JPH03212798A - Gas leakage detector - Google Patents

Abstract

PURPOSE:To improve the degree of freedom of a master set installing position by providing a gas port valve part with a switch to be turned on/off by the rotation of a main valve to detect a state and a status detecting switch for a parallel resonance circuit consisting of a solid vibrator and a capacitor and generating monitoring frequency signals from an antenna. CONSTITUTION:When a monitoring frequency signal having frequency (fn) is sent and oscillated from a loop antenna 13, a change-over switch 12 is switched to the side of a signal receiving part 14 at the timing synchronized with the end of oscillation to resonate a sensor part 4n receiving the monitoring frequency signal in parallel. Thereby, the antennas 8, 13 are electro-magnetically coupled with each other through mutual inductance M and an induced current is generated in the antenna 13. A receiving signal based upon the induced current is inputted to a signal receiving part 14 through the switch 12 and amplified in the receiving part 14 and the amplified signal is inputted to a monitoring part 16 in a monitoring control part 15. The monitoring part 16 decides a gas port from the frequency of the input signal and displays monitoring information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas leak detection device for preventing gas leaks by monitoring the opening/closing status of a main valve at a gas port in a building.

(Prior Art) Home security systems that have entered the practical stage in recent years basically consist of a sensor unit that generates a signal corresponding to the “state” of the monitored object, and a sensor unit that receives the above-mentioned signal generated by this sensor unit. A monitoring/control unit that decodes this to determine the “state” and displays it on a display device or drives an alarm device, and a transmission path that controls the transmission of signals between the sensor unit and the monitoring/control unit. We are prepared.

Generally, a signal line is used as this transmission path, but for example, in a system that monitors the locked status of sliding doors, the upper part of the sensor is attached to the movable sliding door, so the signal line is Since the lines not only get in the way when opening and closing the door, but also spoil the aesthetic appearance, conventionally, for example,
As seen in Japanese Patent No. 7891, there is an attempt to solve this problem by utilizing the interaction of electromagnetic induction.

[Problems to be Solved by the Invention] However, with this method of communicating monitoring information using electromagnetic induction interaction, it is difficult to transmit monitoring information even when the target to be monitored is a movable object such as a gas valve. However, since the resonant current of the LC parallel resonant circuit rapidly attenuates as shown by the solid line and the voltage level ■ in 7th [1N(b), as the required transmission distance increases, The reception level on the receiving side decreases, making it impossible to obtain the level necessary to process the received signal. 7, etc.), Vk, -Vk are the reception levels necessary for the above signal processing, Δt is the time required for switching the switch 12,
To is the maximum allowable processing time allowed for the above signal processing.

Therefore, in conventional devices in which the sensor section is configured with an LC parallel resonant circuit, the transmitting/receiving end of the sensor section and the transmitting/receiving end of the base unit that sends the monitoring frequency signal to this sensor section must be placed close to each other on the order of several centimeters. Instead, only a wireless range on the order of a few centimeters can be achieved.

For this reason, there is a problem that there are restrictions on the installation position of the main unit, and since one main unit is required for one sensor unit, the open/close status of the main valves of multiple gas ports can be monitored using this method. In this case, there is a problem in that the system becomes quite expensive because it requires as many base units as the number of main valves, and the number of signal lines required also increases.

This invention was made to solve the above problem.
The wireless area can be made larger than before,
An object of the present invention is to provide a gas leak detection device capable of having a plurality of gas ports in one main unit.

(Means for Solving the Problems) In order to achieve the above object, the present invention detects the open/closed state of the main valve of the gas port of the building, and turns ON10F according to the change in state.
A sensor section having a state detection switch that detects the F state, a first antenna for transmitting and receiving disposed at a location spatially separated from the location of the building where the sensor section is disposed, and a changeover switch for the first antenna. a monitoring signal generating section that supplies a monitoring frequency signal through the switch, and a monitoring/control section that receives the signal from the sensor section that the first antenna receives through electromagnetic coupling through the changeover switch. The state detection switch has a switch fixed side part having a pair of movable contacts integrally attached to the main stopper of the valve part of the gas inlet and connected by leads, and a switch fixed side part having a pair of movable contacts fixed to the valve part of the gas inlet. and a switch fixed side part each having a fixed contact that can be connected and separated, and the sensor part is equipped with the state detection switch, and also includes a capacitor and a solid body arranged on the switch fixed side part forming a parallel resonant circuit. vibrator,
and a second antenna for transmitting and receiving that receives the monitoring frequency signal by electromagnetic coupling, the state detection switch is inserted between the second antenna and the parallel resonant circuit, and the changeover switch is connected to the After the monitoring frequency signal is generated, the response signal of the sensor unit that resonates with the monitoring frequency signal is switched to the monitoring/control unit side at a timing when the response signal can be input to the monitoring/control unit through the first antenna. The monitoring/control section is configured to determine the open/closed state of the main valve based on the presence or absence of the response signal and output it, as well as to control switching of the changeover switch.

