the magnetic body 2 in the axial direction, and is connected and fixed with solder 12 . In this way, one of the electrode connectors is used as the header part 11, and the through conductor 3
Integration with the product reduces the number of parts and assembly man-hours, making assembly easier and reducing costs. Furthermore, it is possible to realize an LC coaxial filter in which the electrical and mechanical connection of the through conductor 3 to the lead electrode 9 is highly reliable.

A washer-shaped stopper 13 made of a metal plate is press-fitted into the through conductor 3 from the end opposite to the header part 11 with the magnetic body 2 in between.
is brought into contact with a lead electrode 10 led out from the inner peripheral electrode 8 of the ceramic capacitor 1 to the other end surface, and soldered 14
It is fixed by.

When using such a fastener 13, the magnetic body 2 is positioned in the axial direction by the header portion 11,
In this state, the entire temporary assembly is completed simply by press-fitting the stopper 13 into the through conductor 3, making the assembly work very easy.

The stopper 13 is formed to have an outer diameter approximately equal to the outer diameter of the magnetic body 2 including the lead electrode 10,
As shown in FIG. 4, about three to four cutout parts 15 are provided on the outer periphery, and solder 14 is attached to the lead electrode 10 through the cutout parts 15. As the soldering area of the stopper 13 to the lead electrode 10 increases, the soldering strength increases, but on the other hand, the difference in linear expansion coefficient between the ceramic capacitor 1 and the solder 14 has an adverse effect, and the magnetic capacitor 1, or the electrodes are likely to peel off. In addition, the electrodes 8 and 10 formed by silver baking may suffer from solder eating, resulting in a decrease in electrode adhesion strength and a tendency to cause interfacial peeling, gaps, etc.

Therefore, in the present invention, as described above, the fastener 13 is provided with a cutout portion 15, and the structure is such that soldering is performed through the cutout portion 15. With such a structure, it is possible to set the soldering area appropriately, ensure sufficient soldering strength, and prevent the adverse effects caused by the coefficient of linear expansion of the solder and the phenomenon of solder eating, thereby improving reliability. can. The number, shape, etc. of the defective portions 15 may be arbitrary, and they may also be provided as through holes.

Further, the stopper 13 is provided with a protrusion 16 on a surface facing the magnetic body 2, which engages with the inner diameter surface of the magnetic body 2 to perform radial positioning. The protrusion 1
6 is 3 to 4 concentrically arranged with respect to the center of the shaft hole 17.
There are several. The diameter d ₂ of the arrangement circle P of the protrusion 16 is
The dimension is set to be approximately equal to the inner diameter d ₁ of the magnetic body 2 . Therefore, when the stopper 13 is brought into contact with the lead electrode 10 on the end surface of the magnetic body 2, the magnetic body 2
The protrusion 16 fits into and abuts on the inner diameter surface of the magnetic body 2, and the stopper 13 is positioned in the radial direction with respect to the magnetic body 2. Since the protrusion 16 is arranged coaxially with the center of the shaft hole 17 through which the through conductor 3 is inserted, the radial positioning of the stopper 13 allows
The center of the shaft hole 17 comes to substantially coincide with the axis of the magnetic body 2. Therefore, the eccentricity of the through conductor 3 is eliminated, and an LC coaxial filter that is particularly suitable as a component of a multipolar input/output connector can be realized. The protrusion 16 is not limited to the one shown in the embodiment, and may be formed, for example, in a convex annular shape.

As the ceramic capacitor 1, in addition to a dielectric ceramic capacitor, it is also possible to use a semiconductor ceramic capacitor such as a grain boundary insulation type or a ring element reoxidation type. When a semiconductor ceramic capacitor is used, a capacitance that is 10 times or more larger than that of a dielectric ceramic capacitor can be obtained, so it is possible to improve the filter function or achieve miniaturization by increasing the obtained capacitance.

As described above, according to the present invention, the following effects can be obtained.

(a) Since a capacitor having an outer circumferential electrode and two inner circumferential electrodes separated from each other by a gap in the center is installed coaxially on the outside of the cylindrical magnetic body, the number of parts and assembly man-hours are reduced. It is possible to provide an LC coaxial filter that is easy to assemble and is inexpensive.

(b) Since a capacitor having an outer circumferential electrode and two inner circumferential electrodes separated from each other by a gap in the center is installed coaxially on the outside of a cylindrical magnetic body, a ceramic capacitor whose material is brittle can be replaced with a magnetic capacitor. In addition to reinforcing the ceramic capacitor with a solid body to prevent damage or cracks, the capacitor is made thinner or has a longer shaft length to increase the acquired capacitance or inductance and improve the filter action. We can provide coaxial filters.

(c) Opposite ends of the two inner peripheral electrodes are led out to both end faces in the axial direction of the magnetic material to form lead electrodes, respectively, and a header is attached to the other end of the through conductor which has a header part on one end. A washer-like clasp was inserted between the parts so as to sandwich the magnetic material from both ends, and the clasp was brought into contact with one of the lead electrodes and soldered. Reliable LC with mechanical connection
We can provide coaxial filters.

(d) The fastener is formed by coaxially forming a protrusion that fits and contacts the inner diameter surface of the magnetic material around the shaft hole through which the through conductor passes, on the surface that contacts one of the lead electrodes. It is possible to provide a highly reliable, high-quality LC coaxial filter that eliminates the eccentricity of the through conductor and prevents accidents such as bending of the through conductor, peeling of the electrode connection body from the lead electrode, or damage to the capacitor due to the bending of the through conductor.

(e) The fastener has a defect in its periphery and is soldered and fixed to the lead electrode through this defect.The soldering area is set appropriately to ensure sufficient soldering strength, and the solder line It is possible to provide an LC coaxial filter with improved reliability by preventing the adverse effects of expansion coefficient and solder eating phenomenon.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of a conventional LC coaxial filter, Fig. 2 is an equivalent circuit diagram thereof, Fig. 3 is a front sectional view of an LC coaxial filter according to the present invention, and Fig. 4 is an enlarged side view thereof. It is a diagram. 1...Magnetic capacitor, 2...Magnetic material, 3...
Through conductor, 6, 7, 8... electrode, 9, 10... lead electrode, 11... header part, 13... fastener,
16... Protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) A capacitor having an outer circumferential electrode and two inner circumferential electrodes separated from each other by a gap in the center on the outside of a cylindrical magnetic body through which a through conductor is passed. The through conductor is provided coaxially and integrally, and opposite ends of the two inner peripheral electrodes are led out to both end faces in the axial direction of the magnetic body to form lead electrodes, respectively, and the through conductor has a header portion on one end side. An LC coaxial type in which a washer-shaped fastener is inserted between the end side and the header part so as to sandwich the magnetic material from both ends, and the fastener is brought into contact with one of the lead electrodes and soldered. In the filter, the stopper has a protrusion coaxially arranged around the shaft hole through which the through conductor passes, on the surface that contacts one of the lead electrodes, and that fits and contacts the inner diameter surface of the magnetic body. What is claimed is: 1. An LC coaxial filter characterized in that the LC coaxial filter is formed with a cutout portion at the periphery thereof, and is fixed to the lead electrode by soldering through the cutout portion. (2) The LC coaxial filter according to claim 1, wherein the capacitor is a semiconductor ceramic capacitor.