JP2001285004A - Line filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a small-sized line filter, which is easy to manufacture by facilitating resin injecting operation for coil fixation, eliminating an unnecessary space below a terminal base, and forming a small-sized core which is smaller than the magnetic path sectional area needed for conventional materials. SOLUTION: A resin-made lower case, which has cuts at center upper parts of right and left sidewalls and is partitioned by two partition walls, is molded on a fitting metal plate and a coil is fixed to the center part of the case with resin. Repeated terminal plates, having their external terminals connected, are fixed to both ends across the partition walls of the coil with resin by connecting a composite capacitor arranged below and the coil terminal is connected to constitute a line filter covered with a detachable upper case having an air vent and an input/output cable lead-in groove. Furthermore, a core wound with a thin strip of amorphous superfine crystal alloy is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line filter which is inserted between a commercial power supply and a load device and reduces noise transmitted from the power supply to the load device and noise transmitted from the load device to the power supply.

[0002]

2. Description of the Related Art A conventional line filter includes a ring core formed by winding a magnetic metal ribbon, manganese, zinc (Mn, Z).
n) A line choke coil was formed by winding a ferrite-sintered ring core with a wire having a thickness corresponding to the current flow. Twisted wires are used for coil conductors wound around the wire with small current capacity, and those with large current capacity are used to reduce eddy current loss due to AC magnetic field and improve workability of wound wire. For this reason, a double wire made of insulated single wires in parallel and a thick round wire are used.

In the case of a laminated silicon steel sheet, an EI core or a CC core is used, and in the case of a ferrite core, a block-shaped closed magnetic circuit core such as a ring core is used. The EI core and the CC core are wound on a bobbin in advance, and after the divided cores are inserted and then joined together, the joint surface is required to have smoothness.

The line filter has the above-mentioned block-shaped core, two coils for the single phase and three coils for the three phase, the common mode coil is wound in the same direction, and the normal mode coil for the single phase is reversed. The three-phase normal mode coil forms a line filter by using three individual coils having no coupling between the coils.

[0005] Silicon steel sheets have high magnetic permeability, but their frequency characteristics do not extend to the high frequency range, so that they cannot be used in the frequency band of several tens KH or more. Ferrite, which does not have a large saturation magnetic flux density and is easily magnetically saturated, has to be used as a large line filter because a core having a large sectional area is used for high power applications. When the core has a low saturation magnetic flux density and is magnetically saturated, a gap is provided on the outer periphery of the closed magnetic path core to form a semi-closed magnetic path core having an open magnetic path to avoid magnetic saturation.

Although the demand for downsizing of line filters is also increasing due to the influence of downsizing of electronic equipment, the conventional three-phase line filter which commercialized the circuit diagram shown in FIG. 2 has a case as shown in FIG. On both side walls of the relay terminal plate 9
And fix the individual capacitors 10 underneath.
After arranging them and forming a delta-connected X capacitor or a star-connected Y capacitor and connecting them to the relay terminal plate, after arranging a coil in the center of the case and connecting to the relay terminal plate, The coil and the capacitor were fixed by casting resin 8 into the case.

However, the work of fixing the two relay terminal blocks to both side walls of the case with screws, arranging the composite capacitor under the two terminals and connecting to the relay terminal block is complicated in a narrow space, and the man-hour is complicated. Was hanging. In addition, since individual capacitors are used, the shape in which three capacitors are arranged is not uniform with the shape of the coil, and it is inevitable that an extra space is formed, and it is difficult to reduce the size.

For individual capacitors, complicated resin casting work is performed in order to put the capacitor element in the capacitor case to prevent moisture and fix it. The external dimensions of the capacitor case are larger than the external dimensions of the capacitor element by 5 mm or more. It was difficult to reduce the size of the filter. Furthermore, since the resin is cast for fixing to the filter case, the resin casting operation has been performed twice.

[0009]

SUMMARY OF THE INVENTION In a conventional line filter, a resin casting operation for fixing a coil in a conventional line filter is facilitated, an extra space under a terminal block is eliminated, and a size is reduced. From the cross section of the magnetic path
Another object of the present invention is to form a small line filter by forming a small core having a smaller magnetic path cross-sectional area.

[0010]

According to a first aspect of the present invention, there is provided a line filter including a composite capacitor at both ends of a plurality of coils each having a copper wire wound around a ring core. With a notch at the top,
The resin is fixed in the center of the lower case made of resin, the inside of which is separated by a partition, and the coil is fixed in the center.
A line filter, wherein the coil terminal is connected to the relay terminal plate, and an upper case provided with a ventilation hole and an input / output cable introduction groove is covered.