In the second aspect, when there are a plurality of gas ports to be monitored and a plurality of sensor sections, the monitoring signal generating section cyclically sends out frequency signals having different frequencies at predetermined intervals, Each of the sensor sections is configured to resonate with one of the frequencies of the frequency signals, and the monitoring/control section identifies the monitored object and its state from the frequency of the response signal and the presence or absence of the signal.

Further, in claim 3, the switch fixed side portion of the status switch has a shape consisting of a flat box-shaped cover body with a lower opening that is tightly fitted onto the main stopper, and a flange portion of the cover body that spreads from the above-mentioned opening. and a pair of movable contacts are provided at the boundary between the two, and the switch fixed side part has a hole through which the movable contact mounting part of the cover body covering the main stopper projects so as to be slidable and rotatable. , a non-planar plate body fixed to a gas valve part with a band covering a part of the valve part, and a pair of fixed contacts are provided on the peripheral end surface of the hole.

[Effect]

In this invention, when the main valve of the gas port valve is closed, the switch fixed side part of the status detection switch rotates integrally with the main valve, and the LCX parallel resonant circuit consisting of the second antenna, the capacitor, and the solid-state resonator is connected. Since the L is closed, the monitoring frequency signal received through the second antenna
The CX parallel resonant circuit resonates, and a response signal due to the resonant current is received by the first antenna through electromagnetic coupling. When the state detection switch is open, the second antenna is disconnected and the response signal is not generated. The response signal received via the first antenna is input to the monitoring/control circuit, so that the monitoring/control circuit detects the open/closed state of the main valve based on the presence of this response signal. In addition, if there are multiple gas ports and multiple sensor units, each sensor unit resonates at its assigned frequency, so the condition can be detected from the presence or absence of a response signal, and the monitored target can be identified from the frequency. be done.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Fig. 1, ■ is a display panel, which has a display section 2 that displays the open/closed state of the main valves of the gas ports installed on each floor of the building, and inside is a main unit (Fig. 5), which will be described later. is provided. Display section 2 No., 3+, No.
3z, No, 3z, . . . are segmented displays that display the open/closed states of the main valves of the respective gas ports, and when the main valves of the corresponding gas ports are open, the light emitting elements inside light up.

13 is a loop antenna for transmitting and receiving, and 18 is an antenna for transmitting and receiving, both of which will be described later.

Reference numeral 3 shows one example of the gas port, and as shown in FIG. 2, a switch fixed side portion 5 of a state detection switch 7 constituting the sensor portion 4 is attached to the valve portion 3A. As shown in FIG. 3, this switch fixed side part 5 is a plate made of an insulating member and has an arcuate shape when viewed from the end, and has a hole 5A in the center. Contacts E1 and E2 are attached at opposite positions with the center of the hole in between.

6 is a switch fixed side part of the state detection switch 7,
It has an insulating flat box-shaped cover body 6A that is placed over the main stopper 3B of the valve part 3A, and a flange part (sliding part) 6B that spreads from the open end of the cover body 6A.
The fixed contacts EAI and E are provided at the boundary between A and the flange 6B.
Movable contact EBI that can contact A2, EB2 is lead 6C
are connected and arranged.

To install the condition detection switch chia consisting of the switch fixed side part 5 and the switch fixed side part 6, the cover body 6A of the switch fixed side part 6 is fitted onto the main valve 3B, and the flange part 6B is attached to the valve part 3A.
After contacting the outer surface of the switch, press the hole 5A of the switch fixed side part 5.
Then, the upper half of the valve part 3A is covered from above the collar part 6B by passing through the part of the main stopcock 3B covered by the cover body 6A, and the two bands 8 are attached to the valve part 3A. In this attached state, when the main valve 3B is in the "closed" state, as shown in FIG. When in the "open" state, as shown in Figure 4(b), the contact EA
I and EBI are separated, and contacts EA2 and EB2 are also separated.

On the switch fixed side part 5, a crystal oscillator 20 and a capacitor (capacitance C2) 19 electrically connected in parallel are housed in a case 9, and one end of this parallel circuit is connected to the electrode EAI. The other end of the antenna 18 is connected to one end of the antenna 18, and the other end of the antenna 18 is connected to the electrode EA2.

The sensor unit 4, which includes a state detection switch 7, a crystal oscillator (X) 20, an antenna 18, and a capacitor 19, has a sixth
As shown in the figure, an LCX parallel resonant circuit is constructed.

