JPH0720859Y2 - Coaxial connector - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a connector useful for use in a coaxial cable for CATV, etc., and particularly, minimizes the intrusion of external noise that tends to enter from the outside in the connector section. On the other hand, the present invention relates to a novel coaxial connector which can maintain a stable connection with an external conductor for a long period of time and can greatly enhance the pulling-out force at a connector connecting portion, thereby significantly improving reliability.

[Prior art] CATV was originally developed for the purpose of retransmission in difficult-to-view areas
After that, they came to see their own development as a self-service network capable of two-way communication in a specific area.

The frequency band used is usually the VHF band, and as a cable for that purpose, a coaxial cable is widely used that is capable of wide band transmission, has little attenuation, has uniform impedance, and has excellent shielding characteristics. .

FIG. 9 has a half cross-section showing a specific configuration of a conventional example of a connector used when connecting such coaxial cables 1 or between the cables and devices such as a repeater housing. It is a sketch. The illustrated connector is a main body attached to the cable 1 side, and the main body and the mating adapter or receptacles of devices are engaged and connected.

In FIG. 9, 2 is a cable jacket, 3 is an outer conductor, 4
Are insulators, and 5 is a central conductor, which form respective constituent members of the coaxial cable 1.

When the connector is attached to the end portion of the cable 1 as described above, the central conductor 5 is stripped off in a protruding step, the jacket 2 of the outer conductor 3 is stripped off, and the central contact 6 is joined to the central conductor 5. An inner shell 7 is coaxially attached to the outer periphery of the inner shell 7 via insulators 12 and 13 as shown in the figure.

The inner shell 7 and the outer conductor 3 must be electrically connected, but in the conventional example, the electrical connection is made by the structure shown in FIG. 9 and FIG. 10 which is a partially enlarged view thereof. It was

That is, the rear end of the inner shell 7 is formed into a tapered surface 7a that opens outward, and one side surface between the tapered surface 7a and the outer conductor 3 is the tapered surface 7a of the inner shell 7.
A wedge-shaped ring-shaped clamp 10 which is formed on a tapered surface 10a compatible with the other surface and can abut against the outer surface of the exposed outer conductor 3 is provided on the other surface. In this state, by tightening the tightening metal fitting 8 that is screw-fitted to the inner shell 7, a pressing force is generated in the clamp 10 toward the inner shell 7 side, and the taper surface 7a of the inner shell 7 and the clamp
Contact pressure between the wedges is generated between the ten tapered surfaces 10a. As a result, contact pressure is generated on the outer surface of the outer conductor 3 on the bottom surface side of the clamp 10, and thus the clamp
A mechanical and electrical contact pressure can be generated between the outer conductor 3 and the inner shell 7 via 10.

In FIG. 9, 11 is a sealing gasket, and 14 and 15 are O-rings.

[Problems to be Solved by the Invention] Generally, the outer conductor 3 of the coaxial cable 1 is made of a thin pipe such as aluminum, and the tightening force of the clamp 10 easily causes abrasion or deformation on the surface of the conductor 3, During long-term use, due to repeated expansion and contraction due to vibration and temperature change, loosening of the screw of the tightening metal fitting 8 occurs, the gripping force of the clamp 10 with respect to the outer conductor 3 is weakened, and electrical contact is made. The instability sometimes deteriorates, the transmission characteristics are impaired, and the mechanical pulling force is lowered. In particular, under outdoor use conditions, mechanical strength and electrical contact resistance are easily damaged and deteriorated by vibration due to wind force, temperature change, rainwater, ice and snow, corrosive gas, and the like.

For the purpose of preventing such a problem from occurring, a friction sleeve 16 as illustrated in FIGS. 11 (a) to 11 (c) is interposed between the outer conductor 3 and the clamp 10. . In the same figure (a), a large number of ring-shaped projections 16a are formed. However, since the projections 16a are formed at right angles to the pressing and advancing direction of the clamp 10, it is difficult to make the bite well because the biting effect is impeded. Therefore, a large effect cannot be expected. FIG. 9B shows the projection 16b formed in the axial direction of the outer conductor 3, and it is easy to obtain the biting effect, but the projection 16b is in the axial direction, and therefore the force for preventing the pull-out force is insufficient. In FIG. 6C, the dispersion protrusions 16c and 16c are randomly formed, but there are the same problems as in FIG. In addition, a sleeve with a roughened inner surface has been proposed, but if the degree of roughening is small, the length must be lengthened and it is not practical.In all cases, there are merits and demerits, and it is not always possible to expect a sufficient effect. Is the reality.

