JP2902333B2 - Coaxial plug - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coaxial plug used as an output terminal of a coaxial cable for transmitting electric signals such as CATV.

[0002]

2. Description of the Related Art A coaxial plug used for an output terminal of a coaxial cable of this type is connected to a coaxial connector connected to a device such as a TV. When no equipment is provided at the output terminal of the coaxial cable, the coaxial connector is disconnected, and the terminal becomes a so-called empty terminal. A TV that has been commonly used for home listening and radio interference
In the case of retransmission, there is almost no signal transmitted to an adjacent channel, so that even if the terminal is left empty, the occurrence of a failure or the like in a TV that is provided elsewhere did not cause much problem.

However, in the case of a CATV system such as multi-channel transmission and bidirectional CATV, which has recently been introduced, a large number of channels are used, so that signals are also transmitted to adjacent channels, and empty terminals are used. If it is left as it is, a failure or the like will occur in other TVs and the like that are deployed for the following reasons, which is a problem.

[0004] Referring to FIGS. 9 and 10, the failure mode will be described with reference to FIGS. 9 and 10. As shown in FIG.
Since R (voltage standing wave ratio) becomes infinite, a signal is shifted in phase by a reflected wave from the B side terminal, and the signal is degraded. Then, a ghost occurs in a TV or the like connected to the A terminal. Furthermore, amplitude fluctuations also occur due to the phase shift, and the frequency characteristics are degraded.
Also, during BS / CS-IF transmission, the satellite broadcast signal
Since the M modulation is used, truncation noise occurs, and energy diffusion removal failure occurs. Note that the CATV also performs FM modulation, so the same trouble occurs.

[0005] Further, as shown in FIG.
The side B of the splitter of the V system is an empty terminal,
If the coaxial core wire is exposed, external noise will get on the coaxial core wire, and the noise on the vacant terminals of many terminals will be synthesized and go up to the center side. This is called ingress noise. In addition, noise is not only applied to the coaxial core wire, but also to the coaxial cable itself, and if noise from a large number of coaxial cables is combined, the noise also becomes ingress noise. The upstream line cannot be used due to ingress noise.

FIG. 11 shows the return loss characteristics when the output terminal of the series unit is an empty terminal and when the terminal is terminated by a dummy resistor. Although a reflection loss of 20 dB or more can be obtained, when the terminal is a vacant terminal, only a reflection loss of about 15 dB as shown by B is obtained.

FIG. 12 shows the return loss characteristics when the tap-off output terminal branched into four terminals is an empty terminal and when the terminal is terminated by a dummy resistor. Approximately 20
Although a reflection loss of not less than dB is obtained, when one terminal is an empty terminal, the reflection loss characteristic deteriorates so as to undulate as shown by B, and when two terminals are empty terminals, it is shown as C. As described above, only a reflection loss of about 15 dB can be obtained. Further, when three terminals are vacant terminals, only about 12 dB of reflection loss is obtained as shown as D, and when all four terminals are vacant terminals, about 8 dB as shown as E, Only the reflection loss is obtained.

By the way, conventionally, a dummy plug is connected to an empty terminal of a coaxial connector so that such a trouble does not occur. Such a dummy plug is actually fair 6-1.
No. 7363, which will be described with reference to FIG. In this figure, 01 is a dummy plug, 02
Is a center contact, 03 is a dummy resistor having the characteristic impedance of a coaxial cable, 04 is a shell, 05 is a soldering part for connecting the dummy resistor 03 to the shell 04,
06 is a connection nut. And this dummy plug 0
1 is connected to a coaxial connector (not shown), the transmitted electric signal flows into the center contact 02 of the dummy plug 01 via the center contact of the coaxial connector, and the dummy resistor 03, the soldered portion 05, the shell 04, and the connection It is grounded via a nut 06 to the connector body of the coaxial connector. Thus, by terminating the electric signal by the dummy resistor 03 of the dummy plug 01, reflection of the electric signal and intrusion of external noise are prevented.

