JPS6367240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device installed in a gas pipe to issue a gas leak alarm, and a gas leak alarm device having a function of automatically shutting off the gas pipe.

2. Description of the Related Art Generally, gas piping for fuel gas, other flammable gases, toxic gases, and foul-smelling gases uses devices to detect minute leaks and issue an alarm. For example, as shown in FIG. 1, this type of conventional gas leak alarm device has a small-diameter bypass flow path 2 in a flow path 1 of a gas pipe.
A three-way switching cock 3 is provided at the branch position, and a flowmeter 4 is provided in the bypass flow path 2, such as a floating area flowmeter that allows visual observation of minute flow rates.
By operating the three-way switching knob 3 to close the main flow path 1 and open the bypass flow path 2, a small amount of gas flow is instructed, so that gas leakage at the end piping can be detected. A device that has been used for this purpose is known.

Such conventional devices require manual operation to change the inside of the pipe from a normal flow state to a closed state and visual judgment of the amount of leakage, and it is difficult to use it as a remote and automatic alarm device. It was something that I couldn't do.

In view of the above-mentioned problems, the present invention allows an alarm to be easily connected, and is suitable for remote operation.
In addition, by simply turning on the power circuit, leaks can be detected automatically and an alarm can be issued after the piping goes from its normal flow state to when the various gas appliances connected to the piping are closed and put out of use. The purpose is to provide a gas leak warning device. However, the gist of the configuration is that a primary pressure chamber on one side partitioned by a differential pressure operating means that detects and drives a differential pressure such as a diaphragm is connected to a primary flow path connected to a pressure gas supply source. At the same time, the secondary pressure chamber on the other side is connected to the secondary flow path connected to the gas piping to be inspected, and the differential pressure operating means is driven between the primary flow path and the secondary flow path. A main valve that is connected via a connecting rod and is operated in a direction in which both flow paths are communicated by the operation of the secondary pressure chamber side of the differential pressure operating means, and a bypass that causes a slight leak between both flow paths. and a flow path;
The drive connecting rod is connected to the main valve with a play gap that prevents the main valve from operating even when the secondary pressure chamber is slightly operated from the neutral position of the differential pressure operating means, and is displaced in conjunction with the differential pressure operating means. Equipped with a permanent magnet piece that
The reed switch is operated by the approach of the permanent magnet piece, and the differential pressure operating means operates from the neutral position to the secondary pressure chamber side by an amount of play gap between the drive connecting rod and the main valve. A gas leak alarm device characterized in that the gas leak alarm device is configured to operate, and a communication path is provided between the primary side flow path and the secondary pressure chamber of the device, and a communication path is provided between the communication path and the secondary side flow path. A solenoid valve that normally opens the branch path and closes the communication path is provided in the branch path, and a solenoid of the solenoid valve is connected in series with the reed switch, and the reed switch is turned on when the permanent magnet piece approaches.
The gas leak alarm device is equipped with a gas pipe automatic shutoff function, which opens the communication passage and closes the branch passage from the secondary flow passage, and as a result, closes the main valve. .

Next, an example of the implementation of the present invention will be explained with reference to the drawings from FIG. 2 onwards.

This gas leak alarm device is located in the middle of various gas pipes, and has a lower part provided with a primary flow path 12 and a secondary flow path 13 that connect the supply side gas pipe 10 and the usage side gas pipe 11 to be monitored. It has a body 14. An upper body 15 is airtightly stacked on the lower body 14, and a diaphragm 16 constituting a differential pressure operating means is located between the upper body 15 and the lower body 14.
are clamped and fixed, a primary pressure chamber 17 is formed on the lower body 14 side with the diaphragm 16 as a boundary, and a secondary pressure chamber 18 is formed on the upper body 15 side. The primary pressure chamber 17 is connected to the above-mentioned primary flow path 12, and a branch path 13a from the secondary flow path 13 is opened to communicate with the primary pressure chamber 17. Depending on the pressure difference between the two, the lower one is operated.

On the other hand, between the primary flow path 12 and the secondary flow path 13, a main valve 19 and a valve seat 24 are used in the lower body 14 to open and close the connection, and a bypass flow path 20 that causes slight leakage is provided. It is communicated. This main valve 19 is connected to the aforementioned diaphragm 16 via a drive connecting rod 21, and is opened by the operation of the secondary pressure chamber 18 side of the diaphragm 16.
The valve seat 24 is biased toward the valve seat 24 by a spring 23 inserted into the guide cylinder.

