JPS61208432A - Gas interception device - Google Patents

Abstract

PURPOSE:To secure synthetic safety of gas supplying by a method wherein a driving unit is worked automatically to close a shut-off valve by detecting at an electric current detecting section when an abnormal consumed electric current flows in a micro-computer. CONSTITUTION:In case the micro-computer 5 is under a normal condition, the current flowing into the point (a) of the resistance 12 at the current detecting unit 11 is small and the voltage of the resistance 12 hardly drops while the voltage thereof is almost same as a battery 6 voltage. However, the micro-computer 5 becomes abnormal condition due to noise and aging stress or the like for example and the electric current consumption thereof becomes large; as a result, the voltage drop of the resistance 12 is increased and the potential at the point (a) drops. The output of an AND gate 13 becomes low due to the drop of the potential at the point (a) to drive a driving unit 7 and the shut- off valve 10 is operated. The fail safe may be realized by providing the electric current detecting section when the micro-computer becomes abnormal and the current thereof increases in the circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a gas shutoff device that guarantees the overall safety of the gas supply.

BACKGROUND OF THE INVENTION In recent years, due to the development of microelectronics, gas shutoff devices have become smaller and lower in cost, and have become widespread in general households.

An example of the conventional gas cutoff device mentioned above will be described below with reference to the drawings.

1 is a gas meter, 2 is a gas cutoff device, 3 is a gas meter 1
Flow rate sensor attached to 4, Flow rate interface, 5
is a micro combinator, 6 is a battery, 7 is a valve drive unit,
8 is a resistor, 9 is a transistor, and 10 is a shutoff valve.

The operation of the gas cutoff device configured as described above will be described below. Gas passage 1 as shown by the arrow in Figure 2
Gas flows through the microcomputer 5 through the flow rate sensor 3, and the flow rate information is transmitted from the flow rate sensor 3 to the microcomputer 5 via the flow rate interface 4. When there is an abnormality in the gas flow rate or when a certain flow rate continues for an abnormal period of time, the microcomputer 5 transmits a signal to the valve driving section 7 to operate the shutoff valve 10 to shut off the gas passage 14.

Problems to be Solved by the Invention However, the above configuration does not provide a fail-safe when the microcomputer 5 loses its normal VC due to noise or stress over time. Therefore, it is very dangerous if the shutoff valve 10 does not shut off when it should.

The present invention has been made in view of the problem described in J. J. The object of the present invention is to provide a gas cutoff device that is fail-safe when the microcomputer malfunctions and the current consumption of the microcomputer increases.

Means for Solving the Problems In order to solve the above problems, the gas cutoff device of the present invention has the following features:
A gas flow rate sensor and a shutoff valve, a microcomputer that receives a signal from the flow rate sensor and controls the shutoff valve, and the microcomputer.

- A drive section that drives the cutoff valve in response to a signal from the ignitor, and a current detection section that detects the current consumption of the microconbeater and operates the drive section.

Function The present invention has the above-described configuration so that when the microconbeater consumes a large amount of current due to some abnormality,
This current is detected by the current detection unit and automatically moves the drive unit to close the cutoff valve.

Example The following describes a gas cutoff device according to an embodiment of the present invention.

This will be explained with reference to the drawings.

FIG. 1 shows a configuration diagram of a gas cutoff device in an embodiment of the present invention. In Figure 1, 1 is a gas meter, 2
is a gas cutoff device, 3 is a flow rate sensor attached to the gas meter, 4 is a flow rate interface, 5 is a microcomputer, 6 is a battery, 7 is a valve drive unit, 8 is a resistor, 9 is a transistor, 10 is connected to gas meter 1 A current detection part 11 detects the current consumption of the microcomputer 5 and operates the drive part 7. A current detection part 12 is a resistor, and 13 is an AND gate.

The operation of the gas cutoff device configured as described above will be described below with reference to FIG. 1.

Point a of the resistor 12 of the current detection unit 11 is almost the same as the voltage of the battery 6 when the microcomputer 5 is normal, the current is small and there is almost no voltage drop across the resistor 12. However, if the microconbeater 5 becomes abnormal due to some kind of noise or stress over time, and its current consumption increases, the voltage drop across the resistor 12 increases and the potential at point a decreases. When the potential at point a decreases, and 1
3 becomes low to drive the drive unit 7 and operate the cutoff valve 10.

As described above, according to this embodiment, by providing the current detection section, it is possible to realize a fail-safe when the microcomputer becomes abnormal and its current increases. The operation of the gas cutoff device 2 when there is an abnormality in the gas flow rate during normal operation is the same as in the conventional example, so the same parts as in the conventional example are given the same numbers and detailed explanation will be omitted.

Effects of the Invention As described above, by providing the current detection section, the present invention can perform tool safety by driving the cutoff valve when the microconbeater becomes abnormal and consumes a large amount of current. Moreover, this can be easily achieved at low cost.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a gas cutoff device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional gas cutoff device. 3... Sensor for gas flow, 5... Microcomputer, 7... Drive unit, 10...
- Shutoff valve, 11...Current detection section. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 @ J-・-Nosura Li sensor height 5--Microcomputer 7--Drive sound p 10--One cutoff square 11--List flow inspection part Fig. 2

Claims (1)

[Claims] A gas flow rate sensor and a cutoff valve provided in a gas passage; a microcomputer that receives a signal from the flow rate sensor and controls the cutoff valve; and a drive unit that receives a signal from the microcomputer and drives the cutoff valve. and a current detection unit that detects current consumption of the microcomputer, and when abnormal current consumption flows through the microcomputer, the current detection unit detects and automatically moves the drive unit to close the cutoff valve. Gas shutoff device.