JPH09182284A - Explosion-proof antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an explosion-proof antenna installed in a dangerous place and having a simple structure, easy installation work, reliable transmit-receive performance, along with good explosion-proof structure. SOLUTION: A safety interlock device includes a receiving antenna 4 connected to a FM receiver 3. The FM receiver 3 is stored in a sealed container 30 having an explosion-proof structure and mounted in some dangerous place. Using the receiving antenna 4, a signal is transmitted in wireless between the FM receiver 3 and an electric circuit located in the dangerous place outside the sealed container 30. In addition, a socket 10 having an explosion-proof structure is made of material that transmits the radio wave for the receiving antenna 4, and the receiving antenna 4 is stored in the socket 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof antenna composed of an antenna body installed in a dangerous place, and more particularly to an explosion-proof antenna capable of reliably transmitting and receiving signals while satisfying the conditions of a pressure-proof explosion-proof structure. Here, the hazardous area is flammable gas or vapor of flammable liquid (hereinafter, explosive gas).
Refers to the location where or is likely to exist. Explosion-proof structure means that even if an explosive gas explosion occurs inside the equipment in an electric spark or high-temperature part that has the ability to ignite the explosive gas, the equipment can withstand the explosion and the surrounding area of the equipment. It means a structure that does not cause a flammable spread to natural gas.

[0002]

2. Description of the Related Art Conventionally, FIG.
And the one shown in FIG. FIG. 4 is an overall circuit configuration diagram of a conventional safety maintenance device, and FIG. 5 is a detailed configuration diagram of essential parts in the conventional safety maintenance device shown in FIG. In the figure, the conventional safety retention device 2 is housed in a pressure-resistant explosion-proof fully closed container 30 installed in a hazardous area.
The configuration is such that two blocking capacitors 11 and 12 connected in series are connected between the transmission line 5 that connects the FM receiver 3 housed inside and the receiving antenna 4 provided outside the fully closed container 30. .

The two blocking capacitors 11, 12
Are housed in a socket 13 that is directly screwed into a mounting screw hole 31 of a fully closed container 30 having a flameproof structure, and an epoxy resin 15 is sealed in the socket 13 and connected in series. It is a composition. A screw portion 14 is formed at one end of the socket 13, and the screw portion 14 is screwed into the mounting screw hole 31 of the fully closed container 30 to be mounted in a state satisfying a predetermined pressure-proof and explosion-proof performance. The socket 1
The transmission line 52 extends from one end of the fully closed container 3
In addition to being connected to the FM receiver 3 in 0, the transmission line 51 extends from the other end and is connected to the receiving antenna 4 via the connector 7.

Further, as shown in FIG.
An O-ring 18 for hermetically closing is attached to the side joint between the container and the fully closed container 30, and M is attached to the other end of the socket 13.
The mold connector 16 is directly attached. The M-type connector 16 is connected to a J-type connector (not shown) attached to the end of the transmission line 5 extending from the receiving antenna 4. In addition, a silicone resin 17 is provided on the inner end of the socket 13 to which the M-type connector 16 is connected.
Is enclosed and the socket 13 due to vibration of the transmission line 5
The influence on the blocking capacitors 11 and 12 is reduced. Further, the FM receiver 3 in the fully closed container 30 is AC100V from the power supply on the non-hazardous site side via the power supply wiring 53.
Is applied, and a reception signal is output to the non-hazardous area side.

Next, the assembling / attaching / receiving operation of this embodiment based on the above construction will be described. The socket 13 in the apparatus of this embodiment is screwed into the mounting screw hole 31 of the fully closed container 13 to be mounted. The transmission line 52 extending from one end of the socket 13 is connected to the FM receiver 3, and the fully closed container 30 is closed in a hermetically sealed state. Further, the transmission line 51 extending from the other end of the socket 13 is connected to the transmission line 5 extending from the receiving antenna 4 via the connector 7.
A power supply line 53 and a ground line 54 from a power source (not shown) are connected to the FM receiver 3.

