JPH0339621B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention addresses the problem of performance degradation caused by heat, humidity, and vibration.
The present invention relates to a high-temperature atmosphere sound detection sensor that can detect sound in a high-temperature atmosphere without worrying about damage.

[Conventional technology]

A condenser microphone can be used as an acoustic detection sensor, but its use is limited to normal temperature and humidity.

[Problem that the invention seeks to solve]

This is because when used at high temperatures, the impedance converter, which is integrated with the microphone and is made of a semiconductor or the like, will be destroyed by the heat. Therefore, in order to use the microphone at high temperatures, it is necessary to separate the microphone body and the impedance converter and place the microphone body in the high temperature part and the impedance converter in the low temperature part.
Furthermore, the microphone body and the impedance converter must be placed close to each other in order to prevent a drop in S/N due to induced noise caused by separation of the microphone body and the impedance converter. Therefore, the connection between the microphone body placed in the high-temperature area and the impedance converter placed in the low-temperature area must have an insulating structure.
In addition, a moisture-proof structure is required to prevent capacitance changes due to humidity, decreases in sensitivity due to voltage changes, and instability of output characteristics.

Furthermore, the mounting part of the condenser microphone is equipped with a vibration isolator, and its design is designed to set the natural frequency as low as possible within the practical range and dampen unnecessary external vibrations in the signal detection band. This improves the S/N ratio. However, in order to be used as a sound detection sensor in plants, etc., it must be fixed at the location where it is used, and if this natural frequency matches the low earthquake frequency, resonance will occur and earthquake vibration will occur. Even with a small shield width, a condenser microphone vibrates significantly. For this reason, the condenser microphone may come off from the vibration isolator during an earthquake.
There is a risk of damage. Therefore, in order to prevent this, it is necessary to change the natural frequency to the earthquake frequency (1 to 30
Hz), signal detection band (500~8000Hz)
The vibration-proof structure must be made sufficiently smaller.

However, until now, there has been no technology that considers and implements such heat insulation, moisture proof, and vibration proof structures.

This invention has been made to solve these conventional problems.

[Means for solving problems]

Means for solving the above problems will be explained below using FIGS. 1 and 2, which correspond to embodiments.
This invention includes a microphone body 1 fixed to a seal pipe joint 3 attached to one end of a seal pipe 2, a spring receiver 5 at one end, and one end of a case holder 6 at the other end. is fixed, and a seal pipe 2 is arranged inside, and the seal pipe joint 3 is inserted from one end surface.
However, the anti-vibration case 4 from which the other end of the seal pipe 2 protrudes from the other end surface, the anti-vibration spring 7 installed between the microphone body 1 and the spring holder 5, and the spring holder 5 and the seal pipe holder are connected to each other. a vibration-proof spring 8 installed between the inlet 3, a moisture-proof cover 9 to which the other end of the seal pipe 2 is fixed at one end and a connector base 12 at the other end, an impedance converter 15 and A board holder 13 to which one end of the cap case 14 that houses the impedance converter 15 is attached and fixed to the connector base 12, and a mounting board whose one end is arranged concentrically with the case holder 6. Base 17
a plurality of stays 16, the other ends of which are fixed to the connector base 12 via anti-vibration rubber 20;
A plurality of stays 24 have one end fixed to the other end of the case holder 6 and the other end fixed to the connector base 12, and a plurality of stays 24 fixed to the other end of the cap case 14 and connected to the output side of the impedance converter 15. and a signal line 23 connected to the microphone body 1 and the input side of the impedance converter 15 through the seal pipe joint 3, the seal pipe 2, the moisture-proof cover 9, and the board holder 13. , the natural frequency of the support members such as the stay 16 supported by the mounting base 17, including the elastic members such as the anti-vibration rubber 20, is selected to be outside the expected frequency. The present invention relates to a high-temperature atmosphere acoustic detection sensor characterized in that a member disposed in a high-temperature part is made of a heat-resistant material.