On the other hand, the coaxial connector may be disassembled for replacement of the relay casing or the like. In this case, in the above conventional example, the clamp
Even up to 10 will be dismantled, so if there is a mistake in reconnecting, the connection characteristics may be deteriorated. In particular, such a situation is likely to occur under severe outdoor environmental conditions.

Further, as is well known, the current flowing through the outer conductor 3 of the coaxial cable has a property of flowing concentratedly on the inner surface of the outer conductor due to the skin effect and the proximity effect.

Therefore, when the electrical connection between the outer conductor 3 and the inner shell 7 is made by the configuration shown in the conventional example as described above, the current path is as shown by the dotted line in FIG. 10, and the inner surface of the outer conductor 3 is The flowed electric current flows back to the inner surface of the clamp 10 after being turned back and flows into the inner surface of the clamp 10 as shown in the figure, and then flows into the inner shell 7 in a so-called S-shaped path. Will result in formation.

The formation of such an S-shaped path is in a state equivalent to the insertion of an inductance or capacitance in the electric circuit in the connector portion, which not only has a great possibility of adversely affecting the electric signal, but also causes the external conductor 3 to have a bad influence. If the current flows through the outer surface once and then the current flows through the inner shell 7, the external radio waves coming from the outside to the outer conductor 3 and entering the outer surface are also mixed and input to the inner shell 7 side. As a result, there is a great possibility that noise may be mixed by external radio waves.

The object of the present invention is to solve the above-mentioned problems of the prior art, and to stably and surely maintain the electrical and mechanical contact of the connector for a long period of time, and further, the connector described above. Another object of the present invention is to provide a new coaxial connector which is configured to be able to appropriately eliminate the intrusion of extraneous noise.

[Means for Solving the Problems] The present invention is directed to a center contact connected to a center conductor of a coaxial cable that is projected and stripped off, an inner shell coaxially arranged on the center contact, and a screw to the inner shell. In a connector that has a fastening metal fitting that is fitted and that faces the inner shell to generate a pressing force in the cable tip direction and a gasket fastening metal fitting that applies a tightening force to the sealing gasket, of the outer conductor that does not strip the jacket. A taper taper surface is formed on the inner side in the direction opposite to the cable tip. The small diameter side of the taper surface is almost equal to the inner diameter of the outer conductor, and the large diameter side is an inner taper formed appropriately larger than the inner diameter of the outer conductor. A sleeve is fitted in, and on the outer peripheral side of the outer jacket, a small diameter portion is approximately equal to the outer diameter of the cable outer jacket, and on the large diameter side, a case where the inner taper sleeve is fitted. An outer taper sleeve having an inner taper surface that fits the outer taper surface of the cable end is fitted in correspondence with the inner taper sleeve, and the outer taper sleeve reaches at least the outer conductor inside the taper surface in the longitudinal direction. A plurality of vertical clamp blades protruding so as to obtain are formed, and an outer conductor contact is provided between the inner tapered sleeve and the inner shell to electrically connect the two, and The inner tapered sleeve is made of a conductive spring material, and a conductor accommodating groove for accommodating the outer conductor pressed and deformed by the clamp blade is formed on the outer circumference of the inner tapered sleeve corresponding to the vertical clamp blade of the outer tapered sleeve. In addition, the internal taper sleeve is formed with vertical slits that create elastic force. A.

[Operation] If the cable jacket and the end of the outer conductor are sandwiched between the taper members that are divergent, and if a plurality of clamp blades that penetrate the jacket and reach the outer conductor are formed on the outer taper member side, The clamp blade will not fit into the outer conductor, and the force to grip and fix the outer conductor will be strong, and the contact surface will not loosen even if adverse conditions such as large mechanical vibration or temperature difference are added. And a large pull-out resistance is maintained.