As shown in FIG. 5, the base unit described above has a monitoring signal transmitter 11, and can output different frequencies f, f2, f2, by switching the oscillation circuit or by performing frequency modulation.
Monitoring frequency signals of f3 . 14 is a signal receiving section which takes in the received signal received by the loop antenna 13 via the changeover switch 12, performs signal amplification, etc., and inputs it to the monitoring section 16 of the monitoring/control section 15. I7 is a control section.

41.4□, 43...4.1 is the sensor section 4 described above
The sensor part has the same configuration as the gas port 37.3□
, 33...3o.

71.72.73...7o is a state detection switch having the same configuration as the state detection switch 7. Note that the sensor section 4
1.4□, 43...4. The LCX parallel resonant circuit of l has frequencies f+ and f of the frequency signal sent out by the signal sending unit 11.
z, ri...L so that they resonate at fn, respectively.
The values of x, Cz and X have been chosen.

The control section 17 of the monitoring/control section 15 controls starting and stopping of the signal sending section 11, and also attenuates the response signal from the sensor section every time the signal sending section 11 sends out a frequency signal for monitoring. The switching switch 12 is in charge of switch opening/closing control to switch the switching switch 12 to the signal receiving section 14 side immediately before the switch is switched. Furthermore, the monitoring section 16 of the monitoring control section 15 monitors the output of the signal receiving section 14, identifies the state of the monitored object for each monitored object from the presence or absence of a response signal and the frequency, and displays the corresponding light emitting element of the display section 2. Performs lighting/extinguishing control.

The loop antenna 13 in this embodiment is placed on the ceiling or wall of a room, and the antenna 18 is attached to or embedded in the wall of the room.

In this configuration, the frequency ft is transmitted from the signal sending section 11.
, fz, f3 ... f7 monitoring frequency signals are cyclically transmitted at predetermined time intervals, and the loop antenna 13
It oscillates sequentially and cyclically from

Now, the main valve 3B of the gas port 37 equipped with the sensor section 47 that resonates at frequency f7 is rotated to the "closed" position, the state detection switch 7fi is closed, and the main valves of the other gas ports are set to the "open" position. Suppose there is. Frequency f1, f, , f, ... f7
-1 monitoring frequency signal is being sent from the signal sending section 11, the sensor sections 45.4□, 4. ...4□1 is each status detection switch 1.72.73...
- 711-1 is open, so it does not work. Sensor part 4. ．． is the state detection switch 71. is a closed circuit, so the antenna 18 and the loop antenna 13 are coupled to each other, but do not perform resonance operation.

When the monitoring frequency signal of frequency r, is sent out from the signal sending section 11 and oscillated from the loop antenna 13, the changeover switch 12 is moved to the signal receiving section 14 side (contact side) at a timing synchronized with the end of oscillation. Can be switched. The sensor unit 4, which receives the monitoring frequency signal oscillated from the loop antenna 13, resonates in parallel, and the resonant current flows through the antenna 1.
8, this generates an alternating magnetic flux, and the antennas 18 and 13 are electromagnetically coupled through the mutual inductance M, causing an induced current to flow in the antenna 13. That is, a response signal generated in the sensor section 4 in response to the monitoring frequency signal is received by the antenna 13 by electromagnetic coupling, and this received signal is inputted to the signal receiving section 14 through the changeover switch 12, where it is amplified. It is then supplied to the monitoring section 16 of the monitoring/control section 15. The monitoring unit 16 determines the gas port to which this frequency is assigned from the frequency of the input received signal,
The state of the gas port LJt (in this case, the main valve 3B is in the “closed” state B)
) is sent to the corresponding light emitting element of the display section 2, and the light emitting element is turned on.

At the timing when the above-mentioned signal processing/discrimination processing in the monitoring section 16 is completed, the control section 17 switches the changeover switch 12 to the signal sending section 1 side (contact a side), and the signal generating section 11 switches to the monitoring frequency f. Send out a frequency signal.

By the way, as described above, the resonant current of the LC parallel resonant circuit is rapidly attenuated, but the resonant current of the LCX parallel resonant circuit is, as shown in FIG. 7(a), due to the presence of the crystal oscillator 20. The attenuation becomes gentler than in the case of the LC parallel resonant circuit, and the time To required for the attenuation to reach a receivable critical level becomes longer.

In addition, since the LCX parallel resonant circuit has a high Q, the resonant waveform becomes sharp, and the frequency band required to identify the received response signal is narrow, so multiple response signals in different frequency ranges can be identified without interference. Things become easier.

Therefore, according to this embodiment, the sensor parts 41.4□, 43
...4, the distance between the loop antennas 13 can be increased to, for example, several meters, and it is easy to identify the frequencies of multiple types of response signals within a narrow band. The sensor part can be held on a holder.