[Effect]

When the mounting base 17 is fixed on the low temperature side of the location where it will be used, the microphone body 1, seal pipe 2, vibration isolation springs 7, 8, vibration isolation case 4, and case holder 6 will be placed on the high temperature side, and the cap case 14 and connector base will be placed on the high temperature side. 12, the moisture-proof cover 9, the vibration-proof rubber 20, and the stays 16 and 24 are arranged in the low-temperature part. Heat conduction from the high temperature section to the low temperature section is blocked by the plurality of stays 24 and also by the moisture-proof cover 9. Since the signal line 23 is connected to the impedance converter 15 through the seal pipe 2 and the moisture-proof cover 9, it is not affected by external moisture. Mounting base 17
External vibrations from the microphone body 1 are largely attenuated by the vibration isolating rubber 20, and minute vibrations that cannot be damped and propagated to the microphone body 1 are attenuated by the vibration isolating springs 7 and 8. In addition, supporting members such as the stay 16 supported by the mounting base 17, including elastic members such as the anti-vibration rubber 20, the spring constants of the anti-vibration rubber 20, the anti-vibration springs 7 and 8, and the stay 16. Since the natural frequency determined from the weight of the support members such as the above is set to a value higher than the earthquake frequency and sufficiently lower than the signal detection band, the microphone body 1 will not come off or come off without causing resonance during an earthquake.
It cannot be destroyed. Members disposed in high temperature parts such as the microphone body 1 are made of heat resistant material and are therefore not affected by high temperatures.

〔Example〕

FIGS. 1 and 2 are diagrams showing an embodiment of the present invention. In Figures 1 and 2, 1 is the microphone body, 2 is the seal pipe, and 3 is the seal pipe joint.
The microphone body 1 and one end of the seal pipe 2 are fixed via a seal pipe joint 3. Reference numeral 4 denotes a vibration-proof case, into which a spring receiver 5 is screwed into one end, a case holder 6 is screwed into the other end, and a seal pipe 2 passes through it, and a seal pipe joint 3 extends from one end surface. A seal pipe 2 protrudes from the other end surface. Anti-vibration springs 7 and 8 are attached to one end of the anti-vibration case 4, and specifically, they are attached to the microphone body 1 and the seal pipe joint 3 with the spring receiver 5 in between. . The vibration isolation springs 7 and 8 are spiral springs and are arranged symmetrically. Reference numeral 9 denotes a moisture-proof cover, one end of which is attached to the other end of the seal pipe 2 with a spring holder 10 and a cap 11, and the other end inserted into a connector base 12 with a board holder 13. A cap case 14 houses an impedance converter 15 attached to the substrate holder 13, and is also attached to the substrate holder 13. The board holder 13 is screwed to the connector base 12, and the cap case 14 is fixed to the connector base 12 via the board holder 13. 16 is a stay, one end of which is screwed to the mounting base 17, and the other end is screwed to the connector base 12 with a set screw 18 and a nut 1.
It is fixed to a vibration isolating rubber 20 attached by 9. The stay 16 is elastically fixed to the connector base 12 via a vibration isolating rubber 20. The stays 16 are arranged at intervals of 120°. 21
is a connector which is screwed to the connector cap 22, and is housed in the cap case 14 by screwing the connector cap 22 into the cap case 14. 23 is a signal line that introduces the output signal from the microphone body 1 to the impedance converter 15, and is connected to the input side of the impedance converter 15 through the seal pipe joint 3, the seal pipe 2, the moisture-proof cover 9, and the board holder 13. has been done. The output side of the impedance converter 15 is connected to the input side of the connector 21. 24
is a stay, one end of which is screwed to the case holder 6, and the other end is fixed to the connector base 12 via a heat insulating washer 25. The stays 24 are spaced apart from each other by 120° and are located midway between the stays 16. Although the case holder 6 and the mounting base 17 are arranged concentrically, they are not connected to each other.

When the mounting base 17 is fixed to the low-temperature side of the location, for example, the outer wall of the nuclear reactor insulation box, the microphone body 1, vibration-proof case 4, etc. will be placed on the high-temperature side of the insulation box (300 to 400 degrees Celsius).
In addition, the moisture-proof cover 9, impedance converter 15, etc. are placed in a low temperature section (50° C.). The microphone body 1 and the like arranged in the high temperature part are made of heat-resistant material.
Therefore, they are not affected by high temperatures.

