JPH0663638B2 - Gas shutoff device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas shutoff device that automatically shuts off a gas passage when an abnormality occurs to prevent an accident such as an explosion or poisoning caused by city gas or propane gas. Regarding

2. Description of the Related Art A conventional gas shutoff device of this type, as shown in FIG.
A gas meter in the gas supply line No. 1, and a flow rate measuring means 3 for issuing a signal according to the amount of gas passing through the gas meter;
A shutoff means 4 for stopping the supply of gas is provided, and the shutoff means is judged to be abnormal if the usage condition is judged by the flow rate signal of the flow rate measurement means 3 and the preset individual gas maximum combustion amount condition is deviated. 4 was provided with a control unit 5 for issuing a closing signal.

FIG. 4 shows an example of the configuration of this conventional control unit. Those having the same numbers as in FIG. 3 are components having the same function. The control unit 5 receives the flow rate signal from the flow rate measuring means 3 and detects the combustion amount of the gas appliance being used from the change in the gas flow rate per unit time of a predetermined value or more, and , An initial condition setting unit 7 that sets a predetermined individual maximum combustion amount condition according to the size of the gas meter, and a gas individual maximum combustion amount condition setting unit 8 that stores the setting contents and sends a reference signal to the abnormality determination unit 9. And a closing signal output section for issuing a closing signal to the breaking means 4 in response to the signal from the abnormality judging section 9.
It is composed of 10 and.

Here, the predetermined individual maximum combustion amount condition is to detect the gas flow rate change for each predetermined measurement period, identify how much gas consumption the gas appliance currently used is equivalent to, and determine the individual gas When the consumption exceeds the set value, a shutoff signal is output to the shutoff device, and gas leaks such as cracks in the gas hose and combustion extinction when the gas plug is half-opened are addressed.

FIG. 5 shows an example of obtaining the individual combustion amount. The horizontal axis represents the elapsed time t and the vertical axis represents the combustion amount Qu, and t0, t1, t2, ... T9 represent sampling timing for each unit time. up to t1
No gas appliances are used and the amount of combustion is zero. t2
At that time, it was detected that the amount of combustion increased, and the amount of increase was detected as OA.
That is, the usage state detection unit recognizes that the above condition has occurred. After that, it is determined whether or not the QA exceeds the initially set individual maximum combustion amount condition, and if it exceeds, the gas passage is closed by the shutoff means. If it does not exceed the limit, the measurement is performed subsequently, and it is detected that the combustion amount further increases at time t3 and that value is QB. At this point as well, it is similarly determined whether or not QB is within the condition. Even at t4, it is detected that the combustion amount has increased by QC and a judgment is made. At t7, on the contrary, it is detected that the combustion amount has decreased by QB, but even at this time, it is recognized that the individual maximum combustion amount is QC. In this example, the increase / decrease of the combustion amount is judged at each sampling timing, but a method of making the above judgment in two sampling times is also adopted. That is, it is recognized that there is a change in the combustion amount due to the first change, and when there is no change in the second change, the change amount is determined to be an increase amount or a decrease amount.

Problems to be Solved by the Invention However, in the above-mentioned configuration, since the proper use condition is uniformly determined only by the initial value depending on the capacity of the gas meter installed in the gas pipe, it is not possible to use it in a home where the meter is installed. There was a problem that special conditions were not incorporated.

The present invention solves such a conventional problem, and an object of the present invention is to provide a safer gas shutoff device by measuring the usage pattern of each home.

