JPH09102225A - High-frequency coaxial cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the mechanical strength of an outer conductor. SOLUTION: A first adhesive layer 6 is provided between an outer conductor 4 and an insulator 3. A second adhesive layer 7 is provided between the outer conductor 4 and a sheath 5. The outer conductor 4 is entirely bonded to the insulator 3 or the sheath 5 by one of the adhesive layers. The outer conductor 4 is partially bonded to the sheath 5 or the insulator 3 by the other adhesive layer. Thus the outer conductor 4 can be separated from its surroundings while enhancing the mechanical strength of the outer conductor 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency coaxial cable widely used for high frequency transmission lines.

[0002]

2. Description of the Related Art Conventionally, there is a high frequency coaxial cable using an outer conductor made of a copper or aluminum thin film. Although such coaxial cables are characterized by weight reduction and economic efficiency, the mechanical strength of the outer conductor cannot be sufficiently secured, and the outer conductor may be broken or cracked due to bending of the cable. There was a nature.

Therefore, conventionally, in a high-frequency coaxial cable having a thin-film outer conductor, the outer conductor is integrated with an insulator provided on the inner side in the radial direction, or the outer conductor is provided on the outer side in the radial direction. The mechanical strength of the outer conductor was reinforced by integrating it with the coating. Specifically, a heat-fusible adhesive layer is provided entirely between the outer conductor and the insulator, or between the outer conductor and the coating, and the outer conductor and the insulator, or the outer conductor and the coating are completely bonded. By doing so, the outer conductor was mechanically reinforced.

[0004]

However, in the conventional high-frequency coaxial cable, although the strength of the outer conductor is reinforced in this way, the strength of the outer conductor cannot be said to be sufficient, and the bending of the cable causes It was not possible to completely prevent breakage, cracking and other damage.

The present invention has been made in view of the above circumstances, and an object thereof is to increase the mechanical strength of the outer conductor.

[0006]

In order to achieve the above object, the present invention provides a first adhesive layer between an outer conductor and an insulator provided radially inward of the outer conductor, and at the same time, provides the outer conductor. And a coating provided on the radially outer side of the second
An adhesive layer is provided, and one adhesive layer is entirely provided on the inner peripheral surface or the outer peripheral surface of the outer conductor to adhere the outer conductor and the insulator, or the outer conductor and the cover to the entire surface. And the other adhesive layer is partially provided on the outer peripheral surface or the inner peripheral surface of the outer conductor to partially bond the outer conductor and the coating or the outer conductor and the insulator. ing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described in detail below.

First Embodiment FIG. 1 shows a high frequency coaxial cable 1 according to a first embodiment of the present invention.

This coaxial cable 1 has a frequency of 10 MHz.
An inner conductor 2 made of a single copper wire or a copper stranded wire, and an insulator 3 made of polyethylene or foamed polyethylene and provided around the inner conductor 2 for use in the above high-frequency transmission circuit, An outer conductor 4 made of a copper tape or an aluminum tape having a thickness of about 80 μm and provided around the insulator 3 and a coating 5 made of polyethylene or vinyl and provided around the outer conductor 4. I have it.

The outer conductor 4 is slightly longer than the outer peripheral length of the insulator 3 (for example, 2 to 3) so as to ensure its electrical continuity.
A copper film having a width of about 4 mm is made to wrap around the insulator 3 in the axial direction and is then wound in the circumferential direction, and both ends of the winding are overlapped.

The thickness of the outer conductor 4 is set to about 80 μm for the following reason. That is,
Under the condition of a high frequency transmission line, the attenuation amount and characteristic impedance of the coaxial cable 1 are not related to the thickness or the cross-sectional area of the outer conductor 4. Therefore, the thickness of the outer conductor 4 required for electric sustainability is determined by the skin depth (minimum thickness of the conductor required for transmission of high frequency signals). Therefore, since the skin depth at a frequency of 10 MHz is about 20 μm, it can be seen that the thickness of 60 μm or more is sufficient for the outer conductor 4 made of a copper tape or an aluminum tape. In view of this, in the high frequency coaxial cable 1,
The thickness of the outer conductor 4 is 80 μm.

