JPH08271295A - Detecting equipment of gas leakage - Google Patents

Abstract

PURPOSE: To provide a detecting equipment for a gas leakage which is made small in size, low-cost and lightweight, wherein a manual gas shut-off valve with an earthquake-sensitive shut-off function is incorporated integrally and which has high packaging property and can be made to correspond to an existing installation very simply. CONSTITUTION: A gas shut-off means 3b has a manual operation shaft 61 operating a valve element 28 which shuts off or opens both of a main supply passage and a subordinate supply passage 13b. A spring 67 gives an actuating force constantly to the manual operation shaft 61 in the direction from a second position to a first position. An engagement ball 81 holds the manual operation shaft 61 at the second position against the actuating force. Being displaced by the quake of the seismic intensity of a prescribed value or above, a pendulum 91 cancels the hold of the manual operation shaft 61 by the engagement ball 81, the manual operation shaft 61 is moved from the second position to the first by the actuating force of the spring 67 and thereby the valve element 28 is made to shut-off both of the supply passages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas leakage detection device, and more particularly to a gas leakage detection device for detecting the presence or absence of gas leakage in a low pressure portion of a gas supply pipe such as LP gas or city gas without stopping gas supply. It is a thing.

[0002]

2. Description of the Related Art Conventionally, in a collective supply facility for LP gas, city gas, etc., the gas supply is stopped with respect to the presence or absence of gas leakage in the gas supply pipe of the low pressure part including the buried pipe upstream of the gas monitoring device consisting of a microcomputer gas meter. As a gas leak detection device that can detect gas without any action, the main supply path is closed when the gas flow rate becomes small, and the gas can be supplied only through the sub supply path provided in parallel with this main supply path. It has been proposed to detect the minute gas leakage on the downstream side by monitoring the flow rate of the gas flowing in the sub supply path by the flow rate detecting means provided in the path.

In the proposed apparatus, the main supply passage is closed so that the gas flows only to the sub supply passage when the gas consumption becomes small at night or late at night and the gas flow rate becomes small. The flow rate detecting means can monitor the minute flow rate of the gas flowing through the sub supply path. For this reason, the gas supply passage switching means is provided so that the main supply passage is closed and the gas can be supplied only through the sub supply passage when the gas flow rate becomes small. At this time, if there is no gas consumption and a slight gas leakage does not occur, the flow rate detection means of the sub supply path will not detect the gas flow rate.

It is premised that such a phenomenon occurs at least once during a relatively long predetermined period of 30 days, and if the flow rate detecting means detects the gas flow rate during this predetermined period. If it does not disappear, it is estimated that a minute gas leak has occurred.

As described above, the bypass flow path is provided in a part of the gas supply pipe, the gas is caused to flow through the bypass flow path at a low flow rate, and the flow rate is monitored by the flow rate detecting means provided in the bypass flow path and capable of detecting the minute flow rate. Since it is designed to detect minute gas leaks, it is possible to easily and reliably detect gas leaks in the gas supply pipe without forcibly stopping the gas supply. Since the paths are switched, it is possible to detect the presence or absence of gas leakage in the low-pressure part of the gas supply pipe for LP gas, city gas, etc. with almost no pressure loss, and the switching means is simple and the device is small in size. Has become possible.

As described above, since the pressure loss at the time of passing through the device does not increase, the low pressure branch pipe buried in the ground for supplying the gas already in the low pressure state such as city gas and simple gas equipment. On the other hand, a lamp inner pipe, which is also buried underground, is branched and connected, and gas is supplied to the collective supply facility of the housing complex through this lamp inner pipe that has a manual shut-off valve on the way that can be opened and closed from the surface of the earth. It can be applied to the existing gas supply system.

[0007]

However, in the previously proposed device, the gas supply path of the low pressure part including the buried pipe from the gas leakage detection device to the gas monitoring device composed of the microcomputer gas meter is damaged by an earthquake. There is no provision for a large gas leak to occur. Therefore, in order to be able to deal with such a situation, it is necessary to use a manual gas cutoff valve that is used to cut off gas when replacing a gas meter or replacing a low pressure branch pipe buried underground. It was necessary to install one with a seismic isolation function.

Moreover, in the conventional manual shut-off valve with a seismic shut-off function, a seismic detector detects a seismic intensity of a predetermined value or more, and the solenoid in the manual shut-off valve is electromagnetically driven by this detection to close the valve body. Since it was designed to drive into a state and shut off the gas supply, a power supply and wiring work for that supply were required, which resulted in poor mountability and high costs. There was also the problem of not being able to do it.

Further, if a gas leak detection device is connected immediately after the manual gas cutoff valve and the manual gas cutoff valve and the gas leak detection device are to be housed in a cylindrical container called a pit, a large container is required. Depending on the size, it may be too large to install. 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 expose part of the buried pipe for installation work. It took a lot of work, and it was troublesome to deal with the existing equipment.

Therefore, the present invention has been made in view of the above problems.
In order to prevent a large amount of gas leakage even if the gas supply path in the low pressure part is damaged by an earthquake, a manual gas cutoff valve with a seismic cutoff function may be incorporated and integrated to create a structure suitable for downsizing. It is an object of the present invention to provide a gas leakage detection device that is compact, low in cost, and light in weight, which can be mounted easily and can be easily applied to existing equipment.

[0011]

In order to achieve the above object, the gas leakage detection device according to the present invention is provided in parallel with the main supply passage when the gas flow rate becomes small and the main supply passage is closed. In the gas leakage detection device, wherein the gas can be supplied only through the sub supply path, and the gas leakage on the downstream side is detected by the flow rate monitoring by the flow rate detection means provided in the sub supply path. It has a valve body for blocking or opening both of the passages and a manual operation means for operating the valve body, and the manual operation means opens both the first position for making the valve body shut off both the supply passages and the first position. A gas shutoff means operable to move between the second position and the second position, and a biasing means for constantly applying a biasing force to the manual operating means in the direction from the second position to the first position. The second Locking means for holding the manual operation means in the position at the second position against the urging force of the urging means, and displacement due to a vibration having a seismic intensity of a predetermined value or more. A vibration-sensing means for releasing the holding of the manual operating means, and by releasing the holding of the manual operating means, the manual operating means is moved from the second position to the first position by the urging force of the urging means. To
It is characterized in that the valve body is made to block both the supply paths.

The manual operation means is operable to rotate between a first rotational angle position for causing the valve element to shut off the both supply paths and a second rotational angle position for opening both of them. The urging means has an inner end fixed to the outer periphery of the manual operation means and an outer end fixed to the fixed portion, and is rotated by the rotation of the manual operation means from the first rotation angle position to the second rotation angle position. It is characterized in that it comprises a spring which is wound up and constantly applies a biasing force to the manual operation means in the direction from the second position to the first position.

The vibration-sensing means is always held at a predetermined position, and has a pendulum having a weight portion at its tip end which oscillates in response to a vibration of a seismic intensity of a predetermined value or more, and the pendulum displacement caused by the oscillating movement causes the locking means. And transmitting means for transmitting to the locking means, and releasing the holding of the manual operating means by the displacement transmitted to the locking means via the transmitting means.

An inlet valve opening provided in the middle of the main supply passage, and when the gas flow rate during gas consumption is large, the gas flows upward to open the inlet valve opening, and the gas flow rate when gas is not consumed is small. When the valve body of the gas cutoff means has a valve body that descends due to its own weight to close the inlet valve opening and that is provided in parallel with the sub-supply path, the valve body of the gas cutoff means is the manual operation means. Is operated to open and close an outlet valve opening provided on the downstream side of a downstream side connecting portion of the sub supply path to the main supply path, and open or shut off both the main supply path and the sub supply path. It is characterized by that.