Means for Solving the Problems In order to solve the above problems, the gas shutoff device of the present invention is
Flow rate measuring means that emits a signal according to the amount of gas passing through the gas meter installed in the gas supply line, shutting off means that stops the supply, and gas used from changes in the gas flow rate per unit time above a predetermined value. In a device equipped with a control unit that determines that the combustion amount of the appliance deviates from the preset individual maximum combustion amount condition according to the gas meter and issues a closing signal to the breaking means, a timer that counts a predetermined period, Start signal applying means for starting the timer,
Individual maximum combustion amount storage means for storing the maximum value of the combustion amount of the gas appliance being used during the timer operation, and gas individual maximum combustion for changing the individual maximum combustion amount condition according to the contents of the storage means. According to the present invention, when the start signal is applied to the timer, counting for a predetermined period is started, and the individual maximum combustion amount storage means is provided during the counting period. By the operation of, the holding of the maximum value of the combustion amount of the gas appliance being used is updated from the change of the gas flow rate per unit time of the predetermined value or more. Then, at the same time as the timer ends, the final data is compared and judged by the gas individual maximum combustion amount condition changing means, a predetermined value is selected and sent to the gas individual maximum combustion amount condition setting unit, and the new condition is reset. is there. After that, the abnormality determination unit compares the new setting condition with the signal from the usage state detection unit, and if the condition is not satisfied, it is determined to be abnormal and the cutoff unit is activated.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, those having the same numbers as those in FIG. 4 are components having the same function. The control unit 11 inputs the flow rate signal from the flow rate measuring means 3 similar to the conventional one, and detects the combustion amount of the gas appliance being used from the change of the gas flow rate per unit time of a predetermined value or more. , An initial condition setting unit 7 that sets a predetermined individual maximum combustion amount condition according to the size of the gas meter, and a gas individual maximum combustion amount condition setting unit 12 that stores the setting contents and sends a reference signal to the abnormality determination unit 9.
A closing signal output section 10 for issuing a closing signal to the breaking means 4 in response to a signal from the abnormality judging section 9, a timer 13 for counting a predetermined time, and a starting signal application for sending a starting signal for starting counting to the timer. Means 14, with the start of the operation of the timer, the individual maximum combustion amount storage means 15 for storing the maximum value of the combustion amount of the gas appliance used according to the signal of the use state detection unit, the content of the storage means The gas individual maximum combustion condition changing means 16 which changes the individual maximum combustion amount condition accordingly.

In the above configuration, when the activation signal applying means (for example, the push button switch, the signal transmission means from the outside, etc.) is activated, the activation signal is sent to the timer, and the timer receives the signal and starts counting for a predetermined period. The predetermined period may be set in advance or may be set arbitrarily, and is, for example, a span of one week or one month. Simultaneously with the operation of this timer, the individual maximum combustion amount storage means 15 stores the maximum value of the combustion amount of the gas appliance from the change of the gas flow rate per unit time or more.

Here, the gas flow rate pulse is converted into the calorific value, that is, the gas combustion amount, because the calorific value per the same flow rate pulse varies depending on the type of gas, so when the explosion limit of a gas accident is an evaluation item. This is because it is easier to handle when considering the calorific value.

When the flow rate pulse from the flow rate measuring means 3 per unit time changes by a predetermined value or more (for example, 3% or more),
One of the installed gas appliances will start burning,
Alternatively, the combustion amount is determined by determining that the combustion has stopped. Actually, there are cases where a plurality of gas appliances start or stop burning at the same sampling time, so it is difficult to make a reliable judgment without registering the appliances in advance. It can be useful for judgment. In this way, the individual maximum combustion amount storage means stores the maximum combustion amount of the gas appliance used during the timer operation. Then, at the end of counting, the maximum combustion amount stored in the above is sent to the gas individual maximum combustion amount condition changing means as data.

The maximum combustion amount stored in the above is compared with the initial condition by the gas individual maximum combustion amount condition changing means, and the smaller one is selected. This result is newly set in the setting unit 12 as a new gas individual maximum combustion amount condition, and thereafter, based on this value, it is determined whether or not the individual maximum combustion amount is abnormal. Here, the maximum value of the actually measured maximum individual combustion amount is used for the comparison and examination as it is, but it may be used as the comparison data by multiplying it by a predetermined coefficient.

