JPH10206257A - Gas pressure sensor - Google Patents

Abstract

(57) [Problem] An object of the present invention is to suppress the occurrence of gas leakage at a gas pressure sensor portion at the time of abnormally high temperature around a gas meter or at the time of breakage of internal unit parts due to impact or the like. SOLUTION: An atmosphere opening port for opening the back side of a pressure sensitive part to the atmosphere is constituted by a plurality of opening ports 6 having a diameter which is contracted and closed by softening of a casing 5 at a high temperature higher than a predetermined temperature. Features.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a gas pressure sensor incorporated in a gas meter.

[0002]

2. Description of the Related Art An example of a gas meter incorporating a conventional gas pressure sensor will be described with reference to FIGS. 3A is an overall perspective view of the gas meter, FIG. 3B is a rear view of the main part, FIG. 4A is an exploded perspective view of the main part, and FIG. is there. The gas meter includes a measuring unit 21 for measuring gas consumption, a display unit 22 for displaying the measured value, a shut-off valve 23 for stopping gas supply when any abnormality occurs, and checking for gas pressure fluctuations in the meter to prevent gas leakage. A gas pressure sensor 30 as a gas pressure measuring means for detecting, a vibration sensor 24 for detecting vibration due to an earthquake or the like, a controller 25 for controlling the gas pressure sensor 30 and the shutoff valve 23, and a unit constituted by these are stored. The upper case 26 and the like are included.

Next, a gas pressure sensor will be described with reference to FIG. The pressure sensor has a slightly different structure depending on the operation method such as a piezoresistive method or a capacitance method.
In the case of the gas pressure sensor 30 using the semiconductor element 1 shown in FIG.
A pipe 4 provided with a through-hole 3 reaching the upper surface, and an atmosphere opening 8 for opening the half-faced surface 1b of the element to the atmosphere so that the pressure-sensitive part performs gauge pressure measurement are formed. 2 and a resin casing 7 formed so as to cover the pipe 4. The casing 7 is provided with a flange 7a having a through hole. The gas pressure sensor 30 is connected to the gasket 9, the gas inlet 27, and the O-ring 11 between the tip of the pipe 4 at the flange 7a. It is fixed to the upper case 26 with the screw 12. The sealing material of the gasket 9 and the O-ring 11 keeps the above-mentioned unit components airtight with respect to the outside of the gas meter. The use of the casing 7 holding the gas pressure sensor 30 enables the gas pressure sensor 30 to be removed from the gas meter, thereby facilitating replacement when the gas pressure sensor 30 fails. it can. For this reason, the casing 7 is generally and widely used in gas pressure sensors for gas meters at present.

[0004] The gas meter not only measures the amount of gas used by the customer, but also detects a gas pressure sensor 30 or the vibration sensor 2 when an abnormality such as an earthquake or leakage inside the gas pipe occurs.
Under the control of the controller 25, based on the determination of 4, the shut-off valve 23 is operated to stop the gas supply. The determination of gas shutoff is performed when the vibration level due to the earthquake detected by the vibration sensor 24 reaches a certain level or when the gas pressure sensor 30
Is output when the detected gas pressure in the gas meter indicates an abnormal value.

[0005]

In a gas meter incorporating a conventional gas pressure sensor, when an impact is applied to the entire gas meter due to an earthquake or the like and internal unit components such as the semiconductor element 1 are damaged, FIG. As shown in
The gas in the gas meter may be released through the path 13 from the semiconductor element 1 to the atmosphere opening port 8 to cause a gas leakage state.
Also, if a fire occurs due to a gas leak, the temperature inside the gas meter becomes abnormally high, so that it is conceivable that the shape deformation of the internal unit parts and the like will further progress. Further, in addition to the occurrence of an earthquake or the like, if a gas pressure exceeding the maximum withstand pressure value is applied to the gas pressure sensor 30 due to an abnormality on the gas supply side, the internal unit parts may be damaged or the gas pressure sensor 30 may be damaged. There is a possibility that a gas leak state may occur due to popping out or the like.