Next, the characteristic structure of the high frequency coaxial cable 1 will be described. In the high-frequency coaxial cable 1, the first adhesive layer 6 is provided between the outer conductor 4 and the insulator 3, and the second adhesive layer 7 is provided between the outer conductor 4 and the coating 5. The first adhesive layer 6 is provided between the outer conductor 4 and the insulator 3, and is provided on the entire inner and outer peripheral surfaces of these. Also,
The first adhesive layer 6 is composed of a double-sided adhesive tape or a heat-bonding film containing EVA-based, polyester-based, or other heat-meltable adhesive as an adhesive component, and the outer conductor 4 and the insulator 3 are entirely covered. Is glued to.

The second adhesive layer 7 is composed of adhesive bands 8 which are spirally arranged on the outer peripheral surface of the outer conductor 4 (inner peripheral surface of the coating 5) with a gap in the cable axial direction. The adhesive band 8 is composed of a double-sided adhesive tape or a heat-sealing film containing EVA-based, polyester-based or other heat-sealing adhesive as an adhesive component.

As described above, the second adhesive layer 7 is provided. In the outer peripheral surface of the outer conductor 4 (inner peripheral surface of the coating 5), the peripheral surface area where the second adhesive layer 7 is provided is The ratio of the peripheral surface area not provided is about 2: 3 to 3: 2.

The first and second adhesive layers 6 and 7 are adhered to the cover 5 which is not the insulator 3 as follows. That is, the coating 5 is generally designed to be extruded around the outer conductor 4, and the coating 5 is heated during the extrusion coating operation. Therefore, the preheating of the heating at this time is transmitted to the first and second adhesive layers 6 and 7, and these adhesive layers 6 and 7 are melted to bond the outer conductor 4 and the insulator 3 and the outer conductor 4 and the coating 5 to each other. It

In this way, the first and second adhesive layers 6 and 7 are formed.
In the high-frequency coaxial cable 1 provided with, the outer conductor 4 is entirely adhered to the insulator 3 and is also partially adhered to the cover 5. Therefore, not only is the outer conductor 4 integrally strengthened with the insulator 3 to be reinforced, but the outer conductor 4 is further partially strengthened by being bonded to the coating 5. Therefore, the mechanical strength of the outer conductor 4 is increased, and even if the cable is bent, the outer conductor 4 is not broken or cracked.

Next, the connection between the high frequency coaxial cable 1 and the connector 50 will be described with reference to FIG. The connector 50 is a main body 51, a fastening body 52 connected to the main body 51, and an external conductor contact 5 that is interposed between the main body 51 and the fastening body 52 and connected to the outer conductor 4.
3 and an inner conductor contact 54 connected to the inner conductor 2.
It is comprised including.

At the connection end of the high-frequency coaxial cable 1, an inner conductor contact 54 is connected to the inner conductor 2, and a taper portion 53a provided on the outer conductor contact 53 is provided between the outer conductor 4 and the coating 5. Plug in. Then, in this state, the fastening body 52 is screwed to the main body 51 to press the outer conductor contact 53 against the outer conductor 4 to electrically connect the two. In FIG. 3,
The first and second adhesive layers 6 and 7 are not shown.

In this way, the connector 50 and the high-frequency coaxial cable 1 are connected. Although the outer conductor 4 and the coating 5 are adhered by the second adhesive layer 7,
The adhesion is partial and there are unbonded parts. Therefore, when the outer conductor contact 53 is inserted between the outer conductor 4 and the coating 5, it is relatively easy if the outer conductor contact 53 is inserted by screwing it from a portion not bonded between the outer conductor 4 and the coating 5. The outer conductor contact 53 can be inserted into the.

Second Embodiment FIG. 2 shows a high frequency coaxial cable 10 according to a second embodiment of the present invention.