[0009]

However, it is necessary to attach a dummy connector to the empty terminal when equipment is removed from the output terminal provided at the end of the coaxial cable. Dummy connectors are rarely installed because they are not common. In particular, in ordinary households, as a custom, dummy connectors are hardly attached even if there are empty terminals.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coaxial plug which is used as an output terminal of a coaxial cable and does not cause any trouble even when the terminal is left empty.

[0011]

In order to achieve the above object, a coaxial plug according to the present invention comprises a substantially cylindrical shell, a center contact to which an electric signal is inputted, and a substantially central axis of the shell. A coaxial plug comprising an insulator for arranging a center contact and a connection nut for connecting to a coaxial connector, wherein the coaxial plug is substantially perpendicular to a center axis thereof in the shell.
A circuit board to which one end of the switch member is connected is provided.
In the middle of the center contact, other than the switch member
The switch member is biased so that the ends come into contact,
In a state where the coaxial connector is not connected to the coaxial plug
Wherein the center contact is provided on the circuit board.
Terminated by a dummy resistor
When the connector is connected, the central connector
Energized by an insulating spring to slide on the tact
Switch actuating member slides against the insulating spring.
And its tip is connected to the center contact and the switch.
Between the center contact and the switch.
The switch member is detached and turned off.

In the above coaxial plug, the circuit
One side of the board is grounded and a noise shield plate
It may be formed. Furthermore, to the above coaxial plug
The step is formed on the inner surface of the shell.
By pressing the circuit board into contact, the ground portion of the circuit board is
May be connected to the shell.

[0013]

According to the present invention, the above object can be achieved.
The other coaxial plug includes a substantially cylindrical shell, a center contact to which an electric signal is input, an insulator for arranging the center contact substantially in the shape of a center axis of the shell, and a connection nut for connecting to a coaxial connector. In the coaxial plug, a circuit board to which one end of a switch member is connected substantially perpendicularly to a central axis of the switch member is disposed within the shell, and the other end of the switch member is pressed against the middle of the center contact. In a state where the cross section of the switch member is formed in a V shape, and the coaxial connector is not connected to the coaxial plug, the center contact is terminated by a dummy resistor provided on the circuit board, and the central contact is coaxial with the coaxial plug. When the connector is connected, a switch actuating member provided to slide on the shaft in the shell slides, and Tapered portion which is tapered in the switch actuating member enters between the switch member and the center contact, the switch member from the center contact is obtained so as to be turned off disengaged.

Further, in the above another coaxial plug of the present invention , when the coaxial connector is detached from the coaxial plug, the elasticity of the switch member pushes back the tapered portion of the switch operating member, and The operation member returns to the initial state.

In the coaxial plug of the present invention, when the coaxial connector is not connected to the coaxial plug, the electric signal transmitted from the coaxial cable is transmitted to the center contact, and the electric signal of the circuit board is transmitted through the switch member. Input to the circuit. The electric circuit is provided with a dummy resistor, and an electric signal is transmitted to the shell of the coaxial plug and grounded through the dummy resistor.

When the coaxial connector is connected to the empty coaxial plug, the switch operating member moves to the coaxial cable connection side against the urging force of the elastic body, and the switch member contacts the center contact. Withdraw. Therefore, the circuit for grounding the electric signal is shut off. Further, since the center contact of the coaxial plug is connected to the center contact of the coaxial connector, the electric signal transmitted from the coaxial cable is input to the coaxial connector via the center contact of the coaxial plug and the center contact of the coaxial connector. Further, when the coaxial connector is detached from the coaxial plug, the switch operating member is pushed back to the initial position by the elasticity of the switch member, and the switch member comes into contact with the center contact again.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a coaxial plug according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a coaxial plug according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view when a coaxial connector is connected to the coaxial plug of FIG. 1, and FIG. 3 is an exploded perspective view of the coaxial plug. FIG.

In these figures, D is a coaxial cable through which a CATV signal is transmitted, P is a coaxial plug to which a coaxial cable D is connected, and in the case of the first embodiment, it is an F-type plug. Have been. C is a coaxial connector connected to the coaxial plug P. Reference numeral 1 denotes a conductive core wire of the coaxial cable D, 2 denotes an insulator covering the core wire 1 of the coaxial cable D, 3 denotes a conductive ground mesh wire of the coaxial cable D, and 4 denotes an insulating outside of the coaxial cable D. Reference numeral 5 denotes a crimp ring for fixing the coaxial cable D to the coaxial plug P.

