JP2000004533A - Explosion-proof base station device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability in conducting communication within an explosion-proof area, by disposing a radio device in a pressure withstanding explosion-proof case in an electrically floating condition, and disposing an antenna having a completely explosion-proof structure on the external part of the pressure withstanding explosion-proof case. SOLUTION: An antenna 6 is mounted on a pressure withstanding explosion- proof case 1 without covered with an antenna radome or the like, and the shield part of the antenna 6 is connected to the pressure withstanding explosion- proof case 1 and to the frame ground 5 of the pressure withstanding explosion- proof case 1. A radio 2 is disposed in the pressure withstanding explosion-proof case 1 under such a condition as to be insulated from the pressure withstanding explosion-proof case 1. An antenna barrier 8 is added at the position at which the core wire of the coaxial cable of the antenna 6 protruding to the external atmosphere and the radio 2 are connected to form a safety explosion-proof structure and separate the radio 2 and the antenna 6 in a DC manner. It is thus possible to prevent the radio 2 from being damaged by thunder surges, thereby increasing reliability in conducing communication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof base station apparatus having an explosion-proof structure suitable for use in, for example, an office cordless telephone system.

[0002]

2. Description of the Related Art Conventionally, in order to make a wireless base station flameproof, it is necessary to house it in a metal housing. FIG. 7 is a structural diagram schematically showing a configuration of a conventional explosion-proof base station device.
7, reference numeral 1 denotes an explosion-proof housing made of, for example, aluminum die-casting, 2 denotes a wireless device housed in the explosion-proof housing 1, 3 denotes an external connection wire for connecting the wireless device 2 to the outside, Is the signal ground, which is the ground of the radio 2,
Reference numeral 5 denotes a frame ground, which is the ground of the explosion-proof enclosure 1, 6 denotes an antenna, and 7 denotes an antenna radome that covers the antenna 6.

Next, the operation will be described. In this explosion-proof base station apparatus, the wireless device 2 is made to be explosion-proof against the external atmosphere by the explosion-proof enclosure 1.
The structure that satisfies the explosion-proof specifications is adopted for the configuration of the portion where the external connection wire 3 is drawn out from the antenna, the configuration where the antenna 6 is covered with the antenna radome 7, and the configuration where the antenna 6 is exposed from the explosion-proof enclosure 1. Is done.

[0004] For this reason, the explosion-proof base station apparatus has a pressure-resistant explosion-proof structure, in which the radio 2 is sealed in the explosion-proof enclosure 1 against the external atmosphere. Further, the external connection line 3 is laid in a pipe compatible with a pressure-resistant explosion-proof specification. Further, the pipe and the explosion-proof enclosure 1 are hermetically connected to an external atmosphere by using a packing compatible with an explosion-proof specification. The antenna 6 is attached to the explosion-proof housing 1 via a packing that is compatible with the explosion-proof specification, and the core wire of the antenna 6 is connected to the wireless device 2.

Further, a base station device such as a radio 2 inside the explosion-proof enclosure 1 is directly screwed into the explosion-proof enclosure 1, and the base station apparatus is directly inserted into the explosion-proof enclosure 1. The signal ground 4 and the frame ground 5 are configured to be common since they are screwed.

[0006]

Since the conventional explosion-proof base station apparatus is configured as described above, deterioration of the output from the antenna 6 occurs due to the antenna radome 7 covering the explosion-proof enclosure 1 and the antenna 6. In addition, sufficient receiving sensitivity was not obtained, and the communicable range in the explosion-proof area was narrowed, and the number of installed base stations was increased.
However, since the communication area is small, it cannot be said that the number of times of communication failure is small, and there is a problem that it is not easy to perform satisfactory communication such as repeating handover.

A base station device such as a radio 2 inside the explosion-proof enclosure 1 has a structure in which the radio 2 is mounted on the explosion-proof enclosure 1 by screwing the radio 2 to the explosion-proof enclosure 1. Therefore, the signal ground 4 and the frame ground 5 are shared, and the electric potential of the frame ground 5 is increased by a lightning surge entering from the antenna 6 and the explosion-proof enclosure 1, and is built into the explosion-proof enclosure 1. There is a problem that a device such as the wireless device 2 is damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an explosion-proof base station apparatus which can improve reliability in performing communication in an explosion-proof area and can secure a reliable communication function. With the goal.

It is another object of the present invention to provide an explosion-proof base station device capable of effectively preventing a device such as a radio device built in a pressure-resistant explosion-proof housing from being damaged by a lightning surge or the like.

