JPH0638474Y2 - Electrical signal filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric signal filter, and more particularly to an electric signal filter configured to improve assemblability.

Conventional technology CATV (Cable and Telecommunication Television syste
In m), the image signal is transmitted to a television receiver of each home through a broadband transmission line such as a coaxial cable. This CATV has a large transmission capacity, about 20 ~
50 channels can be viewed on a television receiver. However, since there are pay TV broadcasts among these multi-channels, only pay-broadcasting homes can be watched by the households that have a separate contract. Therefore, an electric signal filter for blocking a specific frequency (pay TV broadcast) of the image signal transmitted through the cable is attached in the middle of the cable distributed to the home of the non-contractor.

This electric signal filter is composed of an input side connector, an output side connector, a cylindrical case and a shield case,
A first filter circuit board and a second filter circuit board that block a specific frequency are inserted in this case,
Wires are connected between both substrates. Further, a pair of shield plates are provided so as to face each other so that the two circuits do not interfere with each other, and spacers made of an insulator are interposed between the pair of shield plates at the ends of the both substrates which are close to each other. .

However, in the conventional electric signal filter described above, the substrate is the first.
Since the 1st and 2nd filter circuit boards are provided separately and both boards are connected by wires, the number of parts is large and the configuration is complicated, and both boards are connected by soldering and then cylindrical However, there is a problem in that the board, spacers, etc. are fluttered when inserting into the case, making it difficult to insert the assembly work.

Then, this invention aims at providing the electric signal filter which solved the said subject.

Means for Solving the Problems The present invention provides the above electric signal filter in which a first filter circuit and a second filter circuit are provided on the same substrate, and the first filter circuit and the second filter of the substrate are provided. A mounting portion for mounting a shield plate is provided between the first and second circuits, a portion surrounding the first filter circuit, a first case including an input side connector of the first filter circuit, and a portion surrounding the second filter circuit. And a second case composed of an output side connector of the second filter circuit, which covers the substrate.

Action The number of parts can be reduced by providing the first and second filter circuits on one board, and the shield plate is fitted and assembled in the mounting recess of the board, and the case and connector are integrated. Since the configuration is simplified, the assembly work can be easily performed.

Embodiment An embodiment of an electric signal filter according to the present invention is shown in FIGS.

In each figure, the electric signal filter is formed by inserting the input side case 2 and the output side case 3 into the substantially cylindrical shield case 1,
A filter circuit board 4 and a shield plate 5 are housed inside the cases 2 and 3.

The filter circuit board 4 includes an input side substrate half 4a provided with a first filter circuit 6, an output side substrate half 4b provided with a second filter circuit 7, and an input side substrate half. A narrow connecting part 4c that connects between 4a and the half board 4b on the output side.
And the mounting recess 4d of the shield plate 5 provided adjacent to the connecting portion 4c are integrally formed. The first and second filter circuits 6 and 7, which are conventionally provided on separate substrates, are LC circuits that are provided on the same substrate 4 and are composed of coils 8a to 8d and capacitors (not shown). They are connected by printed patterns (not shown). Therefore, it is not necessary to separately connect the substrates to each other by wire as in the conventional case. The inductances of the coils 8a to 8d are adjusted according to the frequency to be canceled as described later.

Reference numeral 9 denotes an input side contact, which includes a contact portion 9a for holding a connector pin or a wire (not shown) inserted in the case 2 by a leaf spring action, and an input side of the substrate 4 bent from the contact portion 9a into an L shape. The base end portion 9b is inserted into the small hole 4e and soldered. 10 is an output side contact pin, one end of which is inserted into the output side small hole 4f of the substrate 4 and soldered,
The other end bent in an L shape extends to the output side.

As shown in FIG. 3, the shield plate 5 includes a disc-shaped main body 5a,
Protrusions 5b and 5c projecting above and below the outer periphery of the main body 5a, a fitting portion 5d into which the connecting portion 4c of the substrate is fitted, and a recess 5e for preventing the pattern of the connecting portion 4c from contacting the shield plate 5 And consists of.

As shown in FIGS. 4A to 4C, the input side case 2 is
A male thread 2b for connection is provided at one end of the cylindrical main body 2a,
A knurled portion 2c is provided on the outer periphery of the main body 2a. Inside the main body 2a and the male screw portion 2b, there is provided an inner chamber portion 2d in which the substrate 4 and the contact 9 are housed.
The outer periphery of 2a penetrates into the inner chamber 2d, and the coil 8 on the substrate 4
Holes 2e and 2f for adjusting the inductance of a and 8b are formed. Further, the main body 2a is provided with cutouts 2g, 2h into which the projections 5b, 5c of the shield plate 5 are press-fitted at the ends.

As shown in FIGS. 5A, 5B, and 5C, the output side case 3 is provided with a female thread portion 3b for connection at one end of a main body 3a having the same diameter as the main body 2a of the input side case 2. A knurled portion 3c is provided on the outer periphery of the main body 3a. The inside of the main body 2a is provided with a hollow portion 3d communicating with the female screw portion 3b.
The outer periphery of 3a penetrates into the hollow portion 3d, and the coil 8 on the substrate 4
Holes 3e and 3f for adjusting the inductances of c and 8d are formed. Further, the main body 2a is provided with cutouts 3g, 3h into which the projections 5b, 5c of the shield plate 5 are press-fitted at the ends.

Now, the procedure for assembling the electric signal filter of the present invention will be described.