[0006] The present invention has been made in view of the above,
It is an object of the present invention to provide a gas pressure sensor that can suppress occurrence of gas leakage at a gas pressure sensor portion even when an internal unit component is damaged due to an abnormally high temperature around a gas meter, an impact, or the like.

[0007]

According to a first aspect of the present invention, there is provided a gas meter having a casing provided with an atmosphere opening port for opening a back side of a pressure-sensitive portion to the atmosphere. In the gas pressure sensor for detecting gas pressure, the atmosphere opening port is constituted by a plurality of opening ports having a diameter which is contracted and closed by softening of the casing at a high temperature equal to or higher than a predetermined temperature. . With this configuration, in a normal use state, a function of opening the back side of the pressure-sensitive portion to the atmosphere with a plurality of small-diameter air opening ports is secured, and the gas pressure monitoring operation in the gas meter is performed.
On the other hand, an impact is applied to the entire gas meter due to an earthquake, etc., and the internal unit parts are damaged, and the gas pressure sensor part is in a gas leak state by any chance. When the temperature becomes abnormally high, the casing softens under the influence of the temperature inside the meter, and the air opening having a small diameter contracts and closes.

According to a second aspect of the present invention, there is provided a gas pressure sensor for detecting a gas pressure in a gas meter, comprising a casing having an atmosphere opening port for opening the back side of the pressure sensing portion to the atmosphere. A lid made of a material and provided with a gap for always opening the air opening was provided, and a lid was provided to cover the air opening, and a cover was provided to cover and press the casing and the lid. The gist of the present invention includes a metal holding plate, wherein the leg is softened at a high temperature equal to or higher than a predetermined temperature, the gap is crushed, and the air opening is closed by the lid. With this configuration, in a normal use state, a function of opening the back side of the pressure sensing unit to the atmosphere through the gap between the legs of the lid and the atmosphere opening port is ensured, and the gas pressure monitoring operation in the gas meter is performed. on the other hand,
An impact is applied to the entire gas meter due to the occurrence of an earthquake, etc., and the internal unit components are damaged, the gas pressure sensor part is in a gas leak state, and furthermore, the gas leak ignites and the inside of the gas meter becomes abnormally high due to radiant heat etc. When the temperature rises, the casing softens under the influence of the temperature inside the meter, but at the same time, the legs made of the same material as the casing soften, and the elasticity of the metal presser plate causes the gap to be crushed and the lid to release air. The opening is closed.

According to a third aspect of the present invention, there is provided a gas pressure sensor for detecting a gas pressure in a gas meter, comprising a casing having an atmosphere opening opening for opening the back side of the pressure sensing portion to the atmosphere. And a metal press plate provided to cover the casing while holding the gas pressure sensor in an open state, and preventing a gas pressure sensor main body from jumping out when an abnormal gas pressure occurs in the gas meter. With this configuration, when a gas pressure exceeding the maximum withstand pressure value is applied to the gas pressure sensor due to an abnormality on the gas supply side or the like, the metal pressure plate prevents the gas pressure sensor main body from jumping out.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a first embodiment of the present invention. FIG. 1A is a perspective view of a casing portion, and FIG. 1B is a longitudinal sectional view of a gas pressure sensor. FIG.
In FIG. 2 showing a second embodiment to be described later, the same or equivalent parts as those in FIG. 5 are denoted by the same reference numerals as those in FIG.
First, the configuration of the gas pressure sensor 10 will be described. A casing 5 is provided so as to cover the semiconductor element 1 serving as a pressure-sensitive part, the peripheral circuit board 2 and the pipe 4. Casing 5
Is provided with a flange 5 a for fixing to the upper case 26 with the screw 12. In the present embodiment, the casing 5 is provided with a plurality of air opening ports 6 having a smaller diameter than the conventional technique. By arranging a plurality of the air opening ports 6, even if a part thereof is clogged with impurities such as dust, a function of opening the half facing surface 1b of the semiconductor element to the atmosphere and performing the gauge pressure measurement without any trouble can be obtained.