Reference numeral 11 denotes a center contact of the coaxial plug P made of a conductive metal, and 12 denotes a center contact of the center contact 1.
A slot is provided so that the core wire 1 of the coaxial cable D is inserted and held at the connection portion 1. 14 is a holder made of insulating synthetic resin for holding the center contact 11;
Is a guide portion of the holding body 14 which is an insulator, and guides the core wire 1 of the coaxial cable D when the core wire 1 is inserted into the connection portion 12 of the center contact 11. Reference numeral 17 denotes a shell constituting a cylindrical shell on the outer side of the coaxial plug P, which is made of conductive metal. Reference numeral 18 denotes a resilient claw portion of the shell 17 formed at the end on the side to which the coaxial cable D is connected. The coaxial cable D together with the crimp ring 5 is prevented from coming off the coaxial plug P. Reference numeral 19 denotes a tapered clamp formed in a tapered shape in which the outer diameter gradually decreases toward the tip where the reed claw 18 is formed. The crimp ring 5 is swaged with the coaxial cable D connected to the coaxial plug P. When,
The distance between the crimp ring 5 and the taper clamp portion 19 is gradually reduced, and the crimp ring 5 is crimped on the earth mesh wire 3 and the coating 4 of the coaxial cable D to the shell 17 and fixed. Reference numeral 20 denotes a holder locking step for locking the holder 14, and reference numeral 21 denotes a substrate locking step.

Reference numeral 23 denotes a donut plate-shaped circuit board arranged substantially perpendicular to the center contact 11, which is arranged so as to cover the inside of the shell 17, and in which the entire surface of the coaxial connector connection side is grounded to allow noise to enter. Has been prevented. Reference numeral 24 denotes one end of the electric circuit of the circuit board 23, which is in contact with the shell 17. 25 is a small chip resistor which is provided in the middle of the electric circuit of the circuit board 23, for example, a 75 ohm dummy resistor, and 26 is a small chip resistor which is similarly provided in the middle of the electric circuit of the circuit board 23. It is a chip capacitor. Reference numeral 27 denotes the other end of the electric circuit on the circuit board 23. Reference numeral 28 denotes a switch member made of a conductive elastic metal, one end of which is connected to the other end 27 of the electric circuit of the circuit board 23, and the other end of which is in contact with the center contact 11.

Reference numeral 29 denotes a cylindrical connecting member made of a conductive metal, which is press-fitted into the shell 17, the tip of the shell 17 is caulked after the press-fitting, and the body of the connecting member 29 is fixed to the inner surface of the shell 17. . One end of the connector 29 is connected to the circuit board 2.
3 and pressed against it. Due to this pressing, one end 24 of the electric circuit of the circuit board 23 and the shell 17 are pressed against each other, and the electrical connection is secured. On the other hand, at the other end of the connecting body 29, a step portion 30 for locking the switch operating member 34 is formed on the inner surface, and a step portion 31 for rotatably locking the connection nut 38 is formed on the outer surface. I have.

Reference numeral 33 denotes a synthetic rubber resin spring which is a cylindrical elastic member disposed inside the connecting member 29, and reference numeral 34 denotes a switch operating member made of an insulating synthetic resin material. 35
Is a switch cam formed on the switch actuating member 34, the inner surface of which is cylindrical in cross section and is slidably supported by the center contact 11. The outer surface of the switch cam portion 35 has a truncated cone-shaped cam surface. An engagement portion 36 of the switch operating member 34 contacts the step 30 for the switch operating member of the connecting body 29 to prevent the switch operating member 34 from coming off the connecting body 29 to the outside. The switch actuating member 34 is constantly urged toward the coaxial connector C connection side by the insulating resin spring 33. However, when pressed against the coaxial cable D connection side, the center contact resists the urging force of the resin spring 33. 11 while being guided by the coaxial cable D.