The provision of the notch 11 in the upper central part of the left and right side walls of the lower case shown in FIG. 3 facilitates the assembly of the coil and the resin casting operation, and also reduces the cost of the resin material of the case. As shown in FIG. 1, a relay terminal plate 4 connected to an X capacitor, which is formed by connecting three plastic capacitor elements 5 to one part of both ends of a lower case separated by two partition walls 3 as shown in FIG. A relay terminal plate connected to an X capacitor and a Y capacitor configured in the same manner as above is put in the other portion, and the resin 8 is cast to the height of the relay plate, cured, and fixed.

The relay board is formed by soldering a screw to a printed wiring board, and has a smaller shape and lower cost than a conventional double terminal block. The input / output terminals of the coil are connected to the relay terminal plates to which external terminals are connected, beyond the partition walls before and after the coil, and a removable upper case with resin ventilation holes and input / output cable introduction grooves is provided. Put on. Since the case is made of a resin, even if the input / output cable is connected to the relay terminal and the upper case is put in close contact with the relay terminal, the height can be suppressed without causing a short circuit.

According to a second aspect of the present invention, in the above line filter, one of the composite capacitors is an X capacitor element composed of three capacitor elements stacked in two stages.
The other composite capacitor is an X capacitor element composed of three capacitor elements stacked in two stages, and a Y capacitor element in which three capacitor elements are vertically arranged and the lower terminal is connected to the mounting metal plate. This is a line filter characterized by the following.

An X capacitor element and a Y capacitor element are formed by connecting three bare capacitor elements designed according to the outer shape of the coil. Since a bare element that cannot be put in a case like a conventional individual capacitor is designed in accordance with the space, it can be made compact without extra space. Furthermore, the case of the capacitor becomes unnecessary,
Since the number of times of resin casting is one, material costs and processing costs can be reduced.

According to a third aspect of the present invention, the line filter is characterized in that, in the partition of the lower case of the line filter, an upper side provided with a lead-out groove for the coil terminal is in contact with the upper case.

On the upper side of the partition wall of the lower case, there are provided the same number of lead-out grooves as the coil terminals, and each coil terminal is screwed and fixed to the relay terminal through the groove on the upper side of the partition wall. At this time, the coil terminals are stable without rotating together. In addition, the upper side of the partition wall is in contact with the upper case and thus serves as a support. The upper case made of resin can be thinned to the extent that it is slightly bent, and the amount of resin material can be reduced.

According to a fourth aspect of the present invention, in the line filter, the core is a ring core formed by winding a magnetic ribbon of an amorphous ultrafine crystalline alloy.

As shown in the BH characteristic diagram of FIG. 8, when a core formed by winding a magnetic ribbon of an amorphous ultrafine crystalline alloy is used, a conventional manganese zinc (Mn, Zn) ferrite core is used. As compared with the above, a high-saturation magnetic flux density and a high magnetic permeability make it possible to form a small core having a small magnetic path cross-sectional area. A core formed by winding a magnetic ribbon of an amorphous ultrafine crystal alloy has a higher magnetic permeability and higher Q than a silicon steel sheet having the same thickness.
It is suitable for the core material of a high-frequency choke coil because the frequency characteristics of the characteristics extend to high frequencies.

When the magnetic path cross-sectional area of the core is small and magnetic saturation occurs, a gap is provided on the outer periphery of the closed magnetic path core to increase the saturation magnetic flux density as a semi-closed magnetic path core having an open magnetic path to avoid magnetic saturation. I do. When a DC current is superimposed, the core is likely to be magnetically saturated, so if a core is provided with a gap and a part of the core is an open magnetic path to form a semi-closed magnetic path core, the saturation magnetic flux density and the effective magnetic permeability can be controlled. . Since the amorphous ultrafine crystalline magnetic alloy core has a large magnetic permeability and does not require a large number of windings, it can be used as a small semi-closed magnetic path core having a small magnetic path cross-sectional area.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A two-phase or three-phase power supply coil is arranged at the center of a lower case formed on a mounting metal plate. The composite capacitors and the relay terminal boards corresponding to the numbers are accommodated, and are resin-casted into the above-mentioned three divided portions and fixed.
Further, miniaturization is achieved by using a core formed by winding a ribbon of an amorphous ultrafine crystalline magnetic alloy.