Also, even if the connector is disassembled and removed when replacing the relay housing, etc., the cable side end of the connector is not disassembled and is maintained as it is, and it is possible to maintain high reliability as before after reassembly, Since the inner shell and the outer conductor end are directly connected by the outer conductor contact, the current does not bypass the outer surface of the outer conductor as in the conventional example, and the intrusion of external noise can be minimized.

[Embodiment] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of a connector according to the present invention, and the same reference numerals as those in FIG. 9 show substantially the same structure.

The washer 20 is also present in the conventional example, although not particularly described in FIG.
Therefore, the features of the present invention reside in the inner taper sleeve 21, the outer taper sleeve 22, and the outer conductor contact 24.

These will be described in detail below.

First, the cable 1 in which the central conductor 5 is stripped off and projected has the jacket 2 in a state in which the gasket tightening fitting 9, the gasket 11, the tightening fitting 8, the washer 20, and the outer taper sleeve 22 are temporarily mounted in advance. The inner taper sleeve 21 is fitted into the end of the outer conductor 3 as it is.

FIG. 4 is a vertical sectional view showing a specific example of the inner tapered sleeve 21.

The inner surface of the inner taper sleeve 21 is formed in a normal cylindrical shape, while the outer peripheral surface is formed in a tapered taper surface 21A. Then, the small diameter portion of the tapered surface 21A is configured to have substantially the same diameter as the inner diameter of the outer conductor 3, but the large diameter portion side is formed appropriately larger than the inner diameter of the outer conductor 3 and is adjacent to the large diameter portion. Then, the brim portion 21a is formed, and the inner taper sleeve 21 configured as described above is fitted into the end portion of the outer conductor 3 so that the end of the outer conductor 3 having the outer cover 2 has the brim portion 21a. The outer conductor 3 having the outer cover 2 is fitted into the inner taper sleeve by fitting the outer conductor 3 until the outer conductor 3 is fitted to the inner sleeve.
As shown in the cross-sectional view of FIG. 1, it is slightly opened by 21 to a slightly opened state.

In this state, next, pull back the external taper sleeve 22 that has been temporarily attached to the cable 1 as described above.
The outer conductor 3 having the outer jacket 2 is sandwiched in a state of cooperating with the inner tapered sleeve 21.

FIG. 2 shows a vertical cross section of a specific example of the outer taper sleeve 22 which is sandwiched and mounted in such a manner.

While the tapered surface 21A of the inner tapered sleeve 21 is a taper surface which is tapered in the direction opposite to the tip of the cable 1, the inner tapered surface 22 of the outer tapered sleeve 22 is formed.
A is a taper surface of the inner sleeve 21 which is formed on the corresponding front-opening taper surface and which has the outer jacket 2
21A and the tapered surface 22A of the outer sleeve 22 are configured so that they can be properly clamped.

Then, the taper surface 22A of the outer taper sleeve 22 has a clamp blade 23 that vertically projects in the longitudinal direction of the sleeve.
The clamp blade 23 has a length that allows it to penetrate the jacket 2 of the cable 1 and reach the outer conductor 3. As described above, according to the present invention, the outer jacket 2 is not stripped and the outer jacket 2 is not removed.
Another feature is that it has a merit that it can be used for fixing an external taper clamp.

FIG. 3 is a front view of the outer taper sleeve 22 of FIG. 2 as viewed from the opening side, and shows a state in which four clamp blades 23, 23 are formed. The number of the clamp blades 23 is not limited to four, and an appropriate plurality may be selected and installed.

In this case, more preferably, when the clamp blade 23 is formed to be long and the outer taper sleeve 22 is correspondingly fitted to the inner taper sleeve 21 as shown in the enlarged sectional view of FIG. 2 is not only penetrated, but also the outer conductor 3 underneath is pressed and deformed, and a conductor housing groove 21b capable of housing the pressed and deformed outer conductor 3 is formed on the outer circumference of the inner taper sleeve 21 and then pressed and deformed. If the outer conductor 3 is made to be housed in the housing groove 21b, the outer conductor 3 can be gripped more strongly by the inner and outer taper sleeves 21 and 22.