By the way, until the above timer count ends,
The abnormality determination unit compares the current gas usage state with the initial value that has been set to determine the abnormal state, but after the conditions are newly set based on the gas usage pattern measurement results during timer operation. Determines the abnormal state by comparing with the reset value. Here, when it is determined that there is an abnormality, the shutoff means is activated and the gas passage is closed.

The control unit described above can be easily realized by using a calculation or judgment function by a program operation of a microcomputer or the like. Hereinafter, FIG. 2 shows a schematic program flow.

When the program starts, after setting the initial conditions at A, the flow rate is measured at B, and then at C, the gas usage condition, that is, the change in gas flow rate per unit time from the specified value or more is used. The individual combustion amount of the gas appliance that is operating is detected. Then, at D, it is determined whether or not the timer for a predetermined time is counting, and when counting, the individual maximum combustion amount is stored at E and the maximum value is updated. After that, as in the case where the timer is not operating, the gas individual maximum combustion amount condition is compared with the usage state detection value at F.
As a result of this comparison, if there is an abnormality, the process branches to G and jumps to the H closing signal output unit. When it is not abnormal, it is checked whether or not the changing means is operated by I, and when it is operated, the flow returns to h1, that is, the flow rate measurement of A. When the operation has not been completed, J determines whether or not the timer count has ended, and when it has ended, the individual maximum combustion amount condition changing means is operated with K and reset with L. After that, in F, the reset value is treated as the gas individual maximum combustion amount condition, and compared with the detected value. When the timer count is not finished at J, the process branches to M to determine whether or not the timer is currently counting. If it is counting, N continues counting as it is, and if it is not counting, the presence or absence of a start signal is determined at O. When the activation signal is input, the timer count is started at P. If there is no signal, it returns to A again.

By executing the above program flow, the function of the control unit of the gas shutoff device of the present invention can be realized.

Effects of the Invention As described above, the gas cutoff device of the present invention has the following effects.

(1) By constantly monitoring the gas usage state and comparing it with the set individual maximum combustion conditions, it is possible to detect gas leakage and combustion extinction. If the conditions are exceeded, it is determined that there is an abnormality. In this case, the shutoff means is activated to stop the gas supply, so that it is possible to prevent a dangerous state such as gas explosion or gas poisoning.

(2) Since the actual use pattern of the gas supply system in which the gas meter is installed is observed for a predetermined time by the start signal and the maximum value of the gas appliance combustion amount and the smaller of the initial conditions are reset as the final result, Compared to the conditions that were uniformly determined by the gas meter capacity (number of issues), individual special conditions are also taken into consideration when making decisions, and the safety level against gas accidents is further increased without affecting actual use. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram of a gas shutoff device in an embodiment of the present invention, FIG. 2 is a diagram showing a schematic program flow of a control unit of the device, FIG. 3 is a configuration diagram of a conventional gas shutoff device, and FIG. FIG. 5 is a block diagram of a conventional controller, and FIG. 5 is a diagram showing an example of a gas usage pattern. 2 ... Gas meter, 3 ... Flow rate measuring means, 4 ... Shutoff means, 11 ... Control section, 13 ... Timer, 14 ... Activation signal applying means, 15 ... Individual maximum combustion flow rate storing means, 16 ... Means for changing individual gas maximum combustion amount conditions.

Claims (1)

[Claims] 1. A flow rate measuring means for emitting a signal according to a passing gas amount of a gas meter provided in a gas supply line, a shutoff means for stopping the supply, and a change of a gas flow rate per unit time of a predetermined value or more. A timer that counts a predetermined period, including a control unit that judges that the combustion amount is abnormal when the combustion amount of the gas appliance being used deviates from the preset individual maximum combustion amount condition according to the gas meter, and issues a closing signal to the cutoff means. A start signal applying means for starting the timer, an individual maximum combustion amount storage means for storing a maximum value of the combustion amount of the gas appliance being used during the timer operation, and a content of the storage means. A gas shutoff device comprising: a gas individual maximum combustion amount condition changing means for changing the individual maximum combustion amount condition.