JP3107137B2 - Gas leak detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas leak detecting device, and more particularly to a collective supply system for supplying city gas or the like to each unit of an apartment house. The present invention relates to a gas leak detection device that detects the presence or absence of leakage without stopping gas supply.

[0002]

2. Description of the Related Art In a collective supply facility for city gas and the like,
Each house is equipped with a gas meter that measures the amount of gas used, but recent gas meters monitor the flow rate of gas flowing through the gas meter with a built-in microcomputer and check for leaks in the gas piping between the gas meter and gas equipment. A so-called microcomputer meter capable of making a judgment has been used. Therefore, with respect to gas leakage downstream of the microcomputer meter, safety can be ensured by providing the gas meter with a detection function.

On the other hand, a gas leak detection device is also provided at an inlet of a gas supply pipe in a collective supply facility so that a gas leak in a gas supply pipe leading to a gas meter of each house can be detected, and each house also functions as a gas monitoring device. It has also been proposed to detect the presence or absence of gas leakage in a gas supply pipe in a low-pressure section including a buried pipe upstream of a gas meter without stopping gas supply. It is also conceivable to use a gas leak detection device installed in such a place having the same configuration as the gas meter of each house. But in this case,
Since it is necessary to use a large-capacity gas meter which allows a large amount of gas flow to flow into the inlet of the collective supply facility, the sensitivity for detecting a small gas leak cannot be obtained, which is not feasible.

Therefore, when the gas flow rate decreases,
Flow path switching means for automatically switching the flow path from a large flow path to a small flow path by closing the large flow path so that gas flows only in a bypass flow path as a small flow path provided in parallel with the large flow path A small-capacity membrane gas meter is provided in the small flow path, and the function of this gas meter is used to monitor the gas flow in the small flow path and detect minute gas leakage in the gas flow path up to the microcomputer meter. Some suggestions have been made.

In this proposed leak detection device, when gas consumption at night or late at night is almost eliminated, the gas is passed only through the small flow channel by the flow channel switching device, and the gas is supplied through the gas supply pipe downstream of the flow channel switching device. A small flow rate of flowing gas can be monitored in a small flow path. At this time, if there is no gas consumption and no minute gas leakage occurs, the gas flow rate is not detected.

[0006] Such a condition is assumed to occur at least once during a relatively long predetermined period of, for example, 30 days, and if the gas flow rate is not detected during this predetermined period. Sometimes, it is determined that there is a possibility that minute gas leakage has occurred.

As described above, the bypass flow path is provided in a part of the gas supply pipe, the gas flows through the bypass flow path at a low flow rate, and the minute flow rate provided in the bypass flow path is monitored to detect the minute gas leakage. Therefore, gas leak detection of the gas supply pipe can be easily and reliably performed without forcibly stopping the gas supply.

[0008]

The gas supply pipe is provided with a manual gas shut-off valve used for shutting off gas when replacing a gas meter or replacing a lamp outer pipe buried underground. However, it is housed and mounted in a cylindrical container called a pit, but if a gas leak detection device as described above is also housed in this pit and it is attempted to connect it immediately after a manual gas shut-off valve, a larger container is required. It becomes necessary and may be too large to be installed in some places. Then, in such a case, in order to install the proposed device, it is necessary to significantly change the existing gas supply pipe or the inner pipe, or to perform a mounting work by exposing a part of the buried pipe, There was a problem that the work became large-scale, and it was extremely troublesome to cope with the existing equipment, and the construction cost was increased.

Further, in the above-described conventional apparatus, a large amount of gas leaks due to an earthquake due to damage of a gas supply path in a low-pressure section including a buried pipe from a gas leak detecting device to a gas monitoring device constituted by a microcomputer gas meter. No care has been taken for that. Therefore, in order to be able to cope with such a situation, it was necessary to use a manual gas shut-off valve having a seismic isolation shut-off function. The seismic intensity detected by the vibrator is not less than a predetermined value, and the solenoid is simply driven electromagnetically in the manual shut-off valve by this detection to drive the valve body to the closed state to cut off the gas supply. For this reason, in a situation where the seismic sensor does not work, for example, if the gas supply path is accidentally damaged during road construction, the shutoff valve does not automatically close, and the manual operation is performed. Until the valve was closed, a large amount of gas continued to be blown out from the damaged part, and in this case, there was a problem in housing a manual shut-off valve with a seismic isolation function together with the gas leak detection device in the pit container. .

Accordingly, the present invention has been made in view of the above-described problems,
A main object of the present invention is to provide a gas leak detection device which has a built-in gas cutoff function, has a configuration suitable for miniaturization, improves mountability, and can reduce construction costs.

In view of the above-mentioned problems, the present invention has a built-in gas shut-off function, and is capable of automatically suspending gas supply when a large amount of gas is ejected due to breakage of a gas supply pipe. It is a second object of the present invention to provide a gas leak detection device that has a configuration suitable for miniaturization, improves mountability, and reduces construction costs.

Further, in view of the above problems, the present invention has a built-in gas shut-off function and a built-in seismic cut-off function so that a large amount of gas leak does not occur even if the gas supply pipe is damaged by an earthquake. A third object of the present invention is to provide a gas leak detection device that is integrated, has a configuration suitable for miniaturization, improves mountability, and can reduce construction costs.

[0013]

In order to achieve the above-mentioned main object, a gas leak detecting device according to the present invention comprises:
A valve body provided in the middle of the gas supply path, a diaphragm which receives gas pressures on the upstream side and the downstream side of the valve body on both surfaces thereof and displaces when the gas pressure on the upstream side is higher than the downstream side by a predetermined value or more, and Valve body driving means having a connecting member or the like for connecting the diaphragm and the valve body and transmitting the displacement of the diaphragm to the valve body, and the valve body is automatically turned on or off according to the presence or absence of gas consumption on the downstream side. Automatic opening / closing valve means for opening and closing a valve, gas flow detecting means for detecting a gas flow in a bypass gas flow path provided in parallel with the diaphragm and outputting a gas flow detection signal, and the gas flow detecting means Gas leak determination means for determining gas leakage based on whether or not a gas flow detection signal is continuously input for a predetermined period or more, provided upstream of the bypass gas flow path and upstream of the valve element Under the gas pressure A gas pressure path for receiving the gas pressure on the downstream side of the valve body instead of the upstream side on the surface of the diaphragm, and forcibly changing the gas pressure difference received on both surfaces of the diaphragm. Means.

In order to achieve the above-mentioned main object, the gas leak detecting device according to the present invention further comprises a valve provided in the middle of the gas supply path, and a gas pressure on the upstream side and the downstream side of the valve which are measured on both sides. Valve driving means having a diaphragm which is displaced when the gas pressure on the upstream side is higher than the downstream side by a predetermined value or more, and a connecting member for connecting the diaphragm and the valve body and transmitting the displacement of the diaphragm to the valve body. Automatic opening / closing valve means for automatically opening and closing the valve body according to the presence or absence of gas consumption on the downstream side, and pressure detecting means for detecting the pressure on the downstream side of the valve body And comparing the pressure detected by the pressure detection means with a predetermined value,
Determining means for monitoring the comparison result for a predetermined period to determine gas leakage; and a surface of the diaphragm receiving a gas pressure on the upstream side of the valve body, on a surface of the diaphragm which is downstream of the valve body instead of the upstream side. A gas pressure passage for receiving gas pressure is formed, and a passage switching means for forcibly equalizing a difference in gas pressure received on both surfaces of the diaphragm is provided.

[0015] The valve body driving means includes an elastic member for applying an urging force corresponding to the predetermined gas pressure to the diaphragm in a direction against the displacement.

The passage switching means comprises a rotary valve body that is manually rotated.

In order to achieve the above-mentioned second object, a gas leakage detecting device according to the present invention is connected to a connecting member of the automatic opening / closing valve means, and drives the valve body via the connecting member. A valve drive solenoid for opening and closing the valve, and a solenoid control means for controlling the valve drive solenoid to drive the valve body to close and open the valve,
A differential pressure sensor that detects a difference between the gas pressures on the upstream side and the downstream side of the valve body and outputs a pressure signal corresponding to the magnitude of the differential pressure, wherein the solenoid control means includes: A pressure signal is input, and control is performed to drive the valve drive solenoid to close the valve in response to the input of a pressure signal corresponding to a pressure difference equal to or greater than a predetermined value.

In order to achieve the third object described above, a gas leak detecting device according to the present invention is connected to a connecting member of the automatic opening / closing valve means, and drives the valve body via the connecting member. A valve drive solenoid for opening and closing the valve, and a solenoid control means for controlling the valve drive solenoid to drive the valve body to close and open the valve,
Seismic sensing means for detecting vibration and outputting a vibration detection signal, wherein the solenoid control means inputs a vibration detection signal from the seismic sensing means, and based on the vibration detection signal, a seismic intensity of a predetermined value or more. It is characterized in that control is performed to detect the occurrence of an earthquake and drive the valve drive solenoid to close the valve body.

In order to achieve the above-mentioned main object, a gas leakage detecting device according to the present invention is arranged such that the passage switching means comprises a switching valve body, and a switching drive for driving the switching valve body to form the gas pressure passage. Solenoid, solenoid control means for controlling the switching drive solenoid to drive the switching valve body, and manual operation means for outputting a switching signal by manual operation, the solenoid control means,
A switching signal is input from the manual operation means to control the switching drive solenoid to drive the switching valve body.

In order to achieve the above-mentioned second object, a gas leak detecting device according to the present invention detects a difference between gas pressures on an upstream side and a downstream side of the valve body, and responds to the magnitude of the differential pressure. A differential pressure sensor for outputting a pressure signal, wherein the solenoid control means receives the pressure signal from the differential pressure sensor, and responds to the input of the pressure signal corresponding to a pressure difference equal to or greater than a predetermined value to the switching drive solenoid. A control for driving the switching valve body is performed.

In order to achieve the third object described above, a gas leak detecting device according to the present invention comprises vibration sensing means for detecting a vibration and outputting a vibration detection signal, and the solenoid control means comprises: A vibration detection signal is input from the seismic means, and control is performed to detect the occurrence of an earthquake having a seismic intensity equal to or greater than a predetermined value based on the vibration detection signal and drive the switching valve body with the switching drive solenoid. I have.