Reference numeral 38 denotes a connection nut made of a conductive metal, which is rotatably supported by the connecting body 29. Reference numeral 39 denotes a retaining step which can be brought into contact with the connecting nut step 31 of the connecting body 29, which prevents the connecting nut 38 from coming off the connecting body 29. Reference numeral 40 denotes a female screw portion formed on the inner surface of the connection nut 38. Reference numeral 51 denotes a male screw portion formed on the outer surface of the coaxial connector C.

In FIG. 3, the center contact 11 is inserted into the holding member 14, and then the holding member 14 is fitted with the circuit board 23 on which the switch member 28 is fitted. The holding body 14 thus combined is inserted into the shell 17. On the other hand, connected body 2
9, the switch operating member 34 and the resin spring 33 are inserted, and the connection nut 38 is fitted to the outside of the connecting body 29. Then, the connecting body 29 is fitted into the shell 17 into which the holding body 14 is inserted, pressed, and the end of the shell 17 on the connecting body 29 side is caulked to fix and connect the shell 17 and the connecting body 29.

When connecting the coaxial plug P to the coaxial cable D, the core wire 1 of the coaxial cable D is connected to the connecting portion 12 of the center contact 11 provided on the coaxial plug P as shown in FIG. Insert and connect. Further, the taper clamp 19 of the shell 17 of the coaxial plug P is inserted between the insulator 2 of the coaxial cable D and the ground mesh wire 3 so that the taper clamp 19 and the ground mesh wire 3 are inserted.
And contact. Then, the crimp ring 5 previously fitted to the coaxial cable D is swaged with pliers or the like. Then, the earth mesh wire 3 and the coating 4 are sandwiched by the crimp ring 5 and the taper clamp 19, and the coaxial cable D is fixed to the coaxial plug P. Then, even if the coaxial cable D is pulled in a direction to separate from the coaxial plug P, the coaxial cable D
And the coaxial plug P are prevented from being displaced relative to each other.

When an electric signal flows through the core wire 1 of the coaxial cable D when the coaxial connector C is not connected to the coaxial plug P and is the empty terminal shown in FIG. The signal is input to the center contact 11.
In the case of a conventional coaxial plug, since nothing is electrically in contact with the center contact 11, the light is reflected and returns to the original core wire 1 of the coaxial cable D. However, in the case of the coaxial plug of the present invention, since the switch member 28 is in contact, an electric signal flows through the switch member 28 to the electric circuit of the circuit board 23, and the small chip disposed in the electric circuit. Resistor 25 and small chip capacitor 2
6 through the series circuit 6 and into the shell 17 from the end 24 of the electric circuit. Then, the ground mesh wire 3 of the coaxial cable D passes through the taper clamp portion 19 of the shell 17.
Grounded. With such a configuration, even if the coaxial plug P becomes an empty terminal, it is possible to prevent the electric signal from the coaxial cable D from being reflected, and also prevent the center contact 11 from picking up external noise. .

When the coaxial connector C is connected to the coaxial plug P, which is an empty terminal, as shown in FIG.
The male screw portion 51 of the coaxial connector C is screwed into the female screw portion 40 of the connection nut 38 of the coaxial plug P. Then, the center contact 11 of the coaxial plug P is inserted and connected to the center contact (not shown) of the coaxial connector C. Also,
The distal end of the coaxial connector C presses the switch operating member 34 to displace the switch operating member 34 toward the coaxial cable connection side against the elastic force of the resin spring 33, that is, the urging force. Then, the switch cam portion 35 of the insulating switch operating member 34 enters between the switch member 28 and the center contact 11 of the coaxial plug P to release the contact between the center contact 11 and the switch member 28, and To the small chip resistor 25 is cut off. Therefore, an electric signal can be input from the center contact 11 of the coaxial plug P to the center contact of the coaxial connector C as in the conventional case.

Next, the coaxial connector C is connected to the coaxial plug P
2, the switch operating member 34 returns from the state of FIG. 2 to the state of FIG. 1 by the urging force of the resin spring 33, and the switch member 28 contacts the center contact 11 and is grounded via the small chip resistor 25. . Then, the state returns to the state of the empty terminal.