[0010]

According to the present invention, there is provided an explosion-proof base station apparatus comprising: an explosion-proof enclosure having an explosion-proof structure; a wireless device disposed in the explosion-proof enclosure in an electrically floating state; And an antenna having an intrinsically safe explosion-proof structure arranged outside the explosion-proof housing.

An explosion-proof base station apparatus according to the present invention includes an antenna shield connection structure in which the shield side of an antenna is connected to a frame ground of an explosion-proof enclosure, and an antenna of the antenna outside the explosion-proof enclosure to a wireless device. On the other hand, the intrinsically safe explosion-proof structure is provided with an antenna antenna connecting means for connecting to the wireless device with respect to an AC signal of a predetermined radio frequency while separating the signal from direct current.

In the explosion-proof base station apparatus according to the present invention, a barrier having a characteristic of passing only a specific radio frequency through M coupling of a primary circuit and a secondary circuit, each including a capacitor and having a different ground, is connected to an antenna via an antenna. The means are provided.

An explosion-proof base station apparatus according to the present invention is configured such that a pressure-resistant explosion-proof structure and an intrinsically safe explosion-proof structure for the antenna are applied to a base station apparatus having a plurality of diversity antennas.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is an explanatory diagram showing a configuration of a cordless telephone system in an explosion-proof area to which the explosion-proof base station device according to the first embodiment is applied. In FIG.
Reference numeral 11 denotes an exchange, 12 denotes a base station power supply device, 13 denotes an explosion-proof base station device, and 14 denotes an explosion-proof mobile radio satisfying the intrinsically safe explosion-proof specification.

FIG. 2 is a structural diagram showing the configuration of the explosion-proof base station device according to the first embodiment.
Is a pressure-resistant explosion-proof housing that satisfies the pressure-resistant explosion-proof specification, for example, made of aluminum die-cast. Reference numeral 3 denotes an external connection line, which is laid in a pipe compatible with the explosion-proof specification.
The piping and the explosion-proof enclosure 1 are connected in a hermetically sealed structure to the external atmosphere by using a packing compatible with an explosion-proof specification.

Reference numeral 4 denotes a signal ground, which is a ground of the radio 2. Reference numeral 5 denotes a frame ground, which is a ground of the flameproof enclosure 1. The signal ground 4 and the frame ground 5 are separated. 6 is explosion-proof enclosure 1
The antenna has an intrinsically safe explosion-proof structure that is provided so as to protrude into the outside atmosphere from the outside and satisfies the intrinsically safe explosion-proof specification. The antenna 6 is attached to the explosion-proof enclosure 1 via a waterproof packing. Further, the core wire of the antenna 6 is drawn into the explosion-proof housing 1 while being insulated from the explosion-proof housing 1 via a packing compatible with the explosion-proof specification, and a barrier for the antenna in the explosion-proof housing 1 is provided. (Hereinafter referred to as an antenna barrier) and is connected to the wireless device 2 in an alternating manner. Reference numeral 8 denotes an antenna barrier (antenna antenna connection means, barrier) for separating the antenna 6 and the wireless device 2 from each other in a DC manner and connecting the AC device to supply power to the antenna 6, and includes a primary side including a capacitor. Circuit and 2
The secondary circuit has a characteristic of passing only a specific radio frequency by M coupling.

FIG. 3 is a sectional view showing a structure for mounting the antenna 6 on the explosion-proof enclosure 1, and the same or corresponding parts as those in FIG. FIG.
1a is a frame ground 5 of the explosion-proof enclosure 1.
An antenna shield connection structure in which the shield side of the antenna 6 is connected to the antenna 6;
The shield part is connected to the flameproof enclosure 1. 10a
Is a packing corresponding to the explosion-proof specification for hermetically pulling the coaxial cable portion 6a of the antenna 6 into the explosion-proof enclosure 1 against an external atmosphere, and 10b is a waterproof function for attaching the antenna 6 to the explosion-proof enclosure 1. It is a waterproof packing having.

FIG. 4 is an explanatory diagram showing a connection configuration of the antenna 6 and the antenna barrier 8, and the same or corresponding parts as those in FIGS. 2 and 3 are denoted by the same reference numerals and description thereof is omitted. In FIG. 4, 6b is the core wire of the antenna 6, 8
a is a primary circuit of the antenna barrier 8, and 8b is a secondary circuit. The antenna barrier 8 is configured not to commonly connect the input and output grounds, but to pass only a specific radio frequency through a microstrip line and to have a characteristic of blocking a DC signal. Therefore, only the transmission / reception frequency passes between the core wire 6b of the antenna 6 and the wireless device 2, and cuts off unnecessary voltage such as a lightning surge.