[0022]

According to the above construction, the automatic opening / closing valve means has a valve element provided in the middle of the gas supply path and a valve element driving means for driving the valve element, and the diaphragm of the valve element driving means is provided on the upstream side of the valve element. When the gas pressure on the upstream side of the diaphragm is higher than the downstream side by a predetermined value or more, the displacement is transmitted to the valve via a connecting member or the like. Therefore, when there is gas consumption on the downstream side and the gas pressure on the downstream side drops by a predetermined value or more, the diaphragm is displaced and the valve body is automatically opened, and the gas consumption on the downstream side is eliminated or reduced and the downstream side gas is consumed. When the gas pressure on the upstream side approaches the gas pressure on the upstream side, the diaphragm is displaced in the opposite direction to automatically close the valve body.

A gas flow detecting means provided in a gas bypass passage provided in parallel with the diaphragm detects a gas flow and outputs a gas flow detection signal, and receives a gas flow detection signal from the gas flow detecting means. The gas leak judging means performs a gas leak on the downstream side when a gas flow detection signal is inputted continuously for a predetermined period or more, on the assumption that there is always gas consumption within a predetermined period. Since it is determined that there is a possibility of gas leakage, gas leakage can be detected.

Further, the passage switching means forms a gas pressure path on the surface of the diaphragm receiving the gas pressure on the upstream side for receiving the gas pressure on the downstream side in place of the gas pressure on the upstream side. Since the pressure difference is forcibly made substantially equal, the diaphragm is displaced and the valve body can be closed. Since the valve body can be closed by forming the gas pressure path in this manner, the passage switching means serving as the gas shutoff means and the automatic opening / closing valve means can be easily integrated.

In another gas leak detecting device according to the present invention, the pressure detecting means detects the pressure on the downstream side of the valve body, compares the detected pressure with a predetermined value, and compares the result of the comparison with the predetermined value. If the pressure does not exceed a predetermined value continuously for a predetermined period under the assumption that there is always no gas consumption within a predetermined period, gas leakage will occur downstream. Since it is determined that there is a possibility of occurrence, gas leakage can be detected.

In the valve driving means, since a force corresponding to a predetermined gas pressure for displacing the diaphragm is applied by the elastic means, the desired value can be easily set by selecting the elasticity of the elastic member. it can.

Since the passage switching means comprises a rotary valve which is manually rotated, the valve can be closed at any time by manual operation.

A valve drive solenoid connected in the middle of the connecting member of the automatic opening / closing valve means is controlled by the solenoid control means to drive the valve body to open and close the valve. Solenoid control means for driving the valve drive solenoid to close and open the valve body detects the difference between the gas pressure on the upstream side and the gas pressure on the downstream side of the valve body and detects the magnitude of the differential pressure output from the differential pressure sensor. When the pressure signal corresponding to the pressure difference corresponds to a pressure difference equal to or more than a predetermined value, control is performed to drive the valve drive solenoid to close the valve body in accordance with the pressure difference. When a large amount of gas is ejected due to damage or the like and the gas pressure on the downstream side is reduced, the valve element driving solenoid is driven to close the valve element, and the gas ejection can be stopped.

The solenoid control means detects the occurrence of an earthquake having a seismic intensity greater than or equal to a predetermined value based on the vibration detection signal output from the seismic means, and causes the valve drive solenoid to close the valve. When a large earthquake that may cause damage to the gas supply pipe occurs, the valve drive solenoid drives the valve to close the valve so that gas ejection can be prevented beforehand. it can.

In the gas leakage detection device according to the present invention, the solenoid control means controls the switching drive solenoid in response to the input of the switching signal generated by the manual operation of the manual operation means, and the switching means constitutes the path switching means. Since the gas pressure path is formed by driving the valve element, it is possible to easily integrate the passage switching means as the gas shutoff means and the automatic opening / closing valve means.

The solenoid control means detects the difference between the gas pressure on the upstream side and the gas pressure on the downstream side of the valve body, and outputs a pressure signal corresponding to the magnitude of the differential pressure output from the differential pressure sensor to a pressure difference equal to or greater than a predetermined value. In response to this, the switching valve is driven by the switching drive solenoid in response to this to form a gas pressure path. By the gas pressure path formed by the driving of the body drive solenoid, the diaphragm of the valve body drive means is displaced to drive the valve body to close the valve, thereby automatically stopping the gas ejection.

When the occurrence of an earthquake having a seismic intensity equal to or more than a predetermined value is detected based on a vibration detection signal output from the seismic sensing means, the solenoid control means switches to the switching drive solenoid in response to the vibration. Since the gas pressure path is formed by driving the valve element, when a large earthquake that may damage the gas supply pipe or the like occurs, the valve element is driven by the gas pressure path formed by driving the valve element driving solenoid. The diaphragm of the driving means is displaced and driven so as to close the valve body, thereby preventing gas ejection.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a piping system diagram in which an embodiment of a gas leak detection device of the present invention is applied to gas supply equipment for supplying gas to an apartment house. In the figure, a gas leak detection device 1 has a function of a shut-off valve incorporated therein and has a low-pressure branch pipe 11.
It is configured to be a type that also serves as a main bulb of the lamp outer tube 12 branched from. The gas leak detection device 1 has an inlet 1a
Is connected to the supply side of the lamp outer tube 12 branched from the low-pressure branch pipe 11, in the middle of the lamp outer tube 12 so that the outlet 1 b is on the downstream side. A supply path 13a and a gas bypass path 13d are formed, and an automatic opening / closing valve 2 as automatic opening / closing valve means is provided in the middle of the main supply path 13a.

The automatic opening / closing valve 2 operates so as to automatically open and close the valve body 21 by using and not using gas on the downstream side to open and close the main supply passage 13a, thereby driving the valve body 21. And a valve driving unit 22 as a valve driving unit. The valve drive section 22 has pressure chambers 22b and 22c partitioned by a diaphragm 22a.
One of the gas passages 13b and 13c communicating with the main supply passage 13a on the upstream side and the downstream side of the valve body 21 via the manual passage switching unit 4 is selectively connected to 2b. On the other hand, the valve body 2 is provided in the pressure chamber 22c.
Gas passage 1 communicating with the main supply passage 13a downstream of
3c is always connected.

The diaphragm 22a has the valve 2 on both sides thereof.
The pressures of the pressure chambers 22b and 22c, which are equal to the upstream and downstream gas pressures, respectively, are displaced in response to the differential pressure being equal to or higher than a predetermined value. The displacement of the diaphragm 22a is transmitted to the valve body 21 via the connection mechanism 23, and closes and opens the valve body 21. Valve element 21
The plunger is connected to a part of the connection mechanism 23 and is driven to a valve closed and valve open state by a valve drive solenoid 6 operated under the control of the solenoid control unit 5.

The solenoid control unit 5 includes a differential pressure signal from a differential pressure sensor 7 for detecting a differential pressure between the pressure chambers 22b and 22c, a seismic signal from a vibration sensor 8 for detecting vibration, and a manual reset switch. 9 is input. And
The differential pressure signal input from the differential pressure sensor 7 detects that the differential pressure has exceeded a predetermined value, or the seismic signal from the seismic sensor 8 has detected that an earthquake with a seismic intensity higher than the predetermined value has occurred. Then, the valve body 21 is closed, and the return switch 5a
The valve driving solenoids 6 are respectively operated so as to open the valve body 21 in response to the return signal input by the operation of (1).

The pressure chambers 22b and 22 of the valve drive section 22
c, a gas bypass passage 13d is formed in parallel with the diaphragm 22d.
There is provided a gas flow detection unit 9 which detects a gas flow flowing through d and outputs a gas flow detection signal. The gas flow detection signal from the gas flow detection unit 9 is input to the gas leakage determination unit 10, and the gas leakage determination unit 10 determines the presence or absence of gas leakage based on the gas flow detection signal.

City gas or the like used in the apartment house 14 is supplied from a gas supply source (not shown) to the collective supply facility 15 of the apartment house 14 through the low-pressure branch pipe 11 and the lamp outer tube 13. Equipment 15a corresponding to each house of the collective supply equipment 15
Includes a microcomputer meter (not shown), and the microcomputer meter may have a function of determining a gas leak on the downstream side. The low-pressure branch pipe 11 is a pipe buried underground, and supplies gas which has already been brought to a low pressure state. The lamp inner pipe 13 is a pipe branched from the low-pressure branch pipe 11 and connected thereto, and is buried in the ground like the low-pressure branch pipe 11.

In the above configuration, when gas is consumed in the collective supply equipment 15 downstream of the automatic on-off valve 2, the pressure in the pressure chamber 22c decreases, and the diaphragm 22a reduces the gas pressure in the pressure chamber 22b to the pressure chamber 22c. When the pressure difference between the two becomes higher than a predetermined value, it is displaced downward. When the gas consumption in the downstream side is almost eliminated, the gas pressure in the pressure chamber 22c communicating with the downstream side becomes substantially equal to the gas pressure in the pressure chamber 22b, and the differential pressure equal to or more than a predetermined value disappears. The spring is displaced upward by the force of the urging spring. This displacement is transmitted to the valve body 21 via the power transmission link mechanism 23, and the automatic opening / closing valve 2 is automatically closed, and the main supply path 13a is completely shut off. However, since the gas flows through the gas bypass passage 13d, the gas flow detection unit 9 supplies the gas flow from the gas flow detection unit 9 as long as the gas consumption and the small gas leakage on the downstream side are not completely eliminated. A detection signal is output, and this is
Keep typing.

In general, during a relatively long predetermined period of, for example, 30 days, there is at least a predetermined number of times that gas consumption is completely eliminated. During a predetermined period, the gas flow detection signal from the gas flow detection unit 9 is transmitted to the gas leak determination unit 1.
It is no longer input to 0. Therefore, the gas leak determination unit 10 monitors the gas flow detection signal for a predetermined period, and when the number of times the gas flow detection signal is no longer input is equal to or less than the predetermined number,
It is determined that there is a possibility that minute gas leakage has occurred. When the number of times that the gas flow detection signal is not input during the predetermined period is equal to or more than the predetermined number, it can be determined that the minute gas leakage has not occurred.