Next, a second embodiment of the present invention will be described with reference to FIG. In the description of the second embodiment, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 4, 4
Reference numeral 1 denotes a conductive earth spring for the circuit board 23, one end of which contacts the end 24 of the electric circuit of the circuit board 23, and the other end of which contacts the shell 17. 42 is a connection case body,
43 is a connection spring provided in place of the female screw. The coaxial plug P of the second embodiment is a one-touch plug.

The second embodiment differs from the first embodiment in that the electric circuit on the circuit board 23 is grounded by using a ground spring 41. Further, the connecting body 29 of the first embodiment is not arranged, and a connecting case main body 42 is provided instead of the connecting nut 38.
The distal end of the connection case body 42 is press-fitted into the shell 17 and caulked and fixed. The connection with the coaxial connector C (not shown) is performed by a connection spring 43 provided on the connection case main body 42, similarly to a conventional one-touch plug, instead of screwing. The operation when the coaxial connector C is connected to the coaxial plug P is the same as that of the first embodiment, and will not be described.

Next, the detailed structure of the circuit board 23 is shown in FIG. As shown in this figure, the circuit board 23 on the disk has a ground plane 23-1 formed of copper foil on one entire surface of the insulating plate 23-2 and the other side as shown in FIG. As shown in FIG. 7C, a printed line 23-3 is formed, and a chip resistor 25 and a chip capacitor 2 are formed.
6 are surface-mounted so as to face each other, and the chip resistor 25 and the chip capacitor 26 are connected to the print line 2.
They are connected in series by 3-3.

Then, the circuit board 23 is fitted into a ground spring 41 as shown in FIG. 4D, so that a ground plane 23-1 formed on one surface of the circuit board 23 is grounded via the ground spring 41. I have. Further, the printed line 23-3 to which the chip resistor 25 not connected to the chip capacitor 26 is connected is also connected to the ground spring 4
1 to be grounded. It should be noted that FIG.
As shown in FIG. 7, a switch member 28 is electrically connected to a ring-shaped copper foil portion around a central square hole by soldering or the like. This switch member extends in the opposite direction to the earth spring 41 and acts as a switch for the center contact 8 as described above. Note that FIG.
Circuit boards 23 shown in e and f are applied to the second embodiment, and the circuit boards 2 shown in FIGS.
When the switch member 28 is mounted on the circuit board 3 as shown in FIGS. 3E and 3F, a circuit board 23 applicable to the first embodiment can be obtained.

FIG. 6 shows the configuration of a third embodiment of the coaxial plug of the present invention. In the description of the third embodiment, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted. This third embodiment will be described with respect to the configuration of a portion different from that of the above-described first embodiment. In the third embodiment, the configuration of the switch member 28 ′ and the switch operation member 3
The configuration of the 4 ′ switch cam portion 35 ′ is different, and the resin spring 33 is omitted.

As will be described later, the cross section of the spring portion of the switch member 28 'is formed in a V shape, so that the second moment of area is increased. For this reason, the spring pressure of the switch member 28 'is about twice that of the first and second embodiments. Further, the inclination of the taper of the switch cam portion 35 'is tight. In the first and second embodiments, the taper angle is about 20 °, but in this example, the taper angle is about 30 ° to 45 °. As described above, when the angle of the taper of the switch cam portion 35 'is tight, the switch cam portion 35' is pushed back by the spring force of the switch member 28 'when the coaxial connector connected to the coaxial plug is detached. Resin spring 3
Even if the step 3 is omitted, the switch operating member 34 'is returned to the initial position.

This will be described in more detail with reference to FIG. 7. When the coaxial connector is connected to the coaxial plug, the switch operating member 34 'slides into the connecting body 29 as shown in FIG. It is pushed in. At this time, the tip of the switch cam portion 35 'of the switch operating member 34' penetrates into the switch member 28 'so as to push the switch member 28' open, resulting in the state shown by the solid line in FIG. At this time, the tip of the switch member 28 'comes into pressure contact with the tapered portion of the switch cam portion 35', but the axial force component W1 of the pressure contact force W causes the switch cam portion 35 '.
Will be pushed back. The component force W1 increases as the tapered portion of the switch cam portion 35 'becomes tighter, and increases as the spring force of the switch member 28' increases.

