JP2012104231A - Cable device, connector for leaky coaxial cable, and wireless communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an LCX cable to be effectively utilized in a subfreezing environment, by allowing condensation and freezing of a sheath to be suppressed even when the LCX cable is used in a subfreezing environment.SOLUTION: A cable device for use in a subfreezing environment comprises: a leaky coaxial cable 10 in which an external conductor is coaxially provided so as to surround the peripheral surface of an inner conductor via an insulator and is provided with periodic slots; a connector 20 connected to one end side of the leaky coaxial cable 10; and a heater 30 attached to the connector 20 and heating the external conductor of the leaky coaxial cable 10 via the connector 20.

Description

  Embodiments of the present invention relate to a cable device for using a leaky coaxial cable in a sub-freezing environment. Furthermore, the present invention relates to a connector for a leaky coaxial cable used in a cable device and a wireless communication system using the cable device.

  A leaky coaxial cable in which a slot having a constant period corresponding to a use frequency is provided on an outer conductor is used to uniformly radiate radio waves in the longitudinal direction of the cable. The industry that introduces this leaky coaxial cable is the steel industry and the like, and it is sold mainly for introduction in a relatively high temperature environment.

  In the future, the target of leaky coaxial cables is expected to expand more and more, and in some cases, it is expected to be used in sub-freezing environments. However, when a leaky coaxial cable is used in a sub-freezing environment, it is expected that the outer sheath of the cable will dew and freeze, leading to deterioration of the communication state.

JP-A-5-282924

  One embodiment of the present invention is a cable device that can suppress dew condensation and freezing of the outer skin even when the leaky coaxial cable is used in a sub-freezing environment, and enables effective use of the leaky coaxial cable in a sub-freezing environment. A connector for a leaky coaxial cable and a wireless communication system are provided.

  According to the embodiment, in a cable device used in a sub-freezing environment, an outer conductor is coaxially provided via an insulator so as to surround a peripheral surface of the inner conductor, and a slot having a constant period is provided in the outer conductor. A leaky coaxial cable provided; a connector connected to one end of the leaky coaxial cable; and a heater attached to the connector for heating the outer conductor of the leaky coaxial cable via the connector. It is characterized by.

The perspective view which shows schematic structure of the cable apparatus concerning 1st Embodiment. The side view and sectional drawing which show the structure of the leaky coaxial cable used for 1st Embodiment. The perspective view which shows the structure of the connector for leaky coaxial cables used for 1st Embodiment. The top view which shows typically the structure of the heater used for 1st Embodiment. The perspective view which shows the mode of the assembly of the cable apparatus concerning 1st Embodiment. The schematic diagram which shows the usage example of the cable apparatus concerning 1st Embodiment. The perspective view which shows schematic structure of the cable apparatus concerning 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing a schematic configuration of the cable device according to the first embodiment.

  Reference numeral 10 in the figure denotes a leaky coaxial cable (hereinafter abbreviated as LCX cable), and an LCX cable connector 20 is attached to one end of the LCX cable 10. A ring heater 30 is attached to the side of the connector 20 opposite to the cable 10. In the cable device including the LCX cable 10, the connector 20, and the heater 30, the heater 30 is sandwiched between the connector 20 and the terminator 40 by attaching the terminator 40 to one end of the connector 20. Yes.

  The LCX cable 10 includes an inner conductor 11, an insulator 12, an outer conductor 13, a slot 14, and a jacket 15 as shown in the side view of FIG. 2A and the cross-sectional view of FIG. Yes. That is, the insulator 12 such as polyethylene is formed so as to surround the peripheral surface of the inner conductor 11 made of aluminum or copper pipe. An outer conductor 13 made of aluminum or the like is formed so as to surround the peripheral surface of the insulator 12. The outer conductor 13 is formed with slots 14 having a constant period corresponding to the operating frequency. The outer conductor 13 is covered with a jacket 15 made of polyethylene or the like.

  A support wire 16 is provided in parallel with the inner conductor 11 in a state insulated from the outer conductor 13 by the jacket 15. The support wire 16 is covered with a jacket 15 similarly to the outer conductor 13 and is integrated with the LCX cable 10. The support wire 16 is, for example, a stranded wire of galvanized steel, is stronger in strength than the LCX cable 10, and supports the LCX cable 10. When sufficient strength can be obtained with the LCX cable 10 alone, the support wire 16 is not necessary.