The coaxial cable 10 basically has the same structure as the high frequency coaxial cable 1 of the first embodiment, and the same or similar parts are designated by the same reference numerals. That is, this high frequency coaxial cable 10
It is provided with an inner conductor 2, an insulator 3, an outer conductor 4 made of a copper tape or an aluminum tape, and a coating 5.

Next, the characteristic structure of the high frequency coaxial cable 10 will be described. This high frequency coaxial cable 10
The first adhesive layer 11 is provided between the outer conductor 4 and the insulator 3, and the second adhesive layer 12 is provided between the outer conductor 4 and the coating 5. The first adhesive layer 11 is provided between the outer conductor 4 and the insulator 3, and is provided on the entire inner and outer peripheral surfaces of these. The first adhesive layer 11 is made of EVA, polyester,
It is composed of a double-sided adhesive tape or a heat-sealing film containing another heat-sealing adhesive as an adhesive component, and the outer conductor 4 and the insulator 3 are bonded over the entire surface.

The second adhesive layer 12 is arranged along the outer peripheral surface of the outer conductor 4 (the inner peripheral surface of the coating 5) in the cable axial direction, and is separated from each other in the cable circumferential direction. It consists of

Each adhesive band 13 is formed of a double-sided adhesive tape or a heat-sealing film containing EVA-based, polyester-based or other heat-fusible adhesive as an adhesive component. Although the second adhesive layer 12 is provided in this way, on the outer peripheral surface of the outer conductor 4 (the inner peripheral surface of the coating 5),
The ratio between the peripheral surface area where the second adhesive layer 13 is provided and the peripheral surface area where the second adhesive layer 13 is not provided is preferably about 2: 3 to 3: 2 as in the first embodiment.

In the high-frequency coaxial cable 10 provided with the first and second adhesive layers 11 and 12, the outer conductor 4 is entirely adhered to the insulator 3 and is also partially adhered to the cover 5. There is. Therefore, the outer conductor 4 is not only integrated with the insulator 3 for strength reinforcement, but is also partially adhered to the cover 5 for further strength reinforcement. Therefore, the mechanical strength of the outer conductor 4 is increased, and even if the cable is bent, the outer conductor 4 is not broken or cracked.

This high frequency coaxial cable 10 and connector 5
The connection with 0 is the same as the connection in the first embodiment described with reference to FIG.
When inserting 3 between the outer conductor 4 and the coating 5, the outer conductor contact 53 can be relatively easily inserted by screwing the outer conductor contact 53 from a portion not bonded between the outer conductor 4 and the coating 5. Can be plugged in.

Third Embodiment FIG. 4 shows a high frequency coaxial cable 20 according to a third embodiment of the present invention.

The coaxial cable 20 basically has the same structure as the high frequency coaxial cable 1 of the first embodiment, and the same or similar parts are designated by the same reference numerals. That is, this high frequency coaxial cable 20
It is provided with an inner conductor 2, an insulator 3, an outer conductor 4 made of a copper tape, and a coating 5.

Next, the characteristic structure of the high frequency coaxial cable 20 will be described. This high frequency coaxial cable 20
The first adhesive layer 21 is provided between the outer conductor 4 and the insulator 3, and the second adhesive layer 22 is provided between the outer conductor 4 and the coating 5. The second adhesive layer 22 is provided between the outer conductor 4 and the coating 5, and is provided on the entire inner and outer peripheral surfaces of these. The second adhesive layer 22 is composed of a double-sided adhesive tape or a heat-bonding film containing EVA-based, polyester-based, or other heat-meltable adhesive as an adhesive component, and the outer conductor 4 and the coating 5 are entirely covered. It is glued.