First, the filter circuit board 4 to which the first and second filter circuits 6 and 7, the input side contact 9, and the output side contact pin 10 are soldered is prepared. The input side case 2 has a hollow part 2d in advance.
A rubber seal member 11 having a small hole 11a for inserting a wire is attached to the inner part of the. Further, the output side case 3 is also preliminarily formed with a flat rubber seal member 12 (having a small hole 12a for inserting a wire) in the groove 3i of the female screw portion 3b which is the inner portion of the hollow portion 3d.
Is installed.

Next, the tubular guide member 13 is attached to the input side contact 9 of the filter circuit board 4. The guide member 13 is made of an insulator and protects the contact 9 from being deformed when it is assembled to the input side case 2. Then, the fitting portion 5d of the shield plate 5 is fitted into the connecting portion 4c from the mounting recess 4d of the filter circuit board 4, and the shield plate 5 is integrally assembled to the central portion of the filter circuit board 4. Then, the filter circuit board 4 is inserted into the hollow portion 2d of the input side case 2 with the guide member 13 at the top. At this time, since the filter circuit board 4 is integrally formed and the case and the connector are integrated, the structure is simplified and easy to assemble,
Can be assembled efficiently.

The guide member 13 fits into a small diameter portion provided at the back of the hollow portion 2d, and the shield plate 5 has notches 2g and 2h formed on the protrusions 5b and 5c.
Is pressed into. As a result, the input side connector 9 is assembled in the seal member 11 without being damaged, and the board half 4a of the filter circuit board 4 is positioned by the shield plate 5 with respect to the case 2.

Subsequently, the substrate half 4b on the output side of the filter circuit substrate 4 is inserted into the hollow portion 3d of the output case 3. At that time, the output side connector pin 10 is inserted into the small hole 12a of the shield member 12, and the projections 5b and 5c of the shield plate 5 are press-fitted into the notches 3g and 3h of the output side case 3. In this way, the input side case 2 and the output side case 3 are integrally assembled by press-fitting the protrusions 5b and 5c of the shield plate 5, the filter circuit board 4 is positioned, and the coils 8a to 8d are The adjustment part (not shown) provided on the bottom is for each hole 2e, 2f, 3e, 3f.
To face.

Here, a driver (not shown) or the like is inserted through each of the holes 2e, 2f, 3e, 3f and the adjusting portion (not shown) of each coil 8a-8d is rotated to adjust the inductance of each coil 8a-8d. Then, ring-shaped packings 14 and 15 are attached to the outer peripheral portions of the connector bodies 2a and 3a adjacent to the knurled portions 2c and 3c.

After that, the cases 2 and 3 integrated as described above via the shield plate 5 are inserted into the shield case 1 together with the filter circuit board 4. At this time, both ends 1a, 1b of the shield case 1 are not drawn, and the case 2, 3
Can be easily inserted. Further, since the knurled portions 2c and 3c slightly protruding from the outer circumference of the cases 2 and 3 come into contact with the inner wall of the shield case 1, the cases 2 and 3 are held in the shield case 1 without rattling, and Grounded.

Then, both ends 1a and 1b of the shield case 1 are drawn so as to incline inward, and the packings 14 and 15 mounted on the outer peripheries of the cases 2 and 3 are compressed to the ends 1a and 1b, respectively. Seal between 1 and cases 2 and 3. Therefore, the insides of the cases 2 and 3 are hermetically sealed by the seal members 11 and 12 and the packings 14 and 15, and waterproofness against rainwater is ensured when used outdoors. In addition, the first of the connectors 2 and 3
The second filter circuits 6 and 7 are shielded by the shield plate 5, the cases 2 and 3 and the shield case 1 so as not to exert a magnetic influence on each other.

In this way, the assembled electric signal filter is provided in the middle of the coaxial cable (drop line) connected to the television receiver of each home, and blocks the frequency of the specific channel. Further, when blocking frequencies of two or more channels, the electric signal filters corresponding to the number of channels are connected in series.

Effect of the Invention As described above, the electric signal filter according to the present invention integrates the filter circuit board, which has been conventionally separated, and the shield plate can be directly attached to the filter circuit board. Not only is it unnecessary, but since only one shield plate is required, it is possible to streamline the assembly work by reducing the number of parts. Also, when the filter circuit board is inserted into the connector, it is possible to get the same fray as before. In addition, since the case and the connector are integrated, they can be easily assembled, so that they can be manufactured efficiently, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the electric signal filter according to the present invention, FIG. 2 is a vertical sectional view of the electric signal filter, and FIG. 3 is a vertical sectional view taken along line III-III in FIG. FIG. 4 is a diagram of the input side case, and FIG. 5 is a diagram of the output side case. 1 ... Shield case, 2 ... Input side case, 3 ... Output side case, 4 ... Filter circuit board, 5 ... Shield plate, 6 ... First filter circuit, 7 ... Second filter circuit , 8a to 8d …… Coil, 9 …… Input side contact, 10
...... Output side contact pin.

Claims (1)

[Scope of utility model registration request] 1. A first filter circuit and a second filter circuit are provided on the same substrate, and a mounting portion for mounting a shield plate is provided between the first filter circuit and the second filter circuit of the substrate. A first case composed of a portion surrounding the first filter circuit, an input side connector of the first filter circuit, a portion surrounding the second filter circuit and an output side connector of the second filter circuit And an electric signal filter configured to cover the substrate with the second case.