Therefore, in the third embodiment, the tapered portion of the switch cam portion 35 'is made tight and the spring force of the switch member 28' is increased. Thereby, when the coaxial connector is detached from the coaxial plug, the switch operating member 34 'is pushed back to the initial position by the component force W1 without requiring a resin spring or the like.

Next, the detailed structure of the switch member 28 'is shown in FIG. In this figure, (a) is a front view, (b) is a side view, (c) is a sectional view of a spring portion, and (d) is a sectional view of a base. The switch member 28 'is formed by a spring portion 28-1 for pressing the center contact 11, a base portion 28-4 on which the spring portion 28-1 extends, and a part of the base portion 28-4 cut and raised. Cut-and-raised piece 28-2 and base 28-4
And a flange portion 28-3 formed at the end of the upper portion.

The cross section of the spring portion 28-1 is formed in a V shape as shown in the AA cross section shown in FIG. 3C, and the secondary moment is increased. As a result, it is possible to generate a pressure contact force for sufficiently pushing back the switch cam portion 35 '. The cut and raised piece 28-2 is a switch member 28 '.
Is inserted into the mounting hole of the circuit board 23, it passes through the mounting hole and engages with the mounting hole, and the switch member 28 '
It is provided so as not to deviate from 3.

The electrical characteristics of the coaxial plugs of the first, second, and third embodiments of the present invention described above are such that the circuit board 2 is provided in the coaxial plug.
Although it seems that the characteristics of the VSWR and the like are deteriorated due to the storage of the metal component 3 and metal components, the reflection characteristics of the coaxial plug of the present invention are actually measured as shown in FIG. The characteristics are almost the same as the characteristics, and it is possible to obtain the same good reflection characteristics as in the conventional case where the separate dummy plug 01 is connected to the coaxial connector and terminated.
In particular, in the third embodiment, since the resin spring can be omitted, the electric characteristics are further improved. As described above, according to the present invention, it is possible to improve the transmission quality without terminating the unused terminals of the coaxial plug by any means.

Incidentally, the third embodiment is described with reference to FIG.
However, the present invention can be applied to the second embodiment shown in FIG. 4, and the resin spring can be omitted. In the above description, the small chip resistor 25 is set to 75 ohms, but since the resistance value is set to a value corresponding to the characteristic impedance of the coaxial cable D, 75 ohms or 50 ohms is generally used. A small chip capacitor 26 is provided on the circuit board 23. The small chip capacitor 26 is for cutting a DC voltage for transmitting a coaxial cable, and can be omitted as appropriate when a DC voltage is not transmitted.

The resin spring 33 can be appropriately replaced with another elastic body such as a coil spring, but it is preferable that the elastic body has an insulating property in view of impedance matching. Further, the resin spring 33 also has a function of elastically pressing the circuit board 23, and in the case of the first embodiment, the circuit board 23 is electrically stabilized by the interaction with the connector 29. Can be brought into contact with the step portion 21.

[0043]

According to the present invention, when the coaxial connector is not connected to the coaxial plug, the electric signal transmitted from the coaxial cable is transmitted to the center contact and is transmitted through the switch member. Input to the electric circuit of the circuit board. The electrical circuit is provided with a resistor, through which the electrical signal is transmitted to the shell of the coaxial plug and grounded. Therefore, even if the coaxial plug becomes an empty terminal, it is possible to prevent the electric signal from the coaxial cable from being reflected, and also prevent the center contact from picking up external noise.

Further, when a coaxial connector is connected to the coaxial plug of the present invention, a circuit board provided with a dummy resistor or the like or a structure for turning on / off the dummy resistor is housed in the coaxial plug. Nevertheless, it is possible to maintain the same electrical characteristics as the conventional coaxial plug. Furthermore, since the shell has a cylindrical shape and a step portion is formed therein, and one end of an electric circuit of the circuit board inserted and arranged inside the shell is in direct contact with the step portion of the shell, A member such as a ground spring is not required for grounding between the electric circuit of the circuit board and the shell, so that the number of assembly steps and the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a coaxial plug according to a first embodiment of the present invention.