The main valve 19 is formed hollow, and the lower end of the drive connecting rod 21 is inserted into the upper end of the main valve 19, and is prevented from coming off by a washer 25 attached to the insertion end 21a. This washer 25 is fitted in a position with a slight play gap a from the inner surface of the upper end plate 19a of the main valve 19 when the diaphragm 16 is in the neutral position, and the diaphragm movement corresponding to this play gap a is I try not to let it get across.

Further, the upper end 21b of the drive connecting rod 21 is extended and protrudes into the primary pressure chamber 17, and a permanent magnet piece 26 is fixed to the tip thereof. This permanent magnet piece 26
is a bottom cylindrical plug 18 located at the upper end of the secondary pressure chamber 18.
It is inserted in a. A reed switch 27 is embedded in the cylindrical portion of the plug 18a.

The relationship between the reed switch 27 and the permanent magnet piece 26 is such that the permanent magnet piece 26 is connected to the diaphragm 1.
When the reed switch 27 is moved upward in the figure by the play gap a from the neutral position together with the permanent magnet piece 26, the reed switch 27 is turned on by the magnetic force of the permanent magnet piece 26.

Further, the secondary pressure chamber 18 is connected from the secondary flow path 13 described above.
A communication passage 12a for switching the diaphragm operating pressure is communicated between the branch passage 13a leading to the primary side passage 12 and the primary side passage 12.
and the secondary pressure chamber 18 can be communicated with each other. A three-way solenoid valve 28 for switching the flow path is provided at the intersection of the communication path 12a and the branch path 13a.

In the three-way switching solenoid valve 28, when the solenoid 28a is de-energized, the valve seat 28b closes the communication passage 12b and is energized to the side that communicates the branch passage 13A with the secondary pressure chamber 18, and when the solenoid 28a is energized, the valve seat 28b closes the communication passage 12b. 1
The secondary flow path 3a is closed, and the communication path 12a is operated in the direction of communicating with the secondary pressure chamber 18.

The solenoid 28a of the three-way solenoid valve 28 is incorporated in the same electric circuit as the reed switch 27, that is, the power switch 29, the reed switch 27, and the solenoid 28a are connected in series with the power supply V as shown in FIG. and solenoid 28a
A relay 30 for a self-holding circuit is connected in parallel with this.

Further, a contact 30a of a relay 30 is connected in parallel with the reed switch 27, and once the reed switch 27 is turned on, the solenoid 28a and the relay 30 are energized until the power switch 29 is turned off. A buzzer 31 etc. is energized through 30b to issue an alarm.

In the device configured in this way, the power switch 29 is turned on with the various gas equipment ports of the gas piping 11 communicating with the secondary flow path 13 closed.
In this state, if there is no leakage into the gas piping 11, and more precisely, if there is no leakage larger than the flow rate determined by the capillary tube 20a in the bypass flow path 20 (the same applies hereinafter), the secondary flow path 11
3 has the same pressure as the primary side flow path 12, and both flow paths 12,
Primary pressure chamber 17 and secondary pressure chamber 1 communicated with 13
8 becomes equal pressure, the diaphragm 16 is moved to the neutral position, and the main valve 19 is closed.

In this state, if a leak occurs in the gas pipe 11, the internal pressure of the secondary flow path 13 and the secondary pressure chamber 18 communicating therewith decreases, and the diaphragm 16 is moved toward the secondary pressure chamber 18 side. When the permanent magnet piece 26 moves by the amount of play gap a along with this operation, the reed switch 27 is turned on, thereby activating the relay 30 and simultaneously energizing the solenoid 28a. The communication path 12a from the primary flow path 12 communicates with the secondary pressure chamber 18, and the pressure in the primary flow path 12 and the secondary pressure chamber 18 become the same pressure, thereby returning the diaphragm 16 to the neutral position. , the main valve 19 remains closed.

On the other hand, when using various gas equipment installed in the gas piping 11, the power switch is turned off. Since the secondary pressure chamber 18 is lowered by the primary pressure chamber 17, the diaphragm 16 is moved toward the secondary pressure chamber 18, and in conjunction with this, the main valve 19 is opened, and both flow paths 12 and 13 are in communication. becomes. At this time, power switch 29
is off, the reed switch 27 is turned on by the permanent magnet piece 26, but the relay 30 and solenoid 28a are not energized and the secondary pressure chamber 18 is always connected to the branch path 13a. In other words, the pressure difference between the primary and secondary pressure chambers 17, 18 is maintained.

