JPH0862016A - Flow detection type gas meter with gas interruption mechanism - Google Patents

Abstract

PURPOSE: To obtain a flow rate detection type gas meter with gas interruption mechanism which can be coupled reliably while enhancing the workability by improving the coupling structure especially between a pressure sensor and a gas channel. CONSTITUTION: A pressure sensor 5 is housed in a sensor case 4 and fixed to a mother board 1. A pressure conduction pipe 9 having one end coupled airtightly with the pressure sensor 5 is led out, at the other end thereof, from the sensor case 4. A packing 12 to be fitted airtightly with the other end of the pressure conduction pipe 9 is then received in a hole made through a partition board 10 constituting a gas channel 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate detection type gas meter, and in particular, it is equipped with a pressure sensor for detecting gas pressure. When an inappropriate gas pressure is detected, a command is issued through a microcomputer or the like to operate a shutoff valve. The present invention relates to an improvement in a connection structure between a gas flow path and a pressure sensor in a flow rate detection type gas meter with a gas cutoff mechanism which is configured to stop gas supply.

[0002]

2. Description of the Related Art In a conventional flow rate detection type gas meter with a gas cutoff mechanism, a gas metering mechanism is provided in the middle of a gas flow passage from a gas inlet to a gas outlet, and a part of the gas passage is drilled. A relatively large gas pressure sensor was bolted directly to the relatively large opening via a packing to measure the gas supply pressure.

According to this structure, the opening for introducing the gas pressure to the gas pressure sensor becomes large and the strength of the pipe wall is lowered, and the gas pressure sensor also needs to be relatively large. Also, there is a drawback that it is relatively complicated because it is attached with bolts with a packing interposed.

Therefore, a diaphragm made of conductive single crystal silicon is used as the gas pressure sensor, and the capacitance between the diaphragm and the electrode installed facing it is detected and converted into an analog signal. A highly accurate sensor capable of measuring pressure as a continuous analog amount, and a small high-performance pressure sensor having a size of several mm has been developed by using a manufacturing technique for a silicon wafer. When such a pressure sensor is used in a flow detection type gas meter with a gas shutoff mechanism, for example, such a pressure sensor, a seismic sensor for detecting an earthquake, an integrated circuit for processing signals from these sensors, and an ASI
It is used by fixing C (Application Specific Integrated Circuit) etc. on an electrically insulating substrate, storing it in a sensor case consisting of a circular base and a dome-shaped case, and attaching it to a motherboard equipped with a microcomputer. In this case, a flexible pipe such as a rubber pipe is used for connection with the gas flow path. That is, the pressure sensor has a structure in which, for example, one end of the gas pressure guiding tube is hermetically connected through the dome-shaped case and a flexible pipe such as a rubber tube connected to the gas flow path is connected to the other end. .

[0005]

By the way, the pressure sensor as described above has a good linearity in the relationship between the gas pressure and the output signal, and can measure the gas pressure as a continuous analog quantity. It has the advantage of being able to detect even a slight change in the supply pressure with high accuracy, and because it is configured to be mounted on the motherboard by being housed in the sensor case together with the seismic sensor and ASIC, the degree of freedom of its installation location. It has a high cost and can be downsized and simplified in the overall structure, but since it is connected to the gas flow path with a flexible pipe, it can be used for tasks other than mounting the sensor case to the motherboard. Since flexible pipes need to be connected and there are only two connecting points, it was necessary to pay attention to the prevention of disconnection of the connecting section and ensuring airtightness to prevent gas leakage.

Therefore, the object of the present invention is to
In a flow rate detection type gas meter with a gas cutoff mechanism using a similar pressure sensor, especially the connection structure between the pressure sensor and the gas flow path has been improved so that no separate connection work is required and there is no risk of gas leakage. The present invention is to provide a flow rate detection type gas meter with a gas cutoff mechanism, which has a connection structure that can be connected to an air conditioner, has good workability, and has high reliability.

[0007]

In order to achieve the above object, according to the present invention, the other end of a pressure guiding tube whose one end is airtightly connected to a pressure sensor is hermetically sealed to a packing attached to a partition plate which constitutes a gas flow path. It has a feature that it is inserted into and connected to, and a pressure sensor is provided on the motherboard on which the control electronic device such as a microcomputer is attached, and when the motherboard is attached to the meter, the pressure guiding tube can be connected to the packing at the same time. I am trying.

That is, the flow rate detection type gas meter according to the present invention has a pressure sensor for detecting gas pressure,
It is a flow rate detection type gas meter with a gas cutoff mechanism that operates the cutoff valve to stop the gas supply when an inappropriate gas pressure is detected.The above pressure sensor is housed in the sensor case and attached to the motherboard. The other end of the pressure guiding tube that is airtightly connected to the pressure sensor is led out from the sensor case, and the other end of this pressure guiding tube is provided with a packing that can be airtightly fitted in the partition plate that constitutes the gas flow path. It is characterized by being attached to the hole.