In order to achieve the above object, the gas leakage detection apparatus according to the present invention also closes the main supply passage when the gas flow rate becomes small, and only through the sub-supply passage provided in parallel with the main supply passage. In a gas leakage detection device that can supply gas and that detects gas leakage on the downstream side by monitoring the flow rate by the flow rate detection means provided in the sub-supply path, floats by gas flow when the gas flow rate during gas consumption is large. Has a valve body that opens the valve opening and lowers the valve opening by its own weight to close the valve opening when the gas flow rate when gas is not consumed is small, and only the sub supply path is provided by closing the valve opening by the valve body. Supply path switching means for switching the gas supply path so as to supply gas through the opening and closing means having a valve body for opening and closing a valve opening provided at the inlet of the sub supply path A first position where the valve body of the supply path switching means is closed and the valve body of the opening and closing means is closed, and the valve body of the supply path switching means is released and released. Second for opening the valve body of the opening / closing means
And a biasing means for constantly applying a biasing force to the manual operating means in the direction from the second position to the first position. Locking means for holding the manual operation means at the position 2 in the second position against the urging force of the urging means, and the locking means displacing for receiving a vibration having a seismic intensity of a predetermined value or more. A vibration-sensing means for releasing the holding of the manual operation means by
When the holding of the manual operation means is released, the manual operation means is moved from the second position to the first position by the urging force of the urging means, and the valve body of the supply path switching means is closed. It is characterized in that the valve body of the opening / closing means is closed and the supply paths are shut off.

[0016]

With the above structure, the valve body of the supply path switching means provided in the middle of the main supply path so as to be in parallel with the sub supply path has a main valve having an inlet valve opening below and an outlet valve opening above. It is housed in a vacant space in the middle of the supply path, and when the gas flow rate during gas consumption is large, it floats up by the gas flow and opens the inlet valve opening, and when the gas flow rate is small, it descends by its own weight and closes the inlet valve opening. Since the flow path is switched depending on the magnitude of the flow rate, a large pressure loss does not occur, and the switching gas flow rate can be easily set by selecting the weight of the valve element.

The valve body, which shuts off or opens both the main supply passage and the sub-supply passage, can be moved between a first position where the valve body shuts off both supply passages and a second position where both are opened. The biasing means constantly applies a biasing force to the manual operation means of the gas shutoff means in the direction from the second position to the first position, but the locking means is in the second position. The operating means is held at the second position against the biasing force of the biasing means. Then, the seismic-sensing means is displaced by a vibration having a seismic intensity equal to or higher than a predetermined value to release the holding of the manual operating means by the locking means, so that the manual operating means moves from the second position to the second position by the biasing force of the biasing means. Move it to position 1,
Since the valve body cuts off both supply paths, the gas supply is automatically cut off when a large earthquake occurs.

The manual operation means is operable to rotate between a first rotation angle position where the valve body shuts off both supply paths and a second rotation angle position where both are opened. The urging means has an inner end fixed to the outer periphery of the manual operation means and an outer end fixed to the fixing portion, and is wound up by the rotation of the manual operation means from the first rotation angle position to the second rotation angle position. The manual operation means is composed of a spring which constantly applies a biasing force in the direction from the second position to the first position. When the pendulum, which has a weight portion at its tip that is constantly held at a predetermined position, is shaken and displaced due to the vibration of a seismic intensity of a predetermined value or more, the transmission means transmits the displacement to the locking means. However, since the holding of the manual operation means is released by the displacement transmitted to the locking means, a part of the means used for the manual gas cutoff is used to configure the means for blocking the seismic gas, and also as a drive source. Since it is not necessary to provide an electric motor or the like that requires power supply, size reduction, cost reduction, and weight reduction can be achieved.

The supply passage switching means provided in parallel with the sub supply passage has an inlet valve opening provided in the middle of the main supply passage when the valve body floats by the gas flow when the gas flow rate during gas consumption is large. When the gas flow rate is small and the gas flow rate is small when the gas is not consumed, the gas flow is lowered by its own weight to close the inlet valve port and flow the gas only through the sub supply path. When the valve body of the gas cutoff means is operated by the manual operation means, the outlet valve opening provided on the downstream side of the downstream side connecting portion of the sub supply path to the main supply path is opened and closed, and both the main supply path and the sub supply path are opened. Open or shut off.

Further, in the above structure, the supply passage switching means floats by the gas flow to open the valve opening when the valve body has a large gas flow rate when the gas is consumed, and when the gas flow rate when the gas is not consumed is small, its own weight. The gas is supplied only through the sub supply path by descending to close the valve port. The opening / closing means opens and closes the valve opening provided at the inlet of the sub supply passage. The manual operation means releases the restraint of the valve body of the supply passage switching means and the first position for keeping the valve body of the supply passage switching means closed and the valve body of the opening / closing means closed. In addition, since it is possible to move between the second position where the valve body of the opening / closing means is opened, the gas flow can be completely blocked or not blocked not only in the main supply channel but also in the sub supply channel. It can be done arbitrarily, and when it is necessary to significantly change or repair the existing gas supply pipe or inner pipe, the gas flow can be completely cut off,
The construction can be done safely.

The urging means is second to the manual operating means.
Although the biasing force is constantly applied from the position of 1 to the first position, the locking means causes the manual operation means located at the second position to resist the biasing force of the biasing means to generate the second biasing force. Hold in position. Then, the seismic-sensing means is displaced by a vibration having a seismic intensity equal to or higher than a predetermined value to release the holding of the manual operating means by the locking means, so that the manual operating means moves from the second position to the second position by the biasing force of the biasing means. Since the valve body is moved to the position 1 so that both supply paths are shut off, the gas supply is automatically shut off in the event of a large earthquake or the like.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a piping system diagram in which an embodiment of a gas leakage detection device according to the present invention is applied to a gas supply facility for supplying gas to an apartment house. In the figure,
The gas leak detection device 1 has an inlet 1a connected to the supplier side of the outer lamp inner tube 13 branched from the low pressure branch pipe 11 and an outlet 1b connected downstream in the middle of the outer lamp inner tube 13 to eject the gas. It is configured as a flow path switching type that incorporates the functions of the gas cutoff valve and the main valve of the lamp inner tube.

The gas leakage detection device 1 includes a main supply passage 13a directly connected to the lamp inner tube 13 and the main supply passage 13a.
Has a sub supply path 13b connected in parallel as a bypass flow path. In the main supply path 13a, a supply path switching valve 2 as a supply path switching means and a gas cutoff valve 3 as a cutoff valve means for performing both the jet gas cutoff for shutting off the jet gas and the manual and seismic cutoff are connected in series. It is provided in.
Further, the sub-supply passage 13b is provided with a flow rate detection unit 4 as a flow-rate detection means for detecting the flow rate of the gas flowing through the sub-supply passage 13b. The flow rate detection unit 4 outputs a detection signal according to the detected gas flow rate, and inputs this to a leak determination unit 5 as a leak determination unit. The leakage determination unit 5 determines gas leakage based on the input detection signal.