[0021]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. An embodiment of the present invention based on the circuit diagram of the common mode three-phase line filter shown in FIG. 2 is shown in a plan view and a sectional view of FIG. First, the patterned thickness 1.6
The relay terminal was inserted into each of the three holes of the double-sided copper-clad board having a thickness of 2 mm, and was fixed by soldering from the rear surface side to form a relay terminal plate 4 having three terminals.

Next, an X capacitor in which the three plastic capacitor elements 5 are delta-connected and a Y capacitor in which the three plastic capacitors 5 are star-connected are soldered and connected to the respective relay terminal plates 4 according to the circuit diagram to form a relay terminal plate with a composite capacitor. Was configured. Next, the relay terminal board with the composite capacitor is put into the both ends of the lower case, which is formed on the mounting metal plate 1 shown in FIG.
The epoxy resin 8 was cast and cured by heating.

On the other hand, an amorphous ultrafine crystalline magnetic alloy ribbon (manufactured by Alps Electric Co., Ltd .; Nanopalm) having a thickness of 20 μm and a width of 15 mm is wound and stored in an insulating case, and has an outer diameter of 50 m.
A ring core 6 having a diameter of mΦ, an inner diameter of 20 mmΦ, and a thickness of 17 mm is formed. Three coils 7 each formed by winding a 3 mmφ insulation-coated copper wire around the ring core for 10 turns are formed, and connection terminals are crimped to both ends of each copper wire. The connected three-phase choke coil is placed in the center of the lower case as shown in FIG. 1, the input / output terminals are screwed to the front and rear relay terminals, respectively, and the state where the upper case is covered is shown in FIG. Show.

[0024]

Second Embodiment Based on the circuit diagram of the noise filter for a two-phase power supply of FIG. 5, FIG. 6 shows a state before the epoxy resin is cast in the lower case in the same manner as in the first embodiment.

[0025]

The present invention facilitates resin casting work for fixing a coil in a conventional line filter, eliminates extra space under the terminal block, and reduces the size. By forming a small core having a smaller magnetic path cross-sectional area than the area, a small and inexpensive line filter can be configured.

[0026]

[Brief description of the drawings]

FIG. 1 shows a plan view and a sectional view of a line filter assembly diagram of a first embodiment.

FIG. 2 is a circuit diagram of a line filter according to the first embodiment.

FIG. 3 shows a lower case.

FIG. 4 shows a completed drawing.

FIG. 5 is a circuit diagram of a line filter according to a second embodiment.

6A and 6B are a plan view and a cross-sectional view of an assembly diagram of the line filter according to the second embodiment.

FIG. 7 shows a plan view and a cross-sectional view of a conventional line filter.

FIG. 8 shows a magnetic saturation characteristic diagram of a ferrite core and an amorphous ultrafine crystal alloy core.

[Explanation of symbols]

 1, mounting metal plate 2, lower case 3, partition wall 4, relay terminal plate 5, capacitor element 6, ring core 7, ····· Coil 8 ····· Epoxy resin 9 ····· Dual terminal block 10 ··························

Continued on the front page F term (reference) 4E360 AB12 AB20 AB54 BA02 BA08 BC05 EA27 ED17 ED22 ED27 EE02 EE08 FA08 FA09 GA52 GA53 GB99 5J024 AA01 CA06 DA01 DA25 DA32 EA09

Claims (4)

[Claims] 1. A line filter comprising a composite capacitor at both ends of a plurality of coils in which a copper wire is wound around a ring core. The line filter is formed on a mounting metal plate, provided with a notch at the upper center of left and right side walls, and has a partition inside. The resin is fixed at the center of the lower case made of resin separated by a resin, and at the front and rear parts separated by a partition wall, the relay terminal plate connected to the lower part of the composite capacitor is fixed to the resin. A line filter comprising a coil terminal connected thereto and an upper case having a ventilation hole and an input / output cable introduction groove covered thereon. 2. The line filter according to claim 1, wherein one of the composite capacitors is an X capacitor element composed of three capacitor elements stacked in two stages, and the other composite capacitor has two stages. 3. A line filter comprising: an X capacitor element composed of three capacitor elements superposed on each other; and a Y capacitor element in which three capacitor elements are vertically arranged and a lower terminal is connected to the mounting metal plate. 3. The line filter according to claim 1, wherein an upper side provided with a lead-out groove for the coil terminal is in contact with the upper case. . 4. The line filter according to claim 1, wherein the core is a ring core formed by winding a magnetic ribbon of an amorphous ultrafine crystalline alloy. filter.