A microcomputer is mounted on the mother board as a control electronic device, and when the pressure sensor detects an inappropriate gas pressure, the microcomputer receives an output signal from the pressure sensor and issues an operation command to the shutoff valve, Be sure to stop the supply of.

In addition to the pressure sensor in the sensor case, a seismic sensor and an integrated circuit for processing signals from these sensors, an ASIC (Application Specific I).
It is preferable that the integrated circuits) are collectively collected and fixed on the insulating substrate.

Further, if a ring-shaped projection for sealing is formed on the inner surface of the packing attached to the hole formed in the partition plate forming the gas flow path, the pressure-guide tube can be connected with airtightness. The same effect can be achieved by forming an annular protrusion having a wedge-shaped cross section on the outer periphery of the tip of the pressure guiding tube.

[0012]

As described above, the pressure sensor for detecting the gas pressure is housed in the sensor case and attached to the motherboard, and the other end of the pressure guiding tube whose one end is hermetically connected to the pressure sensor is led out from the sensor case. In the configuration in which the other end of the pressure guiding tube is fitted in the airtight packing in the hole formed in the partition plate which constitutes the gas flow path, the lead-out tube is also hermetically sealed in the packing when the motherboard is mounted on the meter. It can be inserted and connected, and does not require separate connection work such as mounting the motherboard and connecting the outlet pipe. Further, the connecting portion is only one portion of the connecting portion with the packing, so that the connecting portion can be prevented from coming off and gas leakage can be prevented relatively easily.

By mounting a microcomputer as a control electronic device on such a mother board, the electronic function part and the mechanical connecting part of the gas shutoff mechanism can be put into an operation standby state only by the mounting work of the mother board.

In addition to the pressure sensor, the sensor case has a seismic sensor and A for processing signals from these sensors.
If SIC etc. are incorporated, the device can be made compact. Further, if an annular protrusion for sealing is provided on the inner surface of the packing, or if an annular protrusion having a wedge-shaped cross section is formed on the outer periphery of the tip of the pressure guiding tube, the airtightness at the connecting portion between the pressure guiding tube and the packing can be further enhanced. .

[0015]

Embodiments Embodiments shown in the accompanying drawings will be described below. FIG. 1 is a schematic sectional view of a control unit in a flow rate detection type gas meter with a gas cutoff mechanism according to the present invention, FIG. 2 is an enlarged sectional view of a main part, and reference numeral 1 indicates a motherboard attached to the meter, a microcomputer 2, for operation. A battery 3 or the like is mounted as a power source. Reference numeral 4 is a sensor case attached to the mother board 1, in which a pressure sensor 5, a seismic sensor 6 and an ASIC 7 are fixedly housed on an insulating substrate 8 such as ceramics.

The sensor case 4 is composed of a circular base 4a made of plastic, metal or the like and a dome-shaped case 4b. The pressure sensor 5, the seismic sensor 6 and the ASI.
The C7 is mounted and stored on the insulating substrate 8 and is mounted on the lower side of the mother board 1. Reference numeral 9 denotes a gas-conducting tube having gas resistance such as glass, metal and ceramics, one end of which is hermetically connected to the pressure sensor 5 and the other end of which is led out from the dome-shaped case 4b and fixed to the dome-shaped case 4b. ing. If it is made of metal, it can be welded to a dome-shaped case. If it is made of glass or ceramic, a collar is provided on the outer peripheral side of the pressure guiding tube on the outer surface side of the case to restrict movement, and no mechanical force is applied to the pressure sensor 5. It is desirable to fix in this way. Further, when gas resistant plastic is used, the dome-shaped case and 4b can be integrally molded.

Reference numeral 10 is a partition plate for partitioning the gas flow passage 11,
A small hole is bored at a position corresponding to the pressure guiding tube 9, and a packing 12 having a fitting groove 12a for mounting is airtightly mounted on the outer peripheral portion. It is desirable that this packing be made of a polymer material having gas resistance. As shown in the drawing, the other end of the pressure guiding tube 9 is airtightly fitted into the packing 12 so that the gas flow path 11 and the pressure sensor 5 are connected.
And are airtightly connected via a pressure guiding tube 9. Since the sensor case 4 is attached to the mother board 1, if the mother board is attached to the meter, the other end of the pressure guiding tube 9 derived from the sensor case can be fitted into the packing 12 provided on the partition plate 10, thereby providing flexibility. It has a structure that does not require a separate connection work such as when using a sex pipe. Reference numeral 13 is a plurality of input / output terminals, and 14 is an air introduction hole provided in the dome-shaped case 4b for communicating the inside of the sensor case 4 with the atmosphere. A porous sintered metal or the like is provided to prevent dust from entering. Is equipped with a dust filter.

A plurality of annular sealing projections 12b are formed on the inner surface of the packing 12 to ensure airtightness with the pressure guiding tube 9 to be fitted therein. In addition, as shown in FIG.
Forming the annular protrusion 9a having a wedge-shaped cross section as shown in FIG. 3 is effective for improving the sealing property with the packing and ensuring the connected state.