The first adhesive layer 21 is composed of adhesive bands 23 spirally arranged on the inner peripheral surface of the outer conductor 4 (outer peripheral surface of the insulator 3) with a gap in the cable axial direction. The adhesive band 23 is composed of a double-sided adhesive tape or a heat-bonding film containing EVA-based, polyester-based or other heat-meltable adhesive as an adhesive component. Thus, the first adhesive layer 21
However, as in the first embodiment, in the inner peripheral surface of the outer conductor 4 (the outer peripheral surface of the insulator 3), the peripheral surface area in which the first adhesive layer 21 is provided, The ratio with the peripheral surface area not provided is preferably about 2: 3 to 3: 2.

In the high-frequency coaxial cable 20 provided with the first and second adhesive layers 21 and 22, the outer conductor 4 is wholly adhered to the coating 5 and is also partially adhered to the insulator 3. There is. Therefore, the outer conductor 4 is not only strengthened integrally with the coating 5 but also further strengthened because it is partially bonded to the insulator 3. Therefore, the mechanical strength of the outer conductor 4 is increased, and even if the cable is bent, the outer conductor 4 is not broken or cracked.

Next, the connection between the high frequency coaxial cable 20 and the connector 50 will be described with reference to FIG. The connector 60 connected to the high-frequency coaxial cable 20 has the same configuration as the connector 50 described in FIG. 3 except for the outer conductor contact 61, and the same or similar parts are
The same reference numerals are attached. That is, this connector 60
Is a main body 51, a fastening body 52 connected to the main body 51, and an outer conductor contact 61 that is interposed between the main body 51 and the fastening body 52 and connected to the outer conductor 4.
And an inner conductor contact 54 connected to the inner conductor 2.

The inner conductor contact 54 is connected to the inner conductor 2 at the connection end of the high-frequency coaxial cable 20, and the taper portion 61a provided on the outer conductor contact 61 is provided between the outer conductor 4 and the insulator 3. Plug in. Then, in this state, the fastening body 52 is screwed to the main body 51 to connect the outer conductor contact 61 to the outer conductor 4.
It is pressed against to electrically connect both. FIG.
Then, the first and second contact adhesive layers 21 and 22 are not shown.

In this way, the connector 60 and the high-frequency coaxial cable 20 are connected. Although the outer conductor 4 and the insulator 5 are adhered by the first adhesive layer 21, the adhesion is partial. There is a part which is not adhered. Therefore, the outer conductor contact 6
When inserting 1 between the outer conductor 4 and the insulator 3, the outer conductor contact 61 can be relatively easily inserted by screwing the outer conductor contact 61 from a portion not bonded between the outer conductor 4 and the insulator 3. The contact 61 can be inserted.

Fourth Embodiment FIG. 5 shows a high frequency coaxial cable 30 according to a fourth embodiment of the present invention.

The coaxial cable 30 basically has the same structure as the high frequency coaxial cable 1 of the first embodiment, and the same or similar parts are designated by the same reference numerals. That is, this high frequency coaxial cable 30
It has an inner conductor 2, an insulator 3, an outer conductor 4 made of a copper tape or an aluminum tape, and a coating 5.

Next, the characteristic structure of the high frequency coaxial cable 30 will be described. This high frequency coaxial cable 30
The first adhesive layer 31 is provided between the outer conductor 4 and the insulator 3, and the second adhesive layer 32 is provided between the outer conductor 4 and the coating 5. The second adhesive layer 32 is provided between the outer conductor 4 and the coating 5, and is provided on the entire inner and outer peripheral surfaces of these. The second adhesive layer 32 is formed of a double-sided adhesive tape or a heat-sealing film containing EVA-based, polyester-based, or any other heat-sealing adhesive as an adhesive component, and the outer conductor 4 and the coating 5 are entirely covered. It is glued.

The first adhesive layer 31 is located between the outer conductor 4 and the insulator 3, is arranged in the cable axial direction along the inner peripheral surface of the outer conductor 4 (the outer peripheral surface of the insulator 3), and is in the cable circumferential direction. It is composed of a plurality of adhesive bands 33, ...