The gas leak alarm device of the present invention is constructed as described above, and the main valve is placed between the primary and secondary flow paths, and is opened and closed by differential pressure operating means such as a diaphragm. The main valve is opened when the pressure in the secondary flow path is reduced by the pressure operating means, and the reed switch is turned on by a permanent magnet piece that operates in conjunction with the differential pressure operating means. As a result, it became possible to operate the device as a gas leak alarm device simply by turning on the power circuit of the reed switch, which greatly simplified the operation for detecting gas leaks and also made it easier to configure the device to be remotely controlled. It is something.

In addition, in the above-described configuration, the drive connecting rod that interlocks the main valve and the differential pressure operating means is connected to the main valve with a play gap, and the flow path leading to the secondary pressure chamber is connected from the secondary flow path to the primary side. A solenoid valve is installed in the flow path so that it can be switched freely, and when the reed switch is turned on, the secondary pressure chamber is communicated with the primary flow path.When used as an alarm device, the main pressure chamber is always switched on. The valve is maintained in a closed state, and it also functions as a safety device that automatically shuts off the main flow path of the gas piping in the event of a sudden large gas leak.

[Brief explanation of drawings]

FIG. 1 is a sectional view schematically showing a conventional gas leak alarm detector, FIG. 2 is a vertical sectional view of an apparatus according to an embodiment of the present invention, and FIG. 3 is a circuit diagram. a... Play gap, 10... Supply side gas piping, 1
1... Usage side gas piping, 12... Primary side flow path, 1
2a...Communication path, 13...Secondary side flow path, 13a...
... Branch passage, 14 ... Lower body, 15 ... Upper body, 16 ... Diaphragm, 17 ... Primary pressure chamber, 18 ... Secondary pressure chamber, 19 ... Main valve, 20 ...
...Bypass flow path, 21... Drive connection rod, 25...
Washer, 26... Permanent magnet piece, 27... Reed switch, 28... Three-way switching solenoid valve, 28a... Solenoid, 28b... Valve body.

Claims (1)

[Claims] 1. A primary pressure chamber connected to a pressure gas supply source is connected to a primary pressure chamber on one side partitioned by a differential pressure operating means that detects and drives a differential pressure of a diaphragm, etc. , a secondary pressure chamber on the other side is connected to a secondary flow path connected to the gas piping to be inspected, and a connecting rod driven by the differential pressure operating means is connected between the primary flow path and the secondary flow path. a main valve which is connected via a main valve and which is operated in a direction in which both flow passages are communicated by the operation of the secondary pressure chamber side of the differential pressure operating means, and a bypass flow passage which causes a slight leak between both flow passages. The driving connecting rod is connected to the main valve with a play gap that prevents the main valve from interlocking with a slight movement of the secondary pressure chamber from the neutral position of the differential pressure operating means; A reed switch is provided which is operated by the approach of the permanent magnet piece, which moves in conjunction with the permanent magnet piece, and the differential pressure operating means moves from the neutral position to the position corresponding to the play gap between the drive connecting rod and the main valve. A gas leak alarm device characterized in that the reed switch is operated by an operation on the side of a secondary pressure chamber. 2 The primary pressure chamber on one side, which is partitioned by a differential pressure operating means that detects and drives the differential pressure of a diaphragm, is connected to a pressure gas supply source, and the primary pressure chamber on the other side is connected to the A secondary flow path connected to the gas pipe to be inspected is connected to the pressure chamber, and the primary flow path and the secondary flow path are connected to the differential pressure operating means via a drive connecting rod, A main valve that is operated in a direction in which both flow paths are communicated by the operation of the secondary pressure chamber side of the differential pressure operating means, and a bypass flow path that causes a slight leak between both flow paths, The connecting rod is connected to the main valve with a play gap that prevents the main valve from interlocking with a slight movement of the secondary pressure chamber from the neutral position of the differential pressure operating means, and a permanent valve that is displaced in conjunction with the differential pressure operating means. The reed switch is provided with a magnet piece and is operated by the approach of the permanent magnet piece, and the differential pressure operating means moves from the neutral position to the side of the secondary pressure chamber corresponding to the play gap between the drive connecting rod and the main valve. the operation causes the reed switch to operate;
A communication path is provided between the primary side flow path and the secondary pressure chamber, and the branch path is normally opened between the communication path and a branch path from the secondary side flow path, and the communication path is closed. A solenoid of the electromagnetic valve is connected in series with the reed switch, and when the reed switch is turned on by the approach of the permanent magnet piece, the communication path is opened and branched from the secondary flow path. A gas leak alarm device characterized in that a path is closed.