FIG. 2 is a sectional view when a coaxial connector is connected to the coaxial plug of FIG. 1;

FIG. 3 is an exploded perspective view of the coaxial plug.

FIG. 4 is a sectional view of a coaxial plug according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a detailed configuration of a circuit board.

FIG. 6 is a sectional view of a coaxial plug according to a third embodiment of the present invention.

FIG. 7 is a diagram for explaining a relationship between a switch member and a switch cam portion in a third embodiment.

FIG. 8 is a diagram showing a detailed configuration of a switch member.

FIG. 9 is a diagram for explaining connection of home appliances in the CATV system.

FIG. 10 is a diagram for explaining connection of home appliances in a two-way CATV system.

FIG. 11 is a characteristic diagram in a case where the output terminal of the series unit is an empty terminal and a case where the output terminal is terminated by a dummy resistor.

FIG. 12 is a characteristic diagram of the return loss characteristic when the tap-off output terminal branched into four is an empty terminal and when the terminal is terminated by a dummy resistor.

FIG. 13 is a partially cutaway sectional view of a dummy plug.

[Explanation of symbols]

 C Coaxial Connector D Coaxial Cable P Coaxial Plug 11 Center Contact 14 Holder (Insulator) 17 Shell 21 Board Locking Step 23 Circuit Board 25 Chip Resistance (Dummy Resistance) 28 Switch Member 34 Switch Operation Member 38 Connection Nut

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihiro Hirukawa 4-8-33 Shibaura, Minato-ku, Tokyo Inside Kandenko Co., Ltd. (72) Inventor Tadao Makita 4-83-33 Shibaura, Minato-ku, Tokyo (56) References JP-A-6-295771 (JP, A) JP-A-59-76083 (JP, U) JP-A-1-158676 (JP, U) JP-A-59-65482 (JP, U) Japanese Utility Model Showa 61-194970 (JP, U) Japanese Utility Model Showa 63-15582 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01R 13/56-13 / 72 H01R 17/04

Claims (5)

(57) [Claims] 1. A substantially cylindrical shell, a center contact to which an electric signal is input, an insulator for arranging the center contact on a substantially center axis of the shell, and a connection nut for connecting to a coaxial connector. In the coaxial plug provided, a circuit board to which one end of a switch member is connected substantially perpendicularly to a central axis thereof is disposed within the shell, and the switch is arranged such that the other end of the switch member comes into contact with the center contact in the middle. When the member is biased and the coaxial connector is not connected to the coaxial plug, the center contact is terminated by a dummy resistor provided on the circuit board, and when the coaxial connector is connected to the coaxial plug, The central contact in the shell
The switch actuating member urged by an insulating spring to slide on the switch slides against the insulating spring, and its tip is located between the center contact and the switch member. A coaxial plug, wherein the switch member is separated from the center contact and is turned off. Wherein the entire surface ground to one side of the circuit board, the coaxial plug according to claim 1, characterized in that so as to form a shield plate of the noise. 3. A step formed on the inner surface of the shell,
The ground portion of the circuit board is connected to the shell by press-contacting the circuit board.
The coaxial plug according to 1 . 4. A substantially cylindrical shell, a center contact to which an electric signal is input, an insulator for arranging the center contact substantially in the center axis of the shell, and a connection nut for connecting to a coaxial connector. In the coaxial plug provided, a circuit board to which one end of a switch member is connected substantially perpendicularly to a central axis thereof is provided in the shell, and the other end of the switch member is pressed against the center contact. In a state where the cross section of the switch member is formed in a V shape, and the coaxial connector is not connected to the coaxial plug, the center contact is terminated by a dummy resistor provided on the circuit board, and the coaxial connector is connected to the coaxial plug. Is connected, a switch actuating member provided in the shell to slide on its axis slides, and the switch Coaxial plug tapered portion which is tapered Ji actuating member enters between the switch member and the center contact, the switch member from the central contact, characterized in that it is turned off disengaged. 5. When the coaxial connector is detached from the coaxial plug, the elasticity of the switch member pushes back the tapered portion of the switch operation member, thereby returning the switch operation member to an initial state. The coaxial plug according to claim 4, wherein