FIG. 5 is a cross-sectional view showing a structure for fixing the wireless device 2 to the explosion-proof enclosure 1. In FIG. 5, the same or corresponding parts as in FIG. . In FIG. 5, 2a is a housing of the wireless device 2, 9a is a screw for fixing the wireless device 2 to the explosion-proof housing 1, 9b
Is a flat washer and 9c is an insulating bush. As shown in FIG. 5, the screw 9a penetrates the housing 2a of the wireless device 2 and is electrically insulated from the housing 2a of the wireless device 2 by the insulating bush 9c. It is screwed into the formed mounting screw hole. As a result, the wireless device 2 is fixed to the pressure-resistant explosion-proof housing 1 while being electrically insulated.

Next, the operation will be described. Antenna 6
Is mounted on the explosion-proof enclosure 1 without being covered with an antenna radome or the like, and the shield part of the antenna 6 is connected to the explosion-proof enclosure 1 and to the frame ground 5 of the explosion-proof enclosure 1. The core wire 6b of the coaxial cable portion 6a of the antenna 6 is connected to the primary circuit 8a of the antenna barrier 8 and is insulated from the radio 2 in a DC manner, and is connected to the radio 2 with respect to an AC signal in a specific frequency band. Connected. The wireless device 2 is disposed in the explosion-proof enclosure 1 in a state insulated from the explosion-proof enclosure 1 by a structure as shown in FIG. Therefore, even if the wireless device 2 is inserted into the explosion-proof enclosure 1, it is possible to sufficiently transmit and receive radio waves. Furthermore, even if the signal ground 4 and the frame ground 5 are separated, sufficient radio performance can be maintained, and damage to the device from lightning surge can be prevented.

In order to enable wireless communication even in the explosion-proof area, a wireless device such as a radio 2 is placed in the explosion-proof enclosure 1 and only the antenna 6 is taken out of the explosion-proof enclosure 1 to the outside atmosphere. Antenna 6 protruding into the outside atmosphere
An intrinsically safe explosion-proof structure is formed by adding an antenna barrier 8 at the point where the core wire 6b of the coaxial cable portion 6a and the wireless device 2 are connected, and the wireless device 2 and the antenna 6 are separated from each other in a DC manner. Wireless communication can be performed with sufficient transmission / reception sensitivity while maintaining performance.

The signal ground 4 and the frame ground 5 can be separated by adding an antenna barrier 8 and a structure for mounting the wireless device 2 in the explosion-proof enclosure 1 shown in FIG. With double insulation, lightning surge voltage coming from the antenna 6 always falls on the frame ground 5 side of the explosion-proof enclosure 1 and does not jump into the signal ground 4 side of the wireless device, thus preventing damage to the wireless device. Thus, it is possible to prevent the wireless device 2 built in the explosion-proof enclosure 1 from being damaged by a lightning surge entering from the antenna 6.

As described above, according to the first embodiment, an intrinsically safe explosion-proof structure is realized by adding the antenna barrier 8 between the wireless device 2 and the antenna 6, and the antenna 6 is covered with the antenna radome. It is no longer necessary, and the radiation of radio waves can be improved by putting the antenna 6 into the outside atmosphere.
There is an effect that an explosion-proof base station device can be obtained in which deterioration of transmission output and reception sensitivity is eliminated, a communication area can be sufficiently secured, and the number of base stations installed in a dangerous area can be reduced.

Also, as shown in FIG. 1, the exchange 11 is installed in a non-explosion-proof area, and the explosion-proof base station device 13 and the explosion-proof mobile radio 14 are used in the explosion-proof area to enable wireless communication in the explosion-proof area. Explosion-proof base station device is obtained.

Embodiment 2 FIG. 6 shows the first embodiment.
FIG. 10 is a block diagram illustrating a configuration of an explosion-proof base station device according to a second embodiment when the explosion-proof structure is applied to a diversity base station device. 6, the same or corresponding parts as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
, 15 is a diversity antenna, 18a, 18
Reference numerals b, 18c, and 18d denote antenna barriers (antenna antenna connection means, barriers), and 16 denotes a wireless device (wireless device) compatible with the diversity system.

As shown in FIG. 6, even in a base station apparatus having two-system and four-system receiving circuits in the diversity system, radio performance is not deteriorated only by increasing the number of antenna barriers. An explosion-proof base station device can be realized.

[0027]

As described above, according to the present invention, a radio device is disposed in an explosion-proof enclosure having a flame-proof structure in a state of being electrically floating with respect to the explosion-proof enclosure. Intrinsically safe explosion-proof antenna is arranged outside the body, so the radio equipment is electrically insulated from the explosion-proof enclosure, effectively preventing the radio and other equipment from being damaged by lightning surge etc. Moreover, there is no need to cover the antenna with an antenna radome or the explosion-proof enclosure, and the safety, reliability, and reliability of the communication function when performing communication within the explosion-proof area are improved.