Reference numeral 6 is a means operating portion as a manual operating means for manually operating the valve body of the gas cutoff valve 3. The manual operation part 6 is movable by a manual operation between a first position in which the valve body blocks both supply paths 13a and 13b and a second position in which both are opened. In the manual operation part 6,
A biasing force is constantly applied from the biasing portion 7 in the direction from the second position to the first position. The engaging portion 8 engages with the manual operating portion 6 in the second position to hold the manual operating portion 6 in the second position against the biasing force of the biasing portion 7. The seismic sensing unit 9 is displaced by the seismic intensity of a predetermined value or more and is displaced by the manual operation unit 6
The engagement between the and the engaging portion 8 is released. Therefore, even when the engagement between the manual operation portion 6 and the locking portion 8 is released, the manual operation portion 6 is moved from the second position to the first position by the urging force of the urging portion 7.
Is moved to the position to cause the valve body to shut off both supply paths.

2 to 4 as the composite valve device A, the supply path switching valve 2, the gas shutoff valve 3 for shutting off the jetted gas, the gas shutoff valve 3 for both manual and seismic shutoff, and the valve operating portion 6 are shown in FIGS. It is integrally configured as described later.

As described above, the sub supply passage 13b is provided as a bypass flow passage in a part of the main supply passage 13a, the gas is caused to flow only in the sub supply passage 13b at a low flow rate, and the minute flow amount provided in the sub supply passage can be detected. For example, since the flow rate is detected by the flow rate detection unit 4 including a small-capacity gas meter to detect a minute gas leak, the gas leak detection of the light inner tube 13 is performed without forcibly stopping the gas supply. ,
It can be done easily and reliably. Moreover, since the flow path is switched depending on the size of the gas flow,
It is possible to detect the presence or absence of gas leakage in the low-pressure part of the gas supply pipe for LP gas, city gas, etc. with almost no pressure loss. Then, the valve body that has been biased in advance and held in the open state is released in response to a vibration of a seismic intensity equal to or higher than a predetermined value, and the biasing force automatically closes the valve to shut off gas. Therefore, it is possible to prevent gas leakage due to damage to the outer lamp inner tube 13 due to an earthquake, and moreover, the switching means can be simplified and the device can be downsized.

The sub-supply passage 13b has an inlet connected to the main supply passage 13a at an upstream side of the supply passage switching valve 2 and an outlet connected to the main supply passage 13a at an intermediate position between the supply passage switching valve 2 and the gas cutoff valve 3. It is connected in parallel to the path switching valve 2. The leakage determination unit 5 determines gas leakage based on the detection signal from the flow rate detection unit 4.

The LP gas and city gas used in the housing complex 14 are supplied from a gas supply source (not shown) to the low pressure branch pipe 1.
1, the light is supplied to the collective supply facility 15 of the housing complex 14 through the outer pipe 13 of the lamp. The low-pressure branch pipe 11 is a pipe buried in the ground, and supplies gas that has already been brought to a low-pressure pressure state.
The lamp inner pipe 13 is a pipe branched and connected to the low-pressure branch pipe 11, and is buried in the ground like the low-pressure branch pipe 11.

2 to 4 show the structure of a concrete first embodiment of the composite valve apparatus A of FIG. 1, FIG. 2 shows the gas shut-off valve 3 in the non-shut-off state, and FIG. 3 and FIG. It is sectional drawing which shows the shut-off state of the manual and seismic-sensitive gas cutoff valve 3b of the gas cutoff valve 3, respectively. In these drawings showing the composite valve device A, a supply passage switching valve 2, a jet gas shutoff valve 3a for shutting off jet gas and a manual and seismic shutoff valve 3b for shutting off manual and seismic gas.
The gas shut-off valve 3 and the valve operating part 6 of the manual and seismic sensitive gas shut-off valve 3b are integrally configured.

In FIG. 2, the supply path switching valve 2 and the gas shutoff valve 3 for shutting off both the jet gas and the manual and seismic gas are located in a case formed by a lower case C1 and an upper case C2. It is configured. In the lower case C1, the gas leak detection device 1 is connected to the middle of the inner tube 13 of the lamp, so that gas inlets 21a and outlets 21b are formed in left-right opposite directions. On the inner circumferences of the gas inlet 21a and the outlet 21b, the upstream and downstream lamp outer tubes 1
Female threads are formed to threadably connect the three ends, and in particular, a gas inlet 21a is provided with a filter 21c for preventing dust from entering.

The lower case C1 also has a gas inlet 21a.
A partition wall 22 for partitioning the upstream side and the downstream side is provided between the partition wall 22 and the outlet 21b, and two holes 23a and 23b that are open upward are formed adjacent to the partition wall 22.
The inner edge of the hole 23a is projected upward in a cylindrical shape so that the guide tube 2
4a is formed, and a guide tube 24a is formed around it.
A substantially cylindrical outer wall 24b is formed so as to concentrically open and project upward. Further, a gas common path 24c, which is provided so as to project upward and open upward, is continuously provided in the hole 23b. The outer wall 24b and the common gas passage 24c are sealed above them by a curved upper case C3 attached to the lower case 2a using an airtight ring C3.

The lower case C1 is further provided with a hole 25a which is opened on the upstream side of the partition wall 22 so as to be adjacent thereto, and a hole 25a which is adjacent to the hole 23a so as to communicate with a second gas passage S ₂ which will be described later. And a hole 25b that is open to the bottom is formed.
The hole 25a has a flow rate detecting unit 4 including a small-capacity gas meter.
Of the gas flow inlet 4a is connected to the hole 25b at the other end of a gas communication pipe 4c, one end of which is connected to the gas flow outlet 4b of the flow rate detection unit 4, and the other is composed of the flow rate detection unit 4 and the gas communication pipe 4c. A supply path 13b is formed.

The substantially cylindrical outer wall 24b is a guide tube 24.
A cylindrical valve accommodating portion which is formed concentrically with a and which constitutes a valve body guide is provided inside thereof, and a double peripheral wall is formed by both of them. The valve accommodating portion 26 has its upper end kept airtight by the O-ring 26a on the inner peripheral surface of the outer wall 24b and its lower end kept airtight on the inner peripheral surface of the guide tube 24a by the O-ring 26b, and is vertically movable on the outer wall 24b. The valve housing 26 is fitted and is constantly biased upward by the coil spring 27 so that a part of the upper end of the valve housing 26 is held in contact with the upper case C2 in the illustrated state. A space S ₂ that functions as a second gas passage is formed between the inner peripheral surface of the outer wall 24b and the outer peripheral surface of the valve housing portion 26.

An inlet valve opening 26c ₁ and an outlet valve opening 26c ₂ are formed on the lower surface and the upper surface of the valve accommodating portion 26 so as to face each other, and the second gas passage S is formed in the middle portion thereof.
₂ and the downstream end of the sub supply path 13b connected to 2 and the outlet valve port 2
A communication hole 26c ₃ that communicates with 6c ₂ is formed.
A valve body 28 is vertically movably accommodated in the valve accommodating portion 26, and the inner peripheral surface of the valve accommodating portion 26 reduces contact resistance with the valve body 28. Three guide ribs 26c ₄ are formed between the inner peripheral surface and the outer peripheral surface of the valve body 28 so as to form a space S ₁ serving as a first gas passage. The valve body 28 consists of a float of a hollow cylinder in which the end surfaces of the upper and lower closed, the valve packing 28a and 28b close the inlet valve port 26c ₁ and the valve port in contact with the outlet valve port 26c ₂ on the upper and lower surfaces respectively attached There is. The valve packings 28a and 28b are made of an elastically deformable material such as rubber.

When the gas flow rate when the gas is not consumed is small, the valve body 28 descends due to its own weight, and the valve packing 28a comes into contact with the inlet valve port 26c ₁ to close the valve as shown in the figure. , The valve packing 28a is lifted by the gas flow, and the valve packing 28a separates from the inlet valve port 26c ₁ and opens.