  As shown in FIG. 3, the connector 20 is a kind of N-type connector, and includes a cylindrical housing 21 into which an LCX cable is inserted at one end side, and a cylindrical protrusion provided at the other end side of the housing 21. 22 and a pin 24 provided at the center of the protrusion 22.

  The housing 21 is made of a metal material, contacts the outer conductor 13 of the LCX cable 10 inserted from one end side, and is electrically connected. The protrusion 22 has a smaller diameter than the housing 21, is provided coaxially with the housing 21, and is formed integrally with the housing 21. A screw portion 23 is provided on a part of the outer peripheral surface of the protrusion 22. The pin 24 is provided so as to be insulated from the protrusion 22 and coaxially with the protrusion 22. The pin 24 is connected to the inner conductor 11 of the LCX cable 10 inserted in the housing 21.

  The pin 24 is connected to the inner conductor 11 of the LCX cable 10, but the pin 24 can be omitted and the inner conductor 11 itself can be used as the pin of the connector 20.

  As shown in FIG. 4, the ring-shaped heater 30 is provided with a lead portion 32 in a part of a disk body 31 having a hole for insertion into the protruding portion 22 of the connector 20. A resistor 33 is arranged on the disc body 31 along the circumferential direction, and this resistor 33 is energized and heated via the lead portion 32.

  The terminator 40 has a termination resistor inside and is connected to the connector 20, and has a screw portion corresponding to the screw portion 23 of the protrusion 22 of the connector 20.

  In the present embodiment, as shown in FIG. 5, the heater 30 is fitted into the protrusion 22 of the connector 20 with the LCX cable 10 attached to the connector 20. Then, by attaching the terminator 40 to the connector 20 by fastening screws, the state shown in FIG. 1 is obtained. At this time, the heater 30 is sandwiched between the connector 20 and the terminator 40 by the fastening of the screw, and is in close contact with one end surface of the connector 20.

  FIG. 6 is a schematic diagram showing an example of use of the cable device according to the present embodiment, and constitutes a wireless communication system.

  Most of the LCX cable 10 is installed in a sub-freezing environment, and both ends are installed in a room temperature environment. In the figure, reference numeral 100 denotes a freezing room for generating a sub-freezing environment, and the LCX cable 10 is installed so as to cross the freezing room 100. Alternatively, the LCX cable 10 may be installed in the atmosphere of a freezing environment, and both ends of the cable 10 may be indoors in a room temperature environment.

  The connectors 20 shown in FIG. 3 are connected to both ends of the LCX cable 10. One connector 20 is connected to the antenna terminal 111 of the wireless communication device 110 installed in a room temperature environment. A heater 30 shown in FIG. 4 is attached to the other connector 20, and a terminator 40 is connected to the connector 20 to which the heater 30 is attached. Here, the heater 30 may be attached to the connector 20 on the wireless communication device side, not necessarily on the terminator side.

  In such a configuration, when a high-frequency signal is output from the wireless communication device 110 to the LCX cable 10, radio waves leak from the slot 14 of the LCX cable 10, so that wireless communication in a sub-freezing environment is possible.

  At this time, the heater 30 attached to the connector 20 is energized and heated. Since the heater 30 is in close contact with the connector 20, the heat of the heater 30 is efficiently transmitted to the connector 20. Furthermore, since the connector 20 is connected to the outer conductor 13 of the LCX cable 10, heat can be efficiently transmitted to the outer conductor 13 via the connector 20. For this reason, it is possible to prevent condensation or icing of the outer skin 15 of the LCX cable 10 in a sub-freezing environment.

  Condensation and icing of the outer skin 15 are not so much a problem with a normal coaxial cable, but with the LCX cable 10, since the radio wave emitted from the slot 14 is greatly attenuated, it is a fatal problem. The prevention of condensation and icing of the outer skin 15 as in this embodiment eliminates the attenuation factor of the radio wave emitted from the slot 14 and is extremely effective when the LCX cable 10 is used in a sub-freezing environment.