In this case, a conductive spring material such as phosphor bronze or beryllium copper is used as the constituent material of the inner tapered sleeve 21, and a slit 21c for generating an elastic force is formed as shown in the sketch of FIG. If you do so, by making the entire outer diameter of the tapered surface 21A a little larger,
A large elastic pressing force toward the inner surface of the outer conductor 3 can be generated in the inner tapered sleeve 21, a large contact pressure can be generated between the inner tapered sleeve 21 and the outer conductor 3, and the inner tapered sleeve 21 and Outer conductor 3
The mechanical and electrical contact with can be made even stronger. At this time, a plurality of protrusions 21A extending in the longitudinal direction of the taper surface 21A are provided on the outer periphery of the taper surface 21A of the inner taper sleeve 21 as shown in FIG. 5 and a sectional view taken along line AA of FIG. _{If 1} and 21A ₁ are formed, the projection 21A ₁ can bite into the inner surface of the outer conductor 3 and strongly bond the both.

Sufficient gripping force can be secured simply by sandwiching the taper surfaces 21A and 22A, but with each of the configurations described above, the pullout resistance becomes even stronger, and the effect on electrical characteristics is further enhanced. Can be improved.

On the other hand, FIG. 8 shows a specific example of the outer conductor contact 24 provided between the inner tapered sleeve 21 and the inner shell 7, and FIG. 8A is a side view thereof and FIG. Shows the front view. This example shows an example of a spring washer configuration, but this is because it is suitable for obtaining conductivity and contact pressure, and a conductive spring material made of a low alloy (for example, low alloy beryllium copper or low alloy). Alloy phosphor bronze, etc.) is suitable. But,
The shape and composition can be appropriately selected,
It is not limited to the above examples.

In order to assemble the connector according to the present invention, the washer 20 which has been temporarily attached is returned, and the inner shell 7 and the previously-attached tightening metal fitting 8 are screwed together to form the tightening metal fitting. A pressing force in the cable tip direction is generated by 8, and the outer taper sleeve 22 is strongly pressed, whereby the clamp blade 23 pierces the jacket 2 and the clamping pressing force by the inner and outer sleeves 21 and 22 on the outer conductor 3 is exerted. By additionally forming the clamp blade 23 formed on the taper surface 22A of the outer taper sleeve 22 to a long length, the outer conductor 3 is pressed and deformed, and further deformed and stored in the conductor storage groove 21b of the inner taper sleeve. The outer conductor 3 and the inner and outer sleeves 21,
22 are integrally connected.

The pressing force given by the tightening metal fittings 8 applied to both the sleeves 21 and 22 is strongly added to the outer conductor contact 24 provided between the inner taper sleeve 21 and the inner shell 7 as well. The outer conductor contact 24 is pressed firmly against the inner shell 7 so that sufficient electrical contact between the outer conductor 3 and the inner shell 7 is achieved.

As a result, the electrical and mechanical contact between the outer conductor 3 and the inner taper sleeve 21 becomes stronger and stronger, and the outer conductor 3 and the inner shell 7 through the inner taper sleeve 21 become stronger.
The presence of the outer conductor contact 24 also strengthens the electrical and mechanical contact between the electric current and the electric current, and the electric current does not once bypass the outer surface of the outer conductor 3 unlike the conventional example shown in FIG. Directly from the inner surface of the outer conductor 3 to the inner shell 7
Is conducted to. As a result, the possibility that external radio waves are mixed in the signal of the outer conductor 3 of the coaxial cable 1 as in the conventional example is largely eliminated, and the mixing of noise due to external radio waves can be minimized.

Further, if the end portion of the outer conductor 3 in the connector is configured as described above, even if the connector is disassembled for replacement of the relay housing, for example, the inner taper sleeve 21 at the end portion of the outer conductor 3 and The fitted state of the outer taper sleeve 22 is maintained as it is, and it is possible to exert a great merit that it is possible to continue the good electrical contact state before the connector is reassembled.