As a result, the gas flow rate during gas consumption
The valve body 28 is the inlet valve opening 26c₁Open the gas
Inflow port 21a to hole 23a, first gas passage S₁, Gas
The flow path 21c passes through the passage 24c and the hole 23b to reach the outlet 21b.
Gas supply channel 13a, hole 25a, a small capacity gas meter
Gas inlet 4a and gas outlet 4 of the flow rate detector 4
b, the gas communication pipe 4c, and the sub-supply passage 1 including the hole 25b.
3b and the second gas passage S ₂, Communication hole 26c₃And the outlet valve
Mouth 26c₂Through the gas common path 24c and the hole 23b
Two with the sub gas supply path 13b reaching the gas outlet 21b
Gas is supplied through the channel.

On the other hand, when the gas is not consumed, the gas flow rate is small.
When the valve body 28 is opened, the inlet valve opening 26c ₁Shut off the gas flow
From the inlet 21a to the hole 25a, a small capacity gas meter
Gas inlet 4a, gas outlet 4b, gas
A sub-supply passage 13b consisting of a pipe 4c and a hole 25b,
2 gas passage S₂, Communication hole 26c₃And outlet valve opening 26c ₂
Through the gas common passage 24c and the hole 23b, the outlet 21
The gas is supplied only through the gas supply path reaching b.
Is supplied only through the sub supply path 13b.
Therefore, the valve body 28 and the inlet valve opening 26c₁Is the gas supply path
The supply path switching valve 2 for switching between is configured.

The outside of the lamp connected to the gas outlet 21b
When a large amount of gas is ejected due to damage to the inner tube 13
A large amount of gas flows into the main supply path 13a like
Then, due to the large pressure difference between the inside and outside,
A large levitation force acts and the upper end in the valve body guide 26
And the valve packing 28b is moved to the outlet valve opening 26c. ₂
Will come to close. When this happens, the main supply path
Gas flowing not only through 13a but also through sub supply path 13b
Is also closed and supplied to the downstream side of the gas leak detection device 1.
The gas is completely shut off. Therefore, the valve body 28
Packing 28b and outlet valve opening 26c₂And a gas blow
The jet gas shutoff valve 3a for shutting off the jet gas at the time
There is.

A bearing hole 62 for mounting the manually operated shaft 61 is formed in the top portion C2 of the upper case C2, and a support plate 63 is mounted therein by a screw 64. The manual operation shaft 61 is rotatably supported in the bearing hole 62 by a rotation angle of about 90 degrees, and the operation portion 61a at the upper end thereof is projected on the upper surface of the upper case C2 and is provided on the outer periphery of the portion located in the bearing hole 62. An airtight O-ring 61b is attached to keep the inside and outside of the upper case C2 airtight, and the lower end of the upper case C2 is rotatably fitted in the hole 63a of the support plate 63 and is received underneath. The manual operation shaft 61 includes an operation plate 6 having an operation cam surface 65a between the bearing hole 62 and the support plate 63.
5 is attached and when the manual operation shaft 61 is rotated, the operation plate 65 is also rotated. Operation board 6
As shown in FIG. 6, the outer circumference of the No. 5 is formed in a fan shape having an angle sufficiently larger than 90 degrees, and the manual operation shaft 61 is rotated in the maximum counterclockwise direction at the first rotational angle position and in the maximum clockwise direction. At the rotated second rotational angle position, stoppers (not shown) with which both side surfaces of the upper and lower side surfaces abut each other are located on the upper case C2.
The rotation angle of the manual operation shaft 61 is restricted to about 90 degrees.

On the inner surface of the upper case C2, a hanging wall 62a having a surface which is always opposed to a part of the fan-shaped outer peripheral surface of the operation plate 65 in the rotation range thereof is formed. On the hanging wall 62a, when the manual operation shaft 61 is at the second rotation angle position, a locking ball 81 that falls into an engagement recess 65b having a V-shaped cross section formed on the outer peripheral surface of the operation plate 65, and this engagement. A guide hole 62b for accommodating a pressing pin 82 for pressing the stop ball 81 is formed.

A guide hole 6 is formed in the side wall 62c of the upper case C2.
A support hole 62d is formed on the extension line of 2b, and the base portion of the pendulum 91 protruding to the outside of the upper case C2 is swingably supported in the support hole 62d. The pendulum 91 is formed by integrally molding metal including alloy, synthetic resin, ceramic, rubber, etc., and a spherical weight portion 91a is formed at its free end. Further, a biasing shaft 91b is screwed to a projecting end of the pendulum 91 into the upper case C2, and a spring bearing of the biasing shaft 91b is provided so as to apply a biasing force in a direction of pulling the pendulum 91 into the upper case C2. 91c and upper case C
A coil spring 91d is contracted between the inner surface of the second side wall 62c. Due to the urging force applied through the urging shaft 91b, the flange portion 91e of the pendulum 91 is in the upper case C.
It is elastically contacted with the vertical outer wall surface of the second side wall 62c, and is held in the illustrated horizontal state.

The support hole 62d formed in the side wall 62c of the upper case C2 has a pendulum 9e as a fulcrum with the flange portion 91e as a fulcrum.
The taper is provided so as to expand toward the inner side of the upper case C2 so that 1 can swing. The pendulum 91 protruding from the upper case C2 is housed in a pendulum cover C4 attached to the upper case C2 in an airtight state.

As shown in FIG. 5, a forked portion 82a is formed at the end of the pressing pin 82 protruding from the guide hole 62b, and one end of the link rod 83 sandwiched by the forked portion 82a is connected to the connecting pin. 82c is rotatably connected, and a bifurcated portion 91f is formed at the end of the urging shaft 91b.
The other end of the link rod 83 sandwiched between the forked portions 91f is rotatably connected by a connecting pin 91g. Therefore, the biasing force of the coil spring 91d causes the biasing shaft 91b,
It is attached to the pressing pin 82 via the link rod 83.
Therefore, when the locking ball 81 at the tip of the pressing pin 82 is in the state of falling into the engagement recess 65b of the operation plate 65, that is, when the manual operation shaft 61 is at the second rotation angle position, the locking ball 81 In order for 81 to escape from the engaging recess 65b, it is necessary for the locking ball 81 to move over the inclined surface of the engaging recess 65b and enter the guide hole 62b against the biasing force of the coil spring 91d. (See Figure 6)

Below the operation plate 65, the manual operation shaft 61 has an inner end fixed to a nut 61c screwed to the manual operation shaft 61, and an outer end fixed to a pin 63c standing on a support plate 63. A spring 67 is attached in a loaded state for urging the manual operation shaft 61 counterclockwise. The spring 67 is wound up when the manual operation shaft 61 is rotated clockwise from the first rotation angle position to the second rotation angle position, and the urging force acting on the manual operation shaft 61 is maximized. However, the manual operation shaft 61 is held at the second rotation angle position because the locking ball 81 has fallen into the engagement recess 65b at the second rotation angle position.

A thrust shaft hole 63b is formed in the support plate 63 at a position corresponding to the outlet valve port 26c ₂ formed on the upper surface of the valve accommodating portion 26. Thrust shaft hole 63
A thrust shaft 66, which is biased upward by a coil spring 66a and whose upper end is elastically contacted with the operation cam surface 65a, is slidably fitted to b. The lower end of the thrust shaft 66, pressing the closure 66b is formed integrally a pressing member for closing the outlet valve port 26c ₂ is an outlet of the valve housing section 26 from the outside. The pressing closing body 66b has a downward dish shape, and a ring-shaped valve packing 66c is provided on the lower side edge thereof.