Normally, the manual passage switching section 4 includes the automatic on-off valve 2
Is connected to the pressure chamber 22b via the gas passage 13b.
When the main supply passage 13a on the downstream side of the automatic on-off valve 2 is switched to be connected to the pressure chamber 22b via the gas passage 13c, both the pressure chambers 22b and 22c
It is connected to the downstream main supply path 13a via 3c. When this happens, both pressure chambers 22b and 2b
2c is substantially equal, the differential pressure disappears, and the diaphragm 22a is displaced upward by the force of an unillustrated urging spring. The valve is automatically closed, and the main supply path 13a is completely shut off. At this time, the gas does not flow through the gas bypass passage 13d, so that the gas supply pipe can be replaced on the downstream side.

If the lamp inner tube 13 is damaged for some reason on the downstream side and a large amount of gas is blown out therefrom,
On the downstream side, the pressure in the main supply path 13a decreases,
The pressure chamber 22 communicating with this via the gas passage 13c
The pressure in c also decreases. Therefore, both pressure chambers 22b and 2
The differential pressure between 2c becomes very large, and the differential pressure sensor 7 outputs a large differential pressure signal and supplies it to the solenoid control unit 5.
The solenoid control unit 5 energizes the valve drive solenoid 6 in response to the input of a differential pressure signal corresponding to a differential pressure equal to or greater than a predetermined value, and the valve drive solenoid 6 drives the valve body 21 to close the valve in response to this. .

The seismic device 8 outputs a seismic signal according to the vibration of a predetermined seismic intensity or more and supplies the signal to the solenoid control unit 5. The solenoid control unit 5 energizes the valve drive solenoid 6 in response to the input of the seismic signal, and the valve drive solenoid 6 drives the valve element 21 to close the valve in response to this. As described above, a return signal is generated by operating the return switch 5 a and input to the solenoid control unit 5 in order to return and open the valve element 21 driven by the valve drive solenoid 6 to the valve closed state. The solenoid control unit 5 urges the valve drive solenoid 6 in response to the input of the return signal, and drives the valve body 21 in the valve closed state to the valve open state in response to this.

The automatic opening / closing valve 2, manual passage switching section 4, valve drive solenoid 6, differential pressure sensor 7, and gas flow detecting section 9 described above with reference to FIG. 1 are provided in the middle of a lamp outer tube buried underground. In order to be accommodated in a cylindrical container called a pit, it is integrally formed as shown in a side sectional view of FIG. 2, and its cross section is shown in FIG. 3 and its side is shown in FIG. In these figures, the illustration of the lamp inner tube connected to the case main body C1 is omitted, but the automatic on-off valve 2, the gas flow detector 9, and the like show a state when gas is not used. In FIG. 2, the automatic on-off valve 2 and the like are configured in a case formed by a case body C1, a case lid C2, and the like. A gas inlet 11a and an outlet 11b are formed in the case body C1 so as to face left and right in opposite directions in order to connect the gas leak detection device 1 to the middle of the lamp outer tube 13. Flanges are formed on the outer circumferences of the gas inlet 11a and the outlet 11b for connecting the ends of the lamp inner tube 13 on the upstream side and the downstream side, respectively.

In the case body C1, the gas inlet 11
The automatic on-off valve 2 is formed in a space S formed between the gas inlet 11a and the gas outlet 11a.
At the boundary between the space and the space S, an annular nozzle 21 is used as a valve port.
1 are attached using an airtight ring 212. The nozzle 211 is opened in the lateral direction (horizontal direction), and the valve packing 21a of the circular valve body 21 is separated from the space S side so that the valve is closed and the valve is opened. The valve packing 21a of the valve body 21 is hermetically mounted around the valve body, and is formed of a material such as nitrile rubber that can be elastically deformed. In addition, since the opening of the nozzle 211 as a valve port is opened in the horizontal direction, dust mixed in the gas flow is
It is difficult to accumulate on the contact portion between the valve body 21 and the valve body 21, and the complete closing of the valve can be maintained without damaging the valve closing. Further, a filter 210 is provided at the gas inlet 11a so that large dust mixed in the gas flow does not enter the inside.

The valve body 21 has a central hole 21b in which a valve shaft 21 is provided.
The valve shaft 21c is fitted in a gas-tight manner. One end of the valve shaft 21c is inserted into a guide tube 213 formed integrally with the nozzle at the center of the nozzle 211, and the other end is a power transmission link described later. respectively slidably inserted in the guide hole 23b ₁ formed in the support block 23b mechanism 23, the valve shaft 21c is guided so as to keep the horizontal state.

The case body C1 has an inlet 11a.
Between the nozzle C and the nozzle 211 upward.
a is formed and the opening C1b
Has been opened. This opening C1b is provided with an airtight ring 11c.
A space for accommodating the differential pressure sensor 7 composed of a semiconductor pressure sensor is formed above the case cover C2 corresponding to the space S and closed by a case cover C2 that is hermetically attached using the above. A cap-shaped container C21 is hermetically attached using an airtight ring 11d.

A recess C2a is formed below the case cover C2 corresponding to the space S, and a mounting bracket C22 having a recess C22a at an upper portion corresponding to the recess C2a is formed around the periphery by a set screw 11e. Fixed.
The mounting bracket C22 fixes the periphery of the diaphragm 22a in an airtight manner with the inner surface of the case lid C2 via an airtight ring 11f. The space formed by the concave portion C22a of the mounting bracket C22 has an opening at the bottom, and communicates with the space S. Therefore, the diaphragm 22a is provided between the space S of the case body C1 and the case lid C2.
And a space S1 formed by the concave portion C2a, a pressure chamber 22c formed of the space S and a pressure chamber 22b formed of the space S1 are formed.

The case cover C2 is provided with a pressure-guiding hole C23 for guiding the pressure in the pressure chamber 22b on one pressure-receiving surface of the differential pressure sensor 7, and a pressure chamber via the pressure-guiding tube 7a on the other pressure-receiving surface. A pressure guiding hole (not shown) for guiding the pressure of 22c is provided. Therefore, the differential pressure sensor 7 is connected to the pressure chambers 22b and 2b.
Outputs size differential pressure signal of which corresponds to the difference between the pressure in 2c, the pressure difference signal is solenoid control unit of a remote monitoring panel KB via the signal line L ₁ drawn by hermetically from the container C21 5 is transmitted. The monitoring panel KB can be installed in a management room of the apartment house 14 or the like.

The case cover C2 is further provided with a hole C2b for communicating the space S1 with the upstream side of the automatic on-off valve 2 through the hole C1a of the case body C1.
C2 for branching from 2b and communicating with the pressure chamber 22c
c is formed. At a branch point of the hole C2c from the hole C2b, a manual passage switching unit 4 is provided. The manual passage switching section 4 includes a passage switching piece 42 that is rotated by a manual operation knob 41. In FIG.
A communication hole 42a for communicating the pressure in the space S1 so as to maintain the pressure in the upstream side of the automatic on-off valve 2 when in the normal position as shown in FIG. 5A, and a 90 ° rotation as shown in FIG. A communication hole 42b that connects the space S1 with the space S when the space S1 is located is formed.

The diaphragm 22a is formed of an elastic film having flexibility such as rubber, a central portion thereof is sandwiched between the circular plate 22a ₁ and a small-diameter retainer disc 22a ₂ receives a large diameter is kept flat I have. Screw 22a ₃ through the central through-hole of the holding disc 22b ₂ and the receiving disc 22a ₁ is inserted, it is screwed into the screw hole 22a ₅ of the coupling piece 22a ₄ on the lower surface side of the disc 22a ₁ its tip receiving It is tightened. Thus, between the connecting pieces 22a ₄ the head of the screw 22a _3, the pressing disc 22a ₂ diaphragms 22a and the receiving disc 22a ₁ is pinched by hermetically connecting piece 22a ₄ and diaphragm 22a It is integrated. The above-mentioned mounting bracket C is attached to the diaphragm 22a.
22 and the receiving disk 22a ₁ and the connecting piece 22a
The biasing force is constantly applied in the direction of the space S1 by ₄ and the coil spring 22a ₆ as concentrically positioned arranged elastic member.

Connecting piece 22a integral with diaphragm 22a
₄ and the valve shaft 21c integral with the valve body 21 are connected to the valve body 21 by transmitting the vertical movement of the diaphragm 22a to the valve body 21 and converting the valve body 21 into horizontal movement for driving the valve body 21 in the horizontal direction.
Are connected via a power transmission link mechanism 23 as a connecting member that comes into contact with and separates from the power transmission mechanism. Power transmission link mechanism 2
3 is a lever 23c rotatably supported by a support block 23b fixed in the space S by a screw 23a;
One end shaped end tip of F of the lever, a linear link 23d whose other end is respectively rotatably connected to the coupling piece 22a _4, one end bent portion of the lever 23c, the other end A link 23e, which is rotatably connected to the distal end of the other end of the valve stem 21c, is provided.
3d is inserted through an opening C22b opened in the mounting bracket C22.

The other end of the lever 23a has a lever 2
Link 2 for linking 3a with valve drive solenoid 6
One end of 3f is rotatably connected. Solenoid 6
Is a solenoid plunger 6b biased in the projecting direction by the coil spring 6a, a solenoid coil 6c that attracts the solenoid plunger 6b against the biasing force of the coil spring 6a by energizing in one direction, and a biasing force by the coil spring 6a. And a magnet 6d for attracting and holding the solenoid plunger 6b sucked against the solenoid plunger 6b. The solenoid plunger 6b attracted by the magnet 6d becomes a solenoid coil 6c.
By generating a magnetic field that negates the attraction force of the magnet 6d by energizing in the opposite direction, the coil 6a is returned to the protruding state by the urging force of the coil spring 6a.

A long hole 23g is formed at the other end of the link 23f, and an engaging pin 6e provided at the tip of the solenoid plunger 6b is slidably fitted in the long hole 23g. The engagement pin 6e of the solenoid plunger 6b is located at the upper end side of the elongated hole 23g and allows the link 23f to move when the solenoid plunger 6b is not sucked, so that the valve body 21 is closed with the displacement of the diaphragm 22a. -Although the valve opening movement is permitted, in the suction state of the solenoid plunger 6b, it is located at the lower end side of the elongated hole 23g and the movement of the link 23f is disabled. Restrict movement.

The above-described valve drive solenoid 6 is mounted on the lower surface of the case body C1 and is housed in an airtight space formed by a cap-shaped container C11 which is airtightly mounted on the lower surface by using an airtight ring 11g. . Container C
11 power line L ₂ for supplying a power supply to the solenoid coil 6c is drawn hermetically from which is transmitted to the solenoid control unit 5 of the remote monitoring panel KB.