The adhesive band 33 is made of EVA, polyester,
It is composed of a double-sided adhesive tape or a heat-sealing film containing another heat-sealing adhesive as an adhesive component. Although the first adhesive layer 31 is provided in this way,
As in the embodiment described above, in the inner peripheral surface of the outer conductor 4 (the outer peripheral surface of the insulator 3), the ratio of the peripheral surface area where the first adhesive layer 31 is provided and the peripheral surface area where the first adhesive layer 31 is not provided is 2:
About 3 to 3: 2 is suitable.

In this way, the first and second adhesive layers 31,
In the high-frequency coaxial cable 30 provided with 32, the outer conductor 4 is entirely adhered to the coating 5, while the insulator 3
It is also partially bonded. Therefore, the outer conductor 4
Is not only integrally strengthened with the coating 5, but is further strengthened by being partially bonded to the insulator 3. Therefore, the mechanical strength of the outer conductor 4 is increased, and even if the cable is bent, the outer conductor 4 is not broken or cracked.

The connection between the high-frequency coaxial cable 30 and the connector 50 is the same as the connection in the third embodiment described with reference to FIG. 6, and the outer conductor contact 53 connects the outer conductor 4 and the insulator 3 to each other. If the outer conductor contact 61 is inserted by screwing it from a portion not bonded between the outer conductor 4 and the insulator 3, the outer conductor contact 61 can be relatively easily inserted.

[0042]

EXAMPLES As concrete examples of the present invention, examples of the structure and dimensions of the CATV coaxial cable are as follows.

[0043]

[Table 1]

[0044]

As described above, according to the present invention, the outer conductor is not only integrally strengthened with one of the insulator and the coating to be reinforced but also partially bonded to the other. , It is supposed to be further strengthened. for that reason,
The mechanical strength of the outer conductor has increased, and it is no longer broken or cracked when the cable is bent.

Further, even though the outer conductor is adhered to the insulator and the coating, the outer conductor can be easily separated from the surrounding members (the outer conductor or the coating), so that the connector can be easily attached to the connector. There is an effect that reliable connector connection can be performed without any trouble in connection work.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure of a high-frequency coaxial cable according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a structure of a high frequency coaxial cable according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a connection structure between a high-frequency coaxial cable and a connector according to the first and second embodiments.

FIG. 4 is a perspective view showing a structure of a high-frequency coaxial cable according to a third embodiment of the present invention.

FIG. 5 is a perspective view showing a structure of a high frequency coaxial cable according to a fourth embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a connection structure between a straight frequency coaxial cable and a connector according to the third and fourth embodiments.

[Explanation of symbols]

 3 Insulator 4 Outer Conductor 5 Coating 6 First Adhesive Layer 7 Second Adhesive Layer 11 First Adhesive Layer 12 Second Adhesive Layer 21 First Adhesive Layer 22 Second Adhesive Layer 31 First Adhesive Layer 32 Second Adhesive Layer

Claims (4)

[Claims] 1. A first adhesive layer is provided between an outer conductor and an insulator provided radially inside thereof, and a second adhesive layer is provided between the outer conductor and a coating provided radially outside thereof. And one adhesive layer is entirely provided on the inner peripheral surface or the outer peripheral surface of the outer conductor to adhere the outer conductor and the insulator, or the outer conductor and the coating to the entire surface. The other adhesive layer is partially provided on the outer peripheral surface or the inner peripheral surface of the outer conductor and partially adheres the outer conductor and the coating or the outer conductor and the insulator to each other. . 2. The other adhesive layer is composed of adhesive bands arranged in a spiral shape on the outer peripheral surface or the inner peripheral surface of the outer conductor with a gap in the cable axial direction. The high-frequency coaxial cable described. 3. The other adhesive layer is composed of a plurality of adhesive bands that are arranged on the outer peripheral surface or the inner peripheral surface of the outer conductor along the cable axial direction and at a distance from each other in the cable circumferential direction. The high frequency coaxial cable according to claim 1, which is characterized in that. 4. The high frequency coaxial cable according to claim 1, wherein the first and second adhesive layers are composed of heat-fusible adhesive layers.