In the receiving operation, when the radio wave in the dangerous area is received by the receiving antenna 4, it propagates through the transmission lines 5 and 51, and the FM receiver via the two blocking capacitors 11 and 12 connected in series. Input to 3. That is, the transmission line 5,
Since the signal propagating through 51 is a high frequency signal, it is propagated as it is to the FM receiver 3 without being blocked by the two blocking capacitors 11 and 12. After being received and detected by the FM receiver 3, the FM signal is output to the non-hazardous area side. When an accident occurs in the FM receiver 3 which is driven by being supplied with 100 V AC applied from the power supply wiring 53, the blocking capacitors 11 and 1 are provided.
2 blocks the output of the AC100V to the receiving antenna 4 side, and the receiving antenna 4 outside the fully closed container 30 serves as an intrinsically safe circuit.

[0007]

Since the conventional safety device is constructed as described above, two blocking capacitors 11 connected in series between the FM receiver 3 and the receiving antenna 4 are provided. 12 is connected to make the transmission line 5 redundant, which has a problem that the circuit configuration becomes complicated and the number of parts increases. Such a transmission line 5
By limiting the inflow of electrical energy from the non-intrinsic circuit to the related intrinsically safe circuit by redundancy of the above, an intrinsically safe explosion-proof structure can be realized, but two blocking capacitors connected in series There is a problem that the signal levels related to transmission and reception are attenuated by 11 and 12 and reliable transmission and reception cannot be performed. Here, the intrinsically safe circuit refers to a circuit having an intrinsically safe explosion-proof structure, which has been confirmed by a test or the like by a public engine that an explosive gas will not be ignited by an electric spark or a high temperature part generated in a normal state and an accident. Also,
A non-intrinsically safe circuit is a circuit that does not have an intrinsically safe explosion-proof structure.

Further, in the above-mentioned conventional safety retaining device,
The two blocking capacitors 11 and 12 are housed in a socket 13 that is directly screwed into the fully-closed container 30, and an epoxy resin 15 is sealed and sealed in this socket 13, which complicates the mounting structure. Have the problem of doing. Furthermore, the blocking capacitor 1 in the fully closed container 30
The shield wire of the transmission line 52 connected to the terminals 1 and 12 must be subjected to special third-class grounding work by the connection line 55, which complicates the installation work and also has the problem of complicating the circuit configuration. Was. The present invention has been made to solve the above problems, and an object of the present invention is to propose an explosion-proof antenna that can reliably transmit and receive signals with a pressure-proof explosion-proof structure and that can simplify the device itself and the installation work. .

[0009]

In the explosion-proof antenna according to the present invention, the antenna main body is connected to an electric circuit housed in a fully closed container having a pressure-proof explosion-proof structure installed in a dangerous place, and the electric circuit and the above-mentioned whole body are connected. In an explosion-proof antenna that wirelessly transmits and receives a signal to and from an electric circuit installed in a dangerous place outside a closed container, the container is formed as a pressure-proof explosion-proof structure with a material that transmits the radio waves transmitted and received by the antenna body. The antenna main body is housed in the container. As described above, in the present invention, the antenna main body is housed in a container formed of a material that transmits radio waves and having a flameproof structure, and the antenna main body and the electric circuit housed in the fully closed container are connected. Therefore, there is no need for circuit redundancy such as connecting multiple blocking capacitors in series in order to configure a circuit with an intrinsically safe explosion-proof structure, and the pressure-proof explosion-proof structure allows signal transmission / reception without causing signal level attenuation. In addition to performing surely, it is possible to configure the entire device with a simple circuit configuration and a simple structure. Also, since the antenna body itself is housed in a container and this antenna body and the electric circuit in the fully closed container are connected by a transmission line, perform a third-class grounding work for the cider wire of the transmission line. Without the device can be configured.

Further, the explosion-proof antenna according to the present invention is such that the container is directly connected so as to satisfy the pressure-proof explosion-proof structure in a communication state of the fully closed container, if necessary. Further, the explosion-proof antenna according to the present invention, if necessary, the container is formed as a fully closed container, the antenna main body housed in the container and an electric circuit housed in the pressure-proof explosion-proof structure fully closed container. Are connected by an insulation-coated transmission line.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment of the Present Invention) A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows the overall circuit configuration of the explosion-proof antenna according to this embodiment. In the same figure, in the explosion-proof antenna 1 according to the present embodiment, a fully closed container 30 having a pressure-proof explosion-proof structure and a receiving antenna 4 are installed in a dangerous place as in the conventional device.
It is configured to accommodate the M receiver 3, but this reception antenna 4
Is attached to the socket 10 as a container in a different structure.