As shown in FIG. 2, when the thrust shaft 66 is biased by the coil spring 66a and is elastically contacted with the lowest surface of the operation cam surface 65a, that is, the manual operation shaft 61.
Is in the second rotation angle position, the pressing block 66
b is at an upper position away from the outlet of the outlet valve port 26c ₂ , and this state is maintained by the locking ball 81 falling into the engaging recess 65b (FIG. 5).

However, when an operating handle (not shown) is attached to the operating portion 61a and the manual operating shaft 61 is rotated in the direction of the first rotational angle position with a large force, the engaging concave portion 65b together with the operating plate 65 is operated. Is forcibly moved, so that the locking ball 81 overcomes the biasing force of the coil spring 91d and rides over the inclined surface of the engaging recess 65b to engage the engaging recess 65.
It escapes from b and is retracted into the guide hole 62b.

Once the locking ball 81 comes out of the engaging recess 65b, the manually operated shaft 61 is urged by the spring 67 wound up, as shown in FIG.
The second rotation angle position is rotated counterclockwise by approximately 90 degrees from the second rotation angle position, and the operation plate 65 comes into contact with a stopper (not shown) and stops. At this time, since the operation cam surface 65a is also rotated 90 degrees, the operation cam surface 65a to which the thrust shaft 66 elastically contacts changes from the lowest surface to the highest surface via the inclined surface. As a result, the thrust shaft 66 is pushed down against the biasing force of the coil spring 66a, and the pressing closing body 66b is lowered.

The holding state of the manual operation shaft 61 at the second rotational angle position corresponds to a predetermined value, eg, a seismic intensity of 80.
The vibration of an earthquake with an intensity of 250 gal (1 gal = 9.8 x 1000 newton) or more, for example, a vibration caused by an earthquake, causes the weight part 9 of the pendulum 91 to be 9 parts by weight.
When acting on 1a, the pendulum 91 causes the coil spring 91d.
As shown in FIG. 4, it swings downward with the collar portion 91e serving as a fulcrum against the holding force of. Due to this swing, the urging shaft 91b in the upper case C2 is displaced upward, and due to this displacement, the connecting portion between the urging shaft 91b and the link rod 83 and the link rod 83 and the pressing pin 82 are provided. While the connecting portion rotates, the pressing pin 82 is pulled out via the link rod 83 and retracted.

Due to the movement and retraction of the pressing pin 82, the force that has prevented the movement of the locking ball 81 that has fallen into the engagement concave portion 65b disappears, and the urging force applied to the manual operation shaft 61 causes the operation plate. Engaging recess 65b with 65
Is about to move, the locking ball 81 also moves into the guide hole 62b.
It will be retracted inward and will come out from the engagement recessed part 65b. Once the locking ball 81 escapes from the engagement recess 65b, the manual operation shaft 61 is wound up and the spring 6 is wound.
As shown in FIG. 6, the urging force of 7 rotates the counterclockwise direction from the second rotational angle position to approximately 9 °.
The operation plate 65 is driven to rotate by 0 ° and stops by contacting the stopper. At this time, since the operation cam surface 65a is also rotated 90 degrees together, the operation cam surface 6 to which the thrust shaft 66 is elastically contacted
5a changes from the lowest surface to the highest surface through the inclined surface. As a result, the thrust shaft 66 is pushed down against the biasing force of the coil spring 66a, and the pressing closing body 66b is lowered.

When the pressing closing body 66b descends, the valve packing 66c comes into contact with the upper surface of the valve accommodating portion 26 so as to close the outlet of the outlet valve opening 26c ₂ . When the pressing closing body 66b further descends after the contact, the valve housing portion 26 is pushed down against the coil spring 27 that biases the valve housing portion 26 upward. Then, as shown in FIG. 3 or 4, when the thrust shaft 66 comes into elastic contact with the highest surface of the operation cam surface 65a, further lowering of the pressing block 66b is stopped. From the above, the elastic contact force of the valve packing 66c of the pressing closing body 66b with respect to the upper surface of the valve housing portion 26 is
It is determined by the coil spring 27 that biases the valve housing portion 26 upward.

As is apparent from the above description, the pressing closing body 66b and the outlet valve port 26c ₂ are both the manual and seismic isolation valve 3b.
The manual operation shaft 61 and the operation plate 65 constitute the manual operation unit 6. Further, the spring 67 constitutes the biasing portion 7 which constantly applies a biasing force to the manually operated shaft 61 in the direction from the second position to the first position, and the coil spring 91d,
The urging shaft 91b, the link rod 83, the pressing pin 82, the locking ball 81, and the engaging recessed portion 65b of the operation plate 65 prevent the manual operation shaft 61 in the second position from resisting the urging force of the spring 67. The locking portion 8 is held at the position 2.
Further, the pendulum 91 constitutes a vibration sensing portion 9 which is displaced by receiving a vibration having a seismic intensity equal to or higher than a predetermined value and which releases the holding of the manually operated shaft 61 by the locking portion 8.

As a small-capacity gas meter that constitutes the flow rate detection unit 4, two chambers partitioned by a diaphragm are provided.
A switching valve that alternately switches one chamber to the gas inflow chamber and the other to the outflow chamber by the movement of the diaphragm is provided, and the magnet that rotates in response to this switching operation turns the reed switch on and off to adjust the flow rate. A diaphragm type that generates a periodic detection signal is used.

This detection signal is transmitted via the lead wire L to the leakage determination section 5 of the remote monitoring panel. In addition to the leakage determination display 5a, the leakage determination unit 5 is provided with a power supply display 5b and a shutoff display 5c. In addition, blocking display 5
c is a lead provided on the outside of the upper case C2 by providing a magnet 65c (FIG. 3) on the operation plate 65 that rotates together with the manual operation shaft 61, and moving this magnet when the manual operation shaft 61 is rotated to the closed position. It can be turned on by turning on the switch 65d and pulling the lead wire L ₁ of the reed switch together with the lead wire L to the leakage determination section 5.

The leakage determination section 5 is for inputting the detection signal from the flow rate detection section 4 to detect the presence or absence of gas leakage, and monitors continuous input or intermittent input of the detection signal, for example input of the detection signal. The number of times when the flow rate is 0 can be counted, and a counter that can hold the count value can be provided, or the number of times can be stored in the memory. Then, when the presence or absence of this count or the number of times is confirmed for a certain period of, for example, 30 days, it is determined whether or not there is a possibility of leakage. Furthermore, the leak detection signal from the leak determination unit 5 may be transmitted to the management center side via a telephone line, and leak monitoring may be performed at a remote place for the presence or absence of a leak.

With the structure described above, the valve body 28 is
When the gas flow rate is large, the inlet valve port 26c ₁ is opened, and when the gas flow rate is small, the valve is closed. The flow path is switched depending on the flow rate, so that a large pressure loss does not occur. Further, the switching gas flow rate can be set by selecting the weight of the valve body 28. Then, when a large amount of gas is ejected due to damage to the inner tube 13 outside the lamp, the valve body 28 floats and the outlet valve port 26c ₂ is closed, so that leakage of the ejected gas can be prevented. Further, when the pendulum 91 vibrates due to a vibration having a seismic intensity of a predetermined value or more, or when the manual operation shaft 61 is forcibly rotated, the manual operation shaft 61 is held against the biasing force of the spring 67. Since the locking that had been performed is released, the manual operation shaft 61 is automatically rotated by the urging force of the spring 67, and the operation cam surface 65a of the operation plate 65 is also rotated together therewith, so the thrust shaft 66 is pushed down. To prevent a large amount of gas leakage when the pressure blocker 66b descends and the outlet of the outlet valve port 26c ₂ becomes blocked, and the supply path is blocked before it is damaged by vibrations. You can

The above-described valve complex apparatus A and the flow rate detecting unit 4 integrated with the valve complex apparatus A are installed in a manhole with a lid in the ground where the inner tube 13 for a lamp is buried.