Note that although a crystal resonator is used in the sensor section of the above embodiment, any resonator with a high Q may be used.

〔Effect of the invention〕

As explained above, this invention is equipped with a state detection switch having a contact point that turns ON/OFF according to the rotation of the main valve, and a state detection switch having a parallel resonant circuit consisting of a solid vibrator and a capacitor, in the valve part of the gas inlet. At the same time, an antenna is provided which is connected to the parallel resonant circuit through the state detection switch, and the response signal from the sensor section to the monitoring frequency signal is generated by the LCX parallel resonant circuit, thereby achieving a response with a low attenuation rate. Since the signal can be generated, the installation distance of the parent unit to the sensor section can be increased compared to the conventional method, which increases the degree of freedom regarding the installation location of the parent unit compared to the past. It is possible to realize a system with multiple sensor units, and to detect gas leaks from gas ports in buildings at a lower cost than in the past.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram showing an embodiment of this invention;
The figure is a side view of the sensor unit attached to the gas port in the above embodiment, Figure 3 is a perspective view of the sensor unit before assembly, and Figures 4 (a) and (b) are for detecting the state of the sensor unit, respectively. A diagram showing the closed and open states of the switch, FIG. 5 is a circuit configuration diagram of the above embodiment, FIG. 6 is a diagram showing an example of the circuit of the main part in the above embodiment, and FIG. 7(a) is the above embodiment. FIG. 7(b) is a waveform diagram of a conventional response signal. 3.3I, 3□, 33...3. l-Gas port, 3A-
Valve part, 3B-main valve, 4.4I, 4□, 43...4,, - sensor part, 5
-Switch fixed side part, 5A-hole, 6-switch fixed side part, 6A-cover body, 6B---flange part, 6C lead, 7.71.7□, 73...7. , - Condition detection switch. No. 11 sending unit, 12-switch switch, 1 antenna, 14--signal receiving unit, 15 control unit, 1
6-monitoring unit, 17-control unit, 2 antennas, 19-capacitor, 20 actuator. EAI, E^2, EBI, E B2
= contact point.

Claims (3)

[Claims] (1) A sensor unit with a status detection switch that detects the open/closed status of the main valve of the gas inlet of the building and turns it on/off according to the change in status, and is spatially separated from the location in the building where the above sensor unit is installed. a first antenna for transmitting and receiving disposed at a location where the signal is received; a monitoring signal generator that supplies a monitoring frequency signal to the first antenna via a changeover switch; and the first antenna receives the signal through electromagnetic coupling. and a monitoring/control unit that receives signals from the sensor unit via the changeover switch, and the state detection switch is provided with a pair of leads connected to the valve main valve of the gas port. The switch includes a movable side portion having a movable contact and a fixed side portion of the switch that is fixed to the valve portion of the gas port and has a fixed contact that can connect and separate from the pair of movable contacts, and the sensor portion includes the state detection switch. In addition, it has a capacitor and a solid-state resonator that form a parallel resonant circuit and are disposed on the fixed side part of the switch, and a second antenna for transmitting and receiving that receives the monitoring frequency signal by electromagnetic coupling,
The state detection switch is inserted between the second antenna and the parallel resonant circuit, and the changeover switch detects a response signal of the sensor unit that resonates with the monitoring frequency signal after the monitoring frequency signal is generated. is switched to the monitoring/control unit side at a timing when the signal can be input to the monitoring/control unit through the first antenna, and the monitoring/control unit determines the open/closed state of the main valve from the presence or absence of the response signal. A gas leak detection device characterized in that it outputs an output and also controls switching of the changeover switch. (2) When there are multiple gas ports and multiple sensor units, the monitoring signal generation unit cyclically sends out frequency signals with different frequencies at predetermined intervals, and each sensor unit Claim characterized in that the monitor resonates with any one frequency of the monitoring frequency signal, and the monitoring/control unit identifies the monitored object and its state from the frequency of the response signal transmitted by the sensor unit and the presence or absence of the signal. 1. The gas leak detection device according to 1. (3) The switch movable side part has a shape consisting of a flat box-shaped cover body with a lower opening that is tightly fitted to the outside of the main stopcock, and a flange part of the cover body that spreads from the above-mentioned opening, and the boundary between the two parts. A pair of movable contacts are provided in the gas port valve part, and the switch fixing part has a hole through which the movable contact mounting part of the cover body covering the main valve protrudes so as to be able to slide and rotate. 3. The gas leak detection device according to claim 1, wherein the gas leak detection device is a non-planar plate body fixed with a band so as to cover a part of the hole, and a pair of fixed contacts are provided on the peripheral end surface of the hole.