Next, the operation of the embodiment constructed as described above will be described. In a normal use state, a function of opening the opposite surface of the pressure-sensitive portion to the atmosphere by the plurality of atmosphere opening ports 6 is ensured, so that the pressure measurement operation in the gas meter can be performed without any problem. Then, when an abnormality such as internal leakage of the gas pipe occurs, the shutoff valve is operated by the control of the controller based on the detection value of the gas pressure sensor 10 to stop the gas supply. Also, an impact is applied to the entire gas meter due to an earthquake or the like, and internal unit components such as the semiconductor element 1 are damaged, and the gas pressure sensor 10 is in a gas leak state by any chance, and furthermore, the gas leak causes ignition and the gas meter is radiated by heat. When the temperature inside the casing becomes abnormally high, the casing 5 softens under the influence of the temperature inside the meter, and the air opening port 6 having a small diameter contracts and closes. As a result, the residual gas inside the casing 5 is prevented from flowing out further.

As described above, according to the present embodiment,
In the unlikely event that a gas leak occurs at the gas pressure sensor 10 and further ignition occurs due to the gas leak, the casing 5 softens under the influence of the temperature inside the meter due to an abnormal rise in the temperature inside the gas meter, and is opened to the atmosphere with a small diameter. The mouth 6 contracts and closes. Therefore, when the controller of the gas meter does not function and the shut-off valve does not operate, and even if the gas is filled in the casing, the gas in the gas meter is not further discharged to the outside.

FIG. 2 shows a second embodiment of the present invention. FIG. 1A is an exploded perspective view of a casing, a lid, and a metal holding plate, and FIG. 1B is a longitudinal sectional view of a gas pressure sensor. First, the configuration of the gas pressure sensor 20 will be described.
In the present embodiment, the lid 14 is provided so as to cover the air opening 8 of the casing 7, and further, the casing 7 and the lid 1 are provided.
A metal holding plate 15 is fastened and fixed with screws 12 so as to cover and hold the metal holding plate 4. A leg 14 a made of the same material as the casing 7 is formed in the lid 14, and an appropriate number of gaps 14 b are formed in the leg 14 a so that the air opening 8 of the casing 7 functions. ing. The gap 14b makes it possible to open the half-faced surface 1b of the semiconductor element to the atmosphere and measure the gauge pressure without any trouble.

Next, the operation of the present embodiment configured as described above will be described. In a normal use state, the function of opening the opposite surface of the pressure-sensitive portion to the atmosphere is secured by the gap 14b of the leg 14a of the lid 14 and the atmosphere opening port 8, so that the pressure measurement operation in the gas meter can be performed without any problem. Become. Then, when an abnormality such as internal leakage of the gas pipe occurs, the shutoff valve is operated by the control of the controller based on the detection value of the gas pressure sensor 10 to stop the gas supply. Also, an impact is applied to the entire gas meter due to an earthquake or the like, and internal unit components such as the semiconductor element 1 are damaged, and the gas pressure sensor 10 is in a gas leak state by any chance, and furthermore, the gas leak causes ignition and the gas meter is radiated by heat. When the temperature inside the casing becomes abnormally high, the casing 7 is softened under the influence of the temperature inside the meter. At the same time, the casing 7 is made of the same material as the casing 7 pressed against the casing 7 by the elasticity of the metal holding plate 15. The leg 14a of the lid 14 also softens. For this reason, the gap 14b is crushed and integrated with the casing 7, and the atmosphere opening port 8 is closed. Therefore, when the controller of the gas meter does not function and the shut-off valve does not operate, and even when the gas is filled in the casing, the gas in the gas meter is not further released to the outside.

Further, even when a gas pressure exceeding the maximum withstand pressure value is applied to the gas pressure sensor 20 due to an abnormality on the gas supply side, the metal pressure plate 15 prevents the gas pressure sensor 20 from jumping out. There is no risk of gas leakage.

Further, the present embodiment can be applied to a package and a casing of a commercially available pressure sensor, and any pressure sensor can be easily and inexpensively provided with a gas leakage countermeasure.