The case holder 6 in the high temperature section and the connector base 12 in the low temperature section are connected by a stay 24, but the stay 24 is made of stainless steel with low thermal conductivity, and its cross-sectional area is as small as possible.
Its length is made as long as possible. This is because the amount of heat flowing per unit time in heat conduction is proportional to thermal conductivity and cross-sectional area, and inversely proportional to length. Therefore, heat conduction from the case holder 6 is blocked by the stay 24. Stay 24
The reason why a plurality of are arranged and inclined is to minimize the cross-sectional area and obtain the strength to support the case holder 6.

The seal pipe 2 in the high temperature section and the connector base 12 in the low temperature section are connected by a moisture-proof cover 9, which is made of heat-resistant rubber with a small spring constant so as not to affect the vibration-proofing effect. There is. The cap case 1 is removed by the moisture-proof cover 9.
4 is prevented from entering, and heat conduction from the seal pipe 2 to the connector base 12 is blocked. The microphone body 1 and the seal pipe 2 are supported via a moisture-proof cover 9 from a connector base 12 so as to be movable left and right.

External vibration from the mounting base 17 is removed from the stay 16.
The vibration is propagated to the connector base 12 via the vibration isolating rubber 20. It further propagates to the seal pipe 2 and seal pipe joint 3 via the moisture-proof cover 9, and at the same time propagates to the case holder 6, vibration-proof case 4, and spring receiver 5 via the stay 24, and finally to the vibration-proof spring 7, 8. Propagates to the microphone body 1. Naturally, it also propagates to the substrate holder 13, cap case 14, etc. However, the support members such as the stay 16 supported by the mounting base 17, including the elastic members such as the vibration isolating rubber 20, have The natural frequency determined from the weight of supporting members such as
Hz), vibration components higher than this natural frequency are first greatly attenuated by the anti-vibration rubber 20 (-30±10 dB). Furthermore, the slight vibrations that propagate without being damped are attenuated by the vibration isolation springs 7 and 8 (-
5dB). In addition, the support members such as the stay 16 supported by the mounting base 17 will not resonate during an earthquake, and the microphone body 1 will not come off.
It will not be damaged.

The anti-vibration rubber 20 elastically supports the entire connector base 12, etc., and in order to prevent large vibrations at this support portion, the spring constant is selected so that the spring constant of the plurality of anti-vibration rubbers 20 as a whole is large. There is. Therefore, even against low frequency vibrations such as earthquakes, the entire structure does not become unstable and can maintain sufficient strength. The reason why rubber was used as the vibration isolator was because the vibration amplitude during resonance is smaller than that of metal springs, and the damping effect is also large due to its internal viscosity. Metal springs are used as the anti-vibration springs 7 and 8, and since the anti-vibration springs 7 and 8 only have to elastically support the lightweight microphone body 1 instead of supporting the entire body, sufficient strength can be maintained even if they are thin and weak. dripping The reason why metal springs are used as the anti-vibration springs 7 and 8 is that it is easier to determine the spring constant compared to rubber.
Therefore, it is considered that the natural frequency can be set easily and accurately. Anti-vibration springs 7, 8
Since they are arranged symmetrically, the spring constant hardly changes in either the left-right direction or the up-down direction, and they can be easily assembled.

In the above embodiment, the case holder 6 and the mounting base 17 are not connected, and the case holder 6 is supported by the connector base 12 via the stay 24, but as shown in FIG. To,
The case holder 6 and the mounting base 17 may be screwed together, the case holder 6 may be supported by the mounting base 17, and the stay between the case holder 6 and the connector base 12 may be omitted. In this case, since the mounting base 17 becomes high temperature, the stay 17 must
6 is formed similarly to the stay 24 in FIG. Further, since the stay 16 does not support the case holder 6 or the vibration-proof cover 4, its mechanical strength can be reduced. External vibration from the mounting base 17 is divided into 6 systems of case holders and 16 systems of stays, and is attenuated by anti-vibration springs 7 and 8 and anti-vibration rubber 20.

