JP4219304B2 - Gas alarm - Google Patents

Description

  The present invention relates to a gas alarm device that performs an alarm operation when a detection output that detects the presence of a gas to be detected exceeds a predetermined alarm operation level.

It is preferable that a gas alarm for detecting and notifying a gas leak or the like is periodically inspected in order to operate properly. Conventionally, as this type of gas alarm device, one that performs inspection using a gas detection means for detecting the presence of a gas to be detected as it is is known.
That is, for example, an inspector of a gas alarm device having a gas detection means and a notification means supplies to this gas detection means a gas to be detected or an inspection gas having a gas detection capability equivalent to this gas to be detected. Thus, the gas detection operation of the gas detection means and the notification operation of the notification means are confirmed.

  When performing such inspection operations, for gas alarms that detect hydrocarbon gas, such as city gas alarms, isobutane gas filled in lighters that are easily available as inspection gas by the inspector Is often substituted. Since such a gas is very rich, at the start of inspection, a rich gas is rapidly supplied to the gas detection means in a short time, and the alarm means starts to operate quickly. However, the supplied inspection gas is not easily diffused and dissipated, and the alarm operation is continued for a long time. Then, even if the alarm means is activated in a short time, it will take a long time to wait for the operation to stop, and the inspection time will not be shortened. In addition, when the inspection gas is adsorbed to other members in the gas alarm device such as an interference gas filter and gradually diffused and supplied to the gas detection means, such a phenomenon appears more remarkably.

  In response to such a problem, the inventor of the present application has proposed a gas alarm device and an inspection mechanism thereof that can easily and reliably check the operation of the gas alarm device in a short time (for example, Patent Document 1). This is because, for example, in a gas alarm device having an alarm mechanism that operates when a detection output that detects the presence of a gas to be detected exceeds a predetermined output alarm output during normal operation, the detection is performed during an inspection operation. The alarm inspection level is set so that the alarm mechanism performs an alarm operation when the output exceeds an alarm inspection output lower than the predetermined output when performing normal gas detection. In other words, the output that must be raised before the alarm mechanism starts the alarm operation is low, the alarm inspection output is reached in a short time and the alarm operation is performed, and the amount of inspection gas supplied within that time is also small Become. Therefore, the inspection gas used for the inspection of the gas alarm device diffuses, and it does not take a long time for the detection output to drop to a level where the alarm operation is unnecessary, and the inspection work proceeds quickly. It will be possible.

Japanese Patent Laid-Open No. 2002-269657 (page 2-3, FIGS. 3, 4)

  However, in order to prevent inspection gas from adhering to interference gas filters etc. using activated carbon and deactivating this activated carbon, an inspection gas injection hole is provided on the side, and interference gas is provided on the ceiling. In some cases, a gas sensor element is covered with a cap provided with a filter. In this case, the inspection gas can be guided to the gas sensor element inside the cap from the injection hole provided on the side surface of the cap without going through the interfering gas filter. Deteriorate. As a result, the time until the inspection gas diffuses and falls below the alarm inspection level shown in Patent Document 1 also becomes longer. For this reason, the alarm operation continues for a long period of time. Since this alarm operation is often accompanied by an alarm sound, for example, if such an alarm sound lasts for 2 to 3 minutes, the user is also anxious.

  This invention is made | formed in view of the said subject, and is providing the gas alarm device which can perform operation | movement inspection in a short time.

  Furthermore, the characteristic configuration of the gas alarm device according to the present invention for achieving the above object is that an alarm is activated when a detection output that detects the presence of a gas to be detected exceeds an alarm operation level, When a low preliminary alarm operation level is exceeded, a preliminary alarm is activated. In a normal operation state, an alarm level is set as the alarm operation level, and a preliminary alarm level is set as the preliminary alarm operation level. An alarm inspection level lower than the alarm level is set as an operation level, a preliminary alarm inspection level lower than the preliminary alarm level is set as the preliminary alarm operation level, and the normal operation is performed after a predetermined time has elapsed in the inspection operation state. When transitioning to a state, and the detection output exceeds the preliminary alarm level at the start of the normal operation state Until a predetermined standby time has elapsed, in that no said preliminary alarm operation.

  According to this characteristic configuration, it is possible to suitably prevent the preliminary alarm operation due to the influence of the inspection gas remaining in the gas alarm device after shifting to the normal operation state. As a result, the user does not feel uneasy. Further, of the alarm operation and the preliminary alarm operation, only the preliminary alarm operation that is a notification operation at a low level is not operated over a predetermined waiting period, and the alarm operation that is a high-level notification operation, Since there are no restrictions, an alarm is activated even if a gas leak occurs during this standby period. Therefore, unnecessary preliminary alarm operation can be suppressed while ensuring the safety of the gas alarm device.

  Further, the characteristic configuration of the gas alarm device according to the present invention for achieving the above object is that an alarm action is performed when a detection output that detects the presence of a gas to be detected exceeds an alarm operation level, and the alarm operation level is lower than the alarm operation level. When a low preliminary alarm operation level is exceeded, a preliminary alarm is activated. In a normal operation state, an alarm level is set as the alarm operation level, and a preliminary alarm level is set as the preliminary alarm operation level. An alarm inspection level lower than the alarm level is set as an operation level, a preliminary alarm inspection level lower than the preliminary alarm level is set as the preliminary alarm operation level, and the normal operation is performed after a predetermined time has elapsed in the inspection operation state. Transition to a state, and when the detection output exceeds the preliminary alarm level at the start of the normal operation state, Serial to below pre-warning level, in that no said preliminary alarm operation.

  According to this characteristic configuration, it is possible to suitably prevent the preliminary alarm operation due to the influence of the inspection gas remaining in the gas alarm device after shifting to the normal operation state. As a result, the user does not feel uneasy. Further, only the preliminary alarm operation that is a notification operation at a low level out of the alarm operation and the preliminary alarm operation is not operated until the preliminary alarm level is once lowered. The alarm operation, which is a high-level notification operation, is not restricted, so that an alarm operation is performed even if a gas leak occurs during this standby period. Therefore, unnecessary preliminary alarm operation can be suppressed while ensuring the safety of the gas alarm device.

Furthermore, the gas alarm device according to the present invention for achieving the above object is a preliminary alarm that operates when a detection output that detects the presence of a gas to be detected exceeds an alarm operation level and is lower than the alarm operation level. A preliminary alarm is activated when the operation level is exceeded, and in the normal operation state, the alarm level is set as the alarm operation level, the preliminary alarm level is set as the preliminary alarm operation level, and in the inspection operation state, the alarm operation level is set as the alarm operation level. A warning inspection level lower than the warning level is set as a preliminary warning operation level lower than the preliminary warning level as the preliminary warning operation level, and after a predetermined time has elapsed in the inspection operation state, transition to the normal operation state And has the following characteristic configuration.
In the inspection operation state, the gas alarm device starts the alarm operation, and after a predetermined time has elapsed, sets the alarm operation level to the alarm level, and sets the preliminary alarm operation level to the preliminary alarm level. When the detection output exceeds the preliminary alarm level at the start of the normal operation state, the preliminary alarm does not operate until a predetermined standby time elapses .
Alternatively, the gas alarm device starts the alarm operation in the inspection operation state, sets the alarm operation level to the alarm level after a lapse of a predetermined time, and sets the preliminary alarm operation level to the preliminary alarm level. In addition, if the detection output exceeds the preliminary alarm level at the start of the normal operation state, the preliminary alarm operation is not performed until the detection output falls below the preliminary alarm level.

  According to this characteristic configuration, after confirming that the alarm operation of the gas alarm device operates correctly, the alarm operation and the preliminary alarm operation are not continued unnecessarily for a long time. In addition, since the above effect is obtained by setting the alarm level and the preliminary alarm level, which are threshold values for operating the alarm operation and the preliminary alarm operation during normal operation, to the alarm operation level and the preliminary alarm operation level, it should be inspected. When a gas leak occurs in the operating state, the alarm device correctly performs an alarm operation and a preliminary alarm operation. Therefore, the inspection time can be shortened while ensuring the safety of the gas alarm device.

Furthermore, according to the above characteristic configuration, it is possible to suitably prevent the alarm device from operating due to the influence of the inspection gas remaining in the gas alarm device after shifting to the normal operation state. As a result, the user does not feel uneasy. Further, of the alarm operation and the preliminary alarm operation, only the preliminary alarm operation that is a notification operation at a low level is not operated over a predetermined waiting period, and the alarm operation that is a high-level notification operation, Since there are no restrictions, the alarm device operates correctly even if a gas leak occurs during this standby period. The same applies to the case where only the preliminary alarm operation, which is a notification operation at a low level, between the alarm operation and the preliminary alarm operation is not operated until it falls below the preliminary alarm level. The alarm operation, which is a high-level notification operation, is not restricted, so that the alarm device operates correctly even if a gas leak occurs during this period. Therefore, unnecessary operation of the alarm device can be suppressed while ensuring the safety of the gas alarm device.

  Further, in addition to this characteristic configuration, after the preliminary alarm operation level is set to the preliminary alarm level in the inspection operation state, the preliminary alarm operation may not be performed in the inspection operation state.

  If comprised in this way, after confirming alarm operation | movement, since an alarm device will be in the alerting | reporting state which shows that the to-be-detected gas is not detected immediately, inspection work will be completed still earlier. When the inspection gas is supplied to the gas alarm device at the time of the inspection work, the preliminary alarm state is set first, and then the alarm state is set. Therefore, if the confirmation up to the alarm state is completed, the inspection work is sufficient. Therefore, it is not necessary to confirm the preliminary alarm state again after the alarm state, and the inspection work is completed earlier by such a configuration.

Moreover, it is preferable that the gas alarm device having the above-described features is in an inspection operation state after a predetermined rise time has elapsed since the power was turned on.
For each gas alarm device that enters the inspection state with the inspection switch and then returns to the normal operation state after a predetermined inspection time has elapsed, or enters the inspection state with the inspection switch and enters the normal operation state with the return switch. The effect of the present invention can be sufficiently obtained even if it is configured to have. However, if the inspection operation state is entered after the predetermined startup time has elapsed since the power was turned on, there will be no inspection omission, and if it enters the normal operation state after the inspection time has elapsed, Since there is no inconvenience such as forgetting to return to, the configuration is more preferable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram illustrating an example of a gas alarm device according to an embodiment of the present invention. As shown in FIG. 1, the gas alarm device of this example includes a gas detector 1 that detects the presence of a gas to be detected, and a control that determines that the gas detector 1 has detected a gas to be detected that has a predetermined concentration or more. 2 and an alarm device 3 for notifying that the gas concentration is abnormal and the state of the gas alarm device.

[Gas detector]
FIG. 2 is a perspective view showing an example of a gas sensor included in the gas detection unit of FIG. A gas sensor 40 is provided in the gas detection unit 1 that detects a gas to be detected, and the gas sensor 40 includes a gas detection element 4 that is sensitive to a combustible gas as the gas to be detected. The detected gas inflow hole into which the detected gas of the gas sensor 40 flows is provided with a breathable porous sheet 14 containing, for example, activated carbon that adsorbs interfering gas. Further, at the time of inspection, a pinhole 15 as an inspection gas injection hole is provided so that the gas to be detected can reach the gas detection element 4 directly without passing through the porous sheet 14. This gas sensor 40 (gas detection element 4) is configured to obtain an output signal by being incorporated in a bridge circuit or the like as shown in FIG. 1, and the detection output G of the gas to be detected obtained by this gas sensor 40 is: The data is output to the control unit 2 via the output unit 16. In addition, this bridge circuit is configured so that a bridge output is obtained by energizing in a pulse manner at a predetermined interval DT by control based on a timer (second timer described later) in the measurement unit 9 in the control unit 2. (The control path is not shown).

  FIG. 3 is a perspective view showing an example of a gas detection element included in the gas sensor of FIG. In this gas detection element, for example, as shown in FIG. 3, a sensitive layer 12 mainly composed of a metal oxide semiconductor such as tin oxide is applied and fired on a noble metal wire coil 11 such as platinum, palladium, platinum-palladium alloy or the like. This is a hot-wire semiconductor gas detection element formed as described above. Furthermore, a filter layer 13 that removes other interfering gases and improves the selectivity of the combustible gas may be provided on the outer surface of the sensitive layer 12.

[Control unit]
Then, the structure of the control part 2 is demonstrated based on FIG. The control unit 2 is preferably configured using a microcomputer or a logic circuit. The control unit 2 may be configured by a single microcomputer, or may be configured by combining a plurality of elements such as a flash memory, an A / D converter, and an OP amplifier.

  The comparison unit 5 determines whether or not the detection output G input to the control unit 2 exceeds a predetermined threshold set in the level setting unit 6. This threshold level is stored in the storage unit 10. In this example, it is determined whether or not the two threshold values of the alarm operation level W2 and the preliminary alarm operation level W1 lower than the alarm operation level W2 are exceeded. Accordingly, the level setting unit 6 has threshold values set for these two, and these threshold values are read from the storage unit 10 and set. The following description is based on the configuration having these two threshold values, the alarm operation level W2 and the preliminary alarm operation level W1, but of course, the configuration has only one threshold value (for example, the alarm operation level W2). However, the present invention can be applied.

  Based on the determination result in the comparison unit 5 between the alarm operation level W2 and the preliminary alarm operation level W1 and the detection output G, the main control unit 7 determines whether notification is possible. If the main control unit 7 determines that notification is necessary, the main control unit 7 instructs the alarm control unit 8 to drive the alarm device 3. The alarm control unit 8 controls each unit of the alarm device 3 so as to perform an alarm operation (notification operation) corresponding to each unit. Specifically, when the main control unit 7 receives the determination result that the detection output G exceeds the alarm operation level W2 from the comparison unit 5, the main control unit 7 starts the alarm operation for the alarm control unit 8. Give instructions. When the determination result that the alarm action level W2 is not exceeded but exceeds the preliminary alarm action level W1 is received, an instruction is issued to the alarm control unit 8 to activate the preliminary alarm action. If the preliminary warning operation level W1 has not been reached, the warning control unit 8 is instructed to continue the current control. Of course, the alarm control unit 8 may continue the current control without issuing a new instruction. The measuring unit 9 in the control unit 2 includes a timer and a counter. The measuring unit 9 measures a predetermined interval DT for obtaining the detection output G from the gas detecting unit 1 or a gas alarm of this example described later. It has a function to measure the period of various operating states.

[Alarm device]
Next, the configuration of the alarm device 3 will be described with reference to FIG. The units of the alarm device 3 controlled by the alarm control unit 8 of the control unit 2 are, for example, a green LED (light emitting diode) 31, a red LED 32, and a buzzer 33. In this example, the green LED 31 is also a pilot lamp indicating that the gas alarm is powered on. For example, the green LED 31 blinks in a period such as when the gas alarm device of this example is in the initialization process after the power is turned on, and lights up when a predetermined rise time T1 has elapsed after the power is turned on. The rising time T1 is measured by a first timer in the measuring unit 9 in this example. When the control unit 2 determines that the detection output G exceeds the alarm operation level W2 and is controlled to perform an alarm operation, the red LED 32 is lit and the buzzer 33 sounds. Similarly, when it is controlled to perform the preliminary alarm operation, the red LED 32 blinks and the buzzer 33 stops.

[Control flow]
The gas alarm device of this example enters an inspection operation state when a predetermined rise time T1 elapses after the power is turned on. The inspection operation state is continued for a predetermined inspection time T2, and when the inspection operation state is finished, the normal operation state is established. It is controlled to become. These times are measured by a first timer in the measuring unit 9. Of course, an inspection switch or the like is provided, and the switch enters an inspection state. After a predetermined inspection time T2, the normal operation state is restored, the inspection switch enters the inspection state, and the return switch enters the normal operation state. It may be controlled. As in this example, if the inspection operation state is entered after the predetermined startup time T1 has elapsed since the power was turned on, no inspection omission occurs, and the inspection is performed when the normal operation state is established after the inspection time T2 has elapsed. In this case, there is no inconvenience such as forgetting to return to the normal operation state.

  Next, control of the gas alarm device of this embodiment is demonstrated based on FIGS. 4-6 is a flowchart which shows an example of control of the gas alarm which concerns on embodiment of this invention. As shown in FIG. 4, the gas alarm device of this example performs a startup operation including an initialization process after the power is turned on until a predetermined startup time T1 elapses (# 100). After the state, as shown in FIG. 5, the inspection operation state is entered until a predetermined inspection time T2 elapses (# 200). When this inspection operation state is completed, normal operation is performed as shown in FIG. It is controlled to enter a normal state and perform a normal operation (# 300). Details of each process will be described below.

[Start-up operation]
The startup operation will be described with reference to FIG. The gas alarm device of this example starts its operation when the power is turned on (# 0), and first performs an initialization process (# 1). Here, the initialization processing is setting of initial values to the respective units in the control unit 2, for example, resetting of the first timer, the second timer and the counter included in the measuring unit 9, and blinking operation of the green LED 31. The operation instruction to be performed. Further, the alarm operation level W2 and the preliminary alarm operation level W1 included in the level setting unit 6 are set to values lower than the values in the normal operation state (# 2). That is, the alarm operation level W2 is set to a predetermined second stage level L2 that is an alarm inspection level, not an alarm level. The preliminary warning operation level W1 is not a preliminary warning level, but is set to a predetermined first stage level L1, which is a preliminary warning check level.

In this example, in the normal operation state, the alarm level set to the alarm operation level W2 is the third stage level L3, and the preliminary alarm level set to the preliminary alarm operation level W1 is the second stage level L2. Each stage level L1-L3 is
Third stage level L3> Second stage level L2> First stage level L1
The alarm operation level W2 and the preliminary alarm operation level W1 set in the level setting unit 6 at the start-up operation are step by step with respect to the alarm operation level W2 and the preliminary alarm operation level W1 in the normal operation state. It is a low value. In this example, three stages L1 to L3 are provided, and the alarm action level W2 in the inspection operation and the preliminary alarm action level W1 in the normal action are set to the same second stage level L2. For example, four stages L1 to L4 may be provided.

  Subsequently, it is confirmed whether or not the first timer has passed a predetermined rise time T1 (# 3). In this example, the rise time T1 is set to 30 seconds. Since the first timer is reset to zero in the initialization step # 1, this confirms whether or not the rise time T1 has elapsed since the power was turned on. If the start-up time T1 has not elapsed, step # 3 is repeated. During this time, the green LED 31 is blinked by the alarm control unit 8 to notify that it is in the rising operation state.

  When it is confirmed that the startup time T1 has passed (# 3), the detection output G is captured and the green LED 31 is turned on to notify the end of the startup operation. At the same time, the first timer and the second timer are reset to zero (# 4). The second timer measures a predetermined interval DT for taking out the detection output G from the gas detection unit 1, and in this example, the predetermined interval DT is 10 seconds.

  Next, it is determined whether or not the detection output G from the gas detector 1 exceeds the preliminary alarm operation level W1 (= first stage level L1) (# 5). Here, if the preliminary alarm operation level W1 is exceeded, the power may have been turned on during the gas leak, so the process does not proceed to the inspection operation process (# 200), and the route indicated by $ 2 in the figure. Then, the process proceeds to the normal operation process (# 300). If the preliminary alarm operation level W1 is not exceeded, the process proceeds to the inspection operation process (# 200) from the route $ 1 in the figure.

[Inspection operation]
Next, the inspection operation will be described based on FIG. When the inspection operation state is entered, the second timer checks whether or not the predetermined interval DT has passed (# 6), and if not, the check is repeated until it passes. When it is confirmed that the predetermined interval DT has elapsed, the second timer is reset and the detection output G is taken in (# 7), and then the detection output G is determined. Note that the alarm action level W2 and the preliminary alarm action level W1 used for the determination are already set as values for the inspection action state in Step # 2, and are used as they are.

  First, it is determined whether or not the detection output G exceeds the preliminary alarm operation level W1 (= preliminary alarm inspection level = first stage level L1) (# 8). If it is determined that the preliminary alarm operation level W1 is exceeded, it is next determined whether or not the alarm operation level W2 (= alarm inspection level = second stage level L2) is exceeded (# 9). If it is determined that the alarm operation level W2 is exceeded, the alarm control unit 8 instructs the alarm device 3 to perform an alarm operation (# 10a), and the counter of the measurement unit 9 is incremented (+1) (# 11a). ). Thereby, the red LED 32 is turned on and the buzzer 33 sounds. If it is determined in step # 9 that the alarm operation level W2 is not exceeded, the alarm control unit 8 instructs the alarm device 3 to perform a preliminary alarm operation (# 10b), and then the counter of the measurement unit 9 is reset. (# 11b). Since this counter is provided for measuring a period during which the alarm is being operated, the counter is reset when the alarm is not being performed. Therefore, even if it is determined in step # 8 that the preliminary alarm operation level W1 has not been exceeded, this counter is reset in step 11b.

In step # 10a, an alarm action instruction is issued. In step # 11a, the counter for measuring the duration of the alarm action is incremented. Next, in step # 12,
Counter value = Predetermined confirmation time / Predetermined interval = T3 / DT
Confirm whether or not The predetermined confirmation time T3 is a time for which it is considered that the detection output G has sufficiently exceeded the alarm level in the inspection operation state, and is 30 seconds in this example. As described above, in this example, the detection output G is obtained at every predetermined interval DT, and the predetermined interval DT is 10 seconds. Therefore, if T3 / DT = 3 and the counter value has reached 3, the detection output G of the gas to be detected has continuously exceeded the alarm operation level W2 for 30 seconds of the predetermined confirmation time T3.

Here, if the detection output G continuously exceeds the alarm operation level W2 for 30 seconds which is the predetermined confirmation time T3, the alarm operation level W2 is changed from the second stage level L2 to the third stage level L3, and the preliminary alarm level. Is changed from the first stage level L1 to the second stage level L2 (# 13).
Third stage level L3> Second stage level L2> First stage level L1
Thus, the alarm operation level W2 and the preliminary alarm operation level W1 are raised to a threshold value that is increased step by step to the threshold value during normal operation while being in the inspection operation state. By controlling in this way, the threshold level is raised after confirmation of the alarm operation during the confirmation time T3 (= 30 seconds), so even if gas that has not diffused completely remains in the gas alarm device The alarm operation can be terminated early.

  Subsequently, the first timer confirms whether or not a predetermined inspection time T2 has elapsed (# 14). The predetermined inspection time T2 is a time during which the gas alarm device of this example continues the inspection operation state, and is 3 minutes 30 seconds in this example. When the value of the first timer has not reached the inspection time T2 and the inspection operation state is continued, the process returns to step # 6 and the inspection operation control (# 200) is continued. When the value of the first timer has reached the inspection time T2, the control proceeds to the normal operation control (# 300) via the path $ 2, and the normal operation control (# 300) described below is performed.

[Normal operation]
Next, the normal operation will be described with reference to FIG. When shifting to the normal operation state, first, it is confirmed whether or not an alarm operation or a preliminary alarm operation is performed (# 15), and if it is performed, the first timer is reset (# 16a). A predetermined waiting time T4 is set in the first timer (# 16b). If the detected gas is injected at the end of the inspection operation state and the alarm operation or the preliminary alarm operation is performed, the detected gas cannot be diffused even if the normal operation state is shifted, and at least the preliminary alarm operation The state may continue. Therefore, when the alarm operation or the preliminary alarm operation is performed at the time of transition to the normal operation state, in anticipation that the inspection operation is extended, during the waiting time T4 from the transition to the normal operation state, This is because the control is performed in the subsequent determination process (# 22) so that the preliminary alarm operation is not performed. In this example, it is determined in step # 15 that “alarm or preliminary alarm instruction is being performed?”, But “is the detection output exceeding the preliminary alarm level (= second stage level L2)?” It is also good.

  When the alarm operation or the preliminary alarm operation is not performed at the time of transition to the normal operation state, the standby time T4 is set in the first timer in step 16b, but this is determined in the subsequent determination process (# 22) This is because it is determined that the waiting time T4 has already passed.

  Subsequently, the alarm action level W2 is set to the third stage level L3 which is an alarm level, and the preliminary alarm action level W1 is set to the second stage level L2 which is a preliminary alarm level (# 17). In the inspection operation (# 200), the operation does not necessarily go through step # 13, and the normal operation state may be directly started from the start-up operation (# 100). In these cases, the alarm operation level W2 and the preliminary alarm operation level Since W1 remains set suitable for the inspection operation state, it is necessary to reset it to a value suitable for normal operation in step # 17. When this setting is completed, the detection output G of the gas to be detected is fetched at a predetermined interval DT at step # 18 and the level of the detection output G is determined.

  As in the inspection operation state, first, it is determined whether or not the detection output G exceeds the preliminary alarm operation level W1 (= preliminary alarm level = second stage level L2) (# 20). If it does not exceed the preliminary alarm operation level W1, the process returns to step 18 and the determination of the detection output G is repeated at a predetermined interval DT. If it exceeds the preliminary alarm operation level W1, it is next determined whether or not the alarm operation level W2 (= alarm level = third stage level L3) is exceeded (# 21). If the alarm level W1 is exceeded, control is performed so that the red LED 32 of the alarm device 3 is lit and the buzzer 33 sounds regardless of the above-described standby time T4 (# 23b). On the other hand, if the alarm operation level W2 is not exceeded, the detection output G at this time is a value for which a preliminary alarm operation should be performed, so it is confirmed whether or not the first timer has passed the waiting time T4 (# 22). ) If the waiting time T4 is exceeded, the red LED 33 of the alarm device 3 is blinked (# 23a). If the waiting time T4 has not been exceeded, the process returns to step 18. Thereafter, this normal operation state is repeatedly executed.

  Here, during the standby time T4, only the preliminary alarm operation is controlled so as not to perform the notification operation, and the alarm operation is controlled to be notified. By controlling in this way, if there is a real gas leak during the standby time T4, an alarm operation is performed, which is preferable without creating a blank period for gas leak detection.

  In this example, the standby time T4 is provided and the preliminary alarm operation is stopped during this time. However, for example, the preliminary alarm operation can be stopped until the detection output G falls below the preliminary alarm operation level W1. . In this case, in the flowchart shown in FIG. 6, “reset first timer” after branching to the No side of Step # 22, and “set T4 to the first timer” after branching to the No side of Step # 20. What is necessary is just to add processing. If this is done, the standby time T4 is always reset when branching to the No side in Step # 22, so there is no branching to Yes side in Step # 22, and the preliminary alarm operation is not activated during that time. If the detected gas diffuses during this time and the detection output G falls below the preliminary alarm operation level W1, the first timer is set to T4 after branching to the No side of step # 20. When the value exceeds the preliminary alarm operation level W2, the process branches from step # 22 to # 23a to start the preliminary alarm operation.

  In addition, the above may be combined, and the preliminary alarm operation may not be started until the detection output G falls below the preliminary alarm operation level W1 or the standby time T4 has elapsed. In this case, in the flowchart shown in FIG. 6, after branching to the No side of Step # 20, a process of “setting T4 to the first timer” may be added. If the standby time T4 elapses until the detection output G falls below the preliminary alarm operation level W1, the process branches from step # 22 to # 23a, and the detection output G can fall below the preliminary alarm operation level W1 until the standby time T4 elapses. For example, since T4 is set in the first timer after branching to the No side of Step # 20, the preliminary alarm operation is started thereafter.

  The predetermined confirmation time T3 and the predetermined standby time T4 can be changed. Preferably, the predetermined confirmation time T3 and the predetermined standby time T4 can be set in units of a predetermined interval DT for sampling the detection output G from the gas detection unit 1 in this example. It is good to configure. For example, since the interval DT is 10 seconds in this example, an example is shown in which the confirmation time T3 is 30 seconds (DT × 3) and the standby time T4 is 60 seconds (DT × 6). This setting can be set in the storage unit 10 in advance. For example, when the storage unit 10 includes a memory having a bit width of 8 bits, numerical values from 0 to 255 can be set on the hardware configuration, and the confirmation time T3 and the standby time T4 are theoretically 0 to 2550. A range of seconds can be set at 10 second intervals. Actually, a suitable range is determined as a settable range based on software programs and specifications in actual operation.

Hereinafter, based on FIGS. 7 to 11, an operation example along the above flow will be described. In this operation example, the inspection operation state is controlled 30 seconds after the power is turned on, and the inspection operation state is controlled for 3 minutes 30 seconds, and then the normal operation state is controlled. Further, the alarm operation level W2 is indicated by a solid line, and the preliminary alarm operation level W1 is indicated by a dotted line.
[First operation example]
As shown in FIG. 7, in the inspection operation state, the alarm operation level W2 is set to the second stage level L2, and the preliminary alarm operation level W1 is set to the first stage level L1. When the detection output G by the gas detector 1 exceeds the preliminary alarm operation level W1 (= first stage level L1) in the vicinity of 1 minute and 30 seconds, the red LED 32 blinks to perform the preliminary alarm operation. When the further increased detection output G exceeds the alarm operation level W2 (= second stage level L2) in the vicinity of 1 minute and 40 seconds, the red LED 32 is turned on and the buzzer 33 is sounded to perform the alarm operation. When this alarm operation state continues for a predetermined confirmation time T3 (30 seconds in this example), the alarm operation level W2 is changed from the second stage level L2 to the third stage level L3, and the preliminary alarm operation level W1 is changed from the first stage level L1. It is updated to the second stage level L2. Therefore, the detection output G falls below the alarm operation level W2 (= third stage level L3), and transitions from the alarm operation state to the preliminary alarm operation state. Thereafter, when the detection output G falls below the preliminary alarm operation level W1 (second stage level L2), the preliminary alarm state is also ended, and the alarm device 3 is in a notification state indicating a normal state at 2 minutes 40 seconds from the time of power-on. It becomes. Thus, the inspection can be completed in a short time.

  Here, when the alarm alarm level according to the present invention is not controlled and the alarm operation level W2 and the preliminary alarm operation level W1 are fixed during the inspection operation state as shown in FIG. Even in the case of the detection output G, the alarm operation state continues for 1 minute. The preliminary alarm state ends and the alarm device 3 enters a notification state indicating a normal state at a time of 3 minutes and 20 seconds from the time of power-on. Therefore, it takes a long time to complete the inspection.

[Second operation example]
The detection output G shown in FIG. 9 has a waveform that exceeds the alarm operation level W2 (= second stage level L2) at the end of the inspection operation state (around 3 minutes 50 seconds). Therefore, before the alarm state continues for 30 seconds, the inspection operation state shifts to the normal operation state, and accordingly, the alarm operation level W2 is changed from the second stage level L2 to the third stage level L3, and the preliminary alarm operation level W1. Is updated from the first stage level L1 to the second stage level L2. As a result, the detection output G that exceeds the second stage level L2 but falls below the third stage level L3 transitions from the alarm operation state to the preliminary alarm state.

  However, since the gas alarm device is already in the normal operation state, this notification may cause the user to be misidentified and may cause anxiety based on the misidentification. Therefore, as shown in FIG. 9, a preliminary alarm is provided for a period considered to be sufficient for the diffusion of the inspection gas immediately after the transition to the normal operation state, for example, for a predetermined waiting time T4 (60 seconds in this example). The operation is not performed. If a true gas leak occurs during this time, the detection output G exceeds the alarm level (= third stage level L3) and enters an alarm state, and there is no safety problem because the gas leak is notified.

  Here, when the control with the predetermined waiting time T4 is not performed as in the gas alarm device according to the present invention, as shown in FIG. 10, even if the detection output G has the same waveform as in FIG. After the transition to the normal operation state, the preliminary alarm state continues.

[Third operation example]
In the second operation example, the operation example has been described in which the preliminary alarm operation caused by the influence of the inspection gas is not performed for a certain period immediately after the transition to the normal operation state. This can be adopted even in the inspection operation state. When the inspection gas is supplied, the preliminary alarm state is entered first, and then the alarm state is entered. Therefore, if the confirmation up to the alarm state is completed, the inspection work is sufficient. Therefore, reconfirmation of the preliminary alarm state that appears after the alarm state is not always necessary. Therefore, it may be controlled so that the preliminary alarm operation is not performed after the alarm operation state is once entered in the inspection operation state and the alarm operation state is continued for a predetermined confirmation time T3.

  For this control, for example, in step # 13 of the flowchart shown in FIG. 5, both the alarm action level W2 and the preliminary alarm action level W1 may be set to the third stage level L3. If controlled in this way, the alarm operation state is once entered, and after this alarm operation state is continued for a predetermined confirmation time T3, the alarm operation level W2 and the preliminary alarm operation level W1 have the same threshold value. Therefore, after this setting, during the inspection operation (# 200), if branching to the Yes side in Step # 8, Step # 9 will always branch to the Yes side, and the preliminary alarm operation instruction in Step # 10b As a result, it is possible to prevent the preliminary alarm operation from being performed.

  FIG. 11 shows an example of the operation in this way for the detection output G having the same waveform as that in the first operation example. The preliminary alarm operation is not performed for a predetermined time T5 (inspection completion time T5) after the alarm operation state is once set in the inspection operation state and this alarm operation state is continued for a predetermined confirmation time T3. Compared with FIG. 7, the inspection is completed in a shorter time.

  As described above, according to the present invention, it is possible to provide a gas alarm device capable of performing an operation check in a short time.

The schematic block diagram which shows an example of the gas alarm which concerns on embodiment of this invention The perspective view which shows an example of the gas sensor which the gas detection part of FIG. 1 has. The perspective view which shows an example of the gas detection element which the gas sensor of FIG. 2 has The flowchart which shows an example of control of the gas alarm which concerns on embodiment of this invention The flowchart which shows an example of control of the gas alarm which concerns on embodiment of this invention The flowchart which shows an example of control of the gas alarm which concerns on embodiment of this invention The figure which shows the 1st example of the gas detection operation | movement of the gas alarm device which concerns on embodiment of this invention. The figure which shows the 1st example of the gas detection operation of a gas alarm The figure which shows the 2nd example of the gas detection operation | movement of the gas alarm device which concerns on embodiment of this invention. The figure which shows the 2nd example of the gas detection operation of a gas alarm The figure which shows the 3rd example of the gas detection operation | movement of the gas alarm which concerns on embodiment of this invention.

Explanation of symbols

G Detection output L3 Third stage level L2 Second stage level T3 Confirmation time W2 Alarm action level

Claims (6)

When the detection output that detects the presence of the gas to be detected exceeds an alarm operation level, an alarm is activated, and when a pre-alarm operation level lower than the alarm operation level is exceeded, a pre-alarm operation is performed,
In a normal operation state, an alarm level is set as the alarm operation level, a preliminary alarm level is set as the preliminary alarm operation level,
In the inspection operation state, an alarm inspection level lower than the alarm level is set as the alarm operation level, and a preliminary alarm inspection level lower than the preliminary alarm level is set as the preliminary alarm operation level,
A gas alarm device that transitions to the normal operation state after a predetermined time has elapsed in the inspection operation state,
If the detection output exceeds the preliminary alarm level at the start of the normal operation state, the gas alarm device that does not operate the preliminary alarm until a predetermined standby time elapses. When the detection output that detects the presence of the gas to be detected exceeds an alarm operation level, an alarm is activated, and when a pre-alarm operation level lower than the alarm operation level is exceeded, a pre-alarm operation is performed,
In a normal operation state, an alarm level is set as the alarm operation level, a preliminary alarm level is set as the preliminary alarm operation level,
In the inspection operation state, an alarm inspection level lower than the alarm level is set as the alarm operation level, and a preliminary alarm inspection level lower than the preliminary alarm level is set as the preliminary alarm operation level,
A gas alarm device that transitions to the normal operation state after a predetermined time has elapsed in the inspection operation state,
If the detection output exceeds the preliminary alarm level at the start of the normal operation state, the gas alarm does not operate until the preliminary alarm level falls below. When the detection output that detects the presence of the gas to be detected exceeds an alarm operation level, an alarm is activated, and when a pre-alarm operation level lower than the alarm operation level is exceeded, a pre-alarm operation is performed,
  In a normal operation state, an alarm level is set as the alarm operation level, a preliminary alarm level is set as the preliminary alarm operation level,
  In the inspection operation state, an alarm inspection level lower than the alarm level is set as the alarm operation level, and a preliminary alarm inspection level lower than the preliminary alarm level is set as the preliminary alarm operation level,
  A gas alarm device that transitions to the normal operation state after a predetermined time has elapsed in the inspection operation state,
  In the inspection operation state, after the alarm operation is started and a predetermined time has elapsed, the alarm operation level is set to the alarm level, the preliminary alarm operation level is set to the preliminary alarm level, and
  If the detection output exceeds the preliminary alarm level at the start of the normal operation state, the gas alarm does not operate until the preliminary alarm level falls below. When the detection output that detects the presence of the gas to be detected exceeds an alarm operation level, an alarm is activated, and when a pre-alarm operation level lower than the alarm operation level is exceeded, a pre-alarm operation is performed,
In a normal operation state, an alarm level is set as the alarm operation level, a preliminary alarm level is set as the preliminary alarm operation level,
In the inspection operation state, an alarm inspection level lower than the alarm level is set as the alarm operation level, and a preliminary alarm inspection level lower than the preliminary alarm level is set as the preliminary alarm operation level,
A gas alarm device that transitions to the normal operation state after a predetermined time has elapsed in the inspection operation state,
In the inspection operation state, after the alarm operation is started and a predetermined time elapses, the alarm operation level is set to the alarm level, the preliminary alarm operation level is set to the preliminary alarm level, and
If the detection output exceeds the preliminary alarm level at the start of the normal operation state, the gas alarm device that does not perform the preliminary alarm until a predetermined standby time elapses. The gas alarm device according to claim 3 or 4 , wherein in the inspection operation state, the preliminary alarm operation level is set to the preliminary alarm level, and then the preliminary alarm operation is not performed in the inspection operation state.   The gas alarm device according to any one of claims 1 to 5, which enters an inspection operation state after a predetermined rise time has elapsed since the power was turned on.

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