Next, the operation of this embodiment will be described. Normally, the manual operation shaft 61 remains at the second rotation angle position where the operation cam surface 65a is rotated so that the pressing block 66b is located above. Tokiben body 28 to the main supply path 13a is not gas flow valve packing 28a drops by its own weight is in contact with the inlet valve port 26c ₁ (the state shown in FIG. 2). A large amount of gas is supplied to the main supply path 13a
Flow into the inlet valve opening 26c ₁
Is opened, the gas flows through the inlet valve opening 26c ₁ to the first gas passage S ₁ and the outlet valve opening 26c ₂ , and the hole 25a
The gas that has flowed out of the flow rate detection unit 4 through the gas flow path 4c flows through the gas pipe 4c through the hole 25b to the second gas passage S ₂ and the outlet valve port 26c ₂ . That is, the gas flows through both the main supply passage 13a and the sub supply passage 13b.

When the gas consumption is almost exhausted, such as at night or in the middle of the night, the valve body 28 lowers due to its own weight, and the valve packing 28a comes into contact with the inlet valve opening 26c ₁ and the inlet valve opening 26c.
_The gas flow passing through ₁ is blocked, and only the gas flowing to the flow rate detecting unit 4 through the hole 25a is left. As a result, it becomes possible to monitor the minute gas flow rate flowing to the flow rate detection unit 4. At this time, if there is no gas consumption and no minute gas leakage occurs, the flow rate detection unit 4 will not detect the gas flow rate. Then, as in the conventional case, on the assumption that such a phenomenon occurs at least once during a relatively long predetermined period of 30 days, for example, if the flow rate detection unit 4 determines the gas flow rate during this predetermined period. When the detection is not lost, it is judged that a minute gas leak has occurred.

In addition, for some reason such as construction
There was a situation where the inner pipe 13 was damaged and a large amount of gas was ejected.
If a large amount of gas flows through the main supply path 13a
And a large levitation force is applied to the valve body 28,
Lifted and outlet valve opening 26c ₂Valve packing 28b
Contact, outlet valve port 26c₂Main supply path 13a passing through
Since both gas flows in the sub supply path 13b and the sub supply path 13b are cut off,
The gas leakage from the damaged part can be completely eliminated.
It

As shown in FIG. 4, when a tremor with a seismic intensity greater than a predetermined value acts on the pendulum 91, the holding force that holds the manual operation shaft 61 at the second rotational angle position is released. To be done. When the holding force is released, the manual operation shaft 61
Is automatically rotated to the first rotation angle position by the urging force of the spring 67, and the operation cam surface 65a pushes the pressing closing body 66b downward. This pressing block 6
By the lowering of 6b, the outlet of the valve body accommodating portion is blocked, the gas flow of both the main supply passage 13a and the sub supply passage 13b is blocked, and then the outer lamp inner tube 13 may be damaged by vibration. Even if there is, a large amount of gas will be prevented from being ejected.

With this configuration, it was conventionally necessary to separately provide a seismic isolation valve upstream of the gas flow, but the gas leakage detection device of the present embodiment has a spring 67 for biasing the manually operated shaft 61 and a spring 67. It is not necessary because it is a dual-purpose switching valve that incorporates the function of a seismic isolation valve by adding a member that locks and releases the manually operated shaft, thus reducing the size, cost and weight. Can be achieved.

When the existing gas supply pipe or inner pipe needs to be largely changed or repaired, the gas is in a bad condition even if it is a small amount. It is necessary to cut off the flow completely. In such a case, as shown in FIG. 3, when the manual operation shaft 61 is rotated to lower the pressing closing body 66b, the pressing closing body 66 is rotated.
The valve packing 66c of b abuts the upper surface of the valve accommodating portion 26 to close the outlet valve port 26c ₂ from the outside and pushes down the valve accommodating portion 26 against the biasing force of the coil spring 27.
The valve packing 66c is held in a state of being elastically contacted with the upper surface of the valve body guide 28 by a force corresponding to the biasing force of the coil spring 27. In this state, the gas flow of both the main supply passage 13a and the sub supply passage 13b passing through the outlet valve opening 26c ₂ is completely cut off, so that the existing gas supply pipe or inner pipe is largely changed or repaired. You will be able to safely carry out construction work.

After the construction is completed, the manual operation shaft 61 is rotated in the opposite direction to raise the pressing block 66b, and the outlet valve opening 26c ₂
The outlet is opened and gas can flow normally. Conventionally, it was necessary to separately provide a manual shutoff valve upstream of the gas flow, but the gas leakage detection device of the present embodiment has a manual operation shaft 6
1 and the pressure closing body 66b are added to form a switching valve that incorporates the function of a flow path shutoff valve, so that there is no need for it. Therefore, size reduction, cost reduction, and weight reduction can be achieved.

In the embodiment described above, the supply path switching valve 2
Above the valve body 28 of the outlet valve opening 26c ₂Together with
The outlet of the sub supply path 13b is the outlet valve opening 26c.₂Upstream of
Connect the valve 28 to the main supply path 13a, and
The valve body 28 and the outlet valve opening 26c₂
The jet gas cutoff valve 3a is configured so that
Therefore, the valve body 28 of the jet gas cutoff valve 3a is connected to the supply passage
Fully interrupts the jetted gas flow in conjunction with the valve body of the replacement valve 2.
Therefore, it is necessary to separately provide a jet gas cutoff valve separately.
No longer needed.

[0066] manual operation shaft 61 and the pressing closure 66b is provided above the outlet valve port 26c _2, the outlet valve port 26 of the pressing closure 66b are depressed by the operation of the manual operation shaft 61
Block the outlet of c ₂ from above and manually and seismically sensitive gas cutoff valve 3b
Since the valve is closed, the manual and seismic-sensing gas cutoff valve 3b shares the valve opening of the jet gas cutoff valve 3a and contributes to complete cutoff of the gas flow. Alternatively, it can be optionally shut off, and when there is a need to make major changes to existing gas supply pipes or inner pipes or to perform repairs, it is possible to completely shut off the gas flow. You can do it safely.

In the above-described embodiment, the pendulum 91 is configured to be held horizontally so as to effectively respond to the vertical vibration to block the seismic vibration. However, it is effective for the horizontal vibration. In the case of making a response, it is also possible to vertically arrange the pendulum 91 as shown in FIG. Furthermore, in order to effectively respond to both vertical and horizontal vibrations, the axis of the pendulum 91 in the embodiment shown in FIG. 2 may be bent at a right angle midway as shown in FIG. . By doing so, the base portion of the pendulum 91 will be displaced as shown in FIG. 9 regardless of whether vertical vibration or horizontal vibration is applied to the weight portion 91a at the tip, so that seismic isolation can be effectively performed. You will be told.

10 and 11 show another embodiment. The same parts as those described above with reference to FIG. 2 and the like are designated by the same reference numerals and detailed description thereof will be omitted. FIG. 10 is a block diagram showing a piping system diagram in which another embodiment of the gas leakage detection device according to the present invention is applied to gas supply equipment for supplying gas to a housing complex. In the figure, the gas leakage detection device 1 is configured as a flow path switching type that incorporates a function of a shutoff valve and also serves as a main valve of an outer lamp inner tube branched from a low pressure branch pipe 11. A supply path switching valve 2 as a supply path switching means is connected to the main supply path 13a, and an opening / closing valve 2a as an opening / closing means is connected to an inlet of the sub supply path 13a. The supply path switching valve 2 and the opening / closing valve 2a are adapted to be closed by interlocking with each other by a manual operation unit 6 described later.