[0056] The power transmission link mechanism 23 described above, since constitute a reduction mechanism to reduce the amount of movement of the valve shaft 21c than the displacement amount of the coupling piece 22a ₄ due to the displacement of the diaphragm 22a, a small differential pressure Also, a large force for driving the valve element 21 can be obtained, and the valve element 21 can be made to respond sensitively to the gas flow. Further, since the link and the lever are connected by the pivot, the frictional resistance is reduced, and the valve body 21 can be driven with a small differential pressure from this point as well, and can respond responsively to the gas flow. In addition, the diaphragm 22
a and the power transmission link mechanism 23 constitute valve driving means.

In the case body C1, as shown in FIG.
A concave portion C1d for forming the gas flow detecting section 9 on the side surface thereof
Is formed, and the bottom of the concave portion C1d communicates with the space S.
Hole C1e is formed. On the side of the case body C1
Further, the container C12 having the concave portion C12a is an airtight ring.
11h and attached to the recesses C1d and C12a.
Thus, a flow detection chamber 9a is formed. This flow detection chamber 9
a indicates that the peripheral portion is sandwiched between the case body C1 and the container C12.
Of the inlet pressure chamber 9a ₁And ream
Outlet pressure chamber 9a connected to space S through through hole C1e
_TwoAnd is divided into. In addition, the inlet pressure chamber 9a₁Is
Communication hole C12b formed in the container C12 and the case body C
1 and the case cover C2.
Pressure chamber composed of the space S1 through the communication hole C25
22b, that is, connected to the upstream side of the automatic on-off valve 2
I have.

As shown in the enlarged view of FIG. 6, a receiving disk 9c is provided on one surface of the diaphragm 9b, and a holding disk 9d is provided on the other surface. Receiving disk 9c,
A circular hole 9 is formed in the center of the diaphragm 9b and the holding disk 9d.
c ₁ , 9b _1, and 9d ₁ are respectively formed, and the peripheral edges of the circular holes 9c ₁ and 9d ₁ are fitted to each other by being raised on the holding disk 9d side. Circular holes 9c ₁ , 9b ₁ and 9d
The _1, microporous 9e ₁ communicating the inlet pressure chamber 9a ₁ and the outlet pressure chamber 9a ₂ in center flange 9e ₂ in one end, a nozzle member 9e for screw 9e ₃ is formed respectively are inserted into the outer periphery ing. Then, the receiving disk 9c and the diaphragm 9
b, the pressing disc 9d and the nozzle member 9e is by screwing the cap-shaped nut 9f to the screw 9e ₃ of the insertion end periphery, received disc 9c, diaphragm 9b and the presser disc 9d is flange 9e ₂ and the cap-like It is sandwiched and integrated with the nut 9f.

[0059] The flange 9e ₂ of the nozzle member 9e, micropores 9
Magnet holder 9h for holding the magnet 9g have a gap of increased e ₁ are caulked stop,
Inlet pressure chamber 9a in the magnet holder 9h ₁ and micropores 9
flow path 9h ₁ for communicating e ₁ is formed. Note that a coil spring 9i is contracted between the case body C1 and the holding disk 9d, and the diaphragm 9b is urged rightward in the figure. This coil spring 9
i is positioned so that the biasing force due to this does not change because the position of the coil spring 9i is shifted.

A thin partition plate 9j is attached to the bottom of the concave portion C12a of the container C12 via an airtight ring to form a storage chamber 9k, and the storage chamber 9k faces the magnet 9g with the partition plate 9j interposed therebetween. on the outside of the inlet pressure chamber 9a _1, turned on by approach of the magnet 9 g, reed switch 9m to off is fixed by spaced, also outputs an on-off signal of the reed switch 9m as a flow rate detection signal, which is a signal line remote monitoring panel KB through the L ₃
Is transmitted to the gas leak determination unit 10.

In the gas flow detector 9 having the above configuration,
As the gas flows through the fine holes 9e _1, the flow rate Q (m ³ /
h), the diameter of the micropores 9e ₁ D (mm), microporous 9e ₁
Pressure difference ΔP (mmH ₂ O) generated between the inlet pressure chamber 9a ₁ and the outlet pressure chamber 9a ₂ , the gas density is ρ (a numerical value based on air), and the count is k (0.0092). holds the following equation, the differential pressure ΔP occurs in the inlet pressure chamber 9a ₁ and the outlet pressure chamber 9a _2. Q = k × D ² × (ΔP / ρ) ^1/2

[0062] As apparent from the above equation, by setting the diameter D of the micropores 9e ₁ suitably generates a pressure difference ΔP of the predetermined abnormalities by small gas flow, the diaphragm 9b by utilizing this pressure difference Can be displaced leftward against the urging force of the coil spring 9i. The displacement of the diaphragm 9b can be detected when the magnet 9g displaced together with the diaphragm 9b is separated from the reed switch 9m and the reed switch 9m is turned off. Therefore, by setting the above-mentioned predetermined value in accordance with the minute gas leakage to be detected, the reed switch 9m can be kept in the off state even by the gas flow accompanying the minute gas leakage.

As described above, the monitor panel KB containing the solenoid control unit 5 and the gas leak determination unit 10 has a power supply voltage drop display 5b, a leak display 10a, and a shut-off display 5c.
A reset switch 5a that is operated when returning from the shut-off state is provided, and the seismic sensor 8 is connected.

In the above configuration, when the gas is consumed within the capacity range in the collective supply equipment downstream of the automatic on-off valve 2, the pressure in the pressure chamber 22c decreases, and as shown in FIG. The pressure difference between the chambers 22b and 22c causes the coil spring 22a ₆ to be displaced downward against the urging force of the coil spring 22a ₆ . Due to this displacement, the link 23d of the power transmission link mechanism 23 descends and rotates the lever 23c in the counterclockwise direction. By the rotation of the lever 23c, the link 23e, the valve shaft 21c connected thereto, and the valve body 21 integrated with the valve shaft 21c are moved together in the right direction, whereby the valve packing 2 of the valve body 21 from the nozzle 211 is moved.
1a is separated and the valve is opened.

The outlet pressure chamber 9a ₂ of the gas flow detecting section 9
The internal pressure of the diaphragm 9b also decreases as shown in FIG.
Is displaced to the left against the biasing force of the coil spring 9i by the differential pressure of the inlet pressure chamber 9a ₁ and the outlet pressure chamber 9a _2. As a result, the magnet 9g moves together with the diaphragm 9b and moves away from the reed switch 9m, so that the reed switch 9m is turned off. When the reed switch 9m is turned off, a gas flow detection signal indicating that there is a gas flow. Is generated.

Next, when the gas consumption on the downstream side of the automatic shutoff valve 2 is almost eliminated, the pressure in the pressure chamber 22c communicating with the downstream side becomes substantially equal to the pressure in the pressure chamber 22b, and the differential pressure disappears. , As shown in FIG.
2a is displaced upward by the urging force of the coil spoiler 22a ₆ , and this displacement is transmitted to the valve body 21 via the power transmission link mechanism 23, so that the automatic on-off valve 2 automatically closes and the main supply Road 13a is completely blocked. However, a slightly differential pressure is generated between the inlet pressure chamber 9a ₁ and the outlet pressure chamber 9a ₂ to flow the gas through the micropores 9e ₁ of the gas flow detection unit 9, by this pressure difference, as shown in FIG. 8 Then, the diaphragm 9b is displaced leftward against the urging force of the coil spring 9i to turn off the reed switch 9m, and a gas flow detection signal indicating that there is a gas flow is generated by turning off the reed switch 9m. Such a gas flow detection signal is output as long as the consumption of the minute gas or the leakage of the minute gas on the downstream side as well as when the gas is used on the downstream side.

Such a signal always disappears a predetermined number of times during a relatively long predetermined period of 30 days, for example, when there is no minute gas leakage. However, when a minute gas leakage occurs, a gas flow detection signal is generated. to continue. Therefore, when the gas flow detection signal is not input more than a predetermined number of times during a predetermined period, it can be determined that there is a possibility that a minute gas leak has occurred.

If the downstream lamp outer tube (not shown) is damaged for some reason and a large amount of gas is blown out therefrom, the pressure in the pressure chamber 22c is greatly reduced and the pressure between the two pressure chambers 22b and 22c is reduced. The pressure difference becomes very large, and as shown in FIG.
disc 22a ₁ received against the urging force is mounting bracket of a ₆ C2
Displaced downward until it hits the bottom of the second concave portion C22a. As a result, the valve element 21 is fully moved rightward via the power transmission link mechanism 23, whereby the valve packing 21a of the valve element 21 is brought into contact with and separated from the nozzle 211, and the valve is opened to the maximum opening. At this time, a large differential pressure is applied to the differential pressure sensor 7, and a large level differential pressure signal is output. Therefore, it is determined from the level of the differential pressure signal that a differential pressure equal to or higher than a predetermined value that does not occur due to normal gas consumption is generated, and that a large amount of gas ejection is determined.

When a large amount of gas is blown out and a pressure difference equal to or higher than a predetermined value is generated and a large level pressure difference signal is generated, the solenoid control unit 5 (FIG. 1) controls the solenoid coil 6c of the valve drive solenoid 6 in one direction. The current is applied to energize. When the solenoid coil 6c is energized by this one-way energization and the solenoid plunger 6b is attracted as shown in FIG. 10, the solenoid plunger 6b is held in that state by the attraction force of the magnet 6d even after the energization is stopped. Continue to be. When the solenoid plunger 6b is attracted, the link 23f is moved downward and the lever 23
is rotated clockwise, the valve shaft 21c is moved to the left, and the valve packing 21a of the valve body 21 is
And the valve is forcibly closed. In addition, seismic sensor 8
When a seismic signal is output in response to a seismic intensity above the specified seismic intensity,
The solenoid control unit 5 energizes the valve drive solenoid 6 in response to the input of the seismic signal, and the valve drive solenoid 6
Drives the valve body 21 to close the valve.

