JPS6042508Y2 - noise filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a noise filter suitable for use as a power line filter or the like.

Figure 1 shows the circuit configuration of this type of noise filter,
A capacitor 3 for removing symmetrical wave component (line-to-line) noise is connected between windings 2A and 2B of the common mode tick coil 10, and capacitors 4A and 4B for removing asymmetrical wave component (line-to-ground) noise are connected. The connection points of 4A and 4B are grounded to the metal storage case.

By the way, the capacitor 4A for removing asymmetric wave component noise
, 4B, if a normal lead wire type disc-shaped ceramic capacitor is used, the lead wire will behave as an inductive reactance, and as the frequency increases, the impedance between the line and the ground will increase, and the asymmetric wave component This will impair the noise removal effect.

For this reason, the applicant of the present invention proposed a noise filter in Japanese Utility Model Publication No. 5105-1983, which has a structure in which one side of a bare plate-shaped ceramic capacitor is directly attached to a metal storage case.

2 and 3 show a conventional noise filter disclosed in Japanese Utility Model Publication No. 55-51059.

In these figures, the lower surfaces of the plate-shaped ceramic capacitors IIA and IIB are directly attached to the bottom surface of the metal storage case 10 by soldering, etc., and the approximately U-shaped conductor 12 is attached to the upper surface by soldering. installed.

Further, the metal storage case 10 is provided with metal terminals 13A to 13D which are held through and held through an insulator.

A common mode choke coil 14 and an interline capacitor 15 are housed in the metal storage case 10, and one ends of a pair of windings 14A and 14B of the common mode choke coil 14 are connected to metal terminals 13A and 13B, respectively, via a conductor 12. The other ends are connected to metal terminals 13C and 13D, respectively, and a capacitor 15 is connected between metal terminals 13C and 13B.

With the configuration shown in FIGS. 2 and 3 above, the bottom surface of the bare disc-shaped ceramic capacitors IIA and IIB is directly connected to the metal storage case 10, and the conductor 12 on the top surface enters the line in series and acts as an actance. Asymmetrical wave component noise can be removed up to the high frequency range.

However, in the case of the structure shown in FIGS. 2 and 3, in reality, the capacitors of the bare disc-shaped ceramic capacitors IIA and 11B and the other coils 14. In order to fix the capacitor 15, it is necessary to mold the inside of the metal storage case 10 with mold resin 16, and the amount of resin required tends to be large.

Furthermore, the manufacturing process of attaching the bare disc-shaped ceramic capacitors 11A and 11B to the metal storage case 10 having a large depth and then disposing the conductor 12 thereon tends to be unsuitable for mass production in terms of workability and the like.

The present invention eliminates the above-mentioned drawbacks, casts resin only around the bare plate ceramic capacitor, and uses an insulating frame to support the coil, etc., thereby facilitating manufacturing and assembly, improving mass productivity, and The present invention aims to provide a noise filter that can reduce the cost.

Embodiments of the noise filter according to the present invention will be described below with reference to the drawings.

4 and 5, bare disc-shaped ceramic capacitors IIA, IIB, common mode choke coil 14
The exterior case that houses the capacitor 15 is constructed by integrating a metal bottom plate 20, an insulating frame 21 made of insulating resin, and an insulating lid 22 made of insulating resin.

The metal bottom plate 20 has a bent protrusion 2 that fits into the insulating frame 21.
3, a slit-like groove 25 for attaching the box-shaped capacitor storage container 24, and a nut portion 27 screwed into the screw 26 for integrating the metal bottom plate 20, the insulating frame 21, and the insulating cover 22. It has

The box-shaped capacitor storage container 24 has a pair of 3° insertion pieces on its lower edge that are inserted into the slit-like grooves 25 as shown in FIG.
A ground piece 31 extends from the upper edge.

Inside this box-shaped capacitor storage container 24, bare disc-shaped ceramic capacitors IIA and IIB are arranged so that their bottom surfaces are in contact with each other.
are respectively arranged, and conductors 12 as lead wires are connected to the upper surfaces of both capacitors, respectively.

Normally, the capacitors IIA, IIB and the conductor 12 are connected and fixed by soldering, and the inside of the box-shaped capacitor storage container 24 is filled with molding resin 32 in order to protect the capacitors and ensure their fixation.

After resin casting, the box-shaped capacitor storage container 24 is inserted into the insertion piece 3.
0 is inserted into the slit-like groove 25, caulked, and then fixed by soldering so as to be in contact with the metal bottom plate 20.

The insulating frame 21 has a coil storage section 40 into which the common mode choke coil 14 is placed, and a coil positioning projection 41 for positioning and fixing the coil 14 is formed in the center of the coil storage section 40. .

A through hole 42 is formed in the coil positioning convex portion 41 for inserting the screw 26 therethrough.

Furthermore, alignment recesses 44 that fit with alignment protrusions 43 of the insulating lid 22 are formed at the four corners of the upper end surface of the insulating frame 21, and Faston terminals 45A to 45E as metal terminals are connected to the insulating frame 21. It is sandwiched between the insulating cover body 22 and provided so as to pass through between the two.

The coil 14 is arranged in the coil storage part 40 and held in a state where it is fitted or engaged with the coil positioning convex part 41, and the capacitor 15 is arranged in the remaining space within the insulating frame 21.