This socket 10 has the receiving antenna 4
A material that transmits the radio waves received by, for example, plastic,
A synthetic resin such as epoxy resin or glass is formed into a pressure-proof explosion-proof hollow cylindrical body, and the screw portion 14 formed at the base of the hollow cylindrical body is attached to the mounting screw hole 31 of the fully closed container 30.
It is configured to be screwed and locked so that the inside is in communication with. The locking of the socket 10 to the fully closed container 30 is configured such that the screw portion 14 is screwed into the mounting screw hole 31 to satisfy a predetermined pressure-proof explosion-proof structure. Further, the socket 10 screwed into the mounting screw hole 31 of the fully closed container 30 has a structure in which a lock nut 10 a is attached near the end of the screw portion 14 to be tightly engaged with the fully closed container 30. is there.

Next, the assembling / attaching operation and the receiving operation of this embodiment based on the above-mentioned structure will be described. First, the FM receiver 3 is housed in the fully closed container 30, and the power supply wiring 53 and the ground wiring 54 are connected to the FM receiver 3, respectively, and the reception antenna 4 is connected to one end of the transmission line 5.
0 is also connected. The connected transmission line 50 and the receiving antenna 4 are inserted into the mounting screw holes 31 of the fully closed container 30 from the inside to the outside, and pulled out to the outside of the fully closed container 30. With the received reception antenna 4 housed in the socket 10, the screw portion 14 of the socket 10 is screwed into the mounting screw hole 31 of the fully closed container 30. By further screwing the lock nut 10a onto the screwed screw portion 14, the socket 10 is fixedly locked to the fully closed container 30.

Incidentally, the socket 10 of the receiving antenna 4
Is stored before connecting the transmission line 50 to the FM receiver 3, and after the receiving antenna 4 is housed in the socket 10, the transmission line 50 whose one end is connected to the receiving antenna 4 is completely closed. The mounting screw hole 31 of 30 is inserted from the outside toward the inside, and the screw portion 14 is screwed into the mounting screw hole 31 so that the socket 10 is fixedly engaged with the fully closed container 30.
Further, the other end of the inserted transmission line 50 can be connected to the FM receiver 3 housed in the fully closed container 30.

(Second Embodiment of the Present Invention) FIG. 2 is a sectional view showing the essential configuration of an explosion-proof antenna according to a second embodiment of the present invention. In the figure, the explosion-proof antenna according to the second embodiment has an FM receiver (not shown) housed in a fully closed container 30 as in the embodiment shown in FIG. 1 and transmits to this FM receiver. The receiving antenna 4 connected via the line 50 is housed in the socket 10 that satisfies the pressure-proof and explosion-proof structure made of a signal-transmissive material, but the mounting structure of the socket 10 to the fully closed container 30 is different. It is a configuration.

This socket 10 is formed of a tubular body having one side closed and an opening on the other side. The socket 10 is formed with a flange 10c around the opening of the tubular body, and is fixed to the flange 10C. Fully closed container 3 by screwing together the screw 10b
It is fixed so as to cover the insertion hole 33 of 0. The epoxy resin 30a is placed in the insertion hole 33 of the fully closed container 30.
Is sealed to ensure the airtightness of the fully closed container 30. Further, by encapsulating the epoxy resin 30a, the socket 10
The receiving antenna 4 can be reliably positioned and fixed at a predetermined position inside. The epoxy resin 30a enclosed in the insertion hole 33 may be replaced with a compound material such as silicone resin or a sealing material, or a packing material such as rubber or synthetic rubber.

(Third Embodiment of the Present Invention) FIG. 3 is a partially cutaway view of the explosion-proof antenna according to the third embodiment of the present invention. In the same figure, the explosion-proof antenna according to the third embodiment has an FM receiver (not shown) housed in a fully closed container 30 as in the embodiment shown in FIG. 1 and transmits to this FM receiver. The receiving antenna 4 connected via the line 50 is housed in the socket 10, but the socket 10 is mounted separately from the fully closed container 30. This socket 10
Is a configuration in which the flange 10c formed on the opening side of the tubular body and the one end 81 of the connector 8 are joined to form a closed container. The connector 8 has a structure in which a cable-shaped transmission line 5 having one end connected to the receiving antenna 4 housed in the cylindrical body of the socket 10 is fixedly held at the other end 82. The other end of the transmission line 5 is the other end 9 of the connector 9.
2 is fixed and held, and the screw portion 91 of the connector 9 is screwed into the mounting screw hole 31 of the fully closed container 30 to fix the transmission line 5 to the fully closed container 30.