Although the first and second embodiments have been described separately, the gas leakage prevention effect is further enhanced by using the first and second embodiments together. be able to.

[0019]

As described above, according to the first aspect of the present invention, the atmosphere opening port for opening the back side of the pressure sensing portion to the atmosphere is shrunk by the softening of the casing when the temperature is higher than a predetermined temperature. Since the gas pressure sensor part is in a gas leak state due to a plurality of open ports having a closed diameter, if a gas leak occurs and further ignition occurs, the casing inside the gas When the gas meter controller does not function and the shut-off valve does not operate, and the casing is filled with gas, the Gas leakage can be suppressed.

According to the second aspect of the present invention, there is provided a lid which is made of the same material as the casing and has a gap formed therein for always opening the air opening, and a lid provided to cover the air opening. A metal press plate provided so as to cover and press the casing and the lid, and at a high temperature of a predetermined temperature or higher, the legs soften, the gap is crushed, and the lid opens the atmosphere opening port. If the gas pressure sensor part is in a gas leak state due to the closed structure, and if the gas leak causes a fire, the temperature of the gas meter abnormally rises, the legs soften, and the elasticity of the metal holding plate Since the gap is crushed and the air opening is closed by the lid,
Even when the shut-off valve does not operate because the controller of the gas meter does not function and the inside of the casing is filled with gas, further gas leakage can be suppressed.

According to a third aspect of the present invention, the gas pressure sensor is provided so as to cover the casing while keeping an atmosphere opening port for opening the back side of the pressure sensing portion to the atmosphere, and when the gas pressure in the gas meter is abnormal, the gas pressure is increased. A metal presser plate is provided to prevent the sensor body from popping out, so even if a gas pressure exceeding the maximum withstand pressure value is applied to the gas pressure sensor due to an abnormality on the gas supply side, etc. By preventing the pressure sensor main body from jumping out, it is possible to prevent gas leakage at the gas pressure sensor portion.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of a gas pressure sensor according to the present invention, and a perspective view of a casing part.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the present invention and an exploded perspective view of a metal holding plate and the like.

FIG. 3 is a perspective view of a gas meter incorporating a conventional gas pressure sensor and a rear view of a main part thereof.

FIG. 4 is a cross-sectional view of a gas meter incorporating a conventional gas pressure sensor and an exploded perspective view of a main part thereof.

FIG. 5 is a longitudinal sectional view of a conventional gas pressure sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor element used as a pressure sensing part 5, 7 Casing 6 Small air opening 8 Air opening 10, 20 Gas pressure sensor 14 Cover 14a Leg 14b Gap 15 Metal holding plate

 ──────────────────────────────────────────────────の Continuing on the front page (72) Quantum inventor Nakata Quantum 70, Yanagicho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture

Claims (3)

[Claims] 1. A gas pressure sensor for detecting a gas pressure in a gas meter, comprising: a casing having an atmosphere opening port for opening a back side of a pressure sensing portion to the atmosphere, wherein the atmosphere opening port has a predetermined temperature or higher. A gas pressure sensor comprising a plurality of open ports having a diameter that is contracted and closed by softening of the casing at a high temperature. 2. A gas pressure sensor for detecting a gas pressure in a gas meter, comprising a casing having an atmosphere opening port for opening the back side of the pressure sensing section to the atmosphere. A lid provided with a gap for opening the atmosphere opening port, a lid provided to cover the atmosphere opening port, and a metal press plate provided to cover and press the casing and the lid are provided. A gas pressure sensor having a configuration in which the leg portion is softened at a high temperature equal to or higher than a predetermined temperature, the gap is crushed, and the lid is closed with the lid. 3. A gas pressure sensor for detecting a gas pressure in a gas meter, comprising a casing having an atmosphere opening port for opening the back side of the pressure sensing section to the atmosphere, wherein the atmosphere opening port is kept open. A gas pressure sensor provided to cover the casing while preventing a gas pressure sensor main body from jumping out when an abnormal gas pressure in the gas meter occurs.