  In addition, the metal part is exposed in the connector 20 and the terminator 40 on one end side of the LCX cable 10, and if this part is in a sub-freezing environment, heat dissipation becomes extremely large. Therefore, it is desirable to install the connector 20 and the terminator 40 in a normal room temperature environment, not in a freezing environment. In addition, the other end side of the LCX cable 10 is connected to the antenna terminal 111 of the wireless communication device 110, and the wireless communication device 110 is installed in a normal room temperature environment, not under a freezing environment. Heat dissipation is not a problem. Therefore, the heat dissipated by the heater 30 can be reduced as much as possible while using the LCX cable 10 in a sub-freezing environment.

  As described above, according to the present embodiment, the connector 20 of the LCX cable 10 is provided with the heater 30 so that the connector 20 can be heated, and heat can be transmitted from the connector 20 to the external conductor 13 of the LCX cable 10. it can. For this reason, even when used in a sub-freezing environment, condensation or freezing of the outer skin 15 of the LCX cable 10 can be prevented in advance, and a stable communication state can be maintained.

(Second Embodiment)
FIG. 7 is a perspective view showing a schematic configuration of the cable device according to the second embodiment. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between this embodiment and the first embodiment described above is the structure of the heater. That is, the cylindrical heater 50 is provided so as to surround not the end surface of the connector 20 but the outer peripheral surface of the housing 21 of the connector 20. As in the first embodiment, the heater 50 has a resistor along the circumferential direction and can be heated by energization.

  Even in such a configuration, the connector 20 can be heated by energizing and heating the heater 50, and heat can be transmitted to the external conductor 13 of the LCX cable 10 via the connector 20. Therefore, the same effect as the first embodiment can be obtained.

(Modification)
The present invention is not limited to the above-described embodiments. The shape of the connector is not limited to that shown in FIG. 3 as long as it is connected to one end of the LCX cable and can be connected to an external device or a terminator.

  The structure of the heater is not limited to that shown in FIGS. 4 and 7, and any structure can be used as long as it can heat a metal part such as a connector housing or a protrusion electrically and mechanically connected to the housing. Good.

  Further, in the embodiment, heating is performed from the connector on one end side of the LCX cable, but it is also possible to heat from both ends of the cable by providing a heater on the connector on the other end side of the cable.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 ... Leaky coaxial cable (LCX cable)
DESCRIPTION OF SYMBOLS 11 ... Internal conductor 12 ... Insulator 13 ... Outer conductor 14 ... Slot 15 ... Jacket | cover 16 ... Support wire 20 ... Connector 21 ... Housing 22 ... Projection part 23 ... Screw part 24 ... Pin 30, 50 ... Heater 31 ... Lead part 32 ... resistor 40 ... terminator

Claims (6)

A leaky coaxial cable in which an outer conductor is coaxially provided via an insulator so as to surround a peripheral surface of the inner conductor, and a slot having a constant period is provided in the outer conductor;
A connector connected to one end of the leaky coaxial cable;
A heater attached to the connector and heating an outer conductor of the leaky coaxial cable through the connector;
A cable device comprising:   The cable apparatus according to claim 1, wherein the heater is heated by energization.   The heater is formed of a ring-shaped member attached to a surface of the connector opposite to the leaky coaxial cable, and the connector is connected to an antenna terminal or a terminator of a wireless communication device. The cable device according to claim 1, wherein the cable device is sandwiched between a terminator and the connector and is in close contact with the connector.   The cable device according to claim 1 or 2, wherein the heater is fixed to the outer peripheral surface of the connector. A connector connected to one end of a leaky coaxial cable,
A leaky coaxial cable comprising a metal housing electrically connected to an outer conductor of the leaky coaxial cable, or a heater for heating a metal part electrically and mechanically connected to the housing. connector. Leakage coaxial where the outer conductor is coaxially provided via an insulator so as to surround the peripheral surface of the inner conductor, the outer conductor is provided with a slot with a fixed period, and the portions other than both ends are installed in a sub-freezing environment. Cable and
A first connector connected to one end of the leaky coaxial cable;
A second connector connected to the other end of the leaky coaxial cable;
A heater attached to at least one of the first and second connectors and heating an outer conductor of the leaky coaxial cable via the connector;
A wireless communication device connected to the first connector;
A terminator connected to the second connector;
A wireless communication system comprising:

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