When returning the valve body 21 driven by the valve drive solenoid 6 to the valve closed state after confirming safety, the return switch 5a is operated to input a return signal to the solenoid control unit 5. do it. In response to the input of the return signal, the solenoid control unit 5 controls the valve driving solenoid 6
A current in the opposite direction is applied to the solenoid coil 6c to energize the solenoid coil 6c. The energization in the opposite direction causes the solenoid coil 6c
Generates a magnetic field that counteracts the attraction force of the magnet 6d that holds the solenoid plunger 6b in the state of FIG. 10, so that the solenoid plunger 6b is returned to the state of FIG. 2 by the urging force of the coil spring 6a. become.

As shown in FIG. 11, a ROM 1 storing a predetermined control program is stored in the above-mentioned monitoring panel KB.
01, and a RAM 102 in which various work areas are formed together with a data area for storing various data,
A microcomputer (CPU) 100 serving as the above-described solenoid control unit 5 and gas leak determination unit 10 is provided. The circuit in the monitoring panel KB operates by the power supply voltage supplied from the power supply circuit 110 using the battery 111 as a power supply, and a battery voltage drop detection circuit 120 that monitors the battery voltage in the power supply circuit 110 and detects the drop is provided. The output is input to the CPU 100.

The monitoring panel KB is provided with interface (I / F) circuits 7a, 8a and 9a for the CPU 100 to input signals from the differential pressure sensor 7, the seismic sensor 8 and the gas flow detector 9. In addition, a solenoid drive circuit 6a for driving and controlling the valve drive solenoid 6 is provided. The CPU 100 has a power supply voltage drop display 5b based on a signal from the battery voltage drop detection circuit 120, and a leak display 1 based on a gas leak determination based on a signal from the gas flow detection unit 9.
0a, the light emitting diodes LED _5b , LED _10a , which respectively drive the valve drive solenoid 6 in response to signals from the differential pressure sensor 7 and the seismic sensor 8 to perform a cutoff display 5c indicating that the valve body 21 has been closed. The LED _5c is connected, and the reset switch 5a that is operated when returning from the cutoff state is connected.

The solenoid drive circuit 6a includes a battery 11
The CPU 10 is configured to use the discharge current of the charge to drive the valve drive solenoid 6 using the power supply 1 as a power source.
Charging is started in response to a valve closing charge start signal from 0, and it is detected that sufficient charge for driving the solenoid has been performed, and a detection signal is sent to the CPU 100, and the CPU 100 outputs the detection signal accordingly. The charge is discharged in response to the valve closing signal to cause a current to flow through the solenoid in the valve closing direction.
Further, charging is started in response to a valve opening charging start signal from the CPU 100, and when it is detected that sufficient charging has been performed to drive the solenoid and a detection signal is sent to the CPU 100, the CPU 100 responds accordingly. The charge is discharged in response to the output valve opening signal to cause the solenoid to flow a current in the valve opening direction.

In the above configuration, the CPU 100 performs a minute gas warning process, a pressure abnormal cutoff process, a seismic sensor cutoff process, and a battery voltage drop warning process. In the minute gas cutoff processing, for example, it is monitored whether or not the reed switch 9m of the gas flow detecting unit 9 is turned on at every predetermined time of 10 minutes.
That is, it is determined that gas is present by turning on the reed switch 9m. When the gas flow continues for 24 hours, the number of days of leakage measurement is counted up. The counted number of leakage measurement days is reset by detecting that the gas flow has disappeared.

When the counted number of leak measurement days reaches 30 days, the leak display 10a is flashed, and then the operation waits for the return switch 5a to be operated. When the return switch 5a is turned on, the blinking of the leak display 10a is stopped. That is, when the gas flow is continuously detected for 30 days and the reed switch 9m is kept ON, it is determined that there is a gas leak, and the leak display 10a for warning the leak is blinked.

In the abnormal pressure cutoff process, the differential pressure is, for example, 20 mmH ₂ O by the differential pressure signal from the differential pressure sensor 7.
When the reed switch 9m detects that the gas flow is 3 l / h or more when the predetermined pressure value or more is maintained for x seconds or more, the valve drive solenoid 6 is driven to close the valve body 21. And shut off the gas. Then shut off display 5
After blinking c, the operation waits for the return switch 5a to be operated. When the return switch 5a is turned on, the leak display 1
The blinking of 0a is stopped.

In the seismic sensor cutoff process, the seismic
When the built-in seismic switch is turned on, the signal from the seismic sensor 8 is monitored, and as shown in FIG.
It is determined whether or not a make signal that repeats ON / OFF for more than ms has been generated. When the generation of the make signal is determined, it is determined whether or not there is a gas flow based on whether or not the reed switch 9m of the gas flow detection unit 9 is turned on.
Immediately when there is a gas flow as shown in FIG. 2 (b), and when there is no gas flow as shown in FIG. , The valve body 21 is closed and the cutoff display 5c
Blinks and waits for the return switch 5a to be operated. When the return switch 5a is turned on, a return signal is output to open the valve body 21 and the blinking of the cutoff display 5c is stopped.

In the battery voltage drop warning process, the battery voltage of the battery 111 built in the power supply circuit 110 is checked at regular intervals of, for example, 48 hours. Flashes to warn you.

The details of the operation of the gas leakage detection device outlined above will be described in detail below with reference to the flowcharts of FIGS. 13 to 18 showing the processing performed by the CPU 100 according to a predetermined control program. The CPU 100 starts the operation of the main routine of FIG.
The first step S1 performs a small gas leak warning process, the next step S3 performs an abnormal pressure cutoff process, the step S5 performs a seismic device cutoff process, and the step S7 performs a battery voltage drop warning process. Return to S1.

The small gas leakage warning process in step S1 is as follows.
The subroutine of FIG. 14 is performed. In the first step S11, it is determined whether or not the time measurement of, for example, a 10-minute timer has elapsed. When the determination is ΝO, the process returns to the main routine. When 10 minutes have elapsed and the determination in step S11 is YES, the process proceeds to step S12, where it is determined whether or not the reed switch 9m of the gas flow detection unit 9 is on, and it is determined whether or not there is a gas flow.

If the determination in step S12 is YES, the process proceeds to step S13 to determine whether the 24-hour timer has elapsed. If the determination is $ O, the process returns to the main routine. YES in step S13
In other words, when the gas flow monitored at 10 minute intervals is 24
If it has been flowing during the time, the flow advances to step S14 to count up the leakage measurement day counter. When the determination in step S12 is ΝO, that is, when the gas flow is not more than 3 l / h and the reed switch 9m is off, the process proceeds to step S15 to reset the counting content of the leak measurement day counter, and then return to step S15. Return to the main routine.

After counting up the leak measurement day counter in step S14, the process proceeds to step S16, where it is determined whether the content of the leak measurement day counter is 30 or not. That is, it is determined whether or not the state where the gas flow has not disappeared for 30 days has continued. When the determination is ΝO, the process returns to the original main routine, and when the determination is YES, the process proceeds to step S17 and the leakage display 1
Start blinking of 0a. Thereafter, the process proceeds to step S18 to wait for the return switch 5a to be turned on. When the return switch 5a is turned on, the process proceeds to step S19 to stop the blinking of the leak display 10a, and then returns to the main routine.

The abnormal pressure shutoff process in step S3 is performed as shown in FIG.
5 and the first step S
At 31, it is determined from the pressure signal from the differential pressure sensor 7 whether or not the differential pressure is equal to or more than 20 mmH ₂ O. This is for judging the possibility that a pressure drop that does not occur in a normal gas use state is caused on the downstream side by a large amount of gas ejection due to, for example, breakage of a gas supply pipe. Step S31
When the determination is ΝO, that is, when a large differential pressure is not generated, the process returns to the original main routine, and the determination is YES.
In the case of, the process proceeds to step S32 to start the x second timer.

Thereafter, the process proceeds to step S33, where the differential pressure is again reduced to ₂₀ mmH ₂ by the pressure signal from the differential pressure sensor 7.
It is determined whether or not it is greater than or equal to O. If the determination is still YES, the process proceeds to step S34 to determine whether or not the x-second timer has timed out. The determination in step S34 is Ν
If the answer is O, the process returns to step S33, and the process proceeds to step S3
3 is ３O or the determination in step S34 is Y
The processing of steps S33 and S34 is repeated until ES is reached.

When the determination in step S33 becomes ΝO, that is, when the differential pressure based on the pressure signal from the differential pressure sensor 7 is no longer than 20 mmH ₂ O before the x-second timer expires, the process proceeds to step S35. After stopping the x second timer, the process returns to the main routine. On the other hand, if the determination in step S34 is YES, that is, the differential pressure based on the pressure signal from the differential pressure sensor 7 is 20 mmH ₂
If the state of not less than O has continued for x seconds, step S3
Proceed to 6. In step S36, the gas flow is 3 l /
h or more, and determines whether the reed switch 9m is on.

When the determination in step S36 is ΔO, it is assumed that a pressure difference of 20 mmH ₂ O or more has not occurred due to a large amount of gas ejection on the downstream side, and the above-mentioned step S33 is assumed.
Return to If the determination in step S36 is YES, 2
Assuming that a pressure difference of 0 mmH ₂ O or more was caused by a large amount of gas ejection on the downstream side, in the next step S37, a shutoff signal for energizing the valve drive solenoid to shut off the gas supply path was output. In step S38, the cutoff display 5
The blinking of c is started.

Thereafter, the flow advances to step S39 to wait for the return switch 5a to be turned on. When the return switch 5a is turned on, the flow advances to step S40 to stop the blinking of the cutoff display 5a, and then returns to the main routine.

The seismic sensor shut-off process in step S5 is as shown in FIG.
Of the first step S5
At 1, it is determined whether or not the seismic sensor 8 is turned on based on a signal from the seismic sensor 8. When the determination in step S51 is ΝO, the process returns to the original main routine, and when the determination in step S51 is YES, the process proceeds to step S52 to perform a seismic sensor makeup determination process. This seismic sensor makeup determination can be specifically performed by a process as shown in the flowchart of FIG. In the flowchart of FIG. 17, after starting the three-second timer in the first step S52a, the process proceeds to step S52b, where it is determined whether or not the signal from the seismic sensor 8 is ON for 40 ms or more.
When the determination in step S52b is ΝO, the process proceeds to step S52c to determine whether three seconds have elapsed. When the determination is ΝO when three seconds have not elapsed, the above-described step S52 is performed.
Returning to b, when 3 seconds have elapsed and the determination is YES, the process returns to the main routine.