This capacitor 15 is connected between Faston terminals 45A and 45B, and one ends of the windings 14A and 14B of the coil 14 are connected to Faston terminals 45C and 45D, respectively.

After completing these wiring operations, the insulating frame 21 is attached to the metal bottom plate 20.
One end of the conductor 12 is connected to the faston terminals 45A, 45B, and the other end is connected to the other ends of the windings 14A, 14B of the coil 14, respectively.

Further, as shown in FIG.
Connected to 5E.

The insulating cover 22 has a through hole 50 through which the screw 26 is inserted, and alignment protrusions 43 at the four corners of the lower end surface.

Then, a metal bottom plate 20, an insulating frame 21 and an insulating lid 22
These three parts are tightened and integrated by inserting the screw 26 into the through holes 50 and 42 and screwing it into the nut part 27.

According to the above embodiment, the following effects can be achieved.

(1) Since the bare disc-shaped ceramic capacitors IIA and IIB are provided in the box-shaped capacitor storage container 24, and only the inside of this box-shaped capacitor storage container 24 is cast with resin, the amount of resin can be saved, and the container 24 Since the depth of the capacitors 11A and 11B to the container 24 can be made shallow,
The connecting and fixing work of the body 12 (7) is easy, and it is suitable for mass production.

(2) Since the insulating frame 21 having the coil storage portion 40 is used, an expensive metal storage case made by drawing or the like can be omitted, and the cost can be reduced.

FIG. 8 shows another embodiment of the present invention, in which the box-shaped capacitor storage container 24A has a positioning protrusion 6 on the bottom surface instead of the insertion piece.
0, and the metal bottom plate 20A has a positioning hole 61 instead of a slit-like groove.

Then, by fitting the positioning protrusion 60 into the positioning hole 61 and soldering it, the box-shaped capacitor storage container 24
A is fixed to the metal bottom plate 2OA.

Note that the other configurations and the obtained effects are the same as those of the above-mentioned embodiments.

FIG. 9 shows another embodiment of the present invention, in which the box-shaped capacitor storage container is omitted.

In this figure, capacitor housing recesses 70A and 70B are integrally formed in metal bottom plate 2OB by drawing or the like, and bare disc-shaped ceramic capacitors 11A and 11B are arranged in these parts.

That is, the lower surfaces of the capacitors 11A and 11B are in the recess 7O.
A, fixed by soldering so as to touch the bottom of 70B,
The middle part of the conductor 12 as a lead wire is soldered to the upper surface of the capacitor, and then the inside of each recess 7OA, 70B is filled with molding resin 71.

Further, a grounding piece 31A is provided on the metal bottom plate 2OB.

Note that the other configurations are the same as those of the previous embodiment.

Even when the structure shown in FIG. 9 is adopted, it is possible to reduce the amount of casting resin and improve workability when providing the capacitors 11A, 11B and the conductor 12.

Note that the faston terminals 45A to 45E may be provided on the insulating frame 21 or the like from the beginning by means such as insert molding, and the number of coils and capacitors can be changed as appropriate.

Further, although the metal bottom plate 20, the insulating frame 21, and the insulating cover 22 are integrated using the screws 26 and the nut portions 22, they may have a structure in which they are fitted and integrated.

As mentioned above, according to the present invention, only the periphery of the plate-shaped ceramic capacitor is cast with resin and an insulating frame is used to support the coil, etc., thereby making assembly easy and mass-producible. A noise filter that can be improved and reduced in cost can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the circuit configuration of a general noise filter, Fig. 2 is a plan sectional view of the conventional noise filter, Fig. 3 is a sectional view of the same side, and Fig. 4 is a circuit diagram of the noise filter according to the present invention. An exploded perspective view showing the embodiment, FIG. 5 is a cross section of the same side, FIG. 6 is an exploded perspective view showing a case where a bare disc-shaped ceramic capacitor is arranged in a box-shaped capacitor storage container, and FIG. 7 is a box-shaped capacitor. A partial cross-sectional view showing the structure for connecting the earth piece of the storage container to the Faston terminal, FIG. 8 is a cross-sectional view of the main part showing another embodiment of the present invention, and FIG. 9 is another embodiment of the present invention. FIG. 11A, 11B... Bare disc-shaped ceramic capacitor, 12... Conductor, 14... Common mode choke coil, 15... Capacitor,
20, 20A, 20B...Metal bottom plate, 21...
...Insulating frame body, 22...Insulating lid body, 24,
24A...Box-shaped capacitor storage container, 32,7
1...Mold resin, 40...Coil storage part, 41...Coil positioning convex part, 45A
〜45E・・・Faston terminal.

Claims (1)

[Scope of utility model registration request] A metal bottom plate having a capacitor storage recess or to which a capacitor storage container is fixed so as to be in contact with the metal bottom plate, an insulating frame having a coil storage part and disposed on the metal bottom plate, and a metal bottom plate disposed on the insulating frame. an insulating lid, a metal terminal provided so as to pass through the insulating frame or the insulating lid, or both, the lower surface of which is in contact with the capacitor accommodating recess or the capacitor accommodating container, and the intermediate portion of the conductor is connected to the upper surface thereof; A bare plate ceramic capacitor arranged and resin-cast is provided, and a coil arranged in the coil storage part, one end of the conductor is connected to the metal terminal, and the other end is connected to the winding end of the coil. A noise filter characterized by being connected.