JP2002269657A - Gas alarm device and inspection mechanism therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas alarm device allowing easy and certain operation inspection in a short time and to provide an inspection mechanism therefor. SOLUTION: This gas alarm device has an alarm mechanism 12 executing alarm operation when a detection output outputted by detecting the presence of a detected gas exceeds an alarm level of a prescribed output. In the gas alarm device, an alarm inspection level is set such that the alarm mechanism 12 executes the alarm operation when the detection output exceeds an alarm inspection output lower than the prescribed output in normal gas detection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas alarm device provided with an alarm mechanism which operates when a detection output for detecting the presence of a gas to be detected exceeds a predetermined output alarm level, and a check mechanism thereof.

[0002]

2. Description of the Related Art Heretofore, as this type of gas alarm, there has been known a gas alarm using a gas detection mechanism for obtaining a detection output of a gas to be detected as an inspection mechanism as it is. That is,
For example, in a gas alarm provided with a gas detection circuit in which a gas detection element is incorporated in a bridge circuit, a bridge output from the gas detection circuit is obtained as a detection output of a gas to be detected, and the detection output is a predetermined output. If a gas detection mechanism is provided that causes the alarm device to sound an alarm, notify a warning message, or flash an alarm lamp when the alarm level is exceeded, the gas alarm The inspector supplies a gas to be detected to the gas detection element incorporated in the gas detection circuit, or a gas for inspection in which the gas detection element has the same gas detection capability as the gas to be detected, The gas detection mechanism is operated as an inspection mechanism to check the gas detection operation of the gas detection element, the output of the gas detection circuit, and the operation of the alarm device. It is being carried out. Note that such an inspection operation is often performed when the power of the gas alarm is turned on.

[0003]

However, when performing such an inspection operation, it is rare that an inspector has a gas to be detected having an appropriate concentration as the inspection gas.
For gas alarms that detect hydrocarbon gas, such as city gas alarms, isobutane gas or the like filled in the lighter is often used in such cases. The gas supplied is very dense. On the other hand, in order for the inspector of the gas alarm device to quickly activate the alarm mechanism of the gas alarm device, the supplied inspection gas quickly reaches the vicinity of the gas detection element, and the gas detection element is used for inspection. Gas must be contacted.

Then, since a rich gas is rapidly supplied, a large amount of inspection is performed in the vicinity of the gas detection element after the supply of the inspection gas until the output from the gas detection element is obtained. Supply gas will be supplied. Then, even if the alarm mechanism starts operating by the output from the gas detection element, the inspection gas supplied in the vicinity of the gas detection element does not easily diffuse and dissipate. Will last for Then, even if the alarm mechanism is activated in a short time, it will take a long time before the operation is stopped. In addition, when the inspection gas is adsorbed by other members in the gas alarm device such as an interfering gas filter and is gradually diffused and supplied to the gas detection element, such a phenomenon appears more remarkably.

[0005] Further, even when another inspection gas is used for another gas alarm, the same situation exists, and a similar tendency may be observed.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a gas alarm device capable of easily and reliably inspecting the operation of the gas alarm device in a short time in view of the above-mentioned disadvantages, and an inspection mechanism for the gas alarm device.

[0007]

To achieve this object, the inspection mechanism according to the present invention is characterized in that an alarm operation is performed when a detection output detecting the presence of a detected gas exceeds an alarm level of a predetermined output. In the inspection mechanism of a gas alarm device having an alarm mechanism, an alarm that causes the alarm mechanism to perform an alarm operation when the detection output exceeds an alarm inspection output lower than the predetermined output when performing normal gas detection. An inspection level is set (corresponding to claim 1), and an alarm mechanism that operates when a detection output detecting the presence of the detected gas exceeds an alarm level of a predetermined output is provided. In the inspection mechanism of a gas alarm device including a preliminary alarm mechanism that operates a preliminary alarm when a detection output that has detected the presence of a predetermined alarm exceeds a preliminary alarm level of a preliminary alarm output lower than the predetermined output, When the intellectual output exceeds an inspection output lower than the predetermined output when performing normal gas detection, an alarm inspection level for causing the alarm mechanism to perform an alarm operation is set, and the gas detection output is set to the inspection output. When a pre-alarm check output lower than the output and lower than the pre-alarm output is exceeded, a pre-alarm check level at which the pre-alarm mechanism operates a pre-alarm is set (corresponding to claim 2).

Further, it is preferable that the inspection mechanism stops the alarm operation when the detection output falls below the alarm inspection level after detecting that the detection output has exceeded the alarm inspection level ( After detecting that the detection output has exceeded the preliminary alarm inspection level, when the detection output falls below the preliminary alarm inspection level, the preliminary alarm operation may be stopped ( (Corresponding to claim 4).

In order to achieve the above object, a gas alarm device according to the present invention comprises the above-mentioned inspection mechanism, and when the detection output exceeds the preliminary alarm inspection level, the preliminary alarm inspection level is set to a preliminary alarm. A level resetting mechanism for a preliminary alarm check output set to the output may be provided (corresponding to claim 5), and when the detection output at the start of operation of the check mechanism exceeds the alarm check output, A level change mechanism for setting an alarm check level to the predetermined output, and a level change for setting the preliminary alarm check level to a preliminary alarm output when a detection output at the start of operation of the check mechanism exceeds a preliminary alarm check output. A mechanism may be provided (corresponding to claims 6 and 7). Further, after the power is turned on, the inspection mechanism is operated after a first predetermined time has elapsed, and the inspection mechanism is stopped after a second predetermined time has elapsed. Preferably includes a control unit that (corresponding to claim 8).

[Effects] That is, the inspection mechanism causes the alarm mechanism to perform an alarm operation when the detection output exceeds an alarm inspection output lower than the predetermined output when performing normal gas detection. Therefore, the output that must be increased before the alarm mechanism starts the alarm operation is low, and the alarm inspection output is reached in a short time and the alarm is activated, and the amount of inspection gas that is supplied within that time Is also reduced. Therefore, the inspection gas used for the inspection of the gas alarm device is diffused, and it does not take a long time for the detection output to decrease to a level at which the alarm operation is not required, and the inspection work proceeds promptly. It becomes possible (corresponding to claim 1). In addition, a detection output that detects the presence of the detected gas includes an alarm mechanism that performs an alarm when the detection output exceeds a predetermined output alarm level, and the detection output that detects the presence of the detection gas is higher than the predetermined output. As described above, in the inspection mechanism of a gas alarm device having a preliminary alarm mechanism that performs a preliminary alarm operation when the preliminary alarm level of the low preliminary alarm output is exceeded, both the alarm operation and the preliminary alarm operation are performed for a small number of inspections. Since the inspection can be performed with the gas amount, the inspection can be quickly performed (corresponding to claim 2).

Further, after detecting that the detection output has exceeded the alarm check level, when the detection output falls below the alarm check level, the alarm operation is stopped (corresponding to claim 3). Alternatively, similarly, after detecting that the detection output has exceeded the preliminary alarm inspection level, when the detection output falls below the preliminary alarm inspection level,
If the preliminary alarm operation is stopped (corresponding to claim 4),
After the alarm mechanism and the preliminary alarm mechanism start alarming and the preliminary alarming operation by the inspection mechanism, the alarming mechanism and the preliminary alarming mechanism can be reliably stopped, and it is possible to confirm until the alarming operation stops. Therefore, it was possible to provide a gas alarm device capable of completing inspection work quickly and reliably.

Further, when the detection output exceeds the preliminary alarm inspection level, a preliminary alarm inspection output level resetting mechanism for setting the preliminary alarm inspection level to the preliminary alarm output is provided. The detection output required before the start of the alarm operation is the preliminary alarm inspection output, whereas the alarm stop mechanism of the preliminary alarm operation operates on the preliminary alarm output. The alarm stop mechanism operates without waiting for the output to drop to the inspection output, and the inspection can be completed quickly (corresponding to claim 5). Similarly, when the detection output exceeds the alarm check output, the alarm check level can be reset to a predetermined output. However, in this case, if the gas concentration for inspection does not reach the alarm level, the alarm stop mechanism works immediately, and it is difficult to determine whether or not the alarm operation has been stopped based on the detection output. Since there is a problem, it is desirable to separately provide means for confirming that the detection output once exceeds the predetermined output.

The detection output at the start of operation of the inspection start mechanism exceeds the output level for inspection, or the detection output at the start of operation of the inspection start mechanism exceeds the output level for preliminary alarm inspection. In this case, according to the above-described setting, an alarm operation or a preliminary alarm operation is started at the same time as the start of the inspection. However, in the alarm operation thus started, the detection output is normally transmitted to the alarm mechanism. I can't confirm that it was done. On the other hand, in the case described above, if the alarm check output level is set to a predetermined output, or if a level change mechanism that sets the preliminary alarm check level to the preliminary alarm output level is provided,
If the alarm operation or the preliminary alarm operation may be started at the same time as the start of the inspection, the output required for the operation start will be changed to a higher setting by the level change mechanism. It is difficult to cause any inconvenience (corresponding to claims 6 and 7). In particular, the preliminary alarm check level works effectively because it may be set considerably lower than the detection output corresponding to the gas concentration requiring a normal alarm. The setting change of the preliminary alarm inspection level can be set to an arbitrary value between the preliminary alarm output and the preliminary alarm inspection output. This is advantageous because it increases the certainty of preventing the occurrence of the error, and makes it easier to control by reducing the set value.

Further, if a control unit is provided which activates the inspection mechanism after a lapse of a first predetermined time after turning on the power and stops the operation of the inspection mechanism after a lapse of a second predetermined time (corresponding to claim 8), Predetermined output level, preliminary alarm output level,
Inspection can be started and ended by reliably switching between the output level for inspection and the output level for preliminary alarm inspection. By providing a first predetermined time after the power is turned on, it is possible to secure an initial stable operation with respect to energization of the gas detection element. It is not necessary to change the setting in which is operated to the setting at the time of normal gas detection, and it is possible to prevent the reliability of the gas detection at the normal time from being impaired due to human error. In addition, the second predetermined time, after the operation of the inspection mechanism, the inspection worker may supply a gas for inspection to the gas alarm device, it is sufficient to set a sufficient time to perform an operation inspection of the gas alarm device, It is set to a predetermined time usually set within 5 minutes.
The operation of the inspection mechanism is such that, instead of the operation timing being automatically set based on power-on, an inspection switch is provided in the gas alarm device, and the inspection is started by the inspection switch. You can do it.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the gas alarm device of the present invention has a sensitive layer 2 formed by sintering a metal oxide semiconductor such as a tin oxide semiconductor on a noble metal wire coil 1 such as platinum, palladium, and platinum-rhodium alloy. The so-called hot-wire semiconductor gas detection element 3 is incorporated in a bridge circuit 4 or the like as shown in FIG. 2, and the bridge voltage is obtained as a detection output of the gas to be detected by a detection mechanism 11 provided in the control unit 5. Alarm mechanism 12 provided in the control unit 5
The auxiliary alarm mechanism 13 can output an alarm to an alarm device 6 such as an alarm buzzer or an alarm lamp.

The control unit 5 includes a detection mechanism 11 which obtains the bridge voltage and transfers it as a detection output corresponding to the gas concentration of the gas to be detected, and a detection output from the detection mechanism 11 during a normal gas detection operation. , An alarm mechanism 12 and a preliminary alarm mechanism 13 for alarming the alarm device 6 are provided. Accordingly, during a normal gas detection operation, when the gas to be detected reaches the sensitive layer 2, the detected gas undergoes an oxidation reaction, a reduction reaction, and the like, and electrons are transferred to and from the sensitive layer 2. Since the apparent resistance value of the layer 2 changes and the resistance value of the entire gas detection element as a combined resistance also changes, the change in the resistance value is regarded as a detection output. Since the magnitude of the detection output depends on the concentration of the gas to be detected, the concentration of the gas to be detected is determined based on the detection output, and whether or not an alarm output is issued can be controlled.

Normally, when the detected output is lower than the alarm level of the predetermined output and exceeds the auxiliary alarm level of the auxiliary alarm output, the controller 5 activates the auxiliary alarm mechanism 13 to perform a preliminary alarm operation. If the output exceeds the alarm level of the predetermined output, the alarm mechanism 12 is operated to perform an alarm operation. Here, for the alarm level, for example, a detection output can be set such that it is determined that the concentration of the gas to be detected such as methane gas and carbon monoxide gas is high enough to affect the human body, For example, in the case of a city gas alarm, an output for a gas corresponding to 1/4 of the LEL concentration of the city gas can be set as the predetermined output. The preliminary alarm level includes
If the concentration of the gas to be detected further increases, such as 1/2 or 1/3 of the predetermined output, it is possible to set a detection output which is considered to possibly reach the predetermined output.
An output for gas corresponding to 1/10 of the LEL concentration of city gas can be set as the preliminary alarm output.

The control unit 5 has an inspection mechanism 14. When the power of the gas alarm is turned on, a timer operates, and after a lapse of a predetermined time, the inspection mechanism 14 operates. A preliminary alarm check level set to the output, an alarm check level set to the alarm check output instead of the alarm level of the predetermined output is set, and the detection output from the detection mechanism is set to the preliminary alarm level or the alarm. Regardless of the level, the operation of the preliminary alarm mechanism and the alarm mechanism is controlled by the preliminary alarm inspection output and the alarm inspection output. The preliminary alarm inspection output level, the preliminary alarm inspection output of the inspection output level, the value of the alarm inspection output, respectively, based on the preliminary alarm output, the predetermined output,
The output value can be set appropriately to 1/2, 1/3, or the like.

If the gas detection output initially obtained when the gas alarm is turned on exceeds the preliminary alarm check output, the preliminary alarm check output level is set to the preliminary alarm check output. A change mechanism 15 is provided, and when the detected gas concentration in the atmosphere is high at the start of the inspection and a relatively high gas detection output is obtained, a normal preliminary alarm output level or a detection output of a predetermined output level is used to generate a preliminary alarm. Also, it is configured to check whether the alarm operation is switched from the non-operation state to the operation state.

Further, when the detection output exceeds a preliminary alarm inspection level set as the preliminary alarm inspection output, a preliminary alarm inspection output level resetting mechanism 16 for setting the preliminary alarm inspection level to the preliminary alarm output is provided. Once the operation of the preliminary alarm is confirmed, the preliminary alarm check level is immediately made to match the preliminary alarm level, eliminating unnecessary alarm operation, enabling the alarm operation to be completed quickly, and the normal gas detection state. Set so that malfunction does not occur even when shifting to.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings based on an example in which the above-mentioned gas alarm is inspected using a gas lighter. In the present embodiment, the control unit 5 is provided with an inspection end mechanism 17 and is turned on 24 hours after the power is turned on.
0 seconds later, the inspection end mechanism 17 operates, resets the preliminary alarm level in place of the preliminary alarm inspection level, and resets the alarm level in place of the alarm inspection level. The operation of the alarm mechanism 13 and the alarm mechanism 12 is controlled. Timer 7
, A pulse voltage is applied to the gas detection element 3 at intervals of 10 seconds after the power is turned on, and a bridge voltage is obtained as a detection output for detecting a gas to be detected. The control unit 5 controls the operation of the alarm mechanism 12 and the like every time the detection output is detected. In addition, as a preliminary alarm operation, the green LED that is normally lit to indicate the energized state flashes and blinks, and as a warning operation, the red LE that is normally unlit is turned off.
D is turned on and an alarm sound is emitted from an alarm buzzer. These LEDs and alarm buzzers are collectively referred to as alarm devices.

As shown in FIG. 3, when the gas alarm of the present invention is turned on, the timer 7 starts operating and
The energization control to obtain an output by energizing the gas detection element 3 every 0 seconds is started. At the start of energization, the gas detection circuit 4
Since the output stability may be lacking, for example, the surface of the sensitive layer 2 of the gas detection element 3 may be dirty, the detection mechanism 11 and the inspection mechanism 14 must be put on standby and inspection should not be started for 30 seconds. , The green LED blinks. 30 seconds after the power is turned on, the green LED is turned on, and the inspection mechanism 14 is operated. 30
If the detection output at the second does not reach the preliminary alarm inspection level of the preliminary alarm inspection output, the preliminary alarm inspection output is set to the preliminary alarm inspection level. Here, when the power of the gas alarm is turned off and on after the gas leak alarm, as shown in FIG. 4, the detection output at 30 seconds may rarely reach the preliminary alarm inspection output, as shown in FIG. In such a case, the preliminary alarm check level is replaced with the preliminary alarm output.

After checking that the green LED is turned on, the inspection worker can check the raw gas from the gas lighter through the ventilation opening or slit provided in the gas detection element 3 of the gas alarm. (About 40 in FIG. 3).
Then, the detected gas concentration near the gas detecting element 3 rises to the preliminary alarm check level at about 45 seconds. Further, the concentration of the gas to be detected increases,
At the second, the green LED starts blinking to confirm the preliminary alarm check operation because it is higher than the preliminary alarm check level and lower than the alarm check level. Usually, at this point, the inspection operator stops supplying the raw gas. Further, at this time, when the detected output exceeds the preliminary alarm inspection level, the preliminary alarm inspection level is set to the preliminary alarm output by the preliminary alarm inspection output level resetting mechanism.

After a further time, the supplied raw gas gradually enters the gas alarm device, and the concentration of the gas to be detected near the gas detecting element 3 further increases. At the time point of 60 seconds, the detection output that has detected the presence of the raw gas has exceeded the predetermined output, so the alarm stop mechanism 18 causes the alarm mechanism 12 to perform an alarm operation. Then, the alarm buzzer sounds and the red LED lights. At the same time, the blinking of the green LED as a preliminary alarm stops.

Thereafter, when a further time elapses, the raw gas entering the gas alarm device gradually diffuses and escapes outside the gas alarm device, and the raw gas concentration in the gas alarm device becomes:
It gradually begins to decrease (at about 100 seconds in FIG. 3). In the figure, the raw gas concentration falls below the alarm check level at 120 seconds. Then, the inspection mechanism 14 stops the alarm operation of the alarm mechanism 12. At the same time, here, the preliminary alarm check level is set to the preliminary alarm output, and since it matches the alarm check level, the state returns to the normal operation without taking the preliminary alarm operation and the green LED is lit. become. At 240 seconds thereafter, the inspection mechanism 14 stops,
The detection output is set at an alarm level instead of the alarm check level, and the setting is carried over so as to perform normal gas detection that can perform an alarm operation on the detected gas. As a result, it can be seen that the alarm operation at the time of the inspection operation of the gas alarm lasts only about one minute, and the inspection operation can be performed quickly.

When the level reset mechanism 16 for the preliminary alarm check output operates in the above description, in FIG. 4, the preliminary alarm check level is set to the preliminary alarm output at the time of normal gas detection.
Since the alarm check level is reset to the predetermined output level, the same check operation as the conventional check operation can be performed. Here, since the initial gas concentration is high, the amount of raw gas supplied at the time of inspection is not so different from the previous example, and it can be seen that the alarm operation at the time of inspection is within about 1 minute.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a gas detection element.

FIG. 2 is a schematic diagram of a gas detection device of the present invention.

FIG. 3 is a diagram showing an output transition during inspection of a gas alarm.

FIG. 4 is a diagram showing an output transition at the time of inspection of a gas alarm device when a level change mechanism operates.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Detection mechanism 12 Alarm mechanism 13 Preliminary alarm mechanism 14 Inspection mechanism 6 Alarm device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Hashimoto 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Takashi Abe 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka No. 1-2 Inside Osaka Gas Co., Ltd. (72) Inventor Yuki Tateishi 2-5-4 Mitsuya Naka, Yodogawa-ku, Osaka-shi, Osaka Inside New Cosmos Electric Co., Ltd. (72) Inventor Yuji Sakai, Mitsuya, Yodogawa-ku, Osaka-shi 2nd-5-4 Shin-Cosmos Electric Co., Ltd. F-term (reference) 5C086 AA02 BA01 CA02 CB12 DA07 DA10 DA12 DA13 DA19 DA20 EA13 EA50

Claims (8)

[Claims] An inspection mechanism of a gas alarm device including an alarm mechanism that operates when a detection output detecting the presence of a detected gas exceeds an alarm level of a predetermined output, wherein the detection output includes: An inspection mechanism for setting an alarm inspection level for causing the alarm mechanism to perform an alarm operation when an alarm inspection output lower than the predetermined output when performing normal gas detection is exceeded. 2. An apparatus according to claim 1, further comprising: an alarm mechanism for operating when a detection output detecting the presence of the gas to be detected exceeds an alarm level of a predetermined output. An inspection mechanism of a gas alarm device including a preliminary alarm mechanism that operates a preliminary alarm when a preliminary alarm level of a preliminary alarm output lower than an output is exceeded, wherein the detection output is a normal gas detection. When an inspection output lower than the predetermined output is exceeded, an alarm inspection level for causing the alarm mechanism to perform an alarm operation is set,
When the gas detection output exceeds a preliminary alarm inspection output lower than the inspection output and lower than the preliminary alarm output, an inspection mechanism that sets a preliminary alarm inspection level at which the preliminary alarm mechanism operates a preliminary alarm. 3. The alarm operation is stopped when the detection output falls below the alarm inspection level after detecting that the detection output has exceeded the alarm inspection level.
Inspection mechanism described in. 4. The pre-alarm operation according to claim 2, wherein the pre-alarm operation is stopped when the detection output falls below the pre-alarm inspection level after detecting that the detection output has exceeded the preliminary alarm inspection level. Inspection mechanism. 5. An inspection mechanism according to claim 2, wherein when the detection output exceeds a preliminary alarm inspection level,
A gas alarm having a preliminary alarm inspection output level resetting mechanism for setting the preliminary alarm inspection level to a preliminary alarm output. 6. An inspection mechanism according to claim 1, wherein when the detection output at the start of operation of the inspection mechanism exceeds the alarm inspection output, the alarm inspection level is changed to the predetermined output. Gas alarm with level change mechanism to set. 7. An inspection mechanism according to claim 2 or 4, wherein when the detection output at the start of operation of the inspection mechanism exceeds the preliminary alarm inspection output, the preliminary alarm inspection level is set to the preliminary alarm output. Gas alarm with a level change mechanism. 8. The control unit according to claim 5, further comprising a control unit that activates the inspection mechanism after a first predetermined time has elapsed after the power is turned on, and stops operation of the inspection mechanism after a second predetermined time has elapsed. The gas alarm described.