If the determination in step S52b is YES, the process proceeds to step S52d, in which it is determined whether or not the signal from the seismic sensor 8 is off for 40 ms or more. S5
It is determined whether or not 3 seconds have elapsed after proceeding to 2e. If 3 seconds have not elapsed and the determination is ΝO, the process returns to step S52d. If 3 seconds have elapsed and the determination is YES, the process returns to the main routine.

When the determination in step S52d is YES, the process proceeds to step S52f, where
The same determination as in step 52b is performed, and the determination process in steps S52g to S52k is performed based on the determination result in step S52f to determine whether the seismic sensor signal as shown in FIG. . Step S52b,
When S52d, S52f, S52h and S52j are YES, the makeup of the seismic sensor is determined and the following step S53 is performed.
Proceed to.

As described above, if it is determined in step S52 that makeup of the seismic sensor 8 has been performed, the flow advances to step S53 to determine whether or not the reed switch 9m of the gas flow detection unit 9 is turned on, and whether or not there is a gas flow. Judge. If the determination in step S53 is YES and it is determined that there is a gas flow, the flow advances to step S54 to output a cutoff signal, and the valve 21
Is caused to flow through the valve drive solenoid 6 in the direction to close the valve. On the other hand, if the determination in step S53 is ΝO and there is no gas flow, the flow advances to step S55 to start a two-minute timer. Thereafter, the flow advances to step S56 to determine whether or not the reed switch 9m of the gas flow detection unit 9 is on. Judge to determine if there is a gas flow. Step S
If the determination in step 53 is YES and it is determined that there is a gas flow, the flow proceeds to step S54 to output a cutoff signal, and
In step S57, the flow advances to step S57 to determine whether two minutes have elapsed. If not, the flow returns to step S56 to repeat the determinations in step S56 and step S57. Return to routine.

After outputting the cutoff signal in step S54, the flow advances to step S58, where the cutoff display 5c is displayed.
To start blinking. Thereafter, the flow advances to step S59 to wait for the return switch 5a to be turned on. When the return switch 5a is turned on, the flow advances to step S60 to output a return signal, and the current in the opposite direction to the current flowing to the valve drive solenoid 6 in step S54. Then, the valve element 21 is opened to stop the blinking of the cutoff display 5a in the next step S61, and then the process returns to the main routine.

The battery voltage drop warning process in step S7 is as follows.
The subroutine of FIG. 18 is performed. In the first step S71, it is determined whether or not the time counting of the 48-hour timer has elapsed. When the determination is ΝO, the process returns to the main routine. If 48 hours have elapsed and the determination in step S71 is YES, the process proceeds to step S72 to determine whether or not the battery voltage has dropped.
In the case of, the process returns to the original main routine. Step S72
If the determination is YES, the process proceeds to step S73, in which the blinking of the low battery indicator 5b is started, and then the process returns to the main routine. The blinking of the low battery display 5b is not stopped unless the CPU 100 is started again by replacing with a new battery.

In the embodiment described above with reference to FIG. 1, a gas leak is detected based on a gas flow detection signal obtained by detecting a gas flow flowing through the gas bypass passage 13d between the pressure chambers 22b and 22c by the gas flow detection unit 9. However, instead of this, as shown in FIG.
The gas leak determination unit 10A detects a gas leak based on a downstream pressure detection signal obtained by detecting the pressure downstream of the automatic on-off valve 2 provided in the middle of 3a by the pressure detection unit 90. Can also. In FIG. 19, the configuration is the same as that of FIG. 1 except that a pressure detection unit 90 and a gas leakage determination unit 10A are provided instead of the gas flow detection unit 9 and the gas leakage determination unit 10.

With the above configuration, the automatic on-off valve 2 automatically closes when the gas on the downstream side is not used. However, in such a state, if the underground temperature or the atmospheric temperature changes, the downstream side of the on-off valve 2 changes. The pressure on the downstream side of the automatic on-off valve 2 rises and falls due to the thermal expansion and thermal contraction of the gas confined in the valve. When this phenomenon is used, the presence or absence of gas leakage can be determined by monitoring the gas pressure downstream of the automatic on-off valve 2 detected by the pressure detection unit 90 for a certain period.

If a gas leak of a predetermined value or more occurs in the gas supply path on the downstream side of the automatic on-off valve 2, the pressure on the downstream side of the automatic on-off valve 2 is changed even if the underground temperature or the atmospheric temperature changes. Does not rise above the supply pressure, and based on such facts, the gas leakage determination unit 10A determines that there is gas leakage. On the other hand, when there is no gas leakage, when no gas is used, and when the temperature in the gas supply pipe rises, the pressure detection unit 90
It is detected that the gas pressure on the downstream side of the automatic on-off valve 2 has become equal to or higher than the supply pressure, and the gas leak determination unit 10A can determine that the gas leak determination unit is normal.

When the gas is in use and the automatic on-off valve 2 is automatically opened, the pressure detected by the pressure detector 90 does not become higher than the gas supply pressure. However, when the gas is not used and the automatic on-off valve 2 is automatically closed, the pressure detected by the pressure detection unit 90 also becomes higher than the supply pressure. In such a state, the temperature in the pipe rises, for example, by 1 ° C. or more, and the pressure detected by the pressure detecting unit 90 rises by 300 Pascal (30 mmH ₂₀ ) or more from the supply pressure. When the pressure detected by the pressure detecting unit 90 becomes higher than the supply pressure by a predetermined value or more, the count value is incremented by the gas leak determining unit 10A.

However, if there is a gas leak exceeding the set value, the supply pressure (about 2 k
Pascal) or more, and the count value is not incremented. If a monitoring period of 30 days is set, the temperature in the pipe rises in the daytime or nighttime gas non-use period during the 30 days, and the supply pressure increases by 3%.
00 when it comes to Pascal (30mmH ₂ 0) or should occur at least twice. Therefore, if the count value is 2 or more in 30 days, it is determined that there is no gas leakage, and if it is less than 2, it is determined that there is a possibility of gas leakage, and an abnormal signal can be output.

In the embodiment described above with reference to FIGS. 1 and 19, when the gas is cut off for gas piping work, the downstream side of the automatic on-off valve 2 is connected to the pressure chamber 22b by manual operation of the manual passage switching section 4. In this case, the pressures in the pressure chambers 22b and 22c become substantially equal, the differential pressure disappears, and the diaphragm 22a is displaced upward by the force of a biasing spring (not shown). The automatic supply valve 21 is automatically transmitted to the valve 21 so that the automatic on-off valve 2 is automatically closed, and the main supply path 13a is completely shut off. In this relation, when a large amount of gas is ejected on the downstream side and the differential pressure between the pressure chambers 22b and 22c becomes very large, and the differential pressure sensor 7 outputs a large differential pressure signal,
Alternatively, when the seismic sensor 8 outputs a seismic signal in response to a vibration equal to or greater than a predetermined seismic intensity, the solenoid control unit 5 to which these signals are input causes the valve drive solenoid 6 to drive the valve body 21 to close the valve. It has become.

For this reason, especially when a large amount of gas is ejected on the downstream side, a large differential pressure is generated between the upstream and downstream of the automatic on-off valve 2. To drive the valve to close the valve, a large-capacity solenoid must be used for the valve drive solenoid 6. However, by adopting a configuration as shown in FIG. it can.

In FIG. 20, the manual passage switching section 4 of FIG. 1 is replaced by a solenoid drive passage switching section 40, the valve drive solenoid 6 is replaced by a switching section drive solenoid 60, and the return switch 5a is replaced by an open / close operation switch 50a. However, other parts are substantially the same as those described above with reference to FIGS. The solenoid drive passage switching unit 40 connects the main supply passage 13a upstream of the automatic on-off valve 2 to the pressure chamber 22b via the gas passage 13b or the main supply passage 13a downstream of the automatic on-off valve 2 to the gas passage. It is selectively connected to the pressure chamber 22b via 13c. The downstream main supply passage 13a is connected to the pressure chamber 2
When the pressure is set to 2b, both the pressure chambers 22b and 22c are connected to the downstream main supply passage 13a via the gas passage 13c. When this happens, both pressure chambers 22b
And 22c are substantially equal to each other so that the differential pressure disappears, and the diaphragm 22a is displaced upward by the force of an unillustrated urging spring.
And the automatic on-off valve 2 is automatically closed.
The main supply path 13a is completely shut off.

Now, the solenoid drive passage switching section 40 connects the main supply passage 13a upstream of the automatic on-off valve 2 to the gas passage 13a.
When the opening / closing operation switch 50a is operated in order to perform the replacement work of the gas supply pipe on the downstream side in a state where the solenoid valve is connected to the pressure chamber 22b via b, an operation signal is input to the solenoid control unit 5. The solenoid control unit 5 urges the switching unit driving solenoid 60 in response to the input of the operation signal, and the switching unit driving solenoid 60 responds to this by switching the solenoid driving passage switching unit 4.
0 to drive the main supply path 13 on the downstream side of the automatic on-off valve 2.
The connection is switched so that a is connected to the pressure chamber 22b via the gas passage 13c. Thereby, both pressure chambers 22b and 2
When the pressure of 2c is substantially equal, the diaphragm 22a is displaced upward, and this displacement is transmitted to the valve body 21, the automatic on-off valve 2 is automatically closed, and the main supply path 13a is completely shut off. .

If the lamp outer tube 13 is damaged for some reason on the downstream side and a large amount of gas is blown out therefrom, the pressure in the main supply passage 13a decreases on the downstream side, and the gas passage 13c The pressure in the pressure chamber 22c that communicates with the pressure drop also decreases. Therefore, both pressure chambers 22
The pressure difference between b and 22c becomes very large, and the pressure difference sensor 7 outputs a large pressure difference signal and supplies it to the solenoid control unit 5. The solenoid control unit 5 switches the switching unit driving solenoid 60 in response to the input of a differential pressure signal corresponding to a differential pressure equal to or greater than a predetermined value.
In response, the switching unit driving solenoid 60 drives the solenoid driving passage switching unit 40 to connect the main supply passage 13a downstream of the automatic on-off valve 2 to the pressure chamber 22b via the gas passage 13c. Switch to As a result, the pressures in the two pressure chambers 22b and 22c become substantially equal, and the diaphragm 22a is displaced upward.
1, the automatic on-off valve 2 is automatically closed, and the main supply path 13a is completely shut off.