According to the present invention, the antenna shield connection structure in which the shield side of the antenna is connected to the frame ground of the explosion-proof enclosure, and the antenna part of the antenna outside the explosion-proof enclosure is directly connected to the radio equipment. On the other hand, since the intrinsically safe explosion-proof structure is provided with an antenna antenna connecting means for connecting to the wireless device with respect to an AC signal of a predetermined radio frequency, a lightning surge or the like entering from the antenna is subjected to the explosion-proof. It can be effectively prevented from flowing to the frame ground of the housing and damaging devices such as radio equipment due to the lightning surge, etc.In addition, there is no need to cover the antenna with an antenna radome or the explosion-proof enclosure, and the This has the effect of improving the security, reliability, and certainty of the communication function when communication is performed by the communication.

According to the present invention, a barrier having a characteristic of passing only a specific radio frequency by the M coupling of the primary side circuit and the secondary side circuit including the capacitor and having different grounds is provided as the antenna antenna connecting means. Since the lightning surge that enters from the antenna flows into the frame ground of the explosion-proof enclosure, it is possible to effectively prevent equipment such as a radio device from being damaged by the lightning surge, etc.
In addition, there is no need to cover the antenna with an antenna radome or the explosion-proof enclosure, and there is an effect that safety, reliability, and reliability of the communication function when performing communication in the explosion-proof area are improved.

According to the present invention, the base station apparatus having a plurality of antennas of the diversity system is configured so that the pressure-resistant explosion-proof structure and the intrinsically safe explosion-proof structure for the antennas are applied. Base station device having a plurality of antennas of the diversity system, which can effectively prevent equipment such as a device from being damaged by lightning surge, and eliminate the need to cover each antenna with an antenna radome or the explosion-proof enclosure. Thus, there is an effect that safety, reliability, and reliability of the communication function when performing communication in the explosion-proof area are improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a cordless telephone system in an explosion-proof area to which an explosion-proof base station device according to Embodiment 1 of the present invention is applied.

FIG. 2 is a structural diagram showing a configuration of an explosion-proof base station device according to Embodiment 1 of the present invention.

FIG. 3 is a cross-sectional view showing a structure for mounting an antenna to a pressure-resistant explosion-proof enclosure of the explosion-proof base station device according to Embodiment 1 of the present invention.

FIG. 4 is an explanatory diagram showing a connection configuration of an antenna and an antenna barrier of the explosion-proof base station device according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a structure for fixing the wireless device of the explosion-proof base station device to the flameproof explosion-proof housing according to Embodiment 1 of the present invention.

FIG. 6 is a block diagram illustrating a configuration of an explosion-proof base station device according to Embodiment 2 of the present invention.

FIG. 7 is a structural diagram schematically showing a configuration of a conventional explosion-proof base station device.

[Explanation of symbols]

1 Explosion-proof enclosure, 1a Antenna shield connection structure,
2,16 radio (wireless device), 5 frame ground, 6,15 antenna, 8,18a, 18b, 18
c, 18d Antenna barrier (antenna antenna connection means, barrier), 8a primary circuit, 8b secondary circuit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) H04Q 7/26 7/30 H05K 9/00 F term (reference) 5E321 AA32 GG05 GG09 5G013 AA07 BA02 CB30 DA09 DA11 5J046 AA05 AA17 AB06 AB10 TA05 TA10 5J047 AA05 AA17 AB06 AB10 BG06 BG07 5K067 AA33 AA35 BB04 EE22 EE32 KK03 KK17

Claims (4)

[Claims] 1. An explosion-proof enclosure having an explosion-proof structure, a wireless device disposed inside the explosion-proof enclosure in an electrically floating state, and an antenna having an intrinsically safe explosion-proof structure disposed outside the enclosure. Explosion-proof base station device with a configuration. 2. An intrinsically safe explosion-proof structure, comprising: an antenna shield connection structure in which a shield side of an antenna is connected to a frame ground of the explosion-proof enclosure; and an antenna part of the antenna outside the explosion-proof enclosure to the wireless device. The explosion-proof base station apparatus according to claim 1, further comprising antenna antenna connecting means for connecting to the wireless device with respect to an AC signal of a predetermined radio frequency while separating the signal from a direct current. 3. The antenna antenna connecting means is a barrier including a capacitor and having a characteristic of passing only a specific radio frequency by M-coupling between a primary circuit and a secondary circuit having different grounds. The explosion-proof base station device according to claim 2. 4. The explosion-proof base station device according to claim 1, wherein the antenna is a plurality of antennas of a diversity system.