The joint surface between the flange 10c of the socket 10 and the one end portion 81 of the connector 8 and the joint portion between the screw portion 91 of the connector 9 and the mounting screw hole 31 of the fully closed container 30 are preset. The structure is formed so as to satisfy the flame escape limit below the standard, that is, the flameproof structure. Although the receiving antenna 4 is housed in the socket 10 in each of the above embodiments,
A transmitting antenna, a transmitting / receiving antenna, etc. may be housed in the socket 10.

Although the FM receiver 3 is housed in the fully closed container 30 in each of the above-mentioned embodiments, it may be composed of other receivers or transmitters / receivers. Further, in each of the above-described embodiments, an O-ring, packing or the like may be interposed between the fully closed container 30 and the socket 10 or the connector 9 and between the socket 10 and the connector 8.

[0020]

As described above, according to the present invention, the antenna main body is housed in the container which is made of a material that transmits radio waves and has a flameproof structure, and the electric circuit housed in the antenna main body and the fully closed container. Since it is configured to connect with, the circuit redundancy such as connecting multiple blocking capacitors in series to configure a circuit having an intrinsically safe explosion-proof structure is not required, and signal-level attenuation occurs with the flameproof explosion-proof structure. It is possible to reliably transmit and receive a signal without performing the above operation, and to achieve an effect that the entire device can be configured with a simple structure and a simple structure. Also, since the antenna body itself is housed in a container and this antenna body and the electric circuit in the fully closed container are connected by a transmission line, perform a third-class grounding work for the cider wire of the transmission line. Instead, it has the effect that the device can be configured.

[Brief description of the drawings]

FIG. 1 is an overall circuit configuration diagram of an explosion-proof antenna according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional configuration diagram of essential parts of an explosion-proof antenna according to a second embodiment of the present invention.

FIG. 3 is a main part configuration diagram in which a part of an explosion-proof antenna according to a third embodiment of the present invention is cut away.

FIG. 4 is an overall circuit configuration diagram of a conventional safety maintenance device.

FIG. 5 is a partial cross-sectional main-part configuration diagram of the conventional safety retention device shown in FIG.

[Explanation of symbols]

 1 Explosion-proof antenna 2 Safety retention device 3 FM receiver 4 Reception antenna 5, 50, 51, 52 Transmission line 10, 13 Socket 7, 8, 9 Connector 10a Lock nut 10b Fixing screw 10c Flange 11, 12, Blocking capacitor 14 Screw Part 15, 30a Epoxy resin 16 M type connector 17 Silicon resin 18 O-ring 19 Set screw 30 Fully closed container 31, 31a Mounting screw hole 32 Lock nut 33 Insertion hole 53 Power supply wiring 54 Ground wiring 81 One end 82, 92 Other end 91 screw part

Claims (3)

[Claims] 1. An antenna circuit connected to an electric circuit housed in a pressure-resistant explosion-proof fully closed container installed in a hazardous area, the electric circuit being installed in a hazardous area outside the fully enclosed container. In an explosion-proof antenna for wirelessly transmitting and receiving a signal between the antenna body and the antenna body, a container is formed as a pressure-proof explosion-proof structure with a material that transmits radio waves transmitted and received by the antenna body, and the antenna body is housed in the container. Explosion-proof antenna characterized by the following. 2. The explosion-proof antenna according to claim 1, wherein the container is directly connected to the fully closed container so as to satisfy a pressure-proof explosion-proof structure in a communication state. 3. The explosion-proof antenna according to claim 1, wherein the container is formed as a fully closed container, and is housed in the antenna main body housed in the container and the fully closed container having the pressure-proof explosion-proof structure. An explosion-proof antenna, characterized in that it is connected to an electric circuit by an insulation-coated transmission line.