[Advantage of the Invention] As described above, according to the connector of the present invention, a necessary and sufficient clamping force is applied by the inner taper sleeve fitted to the outer conductor and the outer taper sleeve attached to the outer periphery thereof. , The outer conductor is gripped mechanically firmly and excellent connection strength can be obtained, while the electrical contact can be well secured for many years. By installing the outer conductor contact, excellent high frequency characteristics are stable. It is possible to eliminate the contamination of external noise that has been seen in the past, etc.
An extremely reliable connector can be obtained, which has a number of excellent advantages.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a connector according to the present invention,
2 is a vertical cross-sectional view of an external taper sleeve used for the connector, FIG. 3 is a front view seen from the taper opening side, FIG. 4 is a vertical cross-sectional view of the internal taper sleeve, and FIG. 5 is an internal taper. FIG. 6 is a schematic view of a modified example of the sleeve, FIG. 6 is a sectional view taken along line AA of FIG. 5, and FIG. 7 is an enlarged sectional view showing a state in which the inner and outer tapered sleeves are fitted to the cable ends.
Figure (a) is a side view of an embodiment of an outer conductor contact, Figure (b) is a front view of the same, Figure 9 is a half-section sketch drawing showing the structure of a conventional connector, and Figure 10 is the clamp portion of Figure 9. FIG. 11A to FIG. 11C are enlarged cross-sectional views in the vicinity and are sketches showing specific examples of three conventionally used friction sleeves. 1: Cable, 2: Outer sheath, 3: Outer conductor, 4: Insulator, 5: Center conductor, 6: Center contact, 7: Inner shell, 8: Tightening fitting, 9:
Gasket clamp, 11: Gasket, 12, 13: Insulator, 2
0: Washer, 21: Internal taper sleeve, 22: External taper sleeve, 23: Clamp blade, 24: External conductor contact.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Mitsuaki Onuki, 3550 Kidayomachi, Tsuchiura City, Ibaraki Prefecture, Hitachi Metals Research Laboratory, Hitachi Cable, Ltd. (72) Osamu Nitta, 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture No. Hitachi Cable Co., Ltd. Hidaka Plant (56) Bibliography Shou 60-192387 (JP, U) Sui 55-75977 (JP, U) Sui 61-87486 (JP, U)

Claims (2)

[Scope of utility model registration request] 1. A center contact 6 connected to a center conductor 5 of a coaxial cable that is stripped and projected, an inner shell 7 coaxially arranged on the center contact 6, and a screw fit to the inner shell 7. , A connector having a tightening member 8 for generating a pressing force in the cable tip direction and a gasket tightening member 9 for applying a tightening force to the sealing gasket 11, wherein the cable is provided inside the outer conductor 3 that does not strip the outer cover 2. A tapered taper surface in the opposite direction to the tip is formed,
The small diameter side of the tapered surface is approximately equal to the inner diameter of the outer conductor 3, and the large diameter side is fitted with an inner taper sleeve 21 formed to be appropriately larger than the inner diameter of the outer conductor 3, and its outer jacket 2
On the outer peripheral side of the outer taper, a small diameter portion is approximately equal to the outer diameter of the cable jacket 2, and a large diameter portion has an inner taper surface that matches the outer taper surface of the cable end portion into which the inner taper sleeve 21 is fitted. A sleeve 22 is fitted to correspond to the inner taper sleeve 21, and the outer taper sleeve 22 is provided with a plurality of vertical clamp blades 23 protruding inward in the longitudinal direction of the taper surface so as to reach at least the outer conductor 3. A coaxial connector which is formed and is provided between the inner tapered sleeve 21 and the inner shell 7 with an outer conductor contact 24 for electrically connecting them. 2. The inner taper sleeve 21 is made of a conductive spring material, and the outer circumference of the inner taper sleeve 21 corresponding to the vertical clamp blade 23 of the outer taper sleeve 22 is pressed and deformed by the clamp blade 23. 2. The coaxial connector according to claim 1, wherein a conductor accommodating groove for accommodating the conductor 3 is formed, and a vertical split slit is formed in the inner taper sleeve 21 to generate an elastic force.