Further, the seismic sensor 8 outputs a seismic signal according to the vibration of a predetermined seismic intensity or more and supplies the signal to the solenoid control unit 5. The solenoid control unit 5 urges the switching unit driving solenoid 60 in response to the input of the seismic signal, and in response to this, the switching unit driving solenoid 60 drives the solenoid driving passage switching unit 40 to downstream of the automatic on-off valve 2. Of the main supply passage 13a is connected to the pressure chamber 22b via the gas passage 13c. As a result, the pressures in the two pressure chambers 22b and 22c become substantially equal, and the diaphragm 22a is displaced upward, and this displacement is transmitted to the valve body 21, and the automatic on-off valve 2 is automatically closed, and the main supply passage is opened. 13a is completely shut off.

As described above, the valve element 2 driven to the valve closed state
Opening / closing operation switch 50 for resetting 1 and opening the valve
When a is manually operated, an operation signal is input to the solenoid control unit 5. The solenoid control unit 5 urges the switching unit driving solenoid 60 in response to the input of the operation signal, and in response to this, the switching unit driving solenoid 60 drives the valve body 21 in the valve closed state to the valve open state.

The automatic on-off valve 2, the solenoid drive passage switching unit 40, and the switching unit drive solenoid 6 described above with reference to FIG.
As shown in the side sectional view of FIG. 21, the reference numerals 0 and the like are integrally formed as in the embodiment of FIG. In FIG.
Above the hole C1a formed in the case body C1, a solenoid drive passage switching unit 40 is integrally provided. In order to configure the solenoid drive passage switching unit 40, a large-diameter hole C1a1 is formed concentrically with the upper end of the hole C1a in the case main body C1, and a case lid C2 is formed in the case body C1.
A hole C2d having a larger diameter than the large diameter hole C1a1 is formed. The boundary between the hole C1a and the large-diameter hole C1a1 and the large-diameter hole C1a
At the boundary between 1 and C2d, nozzles 45a and 45b serving as valve ports are formed, and the upper opening of the large-diameter hole C2d is airtightly closed by a mounting flange 60a of the switching unit drive solenoid 60.

The space between the nozzles 45a and 45b communicates with the pressure chamber 22b through a hole C12a formed in the case body C1 and the case cover C2, and the space above the nozzle 45b is formed in the case body C1 and the case cover C2. The pressure chamber 22c, that is, the valve 21
Is communicated with the empty space S on the upstream side of.

The switching unit drive solenoid 60 is biased in the projecting direction by a coil spring 60b, and the solenoid plunger 6c is biased in one direction by energizing in one direction against the biasing force of the coil spring 60b.
A solenoid coil 60d for sucking the solenoid plunger 0c and a magnet 60e for attracting and holding the solenoid plunger 60c sucked against the urging force of the coil spring 60b. The solenoid plunger 60c attracted by the magnet 60e causes the solenoid 60e to be energized in the reverse direction by energizing the solenoid coil 60d.
By generating a magnetic field that cancels the attraction force of the coil spring 60b, the coil spring 60b returns to the projected state by the urging force.

The solenoid plunger 60c is protruded in a space formed by the large-diameter hole C2d closed by the mounting flange 60a while maintaining an air-tight state by an O-ring. 45f is fixed. Switching valve body 45f is made the valve shaft 45f ₁ and the tip of the valve body 45f ₂ Prefecture, the valve shaft 45f ₁ nozzle 4
Extending through 5b of holes, the valve body 45f ₂ is accommodated in the space between the nozzles 45a and 45b.

The valve body 45f ₂ is provided with a solenoid coil 60
d to the solenoid plunger 6
0c is sucked against the urging force of the coil spring 60b to close the nozzle 45b, and this state is changed to the solenoid plunger 60c by the magnet 60e.
Is held as shown in FIG. Valve body 45f
₂ closes the nozzle 45b, the pressure chamber 22b is connected to the valve body 2 through the hole C12a, the nozzle 45a and the hole C1a.
1 upstream. Therefore, gas pressures on the upstream side and the downstream side of the valve body 21 respectively act on both surfaces of the diaphragm 22a.

In the illustrated state, the magnet 60 is energized by energizing the solenoid coil 60d in the other direction.
When a magnetic field for canceling the suction force of the e is generated, the solenoid plunger 60c held in the state shown in the figure is protruded by the urging force of the coil spring 60b, and the valve body that has closed the nozzle 45b up to that point. 45
so to close the nozzle 45a in place of f _2. The closing of the nozzle 45a causes the pressure chamber 22b to open the hole C1.
2a, the nozzle 45b and the pressure chamber 22 through the hole C12b.
c, that is, the gas pressure on the downstream side of the valve body 21 acts on both surfaces of the diaphragm 22a because it is communicated with the downstream side of the valve body 21. C3 is a container airtightly mounted above the case lid C2,
The switching unit drive solenoid 60 and the differential pressure sensor 7 are accommodated in the container C3. From the container C3, a cable composed of a power supply line for driving the switching unit drive solenoid 60 and a signal line for outputting a differential pressure signal from the differential pressure sensor 7 is pulled out while maintaining airtightness, and is connected to the monitoring panel KB. .

In the embodiment of FIG. 2, in addition to the power supply voltage drop display 5b, the leak display 5a, and the cutoff display 5c,
A reset switch 5a that is operated when returning from the shut-off state is provided, and the seismic sensor 8 is connected. In the embodiment of FIG. An overflow indicator 5d that is lit when a differential pressure equal to or greater than a predetermined value is detected by the pressure signal, and a seismic indicator 5e that is illuminated when an earthquake with a seismic intensity equal to or greater than the predetermined value is detected due to seismic sensation by the seismic sensor 8. Are provided, and an opening operation button 50a ₁ and a closing operation button 50a ₂ of the opening / closing operation switch 50a are arranged instead of the reset switch 5a.

In the above configuration, the operation of the automatic on-off valve 2 is the same as that shown in FIG.
Other operations will be described with reference to FIG. Now, when the solenoid driving passage switching unit 40 is in the illustrated state, when operating the closing operation buttons 50a ₂ of the monitoring panel KB, closing operation signal is inputted to the solenoid control unit 5, the solenoid control unit 5 accordingly Then, the solenoid coil 60d of the switching unit drive solenoid 60 is energized by applying a current in a direction to generate a magnetic field for canceling the attraction force of the solenoid plunger 60c by the magnet 60e. It is moved in the projecting direction by the urging force of the coil spring 60b,
The valve body 45f ₂ is a nozzle 4 which has been closed nozzle 45b
The nozzle 45a is closed instead of 5b. Therefore, the main supply passage 13a on the downstream side of the automatic on-off valve 2 is switched to be connected to the pressure chamber 22b via the gas passage 13c. As a result, the pressures of the two pressure chambers 22b and 22c become substantially equal, and the diaphragm 22a is displaced upward,
This displacement is transmitted to the valve body 21, and the automatic on-off valve 2 is automatically closed, and the main supply path 13a is completely shut off.

When the solenoid drive passage switching unit 40 is in the state shown in the figure, the lamp outer tube 13 is damaged for some reason on the downstream side, and the differential pressure sensor 7 outputs a large differential pressure signal accordingly. At this time, or even when the seismic sensor 8 outputs a seismic signal in response to a vibration equal to or greater than a predetermined seismic intensity, the solenoid control unit 5 activates the switching unit drive solenoid 60 in response to the input of the seismic signal, In response to this, the switching unit drive solenoid 60 drives the solenoid drive passage switching unit 40 to switch the main supply passage 13a downstream of the automatic on-off valve 2 to connect to the pressure chamber 22b via the gas passage 13c. The main supply path 13a is completely shut off.

The valve 2 driven as described above in the valve closed state
Opening / closing operation switch 50 for resetting 1 and opening the valve
When a is manually operated, an operation signal is input to the solenoid control unit 5. The solenoid control unit 5 urges the switching unit driving solenoid 60 in response to the input of the operation signal, and in response to this, the switching unit driving solenoid 60 drives the valve body 21 in the valve closed state to the valve open state.

In this embodiment, the means for detecting gas leakage is not specifically shown, but the gas leakage is performed based on the gas flow signal from the gas flow detection unit 9 shown in FIG. However, it is also possible to detect gas leakage by monitoring the gas pressure on the downstream side of the valve body 21 shown in FIG.

[0117]

As described above, according to the present invention, it is assumed that the gas flow detecting means detects a gas flow and outputs a gas flow detection signal, and there is no gas consumption within a predetermined period. Therefore, when a gas flow detection signal is input continuously for a predetermined period or more, it is determined that there is a possibility that gas leakage has occurred on the downstream side, so that gas leakage can be detected. Alternatively, the pressure detecting means detects the pressure on the downstream side of the valve body, compares the detected pressure with a predetermined value, monitors the comparison result for a predetermined period, and confirms that no gas is consumed within the predetermined period. If the pressure does not exceed a predetermined value continuously for a predetermined period or more on the assumption that there is always a gas leak, it is determined that there is a possibility that gas leakage has occurred on the downstream side. Leaks can be detected.

Further, the passage switching means forms a gas pressure path for receiving the gas pressure on the downstream side instead of the upstream side on the surface of the diaphragm receiving the gas pressure on the upstream side. Since the pressure difference is forcibly made substantially equal, the diaphragm is displaced and the valve body can be closed. Since the valve body can be closed by forming the gas pressure path in this manner, the passage switching means serving as the gas shutoff means and the automatic opening / closing valve means can be easily integrated. Therefore, while having a built-in gas shut-off function, a configuration suitable for miniaturization can be taken to improve mountability and reduce construction costs. Since the passage switching means includes a rotary valve body that is manually rotated, the valve body can be manually closed at any time. In particular, since a force corresponding to a predetermined gas pressure for displacing the diaphragm is applied by the elastic means, it is possible to easily set the desired value by selecting the elasticity of the elastic member.

The solenoid control means for driving the valve drive solenoid to close and open the valve body detects the difference between the gas pressure on the upstream side and the gas pressure on the downstream side of the valve body and outputs the difference pressure sensor. When the pressure signal corresponding to the magnitude of the differential pressure is equivalent to a pressure difference equal to or greater than a predetermined value, the valve element is valved to a valve driving solenoid connected in the middle of the connecting member of the automatic opening / closing valve means accordingly. Since the control to drive to close is performed, when a large amount of gas is ejected due to breakage of the gas supply pipe on the downstream side and the gas pressure on the downstream side decreases, the valve element driving solenoid closes the valve element. To stop the gas ejection.

The solenoid control means detects the occurrence of an earthquake having a seismic intensity equal to or greater than a predetermined value based on the vibration detection signal output from the seismic sensing means, and causes the valve drive solenoid to close the valve. When a large earthquake that may cause damage to the gas supply pipe occurs, the valve drive solenoid drives the valve to close the valve so that gas ejection can be prevented beforehand. In addition, a seismic isolation function can be incorporated and integrated so that a large amount of gas leakage does not occur even if the gas supply pipe is damaged by an earthquake.

In the gas leak detection device according to the present invention, the solenoid control means controls the switching drive solenoid in response to the input of the switching signal generated by the manual operation of the manual operation means, and the switching means constitutes the passage switching means. Since the gas pressure path is formed by driving the valve element, it is possible to easily integrate the passage switching means as the gas shutoff means and the automatic opening / closing valve means.

When the pressure signal output from the differential pressure sensor is equivalent to a pressure difference equal to or greater than a predetermined value, the solenoid control means drives the switching drive solenoid to switch the switching valve body in response to the pressure signal, thereby controlling the gas pressure. When a large amount of gas is ejected due to breakage of the downstream gas supply path, the diaphragm of the valve element driving means is displaced by the gas pressure path formed by driving the valve element driving solenoid. By driving the valve body to close the valve, gas ejection can be automatically stopped.

When the occurrence of an earthquake having a seismic intensity equal to or more than a predetermined value is detected based on the vibration detection signal output from the seismic sensing means, the switching valve is driven by the switching drive solenoid in response to the detection, and the gas pressure path is controlled. Therefore, when a large earthquake that may cause damage to the gas supply pipe or the like occurs, the diaphragm of the valve element driving means is displaced by the gas pressure path formed by driving the valve element driving solenoid, thereby displacing the valve. The body is driven so as to close the valve, and gas ejection can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a gas leak detection device of the present invention for a gas supply facility for supplying gas to an apartment house.

FIG. 2 is a side sectional view showing a closed state of an automatic on-off valve which is a main part of the gas leakage detection device of FIG.

FIG. 3 is a cross-sectional view showing a gas flow detection unit which is a main part of the gas leakage detection device of FIG.

FIG. 4 is an external view of the apparatus of FIG.

FIG. 5 is a partially enlarged view showing a switching state of a manual passage fog switching unit.

FIG. 6 is an enlarged view of a main part of the gas flow detection unit in FIG. 3;

FIG. 7 is a side sectional view showing a state of an automatic on-off valve in a normal use state of gas.

FIG. 8 is a cross-sectional view of the gas detection unit in a normal use state of gas.

FIG. 9 is a side sectional view showing a state of the automatic on-off valve when the gas flow is large.

FIG. 10 is a side sectional view showing a state of an automatic on-off valve when an earthquake occurs.

FIG. 11 is a block diagram showing one embodiment of a gas leak detection device according to the present invention.

FIG. 12 is a timing chart showing signals of respective units in FIG.

FIG. 13 is a main flowchart showing a process performed by a CPU in FIG. 11;

FIG. 14 is a flowchart of a small gas leakage warning process in FIG. 13;

FIG. 15 is a flowchart of an abnormal pressure cutoff process in FIG. 13;

FIG. 16 is a flowchart of a seismic sensor shutoff process in FIG.

FIG. 17 is a flowchart of a seismic sensor make determination process in FIG. 16;

FIG. 18 is a flowchart of a battery voltage drop warning process in FIG.

FIG. 19 is a block diagram showing another embodiment in which a part of the gas leak detection device of the present invention of FIG. 1 is modified.

20 is a block diagram showing another embodiment in which another part of the gas leak detection device of the present invention in FIG. 1 is modified.

FIG. 21 is a side sectional view showing a state of an automatic on-off valve and a solenoid drive passage switching unit which are main parts of the gas leakage detection device of FIG. 20;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Gas leak detection apparatus 2 Automatic opening / closing valve means (automatic opening / closing valve) 4 Passage switching means (passage switching part) 5 Solenoid control means (solenoid control part) 6 Valve drive solenoid 7 Differential pressure sensor 8 Vibration sensing means (Seismic sensor) DESCRIPTION OF SYMBOLS 10 Gas leak determination means (gas leak determination part) 10A Determination means (gas leak determination part) 13 Gas supply path (outer tube of lamp) 13d Gas bypass passage 21 Valve 22a Diaphragm 22a ₆ Elastic member 23 Connecting member 42 Rotating valve 45f switching valve body 50 manual operating means 60 switching section driving solenoid 90 pressure detecting means (pressure detecting section)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuji Hosohara 3-21-4-2, Kamariya Minami, Kanazawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Kouichi Suyama 3305, 3305 Shiomidai, Isogo-ku, Yokohama-shi, Kanagawa 514 No. (72) Inventor Takaomi Raft 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Akeshi 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Osaka Inside Gas Co., Ltd. (72) Inventor Junichi Ando 19-18 Sakuradacho, Atsuta-ku, Nagoya-shi, Aichi Prefecture Inside Toho Gas Co., Ltd. 72) Inventor Koji Matsunaga 23 Minami Kashima, Futamata-cho, Tenryu-shi, Shizuoka Prefecture, Japan Yazaki Keiki Co., Ltd. Masaharu Moriguchi (56) References JP-A-5-273072 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01F 3/22 G01F 1/00

Claims (9)

(57) [Claims] A valve body provided in the gas supply path;
A diaphragm that receives gas pressures on the upstream side and the downstream side of the valve body on both surfaces and is displaced when the gas pressure on the upstream side is higher than the downstream side by a predetermined value or more, and connects the diaphragm to the valve body to reduce the displacement of the diaphragm. Automatic opening and closing valve means comprising a valve element driving means having a connecting member or the like transmitting to the valve element, wherein the valve element is automatically opened and closed according to the presence or absence of gas consumption on the downstream side, Gas flow detection means for detecting a gas flow in a gas bypass passage provided in parallel with the diaphragm and outputting a gas flow detection signal; and wherein the gas flow detection signal from the gas flow detection means is continuous for a predetermined period or more. Gas leak determining means for determining gas leak depending on whether the pressure has been input, and a gas leak determining means provided on the upstream side of the gas bypass passage and receiving a gas pressure on the upstream side of the valve body. A gas pressure passage for receiving a gas pressure on the downstream side of the valve body in place of the valve body, and a passage switching means for forcibly equalizing a difference in gas pressure received on both surfaces of the diaphragm. Gas leak detection device. 2. A valve element provided in the gas supply path,
A diaphragm that receives gas pressures on the upstream side and the downstream side of the valve body on both surfaces and is displaced when the gas pressure on the upstream side is higher than the downstream side by a predetermined value or more, and connects the diaphragm to the valve body to reduce the displacement of the diaphragm. Automatic opening and closing valve means comprising a valve element driving means having a connecting member or the like transmitting to the valve element, wherein the valve element is automatically opened and closed according to the presence or absence of gas consumption on the downstream side, Pressure detecting means for detecting the pressure on the downstream side of the valve element; comparing the pressure detected by the pressure detecting means with a predetermined value, and monitoring the comparison result for a predetermined period to determine gas leakage. Forming, on the surface of the diaphragm receiving gas pressure on the upstream side of the valve body, a gas pressure path for receiving gas pressure on the downstream side of the valve body in place of the upstream side, and forming a gas pressure path on both sides of the diaphragm; The difference in gas pressure experienced by Gas leakage detection device, characterized in that it comprises a passage switching means for equally braking manner. 3. The valve driving means according to claim 1, further comprising: an elastic member for applying an urging force corresponding to the predetermined gas pressure to the diaphragm in a direction against the displacement. Or the gas leak detection device according to 2. 4. The gas leakage detection device according to claim 1, wherein said passage switching means comprises a rotary valve body that is manually rotated. 5. A valve driving solenoid which is connected in the middle of a connecting member of the automatic opening / closing valve means and drives the valve body via the connecting member to open and close the valve; Solenoid control means for performing control to drive the valve to close and open the valve, and detects a difference in gas pressure between the upstream side and the downstream side of the valve body and outputs a pressure signal according to the magnitude of the differential pressure. A pressure signal from the differential pressure sensor, and the valve drive solenoid receives the pressure signal corresponding to a pressure difference equal to or greater than a predetermined value. The gas leakage detection device according to any one of claims 1 to 4, wherein control for driving the gas leakage valve is performed. 6. A valve driving solenoid which is connected in the middle of a connecting member of said automatic opening / closing valve means and drives said valve body via said connecting member to open and close a valve; and said valve being connected to said valve driving solenoid. Solenoid control means for performing control to drive the body to close and open the valve, and seismic means for detecting vibration and outputting a vibration detection signal, wherein the solenoid control means A vibration detection signal is input, and control is performed to detect the occurrence of an earthquake having a seismic intensity equal to or greater than a predetermined value based on the vibration detection signal and drive the valve drive solenoid to close the valve body. The gas leak detection device according to claim 1. 7. A switching drive solenoid for driving the switching valve body to form the gas pressure path, wherein the passage switching means comprises a switching valve body, and controlling the switching drive solenoid to drive the switching valve body. And a manual operation means for outputting a switching signal by manual operation, wherein the solenoid control means receives a switching signal from the manual operation means and switches the switching valve body to the switching drive solenoid. The gas leakage detection device according to any one of claims 1 to 3, wherein control for driving the gas leakage is performed. 8. A differential pressure sensor for detecting a difference between gas pressures on an upstream side and a downstream side of the valve body and outputting a pressure signal according to the magnitude of the differential pressure, wherein the solenoid control means includes 8. A control circuit according to claim 7, wherein a pressure signal from a pressure sensor is input, and control is performed to cause said switching drive solenoid to drive said switching valve element in response to an input of a pressure signal corresponding to a pressure difference equal to or greater than a predetermined value. Gas leak detection device. 9. A vibration sensing means for detecting a vibration and outputting a vibration detection signal, wherein said solenoid control means receives a vibration detection signal from said vibration sensing means and determines a predetermined value based on said vibration detection signal. 8. The gas leakage detection device according to claim 7, wherein an occurrence of an earthquake having a seismic intensity greater than or equal to the value is detected, and control for driving the switching valve body by the switching drive solenoid is performed.