FIG. 11 shows a specific structure of the composite valve device A. The lower case C1 is provided with holes 25a and 25b 'which are opened downward with the partition wall 22 interposed therebetween, and a flow rate detecting portion composed of a gas meter is provided therein. The gas inflow port 4 and the gas outflow port 4 are connected to each other. The holes 23a and 23b opened upward with the partition wall 22 interposed therebetween are communicated with each other by sealingly mounting the upper case C2, and form a part of the main supply path. Guide tube 24a of the hole 23a
A lower end portion of a valve body guide 26 'having a valve opening 26a is attached to the airtightly and slidably using an O-ring 26b. In addition, the valve body guide 26 'is upright 3
Formed a to 4 struts 26'a in a shape connected by a ring 26'b at its upper end, the gas passage S ₃ gas pass freely between the posts 26'a when the valve body 28 'has emerged You can do it. Valve opening 2 of valve body guide 26 '
At the bottom of the 6a, the upper end of three or four arms 26'c are mounted equiangularly gas passage S ₄ is formed, and and lower ends of these arms 26'c is smaller in diameter than the valve port 26a which Is attached to a cylindrical portion 26'd of a concentric circle.

A valve rod 26'e is provided in the cylindrical portion 26'd.
Is inserted slidably in the thrust direction, and the stop ring 2
The coil spring 26'g contracted between 6'f and the cylindrical portion 26'd projects and holds the coil spring 26'g downward. The arm 26'c and the cylindrical portion 26'd are integrally formed to form a valve rod support member that supports the valve rod 26'e. A coil spring 26′h is contracted between the valve body guide 26 ′ and the outer peripheral portion of the guide cylinder 24a so as to push up the valve body guide 26 ′ from below. As a result, the valve body guide 26 'is pushed up until a part thereof comes into contact with the stopper 26'i.

The valve element 2 arranged in the valve element guide 26 '.
8'has a valve packing 28a attached only to its lower surface. The valve body 28 ′ can move up and down inside the valve body guide 26 ′, and when the gas flow is large, the valve body 28 ′ is pushed up by the gas flow and floats up, the valve packing 28 a moves away from the valve opening 26 a, and the gas flows into the valve opening 26 a. , Through gas passage S ₃ hole 2
3b, and when the gas flow is small, it falls due to its own weight, and the valve packing 28a contacts the valve opening 26a to close the valve opening 26a and shut off the gas flow.

Hole 25a to which the inlet of the sub supply path is connected
A valve opening 25c is provided at the upper end of the valve and is opened and closed by the valve body 25d. The valve body 25d is formed in a nail shape, and the needle portion is passed through the valve opening 25c as a guide rod. A coil spring 25e is provided outside the valve opening 25c and supports the nail head of the valve body 25d from below. Valve 2
5d is normally lifted by the coil spring 25e to open the valve opening 25c, but when it is pushed down by the valve rod 26'e, the valve opening 25c is opened.

At the lower end of the thrust shaft 66 slidably fitted in the thrust shaft hole 63b of the support plate 63, the pressing means 6 is provided.
6d is integrally provided. The pressing means 66d includes a disc member 66d ₁ that presses the upper end of the valve body guide 26 ', and the valve body 2
A valve holding member 66d ₂ pressing the upper surface of 8 'consists disk member 46d ₁ and the valve pressing member 66d ₂ and the supporting support member 66d ₃ Prefecture, the valve holding member 66d ₂ is pivotably at the bent portion The lever member is a substantially L-shaped lever member that is pivotally supported on one end, one end of which is elastically contacted with the upper end edge of the valve body guide 26 ', and the other end of which is displaced downward by its clockwise rotation. Is elastically contacted with the upper end surface of the valve body 28 '.

In the state shown in FIG. 11, the locking ball 81 is at the second rotational angle position where it has fallen into the engagement recess 65d of the operation plate 65, and the disc member 66d ₁ and the valve body pressing member 66d ₂ of the pressing means 66d are Valve body guide 26 'and valve body 28'
However, when the manual operation shaft 61 is rotated in the direction of the first rotation angle position by a large force, the operation cam surface 65a of the operation plate 65 is also rotated by 90 degrees. The operation cam surface 65a to which the thrust shaft 66 elastically contacts changes from the lowest surface to the highest surface via the inclined surface. As a result, the thrust shaft 66 is pushed down against the biasing force of the coil spring 66a, and the pressing means 66d is lowered.

By the lowering of the pressing means 66d, first, the valve body pressing member 66d ₂ rotates in the clockwise direction, and the other end hits the upper surface of the valve body 28 'and pushes down the valve body 28', so that the valve body 28 ' The valve packing 28a is brought into contact with the valve opening 26a to close the valve opening 26a. Then, the disc member 46d ₁ abuts on the valve body guide 26 ′ at a timing when the valve body 28 ′ cannot be lowered any more, and when this causes the pressing means 66d to further descend against the coil spring 26′h,
The disc member 46d ₁ connects the valve body guide 26 'to the valve body 28'.
Along with this, the coil spring 26'h is pushed down, and at the same time, the valve rod 26'e of the valve rod support body pushes the valve body 25d downward against the coil spring 25e. When the valve body 25d is pushed down, the valve port 25c is closed. The valve body 25d is the valve opening 25.
When it hits c and cannot be lowered further, coil spring 2
Since 6'g compresses and the valve rod 26'e escapes, even if the valve body guide 26 'further descends, an unnecessarily large force is not applied to the openings of the valve body 25 and the valve opening 25c.

In the holding state of the manual operation shaft 61 at the second rotational angle position, the pendulum 9 has a vibration with a seismic intensity of a predetermined value or more.
When it acts on the first weight portion 91a and swings downward with the collar portion 91e as a fulcrum, it is released by retracting the pressing pin 82 via the link rod 83. As a result, similarly to when the manual operation shaft 61 is rotated, the manual operation shaft 61 is rotated counterclockwise from the second rotation angle position to the first rotation angle position by approximately 90 degrees by the urging force of the spring 67. When the thrust shaft 66 is driven dynamically and is pushed down against the biasing force of the coil spring 66a and the pushing means 66d is lowered, the valve body 25d is pushed down and the valve port 25c is closed.

With the above construction, when it becomes necessary to significantly change or repair the existing gas supply pipe or inner pipe, the manual operation shaft 61 is rotated to operate the main supply. To shut off both the passage 13a and the sub-supply passage 13b to completely shut off the gas flow so that the existing gas supply pipe or inner pipe can be changed significantly or repaired safely. become.

After the construction is completed, the manual operation shaft 61 is reversely rotated, so that the main supply path 13a and the sub supply path 13b are rotated.
Both can be opened to restore gas flow and resume gas use.

When a vibration with a seismic intensity of a predetermined value or more is applied due to the occurrence of an earthquake or the like, both the main supply passage 13a and the sub supply passage 13b are automatically cut off to completely cut off the gas flow. Since it is possible to prevent a large amount of gas from being blown out due to breakage of the inner tube 13 of the lamp without separately providing a stop valve having a seismic function, it is possible to achieve size reduction, cost reduction, and weight reduction.

[0080]

As described above, according to the present invention, since the main supply path is switched depending on the magnitude of the flow rate, a large pressure loss is not generated, and switching is performed by selecting the weight of the member constituting the valve body. The gas flow rate can be easily set.