Since the distance between the lower surface of the mother board 1 and the partition plate 10 is about 20 mm, and the distance between the sensor case 4 and the partition plate 10 is about 10 mm, the length of the pressure guiding tube 9 and the partition plate 10 from the sensor case side. Protruding packing 12
The thickness of can be selected according to this gap. Packing 1
If 2 has a certain thickness and the tip of the pressure guiding tube 9 is fitted to an appropriate depth, even if the distance between the motherboard 1 and the partition plate 10 that has a difference in expansion due to temperature change, This can be absorbed. Further, if a material having a high degree of strength and strength such as Teflon is selected as the material of the packing, the packing can be lengthened and the pressure guiding tube can be shortened.

The sensor case 4 is attached to the mother board 1
If it is attached to the upper surface of the board 1, it requires holes for leading the pressure guiding tube 9 to the mother board 1 and the insulating board 8, and the pressure sensor 5 is attached to the insulating board 8 in the state of facing down. For comparison of the atmospheric pressure of the sensor, it is necessary to provide a space between the insulating substrate and the pressure sensor, which reduces reliability and is not preferable. On the other hand, when the sensor case 1 is attached to the lower surface of the mother board 1, there are advantages such as the above-mentioned drawbacks and a small possibility that water drops or the like block the atmosphere introduction hole 14.

[0021]

As is clear from the above description,
A flow rate detection type gas meter with a gas cutoff mechanism according to the present invention has a sensor case accommodating a pressure sensor for detecting gas pressure attached to a mother board, and a packing for inserting the other end of a pressure guiding tube derived from the sensor case into a gas flow. Since it is attached to the partition plate that divides the passage, the pressure guiding tube can be fitted into the packing by the work of attaching the motherboard to the meter, and the workability is extremely good, and the connecting point is the part of the connection with the packing. Since there is only one location, prevention of disconnection of the connecting portion and prevention of gas leakage can be easily achieved, and a highly reliable detection configuration can be achieved.

Further, since the pressure sensor and the gas flow path are connected by the shortest straight line, there is an advantage that the time delay for detecting the pressure fluctuation becomes minute and the safety is improved.

Furthermore, since the electronic equipment for control is mounted on a motherboard on which a microcomputer or the like is mounted, the electronic function part and the mechanical connection part of the gas cutoff mechanism can be put into an operation standby state only by mounting the motherboard. it can. In addition to pressure sensors, seismic sensors required in this type of gas meter and ASI that processes signals from these sensors
C and the like can be incorporated in the sensor case together with the pressure sensor, and the device can be made compact.

Since the pressure guide tube and the packing are connected to the meter on the mother board without delusion, they are securely connected with airtightness. However, an annular projection for sealing is provided on the inner surface of the packing, or the pressure guide tube is packed. In the structure in which the annular protrusion having a wedge-shaped cross section is formed on the outer periphery of the tip portion, a better connected state with more airtightness can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a control unit in a flow rate detection type gas meter with a gas cutoff mechanism according to the present invention,

FIG. 2 is an enlarged sectional view of an essential part,

FIG. 3 is a cross-sectional view of essential parts showing another embodiment of the airtight connection structure between the pressure guiding tube and the packing.

[Explanation of symbols]

1 ... Motherboard 2 ... Microcomputer 4 ... Sensor case 4a ... Circular base 4b ... Dome case 5 ... Pressure sensor 6 ... Seismic sensor 7 ... ASIC 8 ... Insulating substrate 9 ... Pressure guide tube 9a ... Annular protrusion 10 ... Partition plate 11 ... Gas flow path 12 ... Packing 12b ... Sealing annular protrusion

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Masahiro Yasui 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd. No. 4-9 Inside Sensor Technology Laboratory Co., Ltd. (72) Inventor Toshihiro Fujii 7-30-8 Oi, Shinagawa-ku, Tokyo In Nishiyama Co., Ltd.

Claims (4)

[Claims] 1. A flow rate detection type gas meter with a gas cutoff mechanism, which has a pressure sensor for detecting gas pressure, and operates a cutoff valve to stop the gas supply when an inappropriate gas pressure is detected, The above pressure sensor is housed in a sensor case and attached to a motherboard, and the other end of the pressure guiding tube whose one end is airtightly connected to the pressure sensor can be pulled out from the sensor case, and the other end of this pressure guiding tube can be fitted airtightly. Flow meter with a gas cut-off mechanism, in which various packings are attached to holes formed in the partition plate that constitutes the gas flow path. 2. A control microcomputer is mounted on a motherboard, and a pressure sensor is provided in the sensor case.
The flow detection gas meter with a gas shutoff mechanism according to claim 1, wherein the seismic sensor and the ASIC are fixed and housed on an insulating substrate. 3. A flow rate detection type gas meter with a gas shutoff mechanism according to claim 1, wherein an annular projection for sealing is formed on the inner surface of the packing. 4. A flow rate detection type gas meter with a gas shutoff mechanism according to claim 1, wherein an annular projection having a wedge-shaped cross section is formed on the outer periphery of the tip of the pressure guiding tube.