In the above embodiment, the anti-vibration springs 7 and 8 are attached to one end of the anti-vibration case 4, but as shown in FIG. 4, the anti-vibration spring 8 is attached to the other end of the anti-vibration case 4. You may. That is, one end of the seal pipe 2 is screwed directly into the microphone body 1, the vibration-proof spring 7 is attached between the microphone body 1 and the spring holder 5, and the spring holder 11 is fixed to the other end of the seal pipe 2.
A vibration isolation spring 8 is attached between the case holder 6 and the case holder 6.

In the embodiment described above, one end of the moisture-proof cover 9 protrudes upward, and the other end is inserted between the connector base 12 and the board holder 13, and is connected to the connector base by screwing the board holder 13 and the connector base 12 together. However, as shown in Fig. 5, by changing the shapes of the moisture-proof cover 9, spring holder 10, and cap 11, one end of the moisture-proof cover 9 is exposed downward, and the other end is attached to the connector base. 12 and the base cap 26, and may be fixed to the connector base 12 by screwing the base cap 26 and the connector base 12 together. In addition, in FIG. 5, 27 is a heat insulating washer, 28 is a heat-insulating stay, and a plurality of them are provided.

〔Effect of the invention〕

As explained above, in this invention, when the mounting base is fixed on the low temperature side of the location where it is used, the microphone body is placed in the high temperature part, the impedance converter is placed in the low temperature part, and heat conduction from the high temperature part to the low temperature part is prevented. , since it is interrupted by a stay with a small cross-sectional area, it is possible to prevent performance deterioration of the impedance converter due to heat. Further, since the signal line is sealed inside the seal pipe and the moisture-proof cover and connected to the impedance converter, it is not affected by external moisture and performance deterioration due to moisture can be prevented. Furthermore, since external vibrations from the mounting base are sufficiently attenuated by the vibration isolating rubber and vibration isolating spring, the S/N of the device can be improved. Furthermore, since the natural frequency of the device is set higher than the earthquake frequency, resonance does not occur during an earthquake, and damage to the device can be prevented. Therefore, according to the present invention, it is possible to perform acoustic detection in a high-temperature atmosphere without worrying about performance deterioration or damage due to heat, humidity, or vibration.

[Brief explanation of the drawing]

1 and 2 are views showing one embodiment of the present invention, in which FIG. 1 is a half-sectional view, FIG. 2 is a perspective view, and FIG.
FIGS. 4 and 5 are half-sectional views showing other embodiments of the present invention. 1...Microphone body, 2...Seal pipe, 4...
... Anti-vibration case, 7, 8 ... Anti-vibration spring, 9 ... Moisture-proof cover, 12 ... Connector base, 15 ... Impedance converter, 16 ... Stay, 17 ...
Mounting base, 20... anti-vibration rubber, 23... signal line, 24... stay.

Claims (1)

[Claims] 1 A microphone body fixed to a seal pipe joint attached to one end of a seal pipe, a spring receiver fixed to one end, one end of a case holder fixed to the other end, and the above-mentioned a vibration-proof case in which a seal pipe is disposed inside, the seal pipe joint protruding from one end face, and the other end of the seal pipe protruding from the other end face;
an anti-vibration spring installed between the microphone body and the spring holder; an anti-vibration spring installed between the spring holder and the seal pipe joint; and one end of the seal pipe. The other end is attached to a moisture-proof cover to which a connector base is fixed, an impedance converter, and one end of a cap case that houses the impedance converter therein, and is fixed to the connector base. a plurality of stays, one end of which is fixed to a mounting base arranged concentrically with the case holder, the other end of which is fixed to the connector base via anti-vibration rubber; is fixed to the other end of the case holder and the other end is fixed to the connector base, and a plurality of stays are fixed to the other end of the cap case and connected to the output side of the impedance converter. a connector and the sealed pipe joint;
A signal line is connected to the microphone body and the input side of the impedance converter through the seal pipe, the moisture-proof cover, and the board holder, and includes an elastic member such as the vibration-proof rubber, and the mounting The natural frequency of the supporting member such as the stay supported by the base is selected to be outside the expected frequency, and the member placed in the high temperature part of the microphone body is made of heat-resistant material. A high-temperature atmosphere acoustic detection sensor featuring: