JP5369789B2 - Gas shut-off device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a difference between gas total use amount and a sum of a plurality of change amounts held by a gas shut-off device. <P>SOLUTION: The gas shut-off device includes a flow rate detection part 11, a flow rate calculation part 12, an increase/decrease calculation part 13, an increase/decrease determination part 14, a valve drive part 15, a valve 16, a difference determination part 17, an increase/decrease correction part 18, and normal time difference determination part 19. The increase/decrease determination part 14 acquires corrected change amount G calculated by the increase/decrease correction part 18 based on a difference value H determined step by step in the difference determination part 17 or the normal time difference determination part 19, and adopts the corrected change amount G as new change amount C. Thus, this can prevent elongation of gas use time until a gas passage is closed. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention improves the flow rate monitoring function of the gas shut-off device.

  Conventionally, this type of gas shut-off device is described in the prior art document as a configuration described in Patent Document 1.

FIG. 4 shows a conventional gas shut-off device described in Patent Document 1. As shown in FIG. As shown in FIG. 4, a flow rate detection unit 1 that outputs a flow rate signal a corresponding to a gas flow rate that passes through the gas passage, and a flow rate that calculates a flow rate b when the flow rate signal a of the flow rate detection unit 1 is received. When the flow rate b of the calculation unit 2 and the flow rate calculation unit 2 is received, the value of the flow rate b acquired last time is compared with the flow rate b acquired this time, and the change c is output when there is a change. If the change amount c output from the calculation unit 3 and the increase / decrease calculation unit 3 is an increase amount, the change amount c is added and held if the use of a new gas appliance is started. Managing the plurality of variation amounts c while deleting the closest variation amount c held as having stopped using the appliance, and rearranging the plurality of retained variation amounts c in descending order. , The largest said holding after realigning An increase / decrease determination unit that extracts a usage time calculated based on the conversion amount c and starts timing, and outputs a valve drive signal d when the usage time elapses before the change amount c of the increase / decrease calculation unit 3 is acquired again. 4, a valve driving unit 5 that outputs a closing signal e when the valve driving signal d of the increase / decrease determination unit 4 is received, and a valve that closes a gas passage when receiving the closing signal e of the valve driving unit 5. (For example, refer patent document 1).
JP-A 61-289227

  Patent Document 1 describes addition and deletion of change amounts held by a plurality of gas shut-off devices, but there is no description regarding correction of change amounts. However, since the handling of this variation is described as background art, it is illustrated.

  However, in the above-mentioned conventional configuration, when the total amount of gas actually used decreases, the close amount of change that the gas shut-off device holds is deleted, so when the change amount is deleted It is a well-known fact that an error occurs in the sum of the total amount of gas actually used and the amount of change held in the gas shut-off device. That is, FIG. 2 shows the total amount of gas used by the three devices, “device 1” of device 1, “device 2” of device 2, and “device 3” of device 3.

  As shown in FIG. 2 (a), when “container 1” starts to be used, “container 2” starts to use, “container 3” starts to use, and the total amount of gas used decreases, FIG. ), It is good if the total gas usage increases as “Vessel 1”, “Vessel 1” + “Vacuum 2”, “Vacuum 1” + “Vacuum 2” + “Vacuum 3”. In order to estimate and delete the gas appliance that is close when the usage amount decreases as “Vessel 2”, if the usage amount registered in “Vessel 2” is larger than the actual reduction amount, this error (in this example, Deficiency) will occur.

In this way, an error (in this example, a shortage) may occur each time the total gas usage decreases, and the sum of the errors may also increase (the reverse pattern in which the actually reduced amount increases) There was a case where the balance was kept). If the sum of these errors increases, the sum of the changes held by the gas shut-off device decreases, so the largest change itself is inevitably a small value that is far from the actual gas appliance usage. End up. It is a well-known fact that when the usage time is extracted based on the amount of change that has become small apart from the actual gas appliance, the time until the gas passage is closed increases (the type of gas appliance such as a water heater or a fan heater). The amount of usage and the amount of time determined for each are inversely proportional (because the amount of gas used is short and the amount of gas used is short). For this reason, since it becomes later than the time to originally close the gas passage, there is a problem that it may become unsafe in use of the gas.

  The present invention solves the above-described conventional problems, and the shortest amount (the present device 3 in the present example) that the gas shut-off device holds as shown in FIG. In the example, the actual total gas consumption and gas are taken into account by adding the correction amount) (if the magnitude relationship between the near change to be deleted and the reduced change is reversed, the shortage is subtracted from the largest change) The purpose is to correct the deviation and deviation from the sum of the change amounts held by a plurality of shut-off devices.

  In order to solve the above-described conventional problems, the gas shutoff device according to the present invention has a difference value H that is greater than or equal to the deviation width determination value provided stepwise by the increase / decrease determination unit 14 based on the flow rate B from the increase / decrease correction unit 18. The largest change amount is deleted by acquiring the corrected change amount G output to, and is held as a new change amount C.

  Thus, the gas shut-off device can correct the deviation and deviation between the total amount of gas actually used and the sum of the change amounts held by the gas shut-off device.

  The gas shut-off device of the present invention extracts the gas usage time with the largest change amount of the conventional one, and at the same time, the sum of the total amount of gas actually used and the change amount held by the gas shut-off device. When there is a divergence between 齟齬 and 発 生, the difference can be corrected, and the time until the gas passage is closed is prevented from becoming longer due to 齟齬 and divergence. By holding the amount as a new change amount, the largest change amount held by the gas shut-off device may be larger than the maximum amount of gas equipment actually used, Even if it becomes larger, the time until the gas passage is closed is shortened, so that the gas appliance can be stopped at an early stage, so safety can be ensured). Achieving balance

According to a first aspect of the present invention, there is provided a flow rate detection unit that outputs a flow rate signal corresponding to a gas flow rate passing through the gas passage, a flow rate calculation unit that calculates a flow rate when receiving the flow rate signal of the flow rate detection unit, and the flow rate When the flow rate of the calculation unit is received, the flow rate value acquired last time is compared with the flow rate acquired this time, and if there is a change, an increase / decrease calculation unit that outputs the change amount and an increase / decrease processing signal of the increase / decrease determination unit are received. And obtaining all of the change amounts held by the increase / decrease determination unit, calculating a difference between the acquired sum of the change amounts and the flow rate of the flow rate calculation unit as a divergence value, The deviation width determination value extracted based on the magnitude of the flow rate is compared with the deviation value, and if there is no deviation value equal to or greater than the deviation width determination value, the deviation value is set to zero and equal to or greater than the deviation width determination value. If there is a deviation value, the deviation value is output. The divergence determination unit and the divergence value of the divergence determination unit are acquired, and if the divergence value is not zero, the difference value is added to or subtracted from the largest change amount held by the increase / decrease determination unit. And an increase / decrease correction unit that outputs the corrected change amount, and if the change amount output by the increase / decrease calculation unit is an increase amount, add and hold the change amount, assuming that the use of a new gas appliance is started, If it is a decrease amount, it is held that the use of the gas appliance has been stopped, and while deleting the closest change amount, a plurality of the change amounts are managed and the increase / decrease processed signal is output, and the increase / decrease correction When the corrected change amount of the unit is acquired, the largest change amount held is deleted, the corrected change amount is held as a new change amount, and the largest change amount held Based on the usage time is extracted When the time of use elapses before the change amount of the increase / decrease calculation unit is acquired again, the increase / decrease determination unit that outputs a valve drive signal and the valve drive signal of the increase / decrease determination unit are closed A valve drive unit that outputs a signal; and a valve that closes the gas passage when receiving the closing signal of the valve drive unit, so that the increase / decrease correction unit is configured to control the flow rate based on the deviation value of the deviation determination unit. By matching the flow rate of the calculation unit and the plurality of change amounts held by the increase / decrease determination unit, it is possible to prevent wrinkles and deviations.

According to a second aspect of the present invention, there is provided a flow rate detection unit that outputs a flow rate signal corresponding to a gas flow rate passing through the gas passage, a flow rate calculation unit that calculates a flow rate when receiving the flow rate signal of the flow rate detection unit, and the flow rate When the flow rate of the calculation unit is received, the flow rate value acquired last time is compared with the flow rate acquired this time, and if there is a change, an increase / decrease calculation unit that outputs a change amount and the change amount of the increase / decrease calculation unit are received The flow rate of the flow rate calculation unit is acquired and held as a reference value, and every time the flow rate of a new flow rate calculation unit is acquired, a difference from the reference value is calculated as a deviation value. The deviation width determination value extracted based on the magnitude of the flow rate is compared with the deviation value, and if there is no deviation value equal to or greater than the deviation width determination value, the deviation value is set to zero and equal to or greater than the deviation width determination value. If there is a deviation value, the deviation value is And Permanent deviation determination unit which force again to obtain the flow rate of the flow rate calculation unit and the reference value, the obtains the deviation value of the constant deviation determination unit, decrease determination unit if the deviation value can not emerge zero If the change amount output from the increase / decrease calculation unit is an increase amount, an increase / decrease correction unit that outputs the corrected change amount by adding / subtracting the deviation value to the largest change amount among The change amount is added and held as the start of use of a new gas appliance, and if it is a decrease amount, the change amount is deleted while deleting the closest change amount held as if the use of the gas appliance is stopped. The change amount is managed, and when the corrected change amount of the increase / decrease correction unit is acquired, the largest change amount held is deleted, and the corrected change amount is held as a new change amount. To the largest amount of change When the usage time elapses before the usage time is extracted and at least one of the change amount of the increase / decrease calculation unit or the corrected change amount of the increase / decrease correction unit is acquired again, the valve is driven. The increase / decrease determination unit that outputs a signal, a valve drive unit that outputs a closing signal when receiving the valve drive signal of the increase / decrease determination unit, and a valve that closes a gas passage when receiving the closing signal of the valve driving unit With this, the increase / decrease correction unit can monitor the flow rate of the flow rate calculation unit based on the divergence value of the constant divergence determination unit, and can prevent stagnation and divergence.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a functional block diagram of a gas cutoff device in Embodiment 1 of the present invention.

  In FIG. 1, the flow rate detection unit 11 may detect a gas flow rate from a difference in ultrasonic propagation time by attaching an ultrasonic sensor facing the gas passage (for example, an ultrasonic sensor facing the gas passage), A gas flow path may be created in the gas passage, and the gas flow rate may be detected from vibrations that occur when the gas flows through the gas path. The gas flow rate is measured each time the gas flow rate is measured and reaches a certain flow rate. The flow rate signal A is output in response to the same effect even if it is detected.

  When the flow rate calculation unit 12 receives the flow rate signal A from the flow rate detection unit 11, the flow rate calculation unit 12 calculates the flow rate B.

When the flow rate calculation unit 13 receives the flow rate B of the flow rate calculation unit 12, the increase / decrease calculation unit 13 compares the value of the flow rate B acquired last time with the flow rate B acquired this time. If there is no change, nothing is performed. The change amount C is output. (The same effect can be obtained even if it is determined by a predetermined difference value or more, or by the change rate).

  When the deviation determination unit 17 receives the increase / decrease processing signal F from the increase / decrease determination unit 14, the deviation determination unit 17 acquires all the change amounts C held by the increase / decrease determination unit 14 (for example, the total use of gas in FIG. 2C). When the amount decreases, the data of “device 1” and “device 3” is obtained), and the difference between the sum of the obtained change amount C and the flow rate B of the flow rate calculation unit 12 is calculated as the deviation value H, and the flow rate calculation unit The deviation width determination value extracted based on the magnitude of the flow rate B of 12 (for example, the flow width B as shown in the table shown in FIG. The same effect can be obtained by calculating the deviation width determination value by multiplying the flow rate B by a predetermined coefficient, and the table in Fig. 3 is an example for extracting the deviation width determination value, and the deviation width determination value is convenient. The value may be changed freely including 0 L / h based on safety and safety, and the coefficient is 0 as well. The deviation value H is determined, and if there is no deviation value H equal to or greater than the deviation width determination value (for example, if the flow rate B is 150 L / h, the deviation width determination value is 5 L / h), the deviation value H is determined. If there is a deviation value H equal to or greater than the deviation width judgment value, the deviation value H is output.

  The increase / decrease correction unit 18 acquires the divergence value H of the divergence determination unit 17, and if the divergence value H is not zero, it is at least the largest among the increase / decrease determination units 14 (for example, the plurality are held). Obtain all the changes and obtain the change amount C (for example, the same effect can be obtained even if the largest change amount C is extracted from them) (for example, the total amount of gas used in FIG. 2C is reduced) At that time, the data of “device 1” and “device 3” are obtained), and the largest change amount C obtained from the increase / decrease determination unit 14 (for example, the total amount of gas used (= flow rate B) in FIG. 2C). The "developers 1" and "apparatus 3" acquired when the value of "apparatus 1" is "apparatus 3", so "apparatus 3" is added to or subtracted from the deviation value H (correction amount). If it is mainly used, only the addition side is used. If the main purpose is to improve convenience, only the subtraction side is used. On the other hand the aperture crowded by correcting also may) to corrected change amount G (e.g., and FIG. 2 (c) outputting the at the "vessel 3+ correction amount").

  The increase / decrease determination unit 14 adds and holds the change amount C if the change amount C output from the increase / decrease calculation unit 13 is an increase amount, and starts to use a new gas appliance. A plurality of changes while deleting the change amount C that is the closest (for example, it is possible to compare all the change amounts C that are held with the decrease amount and have the smallest difference). When the amount C is managed and the increased / decreased signal F is output and the corrected change amount G of the increase / decrease correction unit 18 is acquired, the largest change amount C held is deleted and the corrected change amount G is newly changed. Retained as the amount C, the plurality of retained variation amounts C are rearranged in order from the largest (if the increase / decrease correction unit 18 adds and corrects the largest variation amount C, the largest change before the correction) Since the corrected change amount G is larger than the amount C, Than large change amount C in the second holding a reliably large corrected change amount G.

  On the other hand, when the largest change amount C is subtracted and corrected, the corrected change amount G is smaller than the largest change amount C before correction. Therefore, the corrected change amount G may continue to be the largest change amount C, or the second largest change amount C among the plurality of held changes C may be larger than the corrected change amount G. (Depending on the magnitude of the correction amount subjected to the subtraction correction, the n-th change amount C may be larger than the corrected change amount G).

  That is, if a deviation width H of 150 L / h is detected when the four change amounts C of 400 L / h, 350 L / h, 300 L / h, and 200 L / h are held before correction, the correction is completed. The amount of change is 400 L / h-150 L / h = 250 L / h. In this case, 350 L / h of the second largest variation C is larger, and 300 L / h of the third largest variation C is larger, and 350 L / h, 300 L / h, 250 L when rearranged. / H, 200 L / h.

In addition, when the deviation width H is 20 L / h, 400 L / h− 20 L / h = 380 L / h, and when realigned, 380 L / h, 350 L / h, 300 L / h, and 200 L / h are obtained. Subsequently, the corrected change amount G becomes the largest change amount C). Therefore, it is necessary to register the corrected change amount G as one change amount C among the plurality of registered change amounts, and then rearrange them in a large order), and based on the largest change amount C retained after the reordering The use time is extracted and the time is started, and the use time elapses before the change amount C of the increase / decrease calculation unit 13 is acquired again (for example, when only the largest change amount C is regarded as important, the increase / decrease calculation unit 13 If the change amount C obtained from (1) does not become the largest change amount C, the timing may be continued), and the valve drive signal D is output.

  When the valve drive unit 15 receives the valve drive signal D of the increase / decrease determination unit 14, the valve drive unit 15 outputs a closing signal E, and when the valve 16 receives the closing signal E of the valve drive unit 15, the valve passage 15 is closed.

  As described above, in the present embodiment, the increase / decrease determination unit 14 holds the corrected change amount G calculated by the increase / decrease correction unit 18 based on the deviation value H of the deviation determination unit 17 as the new change amount C, and the flow rate calculation unit It is possible to prevent wrinkles and divergence by matching the flow rate B of 12 and the sum of the plurality of change amounts C held by the increase / decrease determination unit 14.

(Embodiment 2)
FIG. 1 shows a functional block diagram of a gas cutoff device according to Embodiment 2 of the present invention. In addition, since the thing of the symbol same as Embodiment 1 is the same function, description is abbreviate | omitted. Further, the deviation determination unit 17 is not included in the second embodiment.

  The constant deviation determination unit 19 receives the change amount C of the increase / decrease calculation unit 13, acquires the flow rate B of the flow rate calculation unit 12 and holds it as a reference value, and each time a new flow rate B of the flow rate calculation unit 12 is acquired, the reference A difference value is calculated as a deviation value H, and a deviation width judgment value extracted based on the magnitude of the flow rate B of the flow rate calculation unit 12 (for example, the flow rate B as shown in the table of FIG. 3 is divided in stages. The corresponding deviation width determination value may be extracted, or the same effect can be obtained by calculating the deviation width determination value by multiplying a predetermined coefficient by the flow rate B. The table of FIG. This is an example for extraction, and the divergence width judgment value may be freely changed including 0 L / h based on convenience and safety, and the coefficient may also be set to 0) and the divergence value H Is greater than the deviation width judgment value (for example, if the flow rate B is 150 L / h, the deviation width If there is no deviation value H of 5L / h), the deviation value H is set to zero, and if there is a deviation value H greater than the deviation width judgment value, the deviation value H is output and the flow rate B of the flow rate calculation unit 12 is acquired again. Use the reference value.

  Although the increase / decrease correction unit 18 has acquired the deviation value H from the deviation determination unit 17 in the first embodiment, the increase / decrease correction unit 18 always acquires the deviation value H from the deviation determination unit 19.

  The increase / decrease determination unit 14 does not output the increase / decrease processed signal F. In addition, the usage time elapses before acquiring at least one of the change amount C of the increase / decrease calculation unit 13 or the corrected change amount G of the increase / decrease correction unit 18 (for example, when only the largest change amount C is emphasized). If the change amount C acquired from the increase / decrease calculation unit 13 or the corrected change amount G does not become the largest change amount C, the timing may be continued), and the valve drive signal D is output (for example, Assuming that “unit 1” and “unit 3” are obtained when the total amount of gas used in FIG. 2C differs from the reference value by a predetermined value or more (total amount of gas used (= flow rate B)). When there is a decrease, the difference between the total amount of gas used and the sum of the amount of change C held by the gas shut-off device (increase / decrease determination unit 14) does not occur, and then the increase / decrease calculation unit 13 detects the change Imagine a case where the total gas consumption (= flow rate B) gradually decreases without being able to To have) the "vessel 1" and "vessels 3" since the large "vessel 3 'is a large variation amount C becomes most, the corrected change amount G" instrumental 3+ correction amount ").

  As described above, in this embodiment, the increase / decrease determination unit 14 holds the corrected change amount G calculated by the increase / decrease correction unit 18 based on the deviation value H of the constant deviation determination unit 19 as a new change amount C. The divergence determination unit 19 always prevents the divergence and the divergence by matching the flow rate B of the flow rate calculation unit 12 with the sum of the plurality of change amounts C held by the increase / decrease determination unit 14 via the increase / decrease correction unit 18. be able to.

  In the first and second embodiments, when the total gas usage is largely changed in the first embodiment, the total gas usage is different in the second embodiment when there is no change in the total gas usage. Detects the occurrence of a difference between the amount used (= flow rate B) and the sum of the amount of change C held by the gas shut-off device in stages based on the total amount used (= flow rate B). This makes it possible to correct the situation and prevent the discrepancy and deviation.

  By this correction, the largest change amount C is deleted and the corrected change amount G is held as a new change amount C, so that the gas shut-off device holds more than the maximum amount of gas appliance actually used. The largest amount of change C may be larger, but even if it becomes larger, the time until the gas passage is closed is shortened. Can be secured.

  Note that the first embodiment and the second embodiment can be combined.

  As described above, the gas shutoff device according to the present invention maintains the actual total gas use amount and the gas shutoff device in combination with the estimation of the presence / absence of the use of the gas appliance by increasing / decreasing the total use amount of the conventional gas. If there is a discrepancy between the change amount and the sum of the changes, it can be corrected, and safety can be secured and convenience can be improved. It can also be applied to uses such as meters.