Further, due to a vibration having a seismic intensity of a predetermined value or more,
Since both the main supply path and the sub supply path can be closed at the same time, there is no need to provide a separate shutoff valve with a seismic function, which is economical and cost-saving, and at the same time downsizing, Weight reduction can be achieved.

Furthermore, since the main supply passage and the sub supply passage can be closed at the same time at any time, it also has the function of a passage closing valve, and it is economical without the need to provide a separate manual shutoff valve. The cost can be reduced, and at the same time the size and weight can be reduced.

Furthermore, without providing a separate manual shutoff valve,
The existing gas supply pipes and inner pipes can be remarkably changed or repaired safely, and the mountability is high and the existing facilities can be handled very easily.

[Brief description of drawings]

FIG. 1 is a block diagram showing a piping system diagram to which an embodiment of a gas leakage detection device of the present invention is applied.

FIG. 2 is a cross-sectional view showing an open state of a gas cutoff valve of the combined valve device of FIG.

FIG. 3 is a cross-sectional view showing a closed state of a gas cutoff valve of the combined valve device of FIG.

FIG. 4 is a cross-sectional view showing a closed state of a seismic-sensing gas cutoff valve of the combined valve device of FIG.

5 is an enlarged cross-sectional view of a portion of FIG. 2 in a plane orthogonal to the cross section of FIG.

6 is an enlarged cross-sectional view of a part of FIG. 2 in a plane orthogonal to the cross section of FIG. 2 in a state different from FIG.

FIG. 7 is a cross-sectional view showing a modified example of a part of the composite valve device of FIG.

8 is a cross-sectional view showing another modified example of a part of the combined valve device of FIG.

9 is a sectional view showing a different state in the example of FIG.

FIG. 10 is a block diagram showing a piping system diagram to which another embodiment of the gas leakage detection device of the present invention is applied.

11 is a cross-sectional view showing an open state of a gas cutoff valve of the combined valve device of FIG.

[Explanation of symbols]

1 gas leakage detection device 2 supply path switching means (supply path switching valve) 2a opening / closing means 3 gas cutoff valve 3a jetting gas cutoff valve 3b gas cutoff means (manual and seismic gas cutoff valve) 4 flow rate detection means (flow rate detection part) 5 Leakage determination means (leakage determination part) 6 Manual operation means (manual operation part) 67 Spring spring 7 Biasing means (biasing part) 8 Locking means (locking part) 83 Transmission means (link rod) 9 Seismic sensing means (Earthquake-sensing part) 91 Pendulum 91a Weight part 13a Main supply path 13b Sub supply path 28 Valve body 26c ₂ Outlet valve opening

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G08B 21/00 G08B 21/00 W (72) Inventor Yasuji Hosawara Minami Kauriya, Kanazawa-ku, Yokohama, Kanagawa Prefecture 3 −21−4−2 (72) Inventor Takeichi Suyama 3-3, 3305, Shiomidai, Isogo-ku, Yokohama, Kanagawa Prefecture 3305, Building 514 (72) Inventor Takaomi Rai 4-1-2, Hiranocho, Chuo-ku, Osaka City, Osaka Prefecture Within Gas Co., Ltd. (72) Inventor Akashi Kegasa 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Within Osaka Gas Co., Ltd. (72) Inventor Junichi Ando 19-18 Sakurada-cho, Atsuta-ku, Nagoya-shi, Aichi Prefecture Toho Gas Co., Ltd. (72) Inventor Mutsumi Nakamura 23 Minami Kashima, Futamatata, Tenryu City, Shizuoka Prefecture Yazaki Keiki Co., Ltd.

Claims (5)

[Claims] 1. A main supply passage is closed when the gas flow rate becomes small, and gas can be supplied only through a sub supply passage provided in parallel with the main supply passage. In a gas leakage detection device configured to detect gas leakage on the downstream side by flow rate monitoring, a valve body that shuts off or opens both the main supply path and the sub supply path, and a manual operation means for operating the valve body. A gas shut-off means that is operable to move between a first position that causes the valve body to shut off the both supply paths and a second position that opens the both supply paths; A biasing means for constantly applying a biasing force to the manual operating means in the direction from the second position to the first position, and a manual operating means in the second position for resisting the biasing force by the biasing means. The second position And a vibration-sensing means for displacing the manual operation means held by the locking means by being displaced by a vibration having a seismic intensity equal to or higher than a predetermined value, and releasing the holding of the manual operation means. By this, the manual operation means is moved from the second position to the first position by the urging force of the urging means, and the valve body is made to shut off the both supply paths. Leak detection device. 2. The manual operation means is rotatable between a first rotation angle position that causes the valve body to block both supply paths and a second rotation angle position that opens both of the supply paths. The urging means has an inner end fixed to an outer periphery of the manual operation means and an outer end fixed to a fixing portion, and is configured to rotate the manual operation means from the first rotation angle position to the second rotation angle position. 2. The gas leakage detection device according to claim 1, wherein the gas leakage detection device comprises a spring which is rolled up by motion to constantly apply a biasing force to the manual operation means in the direction from the second position to the first position. 3. A pendulum having a weight portion at a tip thereof, which is held at a predetermined position at all times and swings when it receives a vibration having a seismic intensity of a predetermined value or more, and the displacement of the pendulum caused by the swing. 3. A gas leak according to claim 1, further comprising: a transmission means for transmitting to the stop means, and the holding of the manual operation means is released by the displacement transmitted to the locking means via the transmission means. Detection device. 4. An inlet valve opening provided in the middle of the main supply passage, and when the gas flow rate during gas consumption is large, the gas flow causes the gas flow to levitate to open the inlet valve opening, and the gas flow rate when gas is not consumed. Has a valve body that descends due to its own weight to close the inlet valve opening when it is small, and comprises a supply path switching means provided in parallel with the sub supply path, wherein the valve body of the gas cutoff means is the manual operation. It is operated by the operating means to open and close the outlet valve port provided on the downstream side of the downstream side connecting portion of the sub supply path to the main supply path, and open both the main supply path and the sub supply path. The gas leakage detection device according to claim 1, wherein the gas leakage detection device is cut off. 5. The main supply path is closed when the gas flow rate becomes small, and the gas can be supplied only through the sub supply path provided in parallel with the main supply path, and the flow rate detecting means provided in the sub supply path is used. In a gas leakage detection device that detects gas leakage on the downstream side by flow rate monitoring, when the gas flow rate when gas consumption is large, it floats up by the gas flow and opens the valve opening, and the gas flow rate when gas is not consumed And a supply path switching means for switching the gas supply path so that gas is supplied only through the sub supply path when the valve body closes down to close the valve opening when the weight is small. An opening / closing means having a valve body for opening and closing a valve port provided at the inlet of the sub supply path; and a closing means for restricting the valve body of the supply path switching means in a closed state. Between a first position in which the valve body of the above is closed and a second position in which the valve body of the supply path switching means is released by releasing the constraint and the valve body of the opening / closing means is opened. An operable manual operation means, an urging means for constantly applying an urging force to the manual operation means in the direction from the second position to the first position, and the manual operation in the second position The locking means for holding the means in the second position against the biasing force of the biasing means and the displacement of the locking means for receiving the vibration of a seismic intensity of a predetermined value or more to hold the manual operation means. And a vibration-sensing means for releasing the holding of the manual operation means, the manual operation means is moved from the second position to the first position by the urging force of the urging means, and the supply path is provided. The valve body of the switching means is restrained in a closed state, and the valve body of the opening / closing means is also provided. The closed state, the gas leakage detection device which is characterized in that so as to block the two supply paths.