Functional block diagram of the gas cutoff device according to Embodiments 1 and 2 of the present invention (A) The figure which shows the usage pattern of a gas, (b) The figure showing the amount of change which the usage pattern of a gas and the conventional gas interruption | blocking apparatus hold | maintained, (c) The usage pattern of gas and this Embodiment 1, Figure showing the amount of change held by the gas shutoff device 2 Figure showing a table showing the relationship between the flow rate of the flow rate calculation unit and the deviation width judgment value Functional block diagram of a conventional gas shut-off device

DESCRIPTION OF SYMBOLS 11 Flow rate detection part 12 Flow rate calculation part 13 Increase / decrease calculation part 14 Increase / decrease determination part 15 Valve drive part 16 Valve 17 Deviation determination part 18 Increase / decrease correction part 19 Constant deviation determination part

Claims (2)

A flow rate detection unit that outputs a flow rate signal corresponding to a gas flow rate passing through the gas passage, a flow rate calculation unit that calculates a flow rate when receiving the flow rate signal of the flow rate detection unit, and the flow rate of the flow rate calculation unit When receiving, the value of the flow rate acquired last time is compared with the flow rate acquired this time, and if there is a change, an increase / decrease calculation unit that outputs the change amount, and when an increase / decrease processing signal of the increase / decrease determination unit is received, the increase / decrease determination unit Obtains all of the change amounts held by a plurality, calculates the difference between the obtained sum of the change amounts and the flow rate of the flow rate calculation unit as a divergence value, and sets the magnitude of the flow rate of the flow rate calculation unit. The divergence width determination value extracted based on the divergence value is compared, and if there is no divergence value equal to or greater than the divergence width determination value, the divergence value is set to zero, and the divergence value equal to or greater than the divergence width determination value exists. Deviation judgment unit for outputting the deviation value The deviation value of the deviation determination unit is acquired, and if the deviation value is not zero, the corrected value is corrected by adding / subtracting the deviation value to / from the largest change amount held by the increase / decrease determination unit. An increase / decrease correction unit that outputs an amount, and if the change amount output by the increase / decrease calculation unit is an increase amount, the change amount is added and held as if a new gas appliance has started to be used. Managing the plurality of change amounts while deleting the closest change amount held as having stopped using the gas appliance and outputting the increase / decrease processed signal, the corrected increase / decrease unit being corrected When the change amount is acquired, the largest change amount held is deleted, the corrected change amount is held as a new change amount, and the usage time is set based on the largest change amount held. Extract and start timing, And an increase / decrease determination unit that outputs a valve drive signal when the usage time elapses before the change amount of the increase / decrease calculation unit is acquired, and a valve that outputs a closing signal when the valve drive signal of the increase / decrease determination unit is received. A gas shut-off device comprising: a drive unit; and a valve for closing the gas passage when receiving the closing signal of the valve driving unit. A flow rate detection unit that outputs a flow rate signal corresponding to a gas flow rate passing through the gas passage, a flow rate calculation unit that calculates a flow rate when receiving the flow rate signal of the flow rate detection unit, and the flow rate of the flow rate calculation unit When received, the value of the flow rate acquired last time is compared with the flow rate acquired this time, and if there is a change, an increase / decrease calculation unit that outputs a change amount, and when the change amount of the increase / decrease calculation unit is received, the flow rate calculation unit The flow rate is acquired and held as a reference value, and each time the flow rate of a new flow rate calculation unit is acquired, a difference from the reference value is calculated as a deviation value, and the flow rate of the flow rate calculation unit is calculated. The divergence width determination value extracted based on the divergence value is compared, and if there is no divergence value equal to or greater than the divergence width determination value, the divergence value is set to zero, and the divergence value equal to or greater than the divergence width determination value exists. Output the deviation value and the flow rate And Permanent deviation determination unit, wherein the flow rate of the exit portion again acquired and the said reference value, obtains the deviation value of the constant deviation determination unit, decrease determination unit is more retained if the deviation value can not emerge zero An increase / decrease correction unit for adding / subtracting the deviation value to / from the largest change amount and outputting a corrected change amount, and a new gas appliance if the change amount output by the increase / decrease calculation unit is an increase amount The amount of change is added and held as the start of use, and the amount of change is deleted while deleting the closest amount of change that is held as if the use of the gas appliance is stopped if the amount is reduced. If the corrected change amount of the increase / decrease correction unit is acquired, the largest change amount held is deleted, the corrected change amount is held as a new change amount, and held. Usage time based on the largest amount of change Extract and start timing, and output the valve drive signal when the usage time elapses before acquiring at least one of the change amount of the increase / decrease calculation unit or the corrected change amount of the increase / decrease correction unit The increase / decrease determination unit, a valve drive unit that outputs a closing signal when receiving the valve driving signal of the increase / decrease determination unit, and a valve that closes a gas passage when receiving the closing signal of the valve driving unit. Gas shut-off device characterized by